Plasma membrane targeting of exocytic SNARE proteins.
SNARE proteins play a central role in the process of intracellular membrane fusion. Indeed, the interaction of SNAREs present on two opposing membranes is generally believed to provide the driving force to initiate membrane fusion. Eukaryotic cells express a large number of SNARE isoforms, and the function of individual SNAREs is required for specific intracellular fusion events. Exocytosis, the fusion of secretory vesicles with the plasma membrane, employs the proteins syntaxin and SNAP-25 as plasma membrane SNAREs. As a result, exocytosis is dependent upon the targeting of these proteins to the plasma membrane; however, the mechanisms that underlie trafficking of exocytic syntaxin and SNAP-25 proteins to the cell surface are poorly understood. The intracellular trafficking itinerary of these proteins is particularly intriguing as syntaxins are tail-anchored (or Type IV) membrane proteins, whereas SNAP-25 is anchored to membranes via a central palmitoylated domain-there is no common consensus for the trafficking of such proteins within the cell. In this review, we discuss the plasma membrane targeting of these essential exocytic SNARE proteins.
Salaün
Christine
C
Henry Wellcome Laboratory of Cell Biology, Division of Biochemistry & Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, United Kingdom.
James
Declan J
DJ
Greaves
Jennifer
J
Chamberlain
Luke H
LH
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D005089:Exocytosis; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D051938:Munc18 Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism; D050765:Qa-SNARE Proteins; D050600:SNARE Proteins; D050825:Synaptosomal-Associated Protein 25; D033921:Vesicular Transport Proteins / Q000378:metabolism*
D008565:Membrane Proteins; D051938:Munc18 Proteins; D009419:Nerve Tissue Proteins; D050765:Qa-SNARE Proteins; C494208:SNAP25 protein, human; D050600:SNARE Proteins; D050825:Synaptosomal-Associated Protein 25; D033921:Vesicular Transport Proteins