Background of the antigen
Munc 13s are homologues of the C. elegans unc-13 gene product. Three brain specific isoforms are expressed in rat: Munc 13-1, -13-2, and -13-3. Munc 13-1 is a peripheral membrane protein that is enriched in synaptosomes and localized to plasma membranes but absent from synaptic vesicles. It has multiple regulatory domains (C1 and C2 domains) that may mediate diacylglycerol, phospholipid, and calcium binding. The C terminus of Munc 13-1 interacts directly with a putative coiled coil domain in the N-terminal part of syntaxin. It has been shown that Munc 13 is involved in priming synaptic vesicles. These activated vesicles can be released immediately on Ca2+ influx.
