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Raab JE, Hamilton DJ, Harju TB, Huynh TN, Russo BC. Pushing boundaries: mechanisms enabling bacterial pathogens to spread between cells. Infect Immun 2024; 92:e0052423. [PMID: 38661369 DOI: 10.1128/iai.00524-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
For multiple intracellular bacterial pathogens, the ability to spread directly into adjacent epithelial cells is an essential step for disease in humans. For pathogens such as Shigella, Listeria, Rickettsia, and Burkholderia, this intercellular movement frequently requires the pathogens to manipulate the host actin cytoskeleton and deform the plasma membrane into structures known as protrusions, which extend into neighboring cells. The protrusion is then typically resolved into a double-membrane vacuole (DMV) from which the pathogen quickly escapes into the cytosol, where additional rounds of intercellular spread occur. Significant progress over the last few years has begun to define the mechanisms by which intracellular bacterial pathogens spread. This review highlights the interactions of bacterial and host factors that drive mechanisms required for intercellular spread with a focus on how protrusion structures form and resolve.
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Affiliation(s)
- Julie E Raab
- Department of Immunology and Microbiology, School of Medicine, University of Colorado-Anschutz Medical Campus, Denver, Colorado, USA
| | - Desmond J Hamilton
- Department of Immunology and Microbiology, School of Medicine, University of Colorado-Anschutz Medical Campus, Denver, Colorado, USA
| | - Tucker B Harju
- Department of Immunology and Microbiology, School of Medicine, University of Colorado-Anschutz Medical Campus, Denver, Colorado, USA
| | - Thao N Huynh
- Department of Immunology and Microbiology, School of Medicine, University of Colorado-Anschutz Medical Campus, Denver, Colorado, USA
| | - Brian C Russo
- Department of Immunology and Microbiology, School of Medicine, University of Colorado-Anschutz Medical Campus, Denver, Colorado, USA
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Miles SL, Holt KE, Mostowy S. Recent advances in modelling Shigella infection. Trends Microbiol 2024; 32:917-924. [PMID: 38423917 DOI: 10.1016/j.tim.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/06/2024] [Accepted: 02/06/2024] [Indexed: 03/02/2024]
Abstract
Shigella is an important human-adapted pathogen which contributes to a large global burden of diarrhoeal disease. Together with the increasing threat of antimicrobial resistance and lack of an effective vaccine, there is great urgency to identify novel therapeutics and preventatives to combat Shigella infection. In this review, we discuss the development of innovative technologies and animal models to study mechanisms underlying Shigella infection of humans. We examine recent literature introducing (i) the organ-on-chip model, and its substantial contribution towards understanding the biomechanics of Shigella infection, (ii) the zebrafish infection model, which has delivered transformative insights into the epidemiological success of clinical isolates and the innate immune response to Shigella, (iii) a pioneering oral mouse model of shigellosis, which has helped to discover new inflammasome biology and protective mechanisms against shigellosis, and (iv) the controlled human infection model, which has been effective in translating basic research into human health impact and assessing suitability of novel vaccine candidates. We consider the recent contributions of each model and discuss where the future of modelling Shigella infection lies.
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Affiliation(s)
- Sydney L Miles
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Kathryn E Holt
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Victoria 3004, Australia
| | - Serge Mostowy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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Giménez A, Del Giudice MG, López PV, Guaimas F, Sámano-Sánchez H, Gibson TJ, Chemes LB, Arregui CO, Ugalde JE, Czibener C. Brucella NpeA is a secreted Type IV effector containing an N-WASP-binding short linear motif that promotes niche formation. mBio 2024; 15:e0072624. [PMID: 38847540 PMCID: PMC11253601 DOI: 10.1128/mbio.00726-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 05/01/2024] [Indexed: 07/18/2024] Open
Abstract
The modulation of actin polymerization is a common theme among microbial pathogens. Even though microorganisms show a wide repertoire of strategies to subvert the activity of actin, most of them converge in the ones that activate nucleating factors, such as the Arp2/3 complex. Brucella spp. are intracellular pathogens capable of establishing chronic infections in their hosts. The ability to subvert the host cell response is dependent on the capacity of the bacterium to attach, invade, avoid degradation in the phagocytic compartment, replicate in an endoplasmic reticulum-derived compartment and egress. Even though a significant number of mechanisms deployed by Brucella in these different phases have been identified and characterized, none of them have been described to target actin as a cellular component. In this manuscript, we describe the identification of a novel virulence factor (NpeA) that promotes niche formation. NpeA harbors a short linear motif (SLiM) present within an amphipathic alpha helix that has been described to bind the GTPase-binding domain (GBD) of N-WASP and stabilizes the autoinhibited state. Our results show that NpeA is secreted in a Type IV secretion system-dependent manner and that deletion of the gene diminishes the intracellular replication capacity of the bacterium. In vitro and ex vivo experiments demonstrate that NpeA binds N-WASP and that the short linear motif is required for the biological activity of the protein.IMPORTANCEThe modulation of actin-binding effectors that regulate the activity of this fundamental cellular protein is a common theme among bacterial pathogens. The neural Wiskott-Aldrich syndrome protein (N-WASP) is a protein that several pathogens target to hijack actin dynamics. The highly adapted intracellular bacterium Brucella has evolved a wide repertoire of virulence factors that modulate many activities of the host cell to establish successful intracellular replication niches, but, to date, no effector proteins have been implicated in the modulation of actin dynamics. We present here the identification of a virulence factor that harbors a short linear motif (SLiM) present within an amphipathic alpha helix that has been described to bind the GTPase-binding domain (GBD) of N-WASP stabilizing its autoinhibited state. We demonstrate that this protein is a Type IV secretion effector that targets N-WASP-promoting intracellular survival and niche formation.
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Affiliation(s)
- Agostina Giménez
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Mariela G. Del Giudice
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Paula V. López
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Francisco Guaimas
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Hugo Sámano-Sánchez
- Zhejiang University School of Medicine, International Campus, Zhejiang University, Haining, China
- Biomedical Sciences, Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
| | - Toby J. Gibson
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Lucía B. Chemes
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Carlos O. Arregui
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Juan E. Ugalde
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
| | - Cecilia Czibener
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Buenos Aires, Argentina
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Chatterjee P, Mukherjee S, Majumder P. Shaping Drosophila eggs: unveiling the roles of Arpc1 and cpb in morphogenesis. Funct Integr Genomics 2024; 24:120. [PMID: 38960936 DOI: 10.1007/s10142-024-01396-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 06/15/2024] [Accepted: 06/18/2024] [Indexed: 07/05/2024]
Abstract
The Drosophila egg chamber (EC) starts as a spherical tissue at the beginning. With maturation, the outer follicle cells of EC collectively migrate in a direction perpendicular to the anterior-posterior axis, to shape EC from spherical to ellipsoidal. Filamentous actin (F-actin) plays a significant role in shaping individual migratory cells to the overall EC shape, like in every cell migration. The primary focus of this article is to unveil the function of different Actin Binding Proteins (ABPs) in regulating mature Drosophila egg shape. We have screened 66 ABPs, and the genetic screening data revealed that individual knockdown of Arp2/3 complex genes and the "capping protein β" (cpb) gene have severely altered the egg phenotype. Arpc1 and cpb RNAi mediated knockdown resulted in the formation of spherical eggs which are devoid of dorsal appendages. Studies also showed the role of Arpc1 and cpb on the number of laid eggs and follicle cell morphology. Furthermore, the depletion of Arpc1 and cpb resulted in a change in F-actin quantity. Together, the data indicate that Arpc1 and cpb regulate Drosophila egg shape, F-actin management, egg-laying characteristics and dorsal appendages formation.
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Affiliation(s)
- Poulami Chatterjee
- Department of Life Sciences, Presidency University, 86/1 College Street, Kolkata, 700073, India
| | - Sandipan Mukherjee
- Department of Life Sciences, Presidency University, 86/1 College Street, Kolkata, 700073, India
| | - Pralay Majumder
- Department of Life Sciences, Presidency University, 86/1 College Street, Kolkata, 700073, India.
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Homa KE, Hocky GM, Suarez C, Kovar DR. Arp2/3 complex- and formin-mediated actin cytoskeleton networks facilitate actin binding protein sorting in fission yeast. Eur J Cell Biol 2024; 103:151404. [PMID: 38493594 PMCID: PMC11211059 DOI: 10.1016/j.ejcb.2024.151404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 03/01/2024] [Accepted: 03/13/2024] [Indexed: 03/19/2024] Open
Abstract
While it is well-established that F-actin networks with specific organizations and dynamics are tightly regulated by distinct sets of associated actin-binding proteins (ABPs), how ABPs self-sort to particular F-actin networks remains largely unclear. We report that actin assembly factors Arp2/3 complex and formin Cdc12 tune the association of ABPs fimbrin Fim1 and tropomyosin Cdc8 to different F-actin networks in fission yeast. Genetic and pharmacological disruption of F-actin networks revealed that Fim1 is preferentially directed to Arp2/3-complex mediated actin patches, whereas Cdc8 is preferentially targeted to formin Cdc12-mediated filaments in the contractile ring. To investigate the role of Arp2/3 complex- and formin Cdc12-mediated actin assembly, we used four-color TIRF microscopy to observe the in vitro reconstitution of ABP sorting with purified proteins. Fim1 or Cdc8 alone bind similarly well to filaments assembled by either assembly factor. However, in 'competition' reactions containing both actin assembly factors and both ABPs, ∼2.0-fold more Fim1 and ∼3.5-fold more Cdc8 accumulates on Arp2/3 complex branch points and formin Cdc12-assembled actin filaments, respectively. These findings indicate that F-actin assembly factors Arp2/3 complex and formin Cdc12 help facilitate the recruitment of specific ABPs, thereby tuning ABP sorting and subsequently establishing the identity of F-actin networks in fission yeast.
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Affiliation(s)
- Kaitlin E Homa
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL, United States
| | - Glen M Hocky
- Department of Chemistry, New York University, New York, NY, United States
| | - Cristian Suarez
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL, United States
| | - David R Kovar
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL, United States; Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, United States.
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Matanza XM, Clements A. Pathogenicity and virulence of Shigella sonnei: A highly drug-resistant pathogen of increasing prevalence. Virulence 2023; 14:2280838. [PMID: 37994877 PMCID: PMC10732612 DOI: 10.1080/21505594.2023.2280838] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 11/01/2023] [Indexed: 11/24/2023] Open
Abstract
Shigella spp. are the causative agent of shigellosis (or bacillary dysentery), a diarrhoeal disease characterized for the bacterial invasion of gut epithelial cells. Among the 4 species included in the genus, Shigella flexneri is principally responsible for the disease in the developing world while Shigella sonnei is the main causative agent in high-income countries. Remarkably, as more countries improve their socioeconomic conditions, we observe an increase in the relative prevalence of S. sonnei. To date, the reasons behind this change in aetiology depending on economic growth are not understood. S. flexneri has been widely used as a model to study the pathogenesis of the genus, but as more research data are collected, important discrepancies with S. sonnei have come to light. In comparison to S. flexneri, S. sonnei can be differentiated in numerous aspects; it presents a characteristic O-antigen identical to that of one serogroup of the environmental bacterium Plesiomonas shigelloides, a group 4 capsule, antibacterial mechanisms to outcompete and displace gut commensal bacteria, and a poorer adaptation to an intracellular lifestyle. In addition, the World Health Organization (WHO) have recognized the significant threat posed by antibiotic-resistant strains of S. sonnei, demanding new approaches. This review gathers knowledge on what is known about S. sonnei within the context of other Shigella spp. and aims to open the door for future research on understanding the increasing spread of this pathogen.
