Figure 4.

Whole cell currents in cells expressing EYFP-Stim1 and Orai2. (A) Average time course of current development at −100 mV for HEK293 cells overexpressing both Orai2 and Stim1 (n=10, ± SEM). Currents were activated by store depletion using IP₃ and BAPTA in the pipette, and were recorded under the presence of 2 mM Ca²⁺ in the bathing solution. (B) Representative time course (n=9) of current development under the presence of 2 mM Ca²⁺ followed by the addition of divalent-free solution (0.1 mM EGTA) (DVF) and nominally Ca²⁺ free external solution (NCF). (C) Current-Voltage relationship taken from the same recording seen in (B) showing the inwardly rectifying Orai2 + Stim1 currents that are transiently potentiated by switching to DVF conditions.