Figure 6. ORAI1 and STIM1 are required for PAR2- and TG-evoked Ca²⁺ influx.

(A) Representative response to SLIGRL (100μM) following pretreatment with vehicle (black) or 2-aminoethoxydiphenyl borate (50 μM 2-APB; red). (B) Representative response to tryptase (100nM) following pretreatment with vehicle (black) or 2-APB (red). (C) Average steady state Ca²⁺ level following SLIGRL- or tryptase (TRY)-evoked Ca²⁺ influx (2 mM Ca²⁺), in the presence of 2-APB (red), lanthanum (50nM La³⁺, blue), or vehicle (CTRL, black). n≥1000 cells. (D) Representative current-voltage trace in the presence of SLIGRL (100μM) in perforated-patch, whole-cell voltage-clamp recordings. Representative baseline subtracted currents before (red) and during application of SLIGRL (black). n≥3 cells/condition. (E) siRNA-induced silencing of STIM1 (red), ORAI1 (blue), and ORAI2 (grey) mRNA in keratinocytes. Expression was normalized to scrambled-siRNA control (black). n≥1000 cells. (F) Representative traces of SLIGRL-evoked (100μM) Ca²⁺ signals following treatment with siRNA targeting STIM1 (red) or scrambled control (CTRL, black). (G) Average steady state Ca²⁺ concentration after treatment with SLIGRL (100μM) or TG (1μM) in cells treated with scrambled siRNA (black), STIM1 (red), ORAI1 (blue), or ORAI2 (grey) siRNA. n≥500 cells. *P<0.05; **P<0.01, ***P<0.001. Error bars represent s.e.m.