title: Escherichia coli lacZ strains engineered for detection of frameshift mutations induced by aromatic amines and nitroaromatic compounds.
abstract: Escherichia coli lacZ strains CC107-CC111, which detect specific frameshift mutations, were used to study the mutational specificities of 2-nitro-3-methylimidazo[4,5-f] quinoline (NO2-IQ) and rat hepatic S9-activated 2-amino-3-methylimidazo[4,5-f]quinoline (IQ). New constructs were made in which UvrABC-dependent excision repair was eliminated (strains DJ3107-DJ3111), followed by introduction of plasmid pYG219 conferring acetyl CoA:arylamine N-acetyltransferase/acetyl CoA:arylhydroxylamine O-acetyltransferase (NAT/OAT) activity (strains DJ3207-DJ3211). Sensitivity to mutagens was greatly enhanced. The mutational specificity of NO2-IQ was identical to that of the corresponding amine, IQ. The most prominent mutations caused by the two compounds were -2(CGGC) and 1(CG) frameshifts. +1(AT) Frameshifts play a minor role in the pattern of mutational specificity. Induction of all three mutations was similarly influenced by NAT/OAT activation and UvrABC-dependent excision repair. These new tester strains provide an effective tool for the study of aromatic amine mutational specificity and the influences of excision repair and NAT/OAT activation.
authors.affiliation: Guelph-Waterloo Centre for Graduate Work in Chemistry, Department of Chemistry and Biochemistry, University of Guelph, Ontario, Canada.
authors.forename: T M
authors.initials: TM
authors.lastname: Marwood
authors.forename: D
authors.initials: D
authors.lastname: Meyer
authors.forename: P D
authors.initials: PD
authors.lastname: Josephy
mesh_terms: D000123:Acetyltransferases; D000217:Acyltransferases / Q000378:metabolism; D000483:Alleles; D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism; D001483:Base Sequence; D004260:DNA Repair; D004789:Enzyme Activation; D004926:Escherichia coli / Q000235:genetics*; D016368:Frameshift Mutation / Q000187:drug effects; D007763:Lac Operon; D008969:Molecular Sequence Data; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D011804:Quinolines / Q000633:toxicity*; D051381:Rats; D012680:Sensitivity and Specificity
chemical_list: D009153:Mutagens; D011804:Quinolines; C071417:2-nitro-3-methylimidazo(4,5-f)quinoline; C029216:2-amino-3-methylimidazo(4,5-f)quinoline; D000217:Acyltransferases; D000123:Acetyltransferases; C019736:N-hydroxyarylamine O-acetyltransferase; D001191:Arylamine N-Acetyltransferase