title: Poly(ADP-ribose) polymerase-1 could facilitate the religation of topoisomerase I-linked DNA inhibited by camptothecin.
abstract: Poly(ADP-ribose) polymerase-1 (PARP-1) is known to have an important role in camptothecin sensitivity and interacts with topoisomerase I. In the present study, the impact of PARP-1 on the topoisomerase I-DNA complex stabilized by camptothecin was assessed. It was shown that NH2 terminus-truncated topoisomerase I (amino acids 201-765) showed at least 4-fold less sensitivity to camptothecin than full-length topoisomerase I in the oligonucleotide religation assay. PARP-1 could prevent the action of camptothecin on the religation activity of full-length topoisomerase I, which is linked to DNA in a stoichiometrical manner. However, the religation activity of NH2 terminus-truncated topoisomerase I, which is linked to DNA, could not be enhanced by PARP-1 in the presence of camptothecin. Both full-length and NH2 terminus-truncated topoisomerase I interact with PARP-1. This data suggests that PARP-1 destabilizes the topoisomerase I-camptothecin-DNA complex with the participation of the NH2-terminal domain of topoisomerase I. Poly(ADP-ribosyl)ation of topoisomerase I by PARP-1 in the presence its substrate, NAD, could also promote the religation activity of full-length topoisomerase I as well as NH2 terminus-truncated topoisomerase I. PARP-1 inhibitors (3-aminobenzamide, PJ34) could inhibit this process. Therefore, PARP-1 could facilitate the religation activity of topoisomerase I by itself through topoisomerase I-PARP-1 interaction (PARP-1 action) or by the formation of poly(ADP-ribosyl)ation of topoisomerase I (PARP-1/NAD action). This study also implies that PARP-1 and PARP-1/NAD actions need to be highly regulated by cellular factors for camptothecin to exert its cytotoxicity inside the cells. We propose ATP to be one of the important regulatory factors.
authors.affiliation: Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520-8066, USA.
authors.forename: Shin-Young
authors.initials: SY
authors.lastname: Park
authors.forename: Yung-Chi
authors.initials: YC
authors.lastname: Cheng
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D002166:Camptothecin / Q000494:pharmacology*; D004247:DNA / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004264:DNA Topoisomerases, Type I / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D009243:NAD / Q000378:metabolism; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D059004:Topoisomerase I Inhibitors
chemical_list: D009841:Oligonucleotides; D010446:Peptide Fragments; D011994:Recombinant Proteins; D059004:Topoisomerase I Inhibitors; D009243:NAD; D000255:Adenosine Triphosphate; D004247:DNA; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D004264:DNA Topoisomerases, Type I; D002166:Camptothecin