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Klein JA, Predeus AV, Greissl AR, Clark-Herrera MM, Cruz E, Cundiff JA, Haeberle AL, Howell M, Lele A, Robinson DJ, Westerman TL, Wrande M, Wright SJ, Green NM, Vallance BA, McClelland M, Mejia A, Goodman AG, Elfenbein JR, Knodler LA. Pathogenic diversification of the gut commensal Providencia alcalifaciens via acquisition of a second type III secretion system. Infect Immun 2024:e0031424. [PMID: 39254346 DOI: 10.1128/iai.00314-24] [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: 07/22/2024] [Accepted: 08/13/2024] [Indexed: 09/11/2024] Open
Abstract
Providencia alcalifaciens is a Gram-negative bacterium found in various water and land environments and organisms, including insects and mammals. Some P. alcalifaciens strains encode gene homologs of virulence factors found in pathogenic Enterobacterales members, such as Salmonella enterica serovar Typhimurium and Shigella flexneri. Whether these genes are pathogenic determinants in P. alcalifaciens is not known. In this study, we investigated P. alcalifaciens-host interactions at the cellular level, focusing on the role of two type III secretion systems (T3SS) belonging to the Inv-Mxi/Spa family. T3SS1b is widespread in Providencia spp. and encoded on the chromosome. A large plasmid that is present in a subset of P. alcalifaciens strains, primarily isolated from diarrheal patients, encodes for T3SS1a. We show that P. alcalifaciens 205/92 is internalized into eukaryotic cells, lyses its internalization vacuole, and proliferates in the cytosol. This triggers caspase-4-dependent inflammasome responses in gut epithelial cells. The requirement for the T3SS1a in entry, vacuole lysis, and cytosolic proliferation is host cell type-specific, playing a more prominent role in intestinal epithelial cells than in macrophages or insect cells. In a bovine ligated intestinal loop model, P. alcalifaciens colonizes the intestinal mucosa and induces mild epithelial damage with negligible fluid accumulation in a T3SS1a- and T3SS1b-independent manner. However, T3SS1b was required for the rapid killing of Drosophila melanogaster. We propose that the acquisition of two T3SS has allowed P. alcalifaciens to diversify its host range, from a highly virulent pathogen of insects to an opportunistic gastrointestinal pathogen of animals.
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Affiliation(s)
- Jessica A Klein
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | | | - Aimee R Greissl
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Mattie M Clark-Herrera
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Eddy Cruz
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jennifer A Cundiff
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Amanda L Haeberle
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Maya Howell
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Aaditi Lele
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Donna J Robinson
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Trina L Westerman
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Marie Wrande
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Sarah J Wright
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Nicole M Green
- Public Health Laboratory, Los Angeles County Department of Public Health, Downey, California, USA
| | - Bruce A Vallance
- Division of Gastroenterology, Hepatology and Nutrition, BC Children's Hospital and the University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael McClelland
- Department of Microbiology and Molecular Genetics, University of California, Irvine, California, USA
| | - Andres Mejia
- Comparative Pathology Laboratory, Research Animal Resources and Compliance, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alan G Goodman
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Johanna R Elfenbein
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Leigh A Knodler
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
- Department of Microbiology and Molecular Genetics, Robert Larner College of Medicine at The University of Vermont, Burlington, Vermont, USA
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Klein JA, Predeus AV, Greissl AR, Clark-Herrera MM, Cruz E, Cundiff JA, Haeberle AL, Howell M, Lele A, Robinson DJ, Westerman TL, Wrande M, Wright SJ, Green NM, Vallance BA, McClelland M, Mejia A, Goodman AG, Elfenbein JR, Knodler LA. Pathogenic diversification of the gut commensal Providencia alcalifaciens via acquisition of a second type III secretion system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.595826. [PMID: 38895369 PMCID: PMC11185699 DOI: 10.1101/2024.06.07.595826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Providencia alcalifaciens is a Gram-negative bacterium found in a wide variety of water and land environments and organisms. It has been isolated as part of the gut microbiome of animals and insects, as well as from stool samples of patients with diarrhea. Specific P. alcalifaciens strains encode gene homologs of virulence factors found in other pathogenic members of the same Enterobacterales order, such as Salmonella enterica serovar Typhimurium and Shigella flexneri. Whether these genes are also pathogenic determinants in P. alcalifaciens is not known. Here we have used P. alcalifaciens 205/92, a clinical isolate, with in vitro and in vivo infection models to investigate P. alcalifaciens -host interactions at the cellular level. Our particular focus was the role of two type III secretion systems (T3SS) belonging to the Inv-Mxi/Spa family. T3SS 1b is widespread in Providencia spp. and encoded on the chromosome. T3SS 1a is encoded on a large plasmid that is present in a subset of P. alcalifaciens strains, which are primarily isolates from diarrheal patients. Using a combination of electron and fluorescence microscopy and gentamicin protection assays we show that P. alcalifaciens 205/92 is internalized into eukaryotic cells, rapidly lyses its internalization vacuole and proliferates in the cytosol. This triggers caspase-4 dependent inflammasome responses in gut epithelial cells. The requirement for the T3SS 1a in entry, vacuole lysis and cytosolic proliferation is host-cell type specific, playing a more prominent role in human intestinal epithelial cells as compared to macrophages. In a bovine ligated intestinal loop model, P. alcalifaciens colonizes the intestinal mucosa, inducing mild epithelial damage with negligible fluid accumulation. No overt role for T3SS 1a or T3SS 1b was seen in the calf infection model. However, T3SS 1b was required for the rapid killing of Drosophila melanogaster . We propose that the acquisition of two T3SS by horizontal gene transfer has allowed P. alcalifaciens to diversify its host range, from a highly virulent pathogen of insects to an opportunistic gastrointestinal pathogen of animals.
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Valenzuela-Valderas KN, Farrashzadeh E, Chang YY, Shi Y, Raudonis R, Leung BM, Rohde JR, Enninga J, Cheng Z. RACK1 promotes Shigella flexneri actin-mediated invasion, motility, and cell-to-cell spreading. iScience 2023; 26:108216. [PMID: 37953961 PMCID: PMC10637933 DOI: 10.1016/j.isci.2023.108216] [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: 04/28/2023] [Revised: 08/19/2023] [Accepted: 10/11/2023] [Indexed: 11/14/2023] Open
Abstract
Shigella flexneri is an intracellular bacterium that hijacks the host actin cytoskeleton to invade and disseminate within the colonic epithelium. Shigella's virulence factors induce actin polymerization, leading to bacterial uptake, actin tail formation, actin-mediated motility, and cell-to-cell spreading. Many host factors involved in the Shigella-prompted actin rearrangements remain elusive. Here, we studied the role of a host protein receptor for activated C kinase 1 (RACK1) in actin cytoskeleton dynamics and Shigella infection. We used time-lapse imaging to demonstrate that RACK1 facilitates Shigella-induced actin cytoskeleton remodeling at multiple levels during infection of epithelial cells. Silencing RACK1 expression impaired Shigella-induced rapid polymerizing structures, reducing host cell invasion, bacterial motility, and cell-to-cell spreading. In uninfected cells, RACK1 silencing reduced jasplakinolide-mediated filamentous actin aggregate formation and negatively affected actin turnover in fast polymerizing structures, such as membrane ruffles. Our findings provide a role of RACK1 in actin cytoskeleton dynamics and Shigella infection.
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Affiliation(s)
| | - Elmira Farrashzadeh
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Yuen-Yan Chang
- Unité Dynamique des interactions hôtes-pathogènes, Institut Pasteur and CNRS UMR3691, Université de Paris-Cité, 75724 Paris, France
| | - Yunnuo Shi
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Renee Raudonis
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Brendan M. Leung
- Department of Applied Oral Sciences, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - John R. Rohde
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Jost Enninga
- Unité Dynamique des interactions hôtes-pathogènes, Institut Pasteur and CNRS UMR3691, Université de Paris-Cité, 75724 Paris, France
| | - Zhenyu Cheng
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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Hartland EL, Ghosal D, Giogha C. Manipulation of epithelial cell architecture by the bacterial pathogens Listeria and Shigella. Curr Opin Cell Biol 2022; 79:102131. [PMID: 36215855 DOI: 10.1016/j.ceb.2022.102131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 08/22/2022] [Accepted: 09/06/2022] [Indexed: 01/31/2023]
Abstract
Subversion of the host cell cytoskeleton is a virulence attribute common to many bacterial pathogens. On mucosal surfaces, bacteria have evolved distinct ways of interacting with the polarised epithelium and manipulating host cell structure to propagate infection. For example, Shigella and Listeria induce cytoskeletal changes to induce their own uptake into enterocytes in order to replicate within an intracellular environment and then spread from cell-to-cell by harnessing the host actin cytoskeleton. In this review, we highlight some recent studies that advance our understanding of the role of the host cell cytoskeleton in the mechanical and molecular processes of pathogen invasion, cell-to-cell spread and the impact of infection on epithelial intercellular tension and innate mucosal defence.
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Affiliation(s)
- Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia; Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia.
| | - Debnath Ghosal
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Cristina Giogha
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia; Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia
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Ferrari ML, Charova SN, Sansonetti PJ, Mylonas E, Gazi AD. Structural Insights of Shigella Translocator IpaB and Its Chaperone IpgC in Solution. Front Cell Infect Microbiol 2021; 11:673122. [PMID: 33996640 PMCID: PMC8117225 DOI: 10.3389/fcimb.2021.673122] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/12/2021] [Indexed: 12/18/2022] Open
Abstract
Bacterial Type III Secretion Systems (T3SSs) are specialized multicomponent nanomachines that mediate the transport of proteins either to extracellular locations or deliver Type III Secretion effectors directly into eukaryotic host cell cytoplasm. Shigella, the causing agent of bacillary dysentery or shigellosis, bears a set of T3SS proteins termed translocators that form a pore in the host cell membrane. IpaB, the major translocator of the system, is a key factor in promoting Shigella pathogenicity. Prior to secretion, IpaB is maintained inside the bacterial cytoplasm in a secretion competent folding state thanks to its cognate chaperone IpgC. IpgC couples T3SS activation to transcription of effector genes through its binding to MxiE, probably after the delivery of IpaB to the secretion export gate. Small Angle X-ray Scattering experiments and modeling reveal that IpgC is found in different oligomeric states in solution, as it forms a stable heterodimer with full-length IpaB in contrast to an aggregation-prone homodimer in the absence of the translocator. These results support a stoichiometry of interaction 1:1 in the IpgC/IpaB complex and the multi-functional nature of IpgC under different T3SS states.
