Coupling of the proto-oncogene product XXXX to the @entity470 .

@entity1 @entity404 @entity470 @entity2733 @entity5315 @entity4179 @entity10240 @entity1521 @entity669 @entity4357 @entity1473
The proto-oncogene product, @entity5315 , is a 120-kDa protein present in lymphocytes that contains numerous PXXP motifs in its @entity1473 -terminal region and constitutively binds the SH3-containing adaptor protein @entity10240 . Cross-linking of CD3 and @entity404 receptors in Jurkat T cells causes @entity669 phosphorylation of @entity5315 and its association with @entity4357 3'-kinase (Meisner, H., Conway, B., Hartley, D., and Czech, M. P. (1995) Mol. Cell. Biol. 15, 3571-3578). Here we demonstrate that @entity5315 is also present in nonlymphoid cells, and that @entity4179 ( @entity4179 ) elicits its rapid @entity669 phosphorylation in @entity1 embryonic 293 cells. Immunoprecipitates of @entity5315 from lysates of these cells contain @entity10240 in the basal state, while @entity4179 stimulation causes co-precipitation of @entity669 -phosphorylated @entity4179 receptors. Similarly, @entity470 immunoprecipitates from @entity4179 -treated 293 cells contain @entity5315 and @entity10240 . Both @entity10240 and @entity4179 receptors are released from @entity5315 in the presence of a @entity1521 -rich peptide that binds the @entity2733 -terminal SH3 domain of @entity10240 . These results indicate that autophosphorylated @entity4179 receptors associate with the SH2 domain of @entity10240 , which is complexed through its SH3 domain with @entity1521 -rich regions of @entity5315 . Such recruitment of @entity5315 to @entity4179 receptors may reflect an important mechanism for its @entity669 phosphorylation and for assembling signaling components that mediate or modulate @entity4179 actions.
