An ectopic CTCF-dependent transcriptional insulator influences the choice of Výý gene segments for VDJ recombination at TCRýý locus.
An ectopic CTCF-dependent transcriptional insulator influences the choice of Výý gene segments for VDJ recombination at TCRýý locus.
复制标题
异位 CTCF 依赖性转录绝缘体影响 TCR×× 基因座上 VDJ 重组的 V×× 基因片段的选择。
DOI：
10.1093/nar/gks556
复制
发表时间：
2012
影响因子：
14.9
通讯作者：
Srivastava,Madhulika
中科院分区：
文献类型：
--
作者：
Shrimali,Sweety;Srivastava,Surabhi;Varma,Garima;Grinberg,Alex;Pfeifer,Karl;Srivastava,Madhulika
绝缘体通过将染色质组织成不同的结构域来调节增强子和启动子之间的相互作用，从而调节转录。为了更好地了解绝缘体定义的染色质结构域的性质，我们分析了绝缘体干扰 VDJ 重组的能力，这一过程严重依赖于不同类型顺式作用 DNA 元件之间的长程相互作用。通过基因操作将一个成熟的 CTCF 依赖性转录绝缘子 H19 印记控制区 (H19-ICR) 插入小鼠 TCRβ 基因座中。对突变小鼠的分析表明，绝缘子在体内异源环境中保留了其 CTCF 和位置依赖性增强子阻断潜力。值得注意的是，插入的 H19-ICR 似乎能够调节 TCRβ 基因座的重组信号序列元件之间的顺式 DNA 相互作用，从而导致突变小鼠中 Vβ 片段用于 Vβ 到 DβJβ 重组的用途发生显着改变。这揭示了 CTCF 控制增强子-启动子相互作用以外的长范围顺式 DNA 相互作用的新能力，并表明 CTCF 依赖性绝缘体可能在转录控制之外的基因组组织中发挥多样化和复杂的作用。我们对 TCRβ 突变位点的功能分析支持了 CTCF 在控制 VDJ 重组中的新兴作用。
Insulators regulate transcription as they modulate the interactions between enhancers and promoters by organizing the chromatin into distinct domains. To gain better understanding of the nature of chromatin domains defined by insulators, we analyzed the ability of an insulator to interfere in VDJ recombination, a process that is critically dependent on long-range interactions between diverse types ofcis-acting DNA elements. A well-established CTCF-dependent transcriptional insulator,H19imprint control region (H19-ICR), was inserted in the mouse TCRβ locus by genetic manipulation. Analysis of the mutant mice demonstrated that the insulator retains its CTCF and position-dependent enhancer-blocking potential in this heterologous contextin vivo.Remarkably, the insertedH19-ICRappears to have the ability to modulatecis-DNA interactions between recombination signal sequence elements of the TCRβ locus leading to a dramatically altered usage of Vβ segments for Vβ-to-DβJβ recombination in the mutant mice. This reveals a novel ability of CTCF to govern long rangecis-DNA interactions other than enhancer–promoter interactions and suggests that CTCF-dependent insulators may play a diverse and complex role in genome organization beyond transcriptional control. Our functional analysis of mutated TCRβ locus supports the emerging role of CTCF in governing VDJ recombination.