SYNDET IS A NOVEL SNAP-25 RELATED PROTEIN EXPRESSED IN MANY TISSUES

SNAP-25 is a synaptosomal associated protein localized at the plasma m embrane of nerve terminals, SNAP-25 associates with syntaxin 1 and ves icle-associated membrane protein-2 (VAMP-2) and is thought to form a c omplex essential for neurotransmitter release, We have identified synd et, a novel protein related to the family of SNAP-25 isoforms, Like SN AP-25, syndet has regions with high probability of forming coiled coil s, a cysteine rich-domain, and lacks a signal sequence or transmembran e domains, Syndet is tightly bound to membranes, possibly by acylation within the cysteine-rich domain, Syndet is expressed in non-neuronal tissues. In adipocytes, syndet is found at the plasma membrane and in an intracellular compartment. The identification of syndet supports th e hypothesis that multiple SNAP-25 related proteins ensure specificity of vesicle fusion at the cell surface.