Mutation of a single residue promotes gating of vertebrate and invertebrate two-pore domain potassium channels

Nat Commun. 2019 Feb 15;10(1):787. doi: 10.1038/s41467-019-08710-3.

Abstract

Mutations that modulate the activity of ion channels are essential tools to understand the biophysical determinants that control their gating. Here, we reveal the conserved role played by a single amino acid position (TM2.6) located in the second transmembrane domain of two-pore domain potassium (K2P) channels. Mutations of TM2.6 to aspartate or asparagine increase channel activity for all vertebrate K2P channels. Using two-electrode voltage-clamp and single-channel recording techniques, we find that mutation of TM2.6 promotes channel gating via the selectivity filter gate and increases single channel open probability. Furthermore, channel gating can be progressively tuned by using different amino acid substitutions. Finally, we show that the role of TM2.6 was conserved during evolution by rationally designing gain-of-function mutations in four Caenorhabditis elegans K2P channels using CRISPR/Cas9 gene editing. This study thus describes a simple and powerful strategy to systematically manipulate the activity of an entire family of potassium channels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CRISPR-Cas Systems / genetics
  • CRISPR-Cas Systems / physiology
  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism
  • Drosophila
  • Evolution, Molecular
  • Humans
  • Invertebrates
  • Membrane Potentials / genetics
  • Membrane Potentials / physiology*
  • Mutation / genetics
  • Potassium Channels, Tandem Pore Domain / genetics
  • Potassium Channels, Tandem Pore Domain / metabolism*
  • Vertebrates

Substances

  • Caenorhabditis elegans Proteins
  • Potassium Channels, Tandem Pore Domain