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Affiliation(s)
- Xosé M. Matanza
- Centre for Bacterial Resistance Biology, Department of Life Sciences, Imperial College London, London, UK
| | - Abigail Clements
- Centre for Bacterial Resistance Biology, Department of Life Sciences, Imperial College London, London, UK
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Suarez C, Winkelman JD, Harker AJ, Ye HJ, McCall PM, Morganthaler AN, Gardel ML, Kovar DR. Reconstitution of the transition from a lamellipodia- to filopodia-like actin network with purified proteins. Eur J Cell Biol 2023; 102:151367. [PMID: 37890285 DOI: 10.1016/j.ejcb.2023.151367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 09/29/2023] [Accepted: 10/19/2023] [Indexed: 10/29/2023] Open
Abstract
How cells utilize complex mixtures of actin binding proteins to assemble and maintain functionally diverse actin filament networks with distinct architectures and dynamics within a common cytoplasm is a longstanding question in cell biology. A compelling example of complex and specialized actin structures in cells are filopodia which sense extracellular chemical and mechanical signals to help steer motile cells. Filopodia have distinct actin architecture, composed of long, parallel actin filaments bundled by fascin, which form finger-like membrane protrusions. Elongation of the parallel actin filaments in filopodia can be mediated by two processive actin filament elongation factors, formin and Ena/VASP, which localize to the tips of filopodia. There remains debate as to how the architecture of filopodia are generated, with one hypothesis proposing that filopodia are generated from the lamellipodia, which consists of densely packed, branched actin filaments nucleated by Arp2/3 complex and kept short by capping protein. It remains unclear if different actin filament elongation factors are necessary and sufficient to facilitate the emergence of filopodia with diverse characteristics from a highly dense network of short-branched capped filaments. To address this question, we combined bead motility and micropatterning biomimetic assays with multi-color Total Internal Reflection Fluorescence microscopy imaging, to successfully reconstitute the formation of filopodia-like networks (FLN) from densely-branched lamellipodia-like networks (LLN) with eight purified proteins (actin, profilin, Arp2/3 complex, Wasp pWA, fascin, capping protein, VASP and formin mDia2). Saturating capping protein concentrations inhibit FLN assembly, but the addition of either formin or Ena/VASP differentially rescues the formation of FLN from LLN. Specifically, we found that formin/mDia2-generated FLNs are relatively long and lack capping protein, whereas VASP-generated FLNs are comparatively short and contain capping protein, indicating that the actin elongation factor can affect the architecture and composition of FLN emerging from LLN. Our biomimetic reconstitution systems reveal that formin or VASP are necessary and sufficient to induce the transition from a LLN to a FLN, and establish robust in vitro platforms to investigate FLN assembly mechanisms.
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Affiliation(s)
- Cristian Suarez
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637, USA.
| | - Jonathan D Winkelman
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA
| | - Alyssa J Harker
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Hannah J Ye
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Patrick M McCall
- Department of Physics, The University of Chicago, Chicago, IL 60637, USA; James Franck Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Alisha N Morganthaler
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Margaret L Gardel
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA; Department of Physics, The University of Chicago, Chicago, IL 60637, USA; James Franck Institute, The University of Chicago, Chicago, IL 60637, USA; Pritzker School for Molecular Engineering, The University of Chicago, Chicago, IL 60637, USA
| | - David R Kovar
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637, USA; Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA.
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Alphonse N, Odendall C. Animal models of shigellosis: a historical overview. Curr Opin Immunol 2023; 85:102399. [PMID: 37952487 DOI: 10.1016/j.coi.2023.102399] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 11/14/2023]
Abstract
Shigella spp. are major causative agents of bacillary dysentery, a severe enteric disease characterized by destruction and inflammation of the colonic epithelium accompanied by acute diarrhea, fever, and abdominal pain. Although antibiotics have traditionally been effective, the prevalence of multidrug-resistant strains is increasing, stressing the urgent need for a vaccine. The human-specific nature of shigellosis and the absence of a dependable animal model have posed significant obstacles in understanding Shigella pathogenesis and the host immune response, both of which are crucial for the development of an effective vaccine. Efforts have been made over time to develop a physiological model that mimics the pathological features of the human disease with limited success until the recent development of genetically modified mouse models. In this review, we provide an overview of Shigella pathogenesis and chronicle the historical development of various shigellosis models, emphasizing their strengths and weaknesses.
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Affiliation(s)
- Noémie Alphonse
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK; Immunoregulation Laboratory, Francis Crick Institute, London, UK.
| | - Charlotte Odendall
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK.
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Li S, Anvari S, Ptacek G, Upadhyay I, Kaminski RW, Sack DA, Zhang W. A broadly immunogenic polyvalent Shigella multiepitope fusion antigen protein protects against Shigella sonnei and Shigella flexneri lethal pulmonary challenges in mice. Infect Immun 2023; 91:e0031623. [PMID: 37795982 PMCID: PMC10652900 DOI: 10.1128/iai.00316-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 08/21/2023] [Indexed: 10/06/2023] Open
Abstract
There are no licensed vaccines for Shigella, a leading cause of children's diarrhea and a common etiology of travelers' diarrhea. To develop a cross-protective Shigella vaccine, in this study, we constructed a polyvalent protein immunogen to present conserved immunodominant epitopes of Shigella invasion plasmid antigens B (IpaB) and D (IpaD), VirG, GuaB, and Shiga toxins on backbone protein IpaD, by applying an epitope- and structure-based multiepitope-fusion-antigen (MEFA) vaccinology platform, examined protein (Shigella MEFA) broad immunogenicity, and evaluated antibody function against Shigella invasion and Shiga toxin cytotoxicity but also protection against Shigella lethal challenge. Mice intramuscularly immunized with Shigella MEFA protein developed IgG responses to IpaB, IpaD, VirG, GuaB, and Shiga toxins 1 and 2; mouse sera significantly reduced invasion of Shigella sonnei, Shigella flexneri serotype 2a, 3a, or 6, Shigella boydii, and Shigella dysenteriae type 1 and neutralized cytotoxicity of Shiga toxins of Shigella and Shiga toxin-producing Escherichia coli in vitro. Moreover, mice intranasally immunized with Shigella MEFA protein (adjuvanted with dmLT) developed antigen-specific serum IgG, lung IgG and IgA, and fecal IgA antibodies, and survived from lethal pulmonary challenge with S. sonnei or S. flexneri serotype 2a, 3a, or 6. In contrast, the control mice died, became unresponsive, or lost 20% of body weight in 48 h. These results indicated that this Shigella MEFA protein is broadly immunogenic, induces broadly functional antibodies, and cross-protects against lethal pulmonary challenges with S. sonnei or S. flexneri serotypes, suggesting a potential application of this polyvalent MEFA protein in Shigella vaccine development.
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Affiliation(s)
- Siqi Li
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Shaghayegh Anvari
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
| | - Galen Ptacek
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Ipshita Upadhyay
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Robert W. Kaminski
- Department of Enteric Infections, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - David A. Sack
- Department of International Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Weiping Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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Gélin M, Schaeffer A, Gaillard J, Guérin C, Vianay B, Orhant-Prioux M, Braun M, Leterrier C, Blanchoin L, Théry M. Microtubules under mechanical pressure can breach dense actin networks. J Cell Sci 2023; 136:jcs261667. [PMID: 37870087 DOI: 10.1242/jcs.261667] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 09/25/2023] [Indexed: 10/24/2023] Open
Abstract
The crosstalk between the actin network and microtubules is essential for cell polarity. It orchestrates microtubule organization within the cell, driven by the asymmetry of actin architecture along the cell periphery. The physical intertwining of these networks regulates spatial organization and force distribution in the microtubule network. Although their biochemical interactions are becoming clearer, the mechanical aspects remain less understood. To explore this mechanical interplay, we developed an in vitro reconstitution assay to investigate how dynamic microtubules interact with various actin filament structures. Our findings revealed that microtubules can align and move along linear actin filament bundles through polymerization force. However, they are unable to pass through when encountering dense branched actin meshworks, similar to those present in the lamellipodium along the periphery of the cell. Interestingly, immobilizing microtubules through crosslinking with actin or other means allow the buildup of pressure, enabling them to breach these dense actin barriers. This mechanism offers insights into microtubule progression towards the cell periphery, with them overcoming obstacles within the denser parts of the actin network and ultimately contributing to cell polarity establishment.
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Affiliation(s)
- Matthieu Gélin
- Université Paris cité, CEA, INSERM, Institut de Recherche Saint Louis, UMR976 HIPI, CytoMorpho Lab, Avenue Claude Vellefaux, 75010 Paris, France
| | - Alexandre Schaeffer
- Université Paris cité, CEA, INSERM, Institut de Recherche Saint Louis, UMR976 HIPI, CytoMorpho Lab, Avenue Claude Vellefaux, 75010 Paris, France
| | - Jérémie Gaillard
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, UMR5168-LPCV, CytoMorpho Lab, Avenue des Martyrs, 38054 Grenoble, France
| | - Christophe Guérin
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, UMR5168-LPCV, CytoMorpho Lab, Avenue des Martyrs, 38054 Grenoble, France
| | - Benoit Vianay
- Université Paris cité, CEA, INSERM, Institut de Recherche Saint Louis, UMR976 HIPI, CytoMorpho Lab, Avenue Claude Vellefaux, 75010 Paris, France
| | - Magali Orhant-Prioux
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, UMR5168-LPCV, CytoMorpho Lab, Avenue des Martyrs, 38054 Grenoble, France
| | - Marcus Braun
- Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, 25250 Vestec, Prague West, Czech Republic
| | - Christophe Leterrier
- Aix Marseille Université, CNRS, INP UMR7051, NeuroCyto, 13385, Marseille, France
| | - Laurent Blanchoin
- Université Paris cité, CEA, INSERM, Institut de Recherche Saint Louis, UMR976 HIPI, CytoMorpho Lab, Avenue Claude Vellefaux, 75010 Paris, France
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, UMR5168-LPCV, CytoMorpho Lab, Avenue des Martyrs, 38054 Grenoble, France
| | - Manuel Théry
- Université Paris cité, CEA, INSERM, Institut de Recherche Saint Louis, UMR976 HIPI, CytoMorpho Lab, Avenue Claude Vellefaux, 75010 Paris, France
- Université Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, UMR5168-LPCV, CytoMorpho Lab, Avenue des Martyrs, 38054 Grenoble, France
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Colin A, Orhant-Prioux M, Guérin C, Savinov M, Cao W, Vianay B, Scarfone I, Roux A, De La Cruz EM, Mogilner A, Théry M, Blanchoin L. Friction patterns guide actin network contraction. Proc Natl Acad Sci U S A 2023; 120:e2300416120. [PMID: 37725653 PMCID: PMC10523593 DOI: 10.1073/pnas.2300416120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 08/09/2023] [Indexed: 09/21/2023] Open
Abstract
The shape of cells is the outcome of the balance of inner forces produced by the actomyosin network and the resistive forces produced by cell adhesion to their environment. The specific contributions of contractile, anchoring and friction forces to network deformation rate and orientation are difficult to disentangle in living cells where they influence each other. Here, we reconstituted contractile actomyosin networks in vitro to study specifically the role of the friction forces between the network and its anchoring substrate. To modulate the magnitude and spatial distribution of friction forces, we used glass or lipids surface micropatterning to control the initial shape of the network. We adapted the concentration of Nucleating Promoting Factor on each surface to induce the assembly of actin networks of similar densities and compare the deformation of the network toward the centroid of the pattern shape upon myosin-induced contraction. We found that actin network deformation was faster and more coordinated on lipid bilayers than on glass, showing the resistance of friction to network contraction. To further study the role of the spatial distribution of these friction forces, we designed heterogeneous micropatterns made of glass and lipids. The deformation upon contraction was no longer symmetric but biased toward the region of higher friction. Furthermore, we showed that the pattern of friction could robustly drive network contraction and dominate the contribution of asymmetric distributions of myosins. Therefore, we demonstrate that during contraction, both the active and resistive forces are essential to direct the actin network deformation.
