Fig. 1.

siRNA directed against STIM1 inhibits, and overexpression of STIM1 increases, both CRAC channel activity and ARC channel activity. (A) Currents via CRAC channels and ARC channels following transfection of siRNA against STIM1 (siRNA – green) and overexpression of STIM1 (O/E – brown). Mean inward currents, measured at −80 mV, are represented as a percent of the corresponding control values. (B) Corresponding representative current-voltage relationships of the currents through the CRAC channels (top) and the ARC channels (bottom). Shown for comparison are the respective representative current-voltage relationships from a control cells (black). CRAC channels were activated by using a Ca²⁺-free pipette solution containing the potent InsP₃ receptor agonist adenophostin A (2 μM) [12], whilst the ARC channels were activated by exogenous arachidonic acid (8 μM) [7]. Data redrawn from [21].