O'Sullivan Justin M, Tan-Wong Sue Mei, Morillon Antonin, Lee Barbara, Coles Joel, Mellor Jane, Proudfoot Nick J
Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK.
Nat Genet. 2004 Sep;36(9):1014-8. doi: 10.1038/ng1411. Epub 2004 Aug 15.
Mechanistic analysis of transcriptional initiation and termination by RNA polymerase II (PolII) indicates that some factors are common to both processes. Here we show that two long genes of Saccharomyces cerevisiae, FMP27 and SEN1, exist in a looped conformation, effectively bringing together their promoter and terminator regions. We also show that PolII is located at both ends of FMP27 when this gene is transcribed from a GAL1 promoter under induced and noninduced conditions. Under these conditions, the C-terminal domain of the large subunit of PolII is phosphorylated at Ser5. Notably, inactivation of Kin28p causes a loss of both Ser5 phosphorylation and the loop conformation. These data suggest that gene loops are involved in the early stages of transcriptional activation. They also predict a previously unknown structural dimension to gene regulation, in which both ends of the transcription unit are defined before and during the transcription cycle.
对RNA聚合酶II（PolII）转录起始和终止的机制分析表明，某些因子在这两个过程中是共有的。我们在此表明，酿酒酵母的两个长基因FMP27和SEN1以环状构象存在，有效地将它们的启动子和终止子区域聚集在一起。我们还表明，当该基因在诱导和非诱导条件下从GAL1启动子转录时，PolII位于FMP27的两端。在这些条件下，PolII大亚基的C末端结构域在Ser5处被磷酸化。值得注意的是，Kin28p的失活导致Ser5磷酸化和环状构象的丧失。这些数据表明基因环参与转录激活的早期阶段。它们还预测了基因调控中一个以前未知的结构维度，即转录单元的两端在转录周期之前和期间就已确定。
