概括
一种新型的转录因子Sp1激活了像SV40早期促进体这样的特定促进体. Sp1 结合到 21 bp 重复在启动部位的上游,直接驱动由 RNA 聚合酶 II 的转录.
科学领域:
- 分子生物学分子生物学
- 基因规则 基因规则
- 生物化学 生物化学
背景情况:
- 基因转录是一种由特定的转录因子调节的基本生物过程.
- 猿人病毒40 (SV40) 早期促销者是研究转录调节的良好特征系统.
研究的目的:
- 识别和描述参与激活SV40早期促销者的促销器特异性转录因子.
- 阐明Sp1调解转录激活的机制.
主要方法:
- 细分HeLa细胞提取物以分离蛋白质因子.
- 对SV40早期促进器删除突变物的分析.
- DNAase足迹测定测试以确定蛋白质-DNA结合位点.
- 在蛋白质净化过程中,转录刺激活性与促进体结合活性的相关性.
主要成果:
- 鉴定Sp1作为一种促进体特异性转录因子,激活SV40早期促进体.
- 确定Sp1激活需要在串联21bp中进行序列的确定,在转录启动地点上游重复.
- 通过DNAase足迹证明直接与这些21bp重复序列结合Sp1.
- 在Sp1的转录刺激和DNA结合活动之间的相关性.
结论:
- Sp1直接与特定的上游促进元 (21 bp重复) 结合,以激活转录.
- 这种直接结合机制对于由RNA聚合酶II对SV40早期促进体的Sp1-介导的转录激活至关重要.
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