ADP-ribosyltransferase that mediates mono-ADP-ribosylation of glutamate and aspartate residues on target proteins ( , ). In contrast to PARP1 and PARP2, it is not able to mediate poly-ADP-ribosylation . Catalyzes mono-ADP-ribosylation of GSK3B, leading to negatively regulate GSK3B kinase activity . Involved in translesion DNA synthesis in response to DNA damage via its interaction with PCNA .
Subcellular locations: Nucleus, Nucleolus, Cytoplasm
Shuttles between the nuclear and cytoplasmic compartment . A subpopulation concentrates in the nucleolus during late G1/S phase .
Highly expressed in spleen and thymus . Intermediate levels in liver, kidney, pancreas, prostate, testis, ovary, intestine, and leukocytes . Low expression in heart, brain, placenta, lung, skeletal muscle, and colon .