Individual roles of N-linked oligosaccharide chains in intracellular transport of the paramyxovirus SV5 fusion protein.
The role of N-linked glycosylation in the assembly, intracellular transport, and fusion activity of the paramyxovirus SV5 fusion (F) protein was examined. Each of the six potential glycosylation sites in the F protein was individually removed by oligonucleotide-directed mutagenesis on a cDNA clone encoding the SV5 F protein. When the mutant F proteins were expressed in eukaryotic cells using the vaccinia virus-T7 transient expression system they all had a significant change in gel mobility, indicating that all six sites in the F protein are used for the addition of N-linked oligosaccharides. All of the mutant F proteins could form a homooligomer. Removal of individual carbohydrate chains from the F2 subunit had little effect on the surface expression of the F protein. However, removal of individual carbohydrate chains from the F1 subunit had deleterious effects, which ranged from a partial delay in intracellular transport and decreased stability of the protein to severe transport delays and acute instability of the F protein.
Bagai
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Howard Hughes Medical Institute, Northwestern University, Evanston, Illinois 60208-3500, USA.
Lamb
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RA
D001693:Biological Transport, Active; D018076:DNA, Complementary / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D006031:Glycosylation; D006056:Golgi Apparatus / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D016297:Mutagenesis, Site-Directed; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D018108:Respirovirus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014760:Viral Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D018076:DNA, Complementary; D004279:DNA, Viral; D009844:Oligosaccharides; D014760:Viral Fusion Proteins