Molecular Basis for the N-Terminal Bromodomain-and-Extra-Terminal-Family Selectivity of a Dual Kinase–Bromodomain Inhibitor
作者:Anand Divakaran、Siva K. Talluri、Alex M. Ayoub、Neeraj K. Mishra、Huarui Cui、John C. Widen、Norbert Berndt、Jin-Yi Zhu、Angela S. Carlson、Joseph J. Topczewski、Ernst K. Schonbrunn、Daniel A. Harki、William C. K. Pomerantz
DOI:10.1021/acs.jmedchem.8b01248
日期:2018.10.25
As regulators of transcription, epigenetic proteins that interpret post-translational modifications to N-terminal histone tails are essential for maintaining cellular homeostasis. When dysregulated, "reader" proteins become drivers of disease. In the case of bromodomains, which recognize N-epsilon-acetylated lysine, selective inhibition of individual bromodomain-and-extra-terminal (BET)family bromodomains has proven challenging. We describe the >55-fold N-terminal-BET bromodomain selectivity of 1,4,5-trisubstituted-imidazole dual kinase-bromodomain inhibitors. Selectivity for the BRD4 N-terminal bromodomain (BRD4(1)) over its second bromodomain (BRD4(2)) arises from the displacement of ordered waters and the conformational flexibility of lysine-141 in BRD4(1). Cellular efficacy was demonstrated via reduction of c-Myc expression, inhibition of NF-kappa B signaling, and suppression of IL-8 production through potential synergistic inhibition of BRD4(1) and p38a. These dual inhibitors provide a new scaffold for domain-selective inhibition of BRD4, the aberrant function of which plays a key role in cancer and inflammatory signaling.