ホストのプロテアソームの分解により,細胞内細菌の成長に不可欠なアミノ酸が生成されます
Christopher T D Price1, Tasneem Al-Quadan, Marina Santic
1Department of Microbiology and Immunology, College of Medicine, University of Louisville, KY 40202, USA.
Science (New York, N.Y.)
|November 19, 2011
まとめ
Legionella pneumophilaは,そのAnkBエフェクターを使用して宿主細胞のタンパク質分解を誘発し,アミーバ,ヒト細胞,マウスの細菌の成長に不可欠なアミノ酸を生成します.
科学分野:
- 微生物学 微生物学とは
- 細胞生物学 細胞生物学
- バイオケミストリー バイオケミストリー
背景:
- レジオネラ・プネオフィラ (Legionella pneumophila) は,特殊な真空球 (LCV) の内部で複製する細胞内細菌である.
- LCV膜は,宿主ファルネシレーションで固定されるAnkB F-boxタンパク質を含む細菌エフェクタによって標的にされます.
- 栄養素獲得戦略を理解することは,レジオネラ菌感染症の制御に不可欠です.
研究 の 目的:
- レジオネラ肺炎菌 (Legionella pneumophila) の栄養素獲得におけるAnkBの役割を調査する.
- レジオネラ菌が宿主細胞の機械をどのように利用して増殖するかを決定する.
- 細胞内細菌の生存に不可欠な宿主由来資源を特定する.
主な方法:
- Legionella pneumophilaの ankB null変異体を生成して分析する.
- 宿主細胞 (アメーバ,ヒト細胞) とin vivo (マウス) の細菌の増殖を評価する.
- アミノ酸,システイン,セリン,ピルベート,またはシトラートによる補給測定法により,変異した現象型を救う.
主要な成果:
- AnkBによって媒介されるLCVのLys(48) 結合ポリユビキチン化タンパク質の宿主タンパク質分解により,アミノ酸が生成されます.
- ankB変異体は,アメーバとヒトの細胞に重度の増殖欠陥を示しており,アミノ酸補給によって救出されています.
- ネズミのアンクB変異体の肺内増殖欠陥は,アミノ酸またはシステインの注射によって救われます.
結論:
- レジオネラ肺炎菌は,宿主タンパク質を分解するために,宿主タンパク質システムを積極的にハイジャックします.
- 生成されたアミノ酸は,細菌の増殖のための重要な炭素とエネルギー源として機能します.
- この栄養素獲得のメカニズムは,進化的に遠く離れた宿主において保存され,レジオネラ菌の重要な生存戦略を強調しています.
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