Octamer and Sox elements are required for transcriptional cis regulation of Nanog gene expression
Octamer and Sox elements are required for transcriptional cis regulation of Nanog gene expression
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DOI：
10.1128/mcb.25.6.2475-2485.2005
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发表时间：
2005-03-01
影响因子：
5.3
通讯作者：
Tada, T
中科院分区：
文献类型：
--
作者：
Kuroda, T;Tada, M;Tada, T
多能细胞特异性基因Nanog编码一种携带同源结构域的转录因子，这是维持干细胞未分化状态所必需的。然而，调控Nanog基因表达的分子机制在很大程度上是未知的。为了解决这个重要的问题，我们使用荧光素酶测定来监测基因5'侧区域缺失片段的相对活性。发现相邻的一对高度保守的八聚体和sox结合位点对于激活多能状态特异性基因表达至关重要。此外，包含Octamer/Sox元件的5'端片段足以诱导绿色荧光蛋白报告基因的正确表达，甚至在人胚胎干细胞（ES）中也是如此。OCT4和SOX2与该元件结合的潜力通过F9胚胎癌细胞和胚胎第12.5天胚胎的胚胎生殖细胞提取物的电泳迁移转移实验得到验证。然而，在ES细胞提取物中，OCT4与一个未定义因子的复合物优先结合到Octamer/Sox元件上。因此，Nanog转录可能通过Oct4和Sox2之间的相互作用或一种新的多能细胞特异性Sox元件结合因子（在ES细胞中很突出）来调节。
The pluripotential cell-specific gene Nanog encodes a homeodomain-bearing transcription factor required for maintaining the undifferentiated state of stem cells. However, the molecular mechanisms that regulate Nanog gene expression are largely unknown. To address this important issue, we used luciferase assays to monitor the relative activities of deletion fragments from the 5'-flanking region of the gene. An adjacent pair of highly conserved Octamer- and Sox-binding sites was found to be essential for activating pluripotential state-specific gene expression. Furthermore, the 5'-end fragment encompassing the Octamer/Sox element was sufficient for inducing the proper expression of a green fluorescent protein reporter gene even in human embryonic stem (ES) cells. The potential of OCT4 and SOX2 to bind to this element was verified by electrophoretic mobility shift assays with extracts from F9 embryonal carcinoma cells and embryonic germ cells derived from embryonic day 12.5 embryos. However, in ES cell extracts, a complex of OCT4 with an undefined factor preferentially bound to the Octamer/Sox element. Thus, Nanog transcription may be regulated through an interaction between Oct4 and Sox2 or a novel pluripotential cell-specific Sox element-binding factor which is prominent in ES cells.