Synthesis of the precursor to avian RNA tumor virus internal structural proteins early after infection.

Gallis, B M and Eisenman, R N and Diggelmann, H (1976) Synthesis of the precursor to avian RNA tumor virus internal structural proteins early after infection. Virology, 74 (2). pp. 302-313. ISSN 0042-6822

Abstract

The synthesis of the 76,000-dalton precursor (Pr 76) of the avian RNA tumor virus internal structural proteins was studied as a function of time after infection of chick embryo fibroblasts (CEF) with avian myeloblastosis virus (AMV). During the course of infection, cells were pulse-labeled with [35S]methionine, lysed, and the labeled viral polypeptide precursor was precipitated with antibody against detergent-lysed AMV. Pr 76 was detected by SDS gel electrophoresis of immune precipitates. The earliest time at which Pr 76 synthesis could be detected was 3 hr after infection. Pr 76 synthesis remained low (about 1% of the level of synthesis several days after infection) and constant from 3 until 7 hr after infection. Between 7 and 9 hr after infection, Pr 76 synthesis increased by fivefold. Cells treated with cycloheximide during the first 8 or 12 hr after infection showed an 85–90% inhibition of Pr 76 synthesis and virus production measured late during infection. This finding does not necessarily imply that early viral protein synthesis is required for a productive infection, because cycloheximide also inhibited chick embryo fibroblast DNA synthesis. If cells were treated prior to and during infection with actinomycin D or cytosine arabinoside, precursor synthesis was still observed early (3 to 7 hr after infection). The amount of precursor synthesized early in the presence of inhibitors was similar to that synthesized in the absence of inhibitors, suggesting that the incoming RNA served as a messenger RNA for Pr 76.

Repository Administrators Only

View Item