Membrane anchors of vesicular stomatitis virus: characterization and incorporation into virions

Abstract

Wild-type vesicular stomatitis virus-infected cells contained multiple carboxy-terminal fragments of the envelope glycoprotein G. They migrated in 16% polyacrylamide gels with two dominant apparent molecular weights, 14,000 and 9,000. Both fragments were immunoprecipitated by two antibodies, anti-G(COOH) and anti-G(stem), made against the last 15 amino acids at the carboxy terminus and against the first 22 amino acids of the ectodomain adjacent to the transmembrane region of G, respectively. Pulse-chase experiments in the presence and absence of tunicamycin indicated that the higher-molecular-weight fragment, Gal, was generated first, presumably in the rough endoplasmic reticulum, and then apparently chased into the faster-migrating, stable fragment, Ga2. Exposure of infected cells to radioactive palmitic acid labeled Ga2. Ga2 was detected in purified virions. These results show that a polypeptide approximately 71 amino acids long is transported and incorporated into budding virions. What signals are operative and whether this C-terminal fragment of G protein is transported as a complex with other viral or host cell proteins are presently unknown.