Balciunas D, Ronne H
Ludwig Institute for Cancer Research, Uppsala Biomedical Center, Sweden.
Nucleic Acids Res. 1995 Nov 11;23(21):4421-5. doi: 10.1093/nar/23.21.4421.
Glucose triggers a complex response in yeast which includes induction and repression of a large number of genes. Glucose repression is in part mediated by the Mig1 repressor, a zinc finger protein that binds to the promoters of many glucose repressed genes. However, some genes that are required for gluconeogenic growth are also repressed by a Mig1-independent mechanism. We have isolated mutations in three genes that are involved in this Mig1-independent component of repression and cloned the genes by complementation. All three genes encode subunits of the recently discovered RNA polymerase II mediator complex. Two of them are yeast cyclin C and its associated kinase. Disruptions of the three genes have identical phenotypes with respect to glucose repression and show no synergism with each other. This suggests that these three subunits of the mediator complex function closely together in transmitting the transcriptional response to glucose.
葡萄糖在酵母中引发复杂反应，其中包括大量基因的诱导和抑制。葡萄糖抑制部分由Mig1阻遏物介导，Mig1是一种锌指蛋白，可与许多受葡萄糖抑制基因的启动子结合。然而，糖异生生长所需的一些基因也通过不依赖Mig1的机制被抑制。我们分离出了参与这种不依赖Mig1的抑制成分的三个基因中的突变，并通过互补克隆了这些基因。所有这三个基因都编码最近发现的RNA聚合酶II中介复合物的亚基。其中两个是酵母细胞周期蛋白C及其相关激酶。这三个基因的破坏在葡萄糖抑制方面具有相同的表型，并且彼此之间没有协同作用。这表明中介复合物的这三个亚基在传递对葡萄糖的转录反应中紧密协同发挥作用。
