Figure 2.

Topology and sequence alignment of Cav1.2, Nav1.2, and Nav1.4 channels. Ca²⁺ and Na⁺ channels consist of the main α subunit and other auxiliary subunits. α subunit has 4 domains and each domains contain 6 segments. Each segment 4 plays a membrane voltage sensor and segments 5 and 6 form channel pore. The mutated amino acid residues are underlined in the pore-forming segment 6. The underlined specific amino acid residues in these channels are thought to interact with 20(S)-ginsenoside Rg₃ (Rg₃) (Lee et al., 2008b; Choi et al., 2009).