Fig. 1: P300/CBP TAZ2 domain truncations inhibit cell growth and increase histone H3K18 and H3K27 acetylation.

a Schematic of the p300/CBP protein structure. Amino acid numbers, domains, and the catalytic core are labeled. TAZ transcriptional adapter zinc-binding domain, KIX kinase-inducible domain interacting domain, BRD bromodomain, RING Really Interesting New Gene domain, PHD plant homeodomain, HAT histone acetyltransferase domain, ZZ ZZ-type zinc finger, IBiD IRF-3 binding domain. b CRISPR-knockout hyper-sensitivity (CKHS) profiles of p300/CBP tiling sgRNA screens in RKO (p300 null, CBP WT) and DLD-1 (p300 and CBP WT) cell lines. X-axis is amino acid location of p300/CBP with domains color-coded as in a. Y-axis is Z-score of sgRNA count with negative values indicating dropout effect. Each dot represents an sgRNA mapped to the amino acid location in X-axis. Gray and blue dots represent filtered and remaining sgRNAs, respectively. Red lines show the segmented protein regions and sgRNAs dropout signal levels. c, d Growth curves of DLD-1 cells expressing sgRNAs targeting the HAT, TAZ2, ZZ, and IBiD domains of p300 c and CBP d. Error bars represent the standard error of the mean (s.e.m.) of 3 biological replicates. *, **, *** indicate p-values < 0.05, <0.01, and <0.001, respectively. N.S.: not significant (Two-way ANOVA). All p-values are calculated with the GFP-sg as control and are 0.5986, 0.0015, 0.0091, 0.1951 and 0.6126 for p300 HAT-sg, TAZ2-sg1, TAZ2-sg2, ZZ-sg and IBiD-sg, respectively, and 0.9902, 0.0058, 0.0003, 0.036 and 0.9747 for CBP HAT-sg, TAZ2-sg1, TAZ2-sg2, ZZ-sg and IBiD-sg, respectively. e, f Western blots of p300, CBP, and H3 acetylation in cells as in c, d. Red asterisks indicate the truncated proteins. Bands below the full-length and truncated p300/CBP proteins are degraded proteins that occurred during sample preparation. g Western blots of p300 and histone acetylation in the cell lines containing p300 truncations (OVCAR-5 and OVCAR-8) and p300 WT cell lines (others). Red asterisk indicates truncated p300. In e–g, blots are representative data from three biological experiments. h Boxplot of normalized mass spectrometry signals of H3K18ac and H3K27ac containing peptides from CCLE cell lines with the indicated p300/CBP status. The boxplots are generated by R and show 0, 0.25,0.5, 0.75, and 1 quantile. p300/CBP WT n = 1571 cell lines, p300/CBP TAZ2 truncations n = 15 cell lines, p300/CBP other truncations n = 100 cell lines. *, **, ***, and **** indicate p-values < 0.05, <0.01, <0.001, and <0.0001, respectively. N.S.: not significant (FDR adjusted Wilcoxon rank sum test). p-values from left to right are: 9.76E-5, 1.36E-3, 9.76E-5, 2.25E-2, 7.15E-3, 2.41E-1,1.30E-2, 4.27E-3, 3.20E-4, 1.05E-4, 3.28E-4, 3.99E-3. Source data are provided as a Source Data file.