相关实验视频
Updated: May 22, 2025

09:25
Quantifying Subcellular Ubiquitin-proteasome Activity in the Rodent Brain
Published on: May 21, 2019
6.6K
对无处不在素独立的midnolin-proteasome通路的结构洞察
Nagesh Peddada1, Xue Zhong1, Yan Yin1
1Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX 75390.
概括
米德诺林 (MIDN) 增强蛋白质酶活性和B细胞恶性瘤存活率. 它的泛素类域结合RPN11,而其C端螺旋结合RPN1,将基质定位为降解.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 癌症生物学 癌症生物学
背景情况:
- 米德诺林 (MIDN) 蛋白质增强了淋巴细胞中的蛋白质酶体活性.
- 在B型淋巴瘤恶性瘤中,MIDN促进了生存和扩散.
- MIDN与蛋白酶体相互作用的确切机制及其无无基因素独立基质降解途径尚不清楚.
研究的目的:
- 阐明中诺林 (MIDN) 与人类蛋白质组相互作用的结构机制.
- 了解MIDN如何以无素独立的方式促进基质降解.
- 为了揭示MIDN结合蛋白质组的构造状态.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定结构.
- 这项研究分析了基质参与,MIDN结合的人类蛋白质组复合体.
- 解决了两个不同的形态状态.
主要成果:
- MIDN通过其类似于ubiquitin的域通过结合RPN11 (PSMD14) 来诱导蛋白质酶体构造.
- MIDN同时将RPN1 (PSMD2) 与其C端α螺旋结合在一起.
- 这种双重结合将基质携带的Catch域放置在蛋白质体的ATPase通道上方,用于转位.
结论:
- 无论是与蛋白质体结合的全域类域还是C端α螺旋体,都对MIDN刺激其活性至关重要.
- 这些发现为MIDN在增强蛋白酶体功能和B细胞恶性瘤中的作用提供了结构基础.
- MIDN 作为一种类似于乌比奎丁的基质,调节蛋白酶体构造和基质进入.
相关概念视频
The Proteasome
790
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...
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...
790
The Proteasome Structure
670
The ubiquitin-proteasome pathway is a well-known mechanism utilized by eukaryotic cells to remove cytoplasmic proteins that are misfolded, damaged, or no longer needed. In this pathway, the protein that needs to be eliminated undergoes a process called ubiquitination, where a chain of ubiquitin molecules is attached to the 48th lysine residue of the target protein. This ubiquitin modification helps the proteasome distinguish between a target protein and a healthy protein.
The proteasome is an...
The proteasome is an...
670
Regulated Protein Degradation
7.1K
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...
7.1K
Covalently Linked Protein Regulators
6.7K
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....
6.7K
Translocation of Proteins into the Mitochondria
3.0K
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
3.0K
Export of Misfolded Proteins out of the ER
3.4K
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
3.4K

