title: Structural Basis of Detection and Signaling of DNA Single-Strand Breaks by Human PARP-1.
abstract: Poly(ADP-ribose)polymerase 1 (PARP-1) is a key eukaryotic stress sensor that responds in seconds to DNA single-strand breaks (SSBs), the most frequent genomic damage. A burst of poly(ADP-ribose) synthesis initiates DNA damage response, whereas PARP-1 inhibition kills BRCA-deficient tumor cells selectively, providing the first anti-cancer therapy based on synthetic lethality. However, the mechanism underlying PARP-1's function remained obscure; inherent dynamics of SSBs and PARP-1's multi-domain architecture hindered structural studies. Here we reveal the structural basis of SSB detection and how multi-domain folding underlies the allosteric switch that determines PARP-1's signaling response. Two flexibly linked N-terminal zinc fingers recognize the extreme deformability of SSBs and drive co-operative, stepwise self-assembly of remaining PARP-1 domains to control the activity of the C-terminal catalytic domain. Automodification in cis explains the subsequent release of monomeric PARP-1 from DNA, allowing repair and replication to proceed. Our results provide a molecular framework for understanding PARP inhibitor action and, more generally, allosteric control of dynamic, multi-domain proteins.
authors.affiliation: Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Eustermann
authors.affiliation: Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
authors.forename: Wing-Fung
authors.initials: WF
authors.lastname: Wu
authors.affiliation: Department of Molecular Biology and Biochemistry, Sidney Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, Bluemle Life Sciences Building, Room 804, Philadelphia, PA 19107, USA.
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Langelier
authors.affiliation: Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
authors.forename: Ji-Chun
authors.initials: JC
authors.lastname: Yang
authors.affiliation: Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Easton
authors.affiliation: Department of Molecular Biology and Biochemistry, Sidney Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, Bluemle Life Sciences Building, Room 804, Philadelphia, PA 19107, USA.
authors.forename: Amanda A
authors.initials: AA
authors.lastname: Riccio
authors.affiliation: Department of Molecular Biology and Biochemistry, Sidney Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, Bluemle Life Sciences Building, Room 804, Philadelphia, PA 19107, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Pascal
authors.affiliation: Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK. Electronic address: dn@mrc-lmb.cam.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Neuhaus
mesh_terms: D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D053904:DNA Breaks, Single-Stranded; D004260:DNA Repair; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry* / Q000378:metabolism*; D017510:Protein Folding; D016335:Zinc Fingers
chemical_list: D004247:DNA; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases