Background information
Munc18 may participate in the regulation of synaptic vesicle docking and fusion, possibly through interaction with GTP binding proteins. It is essential for neurotransmission and binds syntaxin, a component of the synaptic vesicle fusion machinery probably in a 1:1 ratio. Munc18 can interact with syntaxins 1, 2, and 3 but not syntaxin 4. It may play a role in determining the specificity of intracellular fusion reactions. Mutations in Munc18 can result in accumulations of acetylcholine and paralytic phenotype suggestive of a neurotransmitter release defect. Two Munc18 isoforms have recently been identified. Munc18-1 has been shown to be primarily expressed in brain, while Munc18-2 is expressed in most tissues.
