Fig. 6.

L122D, G236D, L239D, and V242D mutations in the TASK-3 pore disrupt inhibition by A1899 and doxapram (Dox). (A and C) Ussing chamber potassium current records using Fischer rat thyroid cell monolayers transiently expressing rat TASK-3 channels (wild type and L122D). (B and D) Ussing chamber concentration response for A1899 and doxapram. A1899 IC₅₀ (in nM; data are the mean with 95% confidence interval): 36 (23–56) for wild type, 1744 (1392–2185) for V242D***, 9490 (6432–14,000) for G236D***, >10,000 for L239D, and >10,000 for L122D. Doxapram IC₅₀ (in μM): 16 (12–21) for wild type, 176 (154–201) for L239D***, 202 (163–249) for V242D***, 865 (742–1009) for G236D***, and 1349 (1096–1660) for L122D***. Data are fitted as in Fig. 3; n = at least 3 for each. ***P < 0.001 relative to wild-type TASK-3.