• Open Access

Regulation of raft-dependent endocytosis

Authors


  • Guest Editor: R.V. Stan

*Correspondence to:Dr Ivan R.NABI
Department of Cellular and Physiological Sciences, Life
Sciences Institute, University of British Columbia, 2350
Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3.
Tel.:(604) 82 2-70 00;
Fax:(604) 82 2-23 16
E-mail: ivan.robert.nabi@ubc.ca

Abstract

  • • Introduction
  • • Raft-dependent endocytosis encompasses various pathways
  • • Cav1 and the regulation of raft-dependent endocytosis
  • • Signaling and raft-dependent endocytosis
  • • Conclusion

Abstract

Raft-dependent endocytosis is in large part defined as the cholesterol-sensitive, clathrin-independent internalization of ligands and receptors from the plasma membrane. It encompasses the endocytosis of caveo-lae, smooth plasmalemmal vesicles that form a subdomain of cholesterol and sphingolipid-rich lipid rafts and that are enriched for caveolin-1. While sharing common mechanisms, like cholesterol sensitivity, raft endocytic routes show differential regulation by various cellular components including caveolin-1, dynamin-2 and regulators of the actin cytoskeleton. Dynamin-dependent raft pathways, mediated by caveolae and morphologically equivalent non-caveolin vesicular intermediates, are referred to as caveolae/raft-dependent endocytosis. In contrast, dynamin-independent raft pathways are mediated by non-caveolar intermediates. Raft-dependent endocytosis is regulated by tyrosine kinase inhibitors and, through the regulation of the internalization of various ligands, receptors and effectors, is also a determinant of cellular signaling. In this review, we characterize and discuss the regulation of raft-dependent endocytic pathways and the role of key regulators such as caveolin-1.

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