A protease pathway for the repair of topoisomerase II-DNA covalent complexes

Ailing Zhang, Yi Lisa Lyu, Chao Po Lin, Nai Zhou, Anna M. Azarova, Laurence M. Wood, Leroy-Fong Liu

Research output: Contribution to journalArticle

88 Citations (Scopus)

Abstract

Despite rapid advances in the field of DNA repair, little is known about the repair of protein-DNA adducts. Previous studies have demonstrated that topoisomerase II (TopII)-DNA adducts (TopII-DNA covalent complexes) are rapidly degraded by the proteasome. It has been hypothesized that proteasomal degradation of TopII-DNA covalent adducts exposes TopII-concealed DNA double-strand breaks (DSBs) for repair. To test this hypothesis, the anticancer drug, VP-16 (etoposide), was employed to induce TopII-DNA covalent complexes in mammalian cells, and the involvement of proteasome in processing TopII-DNA covalent complexes into DSBs was investigated. Consistent with the hypothesis, VP-16-induced DSBs as monitored by neutral comet assay, as well as DNA damage signals (e.g. γ-H2AX) were significantly reduced in the presence of the proteasome inhibitor, MG132. Using both top2β knock-out mouse embryonic fibroblasts and Top2β small interfering RNA knockdown PC12 cells, as well as postmitotic neurons in which TopIIβ was absent, we showed that VP-16-induced DNA damage signals were attenuated upon proteasome inhibition, suggesting the involvement of proteasome in the repair/processing of both TopIIα-DNA and TopIIβ-DNA adducts. By contrast, hydrogen peroxide-induced γ-H2AX was unaffected upon proteasome inhibition, suggesting a specific requirement of the proteasome pathway in the processing of TopII-DNA covalent complexes into DNA damage.

Original languageEnglish
Pages (from-to)35997-36003
Number of pages7
JournalJournal of Biological Chemistry
Volume281
Issue number47
DOIs
Publication statusPublished - Nov 24 2006
Externally publishedYes

Fingerprint

Type II DNA Topoisomerase
Repair
Peptide Hydrolases
Proteasome Endopeptidase Complex
Etoposide
DNA Adducts
DNA
DNA Damage
Processing
Proteasome Inhibitors
Fibroblasts
Comet Assay
Double-Stranded DNA Breaks
Hydrogen Peroxide
Small Interfering RNA
Neurons
PC12 Cells
Assays
Knockout Mice
DNA Repair

ASJC Scopus subject areas

  • Biochemistry

Cite this

Zhang, A., Lyu, Y. L., Lin, C. P., Zhou, N., Azarova, A. M., Wood, L. M., & Liu, L-F. (2006). A protease pathway for the repair of topoisomerase II-DNA covalent complexes. Journal of Biological Chemistry, 281(47), 35997-36003. https://doi.org/10.1074/jbc.M604149200

A protease pathway for the repair of topoisomerase II-DNA covalent complexes. / Zhang, Ailing; Lyu, Yi Lisa; Lin, Chao Po; Zhou, Nai; Azarova, Anna M.; Wood, Laurence M.; Liu, Leroy-Fong.

In: Journal of Biological Chemistry, Vol. 281, No. 47, 24.11.2006, p. 35997-36003.

Research output: Contribution to journalArticle

Zhang, A, Lyu, YL, Lin, CP, Zhou, N, Azarova, AM, Wood, LM & Liu, L-F 2006, 'A protease pathway for the repair of topoisomerase II-DNA covalent complexes', Journal of Biological Chemistry, vol. 281, no. 47, pp. 35997-36003. https://doi.org/10.1074/jbc.M604149200
Zhang A, Lyu YL, Lin CP, Zhou N, Azarova AM, Wood LM et al. A protease pathway for the repair of topoisomerase II-DNA covalent complexes. Journal of Biological Chemistry. 2006 Nov 24;281(47):35997-36003. https://doi.org/10.1074/jbc.M604149200
Zhang, Ailing ; Lyu, Yi Lisa ; Lin, Chao Po ; Zhou, Nai ; Azarova, Anna M. ; Wood, Laurence M. ; Liu, Leroy-Fong. / A protease pathway for the repair of topoisomerase II-DNA covalent complexes. In: Journal of Biological Chemistry. 2006 ; Vol. 281, No. 47. pp. 35997-36003.
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