A GATA box in the GATA-1 gene hematopoietic enhancer is a critical element in the network of GATA factors and sites that regulate this gene
A GATA box in the GATA-1 gene hematopoietic enhancer is a critical element in the network of GATA factors and sites that regulate this gene
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DOI：
10.1128/mcb.20.2.713-723.2000
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发表时间：
2000-01-01
影响因子：
5.3
通讯作者：
Yamamoto, M
中科院分区：
文献类型：
--
作者：
Nishimura, S;Takahashi, S;Yamamoto, M
GATA-1基因第一个造血外显子的kbp -3.9至-2.6 5'区域对于在原始和最终红系谱系中概括基因表达是必要的。在转染分析中，该区域以位置和方向无关的方式激活来自人工启动子的报告基因表达，表明该区域具有GATA-1基因造血增强子（G1HE）的功能。然而，在体内转基因胚胎中分析时，G1HE的活性依赖于方向，并且还需要内源性GATA-1基因造血启动子的存在。为了确定G1HE的边界，我们制备了一系列缺失构建体，并在转染和转基因小鼠分析中进行了测试。我们发现，G1HE包含一个149 bp的核心区域，该区域对原始和终代红细胞中的GATA-1基因表达至关重要，但在巨核细胞中，G1HE的表达需要核心加上G1HE的其他序列。这个核心区域包含一个GATA、一个GAT和两个E盒。突变分析显示，只有GATA盒子对基因调控活性至关重要。重要的是，G1HE在SCL-/-胚胎中是活跃的，因此这些结果表明GATA因子和GATA结合位点的关键网络的存在控制着该基因的表达。
A region located at kbp -3.9 to -2.6 5' to the first hematopoietic exon of the GATA-1 gene is necessary to recapitulate gene expression in both the primitive and definitive erythroid lineages. In transfection analyses, this region activated reporter gene expression from an artificial promoter in a position- and orientation-independent manner, indicating that the region functions as the GATA-1 gene hematopoietic enhancer (G1HE), However, when analyzed in transgenic embryos in viveo, G1HE activity was orientation dependent and also required the presence of the endogenous GATA-1 gene hematopoietic promoter. To define the boundaries of G1HE, a series of deletion constructs were prepared and tested in transfection and transgenic mice analyses, We show that G1HE contains a 149-bp core region which is critical for GATA-1 gene expression in both primitive and definitive erythroid cells but that expression in megakaryocytes requires the core plus additional sequences from G1HE. This core region contains one GATA, one GAT, and two E boxes. Mutational analyses revealed that only the GATA box is critical for gene-regulatory activity. Importantly, G1HE was active in SCL-/- embryos, These results thus demonstrate the presence of a critical network of GATA factors and GATA binding sites that controls the expression of this gene.