CaM (E34Q), but not CaM (E12Q), can recover SK channel activity. (A) Time course of the average current level at −80 mV with a patch from an oocyte coexpressing SK channels with CaM (E2Q) while the patch was subjected to different solutions as indicated by the legend. (B) Time course of the average current level at −80 mV with a patch from an oocyte coexpressing SK channels with CaM (E2Q). (C) Dose–response relationship for the patch shown in B was measured after recovery of SK channels with CaM (E34Q) (open circles). Solid line is a fit with the Hill equation (EC₅₀ = 1.24 µM and h = 2.7). Filled circles represent the dose–response relationship measured with a patch from an oocyte coexpressing SK channels with CaM (E34Q) fitted with the Hill equation (EC₅₀ = 1.20 µM and h = 3.7).