CaM differentially interacts with pre-IQ-IQ and EF-pre-IQ-IQ of Cav2.1 and Cav2.2 in pull-down assays. (A and B) GST or GST-tagged Cav2 proteins were incubated with CaM (2.5 µg), and bound CaM was detected by Western blotting. Ponceau staining indicated the amount of each GST protein in the reactions. In B, the signal intensity corresponding to CaM was normalized to that for the GST-protein. A.U., arbitrary units; n.s., not significant; **, P < 0.001, one-way ANOVA and post hoc Tukey test. Data are representative of four independent experiments. (C–F) As in A and B except that variable amounts of CaM (1–10 µg) were used in the assay. In E and F, data were analyzed by two-way ANOVA. There was a significant difference in results obtained for pre-IQ-IQ (P < 0.01) but not EF-pre-IQ-IQ (P = 0.75) of Cav2.1 and Cav2.2. Data are representative of three independent experiments. Data represent mean ± SEM.
