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Your search keyword '"MESH : Peptide Fragments"' showing total 13 results
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13 results on '"MESH : Peptide Fragments"'

1. Fungal peptides from pneumonitis hypersensitivity etiologic agents are able to induce specific cellular immune response

Author

Anne-Pauline Bellanger, Laurence Millon, Bénédicte Rognon, Houssein Gbaguidi-Haore, Thibaud Lignon, Christophe Borg, Gabriel Reboux, Yann Godet, Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Service de parasitologie et mycologie [CHRU de Besançon], Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon), Interactions hôte-greffon-tumeur, ingénierie cellulaire et génique - UFC (UMR INSERM 1098) (RIGHT), Institut National de la Santé et de la Recherche Médicale (INSERM)-Etablissement français du sang [Bourgogne-Franche-Comté] (EFS [Bourgogne-Franche-Comté])-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Service d’Hygiène Hospitalière, Laboratoire Chrono-environnement ( LCE ), Université Bourgogne Franche-Comté ( UBFC ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Centre Hospitalier Régional Universitaire [Besançon] ( CHRU Besançon ), Service d'Oncologie Médicale [CHRU Besançon], Centre Hospitalier Régional Universitaire [Besançon] ( CHRU Besançon ) -Université de Franche-Comté ( UFC ), Service de parasitologie et mycologie [CHU de Besançon], Interactions hôte-greffon-tumeur, ingénierie cellulaire et génique - UFC ( HOTE GREFFON ), and Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Etablissement français du sang [Bourgogne-France-Comté] ( EFS [Bourgogne-France-Comté] ) -Université de Franche-Comté ( UFC )

Subjects
Male, MESH : Aged, Epitope, MESH : Antigens, Fungal, Epitopes, 0302 clinical medicine, MESH: Peptide Fragments, Cells, Cultured, MESH: Middle Aged, ELISPOT, Acquired immune system, Healthy Volunteers, 3. Good health, MESH : Mucorales, MESH: Young Adult, Mucorales, MESH: Mucorales, MESH: Cells, Cultured, Antigens, Fungal, MESH: Epitopes, MESH : Dihydrolipoamide Dehydrogenase, T cell, MESH : Alveolitis, Extrinsic Allergic, Immunology, MESH : Young Adult, MESH : Epitopes, Statistics, Nonparametric, [ SDV.EE.SANT ] Life Sciences [q-bio]/Ecology, environment/Health, Interferon-gamma, 03 medical and health sciences, MESH: Mycobacterium, Humans, MESH : Middle Aged, Aged, Dihydrolipoamide Dehydrogenase, MESH: Antigens, Fungal, MESH: Humans, Histocompatibility Antigens Class I, MESH : Humans, Histocompatibility Antigens Class II, MESH: Adult, Peptide Fragments, MESH : Leukocytes, Mononuclear, 030104 developmental biology, Leukocytes, Mononuclear, MESH: Female, 0301 basic medicine, Enzyme-Linked Immunospot Assay, MESH : Enzyme-Linked Immunospot Assay, MESH: Histocompatibility Antigens Class I, ELISPOT assay, Immunology and Allergy, MESH : Female, Interferon gamma, MESH: Healthy Volunteers, MESH: Aged, Immunity, Cellular, MESH: Statistics, Nonparametric, biology, MESH : Antigens, Bacterial, Middle Aged, MESH : Adult, MESH: Leukocytes, Mononuclear, MESH : Histocompatibility Antigens Class II, medicine.anatomical_structure, Female, MESH : Histocompatibility Antigens Class I, Alveolitis, Extrinsic Allergic, medicine.drug, Adult, MESH: Dihydrolipoamide Dehydrogenase, MESH: Interferon-gamma, MESH : Male, MESH: Alveolitis, Extrinsic Allergic, Major histocompatibility complex, Mycobacterium, MESH: Immunity, Cellular, Young Adult, Immune system, MESH : Cells, Cultured, medicine, MESH : Mycobacterium, MESH : Statistics, Nonparametric, MESH : Interferon-gamma, MESH : Healthy Volunteers, [SDV.EE.SANT]Life Sciences [q-bio]/Ecology, environment/Health, Antigens, Bacterial, MESH: Epitope Mapping, MESH : Peptide Fragments, MESH : Immunity, Cellular, biology.organism_classification, MESH: Male, MESH : Epitope Mapping, biology.protein, MESH: Histocompatibility Antigens Class II, Mycobacterium immunogenum, MESH: Enzyme-Linked Immunospot Assay, Epitope Mapping, Hypersensitivity pneumonitis, MESH: Antigens, Bacterial, 030215 immunology, IFNγ
Abstract

International audience; Hypersensitivity pneumonitis (HP) is an immunoallergic disease due to chronic exposure to high quantities of different microorganisms such as Mycobacterium immunogenum (Mi), a mycobacterium, and Lichtheimia corymbifera (Lc), a filamentous fungus. It has recently been demonstrated that the protein DLDH (dihydrolipoyl dehydrogenase), is common to these microorganisms. This study aimed to investigate the immune potential of overlapping peptide pools covering the MiDLDH and LcDLDH.; A selection of 34 peptides, from the MiDLDH and LcDLDH, able to interact with Major Histocompatibility Complex (MHC) 1 and MHC 2, was obtained using three different epitope prediction websites. By means of ELISPOT assays, we compared the frequency of Interferon gamma (IFNγ) secreting peripheral blood mononuclear cells (PBMC) after stimulation with overlapping peptide pools. Tests were performed using cells from 35 healthy blood donors.; One peptide pool containing five peptides from MiDLDH and able to interact with MHC 2 induced a marked IFNγ specific immune response (Pool F, p

Published
2017
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2. NMR studies of the interaction of calmodulin with IQ motif peptides

Author

Walter J. Chazin, Benjamin Chagot, Steven M. Damo, Michael D. Feldkamp, Center for Structural Biology, Vanderbilt University [Nashville], Ingénierie Moléculaire et Physiopathologie Articulaire ( IMoPA ), Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)

Subjects
MESH: Signal Transduction, MESH : NAV1.5 Voltage-Gated Sodium Channel, Amino Acid Motifs, Intracellular Space, MESH : Intracellular Space, Peptide, Plasma protein binding, EF-hand, Na 15, 15 N-1 H HSQC, IQ motif, NAV1.5 Voltage-Gated Sodium Channel, MESH: Amino Acid Motifs, MESH: Apoproteins, Calcium-binding protein, MESH: Nuclear Magnetic Resonance, Biomolecular, MESH: Peptide Fragments, Calcium signaling, chemistry.chemical_classification, 0303 health sciences, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], biology, EF hand, 030302 biochemistry & molecular biology, MESH : Apoproteins, MESH : Protein Binding, Nuclear magnetic resonance spectroscopy, MESH: Calmodulin, 3. Good health, [SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, Biochemistry, MESH: Calcium, MESH: Intracellular Space, Protein Binding, Signal Transduction, MESH : Calmodulin, [ SDV.BBM.BP ] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, MESH : Amino Acid Motifs, animal structures, Calmodulin, MESH : Nuclear Magnetic Resonance, Biomolecular, calcium signaling, Article, 03 medical and health sciences, NMR spectroscopy, MESH: Protein Binding, Humans, MESH : Calcium, Nuclear Magnetic Resonance, Biomolecular, Ion channel, 030304 developmental biology, MESH : Signal Transduction, MESH: Humans, protein complex, MESH : Peptide Fragments, MESH : Humans, MESH: NAV1.5 Voltage-Gated Sodium Channel, calcium binding protein, Peptide Fragments, co-expression, chemistry, biology.protein, Calcium, Apoproteins, [ SDV.BBM.BS ] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM]
Abstract

International audience; Calmodulin (CaM) is a ubiquitous EF-hand calcium sensor protein that transduces calcium signals in a wide range of signaling pathways. Structural analysis of complexes with peptides has provided valuable insights into the remarkable variety in the way in which CaM interacts with and activates its targets. Among these various targets, CaM has been shown to be an essential component of a calcium-sensing regulatory apparatus for a number of voltage-gated ion channels. NMR spectroscopy has proven to be a powerful tool for the structural characterization of CaM-peptide complexes, in particular for the study of IQ motifs, which bind CaM at the basal level of calcium in cells and thereby serve to localize CaM to its sites of action. We describe here methods for the robust expression and purification of CaM isotopically enriched for NMR analysis, as well as for the complex of CaM with a peptide derived from the IQ motif sequence of the human cardiac sodium channel Na(V)1.5. We also describe methods for NMR analysis of titrations of CaM with IQ motif peptides to determine the stoichiometry of the complex and to identify the residues at the binding interface.

