Figure 3. Distinct contributions of the four VSDs to determining the specific gating properties of Ca_V1.1.

A and B, schematic models showing the role of VSD I in regulating activation kinetics (C) and its modulation by the α₂δ‐1 subunit (B and E). Note that changes in current kinetics are not accompanied by changes in voltage sensitivity and current amplitude. D, G and J, VSD IV regulates the voltage dependence of activation (D and J) and current amplitude (G) by alternative splicing of exon 29. C–E, typical calcium currents of Ca_V1.1a (including exon 29; black), Ca_V1.1e (lacking exon 29; red), Ca_V1.1 with IS3+IS3–S4 linker from Ca_V1.2 (grey), and Ca_V1.1a without α₂δ−1 (orange). F–K, current–voltage relationship (F–H) and conductance–voltage relationships (I–K) of the currents shown above.