Middle t antigen (MTAg) is the transforming protein of polyoma virus. A critical unanswered question in polyoma virus biology is how MTAg expression elicits the dramatic changes associated with oncogenic transformation. MTAg has no known catalytic activities but has been shown to associate with two cellular proteins; pp60c- src and pp62c-yes, both of which are tyrosine kinases. MTAg is thought to function by activating the tyrosine kinase activity of these and possibly other cellular tyrosine kinases. The experiments proposed here utilize recently developed techniques and unique reagents to analyze, in greater detail than has previously been possible, how MTAg associates with and alters the biochemical and biological properties of the src family of tyrosine kinases. MTAg and pp60c-src will be overproduced in insect cells using a baculovirus expression system. pp60c-src and MTAg associate quantitatively when co-produced in insect cells and large quantities of complex are easily isolated. Because pp60c-src and MTAg fail to interact when co-produced in bacteria or yeast and only small quantities of complex are produced in mammalian cells, the baculovirus expression system is the system of choice for studying complex formation. Therefore, this expression system will be used to identify how MTAg specifically enhances the tyrosine kinase activity of pp60c-src interactions are regulated in mammalian cells. Genetic studies will be performed to precisely define the MTAg binding site on pp60c-src and to predict associations with other src family members. Finally, genetic studies will be performed to precisely define the contributions of other src family members to MTAg mediated transformation.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29CA050767-06
Application #
3459637
Study Section
Experimental Virology Study Section (EVR)
Project Start
1989-01-27
Project End
1993-12-31
Budget Start
1993-01-01
Budget End
1993-12-31
Support Year
6
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Beth Israel Deaconess Medical Center
Department
Type
DUNS #
076593722
City
Boston
State
MA
Country
United States
Zip Code
02215
Auger, K R; Carpenter, C L; Shoelson, S E et al. (1992) Polyoma virus middle T antigen-pp60c-src complex associates with purified phosphatidylinositol 3-kinase in vitro. J Biol Chem 267:5408-15
Parker, L L; Atherton-Fessler, S; Lee, M S et al. (1991) Cyclin promotes the tyrosine phosphorylation of p34cdc2 in a wee1+ dependent manner. EMBO J 10:1255-63
Swenson, K I; Piwnica-Worms, H; McNamee, H et al. (1990) Tyrosine phosphorylation of the gap junction protein connexin43 is required for the pp60v-src-induced inhibition of communication. Cell Regul 1:989-1002
Furukawa, Y; Piwnica-Worms, H; Ernst, T J et al. (1990) cdc2 gene expression at the G1 to S transition in human T lymphocytes. Science 250:805-8
Piwnica-Worms, H; Williams, N G; Cheng, S H et al. (1990) Regulation of pp60c-src and its interaction with polyomavirus middle T antigen in insect cells. J Virol 64:61-8