Poly(A)-binding protein is associated with neuronal BC1 and BC200 ribonucleoprotein particles
Poly(A)-binding protein is associated with neuronal BC1 and BC200 ribonucleoprotein particles
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DOI：
10.1016/s0022-2836(02)00655-1
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发表时间：
2002-08-16
影响因子：
5.6
通讯作者：
Brosius, J
中科院分区：
文献类型：
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作者：
Muddashetty, RS;Khanam, T;Brosius, J
BC1 RNA和BC200 RNA是两种非同源的小的非信使RNA（snmRNAs），它们在进化上是最近通过逆转录产生的。这一过程赋予RNA聚合酶III转录物以富含腺苷的中央区域。这两种RNA几乎只在神经元中表达，在神经元中它们作为核糖核蛋白颗粒（RNP）被转运到树突过程中。在这里，我们证明了与各种实验方法，聚（A）结合蛋白（PABP 1），翻译起始的调节剂，结合RNA在体外和体内。我们在三杂交筛选中鉴定了PABP与BC200 RNA的结合，并在电泳迁移率变化试验中以及通过来自粗提物、免疫耗竭提取物、部分纯化的RNP和用裸RNA转染的细胞的BC1和BC200 RNA的抗PABP免疫沉淀证实了这种结合。此外，PABP免疫反应定位于神经元树突。使用BC1和BC200 RNA的变体的竞争实验表明，这两种RNA的中央富含腺苷的区域介导与PABP的结合。这些发现支持了BC1和BC200 RNP参与神经元树突中蛋白质翻译的假设。(C)2002爱思唯尔科技有限公司。保留所有权利。
BC1 RNA and BC200 RNA are two non-homologous, small non-messenger RNAs (snmRNAs) that were generated, evolutionarily, quite recently by retroposition. This process endowed the RNA polymerase III transcripts with central adenosine-rich regions. Both RNAs are expressed almost exclusively in neurons, where they are transported into dendritic processes as ribonucleoprotein particles (RNPs). Here, we demonstrate with a variety of experimental approaches that poly(A)-binding protein (PABP1), a regulator of translation initiation, binds to both RNAs in vitro and in vivo. We identified the association of PABP with BC200 RNA in a tri-hybrid screen and confirmed this binding in electrophoretic mobility-shift assays and via anti-PABP immunoprecipitation of BC1 and BC200 RNAs from crude extracts, immunodepleted extracts, partially purified RNPs and cells transfected with naked RNA. Furthermore, PABP immunoreactivity was localized to neuronal dendrites. Competition experiments using variants of BC1 and BC200 RNAs demonstrated that the central adenosine-rich region of both RNAs mediates binding to PABP. These findings lend support to the hypothesis that the BC1 and BC200 RNPs are involved in protein translation in neuronal dendrites. (C) 2002 Elsevier Science Ltd. All rights reserved.