1
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Lablaine A, Chamot S, Serrano M, Billaudeau C, Bornard I, Carballido-López R, Carlin F, Henriques AO, Broussolle V. A new fluorescence-based approach for direct visualization of coat formation during sporulation in Bacillus cereus. Sci Rep 2023; 13:15136. [PMID: 37704668 PMCID: PMC10499802 DOI: 10.1038/s41598-023-42143-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 09/06/2023] [Indexed: 09/15/2023] Open
Abstract
The human pathogenic bacteria Bacillus cereus, Bacillus anthracis and the entomopathogenic Bacillus thuringiensis form spores encased in a protein coat surrounded by a balloon-like exosporium. These structures mediate spore interactions with its environment, including the host immune system, control the transit of molecules that trigger germination and thus are essential for the spore life cycle. Formation of the coat and exosporium has been traditionally visualized by transmission electronic microscopy on fixed cells. Recently, we showed that assembly of the exosporium can be directly observed in live B. cereus cells by super resolution-structured illumination microscopy (SR-SIM) using the membrane MitoTrackerGreen (MTG) dye. Here, we demonstrate that the different steps of coat formation can also be visualized by SR-SIM using MTG and SNAP-cell TMR-star dyes during B. cereus sporulation. We used these markers to characterize a subpopulation of engulfment-defective B. cereus cells that develops at a suboptimal sporulation temperature. Importantly, we predicted and confirmed that synthesis and accumulation of coat material, as well as synthesis of the σK-dependent protein BxpB, occur in cells arrested during engulfment. These results suggest that, unlike the well-studied model organism Bacillus subtilis, the activity of σK is not strictly linked to the state of forespore development in B. cereus.
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Affiliation(s)
- Armand Lablaine
- INRAE, Avignon Université, UMR SQPOV, 84000, Avignon, France
- MICALIS Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | | | - Mónica Serrano
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Cyrille Billaudeau
- MICALIS Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | | | - Rut Carballido-López
- MICALIS Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Frédéric Carlin
- INRAE, Avignon Université, UMR SQPOV, 84000, Avignon, France
| | - Adriano O Henriques
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
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2
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Barbotin AGL, Lablaine A, Billaudeau C, Sezgin E, Carballido-López R. Measuring the fluidity of the membrane of Bacillus subtilis using TIR-FCS. Biophys J 2023; 122:362a. [PMID: 36783837 DOI: 10.1016/j.bpj.2022.11.1999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Aurélien G L Barbotin
- Micalis Institute, National Research Institute for Agriculture, Food and Environment, Jouy-en-Josas, Paris, France
| | - Armand Lablaine
- Micalis Institute, National Research Institute for Agriculture, Food and Environment, Jouy-en-Josas, Paris, France
| | - Cyrille Billaudeau
- Micalis Institute, National Research Institute for Agriculture, Food and Environment, Jouy-en-Josas, Paris, France
| | | | - Rut Carballido-López
- Micalis Institute, National Research Institute for Agriculture, Food and Environment, Jouy-en-Josas, Paris, France
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3
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Labarde A, Jakutyte L, Billaudeau C, Fauler B, López-Sanz M, Ponien P, Jacquet E, Mielke T, Ayora S, Carballido-López R, Tavares P. Temporal compartmentalization of viral infection in bacterial cells. Proc Natl Acad Sci U S A 2021; 118:e2018297118. [PMID: 34244425 PMCID: PMC8285916 DOI: 10.1073/pnas.2018297118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Virus infection causes major rearrangements in the subcellular architecture of eukaryotes, but its impact in prokaryotic cells was much less characterized. Here, we show that infection of the bacterium Bacillus subtilis by bacteriophage SPP1 leads to a hijacking of host replication proteins to assemble hybrid viral-bacterial replisomes for SPP1 genome replication. Their biosynthetic activity doubles the cell total DNA content within 15 min. Replisomes operate at several independent locations within a single viral DNA focus positioned asymmetrically in the cell. This large nucleoprotein complex is a self-contained compartment whose boundaries are delimited neither by a membrane nor by a protein cage. Later during infection, SPP1 procapsids localize at the periphery of the viral DNA compartment for genome packaging. The resulting DNA-filled capsids do not remain associated to the DNA transactions compartment. They bind to phage tails to build infectious particles that are stored in warehouse compartments spatially independent from the viral DNA. Free SPP1 structural proteins are recruited to the dynamic phage-induced compartments following an order that recapitulates the viral particle assembly pathway. These findings show that bacteriophages restructure the crowded host cytoplasm to confine at different cellular locations the sequential processes that are essential for their multiplication.
