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He L, Lin Y, Ge ZH, He SY, Zhao BB, Shen D, He JG, Lu YJ. The Legionella pneumophila effector WipA disrupts host F-actin polymerisation by hijacking phosphotyrosine signalling. Cell Microbiol 2019; 21:e13014. [PMID: 30702192 DOI: 10.1111/cmi.13014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/15/2019] [Accepted: 01/28/2019] [Indexed: 11/29/2022]
Abstract
The major virulence determinant of Legionella pneumophila is the type IVB secretion system (T4BSS), which delivers approximately 330 effector proteins into the host cell to modulate various cellular processes. However, the functions of most effector proteins remain unclear. WipA, an effector, was the first phosphotyrosine phosphatase of Legionella with unknown function. In this study, we found that WipA induced relatively strong growth defects in yeast in a phosphatase activity-dependent manner. Phosphoproteomics data showed that WipA was likely involved into endocytosis, FcγR-mediated phagocytosis, tight junction, and regulation of actin cytoskeleton pathways. Western blotting further confirmed WipA dephosphorylates several proteins associated with actin polymerisation, such as p-N-WASP, p-ARP3, p-ACK1, and p-NCK1. Thus, we hypothesised that WipA targets N-WASP/ARP2/3 complex signalling pathway, leading to disturbance of actin polymerisation. Indeed, we demonstrated that WipA inhibits host F-actin polymerisation by reducing the G-actin to F-actin transition during L. penumophila infection. Furthermore, the intracellular proliferation of wipA/legK2 double mutant was significantly impaired at the late stage of infection, although the absence of WipA does not confer any further effect on actin polymerisation to the legK2 mutant. Collectively, this study provides unique insights into the WipA-mediated regulation of host actin polymerisation and assists us to elucidate the pathogenic mechanisms of L. pnuemophila infection.
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Affiliation(s)
- Lei He
- School of life sciences, Sun Yat-sen University, Guangzhou, China.,Biomedical Center, Sun Yat-sen University, Guangzhou, China
| | - Yun Lin
- School of life sciences, Sun Yat-sen University, Guangzhou, China.,Biomedical Center, Sun Yat-sen University, Guangzhou, China
| | - Zhen-Huang Ge
- School of life sciences, Sun Yat-sen University, Guangzhou, China.,Biomedical Center, Sun Yat-sen University, Guangzhou, China
| | - Shi-Yu He
- School of life sciences, Sun Yat-sen University, Guangzhou, China.,Biomedical Center, Sun Yat-sen University, Guangzhou, China
| | - Bei-Bei Zhao
- School of life sciences, Sun Yat-sen University, Guangzhou, China.,Biomedical Center, Sun Yat-sen University, Guangzhou, China
| | - Dong Shen
- School of life sciences, Sun Yat-sen University, Guangzhou, China.,Biomedical Center, Sun Yat-sen University, Guangzhou, China
| | - Jian-Guo He
- School of life sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou, China
| | - Yong-Jun Lu
- School of life sciences, Sun Yat-sen University, Guangzhou, China.,Biomedical Center, Sun Yat-sen University, Guangzhou, China
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2
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Fernández-Calleja V, Fernández-Nestosa MJ, Hernández P, Schvartzman JB, Krimer DB. CRISPR/Cas9-mediated deletion of the Wiskott-Aldrich syndrome locus causes actin cytoskeleton disorganization in murine erythroleukemia cells. PeerJ 2019; 7:e6284. [PMID: 30671311 PMCID: PMC6339507 DOI: 10.7717/peerj.6284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 12/14/2018] [Indexed: 01/18/2023] Open
Abstract
Wiskott-Aldrich syndrome (WAS) is a recessive X-linked inmmunodeficiency caused by loss-of-function mutations in the gene encoding the WAS protein (WASp). WASp plays an important role in the polymerization of the actin cytoskeleton in hematopoietic cells through activation of the Arp2/3 complex. In a previous study, we found that actin cytoskeleton proteins, including WASp, were silenced in murine erythroleukemia cells defective in differentiation. Here, we designed a CRISPR/Cas9 strategy to delete a 9.5-kb genomic region encompassing the Was gene in the X chromosome of murine erythroleukemia (MEL) cells. We show that Was-deficient MEL cells have a poor organization of the actin cytoskeleton that can be recovered by restoring Was expression. We found that whereas the total amount of actin protein was similar between wild-type and Was knockout MEL cells, the latter exhibited an altered ratio of monomeric G-actin to polymeric F-actin. We also demonstrate that Was overexpression can mediate the activation of Bruton’s tyrosine kinase. Overall, these findings support the role of WASp as a key regulator of F-actin in erythroid cells.
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Affiliation(s)
- Vanessa Fernández-Calleja
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Spanish National Research Council (CSIC), Madrid, Spain
| | | | - Pablo Hernández
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Spanish National Research Council (CSIC), Madrid, Spain
| | - Jorge B Schvartzman
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Spanish National Research Council (CSIC), Madrid, Spain
| | - Dora B Krimer
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Spanish National Research Council (CSIC), Madrid, Spain
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3
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Li J, Yin W, Jing Y, Kang D, Yang L, Cheng J, Yu Z, Peng Z, Li X, Wen Y, Sun X, Ren B, Liu C. The Coordination Between B Cell Receptor Signaling and the Actin Cytoskeleton During B Cell Activation. Front Immunol 2019; 9:3096. [PMID: 30687315 PMCID: PMC6333714 DOI: 10.3389/fimmu.2018.03096] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 12/13/2018] [Indexed: 01/27/2023] Open
Abstract
B-cell activation plays a crucial part in the immune system and is initiated via interaction between the B cell receptor (BCR) and specific antigens. In recent years with the help of modern imaging techniques, it was found that the cortical actin cytoskeleton changes dramatically during B-cell activation. In this review, we discuss how actin-cytoskeleton reorganization regulates BCR signaling in different stages of B-cell activation, specifically when stimulated by antigens, and also how this reorganization is mediated by BCR signaling molecules. Abnormal BCR signaling is associated with the progression of lymphoma and immunological diseases including autoimmune disorders, and recent studies have proved that impaired actin cytoskeleton can devastate the normal activation of B cells. Therefore, to figure out the coordination between the actin cytoskeleton and BCR signaling may reveal an underlying mechanism of B-cell activation, which has potential for new treatments for B-cell associated diseases.
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Affiliation(s)
- Jingwen Li
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Yin
- Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yukai Jing
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Danqing Kang
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lu Yang
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiali Cheng
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ze Yu
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zican Peng
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xingbo Li
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yue Wen
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xizi Sun
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Boxu Ren
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, China
- Clinical Molecular Immunology Center, School of Medicine, Yangtze University, Jingzhou, China
| | - Chaohong Liu
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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4
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NPM-ALK phosphorylates WASp Y102 and contributes to oncogenesis of anaplastic large cell lymphoma. Oncogene 2016; 36:2085-2094. [PMID: 27694894 DOI: 10.1038/onc.2016.366] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 08/21/2016] [Accepted: 08/24/2016] [Indexed: 12/26/2022]
Abstract
Mechanisms by which NPM-ALK signaling regulates cell migration, invasion and contributes to the oncogenesis of anaplastic large cell lymphoma (ALCL) are not completely understood. In an attempt to identify novel actin signaling pathways regulated by NPM-ALK, a comprehensive phosphoproteome analysis of ALCL cell lines was performed in the presence or absence of NPM-ALK activity. Numerous phosphoproteins involved in actin dynamics including Wiskott-Aldrich syndrome protein (WASp) were regulated by NPM-ALK. Network analysis revealed that WASp is a central component of the NPM-ALK-dependent actin signaling pathway. Here we show that NPM-ALK phosphorylates WASp at its known activation site (Y290) as well as at a novel residue (Y102). Phosphorylation of WASp at Y102 negatively regulates its interaction with Wiskott-Aldrich interacting protein and decreases its protein stability. Phosphorylation of WASp at Y102 enhances anchorage-independent growth and tumor growth in an in vivo xenograft model and enhances invasive properties of ALCL. We show that knock-down of WASp or expression of Y102F mutant of WASp decreases colony formation and in vivo tumor growth. Our results show that WASp is a novel substrate of ALK and has a critical role in regulating invasiveness and oncogenesis of ALCL.
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Abstract
The presence of a small population of cells or DNA in one individual that derives from another genetically distinct person is referred to as microchimerism; this process may occur in course of pregnancy from mother to fetus, and vice versa. The clinical similarities between some features of autoimmune diseases and the chronic graft versus host disease, the increased incidence of autoimmune diseases observed in women after childbearing age, and the long-term persistence of microchimerism have raised the hypothesis that microchimerism could be involved in the pathogenesis of autoimmune diseases. To assess the possible relationship between pregnancy and the incidence of systemic sclerosis we performed a hospital-based case-control study. Our results, indicating a reduced risk for systemic sclerosis in women who had been pregnant in comparison with women who had not, seem to indicate that pregnancy is not a risk factor for systemic sclerosis.
