1
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Ukleja M, Kricks L, Torrens G, Peschiera I, Rodrigues-Lopes I, Krupka M, García-Fernández J, Melero R, Del Campo R, Eulalio A, Mateus A, López-Bravo M, Rico AI, Cava F, Lopez D. Flotillin-mediated stabilization of unfolded proteins in bacterial membrane microdomains. Nat Commun 2024; 15:5583. [PMID: 38961085 PMCID: PMC11222466 DOI: 10.1038/s41467-024-49951-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 06/26/2024] [Indexed: 07/05/2024] Open
Abstract
The function of many bacterial processes depends on the formation of functional membrane microdomains (FMMs), which resemble the lipid rafts of eukaryotic cells. However, the mechanism and the biological function of these membrane microdomains remain unclear. Here, we show that FMMs in the pathogen methicillin-resistant Staphylococcus aureus (MRSA) are dedicated to confining and stabilizing proteins unfolded due to cellular stress. The FMM scaffold protein flotillin forms a clamp-shaped oligomer that holds unfolded proteins, stabilizing them and favoring their correct folding. This process does not impose a direct energy cost on the cell and is crucial to survival of ATP-depleted bacteria, and thus to pathogenesis. Consequently, FMM disassembling causes the accumulation of unfolded proteins, which compromise MRSA viability during infection and cause penicillin re-sensitization due to PBP2a unfolding. Thus, our results indicate that FMMs mediate ATP-independent stabilization of unfolded proteins, which is essential for bacterial viability during infection.
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Affiliation(s)
- Marta Ukleja
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Lara Kricks
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Gabriel Torrens
- Department of Molecular Biology, Umeå University, Umeå, SE-901 87, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS). Umeå Center for Microbial Research (UCMR). Science for Life Laboratory (SciLifeLab), Umeå, SE-901 87, Sweden
| | - Ilaria Peschiera
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Ines Rodrigues-Lopes
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504, Coimbra, Portugal
| | - Marcin Krupka
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Julia García-Fernández
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Roberto Melero
- Department of Structural Biology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Rosa Del Campo
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Ramón y Cajal Hospital, 28034, Madrid, Spain
| | - Ana Eulalio
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504, Coimbra, Portugal
- Department of Life Sciences, Center for Bacterial Resistance Biology, Imperial College London, London, SW7 2AZ, United Kingdom
| | - André Mateus
- The Laboratory for Molecular Infection Medicine Sweden (MIMS). Umeå Center for Microbial Research (UCMR). Science for Life Laboratory (SciLifeLab), Umeå, SE-901 87, Sweden
- Department of Chemistry, Umeå University, Umeå, SE-901 87, Sweden
| | - María López-Bravo
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Ana I Rico
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Felipe Cava
- Department of Molecular Biology, Umeå University, Umeå, SE-901 87, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS). Umeå Center for Microbial Research (UCMR). Science for Life Laboratory (SciLifeLab), Umeå, SE-901 87, Sweden
| | - Daniel Lopez
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain.
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2
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Bramkamp M, Scheffers DJ. Bacterial membrane dynamics: Compartmentalization and repair. Mol Microbiol 2023; 120:490-501. [PMID: 37243899 DOI: 10.1111/mmi.15077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/08/2023] [Accepted: 05/10/2023] [Indexed: 05/29/2023]
Abstract
In every bacterial cell, the plasma membrane plays a key role in viability as it forms a selective barrier between the inside of the cell and its environment. This barrier function depends on the physical state of the lipid bilayer and the proteins embedded or associated with the bilayer. Over the past decade or so, it has become apparent that many membrane-organizing proteins and principles, which were described in eukaryote systems, are ubiquitous and play important roles in bacterial cells. In this minireview, we focus on the enigmatic roles of bacterial flotillins in membrane compartmentalization and bacterial dynamins and ESCRT-like systems in membrane repair and remodeling.
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Affiliation(s)
- Marc Bramkamp
- Institute for General Microbiology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Dirk-Jan Scheffers
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
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3
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Dupuy P, Gutierrez C, Neyrolles O. Modulation of bacterial membrane proteins activity by clustering into plasma membrane nanodomains. Mol Microbiol 2023; 120:502-507. [PMID: 37303242 DOI: 10.1111/mmi.15105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 05/25/2023] [Accepted: 05/29/2023] [Indexed: 06/13/2023]
Abstract
Recent research has demonstrated specific protein clustering within membrane subdomains in bacteria, challenging the long-held belief that prokaryotes lack these subdomains. This mini review provides examples of bacterial membrane protein clustering, discussing the benefits of protein assembly in membranes and highlighting how clustering regulates protein activity.
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Affiliation(s)
- Pierre Dupuy
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Claude Gutierrez
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Olivier Neyrolles
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
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4
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Wessel AK, Yoshii Y, Reder A, Boudjemaa R, Szczesna M, Betton JM, Bernal-Bayard J, Beloin C, Lopez D, Völker U, Ghigo JM. Escherichia coli SPFH Membrane Microdomain Proteins HflKC Contribute to Aminoglycoside and Oxidative Stress Tolerance. Microbiol Spectr 2023; 11:e0176723. [PMID: 37347165 PMCID: PMC10434171 DOI: 10.1128/spectrum.01767-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 06/01/2023] [Indexed: 06/23/2023] Open
Abstract
Many eukaryotic membrane-dependent functions are often spatially and temporally regulated by membrane microdomains (FMMs), also known as lipid rafts. These domains are enriched in polyisoprenoid lipids and scaffolding proteins belonging to the stomatin, prohibitin, flotillin, and HflK/C (SPFH) protein superfamily that was also identified in Gram-positive bacteria. In contrast, little is still known about FMMs in Gram-negative bacteria. In Escherichia coli K-12, 4 SPFH proteins, YqiK, QmcA, HflK, and HflC, were shown to localize in discrete polar or lateral inner membrane locations, raising the possibility that E. coli SPFH proteins could contribute to the assembly of inner membrane FMMs and the regulation of cellular processes. Here, we studied the determinant of the localization of QmcA and HflC and showed that FMM-associated cardiolipin lipid biosynthesis is required for their native localization pattern. Using Biolog phenotypic arrays, we showed that a mutant lacking all SPFH genes displayed increased sensitivity to aminoglycosides and oxidative stress that is due to the absence of HflKC. Our study therefore provides further insights into the contribution of SPFH proteins to stress tolerance in E. coli. IMPORTANCE Eukaryotic cells often segregate physiological processes in cholesterol-rich functional membrane microdomains. These domains are also called lipid rafts and contain proteins of the stomatin, prohibitin, flotillin, and HflK/C (SPFH) superfamily, which are also present in prokaryotes but have been mostly studied in Gram-positive bacteria. Here, we showed that the cell localization of the SPFH proteins QmcA and HflKC in the Gram-negative bacterium E. coli is altered in the absence of cardiolipin lipid synthesis. This suggests that cardiolipins contribute to E. coli membrane microdomain assembly. Using a broad phenotypic analysis, we also showed that HflKC contribute to E. coli tolerance to aminoglycosides and oxidative stress. Our study, therefore, provides new insights into the cellular processes associated with SPFH proteins in E. coli.
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Affiliation(s)
- Aimee K. Wessel
- Institut Pasteur, Université de Paris-Cité, CNRS UMR6047, Genetics of Biofilms Laboratory, Paris, France
| | - Yutaka Yoshii
- Institut Pasteur, Université de Paris-Cité, CNRS UMR6047, Genetics of Biofilms Laboratory, Paris, France
| | - Alexander Reder
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | | | - Magdalena Szczesna
- Institut Pasteur, Université de Paris-Cité, CNRS UMR6047, Genetics of Biofilms Laboratory, Paris, France
- Centre for Bacteriology Resistance Biology, Imperial College London, London, United Kingdom
| | - Jean-Michel Betton
- Institut Pasteur, Université de Paris-Cité, UMR UMR6047, Stress adaptation and metabolism in enterobacteria, Paris, France
| | - Joaquin Bernal-Bayard
- Institut Pasteur, Université de Paris-Cité, CNRS UMR6047, Genetics of Biofilms Laboratory, Paris, France
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Christophe Beloin
- Institut Pasteur, Université de Paris-Cité, CNRS UMR6047, Genetics of Biofilms Laboratory, Paris, France
| | - Daniel Lopez
- Universidad Autonoma de Madrid, Centro Nacional de Biotecnologia, Madrid, Spain
| | - Uwe Völker
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Jean-Marc Ghigo
- Institut Pasteur, Université de Paris-Cité, CNRS UMR6047, Genetics of Biofilms Laboratory, Paris, France
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5
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Mitchison-Field LM, Belin BJ. Bacterial lipid biophysics and membrane organization. Curr Opin Microbiol 2023; 74:102315. [PMID: 37058914 PMCID: PMC10523990 DOI: 10.1016/j.mib.2023.102315] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 04/16/2023]
Abstract
The formation of lateral microdomains is emerging as a central organizing principle in bacterial membranes. These microdomains are targets of antibiotic development and have the potential to enhance natural product synthesis, but the rules governing their assembly are unclear. Previous studies have suggested that microdomain formation is promoted by lipid phase separation, particularly by cardiolipin (CL) and isoprenoid lipids, and there is strong evidence that CL biosynthesis is required for recruitment of membrane proteins to cell poles and division sites. New work demonstrates that additional bacterial lipids may mediate membrane protein localization and function, opening the field for mechanistic evaluation of lipid-driven membrane organization in vivo.
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Affiliation(s)
- Lorna My Mitchison-Field
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD, USA; Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Brittany J Belin
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD, USA; Department of Biology, Johns Hopkins University, Baltimore, MD, USA.
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6
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Gupta S, Mandal T. Simulation study of domain formation in a model bacterial membrane. Phys Chem Chem Phys 2022; 24:18133-18143. [PMID: 35856570 DOI: 10.1039/d2cp01873j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent experimental studies revealed that functional membrane microdomains (FMMs) are formed in prokaryotic cells which are structurally and functionally similar to the lipid rafts formed in eukaryotic cells. In this study, we employ coarse-grained molecular dynamics simulations to investigate the mechanism of domain formation and its physiochemical properties in a model methicillin-resistant staphylococcus aureus (MRSA) cell membrane. We find that domains are formed through lateral segregation of staphyloxanthin (STX), a carotenoid which shields the bacteria from the host's immune because of its antioxidant nature. Simulation results suggest that membrane integrity increases with the size of the domain, which is assessed by computing bond order parameter of the lipid tails, membrane expansion modulus and water permeability across the membrane. Various membrane domain proteins such as flotillin-like protein floA and penicillin binding protein (PBP2a) preferentially bind with the STX and accumulate in the membrane domain which is consistent with the recent experimental results.
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Affiliation(s)
- Shivam Gupta
- Department of Physics, Indian Institute of Technology Kanpur, Kanpur-208016, India.
| | - Taraknath Mandal
- Department of Physics, Indian Institute of Technology Kanpur, Kanpur-208016, India.
