How does synaptotagmin trigger neurotransmitter release?

Howard Hughes Medical Institute and Department of Physiology, University of Wisconsin, Madison, WI 53706, USA.
Annual Review of Biochemistry (Impact Factor: 26.53). 02/2008; 77:615-41. DOI: 10.1146/annurev.biochem.77.062005.101135
Source: PubMed

ABSTRACT Neurotransmitter release at synapses involves a highly specialized form of membrane fusion that is triggered by Ca(2+) ions and is optimized for speed. These observations were established decades ago, but only recently have the molecular mechanisms that underlie this process begun to come into view. Here, we summarize findings obtained from genetically modified neurons and neuroendocrine cells, as well as from reconstituted systems, which are beginning to reveal the molecular mechanism by which Ca(2+)-acting on the synaptic vesicle (SV) protein synaptotagmin I (syt)-triggers rapid exocytosis. This work sheds light not only on presynaptic aspects of synaptic transmission, but also on the fundamental problem of membrane fusion, which has remained a puzzle that has yet to be solved in any biological system.

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