Vid24p, a novel protein localized to the fructose-1, 6-bisphosphatase-containing vesicles, regulates targeting of fructose-1,6-bisphosphatase from the vesicles to the vacuole for degradation

J Cell Biol. 1998 Mar 23;140(6):1347-56. doi: 10.1083/jcb.140.6.1347.

Abstract

Glucose regulates the degradation of the key gluconeogenic enzyme, fructose-1,6-bisphosphatase (FBPase), in Saccharomyces cerevisiae. FBPase is targeted from the cytosol to a novel type of vesicle, and then to the vacuole for degradation when yeast cells are transferred from medium containing poor carbon sources to fresh glucose. To identify proteins involved in the FBPase degradation pathway, we cloned our first VID (vacuolar import and degradation) gene. The VID24 gene was identified by complementation of the FBPase degradation defect of the vid24-1 mutant. Vid24p is a novel protein of 41 kD and is synthesized in response to glucose. Vid24p is localized to the FBPase-containing vesicles as a peripheral membrane protein. In the absence of functional Vid24p, FBPase accumulates in the vesicles and fails to move to the vacuole, suggesting that Vid24p regulates FBPase targeting from the vesicles to the vacuole. FBPase sequestration into the vesicles is not affected in the vid24-1 mutant, indicating that Vid24p acts after FBPase sequestration into the vesicles has occurred. Vid24p is the first protein identified that marks the FBPase-containing vesicles and plays a critical role in delivering FBPase from the vesicles to the vacuole for degradation.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Biological Transport / drug effects
  • Biological Transport / physiology
  • Cloning, Molecular
  • Cytoplasmic Granules / metabolism
  • Fructose-Bisphosphatase / analysis*
  • Fructose-Bisphosphatase / metabolism
  • Fungal Proteins / analysis
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Gene Expression Regulation, Fungal
  • Glucose / pharmacology
  • Intracellular Membranes / metabolism*
  • Molecular Sequence Data
  • Mutation / physiology
  • Saccharomyces cerevisiae / chemistry
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae Proteins*
  • Vacuoles / metabolism*
  • Vesicular Transport Proteins

Substances

  • Fungal Proteins
  • Saccharomyces cerevisiae Proteins
  • VID24 protein, S cerevisiae
  • Vesicular Transport Proteins
  • Fructose-Bisphosphatase
  • Glucose

Associated data

  • GENBANK/U86750