Published
2013
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3. Autoimmune mediated regulation of ovarian tumor growth

Author

Vincent K. Tuohy, Cengiz Z. Altuntas, Ritika Jaini, Daniel Jane-wit, Pavani Kesaraju, Christopher A. Flask, Jean Yves Picard, Martin Dutertre, Kelly K Covey, Justin M. Johnson, Lerner Research Institute, Cleveland Clinic, Equipe 7, Centre de Recherche en Cancérologie de Lyon (UNICANCER/CRCL), Centre Léon Bérard [Lyon]-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre Léon Bérard [Lyon]-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Endocrinologie et Génétique de la Reproduction et du Développement, Université Paris-Sud - Paris 11 (UP11)-IFR13-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherche en Cancérologie de Lyon ( CRCL ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Centre Léon Bérard [Lyon]-Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Centre Léon Bérard [Lyon]-Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), and Université Paris-Sud - Paris 11 ( UP11 ) -IFR13-Institut National de la Santé et de la Recherche Médicale ( INSERM )

Subjects
MESH : Molecular Sequence Data, endocrine system diseases, Autoimmunity, MESH: Amino Acid Sequence, medicine.disease_cause, HER2/neu, MESH: Cancer Vaccines, [ SDV.CAN ] Life Sciences [q-bio]/Cancer, Ovarian tumor, Mice, 0302 clinical medicine, MESH: Autoimmune Diseases, MESH : Autoimmunity, MESH : Female, MESH: Animals, MESH: Peptide Fragments, Ovarian Neoplasms, 0303 health sciences, biology, MESH : Amino Acid Sequence, MESH : Cancer Vaccines, Obstetrics and Gynecology, Anti-Müllerian hormone, MESH : Mice, Transgenic, female genital diseases and pregnancy complications, 3. Good health, Premature ovarian failure, MESH: Ovarian Neoplasms, medicine.anatomical_structure, Oncology, 030220 oncology & carcinogenesis, MESH: Cell Growth Processes, Female, endocrine system, MESH: Mice, Transgenic, Molecular Sequence Data, Ovary, Mice, Transgenic, [SDV.CAN]Life Sciences [q-bio]/Cancer, Cell Growth Processes, MESH : Mice, Inbred C57BL, Cancer Vaccines, Article, Autoimmune Diseases, 03 medical and health sciences, Immune system, MESH : Autoimmune Diseases, MESH: Mice, Inbred C57BL, MESH : Mice, MESH: Autoimmunity, medicine, Animals, Humans, Inhibins, Amino Acid Sequence, MESH: Mice, 030304 developmental biology, MESH: Molecular Sequence Data, MESH: Humans, MESH : Inhibins, business.industry, MESH : Ovarian Neoplasms, MESH : Peptide Fragments, MESH : Humans, MESH: Inhibins, medicine.disease, MESH : Disease Models, Animal, Peptide Fragments, Mice, Inbred C57BL, Disease Models, Animal, MESH : Cell Growth Processes, Immunology, biology.protein, Cancer vaccine, MESH : Animals, MESH: Disease Models, Animal, business, MESH: Female
Abstract

International audience; OBJECTIVES: An immune response sufficient to induce organ failure may provide protection and therapy against tumors derived from the targeted organ particularly when removal or ablation of the organ is part of the standard therapy and does not threaten survival. We have previously shown that a targeted immune response directed against the ovarian-specific protein, inhibin-α, causes ovarian failure. Here we determined whether inhibin-α autoimmunity is effective in both prevention and treatment of ovarian tumors. METHODS: A transgene consisting of the SV40 large tumor transformation antigen under the regulation of an anti-Mullerian hormone promoter (AMH-SV40Tag) was transferred by backcrossing for 12 generations to SJL/J mice producing SJL.AMH-SV40Tag (H-2(s)) females that develop a high incidence of autochthonous granulosa cell tumors. We determined whether immunization of SJL.AMH-SV40Tag female mice with the IA(s)-restricted p215-234 peptide of mouse inhibin-α was capable of preventing and treating these ovarian tumors. RESULTS: The growth of autochthonous ovarian granulosa cell tumors in SJL.AMH-SV40Tag transgenic mice was significantly inhibited in mice immunized with Inα 215-234. In addition, significant inhibition of tumor growth occurred when mice with established ovarian granulosa cell tumors were therapeutically vaccinated with Inα 215-234. CONCLUSIONS: Our results indicate that induction of ovarian-specific autoimmunity may serve as an effective way to prevent the emergence of autochthonous ovarian tumors and control the growth of established ovarian malignancies.

Published
2012
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4. TCR stimulation drives cleavage and shedding of the ITIM receptor CD31

Author

Fornasa, Giulia, Groyer, Emilie, Clement, Marc, Dimitrov, Jordan, Compain, Caroline, Gaston, Anh-Thu, Varthaman, Aditi, Khallou-Laschet, Jamila, Newman, Debra, Graff-Dubois, Stéphanie, Nicoletti, Antonino, Caligiuri, Giuseppina, Hémostase, bio-ingénierie et remodelage cardiovasculaires (LBPC), Université Paris Diderot - Paris 7 (UPD7)-Université Paris 13 (UP13)-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Galilée, Centre de Recherche des Cordeliers (CRC (UMR_S 872)), Université Paris Descartes - Paris 5 (UPD5)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Blood Research Institute, BloodCenter of Wisconsin, Immunité et Infection, Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR113-Université Pierre et Marie Curie - Paris 6 (UPMC), This work was supported in part by grants from the 'Fondation de France' (Engt 2006-005656 and 2008- 002724), the 'Fondation pour la Recherche Médicale' (DCV20070409268) and the 'Agence Nationale de la Recherche' (project 'RELATE' and project 'BROSCI'). G.F. is the recipient of a training grant from the 'Ministère affaires étrangères' (Egide N°636511F) and of the 'Groupe de Reflexion sur la Recherche Cardio-vasculaire et la Féderation Française de Cardiologie'. E.G. was the recipient of a research grant from the 'Fondation pour la Recherche Médicale' (FDT20071211595)., ANR: project 'RELATE and 'BROSCI',project 'RELATE and 'BROSCI', Université Pierre et Marie Curie - Paris 6 (UPMC)-IFR113-Institut National de la Santé et de la Recherche Médicale (INSERM), Hémostase, bio-ingénierie et remodelage cardiovasculaires ( LBPC ), Université Paris 13 ( UP13 ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Université Sorbonne Paris Cité ( USPC ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Institut Galilée, Centre de Recherche des Cordeliers ( CRC (UMR_S 872) ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Université Paris Descartes - Paris 5 ( UPD5 ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -IFR113-Institut National de la Santé et de la Recherche Médicale ( INSERM ), ANR : project 'RELATE and 'BROSCI',project 'RELATE and 'BROSCI', Université Paris 13 (UP13)-Université Paris Diderot - Paris 7 (UPD7)-Institut Galilée-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), and ANR-07-PHYS-0021,RELATE,Regulation des lymphocytes dans les manifestations atherothrombotiques(2007)