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Affiliation(s)
- Mariana L. Ferrari
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France
- INSERM U1202, Paris, France
| | - Spyridoula N. Charova
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology – Hellas (IMBB-FORTH), Heraklion, Crete, Greece
| | - Philippe J. Sansonetti
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France
- INSERM U1202, Paris, France
- Collège de France, Paris, France
| | - Efstratios Mylonas
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology – Hellas (IMBB-FORTH), Heraklion, Crete, Greece
| | - Anastasia D. Gazi
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France
- INSERM U1202, Paris, France
- UtechS Ultrastructural Bio-Imaging (UBI), Institut Pasteur, Paris, France
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Manipulation of Focal Adhesion Signaling by Pathogenic Microbes. Int J Mol Sci 2021; 22:ijms22031358. [PMID: 33572997 PMCID: PMC7866387 DOI: 10.3390/ijms22031358] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 12/22/2022] Open
Abstract
Focal adhesions (FAs) serve as dynamic signaling hubs within the cell. They connect intracellular actin to the extracellular matrix (ECM) and respond to environmental cues. In doing so, these structures facilitate important processes such as cell-ECM adhesion and migration. Pathogenic microbes often modify the host cell actin cytoskeleton in their pursuit of an ideal replicative niche or during invasion to facilitate uptake. As actin-interfacing structures, FA dynamics are also intimately tied to actin cytoskeletal organization. Indeed, exploitation of FAs is another avenue by which pathogenic microbes ensure their uptake, survival and dissemination. This is often achieved through the secretion of effector proteins which target specific protein components within the FA. Molecular mimicry of the leucine-aspartic acid (LD) motif or vinculin-binding domains (VBDs) commonly found within FA proteins is a common microbial strategy. Other effectors may induce post-translational modifications to FA proteins through the regulation of phosphorylation sites or proteolytic cleavage. In this review, we present an overview of the regulatory mechanisms governing host cell FAs, and provide examples of how pathogenic microbes have evolved to co-opt them to their own advantage. Recent technological advances pose exciting opportunities for delving deeper into the mechanistic details by which pathogenic microbes modify FAs.
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Differential expression and correlation analysis of miRNA-mRNA profiles in swine testicular cells infected with porcine epidemic diarrhea virus. Sci Rep 2021; 11:1868. [PMID: 33479333 PMCID: PMC7820490 DOI: 10.1038/s41598-021-81189-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 01/04/2021] [Indexed: 01/29/2023] Open
Abstract
The variant virulent porcine epidemic diarrhea virus (PEDV) strain (YN15) can cause severe porcine epidemic diarrhea (PED); however, the attenuated vaccine-like PEDV strain (YN144) can induce immunity in piglets. To investigate the differences in pathogenesis and epigenetic mechanisms between the two strains, differential expression and correlation analyses of the microRNA (miRNA) and mRNA in swine testicular (ST) cells infected with YN15, YN144, and mock were performed on three comparison groups (YN15 vs Control, YN144 vs Control, and YN15 vs YN144). The mRNA and miRNA expression profiles were obtained using next-generation sequencing (NGS), and the differentially expressed (DE) (p-value < 0.05) mRNA and miRNA were obtained using DESeq R package. mRNAs targeted by DE miRNAs were predicted using the miRanda algortithm. 8039, 8631 and 3310 DE mRNAs, and 36, 36, and 22 DE miRNAs were identified in the three comparison groups, respectively. 14,140, 15,367 and 3771 DE miRNA-mRNA (targeted by DE miRNAs) interaction pairs with negatively correlated expression patterns were identified, and interaction networks were constructed using Cytoscape. Six DE miRNAs and six DE mRNAs were randomly selected to verify the sequencing data by real-time relative quantitative reverse transcription polymerase chain reaction (qRT-PCR). Based on bioinformatics analysis, we discovered the differences were mostly involved in host immune responses and viral pathogenicity, including NF-κB signaling pathway and bacterial invasion of epithelial cells, etc. This is the first comprehensive comparison of DE miRNA-mRNA pairs in YN15 and YN144 infection in vitro, which could provide novel strategies for the prevention and control of PED.
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Khalid K, Tan X, Mohd Zaid HF, Tao Y, Lye Chew C, Chu DT, Lam MK, Ho YC, Lim JW, Chin Wei L. Advanced in developmental organic and inorganic nanomaterial: a review. Bioengineered 2020; 11:328-355. [PMID: 32138595 PMCID: PMC7161543 DOI: 10.1080/21655979.2020.1736240] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 02/16/2020] [Accepted: 02/17/2020] [Indexed: 02/08/2023] Open
Abstract
With the unique properties such as high surface area to volume ratio, stability, inertness, ease of functionalization, as well as novel optical, electrical, and magnetic behaviors, nanomaterials have a wide range of applications in various fields with the common types including nanotubes, dendrimers, quantum dots, and fullerenes. With the aim of providing useful insights to help future development of efficient and commercially viable technology for large-scale production, this review focused on the science and applications of inorganic and organic nanomaterials, emphasizing on their synthesis, processing, characterization, and applications on different fields. The applications of nanomaterials on imaging, cell and gene delivery, biosensor, cancer treatment, therapy, and others were discussed in depth. Last but not least, the future prospects and challenges in nanoscience and nanotechnology were also explored.
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Affiliation(s)
- Khalisanni Khalid
- Malaysian Agricultural Research and Development Institute (MARDI), Serdang, Malaysia
- Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Xuefei Tan
- College of Materials and Chemical Engineering, Heilongjiang Institute of Technology, Harbin, PR China
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, PR China
- Dalian SEM Bio-Engineering Technology Co., Ltd, Dalian, PR China
| | - Hayyiratul Fatimah Mohd Zaid
- Fundamental and Applied Sciences Department, Centre of Innovative Nanostructures & Nanodevices (COINN), Institute of Autonomous System, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Malaysia
| | - Yang Tao
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Chien Lye Chew
- Sime Darby Plantation Research (Formerly Known as Sime Darby Research), R&D Centre – Carey Island, Pulau Carey, Malaysia
| | - Dinh-Toi Chu
- Faculty of Biology, Hanoi National University of Education, Hanoi, Vietnam
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo and Oslo University Hospital, Norway
| | - Man Kee Lam
- Department of Chemical Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Yeek-Chia Ho
- Civil and Environmental Engineering Department, Univesiti Teknologi PETRONAS, Seri Iskandar, Malaysia
- Center for Urban Resource Sustainably, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Jun Wei Lim
- Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
- Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia Lim
| | - Lai Chin Wei
- Nanotechnology & Catalysis Research Centre (NANOCAT), University of Malaya (UM), Kuala Lumpur, Malaysia
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Shigella IpaA Binding to Talin Stimulates Filopodial Capture and Cell Adhesion. Cell Rep 2020; 26:921-932.e6. [PMID: 30673614 DOI: 10.1016/j.celrep.2018.12.091] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 11/07/2018] [Accepted: 12/20/2018] [Indexed: 01/22/2023] Open
Abstract
The Shigella type III effector IpaA contains three binding sites for the focal adhesion protein vinculin (VBSs), which are involved in bacterial invasion of host cells. Here, we report that IpaA VBS3 unexpectedly binds to talin. The 2.5 Å resolution crystal structure of IpaA VBS3 in complex with the talin H1-H4 helices shows a tightly folded α-helical bundle, which is in contrast to the bundle unraveling upon vinculin interaction. High-affinity binding to talin H1-H4 requires a core of hydrophobic residues and electrostatic interactions conserved in talin VBS H46. Remarkably, IpaA VBS3 localizes to filopodial distal adhesions enriched in talin, but not vinculin. In addition, IpaA VBS3 binding to talin was required for filopodial adhesions and efficient capture of Shigella. These results point to the functional diversity of VBSs and support a specific role for talin binding by a subset of VBSs in the formation of filopodial adhesions.
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Mukhopadhyay S, Ganguli S, Chakrabarti S. <em>Shigella</em> pathogenesis: molecular and computational insights. AIMS MOLECULAR SCIENCE 2020. [DOI: 10.3934/molsci.2020007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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Kadari M, Lakhloufi D, Delforge V, Imbault V, Communi D, Smeesters P, Botteaux A. Multiple proteins arising from a single gene: The role of the Spa33 variants in Shigella T3SS regulation. Microbiologyopen 2019; 8:e932. [PMID: 31517452 PMCID: PMC6925163 DOI: 10.1002/mbo3.932] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/14/2019] [Accepted: 08/16/2019] [Indexed: 12/12/2022] Open
Abstract
Shigella invasion and dissemination in intestinal epithelial cells relies on a type 3 secretion system (T3SS), which mediates translocation of virulence proteins into host cells. T3SSs are composed of three major parts: an extracellular needle, a basal body, and a cytoplasmic complex. Three categories of proteins are hierarchically secreted: (a) the needle components, (b) the translocator proteins which form a pore (translocon) inside the host cell membrane and (c) the effectors interfering with the host cell signaling pathways. In the absence of host cell contact, the T3SS is maintained in an “off” state by the presence of a tip complex. Secretion is activated by host cell contact which allows the release of a gatekeeper protein called MxiC. In this work, we have investigated the role of Spa33, a component of the cytoplasmic complex, in the regulation of secretion. The spa33 gene encodes a 33‐kDa protein and a smaller fragment of 12 kDa (Spa33C) which are both essential components of the cytoplasmic complex. We have shown that the spa33 gene gives rise to 5 fragments of various sizes. Among them, three are necessary for T3SS. Interestingly, we have shown that Spa33 is implicated in the regulation of secretion. Indeed, the mutation of a single residue in Spa33 induces an effector mutant phenotype, in which MxiC is sequestered. Moreover, we have shown a direct interaction between Spa33 and MxiC.
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Affiliation(s)
- Mahendar Kadari
- Laboratory of Molecular Bacteriology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - Dalila Lakhloufi
- Laboratory of Molecular Bacteriology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - Valérie Delforge
- Laboratory of Molecular Bacteriology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - Virginie Imbault
- Mass Spectrometry and Proteomics Facility, IRIBHM, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - David Communi
- Mass Spectrometry and Proteomics Facility, IRIBHM, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - Pierre Smeesters
- Laboratory of Molecular Bacteriology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium.,Department of Pediatrics, Academic Children Hospital Queen Fabiola, Université libre de Bruxelles, Brussels, Belgium.,Tropical disease Group, Murdoch Children's, Research Institute, Melbourne, Vic., Australia.,Center for International Child Health, University of Melbourne, Melbourne, Vic., Australia
| | - Anne Botteaux
- Laboratory of Molecular Bacteriology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
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12
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Liu S, Feng J, Pu J, Xu X, Lu S, Yang J, Wang Y, Jin D, Du X, Meng X, Luo X, Sun H, Xiong Y, Ye C, Lan R, Xu J. Genomic and molecular characterisation of Escherichia marmotae from wild rodents in Qinghai-Tibet plateau as a potential pathogen. Sci Rep 2019; 9:10619. [PMID: 31337784 PMCID: PMC6650469 DOI: 10.1038/s41598-019-46831-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 07/03/2019] [Indexed: 12/25/2022] Open
Abstract
Wildlife is a reservoir of emerging infectious diseases of humans and domestic animals. Marmota himalayana mainly resides 2800-4000 m above sea level in the Qinghai-Tibetan Plateau, and is the primary animal reservoir of plague pathogen Yersinia pestis. Recently we isolated a new species, Escherichia marmotae from the faeces of M. himalayana. In this study we characterised E. marmotae by genomic analysis and in vitro virulence testing to determine its potential as a human pathogen. We sequenced the genomes of the seven E. marmotae strains and found that they contained a plasmid that carried a Shigella-like type III secretion system (T3SS) and their effectors, and shared the same O antigen gene cluster as Shigella dysenterae 8 and E. coli O38. We also showed that E. marmotae was invasive to HEp-2 cells although it was much less invasive than Shigella. Thus E. marmotae is likely to be an invasive pathogen. However, E. marmotae has a truncated IpaA invasin, and lacks the environmental response regulator VirF and the IcsA-actin based intracellular motility, rendering it far less invasive in comparison to Shigella. E. marmotae also carried a diverse set of virulence factors in addition to the T3SS, including an IS1414 encoded enterotoxin gene astA with 37 copies, E. coli virulence genes lifA/efa, cif, and epeA, and the sfp gene cluster, Yersinia T3SS effector yopJ, one Type II secretion system and two Type VI secretion systems. Therefore, E. marmotae is a potential invasive pathogen.
