Glycosylation of measles virus haemagglutinin protein in infected cells.
Processing of the measles virus haemagglutinin (H) protein was analysed by the pulse-chase method, immunoprecipitation with an anti-H monoclonal antibody and SDS-polyacrylamide gel electrophoresis, combined with the addition of carbonyl cyanide m-chlorophenylhydrazone (CCCP) or monensin (inhibitors of intracellular processing of secretory proteins) to cultures and digestion of the protein with endoglycosidase H or neuraminidase. The apparent Mr of the H protein was increased from 74K to 78K during the chase period. Addition of either CCCP or monensin to the chase medium inhibited the appearance of the 78K H protein, but not the immunoreactivity of the H protein or dimer formation, suggesting that these two events occur in the rough endoplasmic reticulum. The 74K H protein processed in the presence of CCCP was fully sensitive to endoglycosidase H digestion, whereas the 74K H protein processed in the presence of monensin was partially resistant to endoglycosidase H. In experiments using 3H-labelled sugars, [3H]galactose was incorporated into the 74K H protein in the presence of monensin. Neuraminidase treatment increased the electrophoretic mobility of the 78K H protein to 74K. Only the 78K H protein was detected on the surface of untreated cells, and it was resistant to endoglycosidase H digestion. These data suggest that after galactose addition sialic acid is added to the H protein in the trans-Golgi complex and then the mature 78K H protein is transported to the cell surface.
Department of Bacteriology, School of Medicine, Kanazawa University, Japan.
H
H
Ogura
H
H
Sato
S
S
Kamiya
S
S
Nakamura
D006026:Glycoside Hydrolases / Q000378:metabolism; D006031:Glycosylation; D006367:HeLa Cells; D006388:Hemagglutinins / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008459:Measles virus / Q000378:metabolism* / Q000502:physiology; D009439:Neuraminidase / Q000378:metabolism; D011233:Precipitin Tests; D011499:Protein Processing, Post-Translational; D014779:Virus Replication
D006388:Hemagglutinins; D006026:Glycoside Hydrolases; D009439:Neuraminidase