The proximal promoter region of the gene encoding human 17 beta-hydroxysteroid dehydrogenase type 1 contains GATA, AP-2, and Sp1 response elements: Analysis of promoter function in choriocarcinoma cells
The proximal promoter region of the gene encoding human 17 beta-hydroxysteroid dehydrogenase type 1 contains GATA, AP-2, and Sp1 response elements: Analysis of promoter function in choriocarcinoma cells
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DOI：
10.1210/en.138.8.3417
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发表时间：
1997-08-01
期刊：
影响因子：
4.8
通讯作者：
Vihko, R
中科院分区：
文献类型：
--
作者：
Piao, YS;Peltoketo, H;Vihko, R
HSD17B1基因-78~+9的5‘侧翼区为启动子，HSD17B1的沉默元件位于-113~-78位。在目前的研究中，我们利用凝胶迁移率改变、分析和报告基因分析，确定了该基因近端5‘侧翼区的三个调控元件。首先，发现抗Sp1和Sp3抗体识别的核因子与Sp1基序结合在-52到-43区域。SPL结合位点的突变使JEG-3细胞中的启动子活性降低到30%，在JAR细胞中降低到60%，这表明与Sp1基序的结合在HSD17B1启动子的完整功能中起着重要作用。其次，在JEG-3细胞中，AP-2与其基序的结合导致Sp1和Sp3的结合减少，并且AP-2元件的突变使启动子活性增加260%。这些数据表明，AP-2可以通过阻止与Sp1基序结合来抑制HSD17B1启动子的功能。最后，GATA因子，特别是GATA-3，被证明在HSD17B1沉默区域结合了它们的同源序列，而引入GATA结合位点的突变使转录活性增加到不含沉默元件的构建物中的水平。因此，GATA-3似乎阻止了构建体中的转录，因此，GATA基序也可能作为HSD17B1转录的负控制元件发挥作用。
The 5'-flanking region from -78 to +9 in the HSD17B1 gene serves as a promoter, and an HSD17B1 silencer element is located in position -113 to -78. In the present studies, we have characterized three regulatory elements in the proximal 5'-flanking regions of the gene, using electrophoretic mobility shift, assays and reporter gene analysis. First, nuclear factors recognized by antibodies against Sp1 and Sp3 were found to bind the Sp1 motif in the region from -52 to -43. Mutation of the Spl-binding site decreased the promoter activity to 30% in JEG-3 cells and to 60% in JAR cells, suggesting that binding to the Sp1 motif has a substantial role in the complete functioning of the HSD17B1 promoter. Second, the binding of AP-2 to its motif in the region from -62 to -53 led to reduced binding of Sp1 and Sp3, and furthermore, mutation of the AP-2 element increased promoter activity to 260% in JEG-3 cells. The data thus implied that AP-2 can repress the function of the HSD17B1 promoter by preventing binding to the Sp1 motif. Finally, GATA factors, GATA-3 in particular, were demonstrated to bind their cognate sequence in the HSD17B1 silencer region, and mutations introduced into the GATA-binding site increased transcriptional activity to the level seen in constructs not containing the silencer element. Thus, GATA-3 seems to prevent transcription in the constructs, and hence, the GATA motif also may operate as a negative control element for HSD17B1 transcription.