DOCSLIB.ORG

Role and Regulation of the Actin-Regulatory Protein Hs1 in Tcr Signaling

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Role and Regulation of the Actin-Regulatory Protein Hs1 in Tcr Signaling University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations Fall 2009 Role and Regulation of the Actin-Regulatory Protein Hs1 in Tcr Signaling Esteban Carrizosa University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Cell Biology Commons, and the Immunology and Infectious Disease Commons Recommended Citation Carrizosa, Esteban, "Role and Regulation of the Actin-Regulatory Protein Hs1 in Tcr Signaling" (2009). Publicly Accessible Penn Dissertations. 91. https://repository.upenn.edu/edissertations/91 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/91 For more information, please contact [email protected]. Role and Regulation of the Actin-Regulatory Protein Hs1 in Tcr Signaling Abstract Numerous aspects of T cell function, including TCR signaling, migration, and execution of effector functions, depend on the actin cytoskeleton. Cytoskeletal rearrangements are driven by the action of actin-regulatory proteins, which promote or antagonize the assembly of actin filaments in esponser to external cues. In this work, we have examined the regulation and function of HS1, a poorly-understood actin regulatory protein, in T cells. This protein, which becomes tyrosine phosphorylated upon T cell activation, is thought to function primarily by stabilizing existing branched actin filaments. Loss of HS1 results in unstable actin responses upon TCR engagement and defective Ca2+ responses, leading to poor activation of the IL2 promoter. TCR engagement leads to phosphorylation of HS1 at Tyr 378 and Tyr 397, creating binding sites for SH2 domain-containing proteins, including Vav1 and Itk. Phosphorylation at these residues is required for Itk-dependent recruitment of HS1 to the IS, Vav1 IS localization, and HS1-dependent actin reorganization and IL2 production. Therefore, in addition to directly interacting with branched actin filaments, HS1 egulationr of Vav1 localization provides another mechanism by which HS1 signals to the actin cytoskeleton. Analysis of Ca2+ responses in HS1-/- T cells reveals that the defect in these cells lies at the level of release from intracellular stores. Phosphorylated HS1 interacts with PLCγ1, and mediates its association with the cytoskeleton and regulates microcluster dynamics. Although HS1 is clearly important for signaling downstream of the TCR, HS1-/- mice exhibit normal T cell development and normal peripheral populations. Surprisingly, HS1 is not required for T cell homing to lymphoid organs, for TCR endocytosis or for CD8+ T cell effector function. However, T cells from HS1-/- mice produce reduced amounts of Ifnγ, and are subsequently less likely to become Ifnγ-producing TH1 effector cells. These data demonstrate that HS1 functions as a cytoskeletal adaptor protein and plays specific olesr downstream of TCR engagement. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Immunology First Advisor Dr. Janis K. Burkhardt Keywords T cells, calcium signaling, HS1, microclusters Subject Categories Cell Biology | Immunology and Infectious Disease This dissertation is available at ScholarlyCommons: https://repository.upenn.edu/edissertations/91 ROLE AND REGULATION OF THE ACTIN-REGULATORY PROTEIN HS1 IN TCR SIGNALING Esteban Carrizosa A DISSERTATION in Immunology Presented to the Faculties of the University of Pennsylvania in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy 2009 _____________________ Dr. Janis K. Burkhardt, Associate Professor, Dissertation Advisor _____________________ Dr. Steven L. Reiner, Professor, Graduate Group Chair Dissertation Committtee: Dr. Gary A. Koretzky Dr. Terri M. Laufer Dr. Paula M. Oliver Dr. Jordan S. Orange Role and regulation of the actin-regulatory protein HS1 in TCR signaling COPYRIGHT 2009 Esteban Carrizosa This work was supported in part by NIH F31AI071385 iii Abstract ROLE AND REGULATION OF THE ACTIN-REGULATORY PROTEIN HS1 IN TCR SIGNALING Esteban Carrizosa Advisor: Dr. Janis K. Burkhardt Numerous aspects of T cell function, including TCR signaling, migration, and execution