FIGURE 6.

The lack of Ca_Vβ prevents the effects of RIM1 on recombinant L-type channels. A, averaged peak L-type current density recorded from HEK-293 cells co-transfected with Ca_V1.2α₁/Ca_Vα₂δ-1 (without Ca_Vβ) in the absence (solid bars) or presence of RIM1 (open bars). The peak amplitudes before and after co-expression of RIM1 were normalized for C_m. Ba²⁺ currents were elicited by 2-s pulses to 0 mV from a V_h of −80 mV for the Ca_V1.2 channel currents and to −30 mV in the case of the Ca_V1.3 channel currents. B and C, comparison of time constants of inactivation (left) and percentages of I_rem (right) in cells expressing Ca_V1.2α₁/Ca_Vα₂δ-1 channels and Ca_V1.3α₁/Ca_Vα₂δ-1, respectively, in the absence (solid bars) or presence (open bars) of RIM1 (n = 16–25 cells). Shown is Western blot analysis of proteins from HEK-293 cells co-transfected with Ca_V1.2α₁/Ca_Vα₂δ-1 with (+) or without (−) RIM1 using an anti-RIM antibody. The examples shown are representative of three separate experiments. Error bars, S.E.