Author: "Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB)" - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB)"' showing total 81 results

Start Over Author "Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB)"

81 results on '"Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB)"'

1. salt stress response of brackish and feshwater strains of Microcystis aeruginosa

Author: Georges des Aulnais, Maxime, Hervé, F., Caruana, Amandine, Briand, Enora, Dittmann, Elke, Bormans, Myriam, Amzil, Zouher, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institute of Biochemistry and Biology University of Potsdam, Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, and Briand, Valerie
Subjects: [SDE.BE] Environmental Sciences/Biodiversity and Ecology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, ComputingMilieux_MISCELLANEOUS
Abstract: National audience
Published: 2019

2. Salt stess response of brackish and freshwater strains of Microcystis aeruginosa

Author: Aulnais, Maxime Gorges Des, Caruana, Amandine, Briand, Enora, Dittmann, Elke, Bormans, Myriam, Amzil, Zouher, Briand, Valerie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institute of Biochemistry and Biology University of Potsdam, Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2
Subjects: [SDE.BE] Environmental Sciences/Biodiversity and Ecology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2019

3. salt stress response of brackish and feshwater strains of Microcystis aeruginosa

Author: Georges Des Aulnais, Maxime, Caruana, Amandine, Briand, Enora, Bormans, Myriam, Amzil, Zouher, Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Briand, Valerie
Subjects: [SDE.BE] Environmental Sciences/Biodiversity and Ecology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, ComputingMilieux_MISCELLANEOUS
Abstract: National audience
Published: 2018

4. Low phosphate activates STOP1-ALMT1 to rapidly inhibit root cell elongation

Author: Jean-Marie Teulon, Edith Laugier, Jean Armengaud, Serge Chiarenza, Audrey Creff, Marie-Christine Thibaud, Benjamin Péret, Steffen Abel, Jens Daniel Müller, Agnès Hagège, Coline Balzergue, Pascale David, Thierry Desnos, Marie Bissler, Christian Godon, Noëlle Becuwe-Linka, Corinne Brouchoud, Etienne Delannoy, Thibault Dartevelle, Claudia-Nicole Meisrimler, Laurent Nussaume, Hélène Javot, Jean-Luc Pellequer, Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Signalisation de l'Adaptation des Végétaux à l'Environnement (SAVE), Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Institut de biologie structurale (IBS - UMR 5075), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Leibniz-Institut für Pflanzenbiochemie, Equipe Développement et Plasticité du Système Racinaire (PLASTICITE), Université de Montpellier (UM)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Innovations technologiques pour la Détection et le Diagnostic (LI2D), Service de Pharmacologie et Immunoanalyse (SPI), Médicaments et Technologies pour la Santé (MTS), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Médicaments et Technologies pour la Santé (MTS), CEA (APTTOX021401, APTTOX021403), ANR11-RSNR-0005,DEMETERRES, ANR-09-BLAN-0118,CHEMIGENA,Génétique d'une voie limitant la croissance racinaire d'Arabidopsis en réponse à la carence phosphatée(2009), ANR-12-ADAP-0019,RNAdapt,Les ARN non-codants dans l'adaptation de la croissance racinaire à la carence phosphate(2012), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Médicaments et Technologies pour la Santé (MTS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ANR-11-RSNR-0005,DEMETERRES,Développement de Méthodes bio-et Eco-Technologiques pour la Remédiation Raisonnée des Effluents et des Sols en appui à une stratégie de réhabilitation agricole post-accidentelle(2011), Plant Environmental Physiology and Stress Signaling (PEPSS), Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) ( BIAM ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Biologie végétale et microbiologie environnementale - UMR7265 ( BVME ), Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Aix Marseille Université ( AMU ), Biochimie et Physiologie Moléculaire des Plantes ( BPMP ), Centre international d'études supérieures en sciences agronomiques ( Montpellier SupAgro ) -Institut national de la recherche agronomique [Montpellier] ( INRA Montpellier ) -Université de Montpellier ( UM ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut national d’études supérieures agronomiques de Montpellier ( Montpellier SupAgro ), Institut de biologie structurale ( IBS - UMR 5075 ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Laboratoire de Biologie du Développement des Plantes ( LBDP ), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Centre National de la Recherche Scientifique ( CNRS ), Equipe Développement et Plasticité du Système Racinaire ( PLASTICITE ), Centre international d'études supérieures en sciences agronomiques ( Montpellier SupAgro ) -Institut national de la recherche agronomique [Montpellier] ( INRA Montpellier ) -Université de Montpellier ( UM ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut national d’études supérieures agronomiques de Montpellier ( Montpellier SupAgro ) -Centre international d'études supérieures en sciences agronomiques ( Montpellier SupAgro ) -Institut national de la recherche agronomique [Montpellier] ( INRA Montpellier ) -Université de Montpellier ( UM ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut national d’études supérieures agronomiques de Montpellier ( Montpellier SupAgro ), Laboratoire Innovations technologiques pour la Détection et le Diagnostic ( LI2D ), Service de Pharmacologie et Immunoanalyse ( SPI ), Département Médicaments et Technologies pour la Santé ( DMTS ), Direction de Recherche Fondamentale (CEA) ( DRF (CEA) ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) ( DRF (CEA) ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Département Médicaments et Technologies pour la Santé ( DMTS ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Biologie cellulaire et moléculaire des plantes et des bactéries ( BCMPB ), and Investissements d'avenir RSNR Demeterres
Subjects: 0106 biological sciences, 0301 basic medicine, immunité cellulaire, Arabidopsis, Malates, Organic Anion Transporters, General Physics and Astronomy, Plant Roots, 01 natural sciences, chemistry.chemical_compound, Cell Wall, Gene Expression Regulation, Plant, Arabidopsis thaliana, Multidisciplinary, food and beverages, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Plants, Genetically Modified, Apoplast, Hedgehog signaling pathway, Cell biology, Biochemistry, Oxidoreductases, paroi cellulaire, Signal Transduction, [ SDV.BV.BOT ] Life Sciences [q-bio]/Vegetal Biology/Botanics, Science, Iron, Meristem, Cell Enlargement, Biology, capacité de croissance, Article, General Biochemistry, Genetics and Molecular Biology, Phosphates, Cell wall, 03 medical and health sciences, développement de la plante, Transcription factor, Peroxidase, phosphate, prolifération cellulaire, Arabidopsis Proteins, Cell growth, Callose, arabidopsis thaliana, élongation cellulaire, General Chemistry, biology.organism_classification, racine, 030104 developmental biology, chemistry, Transcription Factors, 010606 plant biology & botany
Abstract: Environmental cues profoundly modulate cell proliferation and cell elongation to inform and direct plant growth and development. External phosphate (Pi) limitation inhibits primary root growth in many plant species. However, the underlying Pi sensory mechanisms are unknown. Here we genetically uncouple two Pi sensing pathways in the root apex of Arabidopsis thaliana. First, the rapid inhibition of cell elongation in the transition zone is controlled by transcription factor STOP1, by its direct target, ALMT1, encoding a malate channel, and by ferroxidase LPR1, which together mediate Fe and peroxidase-dependent cell wall stiffening. Second, during the subsequent slow inhibition of cell proliferation in the apical meristem, which is mediated by LPR1-dependent, but largely STOP1–ALMT1-independent, Fe and callose accumulate in the stem cell niche, leading to meristem reduction. Our work uncovers STOP1 and ALMT1 as a signalling pathway of low Pi availability and exuded malate as an unexpected apoplastic inhibitor of root cell wall expansion., Low Pi availability inhibits primary root growth, but the sensory mechanisms are not known. Here the authors uncover a signalling pathway regulating Pi-mediated root growth inhibition in Arabidopsis, involving the transcription factor STOP1, its direct target ALMT1, a malate channel, and ferroxidase LPR1.
Published: 2017

5. SeedUSoon: A New Software Program to Improve Seed Stock Management and Plant Line Exchanges between Research Laboratories

Author: Laurent Nussaume, Hélène Javot, Céline Charavay, Nathalie Pochon, Stéphane Segard, Institut de Biosciences et de Biotechnologies de Grenoble (ex-IRTSV) (BIG), Institut National de la Santé et de la Recherche Médicale (INSERM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Signalisation de l'Adaptation des Végétaux à l'Environnement (SAVE), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Recherche Agronomique (INRA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Plant Environmental Physiology and Stress Signaling (PEPSS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Grenoble Alpes (UGA), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)
Subjects: 0106 biological sciences, 0301 basic medicine, Computer science, Interface (Java), Data management, Context (language use), plant, Certification, Plant Science, 01 natural sciences, 03 medical and health sciences, Methods, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, genetics, genealogy, database, TRACE (psycholinguistics), Stock management, [INFO.INFO-DB]Computer Science [cs]/Databases [cs.DB], business.industry, software, Inheritance (genetic algorithm), food and beverages, Data science, Biotechnology, Material transfer agreement, 030104 developmental biology, MTA, business, seed, 010606 plant biology & botany
Abstract: International audience; Plant research is supported by an ever-growing collection of mutant or transgenic lines. In the past, a typical basic research laboratory would focus on only a few plant lines that were carefully isolated from collections of lines containing random mutations. The subsequent technological breakthrough in high-throughput sequencing, combined with novel and highly efficient mutagenesis techniques (including site-directed mutagenesis), has led to a recent exponential growth in plant line collections used by individual researchers. Tracking the generation and genetic properties of these genetic resources is thus becoming increasingly challenging for researchers. Another difficulty for researchers is controlling the use of seeds protected by a Material Transfer Agreement, as often only the original recipient of the seeds is aware of the existence of such documents. This situation can thus lead to difficult legal situations. Simultaneously, various institutions and the general public now demand more information about the use of genetically modified organisms (GMOs). In response, researchers are seeking new database solutions to address the triple challenge of research competition, legal constraints, and institutional/public demands. To help plant biology laboratories organize, describe, store, trace, and distribute their seeds, we have developed the new program SeedUSoon, with simplicity in mind. This software contains data management functions that allow the separate tracking of distinct mutations, even in successive crossings or mutagenesis. SeedUSoon reflects the biotechnological diversity of mutations and transgenes contained in any specific line, and the history of their inheritance. It can facilitate GMO certification procedures by distinguishing mutations on the basis of the presence/absence of a transgene, and by recording the technology used for their generation. Its interface can be customized to match the context and rules of any laboratory. In addition, SeedUSoon includes functions to help the laboratory protect intellectual property, export data, and facilitate seed exchange between laboratories. The SeedUSoon program, which is customizable to match individual practices and preferences, provides a powerful toolkit to plant laboratories searching for innovative approaches in laboratory management.
Published: 2017
Full Text: View/download PDF

6. Pearl Millet Genetic Traits Shape Rhizobacterial Diversity and Modulate Rhizosphere Aggregation

Author: Papa M. S. Ndour, Mariama Gueye, Mohamed Barakat, Philippe Ortet, Marie Bertrand-Huleux, Anne-Laure Pablo, Damien Dezette, Lydie Chapuis-Lardy, Komi Assigbetsé, Ndjido Ardo Kane, Yves Vigouroux, Wafa Achouak, Ibrahima Ndoye, Thierry Heulin, Laurent Cournac, Institut Sénégalais de Recherches Agricoles [Dakar] (ISRA), Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'Ecologie Microbienne de la Rhizosphère et d'Environnements Extrêmes (LEMIRE), Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes (UMR Eco&Sols), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Diversité, adaptation, développement des plantes (UMR DIADE), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Institut National de la Recherche Agronomique (INRA)-Institut de Recherche pour le Développement (IRD)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA), Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2
Subjects: 0106 biological sciences, 0301 basic medicine, 16S rDNA sequencing, Plant Science, lcsh:Plant culture, 01 natural sciences, 03 medical and health sciences, soil aggregation, Inbred strain, Dry weight, diversité microbienne, Botany, lcsh:SB1-1110, Plant breeding, rhizosheath, rhizobactérie, Original Research, 2. Zero hunger, Rhizosphere, Vegetal Biology, biology, Soil carbon, 15. Life on land, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, biology.organism_classification, EPS producing bacteria, Bacillales, Rhizobiales, 030104 developmental biology, Agronomy, metabarcoding, pennisetum glaucum, pearl millet, rhizosphere, Soil fertility, rhizosphère, Biologie végétale, 010606 plant biology & botany
Abstract: International audience; Root exudation contributes to soil carbon allocation and also to microbial C and energy supply, which subsequently impacts soil aggregation around roots. Biologically-driven soil structural formation is an important driver of soil fertility. Plant genetic determinants of exudation and more generally of factors promoting rhizosphere soil aggregation are largely unknown. Here, we characterized rhizosphere aggregation in a panel of 86 pearl millet inbred lines using a ratio of root-adhering soil dry mass per root tissue dry mass (RAS/RT). This ratio showed significant variations between lines, with a roughly 2-fold amplitude between lowest and highest average values. For 9 lines with contrasting aggregation properties, we then compared the bacterial diversity and composition in root-adhering soil. Bacterial α-diversity metrics increased with the " RAS/RT ratio. " Regarding taxonomic composition, the Rhizobiales were stimulated in lines showing high aggregation level whereas Bacillales were more abundant in lines with low ratio. 184 strains of cultivable exopolysaccharides-producing bacteria have been isolated from the rhizosphere of some lines, including members from Rhizobiales and Bacillales. However, at this stage, we could not find a correlation between abundance of EPS-producing species in bacterial communities and the ratio RAS/RT. These results illustrated the impact of cereals genetic trait variation on soil physical properties and microbial diversity. This opens the possibility of considering plant breeding to help management of soil carbon content and physical characteristics through carbon rhizodeposition in soil.
Published: 2017

7. Lipidomic and transcriptomic analyses of Chlamydomonas reinhardtii under heat stress unveil a direct route for the conversion of membrane lipids into storage lipids

Author: Legeret, B., Schulz-Raffelt, M., Nguyen, H., Auroy, P., Beisson, F., Peltier, G., Blanc, G., Li-Beisson, Y., Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bioénergie et Microalgues (EBM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Clermont-Ferrand (ICCF), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-SIGMA Clermont (SIGMA Clermont)-Centre National de la Recherche Scientifique (CNRS), Hanoi National University of Education (HNUE), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2
Subjects: [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2016

8. Heavy metal accumulation by recombinant mammalian metallothionein within Escherichia coli protects against elevated metal exposure

