LRP130, a single-stranded DNA/RNA-binding protein, localizes at the outer nuclear and endoplasmic reticulum membrane, and interacts with mRNA in vivo.
LRP130, a single-stranded DNA/RNA-binding protein, localizes at the outer nuclear and endoplasmic reticulum membrane, and interacts with mRNA in vivo.
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DOI：
10.1016/j.bbrc.2004.03.103
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发表时间：
2004-05
影响因子：
3.1
通讯作者：
Naoto Tsuchiya;H. Fukuda;K. Nakashima;M. Nagao;T. Sugimura;H. Nakagama
中科院分区：
文献类型：
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作者：
Naoto Tsuchiya;H. Fukuda;K. Nakashima;M. Nagao;T. Sugimura;H. Nakagama
LRP 130（也称为LRPPRC）是RNA和单链DNA结合蛋白，并且最近被鉴定为负责Leigh综合征（一种法国-加拿大型细胞色素c氧化酶缺乏症）的候选基因。然而，LRP 130的生物学功能仍然在很大程度上未得到解决。在本研究中，我们发现小鼠LRP 130的C-末端一半位于120个氨基酸序列内（a.a. 845-964）结合合成的RNA均聚物、聚（G）、聚（U）和聚（C）以及r（CUGCC）6。亚细胞定位的评估表明，核/内质网（ER）和线粒体部分是积极的。为了进一步分析LRP 130的亚细胞定位，将核/ER组分分离成核质（NP）和核膜（NE）/ER，并通过用Triton X-100处理将后者进一步分离成外核膜（ONM）/ER和内核膜（INM）。LRP 130在所有三种组分中均可检测到，并且分布模式与ONM/ER蛋白的已知分布模式良好一致。有趣的是，HeLa细胞的免疫染色证明了LRP 130的核边缘染色，特别是在NE的外部以及ER处，并且LRP 130与poly（A）+RNA的缔合仅限于ONM/ER部分。在HeLa细胞中过表达与EGFP融合的全长小鼠LRP 130导致poly（A）+RNA在细胞核中积累。综合以上结果，我们认为LRP 130是一种新型的RNA结合蛋白，它与NE和ER外的mRNA/mRNP复合物相结合，并在mRNA代谢的调控中发挥作用。
LRP130 (also known as a LRPPRC) is an RNA and single-stranded DNA-binding protein, and recently identified as a candidate gene responsible for the Leigh syndrome, a French-Canadian type cytochrome c oxidase deficiency. However, the biological function of LRP130 still remains largely unresolved. In the present study, we found that the C-terminal half of the mouse LRP130 located within a 120 amino acid sequence (a.a. 845–964) binds to synthetic RNA homopolymers, poly(G), poly(U), and poly(C), as well as r(CUGCC)6. Assessment of the subcellular localization indicated both nuclear/endoplasmic reticulum (ER) and mitochondrial fractions to be positive. To further analyze the subcellular localization of LRP130, a nuclear/ER fraction was fractionated into the nucleoplasm (NP) and nuclear envelope (NE)/ER, and the latter was further separated into outer nuclear membrane (ONM)/ER and inner nuclear membrane (INM) by treatment with Triton X-100. LRP130 was detectable in all three fractions, and the distribution pattern was in good accordance with that known for ONM/ER proteins. Interestingly, immunostaining of HeLa cells demonstrated nuclear rim staining of LRP130, specifically at the outside of the NE and also at ER, and association of LRP130 with poly(A)+RNA was restricted only to the ONM/ER fraction. Overexpression of full-length mouse LRP130 fused with EGFP resulted in nuclear accumulation of poly(A)+RNA in HeLa cells. Taking all these results together, it is suggested that LRP130, a novel type of RNA-binding protein, associates with mRNA/mRNP complexes at the outside of NE and ER, and plays a role in control of mRNA metabolisms.