Specific requirements for the ER to Golgi transport of GPI-anchored proteins in yeast

J Cell Sci. 1997 Nov:110 ( Pt 21):2703-14. doi: 10.1242/jcs.110.21.2703.


GPI-anchored proteins are attached to the membrane via a glycosylphosphatidylinositol-(GPI) anchor whose carbohydrate core is conserved in all eukaryotes. Apart from membrane attachment, the precise role of the GPI-anchor is not known, but it has been proposed to play a role in protein sorting. We have investigated the transport of the yeast GPI-anchored protein Gas1p. We identified two mutant strains involved in very different cellular processes that are blocked selectively in the transport of GPI-anchored proteins before arrival to the Golgi. The end8-1/lcb1-100 mutant is defective in ceramide synthesis. In vitro data suggest a requirement for ceramides after the exit from the ER. We therefore propose that ceramides might function in the fusion of a GPI-containing vesicle with the Golgi, but we cannot exclude a role in the ER. The second mutant that blocks the transport of GPI-anchored proteins to the Golgi is ret1-1, a mutant in the alpha-subunit of coatomer. In both mutants, GPI-anchor attachment is normal and in ret1-1 cells, the GPI-anchors are remodeled with ceramide to the same extent as in wild-type cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Transport
  • Endoplasmic Reticulum / metabolism*
  • Glycosylphosphatidylinositols / metabolism
  • Golgi Apparatus / metabolism*
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism*
  • Mutation
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae / ultrastructure
  • Saccharomyces cerevisiae Proteins*


  • GAS1 protein, S cerevisiae
  • Glycosylphosphatidylinositols
  • Membrane Glycoproteins
  • Saccharomyces cerevisiae Proteins