Sindbis Virus Infection of Chick and Hamster Cells: Synthesis of Virus-Specific Proteins

Abstract

In monolayers of chick embryo fibroblasts or BHK cells infected with Sindbis virus in the presence of actinomycin, host protein synthesis is inhibited by at least 80-90% between 2 and 3 hours after infection. Thereafter, Sindbis specified polypeptide chains form 60-70% of total protein synthesis. In particular, synthesis of the membrane protein of the virus constitutes 25% of total protein synthesis. Twelve to 16 polypeptides induced by virus infection have been identified in infected cells by acrylamide gel electrophoresis. The pattern of virus-specified proteins observed depends upon the length of the labeling period, the host cell, and mutations in the virus genome. The molecular weight of the membrane protein of the Sindbis virion has been estimated to be 53,000 and the core protein is estimated to be 30,000 in molecular weight.