Jantzen H M, Admon A, Bell S P, Tjian R
Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Nature. 1990 Apr 26;344(6269):830-6. doi: 10.1038/344830a0.
The eukaryotic upstream binding factor (UBF), recognizes the ribosomal RNA gene promoter and activates transcription mediated by RNA polymerase I through cooperative interactions with the species-specific factor, SL1. Isolation of complementary DNA clones and sequence analysis reveals similarities between DNA binding domains of human UBF (hUBF) and high mobility group (HMG) protein 1. Expression, cellular localization and in vitro transcription studies establish that cloned hUBF encodes a nucleolar factor that binds specifically to the upstream control element and core of the rRNA gene promoter to activate transcription in a binding site-dependent manner.
真核生物上游结合因子（UBF）可识别核糖体RNA基因启动子，并通过与物种特异性因子SL1的协同相互作用激活RNA聚合酶I介导的转录。互补DNA克隆的分离和序列分析揭示了人类UBF（hUBF）的DNA结合结构域与高迁移率族（HMG）蛋白1之间的相似性。表达、细胞定位和体外转录研究表明，克隆的hUBF编码一种核仁因子，该因子特异性结合rRNA基因启动子的上游控制元件和核心，以结合位点依赖的方式激活转录。
