title: Comparison between mouse and sea urchin orthologs of voltage-gated proton channel suggests role of S3 segment in activation gating.
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.
authors.affiliation: 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.
authors.forename: Souhei
authors.initials: S
authors.lastname: Sakata
authors.affiliation: Lab. of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Nana
authors.initials: N
authors.lastname: Miyawaki
authors.affiliation: Section of Developmental Neurophysiology, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), Okazaki, Aichi, Japan.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: McCormack
authors.affiliation: Lab. of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Arima
authors.affiliation: Lab. of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kawanabe
authors.affiliation: 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.
authors.forename: Nurdan
authors.initials: N
authors.lastname: Özkucur
authors.affiliation: 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.
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Kurokawa
authors.affiliation: Lab. of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Jinno
authors.affiliation: Lab. of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Fujiwara
authors.affiliation: 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.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Okamura
mesh_terms: D000818:Animals; D057809:HEK293 Cells; D006801:Humans; D015640:Ion Channel Gating; D007473:Ion Channels / Q000737:chemistry / Q000502:physiology*; D051379:Mice; D012617:Sea Urchins / Q000378:metabolism*
chemical_list: C540876:Hv1 proton channel, mouse; D007473:Ion Channels
keywords: Gating; Hv1; Membrane protein; Patch clamp; Proton transport; Sea urchin