Extended Data Fig. 5 |. Effects of single amino acid substitutions at positions 69, 72, 144, 416, 417 on iodide transport.

a-e. NIS-mediated I⁻ uptake at steady state. cDNA constructs coding for NIS mutants were transfected into COS7 or HEK cells. I⁻ uptake by these NIS mutants was measured at 20 μM (light gray bars) and 200 μM (dark gray bars) I⁻ at 140 mM Na⁺ for 30 min with or without the NIS-specific inhibitor ClO₄⁻ to determine NIS-mediated transport (values obtained in the presence of ClO₄⁻, which are < 10% of the values obtained in its absence, have already been subtracted). f-j. Kinetic analysis of initial rates of I⁻ uptake (2-min time points) determined at 140 mM Na⁺ and varying concentrations of I⁻. k-o. Kinetic analysis of initial rates of I⁻ uptake (2-min time points) determined at varying concentrations of extracellular Na⁺. All results are expressed as pmol of I⁻ accumulated/μg DNA ± s.e.m. Values represent averages of the results from two or three different experiments, each of which was carried out in triplicate (n ≥ 6).