Author: Patrick Carrier, Sandrine Sauge-Merle, Catherine Lecomte-Pradines, Stéphan Cuiné, Michael S. DuBow, Aix Marseille Université (AMU), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Anti-infectieux : supports moléculaires des résistances et innovations thérapeutiques (RESINFIT), CHU Limoges-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Interactions Protéine Métal (IPM), Laboratoire de Radioécologie et d’Ecotoxicologie, IRSN (Institut de Radioprotection et de Sûreté Nucléaire), DEI/SECRE, Cadarache, France, Bioénergie et Microalgues (EBM), Institut de génétique et microbiologie [Orsay] (IGM), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'écotoxicologie des radionucléides (IRSN/PRP-ENV/SERIS/LECO), Service de Recherche et d'Expertise sur les Risques environnementaux (IRSN/PRP-ENV/SERIS), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Environnement, Bioénergie, Microalgues et Plantes (EBMP), and the 'Toxicologie Nucléaire' program of the CEA
Subjects: Environmental Engineering, [SDV]Life Sciences [q-bio], Health, Toxicology and Mutagenesis, chemistry.chemical_element, 010501 environmental sciences, medicine.disease_cause, 01 natural sciences, Maltose-Binding Proteins, Metal, 03 medical and health sciences, chemistry.chemical_compound, Metals, Heavy, Escherichia coli, medicine, Animals, Environmental Chemistry, Metallothionein, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Environmental Restoration and Remediation, 030304 developmental biology, 0105 earth and related environmental sciences, Arsenite, 2. Zero hunger, 0303 health sciences, Cadmium, Protection, Metallurgy, Public Health, Environmental and Occupational Health, General Medicine, General Chemistry, Periplasmic space, Metal homeostasis, Bioaccumulation, Pollution, Recombinant Proteins, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, Heavy metals, chemistry, Biochemistry, Cytoplasm, visual_art, visual_art.visual_art_medium, Bioremediation
Abstract: International audience; Metallothioneins (MTs) are ubiquitous metal-binding, cysteine-rich, small proteins known to provide protection against toxic heavy metals such as cadmium. In an attempt to increase the ability of bacterial cells to accumulate heavy metals, sheep MTII was produced in fusion with the maltose binding protein (MBP) and localized to the cytoplasmic or periplasmic compartments of Escherichia coli. For all metals tested, higher levels of bioaccumulation were measured with strains over-expressing MBP-MT in comparison with control strains. A marked bioaccumulation of Cd, As, Hg and Zn was observed in the strain over-expressing MBP-MT in the cytoplasm, whereas Cu was accumulated to higher levels when MBP-MT was over-expressed in the periplasm. Metal export systems may also play a role in this bioaccumulation. To illustrate this, we over-expressed MBP-MT in the cytoplasm of two mutant strains of E. coli affected in metal export. The first, deficient in the transporter ZntA described to export numerous divalent metal ions, showed increasing quantities of Zn, Cd, Hg and Pb being bioaccumulated. The second, strain LF20012, deficient in As export, showed that As was bioaccumulated in the form of arsenite. Furthermore, high quantities of accumulated metals, chelated by MBP-MT in the cytoplasm, conferred greater metal resistance levels to the cells in the presence of added toxic metals, such as Cd or Hg, while other metals showed toxic effects when the export systems were deficient. The strain over-expressing MBP-MT in the cytoplasm, in combination, with disruption of metal export systems, could be used to develop strategies for bioremediation.
Published: 2012

9. Root developmental adaptation to phosphate starvation: better safe than sorry

Author: Laurent Nussaume, Benjamin Péret, Thierry Desnos, Mathilde Clément, Centre for Plant Integrative Biology [Nothingham] (CPIB), University of Nottingham, UK (UON), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Plant Environmental Physiology and Stress Signaling (PEPSS), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Signalisation de l'Adaptation des Végétaux à l'Environnement (SAVE), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Arabidopsis, MESH: Plant Roots, chemistry.chemical_element, MESH: Arabidopsis Proteins, Plant Science, MESH: Fertilizers, Root hair, Plant Roots, 01 natural sciences, Phosphates, Phosphorus metabolism, 03 medical and health sciences, chemistry.chemical_compound, Gene Expression Regulation, Plant, Botany, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Arabidopsis thaliana, MESH: Arabidopsis, Phosphorus deficiency, MESH: Gene Expression Regulation, Plant, Fertilizers, MESH: Phosphorus, Lateral root formation, 030304 developmental biology, 2. Zero hunger, 0303 health sciences, biology, Arabidopsis Proteins, Phosphorus, 15. Life on land, Phosphate, biology.organism_classification, Adaptation, Physiological, MESH: Adaptation, Physiological, chemistry, Agronomy, MESH: Phosphates, 010606 plant biology & botany
Abstract: International audience; Phosphorus is a crucial component of major organic molecules such as nucleic acids, ATP and membrane phospholipids. It is present in soils in the form of inorganic phosphate (Pi), which has low availability and poor mobility. To cope with Pi limitations, plants have evolved complex adaptive responses that include morphological and physiological modifications. This review describes how the model plant Arabidopsis thaliana adapts its root system architecture to phosphate deficiency through inhibition of primary root growth, increase in lateral root formation and growth and production of root hairs, which all promote topsoil foraging. A better understanding of plant adaptation to low phosphate will open the way to increased phosphorus use efficiency by crops. Such an improvement is needed in order to adjust how we manage limited phosphorus stocks and to reduce the disastrous environmental effects of phosphate fertilizers overuse.
Published: 2011

10. miR390,Arabidopsis TAS3tasiRNAs, and TheirAUXIN RESPONSE FACTORTargets Define an Autoregulatory Network Quantitatively Regulating Lateral Root Growth

Author: Laurent Nussaume, Alexis Maizel, Elena Marin, Virginie Jouannet, Hervé Vaucheret, Aurélie Herz, Dolf Weijers, Annemarie S. Lokerse, Martin Crespi, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Institut des sciences du végétal (ISV), Centre National de la Recherche Scientifique (CNRS), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Plant Environmental Physiology and Stress Signaling (PEPSS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA))
Subjects: 0106 biological sciences, indoleacetic acids metabolism, Mutant, Arabidopsis, Gene regulatory network, arabidopsis growth and development, MESH: Plant Roots, plant, Plant Science, MESH: RNA, Plant, Plant Roots, Biochemistry, 01 natural sciences, génétique, Plant Growth Regulators, Gene Expression Regulation, Plant, Genes, Reporter, Génétique des plantes, MESH: RNA, Small Interfering, MESH: Gene Expression Regulation, Developmental, Gene expression, interfering rna, MESH: Arabidopsis, Gene Regulatory Networks, RNA, Small Interfering, Research Articles, développement, MESH: Gene Regulatory Networks, Regulation of gene expression, chemistry.chemical_classification, Genetics, 0303 health sciences, EPS-1, arabidopsis genetic, Gene Expression Regulation, Developmental, food and beverages, gene expression regulation, MESH: Transcription Factors, Cell biology, arabidopsis proteins genetic, arabidopsis proteins metabolism, developmental, gene regulatory networks, genes reporter, micrornas genetic, plant growth regulators metabolism, plant roots growth and development, rna plant genetic, rna small interfering genetic, transcription factors genetic, transcription factors metabolism, réseaux, RNA, Plant, trans-acting sirnas, transcription, expression des gènes, complex regulation, MESH: Indoleacetic Acids, Biochemie, MESH: Arabidopsis Proteins, Plants genetics, Biology, 03 medical and health sciences, gene-regulation, Auxin, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, thaliana, MESH: Gene Expression Regulation, Plant, MESH: Plant Growth Regulators, micrornas, métabolisme, 030304 developmental biology, Reporter gene, Indoleacetic Acids, Arabidopsis Proteins, pathway, MESH: Genes, Reporter, fungi, Lateral root, Cell Biology, biogenesis, biology.organism_classification, initiation, racine, chemistry, MESH: MicroRNAs, Transcription Factors, 010606 plant biology & botany
Abstract: L'article original est publié par The American Society of Plant Biologists; International audience; Plants adapt to different environmental conditions by constantly forming new organs in response to morphogenetic signals. Lateral roots branch from the main root in response to local auxin maxima. How a local auxin maximum translates into a robust pattern of gene activation ensuring the proper growth of the newly formed lateral root is largely unknown. Here, we demonstrate that miR390, TAS3-derived trans-acting short-interfering RNAs (tasiRNAs), and AUXIN RESPONSE FACTORS (ARFs) form an auxin-responsive regulatory network controlling lateral root growth. Spatial expression analysis using reporter gene fusions, tasi/miRNA sensors, and mutant analysis showed that miR390 is specifically expressed at the sites of lateral root initiation where it triggers the biogenesis of tasiRNAs. These tasiRNAs inhibit ARF2, ARF3, and ARF4, thus releasing repression of lateral root growth. In addition, ARF2, ARF3, and ARF4 affect auxin-induced miR390 accumulation. Positive and negative feedback regulation of miR390 by ARF2, ARF3, and ARF4 thus ensures the proper definition of the miR390 expression pattern. This regulatory network maintains ARF expression in a concentration range optimal for specifying the timing of lateral root growth, a function similar to its activity during leaf development. These results also show how small regulatory RNAs integrate with auxin signaling to quantitatively regulate organ growth during development.
Published: 2010

11. Hydrogen Production in Chlamydomonas: Photosystem II-Dependent and -Independent Pathways Differ in Their Requirement for Starch Metabolism

Author: Hélène Timpano, Dimitri Tolleter, Stéphan Cuiné, Gilles Peltier, Steven G. Ball, Audrey Beyly, Vincent Chochois, David Dauvillée, Laurent Cournac, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 (UGSF), Institut National de la Recherche Agronomique (INRA)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 0106 biological sciences, Hydrogenase, Photosystem II, Physiology, Intracellular Space, Chlamydomonas reinhardtii, Plastoquinone, Plant Science, Acetates, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, Genetics, Animals, Anaerobiosis, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Electrochemical gradient, 030304 developmental biology, Photosystem, 0303 health sciences, biology, Chlamydomonas, Genetic Complementation Test, Photosystem II Protein Complex, food and beverages, Starch, DCMU, Deuterium, biology.organism_classification, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], chemistry, Biochemistry, Mutation, Sulfur, Hydrogen, Research Article, 010606 plant biology & botany
Abstract: Under sulfur deprivation conditions, the green alga Chlamydomonas reinhardtii produces hydrogen in the light in a sustainable manner thanks to the contribution of two pathways, direct and indirect. In the direct pathway, photosystem II (PSII) supplies electrons to hydrogenase through the photosynthetic electron transport chain, while in the indirect pathway, hydrogen is produced in the absence of PSII through a photosystem I-dependent process. Starch metabolism has been proposed to contribute to both pathways by feeding respiration and maintaining anoxia during the direct pathway and by supplying reductants to the plastoquinone pool during the indirect pathway. At variance with this scheme, we report that a mutant lacking starch (defective for sta6) produces similar hydrogen amounts as the parental strain in conditions of sulfur deprivation. However, when PSII is inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea, conditions where hydrogen is produced by the indirect pathway, hydrogen production is strongly reduced in the starch-deficient mutant. We conclude that starch breakdown contributes to the indirect pathway by feeding electrons to the plastoquinone pool but is dispensable for operation of the direct pathway that prevails in the absence of DCMU. While hydrogenase induction was strongly impaired in the starch-deficient mutant under dark anaerobic conditions, wild-type-like induction was observed in the light. Because this light-driven hydrogenase induction is DCMU insensitive and strongly inhibited by carbonyl cyanide-p-trifluoromethoxyphenylhydrazone or 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone, we conclude that this process is regulated by the proton gradient generated by cyclic electron flow around PSI.
Published: 2009

12. Altered expression of cytosolic/nuclear HSC70-1 molecular chaperone affects development and abiotic stress tolerance in Arabidopsis thaliana

Author: Marie-Anne Roncato, Serge Chiarenza, Nathalie Pochon, Nathalie Leonhardt, Mathilde Clément, Audrey Creff, Anne-Claire Cazalé, Elena Marin, Laurent D. Noël, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2, Unité mixte de recherche interactions plantes-microorganismes, Institut National de la Recherche Agronomique (INRA)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées
Subjects: 0106 biological sciences, SGT1, Physiology, Mutant, Arabidopsis, Y-RAY, AUXIN, Plant Science, 01 natural sciences, DnaK, Cytosol, Gene Expression Regulation, Plant, UV-C, HSP70, 2. Zero hunger, Abiotic component, 0303 health sciences, biology, Salt Tolerance, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Cell biology, Co-chaperone, Glucosyltransferases, embryonic structures, ARSENIC, Signal Transduction, HEAT SHOCK, animal structures, HSC70, Ultraviolet Rays, macromolecular substances, CADMIUM, 03 medical and health sciences, Stress, Physiological, Botany, 030304 developmental biology, Cell Nucleus, Indoleacetic Acids, Arabidopsis Proteins, Abiotic stress, HSC70 Heat-Shock Proteins, ARABIDOPSIS THALIANA, Meristem, biology.organism_classification, MERSITEM, Hsp70, Gamma Rays, Chaperone (protein), biology.protein, CO-CHAPERONE, 010606 plant biology & botany
Abstract: International audience; Molecular chaperones of the heat shock cognate 70 kDa (HSC70) family are highly conserved in all living organisms and assist nascent protein folding in normal physiological conditions as well as in biotic and abiotic stress conditions. In the absence of specific inhibitors or viable knockout mutants, cytosolic/nuclear HSC70-1 overexpression (OE) and mutants in the HSC70 co-chaperone SGT1 (suppressor of G2/M allele of skp1) were used as genetic tools to identify HSC70/SGT1 functions in Arabidopsis development and abiotic stress responses. HSC70-1 OE caused a reduction in root and shoot meristem activities, thus explaining the dwarfism of those plants. In addition, HSC70-1 OE did not impair auxin-dependent phenotypes, suggesting that SGT1 functions previously identified in auxin signalling are HSC70 independent. While responses to abiotic stimuli such as UV-C exposure, phosphate starvation, or seedling de-etiolation were not perturbed by HSC70-1 OE, it specifically conferred γ-ray hypersensitivity and tolerance to salt, cadmium (Cd), and arsenic (As). Cd and As perception was not perturbed, but plants overexpressing HSC70-1 accumulated less Cd, thus providing a possible molecular explanation for their tolerance phenotype. In summary, genetic evidence is provided for HSC70-1 involvement in a limited set of physiological processes, illustrating the essential and yet specific functions of this chaperone in development and abiotic stress responses in Arabidopsis.
Published: 2009

