4-Deoxy-4-fluoro-D-mannose inhibits the glycosylation of the G protein of vesicular stomatitis virus.

The effect of 4-deoxy-4-fluoro-D-mannose (4F-Man), a synthetic analog of D-mannose, on the synthesis of the glycoprotein (G) of vesicular stomatitis virus was examined. Nearly confluent monolayers of cultured BHK21 cells infected with vesicular stomatitis virus were incubated for 2 h with 4F-Man (0-10 mM) or for 1 h with tunicamycin (2 micrograms/ml) and then pulse-labeled with [35S]methionine or [3H]glucosamine. After a 90-min chase period, the cells were lysed and the viral proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. The 35S-labeled G protein from cells exposed to greater than or equal to 1 mM 4F-Man migrated more rapidly than G protein isolated from control cells and with the same electrophoretic mobility as the glycoprotein produced by cells treated with tunicamycin. When infected cells were labeled with [3H]glucosamine, little or no radioactivity was associated with G protein synthesized in the presence of greater than or equal to 1 mM 4F-Man. The conclusion that 4F-Man blocks the glycosylation of the G protein was supported by experiments which demonstrated that the fluorosugar inhibits the synthesis of lipid-linked oligosaccharides.