Vesicle Trafficking: SNARE Domain

The rat synaptic fusion complex comprising Syntaxin-1A (red), Synaptobrevin-II (blue) and SNAP-25B (green).

Domain Binding and Function

The mechanism by which a vesicle fuses with a specific membrane target appears to involve a highly conserved set of proteins called SNAREs (Soluble NSF Attachment protein [SNAP] Receptors). SNARE proteins are thought to mediate most or possibly all cellular membrane fusion events. Most SNAREs are C-terminally anchored integral membrane proteins capable of entering into a coiled-coil interaction with other SNARE proteins. The SNARE domain is a homologous domain of approximately 60 amino acids common to all SNARE proteins. The SNARE domain acts as a protein-protein interaction module in the assembly of a SNARE protein complex. The largely unstructured, monomeric SNARE motifs assemble into a protease resistant core complex. Different SNARE family members are distributed on distinct membranes throughout the cell, suggesting they may play a role in targeting during vesicular transport. However, the formation of SNARE core complexes appears to be rather promiscuous with little specificity.

Structure Reference

  1. Sutton, R.B. et al. (1998) Nature 395(6700), 347–353.

Examples of Domain Proteins

Vesicle Trafficking: SNARE Domain

Binding Examples

SNARE complexes SNARE domain proteins in complexes
Rat Synaptic Fusion SNARE Complex Syntaxin-1A (Sx), Synaptobrevin-II (Sb), SNAP-25B
Yeast Exocytic post-Golgi SNARE Complex Snc2, Sso1, Sec9
Rat Endosomal SNARE Complex Syntaxin-7, Vti 1b, Syntaxin 8