PMID: 20147290
Authors:
Li SJ, Zhao Q, Zhou Q, Unno H, Zhai Y, Sun F
Title:
The role and structure of the carboxyl-terminal domain of the human voltage-gated proton channel Hv1.
Journal:
J Biol Chem. 2010 Apr 16;285(16):12047-54. Epub 2010 Feb 10.
Abstract:
The voltage-gated proton channel Hv1 has a voltage sensor domain but lacks a pore domain. Although the C-terminal domain of Hv1 is known to be responsible for dimeric architecture of the channel, its role and structure are not known. We report that the full-length Hv1 is mainly localized in intracellular compartment membranes rather than the plasma membrane. Truncation of either the N or C terminus alone or both together revealed that the N-terminal deletion did not alter localization, but deletion of the C terminus either alone or together with the N terminus resulted in expression throughout the cell. These results indicate that the C terminus is essential for Hv1 localization but not the N terminus. In the 2.0 A structure of the C-terminal domain, the two monomers form a dimer via a parallel alpha-helical coiled-coil, in which one chloride ion binds with the Neta atom of Arg(264). A pH-dependent structural change of the protein has been observed, but it remains a dimer irrespective of pH value.