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Affiliation(s)
- Alexandra Colin
- Université Grenoble-Alpes, CEA, CNRS, UMR5168, Interdisciplinary Research Institute of Grenoble, CytoMorpho Lab, Grenoble38054, France
| | - Magali Orhant-Prioux
- Université Grenoble-Alpes, CEA, CNRS, UMR5168, Interdisciplinary Research Institute of Grenoble, CytoMorpho Lab, Grenoble38054, France
| | - Christophe Guérin
- Université Grenoble-Alpes, CEA, CNRS, UMR5168, Interdisciplinary Research Institute of Grenoble, CytoMorpho Lab, Grenoble38054, France
| | - Mariya Savinov
- Courant Institute of Mathematical Sciences, New York University, New York, NY10012
| | - Wenxiang Cao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06520-8114
| | - Benoit Vianay
- University of Paris, INSERM, Commissariat à l'énergie atomique et aux énergies alternatives, UMRS1160, Institut de Recherche Saint Louis, CytoMorpho Lab, Hôpital Saint Louis, Paris75010, France
| | - Ilaria Scarfone
- Université Grenoble-Alpes, CEA, CNRS, UMR5168, Interdisciplinary Research Institute of Grenoble, CytoMorpho Lab, Grenoble38054, France
| | - Aurélien Roux
- Department of Biochemistry, University of Geneva, CH-1211Geneva, Switzerland
| | - Enrique M. De La Cruz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06520-8114
| | - Alex Mogilner
- Courant Institute of Mathematical Sciences, New York University, New York, NY10012
| | - Manuel Théry
- Université Grenoble-Alpes, CEA, CNRS, UMR5168, Interdisciplinary Research Institute of Grenoble, CytoMorpho Lab, Grenoble38054, France
- University of Paris, INSERM, Commissariat à l'énergie atomique et aux énergies alternatives, UMRS1160, Institut de Recherche Saint Louis, CytoMorpho Lab, Hôpital Saint Louis, Paris75010, France
| | - Laurent Blanchoin
- Université Grenoble-Alpes, CEA, CNRS, UMR5168, Interdisciplinary Research Institute of Grenoble, CytoMorpho Lab, Grenoble38054, France
- University of Paris, INSERM, Commissariat à l'énergie atomique et aux énergies alternatives, UMRS1160, Institut de Recherche Saint Louis, CytoMorpho Lab, Hôpital Saint Louis, Paris75010, France
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12
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Vickery JM, Toperzer JD, Raab JE, Lenz LL, Colgan SP, Russo BC. Synaptopodin is necessary for Shigella flexneri intercellular spread. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.25.537990. [PMID: 37163027 PMCID: PMC10168286 DOI: 10.1101/2023.04.25.537990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
For many intracellular pathogens, their virulence depends on an ability to spread between cells of an epithelial layer. For intercellular spread to occur, these pathogens deform the plasma membrane into a protrusion structure that is engulfed by the neighboring cell. Although the polymerization of actin is essential for spread, how these pathogens manipulate the actin cytoskeleton in a manner that enables protrusion formation is still incompletely understood. Here, we identify the mammalian actin binding protein synaptopodin as required for efficient intercellular spread. Using a model cytosolic pathogen, Shigella flexneri , we show that synaptopodin contributes to organization of actin around bacteria and increases the length of the actin tail at the posterior pole of the bacteria. We show that synaptopodin presence enables protrusions to form and to resolve at a greater rate, indicating that greater stability of the actin tail enables the bacteria to push against the membrane with greater force. We demonstrate that synaptopodin recruitment around bacteria requires the bacterial protein IcsA, and we show that this recruitment is further enhanced in a type 3 secretion system dependent manner. These data establish synaptopodin as required for intracellular bacteria to reprogram the actin cytoskeleton in a manner that enables efficient protrusion formation and enhance our understanding of the cellular function of synaptopodin. Authors Summary Intercellular spread is essential for many cytosolic dwelling pathogens during their infectious life cycle. Despite knowing the steps required for intercellular spread, relatively little is known about the host-pathogen interactions that enable these steps to occur. Here, we identify a requirement for the actin binding protein synaptopodin during intercellular spread by cytosolic bacteria. We show synaptopodin is necessary for the stability and recruitment of polymerized actin around bacteria. We also demonstrate synaptopodin is necessary to form plasma membrane structures known as protrusions that are necessary for the movement of these bacteria between cells. Thus, these findings implicate synaptopodin as an important actin-binding protein for the virulence of intracellular pathogens that require the actin cytoskeleton for their spread between cells.
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13
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Colin A, Kotila T, Guérin C, Orhant-Prioux M, Vianay B, Mogilner A, Lappalainen P, Théry M, Blanchoin L. Recycling of the actin monomer pool limits the lifetime of network turnover. EMBO J 2023; 42:e112717. [PMID: 36912152 PMCID: PMC10152149 DOI: 10.15252/embj.2022112717] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 02/10/2023] [Accepted: 02/21/2023] [Indexed: 03/14/2023] Open
Abstract
Intracellular organization is largely mediated by actin turnover. Cellular actin networks continuously assemble and disassemble, while maintaining their overall appearance. This behavior, called "dynamic steady state," allows cells to sense and adapt to their environment. However, how structural stability can be maintained during the constant turnover of a limited actin monomer pool is poorly understood. To answer this question, we developed an experimental system where polystyrene beads are propelled by an actin comet in a microwell containing a limited amount of components. We used the speed and the size of the actin comet tails to evaluate the system's monomer consumption and its lifetime. We established the relative contribution of actin assembly, disassembly, and recycling for a bead movement over tens of hours. Recycling mediated by cyclase-associated protein (CAP) is the key step in allowing the reuse of monomers for multiple assembly cycles. ATP supply and protein aging are also factors that limit the lifetime of actin turnover. This work reveals the balancing mechanism for long-term network assembly with a limited amount of building blocks.
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Affiliation(s)
- Alexandra Colin
- CytoMorpho Lab, Laboratoire de Physiologie Cellulaire & Végétale, Interdisciplinary Research Institute of Grenoble, University of Grenoble-Alpes, CEA, CNRS, INRA, Grenoble, France
| | - Tommi Kotila
- Institute of Biotechnology and Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Christophe Guérin
- CytoMorpho Lab, Laboratoire de Physiologie Cellulaire & Végétale, Interdisciplinary Research Institute of Grenoble, University of Grenoble-Alpes, CEA, CNRS, INRA, Grenoble, France
| | - Magali Orhant-Prioux
- CytoMorpho Lab, Laboratoire de Physiologie Cellulaire & Végétale, Interdisciplinary Research Institute of Grenoble, University of Grenoble-Alpes, CEA, CNRS, INRA, Grenoble, France
| | - Benoit Vianay
- CytoMorpho Lab, Institut de Recherche Saint Louis, U976 Human Immunology Pathophysiology Immunotherapy (HIPI), University of Paris, INSERM, CEA, Paris, France
| | - Alex Mogilner
- Courant Institute of Mathematical Sciences, New York University, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Pekka Lappalainen
- Institute of Biotechnology and Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Manuel Théry
- CytoMorpho Lab, Laboratoire de Physiologie Cellulaire & Végétale, Interdisciplinary Research Institute of Grenoble, University of Grenoble-Alpes, CEA, CNRS, INRA, Grenoble, France.,CytoMorpho Lab, Institut de Recherche Saint Louis, U976 Human Immunology Pathophysiology Immunotherapy (HIPI), University of Paris, INSERM, CEA, Paris, France
| | - Laurent Blanchoin
- CytoMorpho Lab, Laboratoire de Physiologie Cellulaire & Végétale, Interdisciplinary Research Institute of Grenoble, University of Grenoble-Alpes, CEA, CNRS, INRA, Grenoble, France.,CytoMorpho Lab, Institut de Recherche Saint Louis, U976 Human Immunology Pathophysiology Immunotherapy (HIPI), University of Paris, INSERM, CEA, Paris, France
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14
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Baldauf L, Frey F, Arribas Perez M, Idema T, Koenderink GH. Branched actin cortices reconstituted in vesicles sense membrane curvature. Biophys J 2023:S0006-3495(23)00124-8. [PMID: 36806830 DOI: 10.1016/j.bpj.2023.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/16/2022] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
The actin cortex is a complex cytoskeletal machinery that drives and responds to changes in cell shape. It must generate or adapt to plasma membrane curvature to facilitate diverse functions such as cell division, migration, and phagocytosis. Due to the complex molecular makeup of the actin cortex, it remains unclear whether actin networks are inherently able to sense and generate membrane curvature, or whether they rely on their diverse binding partners to accomplish this. Here, we show that curvature sensing is an inherent capability of branched actin networks nucleated by Arp2/3 and VCA. We develop a robust method to encapsulate actin inside giant unilamellar vesicles (GUVs) and assemble an actin cortex at the inner surface of the GUV membrane. We show that actin forms a uniform and thin cortical layer when present at high concentration and distinct patches associated with negative membrane curvature at low concentration. Serendipitously, we find that the GUV production method also produces dumbbell-shaped GUVs, which we explain using mathematical modeling in terms of membrane hemifusion of nested GUVs. We find that branched actin networks preferentially assemble at the neck of the dumbbells, which possess a micrometer-range convex curvature comparable with the curvature of the actin patches found in spherical GUVs. Minimal branched actin networks can thus sense membrane curvature, which may help mammalian cells to robustly recruit actin to curved membranes to facilitate diverse cellular functions such as cytokinesis and migration.
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Affiliation(s)
- Lucia Baldauf
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Felix Frey
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Marcos Arribas Perez
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Timon Idema
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands.
| | - Gijsje H Koenderink
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands.
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15
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Sharafutdinov I, Knorr J, Rottner K, Backert S, Tegtmeyer N. Cortactin: A universal host cytoskeletal target of Gram-negative and Gram-positive bacterial pathogens. Mol Microbiol 2022; 118:623-636. [PMID: 36396951 DOI: 10.1111/mmi.15002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 11/19/2022]
Abstract
Pathogenic bacteria possess a great potential of causing infectious diseases and represent a serious threat to human and animal health. Understanding the molecular basis of infection development can provide new valuable strategies for disease prevention and better control. In host-pathogen interactions, actin-cytoskeletal dynamics play a crucial role in the successful adherence, invasion, and intracellular motility of many intruding microbial pathogens. Cortactin, a major cellular factor that promotes actin polymerization and other functions, appears as a central regulator of host-pathogen interactions and different human diseases including cancer development. Various important microbes have been reported to hijack cortactin signaling during infection. The primary regulation of cortactin appears to proceed via serine and/or tyrosine phosphorylation events by upstream kinases, acetylation, and interaction with various other host proteins, including the Arp2/3 complex, filamentous actin, the actin nucleation promoting factor N-WASP, focal adhesion kinase FAK, the large GTPase dynamin-2, the guanine nucleotide exchange factor Vav2, and the actin-stabilizing protein CD2AP. Given that many signaling factors can affect cortactin activities, several microbes target certain unique pathways, while also sharing some common features. Here we review our current knowledge of the hallmarks of cortactin as a major target for eminent Gram-negative and Gram-positive bacterial pathogens in humans.
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Affiliation(s)
- Irshad Sharafutdinov
- Department of Biology, Division of Microbiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jakob Knorr
- Department of Biology, Division of Microbiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Klemens Rottner
- Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Steffen Backert
- Department of Biology, Division of Microbiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Nicole Tegtmeyer
- Department of Biology, Division of Microbiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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16
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Clarke KR, Hor L, Pilapitiya A, Luirink J, Paxman JJ, Heras B. Phylogenetic Classification and Functional Review of Autotransporters. Front Immunol 2022; 13:921272. [PMID: 35860281 PMCID: PMC9289746 DOI: 10.3389/fimmu.2022.921272] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 06/06/2022] [Indexed: 11/30/2022] Open
Abstract
Autotransporters are the core component of a molecular nano-machine that delivers cargo proteins across the outer membrane of Gram-negative bacteria. Part of the type V secretion system, this large family of proteins play a central role in controlling bacterial interactions with their environment by promoting adhesion to surfaces, biofilm formation, host colonization and invasion as well as cytotoxicity and immunomodulation. As such, autotransporters are key facilitators of fitness and pathogenesis and enable co-operation or competition with other bacteria. Recent years have witnessed a dramatic increase in the number of autotransporter sequences reported and a steady rise in functional studies, which further link these proteins to multiple virulence phenotypes. In this review we provide an overview of our current knowledge on classical autotransporter proteins, the archetype of this protein superfamily. We also carry out a phylogenetic analysis of their functional domains and present a new classification system for this exquisitely diverse group of bacterial proteins. The sixteen phylogenetic divisions identified establish sensible relationships between well characterized autotransporters and inform structural and functional predictions of uncharacterized proteins, which may guide future research aimed at addressing multiple unanswered aspects in this group of therapeutically important bacterial factors.
