Fig. 7.

Anion transport assays for the SLC26 proteins. (A) Electrophysiological SO₄²⁻/Cl⁻ antiport assays in stable HEK293T cell lines heterologously expressing chicken (cPrestin) and zebrafish (zPrestin) constructs in a doxycycline-inducible manner (1 µg/mL one day prior to experiment). (B) Fluorometric HCO₃⁻/Cl⁻ (Left) and I⁻/Cl⁻ (Right) antiport assays in stable HEK293T cell lines heterologously expressing human pendrin constructs in a doxycycline-inducible manner (0.1 to 10 µg/mL 1 d prior to experiment). (C) Electrophysiological chloride transport (Left) and fluorometric iodide transport (Right) assays in stable HEK293T cell lines heterologously expressing human SLC26A9 constructs in a doxycycline-inducible manner (1 µg/mL 1 d prior to experiment). In all panels, the short horizontal solid lines indicate the means and SDs, while the horizontal broken line with gray shading indicates the basal transport activity (means ± SDs) of noninduced cells (negative controls).