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Updated: Jun 16, 2026

07:23
Describing a Transcription Factor Dependent Regulation of the MicroRNA Transcriptome
Published on: June 15, 2016
マイクロRNAによる遺伝子発現の転写制御
Basel Khraiwesh1, M Asif Arif, Gotelinde I Seumel
1Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestrasse 1, 79104 Freiburg, Germany.
Cell
|January 21, 2010
まとめ
マイクロRNA (miRNA) は通常,転写後の遺伝子を静止させます. モスでは,特定の変異が明らかにされたmiRNAsは,miRNAとターゲットRNAレベルに依存するDNAメチル化による表遺伝的サイレンシングを開始します.
科学分野:
- 植物生物学 植物生物学
- エピジェネティクス エピジェネティクス
- 分子生物学は分子生物学である.
背景:
- マイクロRNA (miRNA) は,植物や動物における遺伝子発現を転写後に制御する小さなRNAである.
- 小型の干渉RNA (siRNAs) が転写遺伝子の静止を誘発することが知られているが,この過程におけるmiRNAsの役割はあまり理解されていない.
研究 の 目的:
- 転写遺伝子調節におけるマイクロRNA (miRNA) の役割を調査する.
- miRNAsが表遺伝子サイレンシングに影響を与えるかもしれないメカニズムを解明する.
主な方法:
- DICER-LIKE1b遺伝子が欠けているモスの変異体Physcomitrella patensを使用しています.
- miRNAの成熟,標的RNAの分裂,トランスクリプトレベル,DNAメチル化パターンの分析.
- 経路誘導を観察するために,野生型のモスをホルモンで治療する.
主要な成果:
- DICER-LIKE1bのない突然変異体は正常なmiRNA成熟を示したが,標的RNA分裂は廃止され,トランスクリプトレベルが低下した.
- これらの変異体はmiRNA:target-RNAの二重複を蓄積し,標的遺伝子のハイパーメチル化を示し,その結果,遺伝子の静止が起こりました.
- 観察されたエピジェネティックサイレンシング経路は,ホルモン治療を受けた野生型のモスでも誘発された.
結論:
- マイクロRNAs (miRNAs) は,DNAメチル化によって,正規の転写後の役割とは独立して,エピジェネティックサイレンシングを開始することができます.
- このエピジェネティックサイレンシング経路の開始は,miRNAとターゲットRNAの比率に依存しています.
- この発見は,植物におけるmiRNAによる遺伝子調節の新たな層を明らかにしている.
関連する概念動画
MicroRNAs
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...
MicroRNAs
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...
MicroRNAs
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...
Regulation of Expression Occurs at Multiple Steps
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Regulation of Expression Occurs at Multiple Steps
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Regulation of Expression at Multiple Steps
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a...