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Affiliation(s)
- Kaitlin R. Clarke
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
| | - Lilian Hor
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
| | - Akila Pilapitiya
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
| | - Joen Luirink
- Department of Molecular Microbiology, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit, Amsterdam, Netherlands
| | - Jason J. Paxman
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
- *Correspondence: Begoña Heras, ; Jason J. Paxman,
| | - Begoña Heras
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
- *Correspondence: Begoña Heras, ; Jason J. Paxman,
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17
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Hill NS, Welch MD. A glycine-rich PE_PGRS protein governs mycobacterial actin-based motility. Nat Commun 2022; 13:3608. [PMID: 35750685 PMCID: PMC9232537 DOI: 10.1038/s41467-022-31333-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 06/14/2022] [Indexed: 11/09/2022] Open
Abstract
Many key insights into actin regulation have been derived through examining how microbial pathogens intercept the actin cytoskeleton during infection. Mycobacterium marinum, a close relative of the human pathogen Mycobacterium tuberculosis, polymerizes host actin at the bacterial surface to drive intracellular movement and cell-to-cell spread during infection. However, the mycobacterial factor that commandeers actin polymerization has remained elusive. Here, we report the identification and characterization of the M. marinum actin-based motility factor designated mycobacterial intracellular rockets A (MirA), which is a member of the glycine-rich PE_PGRS protein family. MirA contains an amphipathic helix to anchor into the mycobacterial outer membrane and, surprisingly, also the surface of host lipid droplet organelles. MirA directly binds to and activates the host protein N-WASP to stimulate actin polymerization through the Arp2/3 complex, directing both bacterial and lipid droplet actin-based motility. MirA is dissimilar to known N-WASP activating ligands and may represent a new class of microbial and host actin regulator. Additionally, the MirA-N-WASP interaction represents a model to understand how the enigmatic PE_PGRS proteins contribute to mycobacterial pathogenesis.
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Affiliation(s)
- Norbert S Hill
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
| | - Matthew D Welch
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
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18
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Nasser A, Mosadegh M, Azimi T, Shariati A. Molecular mechanisms of Shigella effector proteins: a common pathogen among diarrheic pediatric population. Mol Cell Pediatr 2022; 9:12. [PMID: 35718793 PMCID: PMC9207015 DOI: 10.1186/s40348-022-00145-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 05/06/2022] [Indexed: 12/16/2022] Open
Abstract
Different gastrointestinal pathogens cause diarrhea which is a very common problem in children aged under 5 years. Among bacterial pathogens, Shigella is one of the main causes of diarrhea among children, and it accounts for approximately 11% of all deaths among children aged under 5 years. The case-fatality rates for Shigella among the infants and children aged 1 to 4 years are 13.9% and 9.4%, respectively. Shigella uses unique effector proteins to modulate intracellular pathways. Shigella cannot invade epithelial cells on the apical site; therefore, it needs to pass epithelium through other cells rather than the epithelial cell. After passing epithelium, macrophage swallows Shigella, and the latter should prepare itself to exhibit at least two types of responses: (I) escaping phagocyte and (II) mediating invasion of and injury to the recurrent PMN. The presence of PMN and invitation to a greater degree resulted in gut membrane injuries and greater bacterial penetration. Infiltration of Shigella to the basolateral space mediates (A) cell attachment, (B) cell entry, (C) evasion of autophagy recognition, (D) vacuole formation and and vacuole rapture, (E) intracellular life, (F) Shiga toxin, and (G) immune response. In this review, an attempt is made to explain the role of each factor in Shigella infection.
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Affiliation(s)
- Ahmad Nasser
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehrdad Mosadegh
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Taher Azimi
- Department of Bacteriology & Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Aref Shariati
- Molecular and medicine research center, Khomein University of Medical Sciences, Khomein, Iran
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19
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Fujise K, Noguchi S, Takeda T. Centronuclear Myopathy Caused by Defective Membrane Remodelling of Dynamin 2 and BIN1 Variants. Int J Mol Sci 2022; 23:ijms23116274. [PMID: 35682949 PMCID: PMC9181712 DOI: 10.3390/ijms23116274] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 05/31/2022] [Accepted: 06/01/2022] [Indexed: 02/01/2023] Open
Abstract
Centronuclear myopathy (CNM) is a congenital myopathy characterised by centralised nuclei in skeletal myofibers. T-tubules, sarcolemmal invaginations required for excitation-contraction coupling, are disorganised in the skeletal muscles of CNM patients. Previous studies showed that various endocytic proteins are involved in T-tubule biogenesis and their dysfunction is tightly associated with CNM pathogenesis. DNM2 and BIN1 are two causative genes for CNM that encode essential membrane remodelling proteins in endocytosis, dynamin 2 and BIN1, respectively. In this review, we overview the functions of dynamin 2 and BIN1 in T-tubule biogenesis and discuss how their dysfunction in membrane remodelling leads to CNM pathogenesis.
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Affiliation(s)
- Kenshiro Fujise
- Departments of Neuroscience and Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520-8001, USA;
| | - Satoru Noguchi
- National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Tokyo 187-8502, Japan;
| | - Tetsuya Takeda
- Department of Biochemistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Shikata-cho 2-5-1, Kita-ku, Okayama 700-8558, Japan
- Correspondence: ; Tel.: +81-86-235-7125; Fax: +81-86-235-7126
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20
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Kramer DA, Piper HK, Chen B. WASP family proteins: Molecular mechanisms and implications in human disease. Eur J Cell Biol 2022; 101:151244. [PMID: 35667337 PMCID: PMC9357188 DOI: 10.1016/j.ejcb.2022.151244] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 02/08/2023] Open
Abstract
Proteins of the Wiskott-Aldrich syndrome protein (WASP) family play a central role in regulating actin cytoskeletal dynamics in a wide range of cellular processes. Genetic mutations or misregulation of these proteins are tightly associated with many diseases. The WASP-family proteins act by transmitting various upstream signals to their conserved WH2-Central-Acidic (WCA) peptide sequence at the C-terminus, which in turn binds to the Arp2/3 complex to stimulate the formation of branched actin networks at membranes. Despite this common feature, the regulatory mechanisms and cellular functions of distinct WASP-family proteins are very different. Here, we summarize and clarify our current understanding of WASP-family proteins and how disruption of their functions is related to human disease.
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Affiliation(s)
- Daniel A Kramer
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, 2437 Pammel Drive, Ames, IA 50011, USA
| | - Hannah K Piper
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, 2437 Pammel Drive, Ames, IA 50011, USA
| | - Baoyu Chen
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, 2437 Pammel Drive, Ames, IA 50011, USA.
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21
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Dhanda AS, Guttman JA. Localization of host endocytic and actin-associated proteins during Shigella flexneri intracellular motility and intercellular spreading. Anat Rec (Hoboken) 2022; 306:1088-1110. [PMID: 35582740 DOI: 10.1002/ar.24955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/24/2022] [Accepted: 04/27/2022] [Indexed: 11/10/2022]
Abstract
Shigella flexneri (S. flexneri), the causative agent of bacillary dysentery, uses an effector-mediated strategy to hijack host cells and cause disease. To propagate and spread within human tissues, S. flexneri bacteria commandeer the host actin cytoskeleton to generate slender actin-rich comet tails to move intracellularly, and later, plasma membrane actin-based protrusions to move directly between adjacent host cells. To facilitate intercellular bacterial spreading, large micron-sized endocytic-like membrane invaginations form at the periphery of neighboring host cells that come into contact with S. flexneri-containing membrane protrusions. While S. flexneri comet tails and membrane protrusions consist primarily of host actin cytoskeletal proteins, S. flexneri membrane invaginations remain poorly understood with only clathrin and the clathrin adapter epsin-1 localized to the structures. Tangentially, we recently reported that Listeria monocytogenes, another actin-hijacking pathogen, exploits an assortment of caveolar and actin-bundling proteins at their micron-sized membrane invaginations formed during their cell-to-cell movement. Thus, to further characterize the S. flexneri disease process, we set out to catalog the distribution of a variety of actin-associated and caveolar proteins during S. flexneri actin-based motility and cell-to-cell spreading. Here we show that actin-associated proteins found at L. monocytogenes comet tails and membrane protrusions mimic those present at S. flexneri comet tails with the exception of α-actinins 1 and 4, which were shed from S. flexneri membrane protrusions. We also demonstrate that all known host endocytic components found at L. monocytogenes membrane invaginations are also present at those formed during S. flexneri infections.
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Affiliation(s)
- Aaron Singh Dhanda
- Department of Biological Sciences, Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Julian Andrew Guttman
- Department of Biological Sciences, Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
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22
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Chung YJ, Salvi A, Kalailingam P, Alnawaz M, Tan SH, Pan JY, Tan NS, Thanabalu T. N-WASP Attenuates Cell Proliferation and Migration through ERK2-Dependent Enhanced Expression of TXNIP. BIOLOGY 2022; 11:biology11040582. [PMID: 35453780 PMCID: PMC9029996 DOI: 10.3390/biology11040582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/10/2022] [Accepted: 04/08/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary Neural Wiskott–Aldrich Syndrome Protein (N-WASP) regulates actin cytoskeleton remodeling and can, it has been suggested, suppress several cancers. In this study, HSC-5 cells, a mammalian cell line with reduced N-WASP expression, were used to generate control cells and HSC-5 cells with increased N-WASP expression that is comparable to that of normal keratinocytes. The two cell lines were used to elucidate the regulation of cell proliferation and migration by N-WASP. Our findings suggest that N-WASP increases ERK2-dependent phosphorylation of FOXO1 and increases TXNIP expression, which reduces cell proliferation and migration. This study is the first to propose an antiproliferative role of N-WASP, which is mediated via ERK2, and it suggests new avenues for cancer therapeutic research and treatment. Abstract Neural Wiskott–Aldrich Syndrome Protein (N-WASP) regulates actin cytoskeleton remodeling. It has been known that reduced N-WASP expression in breast and colorectal cancers is associated with poor prognosis. Here, we found reduced N-WASP expression in squamous cell carcinoma (SCC) patient samples. The SCC cell line HSC-5 with reduced N-WASP expression was used to generate HSC-5CN (control) and HSC-5NW (N-WASP overexpression) cells. HSC-5NW cells had reduced cell proliferation and migration compared to HSC-5CN cells. HSC-5NW cells had increased phospho-ERK2 (extracellular signal-regulated kinase 2), phosphorylated Forkhead box protein class O1 (FOXO1) and reduced nuclear FOXO1 staining compared to HSC-5CN cells. Proteasome inhibition stabilized total FOXO1, however, not nuclear staining, suggesting that FOXO1 could be degraded in the cytoplasm. Inhibition of ERK2 enhanced nuclear FOXO1 levels and restored cell proliferation and migration of HSC-5NW to those of HSC-5CN cells, suggesting that ERK2 regulates FOXO1 activity. The expression of thioredoxin-interacting protein (TXNIP), a FOXO1 target that inhibits thioredoxin and glucose uptake, was higher in HSC-5NW cells than in HSC-5CN cells. Knockdown of TXNIP in HSC-5NW cells restored cell proliferation and migration to those of HSC-5CN cells. Thus, we propose that N-WASP regulates cell proliferation and migration via an N-WASP-ERK2-FOXO1-TXNIP pathway.
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Affiliation(s)
- Yat Joong Chung
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore; (Y.J.C.); (A.S.); (P.K.); (M.A.); (N.S.T.)
| | - Amrita Salvi
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore; (Y.J.C.); (A.S.); (P.K.); (M.A.); (N.S.T.)
| | - Pazhanichamy Kalailingam
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore; (Y.J.C.); (A.S.); (P.K.); (M.A.); (N.S.T.)
| | - Myra Alnawaz
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore; (Y.J.C.); (A.S.); (P.K.); (M.A.); (N.S.T.)
| | - Suat Hoon Tan
- National Skin Centre, 1 Mandalay Road, Singapore 308205, Singapore; (S.H.T.); (J.Y.P.)
| | - Jiun Yit Pan
- National Skin Centre, 1 Mandalay Road, Singapore 308205, Singapore; (S.H.T.); (J.Y.P.)
| | - Nguan Soon Tan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore; (Y.J.C.); (A.S.); (P.K.); (M.A.); (N.S.T.)
