Fig. 2: p300BRPHZ is heterogeneously acetylated and SIRT2-induced deacetylation promotes phase separation of p300BRPHZ.
a, b Representative images of two independently expressed and purified p300BRPHZ samples containing 13 µM protein and 12% PEG in a 50 µm × 50 µm square region on cover slides under a microscope. c, d Liquid chromatography–mass spectrometry (LC–MS) analysis of p300BRPHZ shown in (a). A table of peak mass and the corresponding number of acetylated lysine residues identified by mass spectrometry analysis are shown in (c) and (d). e, f Representative images of p300BRPHZ samples shown in (a) and (b) were treated with the deacetylase SIRT2. g, h LC–MS analysis of p300BRPHZ shown in (e). A table of peak mass and the corresponding number of acetylated lysine residues identified by mass spectrometry analysis are shown in (g) and (h). i Quantification of droplets counted in images acquired for the samples in (a, b, e, f). The number of droplets was counted in five non-overlapping 50 µm × 50 µm square regions and the mean value was plotted. Error bars represent SD. j Acetylated sites in p300BRPHZ identified by LC–MS/MS. Vertical bars indicate differences in signal intensities of identical tryptic peptides derived from untreated vs. SIRT2-treated samples on the log2 scale. The highest intensities exceeding the plot were essentially qualitative, as they were only present in the untreated sample. A schematic representation of p300BRPHZ is shown above. Source data are provided in the Source Data file.
