InterPro domain: IPR000727

The process of vesicular fusion with target membranes depends on a set of SNAREs (SNAP-Receptors), which are associated with the fusing membranes [ 1 , 2 ]. These proteins are classified as v-SNAREs and t-SNAREs based on their localisation on vesicle or target membrane while another classification scheme defines R-SNAREs and Q-SNAREs, as based on the conserved arginine or glutamine residue in the centre of the SNARE motif [ 3 ]. Target SNAREs (t-SNAREs) are localised on the target membrane and belong to two different families, the syntaxin-like family and the SNAP-25 like family. One member of each family, together with a v-SNARE localised on the vesicular membrane, are required for fusion.

The N- and C-terminal coiled-coil domains of members of the SNAP-25 family and the most C-terminal coiled-coil domain of the syntaxin family are related to each other and form a new homology domain of approximately 60 amino acids. This domain is also found in other known proteins involved in vesicular membrane traffic, some of which belong to different protein families [ 4 ].

1. Immunocytochemical localization of synaptic proteins at vesicular organelles in PC12 cells. Neurochem. Res. 22, 941-50
2. Neurotransmitter release - four years of SNARE complexes. Curr. Opin. Neurobiol. 7, 310-5
3. Conserved structural features of the synaptic fusion complex: SNARE proteins reclassified as Q- and R-SNAREs. Proc. Natl. Acad. Sci. U.S.A. 95, 15781-6
4. A conserved domain is present in different families of vesicular fusion proteins: a new superfamily. Proc. Natl. Acad. Sci. U.S.A. 94, 3046-51