115 results on '"Fleurie A"'
Search Results
2. Use of Immune Profiling Panel to assess the immune response of septic patients for prediction of worsening as a composite endpoint
- Author
-
Peronnet, Estelle, Terraz, Gabriel, Cerrato, Elisabeth, Imhoff, Katia, Blein, Sophie, Brengel-Pesce, Karen, Bodinier, Maxime, Fleurie, Aurore, Rimmelé, Thomas, Lukaszewicz, Anne-Claire, Monneret, Guillaume, and Llitjos, Jean-François
- Published
- 2024
- Full Text
- View/download PDF
3. Identification of early predictive biomarkers for severe cytokine release syndrome in pediatric patients with chimeric antigen receptor T-cell therapy
- Author
-
Meng Su, Luoquan Chen, Li Xie, Aurore Fleurie, Renaud Jonquieres, Qing Cao, Benshang Li, Ji Liang, and Yanjing Tang
- Subjects
CAR-T cell therapy ,cytokine release syndrome (CRS) ,biomarker ,early prediction ,decision tree model ,Immunologic diseases. Allergy ,RC581-607 - Abstract
CAR-T cell therapy is a revolutionary new treatment for hematological malignancies, but it can also result in significant adverse effects, with cytokine release syndrome (CRS) being the most common and potentially life-threatening. The identification of biomarkers to predict the severity of CRS is crucial to ensure the safety and efficacy of CAR-T therapy. To achieve this goal, we characterized the expression profiles of seven cytokines, four conventional biochemical markers, and five hematological markers prior to and following CAR-T cell infusion. Our results revealed that IL-2, IFN-γ, IL-6, and IL-10 are the key cytokines for predicting severe CRS (sCRS). Notably, IL-2 levels rise at an earlier stage of sCRS and have the potential to serve as the most effective cytokine for promptly detecting the condition’s onset. Furthermore, combining these cytokine biomarkers with hematological factors such as lymphocyte counts can further enhance their predictive performance. Finally, a predictive tree model including lymphocyte counts, IL-2, and IL-6 achieved an accuracy of 85.11% (95% CI = 0.763–0.916) for early prediction of sCRS. The model was validated in an independent cohort and achieved an accuracy of 74.47% (95% CI = 0.597–0.861). This new prediction model has the potential to become an effective tool for assessing the risk of CRS in clinical practice.
- Published
- 2024
- Full Text
- View/download PDF
4. Advancing respiratory virus diagnostics: integrating the nasal IFN-I score for improved viral detection
- Author
-
Mommert-Tripon, Marine, Parraud, Delphine, Grosbois, Cloé, Gaymard, Alexandre, Cheynet, Valérie, Lina, Bruno, Oriol, Guy, Laurent, Frédéric, Dupré, Caroline, Semanas, Quentin, Bal, Antonin, Generenaz, Laurence, Pons, Sylvie, Brengel-Pesce, Karen, Guichard, Audrey, Mouton, William, Morfin, Florence, Fleurie, Aurore, and Trouillet-Assant, Sophie
- Published
- 2024
- Full Text
- View/download PDF
5. Identification of a sub-group of critically ill patients with high risk of intensive care unit-acquired infections and poor clinical course using a transcriptomic score
- Author
-
Bodinier, Maxime, Monneret, Guillaume, Casimir, Marie, Fleurie, Aurore, Conti, Filippo, Venet, Fabienne, Cazalis, Marie-Angélique, Cerrato, Elisabeth, Peronnet, Estelle, Rimmelé, Thomas, Lukaszewicz, Anne-Claire, Brengel-Pesce, Karen, and Llitjos, Jean-François
- Published
- 2023
- Full Text
- View/download PDF
6. Amphiphilic proteins coassemble into multiphasic condensates and act as biomolecular surfactants
- Author
-
Kelley, Fleurie M., Favetta, Bruna, Regy, Roshan Mammen, Mittal, Jeetain, and Schuster, Benjamin S.
- Published
- 2021
7. Characterization of triatomine bloodmeal sources using direct Sanger sequencing and amplicon deep sequencing methods
- Author
-
Sujata Balasubramanian, Rachel Curtis-Robles, Bhagath Chirra, Lisa D. Auckland, Alan Mai, Virgilio Bocanegra-Garcia, Patti Clark, Wilhelmina Clark, Mark Cottingham, Geraldine Fleurie, Charles D. Johnson, Richard P. Metz, Shichen Wang, Nicholas J. Hathaway, Jeffrey A. Bailey, Gabriel L. Hamer, and Sarah A. Hamer
- Subjects
Medicine ,Science - Abstract
Abstract Knowledge of host associations of blood-feeding vectors may afford insights into managing disease systems and protecting public health. However, the ability of methods to distinguish bloodmeal sources varies widely. We used two methods—Sanger sequencing and amplicon deep sequencing—to target a 228 bp region of the vertebrate Cytochrome b gene and determine hosts fed upon by triatomines (n = 115) collected primarily in Texas, USA. Direct Sanger sequencing of PCR amplicons was successful for 36 samples (31%). Sanger sequencing revealed 15 distinct host species, which included humans, domestic animals (Canis lupus familiaris, Ovis aries, Gallus gallus, Bos taurus, Felis catus, and Capra hircus), wildlife (Rattus rattus, Incilius nebulifer, Sciurus carolinensis, Sciurus niger, and Odocoileus virginianus), and captive animals (Panthera tigris, Colobus spp., and Chelonoidis carbonaria). Samples sequenced by the Sanger method were also subjected to Illumina MiSeq amplicon deep sequencing. The amplicon deep sequencing results (average of 302,080 usable reads per sample) replicated the host community revealed using Sanger sequencing, and detected additional hosts in five triatomines (13.9%), including two additional blood sources (Procyon lotor and Bassariscus astutus). Up to four bloodmeal sources were detected in a single triatomine (I. nebulifer, Homo sapiens, C. lupus familiaris, and S. carolinensis). Enhanced understanding of vector-host-parasite networks may allow for integrated vector management programs focusing on highly-utilized and highly-infected host species.
