Evidence for a multiprotein gamma-2 herpesvirus entry complex.
Herpesviruses use multiple virion glycoproteins to enter cells. How these work together is not well understood: some may act separately or they may form a single complex. Murine gammaherpesvirus 68 (MHV-68) gB, gH, gL, and gp150 all participate in entry. gB and gL are involved in binding, gB and gH are conserved fusion proteins, and gp150 inhibits cell binding until glycosaminoglycans are engaged. Here we show that a gH-specific antibody coprecipitates gB and thus that gH and gB are associated in the virion membrane. A gH/gL-specific antibody also coprecipitated gB, implying a tripartite complex of gL/gH/gB, although the gH/gB association did not require gL. The association was also independent of gp150, and gp150 was not demonstrably bound to gB or gH. However, gp150 incorporation into virions was partly gL dependent, suggesting that it too contributes to a single entry complex. gp150- and gL- gp150- mutants bound better than the wild type to B cells and readily colonized B cells in vivo. Thus, gp150 and gL appear to be epithelial cell-adapted accessories of a core gB/gH entry complex. The cell binding revealed by gp150 disruption did not require gL and therefore seemed most likely to involve gB.
Gillet
Laurent
L
Division of Virology, Department of Pathology, Tennis Court Road, Cambridge CB2 1QP, United Kingdom.
Stevenson
Philip G
PG
D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D005260:Female; D017353:Gene Deletion; D006566:Herpesviridae Infections / Q000821:virology; D047468:Immunoprecipitation; D051379:Mice; D008807:Mice, Inbred BALB C; D018144:Rhadinovirus / Q000502:physiology*; D014412:Tumor Virus Infections / Q000821:virology; D014759:Viral Envelope Proteins / Q000032:analysis* / Q000378:metabolism*; D014771:Virion / Q000737:chemistry*; D053586:Virus Internalization
D014759:Viral Envelope Proteins; C089386:glycoprotein B, murine gammaherpesvirus 68