ADPribosyl

ADPribosyl refers to the ADP-ribosyl group or the biochemical process known as ADP-ribosylation, a post-translational and regulatory modification in which an ADP-ribose moiety is transferred to target substrates. The donor is typically nicotinamide adenine dinucleotide (NAD+), which is cleaved to yield the ADP-ribose unit that becomes covalently attached to a substrate. ADPribosylation occurs in two main forms: mono-ADP-ribosylation (MAR), the addition of a single ADP-ribose unit, and poly-ADP-ribosylation (PAR), the formation of poly(ADP-ribose) chains.

Enzymes that mediate ADPribosylation are called ADP-ribosyltransferases (ARTs) for MAR and poly(ADP-ribose) polymerases (PARPs) for PAR. Target substrates include proteins, and in some contexts nucleic acids or small molecules. The modification can affect protein function, interaction networks, localization, and activity, and plays a central role in cellular processes such as the DNA damage response, chromatin remodeling, transcriptional regulation, and stress signaling. In bacterial systems, certain toxins use ART activity to modify host proteins, disrupting signaling or metabolism.

Reversal of ADPribosylation is achieved by hydrolases and glycohydrolases, such as ARH1 and ARH3 for MAR and PARG for PAR chains, enabling dynamic regulation. Dysregulation of ADPribosylation has been linked to diseases, including cancer and inflammatory disorders, and it is a target of therapeutic research. Detection and study rely on mass spectrometry, specialized antibodies or affinity reagents, and analyses of PAR chains and MAR-modified substrates.