Role of synaptotagmin in Ca2+-triggered exocytosis.
The Ca(2+)-binding synaptic-vesicle protein synaptotagmin I has attracted considerable interest as a potential Ca(2+) sensor that regulates exocytosis from neurons and neuroendocrine cells. Recent studies have shed new light on the structure, biochemical/biophysical properties and function of synaptotagmin, and the emerging view is that it plays an important role in both exocytosis and endocytosis. At least a dozen additional isoforms exist, some of which are expressed outside of the nervous system, suggesting that synaptotagmins might regulate membrane traffic in a variety of cell types. Here we provide an overview of the members of this gene family, with particular emphasis on the question of whether and how synaptotagmin I functions during the final stages of membrane fusion: does it regulate the Ca(2+)-triggered opening and dilation of fusion pores?
Tucker
Ward C
WC
Department of Physiology, SMI 129, University of Wisconsin, 1300 University Avenue, Madison, WI 53706, U.S.A.
Chapman
Edwin R
ER
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins; D002462:Cell Membrane / Q000378:metabolism; D004705:Endocytosis; D005089:Exocytosis; D006801:Humans; D007700:Kinetics; D008561:Membrane Fusion; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000502:physiology*; D008565:Membrane Proteins / Q000378:metabolism; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000502:physiology*; D009420:Nervous System / Q000378:metabolism; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D050600:SNARE Proteins; D050863:Synaptotagmin I; D050857:Synaptotagmins; D033921:Vesicular Transport Proteins
D002135:Calcium-Binding Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D050600:SNARE Proteins; C494310:SYT1 protein, human; D050863:Synaptotagmin I; D033921:Vesicular Transport Proteins; D050857:Synaptotagmins; D002118:Calcium