The glucocorticoid receptor is associated with the RNA-binding nuclear matrix protein hnRNP U
The glucocorticoid receptor is associated with the RNA-binding nuclear matrix protein hnRNP U
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DOI：
10.1074/jbc.272.45.28471
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发表时间：
1997-11-07
影响因子：
4.8
通讯作者：
Renkawitz, R
中科院分区：
文献类型：
--
作者：
Eggert, M;Michel, J;Renkawitz, R
糖皮质激素受体（GR）是一种配体依赖性转录因子，能够通过与其反应元件结合，与其他转录因子相互作用，并接触几种辅助蛋白（如辅激活因子）来调节基因活性。在这里，我们表明，GRIP 120，我们已经确定与糖皮质激素受体的相互作用的因素之一，是相同的异质核核糖核蛋白U（hnRNP U），核基质蛋白结合RNA以及支架附着区，GR hnRNP U复合物被确定通过印迹和免疫共沉淀。GR和hnRNP U的亚核分布的特点是通过间接免疫荧光标记和共聚焦激光显微镜表明这两种蛋白质的共定位，使用核转运缺陷缺失的hnRNP U，核转位被认为是依赖于GR和地塞米松。瞬时转染被用来确定可能的相互作用域，过表达的hnRNP U干扰糖皮质激素的诱导，和两种蛋白质的COOH-末端结构域是足够的，在介导的转录干扰，一个可能的功能作用，这种GR结合蛋白除了其结合到核基质，RNA，和支架附着区进行了讨论。
The glucocorticoid receptor (GR) is a ligand-dependent transcription factor that is able to modulate gene activity by binding to its response element, interacting with other transcription factors, and contacting several accessory proteins such as coactivators. Here we show that GRIP120, one of the factors we have identified to interact with the glucocorticoid receptor, is identical to the heterogeneous nuclear ribonucleoprotein U (hnRNP U), a nuclear matrix protein binding to RNA as well as to scaffold attachment regions, GR hnRNP U complexes were identified by blotting and coimmunoprecipitation. The subnuclear distribution of GR and hnRNP U was characterized by indirect immunofluorescent labeling and confocal laser microscopy demonstrating a colocalization of both proteins, Using a nuclear transport-deficient deletion of hnRNP U, nuclear translocation was seen to be dependent on GR and dexamethasone. Transient transfections were used to identify possible interaction domains, Overexpressed hnRNP U interfered with glucocorticoid induction, and the COOH-terminal domains of both proteins were sufficient in mediating the transcriptional interference, A possible functional role for this GR binding-protein in addition to its binding to the nuclear matrix, to RNA, and to scaffold attachment regions is discussed.