5' エンド ニコチナミドアデニン・ディヌクレオチド・キャップ 人体細胞 DXO媒介によるDNA分解を促す
Xinfu Jiao1, Selom K Doamekpor2, Jeremy G Bird3
1Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA.
Cell
|March 12, 2017
まとめ
哺乳類の細胞には新しいRNAキャップ,ニコチナミドアデニン・ディヌクレオチド (NAD+) があり,m7Gキャップとは異なり,RNAの分解を促進する. DXO酵素はこれらのNAD+キャップを取り除き,細胞内NAD+キャップのRNAレベルを調節する.
科学分野:
- 分子生物学
- RNA 生物学
- 生物化学
背景:
- ユカリオットのmRNAは通常,N7-メチルグアノシン (m7G) カップを有し,翻訳と安定性には極めて重要です.
- 哺乳類の細胞は,ニコチナミドアデニン・ディヌクレオチド (NAD+) という別の5'エンドキャップを持っています.
- m7Gキャップとは異なり,NAD+キャップは翻訳を阻害し,mRNAの分解を促進する.
研究 の 目的:
- 哺乳類のRNAキャップとしてNAD+を確立する.
- NAD+キャップを除去する酵素を特定する.
- NAD+キャップの除去と細胞の調節のメカニズムを解明する.
主な方法:
- 3'-NADP+によるDXO/Rai1酵素の共結晶化
- deNADding反応を研究するための酵素分析.
- DXOの除去を伴う細胞実験で,NAD+で覆われたRNAのレベルを観察する.
主要な成果:
- DXO/Rai1酵素はNAD+キャップを効率的に除去し,NAD+と5'-リン酸RNAを生成する.
- コクリスタル構造は,deNADding反応の分子機構を明らかにした.
- 細胞内のDXOの減少は,NAD+キャップされたmRNAとsnoRNAのレベルを高めました.
結論:
- NAD+は新種の哺乳類のRNAキャップとして識別される.
- DXOは,細胞内NAD+キャプテッドRNAレベルを調節する,deNADding酵素として機能する.
- NAD+のキャピングはRNAの分解経路に影響を与え,処理されたRNAの末端に発生することがあります.
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