Fig. 3: PICNIC captures the different condensation behavior of paralogs and mutant sequences.

a The three paralogs of the synuclein family in human share high sequence identity as depicted in the multiple sequence alignment. b Structural models for α-synuclein (yellow), β-synuclein (cyan) and γ-synuclein (green), predicted by AlphaFold2 reveal that β-synuclein has a bent structure. c Despite the high sequence similarity, only α- and γ-synuclein are part of biomolecular condensates, while β-synuclein has not been found in any biomolecular condensates yet and was shown not to phase separate in vitro. d Comparison of prediction scores of different tools in identifying condensate forming (α and γ, green) and non-condensate forming paralog (β, red). PICNIC accurately predicts the condensate-forming ability of the synuclein family, and ranks β-synuclein the lowest, while other tools give equivalent scores to all paralogs or fail to identify the right trend. Vertical lines indicate the threshold used by the various methods to classify condensate-forming proteins. e PICNIC scores of WT (shown as stars) and mutant sequences assembled from the literature (Table S1). f Example of PICNIC’s performance on the mutated sequences of CBX2⁷³. Whereas the scores for the canonical sequence and mutant CBX2_DEA, that both form condensates (green stars) are high, the score decreases for the mutants with reduced ability to condensate (empty red stars) (CBX2_N10) and (CBX2_N16), and for the mutants CBX2_N13 and CBX2_N23 that do not form condensates (red stars). Sequence alignment of the canonical sequence of CBX2 and the mutated sequences studied here. On the left panel the structural alignment between CBX2 (green) and CBX2_N13 (red), as well as CBX2 (green) and CBX2_N23 (purple) points out that even with preserved SSE, their 3D orientation affects the proteins’ property to condensate. Source data are provided as a Source Data file.