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Affiliation(s)
- Sha Liu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China.,Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Jie Feng
- Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Beijing, 100101, China
| | - Ji Pu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Xuefang Xu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Shan Lu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Jing Yang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Yiting Wang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Dong Jin
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Xiaochen Du
- Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Beijing, 100101, China
| | - Xiangli Meng
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Xia Luo
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Hui Sun
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Yanwen Xiong
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Changyun Ye
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
| | - Jianguo Xu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center of Diagnosis and Treatment of Infectious Diseases, National Institute of Communicable Disease Control and Prevention, Chinese Center of Disease Control and Prevention, Beijing, 102206, China. .,Shanghai Institute of Emerging and Re-emerging infectious diseases, Shanghai Public Health Clinical Center, Shanghai, 201508, China.
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13
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Shigella promotes major alteration of gut epithelial physiology and tissue invasion by shutting off host intracellular transport. Proc Natl Acad Sci U S A 2019; 116:13582-13591. [PMID: 31209035 DOI: 10.1073/pnas.1902922116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Intracellular trafficking pathways in eukaryotic cells are essential to maintain organelle identity and structure, and to regulate cell communication with its environment. Shigella flexneri invades and subverts the human colonic epithelium by the injection of virulence factors through a type 3 secretion system (T3SS). In this work, we report the multiple effects of two S. flexneri effectors, IpaJ and VirA, which target small GTPases of the Arf and Rab families, consequently inhibiting several intracellular trafficking pathways. IpaJ and VirA induce large-scale impairment of host protein secretion and block the recycling of surface receptors. Moreover, these two effectors decrease clathrin-dependent and -independent endocytosis. Therefore, S. flexneri infection induces a global blockage of host cell intracellular transport, affecting the exchange between cells and their external environment. The combined action of these effectors disorganizes the epithelial cell polarity, disturbs epithelial barrier integrity, promotes multiple invasion events, and enhances the pathogen capacity to penetrate into the colonic tissue in vivo.
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Abstract
ABSTRACT
Shigella
is a genus of Gram-negative enteropathogens that have long been, and continue to be, an important public health concern worldwide. Over the past several decades,
Shigella
spp. have also served as model pathogens in the study of bacterial pathogenesis, and
Shigella flexneri
has become one of the best-studied pathogens on a molecular, cellular, and tissue level. In the arms race between
Shigella
and the host immune system,
Shigella
has developed highly sophisticated mechanisms to subvert host cell processes in order to promote infection, escape immune detection, and prevent bacterial clearance. Here, we give an overview of
Shigella
pathogenesis while highlighting innovative techniques and methods whose application has significantly advanced our understanding of
Shigella
pathogenesis in recent years.
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15
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Monserrat-Martinez A, Gambin Y, Sierecki E. Thinking Outside the Bug: Molecular Targets and Strategies to Overcome Antibiotic Resistance. Int J Mol Sci 2019; 20:E1255. [PMID: 30871132 PMCID: PMC6470534 DOI: 10.3390/ijms20061255] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/04/2019] [Accepted: 03/04/2019] [Indexed: 12/25/2022] Open
Abstract
Since their discovery in the early 20th century, antibiotics have been used as the primary weapon against bacterial infections. Due to their prophylactic effect, they are also used as part of the cocktail of drugs given to treat complex diseases such as cancer or during surgery, in order to prevent infection. This has resulted in a decrease of mortality from infectious diseases and an increase in life expectancy in the last 100 years. However, as a consequence of administering antibiotics broadly to the population and sometimes misusing them, antibiotic-resistant bacteria have appeared. The emergence of resistant strains is a global health threat to humanity. Highly-resistant bacteria like Staphylococcus aureus (methicillin-resistant) or Enterococcus faecium (vancomycin-resistant) have led to complications in intensive care units, increasing medical costs and putting patient lives at risk. The appearance of these resistant strains together with the difficulty in finding new antimicrobials has alarmed the scientific community. Most of the strategies currently employed to develop new antibiotics point towards novel approaches for drug design based on prodrugs or rational design of new molecules. However, targeting crucial bacterial processes by these means will keep creating evolutionary pressure towards drug resistance. In this review, we discuss antibiotic resistance and new options for antibiotic discovery, focusing in particular on new alternatives aiming to disarm the bacteria or empower the host to avoid disease onset.
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Affiliation(s)
- Ana Monserrat-Martinez
- European Molecular Biology Laboratory Australia (EMBL Australia) Node in Single Molecule Science, Sydney, NSW 2031, Australia.
- School of Medical Sciences, The University of New South Wales, Sydney, NSW 2031, Australia.
| | - Yann Gambin
- European Molecular Biology Laboratory Australia (EMBL Australia) Node in Single Molecule Science, Sydney, NSW 2031, Australia.
- School of Medical Sciences, The University of New South Wales, Sydney, NSW 2031, Australia.
| | - Emma Sierecki
- European Molecular Biology Laboratory Australia (EMBL Australia) Node in Single Molecule Science, Sydney, NSW 2031, Australia.
- School of Medical Sciences, The University of New South Wales, Sydney, NSW 2031, Australia.
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16
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Ndungo E, Randall A, Hazen TH, Kania DA, Trappl-Kimmons K, Liang X, Barry EM, Kotloff KL, Chakraborty S, Mani S, Rasko DA, Pasetti MF. A Novel Shigella Proteome Microarray Discriminates Targets of Human Antibody Reactivity following Oral Vaccination and Experimental Challenge. mSphere 2018; 3:e00260-18. [PMID: 30068560 PMCID: PMC6070737 DOI: 10.1128/msphere.00260-18] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/10/2018] [Indexed: 12/14/2022] Open
Abstract
Shigella spp. are a major cause of diarrhea and dysentery in children under 5 years old in the developing world. The development of an effective vaccine remains a public health priority, necessitating improved understanding of immune responses to Shigella and identification of protective antigens. We report the development of a core Shigella proteome microarray consisting of 2,133 antigen targets common to all Shigella species. We evaluated the microarray with serum samples from volunteers immunized with either an inactivated whole-cell S. flexneri serotype 2a (Sf2aWC) vaccine or a live attenuated S. flexneri 2a vaccine strain (CVD 1204) or challenged with wild-type S. flexneri 2a (Sf2a challenge). Baseline reactivities to most antigens were detected postintervention in all three groups. Similar immune profiles were observed after CVD 1204 vaccination and Sf2a challenge. Antigens with the largest increases in mean reactivity postintervention were members of the type three secretion system (T3SS), some of which are regarded as promising vaccine targets: these are the invasion plasmid antigens (Ipas) IpaB, IpaC, and IpaD. In addition, new immunogenic targets (IpaA, IpaH, and SepA) were identified. Importantly, immunoreactivities to antigens in the microarray correlated well with antibody titers determined by enzyme-linked immunosorbent assay (ELISA), validating the use of the microarray platform. Finally, our analysis uncovered an immune signature consisting of three conserved proteins (IpaA, IpaB, and IpaC) that was predictive of protection against shigellosis. In conclusion, the Shigella proteome microarray is a robust platform for interrogating serological reactivity to multiple antigens at once and identifying novel targets for the development of broadly protective vaccines.IMPORTANCE Each year, more than 180 million cases of severe diarrhea caused by Shigella occur globally. Those affected (mostly children in poor regions) experience long-term sequelae that severely impair quality of life. Without a licensed vaccine, the burden of disease represents a daunting challenge. An improved understanding of immune responses to Shigella is necessary to support ongoing efforts to identify a safe and effective vaccine. We developed a microarray containing >2,000 proteins common to all Shigella species. Using sera from human adults who received a killed whole-cell or live attenuated vaccine or were experimentally challenged with virulent organisms, we identified new immune-reactive antigens and defined a T3SS protein signature associated with clinical protection.
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Affiliation(s)
- Esther Ndungo
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Arlo Randall
- Antigen Discovery, Inc., Irvine, California, USA
| | - Tracy H Hazen
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Dane A Kania
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | - Xiaowu Liang
- Antigen Discovery, Inc., Irvine, California, USA
| | - Eileen M Barry
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Karen L Kotloff
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Subhra Chakraborty
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | | | - David A Rasko
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Marcela F Pasetti
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
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17
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Synthetic bottom-up approach reveals the complex interplay of Shigella effectors in regulation of epithelial cell death. Proc Natl Acad Sci U S A 2018; 115:6452-6457. [PMID: 29866849 DOI: 10.1073/pnas.1801310115] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Over the course of an infection, many Gram-negative bacterial pathogens use complex nanomachines to directly inject tens to hundreds of proteins (effectors) into the cytosol of infected host cells. These effectors rewire processes to promote bacterial replication and spread. The roles of effectors in pathogenesis have traditionally been investigated by screening for phenotypes associated with their absence, a top-down approach that can be limited, as effectors often act in a functionally redundant or additive manner. Here we describe a synthetic Escherichia coli-based bottom-up platform to conduct gain-of-function screens for roles of individual Shigella effectors in pathogenesis. As proof of concept, we screened for Shigella effectors that limit cell death induced on cytosolic entry of bacteria into epithelial cells. Using this platform, in addition to OspC3, an effector known to inhibit cell death via pyroptosis, we have identified OspD2 and IpaH1.4 as cell death inhibitors. In contrast to almost all type III effectors, OspD2 does not target a host cell process, but rather regulates the activity of the Shigella type III secretion apparatus limiting the cytosolic delivery (translocation) of effectors during an infection. Remarkably, by limiting the translocation of a single effector, VirA, OspD2 controls the timing of epithelial cell death via calpain-mediated necrosis. Together, these studies provide insight into the intricate manner by which Shigella effectors interact to establish a productive intracytoplasmic replication niche before the death of infected epithelial cells.
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18
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Belotserkovsky I, Sansonetti PJ. Shigella and Enteroinvasive Escherichia Coli. Curr Top Microbiol Immunol 2018; 416:1-26. [PMID: 30218158 DOI: 10.1007/82_2018_104] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Shigella and enteroinvasive Escherichia coli (EIEC) are gram-negative bacteria responsible for bacillary dysentery (shigellosis) in humans, which is characterized by invasion and inflammatory destruction of the human colonic epithelium. Different EIEC and Shigella subgroups rose independently from commensal E. coli through patho-adaptive evolution that included loss of functional genes interfering with the virulence and/or with the intracellular lifestyle of the bacteria, as well as acquisition of genetic elements harboring virulence genes. Among the latter is the large virulence plasmid encoding for a type three secretion system (T3SS), which enables translocation of virulence proteins (effectors) from the bacterium directly into the host cell cytoplasm. These effectors enable the pathogen to subvert epithelial cell functions, promoting its own uptake, replication in the host cytosol, and dissemination to adjacent cells while concomitantly inhibiting pro-inflammatory cell death. Furthermore, T3SS effectors are directly involved in Shigella manipulation of immune cells causing their dysfunction and promoting cell death. In the current chapter, we first describe the evolution of the enteroinvasive pathovars and then summarize the overall knowledge concerning the pathogenesis of these bacteria, with a particular focus on Shigella flexneri. Subversion of host cell functions in the human gut, both epithelial and immune cells, by different virulence factors is especially highlighted.
