病原体エフェクターXopQを直接認識する活性化ROQ1レジストソームの構造
Raoul Martin1,2, Tiancong Qi3,4, Haibo Zhang3
1Biophysics Graduate Group, University of California, Berkeley, CA 94720, USA.
まとめ
植物の免疫受容体であるヌクレオチド結合ルシンの豊富なリピート受容体 (NLR) は,バクテリアのエフェクターを直接認識する. この結合は,NLRのオリゴメリゼーションと植物免疫信号伝達経路の活性化を引き起こします.
科学分野:
- 植物免疫
- 分子生物学
- 構造生物学
背景:
- 植物と動物は,病原体感染を検出するために細胞内核酸結合レセプター (NLR) を利用する.
- NLRが病原体エフェクターを感知し,免疫反応を起こす正確なメカニズムは完全に理解されていません.
研究 の 目的:
- エフェクタ認識とNLRのアクティベーションの構造的基礎を解明する.
- 活性化されたROQ1 NLRがXanthomonas euvesicatoriaエフェクタ XopQに結合する構造を記述する.
主な方法:
- クリオ電子顕微鏡 (cryo-EM) で 3.8 アングストームの解像度.
- NLRエフェクタ複合体の構造分析
主要な成果:
- 構造は,XopQエフェクターの活性部位と表面残留の両方にROQ1の直接結合を明らかにします.
- 活性化されたROQ1はテトラメリックレジストソームを形成し,信号伝達のためにToll型インタールキン-1受容体 (TIR) ドメインを結合させます.
- これは,NLRのオリゴメリゼーションと活性化につながる直接的エフェクタ認識メカニズムを示唆する.
結論:
- NLRによる病原体エフェクターの直接的認識は,植物免疫を開始するための重要なメカニズムです.
- オリゴメリゼーションによる植物レジストソームの活性化は,TIRドメイン経由で下流免疫シグナル伝達を促進する.
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