Mammalian N1-adenosine PARylation is a reversible DNA modification

• DOI: 10.1038/s41467-022-33731-w
• Publication Date: 2022-10-17T14:09:41Z
• Authors: Michael U. Musheev; Lars Schomacher; Amitava Basu; Dandan Han; Laura Krebs; Carola Scholz; Christof Niehrs
• Keywords: 0301 basic medicine; 570; Poly Adenosine Diphosphate Ribose; Adenosine; Glycoside Hydrolases; Science; Poly (ADP-Ribose) Polymerase-1; DNA, Single-Stranded; Poly(ADP-ribose) Polymerase Inhibitors; Article; 570 Life sciences; Poly ADP Ribosylation; 03 medical and health sciences; Tandem Mass Spectrometry; Animals; Mammals; 0303 health sciences; Deoxyadenosines; Q; DNA; Adenosine Diphosphate; ddc:570; Chromatography, Liquid; 570 Biowissenschaften

AbstractPoly-ADP-ribosylation (PARylation) is regarded as a protein-specific modification. However, some PARPs were recently shown to modify DNA termini in vitro. Here, we use ultrasensitive mass spectrometry (LC-MS/MS), anti-PAR antibodies, and anti-PAR reagents to show that mammalian DNA is physiologically PARylated and to different levels in primary tissues. Inhibition of PAR glycohydrolase (PARG) increases DNA PARylation, supporting that the modification is reversible. DNA PARylation requires PARP1 and in vitro PARP1 PARylates single-stranded DNA, while PARG reverts the modification. DNA PARylation occurs at the N1-position of adenosine residues to form N1-Poly(ADP-ribosyl)-deoxyadenosine. Through partial hydrolysis of mammalian gDNA we identify PAR-DNA via the diagnostic deamination product N1-ribosyl-deoxyinosine to occur in vivo. The discovery of N1-adenosine PARylation as a DNA modification establishes the conceptual and methodological framework to elucidate its biological relevance and extends the role of PARP enzymes.