Mutagenesis induced by a single 1,N6-ethenodeoxyadenosine adduct in human cells.
To study the genotoxic properties of 1,N6-ethenodeoxyadenosine (epsilondA) in human cells, a novel site-specific mutagenesis approach was developed, in which a single DNA adduct was uniquely placed in either strand of a shuttle plasmid vector. The analysis of progeny plasmid derived from the modified strand shows that epsilondA, when incorporated into the position of the second A of 5'-CAA (codon 61 of the ras gene), is mutagenic in human cells, inducing A-->T, A-->G, and A-->C mutations. The efficient induction of A-->T transversions in experiments using modified double- and singlestranded DNA substrates supports the hypothesis that A:T-->T:A transversions in human and animal tumors induced by vinyl compounds reflect misinsertion of dAMP opposite this adduct. Mutagenic events were similar when the adduct was incorporated into either the leading or the lagging strand. EpsilondA was more mutagenic than 8-oxodeoxyguanosine, which induced targeted G-->T transversions in HeLa cells. In Escherichia coli, epsilondA did not significantly miscode (<0.27%) even in the presence of induced SOS functions.
Levine
R L
RL
Molecular and Cellular Pharmacology Program, State University of New York at Stony Brook, 11794-8651, USA.
Yang
I Y
IY
Hossain
M
M
Pandya
G A
GA
Grollman
A P
AP
Moriya
M
M
D001483:Base Sequence; D003062:Codon; D004247:DNA / Q000138:chemical synthesis / Q000187:drug effects / Q000235:genetics; D018736:DNA Adducts / Q000235:genetics; D004249:DNA Damage / Q000235:genetics; D003838:Deoxyadenine Nucleotides / Q000235:genetics; D003839:Deoxyadenosines / Q000235:genetics* / Q000633:toxicity*; D004926:Escherichia coli / Q000235:genetics; D017353:Gene Deletion; D011905:Genes, ras / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D014162:Transfection; D014169:Transformation, Bacterial
D003062:Codon; D018736:DNA Adducts; D003838:Deoxyadenine Nucleotides; D003839:Deoxyadenosines; C012873:2'-deoxy-5'-adenosine monophosphate; C032221:1,N(6)-ethenodeoxyadenosine; D004247:DNA