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Affiliation(s)
- Ilia Belotserkovsky
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 28 Rue Du Dr Roux, 75724 Cedex 15, Paris, France.
| | - Philippe J Sansonetti
- Microbiologie et Maladies Infectieuses, Collège de France, 11 Place Marcelin Berthelot, 75005, Paris, France
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19
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El Hajjami N, Moussa S, Houssa J, Monteyne D, Perez-Morga D, Botteaux A. The inner-rod component of Shigella flexneri type 3 secretion system, MxiI, is involved in the transmission of the secretion activation signal by its interaction with MxiC. Microbiologyopen 2017; 7. [PMID: 29194994 PMCID: PMC5822323 DOI: 10.1002/mbo3.520] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 05/29/2017] [Accepted: 06/13/2017] [Indexed: 11/28/2022] Open
Abstract
The virulence of Shigella mainly resides in the use of a Type 3 Secretion System (T3SS) to inject several proteins inside the host cell. Three categories of proteins are hierarchically secreted: (1) the needle components (MxiH and MxiI), (2) the translocator proteins which form a pore (translocon) inside the host cell membrane, and (3) the effectors interfering with the host cell signaling pathways. In the absence of host cell contact, the T3SS is maintained in an “off” state by the presence of a tip complex. We have previously identified a gatekeeper protein, MxiC, which sequesters effectors inside the bacteria probably by interacting with MxiI, the inner‐rod component. Upon cell contact and translocon insertion, a signal is most likely transmitted from the top of the needle to the base, passing through the needle and allowing effectors release. However, the molecular mechanism underlying the transmission of the activation signal through the needle is still poorly understood. In this work, we investigate the role of MxiI in the activation of the T3SS by performing a mutational study. Interestingly we have shown that mutations of a single residue in MxiI (T82) induce an mxiC‐like phenotype and prevent the interaction with MxiC. Moreover, we have shown that the L26A mutation significantly reduces T3 secretion. The L26A mutation impairs the interaction between MxiI and Spa40, a keystone component of the switch between needle assembly and translocators secretion. The L26A mutation also sequesters MxiC. All these results highlight the crucial role of MxiI in regulating the secretion and transmitting the activation signal of the T3SS.
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Affiliation(s)
- Nargisse El Hajjami
- Laboratoire de Bactériologie Moléculaire, Faculté de Médecine, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Simon Moussa
- Laboratoire de Bactériologie Moléculaire, Faculté de Médecine, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Jonathan Houssa
- Laboratoire de Bactériologie Moléculaire, Faculté de Médecine, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Daniel Monteyne
- Laboratoire de Parasitologie Moléculaire, Faculté des Sciences, Université Libre de Bruxelles, Charleroi, Belgium.,Center for Microscopy and Molecular Imaging-CMMI, Université Libre de Bruxelles, Gosselies, Belgium
| | - David Perez-Morga
- Laboratoire de Parasitologie Moléculaire, Faculté des Sciences, Université Libre de Bruxelles, Charleroi, Belgium
| | - Anne Botteaux
- Laboratoire de Bactériologie Moléculaire, Faculté de Médecine, Université Libre de Bruxelles, Bruxelles, Belgium
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20
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Ma LL, Sun ZH, Xu YL, Wang SJ, Wang HN, Zhang H, Hu LP, Sun XM, Zhu L, Shang HQ, Zhu RL, Wei K. Screening host proteins required for bacterial adherence after H9N2 virus infection. Vet Microbiol 2017; 213:5-14. [PMID: 29292004 DOI: 10.1016/j.vetmic.2017.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 11/05/2017] [Accepted: 11/05/2017] [Indexed: 02/06/2023]
Abstract
H9N2 subtype low pathogenic avian influenza virus (LPAIV) is distributed worldwide and causes great economic losses in the poultry industry, especially when complicated with other bacterial infections. Tissue damages caused by virus infection provide an opportunity for bacteria invasion, but this mechanism is not sufficient for low pathogenic strains. Moreover, although H9N2 virus infection was demonstrated to promote bacterial infection in several studies, its mechanism remained unclear. In this study, infection experiments in vivo and in vitro demonstrated that the adhesion of Escherichia coli (E. coli) to host cells significantly increased after H9N2 virus infection, and this increase was not caused by pathological damages. Subsequently, we constructed a late chicken embryo infection model and used proteomics techniques to analyze the expression of proteins associated with bacterial adhesion after H9N2 virus infection. A total of 279 significantly differential expressed proteins were detected through isobaric tags for relative and absolute quantitation (iTRAQ) coupled with nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) analysis. The results of Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that differentially expressed proteins were enriched in host innate immunity; cell proliferation, differentiation, and apoptosis; and pathogenicity-related signaling pathways. Finally, we screened out several proteins, such as TGF-β1, integrins, cortactin, E-cadherin, vinculin, and fibromodulin, which were probably associated with bacterial adhesion. The study analyzed the mechanism of secondary bacterial infection induced by H9N2 virus infection from a novel perspective, which provided theoretical and data support for investigating the synergistic infection mechanism between the H9N2 virus and bacteria.
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Affiliation(s)
- Li-Li Ma
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China, China
| | - Zhen-Hong Sun
- Analytic Laboratory, Institute of Preclinical Medicine, Taishan Medical University, Taian 271000, China
| | - Yu-Lin Xu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China, China
| | - Shu-Juan Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China, China
| | - Hui-Ning Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China, China
| | - Hao Zhang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China, China
| | - Li-Ping Hu
- Animal Disease Prevention and Control Center of Shandong Province, Animal Husbandry and Veterinary Bureau of Shandong Province, Jinan, China
| | - Xiao-Mei Sun
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China, China
| | - Lin Zhu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China, China
| | - Hong-Qi Shang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China, China
| | - Rui-Liang Zhu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China, China.
| | - Kai Wei
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, Taian 271000, China, China.
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21
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Vander Broek CW, Zainal Abidin N, Stevens JM. BipC, a Predicted Burkholderia pseudomallei Type 3 Secretion System Translocator Protein with Actin Binding Activity. Front Cell Infect Microbiol 2017; 7:333. [PMID: 28770177 PMCID: PMC5515863 DOI: 10.3389/fcimb.2017.00333] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 07/06/2017] [Indexed: 11/13/2022] Open
Abstract
Burkholderia pseudomallei is an intracellular bacterial pathogen and the causative agent of melioidosis, a severe disease of humans and animals. Like other clinically important Gram-negative bacteria, fundamental to B. pseudomallei pathogenesis is the Bsa Type III Secretion System. The Bsa system injects bacterial effector proteins into the cytoplasm of target host cells subverting cellular pathways for the benefit of the bacteria. It is required for invasion of non-phagocytic host cells, escape from the endocytic compartment into the host cell cytoplasm, and for virulence in murine models of melioidosis. We have recently described the repertoire of effector proteins secreted by the B. pseudomallei Bsa system, however the functions of many of these effector proteins remain an enigma. One such protein is BipC, a homolog of the translocator/effector proteins SipC and IpaC from Salmonella spp. and Shigella flexneri respectively. SipC and IpaC each have separate and distinct roles acting both as translocators, involved in creating a pore in the eukaryotic cell membrane through which effector proteins can transit, and as effectors by interacting with and polymerizing host cell actin. In this study, pull-down assays demonstrate an interaction between BipC and actin. Furthermore, we show that BipC directly interacts with actin, preferentially with actin polymers (F-actin) and has the ability to polymerize actin in a similar manner as that described for SipC. Yet unlike SipC, BipC does not stabilize F-actin filaments, indicating a functionally distinct interaction with actin. Expression of Myc-tagged BipC in HeLa cells induces the formation of pseudopodia similar to that seen for IpaC. This study explores the effector function of BipC and reveals that actin interaction is conserved within the BipC/SipC/IpaC family of translocator/effector proteins.
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Affiliation(s)
- Charles W Vander Broek
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of EdinburghScotland, United Kingdom
| | - Nurhamimah Zainal Abidin
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of EdinburghScotland, United Kingdom
| | - Joanne M Stevens
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of EdinburghScotland, United Kingdom
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22
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Sunkavalli U, Aguilar C, Silva RJ, Sharan M, Cruz AR, Tawk C, Maudet C, Mano M, Eulalio A. Analysis of host microRNA function uncovers a role for miR-29b-2-5p in Shigella capture by filopodia. PLoS Pathog 2017; 13:e1006327. [PMID: 28394930 PMCID: PMC5398735 DOI: 10.1371/journal.ppat.1006327] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 04/20/2017] [Accepted: 03/31/2017] [Indexed: 12/18/2022] Open
Abstract
MicroRNAs play an important role in the interplay between bacterial pathogens and host cells, participating as host defense mechanisms, as well as exploited by bacteria to subvert host cellular functions. Here, we show that microRNAs modulate infection by Shigella flexneri, a major causative agent of bacillary dysentery in humans. Specifically, we characterize the dual regulatory role of miR-29b-2-5p during infection, showing that this microRNA strongly favors Shigella infection by promoting both bacterial binding to host cells and intracellular replication. Using a combination of transcriptome analysis and targeted high-content RNAi screening, we identify UNC5C as a direct target of miR-29b-2-5p and show its pivotal role in the modulation of Shigella binding to host cells. MiR-29b-2-5p, through repression of UNC5C, strongly enhances filopodia formation thus increasing Shigella capture and promoting bacterial invasion. The increase of filopodia formation mediated by miR-29b-2-5p is dependent on RhoF and Cdc42 Rho-GTPases. Interestingly, the levels of miR-29b-2-5p, but not of other mature microRNAs from the same precursor, are decreased upon Shigella replication at late times post-infection, through degradation of the mature microRNA by the exonuclease PNPT1. While the relatively high basal levels of miR-29b-2-5p at the start of infection ensure efficient Shigella capture by host cell filopodia, dampening of miR-29b-2-5p levels later during infection may constitute a bacterial strategy to favor a balanced intracellular replication to avoid premature cell death and favor dissemination to neighboring cells, or alternatively, part of the host response to counteract Shigella infection. Overall, these findings reveal a previously unappreciated role of microRNAs, and in particular miR-29b-2-5p, in the interaction of Shigella with host cells.
