Effects of tunicamycin and monensin on the distribution of highly phosphorylated proteins in cells infected with herpes simplex virus type 1

New aspects of the distribution of highly phosphorylated proteins in cells infected with herpes simplex virus type 1 (HSV-1) were investigated at the ultrastructural level by the use of drugs which inhibit the glycosylation of viral proteins. The highly phosphorylated proteins were localized by the bismuth tartrate procedure applied on sections of glutaraldehyde-fixed cells embedded in Lowicryl. The drugs employed were tunicamycin, which alters the glycosylation activity of the rough endoplasmic reticulum (RER), and monensin, which blocks the migration of vesicles of the Golgi apparatus (GA) thereby impairing the glycosylation function of the GA. Tunicamycin induced proliferation of RER and the accumulation of highly phosphorylated proteins on its membranes and also impaired GA vesicle maturation and inhibited the usual accumulation of phosphorylated proteins within them. Monensin induced proliferation of the nuclear envelope, including both outer and inner membranes, with bismuth bound to staggered segments of the latter, and also affected the GA in that bismuth-binding proteins were accumulated on the external surface of the swollen vesicles instead of the lumen. These data suggests that an injury of one membrane system, RER or GA, engenders consequential effects on the other. This also supports evidence for an interrelationship between post-translational glycosylation and phosphorylation of proteins in HSV infection.