1. Structural Biology and Molecular Biophysics
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The HCN domain couples voltage gating and cAMP response in Hyperpolarization-activated Cyclic Nucleotide-gated channels

  1. Alessandro Porro
  2. Andrea Saponaro
  3. Federica Gasparri
  4. Daniel Bauer
  5. Christine Gross
  6. Matteo Pisoni
  7. Gerardo Abbandonato
  8. Kay Hamacher
  9. Bina Santoro
  10. Gerhard Thiel
  11. Anna Moroni  Is a corresponding author
  1. University of Milan, Italy
  2. Technische Universität Darmstadt, Germany
  3. Columbia University, United States
Research Article
  • Cited 15
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Cite this article as: eLife 2019;8:e49672 doi: 10.7554/eLife.49672

Abstract

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control spontaneous electrical activity in heart and brain. Binding of cAMP to the cyclic nucleotide-binding domain (CNBD) facilitates channel opening by relieving a tonic inhibition exerted by the CNBD. Despite high resolution structures of the HCN1 channel in the cAMP bound and unbound states, the structural mechanism coupling ligand binding to channel gating is unknown. Here we show that the recently identified helical HCN-domain (HCND) mechanically couples the CNBD and channel voltage sensing domain (VSD), possibly acting as a sliding crank that converts the planar rotational movement of the CNBD into a rotational upward displacement of the VSD. This mode of operation and its impact on channel gating are confirmed by computational and experimental data showing that disruption of critical contacts between the three domains affects cAMP- and voltage-dependent gating in three HCN isoforms.

Data availability

All data analyzed during this study are included in the manuscript and supporting files. Source data files for LRT analysis and MD simulations have been deposited in Dyrad and are available at doi:10.5061/dryad.rn85375

The following data sets were generated

Article and author information

Author details

  1. Alessandro Porro

    Department of Biosciences, University of Milan, Milan, Italy
    Competing interests
    The authors declare that no competing interests exist.
  2. Andrea Saponaro

    Department of Biosciences, University of Milan, Milan, Italy
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5035-5174
  3. Federica Gasparri

    Department of Biosciences, University of Milan, Milan, Italy
    Competing interests
    The authors declare that no competing interests exist.
  4. Daniel Bauer

    Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
    Competing interests
    The authors declare that no competing interests exist.
  5. Christine Gross

    Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
    Competing interests
    The authors declare that no competing interests exist.
  6. Matteo Pisoni

    Department of Biosciences, University of Milan, Milan, Italy
    Competing interests
    The authors declare that no competing interests exist.
  7. Gerardo Abbandonato

    Department of Biosciences, University of Milan, Milan, Italy
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7247-051X
  8. Kay Hamacher

    Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
    Competing interests
    The authors declare that no competing interests exist.
  9. Bina Santoro

    Department of Neuroscience, Columbia University, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4277-1992
  10. Gerhard Thiel

    Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
    Competing interests
    The authors declare that no competing interests exist.
  11. Anna Moroni

    Department of Biosciences, University of Milan, Milan, Italy
    For correspondence
    anna.moroni@unimi.it
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1860-406X

Funding

Fondazione Cariplo (2014-0796)

  • Anna Moroni

H2020 European Research Council (ERC-2015-AdG 695078-noMAGIC)

  • Anna Moroni

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

Reviewing Editor

  1. László Csanády, Semmelweis University, Hungary

Publication history

  1. Received: June 25, 2019
  2. Accepted: November 22, 2019
  3. Accepted Manuscript published: November 26, 2019 (version 1)
  4. Version of Record published: December 5, 2019 (version 2)

Copyright

© 2019, Porro 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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