ティミンDNAグリコシラーゼは,リンクされたデアミネーション-塩基切除修復による活性DNA脱メチル化に不可欠です
Salvatore Cortellino1, Jinfei Xu, Mara Sannai
1Cancer Biology Program and Epigenetics and Progenitor Cells Keystone Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
Cell
|July 5, 2011
まとめ
DNA修復酵素であるチミンDNAグリコシラーゼ (TDG) は,哺乳類のゲノムを過剰なDNAメチル化から保護し,重要な規制領域を積極的にデメチル化するために重要である. 欠乏すると胚の死亡が起こり,表遺伝子調節における重要な役割が明らかになる.
科学分野:
- エピジェネティクス エピジェネティクス
- 分子生物学は分子生物学である.
- 発達生物学 発達生物学について
背景:
- DNAメチレーションは,遺伝子サイレンシングの重要な表遺伝的メカニズムです.
- 哺乳類のゲノムをde novoメチル化と活性脱メチル化から保護するメカニズムは,まだ完全に理解されていません.
研究 の 目的:
- DNAメチル化および脱メチル化におけるチミンDNAグリコシラーゼ (TDG) の役割を調査する.
- 哺乳類の発達中の表遺伝子調節におけるTDGの機能を明らかにする.
主な方法:
- マウスにおけるTDGの遺伝子ノックアウトと触媒的不活性化.
- 他のタンパク質とのTDGの相互作用の分析 (AID,GADD45a).
- 推進者募集 (p300) と表遺伝子状態におけるTDGの役割の評価.
主要な成果:
- TDGのノックアウトまたは無効化は,マウスの胚の致死につながる.
- TDGは,p300をレチノ酸調節プロモーターに勧誘するために不可欠です.
- TDGはCpG群島をハイパーメチル化から保護し,規制されたプロモーターおよび強化剤の活性脱メチル化を促進します.
- TDGはAIDとGADD45aと相互作用し,脱メチル化経路における役割を示唆している.
結論:
- TDGは,発達中の適切な表遺伝子状態を維持する上で二重の役割を果たします.
- 2段階のDNA脱メチル化メカニズムが提案されており,AID媒介によるデアミネーションに続いて,TDG媒介の切除修復が行われる.
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