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乘客链裂变有助于将siRNA组装成含Ago2的RNAi酶复合体
Christian Matranga1, Yukihide Tomari, Chanseok Shin
1Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA.
Cell
|November 8, 2005
概括
Argonaute2 (Ago2) 直接与双链小干扰RNA (siRNA) 结合,并分裂乘客链,使导链能够纳入RNA诱导沉默复合体 (RISC). 这种机制对于siRNA介导的基因沉默至关重要.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
- 生物化学 生物化学
背景情况:
- RNA干扰 (RNAi) 途径利用小干扰RNA (siRNAs) 来静止基因表达,通过引导Argonaute2 (Ago2) 分裂信使RNA (mRNAs).
- 蛋白Ago2是RNA诱导沉默复合体 (RISC) 的催化核心,这是负责基因沉默的酶复合体.
- 以前假设一种依赖ATP的基酶在引导链加载到Ago2之前将siRNA链分离出来.
研究的目的:
- 研究siRNA指导链被纳入活性RISC.的机制.
- 确定Ago2在RISC与siRNA组装的初始步骤中的作用.
主要方法:
- 直接观察Ago2与双链siRNAs的相互作用.
- 通过Ago2.2对siRNA乘客链裂变的分析.
- 将siRNA和microRNA (miRNA) 装载机制与RISC进行比较.
主要成果:
- Ago2直接接收来自RISC组装机器的双链siRNAs.
- Ago2将siRNA的乘客链切割,释放单链导向链.
- 这种裂变辅助机制是siRNA加载到RISC的主要途径.
- 乘客链裂变对于结合miRNAs来说不那么重要,miRNAs来自不完美匹配的双重组.
结论:
- 对于siRNA纳入RISC的主要机制是Ago2直接结合siRNA复合体并分裂乘客链.
- 这一发现完善了我们对RNA干扰路径启动的理解,并突出了Ago2.2的关键酶功能.
- 对于microRNAs来说,这种机制是不同的,这表明不同的小RNA类别有不同的加载途径.
相关概念视频
RNA Interference
RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated.
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
RNA Interference
RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated.
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
siRNA - Small Interfering RNAs
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
piRNA - Piwi-interacting RNAs
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
Experimental RNAi
RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the...
Small interfering RNAs (siRNA)
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...

