Figure 8. Inhibition of various mutants of TASK-2 by co-expressed DrVSP activation.

(A and B) Averages of current traces recorded from a HEK-293 cell co-expressing WT TASK-2 or various truncated or point mutated channels together with DrVSP. The potential was held at −75 mV and a pulse to 80 mV with a duration of 40 s was given to activate DrVSP. The graphs report averages with SEMs of 5–10 experiments. The intracellular solution contained 1 mM ATP and 1 mM Mg²⁺. (C) Summary of results of effects of DrVSP activation on currents mediated by WT or mutant TASK-2 channels. The columns report the time taken for currents to decrease by 50% (t_0.5) after stepping the voltage from −75 mV to 80 mV. The results are means ± SEM of 3–10 experiments. In red mutants that gave t_0.5 values significantly smaller than WT with P < 0.05. White columns identify mutants that appeared to be inhibited more slowly than WT TASK-2.