FIGURE 7.
Role of ATP phosphate binding in CFTR regulation by pHi. A, C, E, and G, representative recordings show the effects of pHi on the activity of G551D-, G1349D-, K464A-, and K1250M-CFTR Cl− channels in the presence of ATP (1 mm). Dotted lines indicate where channels are closed, and downward deflections correspond to channel openings. B, D, F, and H, effects of pHi on the NPo of G551D- and G1349D-CFTR and Po of K464A- and K1250M-CFTR. Data are means ± S.E. (n = 6, except G551D- and G1349D-CFTR at pHi = 8.3, where n = 3). The asterisks indicate values that are significantly different from the control value (p < 0.05). In F and H, wild-type CFTR data (circles) are shown for comparison.