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7
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Herschend J, Ernst M, Koren K, Melnik AV, da Silva RR, Røder HL, Damholt ZBV, Hägglund P, Svensson B, Sørensen SJ, Kühl M, Dorrestein PC, Burmølle M. Metabolic Profiling of Interspecies Interactions During Sessile Bacterial Cultivation Reveals Growth and Sporulation Induction in Paenibacillus amylolyticus in Response to Xanthomonas retroflexus. Front Cell Infect Microbiol 2022; 12:805473. [PMID: 35425721 PMCID: PMC9001975 DOI: 10.3389/fcimb.2022.805473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
The toolbox available for microbiologists to study interspecies interactions is rapidly growing, and with continuously more advanced instruments, we are able to expand our knowledge on establishment and function of microbial communities. However, unravelling molecular interspecies interactions in complex biological systems remains a challenge, and interactions are therefore often studied in simplified communities. Here we perform an in-depth characterization of an observed interspecies interaction between two co-isolated bacteria, Xanthomonas retroflexus and Paenibacillus amylolyticus. Using microsensor measurements for mapping the chemical environment, we show how X. retroflexus promoted an alkalization of its local environment through degradation of amino acids and release of ammonia. When the two species were grown in proximity, the modified local environment induced a morphological change and growth of P. amylolyticus followed by sporulation. 2D spatial metabolomics enabled visualization and mapping of the degradation of oligopeptide structures by X. retroflexus and morphological changes of P. amylolyticus through e.g. the release of membrane-associated metabolites. Proteome analysis and microscopy were used to validate the shift from vegetative growth towards sporulation. In summary, we demonstrate how environmental profiling by combined application of microsensor, microscopy, metabolomics and proteomics approaches can reveal growth and sporulation promoting effects resulting from interspecies interactions.
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Affiliation(s)
- Jakob Herschend
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Madeleine Ernst
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States
- Section for Clinical Mass Spectrometry, Danish Center for Neonatal Screening, Department of Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Klaus Koren
- Aarhus University Centre for Water Technology (WATEC), Department of Biology, Aarhus University, Aarhus, Denmark
| | - Alexey V. Melnik
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Ricardo R. da Silva
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Henriette L. Røder
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Zacharias B. V. Damholt
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Per Hägglund
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Birte Svensson
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Søren J. Sørensen
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Pieter C. Dorrestein
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Mette Burmølle
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- *Correspondence: Mette Burmølle,
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8
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Czolkoss S, Safronov X, Rexroth S, Knoke LR, Aktas M, Narberhaus F. Agrobacterium tumefaciens Type IV and Type VI Secretion Systems Reside in Detergent-Resistant Membranes. Front Microbiol 2021; 12:754486. [PMID: 34899640 PMCID: PMC8656257 DOI: 10.3389/fmicb.2021.754486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/25/2021] [Indexed: 11/17/2022] Open
Abstract
Cell membranes are not homogenous but compartmentalized into lateral microdomains, which are considered as biochemical reaction centers for various physiological processes in eukaryotes and prokaryotes. Due to their special lipid and protein composition, some of these microdomains are resistant to treatment with non-ionic detergents and can be purified as detergent-resistant membranes (DRMs). Here we report the proteome of DRMs from the Gram-negative phytopathogen Agrobacterium tumefaciens. Using label-free liquid chromatography-tandem mass spectrometry, we identified proteins enriched in DRMs isolated under normal and virulence-mimicking growth conditions. Prominent microdomain marker proteins such as the SPFH (stomatin/prohibitin/flotillin/HflKC) proteins HflK, HflC and Atu3772, along with the protease FtsH were highly enriched in DRMs isolated under any given condition. Moreover, proteins involved in cell envelope biogenesis, transport and secretion, as well as motility- and chemotaxis-associated proteins were overrepresented in DRMs. Most strikingly, we found virulence-associated proteins such as the VirA/VirG two-component system, and the membrane-spanning type IV and type VI secretion systems enriched in DRMs. Fluorescence microscopy of the cellular localization of both secretion systems and of marker proteins was in agreement with the results from the proteomics approach. These findings suggest that virulence traits are micro-compartmentalized into functional microdomains in A. tumefaciens.
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Affiliation(s)
- Simon Czolkoss
- Department of Microbial Biology, Ruhr University Bochum, Bochum, Germany
| | - Xenia Safronov
- Department of Microbial Biology, Ruhr University Bochum, Bochum, Germany
| | - Sascha Rexroth
- Department of Plant Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Lisa R Knoke
- Department of Microbial Biology, Ruhr University Bochum, Bochum, Germany
| | - Meriyem Aktas
- Department of Microbial Biology, Ruhr University Bochum, Bochum, Germany
| | - Franz Narberhaus
- Department of Microbial Biology, Ruhr University Bochum, Bochum, Germany
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9
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van Tilburg AY, Warmer P, van Heel AJ, Sauer U, Kuipers OP. Membrane composition and organization of Bacillus subtilis 168 and its genome-reduced derivative miniBacillus PG10. Microb Biotechnol 2021; 15:1633-1651. [PMID: 34856064 PMCID: PMC9049611 DOI: 10.1111/1751-7915.13978] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/13/2021] [Accepted: 11/14/2021] [Indexed: 11/30/2022] Open
Abstract
A form of lateral membrane compartmentalization in bacteria is represented by functional membrane microdomains (FMMs). FMMs are important for various cellular processes and offer application possibilities in microbial biotechnology. We designed a lipidomics method to directly measure relative abundances of lipids in detergent‐resistant and detergent‐sensitive membrane fractions of the model bacterium Bacillus subtilis 168 and the biotechnologically attractive miniBacillus PG10 strain. Our study supports previous work suggesting that cardiolipin and prenol lipids are enriched in FMMs of B. subtilis. Additionally, structural analysis of acyl chains of major phospholipids indicated that FMMs display increased order and thickness compared with the surrounding bilayer. Despite the 36% genome reduction, membrane and FMM integrity are largely preserved in miniBacillus PG10, as supported by analysis of membrane fluidity, flotillin distribution and gene expression data. The novel insights in FMM architecture reported here will contribute to further explore the biological significance of FMMs and the means by which FMMs can be exploited as heterologous production platforms. Moreover, our lipidomics method enables comparative FMM lipid profiling between different bacteria.
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Affiliation(s)
- Amanda Y van Tilburg
- Department of Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - Philipp Warmer
- Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland.,Life Science Zürich PhD Program on Systems Biology, Zürich, Switzerland
| | - Auke J van Heel
- Department of Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - Uwe Sauer
- Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
| | - Oscar P Kuipers
- Department of Molecular Genetics, University of Groningen, Groningen, The Netherlands
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10
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Scholz AS, Baur SSM, Wolf D, Bramkamp M. An Stomatin, Prohibitin, Flotillin, and HflK/C-Domain Protein Required to Link the Phage-Shock Protein to the Membrane in Bacillus subtilis. Front Microbiol 2021; 12:754924. [PMID: 34777311 PMCID: PMC8581546 DOI: 10.3389/fmicb.2021.754924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 09/27/2021] [Indexed: 11/28/2022] Open
Abstract
Membrane surveillance and repair is of utmost importance to maintain cellular integrity and allow cellular life. Several systems detect cell envelope stress caused by antimicrobial compounds and abiotic stresses such as solvents, pH-changes and temperature in bacteria. Proteins containing an Stomatin, Prohibitin, Flotillin, and HflK/C (SPFH)-domain, including bacterial flotillins have been shown to be involved in membrane protection and membrane fluidity regulation. Here, we characterize a bacterial SPFH-domain protein, YdjI that is part of a stress induced complex in Bacillus subtilis. We show that YdjI is required to localize the ESCRT-III homolog PspA to the membrane with the help of two membrane integral proteins, YdjG/H. In contrast to classical flotillins, YdjI resides in fluid membrane regions and does not enrich in detergent resistant membrane fractions. However, similarly to FloA and FloT from B. subtilis, deletion of YdjI decreases membrane fluidity. Our data reveal a hardwired connection between phage shock response and SPFH proteins.
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Affiliation(s)
- Abigail Savietto Scholz
- Institute for General Microbiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Sarah S. M. Baur
- Institute for General Microbiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Diana Wolf
- Institute of Microbiology, Technische Universität Dresden, Dresden, Germany
| | - Marc Bramkamp
- Institute for General Microbiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
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11
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Landajuela A, Braun M, Rodrigues CDA, Martínez-Calvo A, Doan T, Horenkamp F, Andronicos A, Shteyn V, Williams ND, Lin C, Wingreen NS, Rudner DZ, Karatekin E. FisB relies on homo-oligomerization and lipid binding to catalyze membrane fission in bacteria. PLoS Biol 2021; 19:e3001314. [PMID: 34185788 PMCID: PMC8274934 DOI: 10.1371/journal.pbio.3001314] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/12/2021] [Accepted: 06/07/2021] [Indexed: 11/18/2022] Open
Abstract
Little is known about mechanisms of membrane fission in bacteria despite their requirement for cytokinesis. The only known dedicated membrane fission machinery in bacteria, fission protein B (FisB), is expressed during sporulation in Bacillus subtilis and is required to release the developing spore into the mother cell cytoplasm. Here, we characterized the requirements for FisB-mediated membrane fission. FisB forms mobile clusters of approximately 12 molecules that give way to an immobile cluster at the engulfment pole containing approximately 40 proteins at the time of membrane fission. Analysis of FisB mutants revealed that binding to acidic lipids and homo-oligomerization are both critical for targeting FisB to the engulfment pole and membrane fission. Experiments using artificial membranes and filamentous cells suggest that FisB does not have an intrinsic ability to sense or induce membrane curvature but can bridge membranes. Finally, modeling suggests that homo-oligomerization and trans-interactions with membranes are sufficient to explain FisB accumulation at the membrane neck that connects the engulfment membrane to the rest of the mother cell membrane during late stages of engulfment. Together, our results show that FisB is a robust and unusual membrane fission protein that relies on homo-oligomerization, lipid binding, and the unique membrane topology generated during engulfment for localization and membrane scission, but surprisingly, not on lipid microdomains, negative-curvature lipids, or curvature sensing.
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Affiliation(s)
- Ane Landajuela
- Cellular and Molecular Physiology, Yale University, New Haven, Connecticut, United States of America
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States of America
| | - Martha Braun
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States of America
- Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
| | | | | | - Thierry Doan
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, Aix-Marseille Université, Marseilles, France
| | - Florian Horenkamp
- Cell Biology, Yale University, New Haven, Connecticut, United States of America
| | - Anna Andronicos
- Cellular and Molecular Physiology, Yale University, New Haven, Connecticut, United States of America
| | - Vladimir Shteyn
- Cellular and Molecular Physiology, Yale University, New Haven, Connecticut, United States of America
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States of America
| | - Nathan D Williams
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States of America
- Cell Biology, Yale University, New Haven, Connecticut, United States of America
| | - Chenxiang Lin
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States of America
- Cell Biology, Yale University, New Haven, Connecticut, United States of America
| | - Ned S Wingreen
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Erdem Karatekin
- Cellular and Molecular Physiology, Yale University, New Haven, Connecticut, United States of America
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States of America
- Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Université de Paris, SPPIN-Saints-Pères Paris Institute for the Neurosciences, Centre National de la Recherche Scientifique (CNRS), Paris, France
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12
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Abstract
Extracellular vesicles (EVs) are membrane-derived lipid bilayers secreted by bacteria and eukaryotic cells. Bacterial membrane vesicles were discovered over 60 years ago and have been extensively studied in Gram-negative bacteria. During their production, EVs are loaded with proteins, nucleic acids, and various compounds that are subsequently released into the environment. Depending on the packaged cargo, EVs have a broad spectrum of action and are involved in pathogenesis, antibiotic resistance, nutrient uptake, and nucleic acid transfer. Due to differences in cell wall structure, EVs in Gram-positive bacteria have been disregarded for decades, and our understanding of their biogenesis and host cell interaction is incomplete. Recently, studies on bacteria such as Staphylococcus aureus, Streptococcus spp., Bacillus subtilis, and Mycobacterium spp. have demonstrated EV production in Gram-positive bacteria and shown the great importance EVs have in Gram-positive bacterial physiology and disease progression. Here, we review the latest findings on the biogenesis and functions of EVs from Gram-positive bacteria and identify key areas for future research.
