Mutagenic effects of 2-hydroxy-dATP on replication in a HeLa extract: induction of substitution and deletion mutations.
The mutagenicity of an oxidized form of dATP, 2-hydroxydeoxyadenosine 5'-triphosphate (2-OH-dATP), was examined using an SV40 origin-dependent in vitro replication system with a HeLa extract. 2-OH-dATP induced mutations in a dose-dependent manner and elicited substitution and deletion mutations. Of the substitutions, a G.C-->A.T transition including a tandem (CC-->TT) mutation was mainly observed. This result agrees with our previous observation that mammalian DNA polymerase alpha misincorporates the oxidized nucleotide opposite C, but is in contrast to the finding that 2-OH-dATP elicits G.C-->T.A transversions in Escherichia coli. This type of mutation was also elicited, but to a lesser extent. Interestingly, the mutagenicity of 2-OH-dATP was enhanced in the presence of 2-hydroxydeoxyadenosine 5'-diphosphate, an inhibitor of the MTH1 protein, suggesting that this protein functions in the hydrolysis of 2-OH-dATP in the replication reaction mixture, and probably in living cells. These results indicate that 2-OH-dATP is mutagenic and that its mutagenicity is suppressed by the MTH1 protein in mammalian cells.
Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan.
Kazuya
K
Satou
Hideyoshi
H
Harashima
Hiroyuki
H
Kamiya
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D001483:Base Sequence; D002457:Cell Extracts; D004261:DNA Replication / Q000187:drug effects* / Q000235:genetics; D016153:Genes, Suppressor; D006367:HeLa Cells; D006801:Humans; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000187:drug effects; D009153:Mutagens / Q000494:pharmacology*; D017354:Point Mutation / Q000187:drug effects; D012343:RNA, Transfer / Q000235:genetics; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion
D002457:Cell Extracts; D009153:Mutagens; C096275:supF tRNA; D000255:Adenosine Triphosphate; D012343:RNA, Transfer