Figure 5
From: Effect of the Brugada syndrome mutation A39V on calmodulin regulation of Cav1.2 channels
Calmodulin lobe mutants differentially affect the kinetics of activation for WT and A39V-Cav1.2 channels in the absence of calcium. A) Plot illustrating the time to maximum activation (Tau) at various voltages for WT-Cav1.2 channels expressed transiently in tsA-201 cells with Cavβ2a/Cavα2δ and recorded in barium with one of CaMWT, CaM12, CaM34 or CaM1234 and with 10 mM BAPTA intracellular. Voltages for which all mutant CaMs differ significantly from the CaMWT condition (* p ≤ 0.05 by one-way ANOVA), and where CaM34 and CaM1234 differ from CaMWT condition (# p ≤ 0.05 by one-way ANOVA). B) Plot for the kinetics of activation of A39V-Cav1.2 channels expressed as in (A). Voltages for which CaM1234 differs significantly from the CaMWT condition ($ p ≤ 0.05 by one-way ANOVA), and where CaM12 and CaM1234 differ from CaMWT condition (& p ≤ 0.05 by one-way ANOVA). C) Sample traces of WT-Cav1.2 channels expressed with CaMWT and CaM1234 at 10 mV. Note that the CaM1234 trace has been normalized to that of CaMWT and that the arrows denote peak of activation for WT-Cav1.2 with either CaMWT (black) or CaM1234 (grey). D) Sample traces of A39V-Cav1.2 channels expressed with CaMWT and CaM1234 at 10 mV. Note that the CaM1234 trace has been normalized to that of CaMWT and that the arrows denote peak of activation for A39V-Cav1.2 with either CaMWT (black) or CaM1234 (grey).