1. Neuroscience
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Distinct modes of endocytotic presynaptic membrane and protein uptake at the calyx of Held terminal of rats and mice

  1. Yuji Okamoto
  2. Noa Lipstein
  3. Yunfeng Hua
  4. Kun-Han Lin
  5. Nils Brose
  6. Takeshi Sakaba
  7. Mitsuharu Midorikawa  Is a corresponding author
  1. Doshisha University, Japan
  2. Max Planck Institute of Experimental Medicine, Germany
  3. Max Planck Institute of Brain Research, Germany
  4. Max-Planck-Institute for Biophysical Chemistry, Germany
Research Article
  • Cited 13
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Cite this article as: eLife 2016;5:e14643 doi: 10.7554/eLife.14643

Abstract

Neurotransmitter is released at synapses by fusion of synaptic vesicles with the plasma membrane. To sustain synaptic transmission, compensatory retrieval of membranes and vesicular proteins is essential. We combined capacitance measurements and pH-imaging via pH-sensitive vesicular protein marker (anti-synaptotagmin2-cypHer5E), and compared the retrieval kinetics of membranes and vesicular proteins at the calyx of Held synapse. Membrane and Syt2 were retrieved with a similar time course when slow endocytosis was elicited. When fast endocytosis was elicited, Syt2 was still retrieved together with the membrane, but endocytosed organelle re-acidification was slowed down, which provides strong evidence for two distinct endocytotic pathways. Strikingly, CaM inhibitors or the inhibition of the Ca2+-calmodulin-Munc13-1 signaling pathway only impaired the uptake of Syt2 while leaving membrane retrieval intact, indicating different recycling mechanisms for membranes and vesicle proteins. Our data identify a novel mechanism of stimulus- and Ca2+-dependent regulation of coordinated endocytosis of synaptic membranes and vesicle proteins.

Article and author information

Author details

  1. Yuji Okamoto

    Graduate School of Brain Science, Doshisha University, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.
  2. Noa Lipstein

    Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.
  3. Yunfeng Hua

    Department of Connectomics, Max Planck Institute of Brain Research, Frankfurt, Germany
    Competing interests
    The authors declare that no competing interests exist.
  4. Kun-Han Lin

    Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.
  5. Nils Brose

    Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.
  6. Takeshi Sakaba

    Graduate School of Brain Science, Doshisha University, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.
  7. Mitsuharu Midorikawa

    Graduate School of Brain Science, Doshisha University, Kyoto, Japan
    For correspondence
    mmidorik@mail.doshisha.ac.jp
    Competing interests
    The authors declare that no competing interests exist.

Ethics

Animal experimentation: Animal care and animal procedures were conducted in accordance with the guidelines of the Physiological Society of Japan, and were approved by the Doshisha University Committee for Regulation on the Conduct of Animal Experiments and Related Activities. All efforts were taken to minimize animal numbers. The generation, maintenance, and use of the Munc13-1W464R mice were approved by the responsible local government organization (Niedersächsisches Landesamt für Verbraucherschutz und Lebensmittelsicherheit, permissions 33.9.42502-04-13/1359 and 33.19-42502-04-15/1817).

Reviewing Editor

  1. Christian Rosenmund, Charité, Universitätsmedizin Berlin, Germany

Publication history

  1. Received: January 22, 2016
  2. Accepted: May 6, 2016
  3. Accepted Manuscript published: May 7, 2016 (version 1)
  4. Version of Record published: June 29, 2016 (version 2)

Copyright

© 2016, Okamoto 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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