Comparison between mouse and sea urchin orthologs of voltage-gated proton channel suggests role of S3 segment in activation gating

Souhei Sakata; Nana Miyawaki; Thomas J McCormack; Hiroki Arima; Akira Kawanabe; Nurdan Özkucur; Tatsuki Kurokawa; Yuka Jinno; Yuichiro Fujiwara; Yasushi Okamura

doi:10.1016/j.bbamem.2016.09.008

Comparison between mouse and sea urchin orthologs of voltage-gated proton channel suggests role of S3 segment in activation gating

Biochim Biophys Acta. 2016 Dec;1858(12):2972-2983. doi: 10.1016/j.bbamem.2016.09.008. Epub 2016 Sep 13.

Authors

Affiliations

¹ Lab. of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan; Institute of Academic Initiative, Osaka University, Suita, Osaka 565-0871, Japan; National Institute of Natural Sciences, Okazaki, Aichi, Japan.
² Lab. of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
³ Section of Developmental Neurophysiology, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), Okazaki, Aichi, Japan.
⁴ Lab. of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan; Department of Anatomy, Medical Theoretical Center, Technische Universität Dresden, Fetscherstrasse 74, 01307 Dresden, Germany.
⁵ Lab. of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan; Section of Developmental Neurophysiology, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), Okazaki, Aichi, Japan.
⁶ Lab. of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan; Section of Developmental Neurophysiology, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), Okazaki, Aichi, Japan; National Institute of Natural Sciences, Okazaki, Aichi, Japan; Graduate School of Frontier Bioscience, Osaka University, Suita, Osaka 565-0871, Japan. Electronic address: yokamura@phys2.med.osaka-u.ac.jp.

PMID: 27637155
DOI: 10.1016/j.bbamem.2016.09.008

Abstract

The voltage-gated proton channel, Hv1, is expressed in blood cells, airway epithelium, sperm and microglia, playing important roles in diverse biological contexts including phagocytosis or sperm maturation through its regulation of membrane potential and pH. The gene encoding Hv1, HVCN1, is widely found across many species and is also conserved in unicellular organisms such as algae or dinoflagellates where Hv1 plays role in calcification or bioluminescence. Voltage-gated proton channels exhibit a large variation of activation rate among different species. Here we identify an Hv1 ortholog from sea urchin, Strongylocentrotus purpuratus, SpHv1. SpHv1 retains most of key properties of Hv1 but exhibits 20-60 times more rapid activation kinetics than mammalian orthologs upon heterologous expression in HEK293T cells. Comparison between SpHv1 and mHv1 highlights novel roles of the third transmembrane segment S3 in activation gating of Hv1.

Keywords: Gating; Hv1; Membrane protein; Patch clamp; Proton transport; Sea urchin.

Publication types

Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

Animals
HEK293 Cells
Humans
Ion Channel Gating*
Ion Channels / chemistry
Ion Channels / physiology*
Mice
Sea Urchins / metabolism*

Substances

Hv1 proton channel, mouse
Ion Channels