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タンパク質チロシンフォスファタゼの過剰発現によるpp60c-srcの細胞変容と活性化
X M Zheng1, Y Wang, C J Pallen
1Cell Regulation Laboratory, National University of Singapore.
Nature
|September 24, 1992
まとめ
タンパク質チロシンフォスファタゼアルファ (PTPα) の過剰発現は,持続的にpp60c-srcキナーゼを活性化させ,細胞変異と腫瘍発生につながります. この活性化には,負の調節部位であるTyr527.7の脱酸化が伴う.
科学分野:
- 細胞生物学 細胞生物学
- 分子腫瘍学 分子腫瘍学
- シグナルトランスデュークション
背景:
- pp60c-srcキナーゼの活動は,細胞サイクル中に厳しく調節され,通常はミトーシス中に増加します.
- pp60c-srcの調節不良は,しばしば変異またはウイルス性オンコタンパク質を通じて,制御不能の細胞成長と癌につながる.
- カーボキシ末端のTyr527部位は,pp60c-srcキナーゼの活性に対する負の調節に不可欠である.
研究 の 目的:
- pp60c-srcキナーゼ活性を調節するタンパク質チロシンフォスファタゼα (PTPα) の役割を調査する.
- PTPαの過剰発現が細胞変容と腫瘍発生を誘発するかどうかを判断する.
- PTPαがpp60c-srcの活性に影響するメカニズムを解明する.
主な方法:
- 細胞におけるPTPαの過剰発現.
- pp60c-srcキナーゼの活性度を評価する.
- Tyr527.のリン酸化状態を分析した.
- 浄化されたPTPαを用いたインビトロ脱酸化アッセイ.
主要な成果:
- PTPαの過剰発現は,pp60c-srcキナーゼの持続的な活性化をもたらした.
- PTPαの過剰発現は,細胞の変容と腫瘍発生につながった.
- PTPα過剰発現する細胞におけるpp60c-srcの活性化は,Tyr527.7.で脱酸化と関連していた.
- 純化されたPTPαが,ppp60c-srcのTyr527を直接分解した in vitro.
結論:
- PTPαは細胞増殖の調節に重要な役割を果たしています.
- PTPαは,少なくとも部分的に,pp60c-srcキナーゼの活性化によってその効果を発揮する.
- PTPαの過剰発現は腫瘍発生性を持ち,pp60c-src活性化による腫瘍発生に寄与する.
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