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8 results on '"Amine Ali Chaouche"'

1. Defining Two Chemosensory Arrays in Shewanella oneidensis

Author

Emma M. Fortier, Sophie Bouillet, Pascale Infossi, Amine Ali Chaouche, Leon Espinosa, Marie-Thérèse Giudici-Orticoni, Emilia M. F. Mauriello, and Chantal Iobbi-Nivol

Subjects
chemosensory systems, chemoreceptors, Shewanella oneidensis, Microbiology, QR1-502
Abstract

Shewanella oneidensis has 2 functional chemosensory systems named Che1 and Che3, and 27 chemoreceptors. Che3 is dedicated to chemotaxis while Che1 could be involved in RpoS post-translational regulation. In this study, we have shown that two chemoreceptors Aer2so and McpAso, genetically related to the Che1 system, form distinct core-signaling units and signal to Che1 and Che3, respectively. Moreover, we observed that Aer2so is a cytoplasmic dynamic chemoreceptor that, when in complex with CheA1 and CheW1, localizes at the two poles and the centre of the cells. Altogether, the results obtained indicate that Che1 and Che3 systems are interconnected by these two chemoreceptors allowing a global response for bacterial survival.

Published
2022
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2. ChrASO, the chromate efflux pump of Shewanella oneidensis, improves chromate survival and reduction.

Author

Hiba Baaziz, Cyril Gambari, Anne Boyeldieu, Amine Ali Chaouche, Radia Alatou, Vincent Méjean, Cécile Jourlin-Castelli, and Michel Fons

Subjects
Medicine, Science
Abstract

The chromate efflux pump encoding gene chrASO was identified on the chromosome of Shewanella oneidensis MR1. Although chrASO is expressed without chromate, its expression level increases when Cr(VI) is added. When deleted, the resulting mutant ΔchrASO exhibits a chromate sensitive phenotype compared to that of the wild-type strain. Interestingly, heterologous expression of chrASO in E. coli confers resistance to high chromate concentration. Moreover, expression of chrASO in S. oneidensis and E. coli significantly improves Cr(VI) reduction. This effect could result either from extracytoplasmic chromate reduction or from a better cell survival leading to enhanced Cr(VI) reduction.

Published
2017
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3. Multiple detection of both attractants and repellents by the <scp>dCache</scp> ‐chemoreceptor SO_1056 of Shewanella oneidensis

Author

Anne Boyeldieu, Jean‐Pierre Poli, Amine Ali Chaouche, Henri‐Pierre Fierobe, Marie‐Thérèse Giudici‐Orticoni, Vincent Méjean, Cécile Jourlin‐Castelli, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Università di Corsica Pasquale Paoli [Université de Corse Pascal Paoli], Partenaires INRAE, and Laboratoire de chimie bactérienne (LCB)

Subjects
dCache domain, ligand binding, Chemotaxis, Malates, Methyl-Accepting Chemotaxis Proteins, Cell Biology, chemoreceptors, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Biochemistry, isothermal titration calorimetry, bacterial chemotaxis, thermal shift assay, Bacterial Proteins, Nickel, Molecular Biology
Abstract

International audience; Chemoreceptors are usually transmembrane proteins dedicated to the detection of compound gradients or signals in the surroundings of a bacterium. After detection, they modulate the activation of CheA-CheY, the core of the chemotactic pathway, to allow cells to move upwards or downwards depending on whether the signal is an attractant or a repellent, respectively. Environmental bacteria such as Shewanella oneidensis harbour dozens of chemoreceptors or MCPs (methyl-accepting chemotaxis proteins). A recent study revealed that MCP SO_1056 of S. oneidensis binds chromate. Here, we show that this MCP also detects an additional attractant (L-malate) and two repellents (nickel and cobalt). The experiments were performed in vivo by the agarose-in-plug technique after overproducing MCP SO_1056 and in vitro, when possible, by submitting the purified ligand-binding domain (LBD) of SO_1056 to a thermal shift assay (TSA) coupled to isothermal titration calorimetry (ITC). ITC assays revealed a K D of 3.4 lM for L-malate and of 47.7 lM for nickel. We conclude that MCP SO_1056 binds attractants and repellents of unrelated composition. The LBD of SO_1056 belongs to the double Cache_1 family and is highly homologous to PctA, a chemoreceptor from Pseudomonas aeruginosa that detects several amino acids. Therefore, LBDs of the same family can bind diverse compounds, confirming that experimental approaches are required to define accurate LBD-binding molecules or signals.

