ADP‐ribosylation of histones by ARTD1: An additional module of the histone code?

ADP‐ribosylation is a covalent post‐translational protein modification catalyzed by ADP‐ribosyltransferases and is involved in important processes such as cell cycle regulation, DNA damage response, replication or transcription. Histones are ADP‐ribosylated by ADP‐ribosyltransferase diphtheria toxin‐like 1 at specific amino acid residues, in particular lysines, of the histones tails. Specific ADP‐ribosyl hydrolases and poly‐ADP‐ribose glucohydrolases degrade the ADP‐ribose polymers. The ADP‐ribose modification is read by zinc finger motifs or macrodomains, which then regulate chromatin structure and transcription. Thus, histone ADP‐ribosylation may be considered an additional component of the histone code.