13. Cadmium and T cell differentiation: Limited impact in vivo but significant toxicity in fetal thymus organ culture

Author: V. Collin-Faure, Muriel Viau, Pierre Richaud, Serge M. Candéias, Jean-Luc Ravanat, Grenoble Institut des Neurosciences (GIN), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Santé et de la Recherche Médicale (INSERM), Biochimie et biophysique des systèmes intégrés (BBSI), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Lésions des Acides Nucléiques (LAN), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut Nanosciences et Cryogénie (INAC), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: DNA repair, T-Lymphocytes, T cell, Cellular differentiation, Population, Apoptosis, Thymus Gland, Biology, Toxicology, Mice, 03 medical and health sciences, Organ Culture Techniques, 0302 clinical medicine, Cadmium Chloride, Pregnancy, medicine, Animals, Tissue Distribution, education, Cells, Cultured, 030304 developmental biology, Pharmacology, 0303 health sciences, education.field_of_study, Cell Differentiation, T lymphocyte, Cell cycle, Carcinogens, Environmental, 3. Good health, Cell biology, Mice, Inbred C57BL, Thymocyte, medicine.anatomical_structure, Gamma Rays, [SDV.TOX]Life Sciences [q-bio]/Toxicology, 030220 oncology & carcinogenesis, Immunology, [SDV.IMM]Life Sciences [q-bio]/Immunology, Female, Spleen, DNA Damage, Nucleotide excision repair
Abstract: International audience; DNA lesions, including oxydated bases, nucleotide damage and double strand breaks, are continuously produced in living cells and represent a threat for genetic stability. Highly conserved repair processes have evolved to maintain DNA integrity. Cadmium (Cd) is an environmental carcinogenic pollutant known to inactivate several proteins involved in DNA repair systems while at the same time creating an oxidative stress that can result in additional DNA lesions. Cd also has potent immunotoxic effects. DNA repair by non-homologous end joining (NHEJ) is absolutely required for T lymphocyte differentiation. In this study, we examined the impact of Cd on non-homologous end joining pathway by analyzing T cell development in the thymus of mice that received Cd-supplemented drinking water. In vivo, the absence of major alteration indicates that Cd does not affect NHEJ, despite its accumulation in the thymus. Cd contamination affects only a discrete population of developing thymocytes. However, these cells are functional as the cellular response observed in mice following gamma-radiation exposure is identical in treated and control mice. Furthermore, Cd diet did not perturb the redox status in thymocytes and more importantly did not generate significant DNA lesions in organs that accumulate the highest concentration of Cd. Our results show that in vivo, Cd does not affect NHEJ or base and nucleotide repair, and that Cd toxicity to T cells is rather linked to cell cycle perturbations.
Published: 2007

14. Constitutive activation of a plasma membrane H+-ATPase prevents abscisic acid-mediated stomatal closure

Author: Miguel Costa, Axel Müller, Jérôme Giraudat, Alain Vavasseur, Bernard Genty, Nathalie Leonhardt, Francesca Fenzi, Christiane Valon, Karine Boivin, Jeffrey Leung, Sylvain Merlot, Laurie Piette, Institut des sciences du végétal (ISV), Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, CarboGen AG, and Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, ATPase, Arabidopsis, Saccharomyces cerevisiae, 01 natural sciences, Article, General Biochemistry, Genetics and Molecular Biology, Necrosis, 03 medical and health sciences, chemistry.chemical_compound, Gene Expression Regulation, Plant, Guard cell, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Molecular Biology, Abscisic acid, Cell Size, Plant Diseases, 030304 developmental biology, 0303 health sciences, General Immunology and Microbiology, biology, General Neuroscience, Cell Membrane, food and beverages, Depolarization, Hyperpolarization (biology), Plants, Genetically Modified, biology.organism_classification, Proton-Translocating ATPases, chemistry, Biochemistry, Mutation, Darkness, biology.protein, Biophysics, Protons, Signal transduction, Abscisic Acid, 010606 plant biology & botany
Abstract: Light activates proton (H(+))-ATPases in guard cells, to drive hyperpolarization of the plasma membrane to initiate stomatal opening, allowing diffusion of ambient CO(2) to photosynthetic tissues. Light to darkness transition, high CO(2) levels and the stress hormone abscisic acid (ABA) promote stomatal closing. The overall H(+)-ATPase activity is diminished by ABA treatments, but the significance of this phenomenon in relationship to stomatal closure is still debated. We report two dominant mutations in the OPEN STOMATA2 (OST2) locus of Arabidopsis that completely abolish stomatal response to ABA, but importantly, to a much lesser extent the responses to CO(2) and darkness. The OST2 gene encodes the major plasma membrane H(+)-ATPase AHA1, and both mutations cause constitutive activity of this pump, leading to necrotic lesions. H(+)-ATPases have been traditionally assumed to be general endpoints of all signaling pathways affecting membrane polarization and transport. Our results provide evidence that AHA1 is a distinct component of an ABA-directed signaling pathway, and that dynamic downregulation of this pump during drought is an essential step in membrane depolarization to initiate stomatal closure.
Published: 2007

15. Structural Consequences of Binding of UO22+ to Apotransferrin: Can This Protein Account for Entry of Uranium into Human Cells?

Author: Françoise Rollin-Genetet, Caroline Torne-Celer, Samuel Gourion-Arsiquaud, Claude Vidaud, Catherine Berthomieu, Sophie Plantevin, Eric Quéméneur, Olivier Pible, Service de Biochimie et Toxicologie Nucléaire (SBTN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and CEA - Cadarache, Laboratoire de Bioénergétique Cellulaire (UMR 6191)
Subjects: Models, Molecular, Circular dichroism, Coordination sphere, Iron, Microdialysis, [SDV]Life Sciences [q-bio], Transferrin receptor, 010402 general chemistry, 01 natural sciences, Biochemistry, 03 medical and health sciences, chemistry.chemical_compound, Protein structure, Receptors, Transferrin, Spectroscopy, Fourier Transform Infrared, Humans, Binding site, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Binding Sites, Calorimetry, Differential Scanning, Circular Dichroism, Spectrum Analysis, Transferrin, Uranyl, Uranium Compounds, 0104 chemical sciences, Crystallography, chemistry, Thermodynamics, Tyrosine, Uranium, Protein stabilization, Apoproteins, K562 Cells, Protein Binding
Abstract: It has been established that transferrin binds a variety of metals. These include toxic uranyl ions which form rather stable uranyl-transferrin derivatives. We determined the extent to which the iron binding sites might accommodate the peculiar topographic profile of the uranyl ion and the consequences of its binding on protein conformation. Indeed, metal intake via endocytosis of the transferrin/transferrin receptor depends on the adequate coordination of the metal in its site, which controls protein conformation and receptor binding. Using UV-vis and Fourier transform infrared difference spectroscopy coupled to a microdialysis system, we showed that at both metal binding sites two tyrosines are uranyl ligands, while histidine does not participate with its coordination sphere. Analysis by circular dichroism and differential scanning calorimetry (DSC) showed major differences between structural changes associated with interactions of iron or uranyl with apotransferrin. Uranyl coordination reduces the level of protein stabilization compared to iron, but this may be simply related to partial lobe closure. The lack of interaction between uranyl-TF and its receptor was shown by flow cytometry using Alexa 488-labeled holotransferrin. We propose a structural model summarizing our conclusion that the uranyl-TF complex adopts an open conformation that is not appropriate for optimal binding to the transferrin receptor.
Published: 2007

16. Detoxification of superoxide without production of H2O2: antioxidant activity of superoxide reductase complexed with ferrocyanide

Author: Catherine Berthomieu, Vincent Nivière, Emilie Tremey, Fernando P. Molina-Heredia, Vincent Favaudon, Virgile Adam, Danièle Touati, Chantal Houée-Levin, Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Chimie Physique D'Orsay (LCPO), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Interactions Protéine Métal (IPM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Institut Jacques Monod (IJM (UMR_7592)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Génotoxicologie, signalisation et radiothérapie expérimentale, Institut Curie [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM), European Synchrotron Radiation Facility (ESRF), Toxicologie Nucléaire program from the Commissariat à l'Energie Atomique (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Chimie et biochimie des centres redox biologiques (CBCRB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Deltaproteobacteria, MESH: Hydrogen-Ion Concentration, MESH: Pulse Radiolysis, Antioxidant, medicine.medical_treatment, MESH: Escherichia coli Proteins, MESH: Superoxides, Crystallography, X-Ray, Photochemistry, MESH: Research Support, Non-U.S. Gov't, 01 natural sciences, Medicinal chemistry, Antioxidants, chemistry.chemical_compound, dismutase, Superoxides, Spectroscopy, Fourier Transform Infrared, Spectroscopy, 0303 health sciences, Multidisciplinary, MESH: Oxidative Stress, Crystallography, biology, Superoxide, MESH: Escherichia coli, Escherichia coli Proteins, Hydrogen-Ion Concentration, Biological Sciences, Aerobiosis, Hydrogen-Ion Concentration Models, Solutions, Superoxide reductase, MESH: Hydrogen Peroxide, pyrococcus-furiosus, Ferrocyanide, Oxidoreductases, Pulse Radiolysis, MESH: Mutation, Non-U.S. Gov't Solutions, MESH: Ferrocyanides, mechanism, FOS: Physical sciences, hydrogen peroxide, superoxide radical, MESH: Solutions, 010402 general chemistry, Research Support, Models, Biological, Redox, Biological Mutation Oxidative Stress, MESH: Spectroscopy, Fourier Transform Infrared, Ferrous, Superoxide dismutase, 03 medical and health sciences, MESH: Aerobiosis, Physics - Chemical Physics, medicine, Escherichia coli, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, MESH: Oxidoreductases, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], MESH: Deltaproteobacteria, 030304 developmental biology, Chemical Physics (physics.chem-ph), Binding Sites, MESH: Antioxidants, MESH: Models, Biological, Active site, Biomolecules (q-bio.BM), [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Hydrogen Peroxide, MESH: Gamma Rays, MESH: Crystallography, X-Ray, 0104 chemical sciences, Oxidative Stress, chemistry, MESH: Binding Sites, Quantitative Biology - Biomolecules, Fourier Transform Infrared, Gamma Rays, FOS: Biological sciences, Mutation, biology.protein, X-Ray, desulfoarculus-baarsii, Ferrocyanides
Abstract: The superoxide radical O 2 ·̅ is a toxic by-product of oxygen metabolism. Two O 2 ·̅ detoxifying enzymes have been described so far, superoxide dismutase and superoxide reductase (SOR), both forming H 2 O 2 as a reaction product. Recently, the SOR active site, a ferrous iron in a [Fe 2+ (N-His) 4 (S-Cys)] pentacoordination, was shown to have the ability to form a complex with the organometallic compound ferrocyanide. Here, we have investigated in detail the reactivity of the SOR–ferrocyanide complex with O 2 ·̅ by pulse and γ-ray radiolysis, infrared, and UV-visible spectroscopies. The complex reacts very efficiently with O 2 ·̅ . However, the presence of the ferrocyanide adduct markedly modifies the reaction mechanism of SOR, with the formation of transient intermediates different from those observed for SOR alone. A one-electron redox chemistry appears to be carried out by the ferrocyanide moiety of the complex, whereas the SOR iron site remains in the reduced state. Surprisingly, the toxic H 2 O 2 species is no longer the reaction product. Accordingly, in vivo experiments showed that formation of the SOR–ferrocyanide complex increased the antioxidant capabilities of SOR expressed in an Escherichia coli sodA sodB recA mutant strain. Altogether, these data describe an unprecedented O 2 ·̅ detoxification activity, catalyzed by the SOR–ferrocyanide complex, which does not conduct to the production of the toxic H 2 O 2 species.
Published: 2015

17. Development and validation of a screening procedure of microalgae for biodiesel production: Application to the genus of marine microalgae Nannochloropsis

Author: Boris Mirabella, Hosni Takache, Ahmed Taleb, Bertrand Legeret, B. Le-Gouic, S. Bouvet, H. Marec, Jack Legrand, Yonghua Li-Beisson, Gilles Peltier, Jeremy Pruvost, Samir Taha, Bioprocédés Appliqués aux Microalgues (GEPEA-BAM), Laboratoire de génie des procédés - environnement - agroalimentaire (GEPEA), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL), Laboratoire d'Ecologie Microbienne de la Rhizosphère et d'Environnements Extrêmes (LEMIRE), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Bioénergie et Microalgues (EBM), Université Libanaise, Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Université de Nantes (UN)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Laboratoire d'Electronique Quantique, Université des Sciences et de la Technologie Houari Boumediene [Alger] (USTHB)-Faculté de Physique, Mines Nantes (Mines Nantes)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ingénierie des Matériaux de Bretagne (LIMATB), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université de Brest (UBO), Institut de Chimie de Clermont-Ferrand (ICCF), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Sigma CLERMONT (Sigma CLERMONT)-Centre National de la Recherche Scientifique (CNRS), Institut Jacques Monod (IJM (UMR_7592)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Lebanese University, AZM Center for Biotechnology Research and Its Applications, Lebanese University, Department of Food Science and Technology, Faculty of Agricultural and Veterinary Medecine, Université de Bretagne Sud (UBS)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université de Brest (UBO)-Université de Brest (UBO), and Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Sigma CLERMONT (Sigma CLERMONT)
Subjects: Aquatic Organisms, Environmental Engineering, Time Factors, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, [SDV]Life Sciences [q-bio], Photobioreactor, Bioengineering, Mass Spectrometry, Photobioreactors, Bioenergy, Botany, Bioreactor, Microalgae, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Food science, Biomass, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, Triglycerides, Biodiesel, biology, Renewable Energy, Sustainability and the Environment, Fatty Acids, Reproducibility of Results, General Medicine, biology.organism_classification, Lipids, Kinetics, Productivity (ecology), Biofuel, Biodiesel production, Biofuels, Nannochloropsis, Stramenopiles, Biotechnology, Chromatography, Liquid
Abstract: International audience; Nannochloropsis has emerged as a promising alga for biodiesel production. However, the genus consists of 6 species and hundreds of strains making strain selection a challenge. Furthermore, oil productivity is instrumental to economic viability of any algal strain for industrial production, which is dependent on growth rate and oil content. In most cases, these two parameters have been studied independently. Thus, the goal of this study is to provide a combined method for evaluating strain performance in specially designed photobioreactors together with an in-depth lipidomic analyses. The nine strains of Nannochloropsis tested showed considerable variations in productivity and lipidomics highlighting the importance of strain selection. Finally, Nannochloropsis gaditana CCMP527 and Nannochloropsis salina CCMP537 emerged as the two most promising strains, with an oil content of 37 and 27 dry wt% after 11-day nitrogen starvation, respectively, resulting in TAG productivity of 13 × 10−3 and 18 × 10−3 kg m−3 d−1, respectively.
Published: 2015

18. Electrochemically induced FTIR difference spectroscopy in the mid- to far infrared (200 μm) domain: A new setup for the analysis of metal–ligand interactions in redox proteins

Author: Laure Marboutin, Catherine Berthomieu, François Dupeyrat, Pierre Bouyer, Interactions Protéine Métal (IPM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), CEA - Cadarache, Laboratoire de Bioénergétique Cellulaire (UMR 6191), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), and Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Infrared, [SDV]Life Sciences [q-bio], Biophysics, Analytical chemistry, Cytochrome c Group, Ligands, 010402 general chemistry, 01 natural sciences, Biochemistry, Spectral line, Biomaterials, symbols.namesake, Far infrared, Spectroscopy, Fourier Transform Infrared, Fourier transform infrared spectroscopy, Spectroscopy, ComputingMilieux_MISCELLANEOUS, 010405 organic chemistry, Chemistry, Organic Chemistry, Proteins, Resonance, General Medicine, 0104 chemical sciences, Metals, Molecular vibration, symbols, Raman spectroscopy, Oxidation-Reduction, Protein Binding
Abstract: We report the setup of an electrochemical cell with chemical–vapor deposition diamond windows and the use of a Bruker 66 SX FTIR spectrometer equipped with DTGS and Si-bolometer detectors and KBr and mylar beam splitters, to record on the same sample, FTIR difference spectra corresponding to the structural changes associated with the change in redox state of active sites in proteins in the whole 1800–50 cm–1 region. With cytochrome c we show that reliable reduced-minus-oxidized FTIR difference spectra are obtained, which correspond to single molecular vibrations. Redox-sensitive IR modes of the cytochrome c are detected until 140 cm–1 with a good signal to noise. This new setup is promising to analyze the infrared spectral region where metal–ligand vibrations are expected to contribute and to extend the analysis of vibrational properties to metal sites or redox states not accessible to (resonance) Raman spectroscopy. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 363–367, 2006 This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Published: 2006

