Molecular determinants of interactions between the N-terminal domain and the transmembrane core that modulate hERG K+ channel gating.

A conserved eag domain in the cytoplasmic amino terminus of the human ether-a-go-go-related gene (hERG) potassium channel is critical for its slow deactivation gating. Introduction of gene fragments encoding the eag domain are able to restore normal deactivation properties of channels from which mos...

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Main Authors: Jorge Fernández-Trillo, Francisco Barros, Angeles Machín, Luis Carretero, Pedro Domínguez, Pilar de la Peña
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3174182?pdf=render
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author Jorge Fernández-Trillo
Francisco Barros
Angeles Machín
Luis Carretero
Pedro Domínguez
Pilar de la Peña
author_facet Jorge Fernández-Trillo
Francisco Barros
Angeles Machín
Luis Carretero
Pedro Domínguez
Pilar de la Peña
author_sort Jorge Fernández-Trillo
collection DOAJ
description A conserved eag domain in the cytoplasmic amino terminus of the human ether-a-go-go-related gene (hERG) potassium channel is critical for its slow deactivation gating. Introduction of gene fragments encoding the eag domain are able to restore normal deactivation properties of channels from which most of the amino terminus has been deleted, and also those lacking exclusively the eag domain or carrying a single point mutation in the initial residues of the N-terminus. Deactivation slowing in the presence of the recombinant domain is not observed with channels carrying a specific Y542C point mutation in the S4-S5 linker. On the other hand, mutations in some initial positions of the recombinant fragment also impair its ability to restore normal deactivation. Fluorescence resonance energy transfer (FRET) analysis of fluorophore-tagged proteins under total internal reflection fluorescence (TIRF) conditions revealed a substantial level of FRET between the introduced N-terminal eag fragments and the eag domain-deleted channels expressed at the membrane, but not between the recombinant eag domain and full-length channels with an intact amino terminus. The FRET signals were also minimized when the recombinant eag fragments carried single point mutations in the initial portion of their amino end, and when Y542C mutated channels were used. These data suggest that the restoration of normal deactivation gating by the N-terminal recombinant eag fragment is an intrinsic effect of this domain directed by the interaction of its N-terminal segment with the gating machinery, likely at the level of the S4-S5 linker.
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spelling doaj.art-0cd719c081424fe2af7881d1474d5fc52022-12-21T17:31:17ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-0169e2467410.1371/journal.pone.0024674Molecular determinants of interactions between the N-terminal domain and the transmembrane core that modulate hERG K+ channel gating.Jorge Fernández-TrilloFrancisco BarrosAngeles MachínLuis CarreteroPedro DomínguezPilar de la PeñaA conserved eag domain in the cytoplasmic amino terminus of the human ether-a-go-go-related gene (hERG) potassium channel is critical for its slow deactivation gating. Introduction of gene fragments encoding the eag domain are able to restore normal deactivation properties of channels from which most of the amino terminus has been deleted, and also those lacking exclusively the eag domain or carrying a single point mutation in the initial residues of the N-terminus. Deactivation slowing in the presence of the recombinant domain is not observed with channels carrying a specific Y542C point mutation in the S4-S5 linker. On the other hand, mutations in some initial positions of the recombinant fragment also impair its ability to restore normal deactivation. Fluorescence resonance energy transfer (FRET) analysis of fluorophore-tagged proteins under total internal reflection fluorescence (TIRF) conditions revealed a substantial level of FRET between the introduced N-terminal eag fragments and the eag domain-deleted channels expressed at the membrane, but not between the recombinant eag domain and full-length channels with an intact amino terminus. The FRET signals were also minimized when the recombinant eag fragments carried single point mutations in the initial portion of their amino end, and when Y542C mutated channels were used. These data suggest that the restoration of normal deactivation gating by the N-terminal recombinant eag fragment is an intrinsic effect of this domain directed by the interaction of its N-terminal segment with the gating machinery, likely at the level of the S4-S5 linker.http://europepmc.org/articles/PMC3174182?pdf=render
spellingShingle Jorge Fernández-Trillo
Francisco Barros
Angeles Machín
Luis Carretero
Pedro Domínguez
Pilar de la Peña
Molecular determinants of interactions between the N-terminal domain and the transmembrane core that modulate hERG K+ channel gating.
PLoS ONE
title Molecular determinants of interactions between the N-terminal domain and the transmembrane core that modulate hERG K+ channel gating.
title_full Molecular determinants of interactions between the N-terminal domain and the transmembrane core that modulate hERG K+ channel gating.
title_fullStr Molecular determinants of interactions between the N-terminal domain and the transmembrane core that modulate hERG K+ channel gating.
title_full_unstemmed Molecular determinants of interactions between the N-terminal domain and the transmembrane core that modulate hERG K+ channel gating.
title_short Molecular determinants of interactions between the N-terminal domain and the transmembrane core that modulate hERG K+ channel gating.
title_sort molecular determinants of interactions between the n terminal domain and the transmembrane core that modulate herg k channel gating
url http://europepmc.org/articles/PMC3174182?pdf=render
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