Structural analysis of the S4-S5 linker of the human KCNQ1 potassium channel

Biochem Biophys Res Commun. 2015 Jan 2;456(1):410-4. doi: 10.1016/j.bbrc.2014.11.097. Epub 2014 Dec 2.

Abstract

KCNQ1 plays important roles in the cardiac action potential and consists of an N-terminal domain, a voltage-sensor domain, a pore domain and a C-terminal domain. KCNQ1 is a voltage-gated potassium channel and its channel activity is regulated by membrane potentials. The linker between transmembrane helices 4 and 5 (S4-S5 linker) is important for transferring the conformational changes from the voltage-sensor domain to the pore domain. In this study, the structure of the S4-S5 linker of KCNQ1 was investigated by solution NMR, circular dichroism and fluorescence spectroscopic studies. The S4-S5 linker adopted a helical structure in detergent micelles. The W248 may interact with the cell membrane.

Keywords: KCNQ1; Micelles; NMR; Potassium channel; Protein structure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials
  • Cell Membrane / metabolism
  • Circular Dichroism
  • Detergents / chemistry
  • Humans
  • Ion Channel Gating
  • KCNQ1 Potassium Channel / chemistry*
  • Magnetic Resonance Spectroscopy
  • Membrane Potentials
  • Micelles
  • Protein Binding
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Spectrometry, Fluorescence

Substances

  • Detergents
  • KCNQ1 Potassium Channel
  • KCNQ1 protein, human
  • Micelles