It is now well recognized that several protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPases) play crucial roles in TCR-mediated T cell activation. Previous studies supported by this grant addressed the role and regulation of the Syk family PTKs ZAP-70 and Syk, and substrates for these kinases. We propose to continue this work by focusing on a new ZAP-70 substrate, the 20-kDa Vaccinia virus VH1-related (VHR) dual-specific phosphatase. We propose: (1) To study VHR tyrosine phosphorylation and establish whether VHR is a direct substrate for ZAP-70. We have found that VHR accumulates in the immune synapse in Ag-specific T cells and is phosphorylated on tyrosine in T lymphocytes, as well as in T cell lines, except those lacking ZAP-70 or ZAP-70 activation by Lck. We wish to continue these experiments by verifying that VHR indeed is phosphorylated directly by ZAP-70. We also plan to examine the site, stoichiometry, and time-course of this phosphorylation, and which stimuli and T cell populations that employ it. (2) To determine the role of VHR phosphorylation for ZAP-70 signaling. It is not yet clear what tyrosine phosphorylation does to VHR, but all results point to a functionally activating effect. We will examine the effects of VHR phosphorylation on MAP kinases and other downstream pathways and determine if it affects the subcellular location, nuclear import, interaction with other proteins, or catalytic activity of VHR. (3) To examine the association of VHR with POZ-domain protein that interacts with VHR (POZtiv). We recently identified this novel VHR-binding protein using the yeast two-hybrid system. We hypothesize that it acts as a scaffold protein for VHR, but releases phospho-VHR. Alternatively, it may be required for some other aspect of VHR biology. These issues will be examined. (4) To study the physiological role of VHR in T cell activation. Finally, we plan to generate T cells and mice that lack VHR to determine how important VHR is. To achieve this goal we will utilize three different approaches, each with its own limitations, namely RNA interference (RNAi), antisense, and mouse knock-outs. These experiments will ask how the absence (or severe reduction) of VHR affects TCR-induced activation of MAP kinases, T cell proliferation, effector functions and immune responses in whole animals.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI035603-12
Application #
6709363
Study Section
Allergy and Immunology Study Section (ALY)
Program Officer
Mallia, Conrad M
Project Start
1994-05-01
Project End
2008-03-30
Budget Start
2004-04-01
Budget End
2005-03-31
Support Year
12
Fiscal Year
2004
Total Cost
$384,000
Indirect Cost
Name
Sanford-Burnham Medical Research Institute
Department
Type
DUNS #
020520466
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Singh, Pratibha; Dejager, Lien; Amand, Mathieu et al. (2015) DUSP3 Genetic Deletion Confers M2-like Macrophage-Dependent Tolerance to Septic Shock. J Immunol 194:4951-62
Musumeci, Lucia; Kuijpers, Marijke J; Gilio, Karen et al. (2015) Dual-specificity phosphatase 3 deficiency or inhibition limits platelet activation and arterial thrombosis. Circulation 131:656-68
Amand, Mathieu; Erpicum, Charlotte; Bajou, Khalid et al. (2014) DUSP3/VHR is a pro-angiogenic atypical dual-specificity phosphatase. Mol Cancer 13:108
Henkens, Rachel; Delvenne, Philippe; Arafa, Mohammad et al. (2008) Cervix carcinoma is associated with an up-regulation and nuclear localization of the dual-specificity protein phosphatase VHR. BMC Cancer 8:147
Kosco, Karena A; Cerignoli, Fabio; Williams, Scott et al. (2008) SKAP55 modulates T cell antigen receptor-induced activation of the Ras-Erk-AP1 pathway by binding RasGRP1. Mol Immunol 45:510-22
Arimura, Yutaka; Vang, Torkel; Tautz, Lutz et al. (2008) TCR-induced downregulation of protein tyrosine phosphatase PEST augments secondary T cell responses. Mol Immunol 45:3074-84
Nika, Konstantina; Tautz, Lutz; Arimura, Yutaka et al. (2007) A weak Lck tail bite is necessary for Lck function in T cell antigen receptor signaling. J Biol Chem 282:36000-9
Friedberg, Ilan; Nika, Konstantina; Tautz, Lutz et al. (2007) Identification and characterization of DUSP27, a novel dual-specific protein phosphatase. FEBS Lett 581:2527-33
Mustelin, Tomas (2007) A brief introduction to the protein phosphatase families. Methods Mol Biol 365:9-22
Makagiansar, Irwan T; Williams, Scott; Mustelin, Tomas et al. (2007) Differential phosphorylation of NG2 proteoglycan by ERK and PKCalpha helps balance cell proliferation and migration. J Cell Biol 178:155-65

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