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13
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Tsai YT, Moore W, Kim H, Budin I. Bringing rafts to life: Lessons learned from lipid organization across diverse biological membranes. Chem Phys Lipids 2020; 233:104984. [PMID: 33203526 DOI: 10.1016/j.chemphyslip.2020.104984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/13/2020] [Accepted: 09/28/2020] [Indexed: 10/23/2022]
Abstract
The ability of lipids to drive lateral organization is a remarkable feature of membranes and has been hypothesized to underlie the architecture of cells. Models for lipid rafts and related domains were originally based on the mammalian plasma membrane, but the nature of heterogeneity in this system is still not fully resolved. However, the concept of lipid-driven organization has been highly influential across biology, and has led to discoveries in organisms that feature a diversity of lipid chemistries and physiological needs. Here we review several emerging and instructive cases of membrane organization in non-mammalian systems. In bacteria, several types of membrane domains that act in metabolism and signaling have been elucidated. These widen our view of what constitutes a raft, but also introduce new questions about the relationship between organization and function. In yeast, observable membrane organization is found in both the plasma membrane and the vacuole. The latter serves as the best example of classic membrane phase partitioning in a living system to date, suggesting that internal organelles are important membranes to investigate across eukaryotes. Finally, we highlight plants as powerful model systems for complex membrane interactions in multicellular organisms. Plant membranes are organized by unique glycosphingolipids, supporting the importance of carbohydrate interactions in organizing lateral domains. These examples demonstrate that membrane organization is a potentially universal phenonenon in biology and argue for the continued broadening of lipid physical chemistry research into a wide range of systems.
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Affiliation(s)
- Yi-Ting Tsai
- Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States
| | - William Moore
- Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States
| | - Hyesoo Kim
- Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States
| | - Itay Budin
- Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States.
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14
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Zielińska A, Savietto A, de Sousa Borges A, Martinez D, Berbon M, Roelofsen JR, Hartman AM, de Boer R, Van der Klei IJ, Hirsch AKH, Habenstein B, Bramkamp M, Scheffers DJ. Flotillin-mediated membrane fluidity controls peptidoglycan synthesis and MreB movement. eLife 2020; 9:e57179. [PMID: 32662773 PMCID: PMC7360373 DOI: 10.7554/elife.57179] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 06/12/2020] [Indexed: 01/07/2023] Open
Abstract
The bacterial plasma membrane is an important cellular compartment. In recent years it has become obvious that protein complexes and lipids are not uniformly distributed within membranes. Current hypotheses suggest that flotillin proteins are required for the formation of complexes of membrane proteins including cell-wall synthetic proteins. We show here that bacterial flotillins are important factors for membrane fluidity homeostasis. Loss of flotillins leads to a decrease in membrane fluidity that in turn leads to alterations in MreB dynamics and, as a consequence, in peptidoglycan synthesis. These alterations are reverted when membrane fluidity is restored by a chemical fluidizer. In vitro, the addition of a flotillin increases membrane fluidity of liposomes. Our data support a model in which flotillins are required for direct control of membrane fluidity rather than for the formation of protein complexes via direct protein-protein interactions.
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Affiliation(s)
- Aleksandra Zielińska
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningenNetherlands
| | - Abigail Savietto
- Biozentrum, Ludwig-Maximilians-Universität MünchenMünchenGermany
- Institute for General Microbiology, Christian-Albrechts-UniversityKielGermany
| | - Anabela de Sousa Borges
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningenNetherlands
| | - Denis Martinez
- Institute of Chemistry & Biology of Membranes & Nanoobjects (UMR5248 CBMN), IECB, CNRS, Université Bordeaux, Institut Polytechnique BordeauxPessacFrance
| | - Melanie Berbon
- Institute of Chemistry & Biology of Membranes & Nanoobjects (UMR5248 CBMN), IECB, CNRS, Université Bordeaux, Institut Polytechnique BordeauxPessacFrance
| | - Joël R Roelofsen
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningenNetherlands
| | - Alwin M Hartman
- Department of Drug Design and Optimization (DDOP), Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI)SaarbrückenGermany
- Department of Pharmacy, Saarland UniversitySaarbrückenGermany
- Stratingh Institute for Chemistry, University of GroningenGroningenNetherlands
| | - Rinse de Boer
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningenNetherlands
| | - Ida J Van der Klei
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningenNetherlands
| | - Anna KH Hirsch
- Department of Drug Design and Optimization (DDOP), Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI)SaarbrückenGermany
- Department of Pharmacy, Saarland UniversitySaarbrückenGermany
- Stratingh Institute for Chemistry, University of GroningenGroningenNetherlands
| | - Birgit Habenstein
- Institute of Chemistry & Biology of Membranes & Nanoobjects (UMR5248 CBMN), IECB, CNRS, Université Bordeaux, Institut Polytechnique BordeauxPessacFrance
| | - Marc Bramkamp
- Biozentrum, Ludwig-Maximilians-Universität MünchenMünchenGermany
- Institute for General Microbiology, Christian-Albrechts-UniversityKielGermany
| | - Dirk-Jan Scheffers
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningenNetherlands
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15
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Nickels JD, Poudel S, Chatterjee S, Farmer A, Cordner D, Campagna SR, Giannone RJ, Hettich RL, Myles DAA, Standaert RF, Katsaras J, Elkins JG. Impact of Fatty-Acid Labeling of Bacillus subtilis Membranes on the Cellular Lipidome and Proteome. Front Microbiol 2020; 11:914. [PMID: 32499768 PMCID: PMC7243436 DOI: 10.3389/fmicb.2020.00914] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/17/2020] [Indexed: 12/22/2022] Open
Abstract
Developing cultivation methods that yield chemically and isotopically defined fatty acid (FA) compositions within bacterial cytoplasmic membranes establishes an in vivo experimental platform to study membrane biophysics and cell membrane regulation using novel approaches. Yet before fully realizing the potential of this method, it is prudent to understand the systemic changes in cells induced by the labeling procedure itself. In this work, analysis of cellular membrane compositions was paired with proteomics to assess how the proteome changes in response to the directed incorporation of exogenous FAs into the membrane of Bacillus subtilis. Key findings from this analysis include an alteration in lipid headgroup distribution, with an increase in phosphatidylglycerol lipids and decrease in phosphatidylethanolamine lipids, possibly providing a fluidizing effect on the cell membrane in response to the induced change in membrane composition. Changes in the abundance of enzymes involved in FA biosynthesis and degradation are observed; along with changes in abundance of cell wall enzymes and isoprenoid lipid production. The observed changes may influence membrane organization, and indeed the well-known lipid raft-associated protein flotillin was found to be substantially down-regulated in the labeled cells – as was the actin-like protein MreB. Taken as a whole, this study provides a greater depth of understanding for this important cell membrane experimental platform and presents a number of new connections to be explored in regard to modulating cell membrane FA composition and its effects on lipid headgroup and raft/cytoskeletal associated proteins.
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Affiliation(s)
- Jonathan D Nickels
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH, United States
| | - Suresh Poudel
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Sneha Chatterjee
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Abigail Farmer
- Department of Chemistry, The University of Tennessee, Knoxville, Knoxville, TN, United States.,Biological and Small Molecule Mass Spectrometry Core, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Destini Cordner
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH, United States
| | - Shawn R Campagna
- Department of Chemistry, The University of Tennessee, Knoxville, Knoxville, TN, United States.,Biological and Small Molecule Mass Spectrometry Core, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Richard J Giannone
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Robert L Hettich
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Dean A A Myles
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Robert F Standaert
- Department of Chemistry, East Tennessee State University, Johnson City, TN, United States
| | - John Katsaras
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Shull Wollan Center - a Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Department of Physics and Astronomy, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - James G Elkins
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
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16
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Yokoyama H, Matsui I. The lipid raft markers stomatin, prohibitin, flotillin, and HflK/C (SPFH)-domain proteins form an operon with NfeD proteins and function with apolar polyisoprenoid lipids. Crit Rev Microbiol 2020; 46:38-48. [PMID: 31983249 DOI: 10.1080/1040841x.2020.1716682] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
SPFH-domain proteins are found in almost all organisms across three domains: archaea, bacteria, and eukaryotes. In eukaryotic organelles, their subfamilies exhibit overlapping distribution and functions; thus, the rationality of annotation to discriminate these subfamilies remains unclear. In this review, the binding ability of prokaryotic SPFH-domain proteins towards nonpolar polyisoprenoides such as squalene and lycopene, rather than cholesterol, is discussed. The hydrophobic region at the C-terminus of SPFH-domain proteins constitutes the main region that binds apolar polyisoprenoid lipids as well as cholesterol and substantively contributes towards lipid raft formation as these regions are self-assembled together with specific lipids. Because the scaffolding proteins caveolins show common topological properties with SPFH-domain proteins such as stomatin and flotillin, the α-helical segments of stomatin proteins can flexibly move along with the membrane surface, with such movement potentially leading to membrane bending via lipid raft clustering through the formation of high order homo-oligomeric complexes of SPFH-domain proteins. We also discuss the functional significance and ancient origin of SPFH-domain proteins and the NfeD protein (STOPP) operon, which can be traced back to the ancient living cells that diverged and evolved to archaea and bacteria. Based on the molecular mechanism whereby the STOPP-protease degrades the C-terminal hydrophobic clusters of SPFH-domain proteins, it is conceivable that STOPP-protease might control the physicochemical properties of lipid rafts.
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Affiliation(s)
- Hideshi Yokoyama
- Department of Medical and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Ikuo Matsui
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
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17
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Fonseca F, Pénicaud C, Tymczyszyn EE, Gómez-Zavaglia A, Passot S. Factors influencing the membrane fluidity and the impact on production of lactic acid bacteria starters. Appl Microbiol Biotechnol 2019; 103:6867-6883. [DOI: 10.1007/s00253-019-10002-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 06/25/2019] [Accepted: 06/27/2019] [Indexed: 01/09/2023]
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18
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Mostofian B, Zhuang T, Cheng X, Nickels JD. Branched-Chain Fatty Acid Content Modulates Structure, Fluidity, and Phase in Model Microbial Cell Membranes. J Phys Chem B 2019; 123:5814-5821. [DOI: 10.1021/acs.jpcb.9b04326] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Barmak Mostofian
- Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Tony Zhuang
- College of Medicine, University of Tennessee, Memphis, Tennessee 38163, United States
| | - Xiaolin Cheng
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jonathan D. Nickels
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio 45221, United States
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19
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Padilla-Vaca F, Vargas-Maya NI, Elizarrarás-Vargas NU, Rangel-Serrano Á, Cardoso-Reyes LR, Razo-Soria T, Membrillo-Hernández J, Franco B. Flotillin homologue is involved in the swimming behavior of Escherichia coli. Arch Microbiol 2019; 201:999-1008. [PMID: 31062059 DOI: 10.1007/s00203-019-01670-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 04/22/2019] [Accepted: 04/24/2019] [Indexed: 01/22/2023]
Abstract
Cellular membrane is a key component for maintaining cell shape and integrity. The classical membrane structure and function by Singer and Nicolson groundbreaking model has depicted the membrane as a homogeneous fluid structure. This view has changed by the discovery of discrete domains containing different lipid compositions, called lipid rafts, which play a key role in signal transduction in eukaryotic cells. In the past few years, lipid raft-like structures have been found in bacteria also, constituted by cardiolipin and other modified lipids, perhaps involved in generating a specific site for protein clustering. Here, we report the analysis of a protein termed YqiK from Escherichia coli, a prohibitin homolog that has been implicated in stress sensing by the formation of membrane-associated microdomains. The E. coli yqiK-deficient mutant strain showed an enhanced swimming behavior and was resistant to ampicillin but its response to other stressing conditions was similar to that of the wild-type strain. The abnormal swimming behavior is reversed when the protein is expressed in trans from a plasmid. Also, we demonstrate that YqiK is not redundant with QmcA, another flotillin homolog found in E. coli. Our results, along with the data available in the literature, suggest that YqiK may be involved in the formation of discrete membrane-associated signaling complexes that regulate and agglomerate signaling proteins to generate cell response to chemotaxis.
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Affiliation(s)
- Felipe Padilla-Vaca
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Noria Alta s/n, Guanajuato, Gto, 36050, Mexico
| | - Naurú Idalia Vargas-Maya
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Noria Alta s/n, Guanajuato, Gto, 36050, Mexico
| | - Narciso Ulises Elizarrarás-Vargas
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Noria Alta s/n, Guanajuato, Gto, 36050, Mexico
| | - Ángeles Rangel-Serrano
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Noria Alta s/n, Guanajuato, Gto, 36050, Mexico
| | - Luis Rafael Cardoso-Reyes
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Noria Alta s/n, Guanajuato, Gto, 36050, Mexico
| | - Tannia Razo-Soria
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Noria Alta s/n, Guanajuato, Gto, 36050, Mexico
| | - Jorge Membrillo-Hernández
- Departamento de Bioingeniería, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Monterrey, Mexico
| | - Bernardo Franco
- División de Ciencias Naturales y Exactas, Departamento de Biología, Universidad de Guanajuato, Noria Alta s/n, Guanajuato, Gto, 36050, Mexico.
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20
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Martins GB, Giacomelli G, Goldbeck O, Seibold GM, Bramkamp M. Substrate-dependent cluster density dynamics of Corynebacterium glutamicum phosphotransferase system permeases. Mol Microbiol 2019; 111:1335-1354. [PMID: 30748039 PMCID: PMC6850760 DOI: 10.1111/mmi.14224] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2019] [Indexed: 11/29/2022]
Abstract
Many bacteria take up carbohydrates by membrane‐integral sugar specific phosphoenolpyruvate‐dependent carbohydrate:phosphotransferase systems (PTS). Although the PTS is centrally involved in regulation of carbon metabolism in different bacteria, little is known about localization and putative oligomerization of the permease subunits (EII). Here, we analyzed localization of the fructose specific PtsF and the glucose specific PtsG transporters, as well as the general components EI and HPr from Corynebacterium glutamicum using widefield and single molecule localization microscopy. PtsF and PtsG form membrane embedded clusters that localize in a punctate pattern. Size, number and fluorescence of the membrane clusters change upon presence or absence of the transported substrate, and a direct influence of EI and HPr was not observed. In presence of the transport substrate, EII clusters significantly increased in size. Photo‐activated localization microscopy data revealed that, in presence of different carbon sources, the number of EII proteins per cluster remains the same, however, the density of these clusters reduces. Our work reveals a simple mechanism for efficient membrane occupancy regulation. Clusters of PTS EII transporters are densely packed in absence of a suitable substrate. In presence of a transported substrate, the EII proteins in individual clusters occupy larger membrane areas.
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Affiliation(s)
- Gustavo Benevides Martins
- Faculty of Biology, Ludwig-Maximilians-Universität München, Großhaderner Straße 2-4, Planegg-Martinsried, 82152, Germany
| | - Giacomo Giacomelli
- Faculty of Biology, Ludwig-Maximilians-Universität München, Großhaderner Straße 2-4, Planegg-Martinsried, 82152, Germany
| | - Oliver Goldbeck
- Institute of Microbiology and Biotechnology, Ulm University, Albert-Einstein Allee 11, Ulm, 89081, Germany
| | - Gerd M Seibold
- Institute of Microbiology and Biotechnology, Ulm University, Albert-Einstein Allee 11, Ulm, 89081, Germany
| | - Marc Bramkamp
- Faculty of Biology, Ludwig-Maximilians-Universität München, Großhaderner Straße 2-4, Planegg-Martinsried, 82152, Germany
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21
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Santos AL, Preta G. Lipids in the cell: organisation regulates function. Cell Mol Life Sci 2018; 75:1909-1927. [PMID: 29427074 PMCID: PMC11105414 DOI: 10.1007/s00018-018-2765-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 01/04/2018] [Accepted: 01/29/2018] [Indexed: 12/19/2022]
Abstract
Lipids are fundamental building blocks of all cells and play important roles in the pathogenesis of different diseases, including inflammation, autoimmune disease, cancer, and neurodegeneration. The lipid composition of different organelles can vary substantially from cell to cell, but increasing evidence demonstrates that lipids become organised specifically in each compartment, and this organisation is essential for regulating cell function. For example, lipid microdomains in the plasma membrane, known as lipid rafts, are platforms for concentrating protein receptors and can influence intra-cellular signalling. Lipid organisation is tightly regulated and can be observed across different model organisms, including bacteria, yeast, Drosophila, and Caenorhabditis elegans, suggesting that lipid organisation is evolutionarily conserved. In this review, we summarise the importance and function of specific lipid domains in main cellular organelles and discuss recent advances that investigate how these specific and highly regulated structures contribute to diverse biological processes.
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Affiliation(s)
- Ana L Santos
- Institut National de la Santé et de la Recherche Médicale, U1001 and Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Giulio Preta
- Institute of Biochemistry, Vilnius University, Sauletekio 7, LT-10257, Vilnius, Lithuania.
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22
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Mielich-Süss B, Wagner RM, Mietrach N, Hertlein T, Marincola G, Ohlsen K, Geibel S, Lopez D. Flotillin scaffold activity contributes to type VII secretion system assembly in Staphylococcus aureus. PLoS Pathog 2017; 13:e1006728. [PMID: 29166667 PMCID: PMC5718613 DOI: 10.1371/journal.ppat.1006728] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 12/06/2017] [Accepted: 11/02/2017] [Indexed: 12/13/2022] Open
Abstract
Scaffold proteins are ubiquitous chaperones that promote efficient interactions between partners of multi-enzymatic protein complexes; although they are well studied in eukaryotes, their role in prokaryotic systems is poorly understood. Bacterial membranes have functional membrane microdomains (FMM), a structure homologous to eukaryotic lipid rafts. Similar to their eukaryotic counterparts, bacterial FMM harbor a scaffold protein termed flotillin that is thought to promote interactions between proteins spatially confined to the FMM. Here we used biochemical approaches to define the scaffold activity of the flotillin homolog FloA of the human pathogen Staphylococcus aureus, using assembly of interacting protein partners of the type VII secretion system (T7SS) as a case study. Staphylococcus aureus cells that lacked FloA showed reduced T7SS function, and thus reduced secretion of T7SS-related effectors, probably due to the supporting scaffold activity of flotillin. We found that the presence of flotillin mediates intermolecular interactions of T7SS proteins. We tested several small molecules that interfere with flotillin scaffold activity, which perturbed T7SS activity in vitro and in vivo. Our results suggest that flotillin assists in the assembly of S. aureus membrane components that participate in infection and influences the infective potential of this pathogen. The recently discovered functional membrane microdomains (FMM) of prokaryotic cells contain a protein homologous to the scaffold protein flotillin found in eukaryotic lipid rafts. It remains to be elucidated whether, like their eukaryotic counterparts, flotillin homolog proteins have a scaffold function in bacteria. Here we show that the Staphylococcus aureus flotillin FloA acts as a scaffold protein, to promote more efficient assembly of membrane-associated protein interacting partners of multi-enzyme complexes. In a case study, we provide biochemical evidence that FloA participates in assembly of the Type VII secretion system and thus contributes to S. aureus infective potential. Targeted dispersion of FMM-related processes using anti-FMM molecules opens up new perspectives for microbial therapies to treat persistent S. aureus infections.
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Affiliation(s)
- Benjamin Mielich-Süss
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
- Institute for Molecular Infection Biology IMIB, University of Würzburg, Würzburg, Germany
| | - Rabea M. Wagner
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
- Institute for Molecular Infection Biology IMIB, University of Würzburg, Würzburg, Germany
- National Center for Biotechnology, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Madrid, Spain
| | - Nicole Mietrach
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
- Institute for Molecular Infection Biology IMIB, University of Würzburg, Würzburg, Germany
- Rudolf Virchow Center - DFG Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Tobias Hertlein
- Institute for Molecular Infection Biology IMIB, University of Würzburg, Würzburg, Germany
| | - Gabriella Marincola
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
- Institute for Molecular Infection Biology IMIB, University of Würzburg, Würzburg, Germany
| | - Knut Ohlsen
- Institute for Molecular Infection Biology IMIB, University of Würzburg, Würzburg, Germany
| | - Sebastian Geibel
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
- Institute for Molecular Infection Biology IMIB, University of Würzburg, Würzburg, Germany
- Rudolf Virchow Center - DFG Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Daniel Lopez
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
- Institute for Molecular Infection Biology IMIB, University of Würzburg, Würzburg, Germany
- National Center for Biotechnology, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Madrid, Spain
- * E-mail:
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23
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García-Fernández E, Koch G, Wagner RM, Fekete A, Stengel ST, Schneider J, Mielich-Süss B, Geibel S, Markert SM, Stigloher C, Lopez D. Membrane Microdomain Disassembly Inhibits MRSA Antibiotic Resistance. Cell 2017; 171:1354-1367.e20. [PMID: 29103614 PMCID: PMC5720476 DOI: 10.1016/j.cell.2017.10.012] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/18/2017] [Accepted: 10/06/2017] [Indexed: 12/21/2022]
Abstract
A number of bacterial cell processes are confined functional membrane microdomains (FMMs), structurally and functionally similar to lipid rafts of eukaryotic cells. How bacteria organize these intricate platforms and what their biological significance is remain important questions. Using the pathogen methicillin-resistant Staphylococcus aureus (MRSA), we show here that membrane-carotenoid interaction with the scaffold protein flotillin leads to FMM formation, which can be visualized using super-resolution array tomography. These membrane platforms accumulate multimeric protein complexes, for which flotillin facilitates efficient oligomerization. One of these proteins is PBP2a, responsible for penicillin resistance in MRSA. Flotillin mutants are defective in PBP2a oligomerization. Perturbation of FMM assembly using available drugs interferes with PBP2a oligomerization and disables MRSA penicillin resistance in vitro and in vivo, resulting in MRSA infections that are susceptible to penicillin treatment. Our study demonstrates that bacteria possess sophisticated cell organization programs and defines alternative therapies to fight multidrug-resistant pathogens using conventional antibiotics. Staphyloxanthin and flotillin preferentially interact and accumulate in FMMs FMMs facilitate efficient oligomerization of multimeric protein complexes PBP2a, which confers β-lactam resistance on S. aureus, is harbored within FMMs FMM disruption disables PBP2a oligomerization and thus, S. aureus antibiotic resistance
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Affiliation(s)
- Esther García-Fernández
- National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), 28049 Madrid, Spain
| | - Gudrun Koch
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080 Würzburg, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Rabea M Wagner
- National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), 28049 Madrid, Spain; Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080 Würzburg, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Agnes Fekete
- Julius-von-Sachs-Institute Biocenter, Pharmaceutical Biology, University of Würzburg, 97082 Würzburg, Germany
| | - Stephanie T Stengel
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080 Würzburg, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Johannes Schneider
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080 Würzburg, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Benjamin Mielich-Süss
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080 Würzburg, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Sebastian Geibel
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080 Würzburg, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany
| | - Sebastian M Markert
- Division of Electron Microscopy, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Christian Stigloher
- Division of Electron Microscopy, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Daniel Lopez
- National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), 28049 Madrid, Spain; Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080 Würzburg, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080 Würzburg, Germany; National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Darwin 3, Campus de Cantoblanco, 28049 Madrid, Spain.
