@article{9804643ea31f4b6c914b4bf2d32838ec,
title = "Membrane bridging by munc13-1 is crucial for neurotransmitter release",
abstract = "Munc13-1 plays a crucial role in neurotransmitter release. We recently proposed that the C-terminal region encompassing the C1, C2B, MUN and C2C domains of Munc13-1 (C1C2BMUNC2C) bridges the synaptic vesicle and plasma membranes through interactions involving the C2C domain and the C1-C2B region. However, the physiological relevance of this model has not been demonstrated. Here we show that C1C2BMUNC2C bridges membranes through opposite ends of its elongated structure. Mutations in putative membrane-binding sites of the C2C domain disrupt the ability of C1C2BMUNC2C to bridge liposomes and to mediate liposome fusion in vitro. These mutations lead to corresponding disruptive effects on synaptic vesicle docking, priming, and Ca2+-triggered neurotransmitter release in mouse neurons. Remarkably, these effects include an almost complete abrogation of release by a single residue substitution in this 200 kDa protein. These results show that bridging the synaptic vesicle and plasma membranes is a central function of Munc13-1.",
author = "Bradley Quade and Marcial Camacho and Xiaowei Zhao and Marta Orlando and Thorsten Trimbuch and Junjie Xu and Wei Li and Daniela Nicastro and Christian Rosenmund and Josep Rizo",
note = "Funding Information: We thank, Miriam Petzold, Berit S{\"o}hl-Kielczynski, Sabine Lenz, Bettina Brokowski and Katja P{\"o}tschke for technical assistance, and the Charit{\'e} viral core facility for virus production and characterization. Cryo-ET data were collected at the University of Texas Southwestern Medical Center (UTSW) Cryo-Electron Microscopy (Cryo-EM) Facility that is funded in part by the CPRIT Core Facility Support Award RP170644. We thank Dr. Daniel Stoddard for training and maintenance of the UTSW Cryo-EM Facility. Electron micrographs of synapses were acquired at the Electron Microscopy Core Facility Campus Charit{\'e} Mitte. The Agilent DD2 console of the 800 MHz spectrometer used for the research presented here was purchased with a shared instrumentation grants from the NIH (S10OD018027 to JR). Bradley Quade was supported by NIH Training Grant T32 GM008297. This work was supported by grant I-1304 from the Welch Foundation (to JR), by NIH Research Project Award R35 NS097333 (to JR), by the Berlin Institute of Health (BIH) Stiftung Charite (to CR) and by the German Research Foundation (DFG) grants SFB958, SFB 1315 and Ro1296/7-1, 8–1 (to CR). Funding Information: National Institute of General Medical Sciences T32 GM008297 Bradley Quade Deutsche Forschungsgemeinschaft SFB958 Christian Rosenmund Deutsche Forschungsgemeinschaft SFB 1315 Christian Rosenmund Deutsche Forschungsgemeinschaft Ro1296/7-1 Christian Rosenmund Deutsche Forschungsgemeinschaft Ro1296/8-1 Christian Rosenmund Berlin Institute of Health Stiftung Charite Christian Rosenmund National Institute of Neurological Disorders and Stroke R35 NS097333 Josep Rizo Welch Foundation I-1304 Josep Rizo National Institutes of Health S10OD018027 Josep Rizo Publisher Copyright: {\textcopyright} Quade et al.",
year = "2019",
month = feb,
doi = "10.7554/eLife.42806",
language = "English (US)",
volume = "8",
journal = "eLife",
issn = "2050-084X",
publisher = "eLife Sciences Publications",
}