Phosphorylation of Polyoma and SV40 Virus Proteins

Abstract

Summary The polypeptides of polyoma and SV40 virions are phosphorylated. An estimate of the amount of phosphorylation of the major virus capsid protein (VP1) has been made using two-dimensional gel electrophoresis to resolve phosphorylated from non-phosphorylated forms. The results suggest that in both polyoma and SV40 virions about 12% of VP1 molecules are phosphorylated. In unassembled VP1 molecules immunoprecipitated from extracts of infected cells the proportion is greater, about 33%. The possibility that phosphorylated VP1 may form the penton proteins of the virus capsid is discussed.