Identification of a FOXA-dependent enhancer of human alcohol dehydrogenase 4 (ADH4).
Identification of a FOXA-dependent enhancer of human alcohol dehydrogenase 4 (ADH4).
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DOI：
10.1016/j.gene.2010.03.013
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发表时间：
2010-07-15
期刊：
影响因子：
3.5
通讯作者：
Edenberg HJ
中科院分区：
文献类型：
--
作者：
Pochareddy S;Edenberg HJ
人酒精脱氢酶4 （ADH4）是参与酒精代谢的关键酶之一。ADH4在肝脏中高度表达，以前的研究发现在近端启动子区域有几个顺式作用元件。在这项研究中，我们已经确定了ADH4的远端上游增强子4E。在HepG2人肝癌细胞中，4E将ADH4基础启动子的活性提高了50倍。4E是细胞特异性的，因为在人肺细胞系H1299中没有检测到增强子活性。我们已经将增强子活性缩小到565 bp的区域，并在该区域确定了多个富集肝脏的转录因子结合位点。通过电泳迁移位移测定，我们证实FOXA蛋白与这些位点结合。位点定向诱变研究表明，位点1和4对增强子功能的影响最大，多个位点的突变具有倍增效应。我们还研究了最小增强子区域的三种变化的影响。两种变异对增强子活性有显著影响，使活性降低0.6倍，而一种变异的影响虽小但显著。不同单倍型的功能活性差异表明，该区域可能在酒精中毒风险中起重要作用。
Human alcohol dehydrogenase 4 (ADH4) is one of the key enzymes involved in the metabolism of alcohol. ADH4 is highly expressed in the liver, and previous studies have revealed several cis-acting elements in the proximal promoter region. In this study we have identified a distal upstream enhancer, 4E, of ADH4. In HepG2 human hepatoma cells, 4E increased the activity of an ADH4 basal promoter by 50-fold. 4E was cell-specific, as no enhancer activity was detected in a human lung cell line, H1299. We have narrowed the enhancer activity to a 565 bp region and have identified multiple liver-enriched transcription factor binding sites in the region. By electrophoretic mobility shift assays, we confirmed binding of FOXA proteins to these sites. Site-directed mutagenesis studies demonstrated that sites 1 and 4 have the biggest effect on enhancer function, and mutations in multiple sites have multiplicative effects. We also studied the effects of three variations in the minimal enhancer region. Two variations had a significant effect on enhancer activity, decreasing the activity to 0.6-fold, while one had small but significant effect. The differences in the functional activity in different haplotypes suggest that this region could play an important role in the risk for alcoholism.
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影响因子：
7
作者：
Siepel, A;Bejerano, G;Haussler, D
通讯作者：
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影响因子：
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作者：
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影响因子：
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作者：
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DOI：
10.1073/pnas.74.10.4378
发表时间：
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影响因子：
11.1
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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