バクテリアのMreBに関連した細胞壁の生物合成複合体の漸進的な移動
Julia Domínguez-Escobar1, Arnaud Chastanet, Alvaro H Crevenna
1Max Planck Institute of Biochemistry, Martinsried, Germany.
まとめ
Bacillus subtilisでは,MreBタンパク質は螺旋状の繊維ではなく,動的なパッチを形成し,細胞壁に沿って移動します. この動きは細胞壁の合成によって推進され,細菌の形状決定を導く.
科学分野:
- バクテリアの細胞生物学
- 微生物の形態変異が生成される.
- 細胞骨格のダイナミクス
背景:
- 棒状のバクテリアは,ペプチドグリカン細胞壁とMreB細胞骨格に形状を依存しています.
- 既存のモデルは,螺旋状のMreBフィラメントが細胞壁合成を導くことを示唆している.
研究 の 目的:
- 生きたバチルス・サブティリスにおけるMreBと細胞壁合成のダイナミックな関係を視覚化するために.
- 細胞形状決定におけるMreB機能の支配的なモデルに挑戦したり,改良したりする.
主な方法:
- トータル内部反射光顕微鏡 (TIRFm) が採用されました.
- 活体バチルス・サブティリス細胞は,指数関数的な成長の間に観察されました.
主要な成果:
- MreBタンパク質は,螺旋状の構造ではなく,離散的で動きやすいパッチに組み込まれています.
- これらのMreBパッチは,細胞軸に垂直した周辺線に沿って移動した.
- 細胞壁合成がパッチの運動性を促進し,MreBは拡散を制限し,動きを方向づけました.
結論:
- 螺旋状MreBフィラメントの支配的なモデルは,成長中のBacillus subtilisにはサポートされていません.
- MreBは,細胞の延長のためにペプチドグリカン合成と結合されたダイナミックなパッチで機能します.
- これは,細菌細胞の形状維持のメカニズムに関する新しい視点を提供します.
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