Figure 1. Assay for high-throughput identification of SLC26A3 inhibitors.

(A) Assay schematic. Extracellular addition of an I^–-containing solution drives slc26a3-mediated Cl^–/I^– exchange, resulting in YFP fluorescence quenching. (B) Representative fluorescence time course data for nontransfected cells, and slc26a3-transfected cells for vehicle control and inactive and active compounds. (C) Absence of slc26a3 regulation by common second messengers, and membrane depolarization. Fluorescence time course data (top) and summary (bottom) for slc26a-mediated Cl^–/I^– exchange under control conditions and after cell treatments to activate cAMP, cGMP, Ca²⁺, or phorbol ester signaling, or depolarization (mean ± SEM, n = 5, differences not significant by one-way ANOVA).