Glyoxal, a major product of DNA oxidation, induces mutations at G:C sites on a shuttle vector plasmid replicated in mammalian cells

Nucleic Acids Res. 1997 May 15;25(10):1897-902. doi: 10.1093/nar/25.10.1897.

Abstract

Glyoxal is a major product of DNA oxidation in which Fenton-type oxygen free radical-forming systems are involved. To determine the mutation spectrum of glyoxal in mammalian cells and to compare the spectrum with those observed in other experimental systems, we analyzed mutations in a bacterial suppressor tRNA gene (supF) in the shuttle vector plasmid pMY189. We treated pMY189 with glyoxal and immediately transfected it into simian COS-7 cells. The cytotoxicity and mutation frequency increased according to the dose of glyoxal. The majority of glyoxal-induced mutations (48%) were single-base substitutions. Eighty three percent of the single-base substitutions occurred at G:C base pairs. Among them, G:C-->T:A transversions were predominant, followed by G:C-->C:G transversions and G:C-->A:T transitions. A:T-->T:A transversions were also observed. Mutational hotspots within the supF gene were detected. These results suggest that glyoxal may play an important role in mutagenesis induced by oxygen free radicals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Composition
  • Base Sequence
  • COS Cells
  • Cell Survival / drug effects
  • Cytosine
  • DNA Replication
  • Genes, Bacterial
  • Genes, Suppressor / genetics*
  • Genetic Vectors*
  • Glyoxal / pharmacology*
  • Guanine
  • Mammals
  • Molecular Sequence Data
  • Mutagenesis
  • Mutagens / pharmacology*
  • Oligodeoxyribonucleotides
  • Plasmids / drug effects*
  • Point Mutation
  • RNA, Transfer / biosynthesis*
  • Sequence Deletion
  • Transfection

Substances

  • Mutagens
  • Oligodeoxyribonucleotides
  • supF tRNA
  • Glyoxal
  • Guanine
  • Cytosine
  • RNA, Transfer