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Affiliation(s)
- A E Turco
- Department of Mother and Child, Section of Genetics, The University of Verona School of Medicine, University Hospital, Verona, Italy
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6
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Khairnar V, Duhan V, Maney SK, Honke N, Shaabani N, Pandyra AA, Seifert M, Pozdeev V, Xu HC, Sharma P, Baldin F, Marquardsen F, Merches K, Lang E, Kirschning C, Westendorf AM, Häussinger D, Lang F, Dittmer U, Küppers R, Recher M, Hardt C, Scheffrahn I, Beauchemin N, Göthert JR, Singer BB, Lang PA, Lang KS. CEACAM1 induces B-cell survival and is essential for protective antiviral antibody production. Nat Commun 2015; 6:6217. [PMID: 25692415 PMCID: PMC4346637 DOI: 10.1038/ncomms7217] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 01/07/2015] [Indexed: 01/03/2023] Open
Abstract
B cells are essential for antiviral immune defence because they produce neutralizing antibodies, present antigen and maintain the lymphoid architecture. Here we show that intrinsic signalling of CEACAM1 is essential for generating efficient B-cell responses. Although CEACAM1 exerts limited influence on the proliferation of B cells, expression of CEACAM1 induces survival of proliferating B cells via the BTK/Syk/NF-κB-axis. The absence of this signalling cascade in naive Ceacam1−/− mice limits the survival of B cells. During systemic infection with cytopathic vesicular stomatitis virus, Ceacam1−/− mice can barely induce neutralizing antibody responses and die early after infection. We find, therefore, that CEACAM1 is a crucial regulator of B-cell survival, influencing B-cell numbers and protective antiviral antibody responses. Antibody responses are regulated by selective survival of B cells with proper antigen specificity. Here the authors show that CEACAM1 is critical for B-cell survival during homeostasis and antiviral responses.
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Affiliation(s)
- Vishal Khairnar
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Vikas Duhan
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Sathish Kumar Maney
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, Düsseldorf 40225, Germany
| | - Nadine Honke
- 1] Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany [2] Clinic of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, Düsseldorf 40225, Germany
| | - Namir Shaabani
- 1] Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany [2] Clinic of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, Düsseldorf 40225, Germany
| | - Aleksandra A Pandyra
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Marc Seifert
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Virchowstrasse 173, Essen 45122, Germany
| | - Vitaly Pozdeev
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, Düsseldorf 40225, Germany
| | - Haifeng C Xu
- 1] Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany [2] Clinic of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, Düsseldorf 40225, Germany
| | - Piyush Sharma
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Fabian Baldin
- Clinic for Primary Immunodeficiency, Medical Outpatient Unit and Immunodeficiency Laboratory, Department of Biomedicine, University Hospital, Basel 4031, Switzerland
| | - Florian Marquardsen
- Clinic for Primary Immunodeficiency, Medical Outpatient Unit and Immunodeficiency Laboratory, Department of Biomedicine, University Hospital, Basel 4031, Switzerland
| | - Katja Merches
- 1] Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany [2] Department of Physiology I, University of Tuebingen, Gmelinstrasse 5, Tuebingen 72076, Germany
| | - Elisabeth Lang
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, Düsseldorf 40225, Germany
| | - Carsten Kirschning
- Institute of Medical Microbiology, Faculty of Medicine, University Hospital Essen, Hufelandstrasse 55, Essen 45122, Germany
| | - Astrid M Westendorf
- Institute of Medical Microbiology, Faculty of Medicine, University Hospital Essen, Hufelandstrasse 55, Essen 45122, Germany
| | - Dieter Häussinger
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, Düsseldorf 40225, Germany
| | - Florian Lang
- Department of Physiology I, University of Tuebingen, Gmelinstrasse 5, Tuebingen 72076, Germany
| | - Ulf Dittmer
- Institute of Virology, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Ralf Küppers
- Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Virchowstrasse 173, Essen 45122, Germany
| | - Mike Recher
- Clinic for Primary Immunodeficiency, Medical Outpatient Unit and Immunodeficiency Laboratory, Department of Biomedicine, University Hospital, Basel 4031, Switzerland
| | - Cornelia Hardt
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Inka Scheffrahn
- Clinic of Gastroenterology and Hepatology, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Nicole Beauchemin
- Rosalind and Morris Goodman Cancer Centre, Departments of Biochemistry, Medicine and Oncology, McIntyre Medical Science Building, Montreal, Quebec, Canada H3G 1Y6
| | - Joachim R Göthert
- Department of Hematology, West German Cancer Center (WTZ), University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Bernhard B Singer
- Institute of Anatomy, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Philipp A Lang
- 1] Clinic of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, Düsseldorf 40225, Germany [2] Department of Molecular Medicine II, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, Düsseldorf 40225, Germany
| | - Karl S Lang
- 1] Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstrasse 55, Essen 45147, Germany [2] Clinic of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, Düsseldorf 40225, Germany
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Matalon O, Reicher B, Barda-Saad M. Wiskott-Aldrich syndrome protein - dynamic regulation of actin homeostasis: from activation through function and signal termination in T lymphocytes. Immunol Rev 2013; 256:10-29. [DOI: 10.1111/imr.12112] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Omri Matalon
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan Israel
| | - Barak Reicher
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan Israel
| | - Mira Barda-Saad
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan Israel
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8
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Schachtner H, Calaminus SDJ, Thomas SG, Machesky LM. Podosomes in adhesion, migration, mechanosensing and matrix remodeling. Cytoskeleton (Hoboken) 2013; 70:572-89. [PMID: 23804547 DOI: 10.1002/cm.21119] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/07/2013] [Accepted: 06/13/2013] [Indexed: 12/30/2022]
Abstract
Cells use various actin-based motile structures to allow them to move across and through matrix of varying density and composition. Podosomes are actin cytoskeletal structures that form in motile cells and that mediate adhesion to substrate, migration, and other specialized functions such as transmigration through cell and matrix barriers. The podosome is a unique and interesting entity, which appears in the light microscope as an individual punctum, but is linked to other podosomes like a node on a network of the underlying cytoskeleton. Here, we discuss the signals that control podosome assembly and dynamics in different cell types and the actin organising proteins that regulate both the inner actin core and integrin-rich surrounding ring structures. We review the structure and composition of podosomes and also their functions in various cell types of both myeloid and endothelial lineage. We also discuss the emerging idea that podosomes can sense matrix stiffness and enable cells to respond to their environment.
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Affiliation(s)
- Hannah Schachtner
- CRUK Beatson Institute for Cancer Research and College of Medical, Veterinary and Life Sciences, Glasgow University, Garscube Campus, Switchback Rd., Bearsden, Glasgow, United Kingdom
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9
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Massaad MJ, Ramesh N, Geha RS. Wiskott-Aldrich syndrome: a comprehensive review. Ann N Y Acad Sci 2013; 1285:26-43. [DOI: 10.1111/nyas.12049] [Citation(s) in RCA: 229] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Michel J. Massaad
- Division of Immunology, Boston Children's Hospital, and Department of Pediatrics; Harvard Medical School; Boston; Massachusetts
| | - Narayanaswamy Ramesh
- Division of Immunology, Boston Children's Hospital, and Department of Pediatrics; Harvard Medical School; Boston; Massachusetts
| | - Raif S. Geha
- Division of Immunology, Boston Children's Hospital, and Department of Pediatrics; Harvard Medical School; Boston; Massachusetts
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10
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Bruton's tyrosine kinase regulates Shigella flexneri dissemination in HT-29 intestinal cells. Infect Immun 2012; 81:598-607. [PMID: 23230296 DOI: 10.1128/iai.00853-12] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Shigella flexneri is a Gram-negative intracellular pathogen that infects the intestinal epithelium and utilizes actin-based motility to spread from cell to cell. S. flexneri actin-based motility has been characterized in various cell lines, but studies in intestinal cells are limited. Here we characterized S. flexneri actin-based motility in HT-29 intestinal cells. In agreement with studies conducted in various cell lines, we showed that S. flexneri relies on neural Wiskott-Aldrich Syndrome protein (N-WASP) in HT-29 cells. We tested the potential role of various tyrosine kinases involved in N-WASP activation and uncovered a previously unappreciated role for Bruton's tyrosine kinase (Btk) in actin tail formation in intestinal cells. We showed that Btk depletion led to a decrease in N-WASP phosphorylation which affected N-WASP recruitment to the bacterial surface, decreased the number of bacteria displaying actin-based motility, and ultimately affected the efficiency of spread from cell to cell. Finally, we showed that the levels of N-WASP phosphorylation and Btk expression were increased in response to infection, which suggests that S. flexneri infection not only triggers the production of proinflammatory factors as previously described but also manipulates cellular processes required for dissemination in intestinal cells.
