Fig. 3.

Mutations in the IF residues of Ca_V2.2 reduce the current. Ca_V2.2 with mutations in the IF residues (Ca_V2.2^IF/AF and Ca_V2.2^IF/AA) was expressed in the HEK293T cells. A. Schematic representation of Ca_V2.2 and the constructs. B. The current-voltage relationship. The cell was whole-cell patched and depolarized for 250 ms from a holding potential of −70 mV to various potentials using Ca²⁺ as the charge carrier. The peak current recorded at each potential was normalized to the inward maxima of each cell. C. The activation curves. Cells were depolarized for 10 ms from a holding potential of −70 mV to various potentials, and the tail inward current obtained at each potential was normalized to the maxima. D. The I₃₀/Ca²⁺ of Ca_V2.2 and the mutants. The current was evoked by a depolarization to +30 mV for 250 ms, and the peak inward current was measured. Data are presented as the mean ± SEM and were analyzed by one-way ANOVA with Fisher's post hoc test. *: p < 0.05 and ***: p < 0.001 compared to the wild-type.