An inverted TATA box directs downstream transcription of the bone sialoprotein gene.
An inverted TATA box directs downstream transcription of the bone sialoprotein gene.
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倒置的 TATA 盒指导骨唾液蛋白基因的下游转录。
DOI：
10.1042/bj3100033
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
J. Sodek
中科院分区：
文献类型：
--
作者：
Jing Li;R. Kim;J. Sodek
TATA盒的方向被认为通过RNA聚合酶II指导真核基因的下游转录。然而，骨唾液蛋白（BSP）基因启动子中的推定TATA盒（编码组织特异性和发育调节的骨基质蛋白）相对于共有TATA盒序列（5 '-TATAAA-3'）是反向的（5 '-TTTATA-3'），并被维生素D3-反应元件重叠。在这里，我们表明，在大鼠BSP基因的倒TATA序列结合重组TATA盒结合蛋白（TBP）的亲和力与观察到的共识TATA盒，和定点突变的倒TATA序列（突变TTTATA到TCTCTA）废除TBP结合和BSP启动子活性。然而，当倒置的TATA序列改变为典型的TATAAA时，TBP和维生素D3受体结合特性以及BSP启动子活性被保留。此外，我们发现，TBP是必需的，以重建在体外转录驱动的BSP启动子。这些研究揭示了天然存在的可以结合TBP并指导下游转录的倒TATA盒，表明TATA盒的方向并不决定高等真核基因的转录方向。因此，在人、大鼠和小鼠BSP基因启动子中保守的反向TATA盒将提供一个极好的体内模型来研究转录因子IID-DNA复合物的极性及其与下游转录的关系。
The orientation of the TATA box is thought to direct downstream transcription of eukaryotic genes by RNA polymerase II. However, the putative TATA box in the promoter of the bone sialoprotein (BSP) gene, which codes for a tissue-specific and developmentally regulated bone matrix protein, is inverted (5'-TTTATA-3') relative to the consensus TATA box sequence (5'-TATAAA-3') and is overlapped by a vitamin D3-response element. Here we show that the inverted TATA sequence in the rat BSP gene binds to recombinant TATA-box-binding protein (TBP) with an affinity similar to that observed with the consensus TATA box, and site-directed point mutations in the inverted TATA sequence (mutating TTTATA into TCTCTA) abrogate both TBP binding and BSP promoter activity. However, when the inverted TATA sequence is changed to a canonical TATAAA, the TBP- and vitamin D3 receptor-binding properties together with the BSP promoter activity are retained. In addition, we found that the TBP is required to reconstitute in vitro transcription driven by the BSP promoter. These studies, which have revealed a naturally occurring inverted TATA box that can bind TBP and direct downstream transcription, demonstrate that the orientation of the TATA box does not determine the direction of transcription in higher eukaryotic genes. Consequently, the inverted TATA box that is conserved in the human, rat and mouse BSP gene promoters will provide an excellent in vivo model to investigate the polarity of the transcription factor IID-DNA complex and its relation to downstream transcription.