转录辅因子复合体CRSP是强化剂结合蛋白Sp1的活性所必需的
1Howard Hughes Medical Institute, University of California at Berkeley, Molecular and Cell Biology, 94720-3204, USA.
Nature
|February 16, 1999
概括
研究人员发现了一种新的人类联合激活器复合物,CRSP,对基因转录至关重要. CRSP与TFIID合作,通过Sp1激活转录,揭示了联合激活器组装的组合机制.
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:
- 在甲基动物中激活基因转录是一个复杂的,多步骤的过程.
- 像Sp1这样的转录增强剂结合因子需要联合激活剂,包括TFIID子单元,才能激活.
- 对于Sp1-介导转录所需的额外辅助因子的身份仍然难以辨认.
研究的目的:
- 识别和描述参与Sp1-介导的转录激活的新型共因子.
- 为了阐明新发现的辅因子复合物的组成和功能,CRSP.
主要方法:
- 净化了CRSP综合体. 清洗了CRSP综合体.
- 通过蛋白质复合体表征来识别子单元.
- 基因克隆和CRSP子单元的序列分析.
- 免疫减弱研究以评估辅因子功能.
主要成果:
- 一个新的人类辅助因子复合体,CRSP (约. 700K M(r)),由九个子单位组成,被确定.
- CRSP对于Sp1的转录激活至关重要,它与TAF{II}s一起工作.
- CRSP子单元与酵母媒介和延长因子具有同质性,包括Med7,Rgr1和TFIIS.
- CRSP p200与核激素受体联合激活子单元TRIP2/PBP相同.
结论:
- CRSP是Sp1-介导基因转录所需的关键协活性剂.
- CRSP的子单元组成表明了物种之间保留的功能域.
- 研究结果表明,在转录激活过程中,共激活剂复合物的组合组合机制存在.
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