protein kinase C conserved region 1 (C1 domain) found in Munc13-2, Munc13-3 and similar proteins
Munc13-2, also called protein unc-13 homolog B (Unc13B), plays a role in vesicle maturation during exocytosis as a target of the diacylglycerol second messenger pathway. It is involved in neurotransmitter release by acting in synaptic vesicle priming prior to vesicle fusion and participates in the activity-dependent refilling of readily releasable vesicle pool (RRP). Munc13-2 is essential for normal release probability at hippocampal mossy fiber synapses. Munc13-3 is almost exclusively expressed in the cerebellum. It acts as a tumor suppressor and plays a critical role in the formation of release sites with calcium channel nanodomains. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.