Protein Domain : Tandem C2 domains nuclear protein, C2A domain IPR037786

Type	Domain
Description	Tac2-N (tandem C2 protein in nucleus) contains two C2 domains and a short C terminus including a WHXL motif, which are key in stabilizing transport vesicles to the plasma membrane by binding to a plasma membrane. However, unlike the usual carboxyl-terminal-type (C-type) tandem C2 proteins, it lacks a transmembrane domain, a Slp-homology domain, and a Munc13-1-interacting domain. Homology search analysis indicate that no known protein motifs are located in its N terminus, making Tac2-N a novel class of Ca2+-independent, C-type tandem C2 proteins [ ].C2 domains fold into an 8-standed β-sandwich that can adopt 2 structural arrangements: type I and type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions [ , ].This entry represents the first C2 domain of Tac2-N.
Short Name	C2A_Tac2-N