Distinct sequence determinants direct intracellular sorting and modification of a yeast vacuolar protease.
We have mapped a sequence determinant in the vacuolar glycoprotein carboxypeptidase Y (CPY) that directs intracellular sorting of this enzyme. Through the study of hybrid proteins, consisting of amino-terminal segments of CPY fused to the secretory enzyme invertase, we have found that the N-terminal 50 amino acids of CPY are sufficient to direct delivery of a CPY-Inv hybrid protein to the yeast vacuole. Our data suggest that this 50 amino acid segment of CPY contains two distinct functional domains; an N-terminal signal peptide followed by a segment of 30 amino acids that contains the vacuolar sorting signal. Deletion of this putative vacuole sorting signal from an otherwise wild-type CPY protein leads to missorting of CPY. Furthermore, examination of the Asn-linked oligosaccharides present on CPY and CPY-Inv hybrid proteins suggests that an additional determinant in CPY specifies the extent to which these proteins are glycosylated in the Golgi complex.
D000595:Amino Acid Sequence; D001483:Base Sequence; D002268:Carboxypeptidases / Q000235:genetics* / Q000378:metabolism; D043402:Cathepsin A; D004262:DNA Restriction Enzymes; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism; D009940:Organoids / Q000201:enzymology*; D010957:Plasmids; D055503:Protein Multimerization; D011499:Protein Processing, Post-Translational; D021382:Protein Sorting Signals / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D014617:Vacuoles / Q000201:enzymology*; D043324:beta-Fructofuranosidase
D021382:Protein Sorting Signals; D029701:Saccharomyces cerevisiae Proteins; D004262:DNA Restriction Enzymes; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase; D002268:Carboxypeptidases; D043402:Cathepsin A; C499283:PRC1 protein, S cerevisiae; C022633:serine carboxypeptidase