of effector functions, depend on the actin cytoskeleton. Cytoskeletal rearrangements are driven by the action of actin-regulatory proteins, which promote or antagonize the assembly of actin filaments in response to external cues. In this work, we have examined the regulation and function of HS1, a poorly-understood actin regulatory protein, in T cells. This protein, which becomes tyrosine phosphorylated upon T cell activation, is thought to function primarily by stabilizing existing branched actin filaments. Loss of HS1 results in unstable actin responses upon TCR engagement and defective Ca2+ responses, leading to poor activation of the IL2 promoter. TCR engagement leads to phosphorylation of HS1 at Tyr 378 and Tyr 397, creating binding sites for SH2 domain- containing proteins, including Vav1 and Itk. Phosphorylation at these residues is required for Itk-dependent recruitment of HS1 to the IS, Vav1 IS localization, and HS1- dependent actin reorganization and IL2 production. Therefore, in addition to directly interacting with branched actin filaments, HS1 regulation of Vav1 localization provides another mechanism by which HS1 signals to the actin cytoskeleton. Analysis of Ca2+ responses in HS1-/- T cells reveals that the defect in these cells lies at the level of release from intracellular stores. Phosphorylated HS1 interacts with PLCγ1, and mediates its iv association with the cytoskeleton and regulates microcluster dynamics. Although HS1 is clearly important for signaling downstream of the TCR, HS1-/- mice exhibit normal T cell development and normal peripheral populations. Surprisingly, HS1 is not required for T cell homing to lymphoid organs, for TCR endocytosis or for CD8+ T cell effector function. However, T cells from HS1-/- mice produce reduced amounts of Ifnγ, and are subsequently less likely to become Ifnγ-producing TH1 effector cells. These data demonstrate that HS1 functions as a cytoskeletal adaptor protein and plays specific roles downstream of TCR engagement. v Table of Contents Chapter 1: Introduction ........................................................................................................ 1 Interaction with APCs and immunological synapse formation .........................................2 CONTROL OF ACTIN DYNAMICS AT THE IMMUNOLOGICAL SYNAPSE .............................4 Arp2/3 complex‐dependent actin regulatory proteins ..................................................................6 INTERPLAY BETWEEN T CELL SIGNALING AND ACTIN DYNAMICS................................ 25 Costimulation‐dependent actin regulatory pathways..................................................................28 Pathways leading to Ca2+ signaling in T cells....................................................................................28 Chapter 2: HS1 functions as an essential actin­regulatory adapter protein at the Immune Synapse............................................................................................................36 Summary ........................................................................................................................................... 36 Introduction..................................................................................................................................... 36 Results................................................................................................................................................ 38 HS1 regulates the accumulation of F‐actin at the immune synapse.......................................38 HS1‐deficient cells fail to stabilize actin following TCR engagement....................................43 Tyrosine phosphorylation of HS1 is required for actin remodeling ......................................47 Tyrosine phosphorylation of HS1 mediates binding to key signaling molecules.............53 HS1 and Vav1 interact specifically and directly..............................................................................53 HS1 is required for maintaining Vav1 at the IS ...............................................................................54 HS1‐mediated actin stabilization is required for sustained TCR signaling.........................57 HS1 is recruited to the periphery of spreading T cells.................................................................63 HS1 binding to F‐actin is important for actin polymerization at the IS................................63 Discussion......................................................................................................................................... 