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Dynamic rearrangement of the intrinsic ligand regulates KCNH potassium channels

KCNH voltage-gated potassium channels (EAG, ERG, and ELK) play significant roles in neuronal and cardiac excitability. They contain cyclic nucleotide-binding homology domains (CNBHDs) but are not directly regulated by cyclic nucleotides. Instead, the CNBHD ligand-binding cavity is occupied by an int...

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Detalles Bibliográficos
Autores principales: Dai, Gucan, James, Zachary M., Zagotta, William N.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Rockefeller University Press 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5881448/
https://www.ncbi.nlm.nih.gov/pubmed/29567795
http://dx.doi.org/10.1085/jgp.201711989
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author Dai, Gucan
James, Zachary M.
Zagotta, William N.
author_facet Dai, Gucan
James, Zachary M.
Zagotta, William N.
author_sort Dai, Gucan
collection PubMed
description KCNH voltage-gated potassium channels (EAG, ERG, and ELK) play significant roles in neuronal and cardiac excitability. They contain cyclic nucleotide-binding homology domains (CNBHDs) but are not directly regulated by cyclic nucleotides. Instead, the CNBHD ligand-binding cavity is occupied by an intrinsic ligand, which resides at the intersubunit interface between the N-terminal eag domain and the C-terminal CNBHD. We show that, in Danio rerio ELK channels, this intrinsic ligand is critical for voltage-dependent potentiation (VDP), a process in which channel opening is stabilized by prior depolarization. We demonstrate that an exogenous peptide corresponding to the intrinsic ligand can bind to and regulate zebrafish ELK channels. This exogenous intrinsic ligand inhibits the channels before VDP and potentiates the channels after VDP. Furthermore, using transition metal ion fluorescence resonance energy transfer and a fluorescent noncanonical amino acid L-Anap, we show that there is a rearrangement of the intrinsic ligand relative to the CNBHD during VDP. We propose that the intrinsic ligand switches from antagonist to agonist as a result of a rearrangement of the eag domain–CNBHD interaction during VDP.
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spelling pubmed-58814482018-10-02 Dynamic rearrangement of the intrinsic ligand regulates KCNH potassium channels Dai, Gucan James, Zachary M. Zagotta, William N. J Gen Physiol Research Articles KCNH voltage-gated potassium channels (EAG, ERG, and ELK) play significant roles in neuronal and cardiac excitability. They contain cyclic nucleotide-binding homology domains (CNBHDs) but are not directly regulated by cyclic nucleotides. Instead, the CNBHD ligand-binding cavity is occupied by an intrinsic ligand, which resides at the intersubunit interface between the N-terminal eag domain and the C-terminal CNBHD. We show that, in Danio rerio ELK channels, this intrinsic ligand is critical for voltage-dependent potentiation (VDP), a process in which channel opening is stabilized by prior depolarization. We demonstrate that an exogenous peptide corresponding to the intrinsic ligand can bind to and regulate zebrafish ELK channels. This exogenous intrinsic ligand inhibits the channels before VDP and potentiates the channels after VDP. Furthermore, using transition metal ion fluorescence resonance energy transfer and a fluorescent noncanonical amino acid L-Anap, we show that there is a rearrangement of the intrinsic ligand relative to the CNBHD during VDP. We propose that the intrinsic ligand switches from antagonist to agonist as a result of a rearrangement of the eag domain–CNBHD interaction during VDP. Rockefeller University Press 2018-04-02 /pmc/articles/PMC5881448/ /pubmed/29567795 http://dx.doi.org/10.1085/jgp.201711989 Text en © Dai et al. http://www.rupress.org/termshttps://creativecommons.org/licenses/by-nc-sa/4.0/This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms (http://www.rupress.org/terms/) ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 International license, as described at https://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Research Articles
Dai, Gucan
James, Zachary M.
Zagotta, William N.
Dynamic rearrangement of the intrinsic ligand regulates KCNH potassium channels
title Dynamic rearrangement of the intrinsic ligand regulates KCNH potassium channels
title_full Dynamic rearrangement of the intrinsic ligand regulates KCNH potassium channels
title_fullStr Dynamic rearrangement of the intrinsic ligand regulates KCNH potassium channels
title_full_unstemmed Dynamic rearrangement of the intrinsic ligand regulates KCNH potassium channels
title_short Dynamic rearrangement of the intrinsic ligand regulates KCNH potassium channels
title_sort dynamic rearrangement of the intrinsic ligand regulates kcnh potassium channels
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5881448/
https://www.ncbi.nlm.nih.gov/pubmed/29567795
http://dx.doi.org/10.1085/jgp.201711989
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