| Primary Identifier | IPR037303 | Type | Domain |
| Short Name | SLP-4/5_C2A |
| description | Synaptotagmin-like proteins (Slps) contain a N-terminal RabBD (Rab-binding) domain and two C-terminal C2 domains, C2A and C2B []. The characteristic feature of the Slp family is the N-terminal domain (referred to as SHD for Slp Homology Domain), which is not found in other C-type tandem C2 proteins []. SHD functions as a specific Rab27A/B-binding domain []. The C2B domain of Slp4 (also known as Granuphilin) interact with the plasma membrane lipid phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P2][]. 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 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 andintersectin 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 [, , , , , , , ]. |
