Unc-13 homolog A (C. elegans) is a protein that in humans is encoded by the UNC13A gene.
This gene encodes a member of the UNC13 family. UNC13A 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. In Drosophila melanogaster, the protein has been shown to define the vesicle release site by regulating the coupling distance between synaptic vesicles and calcium channels in cooperation with another isoform, UNC13B. It is particularly important in most glutamatergic-mediated synapses but not GABA-mediated synapses. It plays a role in dendrite formation by melanocytes and in secretory granule priming in insulin secretion.