Epigenetic modifications of the 35S promoter in cultured gentian cells.
Epigenetic modifications of the 35S promoter in cultured gentian cells.
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DOI：
10.1016/j.plantsci.2011.01.008
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发表时间：
2011-04
期刊：
影响因子：
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通讯作者：
S. Yamasaki;M. Oda;H. Daimon;K. Mitsukuri;M. Johkan;T. Nakatsuka;M. Nishihara;K. Mishiba
中科院分区：
文献类型：
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作者：
S. Yamasaki;M. Oda;H. Daimon;K. Mitsukuri;M. Johkan;T. Nakatsuka;M. Nishihara;K. Mishiba
我们之前的研究发现，在转基因龙胆植物中，严格的基因沉默与CaMV-35S启动子特异性从头甲基化相关。为了分析从头甲基化机制，特别是与组蛋白修饰相关的甲基化机制，产生了源自单一转化事件的35s驱动的表达sgp和沉默的龙胆培养细胞系，并用于表观遗传分析。表达sgfp的主要诱导细胞悬浮培养（PS）在35S启动子区低甲基化，尽管在35S增强子区（- 148至- 85）检测到低水平的从头甲基化。相比之下，来自转基因植物叶片组织的sgp沉默的再诱导细胞悬浮培养（RS）在35S启动子区域发生了高甲基化。染色质免疫沉淀分析显示，RS中沉默的35S启动子区域的组蛋白H3在赖氨酸9上被去乙酰化和二甲基化。有趣的是，在沉默的35S启动子3 '区，也观察到组蛋白H3赖氨酸4的二甲基化。当PS发生35S区域的低甲基化和组蛋白H3乙酰化时，35S增强子区域已经发生了重新甲基化。重新甲基化状态也对5-aza-2 ' -脱氧胞苷处理具有抗性。这些结果表明，增强子区域的从头甲基化是35S沉默的一个原始过程，该过程触发组蛋白H3去乙酰化。
Our previous studies found strict gene silencing associated with CaMV-35S promoter-specific de novo methylation in transgenic gentian plants. To dissect the de novo methylation machinery, especially in association with histone modification, 35S-driven sGFP-expressing and -silenced gentian cultured cell lines that originated from a single transformation event were produced and used for epigenetic analyses. A sGFP-expressing primarily induced cell suspension culture (PS) was hypomethylated in the 35S promoter region, although a low level of de novo methylation at the 35S enhancer region (−148 to −85) was detected. In contrast, a sGFP-silenced re-induced cell suspension culture (RS), which originated from leaf tissues of a transgenic plant, was hypermethylated in the 35S promoter region. Chromatin immunoprecipitation analysis showed that in RS, histone H3 of the silenced 35S promoter region was deacetylated and also dimethylated on lysine 9. Interestingly, in the silenced 35S promoter 3′ region, dimethylation of histone H3 lysine 4 was also observed. When hypomethylation and histone H3 acetylation of the 35S region occurred in PS, de novo methylation at the 35S enhancer region had already taken place. The de novo methylation status was also resistant to 5-aza-2′-deoxycytidine treatment. These results suggest that de novo methylation of the enhancer region is a primitive process of 35S silencing that triggers histone H3 deacetylation.