ピルーバートキナーゼM2は,フォスフォチロシン結合タンパク質である
Heather R Christofk1, Matthew G Vander Heiden, Ning Wu
1Department of Systems Biology.
Nature
|March 14, 2008
まとめ
成長因子は,ピルバートキナーゼM2 (PKM2) の活性を変えることで細胞代謝を調節する. この酵素は,
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 癌細胞の代謝について
背景:
- 成長因子は,細胞内の栄養素吸収とアナボリックプロセスを引き起こす.
- 精密な生化学的メカニズムは,まだ完全に理解されていない.
- 信号タンパク質のチロシンリン酸化が,これらの細胞反応を誘発する.
研究 の 目的:
- 成長因子媒介細胞代謝におけるピルバートキナーゼM2 (PKM2) の役割を調査する.
- フォスフォチロジンシグナル伝達によってPKM2の活性が調節されるメカニズムを解明する.
主な方法:
- 新種のプロテオミックスクリーンを用いて,フォスフォチロシン結合タンパク質を特定した.
- PKM2とチロシンリン酸化ペプチドの相互作用を調査した.
- この相互作用がPKM2の酵素活性とアロステル調節に与える影響を評価した.
主要な成果:
- ピルバ酸キナーゼ (PKM2) のヒトM2 (胎児) アイソフォームを,チロシン-リン酸化ペプチドの直接的,選択的結合体として特定した.
- フォスフォチロジンペプチド結合がフルークトーゼ-1,6-ビスホスファートを放出することによってPKM2の活性を抑制することを実証した.
- この調節が,成長因子の刺激下で,グルコース代謝物をアナボリックなプロセスに誘導する証拠を提供した.
結論:
- PKM2は,フォスフォチロシン結合タンパク質として作用し,成長因子シグナル伝達と代謝調節を結びつける.
- フォスフォチロジンシグナル伝達によるPKM2の抑制は,成長のための細胞資源をリダイレクトします.
- このフォスフォチロシン結合PKM2の発現は,がん細胞の急速な増殖に極めて重要です.
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