Direct stimulation of transcription by negative cofactor 2 (NC2) through TATA-binding protein (TBP)
Direct stimulation of transcription by negative cofactor 2 (NC2) through TATA-binding protein (TBP)
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DOI：
10.1073/pnas.202236699
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发表时间：
2002-10-01
影响因子：
11.1
通讯作者：
Prelich, G
中科院分区：
文献类型：
--
作者：
Cang, Y;Prelich, G
负辅因子2（NC 2）是一种进化上保守的转录调节因子，最初被鉴定为基础转录的抑制剂。其抑制机制已被广泛表征; NC 2与TATA结合蛋白（TBP）结合，阻断TFIIA和TFIIB的募集，从而抑制前起始复合物组装。NC 2也是许多酵母基因在体内表达所必需的，并在果蝇体外转录系统中刺激TATA-少的转录，但负责NC 2介导的转录刺激的机制尚不清楚。在这里，我们建立了酵母NC 2可以直接刺激激活转录从TATA驱动的启动子在体内和体外，而且这种积极的作用需要相同的表面TBP介导的NC 2抑制活性。在这些结果的基础上，我们提出了一个模型来解释NC 2如何通过TBP的同一表面介导阻遏和激活。
Negative cofactor 2 (NC2) is an evolutionarily conserved transcriptional regulator that was originally identified as an inhibitor of basal transcription. its inhibitory mechanism has been extensively characterized; NC2 binds to the TATA-binding protein (TBP), blocking the recruitment of TFIIA and TFIIB, and thereby inhibiting preinitiation complex assembly. NC2 is also required for expression of many yeast genes in vivo and stimulates TATA-less transcription in a Drosophila in vitro transcription system, but the mechanism responsible for the NC2-mediated stimulation of transcription is not understood. Here we establish that yeast NC2 can directly stimulate activated transcription from TATA-driven promoters both in vivo and in vitro, and moreover that this positive role requires the same surface of TBP that mediates the NC2 repression activity. On the basis of these results, we propose a model to explain how NC2 can mediate both repression and activation through the same surface of TBP.