Repair of 8-oxoguanine and Ogg1-incised apurinic sites in a CHO cell line.
The repair mechanisms involved in the removal of 8-oxo-7,8-dihydroguanine (8-oxoG) in damaged DNA have been investigated using cell-free extracts or purified proteins. However, in vivo repair assays are required to further dissect mechanisms involved in the repair of 8-oxoG in the cellular context. In this study, we analyzed the removal of 8-oxoG from plasmids that contain a single 8-oxoG.C base pair in a sequence that can be transcribed (TS) or nontranscribed (NTS) in a chinese hamster ovary (CHO) cell line. The results show that 8-oxoG located in a TS is removed faster than in a NTS, indicating transcription-coupled repair (TCR) of 8-oxoG in rodent cells. The results also show that CHO cells efficiently repair DNA molecules that contain an Ogg1-incised AP site, which is the first intermediate in the course of base excision repair of 8-oxoG.
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Département de Radiobiologie et Radiopathologie UMR217 CNRS-CEA Radiobiologie Moléculaire et Cellulaire BP6 92265-Fontenay aux Roses, France.
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D000818:Animals; D001080:Apurinic Acid / Q000378:metabolism*; D016466:CHO Cells; D019757:Carbon-Oxygen Lyases / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D004249:DNA Damage; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000378:metabolism; D019951:DNA Polymerase beta / Q000378:metabolism; D004260:DNA Repair; D004270:DNA, Circular / Q000235:genetics / Q000378:metabolism; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D043382:DNA-Formamidopyrimidine Glycosylase; D043223:Deoxyribonuclease IV (Phage T4-Induced); D006147:Guanine / Q000031:analogs & derivatives* / Q000378:metabolism*; D009699:N-Glycosyl Hydrolases / Q000502:physiology*; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D000075223:Poly-ADP-Ribose Binding Proteins; D029867:Xenopus Proteins
D004270:DNA, Circular; D000075223:Poly-ADP-Ribose Binding Proteins; D029867:Xenopus Proteins; D001080:Apurinic Acid; C024829:8-hydroxyguanine; D006147:Guanine; D019951:DNA Polymerase beta; D043223:Deoxyribonuclease IV (Phage T4-Induced); D009699:N-Glycosyl Hydrolases; D043382:DNA-Formamidopyrimidine Glycosylase; D019757:Carbon-Oxygen Lyases; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D011088:DNA Ligases; D000072481:DNA Ligase ATP; C000618816:DNA ligase III alpha protein, Xenopus