The state of lipid rafts: from model membranes to cells.
Lipid raft microdomains were conceived as part of a mechanism for the intracellular trafficking of lipids and lipid-anchored proteins. The raft hypothesis is based on the behavior of defined lipid mixtures in liposomes and other model membranes. Experiments in these well-characterized systems led to operational definitions for lipid rafts in cell membranes. These definitions, detergent solubility to define components of rafts, and sensitivity to cholesterol deprivation to define raft functions implicated sphingolipid- and cholesterol-rich lipid rafts in many cell functions. Despite extensive work, the basis for raft formation in cell membranes and the size of rafts and their stability are all uncertain. Recent work converges on very small rafts <10 nm in diameter that may enlarge and stabilize when their constituents are cross-linked.
Edidin
Michael
M
Biology Department, The Johns Hopkins University, Baltimore, Maryland 21218, USA. edidin@jhu.edu
D002784:Cholesterol / Q000737:chemistry* / Q000378:metabolism; D003902:Detergents / Q000737:chemistry; D004847:Epithelial Cells / Q000737:chemistry / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism*; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism; D008560:Membrane Fluidity; D021962:Membrane Microdomains / Q000737:chemistry* / Q000378:metabolism*; D008567:Membranes, Artificial; D013107:Sphingolipids / Q000737:chemistry* / Q000378:metabolism
D003902:Detergents; D008051:Lipid Bilayers; D008055:Lipids; D008081:Liposomes; D008567:Membranes, Artificial; D013107:Sphingolipids; D002784:Cholesterol