Membrane bridging by Munc13-1 is crucial for neurotransmitter release

  1. Bradley Quade
  2. Marcial Camacho
  3. Xiaowei Zhao
  4. Marta Orlando
  5. Thorsten Trimbuch
  6. Junjie Xu
  7. Wei Li
  8. Daniela Nicastro
  9. Christian Rosenmund  Is a corresponding author
  10. Josep Rizo  Is a corresponding author
  1. University of Texas Southwestern Medical Center, United States
  2. Charité-Universitätsmedizin Berlin, Germany

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.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files

Article and author information

Author details

  1. Bradley Quade

    Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Marcial Camacho

    Department of Neurophysiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2367-1259
  3. Xiaowei Zhao

    Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Marta Orlando

    Department of Neurophysiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
  5. Thorsten Trimbuch

    Department of Neurophysiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
  6. Junjie Xu

    Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Wei Li

    Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.
  8. Daniela Nicastro

    Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0122-7173
  9. Christian Rosenmund

    Institut für Neurophysiologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
    For correspondence
    christian.rosenmund@charite.de
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3905-2444
  10. Josep Rizo

    Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
    For correspondence
    Jose.Rizo-Rey@UTSouthwestern.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1773-8311

Funding

National Institute of Neurological Disorders and Stroke (R35 NS097333)

  • Josep Rizo

Welch Foundation (I-1304)

  • Josep Rizo

Deutsche Forschungsgemeinschaft (SFB958)

  • Christian Rosenmund

Deutsche Forschungsgemeinschaft (SFB 1315)

  • Christian Rosenmund

Deutsche Forschungsgemeinschaft (Ro1296/7-1)

  • Christian Rosenmund

Deutsche Forschungsgemeinschaft (8-1)

  • Christian Rosenmund

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Reinhard Jahn, Max Planck Institute for Biophysical Chemistry, Germany

Ethics

Animal experimentation: All animal experiments were conducted according to the rules of the Berlin state government agency for Health and Social Services and the animal welfare committees of Charité Medical University Berlin, Germany (license no. T 0220/09).

Version history

  1. Received: October 12, 2018
  2. Accepted: February 22, 2019
  3. Accepted Manuscript published: February 28, 2019 (version 1)
  4. Version of Record published: March 8, 2019 (version 2)

Copyright

© 2019, Quade et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Bradley Quade
  2. Marcial Camacho
  3. Xiaowei Zhao
  4. Marta Orlando
  5. Thorsten Trimbuch
  6. Junjie Xu
  7. Wei Li
  8. Daniela Nicastro
  9. Christian Rosenmund
  10. Josep Rizo
(2019)
Membrane bridging by Munc13-1 is crucial for neurotransmitter release
eLife 8:e42806.
https://doi.org/10.7554/eLife.42806

Share this article

https://doi.org/10.7554/eLife.42806

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