title: Mutagenic events in Escherichia coli and mammalian cells generated in response to acetylaminofluorene-derived DNA adducts positioned in the Nar I restriction enzyme site.
abstract: Comparative mutagenesis studies of N-(2'-deoxyguanosin-8-yl)-2-acetylaminofluorene (dG-AAF) and N-(2'-deoxyguanosin-8-yl)-2-aminofluorene (dG-AF) adducts positioned in the Nar I restriction enzyme site were performed using Escherichia coli (E. coli) and simian kidney (COS-7) cells. Oligodeoxynucleotides ((5)(')TCCTCG(1)G(2)CG(3)CCTCTC) containing a recognition sequence for the Nar I restriction enzyme were modified site-specifically with dG-AAF or dG-AF. Modified and unmodified oligomers inserted into single-stranded phagemid shuttle vectors were used to transform E. coli or to transfect COS-7 cells. Following replication in host cells, progeny plasmids were recovered and analyzed for mutations. In SOS-induced E. coli, dG-AAF primarily induced one- and two-base deletions. The mutational frequency varied, depending on the position modified in the Nar I site; 91% two-base deletions were observed at G(3), while 8.4% and 2.8% deletions were detected at G(2) and G(1), respectively. In contrast, dG-AF at any position in the Nar I site failed to produce deletions, generating primarily G --> T transversions (mutational frequency, 7.6-8.4%). In COS-7 cells, both dG-AAF and dG-AF primarily induced G --> T transversions. Mutation frequencies for dG-AAF were 9.4-24%, the highest values being at G(1) and G(3). Mutation frequencies for dG-AF were 9.3-21%, the higher value at G(2). We conclude from this study that the mutation potential of dG-AAF and dG-AF depends on the structure of the adduct, the sequence context of the lesion, and the host cell used for the experiment.
authors.affiliation: Laboratory of Chemical Biology, Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, New York 11794-8651, USA.
authors.forename: Xingzhi
authors.initials: X
authors.lastname: Tan
authors.forename: Naomi
authors.initials: N
authors.lastname: Suzuki
authors.forename: Arthur P
authors.initials: AP
authors.lastname: Grollman
authors.forename: Shinya
authors.initials: S
authors.lastname: Shibutani
mesh_terms: D015073:2-Acetylaminofluorene / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D019556:COS Cells / Q000187:drug effects / Q000378:metabolism; D002522:Chlorocebus aethiops; D018736:DNA Adducts / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004252:DNA Mutational Analysis; D004277:DNA, Single-Stranded / Q000138:chemical synthesis; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D005449:Fluorenes / Q000737:chemistry / Q000494:pharmacology*; D016368:Frameshift Mutation; D009153:Mutagens / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis; D010957:Plasmids / Q000138:chemical synthesis; D017354:Point Mutation
chemical_list: D018736:DNA Adducts; D004277:DNA, Single-Stranded; D005449:Fluorenes; D009153:Mutagens; D009838:Oligodeoxyribonucleotides; C031838:N-(deoxyguanosin-8-yl)-2-aminofluorene; C018776:N-(deoxyguanosin-8-yl)acetylaminofluorene; D015073:2-Acetylaminofluorene; D015252:Deoxyribonucleases, Type II Site-Specific; C046719:GGCGCC-specific type II deoxyribonucleases; D003849:Deoxyguanosine