Abstract
Polyomavirus middle tumor antigen (MT) transforms a large number of cell types by binding to and modulating the activities of cellular proteins. Previous genetic analysis defined in MT an independent motif, NPTY (Asn-Pro- Thr-Tyr), required for transformation. This report demonstrates that NPTY is required for interaction between MT and SHC protein, a Src homology 2 (SH2)- containing protooncogene product implicated in activating Ras via association with GRB2 protein. SHC is phosphorylated on tyrosine and associates with GRB2 in MT-transformed cells. These effects require an intact NPTY motif in MT. SHC immunoprecipitates from MT-transformed cells possess kinase activity that phosphorylates not only SHC and MT but also the 85-kDa subunit of phosphatidylinositol 3-kinase. This result suggests that a complex exists that contains, at a minimum, MT, Src family tyrosine kinases, phosphatidylinositol 3-kinase, and SHC.
Original language | English (US) |
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Pages (from-to) | 6344-6348 |
Number of pages | 5 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 91 |
Issue number | 14 |
DOIs | |
State | Published - 1994 |
ASJC Scopus subject areas
- General