- Lee Kong Chian School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore 308232, Singapore
| | - Thirumaran Thanabalu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore; (Y.J.C.); (A.S.); (P.K.); (M.A.); (N.S.T.)
- Correspondence: ; Tel.: +65-6316-2832; Fax: +65-6791-3856
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23
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Köseoğlu VK, Jones MK, Agaisse H. The type 3 secretion effector IpgD promotes S. flexneri dissemination. PLoS Pathog 2022; 18:e1010324. [PMID: 35130324 PMCID: PMC8853559 DOI: 10.1371/journal.ppat.1010324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 02/17/2022] [Accepted: 01/31/2022] [Indexed: 12/15/2022] Open
Abstract
The bacterial pathogen Shigella flexneri causes 270 million cases of bacillary dysentery worldwide every year, resulting in more than 200,000 deaths. S. flexneri pathogenic properties rely on its ability to invade epithelial cells and spread from cell to cell within the colonic epithelium. This dissemination process relies on actin-based motility in the cytosol of infected cells and formation of membrane protrusions that project into adjacent cells and resolve into double-membrane vacuoles (DMVs) from which the pathogen escapes, thereby achieving cell-to-cell spread. S. flexneri dissemination is facilitated by the type 3 secretion system (T3SS) through poorly understood mechanisms. Here, we show that the T3SS effector IpgD facilitates the resolution of membrane protrusions into DMVs during S. flexneri dissemination. The phosphatidylinositol 4-phosphatase activity of IpgD decreases PtdIns(4,5)P2 levels in membrane protrusions, thereby counteracting de novo cortical actin formation in protrusions, a process that restricts the resolution of protrusions into DMVs. Finally, using an infant rabbit model of shigellosis, we show that IpgD is required for efficient cell-to-cell spread in vivo and contributes to the severity of dysentery. The intracellular pathogen Shigella flexneri is the causative agent of bacillary dysentery (blood in stool). Invasion of epithelial cells and cell-to-cell spread are critical determinants of S. flexneri pathogenesis. Cell-to-cell spread relies on the formation of membrane protrusions that project into adjacent cells and resolve into vacuoles. The molecular mechanisms supporting this dissemination process are poorly understood. In this study, we show that S. flexneri employs the phosphatidylinositol phosphatase activity of the T3SS effector protein IpgD to manipulate phosphoinositides in the protrusion membrane. Manipulation of phosphoinositide signaling restricts the formation of actin networks underneath the protrusion membrane, which would otherwise prevent the scission of protrusions into vacuoles. We also demonstrate that IpgD is required for efficient dissemination in the colon of infant rabbits and contributes to the severity of disease. This study exemplifies how manipulation of phosphoinositide signaling by intracellular pathogens supports bacterial pathogenesis.
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Affiliation(s)
- Volkan K. Köseoğlu
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, Virginia, United States of America
| | - Marieke K. Jones
- Claude Moore Health Sciences Library, University of Virginia, Charlottesville, Virginia, United States of America
| | - Hervé Agaisse
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, Virginia, United States of America
- * E-mail:
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24
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Leung G, Zhou Y, Ostrowski P, Mylvaganam S, Boroumand P, Mulder DJ, Guo C, Muise AM, Freeman SA. ARPC1B binds WASP to control actin polymerization and curtail tonic signaling in B cells. JCI Insight 2021; 6:149376. [PMID: 34673575 PMCID: PMC8675194 DOI: 10.1172/jci.insight.149376] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 10/20/2021] [Indexed: 01/08/2023] Open
Abstract
Immune cells exhibit low-level, constitutive signaling at rest (tonic signaling). Such tonic signals are required for fundamental processes, including the survival of B lymphocytes, but when they are elevated by genetic or environmental causes, they can lead to autoimmunity. Events that control ongoing signal transduction are, therefore, tightly regulated by submembrane cytoskeletal polymers like F-actin. The actin-binding proteins that underpin the process, however, are poorly described. By investigating patients with ARPC1B deficiency, we report that ARPC1B-containing ARP2/3 complexes are stimulated by Wiskott Aldrich Syndrome protein (WASP) to nucleate the branched actin networks that control tonic signaling from the B cell receptor (BCR). Despite an upregulation of ARPC1A, ARPC1B-deficient cells were not capable of WASP-mediated nucleation by ARP2/3, and this caused the loss of WASP-dependent structures, including podosomes in macrophages and lamellipodia in B cells. In the B cell compartment, ARPC1B deficiency also led to weakening of the cortical F-actin cytoskeleton that normally curtails the diffusion of BCRs and ultimately resulted in increased tonic lipid signaling, oscillatory calcium release from the endoplasmic reticulum (ER), and phosphorylated Akt. These events contributed to skewing the threshold for B cell activation in response to microbial-associated molecular patterns (MAMPs). Thus, ARPC1B is critical for ARP2/3 complexes to control steady-state signaling of immune cells.
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Affiliation(s)
- Gabriella Leung
- Program in Cell Biology and.,SickKids Inflammatory Bowel Disease Centre, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | | - Daniel J Mulder
- Program in Cell Biology and.,SickKids Inflammatory Bowel Disease Centre, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Conghui Guo
- Program in Cell Biology and.,SickKids Inflammatory Bowel Disease Centre, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Aleixo M Muise
- Program in Cell Biology and.,SickKids Inflammatory Bowel Disease Centre, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Biochemistry and.,Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
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25
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Quereda JJ, Morón-García A, Palacios-Gorba C, Dessaux C, García-del Portillo F, Pucciarelli MG, Ortega AD. Pathogenicity and virulence of Listeria monocytogenes: A trip from environmental to medical microbiology. Virulence 2021; 12:2509-2545. [PMID: 34612177 PMCID: PMC8496543 DOI: 10.1080/21505594.2021.1975526] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 01/02/2023] Open
Abstract
Listeria monocytogenes is a saprophytic gram-positive bacterium, and an opportunistic foodborne pathogen that can produce listeriosis in humans and animals. It has evolved an exceptional ability to adapt to stress conditions encountered in different environments, resulting in a ubiquitous distribution. Because some food preservation methods and disinfection protocols in food-processing environments cannot efficiently prevent contaminations, L. monocytogenes constitutes a threat to human health and a challenge to food safety. In the host, Listeria colonizes the gastrointestinal tract, crosses the intestinal barrier, and disseminates through the blood to target organs. In immunocompromised individuals, the elderly, and pregnant women, the pathogen can cross the blood-brain and placental barriers, leading to neurolisteriosis and materno-fetal listeriosis. Molecular and cell biology studies of infection have proven L. monocytogenes to be a versatile pathogen that deploys unique strategies to invade different cell types, survive and move inside the eukaryotic host cell, and spread from cell to cell. Here, we present the multifaceted Listeria life cycle from a comprehensive perspective. We discuss genetic features of pathogenic Listeria species, analyze factors involved in food contamination, and review bacterial strategies to tolerate stresses encountered both during food processing and along the host's gastrointestinal tract. Then we dissect host-pathogen interactions underlying listerial pathogenesis in mammals from a cell biology and systemic point of view. Finally, we summarize the epidemiology, pathophysiology, and clinical features of listeriosis in humans and animals. This work aims to gather information from different fields crucial for a comprehensive understanding of the pathogenesis of L. monocytogenes.
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Affiliation(s)
- Juan J. Quereda
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities. Valencia, Spain
| | - Alvaro Morón-García
- Departamento de Biología Celular. Facultad de Ciencias Biológicas, Universidad Complutense de Madrid. Madrid, Spain
| | - Carla Palacios-Gorba
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities. Valencia, Spain
| | - Charlotte Dessaux
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB)- Consejo Superior De Investigaciones Científicas (CSIC), Madrid, Spain
| | - Francisco García-del Portillo
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB)- Consejo Superior De Investigaciones Científicas (CSIC), Madrid, Spain
| | - M. Graciela Pucciarelli
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB)- Consejo Superior De Investigaciones Científicas (CSIC), Madrid, Spain
- Centro de Biología Molecular ‘Severo Ochoa’. Departamento de Biología Molecular, Facultad de Ciencias, Universidad Autónoma de Madrid. Madrid, Spain
| | - Alvaro D. Ortega
- Departamento de Biología Celular. Facultad de Ciencias Biológicas, Universidad Complutense de Madrid. Madrid, Spain
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB)- Consejo Superior De Investigaciones Científicas (CSIC), Madrid, Spain
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26
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Kutsch M, Coers J. Human guanylate binding proteins: nanomachines orchestrating host defense. FEBS J 2021; 288:5826-5849. [PMID: 33314740 PMCID: PMC8196077 DOI: 10.1111/febs.15662] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/27/2020] [Accepted: 12/07/2020] [Indexed: 02/06/2023]
Abstract
Disease-causing microorganisms not only breach anatomical barriers and invade tissues but also frequently enter host cells, nutrient-enriched environments amenable to support parasitic microbial growth. Protection from many infectious diseases is therefore reliant on the ability of individual host cells to combat intracellular infections through the execution of cell-autonomous defense programs. Central players in human cell-autonomous immunity are members of the family of dynamin-related guanylate binding proteins (GBPs). The importance of these interferon-inducible GTPases in host defense to viral, bacterial, and protozoan pathogens has been established for some time; only recently, cell biological and biochemical studies that largely focused on the prenylated paralogs GBP1, GBP2, and GBP5 have provided us with robust molecular frameworks for GBP-mediated immunity. Specifically, the recent characterization of GBP1 as a bona fide pattern recognition receptor for bacterial lipopolysaccharide (LPS) disrupting the integrity of bacterial outer membranes through LPS aggregation, the discovery of a link between hydrolysis-induced GMP production by GBP1 and inflammasome activation, and the classification of GBP2 and GBP5 as inhibitors of viral envelope glycoprotein processing via suppression of the host endoprotease furin have paved the way for a vastly improved conceptual understanding of the molecular mechanisms by which GBP nanomachines execute cell-autonomous immunity. The herein discussed models incorporate our current knowledge of the antimicrobial, proinflammatory, and biochemical properties of human GBPs and thereby provide testable hypotheses that will guide future studies into the intricacies of GBP-controlled host defense and their role in human disease.
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Affiliation(s)
- Miriam Kutsch
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 22710, USA
| | - Jörn Coers
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 22710, USA
- Department of Immunology, Duke University Medical Center, Durham, North Carolina 22710, USA
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27
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Lobato-Márquez D, Xu J, Güler GÖ, Ojiakor A, Pilhofer M, Mostowy S. Mechanistic insight into bacterial entrapment by septin cage reconstitution. Nat Commun 2021; 12:4511. [PMID: 34301939 PMCID: PMC8302635 DOI: 10.1038/s41467-021-24721-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 07/01/2021] [Indexed: 11/22/2022] Open
Abstract
Septins are cytoskeletal proteins that assemble into hetero-oligomeric complexes and sense micron-scale membrane curvature. During infection with Shigella flexneri, an invasive enteropathogen, septins restrict actin tail formation by entrapping bacteria in cage-like structures. Here, we reconstitute septin cages in vitro using purified recombinant septin complexes (SEPT2-SEPT6-SEPT7), and study how these recognize bacterial cells and assemble on their surface. We show that septin complexes recognize the pole of growing Shigella cells. An amphipathic helix domain in human SEPT6 enables septins to sense positively curved membranes and entrap bacterial cells. Shigella strains lacking lipopolysaccharide components are more efficiently entrapped in septin cages. Finally, cryo-electron tomography of in vitro cages reveals how septins assemble as filaments on the bacterial cell surface. Septins are cytoskeletal proteins that assemble into complexes and contribute to immunity by entrapping intracellular bacteria in cage-like structures. Here, Lobato-Márquez et al. reconstitute septin cages in vitro using purified recombinant complexes, and study how these recognize bacterial cells and assemble as filaments on their surface.
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Affiliation(s)
- Damián Lobato-Márquez
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK.
| | - Jingwei Xu
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
| | - Gizem Özbaykal Güler
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Adaobi Ojiakor
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Martin Pilhofer
- Department of Biology, Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
| | - Serge Mostowy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK.
