Fig. 1

Functional characterization of LjCASTOR-2TM reveals that LjCASTOR is a Ca²⁺-regulated Ca²⁺ channel. a Whole-cell current recordings in the presence of 150 mM [Na⁺] and 10 μM [Ca²⁺] in the pipette solution (intracellular) and 150 mM [Na⁺] or NMDG in the bath solution. LjCASTOR-2TM is not permeable to NMDG. b Inward rectification of the current caused by intracellular Mg²⁺ ions. The recordings were obtained from the inside-out patches with the symmetrical 150 mM [Na⁺] in the presence of 10 μM [Ca²⁺] and 0 or 1 mM [Mg²⁺] in the bath solution (intracellular). c Cytosolic [Ca²⁺]-dependent activation of LjCASTOR-2TM. The recordings were obtained from the inside-out patches with 150 mM [Na⁺] in the pipette solution (extracellular). The bath solution (intracellular) contained 150 mM [K⁺] with various [Ca²⁺]. Data points are mean ± s.e.m. (n = 5 independent experiments). d Selectivity of LjCASTOR-2TM between Na⁺ and K⁺. Sample traces and I–V curve were obtained from the outside-out patches with 150 mM [Na⁺] and 10 μM [Ca²⁺] in the pipette solution (intracellular) and 150 mM [K⁺] in the bath solution (extracellular). \({\rm{P}}_{{\rm{Na}}^+} \)/\({\rm{P}}_{{\rm{K}}^+} \) value was calculated from the reversal potential (E_rev = mean ± s.d. of five independent experiments). e Selectivity of LjCASTOR-2TM between Na⁺ and Ca²⁺. Sample traces and I–V curve were obtained from the outside-out patches with 150 mM [Na⁺] and 10 μM [Ca²⁺] in the pipette solution (intracellular) and 15 mM [Ca²⁺] in the bath solution (extracellular). \({\rm{P}}_{{\rm{Ca}}^{2+}} \)/\({\rm{P}}_{{\rm{Na}}^+} \) value was calculated from the reversal potential (E_rev = mean ± s.d. of five independent experiments). f Inhibition of LjCASTOR-2TM by La³⁺. The recordings were obtained from the outside-out patches with 150 mM [Na⁺] and 10 μM [Ca²⁺] in the pipette solution (intracellular) and 150 mM [Na⁺] and 0 or 100 μM [La³⁺] in the bath solution (extracellular)