Effects of transport inhibitors on the generation and transport of a soluble viral glycoprotein

The generation and transport of the soluble glycoprotein (Gs) of wild-type vesicular stomatitis virus (VSV) were studied using cell fractionation and transport inhibitors. Gs was found in the rough endoplasmic reticulum (RER) and the Golgi-enriched membrane fractions of infected Chinese hamster ovary cells. The identity of intracellular Gs was confirmed by its precipitation with a monoclonal antibody to the ectodomain but not with a anti-peptide antibody directed against the first 15 amino acids at the carboxy terminus of the VSV transmembrane glycoprotein G. Their extracellular appearance was affected in a concentration-dependent manner by monensin and carbonyl cyanide m-chlorophenylhydrazone (CCCP) and was completely inhibited by incubation at 20 degrees. Inhibitors failed to dissociate the transport of Gs from G. These experiments indicate that in fibroblast cells Gs can be generated intracellularly, probably in the RER, and that Gs, like G, is transported from there to the Golgi complex and then presumably to the extracellular environment.