Rapid inhibition of pinocytosis in baby hamster kidney (BHK-21) cells following infection with vesicular stomatitis virus

Infection of baby hamster kidney cells with vesicular stomatitis virus (VSV) caused a reduced rate of pinocytosis (as judged by the uptake of horseradish peroxidase) after 1 h, and maximum inhibition (60-80%) was observed at 4-6 h. This inhibition occurred 2-3 h before release of virus or changes in cell morphology. Analytical cell fractionation of homogenates of VSV-infected cells indicated that the horseradish peroxidase taken up by pinocytosis was transferred to lysosomes. The inhibition of pinocytosis required viral gene expression: little or no inhibition was detected in cells infected with UV-irradiated virus, wild-type virus in the presence of cycloheximide, or a temperature- sensitive mutant which failed to synthesize viral proteins. When cells were infected with temperature-sensitive viruses with mutations in the five VSV genes, an inhibition of pinocytosis was observed only when the viral transmembrane glycoprotein was present on the surface of the cells.