Figure 3

Control of Ca²⁺ release with red light.

(A) Red light-inducible dimerization of the PhyB/PIF6 system allows the plasma membrane recruitment of Gα_q and triggers cytosolic Ca²⁺ release. (B) Constructs for PhyB-FusionRed-CAAX and PIF6-Gα_q. (C) Homogeneous cellular diffusion of GCaMP3 in HeLa cell (upper panel) and the plasma membrane localization of PhyB-FusionRed-CAAX (lower panel). (D) Ca²⁺ imaging of the PhyB/PIF6-based approach with pulsed red light illumination. Time-lapse fluorescence imaging showed that repeatable response of GCaMP3 was evoked upon activation light at 635 nm (red bars), 735 nm far-red (deep red bars) illumination was used as the inactivation light. (E) Negative control in the absence of PhyB-FusionRed-CAAX did not show red light-dependent response. (F) Negative control in the absence of PIF6-Gα_q did not show red light-dependent response.