权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Control of translation and mRNA degradation by mPnP components

mPnP 成分控制翻译和 mRNA 降解

基本信息

批准号：
17590083
负责人：
MATSUMOTO Ken
金额：
$ 2.3万
依托单位：
The Institute of Physical and Chemical Research
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17590083/
关键词：
mRNA translational control ribonucleonrotein narticle Xenonus P-body

项目摘要

Cytoplasmic mRNPs are substrates of the translational apparatus in eukaryotic cells. The poly(A) binding protein and the Y-box protein YB-1 are common major components of cytoplasmic mRNPs in somatic cells of different organisms. Y-box proteins are presumed to bind to the mRNA body in the cytoplasmic mRNPs and are likely responsible for packaging of mRNAs into mRNPs. Y-box proteins are also implicated in translational masking of maternal and paternal mRNAs in germ cells. Regulation of the availability of Y-box proteins in cells would have an influence on mRNA metabolism and the control of cell proliferation.By immunoprecipitation of the epitope-tagged Y-box proteins expressed in somatic cells or Xenopus oocytes, we have isolated Y-box protein-associated RNPs. Protein components of these RNPs include the poly(A) binding protein, a DEAD-box ATPase (RCK/p54 in mammals or Xp54 in Xenopus) and a number of RNA binding proteins. Among these, we identified Xenopus RAP55 (xRAP55) as a component of maternal mRNPs. Recombinant xRAP55 repressed translation, together with Xp54, in an in vitro translation system. In addition, xRAP55 repressed translation in oocytes when tethered with a reporter mRNA. RAP55 and the Y-box proteins localized to cytoplasmic foci in Xenopus oocytes and the processing bodies (P-bodies) in cultured human cells. Interestingly, upon heat stress, whereas RAP55 and RCK were detected both in the P-bodies and stress granules (SGs), YB-1 was accumulated in SGs and almost excluded from the P-bodies. Our results suggest that remodeling of mRNP would take place when mRNAs move between these cytoplasmic structures.

胞质mRNP是真核细胞中翻译装置的底物。poly（A）结合蛋白和Y-box蛋白YB-1是不同生物体细胞中细胞质mRNP的共同主要组分。推测Y盒蛋白与细胞质mRNP中的mRNA体结合，并且可能负责将mRNA包装成mRNP。Y-盒蛋白还涉及生殖细胞中母本和父本mRNA的翻译掩蔽。Y-box蛋白在细胞中的表达调控会影响mRNA的代谢和细胞增殖的控制，我们通过免疫沉淀的抗原表位标记的Y-box蛋白在体细胞或爪蟾卵母细胞中的表达，分离出Y-box蛋白相关的RNP。这些RNP的蛋白质组分包括poly（A）结合蛋白、DEAD盒ATP酶（哺乳动物中的RCK/p54或非洲爪蟾中的Xp 54）和许多RNA结合蛋白。其中，我们确定了非洲爪蟾RAP 55（xRAP 55）作为母体mRNP的组成部分。在体外翻译系统中，重组xRAP 55与Xp 54一起抑制翻译。此外，xRAP 55抑制翻译卵母细胞时，拴与报告mRNA。RAP 55和Y-box蛋白定位于非洲爪蟾卵母细胞的胞质病灶和培养的人类细胞的加工体（P-体）。有趣的是，在热胁迫下，RAP 55和RCK在P-体和应激颗粒（SG）中均被检测到，而YB-1在SG中积累并且几乎被排除在P-体之外。我们的研究结果表明，mRNP的重塑将发生在mRNA在这些细胞质结构之间移动时。