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11
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Impaired cell adhesion, apoptosis, and signaling in WASP gene-disrupted Nalm-6 pre-B cells and recovery of cell adhesion using a transducible form of WASp. Int J Hematol 2012; 95:299-310. [DOI: 10.1007/s12185-012-1013-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 01/18/2012] [Accepted: 01/19/2012] [Indexed: 10/14/2022]
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12
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Invadosome regulation by adhesion signaling. Curr Opin Cell Biol 2011; 23:597-606. [DOI: 10.1016/j.ceb.2011.04.002] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 04/11/2011] [Accepted: 04/11/2011] [Indexed: 12/16/2022]
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13
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Dovas A, Cox D. Regulation of WASp by phosphorylation: Activation or other functions? Commun Integr Biol 2011; 3:101-5. [PMID: 20585499 DOI: 10.4161/cib.3.2.10759] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2009] [Accepted: 11/28/2009] [Indexed: 11/19/2022] Open
Abstract
Wiskott-Aldrich Syndrome protein (WASp) is an actin nucleation-promoting factor that regulates actin polymerisation via the Arp2/3 complex. Its mutation in human syndromes has led to extensive studies on the regulation and activities of this molecule. Several mechanisms for the regulation of WASp activity have been proposed, however, the role of tyrosine phosphorylation remains controversial, particularly due to inconsistencies between results obtained through biochemical and cell biological approaches. In this mini-review, we are addressing the major aspects of WASp regulation with an emphasis on the role of tyrosine phosphorylation on WASp activities.
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14
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Itk: the rheostat of the T cell response. JOURNAL OF SIGNAL TRANSDUCTION 2011; 2011:297868. [PMID: 21747996 PMCID: PMC3116522 DOI: 10.1155/2011/297868] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 01/19/2011] [Indexed: 12/28/2022]
Abstract
The nonreceptor tyrosine kinase Itk plays a key role in TCR-initiated signaling that directly and significantly affects the regulation of PLCγ1 and the consequent mobilization of Ca2+. Itk also participates in the regulation of cytoskeletal reorganization as well as cellular adhesion, which is necessary for a productive T cell response. The functional cellular outcome of these molecular regulations by Itk renders it an important mediator of T cell development and differentiation. This paper encompasses the structure of Itk, the signaling parameters leading to Itk activation, and Itk effects on molecular pathways resulting in functional cellular outcomes. The incorporation of these factors persuades one to believe that Itk serves as a modulator, or rheostat, critically fine-tuning the T cell response.
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15
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Kalwa H, Michel T. The MARCKS protein plays a critical role in phosphatidylinositol 4,5-bisphosphate metabolism and directed cell movement in vascular endothelial cells. J Biol Chem 2010; 286:2320-30. [PMID: 21097841 DOI: 10.1074/jbc.m110.196022] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The MARCKS protein (myristoylated alanine-rich C kinase substrate) is an actin- and calmodulin-binding protein that is expressed in many mammalian tissues. The role of MARCKS in endothelial signaling responses is incompletely understood. We found that siRNA-mediated knockdown of MARCKS in cultured endothelial cells abrogated directed cell movement in a wound healing assay. We used biochemical and cell imaging approaches to explore the role of MARCKS in endothelial signal transduction pathways activated by insulin. Insulin treatment of vascular endothelial cells promoted the dose- and time-dependent phosphorylation of MARCKS. Cell imaging and hydrodynamic approaches revealed that MARCKS is targeted to plasmalemmal caveolae and undergoes subcellular translocation in response to insulin. Insulin treatment promoted an increase in levels of the signaling phospholipid phosphatidylinositol 4,5-bisphosphate (PIP(2)) in plasmalemmal caveolae. The insulin-stimulated increase in caveolar PIP(2) was blocked by siRNA-mediated knockdown of MARCKS, as determined using both biochemical assays and imaging studies using FRET-based PIP(2) biosensors. The critical role of PIP(2) in MARCKS responses was explored by examining the PIP(2)- and actin-binding proteins Arp2/3 and N-WASP. Insulin promoted the rapid and robust phosphorylation of both N-WASP and Arp2/3, but these phosphorylation responses were markedly attenuated by siRNA-mediated MARCKS knockdown. Moreover, MARCKS knockdown effectively abrogated N-WASP activation in response to insulin, as determined using a FRET-based N-WASP activity biosensor. Taken together, these studies show that MARCKS plays a key role in insulin-dependent endothelial signaling to PIP(2) and is a critical determinant of actin assembly and directed cell movement in the vascular endothelium.
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Affiliation(s)
- Hermann Kalwa
- Cardiovascular Medicine Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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16
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Impaired NK-cell migration in WAS/XLT patients: role of Cdc42/WASp pathway in the control of chemokine-induced beta2 integrin high-affinity state. Blood 2010; 115:2818-26. [PMID: 20130240 DOI: 10.1182/blood-2009-07-235804] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
We analyzed the involvement of Wiskott-Aldrich syndrome protein (WASp), a critical regulator of actin cytoskeleton remodeling, in the control of natural killer (NK)-cell migration. NK cells derived from patients with Wiskott-Aldrich syndrome/X-linked thrombocytopenia (WAS/XLT), carrying different mutations in the WASP coding gene, displayed reduced migration through intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), or endothelial cells in response to CXCL12/stromal cell-derived factor-1 and CX3CL1/fractalkine. Inhibition of WAS/XLT NK-cell migration was associated with reduced ability of these cells to up-regulate the expression of CD18 activation neoepitope and to adhere to ICAM-1 or VCAM-1 following chemokine stimulation. Moreover, chemokine receptor or beta1 or beta2 integrin engagement on NK cells rapidly resulted in Cdc42 activation and WASp tyrosine phosphorylation as well as in WASp association with Fyn and Pyk-2 tyrosine kinases. NK-cell pretreatment with wiskostatin, to prevent Cdc42/WASp association, impaired chemokine-induced NK-cell migration through ICAM-1 and beta2 integrin activation-dependent neoepitope expression. These results show that the Cdc42/WASp pathway plays a crucial role in the regulation of NK-cell migration by acting as a critical component of the chemokine-induced inside-out signaling that regulates lymphocyte function-associated antigen-1 function and suggest that after integrin or chemokine receptor engagement WASp function is regulated by the coordinate action of both Cdc42 and tyrosine kinases.
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Abstract
The pleiotropic receptor tyrosine kinase Kit can provide cytoskeletal signals that define cell shape, positioning, and migration, but the underlying mechanisms are less well understood. In this study, we provide evidence that Kit signals through Wiskott-Aldrich syndrome protein (WASP), the central hematopoietic actin nucleation-promoting factor and regulator of the cytoskeleton. Kit ligand (KL) stimulation resulted in transient tyrosine phosphorylation of WASP, as well as interacting proteins WASP-interacting protein and Arp2/3. KL-induced filopodia in bone marrow-derived mast cells (BMMCs) were significantly decreased in number and size in the absence of WASP. KL-dependent regulation of intracellular Ca(2+) levels was aberrant in WASP-deficient BMMCs. When BMMCs were derived from WASP-heterozygous female mice using KL as a growth factor, the cultures eventually developed from a mixture of WASP-positive and -negative populations into a homogenous WASP-positive culture derived from the WASP-positive progenitors. Thus, WASP expression conferred a selective advantage to the development of Kit-dependent hematopoiesis consistent with the selective advantage of WASP-positive hematopoietic cells observed in WAS-heterozygous female humans. Finally, KL-mediated gene expression in wild-type and WASP-deficient BMMCs was compared and revealed that approximately 30% of all Kit-induced changes were WASP dependent. The results indicate that Kit signaling through WASP is necessary for normal Kit-mediated filopodia formation, cell survival, and gene expression, and provide new insight into the mechanism in which WASP exerts a strong selective pressure in hematopoiesis.
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Sharma S, Orlowski G, Song W. Btk regulates B cell receptor-mediated antigen processing and presentation by controlling actin cytoskeleton dynamics in B cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2009; 182:329-39. [PMID: 19109164 PMCID: PMC2855895 DOI: 10.4049/jimmunol.182.1.329] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The high efficiency of Ag processing and presentation by B cells requires Ag-induced BCR signaling and actin cytoskeleton reorganization, although the underlying mechanism for such requirements remains elusive. In this study, we identify Bruton's tyrosine kinase (Btk) as a linker connecting BCR signaling to actin dynamics and the Ag transport pathway. Using xid mice and a Btk inhibitor, we show that BCR engagement increases actin polymerization and Wiskott-Aldrich syndrome protein activation in a Btk-dependent manner. Concurrently, we observe Btk-dependent increases in the levels of phosphatidylinositide-4,5-bisphosphate and phosphorylated Vav upon BCR engagement. The rate of BCR internalization, its movement to late endosomes, and efficiency of BCR-mediated Ag processing and presentation are significantly reduced in both xid and Btk inhibitor-treated B cells. Thus, Btk regulates actin dynamics and Ag transport by activating Wiskott-Aldrich syndrome protein via Vav and phosphatidylinositides. This represents a novel mechanism by which BCR-mediated signaling regulates BCR-mediated Ag processing and presentation.
