Acetylcholine synaptic vesicle docking and priming

Stable Identifier
Reaction [transition]
Homo sapiens
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Docking and priming of acetylcholine loaded transport vesicle occurs once the synaptic vesicle has moved from the cytoplasm to a region apposed to the plasma membrane. The details of the docking and priming reaction have been worked out using synaptic vesicles loaded with glutamate and similar reactions may occur during the transport cycle of acetylcholine. The vesicle is held in close apposition to the plasma membrane by several proteins that bridge the synaptic vesicle to the plasma membrane. Some of these proteins are in the plasma membrane while others are in the synaptic vesicle. Vesicle fusion is preceded by a priming event where molecular interactions between the docked vesicle and the plasma membrane undergo changes. The molecules in the docking and the priming process are known, however, the exact sequence and the precise molecular changes involved in docking and priming are not well dissected. In this reaction the process of docking and priming has been condensed. It is known that Munc18 along with its interactors is critical for membrane docking and fusion events while Munc 13 along with its interacting proteins is central to priming. Munc 13 could act as a positive regulator for the priming recation. Finally the primed fusion complex is clamped in the pre-fusion form by a Complexin. Complexins are Ca2+ independent cytosolic proteins that bind to partly or fully assembled SNARE complexes. Complexins play both a positive and a negative role in the release process.

Literature References
PubMed ID Title Journal Year
15935055 Munc18-1 stabilizes syntaxin 1, but is not essential for syntaxin 1 targeting and SNARE complex formation

de Vries, KJ, Zalm, R, Südhof, TC, Verhage, M, Toonen, RF

J Neurochem 2005
9701566 Interaction of Munc-18-2 with syntaxin 3 controls the association of apical SNAREs in epithelial cells

Olkkonen, VM, Galli, T, Riento, K, Ehnholm, C, Lehtonen, E, Jansson, S

J Cell Sci 1998
17989281 Dual modes of Munc18-1/SNARE interactions are coupled by functionally critical binding to syntaxin-1 N terminus

Dai, H, Sun, J, Rizo, J, Südhof, TC, Dulubova, I, Khvotchev, M

J Neurosci 2007
10440375 Munc13-1 is essential for fusion competence of glutamatergic synaptic vesicles

Südhof, TC, Augustin, I, Rosenmund, C, Brose, N

Nature 1999
Catalyst Activity

SNARE binding activity of Acetylcholine Loaded Synaptic Vesicle [cytosol]

Orthologous Events
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