Fig. 4
From: Liquid–liquid phase separation of H3K27me3 reader BP1 regulates transcriptional repression
IDR2-dependent BP1 phase separation is critical for its localization to nuclear puncta. A Diagrams of IDR-deletion BP1 variants (left panel). Coomassie Brilliant Blue staining of recombinant His-BP1-GFP, His-BP1ΔIDR1-GFP, and His-BP1ΔIDR2-GFP proteins purified from E. coli (right panel). B Assessment of turbidity indicating recombinant His-BP1-GFP, His-BP1ΔIDR1-GFP, and His-BP1ΔIDR2-GFP droplet formation. Tubes contained 30 μM His-BP1-GFP, His-BP1ΔIDR1-GFP, or His-BP1ΔIDR2-GFP in 10% (w/v) PEG 8000. C Representative fluorescence images of His-BP1-GFP, His-BP1ΔIDR1-GFP, and His-BP1ΔIDR2-GFP droplets. Scale bar, 5 μm. D Images showing the vegetative growth phenotypes of wild-type PH-1, ΔBP1, and the complementation strains ΔBP1-C, BP1ΔIDR1-C (lacking IDR1), and BP1ΔIDR2-C (lacking IDR2), grown on PDA medium for 3 days before imaging. E Subcellular localization of the IDR-deletion variants, BP1ΔIDR1-C, and BP1ΔIDR2-C, in mycelia grown in YEPD medium for 24 h. Scale bar, 5 µm. F BP1ΔIDR1-GFP nuclear puncta (upper panels) and BP1ΔIDR2-GFP diffuse nuclear localization (lower panels were subjected to FRAP experiments using a Zeiss LSM 980 confocal laser-scanning microscope). The bleaching laser intensity was set to 50%, and the excitation wavelength was 488 nm. G, H Quantification of BP1ΔIDR1-GFP (G) and BP1ΔIDR2-GFP (H) fluorescence intensity before and after bleaching, with six nuclei analyzed per strain