Inhibition of avian retrovirus protein synthesis in the presence of host cellular mRNA.

Two conditions of in vitro translation are described in which the RNA of Rous sarcoma virus is significantly less efficient at protein synthesis than host cellular chick mRNA. In direct competition, addition of increasing amounts of host cell mRNA inhibits synthesis of gag gene products from RSV RNA. When the denaturant dimethyl sulfoxide is added to a mixture of the two RNA's the inhibition is even greater. These results support the idea that protein synthesis from avian retrovirus RNA is negatively regulated in vivo in the presence of the host cell mRNA.