Fig. 1: Structure and function of TWIK1.
From: Structural Basis for pH-gating of the K+ channel TWIK1 at the selectivity filter
a, b Current-voltage relationships from TWIK1-expressing cells at high and low pHext in (a) high [K+]ext and (b) low [K+]ext. a, ((right) Fraction of current remaining after extracellular acidification in high [K+]ext (IpH 5.5/IpH 8 at 60 mV = 0.11 ± 0.03, mean ± sem from n = 4 and 6 cells for high [K+]ext and low [K+]ext, respectively. c Cryo-EM map at pH 5.5 viewed from the membrane plane. Nanodisc is transparent and TWIK1 subunits are magenta and white. d TWIK1 model colored as in c with K+ ions orange and disulfide yellow. e Cartoon representation of a TWIK1 protomer with four transmembrane helices (TM1-TM4), two extracellular cap helices (CH1-CH2), two-pore helices (PH1–PH2), two selectivity filters (SF1–SF2), and key residues involved in extracellular pH-gating indicated. Source data for a, b are provided as a Source Data file.
