Allosteric modulation of estrogen receptor conformation by different estrogen response elements.
Allosteric modulation of estrogen receptor conformation by different estrogen response elements.
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DOI：
10.1210/mend.15.7.0671
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发表时间：
2001-07
影响因子：
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通讯作者：
Jennifer R. Wood;Varsha S. Likhite;M. A. Loven;A. Nardulli
中科院分区：
文献类型：
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作者：
Jennifer R. Wood;Varsha S. Likhite;M. A. Loven;A. Nardulli
雌激素调节基因的表达依赖于雌激素受体（ER）与雌激素反应元件（ERE）的相互作用。我们评估了ER激活报告质粒的转录的能力，所述报告质粒含有一致的卵黄蛋白原A2 ERE或不完美的pS2、卵黄蛋白原B1或催产素（OT）ERE。A2 ERE是最有效的转录激活因子。OT ERE在激活转录方面比pS2或B1 ERE显著更有效。在脱氧核糖核酸酶I（DNase I）足迹实验中，MCF-7蛋白比pS2和B1 ERE更有效地保护A2和OT ERE。用V8蛋白酶或蛋白酶K对A2、pS2、B1或OT ERE结合的受体进行有限的蛋白酶消化，产生不同的切割产物，表明单个ERE序列诱导ER构象的特异性变化。糖皮质激素受体相互作用蛋白1和类固醇受体辅激活因子1的受体相互作用结构域有效地结合到A2，pS2，B1和OT ERE结合的受体，并显着稳定的受体-DNA相互作用。在乳腺癌1中扩增的全长p160蛋白的类似水平通过A2、pS2、B1和OT ERE结合的受体从HeLa细胞核提取物中募集。相比之下，B1 ERE结合受体比A2 ERE结合受体招募的转录中介因子2显著减少。这些研究表明，个别ERE序列的ER构象的变构调制影响特定的辅激活蛋白的募集，并导致含有不同ERE序列的基因的差异表达。
Estrogen-regulated gene expression is dependent on interaction of the estrogen receptor (ER) with the estrogen response element (ERE). We assessed the ability of the ER to activate transcription of reporter plasmids containing either the consensus vitellogenin A2 ERE or the imperfect pS2, vitellogenin B1, or oxytocin (OT) ERE. The A2 ERE was the most potent activator of transcription. The OT ERE was significantly more effective in activating transcription than either the pS2 or B1 ERE. In deoxyribonuclease I (DNase I) footprinting experiments, MCF-7 proteins protected A2 and OT EREs more effectively than the pS2 and B1 EREs. Limited protease digestion of the A2, pS2, B1, or OT ERE-bound receptor with V8 protease or proteinase K produced distinct cleavage products demonstrating that individual ERE sequences induce specific changes in ER conformation. Receptor interaction domains of glucocorticoid receptor interacting protein 1 and steroid receptor coactivator 1 bound effectively to the A2, pS2, B1, and OT ERE-bound receptor and significantly stabilized the receptor-DNA interaction. Similar levels of the full-length p160 protein amplified in breast cancer 1 were recruited from HeLa nuclear extracts by the A2, pS2, B1, and OT ERE-bound receptors. In contrast, significantly less transcriptional intermediary factor 2 was recruited by the B1 ERE-bound receptor than by the A2 ERE-bound receptor. These studies suggest that allosteric modulation of ER conformation by individual ERE sequences influences the recruitment of specific coactivator proteins and leads to differential expression of genes containing divergent ERE sequences.