Fatty acylation of yeast glycoproteins proceeds independently of N-linked glycosylation.
The relationship between protein glycosylation and fatty acylation of glycoproteins was studied in the wild-type and asparagine-linked glycosylation-deficient mutants (alg1 and alg2) of Saccharomyces cerevisiae. At the non-permissive temperature (37 degrees C), both mutant cells exhibited increased incorporation of [3H]palmitate into five polypeptides based on SDS-PAGE. In contrast, the wild-type yeast cells contained [3H]palmitate-labeled polypeptides of higher molecular weights, which were converted to the bands seen in the mutant cells upon treatment of the cell extract with endoglycosidase H prior to SDS-PAGE. In addition, labeling of the wild-type yeast cells with [3H]palmitate in the presence of tunicamycin revealed the incorporation of [3H]palmitate into the same five bands as found in the alg1 and alg2 mutants at the non-permissive temperature without tunicamycin. These results indicate that fatty acylation of glycoproteins proceeds independently of protein N-glycosylation in yeast cells.
Appukuttan
P S
PS
Department of Microbiology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799.
Wu
H C
HC
D000215:Acylation; D001692:Biological Transport; D004591:Electrophoresis, Polyacrylamide Gel; D005227:Fatty Acids / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006026:Glycoside Hydrolases; D006031:Glycosylation; D008715:Methionine / Q000032:analysis; D009154:Mutation; D010168:Palmitates / Q000378:metabolism; D010452:Peptide Biosynthesis; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D014415:Tunicamycin
D005227:Fatty Acids; D006023:Glycoproteins; D010168:Palmitates; D014415:Tunicamycin; D008715:Methionine; D006026:Glycoside Hydrolases