title: Recognition of platinum-DNA damage by poly(ADP-ribose) polymerase-1.
abstract: Poly(ADP-ribose) polymerase-1 (PARP-1) was recently identified as a platinum-DNA damage response protein. To investigate the properties of binding of PARP-1 to different platinum-DNA adducts in greater detail, biotinylated DNA probes containing a site-specific cisplatin 1,2-d(GpG) or 1,3-d(GpTpG) intrastrand cross-link or a cisplatin 5'-GC/5'-GC interstrand cross-link (ICL) were utilized in binding assays with cell-free extracts (CFEs) in vitro. The activated state of PARP-1 was generated by treatment of cells with a DNA-damaging agent or by addition of NAD(+) to CFEs. PARP-1 binds with a higher affinity to cisplatin-damaged DNA than to undamaged DNA, and the amount of protein that binds to the most common cisplatin-DNA cross-link, 1,2-d(GpG), is greater than the amount that binds to other types of cisplatin-DNA cross-links. Both DNA damage-activated PARP-1 and unactivated PARP-1 bind to cisplatin-damaged DNA, and both automodified PARP-1 and cleaved PARP-1 bind to cisplatin-DNA lesions. The role of poly(ADP-ribose) (pADPr) in mediating binding of PARP-1 to platinum damage was further investigated. The extent of binding of PARP-1 to the cisplatin 1,2-d(GpG) cross-link decreases upon automodification, and overactivated PARP-1 loses its affinity for the cross-link. Elimination of pADPr facilitates binding of PARP-1 to the cisplatin 1,2-d(GpG) cross-link. PARP-1 also binds to DNA damaged by other platinum compounds, including oxaliplatin and pyriplatin, indicating protein affinity for the damage in an adduct-specific manner rather than recognition of distorted DNA. Our results reveal the unique binding properties for binding of PARP-1 to platinum-DNA damage, providing insights into, and a better understanding of, the cellular response to platinum-based anticancer drugs.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Guangyu
authors.initials: G
authors.lastname: Zhu
authors.forename: Paul
authors.initials: P
authors.lastname: Chang
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Lippard
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D001483:Base Sequence; D002945:Cisplatin / Q000737:chemistry / Q000494:pharmacology; D018736:DNA Adducts / Q000378:metabolism*; D004249:DNA Damage; D006367:HeLa Cells; D006801:Humans; D009944:Organoplatinum Compounds / Q000737:chemistry / Q000494:pharmacology; D000077150:Oxaliplatin; D010984:Platinum / Q000737:chemistry / Q000494:pharmacology*; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D018736:DNA Adducts; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D010984:Platinum; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D002945:Cisplatin