Transmembrane helix straightening and buckling underlies activation of mechanosensitive and thermosensitive K(2P) channels. Academic Article uri icon

Overview

abstract

  • Mechanical and thermal activation of ion channels is central to touch, thermosensation, and pain. The TRAAK/TREK K(2P) potassium channel subfamily produces background currents that alter neuronal excitability in response to pressure, temperature, signaling lipids, and anesthetics. How such diverse stimuli control channel function is unclear. Here we report structures of K(2P)4.1 (TRAAK) bearing C-type gate-activating mutations that reveal a tilting and straightening of the M4 inner transmembrane helix and a buckling of the M2 transmembrane helix. These conformational changes move M4 in a direction opposite to that in classical potassium channel activation mechanisms and open a passage lateral to the pore that faces the lipid bilayer inner leaflet. Together, our findings uncover a unique aspect of K(2P) modulation, indicate a means for how the K(2P) C-terminal cytoplasmic domain affects the C-type gate which lies ∼40Å away, and suggest how lipids and bilayer inner leaflet deformations may gate the channel.

publication date

  • December 11, 2014

Research

keywords

  • Cell Membrane
  • Ion Channel Gating
  • Potassium Channels
  • Temperature

Identity

PubMed Central ID

  • PMC4270892

Scopus Document Identifier

  • 84926368897

Digital Object Identifier (DOI)

  • 10.1016/j.neuron.2014.11.017

PubMed ID

  • 25500157

Additional Document Info

volume

  • 84

issue

  • 6