Figure 5.

Concentration-dependent inhibition of ORAI3 channels by 4-CEP. The concentration-dependent inhibition by 4-CEP was examined in the HEK293 T-REx cells overexpressing mCFP-ORAI3 using whole-cell patch. (A) Example of ORAI3 current induced by 2-APB (50 μM) and the effect of 4-CEP (500 μM). The inhibition was reversible after washout. (B) The 4-CEP-inhibited I/V curve for (A). (C) Effect of 4-CEP at concentrations ranging from 0.1 to 1000 μM; % inhibition of whole-cell current measured at +80 mV was plotted and the curve was fitted using a logistic model with an IC₅₀ for ORAI3 of 71.0 μM (n = 4–10 recordings for each point).