The Doc2 (double C2) family consists of two isoforms (Doc2α and Doc2β) characterized by an N-terminal Munc13-1 interacting domain (Mid) and two C2 domains that interact with Ca2+ and phospholipid at the C-terminus. This Ca2+-binding property is thought to be important to the regulation of neurotransmitter release. In this paper, we report a third isoform of mouse Doc2, named Doc2γ. Doc2γ also contains a putative Mid domain and two C2 domains, and it is 45.6 and 43.2% identical to mouse Doc2α and Doc2β, respectively, at the amino acid level. In contrast to the other Doc2 isoforms, the C2 domains of Doc2γ impair Ca2+-dependent phospholipid binding activity. The highest expression of Doc2γ mRNA was found in the heart, but occurs ubiquitously, the same as Doc2β. These findings indicate that Doc2γ may also function as an effector for Munc13-1 and that it may be involved in the regulation of vesicular trafficking. (C) 2000 Academic Press.
|Number of pages
|Biochemical and Biophysical Research Communications
|Published - 2000 Sept 24
- C2 domain
- Phospholipid binding