Syntaxins were originally thought to be docking proteins, but have more recently been categorized as anchoring proteins that anchor themselves to the cytoplasmic surfaces of cellular membranes. Syntaxins bind to various proteins involved in exocytosis, including VAMPs (vesicle-associated membrane proteins), NSF (N-ethylmaleimide-sensitive factor), SNAPs (soluble NSF attachment proteins) and Synaptotagmin. Endobrevin, also designated VAMP-8 or ED, is a 100 amino acid single-pass type IV membrane protein that belongs to the synaptobrevin family. Similar in sequence to the synaptobrevins, endobrevin is abundantly expressed in kidney, moderately expressed in heart and spleen, and slightly expressed in brain, thymus and liver. Endobrevin interacts specifically with the SNAPs, most likely through an endobrevin-containing SNARE complex.