通过Sp1转录激活的机制:对联合激活剂的证据
1Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Cell
|June 29, 1990
概括
转录因子Sp1需要辅助激活剂来激活,在部分净化的TFIID中存在,但在净化的TFIID中不存在. 这些协同激活剂在Sp1和转录机制之间充当适配器.
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:
- 转录启动是一个复杂的过程,涉及许多蛋白质因素.
- TFIID (转录因子II D) 是一种关键的一般转录因子,它与TATA盒结合并启动转录.
- 共激活剂是增强转录的蛋白质,但不会直接结合DNA.
研究的目的:
- 为了研究协同激活剂在Sp1-介导的转录激活中的作用.
- 为了确定协作激活剂是否是TFIID或单独实体的重要组成部分.
- 为了探索同活性剂-TFIID相互作用的物种特异性.
主要方法:
- 使用部分净化和净化TFIID分数进行复制的转录试验.
- 使用Sp1 (一种特定的转录因子) 和CTF (一种联合激活剂) 的实验.
- 使用来自不同物种 (虫和酵母) 的克隆TFIID蛋白.
主要成果:
- Sp1通过半净化的TFIID激活了含有TATA的促进体的转录,而不是通过纯化的TFIID激活.
- 部分净化的TFIID分数含有对Sp1-介导激活至关重要的协活性剂.
- 同活性剂与TFIID的氨基末端部分相互作用,这些相互作用是特定于物种的.
- 对于TATA-less促进体的Sp1激活,需要一个与联合激活剂分开的独立活动.
结论:
- 协作激活剂需要作为Sp1等转激活剂和一般转录机制之间的分子适配器.
- 这些协同激活剂与TFIID本身不同,对于基底转录是不可用的.
- 同活性剂-TFIID相互作用表现出物种特异性,突出显示了不同生物体中转录调节的复杂性.
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