The immunoglobulin heavy-chain matrix-associating regions are bound by Bright: A B cell-specific trans-activator that describes a new DNA-binding protein family
The immunoglobulin heavy-chain matrix-associating regions are bound by Bright: A B cell-specific trans-activator that describes a new DNA-binding protein family
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DOI：
10.1101/gad.9.24.3067
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发表时间：
1995-12-15
影响因子：
10.5
通讯作者：
Tucker, PW
中科院分区：
文献类型：
--
作者：
Herrscher, RF;Kaplan, MH;Tucker, PW
免疫球蛋白重链（IgH）基因的B淋巴细胞限制性转录由可变区启动子（V-H）和内含子增强子（E mu）内的元件指定。编码一种结合诱导mu重链转录所需的V-H启动子近端位点的蛋白质的基因已被克隆。这种B细胞特异性蛋白被称为Bright （B细胞IgH转录调节剂），存在于可溶性和基质不溶性核组分中。Bright结合了限制ATC序列的小槽，这足以使核基质结合。该序列基序存在于前面描述的靠近启动子和两侧E mu的矩阵相关区域（MARs）。Bright可以通过结合这些位点激活E mu驱动的转录，但只有当它们发生在自然环境和允许E mu活性的细胞系中时。为了结合DNA， Bright需要一个新的四聚结构域和一个先前描述的结构域，该结构域与几种蛋白质共享身份，包括SWI/SNF复合物的一个组成部分SWI1。
B lymphocyte-restricted transcription of immunoglobulin heavy-chain (IgH) genes is specified by elements within the variable region (V-H) promoter and the intronic enhancer (E mu). The gene encoding a protein that binds a V-H promoter proximal site necessary for induced mu-heavy-chain transcription has been cloned. This B-cell specific protein, termed Bright (B cell regulator of IgH transcription), is found in both soluble and matrix insoluble nuclear fractions. Bright binds the minor groove of a restricted ATC sequence that is sufficient for nuclear matrix association. This sequence motif is present in previously described matrix-associating regions (MARs) proximal to the promoter and flanking E mu. Bright can activate E mu-driven transcription by binding these sites, but only when they occur in their natural context and in cell lines permissive for E mu activity. To bind DNA, Bright requires a novel tetramerization domain and a previously undescribed domain that shares identity with several proteins, including SWI1, a component of the SWI/SNF complex.