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Affiliation(s)
- Shruti Sharma
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Gregory Orlowski
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Wenxia Song
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
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Abstract
The fact that the Xid mutation of Btk impairs the ability of pleckstrin homology domain of Btk to bind phosphatidylinositol-(3,4,5)-trisphosphate, a product of class IA phosphoinositide-3 kinases (PI3Ks), has been considered strong evidence for the hypothesis that Btk functions downstream of PI3Ks. We demonstrate here that the Xid mutation renders the Btk protein unstable. Furthermore, class IA PI3K- and Btk-deficient mice show different phenotypes in B-cell development, collectively indicating that PI3Ks and Btk differentially function in BCR signal transduction. Nevertheless, both PI3K and Btk are required for the activation of NF-kappaB, a critical transcription factor family for B-cell development and function. We demonstrate that PI3Ks maintain the expression of NF-kappaB proteins, whereas Btk is known to be essential for IkappaB degradation and the translocation of NF-kappaB to the nucleus. The loss of PI3K activity results in marked reduction of c-Rel and to a lesser extent RelA expression. The lentivirus-mediated introduction of c-Rel corrects both developmental and proliferative defects in response to BCR stimulation in class IA PI3K-deficient B cells. These results show that the PI3K-mediated control of c-Rel expression is essential for B-cell functions.
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Niu H, Leung DTM, Ma CH, Law ECY, Tam FCH, Lim PL. Cells that produce deleterious autoreactive antibodies are vulnerable to suicide. THE JOURNAL OF IMMUNOLOGY 2008; 181:2246-57. [PMID: 18641365 DOI: 10.4049/jimmunol.181.3.2246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
It is puzzling how autoreactive B cells that escape self-tolerance mechanisms manage to produce Abs that target vital cellular processes without succumbing themselves to the potentially deleterious effects of these proteins. We report that censorship indeed exists at this level: when the Ab synthesis in the cell is up-regulated in IL-6-enriched environments (e.g., adjuvant-primed mouse peritoneum), the cell dies of the increased intracellular binding between the Ab and the cellular autoantigen. In the case in which telomerase is the autoantigen, mouse hybridoma cells synthesizing such an autoantibody, which appeared to grow well in culture, could not grow in syngeneic BALB/c mice to form ascites, but grew nevertheless in athymic siblings. Culture experiments demonstrated that peritoneal cell-derived IL-6 (and accessory factors) affected the growth and functions of the hybridoma cells, including the induction of mitochondria-based apoptosis. Electron microscopy revealed an abundance of Abs in the nuclear chromatin of IL-6-stimulated cells, presumably piggy-backed there by telomerase from the cytosol. This nuclear presence was confirmed by light microscopy analysis of isolated nuclei. In two other cases, hybridoma cells synthesizing an autoantibody to GTP or osteopontin also showed similar growth inhibition in vivo. In all cases, Ab function was crucial to the demise of the cells. Thus, autoreactive cells, which synthesize autoantibodies to certain intracellular Ags, live delicately between life and death depending on the cytokine microenvironment. Paradoxically, IL-6, which is normally growth-potentiating for B cells, is proapoptotic for these cells. The findings reveal potential strategies and targets for immunotherapy.
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Affiliation(s)
- Haitao Niu
- Clinical Immunology Unit, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong
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Jongstra-Bilen J, Puig Cano A, Hasija M, Xiao H, Smith CIE, Cybulsky MI. Dual Functions of Bruton’s Tyrosine Kinase and Tec Kinase during Fcγ Receptor-Induced Signaling and Phagocytosis. THE JOURNAL OF IMMUNOLOGY 2008; 181:288-98. [DOI: 10.4049/jimmunol.181.1.288] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Tsuboi S, Meerloo J. Wiskott-Aldrich syndrome protein is a key regulator of the phagocytic cup formation in macrophages. J Biol Chem 2007; 282:34194-203. [PMID: 17890224 DOI: 10.1074/jbc.m705999200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Phagocytosis is a vital first-line host defense mechanism against infection involving the ingestion and digestion of foreign materials such as bacteria by specialized cells, phagocytes. For phagocytes to ingest the foreign materials, they form an actin-based membrane structure called phagocytic cup at the plasma membranes. Formation of the phagocytic cup is impaired in phagocytes from patients with a genetic immunodeficiency disorder, Wiskott-Aldrich syndrome (WAS). The gene defective in WAS encodes Wiskott-Aldrich syndrome protein (WASP). Mutation or deletion of WASP causes impaired formation of the phagocytic cup, suggesting that WASP plays an important role in the phagocytic cup formation. However, the molecular details of its formation remain unknown. We have shown that the WASP C-terminal activity is critical for the phagocytic cup formation in macrophages. We demonstrated that WASP is phosphorylated on tyrosine 291 in macrophages, and the WASP phosphorylation is important for the phagocytic cup formation. In addition, we showed that WASP and WASP-interacting protein (WIP) form a complex at the phagocytic cup and that the WASP.WIP complex plays a critical role in the phagocytic cup formation. Our results indicate that the phosphorylation of WASP and the complex formation of WASP with WIP are the essential molecular steps for the efficient formation of the phagocytic cup in macrophages, suggesting a possible disease mechanism underlying phagocytic defects and recurrent infections in WAS patients.
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Affiliation(s)
- Shigeru Tsuboi
- Infectious and Inflammatory Disease Center and Cell Imaging Facility, Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Gomez-Rodriguez J, Readinger JA, Viorritto IC, Mueller KL, Houghtling RA, Schwartzberg PL. Tec kinases, actin, and cell adhesion. Immunol Rev 2007; 218:45-64. [PMID: 17624943 DOI: 10.1111/j.1600-065x.2007.00534.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Tec family non-receptor tyrosine kinases have been recognized for their roles in the regulation of phospholipase C-gamma and Ca(2+) mobilization downstream from antigen receptors on lymphocytes. Recent data, however, show that the Tec family kinase interleukin-2-inducible T-cell kinase (Itk) also participates in pathways regulating the actin cytoskeleton and 'inside-out' signaling to integrins downstream from the T-cell antigen receptor. Data suggest that Itk may function in a kinase-independent fashion to regulate proper recruitment of the Vav1 guanine nucleotide exchange factor. By enhancing actin cytoskeleton reorganization, recruitment of signaling molecules to the immune synapse, and integrin clustering in response to both antigen and chemokine receptors, the Tec kinases serve as modulators or amplifiers that can increase the duration of T-cell signaling and regulate T-cell functional responses.
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Affiliation(s)
- Julio Gomez-Rodriguez
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Halcomb KE, Contreras CM, Hinman RM, Coursey TG, Wright HL, Satterthwaite AB. Btk and phospholipase C gamma 2 can function independently during B cell development. Eur J Immunol 2007; 37:1033-42. [PMID: 17372989 DOI: 10.1002/eji.200636451] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The pre-BCR and the BCR regulate B cell development via a signalosome nucleated by the adaptor protein B cell linker protein (BLNK). Formation of this complex facilitates activation of phospholipase C (PLC) gamma2 by Bruton's tyrosine kinase (Btk). To determine whether Btk and PLCgamma2 also have separate functions, we generated Btk(-/-)PLCgamma2(-/-) mice. They demonstrated a block in development at the pre-B stage and increased pre-BCR surface expression. This phenotype was more severe than that of Btk(-/-) or PLCgamma2(-/-) mice. Although both Btk and PLCgamma2 were required for proliferation of splenic B cells in response to BCR cross-linking, they contributed differently to anti-IgM-induced phosphorylation of ERK. Btk(-/-) and PLCgamma2(-/-) mice each had a reduced frequency of Iglambda-expressing B cells and impaired migration of pre-B cells towards stromal cell-derived factor 1. However, the increase in pre-B cell malignancy that occurs in BLNK(-/-) mice in the absence of Btk was not observed in the absence of PLCgamma2. Thus, Btk and PLCgamma2 act both in concert and independently throughout B cell development.
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Affiliation(s)
- Kristina E Halcomb
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390-8884, USA
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Caracino D, Jones C, Compton M, Saxe CL. The N-terminus of Dictyostelium Scar interacts with Abi and HSPC300 and is essential for proper regulation and function. Mol Biol Cell 2007; 18:1609-20. [PMID: 17314411 PMCID: PMC1855017 DOI: 10.1091/mbc.e06-06-0518] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Scar/WAVE proteins, members of the conserved Wiskott-Aldrich syndrome (WAS) family, promote actin polymerization by activating the Arp2/3 complex. A number of proteins, including a complex containing Nap1, PIR121, Abi1/2, and HSPC300, interact with Scar/WAVE, though the role of this complex in regulating Scar function remains unclear. Here we identify a short N-terminal region of Dictyostelium Scar that is necessary and sufficient for interaction with HSPC300 and Abi in vitro. Cells expressing Scar lacking this N-terminal region show abnormalities in F-actin distribution, cell morphology, movement, and cytokinesis. This is true even in the presence of wild-type Scar. The data suggest that the first 96 amino acids of Scar are necessary for participation in a large-molecular-weight protein complex, and that this Scar-containing complex is responsible for the proper localization and regulation of Scar. The presence of mis-regulated or unregulated Scar has significant deleterious effects on cells and may explain the need to keep Scar activity tightly controlled in vivo either by assembly in a complex or by rapid degradation.
