改変した核酸を除去することによって,転送RNA特異性の緩和
V Perret1, A Garcia, H Grosjean
1Institut de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Strasbourg, France.
Nature
|April 19, 1990
まとめ
移転RNA (tRNA) の改変は,移転RNA (tRNA) の変異として作用する.
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:
- 遺伝情報のタンパク質への正確な翻訳は,転送RNA (tRNA) とアミノアシル-tRNA合成酵素の間の特定の認識に依存しています.
- 以前の研究では,この分子認識とアミノ酸の充電に不可欠な特定のtRNA領域を特定しました.
- tRNAの同一性における一般的な転写後の塩基改変の役割は,まだ十分に理解されていない.
研究 の 目的:
- アミノアシル-tRNA合成酵素の認識の精度に対する一般的なtRNA塩基改変の貢献を調査する.
- これらの改変がtRNAの同類アミノ酸と非同類アミノ酸の充電に影響するかどうかを判断する.
主な方法:
- 改変されていないとネイティブ,改変されたtRNA (((Asp)) の間のアミノアシレーション効率の比較.
- tRNA (((Asp)) の同種のアミノ酸,アスパルテートとの充電を評価する.
- tRNAの誤充電を評価する (Asp) と同類でないアミノ酸であるアルギニン.
主要な成果:
- 改変されていないtRNA (((Asp) は,ネイティブで改変されたtRNAと同じくらい効率的にアスパルテートで充電されました.
- しかし,未改変のtRNA (((Asp) はアルギニンとの誤充電の効率を大幅に高めました.
- これらの発見は,改変が構造的制約を導入し,誤ったアミノ酸結合を防ぐことを示唆しています.
結論:
- トランスクリプション後のtRNAの改変は,翻訳の正確性を確保するために極めて重要です.
- これらの改変は"反決定因子"として機能し,不適切なアミノ酸でtRNAの充電を防ぐ.
- tRNAの改変は,タンパク質合成の忠実さを維持する上で重要な役割を果たします.
関連する概念動画
Types of RNA
Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
RNA Stability
Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
RNA Stability
Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
Nuclear Export of mRNA
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
Transfer RNA Synthesis
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
mRNA Stability and Gene Expression
The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
Cis-acting Elements involved in mRNA stability


