SIN1/MIP1はリクター-mTOR複合体の完全性を維持し,アクトのリン酸化と基板特異性を調節する
Estela Jacinto1, Valeria Facchinetti, Dou Liu
1Department of Physiology and Biophysics, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
Cell
|September 12, 2006
まとめ
SIN1はmTORC2の重要なサブユニットで,Akt Ser473のリン酸化と細胞生存に不可欠です. その欠如はTORC2の機能を妨げますが,TORC1の機能は妨げず,FoxO1/3a.のような特定のAktのターゲットに影響します.
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.
- バイオケミストリー バイオケミストリー
背景:
- ラパミシン (mTOR) の哺乳類標的は,TORC1およびTORC2複合体を通して細胞の成長と増殖を調節する.
- TORC2はPDK2として関与し,Ser473でAkt/PKBをリン酸化し,この場所はAktの完全な活性化に不可欠です.
- Aktのリン酸化部位の正確な役割とその規制メカニズムについては,さらなる解明が必要である.
研究 の 目的:
- Aktのリン酸化に関与するTORC2の重要なサブユニットを特定する.
- TORC2機能とAktの活性化におけるSIN1/MIP1の役割を調査する.
- ダウンストリームターゲットと細胞生存に対するAkt Ser473リン酸化障害の生理学的影響を決定する.
主な方法:
- 哺乳類の細胞におけるSIN1/MIP1遺伝子の遺伝的消去.
- mTOR複合体内のタンパク質-タンパク質相互作用の生化学分析.
- Ser473とThr308.8でのAkt/PKBリン酸化の評価について
- 既知のAktおよびTORC1ターゲット (FoxO1/3a,TSC2,GSK3,S6K,4E-BP1) のリン酸化状態の評価.
主要な成果:
- SIN1/MIP1は,Rictor-mTOR相互作用にとって重要なTORC2の重要なサブユニットとして特定されました.
- SIN1の遺伝的アブレーションにより,Akt Ser473のリン酸化は廃止され,Thr308のリン酸化は保存された.
- Ser473の酸化障害は,FoxO1/3aのようなAkt標的を選択的に影響し,TSC2,GSK3,TORC1エフェクター (S6K,4E-BP1) は影響を受けなかった.
- SIN1によって媒介されるAkt Ser473のリン酸化におけるTORC2の役割は,細胞生存に不可欠である.
結論:
- SIN1は,TORC2媒介によるAkt Ser473のリン酸化に不可欠である.
- この特定のリン酸化イベントは,細胞生存におけるTORC2の機能にとって極めて重要です.
- Akt Ser473のリン酸化におけるTORC2の役割は,TORC1の活動とは異なり,必要不可欠である.
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