セルアミド-1-ホスファート転送タンパク質による非ベジキュラ輸送は,イコサノイドを調節する
Dhirendra K Simanshu1, Ravi Kanth Kamlekar, Dayanjan S Wijesinghe
1Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
Nature
|July 19, 2013
まとめ
新しく特定された脂質伝達タンパク質CPTPは,特にセラミド-1-ホスファート (C1P) を膜の間に移動させます. このタンパク質は,
科学分野:
- 脂質シグナル伝達と膜密輸
- タンパク質の構造と機能
- 炎症と疾患の病原性である.
背景:
- セラミド-1-ホスファート (C1P) のようなリン酸化スフィンゴリピドは,炎症を含む重要な細胞プロセスを調節する.
- C1Pは,フォスフォリファーゼA2α (cPLA2α) を活性化し,喘息や癌などの疾患に関与する炎症性イコサノイド生成を開始します.
- C1Pの輸送と表示のための効率的な細胞メカニズムは,炎症を制御するために不可欠ですが,非膀移動経路はまだ十分に理解されていません.
研究 の 目的:
- セラミド-1-ホスファート (C1P) の非膀移動に関与する新しいタンパク質を特定し,特徴づけること.
- 脂質転送タンパク質によるC1P認識と結合の分子機構と構造的基礎を解明する.
- C1Pホメオスタシスと下流シグナル伝達の制御における特定されたC1P転送タンパク質の細胞の局所化と機能的役割を調査する.
主な方法:
- 脂質移転活動を評価するための生化学的測定法.
- C1P.に結合した特定されたタンパク質の構造を決定するためのX線結晶学.
- 顕微鏡を用いた細胞の局所化に関する研究.
- RNA干渉 (RNAi) でタンパク質が枯渇し,細胞現象型が観察される.
主要な成果:
- ヒトGLTPD1 (CPTPに改名) と呼ばれる,広く発現する脂質伝達タンパク質は,特定のC1P伝達タンパク質として特定されました.
- 結晶構造は,リン酸ヘッドグループ認識部位と,脂質鎖結合のための適応性のある防水ポケットを含む新しい結合機構を明らかにした.
- CPTPはサイトゾールに局所化し,トランス・ゴルギネットワーク,核,およびプラズマ膜と結合する.
- CPTPの枯渇により,C1Pの分布が変化し,cPLA2αの活性が増加し,炎症性イコサノイド生成が増加しました.
結論:
- CPTPは,構造的にユニークで新しい脂質伝達タンパク質で,C1Pを膜間で特異的に結合し,伝達します.
- CPTPは,C1Pの細胞局在を調節する上で重要な役割を果たし,それによってcPLA2αの活性化と炎症性イコサノイド生成に影響を与えます.
- CPTPのメカニズムの理解は,異常なC1Pシグナル伝達によって引き起こされる炎症性疾患の潜在的な治療標的を提供します.
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