19. Vibrational spectroscopy to study the properties of redox-active tyrosines in photosystem II and other proteins

Author: Rainer Hienerwadel, Catherine Berthomieu, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Luminy Génétique et Biophysique des Plantes (LGBP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CEA - Cadarache, Laboratoire de Bioénergétique Cellulaire (UMR 6191), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Resonance Raman, Free Radicals, Photosystem II, Protein Conformation, [SDV]Life Sciences [q-bio], Radical, Biophysics, Infrared spectroscopy, 010402 general chemistry, Photochemistry, 01 natural sciences, Biochemistry, Redox, Phenoxyl radical, 03 medical and health sciences, chemistry.chemical_compound, Phenols, Metallo-radical enzymes, Fourier transform infrared spectroscopy, Spectroscopy, Heme, ComputingMilieux_MISCELLANEOUS, 0303 health sciences, Hydrogen bond, Chemistry, Spectrum Analysis, 030302 biochemistry & molecular biology, Photosystem II Protein Complex, Hydrogen Bonding, Cell Biology, Carbon, Enzymes, Tyrosinyl radical, 0104 chemical sciences, Models, Chemical, Metals, Tyrosine, Oxidation-Reduction, Fourier transform infrared (FTIR) spectroscopy
Abstract: Tyrosine radicals play catalytic roles in essential metalloenzymes. Their properties—midpoint potential, stability…—or environment varies considerably from one enzyme to the other. To understand the origin of these properties, the redox tyrosines are studied by a number of spectroscopic techniques, including Fourier transform infrared (FTIR) and resonance Raman (RR) spectroscopy. An increasing number of vibrational data are reported for the (modified-) redox active tyrosines in ribonucleotide reductases, photosystem II, heme catalase and peroxidases, galactose and glyoxal oxidases, and cytochrome oxidase. The spectral markers for the tyrosinyl radicals have been recorded on models of (substituted) phenoxyl radicals, free or coordinated to metals. We review these vibrational data and present the correlations existing between the vibrational modes of the radicals and their properties and interactions formed with their environment: we present that the ν7a(C–O) mode of the radical, observed both by RR and FTIR spectroscopy at 1480–1515 cm−1, is a sensitive marker of the hydrogen bonding status of (substituted)-phenoxyl and Tyr , while the ν8a(C–C) mode may probe coordination of the Tyr to a metal. For photosystem II, the information obtained by light-induced FTIR difference spectroscopy for the two redox tyrosines TyrD and TyrZ and their hydrogen bonding partners is discussed in comparison with those obtained by other spectroscopic methods.
Published: 2005

20. Long Distance Charge Redistribution Upon Cu,Zn-Superoxide Dismutase Reduction

Author: Alain Lorphelin, Catherine Berthomieu, François Dupeyrat, Claude Vidaud, CEA - Cadarache, Laboratoire de Bioénergétique Cellulaire (UMR 6191), Service de Biochimie et Toxicologie Nucléaire (SBTN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), and Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_classification, 0303 health sciences, Chemistry, Superoxide, Stereochemistry, [SDV]Life Sciences [q-bio], chemistry.chemical_element, Peptide, Cell Biology, 010402 general chemistry, 01 natural sciences, Biochemistry, Copper, 0104 chemical sciences, Amino acid, 03 medical and health sciences, chemistry.chemical_compound, Tetramer, Peptide bond, Dismutase, Molecular Biology, ComputingMilieux_MISCELLANEOUS, Histidine, 030304 developmental biology
Abstract: Cu,Zn-superoxide dismutase (Cu,Zn-SOD) is a ubiquitous enzyme with an essential role in antioxidant defense. To better understand structural factors at the origin of the highly efficient superoxide dismutation mechanism, we analyzed the consequence of copper reduction on the electronic properties of the backbone and individual amino acids by using electrochemistry coupled to Fourier transform infrared spectroscopy. Comparison of data recorded with bovine erythrocyte and recombinant chloroplastic Cu,Zn-SOD from Lycopersicon esculentum, expressed as a functional tetramer in Escherichia coli and 14N- or fully 15N-labeled, demonstrated that the infrared changes were dominated by reorganizations of peptide bonds and histidine copper ligands. Two main infrared modes of histidine side chain, markers of metal coordination, were identified by using Cu- and Zn-methylimidazole models: the ν(C4C5)at 1605-1594 cm-1 or ≈1586 cm-1 for Nτ or Nπ coordination, and the ν(C5Nτ) at ≈1113-1088 cm-1. These modes, also identified in Cu,Zn-SOD by using 15N labeling, showed that the electronic properties of the histidine Nτ ligands of copper are mostly affected upon copper reduction. A striking conclusion of this work is that peptide groups from loops and β-sheet largely participate in charge redistribution upon copper reduction, and in contrast, electronic properties of polar and charged amino acids of the superoxide access channel remain unaffected. This is notably shown for the strictly conserved Arg-143 by site-directed mutagenesis on chloroplastic Cu,Zn-SOD. Charge compensation by the peptide backbone and preserved electronic properties of the superoxide access channel and docking site upon copper reduction may be the determinant factors for the high reaction kinetics of superoxide with both reduced and oxidized Cu,Zn-SOD.
Published: 2004

21. Structural analysis of B. subtilis CcpA effector binding site

Author: Vincent Chaptal, Virginie Gueguen-Chaignon, Solange Moréra, Cécile Lecampion, Anne Galinier, Josef Deutscher, Sylvie Nessler, Sandrine Poncet, Philippe Meyer, Laboratoire d'enzymologie et biochimie structurales (LEBS), Centre National de la Recherche Scientifique (CNRS), Microbiologie et Génétique Moléculaire (MGM), Institut National de la Recherche Agronomique (INRA)-Institut National Agronomique Paris-Grignon (INA P-G)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2
Subjects: Secondary, Protein Structure, MESH: Protein Structure, Quaternary, MESH: Protein Structure, Secondary, Plasma protein binding, Crystallography, X-Ray, Biochemistry, Protein Structure, Secondary, Quaternary, 03 medical and health sciences, chemistry.chemical_compound, Protein structure, Bacterial Proteins, Structural Biology, Transcription (biology), Fructosediphosphates, MESH: Protein Binding, MESH: Fructosediphosphates, Binding site, Protein Structure, Quaternary, MESH: Bacterial Proteins, Molecular Biology, 030304 developmental biology, 0303 health sciences, Binding Sites, Crystallography, Chemistry, Effector, 030302 biochemistry & molecular biology, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, MESH: Bacillus subtilis, MESH: Crystallography, X-Ray, DNA-Binding Proteins, Repressor Proteins, MESH: Binding Sites, MESH: Repressor Proteins, CCPA, X-Ray, MESH: DNA-Binding Proteins, Protein Binding, Bacillus subtilis
Published: 2006

22. Electrochemically Induced Far-Infrared Difference Spectroscopy on Metalloproteins Using Advanced Synchrotron Technology

Author: Nicolas Bremond, Pascale Roy, Rainer Hienerwadel, Dorothée Berthomieu, Nicolas Vita, Jean-Blaise Brubach, Catherine Berthomieu, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Interactions Protéine Métal (IPM), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: Models, Molecular, Vacuum, Protein Conformation, Infrared, Resonance Raman spectroscopy, Analytical chemistry, Signal-To-Noise Ratio, Ligands, 010402 general chemistry, 01 natural sciences, Analytical Chemistry, law.invention, 03 medical and health sciences, Far infrared, law, Metalloproteins, Spectroscopy, Fourier Transform Infrared, Electrochemistry, Spectroscopy, 030304 developmental biology, 0303 health sciences, Chemistry, Intermolecular force, Temperature, Hydrogen Bonding, Synchrotron, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Chemical bond, Beamline, Synchrotrons
Abstract: International audience; New information on a protein ' s structure, intra- and intermolecular hydrogen bonds, or metal − ligand bond properties can be unraveled in the far-infrared (far-IR)  terahertz  domain (600 − 3cm − 1 or 18 − 0.1 THz). In this study, we compare the performances of thermal sources with synchrotron far-IR to record reaction-induced Fourier trans- form infrared (FT-IR) di ff erence signals with proteins in solution. Using the model protein Cu − azurin placed in a short path length electrochemical cell adapted for transmission spectroscopy in vacuum-purged optics, we show that minute spectral shifts induced by metal isotope labeling or temper- ature changes are detected using the far-IR beamline AILES of the synchrotron SOLEIL. On one hand, these data allow us to identify modes involving Cu − ligand vibrations and pave the way for the analysis of metal sites or metal redox states of proteins not amenable to resonance Raman spectroscopy. On another hand, small band shifts or changes in band intensity upon temperature modi fi cations show that far-IR di ff erence spectroscopy allows one to extract from a complex background hydrogen- bonding signatures directly relevant to the protein function. For Cu − azurin, a temperature-sensitive IR mode involving Cu(II) − His vibrations points to the role of a hydrogen bond between a Cu histidine ligand and the water solvent in tuning the Cu(II) − histidine bond properties. Furthermore, these experimental data support the possible role of a His 117 − water interaction in electron-transfer activity of Cu − azurin proposed by theoretical studies
Published: 2013

23. PredAlgo: a new subcellular localization prediction tool dedicated to green algae

Author: Laurent Cournac, Olivier Vallon, Sabine Brugière, Michael Specht, Norbert Rolland, Ariane Atteia, Myriam Ferro, Michael Hippler, Guillaume Cogne, Gilles Peltier, Christophe Bruley, Marianne Tardif, Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA), Institut de Biosciences et de Biotechnologies de Grenoble (ex-IRTSV) (BIG), Institut National de la Santé et de la Recherche Médicale (INSERM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Grenoble Alpes (UGA), Laboratoire de physiologie cellulaire végétale (LPCV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Recherche Agronomique (INRA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institute for Plant Biochemistry and Biotechnology, Westfälische Wilhelms-Universität Münster (WWU), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Physiologie membranaire et moléculaire du chloroplaste (PMMC), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), 'Bundesministerium für Bildung und Forschung' Grant 0315265C (GOFORSYS partner Golmer Forschungseinheit für Systembiologie)., Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut National de la Santé et de la Recherche Médicale (INSERM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Recherche Agronomique (INRA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Bioénergie et Microalgues (EBM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Recherche Agronomique (INRA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Recherche Agronomique (INRA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Westfälische Wilhelms-Universität Münster = University of Münster (WWU), Environnement, Bioénergie, Microalgues et Plantes (EBMP), and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA))
Subjects: 0106 biological sciences, Chloroplasts, Algae, organellar import, Prasinophyceae, Chlamydomonas reinhardtii, transit peptide, Computational biology, Proteomics, 01 natural sciences, 03 medical and health sciences, proteomics, chloroplast, Transit Peptide, Botany, subcellular localization, Genetics, mitochondrion, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Molecular Biology, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, mass spectrometry, 0303 health sciences, biology, Trebouxiophyceae, Algal Proteins, Computational Biology, biology.organism_classification, Mitochondria, secretory pathway, Chloroplast, Proteome, Neural Networks, Computer, Chloroplast Proteins, protein, Software, 010606 plant biology & botany
Abstract: International audience; The unicellular green alga Chlamydomonas reinhardtii is a prime model for deciphering processes occurring in the intracellular compartments of the photosynthetic cell. Organelle-specific proteomic studies have started to delineate its various subproteomes, but sequence-based prediction software is necessary to assign proteins subcellular localizations at whole genome scale. Unfortunately, existing tools are oriented toward land plants and tend to mispredict the localization of nuclear-encoded algal proteins, predicting many chloroplast proteins as mitochondrion targeted. We thus developed a new tool called PredAlgo that predicts intracellular localization of those proteins to one of three intracellular compartments in green algae: the mitochondrion, the chloroplast, and the secretory pathway. At its core, a neural network, trained using carefully curated sets of C. reinhardtii proteins, divides the N-terminal sequence into overlapping 19-residue windows and scores the probability that they belong to a cleavable targeting sequence for one of the aforementioned organelles. A targeting prediction is then deduced for the protein, and a likely cleavage site is predicted based on the shape of the scoring function along the N-terminal sequence. When assessed on an independent benchmarking set of C. reinhardtii sequences, PredAlgo showed a highly improved discrimination capacity between chloroplast- and mitochondrion-localized proteins. Its predictions matched well the results of chloroplast proteomics studies. When tested on other green algae, it gave good results with Chlorophyceae and Trebouxiophyceae but tended to underpredict mitochondrial proteins in Prasinophyceae. Approximately 18% of the nuclear-encoded C. reinhardtii proteome was predicted to be targeted to the chloroplast and 15% to the mitochondrion.
Published: 2012

24. Investigation of fatty acids accumulation in Nannochloropsis oculata for biodiesel application

Author: Jeremy Pruvost, Gilles Peltier, F. Le Grand, Jack Legrand, Stéphan Cuiné, G. van Vooren, Laboratoire de génie des procédés - environnement - agroalimentaire (GEPEA), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL), Bioprocédés Appliqués aux Microalgues (GEPEA-BAM), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), This work was supported by the French research program CNRS-LIPALG and the French National Research Agency project DIESALG (ANR-12-BIME-0001-02). Support was also provided by the HélioBiotec platform, funded by the European Union (European Regional Development Fund), the Région Provence Alpes Côte d’Azur, the French Ministry of Research, and the Commissariat à l’Energie Atomique et aux Energies Alternatives, ANR-12-BIME-0001,DIESALG,Production de biodiesel par microalgues(2012), Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Université de Nantes (UN)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN), Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 0106 biological sciences, Chromatography, Gas, Environmental Engineering, Photobioreactor, chemistry.chemical_element, Biomass, Bioengineering, Biology, 01 natural sciences, 03 medical and health sciences, Bioenergy, 010608 biotechnology, Aquatic plant, Botany, Microalgae, Bioreactor, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Food science, Waste Management and Disposal, 030304 developmental biology, 0303 health sciences, Biodiesel, Renewable Energy, Sustainability and the Environment, Fatty Acids, General Medicine, Nitrogen, chemistry, 13. Climate action, Biofuel, Biofuels, [SDE]Environmental Sciences, Chromatography, Thin Layer, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract: International audience; Lipids production of the marine microalga species Nannochloropsis oculata was deeply investigated by studying under continuous light the effects of different nitrogen starvation strategies in photobioreactors of various thicknesses. Operating parameters like incident photons flux density (PFD), initial nitrogen (progressive starvation strategy) or biomass concentrations (sudden starvation strategy) were examined, with a detailed analysis of their effects on the quality and production kinetics of total (TL) and triglycerides (TG). In addition to the already known effect of nitrogen starvation to trigger reserve lipids accumulation (mainly TG), it was demonstrated the relevance of the light received per cell affecting TG content and productivities, as well as fatty acids (FA) profiles. With appropriate optimization, N. oculata was confirmed as an interesting candidate for biodiesel application, with high FA accumulation (up to around 50%DW with 43%DW in TG-FA), high productivity (maximum 3.6×10(-3)kg(TG-FA)m(-2)d(-1)) and a TG-FA profile close to palm oil.
Published: 2012

