Role of the C-terminal cytosolic region of the BKα subunit for BK channel modulation by the auxiliary γ1 subunit. (A) Representative current traces of BK channels formed by WT (no label) and the TM-only BKα subunit in the absence and presence of the γ1 subunit in response to depolarization of the membrane potential from −80 mV in 20-mV steps. (B) Voltage dependence of BK channel activation for channels formed by WT and the TM-only BKα subunit in the absence and presence of the γ1 subunit. (C) Immunoprecipitation of the γ1 subunit with WT and the TM-only BKα subunit. For all plots of the G/Gmax–voltage (G-V) relationships here and in other figures, the number of repeats (n) used in plotting the individual G-V curve is the same as that of the corresponding data listed in Table 1. Source data are available for this figure: SourceData F1.