Promotion of V(D)J recombinational accessibility by the intronic E kappa element: Role of the kappa B motif
Promotion of V(D)J recombinational accessibility by the intronic E kappa element: Role of the kappa B motif
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DOI：
10.1093/intimm/7.12.1995
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发表时间：
1995-12-01
影响因子：
4.4
通讯作者：
Alt, FW
中科院分区：
文献类型：
--
作者：
Demengeot, J;Oltz, EM;Alt, FW
在V(D)J重组酶诱导细胞系（HDR37）中，染色体整合的TCR β微位点重组底物的可及性取决于转录增强子元件的结合，如Ig kappa轻链内含子增强子（E kappa）。kappa元件包含几个功能基序，包括kappa B基序，它与NF-kappa B转录因子结合。为了评估E kappa促进V(D)J重组可及性的分子机制，我们比较了野生型E kappa、对应的突变型E kappa B基序序列（E kappa-kappa B-）和kappa B基序二聚体（kappa B2）在TCR β minilocus/HDR37系统中的功能。含有E kappa的迷你位点进行了去甲基化、转录和V(D)J重组，与拷贝数或整合位点无关。含有低拷贝数（一个或两个）的含有E -kappa - B-的微小位点的转染物，如任何拷贝数的enhenherless或含有kappa- b2的微小位点，在所有三个过程中都是无活性的。相比之下，高拷贝数的E - kappa-kappa B-底物的整合子在这三个过程中都表现出依赖于整合位点的激活。总之，这些数据表明kappa B基序在E kappa赋予V(D)J重组可及性的能力中起着关键作用，但它本身不足以介导这一过程。
The accessibility of a chromosomally integrated TCR beta minilocus recombination substrate in a V(D)J recombinase-inducible cell line (HDR37) depends on incorporation of transcriptional enhancer elements such as the Ig kappa light chain intronic enhancer (E kappa). The E kappa element contains several functional motifs including the kappa B motif, which binds the NF-kappa B transcription factor. To assess molecular mechanisms by which E kappa promotes V(D)J recombinational accessibility, we compared the abilities of the wild-type E kappa, a corresponding E kappa sequence with a mutant kappa B motif (E kappa-kappa B-) and a kappa B motif dimer (kappa B2) to function in the context of the TCR beta minilocus/HDR37 system. The E kappa-containing minilocus underwent demethylation, transcription and V(D)J recombination, independently of copy number or integration site. Transfectants containing low copy numbers (one or two) of the E kappa-kappa B--containing minilocus, like enhancerless or kappa B2-containing miniloci at any copy number, were inactive with respect to all three processes. In contrast, high-copy-number integrants of the E kappa-kappa B- substrates showed an integration-site dependent activation of all three processes. Together these data show that the kappa B motif plays a critical role in the ability of E kappa to confer V(D)J recombinational accessibility, but that it is not sufficient to mediate this process by itself.