まとめ
新しい転写因子Sp1は,SV40早期プロモーターのような特定のプロモーターを活性化します. Sp1は開始部位の上流で21bpのリピートに結合し,RNAポリメラーゼIIによる転写を直接誘導する.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝子規制 遺伝子規制
- バイオケミストリー バイオケミストリー
背景:
- 遺伝子転写は,特定の転写因子によって調節される基本的な生物学的プロセスです.
- シミアンウイルス40 (SV40) の早期プロモーターは,転写調節を研究するためのよく特徴づけられたシステムです.
研究 の 目的:
- SV40早期プロモーターの活性化に関与するプロモーター特異の転写因子を特定し,特徴づけること.
- Sp1が転写活性化を媒介するメカニズムを解明する.
主な方法:
- タンパク質因子を分離するために,HeLa細胞抽出物の分化.
- SV40早期プロモーター削除変異体の分析.
- DNAアース足跡測定は,タンパク質-DNA結合部位を決定する.
- タンパク質浄化の過程における転写刺激活性とプロモーター結合活性との相関.
主要な成果:
- SV40早期プロモーターを活性化するプロモーター特異の転写因子としてSp1の識別.
- Sp1の活性化には,トランスクリプション開始部位の上流で21 bpの反復をタンドーム内の配列が必要であることを決定する.
- DNAaseの足跡を介して,これらの21 bpの繰り返し配列に直接のSp1結合の実証.
- Sp1の転写刺激活動とDNA結合活動との相関.
結論:
- Sp1は,特定のアップストリームプロモーター要素 (21 bpの繰り返し) に直接結合して転写を活性化します.
- この直接結合メカニズムは,RNAポリメラーゼIIによるSV40早期プロモーターのSp1媒介の転写活性化に不可欠である.
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