|
|
||||||||




,¶
* National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892;
Department of Pathology, University of Chicago, Chicago, IL 60637;
National Institute of Aging, Gerontology Research Center, National Institutes of Health, Baltimore, MD 21224;
Department of Immunology and Division of Oncology Research, Mayo Clinic, Rochester, MN 55905; and
¶ Department of Pathology, Childrens Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA 19104
The Tec family kinase Itk is an important regulator of Ca2+ mobilization and is required for in vivo responses to Th2-inducing agents. Recent data also implicate Itk in TCR-induced regulation of the actin cytoskeleton. We have evaluated the requirements for Itk function in TCR-induced actin polarization. Reduction of Itk expression via small interfering RNA treatment of the Jurkat human T lymphoma cell line or human peripheral blood T cells disrupted TCR-induced actin polarization, a defect that correlated with decreased recruitment of the Vav guanine nucleotide exchange factor to the site of Ag contact. Vav localization and actin polarization could be rescued by re-expression of either wild-type or kinase-inactive murine Itk but not by Itk containing mutations affecting the pleckstrin homology or Src homology 2 domains. Additionally, we find that Itk is constitutively associated with Vav. Loss of Itk expression did not alter gross patterns of Vav tyrosine phosphorylation but appeared to disrupt the interactions of Vav with SLP-76. Expression of membrane-targeted Vav, Vav-CAAX, can rescue the small interfering RNA to Itk-induced phenotype, implicating the alteration in Vav localization as directly contributing to the actin polarization defect. These data suggest a kinase-independent scaffolding function for Itk in the regulation of Vav localization and TCR-induced actin polarization.
This article has been cited by other articles:
![]() |
J. C. Nolz, L. P. Nacusi, C. M. Segovis, R. B. Medeiros, J. S. Mitchell, Y. Shimizu, and D. D. Billadeau The WAVE2 complex regulates T cell receptor signaling to integrins via Abl- and CrkL-C3G-mediated activation of Rap1 J. Cell Biol., September 22, 2008; 182(6): 1231 - 1244. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. A. Readinger, G. M. Schiralli, J.-K. Jiang, C. J. Thomas, A. August, A. J. Henderson, and P. L. Schwartzberg Selective targeting of ITK blocks multiple steps of HIV replication PNAS, May 6, 2008; 105(18): 6684 - 6689. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Sahu, C. Mueller, A. Fischer, and A. August Differential Sensitivity to Itk Kinase Signals for T Helper 2 Cytokine Production and Chemokine-Mediated Migration J. Immunol., March 15, 2008; 180(6): 3833 - 3838. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q. Qi and A. August Keeping the (Kinase) Party Going: SLP-76 and ITK Dance to the Beat Sci. Signal., July 24, 2007; 2007(396): pe39 - pe39. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. C. Nolz, M. E. Fernandez-Zapico, and D. D. Billadeau TCR/CD28-Stimulated Actin Dynamics Are Required for NFAT1-Mediated Transcription of c-rel Leading to CD28 Response Element Activation J. Immunol., July 15, 2007; 179(2): 1104 - 1112. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Khurana, L. N. Arneson, R. A. Schoon, C. J. Dick, and P. J. Leibson Differential Regulation of Human NK Cell-Mediated Cytotoxicity by the Tyrosine Kinase Itk J. Immunol., March 15, 2007; 178(6): 3575 - 3582. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Konno, M. Kirby, S. A. Anderson, P. L. Schwartzberg, and F. Candotti The expression of Wiskott-Aldrich syndrome protein (WASP) is dependent on WASP-interacting protein (WIP) Int. Immunol., February 1, 2007; 19(2): 185 - 192. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q. Chen, A. Coffey, S. G. Bourgoin, and M. Gadina Cytohesin Binder and Regulator Augments T Cell Receptor-induced Nuclear Factor of Activated T Cells{middle dot}AP-1 Activation through Regulation of the JNK Pathway J. Biol. Chem., July 21, 2006; 281(29): 19985 - 19994. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Yu, A. J. Mohamed, L. Vargas, A. Berglof, G. Finn, K. P. Lu, and C. I. E. Smith Regulation of Bruton Tyrosine Kinase by the Peptidylprolyl Isomerase Pin1 J. Biol. Chem., June 30, 2006; 281(26): 18201 - 18207. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. E. Solomou, K. Keyvanfar, and N. S. Young T-bet, a Th1 transcription factor, is up-regulated in T cells from patients with aplastic anemia Blood, May 15, 2006; 107(10): 3983 - 3991. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. B. Au-Yeung, S. D. Katzman, and D. J. Fowell Cutting Edge: Itk-Dependent Signals Required for CD4+ T Cells to Exert, but Not Gain, Th2 Effector Function J. Immunol., April 1, 2006; 176(7): 3895 - 3899. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Cougoule, S. Hoshino, A. Dart, J. Lim, and E. Caron Dissociation of Recruitment and Activation of the Small G-protein Rac during Fc{gamma} Receptor-mediated Phagocytosis J. Biol. Chem., March 31, 2006; 281(13): 8756 - 8764. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Maoz, R. Koren, I. Ben-Ari, and T. Kleinberger YND1 Interacts with CDC55 and Is a Novel Mediator of E4orf4-induced Toxicity J. Biol. Chem., December 16, 2005; 280(50): 41270 - 41277. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. D. Finkelstein, Y. Shimizu, and P. L. Schwartzberg Tec Kinases Regulate TCR-Mediated Recruitment of Signaling Molecules and Integrin-Dependent Cell Adhesion J. Immunol., November 1, 2005; 175(9): 5923 - 5930. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. C. D. Houtman, R. A. Houghtling, M. Barda-Saad, Y. Toda, and L. E. Samelson Early Phosphorylation Kinetics of Proteins Involved in Proximal TCR-Mediated Signaling Pathways J. Immunol., August 15, 2005; 175(4): 2449 - 2458. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Piotukh, W. Gu, M. Kofler, D. Labudde, V. Helms, and C. Freund Cyclophilin A Binds to Linear Peptide Motifs Containing a Consensus That Is Present in Many Human Proteins J. Biol. Chem., June 24, 2005; 280(25): 23668 - 23674. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |