A deletion that includes the signal peptidase cleavage site impairs processing, glycosylation, and secretion of cell surface yeast acid phosphatase.
We transformed Saccharomyces cerevisiae with a high-copy-number plasmid carrying either the wild-type gene coding for a repressible cell surface acid phosphatase or two modified genes whose products lack a 13- or 14-amino-acid segment spanning or immediately adjacent to the signal peptidase cleavage site. The wild-type gene product underwent proteolytic cleavage of the signal peptide, core glycosylation, and outer chain glycosylation. The deletion spanning the signal peptidase cleavage site led to an unprocessed protein. This modified protein exhibited core glycosylation, whereas its outer chain glycosylation was severely inhibited. Secretion of the deleted protein was impaired, and active enzyme accumulated within the cell. The deletion immediately adjacent to the signal peptidase cleavage site exhibited only a small decrease in the efficiency of processing and had no effect on the efficiency of secretion.
D000135:Acid Phosphatase / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D002872:Chromosome Deletion; D004262:DNA Restriction Enzymes / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism*; D008565:Membrane Proteins; D010957:Plasmids; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D012697:Serine Endopeptidases
D008565:Membrane Proteins; D004262:DNA Restriction Enzymes; D000135:Acid Phosphatase; D010450:Endopeptidases; D012697:Serine Endopeptidases; C026515:type I signal peptidase