関連する実験動画
Updated: May 11, 2026

06:06
In Vitro Analysis of E3 Ubiquitin Ligase Function
Published on: May 14, 2021
Rfu1: ユビキチン経済への刺激
Dieter A Wolf1, Matthew D Petroski
1Burnham Institute for Medical Research, La Jolla, CA 92037, USA. dwolf@burnham.org
Cell
|May 5, 2009
まとめ
細胞のストレスにより,モノウビキキチンに対する需要が増加します. 研究者らは,Rfu1タンパク質をダウンレギュレーションすることによってデウビキチン化酵素Doa4を阻害すると,酵母におけるストレス中にモノビキチンレベルが上昇することを発見した.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
背景:
- 細胞のストレスは,間違った折りたたまれたタンパク質の蓄積を誘発します.
- 誤った折りたたまれたタンパク質は,プロテアソマル分解を必要とし,モノウビキチンへの需要を増加させます.
- モヌビキキチンは,タンパク質を分解のためにタグ付けするために不可欠です.
研究 の 目的:
- 酵母菌における細胞ストレス中にモノウビキチンレベルを調節するメカニズムを調査する.
- ストレス条件下におけるモノウビキチンの可用性を制御する要因を特定する.
主な方法:
- 実験に使用された酵母モデルシステム.
- タンパク質濃度とデウビキチン化酵素活性に関する分析.
- Doa4活動の調節におけるRfu1タンパク質の役割を調査した.
主要な成果:
- モヌビキキチン濃度は,細胞ストレス中に増加することが判明しました.
- ストレス条件下でRfu1タンパク質のダウンレギュレーションが観察されました.
- Rfu1は,デウビキチン化酵素Doa4.4の阻害剤として作用する.
- Doa4の抑制は,モノウビキチン濃度の上昇につながります.
結論:
- Rfu1のダウンレギュレーションは,酵母における細胞ストレス中に十分なモノウビキチンレベルを維持するための重要なメカニズムです.
- Rfu1-Doa4経路は,ストレス下でのタンパク質分解の要求を管理するために重要です.
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.
The Proteasome
Eukaryotic cells can degrade proteins through several pathways. One of the most important amongst these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
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...
The Unfolded Protein Response
The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...
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...
The Proteasome
Eukaryotic cells can degrade proteins through several pathways. One of the most important among these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...

