Which of the following is seen in association with membrane raft?
Ans. c. GPI anchored protein (Ref: Lehninger 5/e p384-386)Stable associations of sphingolipids and cholesterol in the outer leaflet produce a microdomain (rafts) slightly thicker than the other membrane regions that is enriched with specific type of membrane proteins.GPI-Iinked proteins are common in the outer leaflet of these rafts.GPI-Iinked proteins are common in the outer leaflet of these raftsQ.Membrane Microdomain (Rafts)Stable associations of sphingolipids and cholesterol in the outer leaflet produce a microdomain (rafts) slightly thicker than the other membrane regions that is enriched with specific type of membrane proteins.GPl-linked proteins are common in the outer leaflet of these raftsQ.Proteins with one or several covalently attached long-chain acyl groups are seen commonly in the inner leaflet.Caveolin is especially common in inwardly curved rafts called caveolae.Caveolin binds cholesterol in the membrane, and the presence of caveolin forces the associated lipid bilayer to curve inward, forming caveolae (little caves) in the surface of the cell.Caveolae are unusual rafts: they involve both leaflets of the bilayer-the cytoplasmic leaflet, from which the caveolin globular domain project, and the extracellular leaflet, a typical sphingolipid/cholesterol raft with GPI-anchored proteinsQ.Caveolae are implicated in a variety of cellular functions:Membrane trafficking within cellsTransduction of external signals into cellular responses
Mannose binding protein
GTP associated receptor
GPI anchored protein
G-coupled receptor
Membrane Structure & Function