SCAF4とSCAF8は,mRNAアンチターミネータータンパク質
Lea H Gregersen1, Richard Mitter2, Alejandro P Ugalde3
1Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
Cell
|May 21, 2019
まとめ
SCAF4およびSCAF8タンパク質は,代替ポリアデニレーション部位を抑制することによって,早めのmRNA終結を防ぐ. 組み合わせた欠乏は,切断されたmRNA,非機能的なタンパク質,細胞死につながり,遺伝子発現の調節におけるそれらの重要な役割を強調します.
科学分野:
- 分子生物学
- 遺伝子発現の規制
- RNA 処理
背景:
- 正確なメッセンジャーRNA (mRNA) 終結は適切な遺伝子発現に不可欠です.
- 代替ポリアデニレーション (polyA) サイトは,早めの終了と非機能的なトランスクリプトにつながる可能性があります.
研究 の 目的:
- mRNAの終結とポリアデニレーション部位の選択におけるSCAF4とSCAF8タンパク質の役割を調査する.
- SCAF4 と SCAF8 が転写終止を調節するメカニズムを解明する.
主な方法:
- SCAF4とSCAF8のタンパク質が,リン酸化RNAPIIのC端のリピートドメイン (CTD) に結合する分析
- 同時期にSCAF4とSCAF8がノックアウトしたヒト細胞におけるpolyAサイト選択とmRNA終了の調査.
- SCAF4とSCAF8のトランスクリプション延長と終止における独立した機能の特徴づけ.
主要な成果:
- SCAF4とSCAF8は,早期の代替ポリAサイトの使用を抑制するアンチターミネーターとして作用します.
- これらのタンパク質は,高リン酸化RNAPIICTD (Ser2およびSer5) に結合し,別のポリA部位に結合する.
- SCAF4とSCAF8を同時にノックアウトすると,ポリAの選択が変化し,早期終結,短縮されたmRNAが発生し,細胞に致命的になります.
- SCAF8はRNAPIIの延長因子として機能し,SCAF4はSCAF8が存在するとカノニカル終了に不可欠である.
結論:
- SCAF4とSCAF8は早期のmRNA終結を冗長的に抑制しますが,異なる非必須機能を持っています.
- SCAF4とSCAF8は,RNAPIIの延長と終了の間の移行をオーケストラしています.
- これらのタンパク質は,ヒト細胞における正しいポリA部位選択と転写終結を保証し,遺伝子発現の忠実性を維持する.
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