2004 Fiscal Year Final Research Report Summary
Formation of mRNPs and mRNA localization
| Project/Area Number |
15590088
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biological pharmacy
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| Research Institution | RIKEN |
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Principal Investigator |
MATSUMOTO Ken RIKEN, Cellular Biochemistry Laboratory, Senior Researcher, 辻本細胞生化学研究室, 先任研究員 (60222311)
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| Co-Investigator(Kenkyū-buntansha) |
TSUJIMOTO Masafumi RIKEN, Cellular Biochemistry Laboratory, Laboratory Head, 辻本細胞生化学研究室, 主任研究員 (00281668)
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| Project Period (FY) |
2003 – 2004
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| Keywords | mRNP / Y-box protein / Translational control |
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| Research Abstract |
In eukaryotic cells, substrates of the translational machinery are messenger ribonucleoproteins (mRNPs), complexes of mRNAs with a specific set of proteins. In animal female and male germ cells, mRNAs that are required for future development of embryos and sperm are stored as translationally inactive mRNPs in the cytoplasm. The Y-box proteins are major components of cytoplasmic mRNPs in higher eukaryotic cells. Y-box proteins regulate translation in a dose-dependent manner. It has been proposed that Y-box proteins are likely responsible for packaging of mRNAs into mRNPs. Consistent with this proposition, the in vitro reconstitution of mRNA-Y-box protein complexes resulted in compact mRNPs. In such mRNPs, translation of the mRNA was repressed. Conversely, cells in which the genes encoding the Y-box protein YB-1 were disrupted showed slow-growth phenotype and, in these cells, global translation was repressed. Thus, regulation of the availability of Y-box proteins in cells would have an influence on mRNA metabolism and the control of cell proliferation. One of the ways with which Y-box proteins are released from mRNA is to interact with an acidic protein(s). Indeed, our analysis of YB-1-containing complexes isolated from cells identified a Y-box protein-associated acidic protein (YBAP1). The specific association of the YB-1 tail domain with YBAP1 results in the release of YB-1 from the reconstituted YB-1-mRNA complexes. YBAP1 added into the in vitro translation system relieved the translational repression by YB-1. Moreover, we found that in ascidian oocytes the Y-box protein colocalized and associated with Cipem and Ci-macho mRNAs, which are localized at the posterior end of the embryo at the cleavage stage. Our results suggest that associating with the Y-box proteins contributes to the translational control of the localized mRNAs in eggs and embryos.
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Research Products
(20 results)
