Extended Data Fig. 8. Summary of parameters for wild-type Kv4.2 and Kv4.2 mutants and inactivation kinetics obtained at 40 mV.

a. The number of the half-activation voltage (V_1/2,act) and effective charge (z_act) of the voltage-dependent activation experiments obtained by single Boltzmann fittings, the inactivation voltage (V_1/2,inact) and effective charge (z_inact) of the recovery from inactivation experiments obtained by single Boltzmann fittings, and the recovery time constant (τ_rec) of the recovery from inactivation experiments obtained by single exponential fittings are listed as average ± s.e.m. Statistical significance was determined by Dunnett’s test. *, **, and *** denote P < 0.05, P < 0.01, and P < 0.001 for each mutant compared to WT, for each mutant with KChIP1 compared to WT with KChIP1, and each mutant with DPP6S compared to WT with DPP6S. For Kv4.2 F474A/H478A with KChIP1 and Kv4.2 H480A with KChIP1 conditions, only data obtained using prepulses from 10 ms to 90 ms were used for single-exponential fits to calculate the recovery time constant owing to reduced fractional recovery at longer prepulses (marked as ^#). b. Fractional contribution of the slow inactivation component (A_slow/(A_slow + A_fast)) at 40 mV. c. The slow (τ_slow; white) and fast (τ_fast; gray) inactivation time constants at 40 mV. Bars represent means ± s.e.m. (n = 8). Inactivation time constants (τ_slow and τ_fast) and the corresponding amplitude (A_slow and A_fast) were obtained by fitting the inactivation time course to a sum of two exponentials.