- Published
- 2022
- Full Text
- View/download PDF
8. Immune Profiling Panel Gene Set Identifies Critically Ill Patients With Low Monocyte Human Leukocyte Antigen-DR Expression: Preliminary Results From the REAnimation Low Immune Status Marker (REALISM) Study
- Author
-
Peronnet, Estelle, Blein, Sophie, Venet, Fabienne, Cerrato, Elisabeth, Fleurie, Aurore, Llitjos, Jean-François, Kreitmann, Louis, Terraz, Gabriel, Conti, Filippo, Gossez, Morgane, Rimmelé, Thomas, Textoris, Julien, Lukaszewicz, Anne-Claire, Brengel-Pesce, Karen, Monneret, Guillaume, Arnal, Sophie, Augris-Mathieu, Caroline, Bayle, Frederique, Caruso, Liana, Ber, Charles-Eric, Ben-Amor, Asma, Bellocq, Anne-Sophie, Benatir, Farida, Bertin-Maghit, Anne, Bertin-Maghit, Marc, Boibieux, Andre, Bouffard, Yves, Cejka, Jean-Christophe, Cerro, Valerie, Crozon-Clauzel, Jullien, Davidson, Julien, Debord-Peguet, Sophie, Delwarde, Benjamin, Deleat-Besson, Robert, Delsuc, Claire, Devigne, Bertrand, Fayolle-Pivot, Laure, Faure, Alexandre, Floccard, Bernard, Gatel, Julie, Genin, Charline, Girardot, Thibaut, Gregoire, Arnaud, Hengy, Baptiste, Huriaux, Laetitia, Jadaud, Catherine, Lepape, Alain, Leray, Veronique, Lukaszewicz, Anne-Claire, Marcotte, Guillaume, Martin, Olivier, Matray, Marie, Maucort-Boulch, Delphine, Meuret, Pascal, Monard, Celine, Moriceau, Florent, Monneret, Guillaume, Panel, Nathalie, Rahali, Najia, Rimmele, Thomas, Truc, Cyrille, Uberti, Thomas, Vallin, Helene, Venet, Fabienne, Tissot, Sylvie, Zadam, Abbes, Blein, Sophie, Brengel-Pesce, Karen, Cerrato, Elisabeth, Cheynet, Valerie, Gallet-Gorius, Emmanuelle, Guichard, Audrey, Jourdan, Camille, Koenig, Natacha, Mallet, Francois, Meunier, Boris, Moucade, Virginie, Mommert, Marine, Oriol, Guy, Pachot, Alexandre, Peronnet, Estelle, Schrevel, Claire, Tabone, Olivier, Textoris, Julien, Marcos, Javier Yugueros, Becker, Jeremie, Bequet, Frederic, Bounab, Yacine, Brajon, Florian, Canard, Bertrand, Collus, Muriel, Garcon, Nathalie, Gorse, Irene, Guyard, Cyril, Lavocat, Fabien, Leissner, Philippe, Louis, Karen, Mistretta, Maxime, Moriniere, Jeanne, Mouscaz, Yoann, Noailles, Laura, Perret, Magali, Reynier, Frederic, Riffaud, Cindy, Rol, Mary-Luz, Sapay, Nicolas, Tran, Trang, Vedrine, Christophe, Carre, Christophe, Cortez, Pierre, de Monfort, Aymeric, Florin, Karine, Fraisse, Laurent, Fugier, Isabelle, Payrard, Sandrine, Peleraux, Annick, Quemeneur, Laurence, Griffiths, Andrew, Toetsch, Stephanie, Ashton, Teri, Gough, Peter J., Berger, Scott B., Gardiner, David, Gillespie, Iain, Macnamara, Aidan, Raychaudhuri, Aparna, Smylie, Rob, Tan, Lionel, and Tipple, Craig
- Published
- 2023
- Full Text
- View/download PDF
9. Identifying sequence perturbations to an intrinsically disordered protein that determine its phase-separation behavior
- Author
-
Schuster, Benjamin S., Dignon, Gregory L., Tang, Wai Shing, Kelley, Fleurie M., Ranganath, Aishwarya Kanchi, Jahnke, Craig N., Simpkins, Alison G., Regy, Roshan Mammen, Hammer, Daniel A., Good, Matthew C., and Mittal, Jeetain
- Published
- 2020
10. Surface tension and viscosity of protein condensates quantified by micropipette aspiration
- Author
-
Wang, Huan, Kelley, Fleurie M., Milovanovic, Dragomir, Schuster, Benjamin S., and Shi, Zheng
- Published
- 2021
- Full Text
- View/download PDF
11. Mortality Prediction in Sepsis With an Immune-Related Transcriptomics Signature: A Multi-Cohort Analysis
- Author
-
Louis Kreitmann, Maxime Bodinier, Aurore Fleurie, Katia Imhoff, Marie-Angelique Cazalis, Estelle Peronnet, Elisabeth Cerrato, Claire Tardiveau, Filippo Conti, Jean-François Llitjos, Julien Textoris, Guillaume Monneret, Sophie Blein, and Karen Brengel-Pesce
- Subjects
sepsis ,transcriptomics ,predictive modeling ,gene expression analysis ,mortality ,biomarker discovery ,Medicine (General) ,R5-920 - Abstract
BackgroundNovel biomarkers are needed to progress toward individualized patient care in sepsis. The immune profiling panel (IPP) prototype has been designed as a fully-automated multiplex tool measuring expression levels of 26 genes in sepsis patients to explore immune functions, determine sepsis endotypes and guide personalized clinical management. The performance of the IPP gene set to predict 30-day mortality has not been extensively characterized in heterogeneous cohorts of sepsis patients.MethodsPublicly available microarray data of sepsis patients with widely variable demographics, clinical characteristics and ethnical background were co-normalized, and the performance of the IPP gene set to predict 30-day mortality was assessed using a combination of machine learning algorithms.ResultsWe collected data from 1,801 arrays sampled on sepsis patients and 598 sampled on controls in 17 studies. When gene expression was assayed at day 1 following admission (1,437 arrays sampled on sepsis patients, of whom 1,161 were alive and 276 (19.2%) were dead at day 30), the IPP gene set showed good performance to predict 30-day mortality, with an area under the receiving operating characteristics curve (AUROC) of 0.710 (CI 0.652–0.768). Importantly, there was no statistically significant improvement in predictive performance when training the same models with all genes common to the 17 microarray studies (n = 7,122 genes), with an AUROC = 0.755 (CI 0.697–0.813, p = 0.286). In patients with gene expression data sampled at day 3 following admission or later, the IPP gene set had higher performance, with an AUROC = 0.804 (CI 0.643–0.964), while the total gene pool had an AUROC = 0.787 (CI 0.610–0.965, p = 0.811).ConclusionUsing pooled publicly-available gene expression data from multiple cohorts, we showed that the IPP gene set, an immune-related transcriptomics signature conveys relevant information to predict 30-day mortality when sampled at day 1 following admission. Our data also suggests that higher predictive performance could be obtained when assaying gene expression at later time points during the course of sepsis. Prospective studies are needed to confirm these findings using the IPP gene set on its dedicated measurement platform.
- Published
- 2022
- Full Text
- View/download PDF
12. Combining SARS‐CoV‐2 interferon‐gamma release assay with humoral response assessment to define immune memory profiles.
- Author
-
Mouton, William, Oriol, Guy, Compagnon, Christelle, Saade, Carla, Saker, Kahina, Franc, Priscille, Mokdad, Bouchra, Fleurie, Aurore, Lacoux, Xavier, Daniel, Soizic, Berthier, Franck, Barnel, Cécile, Pozzetto, Bruno, Fassier, Jean‐Baptiste, Dubois, Valérie, Djebali, Sophia, Dubois, Maxence, Walzer, Thierry, Marvel, Jacqueline, and Brengel‐Pesce, Karen
- Subjects
IMMUNOLOGIC memory ,HUMORAL immunity ,MEDICAL personnel ,INTERFERON gamma ,INTERFERON gamma release tests - Abstract
Objectives: In the post‐SARS‐CoV‐2 pandemic era, "breakthrough infections" are still documented, due to variants of concerns (VoCs) emergence and waning humoral immunity. Despite widespread utilization, the definition of the anti‐Spike (S) immunoglobulin‐G (IgG) threshold to define protection has unveiled several limitations. Here, we explore the advantages of incorporating T‐cell response assessment to enhance the definition of immune memory profile. Methods: SARS‐CoV‐2 interferon‐gamma release assay test (IGRA) was performed on samples collected longitudinally from immunocompetent healthcare workers throughout their immunization by infection and/or vaccination, anti‐receptor‐binding domain IgG levels were assessed in parallel. The risk of symptomatic infection according to cellular/humoral immune capacities during Omicron BA.1 wave was then estimated. Results: Close to 40% of our samples were exclusively IGRA‐positive, largely due to time elapsed since their last immunization. This suggests that individuals have sustained long‐lasting cellular immunity, while they would have been classified as lacking protective immunity based solely on IgG threshold. Moreover, the Cox regression model highlighted that Omicron BA.1 circulation raises the risk of symptomatic infection while increased anti‐receptor‐binding domain IgG and IGRA levels tended to reduce it. Conclusion: The discrepancy between humoral and cellular responses highlights the significance of assessing the overall adaptive immune response. This integrated approach allows the identification of vulnerable subjects and can be of interest to guide antiviral prophylaxis at an individual level. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. A Vibrio cholerae BolA-Like Protein Is Required for Proper Cell Shape and Cell Envelope Integrity
- Author
-
Aurore Fleurie, Abdelrahim Zoued, Laura Alvarez, Kelly M. Hines, Felipe Cava, Libin Xu, Brigid M. Davis, and Matthew K. Waldor
- Subjects
BolA ,IbaG ,Vibrio cholerae ,cell envelope ,cell shape ,iron-sulfur cluster ,Microbiology ,QR1-502 - Abstract
ABSTRACT BolA family proteins are conserved in Gram-negative bacteria and many eukaryotes. While diverse cellular phenotypes have been linked to this protein family, the molecular pathways through which these proteins mediate their effects are not well described. Here, we investigated the roles of BolA family proteins in Vibrio cholerae, the cholera pathogen. Like Escherichia coli, V. cholerae encodes two BolA proteins, BolA and IbaG. However, in marked contrast to E. coli, where bolA is linked to cell shape and ibaG is not, in V. cholerae, bolA mutants lack morphological defects, whereas ibaG proved critical for the generation and/or maintenance of the pathogen’s morphology. Notably, the bizarre-shaped, multipolar, elongated, and wide cells that predominated in exponential-phase ΔibaG V. cholerae cultures were not observed in stationary-phase cultures. The V. cholerae ΔibaG mutant exhibited increased sensitivity to cell envelope stressors, including cell wall-acting antibiotics and bile, and was defective in intestinal colonization. ΔibaG V. cholerae had reduced peptidoglycan and lipid II and altered outer membrane lipids, likely contributing to the mutant’s morphological defects and sensitivity to envelope stressors. Transposon insertion sequencing analysis of ibaG’s genetic interactions suggested that ibaG is involved in several processes involved in the generation and homeostasis of the cell envelope. Furthermore, copurification studies revealed that IbaG interacts with proteins containing iron-sulfur clusters or involved in their assembly. Collectively, our findings suggest that V. cholerae IbaG controls cell morphology and cell envelope integrity through its role in biogenesis or trafficking of iron-sulfur cluster proteins. IMPORTANCE BolA-like proteins are conserved across prokaryotes and eukaryotes. These proteins have been linked to a variety of phenotypes, but the pathways and mechanisms through which they act have not been extensively characterized. Here, we unraveled the role of the BolA-like protein IbaG in the cholera pathogen Vibrio cholerae. The absence of IbaG was associated with dramatic changes in cell morphology, sensitivity to envelope stressors, and intestinal colonization defects. IbaG was found to be required for biogenesis of several components of the V. cholerae cell envelope and to interact with numerous iron-sulfur cluster-containing proteins and factors involved in their assembly. Thus, our findings suggest that IbaG governs V. cholerae cell shape and cell envelope homeostasis through its effects on iron-sulfur proteins and associated pathways. The diversity of processes involving iron-sulfur-containing proteins is likely a factor underlying the range of phenotypes associated with BolA family proteins.