64 vi Chapter 3: Recruitment of HS1 to the immunological synapse by Itk regulates actin responses and PLCγ1 microcluster dynamics ..................................................73 Summary ........................................................................................................................................... 73 Introduction..................................................................................................................................... 74 Results................................................................................................................................................ 76 Itk‐deficient T cells show unstable lamellipodial protrusions .................................................76 The SH2 domain of Itk mediates
Load more

Recommended publications
  • The Wiskott-Aldrich Syndrome: the Actin Cytoskeleton and Immune Cell Function
    Disease Markers 29 (2010) 157–175 157 DOI 10.3233/DMA-2010-0735 IOS Press The Wiskott-Aldrich syndrome: The actin cytoskeleton and immune cell function Michael P. Blundella, Austen Wortha,b, Gerben Boumaa and Adrian J. Thrashera,b,∗ aMolecular Immunology Unit, UCL Institute of Child Health, London, UK bDepartment of Immunology, Great Ormond Street Hospital NHS Trust, Great Ormond Street, London, UK Abstract. Wiskott-Aldrich syndrome (WAS) is a rare X-linked recessive primary immunodeficiency characterised by immune dysregulation, microthrombocytopaenia, eczema and lymphoid malignancies. Mutations in the WAS gene can lead to distinct syndrome variations which largely, although not exclusively, depend upon the mutation. Premature termination and deletions abrogate Wiskott-Aldrich syndrome protein (WASp) expression and lead to severe disease (WAS). Missense mutations usually result in reduced protein expression and the phenotypically milder X-linked thrombocytopenia (XLT) or attenuated WAS [1–3]. More recently however novel activating mutations have been described that give rise to X-linked neutropenia (XLN), a third syndrome defined by neutropenia with variable myelodysplasia [4–6]. WASP is key in transducing signals from the cell surface to the actin cytoskeleton, and a lack of WASp results in cytoskeletal defects that compromise multiple aspects of normal cellular activity including proliferation, phagocytosis, immune synapse formation, adhesion and directed migration. Keywords: Wiskott-Aldrich syndrome, actin polymerization, lymphocytes,
    [Show full text]
  • Table 2. Significant
    Table 2. Significant (Q < 0.05 and |d | > 0.5) transcripts from the meta-analysis Gene Chr Mb Gene Name Affy ProbeSet cDNA_IDs d HAP/LAP d HAP/LAP d d IS Average d Ztest P values Q-value Symbol ID (study #5) 1 2 STS B2m 2 122 beta-2 microglobulin 1452428_a_at AI848245 1.75334941 4 3.2 4 3.2316485 1.07398E-09 5.69E-08 Man2b1 8 84.4 mannosidase 2, alpha B1 1416340_a_at H4049B01 3.75722111 3.87309653 2.1 1.6 2.84852656 5.32443E-07 1.58E-05 1110032A03Rik 9 50.9 RIKEN cDNA 1110032A03 gene 1417211_a_at H4035E05 4 1.66015788 4 1.7 2.82772795 2.94266E-05 0.000527 NA 9 48.5 --- 1456111_at 3.43701477 1.85785922 4 2 2.8237185 9.97969E-08 3.48E-06 Scn4b 9 45.3 Sodium channel, type IV, beta 1434008_at AI844796 3.79536664 1.63774235 3.3 2.3 2.75319499 1.48057E-08 6.21E-07 polypeptide Gadd45gip1 8 84.1 RIKEN cDNA 2310040G17 gene 1417619_at 4 3.38875643 1.4 2 2.69163229 8.84279E-06 0.0001904 BC056474 15 12.1 Mus musculus cDNA clone 1424117_at H3030A06 3.95752801 2.42838452 1.9 2.2 2.62132809 1.3344E-08 5.66E-07 MGC:67360 IMAGE:6823629, complete cds NA 4 153 guanine nucleotide binding protein, 1454696_at -3.46081884 -4 -1.3 -1.6 -2.6026947 8.58458E-05 0.0012617 beta 1 Gnb1 4 153 guanine nucleotide binding protein, 1417432_a_at H3094D02 -3.13334396 -4 -1.6 -1.7 -2.5946297 1.04542E-05 0.0002202 beta 1 Gadd45gip1 8 84.1 RAD23a homolog (S.
