title: Envelope proteins of vesicular stomatitis virus: effect of temperature-sensitive mutations in complementation groups III and V.
abstract: All five major viral proteins were synthesized in chicken embryo cells infected with vesicular stomatitis virus temperature-sensitive (ts) mutants of complementation groups III and V and maintained at the nonpermissive temperature. The distribution of these proteins among cytoplasmic cellular fractions separated on discontinuous sucrose gradients was identical for wild-type and tsIII-infected cells. Strikingly different patterns were observed for the G protein in gradients from cells infected by tsV mutants; very little, if any, G protein was found in the lightest fraction. Pulse and chase experiments with wild-type, virus-infected cells showed that protein G moves from the heaviest to the lightest fraction before being incorporated into the virion. After shift down to the permissive temperature (30 C), G protein synthesized at 39.6 C in tsV-infected cells became associated with the lightest cellular fraction and later with the released virions. In contrast, M protein, synthesized at 39.6 C in tsIII-infected cells, was not incorporated into the virions after shift down. These data strongly suggest, first, that M protein is encoded by the vesicular stomatitis gene III, and second, that incorporation of G protein in the lightest cellular fraction is a necessary step of vesicular stomatitis maturation. This step is impaired by tsV mutations.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D002642:Chick Embryo; D046508:Culture Techniques; D003593:Cytoplasm / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005816:Genetic Complementation Test; D007930:Leucine / Q000378:metabolism; D009154:Mutation; D013696:Temperature; D014316:Tritium; D014721:Vesicular stomatitis Indiana virus / Q000032:analysis* / Q000378:metabolism; D014764:Viral Proteins / Q000032:analysis / Q000096:biosynthesis
chemical_list: D000596:Amino Acids; D014764:Viral Proteins; D014316:Tritium; D007930:Leucine