- Published
- 2019
- Full Text
- View/download PDF
14. The Worked Example and Expertise Reversal Effect in Less Structured Tasks: Learning to Reason about Legal Cases
- Author
-
Nievelstein, Fleurie, van Gog, Tamara, and van Dijck, Gijs
- Abstract
The worked example effect indicates that learning by studying worked examples is more effective than learning by solving the equivalent problems. The expertise reversal effect indicates that this is only the case for novice learners; once prior knowledge of the task is available problem solving becomes more effective for learning. These effects, however, have mainly been studied using highly structured tasks. This study investigated whether they also occur on less structured tasks, in this case, learning to reason about legal cases. Less structured tasks take longer to master, and hence, examples may remain effective for a longer period of time. Novice and advanced law students received either a description of general process steps they should take, worked examples, worked examples including the process steps, or no instructional support for reasoning. Results show that worked examples were more effective for learning than problem-solving, both for novice and advanced students, even though the latter had significantly more prior knowledge. So, a worked example effect was found for both novice and advanced students, and no evidence for an expertise-reversal effect was found with these less structured tasks. (Contains 2 tables.)
- Published
- 2013
- Full Text
- View/download PDF
15. Effects of Conceptual Knowledge and Availability of Information Sources on Law Students' Legal Reasoning
- Author
-
Nievelstein, Fleurie, van Gog, Tamara, and Boshuizen, Henny P. A.
- Abstract
Due to the complexity of the legal domain, reasoning about law cases is a very complex skill. For novices in law school, legal reasoning is even more complex because they have not yet acquired the conceptual knowledge needed for distilling the relevant information from cases, determining applicable rules, and searching for rules and exceptions in external information sources such as lawbooks. This study investigated the role of conceptual knowledge in solving legal cases when no information sources can be used. Under such "unsupported" circumstances, novice and advanced students performed less well than domain experts, but even experts' performance was rather low. The second question addressed was whether novices even benefit from the availability of information sources (i.e., lawbook), because conceptual knowledge is prerequisite for effective use of such sources. Indeed availability of the lawbook positively affected performance only for advanced students but not for novice students. Implications for learning and instruction in the domain of law are discussed.
- Published
- 2010
- Full Text
- View/download PDF
16. Iatrogenic Transmission of Human T Cell Lymphotropic Virus Type 1 and Hepatitis C Virus through Parenteral Treatment and Chemoprophylaxis of Sleeping Sickness in Colonial Equatorial Africa
- Author
-
Pépin, Jacques, Labbé, Annie-Claude, Mamadou-Yaya, Fleurie, Mbélesso, Pascal, Mbadingaï, Sylvestre, Deslandes, Sylvie, Locas, Marie-Claude, and Frost, Eric
- Published
- 2010
17. Structure Analysis of the Staphylococcus aureus UDP-N-acetyl-mannosamine Dehydrogenase Cap5O Involved in Capsular Polysaccharide Biosynthesis
- Author
-
Gruszczyk, Jakub, Fleurie, Aurore, Olivares-Illana, Vanesa, Béchet, Emmanuelle, Zanella-Cleon, Isabelle, Moréra, Solange, Meyer, Philippe, Pompidor, Guillaume, Kahn, Richard, Grangeasse, Christophe, and Nessler, Sylvie
- Published
- 2011
- Full Text
- View/download PDF
18. MapZ marks the division sites and positions FtsZ rings in Streptococcus pneumoniae
- Author
-
Fleurie, Aurore, Lesterlin, Christian, Manuse, Sylvie, Zhao, Chao, Cluzel, Caroline, Lavergne, Jean-Pierre, Franz- Wachtel, Mirita, Macek, Boris, Combet, Christophe, Kuru, Erkin, VanNieuwenhze, Michael S., Brun, Yves V., Sherratt, David, and Grangeasse, Christophe
- Subjects
Research ,Streptococcus pneumoniae -- Research ,Cell division -- Research ,Microbiological research - Abstract
Recently, some membrane Hanks-type Ser/Thr kinases (10,11) were shown to have a key role in bacterial cell division and morphogenesis (12). S. pneumoniae StkP kinase is crucial for septum assembly, [...], In every living organism, cell division requires accurate identification of the division site and placement of the division machinery. In bacteria, this process is traditionally considered to begin with the polymerization of the highly conserved tubulin-like protein FtsZ into a ring that locates precisely at mid-cell (1). Over the past decades, several systems have been reported to regulate the spatiotemporal assembly and placement of the FtsZ ring (2-5). However, the human pathogen Streptococcus pneumoniae, in common with many other organisms, is devoid of these canonical systems and the mechanisms of positioning the division machinery remain unknown (4,6). Here we characterize a novel factor that locates at the division site before FtsZ and guides septum positioning in pneumococcus. Mid-cell-anchored protein Z (MapZ) forms ring structures at the cell equator and moves apart as the cell elongates, therefore behaving as a permanent beacon of division sites. MapZ then positions the FtsZ ring through direct protein-protein interactions. MapZ-mediated control differs from previously described systems mostly on the basis of negative regulation of FtsZ assembly. Furthermore, MapZ is an endogenous target of the Ser/Thr kinase StkP, which was recently shown to have a central role in cytokinesis and morphogenesis of S. pneumoniae (7-9). We show that both phosphorylated and non-phosphorylated forms of MapZ are required for proper Z-ring formation and dynamics. Altogether, this work uncovers a new mechanism for bacterial cell division that is regulated by phosphorylation and illustrates that nature has evolved a diversity of cell division mechanisms adapted to the different bacterial clades.
- Published
- 2014
19. EXPLORING THE ROLE OF AGENCY ACCREDITATION IN SHAPING SERVICES FOR STREET-INVOLVED YOUTH
- Author
-
Alexandra Fleurie Hunter
- Subjects
street-involved youth ,homelessness ,accreditation ,service delivery ,private accreditation bodies ,standardization ,The family. Marriage. Woman ,HQ1-2044 ,Sociology (General) ,HM401-1281 - Abstract
Over the past decade, the social/human services sector across North America has continually moved towards a strong emphasis on new management systems and tools for performance measurement, as a means to track government investment and to inform services planning. This trend has contributed to the growth of a parallel industry in the form of independent accreditation bodies, which act to develop regulatory standards, as well as to perform evaluations and monitoring. In many communities accreditation now plays a significant role in defining both the eligibility of agencies to apply for government contracts, as well as the performance objectives of organizational management and service delivery. This paper looks at the service system for street-involved youth in Vancouver, Canada, as a site to explore this novel institutional arrangement. Drawing from broader literature on regulatory standards institutions, this paper outlines a research agenda to question the role of accreditation bodies in shaping child and youth care services, as well as the broader values, ideologies, and power dynamics that surround accreditation.
