Identification of a glycosylation site in the woodchuck hepatitis virus preS2 protein and its role in protein trafficking.
The middle surface antigen (M-sAg) of hepadnaviruses is one of three envelope proteins that share a common C-terminal S domain. M-sAg contains the preS2 domain in addition to the S region. The preS2 region of woodchuck hepatitis virus (WHV) contains a potential glycosylation site Asn-Gln-Thr at amino acid (aa) positions 3-5. In this study, we mutated this site by site-directed mutagenesis and confirmed that glycosylation occurs here. In in vitro translation assays, the mutation Thr to Asn at aa 5 significantly impaired glycosylation of M-sAg. The mutated M-sAg formed abnormal clustered structures in transfected cells as determined by immunofluorescent staining. Confocal microscopic analysis showed that an enrichment of this glycosylation-deficient protein in the Golgi apparatus occurred, which is not typical for the wild-type protein. These results are consistent with earlier findings that incorrect glycosylation of viral proteins may interfere with virus assembly.
Schildgen
O
O
Institut für Virologie, Universitätsklinikum Essen, Hufelandstraße 55, 45122 Essen, Germany.
Roggendorf
M
M
Institut für Virologie, Universitätsklinikum Essen, Hufelandstraße 55, 45122 Essen, Germany.
Lu
M
M
Institut für Virologie, Universitätsklinikum Essen, Hufelandstraße 55, 45122 Essen, Germany.
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics; D005814:Genes, Viral; D006031:Glycosylation; D006367:HeLa Cells; D018963:Hepatitis Antigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017919:Hepatitis B Virus, Woodchuck / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D006515:Hepatitis B virus / Q000235:genetics; D006801:Humans; D016297:Mutagenesis, Site-Directed; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013347:Subcellular Fractions / Q000821:virology; D014162:Transfection; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019065:Virus Assembly
D004279:DNA, Viral; D018963:Hepatitis Antigens; D011993:Recombinant Fusion Proteins; D014759:Viral Envelope Proteins