A Novel Role for Nutrition in the Alteration of Functional Microdomains on the Cell Surface
Membrane rafts are ordered microdomains of the plasma membrane consisting of cholesterol, sphingolipids, and saturated fatty acids which appear to regulate many cellular signaling pathways. One such type of membrane raft is caveolae, which are cave-like invaginations of the plasma membrane. Interestingly, changes in the acyl composition of cellular membranes have been shown to alter the specific localization of membrane raft associated proteins and their function. This is noteworthy because modification of membrane acyl composition is readily accomplished through changes in dietary fat composition. Here we describe a common approach used to fractionate cell membranes to obtain an enriched preparation of caveolae and gas chromatographic techniques to determine fatty acyl composition. In addition, methods used to visualize and quantify lipid rafts using a fluorescent probe Laurdan in living cells will also be described.
Key wordsCaveolae Fatty acids Laurdan Lipid rafts Membrane rafts Nutrition
Supported in part by NIH grants CA59034, CA129444, DK071707, and P30ES09106 to R.S. Chapkin and a Natural Sciences and Engineering Research Council of Canada Discovery Grant to D.W.L. Ma.
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