Concentration of GPI-anchored proteins upon ER exit in yeast

Traffic. 2009 Feb;10(2):186-200. doi: 10.1111/j.1600-0854.2008.00857.x. Epub 2008 Nov 20.

Abstract

Previous biochemical work has revealed two parallel routes of exit from the endoplasmic reticulum (ER) in the yeast Saccharomyces cerevisiae, one seemingly specific for glycosyl-phosphatidylinositol (GPI)-anchored proteins. Using the coat protein II (COPII) mutant sec31-1, we visualized ER exit sites (ERES) and identified three distinct ERES populations in vivo. One contains glycosylated pro-alpha-factor, the second contains the GPI-anchored proteins Cwp2p, Ccw14p and Tos6p and the third is enriched with the hexose transporter, Hxt1p. Concentration of GPI-anchored proteins prior to budding requires anchor remodeling, and Hxt1p incorporation into ERES requires the COPII components Sec12p and Sec16p. Additionally, we have found that GPI-anchored protein ER exit is controlled by the p24 family member Emp24p, whereas ER export of most transmembrane proteins requires the Cornichon homologue Erv14p.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems / genetics
  • Amino Acid Transport Systems / metabolism
  • Cell Wall / genetics
  • Cell Wall / metabolism*
  • Cytoplasmic Vesicles / metabolism
  • Endoplasmic Reticulum / metabolism*
  • Glucose Transport Proteins, Facilitative
  • Glycosylphosphatidylinositols / metabolism*
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Monosaccharide Transport Proteins / genetics
  • Monosaccharide Transport Proteins / metabolism
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Temperature
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism

Substances

  • Amino Acid Transport Systems
  • CCW14 protein, S cerevisiae
  • CWP2 protein, S cerevisiae
  • EMP24 protein, S cerevisiae
  • Erv14 protein, S cerevisiae
  • GAP1 protein, S cerevisiae
  • Glucose Transport Proteins, Facilitative
  • Glycosylphosphatidylinositols
  • HXT1 protein, S cerevisiae
  • Membrane Glycoproteins
  • Membrane Proteins
  • Monosaccharide Transport Proteins
  • Saccharomyces cerevisiae Proteins
  • Vesicular Transport Proteins