Fedoseeva Daria M, Kretova Olga V, Gorbacheva Maria A, Tchurikov Nickolai A
Engelhardt Institute of Molecular Biology, Moscow 119334, Russia.
Engelhardt Institute of Molecular Biology, Moscow 119334, Russia.
Gene. 2018 Jan 30;641:151-160. doi: 10.1016/j.gene.2017.10.033. Epub 2017 Oct 16.
Enhancers and insulators are involved in the regulation of gene expression, but the basic underlying mechanisms of action of these elements are unknown. We analyzed the individual effects of the enhancer and the insulator from Drosophila mobile elements copia [enh(copia)] and gypsy using transfected genetic constructs in S2 cells. This system excludes the influence of genomic cis regulatory elements. The enhancer-induced synthesis of 350-1050-nt-long enhancer RNAs (eRNAs) and H3K4me3 and H3K18ac marks, mainly in the region located about 300bp downstream of the enhancer. Insertion of the insulator between the enhancer and the promoter reduced these effects. We also observed the binding of dCTCF to the enhancer and to gypsy insulator. Our data indicate that a single gypsy insulator interacts with both the enhancer and the promoter, while two copies of the gypsy insulator preferentially interact with each other. Our results suggest the formation of chromatin loops that are shaped by the enhancer and the insulator.
增强子和绝缘子参与基因表达调控，但其作用的基本潜在机制尚不清楚。我们使用转染的遗传构建体在S2细胞中分析了果蝇移动元件copia [enh(copia)]和gypsy的增强子和绝缘子的个体效应。该系统排除了基因组顺式调控元件的影响。增强子诱导主要在增强子下游约300bp区域合成350 - 1050nt长的增强子RNA（eRNA）以及H3K4me3和H3K18ac标记。在增强子和启动子之间插入绝缘子会降低这些效应。我们还观察到dCTCF与增强子和gypsy绝缘子的结合。我们的数据表明，单个gypsy绝缘子与增强子和启动子都相互作用，而两个拷贝的gypsy绝缘子则优先相互作用。我们的结果表明形成了由增强子和绝缘子塑造的染色质环。