Subjects
MESH : Molecular Sequence Data, MESH: Immunoglobulins, MESH : Cell Membrane, MESH: Mice, Inbred BALB C, MESH : Mice, Inbred C57BL, MESH: Amino Acid Sequence, MESH: T-Lymphocyte Subsets, MESH: Mice, Knockout, MESH : Receptors, Antigen, T-Cell, MESH : Extracellular Space, MESH : Immunoglobulins, MESH: Protein Structure, Tertiary, MESH: Mice, Inbred C57BL, MESH : Mice, MESH : Cells, Cultured, MESH: Jurkat Cells, [ SDV.IMM ] Life Sciences [q-bio]/Immunology, MESH: Animals, MESH: Peptide Fragments, MESH: Lymphocyte Activation, MESH: Mice, MESH : Mice, Inbred BALB C, MESH : Jurkat Cells, MESH : Lymphocyte Activation, MESH: Molecular Sequence Data, MESH: Humans, MESH : Amino Acid Sequence, MESH : Peptide Fragments, MESH : Humans, MESH: Receptors, Antigen, T-Cell, MESH: Antigens, CD31, MESH : T-Lymphocyte Subsets, MESH: Extracellular Space, MESH : Antigens, CD31, cardiovascular system, MESH : Mice, Knockout, [SDV.IMM]Life Sciences [q-bio]/Immunology, MESH : Animals, MESH : Protein Structure, Tertiary, MESH: Cell Membrane, MESH: Cells, Cultured
Abstract

International audience; CD31 is a transmembrane molecule endowed with T cell regulatory functions owing to the presence of 2 immunotyrosine-based inhibitory motifs. For reasons not understood, CD31 is lost by a portion of circulating T lymphocytes, which appear prone to uncontrolled activation. In this study, we show that extracellular T cell CD31 comprising Ig-like domains 1 to 5 is cleaved and shed from the surface of human T cells upon activation via their TCR. The shed CD31 can be specifically detected as a soluble, truncated protein in human plasma. CD31 shedding results in the loss of its inhibitory function because the necessary cis-homo-oligomerization of the molecule, triggered by the trans-homophilic engagement of the distal Ig-like domain 1, cannot be established by CD31(shed) cells. However, we show that a juxta-membrane extracellular sequence, comprising part of the domain 6, remains expressed at the surface of CD31(shed) T cells. We also show that the immunosuppressive CD31 peptide aa 551-574 is highly homophilic and possibly acts by homo-oligomerizing with the truncated CD31 remaining after its cleavage and shedding. This peptide is able to sustain phosphorylation of the CD31 ITIM(686) and of SHP2 and to inhibit TCR-induced T cell activation. Finally, systemic administration of the peptide in BALB/c mice efficiently suppresses Ag-induced T cell-mediated immune responses in vivo. We conclude that the loss of T cell regulation caused by CD31 shedding driven by TCR stimulation can be rescued by molecular tools able to engage the truncated juxta-membrane extracellular molecule that remains exposed at the surface of CD31(shed) cells.

Published
2010
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5. HIV-1 gp41-specific monoclonal mucosal IgAs derived from highly exposed but IgG-seronegative individuals block HIV-1 epithelial transcytosis and neutralize CD4(+) cell infection: an IgA gene and functional analysis

Author

L. Diomede, Tudor D, C Moog, Reynes Jm, Anne Sophie Drillet, Houimel M, Lucia Lopalco, Morgane Bomsel, Derrien M, Institut Cochin (UMR_S567 / UMR 8104), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Pathogénie des infections Virales Persistantes, Université Louis Pasteur - Strasbourg I-Faculté de Médecine-Institut de Virologie, Institut Pasteur du Cambodge, Réseau International des Instituts Pasteur (RIIP), Institut Cochin ( UMR_S567 / UMR 8104 ), Université Paris Descartes - Paris 5 ( UPD5 ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), Institut Pasteur du Cambodge-Réseau International des Instituts Pasteur ( RIIP ), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Descartes - Paris 5 (UPD5)

Subjects
Immunoglobulin A, Sexually transmitted disease, CD4-Positive T-Lymphocytes, MESH : Molecular Sequence Data, MESH: HIV Envelope Protein gp41, MESH: Virus Internalization, Sequence Homology, MESH : Vagina, HIV Infections, Cervix Uteri, MESH : Sexual Partners, MESH: Amino Acid Sequence, HIV Antibodies, MESH: Antibodies, Monoclonal, MESH: HIV-1, [ SDV.MP ] Life Sciences [q-bio]/Microbiology and Parasitology, Immunology and Allergy, MESH: Sexual Partners, MESH : Female, MESH : Mucous Membrane, MESH: Sequence Homology, Gene Rearrangement, B-Lymphocyte, MESH: Peptide Fragments, MESH : HIV Seronegativity, Conserved Sequence, MESH: HIV Seronegativity, MESH: Conserved Sequence, biology, MESH : Amino Acid Sequence, MESH : Sequence Alignment, MESH: Gene Rearrangement, B-Lymphocyte, MESH : Immunoglobulin A, Secretory, Antibodies, Monoclonal, MESH: CD4-Positive T-Lymphocytes, Environmental exposure, MESH: HIV Infections, MESH: Cervix Uteri, MESH : Adult, MESH : Immunity, Innate, HIV Envelope Protein gp41, MESH: Immunoglobulin Fab Fragments, Sexual Partners, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, Transcytosis, MESH : Antibodies, Monoclonal, MESH : CD4-Positive T-Lymphocytes, Monoclonal, Vagina, Female, MESH: Immunity, Innate, Antibody, MESH : HIV-1, Adult, Immunology, Molecular Sequence Data, MESH: Environmental Exposure, MESH: Sequence Alignment, Gp41, Immunoglobulin Fab Fragments, MESH : HIV Antibodies, MESH : Immunoglobulin Fab Fragments, Peptide Library, MESH : Peptide Library, MESH : Sequence Homology, MESH : Conserved Sequence, HIV Seronegativity, MESH : HIV Infections, MESH : Virus Internalization, Humans, Amino Acid Sequence, Mucous Membrane, MESH: Molecular Sequence Data, MESH: Humans, MESH: HIV Antibodies, MESH : Humans, MESH : Peptide Fragments, MESH: Mucous Membrane, MESH: Adult, Gene rearrangement, Environmental Exposure, Virus Internalization, Virology, Immunity, Innate, Peptide Fragments, MESH : HIV Envelope Protein gp41, MESH: Immunoglobulin A, Secretory, MESH : Gene Rearrangement, B-Lymphocyte, MESH: Vagina, MESH : Cervix Uteri, Immunoglobulin A, Secretory, biology.protein, HIV-1, MESH: Peptide Library, Sequence Alignment, MESH : Environmental Exposure, MESH: Female
Abstract

