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Sharafutdinov I, Harrer A, Müsken M, Rottner K, Sticht H, Täger C, Naumann M, Tegtmeyer N, Backert S. Cortactin-dependent control of Par1b-regulated epithelial cell polarity in Helicobacter infection. CELL INSIGHT 2024; 3:100161. [PMID: 38646547 PMCID: PMC11033139 DOI: 10.1016/j.cellin.2024.100161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 03/01/2024] [Accepted: 03/02/2024] [Indexed: 04/23/2024]
Abstract
Cell polarity is crucial for gastric mucosal barrier integrity and mainly regulated by polarity-regulating kinase partitioning-defective 1b (Par1b). During infection, the carcinogen Helicobacter pylori hijacks Par1b via the bacterial oncoprotein CagA leading to loss of cell polarity, but the precise molecular mechanism is not fully clear. Here we discovered a novel function of the actin-binding protein cortactin in regulating Par1b, which forms a complex with cortactin and the tight junction protein zona occludens-1 (ZO-1). We found that serine phosphorylation at S405/418 and the SH3 domain of cortactin are important for its interaction with both Par1b and ZO-1. Cortactin knockout cells displayed disturbed Par1b cellular localization and exhibited morphological abnormalities that largely compromised transepithelial electrical resistance, epithelial cell polarity, and apical microvilli. H. pylori infection promoted cortactin/Par1b/ZO-1 abnormal interactions in the tight junctions in a CagA-dependent manner. Infection of human gastric organoid-derived mucosoids supported these observations. We therefore hypothesize that CagA disrupts gastric epithelial cell polarity by hijacking cortactin, and thus Par1b and ZO-1, suggesting a new signaling pathway for the development of gastric cancer by Helicobacter.
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Affiliation(s)
- Irshad Sharafutdinov
- Department of Biology, Division of Microbiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058, Erlangen, Germany
| | - Aileen Harrer
- Department of Biology, Division of Microbiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058, Erlangen, Germany
| | - Mathias Müsken
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, D-38124, Braunschweig, Germany
| | - Klemens Rottner
- Department of Cell Biology, Helmholtz Centre for Infection Research, D-38124, Braunschweig, Germany
- Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, D-38106, Braunschweig, Germany
| | - Heinrich Sticht
- Division of Bioinformatics, Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Christian Täger
- Otto von Guericke University, Institute of Experimental Internal Medicine, Medical Faculty, D-39120, Magdeburg, Germany
| | - Michael Naumann
- Otto von Guericke University, Institute of Experimental Internal Medicine, Medical Faculty, D-39120, Magdeburg, Germany
| | - Nicole Tegtmeyer
- Department of Biology, Division of Microbiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058, Erlangen, Germany
| | - Steffen Backert
- Department of Biology, Division of Microbiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058, Erlangen, Germany
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Rottner K, Bieling P. Illuminating cortactin structure and function at actin filament branches. Nat Struct Mol Biol 2024; 31:739-741. [PMID: 38714891 DOI: 10.1038/s41594-024-01297-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2024]
Affiliation(s)
- 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.
| | - Peter Bieling
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
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Liu T, Cao L, Mladenov M, Jegou A, Way M, Moores CA. Cortactin stabilizes actin branches by bridging activated Arp2/3 to its nucleated actin filament. Nat Struct Mol Biol 2024; 31:801-809. [PMID: 38267598 PMCID: PMC11102864 DOI: 10.1038/s41594-023-01205-2] [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: 07/25/2023] [Accepted: 12/18/2023] [Indexed: 01/26/2024]
Abstract
Regulation of the assembly and turnover of branched actin filament networks nucleated by the Arp2/3 complex is essential during many cellular processes, including cell migration and membrane trafficking. Cortactin is important for actin branch stabilization, but the mechanism by which this occurs is unclear. Given this, we determined the structure of vertebrate cortactin-stabilized Arp2/3 actin branches using cryogenic electron microscopy. We find that cortactin interacts with the new daughter filament nucleated by the Arp2/3 complex at the branch site, rather than the initial mother actin filament. Cortactin preferentially binds activated Arp3. It also stabilizes the F-actin-like interface of activated Arp3 with the first actin subunit of the new filament, and its central repeats extend along successive daughter-filament subunits. The preference of cortactin for activated Arp3 explains its retention at the actin branch and accounts for its synergy with other nucleation-promoting factors in regulating branched actin network dynamics.
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Affiliation(s)
- Tianyang Liu
- Institute of Structural and Molecular Biology, Birkbeck College, London, UK
| | - Luyan Cao
- The Francis Crick Institute, London, UK
| | | | - Antoine Jegou
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Michael Way
- The Francis Crick Institute, London, UK.
- Department of Infectious Disease, Imperial College, London, UK.
| | - Carolyn A Moores
- Institute of Structural and Molecular Biology, Birkbeck College, London, UK.
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Yuan Z, Li P, Yang X, Cai X, Wu L, Zhao F, Wen W, Zhou M, Hou Y. FgPfn participates in vegetative growth, sexual reproduction, pathogenicity, and fungicides sensitivity via affecting both microtubules and actin in the filamentous fungus Fusarium graminearum. PLoS Pathog 2024; 20:e1012215. [PMID: 38701108 PMCID: PMC11095717 DOI: 10.1371/journal.ppat.1012215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 05/15/2024] [Accepted: 04/23/2024] [Indexed: 05/05/2024] Open
Abstract
Fusarium head blight (FHB), caused by Fusarium graminearum species complexes (FGSG), is an epidemic disease in wheat and poses a serious threat to wheat production and security worldwide. Profilins are a class of actin-binding proteins that participate in actin depolymerization. However, the roles of profilins in plant fungal pathogens remain largely unexplored. Here, we identified FgPfn, a homolog to profilins in F. graminearum, and the deletion of FgPfn resulted in severe defects in mycelial growth, conidia production, and pathogenicity, accompanied by marked disruptions in toxisomes formation and deoxynivalenol (DON) transport, while sexual development was aborted. Additionally, FgPfn interacted with Fgα1 and Fgβ2, the significant components of microtubules. The organization of microtubules in the ΔFgPfn was strongly inhibited under the treatment of 0.4 μg/mL carbendazim, a well-known group of tubulin interferers, resulting in increased sensitivity to carbendazim. Moreover, FgPfn interacted with both myosin-5 (FgMyo5) and actin (FgAct), the targets of the fungicide phenamacril, and these interactions were reduced after phenamacril treatment. The deletion of FgPfn disrupted the normal organization of FgMyo5 and FgAct cytoskeleton, weakened the interaction between FgMyo5 and FgAct, and resulting in increased sensitivity to phenamacril. The core region of the interaction between FgPfn and FgAct was investigated, revealing that the integrity of both proteins was necessary for their interaction. Furthermore, mutations in R72, R77, R86, G91, I101, A112, G113, and D124 caused the non-interaction between FgPfn and FgAct. The R86K, I101E, and D124E mutants in FgPfn resulted in severe defects in actin organization, development, and pathogenicity. Taken together, this study revealed the role of FgPfn-dependent cytoskeleton in development, DON production and transport, fungicides sensitivity in F. graminearum.
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Affiliation(s)
- Zhili Yuan
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Pengfei Li
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xin Yang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xiaowei Cai
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Luoyu Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Feifei Zhao
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Weidong Wen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Mingguo Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yiping Hou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
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5
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McGuirk ER, Koundinya N, Nagarajan P, Padrick SB, Goode BL. Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization. Eur J Cell Biol 2024; 103:151378. [PMID: 38071835 PMCID: PMC10843626 DOI: 10.1016/j.ejcb.2023.151378] [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: 10/02/2023] [Revised: 12/02/2023] [Accepted: 12/02/2023] [Indexed: 01/28/2024] Open
Abstract
How cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIRF microscopy, we observe that GMF's branch destabilizing activities are potently blocked by cortactin (IC50 = 1.3 nM) and that this inhibition requires direct interactions of cortactin with Arp2/3 complex. The simplest model that would explain these results is competition for binding Arp2/3 complex. However, we find that cortactin and GMF do not compete for free Arp2/3 complex in solution. Further, we use single molecule analysis to show that cortactin's on-rate (3 ×107 s-1 M-1) and off-rate (0.03 s-1) at branch junctions are minimally affected by excess GMF. Together, these results show that cortactin binds with high affinity to branch junctions, where it blocks the destabilizing effects of GMF, possibly by a mechanism that is allosteric in nature. In addition, the affinities we measure for cortactin at actin filament branch junctions (Kd = 0.9 nM) and filament sides (Kd = 206 nM) are approximately 20-fold stronger than previously reported. These observations contribute to an emerging view of molecular complexity in how Arp2/3 complex is regulated through the integration of multiple inputs.
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Affiliation(s)
- Emma R McGuirk
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South Street, Waltham, MA 02454, USA
| | - Neha Koundinya
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South Street, Waltham, MA 02454, USA
| | - Priyashree Nagarajan
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Shae B Padrick
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Bruce L Goode
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South Street, Waltham, MA 02454, USA.
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Cao L, Way M. The stabilization of Arp2/3 complex generated actin filaments. Biochem Soc Trans 2024; 52:343-352. [PMID: 38288872 PMCID: PMC10903444 DOI: 10.1042/bst20230638] [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: 11/01/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 02/29/2024]
Abstract
The Arp2/3 complex, which generates both branched but also linear actin filaments via activation of SPIN90, is evolutionarily conserved in eukaryotes. Several factors regulate the stability of filaments generated by the Arp2/3 complex to maintain the dynamics and architecture of actin networks. In this review, we summarise recent studies on the molecular mechanisms governing the tuning of Arp2/3 complex nucleated actin filaments, which includes investigations using microfluidics and single-molecule imaging to reveal the mechanosensitivity, dissociation and regeneration of actin branches. We also discuss the high-resolution cryo-EM structure of cortactin bound to actin branches, as well as the differences and similarities between the stability of Arp2/3 complex nucleated branches and linear filaments. These new studies provide a clearer picture of the stabilisation of Arp2/3 nucleated filaments at the molecular level. We also identified gaps in our understanding of how different factors collectively contribute to the stabilisation of Arp2/3 complex-generated actin networks.
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Affiliation(s)
- LuYan Cao
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, U.K
| | - Michael Way
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, U.K
- Department of Infectious Disease, Imperial College, London W2 1PG, U.K
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