2-Hydroxy-2'-deoxyadenosine 5'-triphosphate enhances A.T --> C.G mutations caused by 8-hydroxy-2'-deoxyguanosine 5'-triphosphate by suppressing its degradation upon replication in a HeLa extract

Biochemistry. 2007 Jun 5;46(22):6639-46. doi: 10.1021/bi062117r. Epub 2007 May 12.

Abstract

The coexistence effects of multiple kinds of oxidized deoxyribonucleotides were examined using an SV40 origin-dependent in vitro replication system with a HeLa extract. Oxidized dGTP and dATP, 8-hydroxy-2'-deoxyguanosine 5'-triphosphate (8-OH-dGTP) and 2-hydroxy-2'-deoxyadenosine 5'-triphosphate (2-OH-dATP), were used in this study. The mutation frequency synergistically increased when the two oxidized deoxyribonucleotides were together in the reaction. 2-OH-dATP enhanced the mutagenicity of 8-OH-dGTP, since the induced mutations were A.T --> C.G transversions. The contribution of the highly error-prone DNA polymerase eta was unlikely, since similar results were observed with an XP-V cell extract. The possible involvement of 2-hydroxyadenine in the complementary (template) strand was excluded on the basis of experiments using plasmids containing 2-hydroxyadenine as templates in the reactions with 8-OH-dGTP. 2-OH-dATP suppressed hydrolysis of 8-OH-dGTP, suggesting that the inhibition of the MTH1 protein played the major role in the enhancement. These results highlight the importance of specific hydrolysis of 8-OH-dGTP for the suppression of its induced mutation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / analogs & derivatives*
  • Adenosine Triphosphate / pharmacology*
  • Cell Extracts
  • Cell-Free System
  • Cells, Cultured
  • DNA Mutational Analysis
  • DNA Repair Enzymes / drug effects*
  • DNA Repair Enzymes / metabolism
  • DNA Replication / drug effects*
  • Deoxyguanine Nucleotides
  • Guanosine Triphosphate / analogs & derivatives*
  • Guanosine Triphosphate / genetics
  • HeLa Cells
  • Humans
  • Models, Genetic
  • Mutagenesis / drug effects*
  • Mutation*
  • Oxygen / metabolism
  • Phosphoric Monoester Hydrolases

Substances

  • 2-hydroxydeoxyadenosine triphosphate
  • Cell Extracts
  • Deoxyguanine Nucleotides
  • Guanosine Triphosphate
  • deoxyguanosine triphosphate
  • Adenosine Triphosphate
  • Phosphoric Monoester Hydrolases
  • 8-oxodGTPase
  • DNA Repair Enzymes
  • Oxygen