Multiple promoters exist in the human GR gene, one of which is activated by glucocorticoids
Multiple promoters exist in the human GR gene, one of which is activated by glucocorticoids
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DOI：
10.1210/me.15.8.1381
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发表时间：
2001-08-01
影响因子：
--
通讯作者：
Vedeckis, WV
中科院分区：
文献类型：
--
作者：
Breslin, MB;Geng, CD;Vedeckis, WV
一个新的人GR基因序列（hGR 1Ap/e），这是不同于以前确定的人GR启动子和编码序列，已被分离和表征。hGR 1Ap/e序列位于人GR编码序列上游约31 kbp处。该序列（2，056 bp）含有一个新的启动子（hGR 1A启动子; 1，075 bp）和非翻译外显子序列（hGR外显子1A序列; 981 bp）。选择性剪接产生三种不同的含hGR 1A的转录物，1A 1，1A 2和1A 3。含有外显子1A 1、1A 2、1B和1C的GR转录物在许多癌细胞系中以不同水平表达，而含有外显子1A 3的GR转录物在血细胞癌细胞系中表达最丰富。糖皮质激素治疗导致CEM-C7 T淋巴母细胞中含有外显子1A 3的GR转录物上调，并导致IM-9 B淋巴瘤细胞中含有外显子1A 3的转录物下调。使用CEM-C7细胞核提取物的脱氧核糖核酸酶I足迹法揭示了启动子区域中的四个足迹和两个外显子内足迹。大部分基础启动子激活功能存在于+41/+269序列中，该序列包含两个脱氧核糖核酸酶I足迹（FP 5和FP 6）。当将该序列克隆到pXP-1荧光素酶报告基因中时，激素处理导致与GR表达载体共转染的Jurkat T细胞中荧光素酶活性显著增加。FP 5是一个干扰素调节因子结合元件，对基础转录速率有重要作用，但不被类固醇激活。FP 6类似于糖皮质激素反应元件，可以结合GR β。这种新的hGR 1Ap/e序列可能在T细胞白血病和淋巴瘤的诊断、预后和治疗方面具有未来的应用前景。
A new human GR gene sequence (hGR 1Ap/e), which is distinct from the previously identified human GR promoter and coding sequences, has been isolated and characterized. The hGR 1Ap/e sequence is approximately 31 kbp upstream of the human GR coding sequence. This sequence (2,056 bp) contains a novel promoter (the hGR 1A promoter; 1,075 bp) and untranslated exon sequence (hGR exon 1A sequence; 981 bp). Alternative splicing produces three different hGR 1A-containing transcripts, 1A1, 1A2, and 1A3. GR transcripts containing exon 1 All, 1A2, 1B, and IC are expressed at various levels in many cancer cell lines, while the exon 1A3-containing GR transcript is expressed most abundantly in blood cell cancer cell lines. Glucocorticoid hormone treatment causes an upregulation of exon 1A3-containing GR transcripts in CEM-C7 T-lymphoblast cells and a down-regulation of exon 1A3-containing transcripts in IM-9 B-lymphoma cells. Deoxyribonuclease I footprinting using CEM-C7 cell nuclear extract reveals four footprints in the promoter region and two intraexonic footprints. Much of the basal promoter-activating function is found in the +41/+269 sequence, which contains two deoxyribonuclease I footprints (FP5 and FP6). When this sequence is cloned into the pXP-1 luciferase reporter gene, hormone treatment causes a significant increase in luciferase activity in Jurkat T cells that are cotransfected with a GR expression vector. FP5 is an interferon regulatory factor-binding element, and it contributes significantly to basal transcription rate, but it is not activated by steroid. FP6 resembles a glucocorticoid response element and can bind GR beta. This novel hGR 1Ap/e sequence may have future applications for the diagnosis, prognosis, and treatment of T-cell leukemia and lymphoma.