Mellor J, Midgely C, Kingsman A J, Kingsman S M, Kim S
Department of Biochemistry, University of Oxford, United Kingdom.
Mol Gen Genet. 1991 Feb;225(2):217-24. doi: 10.1007/BF00269851.
The interactions between different upstream activator sequences (UAS) and the downstream transcriptional elements of the TRP1 promoter were studied. We have inserted the UAS from the PGK gene into a series of TRP1 promoter deletions such that the PGK UAS is positioned at various distances upstream from or replaces the TRP1 UAS (UAST1). We show that activation of the TRP1 transcription unit I by the PGK UAS shows a marked position dependence, which is solely a function of the position of the PGKUAS relative to sequences involved in the determination of the RNA initiation sites in the TRP1 promoter. No cooperative activation is seen when both UASs are present in the promoter; the PGK UAS is dominant and is not repressed by the TRP1 negative element. In addition, we show that the PGK and TRP1 UASs interact differently with TATA sequence at the TRP1 RNA initiation site. Our results suggest that these UASs are functionally distinct because they use different mechanisms for activating heterologous promoters.
研究了不同上游激活序列（UAS）与TRP1启动子下游转录元件之间的相互作用。我们已将来自PGK基因的UAS插入到一系列TRP1启动子缺失片段中，使得PGK UAS位于TRP1 UAS（UAST1）上游的不同距离处或取代TRP1 UAS。我们发现，PGK UAS对TRP1转录单元I的激活表现出明显的位置依赖性，这仅仅取决于PGK UAS相对于TRP1启动子中参与确定RNA起始位点的序列的位置。当启动子中同时存在两个UAS时，未观察到协同激活；PGK UAS占主导地位，且不受TRP1负元件的抑制。此外，我们表明PGK和TRP1 UAS在TRP1 RNA起始位点与TATA序列的相互作用不同。我们的结果表明，这些UAS在功能上是不同的，因为它们使用不同的机制来激活异源启动子。
