Fig. 3

BP1 undergoes liquid–liquid phase separation in vitro. A Net charge per residue (NCPR) of BP1 was calculated using the Classification of Intrinsically Disordered Ensemble Regions (CIDER) web server (http://pappulab.wustl.edu/CIDER/analysis/). B Hydrophilicity plot of BP1 was predicted using ProtScale (https://web.expasy.org/protscale/). C 3D structure of BP1 was predicted using the AlphaFold Protein Structure Database (https://alphafold.ebi.ac.uk/). D Coomassie Brilliant Blue staining of recombinant His-GFP and His-BP1-GFP proteins purified from E. coli. E Turbidity visualization of recombinant His-GFP and His-BP1-GFP droplet formation. Tubes contained 30 μM His-GFP or His-BP1-GFP in 10% (w/v) PEG 8000 buffer. F Representative fluorescence and differential interference contrast (DIC) images of His-BP1-GFP droplets. Scale bar, 5 μm. G Confocal micrographs showing His-BP1-GFP droplets after phase separation and droplet fusion in vitro. H Phase-separated His-BP1-GFP droplets analyzed by fluorescence recovery after photobleaching (FRAP). The bleaching laser intensity was 100%, and representative images are shown. I Quantification of relative fluorescence recovery of His-BP1-GFP, six nuclei included in the analysis