非テンプレートオリゴアデニレーションは,RISCで分割されたトランスクリプトの劣化を促します
Fadia Ibrahim1, Jennifer Rohr, Won-Joong Jeong
1Biological Sciences and Plant Science Initiative, University of Nebraska, Lincoln, NE 68588, USA.
まとめ
研究者らは,小さな干渉RNA (siRNA) サイレンシングの後,RNA断片を分解するのに不可欠な遺伝子であるMUT68を発見しました. この遺伝子は,標的トランスクリプトの分解を助ける酵素をコードし,RNA干渉の重要なステップを明らかにします.
科学分野:
- 分子生物学は分子生物学である.
- RNA 生物学 RNA 生物学
- 遺伝子規制 遺伝子規制
背景:
- Dicerによって小さな干渉RNA (siRNA) に処理され,RNA誘発サイレンシング複合体 (RISC) に統合された二重鎖RNAは,真核生物の遺伝子サイレンシングを媒介する.
- RNA干渉 (RNAi) は主要な遺伝子静止経路であり,主に同類のトランスクリプトの劣化によって特徴付けられます.
- siRNA媒介の分裂後に生成されたRNA断片の運命は,ほとんど不明のままである.
研究 の 目的:
- siRNA標的トランスクリプトの衰退を制御する分子機構を調査する.
- RNA干渉におけるRNA断片の分割後の処理に関与する遺伝子を特定する.
- 分裂したRNA断片の分解経路における特定の酵素の役割を明らかにする.
主な方法:
- 遺伝子スクリーンを用いたクロミドモナス・ラインハーディ (Chlamydomonas reinhardtii) の遺伝子識別
- 特定された遺伝子の分子クローニングと特徴付け (MUT68).
- MUT68タンパク質の酵素活性を決定する生化学的測定法.
主要な成果:
- siRNA標的トランスクリプトの効率的な分解に不可欠なMUT68遺伝子の識別.
- MUT68は,非正規のポリアデニラートポリメラーゼをコードする.
- MUT68酵素は,siRNA分裂後の5'RNA断片に未テンプレートアデニンを添加し,そのエクソソーム依存の分解を促進する.
結論:
- MUT68は,割れたRNA断片の分解を促進することによって,RNA干渉経路において重要な役割を果たします.
- MUT68のポリアデニレーション活動は,これらの断片をエクソソーム媒介の腐敗に標的化するための重要なステップです.
- この発見は,RNAi媒介による遺伝子サイレンシングの際にRNA分子の完全なライフサイクルに関する新しい洞察を提供します.
関連する概念動画
Transcription
Overview
Transcription is the process of synthesizing RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. Additionally, many other proteins and regulatory sequences are involved in the proper synthesis of messenger RNA (mRNA). Regulation of transcription is responsible for the differentiation of all the different types of cells and often for the proper cellular response to environmental signals.
Transcription Can Produce Different Kinds...
Transcription is the process of synthesizing RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. Additionally, many other proteins and regulatory sequences are involved in the proper synthesis of messenger RNA (mRNA). Regulation of transcription is responsible for the differentiation of all the different types of cells and often for the proper cellular response to environmental signals.
Transcription Can Produce Different Kinds...
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...
RACE - Rapid Amplification of cDNA Ends
Rapid Amplification of cDNA Ends, or RACE, is one of the most effective methods to obtain a full-length cDNA from an mRNA sequence between a known internal region to the unknown sequence at the 5’ or 3’ end. The unknown region is cloned in the cDNA by a gene-specific primer that binds the known end, and a hybrid primer that attaches a predefined anchor sequence to the unknown end of the cDNA. The sequence in between is amplified by PCR with an anchor primer and a gene-specific primer.
Since the...
Since the...
Bacterial Transcription
RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription
Transcription is the synthesis of RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. Additionally, many other proteins and regulatory sequences are involved in correctly synthesizing messenger RNA (mRNA). Transcriptional regulation is responsible for the differentiation of different types of cells and often for the proper cellular response to environmental signals.
Transcription Can Produce Different Kinds of RNA Molecules
In eukaryotes,...
Transcription Can Produce Different Kinds of RNA Molecules
In eukaryotes,...
Transcriptional Regulation: Riboswitches
Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...


