1. Cell Biology
  2. Neuroscience

Redox regulation of Kv7 channels through EF3 hand of calmodulin

  1. Eider Nuñez
  2. Frederick Jones
  3. Arantza Muguruza-Montero
  4. Janire Urrutia
  5. Alejandra Aguado
  6. Covadonga Malo
  7. Ganeko Bernardo-Seisdedos
  8. Carmen Domene
  9. Oscar Millet
  10. Nikita Gamper
  11. Alvaro Villarroel  Is a corresponding author
  1. Spanish National Research Council, Spain
  2. University of Leeds, United Kingdom
  3. Atlas Molecular Pharma SL, Spain
  4. University of Bath, United Kingdom
  5. CIC bioGUNE, Spain
https://doi.org/10.7554/eLife.81961
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  1. Eider Nuñez
  2. Frederick Jones
  3. Arantza Muguruza-Montero
  4. Janire Urrutia
  5. Alejandra Aguado
  6. Covadonga Malo
  7. Ganeko Bernardo-Seisdedos
  8. Carmen Domene
  9. Oscar Millet
  10. Nikita Gamper
  11. Alvaro Villarroel
(2023)
Redox regulation of Kv7 channels through EF3 hand of calmodulin
eLife 12:e81961.
https://doi.org/10.7554/eLife.81961
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Abstract

Neuronal KV7 channels, important regulators of cell excitability, are among the most sensitive proteins to reactive oxygen species. The S2S3 linker of the voltage sensor was reported as a site mediating redox modulation of the channels. Recent structural insights reveal potential interactions between this linker and the Ca2+-binding loop of the third EF-hand of calmodulin (CaM), which embraces an antiparallel fork formed by the C-terminal helices A and B, constituting the Calcium Responsive Domain (CRD). We found that precluding Ca2+ binding to the EF3 hand, but not to EF1, EF2 or EF4 hands, abolishes oxidation-induced enhancement of KV7.4 currents. Monitoring FRET between helices A and B using purified CRD domains tagged with fluorescent proteins, we observed that S2S3 peptides cause a reversal of the signal in the presence of Ca2+, but have no effect in the absence of this cation or if the peptide is oxidized. The capacity of loading EF3 with Ca2+ is essential for this reversal of the FRET signal, whereas the consequences of obliterating Ca2+ binding to EF1, EF2 or EF4 are negligible. Furthermore, we show that EF3 is critical for translating Ca2+ signals to reorient the AB fork. Our data is consistent with the proposal that oxidation of cysteine residues in the S2S3 loop relieves KV7 channels from a constitutive inhibition imposed by interactions between the EF3 hand of CaM which is crucial for this signaling.

Data availability

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

Article and author information

Author details

  1. Eider Nuñez

    Instituto Biofisika, Spanish National Research Council, Leioa, Spain
    Competing interests
    The authors declare that no competing interests exist.

  2. Frederick Jones

    Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.

  3. Arantza Muguruza-Montero

    Instituto Biofisika, Spanish National Research Council, Leioa, Spain
    Competing interests
    The authors declare that no competing interests exist.

  4. Janire Urrutia

    Instituto Biofisika, Spanish National Research Council, Leioa, Spain
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8546-292X

  5. Alejandra Aguado

    Instituto Biofisika, Spanish National Research Council, Leioa, Spain
    Competing interests
    The authors declare that no competing interests exist.

  6. Covadonga Malo

    Instituto Biofisika, Spanish National Research Council, Leioa, Spain
    Competing interests
    The authors declare that no competing interests exist.

  7. Ganeko Bernardo-Seisdedos

    Atlas Molecular Pharma SL, Derio, Spain
    Competing interests
    The authors declare that no competing interests exist.

  8. Carmen Domene

    Department of Chemistry, University of Bath, Bath, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.

  9. Oscar Millet

    Protein Stability and Inherited Disease Laboratory, CIC bioGUNE, Derio, Spain
    Competing interests
    The authors declare that no competing interests exist.

  10. Nikita Gamper

    Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5806-0207

  11. Alvaro Villarroel

    Instituto Biofisika, Spanish National Research Council, Leioa, Spain
    For correspondence
    alvaro.villarroel@csic.es
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1096-7824

Funding

Ministerio de Ciencia e Innovación (PID2021-128286NB-100)

  • Alvaro Villarroel

Eusko Jaurlaritza (PRE_2018-2_0082)

  • Eider Nuñez

Eusko Jaurlaritza (POS_2021_1_0017)

  • Eider Nuñez

Eusko Jaurlaritza (PRE_2018-2_0126)

  • Arantza Muguruza-Montero

Ministerio de Ciencia e Innovación (RTI2018‐097839-B-100)

  • Alvaro Villarroel

Ministerio de Ciencia e Innovación (RTI2018-101269-B-I00)

  • Oscar Millet

Wellcome Trust (212302/Z/18/Z)

  • Nikita Gamper

Medical Research Centre (MR/P015727/1)

  • Frederick Jones

Eusko Jaurlaritza (IT1707-22)

  • Alvaro Villarroel

Eusko Jaurlaritza (IT1165-19)

  • Alvaro Villarroel

Ekonomiaren Garapen eta Lehiakortasun Saila, Eusko Jaurlaritza (BG2019)

  • Alvaro Villarroel

Ekonomiaren Garapen eta Lehiakortasun Saila, Eusko Jaurlaritza (KK-2020/00110)

  • Alvaro Villarroel

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

Reviewing Editor

  1. Henry M Colecraft, Columbia University, United States

Version history

  1. Received: July 18, 2022
  2. Preprint posted: September 13, 2022 (view preprint)
  3. Accepted: February 10, 2023
  4. Accepted Manuscript published: February 20, 2023 (version 1)
  5. Version of Record published: March 6, 2023 (version 2)

Copyright

© 2023, Nuñez 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. Eider Nuñez
  2. Frederick Jones
  3. Arantza Muguruza-Montero
  4. Janire Urrutia
  5. Alejandra Aguado
  6. Covadonga Malo
  7. Ganeko Bernardo-Seisdedos
  8. Carmen Domene
  9. Oscar Millet
  10. Nikita Gamper
  11. Alvaro Villarroel
(2023)
Redox regulation of Kv7 channels through EF3 hand of calmodulin
eLife 12:e81961.
https://doi.org/10.7554/eLife.81961

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