植物ペプチドホルモンフィトスルフォキンによるアロステリック受容体の活性化

Jizong Wang¹, Hongju Li², Zhifu Han¹

¹Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China.

Nature

|August 27, 2015

まとめ

フィトスルフォキン (PSK) の受容体による植物ホルモン認識 (PSKR) は構造的変化を伴う. PSK結合は受容体を安定させ,植物成長の調節のための共同受容体との相互作用を促進します.

科学分野:

植物分子生物学
構造生物学
生物化学

背景:

フィトスルフォキン (PSK) は,植物の成長と発達を調節する重要なペプチドホルモンです.
PSKはレセプターであるフィトスルフォキンレセプター (PSKR) と結合し,レウシンに富んだリピートレセプターキナーゼ (LRR- RK) と結合して機能する.
PSKの知覚,PSKRの活性化,および下流信号の正確なメカニズムはほとんど不明である.

研究の目的:

フィトスルフォカイン受容体 (PSKR) によるフィトスルフォカイン (PSK) 認識の構造的基礎を解明する.
PSK結合時にPSKRのアロステリック活性化メカニズムを理解する.
PSK媒介のシグナル伝達における共受容体の役割を特定する.

主な方法:

様々な状態 (自由,PSK結合,共受容体結合) でのPSKR細胞外LRRドメインの構造を決定するために,X線結晶学を用いた.
構造的な発見を検証し,タンパク質の相互作用を調査するために生化学的および遺伝的分析が使用されました.
構造データと生化学的および遺伝的証拠を組み合わせて,相互作用のインターフェースと機能的結果をマッピングしました.

主要な成果:

結晶構造は,PSKR島域内のβ鎖に結合し,抗βシートを形成する.
PSKの硫酸塩群はPSKRと直接相互作用し,リガンドの認識を強化する.
PSK結合は,SERK募集のためのPSKR島域を安定させることで,体胚形成受容体のようなキナーゼ (SERKs) によるPSKR異体化を促進する.

結論:

この研究は,PSKRがPSKを認識し,アロステル活性化される方法の構造的基礎を提供します.
PSK結合はPSKRをアロステリックに調節し,共受容体相互作用に直接参加することなく促進する.
これらの発見は,農業用途のPSKR活性を調節するための標的小分子設計の道を開く.

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