Syntaxin Binding Protein 6 (STXBP6)

The deduced 222-amino acid protein has a calculated molecular mass of about 25 kD. STXBP6 contains a unique N terminus and a C-terminal tomosyn-like coiled-coil domain. Unlike other SNAREs of the VAMP family, it lacks a hydrophobic stretch that could serve as a transmembrane anchor. The coiled-coil domain of STXBP6 shares 37% and 31% amino acid identity with those of tomosyn and VAMP8, respectively. Northern blot analysis detected highest expression of a 4.0-kb transcript in brain and heart. Western blot analysis of rat tissues showed that Stxbp6 migrated with an apparent molecular mass of about 24 kD. Highest protein levels were detected in brain, with lower levels in heart, adrenal gland, testis, liver, and kidney. Stxbp6 showed strong expression in all specific human brain regions examined.