Herpes simplex virus (HSV) and other alphaherpesviruses assemble enveloped virions in the trans-Golgi network (TGN) or endosomes. Enveloped particles are formed when capsids bud into TGN/endosomes and virus particles are subsequently ferried to the plasma membrane in TGN-derived vesicles. Little is known about the last stages of virus egress from the TGN/endosomes to cell surfaces except that the HSV directs transport of nascent virions to specific cell surface domains, i.e., epithelial cell junctions. Previously, we showed that HSV
glycoprotein gE/gI accumulates extensively in the TGN at early times after
infection and also when expressed without other
viral proteins. At late times of
infection, gE/gI and a cellular
membrane protein, TGN46, were redistributed from the TGN to epithelial cell junctions. We show here that gE/gI and a second
glycoprotein, gB, TGN46, and another cellular
protein,
carboxypeptidase D, all moved to cell junctions after
infection with an HSV mutant unable to produce cytoplasmic capsids. This redistribution did not involve L particles. In contrast to TGN
membrane proteins, several cellular
proteins that normally adhere to the cytoplasmic face of TGN, Golgi, and endosomal membranes remained primarily dispersed throughout the cytoplasm. Therefore, cellular and viral membrane TGN
proteins move to cell junctions at late times of HSV
infection when the production of enveloped particles is blocked. This is consistent with the hypothesis that there are late HSV
proteins that reorganize or redistribute TGN/endosomal compartments to promote virus egress and cell-to-cell spread.