title: Syntaxin requirement for Ca2+-triggered exocytosis in neurons and endocrine cells demonstrated with an engineered neurotoxin.
abstract: Botulinum neurotoxins cleave synaptic SNAREs and block exocytosis, demonstrating that these proteins function in neurosecretion. However, the function of the SNARE syntaxin remains less clear because no neurotoxin cleaves it selectively. Starting with a botulinum neurotoxin that cleaves both syntaxin and SNAP-25, we engineered a version that retains activity against syntaxin but spares SNAP-25. These mutants block synaptic release in neurons and norepinephrine release in neuroendocrine cells, thus establishing an essential role for syntaxin in Ca2+-triggered exocytosis. These mutants can generate syntaxin-free cells as a useful experimental system for research and may lead to pharmaceuticals that target syntaxin selectively.
authors.affiliation: Department of Neuroscience, University of Wisconsin, Madison, Wisconsin 53706-1510, United States.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Wang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Dong
authors.forename: Shihu
authors.initials: S
authors.lastname: Sun
authors.forename: Edwin R
authors.initials: ER
authors.lastname: Chapman
authors.forename: Meyer B
authors.initials: MB
authors.lastname: Jackson
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001905:Botulinum Toxins / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D020134:Catalytic Domain; D002478:Cells, Cultured; D005089:Exocytosis / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D008564:Membrane Potentials; D008958:Models, Molecular; D009154:Mutation; D055099:Neuroendocrine Cells / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism* / Q000502:physiology; D009498:Neurotoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D016716:PC12 Cells; D018408:Patch-Clamp Techniques; D011485:Protein Binding; D015202:Protein Engineering; D017434:Protein Structure, Tertiary; D050765:Qa-SNARE Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D050825:Synaptosomal-Associated Protein 25 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D009498:Neurotoxins; D050765:Qa-SNARE Proteins; C494210:Snap25 protein, rat; D050825:Synaptosomal-Associated Protein 25; D001905:Botulinum Toxins; D002118:Calcium; D009638:Norepinephrine