相关实验视频
Updated: Jun 19, 2026

09:43
Isolation and Characterization of RNA-Containing Exosomes
Published on: January 9, 2012
酵母外体作为一个宏分子子来道RNA基质进行降解的功能
Fabien Bonneau1, Jérôme Basquin, Judith Ebert
1Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.
Cell
|November 3, 2009
概括
外体复合体使用Rrp44核酶降解RNA. RNAs通过外体细胞核进入Rrp44核酶部位进行降解.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 外体是RNA降解的关键宏分子复合体.
- 细胞外体细胞核与 prokaryotic 复合体具有相同的架构,但在催化上是惰性的.
- Rrp44核酶对于活跃的十个子单元的真核外体是必不可少的.
研究的目的:
- 研究Rrp44核酶在活跃的十个子单元外体体内的功能.
- 阐明Rrp44与外体细胞核相互作用的结构基础.
- 了解真核细胞外体体对RNA降解的机制.
主要方法:
- 酵母Rrp44-Rrp41-Rrp45复合物的X射线晶体学 (3.0 A分辨率).
- 生物化学研究分析RNA结合和降解途径.
主要成果:
- 晶体结构揭示了Rrp44与外体细胞核的相互作用及其核酶位点的可访问性.
- 生物化学数据显示,RNAs通过外体细胞核的中央通道线索到达Rrp44外原核酶部位.
- 一个保存的道化机制促进了 RNA 复合体与 3' 扩展的过程性降解,独立于螺旋酶.
结论:
- 细胞外体利用一种保存的RNA线程机制进行降解.
- 虽然外体细胞核失去了催化活性,但基质的招募和结合在 prokaryotes 中保持不变.
- Rrp44核酶活动是功能性真核外体的关键,采用独特的道通道.
相关概念视频
mRNA Stability and Gene Expression
The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
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Nuclear Export of mRNA
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Nuclear Export of mRNA
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
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Stahl et al. discovered exosomes in 1983, but the exosomes were initially considered waste products released from the...
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Overview of Secretory Vesicles
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Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
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Nonsense-mediated mRNA Decay
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
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