    [Show full text]
  • TLR4 Endocytic Trafficking in Macrophages Modulates TLR4
    Glia Maturation Factor-γ Negatively Modulates TLR4 Signaling by Facilitating TLR4 Endocytic Trafficking in Macrophages This information is current as Wulin Aerbajinai, Kevin Lee, Kyung Chin and Griffin P. of September 28, 2021. Rodgers J Immunol 2013; 190:6093-6103; Prepublished online 15 May 2013; doi: 10.4049/jimmunol.1203048 http://www.jimmunol.org/content/190/12/6093 Downloaded from References This article cites 47 articles, 19 of which you can access for free at: http://www.jimmunol.org/content/190/12/6093.full#ref-list-1 http://www.jimmunol.org/ Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication by guest on September 28, 2021 *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. The Journal of Immunology Glia Maturation Factor-g Negatively Modulates TLR4 Signaling by Facilitating TLR4 Endocytic Trafficking in Macrophages Wulin Aerbajinai, Kevin Lee, Kyung Chin, and Griffin P. Rodgers TLR4 signaling must be tightly regulated to provide both effective immune protection and avoid inflammation-induced pathology. Thus, the mechanisms that negatively regulate the TLR4-triggered inflammatory response are of particular importance.
    [Show full text]
  • Encapsulation of the Cytoskeleton: Towards Mimicking the Mechanics of a Cell
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
    [Show full text]
  • A Glance on the Role of Actin in Osteogenic and Adipogenic
    Khan et al. Stem Cell Research & Therapy (2020) 11:283 https://doi.org/10.1186/s13287-020-01789-2 REVIEW Open Access A glance on the role of actin in osteogenic and adipogenic differentiation of mesenchymal stem cells Asmat Ullah Khan† , Rongmei Qu† , Tingyu Fan , Jun Ouyang* and Jingxing Dai* Abstract Mesenchymal stem cells (MSCs) have the capacity to differentiate into multiple lineages including osteogenic and adipogenic lineages. An increasing number of studies have indicated that lineage commitment by MSCs is influenced by actin remodeling. Moreover, actin has roles in determining cell shape, nuclear shape, cell spreading, and cell stiffness, which eventually affect cell differentiation. Osteogenic differentiation is promoted in MSCs that exhibit a large spreading area, increased matrix stiffness, higher levels of actin polymerization, and higher density of stress fibers, whereas adipogenic differentiation is prevalent in MSCs with disrupted actin networks. In addition, the mechanical properties of F-actin empower cells to sense and transduce mechanical stimuli, which are also reported to influence differentiation. Various biomaterials, mechanical, and chemical interventions along with pathogen- induced actin alteration in the form of polymerization and depolymerization in MSC differentiation were studied recently. This review will cover the role of actin and its modifications through the use of different methods in inducing osteogenic and adipogenic differentiation. Keywords: Mesenchymal stem cells (MSCs), Actin, Osteogenesis, Adipogenesis cytoskeleton, Osteogenic differentiation, Adipogenic differentiation, Cytoskeleton Introduction however, this review will focus specifically on the role of Stem cells exhibit a great potential for use in tissue en- actin. gineering because of their regenerative capacity in many Actin is a globular protein with a molecular weight of tissues, including nervous tissue, muscle tissue, adipose approximately 42 kDa and consists of four structural do- tissue, cartilage tissue, and bone tissue.
    [Show full text]
  • Supplementary Table S4. FGA Co-Expressed Gene List in LUAD
    Supplementary Table S4. FGA co-expressed gene list in LUAD tumors Symbol R Locus Description FGG 0.919 4q28 fibrinogen gamma chain FGL1 0.635 8p22 fibrinogen-like 1 SLC7A2 0.536 8p22 solute carrier family 7 (cationic amino acid transporter, y+ system), member 2 DUSP4 0.521 8p12-p11 dual specificity phosphatase 4 HAL 0.51 12q22-q24.1histidine ammonia-lyase PDE4D 0.499 5q12 phosphodiesterase 4D, cAMP-specific FURIN 0.497 15q26.1 furin (paired basic amino acid cleaving enzyme) CPS1 0.49 2q35 carbamoyl-phosphate synthase 1, mitochondrial TESC 0.478 12q24.22 tescalcin INHA 0.465 2q35 inhibin, alpha S100P 0.461 4p16 S100 calcium binding protein P VPS37A 0.447 8p22 vacuolar protein sorting 37 homolog A (S. cerevisiae) SLC16A14 0.447 2q36.3 solute carrier family 16, member 14 PPARGC1A 0.443 4p15.1 peroxisome proliferator-activated receptor