Adp-ribosylation is a process where an ADP-ribose moiety is transferred from NAD+ to a target protein. This process has a crucial role in various cellular processes such as DNA repair, gene expression, and cell signaling. In scientific literature, adp-ribosylation is often described as mono-ADP-ribosylation, poly-ADP-ribosylation, or ADP-ribosyltransferase. Mono-ADP-ribosylation is the transfer of a single ADP-ribose moiety to a target protein, while poly-ADP-ribosylation entails the transfer of multiple ADP-ribose molecules. Additionally, ADP-ribosyltransferases are a class of enzymes that are responsible for catalyzing the ADP-ribosylation reaction.