- Published
- 2015
- Full Text
- View/download PDF
20. Controlled recruitment of particles into biomolecular condensates
- Author
-
Kelley, Fleurie, Ani, Anas, Ma, Yuchen, Linders, Bridget, Favetta, Bruna, Gu, Yuwei, and Schuster, Benjamin S.
- Published
- 2024
- Full Text
- View/download PDF
21. Interplay of the serine/threonine-kinase StkP and the paralogs DivIVA and GpsB in pneumococcal cell elongation and division.
- Author
-
Aurore Fleurie, Sylvie Manuse, Chao Zhao, Nathalie Campo, Caroline Cluzel, Jean-Pierre Lavergne, Céline Freton, Christophe Combet, Sébastien Guiral, Boumediene Soufi, Boris Macek, Erkin Kuru, Michael S VanNieuwenhze, Yves V Brun, Anne-Marie Di Guilmi, Jean-Pierre Claverys, Anne Galinier, and Christophe Grangeasse
- Subjects
Genetics ,QH426-470 - Abstract
Despite years of intensive research, much remains to be discovered to understand the regulatory networks coordinating bacterial cell growth and division. The mechanisms by which Streptococcus pneumoniae achieves its characteristic ellipsoid-cell shape remain largely unknown. In this study, we analyzed the interplay of the cell division paralogs DivIVA and GpsB with the ser/thr kinase StkP. We observed that the deletion of divIVA hindered cell elongation and resulted in cell shortening and rounding. By contrast, the absence of GpsB resulted in hampered cell division and triggered cell elongation. Remarkably, ΔgpsB elongated cells exhibited a helical FtsZ pattern instead of a Z-ring, accompanied by helical patterns for DivIVA and peptidoglycan synthesis. Strikingly, divIVA deletion suppressed the elongated phenotype of ΔgpsB cells. These data suggest that DivIVA promotes cell elongation and that GpsB counteracts it. Analysis of protein-protein interactions revealed that GpsB and DivIVA do not interact with FtsZ but with the cell division protein EzrA, which itself interacts with FtsZ. In addition, GpsB interacts directly with DivIVA. These results are consistent with DivIVA and GpsB acting as a molecular switch to orchestrate peripheral and septal PG synthesis and connecting them with the Z-ring via EzrA. The cellular co-localization of the transpeptidases PBP2x and PBP2b as well as the lipid-flippases FtsW and RodA in ΔgpsB cells further suggest the existence of a single large PG assembly complex. Finally, we show that GpsB is required for septal localization and kinase activity of StkP, and therefore for StkP-dependent phosphorylation of DivIVA. Altogether, we propose that the StkP/DivIVA/GpsB triad finely tunes the two modes of peptidoglycan (peripheral and septal) synthesis responsible for the pneumococcal ellipsoid cell shape.
- Published
- 2014
- Full Text
- View/download PDF
22. Monocyte HLA‐DR expression as an enrollment biomarker in sepsis clinical trials: Evaluation of two sampling tubes and definition of respective clinical thresholds.
- Author
-
Haem Rahimi, Muzhda, Conti, Filippo, Llitjos, Jean‐Francois, Fleurie, Aurore, Cerro, Valérie, Venet, Fabienne, Lukaszewicz, Anne‐Claire, and Monneret, Guillaume
- Published
- 2023
- Full Text
- View/download PDF
23. Uncovering cognitive processes: Different techniques that can contribute to cognitive load research and instruction
- Author
-
Van Gog, Tamara, Kester, Liesbeth, Nievelstein, Fleurie, Giesbers, Bas, and Paas, Fred
- Subjects
Computers ,Psychology and mental health ,Sociology and social work - Abstract
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.chb.2008.12.021 Byline: Tamara van Gog (a), Liesbeth Kester (a), Fleurie Nievelstein (a), Bas Giesbers (c), Fred Paas (a)(b) Keywords: Cognitive load; Verbal reports; Eye tracking; Concept mapping; Example-based learning Abstract: This article discusses the use of different techniques for uncovering cognitive processes, for research and instructional purposes: verbal reporting, eye tracking, and concept mapping. It is argued here that applying these techniques in research inspired by cognitive load theory may increase our understanding of how and why well-known effects of instructional formats come about (e.g., split-attention, redundancy, or worked example effects) and refine or corroborate the proposed theoretical underpinnings of such effects. This knowledge can inform instructional design, and moreover, the effects of these techniques on learning can also be direct, by embedding the techniques in instruction. Author Affiliation: (a) Center for Learning Sciences and Technologies, Open University of The Netherlands, P.O. Box 2960, 6401 DL Heerlen, The Netherlands (b) Psychology Department, Erasmus University Rotterdam, The Netherlands (c) Faculty of Economics and Business Administration, Maastricht University, The Netherlands
- Published
- 2009
24. Comparative analysis of the Tyr-kinases CapB1 and CapB2 fused to their cognate modulators CapA1 and CapA2 from Staphylococcus aureus.
- Author
-
Jakub Gruszczyk, Vanesa Olivares-Illana, Julien Nourikyan, Aurore Fleurie, Emmanuelle Béchet, Virginie Gueguen-Chaignon, Céline Freton, Magali Aumont-Nicaise, Solange Moréra, Christophe Grangeasse, and Sylvie Nessler
- Subjects
Medicine ,Science - Abstract
A particular class of tyrosine-kinases sharing no structural similarity with eukaryotic tyrosine-kinases has been evidenced in a large array of bacterial species. These bacterial tyrosine-kinases are able to autophosphorylate on a C-terminal tyrosine-rich motif. Their autophosphorylation has been shown to play a crucial role in the biosynthesis or export of capsular polysaccharide. The analysis of the first crystal structure of the staphylococcal tyrosine kinase CapB2 associated with the activating domain of the transmembrane modulator CapA1 had brought conclusive explanation for both the autophosphorylation and activation processes. In order to explain why CapA1 activates CapB2 more efficiently than its cognate transmembrane modulator CapA2, we solved the crystal structure of CapA2B2 and compared it with the previously published structure of CapA1B2. This structural analysis did not provide the expected clues about the activation discrepancy observed between the two modulators. Staphylococcus aureus also encodes for a CapB2 homologue named CapB1 displaying more than 70% sequence similarity and being surprisingly nearly unable to autophosphorylate. We solved the crystal structure of CapA1B1 and carefully compare it with the structure of CapA1B2. The active sites of both proteins are highly conserved and the biochemical characterization of mutant proteins engineered to test the importance of small structural discrepancies identified between the two structures did not explain the inactivity of CapB1. We thus tested if CapB1 could phosphorylate other protein substrates or hydrolyze ATP. However, no activity could be detected in our in vitro assays. Taken together, these data question about the biological role of the homologous protein pairs CapA1/CapB1 and CapA2/CapB2 and we discuss about several possible interpretations.
- Published
- 2013
- Full Text
- View/download PDF
25. Identifying sequence perturbations to an intrinsically disordered protein that determine its phase-separation behavior
- Author
-
Craig N. Jahnke, Daniel A. Hammer, Aishwarya Kanchi Ranganath, Jeetain Mittal, Wai Shing Tang, Matthew C. Good, Fleurie M. Kelley, Roshan Mammen Regy, Alison G. Simpkins, Gregory L. Dignon, and Benjamin S. Schuster
- Subjects
Cytoplasm ,Saccharomyces cerevisiae ,Molecular Dynamics Simulation ,010402 general chemistry ,Intrinsically disordered proteins ,Arginine ,01 natural sciences ,Phase Transition ,03 medical and health sciences ,Negative selection ,Protein sequencing ,Protein Domains ,Phase (matter) ,Lipid bilayer ,Caenorhabditis elegans Proteins ,030304 developmental biology ,Sequence (medicine) ,0303 health sciences ,Multidisciplinary ,Chemistry ,Component (thermodynamics) ,Mutagenesis ,Temperature ,Biological Sciences ,0104 chemical sciences ,Intrinsically Disordered Proteins ,Amino Acid Substitution ,Biophysics ,Tyrosine ,Microorganisms, Genetically-Modified ,Hydrophobic and Hydrophilic Interactions ,RNA Helicases - Abstract
Phase separation of intrinsically disordered proteins (IDPs) commonly underlies the formation of membraneless organelles, which compartmentalize molecules intracellularly in the absence of a lipid membrane. Identifying the protein sequence features responsible for IDP phase separation is critical for understanding physiological roles and pathological consequences of biomolecular condensation, as well as for harnessing phase separation for applications in bioinspired materials design. To expand our knowledge of sequence determinants of IDP phase separation, we characterized variants of the intrinsically disordered RGG domain from LAF-1, a model protein involved in phase separation and a key component of P granules. Based on a predictive coarse-grained IDP model, we identified a region of the RGG domain that has high contact probability and is highly conserved between species; deletion of this region significantly disrupts phase separation in vitro and in vivo. We determined the effects of charge patterning on phase behavior through sequence shuffling. We designed sequences with significantly increased phase separation propensity by shuffling the wild-type sequence, which contains well-mixed charged residues, to increase charge segregation. This result indicates the natural sequence is under negative selection to moderate this mode of interaction. We measured the contributions of tyrosine and arginine residues to phase separation experimentally through mutagenesis studies and computationally through direct interrogation of different modes of interaction using all-atom simulations. Finally, we show that despite these sequence perturbations, the RGG-derived condensates remain liquid-like. Together, these studies advance our fundamental understanding of key biophysical principles and sequence features important to phase separation.
