THE RAT QUINONE REDUCTASE ANTIOXIDANT RESPONSE ELEMENT - IDENTIFICATION OF THE NUCLEOTIDE-SEQUENCE REQUIRED FOR BASAL AND INDUCIBLE ACTIVITY AND DETECTION OF ANTIOXIDANT RESPONSE ELEMENT-BINDING PROTEINS IN HEPATOMA AND NON-HEPATOMA CELL-LINES
THE RAT QUINONE REDUCTASE ANTIOXIDANT RESPONSE ELEMENT - IDENTIFICATION OF THE NUCLEOTIDE-SEQUENCE REQUIRED FOR BASAL AND INDUCIBLE ACTIVITY AND DETECTION OF ANTIOXIDANT RESPONSE ELEMENT-BINDING PROTEINS IN HEPATOMA AND NON-HEPATOMA CELL-LINES
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DOI：
10.1074/jbc.270.41.24468
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发表时间：
1995-10-13
影响因子：
4.8
通讯作者：
PICKETT, CB
中科院分区：
文献类型：
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作者：
FAVREAU, LV;PICKETT, CB
通过突变和缺失分析进一步表征了大鼠醌还原酶基因 5' 侧翼区域中发现的抗氧化反应元件 (ARE)。结果表明，包含 13 碱基对回文序列的 31 碱基对 ARE 可以进一步分为三个区域，所有三个区域都是升高基础水平基因表达所必需的。这三个区域包括近端区域。和远端半位点以及由 4 个腺嘌呤核苷酸组成的 3' 侧翼区域。近端半位点和远端半位点均不单独介导β-萘黄酮的转录激活。然而，当放置在一起时，两个半位点恢复了对诱导物的反应性。有趣的是，近端半位点的3'侧翼区域中仅存在4个腺嘌呤核苷酸中的1个，这是对诱导物的反应性所必需的。 ARE 内的点突变表明近端和远端半位点中的多个核苷酸是基础水平基因表达所必需的。使用 ARE 作为探针的电泳迁移率变动分析表明，谷胱甘肽 S-转移酶 Ya 和 P 基因中发现的增强子可识别人 Hep G2 细胞粗核提取物中发现的类似反式作用因子。此外，该复合物可以在大鼠肝脏和大鼠肝癌细胞的核提取物中检测到，但在小鼠 Hepa 1c1c7 细胞或人 HeLa 细胞中检测不到。 ARE-核蛋白复合物也可以在缺乏大量 Jun/Fos 蛋白的 F9 细胞中检测到。尽管大鼠 ARE 类似于含有共有 TRE 的人醌还原酶 ARE，但核心序列中的 2 个核苷酸变化（TGACTCA 与 TGACTTG）消除了大鼠 ARE 中的高亲和力 TRE 基序。大鼠 ARE 在 Hep G2 和其他细胞中形成核蛋白复合物，其特性与 AP-1 不同。
The antioxidant response element (ARE) found in the 5'-flanking region of the rat quinone reductase gene has been further characterized by mutational and deletion analysis. The results indicate that the 31-base pair ARE, which contains a 13-base pair palindromic sequence, can be further separated into three regions, all three of which are required for elevated basal level gene expression. These three regions include the proximal. and distal half-sites as well as a 3'-flanking region consisting of 4 adenine nucleotides. Neither the proximal nor the distal half-site alone mediates transcriptional activation by beta-naphthoflavone. However, when placed together the two half-sites restore responsiveness to the inducer, Interestingly, the presence of only 1 of the 4 adenine nucleotides in the 3'-flanking region of the proximal half-site is required for responsiveness to the inducer. Point mutations within the ARE indicate that several nucleotides in both the proximal and distal half-sites are required for basal level gene expression. Electrophoretic mobility shift analysis using the ARE as the probe indicates that enhancers found in the glutathione S-transferase Ya and P genes recognize a similar trans acting factor(s) found in crude nuclear extracts from human Hep G2 cells. Further, this complex can be detected in nuclear extracts from rat liver and rat hepatoma cells but not in mouse Hepa 1c1c7 cells or in human HeLa cells. The ARE-nucleoprotein complex can also be detected in F9 cells which lack significant levels of Jun/Fos proteins. Although the rat ARE resembles the human quinone reductase ARE which contains a consensus TRE, the 2-nucleotide change in the core sequence (TGACTCA versus TGACTTG) eliminates the high affinity TRE motif in the rat ARE. The rat ARE forms a nucleoprotein complex in Hep G2 and other cells with different properties than AP-1.