Pep12p is a multifunctional yeast syntaxin that controls entry of biosynthetic, endocytic and retrograde traffic into the prevacuolar compartment

Traffic. 2000 Mar;1(3):259-69. doi: 10.1034/j.1600-0854.2000.010308.x.


Delivery of proteins to the vacuole of the yeast Saccharomyces cerevisiae requires the function of the endosomal syntaxin, Pep12p. Many vacuolar proteins, such as the soluble vacuolar hydrolase, carboxypeptidase Y (CPY), traverse the prevacuolar compartment (PVC) en route to the vacuole. Here we show that deletion of the carboxy-terminal transmembrane domain of Pep12p results in a temperature-conditional block in transport of CPY to the PVC. The PVC also receives traffic from the early endosome and the vacuole, and mutation in PEP12 also blocks these other trafficking pathways into the PVC. Therefore, Pep12p is a multifunctional syntaxin that is required for all known trafficking pathways into the yeast PVC. Finally, we found that the internalized pheromone receptor, Ste3p, can cycle out of the PVC in a VPS27-independent fashion.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Endosomes / metabolism*
  • Fungal Proteins / physiology*
  • Membrane Fusion
  • Membrane Proteins / metabolism
  • Membrane Proteins / physiology*
  • Models, Biological
  • Organelles / metabolism
  • Protein Transport / physiology*
  • Qa-SNARE Proteins
  • Receptors, Cell Surface / metabolism
  • Receptors, G-Protein-Coupled*
  • Receptors, Mating Factor
  • Receptors, Pheromone*
  • SNARE Proteins
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae / ultrastructure
  • Saccharomyces cerevisiae Proteins*
  • Temperature
  • Vacuoles / metabolism*
  • Vesicular Transport Proteins*


  • Fungal Proteins
  • Membrane Proteins
  • PEP12 protein, S cerevisiae
  • Qa-SNARE Proteins
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled
  • Receptors, Mating Factor
  • Receptors, Pheromone
  • SNARE Proteins
  • STE3 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Vesicular Transport Proteins