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Affiliation(s)
- Audrey Labarde
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Lina Jakutyte
- Laboratoire de Virologie Moléculaire et Structurale, CNRS Unité Propre de Recherche 3296 and Institut Fédératif de Recherche 115, 91198 Gif-sur-Yvette, France
| | - Cyrille Billaudeau
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Beatrix Fauler
- Microscopy and Cryo-electron Microscopy Service Group, Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195, Berlin, Germany
| | - Maria López-Sanz
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain
| | - Prishila Ponien
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198, Gif-sur-Yvette, France
| | - Eric Jacquet
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198, Gif-sur-Yvette, France
| | - Thorsten Mielke
- Microscopy and Cryo-electron Microscopy Service Group, Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195, Berlin, Germany
| | - Silvia Ayora
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain
| | - Rut Carballido-López
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Paulo Tavares
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France;
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4
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Billaudeau C, Chastanet A, Carballido-López R. Processing TIRF Microscopy Images to Characterize the Dynamics and Morphology of Bacterial Actin-Like Assemblies. Methods Mol Biol 2020; 2101:135-145. [PMID: 31879902 DOI: 10.1007/978-1-0716-0219-5_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Total internal reflection fluorescence (TIRF) microscopy allows the visualization of the dynamic membrane-associated actin-like MreB filaments in live bacterial cells with high temporal resolution. This chapter describes computerized analysis methods to quantitatively characterize the dynamics and morphological properties of MreB assemblies. These include how to (1) segment bacterial cells, (2) perform single-particle tracking (SPT) of MreB filamentous structures, (3) classify their dynamic modes using mean squared displacement (MSD) analysis, and (4) measure their dimensions and orientation.
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Affiliation(s)
- Cyrille Billaudeau
- Micalis Intitute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Arnaud Chastanet
- Micalis Intitute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Rut Carballido-López
- Micalis Intitute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France.
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5
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Krokowski S, Atwal S, Lobato-Márquez D, Chastanet A, Carballido-López R, Salje J, Mostowy S. Shigella MreB promotes polar IcsA positioning for actin tail formation. J Cell Sci 2019; 132:jcs.226217. [PMID: 30992346 PMCID: PMC6526709 DOI: 10.1242/jcs.226217] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 04/01/2019] [Indexed: 01/17/2023] Open
Abstract
Pathogenic Shigella bacteria are a paradigm to address key issues of cell and infection biology. Polar localisation of the Shigella autotransporter protein IcsA is essential for actin tail formation, which is necessary for the bacterium to travel from cell-to-cell; yet how proteins are targeted to the bacterial cell pole is poorly understood. The bacterial actin homologue MreB has been extensively studied in broth culture using model organisms including Escherichia coli, Bacillus subtilis and Caulobacter crescentus, but has never been visualised in rod-shaped pathogenic bacteria during infection of host cells. Here, using single-cell analysis of intracellular Shigella, we discover that MreB accumulates at the cell pole of bacteria forming actin tails, where it colocalises with IcsA. Pharmacological inhibition of host cell actin polymerisation and genetic deletion of IcsA is used to show, respectively, that localisation of MreB to the cell poles precedes actin tail formation and polar localisation of IcsA. Finally, by exploiting the MreB inhibitors A22 and MP265, we demonstrate that MreB polymerisation can support actin tail formation. We conclude that Shigella MreB promotes polar IcsA positioning for actin tail formation, and suggest that understanding the bacterial cytoskeleton during host–pathogen interactions can inspire development of new therapeutic regimes for infection control. This article has an associated First Person interview with the first author of the paper. Summary: The pathogen Shigella forms actin tails to move through the cytosol of infected cells. We show that the bacterial actin homologue MreB can help to position the autotransporter protein IcsA for such actin tail formation.
