TAFII250は,塩基転写因子RAP74をリン酸化する二分型タンパク質キナーゼです
R Dikstein1, S Ruppert, R Tjian
1Howard Hughes Medical Institute, Department of Molecular and Cell Biology University of California, Berkeley, 94720, USA.
Cell
|March 8, 1996
まとめ
TAFII250タンパク質はキナーゼとして働き,RAP74をリン酸化して転写を調節する. TFIID複合体内のTAFII250による標的型リン酸化は,遺伝子転写における新しいシグナル伝達機構を示唆する.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝子転写 遺伝子転写
- タンパク質キナゼス (protein kinases) とは
背景:
- 転写因子TFIIDサブユニット (TAFs) は,転写のためのタンパク質相互作用とDNA認識を媒介する.
- TFIIDの機能の正確な規制メカニズムは,まだ完全に理解されていません.
研究 の 目的:
- 浄化された再結合TAFII250.0.の酵素活性を調べる.
- TAFII250が他の転写因子,特にRAP74.4をリン酸化するかどうかを決定する.
主な方法:
- 再結合TAFII250.0.の浄化について
- TAFII250およびRAP74およびその他の基礎転写因子を含む様々な基板を用いたインビトロキナーゼアッセイ.
- 機能性キナーゼドメインを特定するためにTAFII250の削除分析.
- リン酸化部位分析 (セリン残留物).
主要な成果:
- 浄化された再結合TAFII250は,タンパク質セリンキナーゼ活性を示す.
- TAFII250はRAP74を選択的にリン酸化するが,他のテストされたタンパク質は含まない.
- TAFII250によるRAP74のリン酸化は,無傷のTFIID複合体内で発生する.
- TAFII250には2つのキナーゼドメインがあり,どちらもセリン残基の効率的なRAP74トランスホスフォリレーションに必要なものです.
結論:
- TAFII250は,RAP74を酸化対象とするキナーゼとして機能する.
- TFIID複合体内で発生するこのリン酸化イベントは,トランスクリプション開始におけるTAFII250の調節作用を示唆する.
- この発見は,TAFII250媒介のRAP74のリン酸化を伴うシグナル伝達経路を提案し,転写を調節する.
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