Figure 9.

Block of BK channels by other fungal alkaloids is also abolished by the G311S mutation. (A) A Slo1 G-V curve for activation with 10 µM Ca²⁺ is plotted for currents measured in the absence and presence of 10 nM aflatrem (n = 4 patches). (B) The time course of block by 10 nM aflatrem is shown for one patch. (C) 10 nM aflatrem is without effect on the G-V elicited by 10 µM Ca²⁺ for the Slo1-G311S construct. (D) Over 4 min of application of 10 nM aflatrem produces no reduction in current of Slo1-G311S. (E) The effect of 10 nM penitrem A on the Slo1 G-V curve is plotted. (F) The time course of block of Slo1 by penitrem A is plotted. (G) 10 nM penitrem A is without effect on Slo1-G311S conductance. (H) Over 5 min of application of 10 nM penitrem A has no effect on Slo1-G311S current. (I) Block of the Slo1 G-V by 10 nM verruculogen is plotted. (J) The time course of verruculogen block is displayed. (K) 10 nM verruculogen is without effect on Slo1-G311S conductance. (L) Over 5 min of verruculogen application is without effect on Slo1-G311S current.