関連する実験動画
Updated: May 5, 2026

10:55
Purification of Ubiquitinated p53 Proteins from Mammalian Cells
Published on: March 21, 2022
2.6K
処理された,膜に結合したSPT23転写因子をCDC48 ((UFD1/NPL4),ユビキチン選択的チャペロンによって動員する
1Department of Molecular Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18a, 82152, Martinsried, Germany.
Cell
|December 6, 2001
まとめ
イーストのOLE経路は,調節されたユビキチン/プロテアソーム依存処理 (RUP) によって活性化された転写因子SPT23を使用して,膜流動性を制御します. CDC48 ((UFD1/NPL4) コンプレックスは,核標的化のために処理されたSPT23 (p90) を選択的に解放します.
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
- バイオケミストリー バイオケミストリー
背景:
- イーストのOLE経路は,ER結合酵素Delta9-脂肪酸不飽和酵素 (OLE1) を制御することによって,膜流動性を調節する.
- SPT23は,転写因子であり,哺乳類のNF-kappaBのホモログであり,この経路における重要な調節因子である.
- SPT23は,ER膜に固定された不活性前駆体として存在し,活性化には規制されたユビキチン/プロテアソーム依存処理 (RUP) が必要です.
研究 の 目的:
- SPT23の活性化と,その後の処理と核ターゲティングのメカニズムを解明する.
- SPT23の規制におけるタンパク質複合体のダイナミクスとユビキチネーションの役割を調査する.
- ユビキチン化タンパク質基質の加工におけるCDC48 ((UFD1/NPL4) 複合体の機能を特徴付ける.
主な方法:
- SPT23の二分化と加工の分析.
- アクティベーション中のSPT23のユビキチン化状態の調査.
- SPT23とその加工された形態 (p90) とCDC48 ((UFD1/NPL4) コンプレックスとの相互作用を研究するための生化学分析.
主要な成果:
- SPT23は,規制されたユビキチン/プロテアソーム依存処理 (RUP) を受ける前に二酸化します.
- 処理された形であるp90は,当初,ユビキチン改変を経由して未処理のSPT23前駆体と結合し続けます.
- シャペロン状のCDC48 ((UFD1/NPL4) 複合体は,核転位のためのパートナーからp90を選択的に解放し,ユビキチン化基板を好むことを示しています.
結論:
- SPT23のアクティベーションには,二分化と連続処理のステップが含まれています.
- ウビキチン改変は,加工されたSPT23 (p90) をその前体と結びつける上で重要な役割を果たします.
- CDC48 ((UFD1/NPL4) コンプレックスは,その機能のためにユビキチン化SPT23を選択的に放出する重要な要因として作用し,ユビキチン依存タンパク質処理におけるその役割を強調します.
関連する概念動画
Covalently Linked Protein Regulators
8.2K
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....
8.2K
Regulation of Nuclear Protein Sorting
2.5K
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
2.5K
The Spindle Assembly Checkpoint
2.9K
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
2.9K
The Unfolded Protein Response
5.6K
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...
5.6K
Anaphase Promoting Complex
2.5K
The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
2.5K
Regulation of the Unfolded Protein Response
2.2K
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...
2.2K

