1. Structural Biology and Molecular Biophysics
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The isolated voltage sensing domain of the Shaker potassium channel forms a voltage-gated cation channel

  1. Juan Zhao
  2. Rikard Blunck  Is a corresponding author
  1. Université de Montréal, Canada
Research Article
  • Cited 17
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Cite this article as: eLife 2016;5:e18130 doi: 10.7554/eLife.18130

Abstract

Domains in macromolecular complexes are often considered structurally and functionally conserved while energetically coupled to each other. In the modular voltage-gated ion channels the central ion-conducting pore is surrounded by four voltage sensing domains (VSDs). Here, the energetic coupling is mediated by interactions between the S4-S5 linker, covalently linking the domains, and the proximal C-terminus. In order to characterize the intrinsic gating of the voltage sensing domain in the absence of the pore domain, the Shaker Kv channel was truncated after the 4th transmembrane helix S4 (Shaker-iVSD). Shaker-iVSD showed significantly altered gating kinetics and formed a cation-selective ion channel with a strong preference for protons. Ion conduction in Shaker-iVSD developed despite identical primary sequence, indicating an allosteric influence of the pore domain. Shaker-iVSD also displays pronounced 'relaxation'. Closing of the pore correlates with entry into relaxation suggesting that the two processes are energetically related.

Article and author information

Author details

  1. Juan Zhao

    Departments of Physics and of Physiology, Université de Montréal, Montréal, Canada
    Competing interests
    The authors declare that no competing interests exist.
  2. Rikard Blunck

    Departments of Physics and of Physiology, Université de Montréal, Montréal, Canada
    For correspondence
    rikard.blunck@umontreal.ca
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4484-2907

Funding

Canadian Institutes of Health Research (MOP-136894)

  • Rikard Blunck

Natural Sciences and Engineering Research Council of Canada (DG- 327201-2012)

  • Rikard Blunck

Canadian Institutes of Health Research (MOP-102689)

  • Rikard Blunck

Natural Sciences and Engineering Research Council of Canada (CDMC-CREATE postdoctoral fellowship)

  • Juan Zhao

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: This study was performed in strict accordance with the guidelines of the CDEA of Université de Montréal (licence No. 16-033).

Reviewing Editor

  1. Kenton J Swartz, National Institutes of Health, United States

Publication history

  1. Received: May 24, 2016
  2. Accepted: September 30, 2016
  3. Accepted Manuscript published: October 6, 2016 (version 1)
  4. Version of Record published: November 2, 2016 (version 2)

Copyright

© 2016, Zhao & Blunck

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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