CASEIN KINASE-II IS THE P-PROTEIN PHOSPHORYLATING CELLULAR KINASE ASSOCIATED WITH THE RIBONUCLEOPROTEIN COMPLEX OF PURIFIED VESICULAR STOMATITIS-VIRUS

Protein kinase activities associated with a highly purified transcript ionally active ribonucleoprotein complex from the virions of vesicular stomatitis virus (VSV) were isolated and characterized. Based upon se veral biochemical and immunological criteria, the protein kinase activ ity, which phosphorylated the bacterially expressed unphosphorylated ( P-o) protein, was shown to be cellular casein kinase II (CKII). These studies included inhibition of the protein kinase by specific inhibito rs, phosphorylation of mutant phosphoproteins (P), immunoprecipitation by CKII antibody and Western blot analyses, and finally its ability t o activate P, to synthesize RNA in a transcription-reconstitution reac tion. The P protein is phosphorylated intracellularly by cellular CKII . The present study demonstrates that VSV specifically packages CKII w hich remains strongly associated with the ribonucleoprotein complex du ring morphogenesis.