Conserved POU binding DNA sites in the Sox2 upstream enhancer regulate gene expression in embryonic and neural stem cells
Conserved POU binding DNA sites in the Sox2 upstream enhancer regulate gene expression in embryonic and neural stem cells
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DOI：
10.1074/jbc.m405514200
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发表时间：
2004-10-01
影响因子：
4.8
通讯作者：
Nicolis, SK
中科院分区：
文献类型：
--
作者：
Catena, R;Tiveron, C;Nicolis, SK
Sox 2转录因子早期在胚泡内细胞团的干细胞中表达，后来在神经干细胞中表达。我们以前确定了一个Sox 2 5 '调控区，指导转基因表达的内细胞团，后来，神经干细胞和前脑的前体细胞。在这里，我们确定了一个核心增强子元件能够指定转基因表达的前脑神经前体的小鼠胚胎，我们表明，相同的核心元件有效地激活内细胞团衍生的胚胎干细胞（ES）的转录。能够识别神经因子Brn1和Brn2的POU因子结合位点的突变表明，这些位点有助于神经细胞中的转基因活性。相同的位点对于ES细胞中的活性也是必不可少的，在ES细胞中，它们结合POU家族的不同成员，包括Oct4，如通过凝胶位移测定和染色质免疫沉淀与抗Oct4抗体所示。我们的研究结果表明，在ES和神经前体细胞中，相同的POU结合基序在Sox 2转基因调控中起作用。Oct4可能在ES（内细胞团）细胞中Sox 2的调节中起作用，并且可能在内细胞团和神经细胞之间的过渡中起作用，在神经POU因子如Brn 1和Brn 2的募集之前。
The Sox2 transcription factor is expressed early in the stem cells of the blastocyst inner cell mass and, later, in neural stem cells. We previously identified a Sox2 5'-regulatory region directing transgene expression to the inner cell mass and, later, to neural stem cells and precursors of the forebrain. Here, we identify a core enhancer element able to specify transgene expression in forebrain neural precursors of mouse embryos, and we show that the same core element efficiently activates transcription in inner cell mass-derived embryonic stem (ES) cells. Mutation of POU factor binding sites, able to recognize the neural factors Brn1 and Brn2, shows that these sites contribute to transgene activity in neural cells. The same sites are also essential for activity in ES cells, where they bind different members of the POU family, including Oct4, as shown by gel shift assays and chromatin immunoprecipitation with anti-Oct4 antibodies. Our findings indicate a role for the same POU binding motifs in Sox2 transgene regulation in both ES and neural precursor cells. Oct4 might play a role in the regulation of Sox2 in ES (inner cell mass) cells and, possibly, at the transition between inner cell mass and neural cells, before recruitment of neural POU factors such as Brn1 and Brn2.