The role of Syntaxin-1 in vesicle docking, -priming and neurotransmitter release at central synapses
Final Report Abstract
The synaptic protein Syntaxin1 is critically involved in synaptic transmission, regulated secretion and in additional, yet unknown cell biological processes that are essential for survival of neurons. Still, many aspects of its function, in particularly in mammalian neurons are poorly understood as viable experimental model were lacking. We recently created a Syntaxin1a/1b double knockout model that has allowed us in the realm of this project to gain insights in the function of Syntaxin1 and its putative interaction partner. A major focus of our approach is based on structure function analyses allowing us to examine the role of Syntaxin domains and individual amino acids in the various functions of syntaxin1, by applying a gain of function rescue approach: We established cultures from central neurons of newborn conditional Stx1 DKO mice, removed the endogenous Stx1 protein by lentiviral cre-expression and reexpressed Stx1 variants using lentiviral expression approaches. Comparing wildtype variants with mutant variants that allows us to study various aspects of Stx1 function at the level of function, morphology, ultrastructure, biochemistry and other cell biological assays. Perhaps the most important assay is based on patch clamp electrophysiology from single autaptic neurons to gain insights in Stx1 function. In addition to a structure and hypothesis driven approaches, we also used our knockout-rescue approach to study Syntaxin1 mutations that are associated with neurological disorders, using human genetics as a basis for identifying functionally critical regions of Stx1, and characterized the pathophysiological mechanisms associated with these mutations. Based on these studies, we made significant progress in understanding how Syntaxin1 contributes to the synaptic vesicle fusion process.
Publications
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Membrane bridging by Munc13-1 is crucial for neurotransmitter release. eLife, 8.
Quade, Bradley; Camacho, Marcial; Zhao, Xiaowei; Orlando, Marta; Trimbuch, Thorsten; Xu, Junjie; Li, Wei; Nicastro, Daniela; Rosenmund, Christian & Rizo, Josep
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Epilepsy-causing STX1B mutations translate altered protein functions into distinct phenotypes in mouse neurons. Brain, 143(7), 2119-2138.
Vardar, Gülçin; Gerth, Fabian; Schmitt, Xiao Jakob; Rautenstrauch, Pia; Trimbuch, Thorsten; Schubert, Julian; Lerche, Holger; Rosenmund, Christian & Freund, Christian
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Reexamination of N-terminal domains of syntaxin-1 in vesicle fusion from central murine synapses. eLife, 10.
Vardar, Gülçin; Salazar-Lázaro, Andrea; Brockmann, Marisa; Weber-Boyvat, Marion; Zobel, Sina; Kumbol, Victor Wumbor-Apin; Trimbuch, Thorsten & Rosenmund, Christian
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Syntaxin-1A modulates vesicle fusion in mammalian neurons via juxtamembrane domain dependent palmitoylation of its transmembrane domain. eLife, 11.
Vardar, Gülçin; Salazar-Lázaro, Andrea; Zobel, Sina; Trimbuch, Thorsten & Rosenmund, Christian
