Interplay of positive and negative regulators in transcription initiation by RNA polymerase II holoenzyme
Interplay of positive and negative regulators in transcription initiation by RNA polymerase II holoenzyme
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DOI：
10.1128/mcb.18.8.4455
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发表时间：
1998-08-01
影响因子：
5.3
通讯作者：
Young, RA
中科院分区：
文献类型：
--
作者：
Lee, TI;Wyrick, JJ;Young, RA
蛋白质编码基因的激活涉及到RNA聚合酶II全酶对启动子的招募。由于全酶的Srb4亚单位对大多数II类基因的表达是必不可少的，并且是至少一个转录激活子的靶标，我们推测Srb4的温度敏感突变的抑制子可以识别其他通常参与基因表达调控的因子，我们在这里报告了MED6和SRB6，这两个基因都编码全酶的基本成分，并且这些基因的产物与Srb4物理上相互作用，隐性的抑制子包括NCB1(BUR6)、NCB2、Not1、NOT3、NOT5和CAF1，它们编码NC2和非复合体的亚单位。NC2和NOT蛋白是与TATA盒结合蛋白(TBP)相互作用的一般负调控因子，这些结果表明转录启动涉及全酶特定成分介导的激活和TBP相关调控因子抑制之间的动态平衡。
Activation of protein encoding genes involves recruitment of an RNA polymerase II holoenzyme to promoters. Since the Srb4 subunit of the holoenzyme is essential for expression of most class II genes and is a target of at least one transcriptional activator, we reasoned that suppressors of a temperature-sensitive mutation in Srb4 would identify other factors generally involved in regulation of gene expression, We report here that MED6 and SRB6, both of which encode essential components of the holoenzyme, are among the dominant suppressors and that the products of these genes interact physically with Srb4, The recessive suppressors include NCB1 (BUR6), NCB2, NOT1, NOT3, NOT5, and CAF1, which encode subunits of NC2 and the Not complex. NC2 and Not proteins are general negative regulators which interact with TATA box binding protein (TBP), Taken together, these results suggest that transcription initiation involves a dynamic balance between activation mediated by specific components of the holoenzyme and repression by multiple TBP-associated regulators.