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Affiliation(s)
- Ushasree Sunkavalli
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Carmen Aguilar
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Ricardo Jorge Silva
- UC-BIOTECH, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Malvika Sharan
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Ana Rita Cruz
- UC-BIOTECH, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Caroline Tawk
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Claire Maudet
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Miguel Mano
- UC-BIOTECH, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Ana Eulalio
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
- UC-BIOTECH, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- * E-mail:
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Mattock E, Blocker AJ. How Do the Virulence Factors of Shigella Work Together to Cause Disease? Front Cell Infect Microbiol 2017; 7:64. [PMID: 28393050 PMCID: PMC5364150 DOI: 10.3389/fcimb.2017.00064] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/21/2017] [Indexed: 01/01/2023] Open
Abstract
Shigella is the major cause of bacillary dysentery world-wide. It is divided into four species, named S. flexneri, S. sonnei, S. dysenteriae, and S. boydii, which are distinct genomically and in their ability to cause disease. Shigellosis, the clinical presentation of Shigella infection, is characterized by watery diarrhea, abdominal cramps, and fever. Shigella's ability to cause disease has been attributed to virulence factors, which are encoded on chromosomal pathogenicity islands and the virulence plasmid. However, information on these virulence factors is not often brought together to create a detailed picture of infection, and how this translates into shigellosis symptoms. Firstly, Shigella secretes virulence factors that induce severe inflammation and mediate enterotoxic effects on the colon, producing the classic watery diarrhea seen early in infection. Secondly, Shigella injects virulence effectors into epithelial cells via its Type III Secretion System to subvert the host cell structure and function. This allows invasion of epithelial cells, establishing a replicative niche, and causes erratic destruction of the colonic epithelium. Thirdly, Shigella produces effectors to down-regulate inflammation and the innate immune response. This promotes infection and limits the adaptive immune response, causing the host to remain partially susceptible to re-infection. Combinations of these virulence factors may contribute to the different symptoms and infection capabilities of the diverse Shigella species, in addition to distinct transmission patterns. Further investigation of the dominant species causing disease, using whole-genome sequencing and genotyping, will allow comparison and identification of crucial virulence factors and may contribute to the production of a pan-Shigella vaccine.
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Affiliation(s)
- Emily Mattock
- Faculty of Biomedical Sciences, Schools of Cellular and Molecular Medicine and Biochemistry, University of Bristol Bristol, UK
| | - Ariel J Blocker
- Faculty of Biomedical Sciences, Schools of Cellular and Molecular Medicine and Biochemistry, University of Bristol Bristol, UK
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Abstract
Type III secretion (T3S) systems are found in a large number of gram-negative bacteria where they function to manipulate the biology of infected hosts. Hosts targeted by T3S systems are widely distributed in nature and are represented by animals and plants. T3S systems are found in diverse genera of bacteria and they share a common core structure and function. Effector proteins are delivered by T3S systems into targeted host cells without prior secretion of the effectors into the environment. Instead, an assembled translocon structure functions to translocate effectors across eukaryotic cell membranes. In many cases, T3S systems are essential virulence factors and in some instances they promote symbiotic interactions.
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Affiliation(s)
- Danielle L Jessen Condry
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, USA.
| | - Matthew L Nilles
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, USA
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25
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Kang WT, Vellasamy KM, Rajamani L, Beuerman RW, Vadivelu J. Burkholderia pseudomallei type III secreted protein BipC: role in actin modulation and translocation activities required for the bacterial intracellular lifecycle. PeerJ 2016; 4:e2532. [PMID: 28028452 PMCID: PMC5180589 DOI: 10.7717/peerj.2532] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 09/06/2016] [Indexed: 01/13/2023] Open
Abstract
Melioidosis, an infection caused by the facultative intracellular pathogen Burkholderia pseudomallei, has been classified as an emerging disease with the number of patients steadily increasing at an alarming rate. B. pseudomalleipossess various virulence determinants that allow them to invade the host and evade the host immune response, such as the type III secretion systems (TTSS). The products of this specialized secretion system are particularly important for the B. pseudomallei infection. Lacking in one or more components of the TTSS demonstrated different degrees of defects in the intracellular lifecycle of B. pseudomallei. Further understanding the functional roles of proteins involved in B. pseudomallei TTSS will enable us to dissect the enigma of B. pseudomallei-host cell interaction. In this study, BipC (a translocator), which was previously reported to be involved in the pathogenesis of B. pseudomallei, was further characterized using the bioinformatics and molecular approaches. The bipCgene, coding for a putative invasive protein, was first PCR amplified from B. pseudomallei K96243 genomic DNA and cloned into an expression vector for overexpression in Escherichia coli. The soluble protein was subsequently purified and assayed for actin polymerization and depolymerization. BipC was verified to subvert the host actin dynamics as demonstrated by the capability to polymerize actin in vitro. Homology modeling was also attempted to predict the structure of BipC. Overall, our findings identified that the protein encoded by the bipC gene plays a role as an effector involved in the actin binding activity to facilitate internalization of B. pseudomalleiinto the host cells.
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Affiliation(s)
- Wen Tyng Kang
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Kumutha Malar Vellasamy
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | | | - Roger W Beuerman
- Antimicrobials, Singapore Eye Research Institute (SERI) , Singapore , Singapore
| | - Jamuna Vadivelu
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
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26
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Li Z, Lee H, Zhu C. Molecular mechanisms of mechanotransduction in integrin-mediated cell-matrix adhesion. Exp Cell Res 2016; 349:85-94. [PMID: 27720950 DOI: 10.1016/j.yexcr.2016.10.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 09/30/2016] [Accepted: 10/03/2016] [Indexed: 01/09/2023]
Abstract
Cell-matrix adhesion complexes are multi-protein structures linking the extracellular matrix (ECM) to the cytoskeleton. They are essential to both cell motility and function by bidirectionally sensing and transmitting mechanical and biochemical stimulations. Several types of cell-matrix adhesions have been identified and they share many key molecular components, such as integrins and actin-integrin linkers. Mechanochemical coupling between ECM molecules and the actin cytoskeleton has been observed from the single cell to the single molecule level and from immune cells to neuronal cells. However, the mechanisms underlying force regulation of integrin-mediated mechanotransduction still need to be elucidated. In this review article, we focus on integrin-mediated adhesions and discuss force regulation of cell-matrix adhesions and key adaptor molecules, three different force-dependent behaviors, and molecular mechanisms for mechanochemical coupling in force regulation.
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Affiliation(s)
- Zhenhai Li
- Molecular Modeling and Simulation Group, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Hyunjung Lee
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Cheng Zhu
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; George W Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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27
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Weiner A, Mellouk N, Lopez-Montero N, Chang YY, Souque C, Schmitt C, Enninga J. Macropinosomes are Key Players in Early Shigella Invasion and Vacuolar Escape in Epithelial Cells. PLoS Pathog 2016; 12:e1005602. [PMID: 27182929 PMCID: PMC4868309 DOI: 10.1371/journal.ppat.1005602] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/05/2016] [Indexed: 01/30/2023] Open
Abstract
Intracellular pathogens include all viruses, many bacteria and parasites capable of invading and surviving within host cells. Key to survival is the subversion of host cell pathways by the pathogen for the purpose of propagation and evading the immune system. The intracellular bacterium Shigella flexneri, the causative agent of bacillary dysentery, invades host cells in a vacuole that is subsequently ruptured to allow growth of the pathogen within the host cytoplasm. S. flexneri invasion has been classically described as a macropinocytosis-like process, however the underlying details and the role of macropinosomes in the intracellular bacterial lifestyle have remained elusive. We applied dynamic imaging and advanced large volume correlative light electron microscopy (CLEM) to study the highly transient events of S. flexneri's early invasion into host epithelial cells and elucidate some of its fundamental features. First, we demonstrate a clear distinction between two compartments formed during the first step of invasion: the bacterial containing vacuole and surrounding macropinosomes, often considered identical. Next, we report a functional link between macropinosomes and the process of vacuolar rupture, demonstrating that rupture timing is dependent on the availability of macropinosomes as well as the activity of the small GTPase Rab11 recruited directly to macropinosomes. We go on to reveal that the bacterial containing vacuole and macropinosomes come into direct contact at the onset of vacuolar rupture. Finally, we demonstrate that S. flexneri does not subvert pre-existing host endocytic vesicles during the invasion steps leading to vacuolar rupture, and propose that macropinosomes are the major compartment involved in these events. These results provide the basis for a new model of the early steps of S. flexneri epithelial cell invasion, establishing a different view of the enigmatic process of cytoplasmic access by invasive bacterial pathogens.
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Affiliation(s)
- Allon Weiner
- Institut Pasteur, Dynamics of Host-Pathogen interactions Unit, Paris, France
- * E-mail: (AW); (JE)
| | - Nora Mellouk
- Institut Pasteur, Dynamics of Host-Pathogen interactions Unit, Paris, France
| | | | - Yuen-Yan Chang
- Institut Pasteur, Dynamics of Host-Pathogen interactions Unit, Paris, France
| | - Célia Souque
- Institut Pasteur, Dynamics of Host-Pathogen interactions Unit, Paris, France
| | | | - Jost Enninga
- Institut Pasteur, Dynamics of Host-Pathogen interactions Unit, Paris, France
- * E-mail: (AW); (JE)
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28
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Russo BC, Stamm LM, Raaben M, Kim CM, Kahoud E, Robinson LR, Bose S, Queiroz AL, Herrera BB, Baxt LA, Mor-Vaknin N, Fu Y, Molina G, Markovitz DM, Whelan SP, Goldberg MB. Intermediate filaments enable pathogen docking to trigger type 3 effector translocation. Nat Microbiol 2016; 1:16025. [PMID: 27572444 PMCID: PMC5006386 DOI: 10.1038/nmicrobiol.2016.25] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 02/03/2016] [Indexed: 12/31/2022]
Abstract
Type 3 secretion systems (T3SSs) of bacterial pathogens translocate bacterial effector proteins that mediate disease into the eukaryotic cytosol. Effectors traverse the plasma membrane through a translocon pore formed by T3SS proteins. In a genome-wide selection, we identified the intermediate filament vimentin as required for infection by the T3SS-dependent pathogen S. flexneri. We found that vimentin is required for efficient T3SS translocation of effectors by S. flexneri and other pathogens that use T3SS, Salmonella enterica serovar Typhimurium and Yersinia pseudotuberculosis. Vimentin and the intestinal epithelial intermediate filament keratin 18 interact with the C-terminus of the Shigella translocon pore protein IpaC. Vimentin and its interaction with IpaC are dispensable for pore formation, but are required for stable docking of S. flexneri to cells; moreover, stable docking triggers effector secretion. These findings establish that stable docking of the bacterium specifically requires intermediate filaments, is a process distinct from pore formation, and is a prerequisite for effector secretion.
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Affiliation(s)
- Brian C. Russo
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Luisa M. Stamm
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Matthijs Raaben
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Caleb M. Kim
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Emily Kahoud
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Lindsey R. Robinson
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Sayantan Bose
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Ana L. Queiroz
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Bobby Brooke Herrera
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Leigh A. Baxt
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Nirit Mor-Vaknin
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI 48109, USA
| | - Yang Fu
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Gabriel Molina
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - David M. Markovitz
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI 48109, USA
| | - Sean P. Whelan
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Marcia B. Goldberg
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
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29
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Kühn S, Mannherz HG. Actin: Structure, Function, Dynamics, and Interactions with Bacterial Toxins. Curr Top Microbiol Immunol 2016; 399:1-34. [PMID: 27848038 DOI: 10.1007/82_2016_45] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
Actin is one of the most abundant proteins in any eukaryotic cell and an indispensable component of the cytoskeleton. In mammalian organisms, six highly conserved actin isoforms can be distinguished, which differ by only a few amino acids. In non-muscle cells, actin polymerizes into actin filaments that form actin structures essential for cell shape stabilization, and participates in a number of motile activities like intracellular vesicle transport, cytokinesis, and also cell locomotion. Here, we describe the structure of monomeric and polymeric actin, the polymerization kinetics, and its regulation by actin-binding proteins. Probably due to its conserved nature and abundance, actin and its regulating factors have emerged as prefered targets of bacterial toxins and effectors, which subvert the host actin cytoskeleton to serve bacterial needs.
