Figure 6: Illustration of expected outcomes. Flp-In™T-REx™293 cell line expressing TurboID-TopBP1-mCherry-Cry2 were incubated with 500 µM of biotin and exposed to blue light for 10 min of light-dark cycles (4 sec light followed by 30 sec dark). TopBP1 partner proteins labelled with biotin were pulled-down using streptavidin-coated beads. A) Ser1138 phospho TopBP1, TopBP1, Thr1989 phospho ATR and ATR were detected by immunoblotting. This figure is reprinted with permission from Frattini et al. 2021. B) Immunoblot of TopBP1, BRCA1 and FANCJ isolated with streptavidin-coated beads.