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Affiliation(s)
- Diana Caracino
- *Department of Cell Biology and
- Graduate Program in Microbiology and Molecular Genetics, Emory University School of Medicine, Atlanta, GA 30322; and
| | | | - Mark Compton
- Department of Poultry Science, School of Agriculture, University of Georgia, Athens, GA 30602
| | - Charles L. Saxe
- *Department of Cell Biology and
- Graduate Program in Microbiology and Molecular Genetics, Emory University School of Medicine, Atlanta, GA 30322; and
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Tsuboi S. A complex of Wiskott-Aldrich syndrome protein with mammalian verprolins plays an important role in monocyte chemotaxis. THE JOURNAL OF IMMUNOLOGY 2006; 176:6576-85. [PMID: 16709815 DOI: 10.4049/jimmunol.176.11.6576] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The Wiskott-Aldrich syndrome protein (WASP) is a product of the gene defective in an Xid disorder, Wiskott-Aldrich syndrome. WASP expression is limited to hemopoietic cells, and WASP regulates the actin cytoskeleton. It has been reported that monocytes/macrophages from WASP-deficient Wiskott-Aldrich syndrome patients are severely defective in chemotaxis, resulting in recurrent infection. However, the molecular basis of such chemotactic defects is not understood. Recently, the WASP N-terminal region was found to bind to the three mammalian verprolin homologs: WASP interacting protein (WIP); WIP and CR16 homologous protein (WICH)/WIP-related protein (WIRE); and CR16. Verprolin was originally found to play an important role in the regulation of actin cytoskeleton in yeast. We have shown that WASP, WIP, and WICH/WIRE are expressed predominantly in the human monocyte cell line THP-1 and that WIP and WICH/WIRE are involved in monocyte chemotaxis. When WASP binding to verprolins was blocked, chemotactic migration of monocytes was impaired in both THP-1 cells and primary human monocytes. Increased expression of WASP and WIP enhanced monocyte chemotaxis. Blocking WASP binding to verprolins impaired cell polarization but not actin polymerization. These results indicate that a complex of WASP with mammalian verprolins plays an important role in chemotaxis of monocytes. Our results suggest that WASP and mammalian verprolins function as a unit in monocyte chemotaxis and that the activity of this unit is critical to establish cell polarization. In addition, our results also indicate that the WASP-verprolin complex is involved in other functions such as podosome formation and phagocytosis.
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Affiliation(s)
- Shigeru Tsuboi
- Infectious and Inflammatory Disease Research Center, Burnham Institute for Medical Research, La Jolla, CA 92037, USA.
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Torres E, Rosen MK. Protein-tyrosine Kinase and GTPase Signals Cooperate to Phosphorylate and Activate Wiskott-Aldrich Syndrome Protein (WASP)/Neuronal WASP. J Biol Chem 2006; 281:3513-20. [PMID: 16293614 DOI: 10.1074/jbc.m509416200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein-tyrosine kinases and Rho GTPases regulate many cellular processes, including the reorganization and dynamics of the actin cytoskeleton. The Wiskott-Aldrich syndrome protein (WASP) and its homolog neuronal WASP (N-WASP) are effectors of the Rho GTPase Cdc42 and provide a direct link between activated membrane receptors and the actin cytoskeleton. WASP and N-WASP are also regulated by a large number of other activators, including protein-tyrosine kinases, phosphoinositides, and Src homology 3-containing adaptor proteins, and can therefore serve as signal integrators inside cells. Here we show that Cdc42 and the Src family kinase Lck cooperate at two levels to enhance WASP activation. First, autoinhibition in N-WASP decreases the efficiency (kcat/Km) of phosphorylation and dephosphorylation of the GTPase binding domain by 30- and 40-fold, respectively, and this effect is largely reversed by Cdc42. Second, Cdc42 and the Src homology 3-Src homology 2 module of Lck cooperatively stimulate the activity of phosphorylated WASP, with coupling energy of approximately 2.4 kcal/mol between the two activators. These combined effects provide mechanisms for high specificity in WASP activation by coincident GTPase and kinase signals.
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Affiliation(s)
- Eduardo Torres
- Howard Hughes Medical Institute and Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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Burton EA, Oliver TN, Pendergast AM. Abl kinases regulate actin comet tail elongation via an N-WASP-dependent pathway. Mol Cell Biol 2005; 25:8834-43. [PMID: 16199863 PMCID: PMC1265773 DOI: 10.1128/mcb.25.20.8834-8843.2005] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Microbial pathogens have evolved diverse strategies to modulate the host cell cytoskeleton to achieve a productive infection and have proven instrumental for unraveling the molecular machinery that regulates actin polymerization. Here we uncover a mechanism for Shigella flexneri-induced actin comet tail elongation that links Abl family kinases to N-WASP-dependent actin polymerization. We show that the Abl kinases are required for Shigella actin comet tail formation, maximal intracellular motility, and cell-to-cell spread. Abl phosphorylates N-WASP, a host cell protein required for actin comet tail formation, and mutation of the Abl phosphorylation sites on N-WASP impairs comet tail elongation. Furthermore, we show that defective comet tail formation in cells lacking Abl kinases is rescued by activated forms of N-WASP. These data demonstrate for the first time that the Abl kinases play a role in the intracellular motility and intercellular dissemination of Shigella and uncover a new role for Abl kinases in the regulation of pathogen motility.
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Affiliation(s)
- Elizabeth A Burton
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
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Yokoyama N, Lougheed J, Miller WT. Phosphorylation of WASP by the Cdc42-associated kinase ACK1: dual hydroxyamino acid specificity in a tyrosine kinase. J Biol Chem 2005; 280:42219-26. [PMID: 16257963 DOI: 10.1074/jbc.m506996200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
ACK1 is a nonreceptor tyrosine kinase that associates specifically with Cdc42. Relatively few ACK1 substrates and interacting proteins have been identified. In this study, we demonstrated that ACK1 phosphorylates the Wiskott-Aldrich syndrome protein (WASP), a Cdc42 effector that plays an important role in the formation of new actin filaments. ACK1 and WASP interact in intact cells, and overexpression of ACK1 promotes WASP phosphorylation. Phosphorylation of WASP in vitro was enhanced by the addition of Cdc42 or phosphatidylinositol 4,5-biphosphate, presumably due to release of the autoinhibitory interactions in WASP. Surprisingly, when we mapped the sites of WASP phosphorylation, we found that ACK1 possesses significant serine kinase activity toward WASP (directed at Ser-242), as well as tyrosine kinase activity directed at Tyr-256. A serine peptide derived from the Ser-242 WASP phosphorylation site is also a substrate for ACK1. ACK1 expressed in bacteria retained its serine kinase activity, eliminating the possibility of contamination with a copurifying kinase. Serine phosphorylation of WASP enhanced the ability of WASP to stimulate actin polymerization in mammalian cell lysates. Thus, the tyrosine kinase ACK1 acts as a dual specificity kinase toward this substrate. In contrast to other dual specificity kinases that more closely resemble Ser/Thr kinases, ACK1 is a tyrosine kinase with an active site that can accommodate both types of hydroxyamino acids in substrates.
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Affiliation(s)
- Noriko Yokoyama
- Department of Physiology and Biophysics, School of Medicine, Stony Brook University, New York 11794, USA
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Chandrasekaran V, Beckendorf SK. Tec29 controls actin remodeling and endoreplication during invagination of the Drosophila embryonic salivary glands. Development 2005; 132:3515-24. [PMID: 16000381 DOI: 10.1242/dev.01926] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Epithelial invagination is necessary for formation of many tubular organs, one of which is the Drosophila embryonic salivary gland. We show that actin reorganization and control of endocycle entry are crucial for normal invagination of the salivary placodes. Embryos mutant for Tec29, the Drosophila Tec family tyrosine kinase, showed delayed invagination of the salivary placodes. This invagination delay was partly the result of an accumulation of G-actin in the salivary placodes, indicating that Tec29 is necessary for maintaining the equilibrium between G- and F-actin during invagination of the salivary placodes. Furthermore, normal invagination of the salivary placodes appears to require the proper timing of the endocycle in these cells; Tec29 must delay DNA endoreplication in the salivary placode cells until they have invaginated into the embryo. Taken together, these results show that Tec29 regulates both the actin cytoskeleton and the cell cycle to facilitate the morphogenesis of the embryonic salivary glands. We suggest that apical constriction of the actin cytoskeleton may provide a temporal cue ensuring that endoreplication does not begin until the cells have finished invagination.
