DOC2B

Double C2-like domain-containing protein beta is a is_associated_with::protein that in humans is encoded by the DOC2B is_associated_with::gene.

Function
There are at least two protein isoforms of the Double C2 protein, namely alpha (is_associated_with::DOC2A) and beta (DOC2B), which contain two C2-like domains. DOC2A and DOC2B are encoded by different genes; these genes are at times confused with the unrelated DAB2 gene which was initially named DOC-2. Doc2b enhances Ca(2+)-dependent is_associated_with::exocytosis in is_associated_with::adipocytes, is_associated_with::chromaffin cells of the is_associated_with::adrenal gland and is_associated_with::beta cells in the pancreas. In the central nervous system, Doc2b contributes to the spontaneous release of is_associated_with::neurotransmitters, which was thought to be acting as a high-affinity Ca(2+) sensor for exocytosis of is_associated_with::synaptic vesicles However, further work has shown that while DOC2b is both important for spontaneous exocytosis of is_associated_with::synaptic vesicles and binds is_associated_with::Calcium, it does not in fact change the calcium dependence of spontaneous is_associated_with::synaptic vesicle release and thus can not be the calcium sensor for this process.