PROPERTIES OF A LYMPHOMA CELL TYROSINE PROTEIN KINASE: There is increasing evidence that tyrosine protein kinases have an important role in T lymphocyte activation and cell cycle progression. We have identified a tyrosine protein kinase of apparent molecular weight of 56,000 (pp56Tcell). This enzyme is specific to T lymphoctyes and undergoes phosphorylation by protein kinase C during T lymphocyte activation. The general goal of this application is to determine the function of pp56Tcell in T cell activation. We have developed highly sensitive immunoblotting techniques that allow us to measure the activation pp56Tcell and other tyrosine protein kinases as well as the activation of protein kinase C. These techniques allow us to study these kinases in T cells and determine if their activation correlates with physiological responses. Thus the role of these enzymes will be evaluated in the response of T cells to a wide variety of mitogenic agents. The regulation of pp56Tcell is complex and involves phosphorylation at several sites. These phosphorylation reactions will be studied in detail in order to understand their function and the mechanisms that underlie their regulation. The biosynthetic pathway of pp56Tcell will be characterized to determine if this is regulated by agents that alter the phosphorylation of pp56Tcell. The studies on pp56Tcell will be aided by the production of monoclonal antibodies to pp56Tcell. Antibodies to phosphotyrosine have permitted us to identify a large number of potential substrates for pp56Tcell. These substrates will be purified and characterized in order to determine the function of the tyrosine phosphorylation that we have observed in T cells. The results of this research may provide new insights into the biochemical events involved in the regulation of the activation and growth of normal and malignant cells of the T lymphocyte lineage.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA038821-04A1
Application #
3177169
Study Section
Physiological Chemistry Study Section (PC)
Project Start
1985-01-01
Project End
1993-04-30
Budget Start
1988-07-01
Budget End
1989-04-30
Support Year
4
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of Rochester
Department
Type
School of Medicine & Dentistry
DUNS #
208469486
City
Rochester
State
NY
Country
United States
Zip Code
14627
Quill, H; Riley, M P; Cho, E A et al. (1992) Anergic Th1 cells express altered levels of the protein tyrosine kinases p56lck and p59fyn. J Immunol 149:2887-93
Bramson, H N; Casnellie, J E; Nachod, H et al. (1991) Synthetic fragments of the CD4 receptor cytoplasmic domain and large polycations alter the activities of the pp56lck tyrosine protein kinase. J Biol Chem 266:16219-25
Casnellie, J E (1991) Protein kinase inhibitors: probes for the functions of protein phosphorylation. Adv Pharmacol 22:167-205
Saltzman, E M; White, K; Casnellie, J E (1990) Stimulation of the antigen and interleukin-2 receptors on T lymphocytes activates distinct tyrosine protein kinases. J Biol Chem 265:10138-42
Casnellie, J E; Thom, R E (1990) An activating combination of CD2 antibodies stimulates tyrosine phosphorylation in a T lymphocyte cell line. FEBS Lett 261:331-4
Saltzman, E M; Luhowskyj, S M; Casnellie, J E (1989) The 75,000-dalton interleukin-2 receptor transmits a signal for the activation of a tyrosine protein kinase. J Biol Chem 264:19979-83
Mooney, R A; Bordwell, K L; Luhowskyj, S et al. (1989) The insulin-like effect of vanadate on lipolysis in rat adipocytes is not accompanied by an insulin-like effect on tyrosine phosphorylation. Endocrinology 124:422-9
Thom, R E; Casnellie, J E (1989) Pertussis toxin activates protein kinase C and a tyrosine protein kinase in the human T cell line Jurkat. FEBS Lett 244:181-4
Kaji, H; Casnellie, J E; Hinkle, P M (1988) Thyrotropin releasing hormone action in pituitary cells. Protein kinase C-mediated effects on the epidermal growth factor receptor. J Biol Chem 263:13588-93
Saltzman, E M; Thom, R R; Casnellie, J E (1988) Activation of a tyrosine protein kinase is an early event in the stimulation of T lymphocytes by interleukin-2. J Biol Chem 263:6956-9

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