Background of the antigen
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.
