分離分裂における共同分子の解離経路の描写は,クロスオーバー特異的な解離塩基を特定する
Kseniya Zakharyevich1, Shangming Tang, Yunmei Ma
1Department of Microbiology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
Cell
|April 17, 2012
まとめ
三つの酵素が微分化の際にホリデイの交差点を解消しますが,Sgs1,Exo1,Mlh1-Mlh3を含む新しい経路は,酵母と哺乳類のクロスオーバー形成に不可欠です.
科学分野:
- 遺伝学 遺伝学とは
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
背景:
- ホモログな再結合は,ホリデイ・ジャンクション (HJ) の解像度で高まり,クロスオーバー (CO) またはクロスオーバーでない製品を生成します.
- HJ解析をインビボで制御する特定の酵素は,未だに難解である.
- in vitroで特定された3つのHJ解消候補は,Mus81-Mms4,Slx1-Slx4,およびYen1.1. を含む.
研究 の 目的:
- ミエオティック・ホリデイ・ジャンクション解像度におけるMus81-Mms4,Slx1-Slx4,Yen1のインビヴォの役割を調査する.
- 分離過程における交差形成に起因する主要な要因と経路を特定する.
主な方法:
- 芽生える酵母メオシス中の再結合中間物質の物理的モニタリング.
- 3つの既知のHJ解像度 (mms4 slx4 yen1) で欠乏しているトリプルミュータントの分析.
- 既知の解像度がない場合にクロスオーバー形成の遺伝的依存性を調査する.
主要な成果:
- 特定された3つのエンドヌクレアゼ (Mus81-Mms4,Slx1-Slx4,Yen1) はすべて,HJ解像度 in vivoに寄与する.
- ホリデイ・ジャンクション解像度とクロスオーバーは,これらの解像度が欠けているトリプルミュータントで効率的に発生します.
- この三重変異体でのクロスオーバーは,逆説的にSgs1ヘリカーゼ,Exo1ヌクレアゼ,およびMlh1-Mlh3複合体に依存しています.
結論:
- ミエオティッククロスオーバー形成の新たな,これまで記述されていない経路が存在し,Sgs1,Exo1,Mlh1-Mlh3.3を含む.
- このSgs1-Exo1-Mlh1-Mlh3経路は,芽生えた酵母とおそらく哺乳類におけるクロスオーバーの主要な源である.
- この発見は,メオシスにおけるクロスオーバー制御を統制するメカニズムに関する我々の理解を再定義する.
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