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28
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Pei G, Dorhoi A. NOD-Like Receptors: Guards of Cellular Homeostasis Perturbation during Infection. Int J Mol Sci 2021; 22:ijms22136714. [PMID: 34201509 PMCID: PMC8268748 DOI: 10.3390/ijms22136714] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/14/2021] [Accepted: 06/18/2021] [Indexed: 12/30/2022] Open
Abstract
The innate immune system relies on families of pattern recognition receptors (PRRs) that detect distinct conserved molecular motifs from microbes to initiate antimicrobial responses. Activation of PRRs triggers a series of signaling cascades, leading to the release of pro-inflammatory cytokines, chemokines and antimicrobials, thereby contributing to the early host defense against microbes and regulating adaptive immunity. Additionally, PRRs can detect perturbation of cellular homeostasis caused by pathogens and fine-tune the immune responses. Among PRRs, nucleotide binding oligomerization domain (NOD)-like receptors (NLRs) have attracted particular interest in the context of cellular stress-induced inflammation during infection. Recently, mechanistic insights into the monitoring of cellular homeostasis perturbation by NLRs have been provided. We summarize the current knowledge about the disruption of cellular homeostasis by pathogens and focus on NLRs as innate immune sensors for its detection. We highlight the mechanisms employed by various pathogens to elicit cytoskeleton disruption, organelle stress as well as protein translation block, point out exemplary NLRs that guard cellular homeostasis during infection and introduce the concept of stress-associated molecular patterns (SAMPs). We postulate that integration of information about microbial patterns, danger signals, and SAMPs enables the innate immune system with adequate plasticity and precision in elaborating responses to microbes of variable virulence.
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Affiliation(s)
- Gang Pei
- Institute of Immunology, Friedrich-Loeffler-Institut, 17493 Greifswald, Germany
- Correspondence: (G.P.); (A.D.)
| | - Anca Dorhoi
- Institute of Immunology, Friedrich-Loeffler-Institut, 17493 Greifswald, Germany
- Faculty of Mathematics and Natural Sciences, University of Greifswald, 17489 Greifswald, Germany
- Correspondence: (G.P.); (A.D.)
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29
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Hajra D, Nair AV, Chakravortty D. An elegant nano-injection machinery for sabotaging the host: Role of Type III secretion system in virulence of different human and animal pathogenic bacteria. Phys Life Rev 2021; 38:25-54. [PMID: 34090822 DOI: 10.1016/j.plrev.2021.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 05/23/2021] [Indexed: 01/22/2023]
Abstract
Various Gram-negative bacteria possess a specialized membrane-bound protein secretion system known as the Type III secretion system (T3SS), which transports the bacterial effector proteins into the host cytosol thereby helping in bacterial pathogenesis. The T3SS has a special needle-like translocon that can sense the contact with the host cell membrane and translocate effectors. The export apparatus of T3SS recognizes these effector proteins bound to chaperones and translocates them into the host cell. Once in the host cell cytoplasm, these effector proteins result in modulation of the host system and promote bacterial localization and infection. Using molecular biology, bioinformatics, genetic techniques, electron microscopic studies, and mathematical modeling, the structure and function of the T3SS and the corresponding effector proteins in various bacteria have been studied. The strategies used by different human pathogenic bacteria to modulate the host system and thereby enhance their virulence mechanism using T3SS have also been well studied. Here we review the history, evolution, and general structure of the T3SS, highlighting the details of its comparison with the flagellar export machinery. Also, this article provides mechanistic details about the common role of T3SS in subversion and manipulation of host cellular processes. Additionally, this review describes specific T3SS apparatus and the role of their specific effectors in bacterial pathogenesis by considering several human and animal pathogenic bacteria.
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Affiliation(s)
- Dipasree Hajra
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
| | - Abhilash Vijay Nair
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
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30
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Kühn S, Bergqvist J, Gil M, Valenzuela C, Barrio L, Lebreton S, Zurzolo C, Enninga J. Actin Assembly around the Shigella-Containing Vacuole Promotes Successful Infection. Cell Rep 2021; 31:107638. [PMID: 32402280 PMCID: PMC7225751 DOI: 10.1016/j.celrep.2020.107638] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 03/10/2020] [Accepted: 04/21/2020] [Indexed: 12/13/2022] Open
Abstract
The enteroinvasive bacterium Shigella flexneri forces its uptake into non-phagocytic host cells through the translocation of T3SS effectors that subvert the actin cytoskeleton. Here, we report de novo actin polymerization after cellular entry around the bacterium-containing vacuole (BCV) leading to the formation of a dynamic actin cocoon. This cocoon is thicker than any described cellular actin structure and functions as a gatekeeper for the cytosolic access of the pathogen. Host CDC42, TOCA-1, N-WASP, WIP, the Arp2/3 complex, cortactin, coronin, and cofilin are recruited to the actin cocoon. They are subverted by T3SS effectors, such as IpgD, IpgB1, and IcsB. IcsB immobilizes components of the actin polymerization machinery at the BCV dependent on its fatty acyltransferase activity. This represents a unique microbial subversion strategy through localized entrapment of host actin regulators causing massive actin assembly. We propose that the cocoon promotes subsequent invasion steps for successful Shigella infection. A thick actin cocoon forms de novo around the Shigella-containing vacuole upon entry The effector IcsB entraps host actin regulators at the vacuole by lipidation Cdc42, N-WASP, and the Arp2/3 complex are major actin cocoon regulators Cocoon formation promotes subsequent Shigella niche formation and dissemination
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Affiliation(s)
- Sonja Kühn
- Institut Pasteur, Department of Cell Biology and Infection, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, 75015 Paris, France; CNRS UMR3691, 25 Rue du Dr. Roux, 75015 Paris, France
| | - John Bergqvist
- Institut Pasteur, Department of Cell Biology and Infection, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, 75015 Paris, France; CNRS UMR3691, 25 Rue du Dr. Roux, 75015 Paris, France
| | - Magdalena Gil
- Institut Pasteur, Department of Cell Biology and Infection, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, 75015 Paris, France; CNRS UMR3691, 25 Rue du Dr. Roux, 75015 Paris, France
| | - Camila Valenzuela
- Institut Pasteur, Department of Cell Biology and Infection, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, 75015 Paris, France; CNRS UMR3691, 25 Rue du Dr. Roux, 75015 Paris, France
| | - Laura Barrio
- Institut Pasteur, Department of Cell Biology and Infection, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, 75015 Paris, France; CNRS UMR3691, 25 Rue du Dr. Roux, 75015 Paris, France
| | - Stéphanie Lebreton
- Institut Pasteur, Department of Cell Biology and Infection, Membrane Trafficking and Pathogenesis Unit, 28 Rue du Dr. Roux, 75015 Paris, France
| | - Chiara Zurzolo
- Institut Pasteur, Department of Cell Biology and Infection, Membrane Trafficking and Pathogenesis Unit, 28 Rue du Dr. Roux, 75015 Paris, France
| | - Jost Enninga
- Institut Pasteur, Department of Cell Biology and Infection, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, 75015 Paris, France; CNRS UMR3691, 25 Rue du Dr. Roux, 75015 Paris, France.
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31
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Abstract
Dynamic remodeling of the actin cytoskeleton is an essential feature for virtually all actin-dependent cellular processes, including cell migration, cell cycle progression, chromatin remodeling and gene expression, and even the DNA damage response. An altered actin cytoskeleton is a structural hallmark associated with numerous pathologies ranging from cardiovascular diseases to immune disorders, neurological diseases and cancer. The actin cytoskeleton in cells is regulated through the orchestrated actions of a myriad of actin-binding proteins. In this Review, we provide a brief overview of the structure and functions of the actin-monomer-binding protein profilin-1 (Pfn1) and then discuss how dysregulated expression of Pfn1 contributes to diseases associated with the cardiovascular system.
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Affiliation(s)
| | - David Gau
- Bioengineering, University of Pittsburgh
| | - Partha Roy
- Bioengineering, University of Pittsburgh.,Pathology, University of Pittsburgh, 306 Center for Bioengineering, University of Pittsburgh, 300 Technology Drive, Pittsburgh, PA 15219, USA
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32
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Kutsch M, González-Prieto C, Lesser CF, Coers J. The GBP1 microcapsule interferes with IcsA-dependent septin cage assembly around Shigella flexneri. Pathog Dis 2021; 79:6246431. [PMID: 33885766 DOI: 10.1093/femspd/ftab023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 04/08/2021] [Indexed: 12/20/2022] Open
Abstract
Many cytosolic bacterial pathogens hijack the host actin polymerization machinery to form actin tails that promote direct cell-to-cell spread, enabling these pathogens to avoid extracellular immune defenses. However, these pathogens are still susceptible to intracellular cell-autonomous immune responses that restrict bacterial actin-based motility. Two classes of cytosolic antimotility factors, septins and guanylate-binding proteins (GBPs), have recently been established to block actin tail formation by the human-adapted bacterial pathogen Shigella flexneri. Both septin cages and GBP1 microcapsules restrict S. flexneri cell-to-cell spread by blocking S. flexneri actin-based motility. While septins assemble into cage-like structures around immobile S. flexneri, GBP1 forms microcapsules around both motile and immobile bacteria. The interplay between these two defense programs remains elusive. Here, we demonstrate that GBP1 microcapsules block septin cage assembly, likely by interfering with the function of S. flexneri IcsA, the outer membrane protein that promotes actin-based motility, as this protein is required for septin cage formation. However, S. flexneri that escape from GBP1 microcapsules via the activity of IpaH9.8, a type III secreted effector that promotes the degradation of GBPs, are often captured within septin cages. Thus, our studies reveal how septin cages and GBP1 microcapsules represent complementary host cell antimotility strategies.
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Affiliation(s)
- Miriam Kutsch
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Coral González-Prieto
- Center for Bacterial Pathogenesis, Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02115, USA.,Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Cammie F Lesser
- Center for Bacterial Pathogenesis, Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02115, USA.,Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jörn Coers
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.,Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
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33
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Duncan-Lowey JK, Wiscovitch AL, Wood TE, Goldberg MB, Russo BC. Shigella flexneri Disruption of Cellular Tension Promotes Intercellular Spread. Cell Rep 2020; 33:108409. [PMID: 33238111 PMCID: PMC7792532 DOI: 10.1016/j.celrep.2020.108409] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 09/25/2020] [Accepted: 10/29/2020] [Indexed: 01/18/2023] Open
Abstract
During infection, some bacterial pathogens invade the eukaryotic cytosol and spread between cells of an epithelial monolayer. Intercellular spread occurs when these pathogens push against the plasma membrane, forming protrusions that are engulfed by adjacent cells. Here, we show that IpaC, a Shigella flexneri type 3 secretion system protein, binds the host cell-adhesion protein β-catenin and facilitates efficient protrusion formation. S. flexneri producing a point mutant of IpaC that cannot interact with β-catenin is defective in protrusion formation and spread. Spread is restored by chemical reduction of intercellular tension or genetic depletion of β-catenin, and the magnitude of the protrusion defect correlates with membrane tension, indicating that IpaC reduces membrane tension, which facilitates protrusion formation. IpaC stabilizes adherens junctions and does not alter β-catenin localization at the membrane. Thus, Shigella, like other bacterial pathogens, reduces intercellular tension to efficiently spread between cells.
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Affiliation(s)
- Jeffrey K. Duncan-Lowey
- Center for Bacterial Pathogenesis, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA,Present address: Department of Immunobiology, Yale School of Medicine, New Haven, CT 06511, USA
| | - Alexandra L. Wiscovitch
- Research Scholar Initiative, The Graduate School of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA,Present address: Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32611, USA
| | - Thomas E. Wood
- Center for Bacterial Pathogenesis, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA,Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Marcia B. Goldberg
- Center for Bacterial Pathogenesis, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA,Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA,Correspondence: (M.B.G.), (B.C.R.)
| | - Brian C. Russo
- Center for Bacterial Pathogenesis, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA,Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA,Present address: Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA,Lead Contact,Correspondence: (M.B.G.), (B.C.R.)
