An insulator element 3' to the CFTR gene binds CTCF and reveals an active chromatin hub in primary cells.
An insulator element 3' to the CFTR gene binds CTCF and reveals an active chromatin hub in primary cells.
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DOI：
10.1093/nar/gkn1056
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发表时间：
2009-03
影响因子：
14.9
通讯作者：
Harris A
中科院分区：
文献类型：
--
作者：
Blackledge NP;Ott CJ;Gillen AE;Harris A
人们对CFTR基因表达的调节知之甚少。基因的基础启动子内的元素不能完全解释CFTR表达模式，这表明顺式调控元件位于其他地方，无论是在基因座内或在相邻的染色质。我们先前定位了跨越CFTR基因座的400 kb内的DNase I超敏位点（DHS），包括靠近基因3′端的一簇位点。在这里，我们专注于DHS在+6.8 kb的CFTR翻译终点，以评估其在调节基因表达的潜在作用。这DHS，其中包括一个共识CTCF结合位点，是明显的原代人附睾细胞表达丰富的CFTR mRNA。我们表明，通过DNA酶I足迹和电泳迁移率变动分析，该DHS内的顺式调节元件在体外结合CTCF。我们进一步证明，该元素的功能作为一个增强子阻滞剂在一个完善的体内测定，并通过使用染色质免疫沉淀，它在体内招募CTCF。此外，我们发现，在原代附睾细胞中，+6.8 kb DHS与CFTR启动子密切相互作用，这表明CFTR基因座存在于环状构象中，这是活性染色质枢纽的特征。
Regulation of expression of the CFTR gene is poorly understood. Elements within the basal promoter of the gene do not fully explain CFTR expression patterns, suggesting that cis-regulatory elements are located elsewhere, either within the locus or in adjacent chromatin. We previously mapped DNase I hypersensitive sites (DHS) in 400 kb spanning the CFTR locus including a cluster of sites close to the 3′-end of the gene. Here we focus on a DHS at +6.8 kb from the CFTR translation end-point to evaluate its potential role in regulating expression of the gene. This DHS, which encompasses a consensus CTCF-binding site, was evident in primary human epididymis cells that express abundant CFTR mRNA. We show by DNase I footprinting and electophoretic mobility shift assays that the cis-regulatory element within this DHS binds CTCF in vitro. We further demonstrate that the element functions as an enhancer blocker in a well-established in vivo assay, and by using chromatin immunoprecipitation that it recruits CTCF in vivo. Moreover, we reveal that in primary epididymis cells, the +6.8 kb DHS interacts closely with the CFTR promoter, suggesting that the CFTR locus exists in a looped conformation, characteristic of an active chromatin hub.
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DOI：
10.1073/pnas.94.2.575
发表时间：
1997-01-21
影响因子：
11.1
作者：
Chung, JH;Bell, AC;Felsenfeld, G
通讯作者：
Felsenfeld, G
影响因子：
3.5
作者：
Broackes-Carter, FC;Mouchel, N;Harris, A
通讯作者：
Harris, A
影响因子：
4.1
作者：
Blackledge, Neil P.;Carter, Emma J.;Harris, Ann
通讯作者：
Harris, Ann
影响因子：
64.8
作者：
Hark, AT;Schoenherr, CJ;Tilghman, SM
通讯作者：
Tilghman, SM
影响因子：
64.5
作者：
Kim, Tae Hoon;Abdullaev, Ziedulla K.;Ren, Bing
通讯作者：
Ren, Bing