mRNA 3'-end 処理の品質管理は,核エクソソームと関連しています
P Hilleren1, T McCarthy, M Rosbash
1Howard Hughes Medical Institute, Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721, USA. hilleren@u.arizona.edu
Nature
|October 5, 2001
まとめ
メッセンジャーRNA (mRNA) の加工と輸出は,品質管理のためにリンクされています. Rrp6pを含む核エクソソームは,適切なmRNA 3'-end形成のためのチェックポイントとして機能し,欠陥トランスクリプトを保持します.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- 遺伝学 遺伝学とは
背景:
- メッセンジャーRNA (mRNA) の代謝は,品質管理のために細胞プラズマの輸出と結合した核前mRNA処理を伴う.
- Saccharomyces cerevisiaeでは,欠陥のあるmRNA核の輸出により,超アデニル化と転写部位での転写物の保持が生じます.
- これは,ポリアデニレーションとトランスクリプションサイトからの放出を含む核輸出の結合メカニズムを示唆しています.
研究 の 目的:
- mRNA核の輸出と保持における3'-end処理の役割を調査する.
- 転写部位で不適切に処理されたmRNAの保持に関与する要因を特定する.
- mRNA品質管理における核エクソソームの機能を明らかにする.
主な方法:
- Saccharomyces cerevisiaeにおけるmRNA処理と局所化の分析.
- mRNA代謝におけるRrp6pと核エクソソムの役割を調査する.
- 野生型とエクソソーム変異株のmRNA保持を比較する.
主要な成果:
- ポリアデニル化トランスクリプトと類似して,ポリアデニル化トランスクリプトが欠けているトランスクリプトは,トランスクリプト部位に留まっています.
- この保持メカニズムには,Rrp6pタンパク質と核エクソソームが必要です.
- エクソソーム変異体では,ハイポアデニル化とハイパーアデニル化の両方のmRNAが放出され,翻訳され,品質管理の失敗を示します.
結論:
- Rrp6pを含む核エクソソームは,不適切な3'-end処理されたmRNAを転写部位に留める上で重要な役割を果たしています.
- エクソソームは,mRNAの3'-end形成を監視するチェックポイントとして機能し,輸出前に適切な処理を確保します.
- エクソソームの機能障害は,異常なmRNAの放出と潜在的翻訳につながり,細胞の品質管理を損なう.
関連する概念動画
pre-mRNA Processing
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 guanosine). This 5’ cap helps the...
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 guanosine). This 5’ cap helps the...
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...
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
Pre-mRNA Processing: Modification of pre-mRNA Ends
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 the cell...
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 the cell...
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...
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