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Affiliation(s)
- Sina Krokowski
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Road, London SW7 2AZ, UK.,Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Sharanjeet Atwal
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7JT, UK.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400 PHRI 07103, Thailand.,Public Health Research Institute, Rutgers Biomedical and Health Science, Newark, New Jersey NJ 07103, USA
| | - Damián Lobato-Márquez
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Road, London SW7 2AZ, UK.,Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Arnaud Chastanet
- MICALIS Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Rut Carballido-López
- MICALIS Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Jeanne Salje
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7JT, UK.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400 PHRI 07103, Thailand.,Public Health Research Institute, Rutgers Biomedical and Health Science, Newark, New Jersey NJ 07103, USA
| | - Serge Mostowy
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Road, London SW7 2AZ, UK .,Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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6
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Krokowski S, Lobato-Márquez D, Chastanet A, Pereira PM, Angelis D, Galea D, Larrouy-Maumus G, Henriques R, Spiliotis ET, Carballido-López R, Mostowy S. Septins Recognize and Entrap Dividing Bacterial Cells for Delivery to Lysosomes. Cell Host Microbe 2018; 24:866-874.e4. [PMID: 30543779 PMCID: PMC6299245 DOI: 10.1016/j.chom.2018.11.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 08/14/2018] [Accepted: 11/05/2018] [Indexed: 12/31/2022]
Abstract
The cytoskeleton occupies a central role in cellular immunity by promoting bacterial sensing and antibacterial functions. Septins are cytoskeletal proteins implicated in various cellular processes, including cell division. Septins also assemble into cage-like structures that entrap cytosolic Shigella, yet how septins recognize bacteria is poorly understood. Here, we discover that septins are recruited to regions of micron-scale membrane curvature upon invasion and division by a variety of bacterial species. Cardiolipin, a curvature-specific phospholipid, promotes septin recruitment to highly curved membranes of Shigella, and bacterial mutants lacking cardiolipin exhibit less septin cage entrapment. Chemically inhibiting cell separation to prolong membrane curvature or reducing Shigella cell growth respectively increases and decreases septin cage formation. Once formed, septin cages inhibit Shigella cell division upon recruitment of autophagic and lysosomal machinery. Thus, recognition of dividing bacterial cells by the septin cytoskeleton is a powerful mechanism to restrict the proliferation of intracellular bacterial pathogens.
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Affiliation(s)
- Sina Krokowski
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK; Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | - Damián Lobato-Márquez
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK; Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | - Arnaud Chastanet
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas 78350, France
| | - Pedro Matos Pereira
- Quantitative Imaging and NanoBiophysics Group, MRC Laboratory for Molecular Cell Biology and Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Dimitrios Angelis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Dieter Galea
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Gerald Larrouy-Maumus
- Faculty of Natural Sciences, Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Ricardo Henriques
- Quantitative Imaging and NanoBiophysics Group, MRC Laboratory for Molecular Cell Biology and Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Elias T Spiliotis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Rut Carballido-López
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas 78350, France
| | - Serge Mostowy
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK; Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK.
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7
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Mirouze N, Ferret C, Cornilleau C, Carballido-López R. Antibiotic sensitivity reveals that wall teichoic acids mediate DNA binding during competence in Bacillus subtilis. Nat Commun 2018; 9:5072. [PMID: 30498236 PMCID: PMC6265299 DOI: 10.1038/s41467-018-07553-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 10/22/2018] [Indexed: 12/02/2022] Open
Abstract
Despite decades of investigation of genetic transformation in the model Gram-positive bacterium Bacillus subtilis, the factors responsible for exogenous DNA binding at the surface of competent cells remain to be identified. Here, we report that wall teichoic acids (WTAs), cell wall-anchored anionic glycopolymers associated to numerous critical functions in Gram-positive bacteria, are involved in this initial step of transformation. Using a combination of cell wall-targeting antibiotics and fluorescence microscopy, we show that competence-specific WTAs are produced and specifically localized in the competent cells to mediate DNA binding at the proximity of the transformation apparatus. Furthermore, we propose that TuaH, a putative glycosyl transferase induced during competence, modifies competence-induced WTAs in order to promote (directly or indirectly) DNA binding. On the basis of our results and previous knowledge in the field, we propose a model for DNA binding and transport during genetic transformation in B. subtilis. Natural genetic transformation in bacteria requires DNA binding at the surface of competent cells. Here, Mirouze et al. show that wall teichoic acids are specifically produced or modified during competence in Bacillus subtilis and promote (directly or indirectly) DNA binding at the cell surface.