gamma, coactivator 1 alpha SIK1 0.435 21q22.3 salt-inducible kinase 1 IRS2 0.434 13q34 insulin receptor substrate 2 RND1 0.433 12q12 Rho family GTPase 1 HGD 0.433 3q13.33 homogentisate 1,2-dioxygenase PTP4A1 0.432 6q12 protein tyrosine phosphatase type IVA, member 1 C8orf4 0.428 8p11.2 chromosome 8 open reading frame 4 DDC 0.427 7p12.2 dopa decarboxylase (aromatic L-amino acid decarboxylase) TACC2 0.427 10q26 transforming, acidic coiled-coil containing protein 2 MUC13 0.422 3q21.2 mucin 13, cell surface associated C5 0.412 9q33-q34 complement component 5 NR4A2 0.412 2q22-q23 nuclear receptor subfamily 4, group A, member 2 EYS 0.411 6q12 eyes shut homolog (Drosophila) GPX2 0.406 14q24.1 glutathione peroxidase
    [Show full text]
  • Role of Focal Adhesion Kinase in Small-Cell Lung Cancer and Its Potential As a Therapeutic Target
    cancers Review Role of Focal Adhesion Kinase in Small-Cell Lung Cancer and Its Potential as a Therapeutic Target Frank Aboubakar Nana 1,2 , Marie Vanderputten 1 and Sebahat Ocak 1,3,* 1 Institut de Recherche Expérimentale et Clinique (IREC), Pôle de Pneumologie, ORL et Dermatologie (PNEU), Université catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; [email protected] (F.A.N.); [email protected] (M.V.) 2 Division of Pneumology, Cliniques Universitaires St-Luc, UCL, 1200 Brussels, Belgium 3 Division of Pneumology, CHU UCL Namur (Godinne Site), UCL, 5530 Yvoir, Belgium * Correspondence: [email protected]; Tel.: +32-2-764-9448; Fax: +32-2-764-9440 Received: 15 September 2019; Accepted: 24 October 2019; Published: 29 October 2019 Abstract: Small-cell lung cancer (SCLC) represents 15% of all lung cancers and it is clinically the most aggressive type, being characterized by a tendency for early metastasis, with two-thirds of the patients diagnosed with an extensive stage (ES) disease and a five-year overall survival (OS) as low as 5%. There are still no effective targeted therapies in SCLC despite improved understanding of the molecular steps leading to SCLC development and progression these last years. After four decades, the only modest improvement in OS of patients suffering from ES-SCLC has recently been shown in a trial combining atezolizumab, an anti-PD-L1 immune checkpoint inhibitor, with carboplatin and etoposide, chemotherapy agents. This highlights the need to pursue research efforts in this field. Focal adhesion kinase (FAK) is a non-receptor protein tyrosine kinase that is overexpressed and activated in several cancers, including SCLC, and contributing to cancer progression and metastasis through its important role in cell proliferation, survival, adhesion, spreading, migration, and invasion.
    [Show full text]
  • Ubiquitin in Influenza Virus Entry and Innate Immunity
    viruses Review Ubiquitin in Influenza Virus Entry and Innate Immunity Alina Rudnicka 1 and Yohei Yamauchi 1,2,3,* 1 Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, Zurich CH-8057, Switzerland; [email protected] 2 School of Cellular and Molecular Medicine, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK 3 Structural Biology Research Center, Department of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan * Correspondence: [email protected]; Tel.: +44-117-331-2067 Academic Editors: Eric Freed and Thomas Klimkait Received: 14 September 2016; Accepted: 14 October 2016; Published: 24 October 2016 Abstract: Viruses are obligatory cellular parasites. Their mission is to enter a host cell, to transfer the viral genome, and to replicate progeny whilst diverting cellular immunity. The role of ubiquitin is to regulate fundamental cellular processes such as endocytosis, protein degradation, and immune signaling. Many viruses including influenza A virus (IAV) usurp ubiquitination and ubiquitin-like modifications to establish infection. In this focused review, we discuss how ubiquitin and unanchored ubiquitin regulate IAV host cell entry, and how histone deacetylase 6 (HDAC6), a cytoplasmic deacetylase with ubiquitin-binding activity, mediates IAV capsid uncoating. We also discuss the roles of ubiquitin in innate immunity and its implications in the IAV life cycle. Keywords: ubiquitin; unanchored ubiquitin; HDAC6; aggresome processing; influenza virus; virus entry; virus uncoating; innate immunity; virus–host interactions 1. Ubiquitin and Ubiquitination Ubiquitin is a small, 8.5 kDa protein composed of 76 amino acids expressed in different tissues and present in different subcellular compartments.