25. Understanding and tuning the catalytic bias of hydrogenase

Author: Sébastien Dementin, Abbas Abou Hamdan, Patrick Bertrand, Laurent Cournac, Pierre Richaud, Christophe Léger, Marc Rousset, Pierre-Pol Liebgott, Antonio L. De Lacey, Óscar Gutiérrez-Sanz, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Catalytic Spectroscopy Laboratory (CSIC), Institute of Catalysis and Petroleum Chemistry, Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), instituto de Catalysis y Petroleoquimica (ICP), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN), Groupement énergétique de Cadarache, Agence de l'Environnement et de la Maîtrise de l'Energie (ADEME)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Bioénergie et Microalgues (EBM), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, MESH: Oxidation-Reduction, Models, Molecular, Hydrogenase, MESH: Mutation, Stereochemistry, MESH: Catalytic Domain, MESH: Hydrogenase: chemistry,genetics,metabolism, 010402 general chemistry, Redox, 01 natural sciences, Biochemistry, Reversible reaction, Catalysis, Colloid and Surface Chemistry, Oxidoreductase, Catalytic Domain, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], chemistry.chemical_classification, biology, 010405 organic chemistry, MESH: Desulfovibrio: chemistry,enzymology,genetics, Substrate (chemistry), Active site, General Chemistry, Combinatorial chemistry, 0104 chemical sciences, Enzyme, chemistry, Mutation, biology.protein, Thermodynamics, Desulfovibrio, MESH: Thermodynamics, Oxidation-Reduction, MESH: Models, Molecular, 010606 plant biology & botany
Abstract: International audience; When enzymes are optimized for biotechnological purposes, the goal often is to increase stability or catalytic efficiency. However, many enzymes reversibly convert their substrate and product, and if one is interested in catalysis in only one direction, it may be necessary to prevent the reverse reaction. In other cases, reversibility may be advantageous because only an enzyme that can operate in both directions can turnover at a high rate even under conditions of low thermodynamic driving force. Therefore, understanding the basic mechanisms of reversibility in complex enzymes should help the rational engineering of these proteins. Here, we focus on NiFe hydrogenase, an enzyme that catalyses H2 oxidation and production, and we elucidate the mechanism that governs the catalytic bias (the ratio of maximal rates in the two directions). Unexpectedly, we found that this bias is not mainly determined by redox properties of the active site, but rather by steps which occur on sites of the proteins that are remote from the active site. We evidence a novel strategy for tuning the catalytic bias of an oxidoreductase, which consists in modulating the rate of a step that is limiting only in one direction of the reaction , without modifying the properties of the active site. The four Michaelis parameters (two maximal rates and two values of Km) which characterize the forward and reverse reactions of a one-substrate one-product enzyme are related to each other and to the equilibrium constant of the reaction by the Haldane equation. 1 The forward and reverse maximal rates sometimes differ so much that certain enzymes were designated as "one-way enzymes". 2 The origin of such kinetic asymmetry, referred to as "cat-alytic bias", has rarely been investigated. Jencks proposed that directionality may result from the destabilization of the enzyme-substrate complex, which would decrease the energy required to reach the transition state in the forward direction. 2 This ""Circe effect"" is controversial 3 and has found no echo in the case of oxidoreductas-es, whose directionality is always discussed by comparing the potential of the substrate/product redox couple with the potential of either the active site or the redox centers of the electron transfer (ET) chain, when there is one (see examples in supplementary information). In trying to explain the catalytic bias from a single property of the enzyme (the potential of either the active site or the ET chain), one implicitly assumes that a single redox step, ET either between the substrate and the active site or to/from an electron relay, determines both maximal rates. However, the catalytic cycle of oxidore-ductases involves various steps (substrate binding, product release, proton and electron transfers, active-site chemistry) and it may occur that the rate limiting step (rls) is not the same when the enzyme works forward or backward. Two different steps may define the two maximal rates, and their ratio. Demonstrating that this can occur requires that the rls be defined in both directions in a series of variants that exhibit different catalytic preferences. Hereafter, we do so by characterizing a series of Desulfovibrio fructosovorans (Df) NiFe hydrogenase mutants. Previously, we have shown that the WT enzyme catalyzes H2 production and oxidation at similar maximal rates, and that narrowing the substrate channel using site directed mutagenesis has no effect on the maximal rate of H2 oxidation. 4,5 Here we show that these mutations slow H2 production up to 100-fold. In redox titra-tions, the active site of the mutants that have little reduc-tive activity behaves like in the WT enzyme. We use a novel method based on the isotope-exchange assay to determine the rates of H2 release from the active site to the solvent, and we conclude that this step limits H2 production whereas H2 entry does not determine the maximal rate of H2 oxidation. Conversely, the previous observation 5 that modifying the electron transfer chain selectively slows H2 oxidation shows that electron transfer limits the rate of H2 oxidation but not H2 production. 6 This is the first demonstration, on a specific example, that slowing a step that is rate limiting only when the enzyme works in one direction is a general mechanism for biasing the enzyme in the other direction, independently of the redox properties of the cofactors. We prepared the enzyme samples as described previously. 5 H2 oxidation rates were measured using a spec-trophotometric assay at pH 8, 30°C, with 50mM oxidized methyl viologen (MV), under one atm. of H2. 5 The Km for H2 were measured electrochemically. 5 The voltammo-grams in fig 2 were obtained with the enzyme bound to a rotating graphite electrode. 7 H2 production was followed using mass spectrometry (MS), in a solution initially saturated with Ar, with a saturating concentration of re
Published: 2012

26. Isolation and Characterization of Environmental Bacteria Capable of Extracellular Biosorption of Mercury

Author: Séverine Zirah, Carine Lombard, Jean-Michel Guigner, Paul Soreau, Florence Brian-Jaisson, Manon Vandervennet, Fabienne François, Jean Peduzzi, Grégory Martino, Anne-Laure Molinier, Sylvie Rebuffat, Daniel Garcia, David Pignol, Molécules de Communication et Adaptation des Micro-organismes (MCAM), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, and Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: DNA, Bacterial, Molecular Sequence Data, chemistry.chemical_element, Microbial Sensitivity Tests, 010501 environmental sciences, DNA, Ribosomal, 01 natural sciences, Applied Microbiology and Biotechnology, Bacterial cell structure, 03 medical and health sciences, Bioremediation, Extracellular polymeric substance, Dry weight, RNA, Ribosomal, 16S, Environmental Microbiology, Cluster Analysis, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Effluent, Phylogeny, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, 2. Zero hunger, 0303 health sciences, Bacteria, Ecology, biology, 030306 microbiology, Spectrum Analysis, Polysaccharides, Bacterial, Biosorption, Sequence Analysis, DNA, biology.organism_classification, Geomicrobiology, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 6. Clean water, Mercury (element), chemistry, 13. Climate action, Environmental chemistry, Mercuric Chloride, Environmental Pollutants, Food Science, Biotechnology
Abstract: Accumulation of toxic metals in the environment represents a public health and wildlife concern. Bacteria resistant to toxic metals constitute an attractive biomass for the development of systems to decontaminate soils, sediments, or waters. In particular, biosorption of metals within the bacterial cell wall or secreted extracellular polymeric substances (EPS) is an emerging process for the bioremediation of contaminated water. Here the isolation of bacteria from soil, effluents, and river sediments contaminated with toxic metals permitted the selection of seven bacterial isolates tolerant to mercury and associated with a mucoid phenotype indicative of the production of EPS. Inductively coupled plasma-optical emission spectroscopy and transmission electron microscopy in conjunction with X-ray energy dispersive spectrometry revealed that bacteria incubated in the presence of HgCl 2 sequestered mercury extracellularly as spherical or amorphous deposits. Killed bacterial biomass incubated in the presence of HgCl 2 also generated spherical extracellular mercury deposits, with a sequestration capacity (40 to 120 mg mercury per g [dry weight] of biomass) superior to that of live bacteria (1 to 2 mg mercury per g [dry weight] of biomass). The seven strains were shown to produce EPS, which were characterized by Fourier transform-infrared (FT-IR) spectroscopy and chemical analysis of neutral-carbohydrate, uronic acid, and protein contents. The results highlight the high potential of Hg-tolerant bacteria for applications in the bioremediation of mercury through biosorption onto the biomass surface or secreted EPS.
Published: 2012

27. Structural and Mechanistic Insights into Unusual Thiol Disulfide Oxidoreductase

Author: Latifa Elantak, Olivier Bornet, Laetitia Pieulle, Edwige B. Garcin, Corinne Sebban-Kreuzer, Nicolas Vita, Françoise Guerlesquin, ELANTAK, Latifa, Institut de biologie structurale et microbiologie (IBSM), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Interactions et Modulateurs de Réponses (IMR), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'ingénierie des systèmes macromoléculaires (LISM), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Interactions Protéine Métal (IPM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Laboratoire de chimie bactérienne (LCB), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: [SDV.BBM.BS] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], [SDV]Life Sciences [q-bio], Mutation, Missense, Protein Disulfide-Isomerases, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, 03 medical and health sciences, Structure-Activity Relationship, Protein structure, Bacterial Proteins, Oxidoreductase, [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, Oxidoreductases Acting on Sulfur Group Donors, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Protein disulfide-isomerase, Molecular Biology, Nuclear Magnetic Resonance, Biomolecular, Histidine, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, biology, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Chemistry, Active site, Cell Biology, 0104 chemical sciences, Protein Structure, Tertiary, [SDV] Life Sciences [q-bio], Amino Acid Substitution, Protein Structure and Folding, biology.protein, Thiol, Desulfovibrio, Thioredoxin, Oxidation-Reduction, Cysteine
Abstract: International audience; Cytoplasmic desulfothioredoxin (Dtrx) from the anaerobe Desulfovibrio vulgaris Hildenborough has been identified as a new member of the thiol disulfide oxidoreductase family. The active site of Dtrx contains a particular consensus sequence, CPHC, never seen in the cytoplasmic thioredoxins and generally found in periplasmic oxidases. Unlike canonical thioredoxins (Trx), Dtrx does not present any disulfide reductase activity, but it presents instead an unusual disulfide isomerase activity. We have used NMR spectroscopy to gain insights into the structure and the catalytic mechanism of this unusual Dtrx. The redox potential of Dtrx (-181 mV) is significantly less reducing than that of canonical Trx. A pH dependence study allowed the determination of the pK(a) of all protonable residues, including the cysteine and histidine residues. Thus, the pK(a) values for the thiol group of Cys(31) and Cys(34) are 4.8 and 11.3, respectively. The His(33) pK(a) value, experimentally determined for the first time, differs notably as a function of the redox states, 7.2 for the reduced state and 4.6 for the oxidized state. These data suggest an important role for His(33) in the molecular mechanism of Dtrx catalysis that is confirmed by the properties of mutant DtrxH33G protein. The NMR structure of Dtrx shows a different charge repartition compared with canonical Trx. The results presented are likely indicative of the involvement of this protein in the catalysis of substrates specific of the anaerobe cytoplasm of DvH. The study of Dtrx is an important step toward revealing the molecular details of the thiol-disulfide oxidoreductase catalytic mechanism.
Published: 2012

28. Study of the Thiol/Disulfide Redox Systems of the Anaerobe Desulfovibrio vulgaris Points Out Pyruvate:Ferredoxin Oxidoreductase as a New Target for Thioredoxin 1

Author: Alain Dolla, Matthieu Nouailler, Nicolas Vita, Manon Vinay, Gaël Brasseur, Laetitia Pieulle, Corinne Sebban-Kreuzer, Edwige Garcin, Pierre Stocker, Interactions et Modulateurs de Réponses (IMR), Centre National de la Recherche Scientifique (CNRS), Laboratoire Chimie Provence (LCP), Université de Provence - Aix-Marseille 1-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de chimie bactérienne (LCB), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Interactions Protéine Métal (IPM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Centre National de la Recherche Scientifique (CNRS)-Université de Provence - Aix-Marseille 1-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Pyruvate Synthase, Oxidative phosphorylation, Microbiology, Biochemistry, 03 medical and health sciences, chemistry.chemical_compound, Thioredoxins, Bacterial Proteins, Oxidoreductase, [CHIM]Chemical Sciences, Anaerobiosis, Desulfovibrio vulgaris, Disulfides, Sulfhydryl Compounds, Molecular Biology, Ferredoxin, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, biology, 030306 microbiology, Cell Biology, Glutathione, NAD, biology.organism_classification, Desulfovibrio, chemistry, Mutation, Thiol, Thioredoxin, Reactive Oxygen Species, Oxidation-Reduction
Abstract: International audience; Sulfate reducers have developed a multifaceted adaptative strategy to survive against oxidative stresses. Along with this oxidative stress response, we recently characterized an elegant reversible disulfide bond-dependent protective mechanism in the pyruvate: ferredoxin oxidoreductase (PFOR) of various Desulfovibrio species. Here, we searched for thiol redox systems involved in this mechanism. Using thiol fluorescent labeling, we show that glutathione is not the major thiol/disulfide balance-controlling compound in four different Desulfovibrio species and that no other plentiful low molecular weight thiol can be detected. Enzymatic analyses of two thioredoxins (Trxs) and three thioredoxin reductases allow us to propose the existence of two independent Trx systems in Desulfovibrio vulgaris Hildenborough (DvH). The TR1/Trx1 system corresponds to the typical bacterial Trx system. We measured a TR1 apparent K(m) value for Trx1 of 8.9 mu M. Moreover, our results showed that activity of TR1 was NADPH-dependent. The second system named TR3/Trx3 corresponds to an unconventional Trx system as TR3 used preferentially NADH (K(m) for NADPH, 743 mu M; K(m) for NADH, 5.6 mu M), and Trx3 was unable to reduce insulin. The K(m) value of TR3 for Trx3 was 1.12 mu M. In vitro experiments demonstrated that the TR1/Trx1 system was the only one able to reactivate the oxygen-protected form of Desulfovibrio africanus PFOR. Moreover, ex vivo pulldown assays using the mutant Trx1(C33S) as bait allowed us to capture PFOR from the DvH extract. Altogether, these data demonstrate that PFOR is a new target for Trx1, which is probably involved in the protective switch mechanism of the enzyme.
Published: 2011