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Affiliation(s)
- Nicolas Mirouze
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France. .,Institute for Integrative Biology of the Cell (I2BC), INSERM, CEA, CNRS, Université Paris-Sud, Orsay, 91190, Gif sur Yvette, France.
| | - Cécile Ferret
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Charlène Cornilleau
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.,Inovarion, 75013, Paris, France
| | - Rut Carballido-López
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
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8
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De San Eustaquio-Campillo A, Cornilleau C, Guérin C, Carballido-López R, Chastanet A. PamR, a new MarR-like regulator affecting prophages and metabolic genes expression in Bacillus subtilis. PLoS One 2017; 12:e0189694. [PMID: 29240826 PMCID: PMC5730154 DOI: 10.1371/journal.pone.0189694] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 11/30/2017] [Indexed: 12/26/2022] Open
Abstract
B. subtilis adapts to changing environments by reprogramming its genetic expression through a variety of transcriptional regulators from the global transition state regulators that allow a complete resetting of the cell genetic expression, to stress specific regulators controlling only a limited number of key genes required for optimal adaptation. Among them, MarR-type transcriptional regulators are known to respond to a variety of stresses including antibiotics or oxidative stress, and to control catabolic or virulence gene expression. Here we report the characterization of the ydcFGH operon of B. subtilis, containing a putative MarR-type transcriptional regulator. Using a combination of molecular genetics and high-throughput approaches, we show that this regulator, renamed PamR, controls directly its own expression and influence the expression of large sets of prophage-related and metabolic genes. The extent of the regulon impacted by PamR suggests that this regulator reprograms the metabolic landscape of B. subtilis in response to a yet unknown signal.
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Affiliation(s)
| | - Charlène Cornilleau
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Cyprien Guérin
- MaIAGE, INRA, Université Paris-Saclay, Jouy-en-Josas, France
| | | | - Arnaud Chastanet
- MICALIS, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
- * E-mail:
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9
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Billaudeau C, Chastanet A, Yao Z, Cornilleau C, Mirouze N, Fromion V, Carballido-López R. Contrasting mechanisms of growth in two model rod-shaped bacteria. Nat Commun 2017; 8:15370. [PMID: 28589952 PMCID: PMC5467245 DOI: 10.1038/ncomms15370] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/23/2017] [Indexed: 12/24/2022] Open
Abstract
How cells control their shape and size is a long-standing question in cell biology. Many rod-shaped bacteria elongate their sidewalls by the action of cell wall synthesizing machineries that are associated to actin-like MreB cortical patches. However, little is known about how elongation is regulated to enable varied growth rates and sizes. Here we use total internal reflection fluorescence microscopy and single-particle tracking to visualize MreB isoforms, as a proxy for cell wall synthesis, in Bacillus subtilis and Escherichia coli cells growing in different media and during nutrient upshift. We find that these two model organisms appear to use orthogonal strategies to adapt to growth regime variations: B. subtilis regulates MreB patch speed, while E. coli may mainly regulate the production capacity of MreB-associated cell wall machineries. We present numerical models that link MreB-mediated sidewall synthesis and cell elongation, and argue that the distinct regulatory mechanism employed might reflect the different cell wall integrity constraints in Gram-positive and Gram-negative bacteria. Protein MreB participates in elongation of sidewalls during growth of most rod-shaped bacteria. Here, the authors use fluorescence microscopy and single-particle tracking to visualize MreB, showing that Bacillus subtilis and Escherichia coli appear to use different strategies to adapt to growth rate variations.
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Affiliation(s)
- Cyrille Billaudeau
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Arnaud Chastanet
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Zhizhong Yao
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Charlène Cornilleau
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Nicolas Mirouze
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Vincent Fromion
- MaIAGE, INRA, Université Paris-Saclay, Jouy-en-Josas F78350, France
| | - Rut Carballido-López
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
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10
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Tavares AC, Fernandes PB, Carballido-López R, Pinho MG. MreC and MreD Proteins Are Not Required for Growth of Staphylococcus aureus. PLoS One 2015; 10:e0140523. [PMID: 26470021 PMCID: PMC4607420 DOI: 10.1371/journal.pone.0140523] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/28/2015] [Indexed: 12/31/2022] Open
Abstract
The transmembrane proteins MreC and MreD are present in a wide variety of bacteria and are thought to be involved in cell shape determination. Together with the actin homologue MreB and other morphological elements, they play an essential role in the synthesis of the lateral cell wall in rod-shaped bacteria. In ovococcus, which lack MreB homologues, mreCD are also essential and have been implicated in peripheral cell wall synthesis. In this work we addressed the possible roles of MreC and MreD in the spherical pathogen Staphylococcus aureus. We show that MreC and MreD are not essential for cell viability and do not seem to affect cell morphology, cell volume or cell cycle control. MreC and MreD localize preferentially to the division septa, but do not appear to influence peptidoglycan composition, nor the susceptibility to different antibiotics and to oxidative and osmotic stress agents. Our results suggest that the function of MreCD in S. aureus is not critical for cell division and cell shape determination.
