1. Structural Biology and Molecular Biophysics
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Cryo-EM structures and functional characterization of the murine lipid scramblase TMEM16F

  1. Carolina Alvadia
  2. Novandy K Lim
  3. Vanessa Clerico Mosina
  4. Gert T Oostergetel
  5. Raimund Dutzler  Is a corresponding author
  6. Cristina Paulino  Is a corresponding author
  1. University of Zürich, Switzerland
  2. University of Groningen, Netherlands
Research Article
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Cite this article as: eLife 2019;8:e44365 doi: 10.7554/eLife.44365

Abstract

The lipid scramblase TMEM16F initiates blood coagulation by catalyzing the exposure of phosphatidylserine in platelets. The protein is part of a family of membrane proteins, which encompasses calcium-activated channels for ions and lipids. Here, we reveal features of murine TMEM16F (mTMEM16F) that underlie its function as a lipid scramblase and an ion channel. The cryo-EM data of mTMEM16F in absence and presence of Ca2+ define the ligand-free closed conformation of the protein and the structure of a Ca2+-bound intermediate. Both conformations resemble their counterparts of the scrambling-incompetent anion channel mTMEM16A, yet with distinct differences in the region of ion and lipid permeation. In conjunction with functional data, we demonstrate the relationship between ion conduction and lipid scrambling. Although activated by a common mechanism, both functions appear to be mediated by alternate protein conformations that are at equilibrium in the ligand-bound state.

Data availability

The three-dimensional cryo-EM density maps as well as the modelled coordinated will be deposited in the Electron Microscopy Data Bank and the Protein Data Bank, respectively. The deposition includes the cryo-EM maps, both half-maps, and the mask used for final FSC calculation. The raw data can be provided upon request.

The following data sets were generated

Article and author information

Author details

  1. Carolina Alvadia

    Department of Biochemistry, University of Zürich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8446-1098
  2. Novandy K Lim

    Department of Biochemistry, University of Zürich, Zürich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5098-929X
  3. Vanessa Clerico Mosina

    Department of Structural Biology, University of Groningen, Groningen, Netherlands
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8013-0144
  4. Gert T Oostergetel

    Department of Structural Biology, University of Groningen, Groningen, Netherlands
    Competing interests
    The authors declare that no competing interests exist.
  5. Raimund Dutzler

    Department of Biochemistry, University of Zürich, Zürich, Switzerland
    For correspondence
    dutzler@bioc.uzh.ch
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2193-6129
  6. Cristina Paulino

    Department of Structural Biology, University of Groningen, Groningen, Netherlands
    For correspondence
    c.paulino@rug.nl
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7017-109X

Funding

Nederlandse Organisatie voor Wetenschappelijk Onderzoek (740.018.016)

  • Cristina Paulino

H2020 European Research Council (339116)

  • Raimund Dutzler

H2020 European Research Council (AnoBest)

  • Raimund Dutzler

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

Reviewing Editor

  1. Kenton Jon Swartz, National Institute of Neurological Disorders and Stroke, National Institutes of Health, United States

Publication history

  1. Received: December 12, 2018
  2. Accepted: February 19, 2019
  3. Accepted Manuscript published: February 20, 2019 (version 1)
  4. Version of Record published: March 12, 2019 (version 2)

Copyright

© 2019, Alvadia 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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Further reading

  1. Edited by Kenton J Swartz et al.
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