人間の転写-輸出複合体によるmRNA認識と包装
Belén Pacheco-Fiallos1,2, Matthias K Vorländer1, Daria Riabov-Bassat1
1Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria.
Nature
|April 5, 2023
まとめ
新しく合成されたmRNAはメッセンジャーリボ核タンパク質複合体 (mRNP) にパッケージされ,核から輸出されます. この研究では,トランスクリプション-エクスポート (TREX) 複合体がmRNPを効率的なmRNAエクスポートのためにどのように組織するか明らかにしています.
科学分野:
- 分子生物学
- 構造生物学
- 細胞生物学
背景:
- メッセンジャーRNA (mRNA) は核輸出のためのメッセンジャーリボ核タンパク質複合体 (mRNP) に処理されます.
- トランスクリプション-エクスポート (TREX) コンプレックスはmRNA核エクスポートを媒介するが,そのmRNP認識と組織のメカニズムは不明である.
研究 の 目的:
- TREX複合体によるmRNP認識と組織の構造的メカニズムを解明する.
主な方法:
- TREX複合体に結合した再構成されたおよび内生的なヒトmRNPの構造を決定するために,冷凍電子顕微鏡とトモグラフィーを使用した.
- TREXサブユニットALYREFとmRNP結合エクソン結合複合体の多価相互作用の分析
主要な成果:
- mRNPは,ALYREFとエクソン結合複合体を含む多価相互作用によってTREXによって認識されます.
- エクソン・ジャンクション・コンプレックスは,ALYREFを通じてマルチメリゼーションを行い,mRNPの組織化を容易にする.
- 固有のmRNPは,複数のTREX複合体で覆われたコンパクトな球体を形成する.
結論:
- TREX複合体は,mRNP成分との相互作用によってmRNAを認識し,圧縮し,保護する.
- TREXによるmRNP球体の組織化は,効率的なmRNA生殖と核の輸出に不可欠である.
関連する概念動画
Nuclear Export of mRNA
7.7K
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...
7.7K
pre-mRNA Processing
53.1K
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl...
53.1K
Regulated mRNA Transport
6.3K
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing...
6.3K
Pre-mRNA Processing: Modification of pre-mRNA Ends
9.7K
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
9.7K
Regulation of Expression Occurs at Multiple Steps
22.9K
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...
22.9K
Transfer RNA Synthesis
12.1K
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...
12.1K