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Affiliation(s)
- Andreia C. Tavares
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Pedro B. Fernandes
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Rut Carballido-López
- INRA, UMR 1319 Micalis, F-78350, Jouy-en-Josas, France
- AgroParisTech, UMR Micalis, F-78350, Jouy-en-Josas, France
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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11
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Yao Z, Carballido-López R. Fluorescence Imaging for Bacterial Cell Biology: From Localization to Dynamics, From Ensembles to Single Molecules. Annu Rev Microbiol 2014; 68:459-76. [DOI: 10.1146/annurev-micro-091213-113034] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Zhizhong Yao
- INRA, UMR1319 Micalis, F-78350 Jouy-en-Josas, France;
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12
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Rueff AS, Chastanet A, Domínguez-Escobar J, Yao Z, Yates J, Prejean MV, Delumeau O, Noirot P, Wedlich-Söldner R, Filipe SR, Carballido-López R. An early cytoplasmic step of peptidoglycan synthesis is associated to MreB in Bacillus subtilis. Mol Microbiol 2013; 91:348-62. [PMID: 24261876 DOI: 10.1111/mmi.12467] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2013] [Indexed: 12/23/2022]
Abstract
MreB proteins play a major role during morphogenesis of rod-shaped bacteria by organizing biosynthesis of the peptidoglycan cell wall. However, the mechanisms underlying this process are not well understood. In Bacillus subtilis, membrane-associated MreB polymers have been shown to be associated to elongation-specific complexes containing transmembrane morphogenetic factors and extracellular cell wall assembly proteins. We have now found that an early intracellular step of cell wall synthesis is also associated to MreB. We show that the previously uncharacterized protein YkuR (renamed DapI) is required for synthesis of meso-diaminopimelate (m-DAP), an essential constituent of the peptidoglycan precursor, and that it physically interacts with MreB. Highly inclined laminated optical sheet microscopy revealed that YkuR forms uniformly distributed foci that exhibit fast motion in the cytoplasm, and are not detected in cells lacking MreB. We propose a model in which soluble MreB organizes intracellular steps of peptidoglycan synthesis in the cytoplasm to feed the membrane-associated cell wall synthesizing machineries.
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Affiliation(s)
- Anne-Stéphanie Rueff
- INRA, UMR1319 Micalis, F-78352, Jouy-en-Josas, France; AgroParisTech, UMR1319 Micalis, F-78352, Jouy-en-Josas, France
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13
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Monteferrante CG, MacKichan C, Marchadier E, Prejean MV, Carballido-López R, van Dijl JM. Mapping the twin-arginine protein translocation network of Bacillus subtilis. Proteomics 2013. [PMID: 23180473 DOI: 10.1002/pmic.201200416] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Bacteria employ twin-arginine translocation (Tat) pathways for the transport of folded proteins to extracytoplasmic destinations. In recent years, most studies on bacterial Tat pathways addressed the membrane-bound TatA(B)C subunits of the Tat translocase, and the specific interactions between this translocase and its substrate proteins. In contrast, relatively few studies investigated possible coactors in the TatA(B)C-dependent protein translocation process. The present studies were aimed at identifying interaction partners of the Tat pathway of Bacillus subtilis, which is a paradigm for studies on protein secretion by Gram-positive bacteria. Specifically, 36 interaction partners of the TatA and TatC subunits were identified by rigorous application of the yeast two-hybrid (Y2H) approach. Our Y2H analyses revealed that the three TatA isoforms of B. subtilis can form homo- and heterodimers. Subsequently, the secretion of the Tat substrates YwbN and PhoD was tested in mutant strains lacking genes for the TatAC interaction partners identified in our genome-wide Y2H screens. Our results show that the cell wall-bound protease WprA is important for YwbN secretion, and that the HemAT and CsbC proteins are required for PhoD secretion under phosphate starvation conditions. Taken together, our findings imply that the Bacillus Tat pathway is embedded in an intricate protein-protein interaction network.
