Wilks A, Seldran M, Jost J P
Nucleic Acids Res. 1984 Jan 25;12(2):1163-77. doi: 10.1093/nar/12.2.1163.
A HpaII site 611 base pairs upstream from the 5' end of the chicken vitellogenin II gene exhibits an estrogen-dependent demethylation in hormone-responsive cells. The complete demethylation of this site occurs considerably later than the transcriptional activation of the gene, and therefore appears to be an effect rather than a cause of this activation. In vivo studies using two inhibitors of DNA synthesis (cytosine arabinoside and hydroxyurea) demonstrate that activation of transcription of the gene is independent of DNA synthesis. Surprisingly, the estrogen-dependent demethylation of the HpaII site is also independent of DNA synthesis. The possible involvement of a site-specific demethylase is discussed.
鸡卵黄生成素II基因5'端上游611个碱基对处的一个HpaII位点在激素反应性细胞中呈现出雌激素依赖性去甲基化。该位点的完全去甲基化比基因的转录激活发生得晚得多，因此似乎是这种激活的一个结果而非原因。使用两种DNA合成抑制剂（阿糖胞苷和羟基脲）的体内研究表明，该基因转录的激活与DNA合成无关。令人惊讶的是，HpaII位点的雌激素依赖性去甲基化也与DNA合成无关。文中讨论了位点特异性去甲基酶可能的参与情况。
