title: Voltage-gated proton (H(v)1) channels, a singular voltage sensing domain.
abstract: The main role of voltage-gated proton channels (Hv1) is to extrude protons from the intracellular milieu when, mediated by different cellular processes, the H(+) concentration increases. Hv1 are exquisitely selective for protons and their structure is homologous to the voltage sensing domain (VSD) of other voltage-gated ion channels like sodium, potassium, and calcium channels. In clear contrast to the classical voltage-dependent channels, Hv1 lacks a pore domain and thus permeation necessarily occurs through the voltage sensing domain. Hv1 channels are activated by depolarizing voltages, and increases in internal proton concentration. It has been proposed that local conformational changes of the transmembrane segment S4, driven by depolarization, trigger the molecular rearrangements that open Hv1. However, it is still unclear how the electromechanical coupling is achieved between the VSD and the potential pore, allowing the proton flux from the intracellular to the extracellular side. Here we provide a revised view of voltage activation in Hv1 channels, offering a comparative scenario with other voltage sensing channels domains.
authors: Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360103, Chile.
authors: Karen
authors: K
authors: Castillo
authors: Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360103, Chile.
authors: Amaury
authors: A
authors: Pupo
authors: Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360103, Chile.
authors: David
authors: D
authors: Baez-Nieto
authors: Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360103, Chile.
authors: Gustavo F
authors: GF
authors: Contreras
authors: Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Sciences, Universidad Austral de Chile, Valdivia, Chile.
authors: Francisco J
authors: FJ
authors: Morera
authors: Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360103, Chile.
authors: Alan
authors: A
authors: Neely
authors: Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360103, Chile. Electronic address: ramon.latorre@uv.cl.
authors: Ramon
authors: R
authors: Latorre
authors: Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360103, Chile. Electronic address: carlos.gonzalezl@uv.cl.
authors: Carlos
authors: C
authors: Gonzalez
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006801:Humans; D015640:Ion Channel Gating; D007473:Ion Channels / Q000737:chemistry* / Q000378:metabolism*; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary
chemical_list: D007473:Ion Channels
keywords: Gating charge; H(v)1 channel; Limiting slope method; S4 segment; Voltage sensor domain; Voltage-dependence mechanism