PARP14 is a PARP with both ADP-ribosyl transferase and hydrolase activities

This is the final version. Available on open access from the American Association for the Advancement of Science via the DOI in this recordData availability: The MS proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE (92) partner repository with the dataset identifier PXD043452.PARP14 is a mono-ADP-ribosyl transferase involved in the control of immunity, transcription, and DNA replication stress management. However, little is known about the ADP-ribosylation activity of PARP14, including its substrate specificity or how PARP14-dependent ADP-ribosylation is reversed. We show that PARP14 is a dual-function enzyme with both ADP-ribosyl transferase and hydrolase activity acting on both protein and nucleic acid substrates. In particular, we show that the PARP14 macrodomain 1 is an active ADP-ribosyl hydrolase. We also demonstrate hydrolytic activity for the first macrodomain of PARP9. We reveal that expression of a PARP14 mutant with the inactivated macrodomain 1 results in a marked increase in mono(ADP-ribosyl)ation of proteins in human cells, including PARP14 itself and antiviral PARP13, and displays specific cellular phenotypes. Moreover, we demonstrate that the closely related hydrolytically active macrodomain of SARS2 Nsp3, Mac1, efficiently reverses PARP14 ADP-ribosylation in vitro and in cells, supporting the evolution of viral macrodomains to counteract PARP14-mediated antiviral response.Biotechnology and Biological Sciences Research Council (BBSRC)Wellcome TrustOxford University Challenge Seed FundEdward Penley Abraham Research FundOvarian Cancer Research AllianceResearch Council of NorwaySwedish Research CouncilMedical Research Council (MRC)Novo Nordisk Foundation Center for Protein ResearchDanish Council of Independent ResearchDanish Cancer Societ