Published
2022
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4. The Tol-Pal system of Escherichia coli plays an unexpected role in the import of the oxyanions chromate and phosphate

Author

Amine Ali Chaouche, Laetitia Houot, Denis Duché, Chantal Iobbi-Nivol, Marie-Thérèse Giudici-Orticoni, Michel Fons, Vincent Méjean, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'ingénierie des systèmes macromoléculaires (LISM), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), ANR-18-CE11-0027,MeMoX,Etudes structurales et fonctionnelles de moteurs moléculaires membranaires homologues(2018), BIMBI, Aurélia, and APPEL À PROJETS GÉNÉRIQUE 2018 - Etudes structurales et fonctionnelles de moteurs moléculaires membranaires homologues - - MeMoX2018 - ANR-18-CE11-0027 - AAPG2018 - VALID

Subjects
[SDV.TOX.ECO] Life Sciences [q-bio]/Toxicology/Ecotoxicology, oxyanions uptake, Escherichia coli Proteins, Tol-Pal system, General Medicine, Microbiology, chromate resistance, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Phosphates, Escherichia coli, Chromates, phosphate import, [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Molecular Biology
Abstract

International audience; Chromate is a toxic metal that enters bacteria by using oxyanion importers. Here, we show that each mutant of the Tol-Pal system of Escherichia coli exhibited increased chromate resistance. This system, which spans the cell envelope, plays a major role in envelope integrity and septation. The ΔtolQR mutant accumulated three-fold less chromate than the wild-type. Addition of phosphate but not sulfate to rich medium drastically reduced chromate toxicity and import in the wild-type strain. Furthermore, the intracellular concentration of free inorganic phosphate was significantly reduced for the ΔtolR mutant in comparison to the wild-type strain. Moreover, extracellular labelled phosphate was significantly less incorporated into the ΔtolR mutant. Finally, two distinct TolQR mutant complexes, specifically affected in Tol-Pal energization without affecting the TolQRA complex structure, did not complement the ΔtolQR mutant for inorganic phosphate accumulation. We thus propose that, while the Pst system is well known to import inorganic phosphate, the Tol-Pal system participates to phosphate uptake in particular at medium to high extracellular phosphate concentrations. Since mutations disabling the Tol-Pal system lead to pleiotropic effects, chromate resistance and reduced inorganic phosphate import could occur from an indirect effect of mutations in components of the Tol-Pal system.

Published
2022
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5. Combining two optimized and affordable methods to assign chemoreceptors to a specific signal

Author

Vincent Méjean, Amine Ali Chaouche, Anne Boyeldieu, Cécile Jourlin-Castelli, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Thermal shift assay, Shewanella, Chemoreceptor, [SDV]Life Sciences [q-bio], Biophysics, Bacterial chemotaxis Signal detection Methyl-accepting chemotaxis protein Thermal shift assay Agarose-in-plug bridge assay MBP chimeric Proteins, Ligands, 01 natural sciences, Biochemistry, Signal, Maltose-Binding Proteins, 03 medical and health sciences, chemistry.chemical_compound, Bacterial Proteins, Transition Temperature, Shewanella oneidensis, Molecular Biology, 030304 developmental biology, 0303 health sciences, biology, Chemistry, Methyl-accepting chemotaxis protein, 010401 analytical chemistry, fungi, Chemotaxis, Cell Biology, Ligand (biochemistry), biology.organism_classification, 0104 chemical sciences, nervous system, Agarose, human activities, circulatory and respiratory physiology
Abstract