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24
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Abstract
Glyceroglycolipids are very important in Gram-positive bacteria and cyanobacteria. In Bacillus subtilis, a model organism for the Gram-positive bacteria, the ugtP mutant, which lacks glyceroglucolipids, shows abnormal morphology. Lack of glucolipids has many consequences: abnormal localization of the cytoskeletal protein MreB and activation of some extracytoplasmic function (ECF) sigma factors (σM, σV and σX) in the log phase are two examples. Conversely, the expression of monoglucosyldiacylglycerol (MGlcDG) by 1,2-diacylglycerol 3-glucosyltransferase from Acholeplasma laidlawii (alMGS) almost completely suppresses the ugtP disruptant phenotype. Activation of ECF sigmas in the ugtP mutant is decreased by alMGS expression, and is suppressed to low levels by MgSO4 addition. When alMGS and alDGS (A. laidlawii 1,2-diacylglycerol-3-glucose (1-2)-glucosyltransferase producing diglucosyldiacylglycerol (DGlcDG)) are simultaneously expressed, σX activation is repressed to wild type level. These observations suggest that MGlcDG molecules are required for maintenance of B. subtilis cell shape and regulation of ECF sigmas, and that DGlcDG regulates σX activity. The activation of ECF sigmas is not accompanied by proteolysis of anti-σ. Thus, glyceroglucolipids may have the specific role of helping membrane proteins function by acting in the manner of chaperones.
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Affiliation(s)
- Satoshi Matsuoka
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
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25
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Bagam P, Singh DP, Inda ME, Batra S. Unraveling the role of membrane microdomains during microbial infections. Cell Biol Toxicol 2017; 33:429-455. [PMID: 28275881 PMCID: PMC7088210 DOI: 10.1007/s10565-017-9386-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 02/06/2017] [Indexed: 01/06/2023]
Abstract
Infectious diseases pose major socioeconomic and health-related threats to millions of people across the globe. Strategies to combat infectious diseases derive from our understanding of the complex interactions between the host and specific bacterial, viral, and fungal pathogens. Lipid rafts are membrane microdomains that play important role in life cycle of microbes. Interaction of microbial pathogens with host membrane rafts influences not only their initial colonization but also their spread and the induction of inflammation. Therefore, intervention strategies aimed at modulating the assembly of membrane rafts and/or regulating raft-directed signaling pathways are attractive approaches for the. management of infectious diseases. The current review discusses the latest advances in terms of techniques used to study the role of membrane microdomains in various pathological conditions and provides updated information regarding the role of membrane rafts during bacterial, viral and fungal infections.
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Affiliation(s)
- Prathyusha Bagam
- Laboratory of Pulmonary Immuno-Toxicology, Department of Environmental Toxicology, Health Research Center, Southern University and A&M College, Baton Rouge, LA, 70813, USA
| | - Dhirendra P Singh
- Laboratory of Pulmonary Immuno-Toxicology, Department of Environmental Toxicology, Health Research Center, Southern University and A&M College, Baton Rouge, LA, 70813, USA
| | - Maria Eugenia Inda
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Suipacha, Rosario, Argentina
| | - Sanjay Batra
- Laboratory of Pulmonary Immuno-Toxicology, Department of Environmental Toxicology, Health Research Center, Southern University and A&M College, Baton Rouge, LA, 70813, USA.
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26
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Abstract
The bacterial cytoplasmic membrane is composed of roughly equal proportions of lipids and proteins. The main lipid components are phospholipids, which vary in acyl chain length, saturation, and branching and carry head groups that vary in size and charge. Phospholipid variants determine membrane properties such as fluidity and charge that in turn modulate interactions with membrane-associated proteins. We summarize recent advances in understanding bacterial membrane structure and function, focusing particularly on the possible existence and significance of specialized membrane domains. We review the role of membrane curvature as a spatial cue for recruitment and regulation of proteins involved in morphogenic functions, especially elongation and division. Finally, we examine the role of the membrane, especially regulation of synthesis and fluid properties, in the life cycle of cell wall-deficient L-form bacteria.
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Affiliation(s)
- Henrik Strahl
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, NE2 4AX United Kingdom; ,
| | - Jeff Errington
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, NE2 4AX United Kingdom; ,
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27
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Koch G, Wermser C, Acosta IC, Kricks L, Stengel ST, Yepes A, Lopez D. Attenuating Staphylococcus aureus Virulence by Targeting Flotillin Protein Scaffold Activity. Cell Chem Biol 2017; 24:845-857.e6. [PMID: 28669526 DOI: 10.1016/j.chembiol.2017.05.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/11/2017] [Accepted: 05/30/2017] [Indexed: 01/13/2023]
Abstract
Scaffold proteins are ubiquitous chaperones that bind proteins and facilitate physical interaction of multi-enzyme complexes. Here we used a biochemical approach to dissect the scaffold activity of the flotillin-homolog protein FloA of the multi-drug-resistant human pathogen Staphylococcus aureus. We show that FloA promotes oligomerization of membrane protein complexes, such as the membrane-associated RNase Rny, which forms part of the RNA-degradation machinery called the degradosome. Cells lacking FloA had reduced Rny function and a consequent increase in the targeted sRNA transcripts that negatively regulate S. aureus toxin expression. Small molecules that altered FloA oligomerization also reduced Rny function and decreased the virulence potential of S. aureus in vitro, as well as in vivo, using invertebrate and murine infection models. Our results suggest that flotillin assists in the assembly of protein complexes involved in S. aureus virulence, and could thus be an attractive target for the development of new antimicrobial therapies.
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Affiliation(s)
- Gudrun Koch
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Charlotte Wermser
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Ivan C Acosta
- National Centre for Biotechnology (CNB), Spanish Research Council (CSIC), Darwin 3, Madrid 28049, Spain
| | - Lara Kricks
- National Centre for Biotechnology (CNB), Spanish Research Council (CSIC), Darwin 3, Madrid 28049, Spain
| | - Stephanie T Stengel
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Ana Yepes
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Daniel Lopez
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany; National Centre for Biotechnology (CNB), Spanish Research Council (CSIC), Darwin 3, Madrid 28049, Spain.
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28
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Hutton ML, D'Costa K, Rossiter AE, Wang L, Turner L, Steer DL, Masters SL, Croker BA, Kaparakis-Liaskos M, Ferrero RL. A Helicobacter pylori Homolog of Eukaryotic Flotillin Is Involved in Cholesterol Accumulation, Epithelial Cell Responses and Host Colonization. Front Cell Infect Microbiol 2017; 7:219. [PMID: 28634572 PMCID: PMC5460342 DOI: 10.3389/fcimb.2017.00219] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 05/11/2017] [Indexed: 12/12/2022] Open
Abstract
The human pathogen Helicobacter pylori acquires cholesterol from membrane raft domains in eukaryotic cells, commonly known as "lipid rafts." Incorporation of this cholesterol into the H. pylori cell membrane allows the bacterium to avoid clearance by the host immune system and to resist the effects of antibiotics and antimicrobial peptides. The presence of cholesterol in H. pylori bacteria suggested that this pathogen may have cholesterol-enriched domains within its membrane. Consistent with this suggestion, we identified a hypothetical H. pylori protein (HP0248) with homology to the flotillin proteins normally found in the cholesterol-enriched domains of eukaryotic cells. As shown for eukaryotic flotillin proteins, HP0248 was detected in detergent-resistant membrane fractions of H. pylori. Importantly, H. pylori HP0248 mutants contained lower levels of cholesterol than wild-type bacteria (P < 0.01). HP0248 mutant bacteria also exhibited defects in type IV secretion functions, as indicated by reduced IL-8 responses and CagA translocation in epithelial cells (P < 0.05), and were less able to establish a chronic infection in mice than wild-type bacteria (P < 0.05). Thus, we have identified an H. pylori flotillin protein and shown its importance for bacterial virulence. Taken together, the data demonstrate important roles for H. pylori flotillin in host-pathogen interactions. We propose that H. pylori flotillin may be required for the organization of virulence proteins into membrane raft-like structures in this pathogen.
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Affiliation(s)
- Melanie L. Hutton
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical ResearchMelbourne, VIC, Australia
| | - Kimberley D'Costa
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical ResearchMelbourne, VIC, Australia
| | - Amanda E. Rossiter
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical ResearchMelbourne, VIC, Australia
| | - Lin Wang
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical ResearchMelbourne, VIC, Australia
| | - Lorinda Turner
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical ResearchMelbourne, VIC, Australia
| | - David L. Steer
- Monash Biomedical Proteomics Facility, Monash UniversityMelbourne, VIC, Australia
| | - Seth L. Masters
- Inflammation Division, The Walter and Eliza Hall InstituteMelbourne, VIC, Australia
| | - Ben A. Croker
- Inflammation Division, The Walter and Eliza Hall InstituteMelbourne, VIC, Australia
| | - Maria Kaparakis-Liaskos
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical ResearchMelbourne, VIC, Australia
| | - Richard L. Ferrero
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical ResearchMelbourne, VIC, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash UniversityMelbourne, VIC, Australia
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29
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Nickels JD, Chatterjee S, Stanley CB, Qian S, Cheng X, Myles DAA, Standaert RF, Elkins JG, Katsaras J. The in vivo structure of biological membranes and evidence for lipid domains. PLoS Biol 2017; 15:e2002214. [PMID: 28542493 PMCID: PMC5441578 DOI: 10.1371/journal.pbio.2002214] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/11/2017] [Indexed: 12/19/2022] Open
Abstract
Examining the fundamental structure and processes of living cells at the nanoscale poses a unique analytical challenge, as cells are dynamic, chemically diverse, and fragile. A case in point is the cell membrane, which is too small to be seen directly with optical microscopy and provides little observational contrast for other methods. As a consequence, nanoscale characterization of the membrane has been performed ex vivo or in the presence of exogenous labels used to enhance contrast and impart specificity. Here, we introduce an isotopic labeling strategy in the gram-positive bacterium Bacillus subtilis to investigate the nanoscale structure and organization of its plasma membrane in vivo. Through genetic and chemical manipulation of the organism, we labeled the cell and its membrane independently with specific amounts of hydrogen (H) and deuterium (D). These isotopes have different neutron scattering properties without altering the chemical composition of the cells. From neutron scattering spectra, we confirmed that the B. subtilis cell membrane is lamellar and determined that its average hydrophobic thickness is 24.3 ± 0.9 Ångstroms (Å). Furthermore, by creating neutron contrast within the plane of the membrane using a mixture of H- and D-fatty acids, we detected lateral features smaller than 40 nm that are consistent with the notion of lipid rafts. These experiments-performed under biologically relevant conditions-answer long-standing questions in membrane biology and illustrate a fundamentally new approach for systematic in vivo investigations of cell membrane structure.