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34
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Boujemaa-Paterski R, Martins B, Eibauer M, Beales CT, Geiger B, Medalia O. Talin-activated vinculin interacts with branched actin networks to initiate bundles. eLife 2020; 9:e53990. [PMID: 33185186 PMCID: PMC7682986 DOI: 10.7554/elife.53990] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 11/12/2020] [Indexed: 12/18/2022] Open
Abstract
Vinculin plays a fundamental role in integrin-mediated cell adhesion. Activated by talin, it interacts with diverse adhesome components, enabling mechanical coupling between the actin cytoskeleton and the extracellular matrix. Here we studied the interactions of activated full-length vinculin with actin and the way it regulates the organization and dynamics of the Arp2/3 complex-mediated branched actin network. Through a combination of surface patterning and light microscopy experiments we show that vinculin can bundle dendritic actin networks through rapid binding and filament crosslinking. We show that vinculin promotes stable but flexible actin bundles having a mixed-polarity organization, as confirmed by cryo-electron tomography. Adhesion-like synthetic design of vinculin activation by surface-bound talin revealed that clustered vinculin can initiate and immobilize bundles from mobile Arp2/3-branched networks. Our results provide a molecular basis for coordinate actin bundle formation at nascent adhesions.
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Affiliation(s)
- Rajaa Boujemaa-Paterski
- Department of Biochemistry, University of ZurichZurichSwitzerland
- Université Grenoble AlpesGrenobleFrance
| | - Bruno Martins
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Matthias Eibauer
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Charlie T Beales
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Benjamin Geiger
- Department of Immunology, Weizmann Institute of ScienceRehovotIsrael
| | - Ohad Medalia
- Department of Biochemistry, University of ZurichZurichSwitzerland
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35
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Dhanda AS, Yang D, Guttman JA. Localization of alpha-actinin-4 during infections by actin remodeling bacteria. Anat Rec (Hoboken) 2020; 304:1400-1419. [PMID: 33099893 DOI: 10.1002/ar.24548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/13/2020] [Accepted: 09/12/2020] [Indexed: 11/12/2022]
Abstract
Bacterial pathogens cause disease by subverting the structure and function of their target host cells. Several foodborne agents such as Listeria monocytogenes (L. monocytogenes), Shigella flexneri (S. flexneri), Salmonella enterica serovar Typhimurium (S. Typhimurium) and enteropathogenic Escherichia coli (EPEC) manipulate the host actin cytoskeleton to cause diarrheal (and systemic) infections. During infections, these invasive and adherent pathogens hijack the actin filaments of their host cells and rearrange them into discrete actin-rich structures that promote bacterial adhesion (via pedestals), invasion (via membrane ruffles and endocytic cups), intracellular motility (via comet/rocket tails) and/or intercellular dissemination (via membrane protrusions and invaginations). We have previously shown that actin-rich structures generated by L. monocytogenes contain the host actin cross-linker α-actinin-4. Here we set out to examine α-actinin-4 during other key steps of the L. monocytogenes infectious cycle as well as characterize the subcellular distribution of α-actinin-4 during infections with other model actin-hijacking bacterial pathogens (S. flexneri, S. Typhimurium and EPEC). Although α-actinin-4 is absent at sites of initial L. monocytogenes invasion, we show that it is a new component of the membrane invaginations formed during secondary infections of neighboring host cells. Importantly, we reveal that α-actinin-4 also localizes to the major actin-rich structures generated during cell culture infections with S. flexneri (comet/rocket tails and membrane protrusions), S. Typhimurium (membrane ruffles) and EPEC (pedestals). Taken together, these findings suggest that α-actinin-4 is a host factor that is exploited by an assortment of actin-hijacking bacterial pathogens.
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Affiliation(s)
- Aaron S Dhanda
- Department of Biological Sciences, Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Diana Yang
- Department of Biological Sciences, Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Julian A Guttman
- Department of Biological Sciences, Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
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36
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Pernier J, Morchain A, Caorsi V, Bertin A, Bousquet H, Bassereau P, Coudrier E. Myosin 1b flattens and prunes branched actin filaments. J Cell Sci 2020; 133:jcs247403. [PMID: 32895245 PMCID: PMC7522023 DOI: 10.1242/jcs.247403] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 08/18/2020] [Indexed: 01/29/2023] Open
Abstract
Motile and morphological cellular processes require a spatially and temporally coordinated branched actin network that is controlled by the activity of various regulatory proteins, including the Arp2/3 complex, profilin, cofilin and tropomyosin. We have previously reported that myosin 1b regulates the density of the actin network in the growth cone. Here, by performing in vitro F-actin gliding assays and total internal reflection fluorescence (TIRF) microscopy, we show that this molecular motor flattens (reduces the branch angle) in the Arp2/3-dependent actin branches, resulting in them breaking, and reduces the probability of new branches forming. This experiment reveals that myosin 1b can produce force sufficient enough to break up the Arp2/3-mediated actin junction. Together with the former in vivo studies, this work emphasizes the essential role played by myosins in the architecture and dynamics of actin networks in different cellular regions.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Julien Pernier
- Laboratoire Physico-Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Laboratory Cell Biology and Cancer, Institut Curie, PSL Research University, C.N.R.S. UMR 144, 26 rue d'Ulm, Paris, France
| | - Antoine Morchain
- Laboratoire Physico-Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
| | | | - Aurélie Bertin
- Laboratoire Physico-Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
| | - Hugo Bousquet
- Sorbonne Université, 75005 Paris, France
- Laboratory Cell Biology and Cancer, Institut Curie, PSL Research University, C.N.R.S. UMR 144, 26 rue d'Ulm, Paris, France
| | - Patricia Bassereau
- Laboratoire Physico-Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
| | - Evelyne Coudrier
- Sorbonne Université, 75005 Paris, France
- Laboratory Cell Biology and Cancer, Institut Curie, PSL Research University, C.N.R.S. UMR 144, 26 rue d'Ulm, Paris, France
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37
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Faris R, McCullough A, Andersen SE, Moninger TO, Weber MM. The Chlamydia trachomatis secreted effector TmeA hijacks the N-WASP-ARP2/3 actin remodeling axis to facilitate cellular invasion. PLoS Pathog 2020; 16:e1008878. [PMID: 32946535 PMCID: PMC7526919 DOI: 10.1371/journal.ppat.1008878] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 09/30/2020] [Accepted: 08/12/2020] [Indexed: 11/19/2022] Open
Abstract
As an obligate intracellular pathogen, host cell invasion is paramount to Chlamydia trachomatis proliferation. While the mechanistic underpinnings of this essential process remain ill-defined, it is predicted to involve delivery of prepackaged effector proteins into the host cell that trigger plasma membrane remodeling and cytoskeletal reorganization. The secreted effector proteins TmeA and TarP, have risen to prominence as putative key regulators of cellular invasion and bacterial pathogenesis. Although several studies have begun to unravel molecular details underlying the putative function of TarP, the physiological function of TmeA during host cell invasion is unknown. Here, we show that TmeA employs molecular mimicry to bind to the GTPase binding domain of N-WASP, which results in recruitment of the actin branching ARP2/3 complex to the site of chlamydial entry. Electron microscopy revealed that TmeA mutants are deficient in filopodia capture, suggesting that TmeA/N-WASP interactions ultimately modulate host cell plasma membrane remodeling events necessary for chlamydial entry. Importantly, while both TmeA and TarP are necessary for effective host cell invasion, we show that these effectors target distinct pathways that ultimately converge on activation of the ARP2/3 complex. In line with this observation, we show that a double mutant suffers from a severe entry defect nearly identical to that observed when ARP3 is chemically inhibited or knocked down. Collectively, our study highlights both TmeA and TarP as essential regulators of chlamydial invasion that modulate the ARP2/3 complex through distinct signaling platforms, resulting in plasma membrane remodeling events that are essential for pathogen uptake.
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Affiliation(s)
- Robert Faris
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Alix McCullough
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Shelby E. Andersen
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Thomas O. Moninger
- Central Microscopy Research Facility, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Mary M. Weber
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States of America
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38
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Liu Y, Dou Y, Yan L, Yang X, He B, Kong L, Smith W. The role of Rho GTPases' substrates Rac and Cdc42 in osteoclastogenesis and relevant natural medicinal products study. Biosci Rep 2020; 40:BSR20200407. [PMID: 32578854 PMCID: PMC7364480 DOI: 10.1042/bsr20200407] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 05/07/2020] [Accepted: 06/23/2020] [Indexed: 12/30/2022] Open
Abstract
Recently, Rho GTPases substrates include Rac (Rac1 and Rac2) and Cdc42 that have been reported to exert multiple cellular functions in osteoclasts, the most prominent of which includes regulating the dynamic actin cytoskeleton rearrangements. In addition, natural products and their molecular frameworks have a long tradition as valuable starting points for medicinal chemistry and drug discovery. Although currently, there are reports about the natural product, which could play a therapeutic role in bone loss diseases (osteoporosis and osteolysis) through the regulation of Rac1/2 and Cdc42 during osteoclasts cytoskeletal structuring. There have been several excellent studies for exploring the therapeutic potentials of various natural products for their role in inhibiting cancer cells migration and function via regulating the Rac1/2 and Cdc42. Herein in this review, we try to focus on recent advancement studies for extensively understanding the role of Rho GTPases substrates Rac1, Rac2 and Cdc42 in osteoclastogenesis, as well as therapeutic potentials of natural medicinal products for their properties on the regulation of Rac1, and/or Rac2 and Cdc42, which is in order to inspire drug discovery in regulating osteoclastogenesis.
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Affiliation(s)
- Yuan Liu
- Department of Spine Surgery, Honghui Hospital, School of Medicine, Xi’an Jiaotong University, Xi'an, China
- Department of Orthopedics, Yan’an University Medical School, Yan’an, China
| | - Yusheng Dou
- Department of Shoulder and Elbow Joint, Honghui Hospital, School of Medicine, Xi’an Jiaotong University, China
| | - Liang Yan
- Department of Spine Surgery, Honghui Hospital, School of Medicine, Xi’an Jiaotong University, Xi'an, China
| | - Xiaobin Yang
- Department of Spine Surgery, Honghui Hospital, School of Medicine, Xi’an Jiaotong University, Xi'an, China
| | - Baorong He
- Department of Spine Surgery, Honghui Hospital, School of Medicine, Xi’an Jiaotong University, Xi'an, China
| | - Lingbo Kong
- Department of Spine Surgery, Honghui Hospital, School of Medicine, Xi’an Jiaotong University, Xi'an, China
| | - Wanli Smith
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, U.S.A
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39
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Dowd GC, Mortuza R, Ireton K. Molecular Mechanisms of Intercellular Dissemination of Bacterial Pathogens. Trends Microbiol 2020; 29:127-141. [PMID: 32682632 DOI: 10.1016/j.tim.2020.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 02/07/2023]
Abstract
Several intracellular bacterial pathogens, including Listeria monocytogenes, Shigella flexerni, and Rickettsia spp. use an actin-based motility process to spread in mammalian cell monolayers. Cell-to-cell spread is mediated by protrusive structures that contain bacteria encased in the host cell plasma membrane. These protrusions, which form in infected host cells, are internalized by neighboring cells. In this review, we summarize key findings on cell-to-cell spread, focusing on recent work on mechanisms of protrusion formation and internalization. We also discuss the dynamic behavior of bacterial populations during spread, and highlight recent findings showing that intercellular spread by an extracellular bacterial pathogen.
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Affiliation(s)
- Georgina C Dowd
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Roman Mortuza
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Keith Ireton
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand.
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40
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Whelan R, McVicker G, Leo JC. Staying out or Going in? The Interplay between Type 3 and Type 5 Secretion Systems in Adhesion and Invasion of Enterobacterial Pathogens. Int J Mol Sci 2020; 21:E4102. [PMID: 32521829 PMCID: PMC7312957 DOI: 10.3390/ijms21114102] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/03/2020] [Accepted: 06/05/2020] [Indexed: 12/12/2022] Open
Abstract
Enteric pathogens rely on a variety of toxins, adhesins and other virulence factors to cause infections. Some of the best studied pathogens belong to the Enterobacterales order; these include enteropathogenic and enterohemorrhagic Escherichia coli, Shigella spp., and the enteropathogenic Yersiniae. The pathogenesis of these organisms involves two different secretion systems, a type 3 secretion system (T3SS) and type 5 secretion systems (T5SSs). The T3SS forms a syringe-like structure spanning both bacterial membranes and the host cell plasma membrane that translocates toxic effector proteins into the cytoplasm of the host cell. T5SSs are also known as autotransporters, and they export part of their own polypeptide to the bacterial cell surface where it exerts its function, such as adhesion to host cell receptors. During infection with these enteropathogens, the T3SS and T5SS act in concert to bring about rearrangements of the host cell cytoskeleton, either to invade the cell, confer intracellular motility, evade phagocytosis or produce novel structures to shelter the bacteria. Thus, in these bacteria, not only the T3SS effectors but also T5SS proteins could be considered "cytoskeletoxins" that bring about profound alterations in host cell cytoskeletal dynamics and lead to pathogenic outcomes.