    [Show full text]
  • Hax-1 Is Required for Rac1-Cortactin Interaction and Ovarian Carcinoma Cell Migration
    www.impactjournals.com/Genes & Cancer/ Genes & Cancer, Vol. 5 (3-4), March 2014 Hax-1 is required for Rac1-Cortactin interaction and ovarian carcinoma cell migration Rohini Gomathinayagam1,*, Muralidharan Jayaraman1,*, Ji Hee Ha1,*, Lakshmi Varadarajalu1, and Danny N. Dhanasekaran1 1 Stephenson Cancer Center and Department of Cell Biology, The University of Oklahoma Health Sciences Center, OK * These Authors contributed equally to this work Correspondence to: Danny N. Dhanasekaran, email: [email protected] Keywords: Hax-1, Rac1, cortactin, cell migration, Metastasis, Ovarian Cancer Received: April 11, 2014 Accepted: May 14, 2014 Published: May 14, 2014 This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ABSTRACT Hax-1 is a multifunctional protein, which is involved in diverse cellular signaling pathways including tumor cell survival and migration. We have shown previously that cell migration stimulated by the oncogenic G protein, G13, requires Hax-1 for the formation of a functional complex involving Gα13, Rac1, and cortactin. However, the role of Hax-1 in cancer cell migration or its role in Rac1-cortactin complex formation, which is known to be required for such migration remains to be characterized. Results focused on resolving the role of Hax-1 in ovarian cancer pathophysiology indicate that Hax-1 is overexpressed in ovarian cancer cells and the silencing of Hax-1 inhibits lysophosphatidic acid (LPA)- or fetal bovine serum-stimulated migration of these cells. In addition, silencing of Hax-1 greatly reduces Rac1-cortactin interaction and their colocalization in SKOV3 cells.
    [Show full text]
  • Cortactin: Coupling Membrane Dynamics to Cortical Actin Assembly
    Oncogene (2001) 20, 6418 ± 6434 ã 2001 Nature Publishing Group All rights reserved 0950 ± 9232/01 $15.00 www.nature.com/onc Cortactin: coupling membrane dynamics to cortical actin assembly Scott A Weed*,1 and J Thomas Parsons2 1Department of Craniofacial Biology, University of Colorado Health Sciences Center, Denver, Colorado, CO 80262, USA; 2Department of Microbiology, Health Sciences Center, University of Virginia, Charlottesville, Virginia, VA 22903, USA Exposure of cells to a variety of external signals causes consists of a highly organized meshwork of ®lamentous rapid changes in plasma membrane morphology. Plasma (F-) actin closely associated with the overlying plasma membrane dynamics, including membrane rue and membrane (Small et al., 1995). In motile cells, F-actin microspike formation, fusion or ®ssion of intracellular underlies two main types of protrusive membranes; vesicles, and the spatial organization of transmembrane lamellipodia, which contain short ®laments of F-actin proteins, is directly controlled by the dynamic reorgani- linked into orthogonal arrays and ®lopodia, comprised zation of the underlying actin cytoskeleton. Two of bundled, crosslinked actin ®laments (Rinnerthaler et members of the Rho family of small GTPases, Cdc42 al., 1988). Work within the last decade has demon- and Rac, have been well established as mediators of strated that Rac and Cdc42, two members of the Rho extracellular signaling events that impact cortical actin family of small GTPases, govern lamellipodia and organization. Actin-based signaling through Cdc42 and ®lopodia formation (Hall, 1998). Cdc42 and Rac play a Rac ultimately results in activation of the actin-related pivotal role in the transmission of extracellular signals protein (Arp) 2/3 complex, which promotes the forma- that induce cortical cytoskeletal rearrangement (Zig- tion of branched actin networks.
