An essential role for the proximal but not the distal cytoplasmic tail of glycoprotein M in murid herpesvirus 4 infection.
Murid herpesvirus-4 (MuHV-4) provides a tractable model with which to define common, conserved features of gamma-herpesvirus biology. The multi-membrane spanning glycoprotein M (gM) is one of only 4 glycoproteins that are essential for MuHV-4 lytic replication. gM binds to gN and is thought to function mainly secondary envelopment and virion egress, for which several predicted trafficking motifs in its C-terminal cytoplasmic tail could be important. We tested the contribution of the gM cytoplasmic tail to MuHV-4 lytic replication by making recombinant viruses with varying C-terminal deletions. Removing an acidic cluster and a distal YXXPhi motif altered the capsid distribution somewhat in infected cells but had little effect on virus replication, either in vitro or in vivo. In contrast, removing a proximal YXXPhi motif as well completely prevented productive replication. gM was still expressed, but unlike its longer forms showed only limited colocalization with co-transfected gN, and in the context of whole virus appeared to support gN expression less well. We conclude that some elements of the gM cytoplasmic tail are dispensible for MuHV-4 replication, but the tail as a whole is not.
May
Janet S
JS
Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom.
Smith
Christopher M
CM
Gill
Michael B
MB
Stevenson
Philip G
PG
D016475:3T3 Cells; D000818:Animals; D015139:Blotting, Southern; D002460:Cell Line; D017124:Conserved Sequence; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D006566:Herpesviridae Infections / Q000503:physiopathology*; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D016296:Mutagenesis; D018144:Rhadinovirus / Q000235:genetics / Q000502:physiology*; D014412:Tumor Virus Infections / Q000503:physiopathology*; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000502:physiology*; D014779:Virus Replication
D004279:DNA, Viral; D014759:Viral Envelope Proteins; C418522:glycoprotein M, Equid herpesvirus 1