FOLIMYCIN (CONCANAMYCIN-A), AN INHIBITOR OF V-TYPE H+-ATPASE, BLOCKS CELL-SURFACE EXPRESSION OF VIRUS-ENVELOPE GLYCOPROTEINS

Folimycin (concanamycin A) inhibited syncytium formation without affecting glycoprotein synthesis. Excretion of the glycoprotein (G protein) of vesicular stomatitis virus into the medium was blocked. Inaccessibility of the cell-associated viral G protein to protease added extracellularly indicates that cell-surface expression of the viral G protein is blocked by folimycin. The viral G protein accumulated intracellularly in the presence of folimycin electrophoresed a little faster than the control mature one excreted to the medium. Glycopeptides derived from the viral G protein bound to concanavalin A-agarose and were endo H-sensitive. Taken together these results indicate that processing of N-glycosidic oligosaccharide is incomplete in the presence of folimycin and suggest that intracellular trafficking is arrested before reaching at the latest to the trans Golgi compartments. © 1993 Academic Press, Inc.