FIGURE 4.

The slc4a10 polypeptide is Cl⁻-dependent and sensitive to the Cl⁻ gradient. A, pH_i recordings from slc4a10-transfected (black) and negative control cells (gray) by fluorescence microscopy. Cells were depleted of Cl⁻ for 30 min prior to the experiment by incubation in Cl⁻-free solution. Cells were acidified by addition of 20 mm propionate/propionic acid to a Na⁺-free solution. The Na⁺-dependent pH_i recovery rate was determined after the readdition of Na⁺, as indicated. B, bar graph showing mean values ± S.E. (error bars) of d[H⁺]_i/dt (n = 6). C, time course of cellular Cl⁻ depletion from ³⁶Cl⁻-loaded cells upon removal of the ion from the extracellular medium. D, pH_i recordings of slc4a10-transfected (black) and negative control cells (gray) by fluorescence microscopy, where Cl⁻ was removed from the extracellular medium as indicated. Bar graph shows the mean values ± S.E. of the maximal change in pH_i (n = 6). E, rat slc4a10-transfected and control cells alkalized by propionic acid (20 mm added to solution) prepulsing and the Cl⁻-dependent pH_i recovery rate determined. Bar graph shows the mean values ± S.E. of the pH_i recovery rates. Error bars = S.E.