title: Miscoding during DNA synthesis on damaged DNA templates catalysed by mammalian cell extracts.
abstract: Oligodeoxynucleotides, modified site-specifically with 7,8-dihydro-8-oxodeoxyguanosine (8-oxodG), 7,8-dihydro-8-oxoadenosine (8-oxodA) and 6-O-methyldeoxyguanosine (O6medG), were used as templates for DNA synthesis in primer-extension reactions catalysed by extracts prepared from human (HeLa) cells, simian kidney (COS-7) cells and various mouse tissues. Fully-extended reaction products were analysed by two-phase polyacrylamide gel electrophoresis (Shibutani, Chem. Res. Toxicol. 6, 625, 1993). Using extracts prepared from HeLa or COS-7 cells, dAMP was preferentially incorporated opposite 8-oxodG; dTMP was incorporated opposite 8-oxodA and dTMP, accompanied by small amounts of dCMP, was incorporated opposite O6medG. Translesional synthesis was strongly inhibited by N-ethylmaleimide and partially inhibited by N-butylphenyl-dGTP. This model system can be used to predict the mutagenic potential of selectively-damaged DNA in mammalian cells.
authors.affiliation: Department of Pharmacological Sciences, State University of New York at Stony Brook 11794-8651.
authors.forename: S
authors.initials: S
authors.lastname: Shibutani
authors.forename: A P
authors.initials: AP
authors.lastname: Grollman
mesh_terms: D000818:Animals; D001483:Base Sequence; D002522:Chlorocebus aethiops; D004247:DNA / Q000096:biosynthesis*; D004249:DNA Damage; D004257:DNA Polymerase II / Q000037:antagonists & inhibitors; D004261:DNA Replication; D003848:Deoxyguanine Nucleotides / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D005260:Female; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D013698:Templates, Genetic
chemical_list: D003848:Deoxyguanine Nucleotides; D009838:Oligodeoxyribonucleotides; C040364:N(2)-(4-n-butylphenyl)-2'-deoxyguanosine 5'-triphosphate; D004247:DNA; D004257:DNA Polymerase II; D005033:Ethylmaleimide