Topoisomerase I-mediated DNA damage.
Topoisomerase I is a ubiquitous and essential enzyme in multicellular organisms. It is involved in multiple DNA transactions including DNA replication, transcription, chromosome condensation and decondensation, and probably DNA recombination. Besides its activity of DNA relaxation necessary to eliminate torsional stresses associated with these processes, topoisomerase I may have other functions related to its interaction with other cellular proteins. Topoisomerase I is the target of the novel anticancer drugs, the camptothecins. Recently a broad range of physiological and environmentally-induced DNA modifications have also been shown to poison topoisomerases. This review summarizes the various factors that enhance or suppress top1 cleavage complexes and discusses the significance of such effects. We also review the different mechanisms that have been proposed for the repair of topoisomerase I-mediated DNA lesions.
Pourquier
P
P
Laboratory of Molecular Pharmacology, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Pommier
Y
Y
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D002384:Catalysis; D004247:DNA / Q000378:metabolism; D004249:DNA Damage; D004260:DNA Repair; D004264:DNA Topoisomerases, Type I / Q000737:chemistry* / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D011485:Protein Binding; D017434:Protein Structure, Tertiary
D000970:Antineoplastic Agents; D004247:DNA; D004264:DNA Topoisomerases, Type I