Format

Send to

Choose Destination
Traffic. 2004 Apr;5(4):255-64.

Lipid rafts and the regulation of exocytosis.

Author information

1
Division of Biochemistry & Molecular Biology, Davidson Building, University of Glasgow, Glasgow, G12 8QQ, United Kingdom.

Abstract

Exocytosis is the process whereby intracellular fluid-filled vesicles fuse with the plasma membrane, incorporating vesicle proteins and lipids into the plasma membrane and releasing vesicle contents into the extracellular milieu. Exocytosis can occur constitutively or can be tightly regulated, for example, neurotransmitter release from nerve endings. The last two decades have witnessed the identification of a vast array of proteins and protein complexes essential for exocytosis. SNARE proteins fill the spotlight as probable mediators of membrane fusion, whereas proteins such as munc18/nsec1, NSF and SNAPs function as essential SNARE regulators. A central question that remains unanswered is how exocytic proteins and protein complexes are spatially regulated. Recent studies suggest that lipid rafts, cholesterol and sphingolipid-rich microdomains, enriched in the plasma membrane, play an essential role in regulated exocytosis pathways. The association of SNAREs with lipid rafts acts to concentrate these proteins at defined sites of the plasma membrane. Furthermore, cholesterol depletion inhibits regulated exocytosis, suggesting that lipid raft domains play a key role in the regulation of exocytosis. This review examines the role of lipid rafts in regulated exocytosis, from a passive role as spatial coordinator of exocytic proteins to a direct role in the membrane fusion reaction.

PMID:
15030567
PMCID:
PMC2394575
DOI:
10.1111/j.1600-0854.2004.0162.x
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center