protein kinase C conserved region 1 (C1 domain) found in Munc13-1 and similar proteins
Munc13-1, also called protein unc-13 homolog A (Unc13A), is a diacylglycerol (DAG) receptor that 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). Loss of MUNC13-1 function causes microcephaly, cortical hyperexcitability, and fatal myasthenia. 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.