title: Specific binding of poly(ADP-ribose) polymerase-1 to cruciform hairpins.
abstract: Poly(ADP-ribose) polymerase-1 (PARP-1) participates in DNA cleavage and rejoining-dependent reactions, such as DNA replication, recombination and repair. PARP-1 is also important in transcriptional regulation, although the determinants for its binding to undamaged genomic DNA have not been defined. Previously, we have shown by low-resolution mapping that PARP-1 may bind to the cruciform-forming regions of its own promoter. Here, using DNase I and nuclease P(1) footprinting and atomic force microscopy, we show that PARP-1 binds to stem/loop boundaries of cruciform hairpins. Cleavage of the cruciform by the junction resolvase T4 endonuclease VII is independent of PARP-1, which indicates that PARP-1 does not bind to the four-arm junctions of the cruciform. Thus, PARP-1 differs from other cruciform-binding proteins by binding to hairpin tips rather than to junctions. Furthermore, our data indicate that PARP-1 can interact with the gene regulatory sequences by binding to the promoter-localized cruciforms.
authors.affiliation: Institute of Biosciences and Technology, Texas A & M University System Health Science Center, 2121 W. Holcombe Blvd., Houston, TX 77030, USA. vpotaman@ibt.tamhsc.edu
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Potaman
authors.forename: Luda S
authors.initials: LS
authors.lastname: Shlyakhtenko
authors.forename: Elena A
authors.initials: EA
authors.lastname: Oussatcheva
authors.forename: Yuri L
authors.initials: YL
authors.lastname: Lyubchenko
authors.forename: Viatcheslav A
authors.initials: VA
authors.lastname: Soldatenkov
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D018983:DNA Footprinting; D005786:Gene Expression Regulation; D006801:Humans; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding
chemical_list: D004247:DNA; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases