SZT2はmTORC1信号のGATOR制御を指示する
Min Peng1, Na Yin1, Ming O Li1
1Immunology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA.
Nature
|February 16, 2017
まとめ
発作値2 (SZT2) タンパク質は,mTORC1シグナル伝達を通じて栄養素を感知し,細胞成長を制御するために重要なGATOR1とGATOR2との複合体を形成します. SZT2欠乏症は,このプロセスを妨害し,マウスの細胞機能障害と新生児死亡を引き起こします.
科学分野:
- 細胞生物学
- 栄養素検出の分子メカニズム
- 信号伝達経路
背景:
- ラパミシン複合体1 (mTORC1) のメカニスティックターゲットは,栄養信号を統合することによって細胞の成長とホメオスタシスを制御する.
- GATOR1とGATOR2を含むGATOR複合体は,Rag GTPasesを通じてmTORC1のシグナリングを調節する.
- メタゾーン特異のSESNタンパク質はGATOR2と相互作用するが,mTORC1の調節におけるその役割は不明である.
研究 の 目的:
- 栄養素センシングとmTORC1の調節におけるSZT2 (発作値2) の機能を調査する.
- SZT2,GATOR複合体,およびSESNタンパク質の相互作用を解明する.
- SZT2オーケストラされたGATOR (SOG) 複合体の細胞ホメオスタシスの役割を理解する.
主な方法:
- SOG複合体の形成と相互作用を特徴付けるための生化学的測定.
- 顕微鏡を用いた細胞局所化研究.
- 様々な栄養条件下でSZT2欠乏細胞とマウスのmTORC1信号の分析
- mTORC1の過剰活性化を救うための遺伝子操作 (過剰発現).
主要な成果:
- SZT2はGATOR1とGATOR2と共に新しいSZT2オーケストラ化されたGATOR (SOG) 複合体を形成し,リゾソームの局所化に不可欠である.
- SZT2欠乏症は,栄養不足による構成的なmTORC1シグナル伝達と,断食中のmTORC1不活性化による新生児死亡を引き起こします.
- DEPDC5 (GATOR1) またはリソソーム標的WDR59 (GATOR2) またはSESN2の過剰発現は,SZT2欠乏細胞におけるmTORC1過活性化を部分的に修正する.
結論:
- SZT2は,SOG複合体のリソソームの局所化を促進することによって,栄養素の検出に重要な役割を果たします.
- リソソーム局所化されたGATOR2は,SESNの誘導により,mTORC1のシグナリングを予期せぬ形で抑制する.
- SOG複合体は,生物のホメオスタシスを維持し,mTORC1の過剰活性化を防ぐために不可欠です.
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