Extended Data Fig. 1: The effect of IRF3 or STAT1 activation and oligomerization on p300 autoacetylation.
From: Transcription factor dimerization activates the p300 acetyltransferase
a, The domain structure of IRF3. The truncation construct used is shown at the bottom. b, Size-exclusion chromatography of IRF3 variants. Red, unphosphorylated IRF3; blue, phosphorylated pIRF3; green, C-terminally truncated IRF3ΔC. Representative data of three independent experiments are shown. c, A constant amount of p300s (2 μM) was incubated alone or in the presence of C-terminally truncated IRF3ΔC (2 μM) for the indicated time points. Samples were analysed by SDS–PAGE followed by Coomassie staining and autoradiography. d, Progress curves of HAT scintillation proximity assay. Histone H4 substrate acetylation in the presence (green) or absence (black) of pIRF3 and varying concentrations of [3H]acetyl-CoA. The degree of histone H4 substrate acetylation at different time points and the initial velocity (cpm min−1) at the indicated acetyl-CoA concentrations were determined and plotted in Fig. 1e. Three independent experiments were performed and the mean value and error bars representing the standard deviation are shown. e, The domain structure of STAT1. The truncation constructs used are shown at the bottom, and the Tyr701 phosphorylation site is indicated. f, Uncropped images of SDS–PAGE gels shown in Fig. 1d. The 14C autoacetylation signal of p300s is shown at the bottom. g, Size-exclusion chromatography of STAT1 variants. Black, STAT1ΔNC; green, STAT1ΔN; red, Y701-phosphorylated pSTAT1ΔNC; blue, Y701-phosphorylated pSTAT1ΔN. h, SDS–PAGE analysis of STAT1 variants and analysis by western blotting. Top, Coomassie staining of SDS–PAGE gel; middle, PonceauS staining; bottom, western blot using anti-Phospho-Stat1 (Tyr701). Representative data of three independent experiments are shown. For gel source data, see Supplementary Fig. 1.
