Synthetic Posttranslational Modifications: Chemical Catalyst-Driven Regioselective Histone Acylation of Native Chromatin.

Posttranslational modifications (PTMs) of histones play an important role in the complex regulatory mechanisms governing gene transcription, and their dysregulation can cause diseases such as cancer. The lack of methods for site-selectively modifying native chromatin, however, limits our understanding of the functional roles of a specific histone PTM, not as a single mark, but in the intertwined PTM network. Here, we report a synthetic catalyst DMAP-SH (DSH), which activates chemically stable thioesters (including acetyl-CoA) under physiological conditions and transfers various acyl groups to the proximate amino groups. Our data suggest that DSH, conjugated with a nucleosome ligand, such as pyrrole-imidazole-polyamide and LANA (latency-associated nuclear antigen)-peptide, promotes both natural (including acetylation, butyrylation, malonylation, and ubiquitination) and non-natural (azido- and phosphoryl labeling) PTMs on histones in recombinant nucleosomes and/or in native chromatin, at lysine residues clo...