title: PARP-1 Activation Requires Local Unfolding of an Autoinhibitory Domain.
abstract: Poly(ADP-ribose) polymerase-1 (PARP-1) creates the posttranslational modification PAR from substrate NAD(+) to regulate multiple cellular processes. DNA breaks sharply elevate PARP-1 catalytic activity to mount a cell survival repair response, whereas persistent PARP-1 hyperactivation during severe genotoxic stress is associated with cell death. The mechanism for tight control of the robust catalytic potential of PARP-1 remains unclear. By monitoring PARP-1 dynamics using hydrogen/deuterium exchange-mass spectrometry (HXMS), we unexpectedly find that a specific portion of the helical subdomain (HD) of the catalytic domain rapidly unfolds when PARP-1 encounters a DNA break. Together with biochemical and crystallographic analysis of HD deletion mutants, we show that the HD is an autoinhibitory domain that blocks productive NAD(+) binding. Our molecular model explains how PARP-1 DNA damage detection leads to local unfolding of the HD that relieves autoinhibition, and has important implications for the design of PARP inhibitors.
authors.affiliation: Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA.
authors.forename: Jennine M
authors.initials: JM
authors.lastname: Dawicki-McKenna
authors.affiliation: Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107-5544, USA.
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Langelier
authors.affiliation: Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA; Graduate Program in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA.
authors.forename: Jamie E
authors.initials: JE
authors.lastname: DeNizio
authors.affiliation: Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107-5544, USA.
authors.forename: Amanda A
authors.initials: AA
authors.lastname: Riccio
authors.affiliation: Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA.
authors.forename: Connie D
authors.initials: CD
authors.lastname: Cao
authors.affiliation: Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA; Graduate Program in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA.
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Karch
authors.affiliation: Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107-5544, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: McCauley
authors.affiliation: Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107-5544, USA.
authors.forename: Jamin D
authors.initials: JD
authors.lastname: Steffen
authors.affiliation: Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA; Graduate Program in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA. Electronic address: blackbe@mail.med.upenn.edu.
authors.forename: Ben E
authors.initials: BE
authors.lastname: Black
authors.affiliation: Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107-5544, USA. Electronic address: john.pascal@umontreal.ca.
authors.forename: John M
authors.initials: JM
authors.lastname: Pascal
mesh_terms: D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism*; D053960:DNA Breaks; D004260:DNA Repair; D041961:Deuterium Exchange Measurement; D006801:Humans; D008958:Models, Molecular; D009154:Mutation; D009243:NAD / Q000378:metabolism; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D058767:Protein Unfolding
chemical_list: D009243:NAD; D004247:DNA; C499320:PARP1 protein, human; C483041:PARP2 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases