Snare specific antibodies reveal distinct patterns of snare expression in the mammalian brain

grantor: University of TorontoNeuronal populations of the mammalian central nervous system display variations in the rate of neurotransmitter release. The SNARE hypothesis proposes that synaptic vesicle release is mediated through the formation of a protein complex composed of syntaxin, SNAP-25, and VAMP. In this thesis I hypothesize that SNARE isoforms are differentially expressed or post-translationally modified within neuronal populations of the central nervous system. The distribution of these proteins may correspond with variations in neurotransmitter release. A SNAP-25 monoclonal antibody was received which was thought to recognize a post-translational modification on SNAP-25. By characterizing this antibody, I localized the epitope to 140 residues within the N-terminus of SNAP-25, and determined that it did not include a phosphate group added by PKC or palmitoylation of four internal cysteine residues. During this investigation, poylclonal antibodies that specifically recognize SNAP-25, syntaxin 2, and syntaxin 3 were generated and, in conjunction with antibodies for syntaxins 1, syntaxin 4, SNAP-25, SNAP-23, VAMPs 1-3, and synaptophysin, were characterized in rat brain. It was found that these SNAREs are differentially distributed in regions of the hippocampus and cerebellum. The distribution of syntaxin 4 was both distinct and overlapping with syntaxin 1 in regions of presynaptic terminals. SNAP-23 and syntaxin 3 expression was uniform throughout the brain, with distinct expression surrounding neuronal bodies.M.Sc