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Affiliation(s)
- Vidya Chandrasekaran
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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Abstract
The Tec family tyrosine kinases are now recognized as important mediators of antigen receptor signaling in lymphocytes. Three members of this family, Itk, Rlk, and Tec, are expressed in T cells and activated in response to T cell receptor (TCR) engagement. Although initial studies demonstrated a role for these proteins in TCR-mediated activation of phospholipase C-gamma, recent data indicate that Tec family kinases also regulate actin cytoskeletal reorganization and cellular adhesion following TCR stimulation. In addition, Tec family kinases are activated downstream of G protein-coupled chemokine receptors, where they play parallel roles in the regulation of Rho GTPases, cell polarization, adhesion, and migration. In all these systems, however, Tec family kinases are not essential signaling components, but instead function to modulate or amplify signaling pathways. Although they quantitatively reduce proximal signaling, mutations that eliminate Tec family kinases in T cells nonetheless qualitatively alter T cell development and differentiation.
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Affiliation(s)
- Leslie J Berg
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
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Finkelstein LD, Schwartzberg PL. Tec kinases: shaping T-cell activation through actin. Trends Cell Biol 2005; 14:443-51. [PMID: 15308211 DOI: 10.1016/j.tcb.2003.07.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Following stimulation, T cells undergo marked actin-dependent changes in shape that are required for productive cellular interactions and movement during immune responses. Reorganization of the actin cytoskeletal is also necessary for the formation of an immunological synapse - the convergence of several signaling molecules at the plasma membrane that occurs after effective T-cell receptor (TCR) signaling. Much emerging evidence indicates that the Tec family of tyrosine kinases has a role in actin cytoskeleton reorganization. Specifically, T cells that lack or express mutant versions of the Tec kinase Itk show impaired TCR-induced actin polymerization, cell polarization and regulation of the signaling events involved in cytoskeletal reorganization. These data, as well as other findings, support roles for Tec kinases in actin cytoskeleton regulation.
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Affiliation(s)
- Lisa D Finkelstein
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Fällman M, Gustavsson A. Cellular mechanisms of bacterial internalization counteracted by Yersinia. INTERNATIONAL REVIEW OF CYTOLOGY 2005; 246:135-88. [PMID: 16164968 DOI: 10.1016/s0074-7696(05)46004-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Upon host-cell contact, human pathogenic Yersinia species inject Yop virulence effectors into the host through a Type III secretion-and-translocation system. These virulence effectors cause a block in phagocytosis (YopE, YopT, YpkA, and YopH) and suppression of inflammatory mediators (YopJ). The Yops that block phagocytosis either interfere with the host cell actin regulation of Rho GTPases (YopE, YopT, and YpkA) or specifically and rapidly inactivate host proteins involved in signaling from the receptor to actin (YopH). The block in uptake has been shown to be activated following binding to Fc, Complement, and beta1-integrin receptors in virtually any kind of host cell. Thus, the use of Yersinia as a model system to study Yersinia-host cell interactions provides a good tool to explore signaling pathways involved in phagocytosis.
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Affiliation(s)
- Maria Fällman
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
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Calle Y, Chou HC, Thrasher AJ, Jones GE. Wiskott-Aldrich syndrome protein and the cytoskeletal dynamics of dendritic cells. J Pathol 2004; 204:460-9. [PMID: 15495215 DOI: 10.1002/path.1651] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The regulated migration and spatial localization of dendritic cells in response to environmental signals are critical events during the initiation of physiological immune responses and maintenance of tolerance. Cells deficient in the Wiskott-Aldrich syndrome protein (WASP) have been used to demonstrate the importance of the dynamic remodelling of the actin-based cytoskeleton during the selective adhesion and migration of these cells. Unlike most cell types, macrophages, dendritic cells, and osteoclasts utilize a specialized adhesive array termed the podosome in order to migrate. Podosomes are composed of many of the same structural and regulatory proteins as seen in the more commonly found focal adhesion, but are unique in their requirement for WASP. Without WASP, podosomes cannot form and the affected cells are obliged to use focal adhesions for their migratory activities. Once activated by a series of upstream regulatory proteins, WASP acts as a scaffold for the binding of the potent actin nucleating protein complex known as Arp2/3. This article reviews the available evidence that suggests that failures in the regulation of the actin cytoskeleton may contribute significantly to the immunopathology of the Wiskott-Aldrich syndrome.
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Affiliation(s)
- Yolanda Calle
- Randall Division of Cell and Molecular Biophysics, King's College London, Guy's Campus, London SE1 1UL, UK
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Brunton VG, MacPherson IRJ, Frame MC. Cell adhesion receptors, tyrosine kinases and actin modulators: a complex three-way circuitry. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2004; 1692:121-44. [PMID: 15246683 DOI: 10.1016/j.bbamcr.2004.04.010] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2004] [Accepted: 04/19/2004] [Indexed: 12/31/2022]
Abstract
The interaction of cells with surrounding matrix and neighbouring cells governs many aspects of cell behaviour. Aside from transmitting signals from the external environment, adhesion receptors also receive signals from the cell interior. Here we review the interrelationship between adhesion receptors, tyrosine kinases (both growth factor receptor and non-receptor) and modulators of the actin cytoskeletal network. Deregulation of many aspects of these signalling pathways in cancer highlights the need for a better understanding of the complexities involved.
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Affiliation(s)
- V G Brunton
- The Beatson Institute for Cancer Research, Cancer Research UK Beatson Laboratories, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD.
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Badour K, Zhang J, Shi F, Leng Y, Collins M, Siminovitch KA. Fyn and PTP-PEST-mediated regulation of Wiskott-Aldrich syndrome protein (WASp) tyrosine phosphorylation is required for coupling T cell antigen receptor engagement to WASp effector function and T cell activation. ACTA ACUST UNITED AC 2004; 199:99-112. [PMID: 14707117 PMCID: PMC1887720 DOI: 10.1084/jem.20030976] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Involvement of the Wiskott-Aldrich syndrome protein (WASp) in promoting cell activation requires its release from autoinhibitory structural constraints and has been attributed to WASp association with activated cdc42. Here, however, we show that T cell development and T cell receptor (TCR)-induced proliferation and actin polymerization proceed normally in WASp-/- mice expressing a WASp transgene lacking the cdc42 binding domain. By contrast, mutation of tyrosine residue Y291, identified here as the major site of TCR-induced WASp tyrosine phosphorylation, abrogated induction of WASp tyrosine phosphorylation and its effector activities, including nuclear factor of activated T cell transcriptional activity, actin polymerization, and immunological synapse formation. TCR-induced WASp tyrosine phosphorylation was also disrupted in T cells lacking Fyn, a kinase shown here to bind, colocalize with, and phosphorylate WASp. By contrast, WASp was tyrosine dephosphorylated by protein tyrosine phosphatase (PTP)-PEST, a tyrosine phosphatase shown here to interact with WASp via proline, serine, threonine phosphatase interacting protein (PSTPIP)1 binding. Although Fyn enhanced WASp-mediated Arp2/3 activation and was required for synapse formation, PTP-PEST combined with PSTPIP1 inhibited WASp-driven actin polymerization and synapse formation. These observations identify key roles for Fyn and PTP-PEST in regulating WASp and imply that inducible WASp tyrosine phosphorylation can occur independently of cdc42 binding, but unlike the cdc42 interaction, is absolutely required for WASp contributions to T cell activation.
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Affiliation(s)
- Karen Badour
- Mount Sinai Hospital, 600 University Avenue, Room 656A, Toronto, Ontario M5G 1X5, Canada
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38
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Imai K, Nonoyama S, Ochs HD. WASP (Wiskott-Aldrich syndrome protein) gene mutations and phenotype. Curr Opin Allergy Clin Immunol 2004; 3:427-36. [PMID: 14612666 DOI: 10.1097/00130832-200312000-00003] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT), characterized by chronic microthrombocytopenia with and without immunodeficiency, are caused by mutations of the WAS protein (WASP) gene. WASP has been reported to interact with many cytoplasmic molecules linking cellular signaling to the actin cytoskeleton. In this review we will focus on recent molecular findings that provide a better understanding of the pathogenesis of this complex disease and explore the correlation of genotype and clinical phenotype. RECENT FINDINGS Recent investigations have provided evidence that WASP and several related proteins are involved in the reorganization of the actin cytoskeleton by activating Arp2/3-mediated actin polymerization. This function is controlled mainly by a small GTPase Cdc42. Activated GTP-bound Cdc42 dissociates the intramolecular autoinhibitory loop formation of WASP. In addition, WASP is involved in cytoplasmic signaling by its interaction with a variety of adaptor molecules or kinases and serves as a link to actin reorganization, which is important for immunological synapse formation, cell trafficking and motility. Tyrosine or serine phosphorylation of WASP increases the actin polymerization activity of WASP via Arp2/3. Mutation analysis of WAS/XLT patients has provided evidence for a strong correlation between phenotype and genotype. Gene therapy for WASP-deficient human lymphocytes and Wasp-deficient mice was performed successfully. SUMMARY The study of WASP and its mutations has led to a better understanding of the pathogenesis of the syndrome (thrombocytopenia, immunodeficiency, atopic dermatitis, autoimmune and malignant diseases) and the mechanisms required for cell mobility, cell-cell interaction and cytoplasmic signaling, as well as thrombopoiesis and maintenance of the number of platelets.
