関連する実験動画
Updated: Jul 25, 2025

09:33
Methods to Classify Cytoplasmic Foci as Mammalian Stress Granules
Published on: May 12, 2017
14.6K
QKIは内部m7G変異したトランスクリプトをストレス粒に変換し,mRNA代謝を調節する
Zhicong Zhao1, Ying Qing2, Lei Dong2
1Department of Systems Biology, Beckman Research Institute of City of Hope, Monrovia, CA 91016, USA; Department of Liver Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China.
Cell
|June 28, 2023
まとめ
振動タンパク質 (QKI) は,内部のN7-メチルグアノシン (m7G) 改変をメッセンジャーRNA (mRNA) に結合させる. この相互作用はmRNAの安定性と翻訳を調節し,がん細胞の化学療法に対する感受性に影響を及ぼします.
科学分野:
- 分子生物学
- RNAの改変
- 癌 研究
背景:
- N7-メチルグアノシン (m7G) の改変は,主に5'キャップでmRNA処理とタンパク質合成に不可欠です.
- メッセンジャーRNA (mRNA) 内の内部m7G変異の機能的意義は,ほとんど未調査のままである.
研究 の 目的:
- mRNAの代謝における内部m7G変異の役割を調査する.
- 内部のm7G改変mRNAを認識し,結合するタンパク質を特定する.
- 細胞のストレス反応と薬剤耐性におけるこの相互作用の機能を明らかにする.
主な方法:
- 内部m7Gメチロームのトランスクリプトーム全体のプロファイリングとマッピング.
- m7G改変mRNAのクエーキングタンパク質 (QKI) 結合部位の特定と特徴づけ
- タンパク質とタンパク質の相互作用 (QKI7とG3BP1) を研究する共免疫プレシピテーションアッセイ
- ストレス下でのmRNAの安定性と翻訳効率の分析
主要な成果:
- 保存された"GANGAN"モチーフを特徴とする,高信頼性の内部m7G改変およびQKI結合のmRNAターゲットが1,000以上特定されました.
- 震動タンパク質 (QKI) は,内部のm7G改変mRNAを選択的に認識し,結合する.
- QKI7は,ストレス粒子の核タンパク質であるG3BP1と相互作用し,m7Gによって改変されたトランスクリプトがストレス粒子に転移することを促進する.
- このプロセスはmRNAの安定性と翻訳を調節し,特にヒッポシグナル伝達経路遺伝子の翻訳を弱め,それによって癌細胞を化学療法に敏感にする.
結論:
- QKIはmRNAの内部m7G変異の読み取りとして機能する.
- 内部のm7G変異とQKI結合は,mRNA代謝とストレスに対する細胞反応において重要な役割を果たします.
- QKI- QKI7- G3BP1軸はmRNAのトランスレーションと安定性を調節し,がん細胞の薬剤耐性および感受性に影響を与えます.
関連する概念動画
Regulation of the Unfolded Protein Response
2.5K
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
2.5K
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
Nonsense-mediated mRNA Decay
10.7K
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
10.7K
MicroRNAs
3.0K
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...
3.0K
mRNA Stability and Gene Expression
5.7K
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
5.7K
Regulation of Expression at Multiple Steps
951
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...
951

