Exogenous Administration of Gangliosides Displaces GPI-anchored Proteins from Lipid Microdomains in Living Cells
AUTOR(ES)
Simons, Mikael
FONTE
The American Society for Cell Biology
RESUMO
Exogenous application of gangliosides to cells affects many cellular functions. We asked whether these effects could be attributed to the influence of gangliosides on the properties of sphingolipid–cholesterol microdomains on the plasma membrane, also termed rafts. The latter are envisaged as lateral assemblies of sphingolipids (including gangliosides), cholesterol, and a specific set of proteins. Rafts have been implicated in processes such as membrane trafficking, signal transduction, and cell adhesion. Recently, using a chemical cross-linking approach with Madin-Darby canine kidney (MDCK) cells permanently expressing a GPI-anchored form of growth hormone decay accelerating factor (GH-DAF) as a model system, we could show that GPI-anchored proteins are clustered in rafts in living cells. Moreover, this clustering was dependent on the level of cholesterol in the cell. Here we show that incubation of MDCK cells with gangliosides abolished subsequent chemical cross-linking of GH-DAF. Furthermore, insertion of gangliosides into the plasma membrane of MDCK GH-DAF cells renders GH-DAF soluble when subjected to extraction with Triton X-114 at 4°C. Our data suggest that exogenous application of gangliosides displaces GPI-anchored proteins from sphingolipid–cholesterol microdomains in living cells.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=25577Documentos Relacionados
- Differential sorting and fate of endocytosed GPI-anchored proteins
- Interactions between saturated acyl chains confer detergent resistance on lipids and glycosylphosphatidylinositol (GPI)-anchored proteins: GPI-anchored proteins in liposomes and cells show similar behavior.
- Release of GPI-anchored membrane proteins by a cell-associated GPI-specific phospholipase D.
- A convenient method for the construction and expression of GPI-anchored proteins.
- Essential Roles for GPI-anchored Proteins in African Trypanosomes Revealed Using Mutants Deficient in GPI8