POLYADENYLYLATION OF PROTEINS IN REOVIRIONS

The reovirus oligoadenylates exist in two states within the virion: free and bound to viral proteins. The latter class of oligonucleotides, after digestion with Penicillium (P1) nuclease, yields adenylic acid and an adenosine-containing compound that is positively charged at pH 1.7, 3.5, or 6.5. In a mixture of [35S]methionine- and [3H]adenosine-labeled reovirus disrupted by sodium dodecyl sulfate/urea, approximately 4% of the radioactivity in [35S]methionine-labeled proteins coelutes with [3H]adenosine-labeled material at a net charge of -1.5 when analyzed by ion-exchange chromatography on DEAE-cellulose. This material migrates in sodium dodecyl sulfate/polyacrylamide gels with mu polypeptides and with a small protein, viii. Radioactivity is not released when the complex is boiled in buffer containing sodium dodecyl sulfate and urea or boiled in 80% dimethyl sulfoxide or when viral RNA is extracted with phenol. Digestion with Pronase converts the [3H]adenosine-labeled compound to oligomers of net charge -8 to -12 which contain nuclease P1- and alkaline phosphatase-sensitive adenylic acid residues as well as adenosine in a P1- and phosphatase-resistant linkage. These data indicate that reovirus contains structural proteins that are covalently bound to an oligoadenylate moiety.