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Affiliation(s)
- Jonathan D. Nickels
- Shull Wollan Center—A Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Sneha Chatterjee
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Christopher B. Stanley
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Shuo Qian
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Xiaolin Cheng
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Dean A. A. Myles
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Robert F. Standaert
- Shull Wollan Center—A Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, United States of America
- * E-mail: (RFS); (JGE); (JK)
| | - James G. Elkins
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
- * E-mail: (RFS); (JGE); (JK)
| | - John Katsaras
- Shull Wollan Center—A Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, United States of America
- * E-mail: (RFS); (JGE); (JK)
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30
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Rashid R, Cazenave-Gassiot A, Gao IH, Nair ZJ, Kumar JK, Gao L, Kline KA, Wenk MR. Comprehensive analysis of phospholipids and glycolipids in the opportunistic pathogen Enterococcus faecalis. PLoS One 2017; 12:e0175886. [PMID: 28423018 PMCID: PMC5397010 DOI: 10.1371/journal.pone.0175886] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 04/02/2017] [Indexed: 02/07/2023] Open
Abstract
Enterococcus faecalis is a Gram-positive, opportunistic, pathogenic bacterium that causes a significant number of antibiotic-resistant infections in hospitalized patients. The development of antibiotic resistance in hospital-associated pathogens is a formidable public health threat. In E. faecalis and other Gram-positive pathogens, correlations exist between lipid composition and antibiotic resistance. Resistance to the last-resort antibiotic daptomycin is accompanied by a decrease in phosphatidylglycerol (PG) levels, whereas multiple peptide resistance factor (MprF) converts anionic PG into cationic lysyl-PG via a trans-esterification reaction, providing resistance to cationic antimicrobial peptides. Unlike previous studies that relied on thin layer chromatography and spectrophotometry, we have performed liquid chromatography-tandem mass spectrometry (LC-MS/MS) directly on lipids extracted from E. faecalis, and quantified the phospholipids through multiple reaction monitoring (MRM). In the daptomycin-sensitive E. faecalis strain OG1RF, we have identified 17 PGs, 8 lysyl-PGs (LPGs), 23 cardiolipins (CL), 3 glycerophospho-diglucosyl-diacylglycerols (GPDGDAG), 5 diglucosyl-diacylglycerols (DGDAG), 3 diacylglycerols (DAGs), and 4 triacylglycerols (TAGs). We have quantified PG and shown that PG levels vary during growth of E. faecalis in vitro. We also show that two daptomycin-resistant (DapR) strains of E. faecalis have substantially lower levels of PG and LPG levels. Since LPG levels in these strains are lower, daptomycin resistance is likely due to the reduction in PG. This lipidome map is the first comprehensive analysis of membrane phospholipids and glycolipids in the important human pathogen E. faecalis, for which antimicrobial resistance and altered lipid homeostasis have been intimately linked.
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Affiliation(s)
- Rafi Rashid
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Amaury Cazenave-Gassiot
- Singapore Lipidomics Incubator, National University of Singapore, Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Iris H. Gao
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Zeus J. Nair
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Jaspal K. Kumar
- Singapore Lipidomics Incubator, National University of Singapore, Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Liang Gao
- Singapore Lipidomics Incubator, National University of Singapore, Singapore, Singapore
- Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Kimberly A. Kline
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail: (KAK); (MRW)
| | - Markus R. Wenk
- Singapore Lipidomics Incubator, National University of Singapore, Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
- * E-mail: (KAK); (MRW)
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31
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Lopez D, Koch G. Exploring functional membrane microdomains in bacteria: an overview. Curr Opin Microbiol 2017; 36:76-84. [PMID: 28237903 DOI: 10.1016/j.mib.2017.02.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/01/2017] [Indexed: 01/08/2023]
Abstract
Recent studies show that internal organization of bacterial cells is more complex than previously appreciated. A clear example of this is the assembly of the nanoscale membrane platforms termed functional membrane microdomains. The lipid composition of these regions differs from that of the surrounding membrane; these domains confine a set of proteins involved in specific cellular processes such as protease secretion and signal transduction. It is currently thought that functional membrane microdomains act as oligomerization platforms and promote efficient oligomerization of interacting protein partners in bacterial membranes. In this review, we highlight the most noteworthy achievements, challenges and controversies of this emerging research field over the past five years.
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Affiliation(s)
- Daniel Lopez
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany; Spanish National Centre for Biotechnology (CNB), Madrid 28049, Spain.
| | - Gudrun Koch
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
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32
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Isolation of detergent-resistant membranes (DRMs) from Escherichia coli. Anal Biochem 2017; 518:1-8. [DOI: 10.1016/j.ab.2016.10.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 09/16/2016] [Accepted: 10/26/2016] [Indexed: 12/21/2022]
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33
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Vega-Cabrera LA, Pardo-López L. Membrane remodeling and organization: Elements common to prokaryotes and eukaryotes. IUBMB Life 2017; 69:55-62. [DOI: 10.1002/iub.1604] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 12/15/2016] [Indexed: 01/14/2023]
Affiliation(s)
- Luz A. Vega-Cabrera
- Instituto de Biotecnología, Universidad Nacional Autónoma de México; Apdo. Postal 510-3 Cuernavaca Morelos México
| | - Liliana Pardo-López
- Instituto de Biotecnología, Universidad Nacional Autónoma de México; Apdo. Postal 510-3 Cuernavaca Morelos México
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34
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Functional Membrane Microdomains Organize Signaling Networks in Bacteria. J Membr Biol 2016; 250:367-378. [PMID: 27566471 DOI: 10.1007/s00232-016-9923-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 08/16/2016] [Indexed: 11/27/2022]
Abstract
Membrane organization is usually associated with the correct function of a number of cellular processes in eukaryotic cells as diverse as signal transduction, protein sorting, membrane trafficking, or pathogen invasion. It has been recently discovered that bacterial membranes are able to compartmentalize their signal transduction pathways in functional membrane microdomains (FMMs). In this review article, we discuss the biological significance of the existence of FMMs in bacteria and comment on possible beneficial roles that FMMs play on the harbored signal transduction cascades. Moreover, four different membrane-associated signal transduction cascades whose functions are linked to the integrity of FMMs are introduced, and the specific role that FMMs play in stabilizing and promoting interactions of their signaling components is discussed. Altogether, FMMs seem to play a relevant role in promoting more efficient activation of signal transduction cascades in bacterial cells and show that bacteria are more sophisticated organisms than previously appreciated.
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35
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Dempwolff F, Schmidt FK, Hervás AB, Stroh A, Rösch TC, Riese CN, Dersch S, Heimerl T, Lucena D, Hülsbusch N, Stuermer CAO, Takeshita N, Fischer R, Eckhardt B, Graumann PL. Super Resolution Fluorescence Microscopy and Tracking of Bacterial Flotillin (Reggie) Paralogs Provide Evidence for Defined-Sized Protein Microdomains within the Bacterial Membrane but Absence of Clusters Containing Detergent-Resistant Proteins. PLoS Genet 2016; 12:e1006116. [PMID: 27362352 PMCID: PMC4928834 DOI: 10.1371/journal.pgen.1006116] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 05/20/2016] [Indexed: 12/14/2022] Open
Abstract
Biological membranes have been proposed to contain microdomains of a specific lipid composition, in which distinct groups of proteins are clustered. Flotillin-like proteins are conserved between pro—and eukaryotes, play an important function in several eukaryotic and bacterial cells, and define in vertebrates a type of so-called detergent-resistant microdomains. Using STED microscopy, we show that two bacterial flotillins, FloA and FloT, form defined assemblies with an average diameter of 85 to 110 nm in the model bacterium Bacillus subtilis. Interestingly, flotillin microdomains are of similar size in eukaryotic cells. The soluble domains of FloA form higher order oligomers of up to several hundred kDa in vitro, showing that like eukaryotic flotillins, bacterial assemblies are based in part on their ability to self-oligomerize. However, B. subtilis paralogs show significantly different diffusion rates, and consequently do not colocalize into a common microdomain. Dual colour time lapse experiments of flotillins together with other detergent-resistant proteins in bacteria show that proteins colocalize for no longer than a few hundred milliseconds, and do not move together. Our data reveal that the bacterial membrane contains defined-sized protein domains rather than functional microdomains dependent on flotillins. Based on their distinct dynamics, FloA and FloT confer spatially distinguishable activities, but do not serve as molecular scaffolds. Many membrane proteins are not uniformly distributed within biological membranes, and may prefer specific lipid environments to function optimally. Using super resolution fluorescence microscopy, we show that several Bacillus subtilis membrane proteins indeed cluster into structures of 60 to 110 nm, verifying the existence of defined-size protein microdomains. Biochemical co-isolation of specific membrane proteins and flotillins, a family of proteins highly conserved between eukaryotic and bacterial cells, suggested that common “functional” microdomains exist, containing so-called “detergent-resistant” membrane proteins, that are centered by flotillins. Through high speed tracking of Bacillus subtilis FloA and FloT we show that both proteins are not present in the same microdomain, but move through the membrane with different velocities. Dual colour time lapse microscopy showed that contrarily to vertebrate flotillins, bacterial flotillins do not move together with detergent-resistant proteins, ruling out the existence of coclusters. The lack of both flotillins, but not of a single one, leads to striking defects in cell shape and in cell growth, indicating important overlapping functions of flotillin paralogs. Our data show that FloA and FloT perform spatially distinct functions, possibly in the insertion of membrane proteins that require a specific lipid environment, based on a close connection between FloA and FloT with the Sec membrane insertion machinery, but do not act as scaffolds for detergent resistant proteins. Our tracking analyses provide an important basis for the understanding of interactions between membrane proteins in living cells.
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Affiliation(s)
- Felix Dempwolff
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Felix K. Schmidt
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Physics, Philipps Universität Marburg, Marburg, Germany
| | - Ana B. Hervás
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Alex Stroh
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Thomas C. Rösch
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Cornelius N. Riese
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Biology, Philipps Universität Marburg, Marburg, Germany
| | - Simon Dersch
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Thomas Heimerl
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Biology, Philipps Universität Marburg, Marburg, Germany
| | - Daniella Lucena
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Nikola Hülsbusch
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Norio Takeshita
- University of Tsukuba, Faculty of Life and Environmental Sciences, Tsukuba, Ibaraki, Japan
- Department of Microbiology, Institute for Applied Bioscience, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Reinhard Fischer
- Department of Microbiology, Institute for Applied Bioscience, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Bruno Eckhardt
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Physics, Philipps Universität Marburg, Marburg, Germany
| | - Peter L. Graumann
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
- * E-mail:
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Sastre DE, Bisson-Filho A, de Mendoza D, Gueiros-Filho FJ. Revisiting the cell biology of the acyl-ACP:phosphate transacylase PlsX suggests that the phospholipid synthesis and cell division machineries are not coupled inBacillus subtilis. Mol Microbiol 2016; 100:621-34. [DOI: 10.1111/mmi.13337] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/26/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Diego Emiliano Sastre
- Departamento de Bioquímica; Instituto de Química, Universidade de São Paulo; São Paulo SP Brazil
| | - Alexandre Bisson-Filho
- Department of Molecular and Cellular Biology and Faculty of Arts and Sciences (FAS) Center for Systems Biology; Harvard University; Cambridge MA 02138 USA
| | - Diego de Mendoza
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), and Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario, Ocampo y Esmeralda, Predio CONICET Rosario; 2000 Rosario Argentina
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Somani VK, Aggarwal S, Singh D, Prasad T, Bhatnagar R. Identification of Novel Raft Marker Protein, FlotP in Bacillus anthracis. Front Microbiol 2016; 7:169. [PMID: 26925042 PMCID: PMC4756111 DOI: 10.3389/fmicb.2016.00169] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 02/01/2016] [Indexed: 01/14/2023] Open
Abstract
Lipid rafts are dynamic, nanoscale assemblies of specific proteins and lipids, distributed heterogeneously on eukaryotic membrane. Flotillin-1, a conserved eukaryotic raft marker protein (RMP) harbor SPFH (Stomatin, Prohibitin, Flotillin, and HflK/C) and oligomerization domains to regulate various cellular processes through its interactions with other signaling or transport proteins. Rafts were thought to be absent in prokaryotes hitherto, but recent report of its presence and significance in physiology of Bacillus subtilis prompted us to investigate the same in pathogenic bacteria (PB) also. In prokaryotes, proteins of SPFH2a subfamily show highest identity to SPFH domain of Flotillin-1. Moreover, bacterial genome organization revealed that Flotillin homolog harboring SPFH2a domain exists in an operon with an upstream gene containing NFeD domain. Here, presence of RMP in PB was initially investigated in silico by analyzing the presence of SPFH2a, oligomerization domains in the concerned gene and NfeD domain in the adjacent upstream gene. After investigating 300 PB, four were found to harbor RMP. Among them, domains of Bas0525 (FlotP) of Bacillus anthracis (BA) showed highest identity with characteristic domains of RMP. Considering the global threat of BA as the bioterror agent, it was selected as a model for further in vitro characterization of rafts in PB. In silico and in vitro analysis showed significant similarity of FlotP with numerous attributes of Flotillin-1. Its punctate distribution on membrane with exclusive localization in detergent resistant membrane fraction; strongly favors presence of raft with RMP FlotP in BA. Furthermore, significant effect of Zaragozic acid (ZA), a raft associated lipid biosynthesis inhibitor, on several patho-physiological attributes of BA such as growth, morphology, membrane rigidity etc., were also observed. Specifically, a considerable decrease in membrane rigidity, strongly recommended presence of an unknown raft associated lipid molecule on membrane of BA. In addition, treatment with ZA decreased secretion of anthrax toxins and FlotP expression, suggesting potential role of raft in pathogenesis and physiology of BA. Thus, the present study not only suggest the existence and role of raft like entity in pathophysiology of BA but also its possible use for the development of novel drugs or vaccines against anthrax.
