Figure 4.

Inclusion of alternative exon 1a or 1 influences the extent of NSCaTE-mediated Ca²⁺-dependent inactivation. (A) The splice variant 1a/8a was co-transfected with CaM_3,4, and the currents were recorded in the presence of low-buffering 0.5 mM EGTA in the internal solution. The top shows example traces in Ca²⁺ (gray) and Ba²⁺ (black). The current bar refers to the Ba²⁺ trace, and the Ca²⁺ trace is normalized to the Ba²⁺ peak. The bottom gives the average CDI; r₃₀₀ refers to the ratio of current at 300 ms of voltage step as compared to the peak current, and f₃₀₀ to the same at 0 mV. The results are means ± SE; cell numbers are shown in parentheses. (B) The results for 1a/8a CDI, high-buffering 10 mM BAPTA, are shown in the same format as in (A). (C) The results for 1/8a CDI, low-buffering, are shown in the same format as in (A). (D) The results for 1/8a CDI, high-buffering, are shown in the same format as in (A). (E) A bar chart reporting the statistics for the f₃₀₀ values is shown. ^∗∗∗p < 0.001; ns, nonsignificant as compared to the vector control (Student’s unpaired t-test).