Fig. 2: SMNDC1 shows biomolecular condensation in vitro and in cellular systems.

a In vitro droplet formation assay with 10 µM GFP or SMNDC1-GFP fusion protein +/− 10% PEG-8000. b In vitro droplet formation assay of SMNDC1-GFP over time with droplet fusion event, marked by red arrows. c In vitro droplet formation assay of SMNDC1-GFP with quantified number of droplets with different protein and NaCl concentrations, +/− 10 ng/µl RNA. d In vitro droplet formation assay of SMNDC1-GFP with the addition of 10 ng/µl total cellular RNA and RNase. e In vitro droplet formation assay of SMNDC1-GFP (green) with 100 ng/µl Cy5-labeled RNA (magenta), overlap white. f In vitro droplet formation assay of different truncations of SMNDC1-GFP + 10 ng/µl total cellular RNA. g Live imaging (SMNDC1-GFP intron 2-3, αTC1), cells were treated with 2.5% or 5% 1,6-hexanediol. Quantifications of GFP intensity and GFP spots/nucleus in different clonal cell lines. Data presented as scatter plot with mean line (n = 4), analyzed by two-tailed, multiple paired t-tests with False Discovery Rate q calculated by Two-stage step-up⁹⁰. h Fluorescence recovery after photobleaching (FRAP) experiment in SMNDC1-GFP intron 2-3, SRRM2-RFP intron 9-10, αTC1-cells. Left: Relative intensity of Hoechst (blue), SMNDC1-GFP (green), and SRRM2-RFP (red) in reference (filled symbols) and bleach region (empty symbols) over time. Data plotted as mean with standard deviation, n = 3. Right: representative images of nucleus with marked reference and bleach region at 3 different timepoints, 0 s (before bleaching), 3 s (directly after bleaching), and 120 s (after recovery).