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Updated: Jul 18, 2026

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Detection of Protein Ubiquitination
Published on: August 19, 2009
Pirh2は,p53誘発のユビキチン-タンパク質リガゼであり,p53の分解を促進する
Roger P Leng1, Yunping Lin, Weili Ma
1Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, Ontario, Canada M5G 2M9.
Cell
|March 26, 2003
まとめ
Pirh2は,新しいE3ユビキチンリガゼで,p53腫瘍抑制剤の分解を促進することによって,p53腫瘍抑制剤を否定的に調節します. この相互作用はフィードバックループを形成し,p53のレベルと機能を制御します.
科学分野:
- 腫瘍学 腫瘍学
- 分子生物学は分子生物学である.
- セルラーレギュレーション セルラーレギュレーション
背景:
- p53腫瘍抑制剤は,ストレス下での細胞増殖を停止することによって,癌を予防するために重要です.
- 翻訳後の改変はp53の活性を厳しく調節し,正常な細胞成長を維持します.
- Mdm2は,p53.5の既知の負の調節剤である.
研究 の 目的:
- p53.3の新たなレギュレータを特定し,特徴づけること.
- Pirh2がp53の機能と安定性に影響するメカニズムを解明する.
主な方法:
- 遺伝子発現分析により,p53-調節遺伝子を特定する.
- タンパク質とタンパク質の相互作用を評価するための共免疫プレシピテーション.
- ウビキチネーションアッセイは,リガース活性を決定する.
- ウェスタン・ブロッティングは,タンパク質のレベルを測定するためのものです.
- p53依存のトランザクティベーションと成長阻害を評価するための機能分析.
主要な成果:
- Ubiquitin-protein ligase活性を持つRING-H2ドメインタンパク質であるPirh2は,p53-調節遺伝子として特定されました.
- Pirh2はp53と物理的に相互作用し,Mdm2.2とは独立してそのユビキチン化と分解を促します.
- Pirh2の発現はp53のタンパク質レベルを低下させ,Pirh2の消去はp53のレベルを上昇させる.
- Pirh2は,p53媒介のトランザクティベーションと成長抑制を抑制する.
結論:
- Pirh2はp53の負の調節剤として作用し,それをユビキチン媒介のタンパク質分解に標的とする.
- Pirh2は,Mdm2.2と同様に,p53機能を制御する自己調節フィードバックループに貢献しています.
- Pirh2は,がんにおけるp53の活性を調節する潜在的な治療標的である.
関連する概念動画
Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
Regulated Protein Degradation
It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Abnormal Proliferation
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
The Unfolded Protein Response
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Export of Misfolded Proteins out of the ER
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Regulation of the Unfolded Protein Response
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...

