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Nanoscale organization of multiple GPI-anchored proteins in living cell membranes

Gousset , K and Krishnamoorthy, G and Rao, M and Mayor, S and Varma, R and Sarasij, R. C and Sharma, P (2004) Nanoscale organization of multiple GPI-anchored proteins in living cell membranes. cell, 116 . pp. 577-589.

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Official URL: http://www.ncbi.nlm.nih.gov/pubmed/14980224

Abstract

Cholesterol and sphingolipid-enriched "rafts" have long been proposed as platforms for the sorting of specific membrane components including glycosyl-phosphatidylinositol-anchored proteins (GPI-APs), however, their existence and physical properties have been controversial. Here, we investigate the size of lipid-dependent organization of GPI-APs in live cells, using homo and hetero-FRET-based experiments, combined with theoretical modeling. These studies reveal an unexpected organization wherein cell surface GPI-APs are present as monomers and a smaller fraction (20%-40%) as nanoscale (<5 nm) cholesterol-sensitive clusters. These clusters are composed of at most four molecules and accommodate diverse GPI-AP species; crosslinking GPI-APs segregates them from preexisting GPI-AP clusters and prevents endocytosis of the crosslinked species via a GPI-AP-selective pinocytic pathway. In conjunction with an analysis of the statistical distribution of the clusters, these observations suggest a mechanism for functional lipid-dependent clustering of GPI-APs.

Item Type:Article
Subjects:Biomedical Science > Nanoscale biological processes
Divisions:Faculty of Medicine, Health and Life Sciences > School of Medicine
ID Code:4081
Deposited By:JNCASR
Deposited On:03 Apr 2009 05:34
Last Modified:09 Apr 2009 05:22

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