Fig. 1
FFm scaffold forms concentration-dependent condensates in living cells. a Schematic of POI-FFm multivalent self-interacting scaffold. Genetically engineered ferritins assemble into ArtiGPOI through a phase separation process (Fm = F36M-FKBP, POI = protein of interest, F = Ferritin, ArtiG = ArtiGranule). b Representative confocal image of ArtiGmCh (red) in HeLa cells, 24 h after transfection of mCherry-FFm construct. Nuclei were stained with Hoechst (blue). Scale bar, 10 µm. c Representative time-lapse confocal images of ArtiGmCh (white) nucleation and growth in HeLa cells expressing mCherry-FFm construct. Scale bar, 10 µm. d Representative time-lapse confocal images of the growth of an isolated condensate (white). Scale bar, 2 µm. e Representative time-lapse confocal images of several ArtiGmCh (white) coalescing into a larger condensate. Scale bar, 2 µm. f Comparison of the temporal evolution of the dilute cytosolic mCherry-FFm fluorescence (dilute phase), with the total cytoplasmic fluorescence (dilute + dense phases) for the lower cell shown in c. The violet dots represent the number of granules measured as a function of time. For the purpose of representation, the images in c, d, and e are slightly saturated