29. Histidine 416 of the periplasmic binding protein NikA is essential for nickel uptake in Escherichia coli

Author: Laura Zeppieri, Juan C. Fontecilla-Camps, Christine Cavazza, Lydie Martin, Emmanuelle Laffly, Mickaël V. Cherrier, Hugo Lebrette, Pierre Richaud, Marie Carrière, Institut de biologie structurale (IBS - UMR 5075 ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Service Interdisciplinaire sur les Systèmes Moléculaires et les Matériaux (ex SCM) (SIS2M UMR 3299), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Models, Molecular, Hydrogenase, Protein Conformation, [SDV]Life Sciences [q-bio], Biophysics, chemistry.chemical_element, Crystallography, X-Ray, 010402 general chemistry, medicine.disease_cause, 01 natural sciences, Biochemistry, 03 medical and health sciences, Nickel, Structural Biology, Nickel uptake, [NiFe] hydrogenase, Escherichia coli, Genetics, medicine, Periplasmic binding protein, Histidine, Molecular Biology, 030304 developmental biology, 0303 health sciences, Escherichia coli Proteins, Binding protein, Biological Transport, Cell Biology, Periplasmic space, Ligand (biochemistry), NikA, 0104 chemical sciences, Transport protein, Amino Acid Substitution, chemistry, Periplasmic Binding Proteins, Mutagenesis, Site-Directed, ATP-Binding Cassette Transporters, Mutant Proteins, Protein Binding
Abstract: International audience; Escherichia coli require nickel for the synthesis of [NiFe] hydrogenases under anaerobic growth conditions. Nickel import depends on the specific ABC‐transporter NikABCDE encoded by the nik operon, which deletion causes the complete abolition of hydrogenase activity. We have previously postulated that the periplasmic binding protein NikA binds a natural metallophore containing three carboxylate functions that coordinate a Ni(II) ion, the fourth ligand being His416, the only direct metal‐protein contact, completing a square‐planar coordination for the metal. The crystal structure of the H416I mutant showed no electron density corresponding to a metal‐chelator complex. In vivo experiments indicate that the mutation causes a significant decrease in nickel uptake and hydrogenase activity. These results confirm the essential role of His416 in nickel transport by NikA.
Published: 2011

30. Original Design of an Oxygen-Tolerant [NiFe] Hydrogenase: Major Effect of a Valine-to-Cysteine Mutation near the Active Site

Author: Sébastien Dementin, Pierre Richaud, Antonio L. De Lacey, Victor M. Fernandez, Christophe Léger, Bruno Guigliarelli, Bénédicte Burlat, Pierre-Pol Liebgott, Myriam Brugna, Laurent Cournac, Marc Rousset, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), instituto de Catalysis y Petroleoquimica (ICP), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Bioénergie et Microalgues (EBM), and Azzopardi, Laure
Subjects: Models, Molecular, Mutant, 01 natural sciences, Biochemistry, Colloid and Surface Chemistry, Catalytic Domain, Electrochemistry, Anaerobiosis, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, Carbon Monoxide, 0303 health sciences, biology, Valine, Aerobiosis, Thermodynamics, Desulfovibrio, Oxidation-Reduction, [CHIM.INOR] Chemical Sciences/Inorganic chemistry, Hydrogenase, Stereochemistry, Inorganic chemistry, Protonation, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, Catalysis, 03 medical and health sciences, Gram-Negative Bacteria, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Cysteine, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], 030304 developmental biology, Aquifex aeolicus, Spectrum Analysis, Cell Membrane, Deuterium Exchange Measurement, Active site, General Chemistry, biology.organism_classification, 0104 chemical sciences, Enzyme Activation, Oxygen, Kinetics, Enzyme, chemistry, Mutation, biology.protein, Hydrogen
Abstract: Hydrogenases are efficient biological catalysts of H(2) oxidation and production. Most of them are inhibited by O(2), and a prerequisite for their use in biotechnological applications under air is to improve their oxygen tolerance. We have previously shown that exchanging the residue at position 74 in the large subunit of the oxygen-sensitive [NiFe] hydrogenase from Desulfovibrio fructosovorans could impact the reaction of the enzyme with O(2) (Dementin, S.; J. Am. Chem. Soc. 2009, 131, 10156-10164; Liebgott, P. P.; Nat. Chem. Biol. 2010, 6, 63-70). This residue, a valine in the wild-type enzyme, located at the bottleneck of the gas channel near the active site, has here been exchanged with a cysteine. A thorough characterization using a combination of kinetic, spectroscopic (EPR, FTIR), and electrochemical studies demonstrates that the V74C mutant has features of the naturally occurring oxygen-tolerant membrane-bound hydrogenases (MBH). The mutant is functional during several minutes under O(2), has impaired H(2)-production activity, and has a weaker affinity for CO than the WT. Upon exposure to O(2), it is converted into the more easily reactivatable inactive form, Ni-B, and this inactive state reactivates about 20 times faster than in the WT enzyme. Control experiments carried out with the V74S and V74N mutants indicate that protonation of the position 74 residue is not the reason the mutants reactivate faster than the WT enzyme. The electrochemical behavior of the V74C mutant toward O(2) is intermediate between that of the WT enzyme from D. fructosovorans and the oxygen-tolerant MBH from Aquifex aeolicus.
Published: 2011

31. Exploring Diversity of Cultivable Aerobic Endospore-forming Bacteria: From Pasteurization to Procedures Without Heat-Shock Selection

Author: Berge, O., Mavingui, Patrick, Heulin, T., Laboratoire d'Ecologie Microbienne de la Rhizosphère et d'Environnements Extrêmes (LEMIRE), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), Station de Pathologie Végétale (AVI-PATHO), Institut National de la Recherche Agronomique (INRA), Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire de Lyon (ENVL)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)
Subjects: [SDV]Life Sciences [q-bio]
Published: 2011

32. Profiling the Active Site of a Copper Enzyme through Its Far-Infrared Fingerprint

Author: François Dupeyrat, Jean-Pierre Flament, Bertrand Xerri, Catherine Berthomieu, Nicolas Vita, Laure Marboutin, Dorothée Berthomieu, Hugo Petitjean, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Interactions Protéine Métal (IPM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Laboratoire de Réactivité de Surface (LRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Infrared, Analytical chemistry, chemistry.chemical_element, Infrared spectroscopy, Ligands, 010402 general chemistry, 01 natural sciences, Catalysis, Metal, 03 medical and health sciences, Far infrared, Catalytic Domain, Spectroscopy, Fourier Transform Infrared, Histidine, Spectroscopy, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, biology, Superoxide Dismutase, 030302 biochemistry & molecular biology, Water, Active site, General Medicine, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, Copper, 0104 chemical sciences, 3. Good health, Crystallography, chemistry, visual_art, Molecular vibration, visual_art.visual_art_medium, biology.protein, Oxidation-Reduction
Abstract: Vibrations of the metal active site of the Cu,Zn-superoxide dismutase enzyme were analyzed by far-infrared difference spectroscopy and theoretical normal mode calculation. Both electrochemically triggered Cu(I) and Cu(II) redox states show well-defined infrared vibrational modes, notably modes of the histidine ligands, the Cu(II)-His(61)-Zn(II) bridge and of the water pseudo-ligand.
Published: 2011

33. The cytosolic/nuclear HSC70 and HSP90 molecular chaperones are important for stomatal closure and modulate abscisic acid-dependent physiological responses in Arabidopsis

Author: Marie-Jo Droillard, Nathalie Leonhardt, Bernard Genty, Laurent D. Noël, Mathilde Clément, Christiane Laurière, Ilja M. Reiter, Jean-Luc Montillet, Laurent Nussaume, Université de la Méditerranée - Aix-Marseille 2, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut des sciences du végétal (ISV), Institut National de la Recherche Agronomique (INRA), Université Paris Diderot - Paris 7 (UPD7), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), UPR2355 Institut des sciences du végétal, Signalisation de l'Adaptation des Végétaux à l'Environnement (SAVE), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Unité mixte de recherche interactions plantes-microorganismes, Institut National de la Recherche Agronomique (INRA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Commissariat a l'Energie Atomique, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Plant Environmental Physiology and Stress Signaling (PEPSS), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, CYTOSOL, Transcription, Genetic, NODULATION, Physiology, CRUCIFERAE, ANGIOSPERMAE, Arabidopsis, Plant Science, 01 natural sciences, ABSCISIC ACID, chemistry.chemical_compound, Gene Expression Regulation, Plant, santé des plantes, Génétique des plantes, Abscisic acid, SESQUITERPENES, Adenosine Triphosphatases, Abiotic component, CHAPERONE, 0303 health sciences, SPERMATOPHYTA, Dehydration, biology, PLANT GROWTH SUBSTANCE, food and beverages, Darkness, Hsp90, PHYSIOLOGICAL PARAMETER, Biochemistry, Seeds, MOLECULAR DOMAIN, STOMATAL CONDUCTANCE, génétique moléculaire, Germination, Environmental Stress and Adaptation to Stress, macromolecular substances, Plants genetics, Genes, Plant, [SDV.GEN.GPL]Life Sciences [q-bio]/Genetics/Plants genetics, 03 medical and health sciences, Heat shock protein, Genetics, STOMATAL MOVEMENT, HSP90 Heat-Shock Proteins, RELATION PLANTE-MICROORGANISME, 030304 developmental biology, Cell Nucleus, DICOTYLEDONE, Arabidopsis Proteins, Abiotic stress, fungi, HSC70 Heat-Shock Proteins, ARABIDOPSIS THALIANA, biology.organism_classification, EXPERIMENTAL PLANT, PLANT PHYSIOLOGY, UNCTIONAL RESPONSE, chemistry, Chaperone (protein), Mutation, Plant Stomata, biology.protein, Peptides, Flagellin, 010606 plant biology & botany
Abstract: L'article original est publié par The American Society of Plant Biologists; International audience; Cytosolic/nuclear molecular chaperones of the heat shock protein families HSP90 and HSC70 are conserved and essential proteins in eukaryotes. These proteins have essentially been implicated in the innate immunity and abiotic stress tolerance in higher plants. Here, we demonstrate that both chaperones are recruited in Arabidopsis (Arabidopsis thaliana) for stomatal closure induced by several environmental signals. Plants overexpressing HSC70-1 or with reduced HSP90.2 activity are compromised in the dark-, CO2-, flagellin 22 peptide-, and abscisic acid (ABA)-induced stomatal closure. HSC70-1 and HSP90 proteins are needed to establish basal expression levels of several ABA-responsive genes, suggesting that these chaperones might also be involved in ABA signaling events. Plants overexpressing HSC70-1 or with reduced HSP90.2 activity are hypersensitive to ABA in seed germination assays, suggesting that several chaperone complexes with distinct substrates might tune tissue-specific responses to ABA and the other biotic and abiotic stimuli studied. This study demonstrates that the HSC70/HSP90 machinery is important for stomatal closure and serves essential functions in plants to integrate signals from their biotic and abiotic environments.
Published: 2011

34. A novel fry1 allele reveals the existence of a mutant phenotype unrelated to 5'->3' exoribonuclease (XRN) activities in Arabidopsis thaliana roots

Author: Marie Christine Thibaud, Elena Marin, Judith Hirsch, Laurent Nussaume, Barry J. Pogson, Martin Crespi, Thierry Desnos, Julie Misson, Allison C. Mallory, Marie Declerck, Vincent Bayle, Alexis Maizel, Hélène Javot, Peter A. Crisp, Pascale David, Hervé Vaucheret, Serge Chiarenza, Gonzalo M. Estavillo, Signalisation de l'Adaptation des Végétaux à l'Environnement (SAVE), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Institut des sciences du végétal (ISV), Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), ANR-06-GPLA-0011,GPLA06022G,RIBOROOT : Involvement of non coding RNAs in the adaptation of root architecture to abiotic stress(2006), Plant Environmental Physiology and Stress Signaling (PEPSS), ANR-GENOPLANT grant (RIBOROOT-ANR06 GPLA 011), the CEA agency, ANR-06-GPLA-0011,RIBOROOT,RIBOROOT : Involvement of non coding RNAs in the adaptation of root architecture to abiotic stress(2006), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, and Marin, Elena
Subjects: 0106 biological sciences, Genetic Screens, Leaves, Angiosperms, Arabidopsis thaliana, Arabidopsis, Gene Expression, lcsh:Medicine, MESH: Plant Roots, Plant Science, medicine.disease_cause, Plant Genetics, 01 natural sciences, Plant Roots, Meristems, Gene Expression Regulation, Plant, Exoribonuclease, MESH: Genes, Plant, Phosphate Transport Proteins, MESH: Arabidopsis, lcsh:Science, 2. Zero hunger, Genetics, Plant Growth and Development, 0303 health sciences, Mutation, Multidisciplinary, biology, MESH: Gene Expression Regulation, Enzymologic, food and beverages, Mutant phenotype, Plants, Phosphate Transporters, Plants, Genetically Modified, Phenotype, Drought adaptation, Phenotypes, Plant Physiology, Root growth, MESH: Exoribonucleases, MESH: Phosphoric Monoester Hydrolases, MESH: Phosphate Transport Proteins, Research Article, MESH: Mutation, Recombinant Fusion Proteins, Green Fluorescent Proteins, inositol polyphosphate 1-phosphatase, 3(2),5-bisphosphate nucleotidase, phosphate starvation, negative regulator, meristem, fiery1, differentiation, expression, architecture de la racine, MESH: Starvation, MESH: Arabidopsis Proteins, Plant Morphology, Genes, Plant, MESH: Phenotype, Gene Expression Regulation, Enzymologic, Phosphates, 03 medical and health sciences, Model Organisms, MESH: Green Fluorescent Proteins, Plant and Algal Models, medicine, MESH: Recombinant Fusion Proteins, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Allele, MESH: Gene Expression Regulation, Plant, Biology, Alleles, 030304 developmental biology, Vascular Plants, Arabidopsis Proteins, gène, MESH: Alleles, tolérance, lcsh:R, Botany, Phosphatases, biology.organism_classification, Phosphoric Monoester Hydrolases, racine, MESH: Plants, Genetically Modified, Starvation, Exoribonucleases, lcsh:Q, 010606 plant biology & botany, Developmental Biology
Abstract: International audience; BackgroundMutations in the FRY1/SAL1 Arabidopsis locus are highly pleiotropic, affecting drought tolerance, leaf shape and root growth. FRY1 encodes a nucleotide phosphatase that in vitro has inositol polyphosphate 1-phosphatase and 3′,(2′),5′-bisphosphate nucleotide phosphatase activities. It is not clear which activity mediates each of the diverse biological functions of FRY1 in planta.Principal FindingsA fry1 mutant was identified in a genetic screen for Arabidopsis mutants deregulated in the expression of Pi High affinity Transporter 1;4 (PHT1;4). Histological analysis revealed that, in roots, FRY1 expression was restricted to the stele and meristems. The fry1 mutant displayed an altered root architecture phenotype and an increased drought tolerance. All of the phenotypes analyzed were complemented with the AHL gene encoding a protein that converts 3′-polyadenosine 5′-phosphate (PAP) into AMP and Pi. PAP is known to inhibit exoribonucleases (XRN) in vitro. Accordingly, an xrn triple mutant with mutations in all three XRNs shared the fry1 drought tolerance and root architecture phenotypes. Interestingly these two traits were also complemented by grafting, revealing that drought tolerance was primarily conferred by the rosette and that the root architecture can be complemented by long-distance regulation derived from leaves. By contrast, PHT1 expression was not altered in xrn mutants or in grafting experiments. Thus, PHT1 up-regulation probably resulted from a local depletion of Pi in the fry1 stele. This hypothesis is supported by the identification of other genes modulated by Pi deficiency in the stele, which are found induced in a fry1 background.Conclusions/SignificanceOur results indicate that the 3′,(2′),5′-bisphosphate nucleotide phosphatase activity of FRY1 is involved in long-distance as well as local regulatory activities in roots. The local up-regulation of PHT1 genes transcription in roots likely results from local depletion of Pi and is independent of the XRNs..
Published: 2011

