核RNaseIIIドロシャは,マイクロRNAの処理を開始する
Yoontae Lee1, Chiyoung Ahn, Jinju Han
1Institute of Molecular Biology and Genetics and School of Biological Sciences, Seoul National University, Seoul 151-742, Korea.
Nature
|September 26, 2003
まとめ
研究者らは,RNase III酵素であるヒトドロシャを,原発マイクロRNA (プリ-ミRNA) を核内の前駆微RNA (プリ-ミRNA) に処理する上で極めて重要であると特定した. この発見は,マイクロRNAのバイオゲネシスと遺伝子調節における重要なステップを明らかにしています.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
- バイオケミストリー バイオケミストリー
背景:
- マイクロRNA (miRNA) は,遺伝子発現に関与する小さな調節RNAである.
- miRNAsの生体生成経路,特に初期処理ステップは完全に理解されていません.
- Dicerは,前駆体miRNAs (pre-miRNAs) をサイトプラズマで処理することが知られている.
研究 の 目的:
- プライマリミRNAトランスクリプト (プリ-ミRNA) をプリ-ミRNAに核処理する酵素を特定する.
- miRNAバイオゲネシスの初期段階を解明する.
主な方法:
- 免疫浄化ヒトドロシャ菌を用いたインビトロ割れ検定.
- RNA干渉 (RNAi) 実験は,ドロシャ枯渇の影響を評価するために,in vivoで行われます.
- プリミRNA,プリミRNA,成熟ミRNAのレベルを分析する.
主要な成果:
- RNase III酵素であるヒトドロシャは,プリミRNA処理のためのコア核酵素として特定されました.
- ドロシャはプリミRNAを直接割って,in vitroでプリミRNAを生成した.
- ドロシャの枯渇は,in vivoではプリミRNAの蓄積につながり,プリミRNAと成熟ミRNAのレベルが低下した.
結論:
- ドロシャは,核におけるmiRNA生物生成の初期段階に不可欠である.
- ドロシャとディッサーは,miRNAの配列処理に協力している可能性が高い.
- これらの発見は,開発と微分化中のmiRNA媒介遺伝子調節におけるDroshaとDicerの役割を強調しています.
関連する概念動画
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...
01:23RNA 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...
01:23RNA 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...
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...
02:30siRNA - 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...
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...