A snc1 endocytosis mutant: phenotypic analysis and suppression by overproduction of dihydrosphingosine phosphate lyase

Mol Biol Cell. 2000 Dec;11(12):4051-65. doi: 10.1091/mbc.11.12.4051.

Abstract

The v-SNARE proteins Snc1p and Snc2p are required for fusion of secretory vesicles with the plasma membrane in yeast. Mutation of a methionine-based sorting signal in the cytoplasmic domain of either Sncp inhibits Sncp endocytosis and prevents recycling of Sncp to the Golgi after exocytosis. snc1-M43A mutant yeast have reduced growth and secretion rates and accumulate post-Golgi secretory vesicles and fragmented vacuoles. However, cells continue to grow and secrete for several hours after de novo Snc2-M42A synthesis is repressed. DPL1, the structural gene for dihydrosphingosine phosphate lyase, was selected as a high copy number snc1-M43A suppressor. Because DPL1 also partially suppresses the growth and secretion phenotypes of a snc deletion, we propose that enhanced degradation of dihydrosphingosine-1-phosphate allows an alternative protein to replace Sncp as the secretory vesicle v-SNARE.

Publication types

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

MeSH terms

  • Aldehyde-Lyases / genetics
  • Aldehyde-Lyases / physiology*
  • Cell Division
  • Endocytosis*
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Fungal Proteins / physiology*
  • Gene Deletion
  • Gene Dosage
  • Genes, Fungal
  • Macromolecular Substances
  • Membrane Proteins / metabolism
  • Mutation
  • Phenotype
  • Protein Transport
  • R-SNARE Proteins
  • SNARE Proteins
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / physiology*
  • Saccharomyces cerevisiae / ultrastructure
  • Saccharomyces cerevisiae Proteins*
  • Secretory Vesicles / metabolism
  • Vesicular Transport Proteins*

Substances

  • Fungal Proteins
  • Macromolecular Substances
  • Membrane Proteins
  • R-SNARE Proteins
  • SNARE Proteins
  • SNC1 protein, S cerevisiae
  • SNC2 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Vesicular Transport Proteins
  • Aldehyde-Lyases
  • sphingosine 1-phosphate lyase (aldolase)