Oct-1 and Oct-2 potentiate functional interactions of a transcription factor with the proximal sequence element of small nuclear RNA genes.
Oct-1 and Oct-2 potentiate functional interactions of a transcription factor with the proximal sequence element of small nuclear RNA genes.
复制标题
Oct-1 和 Oct-2 增强转录因子与小核 RNA 基因的近端序列元件的功能相互作用。
DOI：
10.1128/mcb.12.7.3247-3261.1992
复制
发表时间：
1992
影响因子：
5.3
通讯作者：
Roeder,RG
中科院分区：
文献类型：
--
作者：
Murphy,S;Yoon,JB;Gerster,T;Roeder,RG
RNA聚合酶II-和RNA聚合酶III-转录的小核RNA（snRNA）基因的启动子在转录起始位点上游约55 bp处含有必需且高度保守的近端序列元件（PSE）。此外，所有snRNA基因的上游增强子都含有八聚体结合转录因子（Octs）的结合位点，功能研究表明PSE和八聚体元件协同工作。本研究已经确定并表征了一种新的转录因子（指定PTF），其特异性结合RNA聚合酶II和RNA聚合酶III转录的snRNA基因的PSE序列。PTF结合是显着增强的Oct结合到一个相邻的八聚体网站。这种增强作用受Oct-1、Oct-2或这些因子的保守POU结构域的影响。与这些结果一致，尽管Octs与启动子独立结合，但PTF和Oct-1以相互依赖的方式增强7SK启动子的转录。此外，Oct-1的POU结构域足以在PTF存在下具有显著的体外活性。这些结果表明，必不可少的激活结构域驻留在PTF和PTF结合的Octs的增强在含八聚体的snRNA基因增强子的功能中起着关键作用。
The promoters of both RNA polymerase II- and RNA polymerase Ill-transcribed small nuclear RNA (snRNA) genes contain an essential and highly conserved proximal sequence element (PSE) approximately 55 bp upstream from the transcription start site. In addition, the upstream enhancers of all snRNA genes contain binding sites for octamer-binding transcription factors (Octs), and functional studies have indicated that the PSE and octamer elements work cooperatively. The present study has identified and characterized a novel transcription factor (designated PTF) which specifically binds to the PSE sequence of both RNA polymerase II-and RNA polymerase Ill-transcribed snRNA genes. PTF binding is markedly potentiated by Oct binding to an adjacent octamer site. This potentiation is effected by Oct-1, Oct-2, or the conserved POU domain of these factors. In agreement with these results and despite the independent binding of Octs to the promoter, PTF and Oct-1 enhance transcription from the 7SK promoter in an interdependent manner. Moreover, the POU domain of Oct-1 is sufficient for significant in vitro activity in the presence of PTF. These results suggest that essential activation domains reside in PTF and that the potentiation of PTF binding by Octs plays a key role in the function of octamer-containing snRNA gene enhancers.