Intronic CA-repeat and CA-rich elements:: a new class of regulators of mammalian alternative splicing
Intronic CA-repeat and CA-rich elements:: a new class of regulators of mammalian alternative splicing
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DOI：
10.1038/sj.emboj.7600677
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发表时间：
2005-06-01
期刊：
影响因子：
11.4
通讯作者：
Bindereif, A
中科院分区：
文献类型：
--
作者：
Hui, JY;Hung, LH;Bindereif, A
我们最近发现人内皮型一氧化氮合酶(ENOS)基因内含子多态CA-Repeat区是剪接效率的重要决定因素，需要与hnRNP L特异结合。在这里，我们分析了这个CA-Repeat元件的位置要求，揭示了它在选择性剪接中的潜在作用。此外，我们用SELEX软件定义了hnRNP L的RNA结合特异性：不仅规则的CA重复序列具有高亲和力，而且某些富含CA的簇也被识别。因此，我们系统地在人类基因组数据库中搜索与备选5‘剪接位点(5’s)相关的CA重复序列和富含CA的元件，然后进行微基因转染试验。令人惊讶的是，在我们测试的几个特定的人类基因中，内含子CA RNA元件既可以作为剪接增强剂，也可以作为沉默元件，这取决于它们与替代5‘s的接近程度。检测到hnRNP L与这些不同的CA元件特异性结合。这些数据表明，内含子CA序列构成了新的和广泛的选择性剪接调控元件。
We have recently identified an intronic polymorphic CA-repeat region in the human endothelial nitric oxide synthase ( eNOS) gene as an important determinant of the splicing efficiency, requiring specific binding of hnRNP L. Here, we analyzed the position requirements of this CA-repeat element, which revealed its potential role in alternative splicing. In addition, we defined the RNA binding specificity of hnRNP L by SELEX: not only regular CA repeats are recognized with high affinity but also certain CA-rich clusters. Therefore, we have systematically searched the human genome databases for CA-repeat and CA-rich elements associated with alternative 5' splice sites (5'ss), followed by minigene transfection assays. Surprisingly, in several specific human genes that we tested, intronic CA RNA elements could function either as splicing enhancers or silencers, depending on their proximity to the alternative 5'ss. HnRNP L was detected specifically bound to these diverse CA elements. These data demonstrated that intronic CA sequences constitute novel and widespread regulatory elements of alternative splicing.