International audience; AIDS is mainly a sexually transmitted disease, and accordingly, mucosal tissues are the primary sites of natural human immunodeficiency virus type-1 (HIV-1) transmission. Mucosal immunoglobulin A (IgA) antibody specific for HIV-1 envelope gp41 subunit is one correlate of protection in individuals who are highly sexually exposed to HIV-1 but remain persistently IgG seronegative (HEPS). Understanding these peculiar IgAs at the gene and functional level is possible only with monoclonal IgAs. We have constructed a mucosal Fab IgA library from HEPS and have characterized a series of HIV-1 IgAs specific for gp41 that, in vitro, are transcytosis-blocking and infection-neutralizing. Characterization of their IgA genes shows that Fab specific for the gp41 membrane-proximal region harbors a long heavy-chain CDR3 loop (CDRH3) similar to the two broadly neutralizing IgG monoclonal antibodies, 2F5 and 4E10. Furthermore, the selected Fab IgA shows extensive somatic mutations that cluster in the CDR regions, indicating that affinity maturation due to an antigen-driven process had occurred in HEPS individuals, presumably upon multiple exposures to HIV. This analysis of HEPS monoclonal IgA gives a unique opportunity to correlate an antibody function (resistance to a pathogen in vivo) with an antibody gene. Such neutralizing monoclonal IgAs could be used in microbicide formulation.

Published
2009
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6. Aminopeptidase A contributes to the N-terminal truncation of amyloid beta-peptide

Author

Marie-Claude Fournie-Zaluski, Frédéric Checler, Bernard P. Roques, Jean Sevalle, Audrey Amoyel, Philippe Robert, Institut de pharmacologie moléculaire et cellulaire (IPMC), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Centre Mémoire de Ressources et de Recherche [Nice] (CMRR Nice), Université Côte d'Azur (UCA)-Centre Hospitalier Universitaire de Nice (CHU Nice)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Pharmaleads, Université Paris Descartes - Paris 5 (UPD5), Institut de pharmacologie moléculaire et cellulaire ( IPMC ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Centre Mémoire de Ressources et de Recherche [Nice] ( CMRR Nice ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -CHU Nice, Université Paris Descartes - Paris 5 ( UPD5 ), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), and Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre Hospitalier Universitaire de Nice (CHU Nice)

Subjects
MESH : Cell Line, MESH : Glutamyl Aminopeptidase, cell free amyloid-β production, Peptide, Biochemistry, Aminopeptidase, MESH: Amyloid beta-Protein, MESH: Mice, Knockout, Mice, chemistry.chemical_compound, MESH: Protein Structure, Tertiary, 0302 clinical medicine, inhibitors, Amyloid precursor protein, MESH: Animals, MESH: Peptide Fragments, Mice, Knockout, chemistry.chemical_classification, MESH: Glutamyl Aminopeptidase, 0303 health sciences, biology, MESH : Peptides, MESH: Peptides, MESH : Amyloid beta-Protein, cell death, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], MESH : Protein Structure, Tertiary, Intracellular, amyloid-β degradation, Proteases, Amyloid beta, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Glutamyl Aminopeptidase, Cell Line, 03 medical and health sciences, Cellular and Molecular Neuroscience, Amastatin, MESH : Mice, mental disorders, Animals, Humans, APLP2, MESH: Mice, 030304 developmental biology, Amyloid beta-Peptides, MESH: Humans, [ SDV.BC ] Life Sciences [q-bio]/Cellular Biology, MESH : Humans, MESH : Peptide Fragments, Peptide Fragments, N-terminally truncated amyloid-β fragments, Protein Structure, Tertiary, MESH: Cell Line, chemistry, [ SDV.NEU ] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], biology.protein, MESH : Mice, Knockout, aminopeptidase A, MESH : Animals, Peptides, 030217 neurology & neurosurgery
Abstract

International audience; Several lines of data previously indicated that N-terminally truncated forms of amyloid-beta (Abeta) peptides are likely the earliest and more abundant species immunohistochemically detectable in Alzheimer's disease-affected brains. It is noteworthy that the free N-terminal residue of full-length Abeta (fl-Abeta) is an aspartyl residue, suggesting that Abeta could be susceptible to exopeptidasic attack by aminopeptidase A (APA)-like proteases. In this context, we have examined whether APA could target Abeta peptides in both cell-free and cellular models. We first show that the general aminopeptidase inhibitor amastatin as well as two distinct aminopeptidase A inhibitors EC33 and pl302 both significantly increase the recovery of genuine fl-Abeta peptides generated by cells over-expressing Swedish-mutated beta amyloid precursor protein (APP) while the aminopeptidase N blocker pl250 did not modify fl-Abeta recovery. In agreement with this observation, we establish that over-expressed APA drastically reduces, in a calcium dependent manner, fl-Abeta but not APP IntraCellular Domain in a cell-free model of Abeta production. In agreement with the above data, we show that recombinant APA degrades fl-Abeta in a pl302-sensitive manner. Interestingly, we also show that EC33 and pl302 lower staurosporine-stimulated activation of caspase-3 in wild-type fibroblasts but not in betaAPP/beta-amyloid precursor protein-like protein 2 (APLP2) double knockout fibroblasts, suggesting that protecting endogenous fl-Abeta physiological production triggers neuroprotective phenotype. By contrast, EC33 does not modify staurosporine-induced caspase-3 activation in wild-type and Swedish-mutated betaAPP-HEK293 expressing cells that display exacerbated production of Abeta. Overall, our data establish that APA contributes to the N-terminal truncation of Abeta and suggest that this cleavage is likely abrogating a protective function associated with physiological but not supraphysiological levels of genuine fl-Abeta peptides.

Published
2009
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7. Characterization of E. coli ribosomal particles : combined analysis of whole proteins by mass spectrometry and of proteolytic digests by liquid chromatography-tandem mass spectrometry

Author

Iost, Isabelle, Charollais, Julie, Vinh, Joelle, Pflieger, Delphine, Régulation de l'expression génétique (REG), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Neurobiologie et diversité cellulaire (NDC), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL), Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement (LAMBE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université d'Évry-Val-d'Essonne (UEVE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Delphine Pflieger and Jean Rossier, Institute for Molecular Systems Biology [ETH Zurich] (IMSB), Department of Biology [ETH Zürich] (D-BIOL), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Laboratoire de génétique moléculaire, Centre National de la Recherche Scientifique ( CNRS ), ESPCI ParisTech, Institute for Molecular Systems Biology [ETH Zurich] ( IMSB ), Swiss Federal Institute of Technology in Zürich ( ETH Zürich ), and Pflieger, Delphine

Subjects
Ribosomal Proteins, MALDI-TOF, MESH : Escherichia coli, [CHIM.ANAL] Chemical Sciences/Analytical chemistry, MESH: Peptide Hydrolases, MESH: Escherichia coli Proteins, MESH : Chromatography, Liquid, MESH : Ribosomal Proteins, Mass Spectrometry, MESH : Mass Spectrometry, MESH: Centrifugation, Density Gradient, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, Centrifugation, Density Gradient, Escherichia coli, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, nanoESI-QqTOF, LC-MS/MS, MESH: Peptide Fragments, MESH : Ribosomes, MESH: Mass Spectrometry, MESH: Escherichia coli, MESH : Escherichia coli Proteins, Escherichia coli Proteins, MESH : Peptide Fragments, E. coli, MESH: Ribosomal Proteins, Peptide Fragments, MESH : Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, MESH: Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, [ SDV.BBM.GTP ] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, MESH : Peptide Hydrolases, MESH : Centrifugation, Density Gradient, incomplete particules, MESH: Chromatography, Liquid, MESH: Ribosomes, Ribosomes, Chromatography, Liquid, Peptide Hydrolases
Abstract

International audience; This chapter describes the purification of ribosomal particles from a mutant strain of Escherichia coli using sucrose gradients and the characterization of their protein composition by a combination of mass spectrometry (MS) techniques. The main objective is to identify the ribosomal proteins that are missing in an aberrant ribosomal particle corresponding to a defective large subunit. To address this question, the tryptic digests of the purified ribosomal particles are analyzed by the coupling between liquid chromatography and tandem MS. The presence or absence of a given ribosomal protein in the defective particle is determined by comparing the MS intensities of its identified tryptic peptides with that of the mature large subunit. These analyses also allow identification of proteins copurifying with the ribosomal particles. To detect low-mass proteins escaping identification by the above method, intact proteins are also analyzed by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) and nano-ESI-QqTOF MS.

