Wade P A, Jaehning J A
Department of Biochemistry, Biophysics and Genetics, University of Colorado Health Sciences Center, Denver, 80262, USA.
Mol Cell Biol. 1996 Apr;16(4):1641-8. doi: 10.1128/MCB.16.4.1641.
Signals from transcriptional activators to the general mRNA transcription apparatus are communicated by factors associated with RNA polymerase II or the TATA-binding protein (TBP). Currently, little is known about how gene-specific transcription repressors communicate with RNA polymerase II. We have analyzed the requirements for repression by the saccharomyces cerevisiae Leu3 protein (Leu3p) in a reconstituted transcription system. We have identified a complex form of TBP which is required for communication of the repressing signal. This TFIID-like complex contains a known TBP-associated protein, Mot1p, which has been implicated in the repression of a subset of yeast genes by genetic analysis. Leu3p-dependent repression can be reconstituted with purified Mot1p and recombinant TBP. In addition, a mutation in the Mot1 gene leads to partial derepression of the Leu3p-dependent LEU2 promoter. These in vivo and in vitro observations define a role for Mot1p as a transcriptional corepressor.
转录激活因子与通用mRNA转录装置之间的信号是由与RNA聚合酶II或TATA结合蛋白（TBP）相关的因子传递的。目前，关于基因特异性转录抑制因子如何与RNA聚合酶II进行通讯，我们所知甚少。我们在一个重组转录系统中分析了酿酒酵母亮氨酸3蛋白（Leu3p）进行抑制作用的条件。我们鉴定出一种复杂形式的TBP，它是传递抑制信号所必需的。这种类似TFIID的复合物包含一种已知的TBP相关蛋白Mot1p，通过遗传分析表明它参与了对酵母基因子集的抑制。依赖Leu3p的抑制作用可以用纯化的Mot1p和重组TBP来重建。此外，Mot1基因中的一个突变导致依赖Leu3p的LEU2启动子部分去抑制。这些体内和体外的观察结果确定了Mot1p作为转录共抑制因子的作用。
