Fig. 7.

Truncations of the TMEM16A carboxi-terminus. A. Localization of the non-sense mutations introduced in the TMEM16A(abc) coding sequence to generate truncations of the corresponding protein. TM8: transmembrane domain 8. B. Representative traces (top) and statistics (bottom) from experiments done on transiently-transfected HEK-293 cells with the YFP assay. Arrows indicate the addition of extracellular I⁻ solution plus ionomycin (1 μM). The bar graph reports the quenching rate for wild type and mutant TMEM16A (n = 4–5). The D847X mutant showed a consistently lower I⁻ transport rate. C. Whole-cell patch-clamp data (representative membrane currents and average current–voltage relationships) from HEK-293 cells transiently transfected with the Q938X mutant. The free Ca²⁺ concentration in the pipette solution was 685 nM (n = 9) or 115 nM (n = 8). D. Immunofluorescence analysis of wild type and mutant TMEM16A protein expression in transiently transfected HEK-293 cells.