Voltage-dependent inactivation of RyR2. (A) Example of voltage-dependent inactivation of RyR2 channels that results from switching the holding potential from −30 to +30 mV in a bilayer where multiple RyR2 channels were gated prior to the voltage change. The blue arrow indicates the time of the voltage change and the orange arrows indicate the times of individual channel inactivation. The dashed line indicates 0 pA. (B) Graph comparing the times to channel inactivation after changing the holding potential from −30 to +30 mV in the RyR2 derived from HEK293 cells expressing RyR2-only (black), RyR2+TRIC-A (blue), and RyR2+TRIC-B (red). The curves were fitted according to the equation: $y=n(1−e−kt)$⁠, where t = time in seconds, n is the number of channels (n_RyR2 = 15, n_RyR2+TRIC-A = 15, n_RyR2+TRIC-B = 18), and k is the rate constant (k_RyR2 = 0.264, k_RyR2+TRIC-A = 0.422, k_RyR2+TRIC-B = 4.89). The time for half the channels to become inactivated (half decay time, t_1/2) was 2.62, 1.64, and 0.14 s for RyR2-only, RyR2+TRIC-A, and RyR2+TRIC-B, respectively. Kruskal–Wallis test: P = 0.000003. Post-hoc multiple comparison with Dunn’s correction: significant difference between the t_1/2 of RyR2 derived from HEK293 cells expressing RyR2+TRIC-B and the t_1/2 of cells expressing RyR2-only (indicated by **** for P = 0.000007) or RyR2+TRIC-A (indicated by *** for P = 0.000483).