YB-1 and CTCF differentially regulate the 5-HTT polymorphic intron 2 enhancer which predisposes to a variety of neurological disorders
YB-1 and CTCF differentially regulate the 5-HTT polymorphic intron 2 enhancer which predisposes to a variety of neurological disorders
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DOI：
10.1523/jneurosci.1150-04.2004
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发表时间：
2004-06-30
影响因子：
5.3
通讯作者：
Quinn, JP
中科院分区：
文献类型：
--
作者：
Klenova, E;Scott, AC;Quinn, JP
5-羟色胺转运体（5-HTT）基因在内含子2内含有一个可变数目串联重复（VNTR）结构域，该结构域通常与许多神经系统疾病（包括情感障碍）相关。这种多态性的含义还不清楚，然而，我们以前已经证明，5-HTT VNTR是一个转录调控结构域，和等位基因变异支持差异报告基因在体内和体外表达。本研究的目的是确定负责该VNTR的调节的转录因子。利用酵母单杂交技术，我们发现转录因子Y盒结合蛋白1（YB-1）与5-HTTVNTR相互作用。与此相一致，我们证明了在报告基因测定的多态性VNTR域差异响应外源性YB-1和YB-1将结合到VNTR在体外以序列特异性的方式。有趣的是，先前显示与YB-1相互作用的转录因子CCTC-结合因子（CTCF）干扰VNTR支持YB-1指导的报告基因表达的能力。此外，CTCF在体外阻断YB-1与其DNA识别序列的结合，从而提供了CTCF调节YB-1激活VNTR的可能机制。因此，我们已经确定YB-1和CTCF作为转录因子负责，至少部分，作为转录调控域的VNTR功能的调制。我们的数据表明，一种新的机制，部分解释了不同的VNTR拷贝数的能力，以支持基于YB-1结合位点的差异报告基因表达。
The serotonin transporter (5-HTT) gene contains a variable number tandem repeat ( VNTR) domain within intron 2 that is often associated with a number of neurological conditions, including affective disorders. The implications of this polymorphism are not yet understood, however, we have previously demonstrated that the 5-HTT VNTR is a transcriptional regulatory domain, and the allelic variation supports differential reporter gene expression in vivo and in vitro. The aim of this study was to identify transcription factors responsible for the regulation of this VNTR. Using a yeast one-hybrid screen, we found the transcription factor Y box binding protein 1 (YB-1) interacts with the 5-HTT VNTR. Consistent with this, we demonstrate in a reporter gene assay that the polymorphic VNTR domains differentially respond to exogenous YB-1 and that YB-1 will bind to the VNTR in vitro in a sequence-specific manner. Interestingly, the transcription factor CCTC-binding factor ( CTCF), previously shown to interact with YB-1, interferes with the ability of the VNTR to support YB-1-directed reporter gene expression. In addition, CTCF blocks the binding of YB-1 to its DNA recognition sequences in vitro, thus providing a possible mechanism of regulation of YB-1 activation of the VNTR by CTCF. Therefore, we have identified YB-1 and CTCF as transcription factors responsible, at least in part, for modulation of VNTR function as a transcriptional regulatory domain. Our data suggest a novel mechanism that explains, in part, the ability of the distinct VNTR copy numbers to support differential reporter gene expression based on YB-1 binding sites.