    [Show full text]
  • Cortactin Overexpression Inhibits Ligand-Induced Down-Regulation of the Epidermal Growth Factor Receptor
    Research Article Cortactin Overexpression Inhibits Ligand-Induced Down-regulation of the Epidermal Growth Factor Receptor Paul Timpson,1 Danielle K. Lynch,1 Daniel Schramek,1 Francesca Walker,2 and Roger J. Daly1 1Cancer Research Program, Garvan Institute of Medical Research, St. Vincent’s Hospital, Sydney, New South Wales and 2Ludwig Institute for Cancer Research, Melbourne Tumour Biology Branch, Royal Melbourne Hospital, Victoria, Australia Abstract factor receptor signaling, thereby avoiding aberrant cellular Ligand-induced receptor down-regulation by endocytosis is a stimulation (3, 4). In brief, ligand-induced activation of the EGFR critical process regulating the intensity and duration of leads to the assembly of protein signaling complexes that relay receptor tyrosine kinase signaling. Ubiquitylation of specific various biological signals. Concomitantly, recruitment of the receptor tyrosine kinases, for example, the epidermal growth endocytic machinery occurs and subsequently leads to endosomal factor receptor (EGFR) by the E3 ubiquitin ligase c-Cbl, sorting which can result in lysosomal degradation of the receptor provides a sorting signal for lysosomal degradation and leads and termination of the signal or recycling of the receptor back to to termination of receptor signaling. Cortactin, which couples the cell surface (5–8). The relative efficiency of lysosomal the endocytic machinery to dynamic actin networks, is degradation versus recycling determines the potency of EGFR signaling (9). encoded by EMS1, a gene commonly amplified in breast and head and neck cancers. One mechanism whereby cortactin The recruitment of c-Cbl, a ubiquitin ligase that directs activated overexpression contributes to tumor progression is by receptor tyrosine kinases to lysosomal degradation by tagging them enhancing tumor cell invasion and metastasis.
    [Show full text]
  • Nck Adaptor Proteins Link Tks5 to Invadopodia Actin Regulation and ECM Degradation
    Research Article 2727 Nck adaptor proteins link Tks5 to invadopodia actin regulation and ECM degradation Stanley S. Stylli1, Stacey T. T. I1, Anne M. Verhagen2, San San Xu1, Ian Pass3, Sara A. Courtneidge3 and Peter Lock1,*,‡ 1Department of Surgery, University of Melbourne, Level 5, Clinical Sciences Building, Royal Melbourne Hospital, Parkville, Victoria 3052, Australia 2Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia 3Burnham Institute for Medical Research, Torrey Pines Road, La Jolla, CA 92037, USA *Present address: Biochemistry Department, La Trobe University, Victoria 3086, Australia ‡Author for correspondence (e-mail: [email protected]) Accepted 5 May 2009 Journal of Cell Science 122, 2727-2740 Published by The Company of Biologists 2009 doi:10.1242/jcs.046680 Summary Invadopodia are actin-based projections enriched with overexpression and inhibited by Nck1 depletion. We show that proteases, which invasive cancer cells use to degrade the clustering at the plasma membrane of the Tks5 inter-SH3 region extracellular matrix (ECM). The Phox homology (PX)-Src containing Y557 triggers phosphorylation at this site, facilitating homology (SH)3 domain adaptor protein Tks5 (also known as Nck recruitment and F-actin assembly. These results identify a SH3PXD2A) cooperates with Src tyrosine kinase to promote Src-Tks5-Nck pathway in ECM-degrading invadopodia that invadopodia formation but the underlying pathway is not clear. shows parallels with pathways linking several mammalian and Here we show that Src phosphorylates Tks5 at Y557, inducing pathogen-derived proteins to local actin regulation. it to associate directly with the SH3-SH2 domain adaptor proteins Nck1 and Nck2 in invadopodia.
    [Show full text]