O glycosylation of glycoprotein G of human respiratory syncytial virus is specified within the divergent ectodomain.
cDNAs encoding the G glycoprotein of respiratory syncytial virus and the hemagglutinin-neuraminidase (HN) glycoprotein of parainfluenza virus type 3 were modified by site-specific mutagenesis and restriction fragment replacement to encode chimeric proteins consisting of the cytoplasmic and transmembrane domains of one protein fused to the ectodomain of the other. In the case of the HN ectodomain attached to the G transmembrane and cytoplasmic domains, cell surface expression of the chimera was reduced. Otherwise, the presence of the heterologous transmembrane and cytoplasmic domains had little effect on the processing of the HN or G ectodomain, as assayed by the acquisition of N-linked and O-linked carbohydrates, transport to the cell surface and, in the case of HN, folding, oligomerization, and hemadsorption activity. These results showed that the synthesis and processing of each ectodomain did not require the homologous transmembrane and cytoplasmic domains. In particular, O glycosylation of the G protein was specified fully by its ectodomain, even though this domain is highly divergent among the respiratory syncytial virus antigenic subgroups. In addition, whereas the cytoplasmic and transmembrane domains of the G protein were relatively highly conserved, they were nonetheless fully replaceable without significantly affecting processing.
Collins
P L
PL
Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral / Q000032:analysis / Q000235:genetics*; D001483:Base Sequence; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002678:Chimera; D003062:Codon / Q000235:genetics; D003593:Cytoplasm / Q000378:metabolism; D004279:DNA, Viral / Q000235:genetics; D005455:Fluorescent Antibody Technique; D005822:Genetic Vectors; D006031:Glycosylation; D015707:HN Protein / Q000032:analysis / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010224:Parainfluenza Virus 3, Human / Q000235:genetics; D011499:Protein Processing, Post-Translational; D012136:Respiratory Syncytial Viruses / Q000235:genetics*; D015183:Restriction Mapping; D013539:Simian virus 40 / Q000235:genetics; D014759:Viral Envelope Proteins; D014764:Viral Proteins
D000956:Antigens, Viral; D003062:Codon; D004279:DNA, Viral; D015707:HN Protein; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C116204:attachment protein G