Charge recovery at D110, E116, and R117 partially rescues CFTR to open burst stability. (A–C) Representative single-channel currents of D110R- and D110E- (A), E116R- and E116D- (B), and R117A- and R117K-CFTR (C) recorded under the same conditions as Fig. 2 A. Their all-points amplitude histograms are shown on the right. (D) Mean single-channel amplitude of WT-, D110R-, D110E-, E116R-, E116D-, R117A-, and R117K-CFTR. *, P < 0.05 compared with WT-CFTR. (E) Mean burst duration of WT-, D110R-, D110E-, E116R-, E116D-, R117A-, and R117K-CFTR. #, P < 0.001 indicates differences between D110R- and D110E-CFTR or E116R- and E116D-CFTR; *, P < 0.05 indicates differences between R117A- and R117K-CFTR. n = 4–6 for all mutants. Mean ± SEM is shown.