Voltage-gated proton channel

Identifiers
Symbol	Hv
TCDB	1.A.51
OPM superfamily	8
OPM protein	3wkv

Voltage-gated proton channels are ion channels that have the unique property of opening with depolarization, but in a strongly pH-sensitive manner.^[1] The result is that these channels open only when the electrochemical gradient is outward, such that their opening will only allow protons to leave cells. Their function thus appears to be acid extrusion from cells.^[2]

Another important function occurs in phagocytes (e.g. eosinophils, neutrophils, and macrophages) during the respiratory burst. When bacteria or other microbes are engulfed by phagocytes, the enzyme NADPH oxidase assembles in the membrane and begins to produce reactive oxygen species (ROS) that help kill bacteria.^[3] NADPH oxidase is electrogenic,^[4] moving electrons across the membrane, and proton channels open to allow proton flux to balance the electron movement electrically.^[5] A group of small molecule inhibitors of the Hv1 channel are shown as chemotherapeutics and anti-inflammatory agents.^[6]

Known types

HVCN1

References

↑ Cherny, V.V.; Markin, V.S.; DeCoursey, T.E. (1995), "The voltage-activated hydrogen ion conductance in rat alveolar epithelial cells is determined by the pH gradient" (PDF), Journal of General Physiology (published June 1995), 105 (6), pp. 861–896, doi:10.1085/jgp.105.6.861, retrieved 2008-07-14
↑ DeCoursey, T.E. (2003), "Voltage-gated proton channels and other proton transfer pathways", Physiological Reviews, 83 (2), pp. 475–579, doi:10.1152/physrev.00028.2002 (inactive 2015-02-01), OCLC 205658168, PMID 12663866, retrieved 2008-07-14
↑ Babior, B.M. (1999-03-01), "NADPH Oxidase: An Update." (PDF), Blood, 93 (5), pp. 1464–1476, ISSN 1528-0020, retrieved 2008-07-14
↑ Henderson, L.M.; Chappell, J.B.; Jones, O.T.G. (1987-09-01), "The superoxide-generating NADPH oxidase of human neutrophils is electrogenic and associated with an H+ channel" (PDF), The Biochemical Journal, 246 (2), pp. 325–329, ISSN 0264-6021, OCLC 116254550, retrieved 2008-07-14
↑ Murphy, R.; DeCoursey, T.E. (2006), "Charge compensation during the phagocyte respiratory burst", Biochimica et Biophysica Acta, Bioenergetics (published 2006-08-08), 1757 (8), pp. 996–1011, doi:10.1016/j.bbabio.2006.01.005, PMID 16483534
↑ Hong, L; Pathak, M. M.; Kim, I. H.; Ta, D; Tombola, F (2013). "Voltage-sensing domain of voltage-gated proton channel Hv1 shares mechanism of block with pore domains". Neuron. 77 (2): 274–87. doi:10.1016/j.neuron.2012.11.013. PMC 3559007. PMID 23352164.

Membrane transport protein: ion channels (TC 1A)

Ca²⁺: Calcium channel

Ligand-gated	Inositol trisphosphate receptor 1 2 3 Ryanodine receptor 1 2 3

Voltage-gated	L-type/Ca_vα 1.1 1.2 1.3 1.4 N-type/Ca_vα2.2 P-type/Ca_vα 2.1 Q-type/Ca_vα2.1 R-type/Ca_vα2.3 T-type/Ca_vα 3.1 3.2 3.3 α₂δ-subunits 1 2 β-subunits β1 β2 β3 β4 γ-subunits γ1 γ2 γ3 γ4 Cation channels of sperm 1 2 3 4 Two-pore channel 1 2

Na⁺: Sodium channel

Constitutively active	Epithelial sodium channel α β γ δ

Proton-gated	Amiloride-sensitive cation channel 1 2 3 4

Voltage-gated	Na_vα 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 7A Na_vβ 1 2 3 4

K⁺: Potassium channel

Calcium-activated	BK channel α1 β1 β2 β3 β4 SK channel SK1 SK2 SK3 IK channel IK1 K_Ca 1.1 2.1 2.2 2.3 3.1 4.1 4.2 5.1

Inward-rectifier	K_ATP K_ir 1.1 2.1 2.2 2.3 2.4 2.6 GIRK/K_ir 3.1 3.2 3.3 3.4 K_ir 4.1 4.2 5.1 6.1 6.2 7.1

Tandem pore domain	K2P 1 2 3 4 5 6 7 9 10 12 13 15 16 17 18

Voltage-gated	K_vα1-6 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 6.1 6.2 6.3 6.4 K_vα7-12 7.1 7.2 7.3 7.4 7.5 8.1 8.2 9.1 9.2 9.3 10.1 10.2 11.1/hERG 11.2 11.3 12.1 12.2 12.3 K_vβ 1 2 3 KCNIP 1 2 3 4 minK/ISK minK/ISK-like MiRP 1 2 3 Shaker gene

Miscellaneous

Cl⁻: Chloride channel	Calcium-activated chloride channels Anoctamin ANO1 Bestrophin 1 2 Chloride Channel Accessory 1 2 3 4 CFTR CLCN 1 2 3 4 5 6 7 KA KB CLIC 1 2 3 4 5 6 L1 CLNS 1A 1B

H⁺: Proton channel	HVCN1

M⁺: CNG cation channel	α 1 2 3 4 β 1 2 3 HCN FC 1 2 3 4

M⁺: TRP cation channel	TRPA (1) TRPC 1 2 3 4 4AP 5 6 7 TRPM 1 2 3 4 5 6 7 8 TRPML 1 2 3 TRPN TRPP 1 2 TRPV 1 2 3 4 5 6

H₂O (+ solutes): Porin	Aquaporin 0 1 2 3 4 5 6 7 8 9 Voltage-dependent anion channel 1 2 3 General bacterial porin family

Cytoplasm: Gap junction	Connexin: A GJA1 GJA3 GJA4 GJA5 GJA8 GJA9 GJA10 B GJB1 GJB2 GJB3 GJB4 GJB5 GJB6 GJB7 C GJC1 GJC2 GJC3 D GJD2 GJD3 GJD4) Innexin

By gating mechanism

Ion channel class	Ligand-gated Light-gated Voltage-gated Stretch-activated

see also disorders

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