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Identification of a Munc13-sensitive step in chromaffin cell large dense-core vesicle exocytosis

  1. Kwun-nok Mimi Man
  2. Cordelia Imig
  3. Alexander Matthias Walter
  4. Paulo S Pinheiro
  5. David R Stevens
  6. Jens Rettig
  7. Jakob B Sørensen
  8. Benjamin H Cooper
  9. Nils Brose
  10. Sonja M Wojcik  Is a corresponding author
  1. Max-Planck-Institut fuer Experimentelle Medizin, Germany
  2. Leibniz-Institute for Molecular Pharmacology, Germany
  3. University of Copenhagen, Denmark
  4. Saarland University, Germany
Research Article
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Cite this article as: eLife 2015;4:e10635 doi: 10.7554/eLife.10635

Abstract

It is currently unknown whether the molecular steps of large dense-core vesicle (LDCV) docking and priming are identical to the corresponding reactions in synaptic vesicle (SV) exocytosis. Munc13s are essential for SV docking and priming, and we systematically analyzed their role in LDCV exocytosis using chromaffin cells lacking individual isoforms. We show that particularly Munc13-2 plays a fundamental role in LDCV exocytosis, but in contrast to synapses lacking Munc13s, the corresponding chromaffin cells do not exhibit a vesicle docking defect. We further demonstrate that ubMunc13-2 and Munc13-1 confer Ca2+-dependent LDCV priming with similar affinities, but distinct kinetics. Using a mathematical model, we identify an early LDCV priming step that is strongly dependent upon Munc13s. Our data demonstrate that the molecular steps of SV and LDCV priming are very similar while SV and LDCV docking mechanisms are distinct.

Article and author information

Author details

  1. Kwun-nok Mimi Man

    Department of Molecular Neurobiology, Max-Planck-Institut fuer Experimentelle Medizin, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.
  2. Cordelia Imig

    Department of Molecular Neurobiology, Max-Planck-Institut fuer Experimentelle Medizin, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.
  3. Alexander Matthias Walter

    Leibniz-Institute for Molecular Pharmacology, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
  4. Paulo S Pinheiro

    Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, Lundbeck Foundation Center for Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
    Competing interests
    The authors declare that no competing interests exist.
  5. David R Stevens

    Department of Physiology, Saarland University, Homburg, Germany
    Competing interests
    The authors declare that no competing interests exist.
  6. Jens Rettig

    Department of Physiology, Saarland University, Homburg, Germany
    Competing interests
    The authors declare that no competing interests exist.
  7. Jakob B Sørensen

    Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, Lundbeck Foundation Center for Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
    Competing interests
    The authors declare that no competing interests exist.
  8. Benjamin H Cooper

    Department of Molecular Neurobiology, Max-Planck-Institut fuer Experimentelle Medizin, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.
  9. Nils Brose

    Department of Molecular Neurobiology, Max-Planck-Institut fuer Experimentelle Medizin, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.
  10. Sonja M Wojcik

    Department of Molecular Neurobiology, Max-Planck-Institut fuer Experimentelle Medizin, Göttingen, Germany
    For correspondence
    wojcik@em.mpg.de
    Competing interests
    The authors declare that no competing interests exist.

Ethics

Animal experimentation: All experiments were performed in compliance with the regulations of the local Animal Care and Use Committee of Lower Saxony, Oldenburg, Germany.

Reviewing Editor

  1. Axel T Brunger, Stanford University, United States

Publication history

  1. Received: August 5, 2015
  2. Accepted: November 16, 2015
  3. Accepted Manuscript published: November 17, 2015 (version 1)
  4. Version of Record published: March 8, 2016 (version 2)

Copyright

© 2015, Man 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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