CTCF依存の境界のメチル化は,Igf2遺伝子のインプリント表現を制御する
1Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0540, USA.
Nature
|June 6, 2000
まとめ
ゲノムインプリントは遺伝子発現を調節する. CTCF依存の絶縁剤は,強化剤の活性を阻害することによって,インプリント遺伝子発現を制御し,DNAメチル化により,その機能を特定のアレルに制限する.
科学分野:
- 遺伝学 遺伝学とは
- 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.
背景:
- インスリン型の成長因子2 (Igf2) とH19遺伝子発現は,ゲノムインプリントによって調節されます.
- これらの遺伝子はエンハンサーを共有しているが,H19は母体的に,Igf2は父体的に発現している.
- H19の上流の父性特異メチル化がインプリント化に不可欠である.
研究 の 目的:
- H19.1 の上流のメチル化された領域の機能を調査する.
- 強化剤の活動とインプリントの規制におけるCTCFの役割を決定する.
- DNAメチル化がインプリント遺伝子発現を制御するメカニズムを解明する.
主な方法:
- メチル化領域の削除分析.
- メチル化CpGへのCTCF結合に関するインビトロ研究.
- 強化剤の阻害作用のインビボ評価.
主要な成果:
- メチル化領域には,CTCFに依存する強化剤阻害成分が含まれています.
- CTCF結合部位のメチル化により,CTCF結合が妨げられる.
- CTCFのサイトを削除すると,増強剤阻害活性がなくなり,遺伝子発現が変化します.
- この絶縁体の活動は,DNAメチル化パターンのためにアレル特有である.
結論:
- CTCFに依存する増強ブロックエレメントは,Igf2インプリントを制御する絶縁体として機能します.
- DNAメチレーションは,強化剤の境界を調節することによって,強化剤-促進剤のアクセスを調節する.
- このメカニズムは,DNAメチル化がインプリントされた遺伝子の遺伝子発現をどのように制御するかを強調しています.
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