title: PARP activation regulates the RNA-binding protein NONO in the DNA damage response to DNA double-strand breaks.
abstract: After the generation of DNA double-strand breaks (DSBs), poly(ADP-ribose) polymerase-1 (PARP-1) is one of the first proteins to be recruited and activated through its binding to the free DNA ends. Upon activation, PARP-1 uses NAD+ to generate large amounts of poly(ADP-ribose) (PAR), which facilitates the recruitment of DNA repair factors. Here, we identify the RNA-binding protein NONO, a partner protein of SFPQ, as a novel PAR-binding protein. The protein motif being primarily responsible for PAR-binding is the RNA recognition motif 1 (RRM1), which is also crucial for RNA-binding, highlighting a competition between RNA and PAR as they share the same binding site. Strikingly, the in vivo recruitment of NONO to DNA damage sites completely depends on PAR, generated by activated PARP-1. Furthermore, we show that upon PAR-dependent recruitment, NONO stimulates nonhomologous end joining (NHEJ) and represses homologous recombination (HR) in vivo. Our results therefore place NONO after PARP activation in the context of DNA DSB repair pathway decision. Understanding the mechanism of action of proteins that act in the same pathway as PARP-1 is crucial to shed more light onto the effect of interference on PAR-mediated pathways with PARP inhibitors, which have already reached phase III clinical trials but are until date poorly understood.
authors.affiliation: Cancer Research Unit, Laval University Medical Research Center, CHUQ-CRCHUL, Genome Stability Laboratory, Laval University Cancer Research Center, Hôtel-Dieu de Québec, QC, Canada G1R 2J6.
authors.forename: Jana
authors.initials: J
authors.lastname: Krietsch
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Caron
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Gagné
authors.forename: Chantal
authors.initials: C
authors.lastname: Ethier
authors.forename: Julien
authors.initials: J
authors.lastname: Vignard
authors.forename: Michel
authors.initials: M
authors.lastname: Vincent
authors.forename: Michèle
authors.initials: M
authors.lastname: Rouleau
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hendzel
authors.forename: Guy G
authors.initials: GG
authors.lastname: Poirier
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Masson
mesh_terms: D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism; D053903:DNA Breaks, Double-Stranded; D059766:DNA End-Joining Repair; D004268:DNA-Binding Proteins; D006367:HeLa Cells; D059765:Homologous Recombination; D006801:Humans; D051379:Mice; D034521:Nuclear Matrix-Associated Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D050810:Octamer Transcription Factors / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D000071137:Poly (ADP-Ribose) Polymerase-1; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D016601:RNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D011839:Radiation, Ionizing
chemical_list: D002843:Chromatin; D004268:DNA-Binding Proteins; C083214:NONO protein, human; D034521:Nuclear Matrix-Associated Proteins; D050810:Octamer Transcription Factors; D016601:RNA-Binding Proteins; D011064:Poly Adenosine Diphosphate Ribose; C499321:Parp1 protein, mouse; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases