Thioredoxin is required for vacuole inheritance in Saccharomyces cerevisiae

J Cell Biol. 1996 Mar;132(5):787-94. doi: 10.1083/jcb.132.5.787.

Abstract

The vacuole of Saccharomyces cerevisiae projects a stream of tubules a and vesicles (a "segregation structure") into the bud in early S phase. We have described an in vitro reaction, requiring physiological temperature, ATP, and cytosol, in which isolated vacuoles form segregation structures and fuse. This in vitro reaction is defective when reaction components are prepared from vac mutants that are defective in this process in vivo, Fractionation of the cytosol reveals at least three components, each of which can support the vacuole fusion reaction, and two stimulatory fractions. Purification of one "low molecular weight activity" (LMA1) yields a heterodimeric protein with a thioredoxin subunit. Most of the thioredoxin of yeast is in this complex rather than the well-studied monomer. A deletion of both S. cerevisiae thioredoxin genes causes a striking vacuole inheritance defect in vivo, establishing a role for thioredoxin as a novel factor in this trafficking reaction.

Publication types

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

MeSH terms

  • Cell-Free System
  • Cytosol / chemistry
  • Cytosol / metabolism
  • Fungal Proteins / chemistry
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Gene Deletion
  • Membrane Fusion*
  • Protein Conformation
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / growth & development
  • Saccharomyces cerevisiae / metabolism
  • Thioredoxins / chemistry
  • Thioredoxins / genetics
  • Thioredoxins / metabolism*
  • Vacuoles / genetics*
  • Vacuoles / metabolism

Substances

  • Fungal Proteins
  • Recombinant Proteins
  • Thioredoxins