相关实验视频
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Detection of Protein Ubiquitination
Published on: August 19, 2009
UBXD7结合了多个泛素酶,并使p97参与HIF1alpha周转率
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
概括
蛋白质p97 (也称为VCP) 对于蛋白质降解至关重要. 新的研究揭示了p97与众多的无素结合酶相互作用,这表明它在调节蛋白质周转方面发挥了更广泛的作用.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- p97 (也称为VCP) 是一种依赖ATP的伴侣,参与了与内分泌网膜相关的降解.
- 它在可溶性蛋白质循环中的作用不太清楚,基质结合由含有无素结合域的辅因子介导.
研究的目的:
- 为了研究p97与UBX域蛋白和相关的E3无素连接酶的相互作用.
- 阐明p97在可溶性蛋白质循环中的作用,特别关注缺氧诱导因子1alpha (HIF1alpha).
主要方法:
- 网络蛋白质组学被用来确定蛋白质-蛋白质相互作用.
- 分析了与p97和UBX蛋白相关的乌比基结合域和E3乌比基结合酶.
- 进行了p97的耗尽,以评估其对HIF1alpha水平的影响.
主要成果:
- 发现p97与所有13种哺乳动物UBX域蛋白质组合在一起.
- UBX 蛋白与众多的 E3 泛基因酶相互作用,扩大了已知的 p97.7 相互作用体.
- UBXD7被确定为p97,CUL2 / VHL泛基因酶及其基质HIF1alpha.之间的链接器.
- 由于p97的枯竭导致HIF1alpha的积累,并增加了HIF1alpha目标基因的表达.
结论:
- 通过与UBX蛋白的相互作用,p97与广泛的E3泛素连接酶发生相互作用.
- 这表明p97在全球调节蛋白质周转方面发挥的作用比以前被认为的更为广泛.
- 在p97-UBXD7-CUL2/VHL轴对HIF1alpha降解至关重要.
相关概念视频
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...