Published
2008
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8. A RasGAP SH3 peptide aptamer inhibits RASGAP-Aurora interaction and induces caspase-independent tumor cell death

Author

Pierre Colas, Anne-Laure Mathieu, Françoise Raynaud, Perayot Pamonsinlapatham, Olivier Moncorgé, Réda Hadj-Slimane, Perrine Mercier, Yves Lepelletier, Audrey Barthelaix, Claudine Corneloup, Ivan Mikaelian, Jerome Samson, Marc Bickle, Christiane Garbay, Sylvie Dufour, Matthieu Schapira, Nicolas Hugo, Cytokines, hématopoïèse et réponse immune (CHRI), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Pharmacochimie Moléculaire et Cellulaire (PMC - UMR_S 648), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Descartes - Paris 5 (UPD5), Aptanomics, Compartimentation et dynamique cellulaires (CDC), Centre National de la Recherche Scientifique (CNRS)-Institut Curie [Paris]-Université Pierre et Marie Curie - Paris 6 (UPMC), Favey, Allison, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut Curie [Paris]-Centre National de la Recherche Scientifique (CNRS), Université Paris Descartes - Paris 5 (UPD5) - Institut National de la Santé et de la Recherche Médicale (INSERM) - Centre National de la Recherche Scientifique (CNRS), Pharmacochimie Moléculaire et Cellulaire ( PMC - UMR_S 648 ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Université Paris Descartes - Paris 5 ( UPD5 ), Cytokines, hématopoïèse et réponse immune ( CHRI ), Université Paris Descartes - Paris 5 ( UPD5 ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), Compartimentation et dynamique cellulaires ( CDC ), Centre National de la Recherche Scientifique ( CNRS ) -INSTITUT CURIE-Université Pierre et Marie Curie - Paris 6 ( UPMC ), and Slama, Catherine

Subjects
MESH : Molecular Sequence Data, MESH : ras GTPase-Activating Proteins, Cell Biology/Cell Growth and Division, lcsh:Medicine, Peptide, MESH: Amino Acid Sequence, Biochemistry, MESH: ras GTPase-Activating Proteins, 0302 clinical medicine, Aurora Kinases, lcsh:Science, MESH: Peptide Fragments, Peptide sequence, Conserved Sequence, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, 0303 health sciences, Multidisciplinary, MESH: Conserved Sequence, Effector, MESH : Amino Acid Sequence, MESH : Sequence Alignment, Cell Biology/Cellular Death and Stress Responses, ras GTPase-Activating Proteins, Caspases, 030220 oncology & carcinogenesis, Biochemistry/Drug Discovery, Research Article, Proto-oncogene tyrosine-protein kinase Src, MESH : Protein-Serine-Threonine Kinases, MESH : Recombinant Fusion Proteins, Recombinant Fusion Proteins, Aptamer, Molecular Sequence Data, Aurora B kinase, MESH: Sequence Alignment, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Protein Serine-Threonine Kinases, Biology, MESH: Protein-Serine-Threonine Kinases, Protein–protein interaction, 03 medical and health sciences, MESH : Conserved Sequence, MESH: Recombinant Fusion Proteins, Amino Acid Sequence, Binding site, Molecular Biology, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, 030304 developmental biology, Binding Sites, MESH: Caspases, MESH: Molecular Sequence Data, [ SDV.BC ] Life Sciences [q-bio]/Cellular Biology, MESH : Peptide Fragments, lcsh:R, Biochemistry/Chemical Biology of the Cell, Peptide Fragments, chemistry, MESH: Binding Sites, lcsh:Q, MESH : Caspases, Sequence Alignment, MESH : Binding Sites
Abstract

International audience; The Ras GTPase-activating protein RasGAP catalyzes the conversion of active GTP-bound Ras into inactive GDP-bound Ras. However, RasGAP also acts as a positive effector of Ras and exerts an anti-apoptotic activity that is independent of its GAP function and that involves its SH3 (Src homology) domain. We used a combinatorial peptide aptamer approach to select a collection of RasGAP SH3 specific ligands. We mapped the peptide aptamer binding sites by performing yeast two-hybrid mating assays against a panel of RasGAP SH3 mutants. We examined the biological activity of a peptide aptamer targeting a pocket delineated by residues D295/7, L313 and W317. This aptamer shows a caspase-independent cytotoxic activity on tumor cell lines. It disrupts the interaction between RasGAP and Aurora B kinase. This work identifies the above-mentioned pocket as an interesting therapeutic target to pursue and points its cognate peptide aptamer as a promising guide to discover RasGAP small-molecule drug candidates.

Published
2008
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9. Cellular localization of apelin and its receptor in the anterior pituitary: evidence for a direct stimulatory action of apelin on ACTH release

Author

Marie-Thérèse Bluet-Pajot, Rodrigo Alvear-Perez, Philippe Zizzari, Catherine Llorens-Cortes, Annabelle Réaux-Le Goazigo, Jacques Epelbaum, Neuropeptides centraux et régulations hydrique et cardiovasculaire, Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre interdisciplinaire de recherche en biologie (CIRB), Labex MemoLife, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Collège de France (CdF (institution))-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Labex MemoLife, Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Neurobiologie de la Croissance et de la Senescence, Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre interdisciplinaire de recherche en biologie (CIRB), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Labex MemoLife, Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Collège de France ( CdF ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ), Université Paris Descartes - Paris 5 ( UPD5 ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), and Llorens Cortes, Catherine

