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Full-Text Articles in Life Sciences
Exotic Properties Of A Voltage-Gated Proton Channel From The Snail Helisoma Trivolvis, Sarah Thomas, Vladimir V. Cherny, Deri Morgan, Liana R. Artinian, Vincent Rehder, Susan M. E. Smith, Thomas E. Decoursey
Exotic Properties Of A Voltage-Gated Proton Channel From The Snail Helisoma Trivolvis, Sarah Thomas, Vladimir V. Cherny, Deri Morgan, Liana R. Artinian, Vincent Rehder, Susan M. E. Smith, Thomas E. Decoursey
Faculty and Research Publications
Voltage-gated proton channels, HV1, were first reported in Helix aspersa snail neurons. These H+ channels open very rapidly, two to three orders of magnitude faster than mammalian HV1. Here we identify an HV1 gene in the snail Helisoma trivolvis and verify protein level expression by Western blotting of H. trivolvis brain lysate. Expressed in mammalian cells, HtHV1 currents in most respects resemble those described in other snails, including rapid activation, 476 times faster than hHV1 (human) at pHo 7, between 50 and 90 mV. In contrast to most HV1, activation of HtHV1 is exponential, suggesting first-order kinetics. However, the large …
Histidine168 Is Crucial For Δph-Dependent Gating Of The Human Voltage-Gated Proton Channel, Hhv1, Vladimir V. Cherny, Deri Morgan, Sarah Thomas, Susan M. E. Smith, Thomas E. Decoursey
Histidine168 Is Crucial For Δph-Dependent Gating Of The Human Voltage-Gated Proton Channel, Hhv1, Vladimir V. Cherny, Deri Morgan, Sarah Thomas, Susan M. E. Smith, Thomas E. Decoursey
Faculty and Research Publications
We recently identified a voltage-gated proton channel gene in the snail Helisoma trivolvis, HtHV1, and determined its electrophysiological properties. Consistent with early studies of proton currents in snail neurons, HtHV1 opens rapidly, but it unexpectedly exhibits uniquely defective sensitivity to intracellular pH (pHi). The H+ conductance (gH)-V relationship in the voltage-gated proton channel (HV1) from other species shifts 40 mV when either pHi or pHo (extracellular pH) is changed by 1 unit. This property, called ΔpH-dependent gating, is crucial to the functions of HV1 in many species and in numerous human tissues. The HtHV1 channel exhibits normal pHo dependence but …