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Biotin-based Pulldown Assay to Validate mRNA Targets of Cellular miRNAs
Published on: June 12, 2018
通过转化抑制进行miRNA介导的基因沉默,其次是mRNA死亡基因和衰变
Sergej Djuranovic1, Ali Nahvi, Rachel Green
1Howard Hughes Medical Institute (HHMI) and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Science (New York, N.Y.)
|April 14, 2012
概括
微RNAs (miRNAs) 通过首先阻止翻译来抑制基因表达,然后触发信使RNA (mRNA) 死亡和衰变. 这项研究阐明了miRNA介导的基因沉默的分子机制.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 生物化学 生物化学
背景情况:
- 微RNAs (miRNAs) 是基因表达的关键调节者.
- miRNAs利用翻译抑制,mRNA死亡基因和衰变来实现基因沉默.
- 这些沉默事件的确切顺序仍然不完全理解.
研究的目的:
- 为了阐明miRNA介导的基因沉默中分子事件的时间顺序.
- 定义miRNAs调节基因表达的机制.
主要方法:
- 使用了基于Drosophila S2细胞的可控制表达系统.
- 研究了翻译,死亡和衰变的动力学.
- 采用了一种自然翻译延伸机模型.
主要成果:
- miRNA目标mRNA最初经历翻译抑制.
- 在转化抑制之后,观察到mRNA的死亡和衰变.
- 沉默发生在翻译的早期阶段,可能是启动.
结论:
- 在影响mRNA稳定性之前,miRNA介导的基因沉默会顺序抑制翻译.
- 这些发现确定了早期的翻译步骤作为miRNA作用的首要目标.
- 这澄清了miRNA诱导的基因沉默的分子途径.
相关概念视频
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA...
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...
02:27Nonsense-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,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
02:27Nonsense-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,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
02:51mRNA 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
Cis-acting Elements involved in mRNA stability