Subjects
Male, Pituitary gland, Endocrinology, Diabetes and Metabolism, MESH: Amino Acid Sequence, MESH: Receptors, G-Protein-Coupled, MESH: Base Sequence, MESH : Tissue Distribution, Receptors, G-Protein-Coupled, Rats, Sprague-Dawley, 0302 clinical medicine, MESH: Cricetulus, MESH: Pituitary Gland, MESH: Ligands, MESH : CHO Cells, Tissue Distribution, MESH: Animals, MESH: Peptide Fragments, MESH : Ligands, 0303 health sciences, MESH : Amino Acid Sequence, MESH : Cyclic AMP, MESH: Pituitary Gland, Anterior, MESH : Cricetinae, MESH : Protein Binding, [ SDV.MHEP.EM ] Life Sciences [q-bio]/Human health and pathology/Endocrinology and metabolism, [SDV.MHEP.EM]Life Sciences [q-bio]/Human health and pathology/Endocrinology and metabolism, Apelin, MESH : Adrenocorticotropic Hormone, Intercellular Signaling Peptides and Proteins, MESH : Carrier Proteins, medicine.medical_specialty, endocrine system, MESH : Cell Membrane, MESH : Cricetulus, MESH: Carrier Proteins, Adrenocorticotropic hormone, 03 medical and health sciences, Adrenocorticotropic Hormone, Anterior pituitary, Pituitary Gland, Anterior, MESH: CHO Cells, Physiology (medical), MESH: Protein Binding, MESH: Tissue Distribution, MESH: Adrenocorticotropic Hormone, MESH: Humans, MESH: Molecular Sequence Data, MESH : Humans, Peptide Fragments, Endocrinology, Carrier Proteins, 030217 neurology & neurosurgery, MESH : Molecular Sequence Data, Physiology, MESH: Corticotrophs, MESH: Cricetinae, MESH : Models, Biological, MESH: Rats, Sprague-Dawley, Rats, Inbred WKY, MESH : Pituitary Gland, Receptor, Corticotrophs, Cellular localization, MESH: Cyclic AMP, [SDV.MHEP.EM] Life Sciences [q-bio]/Human health and pathology/Endocrinology and metabolism, Apelin Receptors, MESH : Rats, MESH : Forskolin, medicine.anatomical_structure, MESH: Pituitary Hormones, Anterior, MESH: Calcium, MESH : Receptors, G-Protein-Coupled, MESH : Transfection, MESH: Forskolin, hormones, hormone substitutes, and hormone antagonists, MESH: Rats, Inbred WKY, Endocrine gland, MESH: Rats, MESH : Male, MESH : Rats, Inbred WKY, Biology, Models, Biological, MESH : Pituitary Hormones, Anterior, MESH : Pituitary Gland, Anterior, Pituitary Hormones, Anterior, Internal medicine, medicine, Animals, MESH : Calcium, 030304 developmental biology, Apelin receptor, MESH: Transfection, MESH : Peptide Fragments, MESH: Models, Biological, MESH : Corticotrophs, MESH : Rats, Sprague-Dawley, MESH: Male, Rats, MESH : Peptide Hormones, MESH: Peptide Hormones, MESH : Base Sequence, MESH : Animals, MESH: Cell Membrane
Abstract

Apelin is a bioactive peptide recently identified as the endogenous ligand of the human orphan G protein-coupled receptor APJ. The presence of apelin-immunoreactive nerve fibers, together with the detection of apelin receptor mRNA in the parvocellular part of the paraventricular nucleus and the stimulatory action of apelin on corticotropin-releasing hormone release, indicate that apelin modulates adrenocorticotropin (ACTH) release via an indirect action on the hypothalamus. However, a direct action of apelin in the anterior pituitary cannot be excluded. Here, we provided evidence for the existence of an apelinergic system within the adult male rat pituitary gland. Double immunofluorescence staining indicated that apelin is highly coexpressed in the anterior pituitary, mainly in corticotrophs (96.5 ± 0.3%) and to a much lower extent in somatotropes (3.2 ± 0.2%). Using in situ hybridization combined with immunohistochemistry, a high expression of apelin receptor mRNA was also found in corticotrophs, suggesting a local interaction between apelin and ACTH. In an ex vivo perifusion system of anterior pituitaries, apelin 17 (K17F, 10−6M) significantly increased basal ACTH release by 41%, whereas apelin 10 (R10F, 10−6M), an inactive apelin fragment, was ineffective. In addition, K17F but not R10F induced a dose-dependent increase in K+-evoked ACTH release, with maximal increase being observed for a 10−6M concentration. Taken together, these data outline the potential role of apelin as an autocrine/paracrine-acting peptide on ACTH release and provide morphological and neuroendocrine basis for further studies that explore the physiological role of apelin in the regulation of anterior pituitary functions.

Published
2007
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10. Novel mechanism of resistance to glycopeptide antibiotics in Enterococcus faecium

Author

Arul Marie, J.-C. Quincampoix, Jean-Emmanuel Hugonnet, Louis B. Rice, Laurent Gutmann, Julie Cremniter, Nathalie Josseaume, Lionel Dubost, Jean-Luc Mainardi, Michel Arthur, Lecerf, Maxime, Laboratoire de Recherche Moléculaire sur les Antibiotiques, Université Pierre et Marie Curie - Paris 6 (UPMC)-IFR58-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), AP-HP, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Laboratoire de chimie et biochimie des substances naturelles, Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Medical and Research Services, Louis Stokes Cleveland Veterans Affairs Medical Center, This work was supported by the European Community (COBRA, contract LSHM-CT-2003-503335, 6th PCRD), the National Institute of Allergy and Infectious Diseases (Grant R01 AI45626), and the Fondation pour la Recherche Médicale., Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -IFR58-Université Paris Descartes - Paris 5 ( UPD5 ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ), Assistance publique - Hôpitaux de Paris (AP-HP)-Hôpital Européen Georges Pompidou [APHP] ( HEGP ), Laboratoire de Chimie et Biochimie des Substances Naturelles, and Centre National de la Recherche Scientifique ( CNRS )

Subjects
Cytoplasm, MESH : Muramoylpentapeptide Carboxypeptidase, Enterococcus faecium, MESH : Models, Biological, Muramoylpentapeptide Carboxypeptidase, MESH : Drug Resistance, Bacterial, Biochemistry, Substrate Specificity, Muramoylpentapeptide carboxypeptidase, chemistry.chemical_compound, polycyclic compounds, Peptide bond, MESH: Enterococcus faecium, MESH : Anti-Bacterial Agents, MESH : Enterococcus faecium, MESH: Peptide Fragments, MESH : Peptidoglycan, Alanine, 0303 health sciences, MESH: Microbial Sensitivity Tests, MESH : Substrate Specificity, MESH: Peptidoglycan, Hydrolysis, Glycopeptides, MESH: Amino Acid Substitution, Glycopeptide, Anti-Bacterial Agents, Cross-Linking Reagents, MESH: Muramoylpentapeptide Carboxypeptidase, MESH: Hydrolysis, MESH : Cross-Linking Reagents, MESH : Cytoplasm, MESH : Glycopeptides, Stereochemistry, MESH: Alanine, MESH: Cross-Linking Reagents, Microbial Sensitivity Tests, Peptidoglycan, Biology, beta-Lactams, Models, Biological, Article, 03 medical and health sciences, MESH : Amino Acid Substitution, MESH : beta-Lactams, MESH : Hydrolysis, MESH: beta-Lactams, MESH: Anti-Bacterial Agents, Glycosyltransferase, Drug Resistance, Bacterial, MESH: Drug Resistance, Bacterial, [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, [ SDV.BBM ] Life Sciences [q-bio]/Biochemistry, Molecular Biology, Molecular Biology, 030304 developmental biology, MESH: Glycopeptides, 030306 microbiology, MESH: Cytoplasm, MESH : Peptide Fragments, MESH: Models, Biological, Cell Biology, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, Peptide Fragments, chemistry, Amino Acid Substitution, biology.protein, MESH: Substrate Specificity, MESH : Microbial Sensitivity Tests, MESH : Alanine, Bacteria
Abstract

International audience; Glycopeptides and beta-lactams are the major antibiotics available for the treatment of infections due to Gram-positive bacteria. Emergence of cross-resistance to these drugs by a single mechanism has been considered as unlikely because they inhibit peptidoglycan polymerization by different mechanisms. The glycopeptides bind to the peptidyl-D-Ala(4)-D-Ala(5) extremity of peptidoglycan precursors and block by steric hindrance the essential glycosyltransferase and D,D-transpeptidase activities of the penicillin-binding proteins (PBPs). The beta-lactams are structural analogues of D-Ala(4)-D-Ala(5) and act as suicide substrates of the D,D-transpeptidase module of the PBPs. Here we have shown that bypass of the PBPs by the recently described beta-lactam-insensitive L,D-transpeptidase from Enterococcus faecium (Ldt(fm)) can lead to high level resistance to glycopeptides and beta-lactams. Cross-resistance was selected by glycopeptides alone or serially by beta-lactams and glycopeptides. In the corresponding mutants, UDP-MurNAc-pentapeptide was extensively converted to UDP-MurNAc-tetrapeptide following hydrolysis of D-Ala(5), thereby providing the substrate of Ldt(fm). Complete elimination of D-Ala(5), a residue essential for glycopeptide binding, was possible because Ldt(fm) uses the energy of the L-Lys(3)-D-Ala(4) peptide bond for cross-link formation in contrast to PBPs, which use the energy of the D-Ala(4)-D-Ala(5) bond. This novel mechanism of glycopeptide resistance was unrelated to the previously identified replacement of D-Ala(5) by D-Ser or D-lactate.

