Effects of swapping C-tail regions on the modulatory functions of BKγ subunits. Voltage dependence of BK channel activation in the presence of BKγ subunit chimeras, whose C-tail regions were from different BKγ subunits and whose main bodies were from γ2 (A), γ3 (B), and γ1 (C and D). Thick dot lines are used for the major wild-type BKγ protein(s) intended for comparison. Error bars represent ± SEM.