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Affiliation(s)
- Vikas K Somani
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University New Delhi, India
| | - Somya Aggarwal
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University New Delhi, India
| | - Damini Singh
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University New Delhi, India
| | | | - Rakesh Bhatnagar
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University New Delhi, India
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38
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Cassona CP, Pereira F, Serrano M, Henriques AO. A Fluorescent Reporter for Single Cell Analysis of Gene Expression in Clostridium difficile. Methods Mol Biol 2016; 1476:69-90. [PMID: 27507334 DOI: 10.1007/978-1-4939-6361-4_6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Genetically identical cells growing under homogeneous growth conditions often display cell-cell variation in gene expression. This variation stems from noise in gene expression and can be adaptive allowing for division of labor and bet-hedging strategies. In particular, for bacterial pathogens, the expression of phenotypes related to virulence can show cell-cell variation. Therefore, understanding virulence-related gene expression requires knowledge of gene expression patterns at the single cell level. We describe protocols for the use of fluorescence reporters for single cell analysis of gene expression in the human enteric pathogen Clostridium difficile, a strict anaerobe. The reporters are based on modified versions of the human DNA repair enzyme O ( 6)-alkylguanine-DNA alkyltransferase, called SNAP-tag and CLIP-tag. SNAP becomes covalently labeled upon reaction with O ( 6)-benzylguanine conjugated to a fluorophore, whereas CLIP is labeled by O ( 6)-benzylcytosine conjugates. SNAP and CLIP labeling is orthogonal allowing for dual labeling in the same cells. SNAP and CLIP cassettes optimized for C. difficile can be used for quantitative studies of gene expression at the single cell level. Both the SNAP and CLIP reporters can also be used for studies of protein subcellular localization in C. difficile.
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Affiliation(s)
- Carolina Piçarra Cassona
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Estação Agronómica Nacional, 2780-157, Oeiras, Portugal
| | - Fátima Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Estação Agronómica Nacional, 2780-157, Oeiras, Portugal
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Althanstr. 14, 1090, Vienna, Austria
| | - Mónica Serrano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Estação Agronómica Nacional, 2780-157, Oeiras, Portugal
| | - Adriano O Henriques
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Estação Agronómica Nacional, 2780-157, Oeiras, Portugal.
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Carquin M, D'Auria L, Pollet H, Bongarzone ER, Tyteca D. Recent progress on lipid lateral heterogeneity in plasma membranes: From rafts to submicrometric domains. Prog Lipid Res 2015; 62:1-24. [PMID: 26738447 DOI: 10.1016/j.plipres.2015.12.004] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 12/22/2015] [Accepted: 12/22/2015] [Indexed: 12/29/2022]
Abstract
The concept of transient nanometric domains known as lipid rafts has brought interest to reassess the validity of the Singer-Nicolson model of a fluid bilayer for cell membranes. However, this new view is still insufficient to explain the cellular control of surface lipid diversity or membrane deformability. During the past decades, the hypothesis that some lipids form large (submicrometric/mesoscale vs nanometric rafts) and stable (>min vs s) membrane domains has emerged, largely based on indirect methods. Morphological evidence for stable submicrometric lipid domains, well-accepted for artificial and highly specialized biological membranes, was further reported for a variety of living cells from prokaryot es to yeast and mammalian cells. However, results remained questioned based on limitations of available fluorescent tools, use of poor lipid fixatives, and imaging artifacts due to non-resolved membrane projections. In this review, we will discuss recent evidence generated using powerful and innovative approaches such as lipid-specific toxin fragments that support the existence of submicrometric domains. We will integrate documented mechanisms involved in the formation and maintenance of these domains, and provide a perspective on their relevance on membrane deformability and regulation of membrane protein distribution.
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Affiliation(s)
- Mélanie Carquin
- CELL Unit, de Duve Institute & Université Catholique de Louvain, UCL B1.75.05, Avenue Hippocrate, 75, B-1200 Brussels, Belgium
| | - Ludovic D'Auria
- The Myelin Regeneration Group at the Dept. Anatomy & Cell Biology, College of Medicine, University of Illinois, 808 S. Wood St. MC512, Chicago, IL. 60612. USA
| | - Hélène Pollet
- CELL Unit, de Duve Institute & Université Catholique de Louvain, UCL B1.75.05, Avenue Hippocrate, 75, B-1200 Brussels, Belgium
| | - Ernesto R Bongarzone
- The Myelin Regeneration Group at the Dept. Anatomy & Cell Biology, College of Medicine, University of Illinois, 808 S. Wood St. MC512, Chicago, IL. 60612. USA
| | - Donatienne Tyteca
- CELL Unit, de Duve Institute & Université Catholique de Louvain, UCL B1.75.05, Avenue Hippocrate, 75, B-1200 Brussels, Belgium.
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Abstract
Nearly all bacteria contain a peptidoglycan cell wall. The peptidoglycan precursor molecule is LipidII, containing the basic peptidoglycan building block attached to a lipid. Although the suitability of LipidII as an antibacterial target has long been recognized, progress on elucidating the role(s) of LipidII in bacterial cell biology has been slow. The focus of this review is on exciting new developments, both with respect to antibacterials targeting LipidII as well as the emerging role of LipidII in organizing the membrane and cell wall synthesis. It appears that on both sides of the membrane, LipidII plays crucial roles in organizing cytoskeletal proteins and peptidoglycan synthesis machineries. Finally, the recent discovery of no less than three different categories of LipidII flippases will be discussed.
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Affiliation(s)
- Dirk-Jan Scheffers
- Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
- * E-mail:
| | - Menno B. Tol
- Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
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Magalon A, Alberge F. Distribution and dynamics of OXPHOS complexes in the bacterial cytoplasmic membrane. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:198-213. [PMID: 26545610 DOI: 10.1016/j.bbabio.2015.10.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 10/28/2015] [Accepted: 10/29/2015] [Indexed: 12/23/2022]
Abstract
Oxidative phosphorylation (OXPHOS) is an essential process for most living organisms mostly sustained by protein complexes embedded in the cell membrane. In order to thrive, cells need to quickly respond to changes in the metabolic demand or in their environment. An overview of the strategies that can be employed by bacterial cells to adjust the OXPHOS outcome is provided. Regulation at the level of gene expression can only provide a means to adjust the OXPHOS outcome to long-term trends in the environment. In addition, the actual view is that bioenergetic membranes are highly compartmentalized structures. This review discusses what is known about the spatial organization of OXPHOS complexes and the timescales at which they occur. As exemplified with the commensal gut bacterium Escherichia coli, three levels of spatial organization are at play: supercomplexes, membrane microdomains and polar assemblies. This review provides a particular focus on whether dynamic spatial organization can fine-tune the OXPHOS through the definition of specialized functional membrane microdomains. Putative mechanisms responsible for spatio-temporal regulation of the OXPHOS complexes are discussed. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux.
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Affiliation(s)
- Axel Magalon
- CNRS, Laboratoire de Chimie Bactérienne (UMR 7283), Institut de Microbiologie de la Méditerranée, 13009 Marseille, France; Aix-Marseille University, UMR 7283, 13009 Marseille, France.
| | - François Alberge
- CNRS, Laboratoire de Chimie Bactérienne (UMR 7283), Institut de Microbiologie de la Méditerranée, 13009 Marseille, France; Aix-Marseille University, UMR 7283, 13009 Marseille, France
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42
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Neubauer C, Dalleska NF, Cowley ES, Shikuma NJ, Wu CH, Sessions AL, Newman DK. Lipid remodeling in Rhodopseudomonas palustris TIE-1 upon loss of hopanoids and hopanoid methylation. GEOBIOLOGY 2015; 13:443-53. [PMID: 25923996 DOI: 10.1111/gbi.12143] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/23/2015] [Indexed: 05/17/2023]
Abstract
The sedimentary record of molecular fossils (biomarkers) can potentially provide important insights into the composition of ancient organisms; however, it only captures a small portion of their original lipid content. To interpret what remains, it is important to consider the potential for functional overlap between different lipids in living cells, and how the presence of one type might impact the abundance of another. Hopanoids are a diverse class of steroid analogs made by bacteria and found in soils, sediments, and sedimentary rocks. Here, we examine the trade-off between hopanoid production and that of other membrane lipids. We compare lipidomes of the metabolically versatile α-proteobacterium Rhodopseudomonas palustris TIE-1 and two hopanoid mutants, detecting native hopanoids simultaneously with other types of polar lipids by electrospray ionization mass spectrometry. In all strains, the phospholipids contain high levels of unsaturated fatty acids (often >80%). The degree to which unsaturated fatty acids are modified to cyclopropyl fatty acids varies by phospholipid class. Deletion of the capacity for hopanoid production is accompanied by substantive changes to the lipidome, including a several-fold rise of cardiolipins. Deletion of the ability to make methylated hopanoids has a more subtle effect; however, under photoautotrophic growth conditions, tetrahymanols are upregulated twofold. Together, these results illustrate that the 'lipid fingerprint' produced by a micro-organism can vary depending on the growth condition or loss of single genes, reminding us that the absence of a biomarker does not necessarily imply the absence of a particular source organism.
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Affiliation(s)
- C Neubauer
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - N F Dalleska
- Environmental Analysis Center, California Institute of Technology, Pasadena, CA, USA
| | - E S Cowley
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - N J Shikuma
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - C-H Wu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - A L Sessions
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - D K Newman
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
- Environmental Analysis Center, California Institute of Technology, Pasadena, CA, USA
- Howard Hughes Medical Institute, Pasadena, CA, USA
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43
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Lopez D. Molecular composition of functional microdomains in bacterial membranes. Chem Phys Lipids 2015; 192:3-11. [PMID: 26320704 DOI: 10.1016/j.chemphyslip.2015.08.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 08/10/2015] [Accepted: 08/24/2015] [Indexed: 12/14/2022]
Abstract
Membranes of eukaryotic cells organize a number of proteins related to signal transduction and membrane trafficking into microdomains, which are enriched in particular lipids, like cholesterol and sphingolipids and are commonly referred as to lipid rafts or membrane rafts. The existence of this type of signaling platforms was traditionally associated with eukaryotic membranes because prokaryotic cells were considered too simple organisms to require a sophisticated organization of their signaling networks. However, the research that have been performed during last years have shown that bacteria organize many signaling transduction processes in Functional Membrane Microdomains (FMMs), which are similar to the lipid rafts that are found in eukaryotic cells. The current knowledge of the existence of FMMs in bacteria is described in this review and the specific structural and biological properties of these membrane microdomains are introduced. The organization of FMMs in bacterial membranes reveals an unexpected level of sophistication in signaling transduction and membrane organization that is unprecedented in bacteria, suggesting that bacteria as more complex organisms than previously considered.
