Forsburg S L, Guarente L
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Mol Cell Biol. 1988 Feb;8(2):647-54. doi: 10.1128/mcb.8.2.647-654.1988.
We analyzed upstream activation sequence 2 (UAS2), one of two independent UAS elements in the CYC1 gene of Saccharomyces cerevisiae. Deletions and linker scanning mutations across the 87 base pairs previously defined as UAS2 showed two separate functional elements required for full activity. Region 1, from -230 to -200, contains the principal activation site and responds to the trans-acting regulatory loci HAP2 and HAP3. A portion of region 1 is homologous to two other HAP2-HAP3-responsive UASs and includes the G----A transition mutation UP1, which increases UAS2 activity. This consensus sequence TNATTGGT bears striking similarity to several CAAT box sequences of higher cells. Region 2, from -192 to -178, substantially enhances the activity of region 1, yet has little activity by itself. These regions bind distinct proteins found in crudely fractionated yeast extracts.
我们分析了酿酒酵母CYC1基因中两个独立的上游激活序列元件之一的上游激活序列2（UAS2）。对先前定义为UAS2的87个碱基对进行缺失和接头扫描突变，结果显示出两个完整活性所需的独立功能元件。区域1，从-230到-200，包含主要激活位点，并对反式作用调节基因座HAP2和HAP3作出反应。区域1的一部分与另外两个HAP2-HAP3反应性UAS同源，并且包括增加UAS2活性的G----A转换突变UP1。这个共有序列TNATTGGT与高等细胞的几个CAAT盒序列有显著相似性。区域2，从-192到-178，显著增强区域1的活性，但自身活性很小。这些区域结合在粗分级酵母提取物中发现的不同蛋白质。
