The role and structure of the carboxyl-terminal domain of the human voltage-gated proton channel Hv1.
Li, S.J., Zhao, Q., Zhou, Q., Unno, H., Zhai, Y., Sun, F.(2010) J Biol Chem 285: 12047-12054
- PubMed: 20147290
- DOI: https://doi.org/10.1074/jbc.M109.040360
- Primary Citation of Related Structures:
3A2A - PubMed 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.
Organizational Affiliation:
Key Laboratory of Bioactive Materials, Ministry of Education, College of Physics Science, Nankai University, Tianjin 300071, China. shujieli@nankai.edu.cn