将RITS与新生的转录连接起来,可以启动RNAi和异色染色素依赖的基因沉默
Marc Bühler1, André Verdel, Danesh Moazed
1Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
Cell
|June 6, 2006
概括
将RITS复合体与新生的转录结合在一起,会使裂变酵母中的基因表达沉默. 这种RNA诱导的转录沉默需要RNAi和异染色蛋白蛋白质,影响基因调节.
科学领域:
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 基因规则 基因规则
背景情况:
- 裂变酵母中的RNA诱导转录沉默 (RITS) 复合体通过siRNA依赖的机制参与异染色素的形成.
- 之前提出的RITS模型针对染色体启动沉默.
研究的目的:
- 调查RITS复杂向新生的转录在基因沉默中的作用.
- 阐明RNA诱导的转录沉默的机制和要求.
主要方法:
- 将RITS子单元Tas3与ura4+基因转录的连接.
- 评估基因沉默,RNAi通路依赖性,异染色蛋白参与,siRNA生成和基因组修饰.
- 分析RNA聚合酶II占用率和siRNA核酶的影响.
主要成果:
- 将Tas3连接到ura4+转录引发了沉默,这取决于RNAi和异染色蛋白蛋白 (Swi6/HP1,Clr4/Suv39h,Sir2).
- 沉默伴随着 ura4+ siRNA 生成,H3K9 甲基化和 Swi6 结合.
- siRNA核酶Eri1抑制了新生成的 ura4+ siRNAs 的沉默能力.
- 令人惊的是,沉默并没有改变RNA聚合酶II在绑定或内源位置的占用率.
结论:
- 通过RITS准新生的转录,可以调解染色质修饰和基因沉默.
- 代码转录处理事件对于RNA诱导的转录沉默至关重要.
- 沉默机制可能独立于RNA聚合酶II占用率的变化而运行.
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...
Riboswitches
Riboswitches are non-coding mRNA domains that regulate the transcription and translation of downstream genes without the help of proteins. Riboswitches bind directly to a metabolite and can form unique stem-loop or hairpin structures in response to the amount of the metabolite present. They have two distinct regions – a metabolite-binding aptamer and an expression platform.
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
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...