- Published
- 2020
26. Interaction of Penicillin-Binding Protein 2x and Ser/Thr protein kinase StkP, two key players in Streptococcus pneumoniae R6 morphogenesis
- Author
-
Morlot, C., Bayle, L., Jacq, M., Fleurie, A., Tourcier, G., Galisson, F., Vernet, T., Grangeasse, C., and Di Guilmi, A. M.
- Published
- 2013
- Full Text
- View/download PDF
27. Characterization of triatomine bloodmeal sources using direct Sanger sequencing and amplicon deep sequencing methods.
- Author
-
Balasubramanian, Sujata, Curtis-Robles, Rachel, Chirra, Bhagath, Auckland, Lisa D., Mai, Alan, Bocanegra-Garcia, Virgilio, Clark, Patti, Clark, Wilhelmina, Cottingham, Mark, Fleurie, Geraldine, Johnson, Charles D., Metz, Richard P., Wang, Shichen, Hathaway, Nicholas J., Bailey, Jeffrey A., Hamer, Gabriel L., and Hamer, Sarah A.
- Subjects
RACCOON ,CAPTIVE wild animals ,DOGS ,DOMESTIC animals ,TIGERS ,CATTLE - Abstract
Knowledge of host associations of blood-feeding vectors may afford insights into managing disease systems and protecting public health. However, the ability of methods to distinguish bloodmeal sources varies widely. We used two methods—Sanger sequencing and amplicon deep sequencing—to target a 228 bp region of the vertebrate Cytochrome b gene and determine hosts fed upon by triatomines (n = 115) collected primarily in Texas, USA. Direct Sanger sequencing of PCR amplicons was successful for 36 samples (31%). Sanger sequencing revealed 15 distinct host species, which included humans, domestic animals (Canis lupus familiaris, Ovis aries, Gallus gallus, Bos taurus, Felis catus, and Capra hircus), wildlife (Rattus rattus, Incilius nebulifer, Sciurus carolinensis, Sciurus niger, and Odocoileus virginianus), and captive animals (Panthera tigris, Colobus spp., and Chelonoidis carbonaria). Samples sequenced by the Sanger method were also subjected to Illumina MiSeq amplicon deep sequencing. The amplicon deep sequencing results (average of 302,080 usable reads per sample) replicated the host community revealed using Sanger sequencing, and detected additional hosts in five triatomines (13.9%), including two additional blood sources (Procyon lotor and Bassariscus astutus). Up to four bloodmeal sources were detected in a single triatomine (I. nebulifer, Homo sapiens, C. lupus familiaris, and S. carolinensis). Enhanced understanding of vector-host-parasite networks may allow for integrated vector management programs focusing on highly-utilized and highly-infected host species. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
28. Mutational dissection of the S/T-kinase StkP reveals crucial roles in cell division of Streptococcus pneumoniae
- Author
-
Fleurie, Aurore, Cluzel, Caroline, Guiral, Sébastien, Freton, Céline, Galisson, Frédéric, Zanella-Cleon, Isabelle, Di Guilmi, Anne-Marie, and Grangeasse, Christophe
- Published
- 2012
- Full Text
- View/download PDF
29. Transmission of Hepatitis C virus among spouses in Cameroon and the Central African Republic
- Author
-
Njouom, Richard, Lavoie, Myriam, Foupouapouognigni, Yacouba, Frost, Eric, Deslandes, Sylvie, Mamadou-Yaya, Fleurie, Mbélesso, Pascal, Mbadingai, Sylvestre, and Pépin, Jacques
- Published
- 2011
- Full Text
- View/download PDF
30. A Vibrio cholerae BolA-Like Protein Is Required for Proper Cell Shape and Cell Envelope Integrity
- Author
-
Libin Xu, Abdelrahim Zoued, Matthew K. Waldor, Felipe Cava, Laura Alvarez, Kelly M. Hines, Aurore Fleurie, and Brigid M. Davis
- Subjects
Iron-Sulfur Proteins ,Molecular Biology and Physiology ,cell envelope ,Protein family ,Iron–sulfur cluster ,Peptidoglycan ,Biology ,medicine.disease_cause ,Microbiology ,cell shape ,03 medical and health sciences ,chemistry.chemical_compound ,iron-sulfur cluster ,Mice ,Bacterial Proteins ,Cell Wall ,Virology ,medicine ,Animals ,Homeostasis ,Cell shape ,Vibrio cholerae ,030304 developmental biology ,0303 health sciences ,030306 microbiology ,Cell Membrane ,biology.organism_classification ,Phenotype ,QR1-502 ,3. Good health ,Cell biology ,Animals, Suckling ,Intestines ,chemistry ,Mutation ,BolA ,Cell envelope ,IbaG ,Bacteria ,Research Article - Abstract
BolA-like proteins are conserved across prokaryotes and eukaryotes. These proteins have been linked to a variety of phenotypes, but the pathways and mechanisms through which they act have not been extensively characterized. Here, we unraveled the role of the BolA-like protein IbaG in the cholera pathogen Vibrio cholerae. The absence of IbaG was associated with dramatic changes in cell morphology, sensitivity to envelope stressors, and intestinal colonization defects. IbaG was found to be required for biogenesis of several components of the V. cholerae cell envelope and to interact with numerous iron-sulfur cluster-containing proteins and factors involved in their assembly. Thus, our findings suggest that IbaG governs V. cholerae cell shape and cell envelope homeostasis through its effects on iron-sulfur proteins and associated pathways. The diversity of processes involving iron-sulfur-containing proteins is likely a factor underlying the range of phenotypes associated with BolA family proteins., BolA family proteins are conserved in Gram-negative bacteria and many eukaryotes. While diverse cellular phenotypes have been linked to this protein family, the molecular pathways through which these proteins mediate their effects are not well described. Here, we investigated the roles of BolA family proteins in Vibrio cholerae, the cholera pathogen. Like Escherichia coli, V. cholerae encodes two BolA proteins, BolA and IbaG. However, in marked contrast to E. coli, where bolA is linked to cell shape and ibaG is not, in V. cholerae, bolA mutants lack morphological defects, whereas ibaG proved critical for the generation and/or maintenance of the pathogen’s morphology. Notably, the bizarre-shaped, multipolar, elongated, and wide cells that predominated in exponential-phase ΔibaG V. cholerae cultures were not observed in stationary-phase cultures. The V. cholerae ΔibaG mutant exhibited increased sensitivity to cell envelope stressors, including cell wall-acting antibiotics and bile, and was defective in intestinal colonization. ΔibaG V. cholerae had reduced peptidoglycan and lipid II and altered outer membrane lipids, likely contributing to the mutant’s morphological defects and sensitivity to envelope stressors. Transposon insertion sequencing analysis of ibaG’s genetic interactions suggested that ibaG is involved in several processes involved in the generation and homeostasis of the cell envelope. Furthermore, copurification studies revealed that IbaG interacts with proteins containing iron-sulfur clusters or involved in their assembly. Collectively, our findings suggest that V. cholerae IbaG controls cell morphology and cell envelope integrity through its role in biogenesis or trafficking of iron-sulfur cluster proteins.
