Release of acetylcholine at the synapse

Stable Identifier
Reaction [transition]
Homo sapiens
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Once vesicles are docked, primed and ready to be released fusion of the synaptic vesicle with the plasma membrane can be triggered by an influx of Ca2+ through the voltage gated Ca2+ channels (N, P/Q, R, and L type). Ca2+ influx initiates a cascade of events in which the Ca2+ sensing protein, synaptotagmin-1 (sty-1) is central. Sty-1 promotes the membrane fusion between the synaptic vesicle and the plasma membrane by Ca2+ dependant induction of membrane curvature. Synaptotagmin competes with SNARE complex binding in a Ca2+ dependent manner thereby displacing complexin-1 and causing membrane curvature and fusion of the synaptic vesicle with the plasma membrane. The fusion is characterized by the formation of a trans SNARE complex in which SNAP 25, syntaxin and synaptobrevin along with synaptotagmin, and Rab3a either become a part of the plasma membrane or membrane delimited in the vesicular membrane. Vesicle fusion ultimately results in the release of the acetylcholine into the synaptic cleft.

Literature References
PubMed ID Title Journal Year
17478680 How synaptotagmin promotes membrane fusion

Martens, S, Kozlov, MM, McMahon, HT

Science 2007
12519779 Phosphorylation of Munc18 by protein kinase C regulates the kinetics of exocytosis

Barclay, JW, Craig, TJ, Fisher, RJ, Ciufo, LF, Evans, GJ, Morgan, A, Burgoyne, RD

J Biol Chem 2003
17891149 Synaptotagmin activates membrane fusion through a Ca2+-dependent trans interaction with phospholipids

Stein, A, Radhakrishnan, A, Riedel, D, Fasshauer, D, Jahn, R

Nat Struct Mol Biol 2007
Participant Of
Catalyst Activity
Catalyst Activity
SNARE binding activity of Docked acetylcholine loaded Synaptic Vesicle [plasma membrane]
Physical Entity
Orthologous Events
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