Microdomains of GPI-anchored proteins in living cells revealed by crosslinking

Nature. 1998 Aug 20;394(6695):802-5. doi: 10.1038/29570.


There is some discussion as to whether glycosyl-phosphatidylinositol(GPI)-anchored proteins occur in microdomains in the cell membrane. These putative microdomains have been implicated in processes such as sorting in polarized cells and signal transduction. Complexes enriched in GPI-anchored proteins, cholesterol and glycosphingolipids have been isolated from cell membranes by using non-ionic detergents: these complexes were thought to represent a clustered arrangement of GPI-anchored proteins. However, results obtained when clustering of GPI-anchored proteins induced by antibodies or by detergents was prevented support the idea of a dispersed surface distribution of GPI-anchored proteins at steady state. Here we use chemical crosslinking to show that membrane microdomains of a GPI-anchored protein exist at the surface in living cells. This clustering is specific for the GPI-anchored form, as two transmembrane forms bearing the same ectodomain do not form oligomers. Depletion of membrane cholesterol causes the clustering of GPI-anchored proteins to break up, whereas treatment of cells with detergent substantially increases the size of the complexes. We find that in living cells these GPI-anchored proteins reside in microdomains consisting of at least 15 molecules, which are much smaller than those seen after detergent extraction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD55 Antigens / chemistry*
  • CHO Cells
  • Cell Line
  • Cell Membrane / chemistry
  • Cloning, Molecular
  • Cricetinae
  • Cross-Linking Reagents
  • Detergents
  • Glycosylphosphatidylinositols / chemistry*
  • Growth Hormone / chemistry*
  • Rats


  • CD55 Antigens
  • Cross-Linking Reagents
  • Detergents
  • Glycosylphosphatidylinositols
  • Growth Hormone