35. Plant plasma membrane and phosphate deprivation

Author: Laurent Nussaume, Maryse A. Block, Eric Maréchal, Marie Christine Thibaud, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physiologie cellulaire végétale (LPCV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Recherche Agronomique (INRA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Murphy, A.S., Plant Environmental Physiology and Stress Signaling (PEPSS), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Recherche Agronomique (INRA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)
Subjects: 0106 biological sciences, chemistry.chemical_classification, 0303 health sciences, Rhizosphere, phosphate deficiency, Chemistry, Membrane lipids, Phosphorus, chemistry.chemical_element, Plant, Phosphate, plasma membrane, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, Membrane, Biochemistry, Organic matter, Phosphorus deficiency, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Plastid envelope, metabolism, 030304 developmental biology, 010606 plant biology & botany
Abstract: Phosphorus is a major plant macronutrient, but it is also one of the less accessible mineral elements for these organisms due to the very low solubility of phosphate and phosphorus incorporation in organic matter in soils. Plants have developed multiple strategies to enhance phosphorus acquisition, and much of that activity takes place at the plasma membrane. Phosphorus remobilization from membrane lipids, regulation of transporter activity, and rhizosphere acidification are the primary mechanisms associated with the plasma membrane that function under phosphorus deficiency conditions. In this review, we summarize both lipid remodeling and adjustments of transporters in the plasma membrane of plant cells following Pi deprivation, and discuss the control and coordination of these major modifications in the global response of plants to this stress.
Published: 2011

36. MATH/BTB CRL3 receptors target the homeodomain-leucine zipper ATHB6 to modulate abscisic acid signalling

Author: E, Lechner, N, Leonhardt, H, Eisler, Y, Parmentier, M, Alioua, H, Jacquet, J, Leung, Institut de biologie moléculaire des plantes (IBMP), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Thiriet, Lydie
Subjects: [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2011

37. Is engineering O2 tolerant hydrogenase just a matter of reproducing the active site of O2-resistant enzymes ?

Author: Fanny Leroux, Pierre-Pol Liebgott, Laurent Cournac, Richaud, P., Arlette Kpebe, Bénédicte Burlat, Bruno Guigliarelli, Marc Rousset, Sébastien Dementin, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Développement et évolution (DE), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Azzopardi, Laure
Subjects: [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2010

38. Models for understanding eucaryote development

Author: Cast, Delphine, Cock, J. Mark, Kloareg, Bernard, Menand, Benoît, Michel, Gurvan, Rétaux, Sylvie, Scutt, C.P., Vialette-Guiraud, Aurélie, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Laboratoire de Biologie Intégrative des Modèles Marins (LBI2M), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Végétaux marins et biomolécules, Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-GOEMAR-Centre National de la Recherche Scientifique (CNRS), Luminy Génétique et Biophysique des Plantes (LGBP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut de Neurobiologie Alfred Fessard (INAF), Centre National de la Recherche Scientifique (CNRS), Développement, évolution et plasticité du système nerveux (DEPSN), Reproduction et développement des plantes (RDP), École normale supérieure - Lyon (ENS Lyon)-Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), École normale supérieure de Lyon (ENS de Lyon)-Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Lyon (ENS Lyon)
Subjects: [SDV]Life Sciences [q-bio]
Abstract: International audience; Bien qu’extrêmement diversifiés, il est clairement admis que les êtres vivants ont tous un seul ancêtre commun. Pour reconstituer un scénario évolutif robuste à l’origine de la biodiversité il est essentiel de développer des espèces modèles judicieusement placées et suffisamment dispersées dans " l'arbre de vie ".
Published: 2010

39. Is engineering O2-tolerant hydrogenases just a matter of reproducing the active sites of the naturally occurring O2-resistant enzymes?

Author: Bruno Guigliarelli, Christophe Léger, Arlette Kpebe, Bénédicte Burlat, Patrick Bertrand, Pierre Richaud, Sébastien Dementin, Marc Rousset, Pierre-Pol Liebgott, Fanny Leroux, Laurent Cournac, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Biologie végétale et microbiologie environnementale - UMR7265 (BVME), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Département de génétique médicale [Hôpital de la Timone - APHM], Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)- Hôpital de la Timone [CHU - APHM] (TIMONE)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Bioénergie et Microalgues (EBM), and Institut National de la Santé et de la Recherche Médicale (INSERM)- Hôpital de la Timone [CHU - APHM] (TIMONE)-Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)
Subjects: Hydrogenase, Energy Engineering and Power Technology, chemistry.chemical_element, 010402 general chemistry, Oxygen tolerance, 01 natural sciences, Oxygen, 03 medical and health sciences, Ralstonia, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Eutropha, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, biology, Renewable Energy, Sustainability and the Environment, Chemistry, Active site, Desulfovibrio fructosovorans, Condensed Matter Physics, biology.organism_classification, 0104 chemical sciences, 3. Good health, Fuel Technology, Enzyme, Biochemistry, biology.protein
Abstract: Reproducing the naturally occurring O2-tolerant hydrogenases is a potential strategy to make the oxygen sensitive enzymes, produced by organisms of biotechnological interest, more resistant. The search for resistance “hotspots” that could be transposed into sensitive hydrogenases is underway. Here, we replaced two residues (Y77 and V78) of the oxygen sensitive [NiFe] hydrogenase from Desulfovibrio fructosovorans with Gly and with Cys, respectively, to copy the active site pocket of the resistant membrane-bound [NiFe] enzyme from Ralstonia eutropha and we examined how this affected oxygen sensitivity. The results are discussed in the light of a short review of the recent results dealing with the reactivity of hydrogenases towards oxygen.
Published: 2010

40. Plant thioredoxin CDSP32 regenerates 1-cys methionine sulfoxide reductase B activity through the direct reduction of sulfenic acid

Author: Stéphane D. Lemaire, Pascal Rey, Edith Laugier, Pierre Le Maréchal, Mirko Zaffagnini, Lionel Tarrago, Christophe H. Marchand, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Institut de biochimie et biophysique moléculaire et cellulaire (IBBMC), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Biologie moléculaire et cellulaire des eucaryotes, Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Tarrago L, Laugier E, Zaffagnini M, Marchand CH, Le Maréchal P, Lemaire SD, Rey P., Biodiversité et Biotechnologie Fongiques (BBF), Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Bologna, Laboratoire de génie électrique de Paris (LGEP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-SUPELEC-Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences de Paris-Saclay (Neuro-PSI), Dassault Aviation, Aménagement, Développement, Environnement, Santé et Sociétés (ADES), and Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Segalen - Bordeaux 2-Université Bordeaux Montaigne
Subjects: 0106 biological sciences, MESH: Oxidation-Reduction, [SDV]Life Sciences [q-bio], Arabidopsis, Reductase, 01 natural sciences, Biochemistry, Catalysis, Sulfenic Acids, 03 medical and health sciences, chemistry.chemical_compound, Thioredoxins, MESH: Thioredoxins, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, MESH: Arabidopsis, Molecular Biology, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Methionine, biology, Chemistry, Methionine sulfoxide, Active site, Cell Biology, MESH: Catalysis, SULFENIC ACID, MESH: Mutagenesis, Site-Directed, MESH: Sulfenic Acids, MESH: Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Mutagenesis, Site-Directed, Enzymology, Thiol, biology.protein, Methionine sulfoxide reductase, Electrophoresis, Polyacrylamide Gel, Sulfenic acid, Thioredoxin, Oxidation-Reduction, 010606 plant biology & botany, MESH: Electrophoresis, Polyacrylamide Gel
Abstract: International audience; Thioredoxins (Trxs) are ubiquitous enzymes catalyzing the reduction of disulfide bonds, thanks to a CXXC active site. Among their substrates, 2-Cys methionine sulfoxide reductases B (2-Cys MSRBs) reduce the R diastereoisomer of methionine sulfoxide (MetSO) and possess two redox-active Cys as follows: a catalytic Cys reducing MetSO and a resolving one, involved in disulfide bridge formation. The other MSRB type, 1-Cys MSRBs, possesses only the catalytic Cys, and their regeneration mechanisms by Trxs remain unclear. The plant plastidial Trx CDSP32 is able to provide 1-Cys MSRB with electrons. CDSP32 includes two Trx modules with one potential active site (219)CGPC(222) and three extra Cys. Here, we investigated the redox properties of recombinant Arabidopsis CDSP32 and delineated the biochemical mechanisms of MSRB regeneration by CDSP32. Free thiol titration and 4-acetamido-4'-maleimidyldistilbene-2,2'-disulfonic acid alkylation assays indicated that the Trx possesses only two redox-active Cys, very likely the Cys(219) and Cys(222). Protein electrophoresis analyses coupled to mass spectrometry revealed that CDSP32 forms a heterodimeric complex with MSRB1 via reduction of the sulfenic acid formed on MSRB1 catalytic Cys after MetSO reduction. MSR activity assays using variable CDSP32 amounts revealed that MSRB1 reduction proceeds with a 1:1 stoichiometry, and redox titrations indicated that CDSP32 and MSRB1 possess midpoints potentials of -337 and -328 mV at pH 7.9, respectively, indicating that regeneration of MSRB1 activity by the Trx through sulfenic acid reduction is thermodynamically feasible in physiological conditions.
Published: 2010

41. Characterization of Bacteriophytochromes from Photosynthetic Bacteria: Histidine Kinase Signaling Triggered by Light and Redox Sensing

Author: Giraud, Eric, Lavergne, Jérôme, Vermeglio, Andre, Laboratoire des symbioses tropicales et méditerranéennes (UMR LSTM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université Montpellier 1 (UM1)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, and Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: RHODOPSEUDOMONAS-PALUSTRIS, BILIVERDIN, INVITRO, BRADYRHIZOBIUM, CHROMOPHORE, [SDV]Life Sciences [q-bio], REVEALS, [SDE]Environmental Sciences, PHOTOSYSTEM SYNTHESIS, SITE, AGROBACTERIUM-TUMEFACIENS, PHYTOCHROME
Abstract: International audience; Bacteria detect environmental changes, thanks to two-component signal-transduction systems, composed, in general, of a sensor coupled to a histidine kinase and a DNA binding response regulator. Anoxygenic photosynthetic bacteria like Rhodopseudomonas (Rps.) palustris, possess a highly versatile metabolism and can grow via photosynthesis using light energy or via respiration through oxygen consumption. For photosynthetic bacteria, detecting changes in light quality or quantity, or in oxygen concentration, is therefore of prime importance for adjusting their metabolism for optimal development. A central role is played by bacteriophytochromes for light detection and initiation of regulatory responses. The switch of these chromoproteins between two photointerconvertible forms is the first event in the light-regulated cascade. This chapter describes in vitro and in vivo methods that have been successfully used to investigate the bacteriophytochrome dependent light regulation pathways, in several strains of Rps. palustris and Bradyrhizobium. These approaches range from biochemical and biophysical methods to genetic techniques. Such multiple approaches are indispensable for understanding these complex light-regulated pathway. In a first step, bacteriophytochromes and associated response regulators are overexpressed in Escherichia coli and purified. The spectral and kinetic properties of the two photointerconvertible forms of the purified bacteriophytochromes are then determined by biophysical approaches. Original spectral and kinetic properties found in some of the bacteriophytochromes that we studied necessitated the development of new methods for computing the spectra of the pure forms and the photoconversion yields. In vitro biochemical approaches help to assess the histidine kinase activity of bacteriophytochromes depending on light conditions, the phosphotransfer to response regulators and their affinity to promoter DNA sequences. Finally, gene inactivation tests the importance of specific genes in photosynthesis regulation under particular light and oxygen tension growth conditions. The methods described in this chapter are not restricted to the study of the light-transduction pathways of Rps. palustris and Bradyrhizobium strains but are applicable to the understanding of any bacterial light-regulatory system.
Published: 2010

42. The impact of soil microorganisms on the global budget of delta O-18 in atmospheric CO2

Author: Peylin, Philippe, Wingate, L., Ogee, J., Cuntz, M., Genty, Bernard, Reiter, I., Maseyk, K., Seibt, Uli, Yakir, D., Pendall, E., Barbour, Mm, Mortazavi, B., Burlett, R., Miller, J., Mencuccini, M., Shim, Jh, Hunt, J., Grace, J., Biogéochimie et écologie des milieux continentaux (Bioemco), Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Paris (ENS Paris), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft, Department Environmental Science and Energy Research, Department of Botany, University of Wyoming (UW), Florida State University [Tallahassee] (FSU), Institut de biologie et chimie des protéines [Lyon] (IBCP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institute of Ecology and Resource Management, and University of Edinburgh
Abstract: International audience; Improved global estimates of terrestrial photosynthesis and respiration are critical for predicting the rate of change in atmospheric CO2. The oxygen isotopic composition of atmospheric CO2 can be used to estimate these fluxes because oxygen isotopic exchange between CO2 and water creates distinct isotopic flux signatures. The enzyme carbonic anhydrase (CA) is known to accelerate this exchange in leaves, but the possibility of CA activity in soils is commonly neglected. Here, we report widespread accelerated soil CO2 hydration. Exchange was 10-300 times faster than the un-catalyzed rate, consistent with typical population sizes for CA-containing soil microorganisms. Including accelerated soil hydration in global model simulations modifies contributions from soil and foliage to the global (COO)-O-18 budget and eliminates persistent discrepancies existing between model and atmospheric observations. This enhanced soil hydration also increases the differences between the isotopic signatures of photosynthesis and respiration, particularly in the tropics, increasing the precision of CO2 gross fluxes obtained by using the delta O-18 of atmospheric CO2 by 50%.
Published: 2009

