ADP-ribosylation is a reversible posttranslational modification used to regulate protein function. ADP-ribosyltransferases, such as ART3, transfer ADP-ribose from NAD+ to the target protein, and ADP-ribosylhydrolases (see PARG; MIM 603501) reverse the reaction (Glowacki et al., 2002 [PubMed 12070318]).[supplied by OMIM