ヌクレオソームの喪失は,酵母の下流プロモーターを in vivo で活性化させます
1Molecular Biology Institute, University of California, Los Angeles 90024.
Cell
|December 23, 1988
まとめ
酵母にグルコースを添加すると,核細胞が枯渇し,下流のプロモーター元素が活性化します. このヌクレオソームの喪失は,上流のアクティベーター配列がなくても,遺伝子転写の開始と延長を強化します.
科学分野:
- 分子生物学は分子生物学である.
- イースト遺伝学 イースト遺伝学
- 遺伝子規制 遺伝子規制
背景:
- 核細胞は,遺伝子のアクセシビリティと転写を調節する上で重要な役割を果たします.
- クロマチンの構造が遺伝子発現にどのように影響するかを理解することは,分子生物学にとって根本的なものです.
- イーストのGALプロモーターシステムは,遺伝子発現とクロマチンのダイナミクスを制御するための強力なツールを提供します.
研究 の 目的:
- 酵母における下流のプロモーター元素の活性に対するヌクレオソーム枯渇の影響を調査する.
- ヌクレオソームの損失が,正規の上流の規制配列とは独立してプロモーターを活性化できるかどうかを決定する.
- トランスクリプションの開始と延長におけるヌクレオソーム枯渇の役割を明らかにする.
主な方法:
- GALプロモーター制御下でのヒストンH4遺伝子を持つ酵母菌株を活用する.
- グルコース添加による核細胞の枯渇を誘導する.
- イーストプロモーター (PHO5,CYC1,GAL1) のダウンストリームプロモーター要素 (TATA box,I region) の活性化を評価し,E. coli lacZ遺伝子と融合した.
- アップストリームアクティベーターシーケンス (UAS) の有無を問わず,プロモーターの活動を分析する.
主要な成果:
- グルコースによって誘発される核細胞の枯渇は,PHO5,CYC1,GAL1のダウンストリームプロモーター要素を活性化します.
- PHO5のダウンストリーム要素は,UASの存在に関係なく,核細胞喪失によって活性化されます.
- CYC1およびGAL1プロモーターのUAS要素の削除は,依然として,グルコース媒介による核細胞喪失時に残ったダウンストリームプロモーターの活性化につながります.
- これらの発見は,ニュクレオソームの喪失が,体内での転写開始と延長を強化することを示しています.
結論:
- 核子の枯渇は,酵母における遺伝子転写の活性化における重要な要因である.
- ダウンストリームプロモーター要素は,核細胞喪失によって活性化され,転写開始における直接的な役割を示唆しています.
- ダウンストリームプロモーターを認識するタンパク質は,UAS媒介の複合体形成なしに,少なくとも部分的に機能し続けます.
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