43. Ribonucleotide reductase regulation in response to genotoxic stress in Arabidopsis

Author: Marie-Hélène Montané, Valérie Cognat, Hélène Roa, Guy Houlné, Julien Lang, Murielle Keller, Kevin M. Culligan, Sarah Holec, Marie-Edith Chabouté, Centre National de la Recherche Scientifique (CNRS), Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire (UNH), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Ministere de l'Education Nationale et de la Recherche 042393 France-Berkeley Foundation Region Alsace, and Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, Physiology, DNA damage, [SDV]Life Sciences [q-bio], Molecular Sequence Data, Mutant, Arabidopsis, synchronized plant-cells, homologous recombination, Plant Science, dna-damage response, 01 natural sciences, Gene Expression Regulation, Enzymologic, 03 medical and health sciences, small-subunit, histone gene-expression, Gene Expression Regulation, Plant, comet assay, Ribonucleotide Reductases, Genetics, transcriptional regulation, Amino Acid Sequence, Gene, 030304 developmental biology, Regulation of gene expression, 0303 health sciences, biology, Arabidopsis Proteins, DNA replication, Wild type, biology.organism_classification, Biological Evolution, Molecular biology, Phenotype, Ribonucleotide reductase, Multigene Family, saccharomyces-cerevisiae, tobacco cells, DNA Damage, Research Article, 010606 plant biology & botany, cycle checkpoint
Abstract: Ribonucleotide reductase (RNR) is an essential enzyme that provides dNTPs for DNA replication and repair. Arabidopsis (Arabidopsis thaliana) encodes three AtRNR2-like catalytic subunit genes (AtTSO2, AtRNR2A, and AtRNR2B). However, it is currently unclear what role, if any, each gene contributes to the DNA damage response, and in particular how each gene is transcriptionally regulated in response to replication blocks and DNA damage. To address this, we investigated transcriptional changes of 17-d-old Arabidopsis plants (which are enriched in S-phase cells over younger seedlings) in response to the replication-blocking agent hydroxyurea (HU) and to the DNA double-strand break inducer bleomycin (BLM). Here we show that AtRNR2A and AtRNR2B are specifically induced by HU but not by BLM. Early AtRNR2A induction is decreased in an atr mutant, and this induction is likely required for the replicative stress checkpoint since rnr2a mutants are hypersensitive to HU, whereas AtRNR2B induction is abolished in the rad9-rad17 double mutant. In contrast, AtTSO2 transcription is only activated in response to double-strand breaks (BLM), and this activation is dependent upon AtE2Fa. Both TSO2 and E2Fa are likely required for the DNA damage response since tso2 and e2fa mutants are hypersensitive to BLM. Interestingly, TSO2 gene expression is increased in atr versus wild type, possibly due to higher ATM expression in atr. On the other hand, a transient ATR-dependent H4 up-regulation was observed in wild type in response to HU and BLM, perhaps linked to a transient S-phase arrest. Our results therefore suggest that individual RNR2-likecatalytic subunit genes participate in unique aspects of the cellular response to DNA damage in Arabidopsis.
Published: 2009

44. The impact of soil microorganisms on the global budget of δ18O in atmospheric CO2

Author: Behzad Mortazavi, Bernard Genty, Kadmiel Maseyk, Lisa Wingate, Ilja M. Reiter, Elise Pendall, Dan Yakir, Margaret M. Barbour, Matthias Cuntz, Philippe Peylin, Régis Burlett, Jee H. Shim, John Grace, John B. Miller, Jérôme Ogée, Maurizio Mencuccini, Ulli Seibt, John Hunt, Écologie fonctionnelle et physique de l'environnement (EPHYSE), Institut National de la Recherche Agronomique (INRA), School of GeoSciences, University of Edinburgh, Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Biogéochimie et écologie des milieux continentaux (Bioemco), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC), Weizmann Institute of Science [Rehovot, Israël], Department of Botany, University of Wyoming (UW), Manaaki Whenua – Landcare Research [Lincoln], Department of Biological Sciences, University of Alabama [Tuscaloosa] (UA), Dauphin Island Sea Lab, University of South Alabama, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), National Oceanic and Atmospheric Administration (NOAA), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), Colorado State University [Fort Collins] (CSU), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)
Subjects: cycle du carbone, 010504 meteorology & atmospheric sciences, δ18O, cycle de l'eau, Climate Change, [SDE.MCG]Environmental Sciences/Global Changes, Population, carbonic anhydrase, water cycle, Photosynthesis, 01 natural sciences, Models, Biological, Atmosphere, chemistry.chemical_compound, Flux (metallurgy), carbon cycle, education, Milieux et Changements globaux, isotope, Soil Microbiology, 0105 earth and related environmental sciences, Carbonic Anhydrases, education.field_of_study, Multidisciplinary, Chemistry, oxygen isotopes, 04 agricultural and veterinary sciences, Carbon Dioxide, terrestrial biosphere, 13. Climate action, Environmental chemistry, Soil water, Carbon dioxide, Physical Sciences, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Seasons, Soil microbiology
Abstract: Improved global estimates of terrestrial photosynthesis and respiration are critical for predicting the rate of change in atmospheric CO 2 . The oxygen isotopic composition of atmospheric CO 2 can be used to estimate these fluxes because oxygen isotopic exchange between CO 2 and water creates distinct isotopic flux signatures. The enzyme carbonic anhydrase (CA) is known to accelerate this exchange in leaves, but the possibility of CA activity in soils is commonly neglected. Here, we report widespread accelerated soil CO 2 hydration. Exchange was 10–300 times faster than the uncatalyzed rate, consistent with typical population sizes for CA-containing soil microorganisms. Including accelerated soil hydration in global model simulations modifies contributions from soil and foliage to the global CO 18 O budget and eliminates persistent discrepancies existing between model and atmospheric observations. This enhanced soil hydration also increases the differences between the isotopic signatures of photosynthesis and respiration, particularly in the tropics, increasing the precision of CO 2 gross fluxes obtained by using the δ 18 O of atmospheric CO 2 by 50%.
Published: 2009

45. Mesorhizobium metallidurans sp. nov., a metal-resistant symbiont of Anthyllis vulneraria growing on metallicolous soil in Languedoc, France

Author: Gilles Béna, Brigitte Brunel, Odile Berge, Jean-Claude Cleyet-Marel, José Escarré, Céline Vidal, Lucette Maure, Clémence Chantreuil, Laboratoire des symbioses tropicales et méditerranéennes (UMR LSTM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université Montpellier 1 (UM1)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut de Recherche pour le Développement (IRD), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry - Montpellier 3 (UPVM)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut de Recherche pour le Développement (IRD [France-Sud]), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
Subjects: DNA, Bacterial, [SDV.SA]Life Sciences [q-bio]/Agricultural sciences, Sequence analysis, Molecular Sequence Data, DNA, Ribosomal, Microbiology, Anthyllis vulneraria, 03 medical and health sciences, Bacterial Proteins, Phylogenetics, RNA, Ribosomal, 16S, Sequence Homology, Nucleic Acid, Botany, Cluster Analysis, Phylogeny, Ecology, Evolution, Behavior and Systematics, Alphaproteobacteria, 030304 developmental biology, 0303 health sciences, biology, Phylogenetic tree, 030306 microbiology, Mesorhizobium, Nucleic Acid Hybridization, Fabaceae, Sequence Analysis, DNA, General Medicine, Ribosomal RNA, 16S ribosomal RNA, biology.organism_classification, Bacterial Typing Techniques, Rec A Recombinases, Zinc, SOL METALLICOLE, Taxonomy (biology), France, Cadmium, Transcription Factors
Abstract: International audience; A polyphasic taxonomic approach was used to characterize 31 rhizobial isolates obtained from Anthyllis vulneraria, a metallicolous legume species, growing close to a zinc mine in the south of France (Saint Laurent le Minier). Comparative analysis of nearly full-length 16S rRNA gene sequences showed that these Gram-negative bacteria belonged to the genus Mesorhizobium and that they were related most closely to Mesorhizobium tianshanense ORS 2640T. The phylogenetic relationships of these isolates with other Mesorhizobium species were confirmed by sequencing and analysis of the recA and atpD genes, which were used as alternative chromosomal markers. These novel mesorhizobial strains tolerated high concentrations of heavy metals: 16–32 mM Zn and 0.3–0.5 mM Cd. DNA–DNA hybridizations revealed >73 % relatedness between the strains isolated from A. vulneraria, but only 19–33 % relatedness between these and the type strains of M. tianshanense and Mesorhizobium mediterraneum. These results, together with other phenotypic characteristics, support the conclusion that these isolates represent a single, novel species of the genus Mesorhizobium, for which the name Mesorhizobium metallidurans sp. nov. is proposed. The type strain is STM 2683T (=CFBP 7147T=LMG 24485T).
Published: 2009

46. A zinc-resistant human epithelial cell line is impaired in cadmium and manganese import

Author: Estelle Rousselet, Alexandre Bouron, Thierry Douki, Jean-Marc Moulis, Jocelyne Garcia Chantegrel, Pierre Richaud, Alain Favier, Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Environnement, Bioénergie, Microalgues et Plantes (EBMP), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Lésions des Acides Nucléiques (LAN), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de biologie du stress oxydant, Université Joseph Fourier - Grenoble 1 (UJF), Bioénergie et Microalgues (EBM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2
Subjects: inorganic chemicals, MESH: Oxidation-Reduction, MESH: Biological Transport, Drug Resistance, MESH: Cadmium, chemistry.chemical_element, MESH: Manganese, Zinc, Toxicology, Protein oxidation, MESH: Zinc, HeLa, 03 medical and health sciences, chemistry.chemical_compound, Extracellular, Humans, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], 030304 developmental biology, Cadmium acetate, Pharmacology, MESH: Glutathione, Manganese, 0303 health sciences, Cadmium, MESH: Humans, biology, 030302 biochemistry & molecular biology, Biological Transport, Epithelial Cells, biology.organism_classification, Glutathione, MESH: Hela Cells, chemistry, Biochemistry, Cell culture, MESH: Epithelial Cells, MESH: Drug Resistance, Oxidation-Reduction, Intracellular, HeLa Cells
Abstract: International audience; A human epithelial cell line (HZR) growing with high zinc concentrations has been analyzed for its ability to sustain high cadmium concentrations. Exposure to up to 200 microM of cadmium acetate for 24 h hardly impacted viability, whereas most of parental HeLa cells were killed by less than 10 microM of cadmium. Upon challenge by 35 fold higher cadmium concentrations than HeLa cells, HZR cells did not display increased DNA damage, increased protein oxidation, or changed intracellular cadmium localization. Rather, the main cause of resistance against cadmium was by avoiding cadmium entry into cells, which differs from that against zinc as the latter accumulates inside cells. The zinc-resistant phenotype of these cells was shown to also impair extracellular manganese uptake. Manganese and cadmium competed for entry into HeLa cells. Probing formerly identified cadmium or manganese transport systems in different animal cells did not evidence any significant change between HeLa and HZR cells. These results reveal zinc adaptation influences manganese and cadmium cellular traffic and they highlight previously unknown connections among homeostasis of divalent metals.
Published: 2008

47. Towards hydrogenase engineering for hydrogen production

Author: Rousset, Monique, Cournac, L., Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Wall J.D., Harwood C.S. and Demain A., Azzopardi, Laure, and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2
Published: 2008

48. 'Hydrogen-activating enzymes: activity does not correlate with oxygen sensitivity'

Author: Laurence Girbal, Christophe Léger, Carole Baffert, Bénédicte Burlat, Marie Demuez, Bruno Guigliarelli, Patrick Bertrand, Laurent Cournac, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2, Azzopardi, Laure, and Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Hydrogenase, Time Factors, Hydrogen, Protein Conformation, Kinetics, Inorganic chemistry, chemistry.chemical_element, 02 engineering and technology, Photochemistry, 010402 general chemistry, Oxygen, 01 natural sciences, Sensitivity and Specificity, Catalysis, Electron transfer, Sensitivity (control systems), Electrodes, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, Binding Sites, 010405 organic chemistry, General Chemistry, General Medicine, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Enzyme Activation, Enzyme, chemistry, Protein film voltammetry, 0210 nano-technology
Abstract: International audience
Published: 2008

49. Kinetics of Gas Diffusion in Hydrogenase: New Experimental Approaches

Author: Leroux, F., Dementin, S., Burlat, B., Cournac, L., Volbeda, A., Champion, Stephanie, Martin, Liliane, Guigliarelli, B., Bertrand, P., Fontecilla-Camps, J.C., Rousset, M., Léger, C., Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Chimie Biologique (UCB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2
Subjects: [SDV]Life Sciences [q-bio], [SDV.IDA]Life Sciences [q-bio]/Food engineering, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, [INFO]Computer Science [cs], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2008

50. 'Experimental Approaches to Kinetics of Gas Diffusion in Hydrogenase'

Author: Christophe Léger, Laurent Cournac, Juan C. Fontecilla-Camps, Sébastien Dementin, Lydie Martin, Anne Volbeda, Bruno Guigliarelli, Patrick Bertrand, Stéphanie Champ, Bénédicte Burlat, Marc Rousset, Fanny Leroux, Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB), Université de la Méditerranée - Aix-Marseille 2-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de la Méditerranée - Aix-Marseille 2
Subjects: Hydrogenase, Kinetics, Crystallography, X-Ray, 010402 general chemistry, 01 natural sciences, 03 medical and health sciences, Molecular dynamics, Protein structure, Electrochemistry, Escherichia coli, Gaseous diffusion, Diffusion (business), ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Carbon Monoxide, 0303 health sciences, Binding Sites, Multidisciplinary, biology, Chemistry, Escherichia coli Proteins, Active site, Biological Sciences, Protein Structure, Tertiary, 0104 chemical sciences, Crystallography, Chemical physics, Yield (chemistry), Mutation, biology.protein, Desulfovibrio, Gases, Hydrophobic and Hydrophilic Interactions, Hydrogen, Protein Binding
Abstract: Hydrogenases, which catalyze H 2 to H + conversion as part of the bioenergetic metabolism of many microorganisms, are among the metalloenzymes for which a gas-substrate tunnel has been described by using crystallography and molecular dynamics. However, the correlation between protein structure and gas-diffusion kinetics is unexplored. Here, we introduce two quantitative methods for probing the rates of diffusion within hydrogenases. One uses protein film voltammetry to resolve the kinetics of binding and release of the competitive inhibitor CO; the other is based on interpreting the yield in the isotope exchange assay. We study structurally characterized mutants of a NiFe hydrogenase, and we show that two mutations, which significantly narrow the tunnel near the entrance of the catalytic center, decrease the rates of diffusion of CO and H 2 toward and from the active site by up to 2 orders of magnitude. This proves the existence of a functional channel, which matches the hydrophobic cavity found in the crystal. However, the changes in diffusion rates do not fully correlate with the obstruction induced by the mutation and deduced from the x-ray structures. Our results demonstrate the necessity of measuring diffusion rates and emphasize the role of side-chain dynamics in determining these.
Published: 2008

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Journal

Database

Publisher

81 results on '"Biologie cellulaire et moléculaire des plantes et des bactéries (BCMPB)"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources