tailieunhanh - Báo cáo Y học: Lipid rafts and little caves Compartmentalized signalling in membrane microdomains

Lipid rafts are liquid-ordered membrane microdomains with a unique protein and lipid composition found on the plasma membrane of most, if not all, mammalian cells. A large number of signalling molecules are concentrated within rafts, which have been proposed to function as signalling centres capable of facilitating efficient and specific signal transduction. This review summarizes current knowledge regarding the composition, structure, and dynamic nature of lipid rafts, as well as a number of different signalling path- ways that are compartmentalized within these microdomains | Eur. J. Biochem. 269 737-752 2002 FEBS 2002 REVIEW ARTICLE Lipid rafts and little caves Compartmentalized signalling in membrane microdomains Laura D. Zajchowski and Stephen M. Robbins Departments of Oncology and Biochemistry and Molecular Biology University of Calgary Alberta Canada Lipid rafts are liquid-ordered membrane microdomains with a unique protein and lipid composition found on the plasma membrane of most if not all mammalian cells. A large number of signalling molecules are concentrated within rafts which have been proposed to function as signalling centres capable of facilitating efficient and specific signal transduction. This review summarizes current knowledge regarding the composition structure and dynamic nature of lipid rafts as well as a number of different signalling path ways that are compartmentalized within these microdomains. Potential mechanisms through which lipid rafts carry out their specialized role in signalling are discussed in light of recent experimental evidence. Keywords lipid rafts caveolae caveolin membrane microdomains signal transduction glycosylphosphatidylinositol anchor cholesterol glycosphingolipids. As with most other cellular organelles the plasma membrane is highly organized. Investigations of plasma membrane structure by electron microscopy in the 1950s revealed the presence of multiple small flask-shaped invaginations in the plasma membrane of epithelial and endothelial cells 1 2 . These structures were named caveo-lae or little caves by Yamada 1 based on their characteristic morphology. The cytoplasmic surfaces of caveolae are covered with a membrane coat of which a principal component is a family of 21- to 25-kDa integral membrane proteins called caveolins 3-6 . There are three known caveolin genes caveolin-1 also called VIP21 3 Correspondence to S. M. Robbins Departments of Oncology and Biochemistry Molecular Biology University of Calgary 3330 Hospital Drive . Calgary Alberta Canada T2N 4 N1. Fax 403 283 8727 .