Kinase experiment:

TAF1 binding assays are conducted using the EPIgeneous Binding Domain kit B. Binding is determined by the displacement of an acetylated biotin peptide from a GST-tagged TAF1 protein using HTRF with a Eu3+-conjugated GST antibody donor and streptavidin-conjugated acceptor. Compounds (CeMMEC13) are dispensed into assay plates, ProxiPlate-384 Plus using an Echo 525 Liquid Handler. Binding assays are conducted in a final volume of 20 μL with 5 nM TAF1-GST, 50 nM peptide (SGRGK (ac)GGK (ac)GLGK (ac)GGAK (ac)RHRK (biotin)-acid), 6.25 nM Streptavidin-XL665, 1:200 Anti-GST-Eu3+ cryptate and 0.1% DMSO. Assay reagents are dispensed into plates using a Multidrop combi and incubated at room temperature for 3 h. Fluorescence is measured using a PHERAstar microplate reader using the HTRF module with dual emission protocol (A = excitation of 320 nm, emmission of 665 nm, and B = excitation of 320 nm, emission of 620 nm). Raw data are processed to give an HTRF ratio (channel A/B × 10,000), which is used to generate IC50 curves[1].

Cell experiment:

Cells are seeded on clear flat-bottom 96-well or 384-well plates and treated with the indicated compounds (CeMMEC13) for the specified conditions. Live-cell imaging pictures are taken with the Operetta High Content Screening System, 20× objective and nonconfocal mode[1].

CeMMEC13 is a potent inhibitor of TAF1 (2) bromodomain, with an IC50 of 2.1 uM.

CeMMEC13 is a potent inhibitor of TAF1 (2) bromodomain, with an IC50 of 2.1 uM. CeMMEC13 shows little or no effects on REDNESS, BRD4, CREBBP. CeMMEC13 (0-20 uM) in combination with (S)-JQ1 increases RFP expression in REDS3 cells and is effective reducing the viability of H23 and THP1 cells, better than that of single treatment[1].

References:
[1]. Sdelci S, et al. Mapping the chemical chromatin reactivation landscape identifies BRD4-TAF1 cross-talk. Nat Chem Biol. 2016 Jul;12(7):504-10.