- Published
- 2019
31. Self-regulation and organizational support in university teachers’ professional learning
- Author
-
van de Wiel, Margje W.J., Nievelstein, Fleurie, Beausaert, Simon, Schlusmans, Kathleen, Section Work & Organisational Psychology, RS: FPN WSP I, RS: FPN WSP II, RS: GSBE Theme Learning and Work, RS: GSBE Theme Creativity, Innovation & Entrepreneurship, and Educational Research and Development
- Published
- 2019
32. Quantifying the material properties of protein condensates through micropipette aspiration
- Author
-
Wang, Huan, Kelley, Fleurie, Hoffmann, Christian, Milovanovic, Dragomir, Schuster, Benjamin S., and Shi, Zheng
- Published
- 2022
- Full Text
- View/download PDF
33. Amphiphilic Proteins Coat Membraneless Organelles and Act as Biological Surfactants
- Author
-
Kelley, Fleurie and Schuster, Benjamin S.
- Published
- 2021
- Full Text
- View/download PDF
34. Instructional Support for Novice Law Students: Reducing Search Processes and Explaining Concepts in Cases
- Author
-
Gijs van Dijck, Tamara van Gog, Fleurie Nievelstein, Henny P. A. Boshuizen, Research Group for Methodology of Law and Legal Research, RS-Research Program CELSTEC/OTEC (CO), and Department of Psychology, Education and Child Studies
- Subjects
Cognitive science ,Legal reasoning ,legal reasoning ,Working memory ,Experimental and Cognitive Psychology ,Cognition ,Legislation ,cognitive demands ,law students ,instructional support ,Arts and Humanities (miscellaneous) ,Law ,Developmental and Educational Psychology ,Mental load ,Psychology ,Cognitive psychology - Abstract
Nievelstein, F., Van Gog, T., Van Dijck, G., & Boshuizen, H. P. A. (2010). Instructional support for novice law students: Reducing search processes and explaining concepts in cases. Applied Cognitive Psychology. DOI: 10.1002/acp.1707
- Published
- 2011
- Full Text
- View/download PDF
35. Expertise-related differences in conceptual and ontological knowledge in the legal domain
- Author
-
Els Boshuizen, Tamara van Gog, Frans J. Prins, Fleurie Nievelstein, and RS-Research Program CELSTEC/OTEC (CO)
- Subjects
Ontological knowledge ,ontological knowledge ,Experimental and Cognitive Psychology ,Legislation ,Cognition ,Expertise ,Legal domain ,Ontology (information science) ,Psychology ,Epistemology - Abstract
Nievelstein, F., Van Gog, T., Boshuizen, H. P. A., & Prins, F. J. (2008). Expertise-related differences in conceptual and ontological knowledge in the legal domain. European Journal of Cognitive Psychology, 20, 1043–1064.
- Published
- 2008
- Full Text
- View/download PDF
36. Distracting the self: shifting attention prevents ego depletion
- Author
-
Carolien Martijn, Anita Jansen, Fleurie Nievelstein, Nanne K. de Vries, Hugo J. E. M. Alberts, Clinical Psychological Science, Gezondheidsvoorlichting, RS: FPN CPS II, and RS: CAPHRI School for Public Health and Primary Care
- Subjects
Ego depletion ,media_common.quotation_subject ,Shifting attention ,Self ,Self-control ,Delay of gratification ,behavioral disciplines and activities ,Task (project management) ,Distraction ,Psychology ,General Psychology ,psychological phenomena and processes ,media_common ,Cognitive psychology - Abstract
The present research tested predictions of the strength model of self-control and delay of gratification by examining the affects of initial self-control attempts and also attention on performance. Participants completed a series of two identical physical self-control tasks, namely holding lip a weight, under varying conditions. The results showed that performance decrements can be overcome by attentional strategies. When participants distracted themselves by performing a calculation task during the second self-control measurement, they (lid not show a decline in performance. In contrast, participants who did not distract themselves and those who instead focused oil their muscles while holding up the weight, performed significantly worse on the second measurement. Interestingly, the distraction task reduced regulatory performance when it was performed before the second measurement.
- Published
- 2008
- Full Text
- View/download PDF
37. Interplay of the Serine/Threonine-Kinase StkP and the Paralogs DivIVA and GpsB in Pneumococcal Cell Elongation and Division
- Author
-
Fleurie, Aurore, Manuse, Sylvie, Zhao, Chao, Campo, Nathalie, Cluzel, Caroline, Lavergne, Jean-Pierre, Freton, Céline, Combet, Christophe, Guiral, Sébastien, Soufi, Boumediene, Macek, Boris, Kuru, Erkin, VanNieuwenhze, Michael S., Brun, Yves V., Di Guilmi, Anne-Marie, Claverys, Jean-Pierre, Galinier, Anne, Grangeasse, Christophe, Viollier, Patrick H., Chinese Academy of Sciences [Changchun Branch] (CAS), Laboratoire de microbiologie et génétique moléculaires (LMGM), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Laboratoire de biomécanique (LBM), Université Paris 13 (UP13)-Université Sorbonne Paris Cité (USPC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Informatique Fondamentale et Appliquée de Tours (LIFAT), Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Proteome Ctr Tuebingen, Interfac Inst Cell Biol, Eberhard Karls Universität Tübingen, Institut de biologie structurale [1992-2019] (IBS - UMR 5075 [1992-2019]), 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), Neurobiologie, plasticité tissulaire et métabolisme énergétique (NPTME), Institut de biologie et chimie des protéines [Lyon] (IBCP), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2014
- Full Text
- View/download PDF
38. Interplay of the serine/threonine-kinase StkP and the paralogs DivIVA and GpsB in pneumococcal cell elongation and division
- Author
-
A., Fleurie, S., Manuse, Zhao, C., Campo, N., Cluzel, C., Lavergne, J. P., C., Freton, Combet, C., Guiral, S., B., Soufi, Kuru, E., VanNieuwenhze, M.S., Brun, Y.V., Di, Guilmi, Claverys, J.P., Galinier, A., C., Grangeasse, Laboratoire de microbiologie et génétique moléculaires (LMGM), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Centre de Biologie Intégrative (CBI), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SDV]Life Sciences [q-bio] ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2014
39. Fluorescence and absorption system for researching ultrafast processes in physics, chemistry, and biology
- Author
-
Pleshanov, P. G., Fleurie, C., and Fokin, V. S.
- Published
- 1984
- Full Text
- View/download PDF
40. Comparative analysis of the Tyr-kinases CapB1 and CapB2 fused to their cognate modulators CapA1 and CapA2 from Staphylococcus aureus
- Author
-
Céline Freton, Sylvie Nessler, Jakub Gruszczyk, Virginie Gueguen-Chaignon, Magali Aumont-Nicaise, Solange Moréra, Julien Nourikyan, Christophe Grangeasse, Emmanuelle Bechet, Aurore Fleurie, Vanesa Olivares-Illana, Institut de biologie et chimie des protéines [Lyon] (IBCP), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Models, Molecular ,Staphylococcus aureus ,Structural similarity ,[SDV]Life Sciences [q-bio] ,Molecular Sequence Data ,lcsh:Medicine ,Sequence alignment ,Plasma protein binding ,Biology ,Crystallography, X-Ray ,03 medical and health sciences ,0302 clinical medicine ,Bacterial Proteins ,Catalytic Domain ,Escherichia coli ,Amino Acid Sequence ,Phosphorylation ,lcsh:Science ,Peptide sequence ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,Autophosphorylation ,lcsh:R ,Gene Expression Regulation, Bacterial ,Protein-Tyrosine Kinases ,Protein superfamily ,Recombinant Proteins ,Transmembrane protein ,Protein Structure, Tertiary ,Isoenzymes ,Biochemistry ,Structural Homology, Protein ,lcsh:Q ,Sequence Alignment ,030217 neurology & neurosurgery ,Research Article ,Protein Binding - Abstract
International audience; A particular class of tyrosine-kinases sharing no structural similarity with eukaryotic tyrosine-kinases has been evidenced in a large array of bacterial species. These bacterial tyrosine-kinases are able to autophosphorylate on a C-terminal tyrosine-rich motif. Their autophosphorylation has been shown to play a crucial role in the biosynthesis or export of capsular polysaccharide. The analysis of the first crystal structure of the staphylococcal tyrosine kinase CapB2 associated with the activating domain of the transmembrane modulator CapA1 had brought conclusive explanation for both the autophosphorylation and activation processes. In order to explain why CapA1 activates CapB2 more efficiently than its cognate transmembrane modulator CapA2, we solved the crystal structure of CapA2B2 and compared it with the previously published structure of CapA1B2. This structural analysis did not provide the expected clues about the activation discrepancy observed between the two modulators. Staphylococcus aureus also encodes for a CapB2 homologue named CapB1 displaying more than 70% sequence similarity and being surprisingly nearly unable to autophosphorylate. We solved the crystal structure of CapA1B1 and carefully compare it with the structure of CapA1B2. The active sites of both proteins are highly conserved and the biochemical characterization of mutant proteins engineered to test the importance of small structural discrepancies identified between the two structures did not explain the inactivity of CapB1. We thus tested if CapB1 could phosphorylate other protein substrates or hydrolyze ATP. However, no activity could be detected in our in vitro assays. Taken together, these data question about the biological role of the homologous protein pairs CapA1/CapB1 and CapA2/CapB2 and we discuss about several possible interpretations.
