A NOVEL ROLE OF FRAGILE X MENTAL RETARDATION PROTEIN IN PRE-mRNA ALTERNATIVE SPLICING THROUGH RNA-BINDING PROTEIN 14
A NOVEL ROLE OF FRAGILE X MENTAL RETARDATION PROTEIN IN PRE-mRNA ALTERNATIVE SPLICING THROUGH RNA-BINDING PROTEIN 14
复制标题
脆性 X 智力低下蛋白通过 RNA 结合蛋白 14 在前 mRNA 选择性剪接中的新作用
DOI：
10.1016/j.neuroscience.2017.02.044
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发表时间：
2017-05-04
期刊：
影响因子：
3.3
通讯作者：
Long, Yue-Sheng
中科院分区：
文献类型：
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作者：
Zhou, Lin-Tao;Ye, Shun-Hua;Long, Yue-Sheng
脆性X智力低下蛋白（Fragile X mental retardation protein，FMRP）是脆性X综合征的重要RNA结合蛋白，参与基因表达的转录后调控，与脑发育和突触功能有关。在这里，我们揭示了FMRP在前mRNA选择性剪接（转录后调节的一般事件）中的新作用。使用免疫共沉淀和免疫荧光测定，我们确定FMRP与选择性剪接相关蛋白RNA结合蛋白14（RBM 14）以RNA依赖的方式相互作用，并且这两种蛋白质部分共定位于海马神经元的核中。我们发现，在Fmr 1基因敲除（KO）小鼠的海马中，Protrudin基因中的微外显子L和Tau基因中的外显子10的相对跳跃/包含率降低。FMRP或RBM 14的敲低改变了培养的Neuro-2a细胞中Protrudin和Tau的相对跳跃/包含比率，与Fmr 1 KO小鼠中的情况类似。此外，FMRP的过表达导致相反的剪接模式，这可以通过RBM 14敲低来抵消。RNA免疫沉淀分析表明，FMRP促进RBM 14与mRNA靶点的结合。此外，长形式的Protrudin或短形式的Tau的过表达促进视黄酸处理的神经元分化的Neuro-2a细胞的突起生长。总之，这些数据表明FMRP在通过RBM 14调节前mRNA选择性剪接中的新功能，其可能与正常脑功能和FMRP相关的神经系统疾病相关。(C)2017年IBRO。由爱思唯尔有限公司出版。保留所有权利。
Fragile X mental retardation protein (FMRP), an important RNA-binding protein responsible for fragile X syndrome, is involved in posttranscriptional control of gene expression that links with brain development and synaptic functions. Here, we reveal a novel role of FMRP in pre-mRNA alternative splicing, a general event of posttranscriptional regulation. Using co-immunoprecipitation and immunofluorescence assays, we identified that FMRP interacts with an alternative-splicing-associated protein RNA-binding protein 14 (RBM14) in a RNA-dependent fashion, and the two proteins partially colocalize in the nuclei of hippocampal neurons. We show that the relative skipping/inclusion ratio of the micro-exon L in the Protrudin gene and exon 10 in the Tau gene decreased in the hippocampus of Fmr1 knockout (KO) mice. Knockdown of either FMRP or RBM14 alters the relative skipping/inclusion ratio of Protrudin and Tau in cultured Neuro-2a cells, similar to that in the Fmr1 KO mice. Furthermore, overexpression of FMRP leads to an opposite pattern of the splicing, which can be offset by RBM14 knockdown. RNA immunoprecipitation assays indicate that FMRP promotes RBM14's binding to the mRNA targets. In addition, overexpression of the long form of Protrudin or the short form of Tau promotes protrusion growth of the retinoic acid-treated, neuronal differentiated Neuro-2a cells. Together, these data suggest a novel function of FMRP in the regulation of pre-mRNA alternative splicing through RBM14 that may be associated with normal brain function and FMRP-related neurological disorders. (C) 2017 IBRO. Published by Elsevier Ltd. All rights reserved.