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Affiliation(s)
| | | | - Jack C. Leo
- Antimicrobial Resistance, Omics and Microbiota Group, Department of Biosciences, Nottingham Trent University, Nottingham NG1 4FQ, UK; (R.W.); (G.M.)
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Abstract
The bacterial pathogen Shigella flexneri causes more than 250 million cases of bacillary dysentery (blood in stool) every year across the world. This human-specific disease is characterized by profuse bloody diarrhea, dramatic ulceration of the colonic epithelium and immune cell infiltration of the colonic tissue. A major challenge in understanding the mechanisms supporting bacillary dysentery is the reliance on animal models that do not fully recapitulate the symptoms observed in humans, including bloody diarrhea. Here we outline advances provided by a recently developed infant rabbit model of bacillary dysentery. The infant rabbit model defines bacillary dysentery as a critical combination of massive vascular lesions and dramatic epithelial fenestration due to intracellular infection and cell-to-cell spread, respectively. The infant rabbit model provides an unprecedented framework for understanding how the cell biology of Shigella flexneri infection relates to pathogenesis.
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Affiliation(s)
- Lauren K. Yum
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Hervé Agaisse
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA, USA,CONTACT Hervé Agaisse Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia22908, USA
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42
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Kühn S, Enninga J. The actin comet guides the way: How
Listeria
actin subversion has impacted cell biology, infection biology and structural biology. Cell Microbiol 2020; 22:e13190. [DOI: 10.1111/cmi.13190] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/04/2020] [Accepted: 02/04/2020] [Indexed: 12/31/2022]
Affiliation(s)
- Sonja Kühn
- Unit of Dynamics of Host‐Pathogen InteractionsInstitut Pasteur Paris France
- Centre National de la Recherche Scientifique (CNRS‐UMR3691) Paris France
| | - Jost Enninga
- Unit of Dynamics of Host‐Pathogen InteractionsInstitut Pasteur Paris France
- Centre National de la Recherche Scientifique (CNRS‐UMR3691) Paris France
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The virulence domain of Shigella IcsA contains a subregion with specific host cell adhesion function. PLoS One 2020; 15:e0227425. [PMID: 31910229 PMCID: PMC6946128 DOI: 10.1371/journal.pone.0227425] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/18/2019] [Indexed: 02/08/2023] Open
Abstract
Shigella species cause bacillary dysentery, especially among young individuals. Shigellae target the human colon for invasion; however, the initial adhesion mechanism is poorly understood. The Shigella surface protein IcsA, in addition to its role in actin-based motility, acts as a host cell adhesin through unknown mechanism(s). Here we confirmed the role of IcsA in cell adhesion and defined the region required for IcsA adhesin activity. Purified IcsA passenger domain was able block S. flexneri adherence and was also used as a molecular probe that recognised multiple components from host cells. The region within IcsA's functional passenger domain (aa 138-148) was identified by mutagenesis. Upon the deletion of this region, the purified IcsAΔ138-148 was found to no longer block S. flexneri adherence and had reduced ability to interact with host molecules. Furthermore, S. flexneri expressing IcsAΔ138-148 was found to be significantly defective in both cell adherence and invasion. Taken together, our data identify an adherence region within the IcsA functional domain and provides useful information for designing therapeutics for Shigella infection.
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44
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Functional screenings reveal different requirements for host microRNAs in Salmonella and Shigella infection. Nat Microbiol 2019; 5:192-205. [DOI: 10.1038/s41564-019-0614-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 10/18/2019] [Indexed: 12/15/2022]
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45
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Evolutionary Perspectives on the Moonlighting Functions of Bacterial Factors That Support Actin-Based Motility. mBio 2019; 10:mBio.01520-19. [PMID: 31455648 PMCID: PMC6712393 DOI: 10.1128/mbio.01520-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Various bacterial pathogens display an intracellular lifestyle and spread from cell to cell through actin-based motility (ABM). ABM requires actin polymerization at the bacterial pole and is mediated by the expression of bacterial factors that hijack the host cell actin nucleation machinery or exhibit intrinsic actin nucleation properties. Various bacterial pathogens display an intracellular lifestyle and spread from cell to cell through actin-based motility (ABM). ABM requires actin polymerization at the bacterial pole and is mediated by the expression of bacterial factors that hijack the host cell actin nucleation machinery or exhibit intrinsic actin nucleation properties. It is increasingly recognized that bacterial ABM factors, in addition to having a crucial task during the intracellular phase of infection, display “moonlighting” adhesin functions, such as bacterial aggregation, biofilm formation, and host cell adhesion/invasion. Here, we review our current knowledge of ABM factors and their additional functions, and we propose that intracellular ABM functions have evolved from ancestral, extracellular adhesin functions.
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46
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Michard C, Yum LK, Agaisse H. WIPF2 promotesShigella flexneriactin‐based motility and cell‐to‐cell spread. Cell Microbiol 2019; 21:e13098. [DOI: 10.1111/cmi.13098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 08/08/2019] [Accepted: 08/10/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Céline Michard
- Department of Microbiology, Immunology, and Cancer BiologyUniversity of Virginia Charlottesville Virginia
| | - Lauren K. Yum
- Department of Microbiology, Immunology, and Cancer BiologyUniversity of Virginia Charlottesville Virginia
| | - Hervé Agaisse
- Department of Microbiology, Immunology, and Cancer BiologyUniversity of Virginia Charlottesville Virginia
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47
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Pollard TD. Cell Motility and Cytokinesis: From Mysteries to Molecular Mechanisms in Five Decades. Annu Rev Cell Dev Biol 2019; 35:1-28. [PMID: 31394047 DOI: 10.1146/annurev-cellbio-100818-125427] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This is the story of someone who has been fortunate to work in a field of research where essentially nothing was known at the outset but that blossomed with the discovery of profound insights about two basic biological processes: cell motility and cytokinesis. The field started with no molecules, just a few people, and primitive methods. Over time, technological advances in biophysics, biochemistry, and microscopy allowed the combined efforts of scientists in hundreds of laboratories to explain mysterious processes with molecular mechanisms that can be embodied in mathematical equations and simulated by computers. The success of this field is a tribute to the power of the reductionist strategy for understanding biology.
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Affiliation(s)
- Thomas D Pollard
- Departments of Molecular, Cellular and Developmental Biology; Molecular Biophysics and Biochemistry; and Cell Biology, Yale University, New Haven, Connecticut 06520-8103, USA;
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Abstract
PURPOSE OF REVIEW Diarrhoea is a major global health problem, and recent studies have confirmed Shigella as a major contributor to this burden. Here, we review recent advances in Shigella research; focusing on their epidemiology, pathogenesis, antimicrobial resistance, and the role of the gut microbiome during infection. RECENT FINDINGS Enhanced epidemiological data, combined with new generation diagnostics, has highlighted a greater burden of Shigella disease than was previously estimated, which is not restricted to vulnerable populations in low-middle income countries. As we gain an ever more detailed insight into the orchestrated mechanisms that Shigella exploit to trigger infection, we can also begin to appreciate the complex role of the gut microbiome in preventing and inducing such infections. The use of genomics, in combination with epidemiological data and laboratory investigations, has unravelled the evolution and spread of various species. Such measures have identified resistance to antimicrobials as a key contributor to the success of specific clones. SUMMARY We need to apply novel findings towards sustainable approaches for treating and preventing Shigella infections. Vaccines and alternative treatments are under development and may offer an opportunity to reduce the burden of Shigella disease and restrict the mobility of antimicrobial resistant clones.
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Farina F, Ramkumar N, Brown L, Samandar Eweis D, Anstatt J, Waring T, Bithell J, Scita G, Thery M, Blanchoin L, Zech T, Baum B. Local actin nucleation tunes centrosomal microtubule nucleation during passage through mitosis. EMBO J 2019; 38:e99843. [PMID: 31015335 PMCID: PMC6545563 DOI: 10.15252/embj.201899843] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 04/02/2019] [Accepted: 04/04/2019] [Indexed: 12/19/2022] Open
Abstract
Cells going through mitosis undergo precisely timed changes in cell shape and organisation, which serve to ensure the fair partitioning of cellular components into the two daughter cells. These structural changes are driven by changes in actin filament and microtubule dynamics and organisation. While most evidence suggests that the two cytoskeletal systems are remodelled in parallel during mitosis, recent work in interphase cells has implicated the centrosome in both microtubule and actin nucleation, suggesting the potential for regulatory crosstalk between the two systems. Here, by using both in vitro and in vivo assays to study centrosomal actin nucleation as cells pass through mitosis, we show that mitotic exit is accompanied by a burst in cytoplasmic actin filament formation that depends on WASH and the Arp2/3 complex. This leads to the accumulation of actin around centrosomes as cells enter anaphase and to a corresponding reduction in the density of centrosomal microtubules. Taken together, these data suggest that the mitotic regulation of centrosomal WASH and the Arp2/3 complex controls local actin nucleation, which may function to tune the levels of centrosomal microtubules during passage through mitosis.
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Affiliation(s)
- Francesca Farina
- MRC-LMCB, UCL, London, UK
- IPLS, UCL, London, UK
- IFOM, the FIRC Institute of Molecular Oncology, University of Milan, Milan, Italy
- University of Grenoble, Grenoble, France
| | | | - Louise Brown
- Institute of Translational Medicine, Cellular and Molecular Physiology, University of Liverpool, Liverpool, UK
| | | | | | - Thomas Waring
- Institute of Translational Medicine, Cellular and Molecular Physiology, University of Liverpool, Liverpool, UK
| | - Jessica Bithell
- Institute of Translational Medicine, Cellular and Molecular Physiology, University of Liverpool, Liverpool, UK
| | - Giorgio Scita
- IFOM, the FIRC Institute of Molecular Oncology, University of Milan, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
| | | | | | - Tobias Zech
- Institute of Translational Medicine, Cellular and Molecular Physiology, University of Liverpool, Liverpool, UK
| | - Buzz Baum
- MRC-LMCB, UCL, London, UK
- IPLS, UCL, London, UK
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50
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Abstract
The entry of pathogens into nonphagocytic host cells has received much attention in the past three decades, revealing a vast array of strategies employed by bacteria and viruses. A method of internalization that has been extensively studied in the context of viral infections is the use of the clathrin-mediated pathway. More recently, a role for clathrin in the entry of some intracellular bacterial pathogens was discovered. Classically, clathrin-mediated endocytosis was thought to accommodate internalization only of particles smaller than 150 nm; however, this was challenged upon the discovery that Listeria monocytogenes requires clathrin to enter eukaryotic cells. Now, with discoveries that clathrin is required during other stages of some bacterial infections, another paradigm shift is occurring. There is a more diverse impact of clathrin during infection than previously thought. Much of the recent data describing clathrin utilization in processes such as bacterial attachment, cell-to-cell spread and intracellular growth may be due to newly discovered divergent roles of clathrin in the cell. Not only does clathrin act to facilitate endocytosis from the plasma membrane, but it also participates in budding from endosomes and the Golgi apparatus and in mitosis. Here, the manipulation of clathrin processes by bacterial pathogens, including its traditional role during invasion and alternative ways in which clathrin supports bacterial infection, is discussed. Researching clathrin in the context of bacterial infections will reveal new insights that inform our understanding of host-pathogen interactions and allow researchers to fully appreciate the diverse roles of clathrin in the eukaryotic cell.
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Affiliation(s)
- Eleanor A Latomanski
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Hayley J Newton
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
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