The yeast p24 complex regulates GPI-anchored protein transport and quality control by monitoring anchor remodeling

Mol Biol Cell. 2011 Aug 15;22(16):2924-36. doi: 10.1091/mbc.E11-04-0294. Epub 2011 Jun 16.

Abstract

Glycosylphosphatidylinositol (GPI)-anchored proteins are secretory proteins that are attached to the cell surface of eukaryotic cells by a glycolipid moiety. Once GPI anchoring has occurred in the lumen of the endoplasmic reticulum (ER), the structure of the lipid part on the GPI anchor undergoes a remodeling process prior to ER exit. In this study, we provide evidence suggesting that the yeast p24 complex, through binding specifically to GPI-anchored proteins in an anchor-dependent manner, plays a dual role in their selective trafficking. First, the p24 complex promotes efficient ER exit of remodeled GPI-anchored proteins after concentration by connecting them with the COPII coat and thus facilitates their incorporation into vesicles. Second, it retrieves escaped, unremodeled GPI-anchored proteins from the Golgi to the ER in COPI vesicles. Therefore the p24 complex, by sensing the status of the GPI anchor, regulates GPI-anchored protein intracellular transport and coordinates this with correct anchor remodeling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Endoplasmic Reticulum / metabolism
  • Endoplasmic Reticulum Stress
  • GPI-Linked Proteins / metabolism*
  • Gene Knockout Techniques
  • Glycosylphosphatidylinositols / metabolism*
  • Golgi Apparatus / metabolism
  • Membrane Proteins / metabolism
  • Multiprotein Complexes / chemistry
  • Multiprotein Complexes / genetics
  • Multiprotein Complexes / metabolism*
  • Protein Binding
  • Protein Transport
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Unfolded Protein Response
  • Vesicular Transport Proteins / chemistry
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism*

Substances

  • GPI-Linked Proteins
  • Glycosylphosphatidylinositols
  • Membrane Proteins
  • Multiprotein Complexes
  • SFB3 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Vesicular Transport Proteins