Repair activities of human 8-oxoguanine DNA glycosylase are stimulated by the interaction with human checkpoint sensor Rad9-Rad1-Hus1 complex
SCIE
SCOPUS
- Title
- Repair activities of human 8-oxoguanine DNA glycosylase are stimulated by the interaction with human checkpoint sensor Rad9-Rad1-Hus1 complex
- Authors
- Park, MJ; Park, JH; Hahm, SH; Ko, SI; Lee, YR; Chung, JH; Sohn, SY; Cho, Y; Kang, LW; Han, YS
- Date Issued
- 2009-10-02
- Publisher
- ELSEVIER SCIENCE BV
- Abstract
- Rad9-Rad1-Hus1 (9-1-1) is a checkpoint protein complex playing roles in DNA damage sensing, cell cycle arrest, DNA repair or apoptosis. Human 8-oxoguanine DNA glycosylase (hOGG1) is the major DNA glycosylase responsible for repairing a specific aberrantly oxidized nucleotide, 7,8-dihydro-8-oxoguanine (8-oxoG). In this study, we identified a novel interaction between hOGG1 and human 9-1-1, and investigated the functional consequences of this interaction. Co-immunoprecipitation assays using transiently transfected HEK293 cells demonstrated an interaction between hOGG1 and the 9-1-1 proteins. Subsequently, GST pull-down assays using bacterially expressed and purified hOGG1-His and GST-fused 9-1-1 subunits (GST-hRad9, GST-hRad1, and GST-hHus1) demonstrated that hOGG1 interacted directly with the individual subunits of the human 9-1-1 complex. In vitro excision assay, which employed a DNA duplex containing an 8-oxoG/C mismatch, showed that hRad9, hRad1, and hHus1 enhanced the 8-oxoG excision and P-elimination activities of hOGG1. In addition, the presence of hRad9, hRad1, and hHus1 enhanced the formation of covalently cross-linked hOGG1-8-oxoG/C duplex complexes, as determined by a trapping assay using NaBH4. A trimeric human 9-1-1 complex was purified from Escherichia coli cell transformed with hRad9, His-fused hRad1, or His-fused hHus1 expressing vectors. It also showed the similar activity to enhance in vitro hOGG1 glycosylase activity, compared with individual human 9-1-1 subunits. Detection of 8-oxoG in HEK293 cells using flow cytometric and spectrofluorometric analysis revealed that over-expression of hOGG1 or human 9-1-1 reduced the formation of 8-oxoG residues following the H2O2 treatment. The highest 8-oxoG reduction was observed in HEK293 cells over-expressing hOGG1 and all the three subunits of human 9-1-1. These indicate that individual human 9-1-1 subunits and human 9-1-1 complex showed almost the same abilities to enhance the in vitro 8-oxoG excision activity of hOGG1, but that the greatest effect to remove 8-oxoG residues in H2O2-treated cells was derived from the 9-1-1 complex as a whole. (C) 2009 Elsevier B.V. All rights reserved.
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/26213
- DOI
- 10.1016/J.DNAREP.2009.06.004
- ISSN
- 1568-7864
- Article Type
- Article
- Citation
- DNA REPAIR, vol. 8, no. 10, page. 1190 - 1206, 2009-10-02
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