Chemical epigenetics: the impact of chemical- and chemical biology techniques on bromodomain target validation.

Epigenetics is currently the focus of intense research interest across a broad range of disciplines due to its importance in a multitude of biological processes and disease states. Epigenetic functions result partly from modification of the nucleobases in DNA and RNA, and/or post-translational modifications of histone proteins. These modifications are dynamic, with cellular machinery identified to modulate and interpret the marks. Our focus is on bromodomains, which bind to acetylated lysine residues. Progress in the study of bromodomains, and the development of bromodomain ligands, has been rapid. These advances have been underpinned by many disciplines, but chemistry and chemical biology have undoubtedly played a significant role. Herein, we review the key chemistry and chemical biology approaches that have furthered our study of bromodomains, enabled the development of bromodomain ligands, and played a critical role in the validation of bromodomains as therapeutic targets.