title: N-glycosylation of the premembrane protein of Japanese encephalitis virus is critical for folding of the envelope protein and assembly of virus-like particles.
abstract: Premembrane (prM) and envelope (E) proteins, the major structural proteins of Japanese encephalitis virus (JEV) each contain single potential N-glycosylation site. In this study, the role of N-glycosylation of these proteins on their folding and activity were investigated. Three mutant prM and/or E (prM-E) genes lacking N-glycosylation sites were generated by site-directed mutagenesis. The effects of the N-glycan on folding, secretion and cytotoxicity of mutant proteins were determined by comparison with their wild type (wt) counterparts. Removal of N-glycan from the prM protein resulted in a complete misfolding of the E protein and failure to form virus-like particles (VLPs). A similar removal of N-glycan from the E protein led to a low efficiency of its folding and VLPs formation. The secretion and cytotoxicity of the E protein was also markedly impaired in case the glycosylation sites in the prM or E or both proteins were removed. These results suggest that the N-glycosylation of the prM protein is critical to the folding of the E protein, which makes it pivotal in the cytotoxicity of JEV particles and their production.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, P.R. China.
authors.forename: J
authors.initials: J
authors.lastname: Zai
authors.forename: L
authors.initials: L
authors.lastname: Mei
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: Cao
authors.forename: Z F
authors.initials: ZF
authors.lastname: Fu
authors.forename: H
authors.initials: H
authors.lastname: Chen
authors.forename: Y
authors.initials: Y
authors.lastname: Song
mesh_terms: D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D002470:Cell Survival; D006224:Cricetinae; D004664:Encephalitis Virus, Japanese / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure; D004672:Encephalitis, Japanese / Q000821:virology*; D006031:Glycosylation; D006801:Humans; D009154:Mutation; D011134:Polysaccharides / Q000378:metabolism; D017510:Protein Folding; D014759:Viral Envelope Proteins / Q000737:chemistry*; D014771:Virion / Q000737:chemistry / Q000502:physiology; D019065:Virus Assembly
chemical_list: D011134:Polysaccharides; D014759:Viral Envelope Proteins; C074932:prM protein, Flavivirus