酵母Sm样蛋白在mRNA分解和衰变中起作用.
1Department of Molecular and Cellular Biology and Howard Hughes Medical Institute, University of Arizona, Tucson 85721, USA.
Nature
|April 13, 2000
概括
七种酵母Sm-like (Lsm) 蛋白质对于信使RNA (mRNA) 分解至关重要,这是mRNA降解的关键步骤. 这些Lsm蛋白与切割机械相互作用,表明它们在调节mRNA衰变途径方面发挥了直接作用.
科学领域:
- 分子生物学分子生物学
- 在RNA代谢过程中.
- 单核生物基因表达的表达方式
背景情况:
- 传递 RNA (mRNA) 降解是真核生物中的一个关键过程,主要通过依赖死乙烯化分解发生,随后是5'-至-3'-衰变.
- 以"Sm"图案为特征的Sm类 (Lsm) 蛋白质已知与U6小核RNA复合,对于mRNA前拼接至关重要.
研究的目的:
- 研究酵母Lsm蛋白在mRNA分解和降解中的作用.
- 为了确定Lsm蛋白与mRNA切割机械组件的相互作用.
主要方法:
- 对缺乏特定Lsm蛋白质 (Lsm1-Lsm7) 的酵母突变菌的遗传分析.
- 同免疫沉测试检测蛋白质-蛋白质和蛋白质-RNA相互作用.
- 对野生类型和突变酵母菌株的mRNA切割和降解率的分析.
主要成果:
- 酵母Lsm1-Lsm7蛋白中的突变导致了mRNA分解的抑制.
- 发现Lsm1-Lsm7蛋白与mRNA分解酶 (Dcp1),分解激活剂 (Pat1/Mrt1) 和mRNA.
- 有证据表明,Lsm蛋白通过与mRNA和切割机械的相互作用来促进切割.
结论:
- 酵母Lsm1-Lsm7蛋白质在促进mRNA分解方面发挥着重要作用.
- 参与mRNA衰变的LSM复合体与U6小核RNA相关的LSM复合体不同.
- Lsm 蛋白质形成特定的复合体,调节mRNA代谢的不同方面,包括拼接和衰变.
相关概念视频
mRNA Stability and Gene Expression
6.8K
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
Cis-acting Elements involved in mRNA stability
6.8K
mRNA Stability and Gene Expression
3.6K
No description available
3.6K
Nonsense-mediated mRNA Decay
12.1K
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,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
12.1K
Nonsense-mediated mRNA Decay
3.6K
No description available
3.6K
Nuclear Export of mRNA
9.2K
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...
9.2K
Nuclear Export of mRNA
5.6K
No description available
5.6K


