Evidence that the avian sarcoma virus transforming gene product is a cyclic AMP-independent protein kinase.

Abstract
The avian sarcoma virus [ASV] transforming gene product pp60src was partially purified using ion exchange or immunoaffinity chromatography. These preparations contain a cyclic AMP-independent protein kinase activity capable of transferring radiolabel from [.gamma.-32P]ATP to immune rabbit Ig[immunoglobulin]G, casein and the H chain purified from normal rabbit IgG. The casein kinase activity is specifically inhibited by anti-pp60src IgG. Comparison of the pp60src-protein kinase isolated from cells transformed by a wild-type ASV or by an ASV temperature-sensitive transformation mutant revealed that the latter product had a half-life of 3 min at 41.degree. C whereas that of the wild-type product was 20 min.