ポルIV依存シRNAバイオゲネシスの1つの先駆者1つのsiRNAモデル
Jixian Zhai1, Sylvain Bischof1, Haifeng Wang2
1Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA 90095, USA.
Cell
|October 10, 2015
まとめ
植物RNAポリメラーゼIV (Pol IV) は,アラビドプシスで単一の24ntの小さな干渉RNA (siRNA) を生成する短いRNA前駆体 (P4RNAs) を生成し,RNA誘導DNAメチル化のための新しいメカニズムを明らかにします.
科学分野:
- 植物分子生物学
- エピジェネティクス
- RNA生物学
背景:
- 植物における遺伝子静止には RNAによるDNAメチル化が不可欠です
- 植物特有のRNAポリメラーゼIV (Pol IV) がこのプロセスを開始する.
- 既存のモデルは,Pol IVトランスクリプトが複数のsiRNAを生成することを提案しています.
研究 の 目的:
- Pol IV依存RNA (P4RNAs) の正確な性質と生殖を調査する.
- P4RNAsと24-nt siRNA生成の関係を解明する.
- アラビドプシス・タリアナのRNA誘導DNAメチル化の仕組みを理解する.
主な方法:
- 野生型アラビドプシスのPol IV依存RNA (P4RNA) の分析
- P4RNAの長さ,分布,豊富さ,および鎖バイアスの特徴.
- ヌクレオチドの誤入を含むP4RNAの5'および3'端の改変の調査.
主要な成果:
- P4RNAは意外に短く (30−40nt) 24ntのsiRNAに非常に似ています.
- P4RNAは5'-単リン酸を持ち,3'-誤入核酸を示している.
- 3'-ミスインコーポレーションはサイトシンにおけるDNAメチル化と相関し,共転写フィードバックを示唆する.
結論:
- Pol IVトランスクリプションは短いP4RNAを生成し,マルチsiRNA前駆モデルに挑戦します.
- 24nt siRNAの生体生成には"1つの前駆体,1つのsiRNA"モデルが提案されている.
- DNAメチル化は,共転写フィードバックメカニズムを通じてsiRNAの生成を強化する.
関連する概念動画
siRNA - Small Interfering RNAs
19.0K
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...
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...
19.0K
RNA Interference
28.6K
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...
28.6K
RNA Interference
7.8K
7.8K
piRNA - Piwi-interacting RNAs
7.9K
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...
7.9K
Experimental RNAi
8.3K
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...
8.3K
Bacterial RNA Polymerase
33.6K
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
33.6K


