Abstract
Early after infection of cells with cytomegalovirus, the membranes were modified with respect to both glycoprotein composition and immunological specificity. Virus-specified antigens were inserted into the plasma membrane at 24 h after infection, as much as 2 days before virion and dense body maturation. Although at least four virus-induced glycoproteins were synthesized and bound to plasma and microsomal membranes between 20 and 24 h after infection, virus-specified antigen accumulated primarily on the plasma membrane. In contrast, at late times (72 h) after infection when virus nucleocapsids can be detected in the necleus, virus-specified antigen was prominent on the plasma, endoplasmic reticulum and nuclear membranes. It is proposed that the virus-specified glycoproteins and antigens of this herpesvirus accumulate first on the plasma membrane and then on internal membranes. The appearance of virus-specified antigen on internal membranes coincides with the commencement of virion and dense body envelopment.