ARTD10 substrate identification on protein microarrays: regulation of GSK3β by mono-ADP-ribosylation

Background Although ADP-ribosylation has been described five decades ago, only recently a distinction has been made between eukaryotic intracellular poly- and mono-ADP-ribosylating enzymes. Poly-ADP-ribosylation by ARTD1 (formerly PARP1) is best known for its role in DNA damage repair. Other polymer forming enzymes are ARTD2 (formerly PARP2), ARTD3 (formerly PARP3) and ARTD5/6 (formerly Tankyrase 1/2), the latter being involved in Wnt signaling and regulation of 3BP2. Thus several different functions of poly-ADP-ribosylation have been well described whereas intracellular mono-ADP-ribosylation is currently largely undefined. It is for example not known which proteins function as substrate for the different mono-ARTDs. This is partially due to lack of suitable reagents to study mono-ADP-ribosylation, which limits the current understanding of this post-translational modification.