International audience; Chemotaxis allows bacteria to detect specific compounds and move accordingly. This pathway involves signal detection by chemoreceptors (MCPs). Attributing a chemoreceptor to a ligand is difficult because there is a lot of redundancy in the MCPs that recognize a single ligand. We propose a methodology to define which chemoreceptors bind a given ligand. First, an MCP is overproduced to increase sensitivity to the ligand(s) it recognizes, thus promoting accumulation of cells around an agarose plug containing a low attractant concentration. Second, the ligand-binding domain (LBD) of the chemoreceptor is fused to maltose-binding protein (MBP), which facilitates purification and provides a control for a thermal shift assay (TSA). An increase in the melting temperature of the LBD in the presence of the ligand indicates that the chemoreceptor directly binds it. We showed that overexpression of two Shewanella oneidensis chemoreceptors (SO_0987 and SO_1056) promoted swimming toward an agarose plug containing a low concentration of chromate. The LBD of each of the two chemoreceptors was fused to MBP. A TSA revealed that only the LBD from SO_1056 had its melting temperature increased by chromate. In conclusion, we describe an efficient approach to define chemoreceptor-ligand pairs before undertaking more-sophisticated biochemical and structural studies.

Published
2021
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6. The phosphorylated regulator of chemotaxis is crucial throughout biofilm biogenesis in Shewanella oneidensis

Author

Amine Ali Chaouche, Anne Boyeldieu, Cécile Jourlin-Castelli, Flora Ambre Honoré, Moly Ba, Vincent Méjean, Bioénergétique et Ingénierie des Protéines (BIP ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'ingénierie des systèmes macromoléculaires (LISM), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Information génomique et structurale (IGS), and Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU)

Subjects
Nicotine, Shewanella, [SDV]Life Sciences [q-bio], Mutant, Regulator, Methyl-Accepting Chemotaxis Proteins, Flagellum, Applied Microbiology and Biotechnology, Microbiology, lcsh:Microbial ecology, Article, Anabasine, 03 medical and health sciences, Bacterial Proteins, Shewanella oneidensis, Phosphorylation, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, biology, 030306 microbiology, Chemistry, Effector, Chemotaxis, Escherichia coli Proteins, Biofilm, Gene Expression Regulation, Bacterial, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, Cell biology, Flagella, Biofilms, Mutation, lcsh:QR100-130, bacteria, Phosphorus-Oxygen Lyases, Microbial genetics, Biogenesis, Biotechnology
Abstract

The core of the chemotaxis system of Shewanella oneidensis is made of the CheA3 kinase and the CheY3 regulator. When appropriated, CheA3 phosphorylates CheY3, which, in turn, binds to the rotor of the flagellum to modify the swimming direction. In this study, we showed that phosphorylated CheY3 (CheY3-P) also plays an essential role during biogenesis of the solid-surface-associated biofilm (SSA-biofilm). Indeed, in a ΔcheY3 strain, the formation of this biofilm is abolished. Using the phospho-mimetic CheY3D56E mutant, we showed that CheY-P is required throughout the biogenesis of the biofilm but CheY3 phosphorylation is independent of CheA3 during this process. We have recently found that CheY3 interacts with two diguanylate cyclases (DGCs) and with MxdA, the c-di-GMP effector, probably triggering exopolysaccharide synthesis by the Mxd machinery. Here, we discovered two additional DGCs involved in SSA-biofilm development and showed that one of them interacts with CheY3. We therefore propose that CheY3-P acts together with DGCs to control SSA-biofilm formation. Interestingly, two orthologous CheY regulators complement the biofilm defect of a ΔcheY3 strain, supporting the idea that biofilm formation could involve CheY regulators in other bacteria.

Published
2020
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7. A Network of Paralogous Stress Response Transcription Factors in the Human Pathogen Candida glabrata

Author

Mohammed El Amine Ali Chaouche, Jean-Michel Camadro, Corinne Blugeon, Antonin Thiébaut, Jawad Merhej, Stéphane Le Crom, Gaëlle Lelandais, Juliette Pouch, Frédéric Devaux, Biologie Computationnelle et Quantitative = Laboratory of Computational and Quantitative Biology (LCQB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), 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)-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), GenomiqueENS (Genomique ENS), Institut de biologie de l'ENS Paris (IBENS), Département de Biologie - ENS Paris, 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), 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)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Département de Biologie - 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)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut Jacques Monod (IJM (UMR_7592)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Analyse des Données à Haut Débit en Génomique (ADHDG), Evolution Paris Seine, Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 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)-Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 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), HAL UPMC, Gestionnaire, Institut de Biologie Paris Seine (IBPS), 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)-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)-Centre National de la Recherche Scientifique (CNRS), Plateforme Génomique de l'IBENS, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-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)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Département de Biologie - 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), 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)-Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-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)-Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC), Institut de biologie de l'ENS Paris (UMR 8197/1024) (IBENS), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Département de Biologie - ENS Paris

