HUMAN RIBOSOMAL-RNA TRANSCRIPTION IS MODULATED BY THE COORDINATE BINDING OF 2-FACTORS TO AN UPSTREAM CONTROL ELEMENT
HUMAN RIBOSOMAL-RNA TRANSCRIPTION IS MODULATED BY THE COORDINATE BINDING OF 2-FACTORS TO AN UPSTREAM CONTROL ELEMENT
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DOI：
10.1016/0092-8674(86)90559-3
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发表时间：
1986-06-20
期刊：
影响因子：
64.5
通讯作者：
TJIAN, RT
中科院分区：
文献类型：
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作者：
LEARNED, RM;LEARNED, TK;TJIAN, RT
人rRNA启动子包含两个不同的顺式控制序列，核心和上游控制元件（UCE），作为结合RNA聚合酶I转录起始中涉及的细胞反式激活蛋白的靶标。这些因素之一，SL 1，已被广泛纯化，并显示是一个物种特异性的因素，需要重建在体外RNA合成。DNA酶足迹法显示，虽然SL 1单独不特异性结合rRNA启动子序列，第二个因素，UBF 1，招聘SL 1的模板和指导结合到一个扩展的区域，包括在UCE序列。突变体和人-小鼠杂交启动子的分析表明，蛋白质-DNA相互作用在UCE调节rRNA合成的效率。从人类rRNA启动子转录似乎需要一套不寻常的蛋白质-DNA交易，其中识别和结合上游顺式控制元件是由一个因子（UBF 1）进行的，而激活需要一个额外的因子，SL 1与UBF 1一起作用以触发转录。
The human rRNA promoter contains two distinct cis-control sequences, the core and upstream control element (UCE), that serve as the target for binding cellular trans-activating proteins involved in transcription initiation by RNA polymerase I. One of these factors, SL1, has been extensively purified and shown to be a species-specific factor required to reconstitute in vitro RNA synthesis. DNAase footprinting revealed that although SL1 alone does not bind specifically to rRNA promoter sequences, a second factor, UBF1, recruits SL1 to the template and directs binding to an extended region encompassing sequences in the UCE. Analysis of mutant and human-mouse hybrid promoters indicate that protein-DNA interactions at the UCE modulate the efficiency of rRNA synthesis. Transcription from the human rRNA promoter appears to require an unusual set of protein-DNA transactions in which recognition and binding to an upstream cis-control element is carried out by one factor (UBF1), whereas activation requires an additional factor, SL1 acting in conjunction with UBF1 to trigger transcription.