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Affiliation(s)
- Carmine G Monteferrante
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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14
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Marchadier E, Carballido-López R, Brinster S, Fabret C, Mervelet P, Bessières P, Noirot-Gros MF, Fromion V, Noirot P. An expanded protein-protein interaction network in Bacillus subtilis reveals a group of hubs: Exploration by an integrative approach. Proteomics 2011; 11:2981-91. [PMID: 21630458 DOI: 10.1002/pmic.201000791] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 02/28/2011] [Accepted: 03/22/2011] [Indexed: 11/07/2022]
Abstract
We have generated a protein-protein interaction network in Bacillus subtilis focused on several essential cellular processes such as cell division, cell responses to various stresses, the bacterial cytoskeleton, DNA replication and chromosome maintenance by careful application of the yeast two-hybrid approach. This network, composed of 793 interactions linking 287 proteins with an average connectivity of five interactions per protein, represents a valuable resource for future functional analyses. A striking feature of the network is a group of highly connected hubs (GoH) linking many different cellular processes. Most of the proteins of the GoH have unknown functions and are associated to the membrane. By the integration of available knowledge, in particular of transcriptome data sets, the GoH was decomposed into subgroups of party hubs corresponding to protein complexes or regulatory pathways expressed under different conditions. At a global level, the GoH might function as a very robust group of date hubs having partially redundant functions to integrate information from the different cellular pathways. Our analyses also provide a rational way to study the highly redundant functions of the GoH by a genetic approach.
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15
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Pérez-Núñez D, Briandet R, David B, Gautier C, Renault P, Hallet B, Hols P, Carballido-López R, Guédon E. A new morphogenesis pathway in bacteria: unbalanced activity of cell wall synthesis machineries leads to coccus-to-rod transition and filamentation in ovococci. Mol Microbiol 2010; 79:759-71. [PMID: 21255117 DOI: 10.1111/j.1365-2958.2010.07483.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacteria display a variety of shapes, which have biological relevance. In most eubacteria, cell shape is maintained by the tough peptidoglycan (PG) layer of the cell wall, the sacculus. The organization of PG synthesis machineries, orchestrated by different cytoskeletal elements, determines the specific shapes of sacculi. In rod-shaped bacteria, the actin-like (MreB) and the tubuline-like (FtsZ) cytoskeletons control synthesis of the sidewall (elongation) and the crosswall (septation) respectively. Much less is known concerning cell morphogenesis in cocci, which lack MreB proteins. While spherical cocci exclusively display septal growth, ovococci additionally display peripheral growth, which is responsible of the slight longitudinal expansion that generates their ovoid shape. Here, we report that the ovococcus Lactococcus lactis has the ability to become rod-shaped. L. lactis IL1403 wild-type cells form long aseptate filaments during both biofilm and planktonic growth in a synthetic medium. Nascent PG insertion and the division protein FtsK localize in multiple peripheral rings regularly spaced along the filaments. We show that filamentation results from septation inhibition, and that penicillin-binding proteins PBP2x and PBP2b play a direct role in this process. We propose a model for filament formation in L. lactis, and discuss the possible biological role of such morphological differentiation.
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Affiliation(s)
- Daniel Pérez-Núñez
- INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352 Jouy-en-Josas, France
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16
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Rhayat L, Duperrier S, Carballido-López R, Pellegrini O, Stragier P. Genetic dissection of an inhibitor of the sporulation sigma factor sigma(G). J Mol Biol 2009; 390:835-44. [PMID: 19497328 DOI: 10.1016/j.jmb.2009.05.073] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 05/22/2009] [Accepted: 05/27/2009] [Indexed: 11/18/2022]
Abstract
Sporulation in Bacillus subtilis is controlled by a cascade of four sigma factors that are held into inactive form until the proper stage of development. The Gin protein, encoded by csfB, is able to strongly inhibit the activity of one of these factors, sigma(G), in vivo. The csfB gene is present in a large number of endospore formers, but the various Gin orthologues show little conservation, in striking contrast to their sigma(G) counterparts. We have carried out a mutagenesis analysis of the Gin protein in order to understand its inhibitory properties. By measuring sigma(G) inhibition in the presence of Gin in vivo, assessing Gin ability to bind sigma(G) in a yeast two-hybrid assay, and quantifying Gin-sigma(G) interaction in B. subtilis, we have identified specific residues that play an essential role in binding sigma(G) or in preventing sigma(G) transcriptional activity. Two cysteine pairs, conserved in all Gin orthologues, are essential for Gin activity. Mutations in the first pair are partially complemented by mutations in the second pair, suggesting that Gin exists in oligomeric form, at least as a dimer. Dimerisation is consistent with our in vitro analysis of a purified Gin recombinant protein, which shows that Gin contains 0.5 zinc atom per monomer. Altogether, these results indicate that the conserved cysteines play a structural role, whereas another less conserved region of the protein is involved in interacting with sigma(G). Interestingly, some mutants have kept most of their ability to bind sigma(G) but are completely unable to inhibit sigma(G) transcriptional activity, raising the possibility that Gin might act by a mechanism more complex than just sequestration of sigma(G).