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Affiliation(s)
- Sonja Kühn
- Department of Cell Biology and Infection, Institut Pasteur, Paris, France
| | - Hans Georg Mannherz
- Department of Anatomy and Molecular Embryology, Ruhr-University, Bochum, Germany.
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30
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Thwaites TR, Pedrosa AT, Peacock TP, Carabeo RA. Vinculin Interacts with the Chlamydia Effector TarP Via a Tripartite Vinculin Binding Domain to Mediate Actin Recruitment and Assembly at the Plasma Membrane. Front Cell Infect Microbiol 2015; 5:88. [PMID: 26649283 PMCID: PMC4663276 DOI: 10.3389/fcimb.2015.00088] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 11/16/2015] [Indexed: 12/11/2022] Open
Abstract
The mammalian protein vinculin is often a target of bacterial pathogens to subvert locally host cell actin dynamics. In Chlamydia infection, vinculin has been implicated in RNA interference screens, but the molecular basis for vinculin requirement has not been characterized. In this report, we show that vinculin was involved in the actin recruitment and F-actin assembly at the plasma membrane to facilitate invasion. Vinculin was recruited to the plasma membrane via its interaction with a specific tripartite motif within TarP that resembles the vinculin-binding domain (VBD) found in the Shigella invasion factor IpaA. The TarP-mediated plasma membrane recruitment of vinculin resulted in the localized recruitment of actin. In vitro pulldown assays for protein-protein interaction and imaging-based evaluation of recruitment to the plasma membrane demonstrated the essential role of the vinculin-binding site 1 (VBS1), and the dispensability of VBS2 and VBS3. As further support for the functionality of VBD-vinculin interaction, VBD-mediated actin recruitment required vinculin. Interestingly, while both vinculin and the focal adhesion kinase (FAK) colocalized at the sites of adhesion, the recruitment of one was independent of the other; and the actin recruitment function of the VBD/vinculin signaling axis was independent of the LD/FAK pathway.
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Affiliation(s)
- Tristan R Thwaites
- Programme in Microbiology, Institute of Medical Sciences, University of Aberdeen Aberdeen, UK ; Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London London, UK
| | - Antonio T Pedrosa
- Programme in Microbiology, Institute of Medical Sciences, University of Aberdeen Aberdeen, UK ; Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London London, UK ; School of Molecular Biosciences, Washington State University Pullman, WA, USA
| | - Thomas P Peacock
- Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London London, UK
| | - Rey A Carabeo
- Programme in Microbiology, Institute of Medical Sciences, University of Aberdeen Aberdeen, UK ; Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London London, UK ; School of Molecular Biosciences, Washington State University Pullman, WA, USA
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31
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Sanchez-Villamil J, Navarro-Garcia F. Role of virulence factors on host inflammatory response induced by diarrheagenic Escherichia coli pathotypes. Future Microbiol 2015; 10:1009-33. [DOI: 10.2217/fmb.15.17] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
ABSTRACT Pathogens are able to breach the intestinal barrier, and different bacterial species can display different abilities to colonize hosts and induce inflammation. Inflammatory response studies induced by enteropathogens as Escherichia coli are interesting since it has acquired diverse genetic mobile elements, leading to different E. coli pathotypes. Diarrheagenic E. coli secrete toxins, effectors and virulence factors that exploit the host cell functions to facilitate the bacterial colonization. Many bacterial proteins are delivered to the host cell for subverting the inflammatory response. Hereby, we have highlighted the specific processes used by E. coli pathotypes, by that subvert the inflammatory pathways. These mechanisms include an arrangement of pro- and anti-inflammatory responses to favor the appropriate environmental niche for the bacterial survival and growth.
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Affiliation(s)
- Javier Sanchez-Villamil
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Ap. Postal 14–740, 07000, México DF, Mexico
| | - Fernando Navarro-Garcia
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Ap. Postal 14–740, 07000, México DF, Mexico
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32
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Zheng K, Kitazato K, Wang Y, He Z. Pathogenic microbes manipulate cofilin activity to subvert actin cytoskeleton. Crit Rev Microbiol 2015; 42:677-95. [PMID: 25853495 DOI: 10.3109/1040841x.2015.1010139] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Actin-depolymerizing factor (ADF)/cofilin proteins are key players in controlling the temporal and spatial extent of actin dynamics, which is crucial for mediating host-pathogen interactions. Pathogenic microbes have evolved molecular mechanisms to manipulate cofilin activity to subvert the actin cytoskeletal system in host cells, promoting their internalization into the target cells, modifying the replication niche and facilitating their intracellular and intercellular dissemination. The study of how these pathogens exploit cofilin pathways is crucial for understanding infectious disease and providing potential targets for drug therapies.
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Affiliation(s)
- Kai Zheng
- a Department of Pharmacy, School of Medicine , Shenzhen University , Shenzhen , Guangdong , People's Republic of China .,c Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University , Guangzhou , China
| | - Kaio Kitazato
- b Division of Molecular Pharmacology of Infectious Agents, Department of Molecular Microbiology and Immunology , Nagasaki University , Nagasaki , Japan , and
| | - Yifei Wang
- c Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University , Guangzhou , China
| | - Zhendan He
- a Department of Pharmacy, School of Medicine , Shenzhen University , Shenzhen , Guangdong , People's Republic of China
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33
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Shigella flexneri regulation of ARF6 activation during bacterial entry via an IpgD-mediated positive feedback loop. mBio 2015; 6:e02584. [PMID: 25736891 PMCID: PMC4358011 DOI: 10.1128/mbio.02584-14] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED Entry into cells is critical for virulence of the human bacterial pathogens Shigella spp. Shigella spp. induce membrane ruffle formation and macropinocytic uptake, but the events instigating this process are incompletely understood. The host small GTPase ADP-ribosylation factor 6 (ARF6) functions in membrane trafficking at the plasma membrane and activates membrane ruffle formation. We demonstrate that ARF6 is required for efficient Shigella flexneri entry, is activated by S. flexneri dependent on the phosphatase activity of the type III secreted effector IpgD, and depends on cytohesin guanine nucleotide exchange factors (GEFs) for recruitment to entry sites. The cytohesin GEF ARF nucleotide binding site opener (ARNO) is recruited to these sites, also dependent on IpgD phosphatase activity. ARNO recruitment is independent of ARF6, indicating that, in addition to the described recruitment of ARNO by ARF6, ARNO is recruited upstream of ARF6. Our data provide evidence that ARF6, IpgD, phosphoinositide species, and ARNO constitute a previously undescribed positive feedback loop that amplifies ARF6 activation at bacterial entry sites, thereby promoting efficient S. flexneri uptake. IMPORTANCE Shigella spp. cause diarrhea and dysentery by infection of epithelial cells in the human colon. Critical to disease is the ability of Shigella to enter into cells, yet the mechanisms involved in entry are incompletely understood. We demonstrate that the small GTPase ADP-ribosylation factor 6 (ARF6) is required for efficient cellular entry of Shigella flexneri and that activation of ARF6 depends on the phosphatase activity of the Shigella protein IpgD, which is introduced into cells via the bacterial type III secretion system. We further show that IpgD phosphatase activity is required for recruitment of the ARF6 guanine nucleotide exchange factor (GEF) ARF nucleotide binding site opener (ARNO) to bacterial entry sites and that ARNO lies upstream of ARF6 activation. These relationships define a positive feedback loop that contributes to activation of ARF6 at S. flexneri entry sites and leads to local amplification of signals that promote bacterial entry.
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34
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LeGrand K, Matsumoto H, Young GM. A novel type 3 secretion system effector, YspI of Yersinia enterocolitica, induces cell paralysis by reducing total focal adhesion kinase. Cell Microbiol 2014; 17:688-701. [PMID: 25387594 DOI: 10.1111/cmi.12393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 11/03/2014] [Accepted: 11/08/2014] [Indexed: 12/22/2022]
Abstract
Some of the world's most important diseases are caused by bacterial pathogens that deliver toxic effector proteins directly into eukaryotic cells using type III secretion systems. The myriad of pathological outcomes caused by these pathogens is determined, in part, by the manipulation of host cell physiology due to the specific activities of individual effectors among the unique suite each pathogen employs. YspI was found to be an effector, delivered by Yersinia enterocolitica Biovar 1B, that inhibits host cell motility. The action of YspI comes about through its specific interaction with focal adhesion kinase, FAK, which is a fulcrum of focal adhesion complexes for controlling cellular motility. The interaction was defined by a specific domain of YspI that bound to the FAK kinase domain. Further examination revealed that YspI-FAK interaction leads to a reduction of FAK steady-state levels without altering its phosphorylation state. This collection of observations and results showed YspI displays unique functionality by targeting the key regulator of focal adhesion complexes to inhibit cellular movement.
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Affiliation(s)
- Karen LeGrand
- Microbiology Graduate Group, University of California, Davis, CA, USA; Department of Food Science and Technology, University of California, Davis, CA, USA
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Molecular mechanisms of host cytoskeletal rearrangements by Shigella invasins. Int J Mol Sci 2014; 15:18253-66. [PMID: 25310650 PMCID: PMC4227214 DOI: 10.3390/ijms151018253] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/23/2014] [Accepted: 09/25/2014] [Indexed: 11/16/2022] Open
Abstract
Pathogen-induced reorganization of the host cell cytoskeleton is a common strategy utilized in host cell invasion by many facultative intracellular bacteria, such as Shigella, Listeria, enteroinvasive E. coli and Salmonella. Shigella is an enteroinvasive intracellular pathogen that preferentially infects human epithelial cells and causes bacillary dysentery. Invasion of Shigella into intestinal epithelial cells requires extensive remodeling of the actin cytoskeleton with the aid of pathogenic effector proteins injected into the host cell by the activity of the type III secretion system. These so-called Shigella invasins, including IpaA, IpaC, IpgB1, IpgB2 and IpgD, modulate the actin-regulatory system in a concerted manner to guarantee efficient entry of the bacteria into host cells.
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Tolbert CE, Thompson PM, Superfine R, Burridge K, Campbell SL. Phosphorylation at Y1065 in vinculin mediates actin bundling, cell spreading, and mechanical responses to force. Biochemistry 2014; 53:5526-36. [PMID: 25115937 PMCID: PMC4151700 DOI: 10.1021/bi500678x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
![]()
Vinculin
is an essential structural adaptor protein that localizes
to sites of adhesion and is involved in a number of cell processes
including adhesion, spreading, motility, force transduction, and cell
survival. The C-terminal vinculin tail domain (Vt) contains the necessary
structural components to bind and cross-link actin filaments. Actin
binding to Vt induces a conformational change that promotes dimerization
through the C-terminal hairpin of Vt and enables actin filament cross-linking.
