Glycosylation and processing of prepro-alpha-factor through the yeast secretory pathway.
Events in the synthesis and processing of prepro-alpha-factor have been assessed with the aid of mutants blocked at various stages in the yeast secretory pathway. In normal cells treated with tunicamycin, a precursor accumulates which is identical in molecular weight to the primary translation product synthesized in vitro. At the restrictive temperature in a mutant blocked early in the pathway (sec53), a molecule of similar molecular weight accumulates. In mutants affecting translocation into (sec59) and passage from (sec 18) the endoplasmic reticulum, a glycosylated form of the precursor containing three N-linked core oligosaccharides accumulates; however, it appears that the signal peptide is not removed. The glycosylated precursor first experiences proteolytic processing when accumulated in a mutant (sec7) blocked at the stage of the Golgi apparatus. Substantially greater amounts of the mature pheromone are seen in mutants that accumulate secretory vesicles (sec1, sec2, sec3, sec5).
D005838:Genotype; D006026:Glycoside Hydrolases / Q000378:metabolism; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D000072235:Mating Factor; D010455:Peptides / Q000235:genetics*; D014176:Protein Biosynthesis; D011498:Protein Precursors / Q000235:genetics*; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D013045:Species Specificity
D010455:Peptides; D011498:Protein Precursors; D012333:RNA, Messenger; D000072235:Mating Factor; D006026:Glycoside Hydrolases; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase