C. Dhiba et al., The UL34 gene product of herpes simplex virus type 2 is a tail-anchored type II membrane protein that is significant for virus envelopment, J GEN VIROL, 81, 2000, pp. 2397-2405
The UL34 gene of herpes simplex virus type 2 (HSV-2) is highly conserved in
the herpesvirus family. The UL34 gene product was identified In lysates of
HSV-2-infected cells as protein species with molecular masses of 31 and 32
.5 kDa, the latter being a phosphorylated product. Synthesis of these prote
ins occurred at late times post-infection and was highly dependent on viral
DNA synthesis. Immunofluorescence assays revealed that the UL34 protein wa
s localized in the cytoplasm in a continuous net-like structure, closely re
sembling the staining pattern of the endoplasmic reticulum (ER), in both HS
V-2-infected cells and in cells transiently expressing UL34 protein. Deleti
on mutant analysis showed that this colocalization required the C terminus
of the UL34 protein. The UL34 protein associated with virions but not with
A, B or C capsids. We treated virions, HSV-2-infected cells and cells expre
ssing the UL34 protein with a protease in order to examine the topology of
the UL34 protein. In addition, we constructed UL34 deletion mutant proteins
and examined their intracellular localization. Our data strongly support t
he hypothesis that the UL34 protein is inserted into the viral envelope as
a tail-anchored type II membrane protein and is significant for virus envel
opment.