| Interacting Domains ↕ | CD ↕ Accession (External Link) | Description ↕ |
|---|
Syntaxin | pfam00804 | Syntaxin. Syntaxins are the prototype family of SNARE proteins. They usually consist of three main regions - a C-terminal transmembrane region, a central SNARE domain which is characteristic of and conserved in all syntaxins (pfam05739), and an N-terminal domain that is featured in this entry. This domain varies between syntaxin isoforms; in syntaxin 1A it is found as three alpha-helices with a left-handed twist. It may fold back on the SNARE domain to allow the molecule to adopt a 'closed' configuration that prevents formation of the core fusion complex - it thus has an auto-inhibitory role. The function of syntaxins is determined by their localisation. They are involved in neuronal exocytosis, ER-Golgi transport and Golgi-endosome transport, for example. They also interact with other proteins as well as those involved in SNARE complexes. These include vesicle coat proteins, Rab GTPases, and tethering factors. | SNAP-25 | pfam00835 | SNAP-25 family. SNAP-25 (synaptosome-associated protein 25 kDa) proteins are components of SNARE complexes. Members of this family contain a cluster of cysteine residues that can be palmitoylated for membrane attachment. | Synaptobrevin | pfam00957 | Synaptobrevin. | Synaphin | pfam05835 | Synaphin protein. This family consists of several eukaryotic synaphin 1 and 2 proteins. Synaphin/complexin is a cytosolic protein that preferentially binds to syntaxin within the SNARE complex. Synaphin promotes SNAREs to form precomplexes that oligomerise into higher order structures. A peptide from the central, syntaxin binding domain of synaphin competitively inhibits these two proteins from interacting and prevents SNARE complexes from oligomerising. It is thought that oligomerisation of SNARE complexes into a higher order structure creates a SNARE scaffold for efficient, regulated fusion of synaptic vesicles. Synaphin promotes neuronal exocytosis by promoting interaction between the complementary syntaxin and synaptobrevin transmembrane regions that reside in opposing membranes prior to fusion. | Sec1 | pfam00995 | Proteins involved in synaptic transmission and general secretion, Sec1 family [Intracellular trafficking and secretion] | V-SNARE | pfam05008 | Vesicle transport v-SNARE protein N-terminus. V-SNARE proteins are required for protein traffic between eukaryotic organelles. The v-SNAREs on transport vesicles interact with t-SNAREs on target membranes in order to facilitate this. This domain is the N-terminal half of the V-Snare proteins. |
