Fig. 5. iLight-induced gene transcription activation in mammalian cells.

a Dependence of the SEAP reporter expression on concentration of the exogenous biliverdin in HeLa cells expressing the iLight optogenetic system. SEAP signal was detected after 48 h of 660 nm illumination. b The 72 h-long kinetics of the SEAP reporter expression in HeLa cells with the iLight optogenetic system. Cells were illuminated in one of the following regimes: cells were kept in darkness (black dots); illumination with 660 nm light for 72 h (red dots); illumination with 660 nm light for 24 h followed by 48 h of darkness (blue dots); or illumination with 660 nm light for 24 h followed by 4 h of 780 nm light and 44 h of darkness (green dots). The culture medium samples were collected every 12 h to measure the SEAP signal. c Dependence of the SEAP reporter expression on the power of 660 nm activation light. HeLa cells were kept in darkness or under 660 nm light of the respective light intensities. Numbers indicate fold increase in the SEAP signal over darkness. In b, c, cells were supplemented with 10 µM biliverdin. In a–c, HeLa cells bearing NLS-Gal4-DBD-iLight-VP16 were transfected with pG12-SEAP (12× UAS) reporter plasmid. Box plots show the median (center line), first and third quartiles (box edges), 1× the SD (whiskers), and individual data points. n = 4 independent experiments for all conditions. a.u., arbitrary units. Source Data are available as a Source Data file.