トランスクリプションに対する核群の障壁を克服する
V M Studitsky1, D J Clark, G Felsenfeld
1Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0540, USA.
Cell
|October 6, 1995
まとめ
RNAポリメラーゼは,ヌクレオソームのDNAを転写し,ダイアードに到達する前にバリアで一時停止します. この一時停止は,ヒストン-DNAの接触を断つのではなく,ループされたDNAを転写する難しさによるものです.
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
- 遺伝子発現の表現について
背景:
- 核細胞は,真核生物のDNA包装の基本的な単位である.
- 核個体を通しての転写は,遺伝子調節における重要なステップです.
- 核個体を通しての転写のメカニズムを理解することは,遺伝子発現制御の解読に不可欠です.
研究 の 目的:
- 核細胞核を通してRNAポリメラーゼ (RNAP) 転写の運動学を調査する.
- 核細胞DNAの転写中に一時停止を引き起こす要因を特定する.
- トランスクリプション中のヒストンオクタマー移転のメカニズムを解明する.
主な方法:
- 精製された核細胞とRNAポリメラーゼを用いたインビトロ転写アッセイ.
- 転写運動学と停止部位の分析.
- DNAアクセシビリティとヒストン-DNA相互作用の役割を調査する.
主要な成果:
- RNAPは初期約25bpの核細胞DNAを迅速に転写し,その後バリアに出くわし,減速する.
- バリアは核細胞二酸化物で消失し,迅速な転写が再開され,完全なヒストン八重体移転を示します.
- RNAPの背後にあるDNAを除去すると,バリアの出現が遅れる;より長いテンプレートは,バリアを減少させ,DNAループが一時停止に影響することを示唆する.
結論:
- ヌクレオソーム転写中のRNAPの停止は,ループ内のDNAの転写が困難であるためであり,ヒストン-DNAの接触を断ち切ることによるものではない.
- ポリメラーゼの周りのヒストンオクトーマー転送は,RNAPが二酸化物に到達するまでに完了します.
- 内核体内DNAループはヒストンオクタマー移転の重要な中間物であり,転写運動に影響を与えます.
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