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Currents through Hv1 channels deplete protons in their vicinity

Proton channels have evolved to provide a pH regulatory mechanism, affording the extrusion of protons from the cytoplasm at all membrane potentials. Previous evidence has suggested that channel-mediated acid extrusion could significantly change the local concentration of protons in the vicinity of t...

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Detalles Bibliográficos
Autores principales: De-la-Rosa, Víctor, Suárez-Delgado, Esteban, Rangel-Yescas, Gisela E., Islas, León D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4727945/
https://www.ncbi.nlm.nih.gov/pubmed/26809792
http://dx.doi.org/10.1085/jgp.201511496
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author De-la-Rosa, Víctor
Suárez-Delgado, Esteban
Rangel-Yescas, Gisela E.
Islas, León D.
author_facet De-la-Rosa, Víctor
Suárez-Delgado, Esteban
Rangel-Yescas, Gisela E.
Islas, León D.
author_sort De-la-Rosa, Víctor
collection PubMed
description Proton channels have evolved to provide a pH regulatory mechanism, affording the extrusion of protons from the cytoplasm at all membrane potentials. Previous evidence has suggested that channel-mediated acid extrusion could significantly change the local concentration of protons in the vicinity of the channel. In this work, we directly measure the proton depletion caused by activation of Hv1 proton channels using patch-clamp fluorometry recordings from channels labeled with the Venus fluorescent protein at intracellular domains. The fluorescence of the Venus protein is very sensitive to pH, thus behaving as a genetically encoded sensor of local pH. Eliciting outward proton currents increases the fluorescence intensity of Venus. This dequenching is related to the magnitude of the current and not to channel gating and is dependent on the pH gradient. Our results provide direct evidence of local proton depletion caused by flux through the proton-selective channel.
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spelling pubmed-47279452016-08-01 Currents through Hv1 channels deplete protons in their vicinity De-la-Rosa, Víctor Suárez-Delgado, Esteban Rangel-Yescas, Gisela E. Islas, León D. J Gen Physiol Research Articles Proton channels have evolved to provide a pH regulatory mechanism, affording the extrusion of protons from the cytoplasm at all membrane potentials. Previous evidence has suggested that channel-mediated acid extrusion could significantly change the local concentration of protons in the vicinity of the channel. In this work, we directly measure the proton depletion caused by activation of Hv1 proton channels using patch-clamp fluorometry recordings from channels labeled with the Venus fluorescent protein at intracellular domains. The fluorescence of the Venus protein is very sensitive to pH, thus behaving as a genetically encoded sensor of local pH. Eliciting outward proton currents increases the fluorescence intensity of Venus. This dequenching is related to the magnitude of the current and not to channel gating and is dependent on the pH gradient. Our results provide direct evidence of local proton depletion caused by flux through the proton-selective channel. The Rockefeller University Press 2016-02 /pmc/articles/PMC4727945/ /pubmed/26809792 http://dx.doi.org/10.1085/jgp.201511496 Text en © 2016 De-la-Rosa et al. 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). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).
spellingShingle Research Articles
De-la-Rosa, Víctor
Suárez-Delgado, Esteban
Rangel-Yescas, Gisela E.
Islas, León D.
Currents through Hv1 channels deplete protons in their vicinity
title Currents through Hv1 channels deplete protons in their vicinity
title_full Currents through Hv1 channels deplete protons in their vicinity
title_fullStr Currents through Hv1 channels deplete protons in their vicinity
title_full_unstemmed Currents through Hv1 channels deplete protons in their vicinity
title_short Currents through Hv1 channels deplete protons in their vicinity
title_sort currents through hv1 channels deplete protons in their vicinity
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4727945/
https://www.ncbi.nlm.nih.gov/pubmed/26809792
http://dx.doi.org/10.1085/jgp.201511496
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