Double C2 protein, alpha/beta/gamma (IPR014638)

Short name: Doc2

Overlapping homologous superfamilies

Family relationships


Neurotransmitter release from nerve termini in the brain is regulated by several families of Ca2+-binding proteins with tandem C2 domains (IPR000008) [PMID: 8816702]. The C2 domain confers the ability to binding phospholipids in a Ca2+-dependent fashion.

Doc2 (double C2-like domain-containing protein) has one Munc13-interacting domain (Munc13 is a peripheral membrane protein in the plasma membrane of nerve termini). The interaction between Doc2 and Munc13-1 is thought to underlie the molecular mechanism of phorbol ester enhancement of neurotransmitter release [PMID: 10851170].

Doc2 consists of three isoforms, Doc2alpha, beta and gamma. Doc2alpha is specifically expressed in neuronal cells and has been implicated in Ca2+-dependent neurotransmitter release, whereas Doc2beta is ubiquitously expressed [PMID: 9804756, PMID: 7826360]. In contrast to the other Doc2 isoforms, the C2 domains of Doc2gamma lacks the Ca2+-dependent phospholipid binding activity. The highest expression of Doc2gamma mRNA is found in the heart, but occurs ubiquitously, the same as Doc2beta. Doc2gamma may also function as an effector for Munc13-1 and may be involved in the regulation of vesicular trafficking [PMID: 11027523].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.