Here we show that Src phosphorylation of Y1065 within the C-terminal
hairpin regulates Vt-mediated actin bundling and provide a detailed
characterization of Y1065 mutations. Furthermore, we show that phosphorylation
at Y1065 plays a role in cell spreading and the response to the application
of mechanical force.
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Affiliation(s)
- Caitlin E Tolbert
- Department of Cell Biology and Physiology, ‡Department of Biochemistry and Biophysics, §Graduate Molecular and Cellular Biophysics Program, ∥Department of Physics and Astronomy, and ⊥the Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
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Elongation factor P and modifying enzyme PoxA are necessary for virulence of Shigella flexneri. Infect Immun 2014; 82:3612-21. [PMID: 24935977 DOI: 10.1128/iai.01532-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Elongation factor P (EF-P) is a universally conserved bacterial translation factor. In many bacteria, EF-P is posttranslationally modified by PoxA, which covalently attaches a β-lysine to a conserved lysine residue of EF-P. Here we show that both EF-P and PoxA are necessary for virulence of the human diarrheal pathogen Shigella flexneri. Loss of either EF-P or PoxA leads to an impaired ability of S. flexneri to invade epithelial cells and form plaques in an epithelial cell monolayer. Proteomic analysis of efp and poxA deletion mutants revealed decreased levels of several virulence effector proteins, including IpaA, -B, and -C and IcsA. Additionally, mRNA levels of virB and virF, which encode master virulence regulators, were decreased in the efp mutant. The reduction in virF transcription was at least partially due to decreased levels of CpxA, which activates virF through the response regulator CpxR. The role of CpxAR in reduced synthesis of VirF and its downstream effectors was indicated by restoration of invasion when a mutation resulting in constitutively activated CpxR was introduced into the efp mutant. Thus, modified EF-P is required for appropriate synthesis of proteins involved in the virulence of this bacterial pathogen.
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38
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Simon NC, Barbieri JT. Bacillus cereus Certhrax ADP-ribosylates vinculin to disrupt focal adhesion complexes and cell adhesion. J Biol Chem 2014; 289:10650-10659. [PMID: 24573681 DOI: 10.1074/jbc.m113.500710] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacillus cereus is often associated with mild to moderate gastroenteritis; however, some recent isolates cause inhalational anthrax-like diseases and death. These potential emerging human pathogens express multiple virulence factors. B. cereus strain G9241 expresses anthrax toxin, several polysaccharide capsules, and the novel ADP-ribosyltransferase, Certhrax. In this study, we show that Certhrax ADP-ribosylates Arg-433 of vinculin, a protein that coordinates actin cytoskeleton and extracellular matrix interactions. ADP-ribosylation of vinculin disrupted focal adhesion complexes and redistributed vinculin to the cytoplasm. Exogenous vinculin rescued these phenotypes. This provides a mechanism for strain G9241 to breach host barrier defenses and promote bacterial growth and spread. Certhrax is the first bacterial toxin to add a post-translational modification to vinculin to disrupt the actin cytoskeleton.
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Affiliation(s)
- Nathan C Simon
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Joseph T Barbieri
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226.
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Carayol N, Tran Van Nhieu G. The inside story of Shigella invasion of intestinal epithelial cells. Cold Spring Harb Perspect Med 2013; 3:a016717. [PMID: 24086068 DOI: 10.1101/cshperspect.a016717] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
As opposed to other invasive pathogens that reside into host cells in a parasitic mode, Shigella, the causative agent of bacillary dysentery, invades the colonic mucosa but does not penetrate further to survive into deeper tissues. Instead, Shigella invades, replicates, and disseminates within the colonic mucosa. Bacterial invasion and spreading in intestinal epithelium lead to the elicitation of inflammatory responses responsible for the tissue destruction and shedding in the environment for further infection of other hosts. In this article, we highlight specific features of the Shigella arsenal of virulence determinants injected by a type III secretion apparatus (T3SA) that point to the targeting of intestinal epithelial cells as a discrete route of invasion during the initial event of the infectious process.
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Affiliation(s)
- Nathalie Carayol
- Equipe Communication Intercellulaire et Infections Microbiennes, Centre de Recherche Interdisciplinaire en Biologie (CIRB), Collège de France, Paris, France
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40
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Leerberg JM, Yap AS. Vinculin, cadherin mechanotransduction and homeostasis of cell-cell junctions. PROTOPLASMA 2013; 250:817-829. [PMID: 23274283 DOI: 10.1007/s00709-012-0475-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 12/12/2012] [Indexed: 06/01/2023]
Abstract
Cell adhesion junctions characteristically arise from the cooperative integration of adhesion receptors, cell signalling pathways and the cytoskeleton. This is exemplified by cell-cell interactions mediated by classical cadherin adhesion receptors. These junctions are sites where cadherin adhesion systems functionally couple to the dynamic actin cytoskeleton, a process that entails physical interactions with many actin regulators and regulation by cell signalling pathways. Such integration implies a potential role for molecules that may stand at the interface between adhesion, signalling and the cytoskeleton. One such candidate is the cortical scaffolding protein, vinculin, which is a component of both cell-cell and cell-matrix adhesions. While its contribution to integrin-based adhesions has been extensively studied, less is known about how vinculin contributes to cell-cell adhesions. A major recent advance has come with the realisation that cadherin adhesions are active mechanical structures, where cadherin serves as part of a mechanotransduction pathway by which junctions sense and elicit cellular responses to mechanical stimuli. Vinculin has emerged as an important element in cadherin mechanotransduction, a perspective that illuminates its role in cell-cell interactions. We now review its role as a cortical scaffold and its role in cadherin mechanotransduction.
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Affiliation(s)
- Joanne M Leerberg
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
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41
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Tolbert CE, Burridge K, Campbell SL. Vinculin regulation of F-actin bundle formation: what does it mean for the cell? Cell Adh Migr 2013; 7:219-25. [PMID: 23307141 DOI: 10.4161/cam.23184] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Vinculin is an essential cell adhesion protein, found at both focal adhesions and adherens junctions, where it couples transmembrane proteins to the actin cytoskeleton. Vinculin is involved in controlling cell shape, motility and cell survival, and has more recently been shown to play a role in force transduction. The tail domain of vinculin (Vt) has the ability to both bind and bundle actin filaments. Binding to actin induces a conformational change in Vt believed to promote formation of a Vt dimer that is able to crosslink actin filaments. We have recently provided additional evidence for the actin-induced Vt dimer and have shown that the vinculin carboxyl (C)-terminal hairpin is critical for both the formation of the Vt dimer and for bundling F-actin. We have also demonstrated the importance of the C-terminal hairpin in cells as deletion of this region impacts both adhesion properties and force transduction. Intriguingly, we have identified bundling deficient variants of vinculin that show different cellular phenotypes. These results suggest additional role(s) for the C-terminal hairpin, distinct from its bundling function. In this commentary, we will expand on our previous findings and further investigate these actin bundling deficient vinculin variants.
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Affiliation(s)
- Caitlin E Tolbert
- Department of Cell Biology and Physiology, University of North Carolina School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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42
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Borisova M, Shi Y, Buntru A, Wörner S, Ziegler WH, Hauck CR. Integrin-mediated internalization of Staphylococcus aureus does not require vinculin. BMC Cell Biol 2013; 14:2. [PMID: 23294665 PMCID: PMC3562162 DOI: 10.1186/1471-2121-14-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 12/21/2012] [Indexed: 11/23/2022] Open
Abstract
Background Disease manifestations of Staphylococcus aureus are connected to the fibronectin (Fn)-binding capacity of these Gram-positive pathogens. Fn deposition on the surface of S. aureus allows engagement of α5β1 integrins and triggers uptake by host cells. For several integrin- and actin-associated cytoplasmic proteins, including FAK, Src, N-WASP, tensin and cortactin, a functional role during bacterial invasion has been demonstrated. As reorganization of the actin cytoskeleton is critical for bacterial entry, we investigated whether vinculin, an essential protein linking integrins with the actin cytoskeleton, may contribute to the integrin-mediated internalization of S. aureus. Results Complementation of vinculin in vinculin -/- cells, vinculin overexpression, as well as shRNA-mediated vinculin knock-down in different eukaryotic cell types demonstrate, that vinculin does not have a functional role during the integrin-mediated uptake of S. aureus. Conclusions Our results suggest that vinculin is insignificant for the integrin-mediated uptake of S. aureus despite the critical role of vinculin as a linker between integrins and F-actin.
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Affiliation(s)
- Marina Borisova
- Lehrstuhl Zellbiologie, Universität Konstanz, Postfach X908, 78457 Konstanz, Germany
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43
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Actin cytoskeleton manipulation by effector proteins secreted by diarrheagenic Escherichia coli pathotypes. BIOMED RESEARCH INTERNATIONAL 2012; 2013:374395. [PMID: 23509714 PMCID: PMC3591105 DOI: 10.1155/2013/374395] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 10/22/2012] [Indexed: 11/18/2022]
Abstract
The actin cytoskeleton is a dynamic structure necessary for cell and tissue organization, including the maintenance of epithelial barriers. Disruption of the epithelial barrier coincides with alterations of the actin cytoskeleton in several disease states. These disruptions primarily affect the paracellular space, which is normally regulated by tight junctions. Thereby, the actin cytoskeleton is a common and recurring target of bacterial virulence factors. In order to manipulate the actin cytoskeleton, bacteria secrete and inject toxins and effectors to hijack the host cell machinery, which interferes with host-cell pathways and with a number of actin binding proteins. An interesting model to study actin manipulation by bacterial effectors is Escherichia coli since due to its genome plasticity it has acquired diverse genetic mobile elements, which allow having different E. coli varieties in one bacterial species. These E. coli pathotypes, including intracellular and extracellular bacteria, interact with epithelial cells, and their interactions depend on a specific combination of virulence factors. In this paper we focus on E. coli effectors that mimic host cell proteins to manipulate the actin cytoskeleton. The study of bacterial effector-cytoskeleton interaction will contribute not only to the comprehension of the molecular causes of infectious diseases but also to increase our knowledge of cell biology.
