CTCFが促進するRNAポリメラーゼIIの停止は,DNAメチル化とスプライシングを結びつける
Sanjeev Shukla1, Ersen Kavak, Melissa Gregory
1Center for Cancer Research, Mouse Cancer Genetics Program, National Cancer Institute at Frederick, Frederick, Maryland 21702, USA.
Nature
|October 4, 2011
まとめ
CCCTC結合因子 (CTCF) タンパク質は,RNAポリメラーゼIIの停止を調節することによって,代替スプライシングに影響を与えます. DNAメチル化は,CTCF結合を変化させ,エクソン含有に影響を与え,スプライシングの結果に対する表遺伝的制御を提供することができます.
科学分野:
- 分子生物学は分子生物学である.
- エピジェネティクス エピジェネティクス
- ゲノミクスゲノミクスとは
背景:
- 前伝達 RNA (mRNA) の代替スプライシングは,真核生物におけるトランスクリプトームの複雑性にとって極めて重要です.
- 代替スプライシングの調節は完全に理解されていませんが,共転写スプライソーム組立は,DNA構造が役割を果たす可能性があることを示唆しています.
- ヒストンやDNAメチル化などの表遺伝的変異は,核細胞の占有率とともに,エクソンで濃縮され,スプライシングに対する表遺伝的影響を示唆しています.
研究 の 目的:
- 代替スプライシングの調節におけるDNA結合タンパク質の役割を調査する.
- CCCTC-結合因子 (CTCF) がRNAポリメラーゼIIの停止によって代替スプライシングに影響を与えるかどうかを判断する.
- CTCF結合に対するDNAメチル化の影響とその後の代替スプライシングへの影響を調査する.
主な方法:
- CD45哺乳類モデルシステムを代替スプライシング研究に活用した.
- 代替スプライシングにおけるCTCFの役割を評価するために全ゲノム分析を行った.
- 特定のDNA配列 (例えば,CD45エクソン5) に結合するCTCFに対するDNAメチル化の影響を調査した.
主要な成果:
- CCCTC-結合因子 (CTCF) は,弱い上流エクソンの含有を促進するタンパク質として特定されました.
- CTCFは局所RNAポリメラーゼIIの停止を媒介し,それによって代替スプライシングに影響を与えます.
- DNAメチル化は,CD45エクソン5へのCTCF結合を阻害し,変異したエクソン5の含有につながることが示されました.
結論:
- CTCFは,転写延長を調節することによって,代替スプライシングの調節に直接的な役割を果たします.
- DNAメチル化は,CTCF結合を制御することによって,スプライシングの表遺伝子調節剤として作用する.
- これらの発見は,表遺伝子記号と代替スプライシングの発達制御の間のメカニズム的なリンクを確立しています.
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