BINDING OF TRANSFORMING PROTEIN, P47GAG-CRK, TO A BROAD RANGE OF PHOSPHOTYROSINE-CONTAINING PROTEINS

Although the oncogene product of CT10 virus, p47gag-crk, does not itself phosphorylate proteins at tyrosine residues, it elevates phosphotyrosine in transformed cells. The p47gag-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 p47gag-crk and p60v-src, a phosphotyrosine-containing protein, was abolished by dephosphorylation of p60v-src. This suggests that the SH2 and SH3 regions function to regulate protein interactions in a phosphotyrosine-dependent manner.