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de Azevedo M, Karczewski J, Lefévre F, Azevedo V, Miyoshi A, Wells JM, Langella P, Chatel JM. In vitro and in vivo characterization of DNA delivery using recombinant Lactococcus lactis expressing a mutated form of L. monocytogenes Internalin A. BMC Microbiol 2012; 12:299. [PMID: 23253484 PMCID: PMC3541092 DOI: 10.1186/1471-2180-12-299] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 12/14/2012] [Indexed: 12/20/2022] Open
Abstract
Background The use of food-grade Lactic Acid Bacteria (LAB) as DNA delivery vehicles represents an attractive strategy to deliver DNA vaccines at the mucosal surfaces as they are generally regarded as safe (GRAS). We previously showed that either native Lactococcus lactis (LL) or recombinant invasive LL expressing Fibronectin Binding Protein A of Staphylococcus aureus (LL-FnBPA+) or Internalin A of Listeria monocytogenes (LL-InlA+), were able to deliver and trigger DNA expression by epithelial cells, either in vitro or in vivo. InlA does not bind to its receptor, the murine E-cadherin, thus limiting the use of LL-InlA+ in in vivo murine models. Moreover, FnBPA binds to its receptors, integrins, via fibronectin introducing another limiting factor. In order to avoid the limitations of LL-InlA+ and LL-FnBPA+, a new L. lactis strain was engineered to produce a previously described mutated form of InlA (LL-mInlA+) allowing the binding of mInlA on murine E-cadherin. Results After showing the expression of mInLA at the surface of LL-mInlA+ strain, in vitro gentamycin survival assay in Caco-2 cells showed that LL-mInlA+ is 1000 times more invasive than LL. LL-mInlA+ invasivity was also validated by fluorescence microscopy. LL and LL-mInlA+ were transformed with pValacBLG, a plasmid containing the cDNA of bovine β-Lactoglobulin (BLG), resulting in strains LL-BLG and LL-mInlA+BLG. The plasmid transfer in vitro using LL-mInlA+BLG was increased 10 times compared to LL-BLG. Moreover, the number of mice producing BLG in isolated enterocytes after oral administration of LL-mInlA+BLG in vivo was slightly higher than after oral administration of LL-BLG. Conclusions We confirmed in this study that the production of mInlA at the surface of L. lactis is a promising strategy for plasmid transfer in vitro and in vivo.
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Affiliation(s)
- Marcela de Azevedo
- INRA, UMR1319 Micalis, Commensals and Probiotics-Host Interactions Laboratory, Jouy-en-Josas, France
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45
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Lungu OI, Hallett RA, Choi EJ, Aiken MJ, Hahn KM, Kuhlman B. Designing photoswitchable peptides using the AsLOV2 domain. ACTA ACUST UNITED AC 2012; 19:507-17. [PMID: 22520757 DOI: 10.1016/j.chembiol.2012.02.006] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 01/12/2012] [Accepted: 02/01/2012] [Indexed: 10/28/2022]
Abstract
Photocontrol of functional peptides is a powerful tool for spatial and temporal control of cell signaling events. We show that the genetically encoded light-sensitive LOV2 domain of Avena Sativa phototropin 1 (AsLOV2) can be used to reversibly photomodulate the affinity of peptides for their binding partners. Sequence analysis and molecular modeling were used to embed two peptides into the Jα helix of the AsLOV2 domain while maintaining AsLOV2 structure in the dark but allowing for binding to effector proteins when the Jα helix unfolds in the light. Caged versions of the ipaA and SsrA peptides, LOV-ipaA and LOV-SsrA, bind their targets with 49- and 8-fold enhanced affinity in the light, respectively. These switches can be used as general tools for light-dependent colocalization, which we demonstrate with photo-activable gene transcription in yeast.
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Affiliation(s)
- Oana I Lungu
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
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46
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Chen Y, Aardema J, Misra A, Corey SJ. BAR proteins in cancer and blood disorders. INTERNATIONAL JOURNAL OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 3:198-208. [PMID: 22773959 PMCID: PMC3388730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 04/18/2012] [Indexed: 06/01/2023]
Abstract
Remodeling of the membrane and cytoskeleton is involved in a wide range of normal and pathologic cellular function. These are complex, highly-coordinated biochemical and biophysical processes involving dozens of proteins. Serving as a scaffold for a variety of proteins and possessing a domain that interacts with plasma membranes, the BAR family of proteins contribute to a range of cellular functions characterized by membrane and cytoskeletal remodeling. There are several subgroups of BAR proteins: BAR, N-BAR, I-BAR, and F-BAR. They differ in their ability to induce angles of membrane curvature and in their recruitment of effector proteins. Evidence is accumulating that BAR proteins contribute to cancer cell invasion, T cell trafficking, phagocytosis, and platelet production. In this review, we discuss the physiological function of BAR proteins and discuss how they contribute to blood and cancer disorders.
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Affiliation(s)
- Yolande Chen
- Departments of Pediatrics and Cell & Molecular Biology, Children’s Memorial Hospital, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of MedicineChicago, IL
| | - Jorie Aardema
- Departments of Pediatrics and Cell & Molecular Biology, Children’s Memorial Hospital, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of MedicineChicago, IL
| | - Ashish Misra
- Division of Cardiology, Department of Medicine, Yale University School of MedicineNew Haven, CT, USA
| | - Seth J Corey
- Departments of Pediatrics and Cell & Molecular Biology, Children’s Memorial Hospital, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of MedicineChicago, IL
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Romero S, Grompone G, Carayol N, Mounier J, Guadagnini S, Prevost MC, Sansonetti PJ, Van Nhieu GT. ATP-mediated Erk1/2 activation stimulates bacterial capture by filopodia, which precedes Shigella invasion of epithelial cells. Cell Host Microbe 2011; 9:508-19. [PMID: 21669399 DOI: 10.1016/j.chom.2011.05.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 04/19/2011] [Accepted: 05/23/2011] [Indexed: 11/29/2022]
Abstract
Shigella, the causative agent of bacillary dysentery in humans, invades epithelial cells, using a type III secretory system (T3SS) to inject bacterial effectors into host cells and remodel the actin cytoskeleton. ATP released through connexin hemichanels on the epithelial membrane stimulates Shigella invasion and dissemination in epithelial cells. Here, we show that prior to contact with the cell body, Shigella is captured by nanometer-thin micropodial extensions (NMEs) at a distance from the cell surface, in a process involving the T3SS tip complex proteins and stimulated by ATP- and connexin-mediated signaling. Upon bacterial contact, NMEs retract, bringing bacteria in contact with the cell body, where invasion occurs. ATP stimulates Erk1/2 activation, which controls actin retrograde flow in NMEs and their retraction. These findings reveal previously unappreciated facets of interaction of an invasive bacterium with host cells and a prominent role for Erk1/2 in the control of filopodial dynamics.
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Affiliation(s)
- Stéphane Romero
- Equipe Communication Intercellulaire et Infections Microbiennes, Centre de Recherche Interdisciplinaire en Biologie, Collège de France, 75005 Paris, France
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48
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Park H, Lee JH, Gouin E, Cossart P, Izard T. The rickettsia surface cell antigen 4 applies mimicry to bind to and activate vinculin. J Biol Chem 2011; 286:35096-103. [PMID: 21841197 DOI: 10.1074/jbc.m111.263855] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pathogenic Rickettsia species cause high morbidity and mortality, especially R. prowazekii, the causative agent of typhus. Like many intracellular pathogens, Rickettsia exploit the cytoskeleton to enter and spread within the host cell. Here we report that the cell surface antigen sca4 of Rickettsia co-localizes with vinculin in cells at sites of focal adhesions in sca4-transfected cells and that sca4 binds to and activates vinculin through two vinculin binding sites (VBSs) that are conserved across all Rickettsia. Remarkably, this occurs through molecular mimicry of the vinculin-talin interaction that is also seen with the IpaA invasin of the intracellular pathogen Shigella, where binding of these VBSs to the vinculin seven-helix bundle head domain (Vh1) displaces intramolecular interactions with the vinculin tail domain that normally clamp vinculin in an inactive state. Finally, the vinculin·sca4-VBS crystal structures reveal that vinculin adopts a new conformation when bound to the C-terminal VBS of sca4. Collectively, our data define the mechanism by which sca4 activates vinculin and interacts with the actin cytoskeleton, and they suggest important roles for vinculin in Rickettsia pathogenesis.
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Affiliation(s)
- HaJeung Park
- Cell Adhesion Laboratory, Department of Cancer Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
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49
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Park H, Valencia-Gallardo C, Sharff A, Van Nhieu GT, Izard T. Novel vinculin binding site of the IpaA invasin of Shigella. J Biol Chem 2011; 286:23214-21. [PMID: 21525010 PMCID: PMC3123088 DOI: 10.1074/jbc.m110.184283] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2010] [Revised: 04/05/2011] [Indexed: 11/06/2022] Open
Abstract
Internalization of Shigella into host epithelial cells, where the bacteria replicates and spreads to neighboring cells, requires a type 3 secretion system (T3SS) effector coined IpaA. IpaA binds directly to and activates the cytoskeletal protein vinculin after injection in the host cell cytosol, and this was previously thought to be directed by two amphipathic α-helical vinculin-binding sites (VBS) found in the C-terminal tail domain of IpaA. Here, we report a third VBS, IpaA-VBS3, that is located N-terminal to the other two VBSs of IpaA and show that one IpaA molecule can bind up to three vinculin molecules. Biochemical in vitro Shigella invasion assays and the 1.6 Å crystal structure of the vinculin·IpaA-VBS3 complex showed that IpaA-VBS3 is functionally redundant with the other two IpaA-VBSs in cell invasion and in activating the latent F-actin binding functions of vinculin. Multiple VBSs in IpaA are reminiscent of talin, which harbors 11 VBSs. However, most of the talin VBSs have low affinity and are buried in helix bundles, whereas all three of the VBSs of IpaA are high affinity, readily available, and in close proximity to each other in the IpaA structure. Although deletion of IpaA-VBS3 has no detectable effects on Shigella invasion of epithelial cells, deletion of all three VBSs impaired bacterial invasion to levels found in an ipaA null mutant strain. Thus, IpaA-directed mimicry of talin in activating vinculin occurs through three high affinity VBSs that are essential for Shigella pathogenesis.
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Affiliation(s)
- HaJeung Park
- From the Cell Adhesion Laboratory, Department of Cancer Biology, Scripps Research Institute, Jupiter, Florida 33458
| | - Cesar Valencia-Gallardo
- the Unité de Communication Intercellulaire et Infections Microbiennes, Inserm U971, Collège de France, 75005 Paris Cedex, France, and
| | - Andrew Sharff
- Global Phasing Ltd., Sheraton House, Castle Park, Cambridge CB3 0AX, United Kingdom
| | - Guy Tran Van Nhieu
- the Unité de Communication Intercellulaire et Infections Microbiennes, Inserm U971, Collège de France, 75005 Paris Cedex, France, and
| | - Tina Izard
- From the Cell Adhesion Laboratory, Department of Cancer Biology, Scripps Research Institute, Jupiter, Florida 33458
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Dean P. Functional domains and motifs of bacterial type III effector proteins and their roles in infection. FEMS Microbiol Rev 2011; 35:1100-25. [PMID: 21517912 DOI: 10.1111/j.1574-6976.2011.00271.x] [Citation(s) in RCA: 208] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A key feature of the virulence of many bacterial pathogens is the ability to deliver effector proteins into eukaryotic cells via a dedicated type three secretion system (T3SS). Many bacterial pathogens, including species of Chlamydia, Xanthomonas, Pseudomonas, Ralstonia, Shigella, Salmonella, Escherichia and Yersinia, depend on the T3SS to cause disease. T3SS effectors constitute a large and diverse group of virulence proteins that mimic eukaryotic proteins in structure and function. A salient feature of bacterial effectors is their modular architecture, comprising domains or motifs that confer an array of subversive functions within the eukaryotic cell. These domains/motifs therefore represent a fascinating repertoire of molecular determinants with important roles during infection. This review provides a snapshot of our current understanding of bacterial effector domains and motifs where a defined role in infection has been demonstrated.
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Affiliation(s)
- Paul Dean
- Institute of Cell and Molecular Bioscience, Medical School, University of Newcastle, Newcastle Upon Tyne, UK.
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