イーストにおける転写静音化のメカニズム
1Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, 2153 Sheridan Road, Evanston, IL 60208, USA.
Cell
|January 18, 2005
まとめ
酵母におけるトランスクリプションの静止は,ステリック阻害またはプレイニシテーション複合体の形成を阻害することによって発生しません. 代わりに,アクティベーター結合の下流に作用し,静止されたプロモーターの鍵となるタンパク質の占有量を減少させます.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
- イースト生物学 イースト生物学
背景:
- 染色体位置に依存するトランスクリプションサイレンシングは,遺伝子トランスクリプションを抑制します.
- 2つのモデルが静音化を説明しています: プレイニシアーション複合体の形成の下流のステリック障害またはブロック.
研究 の 目的:
- 発芽酵母におけるトランスクリプションサイレンシングの既存のモデルを定量的にテストする.
- トランスジェニックおよび内生的なロシオの両方でSIR2依存性サイレンシングのメカニズムを調査する.
主な方法:
- 芽生えた酵母に外来および内生レポータータンパク質を活用した.
- URA3のトランスゲンとHMRa/HMLalphaの交配型遺伝子を含め,トランスゲンと内生的なロキの両方を調べました.
主要な成果:
- 結果は,ステリック阻害およびプレイニシテーション複合阻害モデルの両方に矛盾した.
- 静止は,遺伝子アクティベーター結合の下流に作用することを示した.
- TFIIB,RNAポリメラーゼII,TFIIEの占有量が,静止されたプロモーターで著しく減少した.
結論:
- 酵母におけるSIR2依存型転写静止は,遺伝子活性化剤結合の下流で作用する.
- 静音化メカニズムは,重要な転写因子とRNAポリメラーゼII.の占有率を減らすことを含む.
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