植物および細菌のTIR免疫信号によるヘルパーNLRの活性化
Hua Yu1,2, Weiying Xu1,2, Sisi Chen1,2
1Key Laboratory of Plant Design, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
まとめ
植物免疫受容体は,病原体を検出するためにToll/インタールイキン-1受容体 (TIR) ドメインを使用する. この研究は,EDS1-PAD4-ADR1 (EPA) 複合体のシグナルが,
科学分野:
- 植物免疫学
- 分子生物学
- 生物化学
背景:
- 植物細胞内ヌクレオチド結合レピートレセプター (NLR) は,N端のトール/インタールイキン-1レセプター (TIR) ドメインを特徴として,病原体エフェクターを感知し,免疫信号伝達経路を開始するために重要である.
- TIRドメインはNADASE活性を持ち,異なった領域にわたって保存されるフォスフォリボシルアデノシンモノホスファート/二ホスファート (pRib-AMP/ADP) またはサイクルADPR (cADPR) の同位体のようなシグナル分子を生成する.
- リパゼのようなタンパク質であるEDS1とPAD4は信号トランスデューサーとして作用し,センサーTIR-NLRからの情報を,植物の免疫反応を実行するヘルパーNLRADR1に伝達する.
研究 の 目的:
- アラビドプシスのEDS1-PAD4-ADR1 (EPA) ヘテロトリマーの構造と機能を明らかにする.
- 植物および細菌のTIR信号によるEPA複合体の活性化におけるpRib-AMP/ADPおよび関連する分子の役割を調査する.
- 植物免疫におけるシグナル伝達分子としての2'cADPRの潜在的役割を調査する.
主な方法:
- アラビドプシスのEPAヘトロトリマーの構造分析
- EPAとpRib-AMP/ADPの相互作用を決定する生化学的測定法
- 植物と細菌のTIRシグナル伝達経路に関する機能研究で,EPAの活性化を評価する.
主要な成果:
- この研究は,pRib-AMP/ADPとの複合体におけるアラビドプシスのEPAヘテロトリマーの構造を報告している.
- EPAシグナリングは,植物または細菌のTIRシグナリングによって生成されたpRib-AMP/ADPによって活性化されます.
- 2'cADPRはpRib-AMPに水解され,その後EPAシグナリングが活性化され,2'cADPRを生成する細菌TIRドメインもEPA機能を活性化しました.
結論:
- EDS1-PAD4-ADR1 (EPA) コンプレックスは植物免疫シグナル伝達に中心的な役割を果たします.
- この発見は,2'cADPRが一時的なシグナル分子のpRib-AMPの安定した貯蔵形態として機能することを示唆している.
- この研究は,TIR-NLRによって媒介される植物免疫反応の分子機構に関する新しい洞察を提供します.
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