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Effects of glutathione on chromium-induced DNA crosslinking and DNA polymerase arrest.

Publication ,  Journal Article
O'Brien, T; Xu, J; Patierno, SR
Published in: Mol Cell Biochem
June 2001

Hexavalent chromium (Cr (VI)) is reduced intracellularly to Cr (V), Cr (IV) and Cr (III) by ascorbate (Asc), cysteine and glutathione (GSH). These metabolites induce a spectrum of genomic DNA damage resulting in the inhibition of DNA replication. Our previous studies have shown that treatment of DNA with Cr (III) or Cr (VI) plus Asc results in the formation of DNA-Cr-DNA crosslinks (Cr-DDC) and guanine-specific arrests of both prokaryotic and mammalian DNA polymerases. GSH not only acts as a reductant of Cr (VI) but also becomes crosslinked to DNA by Cr, thus, the focus of the present study was to examine the role of GSH in Cr-induced DNA damage and polymerase arrests. Co-incubation of Cr (III) with plasmid DNA in the presence of GSH led to the crosslinking of GSH to DNA. GSH co-treatment with Cr (III) also led to a decrease in the degree of Cr-induced DNA interstrand crosslinks relative to Cr (III) alone, without affecting total Cr DNA binding. DNA polymerase arrests were observed following treatment of DNA with Cr (III) alone, but were markedly reduced when GSH was added to the reaction mixture. Pre-formed polymerase-arresting lesions (Cr-DDC) were not removed by subsequent addition of GSH. Treatment of DNA with Cr (VI), in the presence of GSH, resulted in crosslinking of GSH to DNA, but failed to produce detectable DNA interstrand crosslinks or polymerase arrests. The inhibitory effect of GSH on Cr-induced polymerase arrest was further confirmed in human genomic DNA using quantitative PCR (QPCR) analysis. Treatment of genomic DNA with Cr (III) resulted in a marked inhibition of the amplification of a 1.6 kb target fragment of the p53 gene by Taq polymerase. This was almost completely prevented by co-treatment with GSH and Cr (III). These results indicate that Cr-induced DNA interstrand crosslinks, and not DNA-Cr-GSH crosslinks, are the principal lesions responsible for blocking DNA replication. Moreover, the formation of DNA-Cr-GSH crosslinks may actually preclude the formation of the polymerase arresting lesions.

Duke Scholars

Published In

Mol Cell Biochem

ISSN

0300-8177

Publication Date

June 2001

Volume

222

Issue

1-2

Start / End Page

173 / 182

Location

Netherlands

Related Subject Headings

  • Plasmids
  • Oxidation-Reduction
  • Lung
  • Humans
  • Glutathione
  • Genome
  • Fibroblasts
  • Drug Interactions
  • DNA-Directed DNA Polymerase
  • DNA Replication
 

Citation

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O’Brien, T., Xu, J., & Patierno, S. R. (2001). Effects of glutathione on chromium-induced DNA crosslinking and DNA polymerase arrest. Mol Cell Biochem, 222(1–2), 173–182.
O’Brien, T., J. Xu, and S. R. Patierno. “Effects of glutathione on chromium-induced DNA crosslinking and DNA polymerase arrest.Mol Cell Biochem 222, no. 1–2 (June 2001): 173–82.
O’Brien T, Xu J, Patierno SR. Effects of glutathione on chromium-induced DNA crosslinking and DNA polymerase arrest. Mol Cell Biochem. 2001 Jun;222(1–2):173–82.
O’Brien, T., et al. “Effects of glutathione on chromium-induced DNA crosslinking and DNA polymerase arrest.Mol Cell Biochem, vol. 222, no. 1–2, June 2001, pp. 173–82.
O’Brien T, Xu J, Patierno SR. Effects of glutathione on chromium-induced DNA crosslinking and DNA polymerase arrest. Mol Cell Biochem. 2001 Jun;222(1–2):173–182.
Journal cover image

Published In

Mol Cell Biochem

ISSN

0300-8177

Publication Date

June 2001

Volume

222

Issue

1-2

Start / End Page

173 / 182

Location

Netherlands

Related Subject Headings

  • Plasmids
  • Oxidation-Reduction
  • Lung
  • Humans
  • Glutathione
  • Genome
  • Fibroblasts
  • Drug Interactions
  • DNA-Directed DNA Polymerase
  • DNA Replication