Published
2006
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11. Delayed age-associated decrease in growth hormone pulsatile secretion and increased orexigenic peptide expression in the Lou C/JaLL rat

Author

Jacques Epelbaum, Philippe Zizzari, Marie-Thérèse Bluet-Pajot, Laurent Kappeler, Josette Alliot, Neurobiologie de la Croissance et de la Senescence, Université Paris Descartes - Paris 5 (UPD5) - Institut National de la Santé et de la Recherche Médicale (INSERM) - Centre National de la Recherche Scientifique (CNRS), Zizzari, Philippe, and Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Leptin, Aging, Pro-Opiomelanocortin, Peptide Hormones, Endocrinology, Diabetes and Metabolism, MESH: Insulin-Like Growth Factor I, Gene Expression, MESH : Insulin-Like Growth Factor I, MESH : Neuropeptides, MESH: Neuropeptides, MESH: Eating, Eating, Endocrinology, Agouti-Related Protein, Neuropeptide Y, MESH: Aging, MESH: Animals, Insulin-Like Growth Factor I, MESH: Peptide Fragments, MESH : Body Weight, [SDV.MHEP.EM] Life Sciences [q-bio]/Human health and pathology/Endocrinology and metabolism, Reverse Transcriptase Polymerase Chain Reaction, Intracellular Signaling Peptides and Proteins, MESH: Comparative Study, [SDV.MHEP.EM]Life Sciences [q-bio]/Human health and pathology/Endocrinology and metabolism, Growth hormone–releasing hormone, Ghrelin, Growth hormone secretion, MESH : Neuropeptide Y, Pituitary Gland, MESH : Leptin, medicine.medical_specialty, MESH : Eating, MESH: Gene Expression, MESH : Hypothalamus, Somatotropic cell, Hypothalamus, Biology, MESH : Growth Hormone, Cellular and Molecular Neuroscience, MESH : Intracellular Signaling Peptides and Proteins, Internal medicine, MESH: Intracellular Signaling Peptides and Proteins, medicine, Animals, RNA, Messenger, MESH: Neuropeptide Y, Rats, Wistar, Orexins, Endocrine and Autonomic Systems, Body Weight, Neuropeptides, MESH : Peptide Fragments, MESH : Comparative Study, MESH: Leptin, MESH: Hypothalamus, Peptide Fragments, MESH : Aging, Rats, Orexin, MESH: Body Weight, MESH : Gene Expression, Ageing, Growth Hormone, MESH: Growth Hormone, MESH : Peptide Hormones, MESH: Peptide Hormones, MESH : Animals, Agouti-related peptide
Abstract

International audience; Since modifications in the growth hormone/insulin-like growth factor 1 (GH/IGF-1) axis and/or caloric restriction are involved in the ageing process, GH secretory profiles, total IGF-1, ghrelin, and leptin plasma levels and expression of genes implicated in somatotrope axis and food intake regulation in hypothalamus and pituitary were compared in 3-, 12-, and 24-month-old male Lou C/Jall rats and their parent strain, the Wistar rats. The Lou C/Jall strain may appear as a healthy ageing model, since it does not become obese with age and maintains its caloric intake at 2 years of age. The GH pulsatile secretion decreased from 3 months in Wistar, but only after 12 months in Lou C/Jall rats. The IGF-1 levels were lower in Lou C/Jall rats and decreased more steeply with ageing as compared with Wistar rats. The total ghrelin levels were higher in young Lou C/Jall rats than in Wistar rats, but increased similarly with age in both strains. The leptin concentrations increased with ageing only in Wistar rats. By semiquantitative reverse-transcription polymerase chain reaction, pituitary GH secretagogue receptors and GH mRNA levels were more abundant in Lou C/Jall rats, and the latter decreased with ageing in Wistar rats only. Hypothalamic growth-hormone-releasing hormone and GH secretagogue receptor mRNA levels were similar in both strains and transiently increased only in middle-aged Wistar rats. Agouti-related peptide, neuropeptide Y, and orexin mRNA levels were more abundant in the Lou C/Jall rat hypothalamus, and the two former tended to further increase with age only in this strain. Conversely, the hypothalamic pro-opiomelanocortin mRNA levels were higher in old Wistar rats. In conclusion, ageing in Lou C/Jall rats is associated with a delayed decrease in pulsatile GH secretion in the presence of a lower IGF-1 tone and an increase in the expression of orexigenic neuropeptides in the hypothalamus.

Published
2004
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12. Nucleocytoplasmic shuttling of antigen in mammalian cells conferred by a soluble versus insoluble single-chain antibody fragment equipped with import/export signals

Author

Pierre Martineau, Etienne Weiss, Annie-Paule Sibler, Alexandra Nordhammer, Murielle Masson, Gilles Travé, Institut Gilbert-Laustriat : Biomolécules, Biotechnologie, Innovation Thérapeutique, Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique ( CNRS ), Material Physics Laboratory, Helsinki University of Technology ( TKK ), 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 ), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies ( FEMTO-ST ), Université de Technologie de Belfort-Montbeliard ( UTBM ) -Ecole Nationale Supérieure de Mécanique et des Microtechniques ( ENSMM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Heuristique et Diagnostic des Systèmes Complexes [Compiègne] ( Heudiasyc ), Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'ingénierie osteo-articulaire et dentaire ( LIOAD ), Université de Nantes ( UN ) -IFR26-Institut National de la Santé et de la Recherche Médicale ( INSERM ), Institut de Recherche en Infectiologie de Montpellier ( IRIM ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Montpellier ( UM ), Laboratoire d'Informatique, de Modélisation et d'optimisation des Systèmes ( LIMOS ), Centre National de la Recherche Scientifique ( CNRS ) -Sigma CLERMONT ( Sigma CLERMONT ) -Université d'Auvergne - Clermont-Ferrand I ( UdA ) -Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ), Université Montpellier 1 ( UM1 ), Laboratoire de génie chimique ( LGC ), Institut National Polytechnique [Toulouse] ( INP ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), TKK Helsinki University of Technology (TKK), 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), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Heuristique et Diagnostic des Systèmes Complexes [Compiègne] (Heudiasyc), Université de Technologie de Compiègne (UTC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'ingénierie osteo-articulaire et dentaire (LIOAD), Université de Nantes (UN)-IFR26-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Informatique, de Modélisation et d'optimisation des Systèmes (LIMOS), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Sigma CLERMONT (Sigma CLERMONT)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure des Mines de St Etienne, Université Montpellier 1 (UM1), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Biotechnologie des interactions macromoléculaires (BIM), Centre National de la Recherche Scientifique (CNRS), Institut de Biotechnologie-Pharmacologie, Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-BioRad-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), and Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Technologie de Belfort-Montbeliard (UTBM)

