INDUCIBLE, RECEPTOR-DEPENDENT PROTEIN-DNA INTERACTIONS AT A DIOXIN-RESPONSIVE TRANSCRIPTIONAL ENHANCER
INDUCIBLE, RECEPTOR-DEPENDENT PROTEIN-DNA INTERACTIONS AT A DIOXIN-RESPONSIVE TRANSCRIPTIONAL ENHANCER
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DOI：
10.1073/pnas.85.8.2528
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发表时间：
1988-04-01
影响因子：
11.1
通讯作者：
WHITLOCK, JP
中科院分区：
文献类型：
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作者：
DENISON, MS;FISHER, JM;WHITLOCK, JP
我们已经在小鼠肝癌细胞中鉴定了细胞色素P1 - 450基因5 "侧翼区域内的第三个顺式作用二恶英反应元件（DRE），其被2，3，7，8-四氯二苯并-p-二恶英（TCDD）转录激活。DRE可以激活异源启动子并在任一方向发挥功能;因此，它具有转录增强子的特性。DRE不能激活受体缺陷细胞中的转录;因此，它需要TCDD-受体复合物才能发挥功能。通过使用凝胶阻滞试验，我们表明，核提取物中含有一种蛋白质，结合到DRE在TCDD诱导，受体依赖性，和DNA序列特异性的方式。蛋白质-DNA相互作用发生在细胞暴露于TCDD的10分钟内，并且不需要持续的蛋白质合成。我们的研究结果表明，TCDD-受体复合物与DRE特异性相互作用，并证明了体外蛋白质-DNA相互作用与体内功能之间的关系。我们的研究结果还表明，TCDD-受体复合物的DRE的亲和力可能是相对较高的，在其他诱导增强剂的类似蛋白质-DNA相互作用相比。
We have identified in mouse hepatoma cells a third cis-acting dioxin-responsive element (DRE) within the 5'' flanking region of the cytochrome P1-450 gene, which is transcriptionally activated by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The DRE can activate a heterologous promoter and functions in either orientation; therefore, it has the properties of a transcriptional enhancer. The DRE fails to activate transcription in receptor-defective cells; therefore, it requires TCDD-receptor complexes for its function. By using a gel retardation assay, we show that nuclear extracts contain a protein that binds to the DRE in TCDD-inducible, receptor-dependent, and DNA sequence-specific fashion. The protein-DNA interaction occurs within 10 min of exposure of the cell to TCDD and does not require ongoing protein synthesis. Our results imply that the TCDD-receptor complex interacts specifically with the DRE and demonstrate a relationship between protein-DNA interaction in vitro and function in vivo. Our findings also suggest that the affinity of the TCDD-receptor complex for the DRE may be relatively high in comparison to analogous protein-DNA interactions at other inducible enhancers.