Tyrosine phosphorylation and dephosphorylation of proteins is known to play a central role in regulation of cell growth and differentiation. Activation of resting T or B lymphocytes via their antigen-specific receptors TCR and BCR, respectively) or NK cells through their type III Fcg receptor (CD16), is initiated by rapid tyrosine phosphorylation of a number of regulatory proteins, such as phospholipase Cgl and proteins that bind phosphatidylinositol 3-kinase (PI3K). Identification of the protein tyrosine kinases (PTKs) involved, their regulators and their substrates, is important to our understanding of lymphocyte physiology in health and disease. During the last few years, it has become clear the PTKs of both the Src and Syk families play crucial roles in this signaling. The objective of this competitive renewal is to continue to study the regulation of the catalytic activity of the two Syk family PTKs present in lymphoid cells, Syk and Zap, and investigate their roles in the regulation of tyrosine phosphorylation in these cells.
Specific Aim 1 addresses the role and regulation of Syk and Zap in lymphoid cells. The investigator proposes to build on his advances and continue with more indepth studies as well as experiments addressing the physiological significance of his observations. He anticipates learning what the role, importance, and targets of the Syk family PTKs Syk and Zap are in lymphoid cells, and whether the differential biochemical properties between these two PTKs is of biological importance.
Specific Aim 2 investigates the regulation of SH2 domains by tyrosine phosphorylation, a major discovery supported by this grant. This novel Syk-and Zap-mediated regulation of Lck will be studied in more detail, and he will examine whether it is a more general mechanism in signal transduction.
Specific Aim 3 examines the role of phosphatidylinositol 3-kinase (Pl3K) in Syk- and Zap-mediated signaling. He has reported that PI3K plays an important and complex role downstream of Syk and Zap in the MAP kinase pathway and in the activation of the-NFAT element of the IL-2 gene. He will extend these studies and attempt to define the biochemical steps between Syk or Zap and P13K in TCR signaling and to elucidate the regulation of MAP kinases by P13K in detail. Overall, the proposed studies will provide a detailed characterization of the function and substrates of the Syk family kinases, which seem to play an important role in T and B cell activation in concert with the Src family kinases and other key regulatory enzymes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI035603-08
Application #
6170079
Study Section
Allergy and Immunology Study Section (ALY)
Program Officer
Quill, Helen R
Project Start
1994-05-01
Project End
2003-03-31
Budget Start
2000-04-01
Budget End
2001-03-31
Support Year
8
Fiscal Year
2000
Total Cost
$305,130
Indirect Cost
Name
Sanford-Burnham Medical Research Institute
Department
Type
DUNS #
009214214
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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