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Affiliation(s)
- Kohsuke Imai
- INSERM (The French Institute of Health and Medical Research) U429, Hôpital Necker-Enfants Malades, Paris, France.
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Burns S, Cory GO, Vainchenker W, Thrasher AJ. Mechanisms of WASp-mediated hematologic and immunologic disease. Blood 2004; 104:3454-62. [PMID: 15308573 DOI: 10.1182/blood-2004-04-1678] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Wiskott-Aldrich syndrome protein (WASp) is a key regulator of actin polymerization in hematopoietic cells. The dynamic nature of cytoskeletal changes during a variety of cellular processes demands complex mechanisms for coordinated integration of input signals, precise localization within the cell, and regulated activation of the Arp2/3 complex. Mutations in the Wiskott-Aldrich syndrome gene either inhibit or dysregulate normal WASp function, resulting in clinical diseases with complex and disparate phenotypes. This review highlights recent advances that have enhanced our understanding of the mechanisms by which these molecular defects cause hematologic and immunologic disease.
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Affiliation(s)
- Siobhan Burns
- Molecular Immunology Unit, Institute of Child Health, University College London, 30 Guilford St, London, WC1N 1EH, United Kingdom.
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Gismondi A, Cifaldi L, Mazza C, Giliani S, Parolini S, Morrone S, Jacobelli J, Bandiera E, Notarangelo L, Santoni A. Impaired natural and CD16-mediated NK cell cytotoxicity in patients with WAS and XLT: ability of IL-2 to correct NK cell functional defect. Blood 2004; 104:436-43. [PMID: 15001467 DOI: 10.1182/blood-2003-07-2621] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
In this study we show that Wiskott-Aldrich syndrome protein (WASp), a critical regulator of actin cytoskeleton that belongs to the Scar/WAVE family, plays a crucial role in the control of natural killer (NK) cell cytotoxicity. Analysis of NK cell numbers and cytotoxic activity in patients carrying different mutations in the WASP coding gene indicated that although the percentage of NK cells was normal or increased, natural cytotoxicity and antibody-mediated NK cell cytotoxicity were inhibited in all patients with the classical WAS phenotype and in most patients carrying mutations associated with the X-linked thrombocytopenia (XLT) phenotype. The inhibition of NK cell-mediated cytotoxicity was associated with the reduced ability of WAS and XLT NK cells to form conjugates with susceptible target cells and to accumulate F-actin on binding. Treatment with interleukin-2 (IL-2) corrected the functional defects of NK cells by affecting their ability to bind to sensitive target cells and to accumulate F-actin. In addition, we provide information on the molecular mechanisms that control WASp function, demonstrating that binding of NK cells to sensitive targets or triggering through CD16 by means of reverse antibody-dependent cellular cytotoxicity (ADCC) rapidly activates Cdc42. We also found that WASp undergoes tyrosine phosphorylation upon CD16 or β2-integrin engagement on NK cells. (Blood. 2004;104:436-443)
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Affiliation(s)
- Angela Gismondi
- University "La Sapienza," Viale Regina Elena, 324, 00161 Rome, Italy.
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41
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Wu X, Suetsugu S, Cooper LA, Takenawa T, Guan JL. Focal Adhesion Kinase Regulation of N-WASP Subcellular Localization and Function. J Biol Chem 2004; 279:9565-76. [PMID: 14676198 DOI: 10.1074/jbc.m310739200] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
N-WASP is a member of the WASP family of proteins that regulate actin cytoskeleton remodeling. FAK is a cytoplasmic tyrosine kinase implicated in integrin signaling during cell migration. Here we identify a direct interaction between N-WASP and FAK and show that N-WASP is phosphorylated by FAK at a conserved tyrosine residue, Tyr(256). We found that phosphorylation of Tyr(256) affected N-WASP nuclear localization, suggesting that phosphorylation of N-WASP by FAK may regulate its activity in vivo by altering its subcellular localization. We also showed that the nuclear localization of N-WASP is dependent on its being in the open conformation either after its activation by Cdc42 or the truncation of the C-terminal VCA domain. Phosphorylation of Tyr(256) of N-WASP could reduce its interaction with nuclear importin NPI-1, which might be responsible for its decreased nuclear localization. Lastly, we show that phosphorylation of Tyr(256) plays an important role in promoting cell migration. Together, these results suggest a novel regulatory mechanism of N-WASP by tyrosine phosphorylation and subcellular localization and its potential role in the regulation of cell migration.
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Affiliation(s)
- Xiaoyang Wu
- Department of Molecular Medicine, Cornell University, Ithaca, New York 14853, USA
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42
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Mizutani K, Suetsugu S, Takenawa T. FBP11 regulates nuclear localization of N-WASP and inhibits N-WASP-dependent microspike formation. Biochem Biophys Res Commun 2004; 313:468-74. [PMID: 14697212 DOI: 10.1016/j.bbrc.2003.11.139] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
WASP family proteins are involved in cortical actin cytoskeleton reorganization. Neural Wiskott-Aldrich syndrome protein (N-WASP), a ubiquitously expressed WASP homologous protein, directly binds with Cdc42, activating Arp2/3 complex. In this study, we show that N-WASP-dependent microspike formation is inhibited by formin binding protein 11 (FBP11). Endogenous FBP11 localizes with nuclear-speckles, and co-localization of N-WASP and FBP11 was observed when they were co-expressed. Epidermal growth factor (EGF) induced actin-microspike formation in COS7 cells. However, transient expression of FBP11 suppressed N-WASP-dependent actin-microspike formation by trapping N-WASP in the nucleus. These results indicate that FBP11 regulates localization of N-WASP, thus negatively regulating the function of N-WASP in the cytoplasm.
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Affiliation(s)
- Kiyohito Mizutani
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokane-dai, Minato-ku, Tokyo 108-8639, Japan
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43
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Cho JH, Lee D, Park JH, Lee IB. New gene selection method for classification of cancer subtypes considering within-class variation. FEBS Lett 2003; 551:3-7. [PMID: 12965195 DOI: 10.1016/s0014-5793(03)00819-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In this work we propose a new method for finding gene subsets of microarray data that effectively discriminates subtypes of disease. We developed a new criterion for measuring the relevance of individual genes by using mean and standard deviation of distances from each sample to the class centroid in order to treat the well-known problem of gene selection, large within-class variation. Also this approach has the advantage that it is applicable not only to binary classification but also to multiple classification problems. We demonstrated the performance of the method by applying it to the publicly available microarray datasets, leukemia (two classes) and small round blue cell tumors (four classes). The proposed method provides a very small number of genes compared with the previous methods without loss of discriminating power and thus it can effectively facilitate further biological and clinical researches.
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Affiliation(s)
- Ji-Hoon Cho
- Department of Chemical Engineering, Pohang University of Science and Technology, San 31 Hyoja-Dong, 790-784 Pohang, South Korea
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Jefferies CA, Doyle S, Brunner C, Dunne A, Brint E, Wietek C, Walch E, Wirth T, O'Neill LAJ. Bruton's tyrosine kinase is a Toll/interleukin-1 receptor domain-binding protein that participates in nuclear factor kappaB activation by Toll-like receptor 4. J Biol Chem 2003; 278:26258-64. [PMID: 12724322 DOI: 10.1074/jbc.m301484200] [Citation(s) in RCA: 229] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study we have identified members of the Toll-like receptor (TLR) family (namely, TLRs 4, 6, 8, and 9) as proteins to which the intracellular protein tyrosine kinase, Bruton's tyrosine kinase (Btk), binds. Detailed analysis of the interaction between Btk and TLR8 demonstrates that the presence of both Box 2 and 3 motifs in the Toll/interleukin-1 receptor domain was required for the interaction. Furthermore, co-immunoprecipitation experiments revealed that Btk can also interact with key proteins involved in TLR4 signal transduction, namely, MyD88, Mal (MyD88 adapter-like protein), and interleukin-1 receptor-associated kinase-1, but not TRAF-6. The ability of Btk to interact with TLR4 and Mal suggests a role for Btk in lipopolysaccharide (LPS) signal transduction. Stimulation of the human monocytic cell line THP-1 with LPS resulted in an increase in the level of tyrosine phosphorylation of Btk (indicative of activation). The autokinase activity of Btk was also stimulated after LPS stimulation. In addition, a dominant negative form of Btk inhibited TLR4-mediated activation of a nuclear factor kappaB (NFkappaB)-dependent reporter gene in HEK293 cells as well as LPS-induced activation of NFkappaB in the astrocytoma cell line U373 and the monocytic cell line RAW264.7. Further investigation revealed that the Btk-specific inhibitor, LFM-A13, inhibited the activation of NFkappaB by LPS in THP-1 cells. Our findings implicate Btk as a Toll/interleukin-1 receptor domain-binding protein that is important for NFkappaB activation by TLR4.