Subjects
MESH: Signal Transduction, Cytoplasm, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, MESH : Hela Cells, Antigens, Polyomavirus Transforming, [SDV]Life Sciences [q-bio], MESH : Antigens, MESH: Eukaryotic Cells, [ SDV.CAN ] Life Sciences [q-bio]/Cancer, 0302 clinical medicine, MESH : Protein Transport, MESH : Mammals, MESH : Bacterial Proteins, MESH: Animals, Expression in mammalian cells, MESH: Peptide Fragments, MESH: Bacterial Proteins, ComputingMilieux_MISCELLANEOUS, Mammals, 0303 health sciences, Single-chain Fv, MESH : Cell Nucleus, MESH : Protein Binding, Transfection, MESH: COS Cells, Protein Transport, Eukaryotic Cells, Biochemistry, 030220 oncology & carcinogenesis, COS Cells, MESH: Antigens, MESH : COS Cells, Intracellular, Protein Binding, Signal Transduction, MESH: Cell Nucleus, MESH: Protein Transport, MESH : Cytoplasm, Nucleocytoplasmic indirect transport, Intracellular targeting, Active Transport, Cell Nucleus, NLS/NES, [SDV.CAN]Life Sciences [q-bio]/Cancer, MESH: Active Transport, Cell Nucleus, Biology, MESH: Mammals, Protein–protein interaction, 03 medical and health sciences, Bacterial Proteins, Antigen, MESH : Prokaryotic Cells, Animals, Humans, NLS, MESH: Protein Binding, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Antigens, Nuclear export signal, [ SDV.BBM ] Life Sciences [q-bio]/Biochemistry, Molecular Biology, MESH : Active Transport, Cell Nucleus, 030304 developmental biology, MESH: Prokaryotic Cells, Cell Nucleus, MESH : Signal Transduction, MESH: Humans, MESH: Antigens, Polyomavirus Transforming, MESH: Cytoplasm, MESH : Solubility, MESH : Humans, MESH : Peptide Fragments, MESH : Eukaryotic Cells, [ SDV.BIO ] Life Sciences [q-bio]/Biotechnology, Cell Biology, Peptide Fragments, MESH: Hela Cells, MESH: Solubility, Prokaryotic Cells, Solubility, Functional solubility, MESH : Animals, Nuclear transport, MESH : Antigens, Polyomavirus Transforming, HeLa Cells
Abstract

International audience; The ectopic expression of antibody fragments within mammalian cells is a challenging approach for interfering with or even blocking the biological function of the intracellular target. For this purpose, single-chain Fv (scFv) fragments are generally preferred. Here, by transfecting several mammalian cell lines, we compared the intracellular behavior of two scFvs (13R4 and 1F4) that strongly differ in their requirement of disulphide bonding for the formation of active molecules in bacteria. The scFv 13R4, which is correctly folded in the bacterial cytoplasm, was solubly expressed in all cell lines tested and was distributed in their cytoplasm and nucleus, as well. In addition, by appending to the 13R4 molecules the SV40 T-antigen nuclear localisation signal (NLS) tag, cytoplasmic-coexpressed antigen was efficiently retargeted to the nucleus. Compared to the scFv 13R4, the scFv 1F4, which needs to be secreted in bacteria for activity, accumulated, even with the NLS tag, as insoluble aggregates within the cytoplasm of the transfected cells, thereby severely disturbing fundamental functions of cell physiology. Furthermore, by replacing the NLS tag with a leucine-rich nuclear export signal (NES), the scFv 13R4 was exclusively located in the cytoplasm, whereas the similarly modified scFv 1F4 still promoted cell death. Coexpression of NES-tagged 13R4 fragments with nuclear antigen promoted its efficient retargeting to the cytoplasm. This dominant effect of the NES tag was also observed after exchange of the nuclear signals between the scFv 13R4 and its antigen. Taken together, the results indicate that scFvs that are active in the cytoplasm of bacteria may behave similarly in mammalian cells and that the requirement of their conserved disulphide bridges for activity is a limiting factor for mediating the nuclear import/export of target in a mammalian cell context. The described shuttling effect of antigen conferred by a soluble scFv may represent the basis of a reliable in vivo assay of effective protein- protein interactions.

Published
2003
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13. The H-NS dimerization domain defines a new fold contributing to DNA recognition

Author

Vanessa Bloch, Marie Thérèse Augé, Bruno Robert, Stefan T. Arold, Yinshan Yang, Sylvie Rimsky, Emmanuel Margeat, Alain Chavanieu, Michel Kochoyan, Centre de Biochimie Structurale [Montpellier] ( CBS ), Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Université de Montpellier ( UM ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Bioénergétique, Métalloprotéines et Stress ( LBMS ), Département Biochimie, Biophysique et Biologie Structurale ( B3S ), Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Biologie et de Pharmacologie Appliquée ( LBPA ), École normale supérieure - Cachan ( ENS Cachan ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de Biochimie Structurale [Montpellier] (CBS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire Bioénergétique Membranaire et Stress (LBMS), Département Biochimie, Biophysique et Biologie Structurale (B3S), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Cachan (ENS Cachan), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Models, Molecular, Protein Folding, Magnetic Resonance Spectroscopy, MESH : Molecular Sequence Data, Protein Conformation, MESH : DNA, MESH: Amino Acid Sequence, MESH: Protein Structure, Tertiary, chemistry.chemical_compound, MESH: Protein Conformation, Structural Biology, MESH : Bacterial Proteins, MESH: Peptide Fragments, MESH: Bacterial Proteins, Conserved Sequence, MESH : Protein Conformation, 0303 health sciences, MESH: Conserved Sequence, MESH : Amino Acid Sequence, MESH: DNA, DNA-Binding Proteins, Biochemistry, MESH : Dimerization, MESH : DNA-Binding Proteins, MESH : Mutation, Dimerization, MESH : Protein Structure, Tertiary, MESH: Models, Molecular, Binding domain, MESH : Protein Folding, MESH: Mutation, HMG-box, MESH : Models, Molecular, MESH: Protein Folding, Molecular Sequence Data, Fluorescence Polarization, Computational biology, Biology, DNA-binding protein, 03 medical and health sciences, Bacterial Proteins, MESH : Conserved Sequence, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Amino Acid Sequence, B3 domain, Molecular Biology, Gene, [ SDV.BBM ] Life Sciences [q-bio]/Biochemistry, Molecular Biology, 030304 developmental biology, MESH: Fluorescence Polarization, MESH: Molecular Sequence Data, MESH: Magnetic Resonance Spectroscopy, 030306 microbiology, Circular bacterial chromosome, MESH : Peptide Fragments, DNA, Peptide Fragments, Protein Structure, Tertiary, MESH: Dimerization, Heteronuclear molecule, chemistry, Mutation, MESH : Fluorescence Polarization, MESH : Magnetic Resonance Spectroscopy, MESH: DNA-Binding Proteins
Abstract

International audience; H-NS, a protein found in Gram-negative bacteria, is involved in structuring the bacterial chromosome and acts as a global regulator for the expression of a wide variety of genes. These functions are correlated with both its DNA-binding and oligomerization properties. We have identified the minimal dimerization domain of H-NS, a 46 amino acid-long N-terminal fragment, and determined its structure using heteronuclear NMR spectroscopy. The highly intertwined structure of the dimer, reminiscent of a handshake, defines a new structural fold, which may offer a possibility for discriminating prokaryotic from eukaryotic proteins in drug design. Using mutational analysis, we also show that this N-terminal domain actively contributes to DNA binding, conversely to the current paradigm. Together, our data allows us to propose a model for the action of full length H-NS.

Published
2003
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