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Redox regulation of K(V)7 channels through EF3 hand of calmodulin
Neuronal K(V)7 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 betw...
Autores principales: | , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
eLife Sciences Publications, Ltd
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9988260/ https://www.ncbi.nlm.nih.gov/pubmed/36803414 http://dx.doi.org/10.7554/eLife.81961 |
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author | Nuñez, Eider Jones, Frederick Muguruza-Montero, Arantza Urrutia, Janire Aguado, Alejandra Malo, Covadonga Bernardo-Seisdedos, Ganeko Domene, Carmen Millet, Oscar Gamper, Nikita Villarroel, Alvaro |
author_facet | Nuñez, Eider Jones, Frederick Muguruza-Montero, Arantza Urrutia, Janire Aguado, Alejandra Malo, Covadonga Bernardo-Seisdedos, Ganeko Domene, Carmen Millet, Oscar Gamper, Nikita Villarroel, Alvaro |
author_sort | Nuñez, Eider |
collection | PubMed |
description | Neuronal K(V)7 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 Ca(2+)-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 Ca(2+) binding to the EF3 hand, but not to EF1, EF2, or EF4 hands, abolishes oxidation-induced enhancement of K(V)7.4 currents. Monitoring FRET (Fluorescence Resonance Energy Transfer) between helices A and B using purified CRDs tagged with fluorescent proteins, we observed that S2S3 peptides cause a reversal of the signal in the presence of Ca(2+) but have no effect in the absence of this cation or if the peptide is oxidized. The capacity of loading EF3 with Ca(2+) is essential for this reversal of the FRET signal, whereas the consequences of obliterating Ca(2+) binding to EF1, EF2, or EF4 are negligible. Furthermore, we show that EF3 is critical for translating Ca(2+) signals to reorient the AB fork. Our data are consistent with the proposal that oxidation of cysteine residues in the S2S3 loop relieves K(V)7 channels from a constitutive inhibition imposed by interactions between the EF3 hand of CaM which is crucial for this signaling. |
format | Online Article Text |
id | pubmed-9988260 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | eLife Sciences Publications, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-99882602023-03-07 Redox regulation of K(V)7 channels through EF3 hand of calmodulin Nuñez, Eider Jones, Frederick Muguruza-Montero, Arantza Urrutia, Janire Aguado, Alejandra Malo, Covadonga Bernardo-Seisdedos, Ganeko Domene, Carmen Millet, Oscar Gamper, Nikita Villarroel, Alvaro eLife Neuroscience Neuronal K(V)7 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 Ca(2+)-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 Ca(2+) binding to the EF3 hand, but not to EF1, EF2, or EF4 hands, abolishes oxidation-induced enhancement of K(V)7.4 currents. Monitoring FRET (Fluorescence Resonance Energy Transfer) between helices A and B using purified CRDs tagged with fluorescent proteins, we observed that S2S3 peptides cause a reversal of the signal in the presence of Ca(2+) but have no effect in the absence of this cation or if the peptide is oxidized. The capacity of loading EF3 with Ca(2+) is essential for this reversal of the FRET signal, whereas the consequences of obliterating Ca(2+) binding to EF1, EF2, or EF4 are negligible. Furthermore, we show that EF3 is critical for translating Ca(2+) signals to reorient the AB fork. Our data are consistent with the proposal that oxidation of cysteine residues in the S2S3 loop relieves K(V)7 channels from a constitutive inhibition imposed by interactions between the EF3 hand of CaM which is crucial for this signaling. eLife Sciences Publications, Ltd 2023-02-20 /pmc/articles/PMC9988260/ /pubmed/36803414 http://dx.doi.org/10.7554/eLife.81961 Text en © 2023, Nuñez et al https://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited. |
spellingShingle | Neuroscience Nuñez, Eider Jones, Frederick Muguruza-Montero, Arantza Urrutia, Janire Aguado, Alejandra Malo, Covadonga Bernardo-Seisdedos, Ganeko Domene, Carmen Millet, Oscar Gamper, Nikita Villarroel, Alvaro Redox regulation of K(V)7 channels through EF3 hand of calmodulin |
title | Redox regulation of K(V)7 channels through EF3 hand of calmodulin |
title_full | Redox regulation of K(V)7 channels through EF3 hand of calmodulin |
title_fullStr | Redox regulation of K(V)7 channels through EF3 hand of calmodulin |
title_full_unstemmed | Redox regulation of K(V)7 channels through EF3 hand of calmodulin |
title_short | Redox regulation of K(V)7 channels through EF3 hand of calmodulin |
title_sort | redox regulation of k(v)7 channels through ef3 hand of calmodulin |
topic | Neuroscience |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9988260/ https://www.ncbi.nlm.nih.gov/pubmed/36803414 http://dx.doi.org/10.7554/eLife.81961 |
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