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Affiliation(s)
- Caroline A Jefferies
- Cytokine Research Group, Department of Biochemistry and Biotechnology Institute, Trinity College, Dublin 2, Ireland
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45
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Torres E, Rosen MK. Contingent phosphorylation/dephosphorylation provides a mechanism of molecular memory in WASP. Mol Cell 2003; 11:1215-27. [PMID: 12769846 DOI: 10.1016/s1097-2765(03)00139-4] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Cells can retain information about previous stimuli to produce distinct future responses. The biochemical mechanisms by which this is achieved are not well understood. The Wiskott-Aldrich syndrome protein (WASP) is an effector of the Rho-family GTPase Cdc42, whose activation leads to stimulation of the actin nucleating assembly, Arp2/3 complex. We demonstrate that efficient phosphorylation and dephosphorylation of WASP at Y291 are both contingent on binding to activated Cdc42. Y291 phosphorylation increases the basal activity of WASP toward Arp2/3 complex and enables WASP activation by new stimuli, SH2 domains of Src-family kinases. The requirement for contingency in both phosphorylation and dephosphorylation enables long-term storage of information by WASP following decay of GTPase signals. This biochemical circuitry allows WASP to respond to the levels and timing of GTPase and kinase signals. It provides mechanisms to specifically achieve transient or persistent actin remodeling, as well as long-lasting potentiation of actin-based responses to kinases.
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Affiliation(s)
- Eduardo Torres
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75205, USA
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46
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Cory GOC, Cramer R, Blanchoin L, Ridley AJ. Phosphorylation of the WASP-VCA domain increases its affinity for the Arp2/3 complex and enhances actin polymerization by WASP. Mol Cell 2003; 11:1229-39. [PMID: 12769847 DOI: 10.1016/s1097-2765(03)00172-2] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Wiskott-Aldrich syndrome protein (WASP) and neural (N)-WASP regulate dynamic actin structures through the ability of their VCA domains to bind to and stimulate the actin nucleating activity of the Arp2/3 complex. Here we identify two phosphorylation sites in the VCA domain of WASP at serines 483 and 484. S483 and S484 are substrates for casein kinase 2 in vitro and in vivo. Phosphorylation of these residues increases the affinity of the VCA domain for the Arp2/3 complex 7-fold and is required for efficient in vitro actin polymerization by the full-length WASP molecule. We propose that constitutive VCA domain phosphorylation is required for optimal stimulation of the Arp2/3 complex by WASP.
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Affiliation(s)
- Giles O C Cory
- Ludwig Institute for Cancer Research, Royal Free and University College Medical School Branch, Courtauld Building, 91 Riding House Street, London W1W 7BS, United Kingdom
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47
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Badour K, Zhang J, Siminovitch KA. The Wiskott-Aldrich syndrome protein: forging the link between actin and cell activation. Immunol Rev 2003; 192:98-112. [PMID: 12670398 DOI: 10.1034/j.1600-065x.2003.00031.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The Wiskott-Aldrich syndrome protein (WASp) has emerged as a central player in the regulation of actin remodeling in T cells. The unique domain structure of WASp and other WASp family members enables these proteins to associate with a myriad of signaling effectors and to thereby regulate the coupling of T cell antigen receptor (TCR) engagement to both cytoskeletal rearrangement and transcriptional activation. This review focuses on these biochemical properties of WASp and also on the mechanisms whereby WASp interactions with its cognate ligands influence T cell activation. Because of its capacity to shift intracellular location and thereby dictate both the timing and the spatial distribution of actin polymerization following cell stimulation, WASp is well positioned to play major regulatory roles in directing a wide range of cellular processes and signaling pathways. Further dissection of the functional and biochemical properties of WASp therefore represents a promising avenue towards defining the molecular mechanisms that convey TCR stimulatory signals to the actin cytoskeleton and integrate cytoskeletal and other signaling systems so as to evoke a biological response.
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Affiliation(s)
- Karen Badour
- Department of Medicine, Immunology and Medical Genetics and Microbiology, University of Toronto, Samuel Ontario, Canada
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Suzuki H, Matsuda S, Terauchi Y, Fujiwara M, Ohteki T, Asano T, Behrens TW, Kouro T, Takatsu K, Kadowaki T, Koyasu S. PI3K and Btk differentially regulate B cell antigen receptor-mediated signal transduction. Nat Immunol 2003; 4:280-6. [PMID: 12563258 DOI: 10.1038/ni890] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2002] [Accepted: 01/02/2003] [Indexed: 12/13/2022]
Abstract
Phosphoinositide-3 kinase (PI3K) is thought to activate the tyrosine kinase Btk. However, through analysis of PI3K-/- and Btk-/- mice, B cell antigen receptor (BCR)-induced activation of Btk in mouse B cells was found to be unaffected by PI3K inhibitors or by a lack of PI3K. Consistent with this observation, PI3K-/- Btk-/- double-deficient mice had more severe defects than either single-mutant mouse. NF-kappaB activation along with Bcl-xL and cyclin D2 induction were severely blocked in both PI3K-/- and Btk-/- single-deficient B cells. Transgenic expression of Bcl-xL restored the development and BCR-induced proliferation of B cells in PI3K-/- mice. Our results indicate that PI3K and Btk have unique roles in proximal BCR signaling and that they have a common target further downstream in the activation of NF-kappaB.
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Affiliation(s)
- Harumi Suzuki
- Department of Microbiology and Immunology, Keio University School of Medicine, Tokyo 160-8582, Japan
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49
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Okabe S, Fukuda S, Broxmeyer HE. Src kinase, but not the src kinase family member p56lck, mediates stromal cell-derived factor 1alpha/CXCL12-induced chemotaxis of a T cell line. JOURNAL OF HEMATOTHERAPY & STEM CELL RESEARCH 2002; 11:923-8. [PMID: 12590707 DOI: 10.1089/152581602321080583] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Stromal cell-derived factor 1 (SDF-1/CXCL12) is believed to mediate migration of leukocytes. To explore potential mechanisms, we evaluated the signal transduction pathways activated by SDF-1 in the Jurkat T cell line. Src kinase was phosphorylated and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) activated in a time-related fashion after SDF-1 stimulation. Chemotaxis of Jurkat cells was partially blocked by pretreatment with the src kinase inhibitor PP2 in a dose-dependent manner. Wiskott-Aldrich Syndrome Protein (WASP) regulates actin polymerization and cytoskeletal organization in T cells. We found WASP complexed to activated src after SDF-1 stimulation, suggesting a possible interacting role for src kinase and WASP in mediating SDF-1 action. J.CaM1.6 cells, which have lost expression of the src kinase p56(lck) (lck), responded to chemotaxis induced by SDF-1 as well as the parental Jurkat cells. Because J.CaM1.6 cells respond as well as the parental cells to SDF-1 in terms of ERK activation and tyrosine phosphorylation of WASP after SDF-1 stimulation, it appears that src kinase, but not the src kinase family member lck, mediates chemotaxis of Jurkat cells in response to SDF-1 induction and that src kinase may link with WASP in this effect.
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Affiliation(s)
- Seiichi Okabe
- Department of Microbiology/Immunology and Medicine, and the Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202-5254, USA
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50
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Cory GOC, Garg R, Cramer R, Ridley AJ. Phosphorylation of tyrosine 291 enhances the ability of WASp to stimulate actin polymerization and filopodium formation. Wiskott-Aldrich Syndrome protein. J Biol Chem 2002; 277:45115-21. [PMID: 12235133 DOI: 10.1074/jbc.m203346200] [Citation(s) in RCA: 168] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Wiskott-Aldrich Syndrome protein (WASp) is a key regulator of the Arp2/3 complex and the actin cytoskeleton in hematopoietic cells. WASp is capable of forming an auto-inhibited conformation, which can be disrupted by binding of Cdc42 and phosphatidylinositol 4,5-bisphosphate, leading to its activation. Stimulation of the collagen receptor on platelets and crosslinking the B-cell receptor induce tyrosine phosphorylation of WASp. Here we show that the Src family kinase Hck induces phosphorylation of WASp-Tyr(291) independently of Cdc42 and that this causes a shift in the mobility of WASp upon SDS-PAGE. A phospho-mimicking mutant, WASp-Y291E, exhibited an enhanced ability to stimulate actin polymerization in a cell-free system and when microinjected into primary macrophages induced extensive filopodium formation with greater efficiency than wild-type WASp or a Y291F mutant. We propose that phosphorylation of Tyr(291) directly regulates WASp function.
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Affiliation(s)
- Giles O C Cory
- Ludwig Institute for Cancer Research, Royal Free and University College Medical School Branch, Courtauld Building, 91 Riding House Street, London W1W 7BS, United Kingdom
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