pp60(c-src) has less affinity for the detergent-insoluble cellular matrix than do pp60(v-src) and other viral protein-tyrosine kinases

A difference in affinity for a Nonidet P-40-insoluble cellular matrix was observed between the products of the viral and cellular src genes. It has previously been demonstrated that pp60(v-src) is associated with a detergent-insoluble matrix containing the cellular cytoskeleton. (J.G. Burr, G. Dreyfuss, S. Penman, and J.M. Buchanan, Proc. Natl. Acad. Sci. USA 77:3488, 1980). We observed a similar association of the transforming proteins of Fujinami sarcoma virus (P130(gag-fps)) and Yamaguchi 73 avian sarcoma virus (P90(gag-yes)), both of which are tyrosine-specific protein kinases. However, we found that the endogenous c-src product, pp60(c-src), was not tightly bound to the detergent-insoluble matrix. This does not appear to have been due to differences in the cytoskeleton between transformed and nontransformed cells since pp60(c-src) was also solubilized by nonionic detergent in cells transformed by Rous sarcoma virus. This difference in the affinities of the v-src and c-src products for cytoskeletal proteins may contribute to the inability of pp60(c-src) to transform cells.