Role of the cytoplasmic tail of gE in antibody-induced redistribution of viral glycoproteins expressed on pseudorabies-virus-infected cells

Pseudorabies virus (PrV) glycoprotein gE is a nonessential glycoprotein inv olved in virulence and spread of the virus. It also has an important, yet u nknown, function during antibody-induced capping of viral glycoproteins on the plasma membrane of PrV-infected swine kidney cells. In the present stud y, it was shown, by the use of a PrV strain expressing a truncated gE glyco protein, that the cytoplasmic tail of gE is of significant importance for v iral glycoprotein capping to occur. In addition, using PrV strains carrying point mutations in the cytoplasmic tail of gE, it was demonstrated that tw o tyrosine-based motifs are very important for correct functioning of gE du ring viral glycoprotein capping. Furthermore it was shown that genistein an d tyrphostin, two tyrosine kinase activity inhibitors, inhibit viral glycop rotein capping in a concentration-dependent manner. In conclusion, it can b e stated that efficient antibody-induced viral glycoprotein capping require s the presence of two YxxL sequences in the cytoplasmic tail of glycoprotei n gE, as well as the activation of a tyrosine phosphorylation signal transd uction pathway. (C) 1999 Academic Press.