SNAREs are transmembrane proteins involved in catalysing membrane fusion events in cells. There are two types of SNARE protein, v-SNARE and t-SNARE. The v-SNARE is attatched to the membrane of the vesicle to be released. The t-SNARE is integrated into the target organelles membrane. The v-SNARE's have complimentary shaped t-SNAREs which they bind to.
SNARE proteins (Soluble N-ethymaleimide- sensitive –factor attachment proteins) catalyse membrane fusion events within the cell by bringing together cell membranes and organelle membranes. This process allows for efficient transport of substances within membrane vesicles.
SNAREs are present in organelle membranes and vesicles. They exist in complementary pairs of a t-SNARE (target membrane SNARE) on the membrane and a v-SNARE ( ) on the vesicle. The specific v-SNARE on the vesicle recognises the correct t-SNARE and binds to it and in doing so the vesicle is directed to its correct location in the cell. SNARES provide an “extra layer of specificity” to ensure efficient intracellular trafficking.
Once the SNAREs are bound to each other a SNARE complex is formed in which the helical domains of the t and v SNAREs anchor the vesicle and the plasma membrane together. The v-SNARE consists of just one protein where as the t-SNARE consists of two or three and it is these proteins which bind together forming the four helix bundle.