カルシウムは,タンパク質キナーゼB経路のCaM-Kキナーゼ活性化を通じて細胞生存を促進する
S Yano1, H Tokumitsu, T R Soderling
1Vollum Institute, Oregon Health Sciences University, Portland 97201, USA.
Nature
|December 22, 1998
まとめ
カルシウムシグナル伝達は,Ca2+/カルモジュリン依存タンパク質キナーゼキナーゼ (CaM-KK) 経由でタンパク質キナーゼB (PKB) を活性化することによって,ニューロンをアポトーシスから保護します. この経路はBADをリン酸化し,プログラム細胞死を防止します.
科学分野:
- 神経科学は神経科学である.
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
背景:
- 成長因子は,PI(3) K/PKB経路を通じて細胞をアポトーシスから保護し,BADをリン酸化します.
- 神経細胞におけるカルシウムシグナル伝達は,PI(3) KとMAPキナーゼとは独立して生存を促進することができます.
- プロアポプトティックタンパク質BADは,細胞死を調節する上で重要な役割を果たします.
研究 の 目的:
- ニューロン生存におけるCa2+/カルモジュリン依存タンパク質キナーゼキナーゼ (CaM-KK) の役割を調査する.
- カルシウム流入とアポトーシスの抑制を結びつけるシグナル伝達経路を解明する.
- CaM-KKがタンパク質キナーゼB (PKB) を活性化し,BADのリン酸化に影響を与えるかどうかを判断する.
主な方法:
- NG108ニューロブラストーマ細胞を使用した.
- 血清離脱による誘発性アポトーシス.
- NMDAまたはKClを用いて細胞内Ca2+レベルを調節する.
- 構成的に活性,支配的-負のCaM-KKとPKBを用い,トランスフェクションを行いました.
- 評価された細胞死とタンパク質リン酸化 (BAD).
主要な成果:
- Ca2+/カルモジュリン依存型タンパク質キナーゼキナーゼ (CaM-KK) は,タンパク質キナーゼB (PKB) を直接活性化する.
- 活性化PKBリン酸化物BADはセリン136で活性化され,14-3-3タンパク質との相互作用を促進します.
- 細胞内Ca2+の増加 (NMDAまたはKCl経由) または活性CaM-KKは,NG108細胞の血清離脱誘発アポトシスを有意に阻害しました.
- CaM-KKまたはPKBの抑制は,NMDAの神経保護効果を廃止しました.
結論:
- 新しいCa2+誘発のシグナリングカスケードには,PKBのCaM-KK活性化が含まれています.
- この経路は,BADのリン酸化と,その後のアポトーシスに対する保護につながります.
- このメカニズムは,カルシウムシグナル伝達と,神経細胞におけるプログラム細胞死亡の調節の間の直接的なリンクを提供します.
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