title: Exogenous administration of gangliosides displaces GPI-anchored proteins from lipid microdomains in living cells.
abstract: 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 degrees C. Our data suggest that exogenous application of gangliosides displaces GPI-anchored proteins from sphingolipid-cholesterol microdomains in living cells.
authors.affiliation: Department of Neurology, University of Tübingen, D-77076 Tübingen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Simons
authors.forename: T
authors.initials: T
authors.lastname: Friedrichson
authors.forename: J B
authors.initials: JB
authors.lastname: Schulz
authors.forename: M
authors.initials: M
authors.lastname: Pitto
authors.forename: M
authors.initials: M
authors.lastname: Masserini
authors.forename: T V
authors.initials: TV
authors.lastname: Kurzchalia
mesh_terms: D000818:Animals; D018958:CD55 Antigens / Q000378:metabolism; D016466:CHO Cells; D002352:Carrier Proteins / Q000378:metabolism; D002460:Cell Line; D006224:Cricetinae; D003432:Cross-Linking Reagents; D004285:Dogs; D005455:Fluorescent Antibody Technique; D058973:Folate Receptors, GPI-Anchored; D005677:G(M1) Ganglioside / Q000494:pharmacology; D005732:Gangliosides / Q000494:pharmacology*; D005960:Glucosides / Q000494:pharmacology; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D013006:Growth Hormone / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D009975:Orthomyxoviridae; D011956:Receptors, Cell Surface; D013388:Succinimides
chemical_list: D018958:CD55 Antigens; D002352:Carrier Proteins; D003432:Cross-Linking Reagents; D058973:Folate Receptors, GPI-Anchored; D005732:Gangliosides; D005960:Glucosides; D017261:Glycosylphosphatidylinositols; D008563:Membrane Lipids; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D013388:Succinimides; C018619:octyl-beta-D-glucoside; D005677:G(M1) Ganglioside; D013006:Growth Hormone; C035760:bis(sulfosuccinimidyl)suberate