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Affiliation(s)
- Lamya Rhayat
- CNRS-UPR, Institut de Biologie Physico-Chimique, Université Paris-Diderot, France.
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17
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Karmazyn-Campelli C, Rhayat L, Carballido-López R, Duperrier S, Frandsen N, Stragier P. How the early sporulation sigma factor sigmaF delays the switch to late development in Bacillus subtilis. Mol Microbiol 2008; 67:1169-80. [PMID: 18208527 DOI: 10.1111/j.1365-2958.2008.06121.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sporulation in Bacillus subtilis is a primitive differentiation process involving two cell types, the forespore and the mother cell. Each cell implements two successive transcription programmes controlled by specific sigma factors. We report that activity of sigma(G), the late forespore sigma factor, is kept in check by Gin, the product of csfB, a gene controlled by sigma(F), the early forespore sigma factor. Gin abolishes sigma(G) transcriptional activity when sigma(G) is artificially synthesized during growth, but has no effect on sigma(F). Gin interacts strongly with sigma(G) but not with sigma(F) in a yeast two-hybrid experiment. The absence of Gin allows sigma(G) to be active during sporulation independently of the mother-cell development to which it is normally coupled. Premature sigma(G) activity leads to the formation of slow-germinating spores, and complete deregulation of sigma(G) synthesis is lethal when combined with gin inactivation. Gin allows sigma(F) to delay the switch to the late forespore transcription programme by preventing sigma(G) to take over before the cell has reached a critical stage of development. A similar strategy, following a completely unrelated route, is used by the mother cell.
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Affiliation(s)
- Céline Karmazyn-Campelli
- Université Paris-Diderot, CNRS-UPR9073, Institut de Biologie Physico-Chimique, 75005 Paris, France
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18
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Abstract
The discovery of cytoskeletal elements in prokaryotes has dramatically changed the way we think about bacterial cell morphogenesis. The rod shape of Bacillus subtilis is maintained by the two major polymers (peptidoglycan and teichoic acids) of its thick cell wall and determined by the way these are inserted during growth. The current view is that the dynamic tubulin-like (FtsZ) and actin-like (MreB) cytoskeletons orchestrate, both in time and space, the assembly of macromolecular machineries that effect cell wall synthesis and hydrolysis during cell division and cell elongation, respectively.
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Affiliation(s)
- Rut Carballido-López
- Génétique Microbienne, Institut National de la Recherche Agronomique, 78352 Jouy-en-Josas Cedex, France.
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19
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Abstract
Recent advances have shown conclusively that bacterial cells possess distant but true homologues of actin (MreB, ParM, and the recently uncovered MamK protein). Despite weak amino acid sequence similarity, MreB and ParM exhibit high structural homology to actin. Just like F-actin in eukaryotes, MreB and ParM assemble into highly dynamic filamentous structures in vivo and in vitro. MreB-like proteins are essential for cell viability and have been implicated in major cellular processes, including cell morphogenesis, chromosome segregation, and cell polarity. ParM (a plasmid-encoded actin homologue) is responsible for driving plasmid-DNA partitioning. The dynamic prokaryotic actin-like cytoskeleton is thought to serve as a central organizer for the targeting and accurate positioning of proteins and nucleoprotein complexes, thereby (and by analogy to the eukaryotic cytoskeleton) spatially and temporally controlling macromolecular trafficking in bacterial cells. In this paper, the general properties and known functions of the actin orthologues in bacteria are reviewed.
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Affiliation(s)
- Rut Carballido-López
- Génétique Microbienne, Institut National de la Recherche Agronomique, 78352 Jouy-en-Josas Cedex, France.
