HYPOXIC INDUCTION OF THE HUMAN ERYTHROPOIETIN GENE - COOPERATION BETWEEN THE PROMOTER AND ENHANCER, EACH OF WHICH CONTAINS STEROID-RECEPTOR RESPONSE ELEMENTS
HYPOXIC INDUCTION OF THE HUMAN ERYTHROPOIETIN GENE - COOPERATION BETWEEN THE PROMOTER AND ENHANCER, EACH OF WHICH CONTAINS STEROID-RECEPTOR RESPONSE ELEMENTS
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DOI：
10.1128/mcb.12.12.5373
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发表时间：
1992-12-01
影响因子：
5.3
通讯作者：
BUNN, HF
中科院分区：
文献类型：
--
作者：
BLANCHARD, KL;ACQUAVIVA, AM;BUNN, HF
在整个动物和 Hep3B 细胞中，暴露于缺氧和/或钴会刺激人促红细胞生成素 (Epo) 基因的转录。我们通过瞬时转染 Hep3B 细胞系统地研究了这种诱导所需的启动子和 3' 增强子元件。我们定义了 53 bp 的启动子区域和 43 bp 的增强子区域，赋予缺氧和钴诱导性。每个元素单独产生 6 至 10 倍的感应。它们组合在一起，在刺激后产生 50 倍的诱导，类似于内源性 Epo 基因的 50 至 100 倍的诱导。这些区域中存在两个 DNA 序列同源性区域。我们证明了增强子中特定的 DNA-蛋白质相互作用以及启动子元件在电泳迁移率变动测定中与这些相互作用竞争的能力。 DNase I 足迹和甲基化干扰数据进一步将 43 bp 增强子中的顺式作用元件细化为包含由 2 bp 间隙分隔的类固醇/甲状腺激素受体反应元件半位点直接重复的短区域。 53 bp 启动子中还存在两个半位点共有序列。增强子中半位点序列的位点特异性突变破坏了增强子的功能活性。
Transcription of the human erythropoietin (Epo) gene is stimulated by exposure to hypoxia and/or cobalt in whole animals and in Hep3B cells. We have systematically investigated the promoter and 3' enhancer elements necessary for this induction by transient transfection of Hep3B cells. We define a promoter region of 53 bp and an enhancer region of 43 bp that confer hypoxia and cobalt inducibility. Each element gives rise to a 6- to 10-fold induction alone. In combination they produce a 50-fold induction after stimulation, similar to the 50- to 100-fold induction of the endogenous Epo gene. Two areas of DNA sequence homology are present in these regions. We demonstrate specific DNA-protein interactions in the enhancer and the ability of the promoter element to compete with these interactions in electrophoretic mobility shift assays. DNase I footprinting and methylation interference data further refine the cis-acting element in the 43-bp enhancer to a short region containing a direct repeat of a steroid/thyroid hormone receptor response element half-site separated by a 2-bp gap. Two half-site consensus sequences are also present in the 53-bp promoter. Site-specific mutation of the half-site sequences in the enhancer destroys the functional activity of the enhancer.