RITSを新生トランスクリプトに結び付けると,RNAiおよびヘテロクロマチン依存性の遺伝子静止が始まります
Marc Bühler1, André Verdel, Danesh Moazed
1Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
Cell
|June 6, 2006
まとめ
RITS複合体を新生トランスクリプトに結合させると,分裂酵母における遺伝子発現を静止させます. このRNA誘発の転写サイレンシングは,RNAiとヘテロクロマチンタンパク質を必要とし,遺伝子調節に影響を与えます.
科学分野:
- 分子生物学は分子生物学である.
- エピジェネティクス エピジェネティクス
- 遺伝子規制 遺伝子規制
背景:
- 分裂酵母におけるRNA誘発転写静止 (RITS) 複合体は,siRNAに依存するメカニズムを通じてヘテロクロマチン形成に関与しています.
- 以前のモデルでは,RITSは染色体を標的とし,静音化を開始することを提案していた.
研究 の 目的:
- 遺伝子サイレンシングにおける新生トランスクリプトに対するRITS複合体のターゲティングの役割を調査する.
- RNA誘発型転写サイレンシングのメカニズムと要件を解明する.
主な方法:
- ura4+遺伝子トランスクリプトにRITSサブユニットTas3の結合.
- 遺伝子サイレンシング,RNAi経路依存,ヘテロクロマチンタンパク質の関与,siRNA生成,ヒストンの改変を評価する.
- RNAポリメラーゼIIの占有率とsiRNAヌクレアゼの影響を分析する.
主要な成果:
- ura4+トランスクリプトにTas3を結合させると,RNAiとヘテロクロマチンタンパク質に依存する静音化が誘発される (Swi6/HP1, Clr4/Suv39h, Sir2).
- 静止は ura4+ siRNA生成,H3K9メチル化,および Swi6結合に伴いました.
- siRNA核酵素 Eri1 は,新たに生成された ura4+ siRNA の静止能力を阻害しました.
- 驚くべきことに,静音化により,結合された局所または内生的な局所におけるRNAポリメラーゼIIの占有量が変化しなかった.
結論:
- RITSによる新生トランスクリプトのターゲティングは,クロマチンの改変と遺伝子サイレンシングを媒介する.
- コトランスクリプション処理イベントは,RNA誘発のトランスクリプションサイレンシングに不可欠です.
- 静音化メカニズムは,RNAポリメラーゼIIの占有率の変化とは無関係に動作する可能性があります.
関連する概念動画
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...


