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Dimeric subunit stoichiometry of the human voltage-dependent proton channel Hv1.

ABSTRACT: In voltage-gated Na(+), K(+), and Ca(2+) channels, four voltage-sensor domains operate on a central pore domain in response to membrane voltage. In contrast, the voltage-gated proton channel (Hv) contains only a voltage-sensor domain, lacking a separate pore domain. The subunit stoichiometry and organization of Hv has been unknown. Here, we show that human Hv1 forms a dimer in the membrane and define regions that are close to the dimer interface by using cysteine cross-linking. Two dimeric interfaces appear to exist in Hv1, one mediated by S1 and the adjacent extracellular loop, and the other mediated by a putative intracellular coiled-coil domain. It may be significant that Hv1 uses for its dimer interface a surface that corresponds to the interface between the voltage sensor and pore in Kv channels.

SUBMITTER: Lee SY

PROVIDER: S-EPMC2409406 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature

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Dimeric subunit stoichiometry of the human voltage-dependent proton channel Hv1.

Lee Seok-Yong SY Letts James A JA Mackinnon Roderick R

Proceedings of the National Academy of Sciences of the United States of America 20080528 22

In voltage-gated Na(+), K(+), and Ca(2+) channels, four voltage-sensor domains operate on a central pore domain in response to membrane voltage. In contrast, the voltage-gated proton channel (Hv) contains only a voltage-sensor domain, lacking a separate pore domain. The subunit stoichiometry and organization of Hv has been unknown. Here, we show that human Hv1 forms a dimer in the membrane and define regions that are close to the dimer interface by using cysteine cross-linking. Two dimeric inter ...[more]

PMID: 18509058

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