Figure S2.

Correction for pore block by cytosolic Ca²⁺, for obtaining apparent affinities for channel activation by Ca²⁺ of WT nvTRPM2 and MHR1/2 domain mutants. (A) Ca²⁺ dose–response curves of macroscopic currents from Fig. 7, A–G, normalized to the mean of the currents during bracketing applications of 125 µM Ca²⁺ in the same patch (I/I_125Ca²⁺), for WT and mutant nvTRPM2 channels (color coding follows construct labeling in Fig. 7, A–G). Data represent mean ± SEM from 5 to 10 independent experiments. Colored lines are fits to the Hill equation. (B) Unitary nvTRPM2 current amplitudes (i) at −20 mV in our recording solutions (see Materials and methods), with cytosolic (bath) Ca²⁺ concentrations indicated below each bar. Data represent mean ± SEM from 3 to 14 independent experiments. The P_o/P_o;125Ca²⁺ symbols in Fig. 7 H were obtained as (I/I_125Ca²⁺)/(i/i_125Ca²⁺).