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Carballido-López R, Formstone A, Li Y, Ehrlich SD, Noirot P, Errington J. Actin Homolog MreBH Governs Cell Morphogenesis by Localization of the Cell Wall Hydrolase LytE. Dev Cell 2006; 11:399-409. [PMID: 16950129 DOI: 10.1016/j.devcel.2006.07.017] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Revised: 06/27/2006] [Accepted: 07/22/2006] [Indexed: 11/23/2022]
Abstract
MreB proteins are bacterial actin homologs involved in cell morphogenesis and various other cellular processes. However, the effector proteins used by MreBs remain largely unknown. Bacillus subtilis has three MreB isoforms. Mbl and possibly MreB have previously been shown to be implicated in cell wall synthesis. We have now found that the third isoform, MreBH, colocalizes with the two other MreB isoforms in B. subtilis and also has an important role in cell morphogenesis. MreBH can physically interact with a cell wall hydrolase, LytE, and is required for its helical pattern of extracellular localization. Moreover, lytE and mreBH mutants exhibit similar cell-wall-related defects. We propose that controlled elongation of rod-shaped B. subtilis depends on the coordination of cell wall synthesis and hydrolysis in helical tracts defined by MreB proteins. Our data also suggest that physical interactions with intracellular actin bundles can influence the later localization pattern of extracellular effectors.
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Affiliation(s)
- Rut Carballido-López
- Génétique Microbienne, Institut National de la Recherche Agronomique, 78352 Jouy-en-Josas Cedex, France.
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21
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Abstract
MreB proteins are bacterial homologues of actin that directly determine cell shape and are involved in a range of other cellular processes in non-spherical bacteria. Like F-actin in eukaryotes, MreBs self-assemble into dynamic filamentous structures that are essential for cell viability. Recent studies have demonstrated that the MreB cytoskeletal scaffold governs shape determination by controlling functions related to the bacterial cell wall (probably by recruiting and directing peptidoglycan-synthesizing and modifying proteins). Here I consider general implications for bacterial morphogenesis, and the basis for differences in wall expansion and cylindrical cell shape, based on recent studies aimed to determine the role of MreBs in bacteria with different modes of growth.
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Affiliation(s)
- Rut Carballido-López
- Génétique Microbienne, Institut National de la Recherche Agronomique, 78352 Jouy-en-Josas cedex, France.
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22
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Abstract
Actin and tubulin are the major components of the cytoskeleton that pervades the cytoplasm of all eukaryotic cells. These proteins were traditionally thought not to be present in prokaryotes, but structural and functional homologues of tubulin (FtsZ) and actin (MreB) are now known to be present virtually throughout the eubacteria and in some archae. FtsZ protein is a key player in cell division of bacteria and some eukaryotic organelles. MreB proteins are involved in the regulation of cell shape and the segregation of some bacterial plasmids, and might have a range of other functions. Recent data demonstrate that the bacterial proteins are, like their eukaryotic counterparts, highly dynamic. Here, we review the general properties and functions of actin and tubulin homologues in bacteria, their dynamic behaviour and the implications for understanding cell division and morphogenesis in bacteria.
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Affiliation(s)
- Rut Carballido-López
- Sir William Dunn School of Pathology. University of Oxford, South Parks Road, Oxford OX1 3RE, UK
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23
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Abstract
Mbl is a bacterial actin homolog that controls cell morphogenesis in Bacillus subtilis. A functional GFP-Mbl fusion protein was used to examine the behavior of the helical cables formed by Mbl protein in live B. subtilis cells. The cables undergo dynamic changes during cell cycle progression. They are stable but not rigid while elongating in parallel with cell growth, and they require septum formation to divide/cleave. Fluorescence recovery after photobleaching (FRAP) analysis showed that the cables are continuously remodeled during cell elongation. Turnover occurs along the length of the helical Mbl filaments, with no obvious polarity and a recovery half-time of about 8 min. These findings have important implications for the nature of bacterial cell wall architecture and synthesis.
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Affiliation(s)
- Rut Carballido-López
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, OX1 3RE, Oxford, United Kingdom
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24
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Abstract
In the absence of an overt cytoskeleton, the external cell wall of bacteria has traditionally been assumed to be the primary determinant of cell shape. In the Gram-positive bacterium Bacillus subtilis, two related genes, mreB and mbl, were shown to be required for different aspects of cell morphogenesis. Subcellular localization of the MreB and Mbl proteins revealed that each forms a distinct kind of filamentous helical structure lying close to the cell surface. The distribution of the proteins in different species of bacteria, and the similarity of their sequence to eukaryotic actins, suggest that the MreB-like proteins have a cytoskeletal, actin-like role in bacterial cell morphogenesis.
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Affiliation(s)
- L J Jones
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom
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