Binding of Transforming Protein, P47 gag-crk , to a Broad Range of Phosphotyrosine-containing Proteins

Although the oncogene product of CT10 virus, P47 gag-crk , does not itself phosphorylate proteins at tyrosine residues, it elevates phosphotyrosine in transformed cells. The P47 gag-crk oncoprotein contains SH2 and SH3 domains, which are conserved in several proteins involved in signal transduction, including nonreceptor tyrosine kinases. P47 gag-crk bound in vitro to phosphotyrosine-containing proteins from crk -transformed cells and from cells transformed by oncogenic tyrosine kinases. The association between P47 gag-crk and p60 v- src , a phosphotyrosine-containing protein, was abolished by dephosphorylation of p60 v- src . This suggests that the SH2 and SH3 regions function to regulate protein interactions in a phosphotyrosine-dependent manner.