Rat and human cytomegalovirus ORF116 encodes a virion envelope glycoprotein required for infectivity

• Published in: Virology (New York, N.Y.) Vol. 557; pp. 23 - 33
• Main Authors: Gatault, Philippe, Jones, Iris K.A., Meyer, Christine, Kreklywich, Craig, Alexander, Timothy, Smith, Patricia P., Denton, Michael, Powell, Josh, Orloff, Susan L., Streblow, Daniel N.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-05-2021
• Subjects: Animals; Cytomegalovirus; Cytomegalovirus - chemistry; Cytomegalovirus - genetics; Fibroblasts - virology; Glycoproteins; Glycosylation; Humans; Open Reading Frames - genetics; Rats; RNA, Double-Stranded; Viral entry; Viral Envelope Proteins - genetics; Virion - chemistry; Virus Attachment; Virus Internalization; Cytomegalovirus; Viral entry; Glycoproteins
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2020.12.014

Herpesviruses encode multiple glycoproteins required for different stages of viral attachment, fusion, and envelopment. The protein encoded by the human cytomegalovirus (HCMV) open reading frame UL116 forms a stable complex with glycoprotein H that is incorporated into virions. However, the function of this complex remains unknown. Herein, we characterize R116, the rat CMV (RCMV) putative homolog of UL116. Two R116 transcripts were identified in fibroblasts with three proteins expressed with molecular weights of 42, 58, and 82 kDa. R116 is N-glycosylated, expressed with late viral gene kinetics, and is incorporated into the virion envelope. RCMV lacking R116 failed to result in productive infection of fibroblasts and siRNA knockdown of R116 substantially reduced RCMV infectivity. Complementation in trans of an R116-deficient virus restored ability of the virus to infect fibroblasts. Finally, UL116 knockdown also decreased HCMV infectivity indicating that R116 and UL116 both contribute to viral infectivity.
•Rat cytomegalovirus R116 is a virion-associated glycoprotein.•R116 is required for production of infectious virus.•Human cytomegalovirus UL116 is required for the production of infectious virus.