Figure 2.

Determinants and consequences of ADP-ribose and poly(ADP-ribose) structural diversity. ADP-ribosylation is a multifaceted post-translational modification carried out by the family of ADP-ribosyltransferases diphtheria toxin-like (ARTDs, aka PARPs). Acceptor molecules, such as proteins, DNA, and RNA, are covalently modified with ADP-ribose units, and modifications can consist of either a single moiety (mono-ADP-ribosylation, MARylation)—mediated by mono-ARTs—or linear and/or branched chains (poly(ADP-ribosyl)ation, PARylation)—mediated by poly-ARTs. Determinants such as the activity or naturally occurring mutations of different PARP family members, the interplay with different accessory factors, other post-translational modifications, or the intracellular NAD⁺ concentration might determine the structure of the ADP-ribose modification. Consequently, the different structure of the modification can influence its degradation, downstream binding partners, the formation of biomolecular condensates, and thereby diverse cellular endpoints.