Panel A shows structural views of the 8C 8A(IL1 25) channel, highlighting the E6 residue within the N terminal region and labeling the extracellular domain, transmembrane domain, and intracellular domain. Panel B shows representative whole cell current traces for the E6A mutant, with a scale of 500 picoamperes and 250 milliseconds. Panel C shows a concentration response curve comparing the 8C 8A(IL1 25) channel and the E6A mutant. The x-axis represents DCPIB concentration in micromolar on a logarithmic scale, and the y-axis represents percentage inhibition. Panel D shows relative current over time during DCPIB application followed by washout for the 8C 8A(IL1 25) channel and E6A mutant. The x-axis represents time in minutes, and the y-axis represents relative current. Error bars are shown for the E6A measurements.
Analysis of 8C-8A(IL1 25 ) E6A mutation on DCPIB sensitivity. (A) Side view of the AlphaFold3 model of the entire pore region of 8C-8A(IL125) (Yamada et al., 2025). Only two opposing subunits are shown. (B) Representative whole-cell current of the E6A mutant recorded from a cell dialyzed with normal pipette solution and cell swelling with hypotonic buffer. (C) CRC data recorded at +100 mV. Fit of WT CRC data (black line) from Fig. 3 C is shown for comparison (8C-8A(IL125) n = 6, E6A n = 6). (D) Time course of drug washout in E6A. WT data (gray line) from Fig. 3 E is shown for comparison (8C-8A(IL125) n = 4, E6A n = 4). After full activation, 10 μM DCPIB was applied for 7 min and then washed out for 5 min by continuous perfusion at 1 ml/min. Data are mean ± SEM.