Cell-Free Translation of Messenger RNA of Simian Virus 40: Synthesis of the Major Capsid Protein

Extracts of wheat germ are capable of synthesizing the major capsid protein of simian virus 40. Poly(A)-containing RNA from BS-C-1 cells infected with simian virus 40 directed the synthesis of a novel polypeptide that migrates in polyacrylamide gels together with the major capsid polypeptide of simian virus 40, VP-1. The patterns of the major tryptic peptides of purified VP-1 and the novel polypeptide synthesized in vitro were identical after two-dimensional paper electrophoresis. The novel polypeptide was not synthesized in response to poly(A)-rich RNA from uninfected cells or from virus-infected cells treated with cytosine arabinoside. Messenger RNA from infected cells purified by selective hybridization to DNA of simian virus 40 directs the synthesis of a major polypeptide of electrophoretic mobility similar to that of VP-1 of simian virus 40. This approach should prove useful in identifying additional products specified by DNA tumor viruses.