The induction of adaptive response to alkylating agents in Escherichia coli reduces the frequency of specific C-->T mutations in chloroacetaldehyde-treated M13 glyU phage.
The mutagenicity and repair of cytosine adducts formed in reactions of chloroacetaldehyde (CAA), a metabolite of the human carcinogen vinyl chloride, have been studied. The treatment of single-stranded DNA M13 JCM15472 (glyU313) phage with CAA and subsequent transfection of Escherichia coli K-12 JC15419 (trpA461) tester strain resulted in a dose-dependent increase of phage C-->T transitions and a decrease of phage survival. The induction of the adaptive response to alkylating agents in bacterial cells significantly decreased the frequency of examined C-->T transitions and increased phage survival. The results indicate that both CAA adducts to cytosine, the initially formed 3,N4-(N4-alpha-hydroxyethano)cytosine and the product of its dehydration, 3,N4-ethenocytosine, provoke C-->T transitions and are repaired in adapted bacteria. The role of 3-methyladenine-DNA glycosylase II, which is a part of the adaptive response system in E. coli, in excision of CAA adducts to cytosine, is discussed.
Borys
E
E
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa.
Mroczkowska-Słupska
M M
MM
Kuśmierek
J T
JT
D000079:Acetaldehyde / Q000031:analogs & derivatives / Q000494:pharmacology; D000222:Adaptation, Physiological; D000477:Alkylating Agents / Q000494:pharmacology*; D000926:Anticodon / Q000235:genetics; D001483:Base Sequence; D003090:Coliphages / Q000187:drug effects / Q000235:genetics; D018736:DNA Adducts / Q000378:metabolism; D004260:DNA Repair; D004279:DNA, Viral / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D017354:Point Mutation
D000477:Alkylating Agents; D000926:Anticodon; D018736:DNA Adducts; D004279:DNA, Viral; C004656:chloroacetaldehyde; D000079:Acetaldehyde