ADPribosylate

ADPribosylate refers to the enzymatic process involving the transfer of an ADP-ribose molecule to a target substrate, typically a protein, molecule, or cellular component. This post-translational modification plays a critical role in various biological processes, including DNA repair, gene regulation, immune response, and cell signaling.

The process of ADP-ribosylation is catalyzed by a family of enzymes known as ADP-ribosyltransferases or ARTs. These enzymes utilize nicotinamide adenine dinucleotide (NAD+) as a donor of ADP-ribose units. The transfer of ADP-ribose to specific amino acid residues on target proteins can alter the proteins’ activity, interactions, or stability, influencing cellular functions.

ADPribosylation can occur as either mono-ADP-ribosylation, where a single ADP-ribose molecule is attached, or poly-ADP-ribosylation, involving the formation of long chains of ADP-ribose units. Poly-ADP-ribosylation is particularly significant in DNA repair pathways and stress responses, where it facilitates the recruitment of repair proteins to damaged DNA sites.

Several pathogens, including certain bacteria and viruses, produce ADP-ribosylating toxins that disrupt host cell functions by modifying host proteins. In human cells, enzymes like poly(ADP-ribose) polymerases (PARPs) mediate ADP-ribosylation and are targets for therapeutic interventions, especially in cancer and neurodegenerative diseases.

Overall, ADPribosylation is a versatile and dynamic modification that modulates cellular activities and maintains homeostasis through complex signaling networks.