Subjects
0301 basic medicine, Microbiology (medical), Yap proteins, 030106 microbiology, lcsh:QR1-502, yeast, Microbiology, lcsh:Microbiology, Transcriptome, 03 medical and health sciences, regulatory networks, evolution, transciptome, Gene, Transcription factor, [SDV.MP.MYC]Life Sciences [q-bio]/Microbiology and Parasitology/Mycology, Original Research, 2. Zero hunger, YAP1, Genetics, Candida glabrata, biology, biology.organism_classification, [SDV.MP.MYC] Life Sciences [q-bio]/Microbiology and Parasitology/Mycology, DNA binding site, ChIP-seq, Regulon, Yap, Chromatin immunoprecipitation, transcriptome
Abstract

International audience; The yeast Candida glabrata has become the second cause of systemic candidemia in humans. However, relatively few genome-wide studies have been conducted in this organism and our knowledge of its transcriptional regulatory network is quite limited. In the present work, we combined genome-wide chromatin immunoprecipitation (ChIP-seq), transcriptome analyses, and DNA binding motif predictions to describe the regulatory interactions of the seven Yap (Yeast AP1) transcription factors of C. glabrata. We described a transcriptional network containing 255 regulatory interactions and 309 potential target genes. We predicted with high confidence the preferred DNA binding sites for 5 of the 7 CgYaps and showed a strong conservation of the Yap DNA binding properties between S. cerevisiae and C. glabrata. We provided reliable functional annotation for 3 of the 7 Yaps and identified for Yap1 and Yap5 a core regulon which is conserved in S. cerevisiae, C. glabrata, and C. albicans. We uncovered new roles for CgYap7 in the regulation of iron-sulfur cluster biogenesis, for CgYap1 in the regulation of heme biosynthesis and for CgYap5 in the repression of GRX4 in response to iron starvation. These transcription factors define an interconnected transcriptional network at the crossroads between redox homeostasis, oxygen consumption, and iron metabolism.

Published
2016
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8. A Network of Paralogous Stress Response Transcription Factors in the Human Pathogen Candida glabrata.

Author

Merhej, Jawad, Thiebaut, Antonin, Blugeon, Corinne, Pouch, Juliette, El Amine Ali Chaouche, Mohammed, Camadro, Jean-Michel, Le Crom, Stéphane, Lelandais, Gaëlle, Devaux, Frédéric, De Las Penas, Alejandro, Rodrigues-Pousadaj, Claudina, and Turcotte, Bernard

Subjects
CANDIDA, TRANSCRIPTION factors, YEAST fungi genetics
Abstract

The yeast Candida glabrata has become the second cause of systemic candidemia in humans. However, relatively few genome-wide studies have been conducted in this organism and our knowledge of its transcriptional regulatory network is quite limited. In the present work, we combined genome-wide chromatin immunoprecipitation (ChIP-seq), transcriptome analyses, and DNA binding motif predictions to describe the regulatory interactions of the seven Yap (Yeast AP1) transcription factors of C. glabrata. We described a transcriptional network containing 255 regulatory interactions and 309 potential target genes. We predicted with high confidence the preferred DNA binding sites for 5 of the 7 CgYaps and showed a strong conservation of the Yap DNA binding properties between S. cerevisiae and C. glabrata. We provided reliable functional annotation for 3 of the 7 Yaps and identified for Yap1 and Yap5 a core regulon which is conserved in S. cerevisiae, C. glabrata, and C. albicans. We uncovered new roles for CgYap7 in the regulation of iron-sulfur cluster biogenesis, for CgYap1 in the regulation of heme biosynthesis and for CgYap5 in the repression of GRX4 in response to iron starvation. These transcription factors define an interconnected transcriptional network at the cross-roads between redox homeostasis, oxygen consumption, and iron metabolism. [ABSTRACT FROM AUTHOR]

Published
2016
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