膜融合pHにおけるインフルエンザの血液凝固素の構造的変化
Donald J Benton1, Steven J Gamblin2, Peter B Rosenthal3
1Structural Biology of Disease Processes Laboratory, Francis Crick Institute, London, UK. donald.benton@crick.ac.uk.
Nature
|May 29, 2020
まとめ
インフルエンザウイルスはヘマグルチニン (HA) グリコタンパク質を使って宿主細胞膜と融合します. この研究は,ウイルスの侵入と膜融合メカニズムを理解するために重要な三重ヘリキュールを含む新しいHA構造を明らかにしています.
科学分野:
- 構造生物学
- ウイルス学
- 生物化学
背景:
- インフルエンザなどの封筒型ウイルスは 細胞膜と脂質封筒を融合させ 細胞に感染します
- ウイルス包膜のグリコプロテインは,細胞受容体と結合し,膜融合を促進し,この融合プロセスを媒介する.
- インフルエンザでは,ヘマグルチニン (HA) が鍵となるグリコタンパク質で,細胞吸収後に内皮膜との融合を媒介する.
研究 の 目的:
- 低pHで誘発される膜融合過程におけるインフルエンザヘマグルチニン (HA) の動的構造変化を調査する.
- 核融合に関与するHAのこれまで記述されていない中間構造を特定し,特徴づけること.
主な方法:
- 単粒子の冷凍電子顕微鏡を用いて,HAの構造変化を直接イメージした.
- 形状の再編成の異なる段階を捉えるために,HAはpH 5. 0で異なる期間インキュベートされた.
主要な成果:
- 以前は特徴づけられていなかった3つの異なるHAの形態が特定されました.
- 注目すべき発見は,HA2サブユニットによって形成された150 Å長さのトリプルヘリクロール構造である.
- これらの構造は,HA2がウイルスと内体膜を橋渡しするメカニズムを示唆する.
結論:
- 特定されたHA構造は,ウイルス膜融合を推進する形状的再配置に関する新しい洞察を提供します.
- トリプルヘリクルのHA2コイルは,ウイルスと宿主細胞膜の間の融合を媒介する上で重要な役割を果たす可能性があります.
- この研究は,インフルエンザウイルスの侵入の理解を進めており,抗ウイルス療法のための潜在的な標的を提供します.
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