Figure 3. ARC channel activation of PIP₂ depletion is specifically due to the entry of Ca²⁺.

A, inhibition of Ca²⁺ entry by Gd³⁺ (5 μm) and ARC channel activity by expression of a dominant-negative E81Q-Orai3 mutant both inhibit the ARC channel-mediated decline in Kir2.1 channel currents. B, effect of eliminating Ca²⁺ entry via activated ARC channels by holding the cells at 0 mV for 120 s on the ARC channel-mediated inhibition of Kir2.1 channel currents. All values are means ± SEM with n shown in parentheses.