Cloning of SNAP-23, its tissue distribution and subcellular localization in non-neural cells

grantor: University of TorontoCorrect targeting of proteins to specific cellular compartments is thought to occur via transport vesicles. A current hypothesis proposes that in the nervous system, targeting specificity of synaptic vesicles is achieved by interaction of a vesicle protein (VAMP) and presynaptic plasma membrane proteins (syntaxin and SNAP-25). VAMP and syntaxin isoforms have been identified outside the nervous system, but SNAP-25 expression is restricted to neural and neuroendocrine cells. I hypothesized that functional equivalent(s) of SNAP-25 must exist in non-neural cells to allow intracellular traffic. This Thesis describes the search for a non-neural equivalent of SNAP-25, SNAP-23, by screening a melanoma cDNA library. cDNA clones were isolated, sequenced, and fusion proteins were expressed. With a specific antibody, SNAP-23 was detected in all non-neural tissues and cell lines examined. Subcellular fractionation of 3T3-L1 adipocytes suggested that SNAP-23 was predominantly found at the plasma membrane.M.Sc