The neurofibromatosis type I pre-mRNA is a novel target of CELF protein-mediated splicing regulation
The neurofibromatosis type I pre-mRNA is a novel target of CELF protein-mediated splicing regulation
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DOI：
10.1093/nar/gkp766
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发表时间：
2010-01-01
影响因子：
14.9
通讯作者：
Lou, Hua
中科院分区：
文献类型：
--
作者：
Barron, Victoria A.;Zhu, Hui;Lou, Hua
CUG-BP和ETR-3样因子（CELF）是一个由六种高度保守的RNA结合蛋白组成的家族，它们优先结合富含UG的序列。这些蛋白质的关键功能之一是介导许多组织中的选择性剪接，包括脑、心脏和肌肉。为了充分了解CELF蛋白的功能，重要的是确定CELF蛋白的下游靶标。在这篇文章中，我们报道了I型神经纤维瘤病（NF 1）外显子23 a是神经元样细胞中CELF蛋白介导的剪接调控的新靶点。NF 1调节Ras信号传导，并且排除外显子23 a的同种型显示出比包括外显子23 a的同种型大10倍的下调Ras信号传导的能力。六种CELF蛋白中的五种强烈抑制NF 1外显子23 a的包含。在细胞转染实验中，这些蛋白质的过表达或siRNA敲低改变了NF 1外显子23 a包含的水平。体外结合和剪接分析表明，CELF蛋白通过干扰U2 AF的结合来阻断剪接（65）。这些研究，结合我们以前的调查表明，胡蛋白和TIA-1/TIAR在控制NF 1外显子23 a的列入的作用，突出了这一重要的选择性剪接事件的调控的复杂性。
The CUG-BP and ETR-3 like factors (CELF) are a family of six highly conserved RNA-binding proteins that preferentially bind to UG-rich sequences. One of the key functions of these proteins is to mediate alternative splicing in a number of tissues, including brain, heart and muscle. To fully understand the function of CELF proteins, it is important to identify downstream targets of CELF proteins. In this communication, we report that neurofibromatosis type I (NF1) exon 23a is a novel target of CELF protein-mediated splicing regulation in neuron-like cells. NF1 regulates Ras signaling, and the isoform that excludes exon 23a shows 10 times greater ability to down-regulate Ras signaling than the isoform that includes exon 23a. Five of the six CELF proteins strongly suppress the inclusion of NF1 exon 23a. Over-expression or siRNA knockdown of these proteins in cell transfection experiments altered the levels of NF1 exon 23a inclusion. In vitro binding and splicing analyses demonstrate that CELF proteins block splicing through interfering with binding of U2AF(65). These studies, combined with our previous investigations demonstrating a role for Hu proteins and TIA-1/TIAR in controlling NF1 exon 23a inclusion, highlight the complex nature of regulation of this important alternative splicing event.