Protein sorting in yeast: the localization determinant of yeast vacuolar carboxypeptidase Y resides in the propeptide.

TitleProtein sorting in yeast: the localization determinant of yeast vacuolar carboxypeptidase Y resides in the propeptide.
Publication TypeJournal Article
Year of Publication1987
AuthorsValls LA, Hunter CP, Rothman JH, Stevens TH
JournalCell
Volume48
Issue5
Pagination887-97
Date Published1987 Mar 13
ISSN0092-8674
KeywordsAmino Acid Sequence, Base Sequence, Carboxypeptidases, Cathepsin A, DNA Restriction Enzymes, Enzyme Precursors, Genes, Genes, Fungal, Mutation, Organoids, Protein Processing, Post-Translational, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Vacuoles
Abstract

We have isolated cis-acting mutations in the gene encoding the yeast vacuolar protein carboxypeptidase Y (CPY) that result in missorting and aberrant secretion of up to 95% of newly synthesized CPY. The CPY polypeptides synthesized by these mutants use the late secretory pathway to exit the cell, since the late-acting sec1 mutation prevents their secretion. The mutant versions of CPY are secreted as the proCPY zymogen and are enzymatically activatable in vivo and in vitro. All the mutations, including small deletions and an amino acid substitution, map to the amino-terminal propeptide region and define a discrete yeast vacuolar localization domain whose integrity is required for efficient sorting of the CPY zymogen. Thus, the N-terminal propeptide of CPY carries out at least three functions: it mediates translocation across the endoplasmic reticulum, renders the enzyme inactive during transit, and targets the molecule to the vacuole.

Alternate JournalCell
PubMed ID3028649