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Detection of Protein Ubiquitination
Published on: August 19, 2009
UBXD7は複数のユビキチンリガスを結合し,HIF1alphaのターンオーバーにおいてp97を関与させる
Gabriela Alexandru1, Johannes Graumann, Geoffrey T Smith
1Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
Cell
|September 9, 2008
まとめ
タンパク質p97 (VCPとも呼ばれる) は,タンパク質の分解に不可欠です. 新しい研究は,p97が多数のユビキチンリガゼと相互作用することを明らかにし,タンパク質の回転を調節するより広範な役割を示唆しています.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
背景:
- p97 (VCPとも呼ばれる) は,エンドプラズマの網膜に関連した分解に関与するATP依存のチャペロンである.
- 溶性タンパク質のターンオーバーにおけるその役割は,ユビキチン結合ドメインを含むコファクターによって媒介される基板結合により,あまり理解されていない.
研究 の 目的:
- p97とUBXドメインのタンパク質および関連するE3ユビキチンリガゼとの相互作用を調査する.
- 溶解性タンパク質の循環におけるp97の役割を明らかにし,特に低酸素誘導因子1alpha (HIF1alpha) に焦点を当てた.
主な方法:
- ネットワークプロテオミクスは,タンパク質とタンパク質の相互作用を特定するために使用されました.
- p97およびUBXタンパク質と関連したウビキチン結合ドメインとE3ウビキチンリガゼを分析した.
- HIF1alphaレベルへの影響を評価するために,p97の枯渇が実施されました.
主要な成果:
- p97は,哺乳類のUBXドメインの13のタンパク質すべてと組み合わることが判明しました.
- UBXタンパク質は,多数のE3ユビキチンリガゼと相互作用し,p97.7の既知のインタラクトームを拡張します.
- UBXD7は,p97,CUL2/VHLユビキチンリガゼ,およびその基質HIF1alpha.との間のリンクとして特定されました.
- p97の枯渇は,HIF1alphaの蓄積とHIF1alpha標的遺伝子の発現の増加をもたらした.
結論:
- p97は,UBXタンパク質との相互作用を通じて,E3ユビキチンリガゼの幅広い配列と関わり合います.
- これは,p97が,以前認識されていたよりも,タンパク質のターンオーバーのグローバルな規制においてより広範な役割を果たしていることを示唆しています.
- p97-UBXD7-CUL2/VHL軸は,HIF1αの分解に不可欠である.
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.
Protein Complexes with Interchangeable Parts
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
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...