- Published
- 2013
- Full Text
- View/download PDF
41. Iatrogenic transmission of human T cell lymphotropic virus type 1 and hepatitis C virus through parenteral treatment and chemoprophylaxis of sleeping sickness in colonial Equatorial Africa
- Author
-
Annie-Claude Labbé, Marie-Claude Locas, Pascal Mbélesso, Sylvie Deslandes, Fleurie Mamadou-Yaya, Sylvestre Mbadingai, Eric Frost, Jacques Pépin, Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP), Neuroépidémiologie Tropicale et Comparée (NETEC), and Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST FR CNRS 3503)-Institut d'Epidémiologie Neurologique et de Neurologie Tropicale-Université de Limoges (UNILIM)
- Subjects
Male ,MESH: Chemoprevention ,Iatrogenic Disease ,Hepacivirus ,Antibodies, Viral ,0302 clinical medicine ,Medicine ,African trypanosomiasis ,MESH: Hepacivirus ,030212 general & internal medicine ,Human T cell lymphotropic virus type 1 ,MESH: Aged ,0303 health sciences ,Human T-lymphotropic virus 1 ,MESH: Middle Aged ,virus diseases ,Hepatitis C ,Middle Aged ,MESH: Iatrogenic Disease ,3. Good health ,Central African Republic ,Infectious Diseases ,MESH: Central African Republic ,Chemoprophylaxis ,Injections, Intravenous ,medicine.drug ,Microbiology (medical) ,Sexual transmission ,Antiprotozoal Agents ,Chemoprevention ,03 medical and health sciences ,MESH: Cross-Sectional Studies ,MESH: HTLV-I Infections ,Correspondence ,Humans ,MESH: Antiprotozoal Agents ,030304 developmental biology ,Aged ,MESH: Hepatitis C ,MESH: Humans ,MESH: Human T-lymphotropic virus 1 ,business.industry ,Tropical disease ,medicine.disease ,Virology ,HTLV-I Infections ,MESH: Injections, Intravenous ,MESH: Male ,Cross-Sectional Studies ,Trypanosomiasis, African ,MESH: Trypanosomiasis, African ,Immunology ,[SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie ,business ,Trypanosomiasis ,MESH: Antibodies, Viral ,Pentamidine - Abstract
International audience; BACKGROUND: The simultaneous emergence of human immunodeficiency virus (HIV)-1 group M and HIV-2 into human populations, circa 1921-1940, is attributed to urbanization and changes in sexual behavior. We hypothesized that the initial dissemination of HIV-1, before sexual transmission predominated, was facilitated by the administration, via reusable syringes and needles, of parenteral drugs against tropical diseases. As proxies for highly lethal HIV-1, we investigated risk factors for hepatitis C virus (HCV) and human T cell lymphotropic virus 1 (HTLV-1) infections, blood-borne viruses compatible with prolonged survival, in an area known in 1936-1950 as the most virulent focus of African trypanosomiasis. METHODS: Cross-sectional survey of individuals 55 years and older in Mbimou land and Nola, Central African Republic. Dried blood spots were used for HCV and HTLV-1 serologic testing and nucleic acid detection. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were measured by logistic regression. RESULTS: The only risk factor for HCV genotype 4 infection was treatment of trypanosomiasis before 1951 (OR, 3.13; 95% CI, 1.38-7.09). HTLV-1 infection was associated with having received 2 injections of pentamidine for trypanosomiasis chemoprophylaxis (adjusted OR, 2.03; 95% CI, 1.01-4.06) and with transfusions (adjusted OR, 2.82; 95% CI, 1.04-7.67). From historical data, we predicted that 59% of Mbimous 65 years and older would report treatment for trypanosomiasis before 1951; only 11% did so. CONCLUSIONS: Treatment of trypanosomiasis before 1951 may have caused iatrogenic HCV transmission. Population-wide half-yearly intramuscular pentamidine for trypanosomiasis chemoprophylaxis in 1947-1953 may have caused iatrogenic HTLV-1 transmission. These and other interventions against tropical diseases could have iatrogenically transmitted SIV(cpz), jump-starting the HIV-1 epidemic. The excess mortality among patients with trypanosomiasis treated before 1951 supports this hypothesis.
- Published
- 2010
- Full Text
- View/download PDF
42. Predominance of hepatitis C virus genotype 4 infection and rapid transmission between 1935 and 1965 in the Central African Republic
- Author
-
Annie-Claude Labbé, Fleurie Mamadou-Yaya, Régis Pouillot, Sylvie Deslandes, Eric Frost, Richard Njouom, Sylvestre Mbadingai, Pascal Mbélesso, Dominique Rousset, Jacques Pépin, Centre Pasteur du Cameroun, Réseau International des Instituts Pasteur (RIIP), Laboratoire d'Epidémiologie et de Santé Publique, and Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)
- Subjects
Gene Expression Regulation, Viral ,Time Factors ,Genotype ,Hepacivirus ,Hepatitis C virus ,Molecular Sequence Data ,medicine.disease_cause ,Coalescent theory ,MESH: Genotype ,MESH: Gene Expression Regulation, Viral ,Virology ,medicine ,Humans ,MESH: Molecular Epidemiology ,MESH: Hepacivirus ,MESH: Genetic Variation ,MESH: Phylogeny ,Phylogeny ,MESH: Hepatitis C ,Molecular Epidemiology ,MESH: Humans ,MESH: Molecular Sequence Data ,biology ,Phylogenetic tree ,Molecular epidemiology ,MESH: Time Factors ,Genetic Variation ,virus diseases ,Hepatitis C ,biology.organism_classification ,medicine.disease ,Central African Republic ,MESH: Central African Republic ,[SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology ,Viral disease - Abstract
The molecular epidemiology of hepatitis C virus (HCV) in the Central African Republic (CAR) is poorly documented. Thus, we conducted phylogenetic analyses of NS5B gene sequences from 58 HCV-infected inhabitants of a remote area of south-west CAR, which indicated that 48 (82.8 %) were infected with genotype 4 (HCV-4), five (8.6 %) with genotype 2 and five (8.6 %) with genotype 1. HCV-4 strains were highly heterogeneous, containing previously described subtypes 4k (48 %), 4c (27 %), 4r (4 %), 4f (4 %) and unclassified subtypes (17 %). To estimate the epidemic history of these HCV-4 strains, an evolutionary analysis using the coalescent approach was used. The estimated date of the most recent common ancestor of the CAR HCV-4 strains was 1539 (95 % confidence intervals, 1317–1697). They exhibited a rapid, exponential spread from 1935 to 1965, simultaneously with what was recently reported in neighbouring Cameroon and Gabon. The hypothesis of a massive iatrogenic transmission during interventions for the control of endemic tropical diseases is discussed.
- Published
- 2009
- Full Text
- View/download PDF
43. Learning law: Expertise differences and the effect of instructional support
- Author
-
Nievelstein, Fleurie, Boshuizen, Els, Spoormans, Hubertus, and RS-Research Program CELSTEC/OTEC (CO)
- Subjects
instructional support ,students ,concepts ,expertise ,worked-examples ,laws - Abstract
One of the main aims of law education in both the Civil (European-Continental) law and Common (Anglo-Saxon) law systems is to teach students to reason about cases. As reviewed in Chapter 1, students experience serious difficulties in learning to reason about cases, which seem to arise from the complexity of the domain, the way in which knowledge is acquired in complex domains, as well as the instructional approach widely used in law schools. This approach often consists of ‘learning by doing’, which means that students have to reason about lots of cases throughout their study by using information sources that professionals also use. The studies presented in Chapters 2 to 4 were designed to gain more insight in the kind of difficulties and the underlying causes that students with differing levels of expertise have when they learn to reason about cases in law school, as well as to investigate the requirements for effective instructional approaches that provide more support and might help to diminish or overcome the experienced difficulties.
