The red/far-red light suicide control system REDMAP is so sensitive to light that as low as 0.1 mW∙cm-2 red light (far-red light) can be sensed. The specific mechanism of this system is that when exposed to red light (660 nm), the transactivator (FHY1–VP64) can specifically bind to the light sensor domain (ΔPhyA–Gal4) in the presence of the photosensitive pigment PCB. Then, the complex protein translocates into the nucleus where it can bind to its synthetic promoter (P5×UAS, 5×UAS-P(hCMVmin)) to initiate expression of MazF. Following exposure to far-red light (730 nm), the transactivator dissociates from the light sensor domain (ΔPhyA–Gal4), thereby terminating the expression of MazF. To make it more convenient for future teams to use our collection, we have made a detailed description of all parts on pages in Registry.

Figure 1: Construct design and the principle of the REDMAP-MazF. 5×UAS-P(hCMVmin) was fused to MazF. Gal4 was linked via a linker to PhyA. At the same time, PCB was combined with PhyA. PhyA turned to ΔPhyA. VP64 was linked with FHY1. When 660 nm light illuminating, ΔPhyA combines with VP64. Then, Gal4-ΔPhyA is transported into the nucleus by VP64-FHY1. After that, Gal4 will combine with 5×UAS-P(hCMVmin), activating the transcription of the downstream target gene: MazF. Then MazF works, killing the engineered cells.