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Affiliation(s)
- Daniel Lopez
- Research Center for Infectious Diseases (ZINF), Institute for Molecular Infection Biology (IMIB), University of Würzburg, Josef-Schneider Strasse (2), 97080 Würzburg, Germany; Spanish National Center for Biotechnology (CNB), Campus de Cantoblanco, Darwin 3, 28049 Madrid, Spain.
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44
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Schneider J, Mielich-Süss B, Böhme R, Lopez D. In vivo characterization of the scaffold activity of flotillin on the membrane kinase KinC of Bacillus subtilis. MICROBIOLOGY-SGM 2015; 161:1871-1887. [PMID: 26297017 DOI: 10.1099/mic.0.000137] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Scaffold proteins are ubiquitous chaperones that bind to proteins and facilitate the physical interaction of the components of signal transduction pathways or multi-enzymic complexes. In this study, we used a biochemical approach to dissect the molecular mechanism of a membrane-associated scaffold protein, FloT, a flotillin-homologue protein that is localized in functional membrane microdomains of the bacterium Bacillus subtilis. This study provides unambiguous evidence that FloT physically binds to and interacts with the membrane-bound sensor kinase KinC. This sensor kinase activates biofilm formation in B. subtilis in response to the presence of the self-produced signal surfactin. Furthermore, we have characterized the mechanism by which the interaction of FloT with KinC benefits the activity of KinC. Two separate and synergistic effects constitute this mechanism: first, the scaffold activity of FloT promotes more efficient self-interaction of KinC and facilitates dimerization into its active form. Second, the selective binding of FloT to KinC prevents the occurrence of unspecific aggregation between KinC and other proteins that may generate dead-end intermediates that could titrate the activity of KinC. Flotillin proteins appear to play an important role in prokaryotes in promoting effective binding of signalling proteins with their correct protein partners.
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Affiliation(s)
- Johannes Schneider
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Benjamin Mielich-Süss
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Richard Böhme
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Daniel Lopez
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
- National Center for Biotechnology (CNB), Spanish Research Council (CSIC), Madrid 28050, Spain
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
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45
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Matsumoto K, Hara H, Fishov I, Mileykovskaya E, Norris V. The membrane: transertion as an organizing principle in membrane heterogeneity. Front Microbiol 2015; 6:572. [PMID: 26124753 PMCID: PMC4464175 DOI: 10.3389/fmicb.2015.00572] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/25/2015] [Indexed: 01/05/2023] Open
Abstract
The bacterial membrane exhibits a significantly heterogeneous distribution of lipids and proteins. This heterogeneity results mainly from lipid-lipid, protein-protein, and lipid-protein associations which are orchestrated by the coupled transcription, translation and insertion of nascent proteins into and through membrane (transertion). Transertion is central not only to the individual assembly and disassembly of large physically linked groups of macromolecules (alias hyperstructures) but also to the interactions between these hyperstructures. We review here these interactions in the context of the processes in Bacillus subtilis and Escherichia coli of nutrient sensing, membrane synthesis, cytoskeletal dynamics, DNA replication, chromosome segregation, and cell division.
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Affiliation(s)
- Kouji Matsumoto
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, SaitamaJapan
| | - Hiroshi Hara
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, SaitamaJapan
| | - Itzhak Fishov
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-ShevaIsrael
| | - Eugenia Mileykovskaya
- Department of Biochemistry and Molecular Biology, University of Texas Medical School at HoustonHouston, TX, USA
| | - Vic Norris
- Laboratory of Microbiology Signals and Microenvironment EA 4312, Department of Science, University of Rouen, Mont-Saint-AignanFrance
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46
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López D. Connection of KinC to flotillins and potassium leakage in Bacillus subtilis. MICROBIOLOGY-SGM 2015; 161:1180-1. [PMID: 25934647 DOI: 10.1099/mic.0.000089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Daniel López
- Research Centre for Infectious Diseases - Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
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47
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Schneider J, Klein T, Mielich-Süss B, Koch G, Franke C, Kuipers OP, Kovács ÁT, Sauer M, Lopez D. Spatio-temporal remodeling of functional membrane microdomains organizes the signaling networks of a bacterium. PLoS Genet 2015; 11:e1005140. [PMID: 25909364 PMCID: PMC4409396 DOI: 10.1371/journal.pgen.1005140] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 03/11/2015] [Indexed: 11/18/2022] Open
Abstract
Lipid rafts are membrane microdomains specialized in the regulation of numerous cellular processes related to membrane organization, as diverse as signal transduction, protein sorting, membrane trafficking or pathogen invasion. It has been proposed that this functional diversity would require a heterogeneous population of raft domains with varying compositions. However, a mechanism for such diversification is not known. We recently discovered that bacterial membranes organize their signal transduction pathways in functional membrane microdomains (FMMs) that are structurally and functionally similar to the eukaryotic lipid rafts. In this report, we took advantage of the tractability of the prokaryotic model Bacillus subtilis to provide evidence for the coexistence of two distinct families of FMMs in bacterial membranes, displaying a distinctive distribution of proteins specialized in different biological processes. One family of microdomains harbors the scaffolding flotillin protein FloA that selectively tethers proteins specialized in regulating cell envelope turnover and primary metabolism. A second population of microdomains containing the two scaffolding flotillins, FloA and FloT, arises exclusively at later stages of cell growth and specializes in adaptation of cells to stationary phase. Importantly, the diversification of membrane microdomains does not occur arbitrarily. We discovered that bacterial cells control the spatio-temporal remodeling of microdomains by restricting the activation of FloT expression to stationary phase. This regulation ensures a sequential assembly of functionally specialized membrane microdomains to strategically organize signaling networks at the right time during the lifespan of a bacterium. Cellular membranes organize proteins related to signal transduction, protein sorting and membrane trafficking into the so-called lipid rafts. It has been proposed that the functional diversity of lipid rafts would require a heterogeneous population of raft domains with varying compositions. However, a mechanism for such diversification is not known due in part to the complexity that entails the manipulation of eukaryotic cells. The recent discovery that bacteria organize many cellular processes in membrane microdomains (FMMs), functionally similar to the eukaryotic lipid rafts, prompted us to explore FMMs diversity in the bacterial model Bacillus subtilis. We show that diversification of FMMs occurs in cells and gives rise to functionally distinct microdomains, which compartmentalize distinct signal transduction pathways and regulate the expression of different genetic programs. We discovered that FMMs diversification does not occur randomly. Cells sequentially regulate the specialization of the FMMs during cell growth to ensure an effective and diverse activation of signaling processes.
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Affiliation(s)
- Johannes Schneider
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
| | - Teresa Klein
- Department of Biotechnology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Benjamin Mielich-Süss
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
| | - Gudrun Koch
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
| | - Christian Franke
- Department of Biotechnology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Oscar P. Kuipers
- Molecular Genetics Group,Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Ákos T. Kovács
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University of Jena, Jena, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Daniel Lopez
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
- * E-mail:
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48
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Farnoud AM, Toledo AM, Konopka JB, Del Poeta M, London E. Raft-like membrane domains in pathogenic microorganisms. CURRENT TOPICS IN MEMBRANES 2015; 75:233-68. [PMID: 26015285 DOI: 10.1016/bs.ctm.2015.03.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The lipid bilayer of the plasma membrane is thought to be compartmentalized by the presence of lipid-protein microdomains. In eukaryotic cells, microdomains composed of sterols and sphingolipids, commonly known as lipid rafts, are believed to exist, and reports on the presence of sterol- or protein-mediated microdomains in bacterial cell membranes are also appearing. Despite increasing attention, little is known about microdomains in the plasma membrane of pathogenic microorganisms. This review attempts to provide an overview of the current state of knowledge of lipid rafts in pathogenic fungi and bacteria. The current literature on characterization of microdomains in pathogens is reviewed, and their potential role in growth, pathogenesis, and drug resistance is discussed. Better insight into the structure and function of membrane microdomains in pathogenic microorganisms might lead to a better understanding of their pathogenesis and development of raft-mediated approaches for therapy.
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Affiliation(s)
- Amir M Farnoud
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
| | - Alvaro M Toledo
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
| | - James B Konopka
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
| | - Maurizio Del Poeta
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
| | - Erwin London
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
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Abstract
An interesting concept in the organization of cellular membranes is the proposed existence of lipid rafts. Membranes of eukaryotic cells organize signal transduction proteins into membrane rafts or lipid rafts that are enriched in particular lipids such as cholesterol and are important for the correct functionality of diverse cellular processes. The assembly of lipid rafts in eukaryotes has been considered a fundamental step during the evolution of cellular complexity, suggesting that bacteria and archaea were organisms too simple to require such a sophisticated organization of their cellular membranes. However, it was recently discovered that bacteria organize many signal transduction, protein secretion, and transport processes in functional membrane microdomains, which are equivalent to the lipid rafts of eukaryotic cells. This review contains the most significant advances during the last 4 years in understanding the structural and biological role of lipid rafts in bacteria. Furthermore, this review shows a detailed description of a number of molecular and genetic approaches related to the discovery of bacterial lipid rafts as well as an overview of the group of tentative lipid-protein and protein-protein interactions that give consistency to these sophisticated signaling platforms. Additional data suggesting that lipid rafts are widely distributed in bacteria are presented in this review. Therefore, we discuss the available techniques and optimized protocols for the purification and analysis of raft-associated proteins in various bacterial species to aid in the study of bacterial lipid rafts in other laboratories that could be interested in this topic. Overall, the discovery of lipid rafts in bacteria reveals a new level of sophistication in signal transduction and membrane organization that was unexpected for bacteria and shows that bacteria are more complex than previously appreciated.
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Affiliation(s)
- Marc Bramkamp
- Department of Biology I, University of Munich (LMU), Planegg/Martinsried, Germany
| | - Daniel Lopez
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
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Bach JN, Bramkamp M. Dissecting the molecular properties of prokaryotic flotillins. PLoS One 2015; 10:e0116750. [PMID: 25635948 PMCID: PMC4312047 DOI: 10.1371/journal.pone.0116750] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 12/14/2014] [Indexed: 01/13/2023] Open
Abstract
Flotillins are universally conserved proteins that are present in all kingdoms of life. Recently it was demonstrated that the B. subtilis flotillin YuaG (FloT) has a direct influence on membrane domain formation by orchestrating lipid domains. Thereby it allocates a proper environment for diverse cellular machineries. YuaG creates platforms for signal transduction, processes crucial for biofilm formation, sporulation, competence, secretion, and others. Even though, flotillins are an emerging topic of research in the field of microbiology little is known about the molecular architecture of prokaryotic flotillins. All flotillins share common structural elements and are tethered to the membrane N’- terminally, followed by a so called PHB domain and a flotillin domain. We show here that prokaryotic flotillins are, similarly to eukaryotic flotillins, tethered to the membrane via a hairpin loop. Further it is demonstrated by sedimentation assays that B. subtilis flotillins do not bind to the membrane via their PHB domain contrary to eukaryotic flotillins. Size exclusion chromatography experiments, blue native PAGE and cross linking experiments revealed that B. subtilis YuaG can oligomerize into large clusters via the PHB domain. This illustrates an important difference in the setup of prokaryotic flotillins compared to the organization of eukaryotic flotillins.
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Affiliation(s)
- Juri Niño Bach
- Department of Biology I, Ludwig-Maximilians-University, Munich, Germany
| | - Marc Bramkamp
- Department of Biology I, Ludwig-Maximilians-University, Munich, Germany
- * E-mail:
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