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Updated: Jul 16, 2026

08:35
Examining BCL-2 Family Function with Large Unilamellar Vesicles
Published on: October 5, 2012
RETRACTED: プロアポプトティックBAXとBAKは,IRE1alphaとの直接的な相互作用によって,展開されたタンパク質応答を調節する
Claudio Hetz1, Paula Bernasconi, Jill Fisher
1Howard Hughes Medical Institute, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA 02115, USA. chetz@hsph.harvard.edu
まとめ
プロアポプトティックタンパク質BAXとBAKは,展開タンパク質応答 (UPR) 信号伝達経路の活性化に不可欠です. 欠乏すると,エンドプラズマ網膜のストレス反応が低下し,マウスの肝臓が損傷する.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- ストレス反応 ストレス反応
背景:
- エンドプラズマ網膜 (ER) に誤った折りたたまれたタンパク質の蓄積が展開されたタンパク質応答 (UPR) を開始します.
- UPRは主に,イノシトールを必要とする酵素-1α (IRE1α),ERトランスメブランキナーゼおよびエンドロビヌクレアゼによって媒介されます.
- UPRシグナル伝達におけるアポプトシスタンパク質の役割は,まだ完全に理解されていない.
研究 の 目的:
- UPRシグナル伝達におけるBAXとBAKの役割を調査する.
- BAXとBAKの欠乏がERのストレス反応に与える影響を in vivoとin vitroで検証する.
- アポプトシス経路とUPRを結びつける分子メカニズムを解明する.
主な方法:
- BAXとBAKのダブルノックアウト (DKO) マウスモデルを使用しました.
- DKOマウスと対照 littermatesでチュニカミシンを使用してERストレス誘発.
- IRE1alpha基質のX-box-binding protein 1 (XBP1) とその標的遺伝子を含むUPRシグナル伝達成分を分析した.
- ERストレス細胞におけるBAX/BAKとIRE1alphaの間のタンパク質複合体の形成を研究した.
主要な成果:
- DKOマウスは,チュニカミシン誘発のERストレスに対して異常な反応を示し,広範な肝損傷が特徴でした.
- ERストレスを受けたDKO細胞は,IRE1alphaシグナル伝達が欠乏していた.
- IRE1alpha基板XBP1とその下流の標的遺伝子の発現は,DKOマウスで有意に減少しました.
- BAXとBAKは,その活性化に不可欠なIRE1alphaの細胞塩基ドメインを持つタンパク質複合体を形成することが判明しました.
結論:
- BAXとBAKは,IRE1alpha媒介UPR信号の活性化に不可欠である.
- これらのプロアポプトシスタンパク質は,ER膜で機能し,核アポプトシス経路とUPRをリンクします.
- BAXとBAKの欠如は,ERのストレスに対する適応反応を損なうため,細胞と組織にダメージを与えます.
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