- Published
- 2009
44. Uncovering cognitive processes: Different techniques that can contribute to cognitive load research and instruction
- Author
-
Tamara van Gog, Liesbeth Kester, Fleurie Nievelstein, Fred Paas, Bas Giesbers, Educational Research and Development, RS: GSBE ERD, RS-Research Program CELSTEC/OTEC (CO), and Department of Psychology, Education and Child Studies
- Subjects
Instructional design ,Concept map ,cognitive load ,Eye movement ,Cognition ,concept mapping ,eye tracking ,verbal reports ,Human-Computer Interaction ,Arts and Humanities (miscellaneous) ,Schema (psychology) ,Eye tracking ,Mental load ,Psychology ,example-based learning ,General Psychology ,Cognitive load ,Cognitive psychology - Abstract
This article discusses the use of different techniques for uncovering cognitive processes, for research and instructional purposes: verbal reporting, eye tracking, and concept mapping. It is argued here that applying these techniques in research inspired by cognitive load theory may increase our understanding of how and why well-known effects of instructional formats come about (e.g., split-attention, redundancy, or worked example effects) and refine or corroborate the proposed theoretical underpinnings of such effects. This knowledge can inform instructional design, and moreover, the effects of these techniques on learning can also be direct, by embedding the techniques in instruction.
- Published
- 2009
- Full Text
- View/download PDF
45. Role of eukaryotic-like serine/threonine kinases in bacterial cell division and morphogenesis.
- Author
-
Manuse, Sylvie, Fleurie, Aurore, Zucchini, Laure, Lesterlin, Christian, and Grangeasse, Christophe
- Subjects
- *
SERINE/THREONINE kinases , *BACTERIAL enzymes , *EUKARYOTES , *CELL division , *MORPHOGENESIS , *IMMUNOMODULATORS , *PHOSPHORYLATION , *BACTERIA - Abstract
Bacteria possess a repertoire of versatile protein kinases modulating diverse aspects of their physiology by phosphorylating proteins on various amino acids including histidine, cysteine, aspartic acid, arginine, serine, threonine and tyrosine. One class of membrane serine/threonine protein kinases possesses a catalytic domain sharing a common fold with eukaryotic protein kinases and an extracellular mosaic domain found in bacteria only, named PASTA for 'Penicillin binding proteins And Serine/Threonine kinase Associated'. Over the last decade, evidence has been accumulating that these protein kinases are involved in cell division, morphogenesis and developmental processes in Firmicutes and Actinobacteria. However, observations differ from one species to another suggesting that a general mechanism of activation of their kinase activity is unlikely and that species-specific regulation of cell division is at play. In this review, we survey the latest research on the structural aspects and the cellular functions of bacterial serine/threonine kinases with PASTA motifs to illustrate the diversity of the regulatory mechanisms controlling bacterial cell division and morphogenesis. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
46. EXPLORING THE ROLE OF AGENCY ACCREDITATION IN SHAPING SERVICES FOR STREET-INVOLVED YOUTH.
- Author
-
Hunter, Alexandra Fleurie
- Subjects
EDUCATIONAL accreditation ,SOCIAL services ,HUMAN services ,SERVICES for poor people ,PERFORMANCE evaluation - Abstract
Over the past decade, the social/human services sector across North America has continually moved towards a strong emphasis on new management systems and tools for performance measurement, as a means to track government investment and to inform services planning. This trend has contributed to the growth of a parallel industry in the form of independent accreditation bodies, which act to develop regulatory standards, as well as to perform evaluations and monitoring. In many communities accreditation now plays a significant role in defining both the eligibility of agencies to apply for government contracts, as well as the performance objectives of organizational management and service delivery. This paper looks at the service system for street-involved youth in Vancouver, Canada, as a site to explore this novel institutional arrangement. Drawing from broader literature on regulatory standards institutions, this paper outlines a research agenda to question the role of accreditation bodies in shaping child and youth care services, as well as the broader values, ideologies, and power dynamics that surround accreditation. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
47. 31 Days of VEGANUARY.
- Author
-
FORBES-MARTIN, FLEURIE
- Published
- 2019
48. A vegan’s guide to… Bournemouth.
- Author
-
FORBES-MARTIN, FLEURIE
- Published
- 2018
49. Interaction of Penicillin- Binding Protein 2x and Ser/ Thr protein kinase StkP, two key players in Streptococcus pneumoniae R6 morphogenesis.
- Author
-
Morlot, C., Bayle, L., Jacq, M., Fleurie, A., Tourcier, G., Galisson, F., Vernet, T., Grangeasse, C., and Di Guilmi, A. M.
- Subjects
BACTERIAL cells ,GROWTH factors ,PEPTIDOGLYCANS ,STREPTOCOCCUS pneumoniae ,PENICILLIN - Abstract
Bacterial cell growth and division require the co-ordinated action of peptidoglycan biosynthetic enzymes and cell morphogenesis proteins. However, the regulatory mechanisms that allow generating proper bacterial shape and thus preserving cell integrity remain largely uncharacterized, especially in ovococci. Recently, the conserved eukaryotic-like Ser/ Thr protein kinase of Streptococcus pneumoniae ( StkP) was demonstrated to play a major role in cell shape and division. Here, we investigate the molecular mechanisms underlying the regulatory function(s) of StkP and show that it involves one of the essential actors of septal peptidoglycan synthesis, Penicillin- Binding Protein 2x ( PBP2x). We demonstrate that StkP and PBP2x interact directly and are present in the same membrane-associated complex in S. pneumoniae. We further show that they both display a late-division localization pattern at the division site and that the positioning of PBP2x depends on the presence of the extracellular PASTA domains of StkP. We demonstrate that StkP and PBP2x interaction is mediated by their extracellular regions and that the complex formation is inhibited in vitro in the presence of cell wall fragments. These data suggest that the role of StkP in cell division is modulated by an interaction with PBP2x. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
50. Comparative Analysis of the Tyr-Kinases CapB1 and CapB2 Fused to Their Cognate Modulators CapA1 and CapA2 from Staphylococcus aureus.
- Author
-
Gruszczyk, Jakub, Olivares-Illana, Vanesa, Nourikyan, Julien, Fleurie, Aurore, Béchet, Emmanuelle, Gueguen-Chaignon, Virginie, Freton, Céline, Aumont-Nicaise, Magali, Moréra, Solange, Grangeasse, Christophe, and Nessler, Sylvie
- Subjects
PROTEIN-tyrosine kinases ,BACTERIAL enzymes ,AUTOPHOSPHORYLATION ,CHIMERIC proteins ,BIOSYNTHESIS ,POLYSACCHARIDES ,HYDROLYSIS ,STAPHYLOCOCCUS aureus - Abstract
A particular class of tyrosine-kinases sharing no structural similarity with eukaryotic tyrosine-kinases has been evidenced in a large array of bacterial species. These bacterial tyrosine-kinases are able to autophosphorylate on a C-terminal tyrosine-rich motif. Their autophosphorylation has been shown to play a crucial role in the biosynthesis or export of capsular polysaccharide. The analysis of the first crystal structure of the staphylococcal tyrosine kinase CapB2 associated with the activating domain of the transmembrane modulator CapA1 had brought conclusive explanation for both the autophosphorylation and activation processes. In order to explain why CapA1 activates CapB2 more efficiently than its cognate transmembrane modulator CapA2, we solved the crystal structure of CapA2B2 and compared it with the previously published structure of CapA1B2. This structural analysis did not provide the expected clues about the activation discrepancy observed between the two modulators. Staphylococcus aureus also encodes for a CapB2 homologue named CapB1 displaying more than 70% sequence similarity and being surprisingly nearly unable to autophosphorylate. We solved the crystal structure of CapA1B1 and carefully compare it with the structure of CapA1B2. The active sites of both proteins are highly conserved and the biochemical characterization of mutant proteins engineered to test the importance of small structural discrepancies identified between the two structures did not explain the inactivity of CapB1. We thus tested if CapB1 could phosphorylate other protein substrates or hydrolyze ATP. However, no activity could be detected in our in vitro assays. Taken together, these data question about the biological role of the homologous protein pairs CapA1/CapB1 and CapA2/CapB2 and we discuss about several possible interpretations. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.