Fig. 2: β-Syn promotes the liquid-liquid phase separation of α-Syn through electrostatic interactions.
From: β-synuclein regulates the phase transitions and amyloid conversion of α-synuclein
a Representative confocal images of α-Syn (100 μM, 10% Rho-α-Syn) alone, β-Syn (100 μM, 10% FAM-β-Syn) alone, and colocalized α-Syn (100 μM, 10% Rho-α-Syn) and β-Syn (100 μM, 10% FAM-β-Syn) in α-Syn/β-Syn condensates. Scale bar, 5 μm. α-Syn labeled with Rhodamine B (Rho) exhibits red fluorescence, β-Syn labeled with 5(6)-FAM (FAM) exhibits green fluorescence, and the merged channel shows an orange color. b Quantify the number and mean area of the condensates within the field of view using a ×100 oil immersion objective, n = 3 independent biological samples. **PNumber of condensates (α-Syn vs α-Syn + β-Syn) = 0.0004; **PMean area (α-Syn vs α-Syn + β-Syn) < 0.0001. c The turbidity at 405 nm for the indicated group, CT is shown as 20% PEG alone, n = 3 independent biological samples. *PTurbidity (α-Syn vs β-Syn) = 0.0278, **PTurbidity (α-Syn vs α-Syn + β-Syn) < 0.0001. d Sedimentation-based assay indicated the protein distributions of supernatant (S) and precipitate (P) in the different groups. n = 3 independent experiments. e The percentage of proteins in the precipitate of sedimentation-based assay. n = 3 independent experiments. **PSedimentation (α-Syn + β-Syn vs α-Syn) = 0.0002, **PSedimentation (α-Syn + β-Syn vs β-Syn) < 0.0001. f, g Representative FRAP images (f) and normalized FRAP recovery curves (g) of α-Syn with or without β-Syn, n = 6 condensates per group. Scale bar, 1 μm. α-Syn labeled with Rhodamine B (Rho) exhibits red fluorescence. h Representative differential interference contrast (DIC) images of α-Syn/β-Syn condensates after adding indicated concentrations of NaCl (Top) or 1,6-HD (Bottom). Scale bar, 5 μm, n = 3 independent biological samples. i, j The turbidity at 405 nm for α-Syn/β-Syn condensates after adding indicated concentrations of NaCl and 1,6-HD. n = 3 independent biological samples. **PTurbidity (0 mM NaCl vs 100 mM NaCl) < 0.0001, **PTurbidity (0 mM NaCl vs 200 mM NaCl) < 0.0001, **PTurbidity (0 mM NaCl vs 500 mM NaCl) < 0.0001. All experiments were carried out with α-Syn (100 μM), β-Syn (100 μM), and α-Syn (100 μM) + β-Syn (100 μM) in the presence of 20% PEG. Data are presented as mean ± SD, one-way ANOVA was used for multiple experimental groups without adjustment. *P < 0.05; **P < 0.01; ns, no significance. a–j At least three independent experiments were performed with similar results. Source data are provided as a Source Data file.
