The human cytomegalovirus protein UL116 interacts with the viral ER resident glycoprotein UL148 and promotes the incorporation of gH/gL complexes into virions

摘要: ABSTRACT Heterodimers of glycoproteins H (gH) and L (gL) comprise a basal element the viral membrane fusion machinery conserved across herpesviruses. In human cytomegalovirus (HCMV), glycoprotein encoded by UL116 noncovalently assembles onto gH at position similar to that occupied gL, forming heterodimer is incorporated into virions. However, physiological roles for or its complex with remain be identified. Here, we show promotes expression gH/gL complexes required efficient production infectious cell-free UL116-null mutants 10-fold defect in virions from infected fibroblasts epithelial cells. This accompanied reduced two disulfide-linked play crucial entry: heterotrimer O (gO) pentameric UL128, UL130, UL131. Furthermore, gH/UL116 substantial constituent since an abundant species not covalently linked other glycoproteins, which has long been observed literature, readily detected wild-type but Interestingly, co-immunoprecipitates UL148, ER resident previously shown attenuate ER-associated degradation (ERAD) gO, observe elevated levels UL148-null Collectively, our findings suggest may serve as chaperone support assembly, maturation, incorporation IMPORTANCE HCMV betaherpesvirus causes dangerous opportunistic infections immunocompromised patients, well immune-naive fetus preterm infants. The potential virus enter new host cells governed large part alternative / important gH/gL/gO gH/gL/UL128-131. A recently identified virion complex, comprised bound UL116, adds layer complexity mechanisms contribute infectivity. complexes, interacts ER-resident factor supports gH/gL/gO. Overall, results gH. These have implications understanding cell tropism development vaccines against virus.