A photo-reactive derivative of ganglioside GM1 specifically cross-links VIP21-caveolin on the cell surface.
Previous studies have shown that sphingolipids may be enriched in caveolae, plasmalemmal invaginations implicated in endocytosis and signal transduction. We synthesised a radiolabeled derivative of ganglioside GM1 bearing a photo-reactive cross-linker at the end of its acyl chain. After insertion in the plasma membrane of cultured A431 or MDCK cells and photoactivation, the main protein cross-linked by the GM1 derivative was VIP21-caveolin, an essential structural component of caveolae. This result shows close proximity between GM1 molecules and VIP21-caveolin in the caveolar membrane and strongly implicates sphingolipid segregation in the biogenesis of caveolae.
D000818:Animals; D001345:Autoradiography; D002240:Carbohydrate Sequence; D002352:Carrier Proteins / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D051242:Caveolin 1; D022461:Caveolins; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D004285:Dogs; D015180:Electrophoresis, Gel, Two-Dimensional; D005677:G(M1) Ganglioside / Q000031:analogs & derivatives*; D006801:Humans; D007668:Kidney; D008565:Membrane Proteins / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D014316:Tritium; D014407:Tumor Cells, Cultured
C495540:CAV1 protein, human; D002352:Carrier Proteins; D051242:Caveolin 1; D022461:Caveolins; D003432:Cross-Linking Reagents; D008565:Membrane Proteins; D014316:Tritium; D005677:G(M1) Ganglioside