在26S蛋白酶和Cdc48 ATPase之间的双向基质穿促进了蛋白质降解
Hao Li1, Zhejian Ji1, Joao A Paulo2
1Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
Molecular cell
|February 24, 2024
概括
26S蛋白酶分解了大多数真核蛋白质. 好折叠的蛋白质需要Cdc48 ATPase (p97/VCP) 展开,涉及最小的蛋白质酶系统,Cdc48-UN,Rad23,Ubx5和Shp1,使基质降解成为可能.
科学领域:
- 分子生物学分子生物学
- 蛋白质降解 蛋白质降解
- 乌比奎丁-蛋白酶体系统
背景情况:
- 细胞蛋白质降解主要涉及26S蛋白酶体.
- 缺乏非结构区域的蛋白质在蛋白质体降解之前需要由Cdc48 ATPase (p97/VCP) 与Ufd1-Npl4 (UN) 复合而展开.
研究的目的:
- 复制和分析Cdc48 ATPase依赖的26S蛋白质体对精密折叠模型基质的降解,使用纯化的酵母成分.
主要方法:
- 对Cdc48依赖的蛋白质体降解进行最小的体外系统的重构.
- 使用了纯化的酵母26S蛋白酶,Cdc48-UN复合体,Rad23,Ubx5和Shp1.
- 研究了辅助因子在基质结合和展开中的作用.
主要成果:
- 一个包含26S蛋白酶体,Cdc48-UN,Rad23,Ubx5和Shp1的最小系统成功调解了对折叠良好的基质的降解.
- Rad23和Ubx5分别增强聚比基因与蛋白质酶和Cdc48-UN的结合,促进基质竞争.
- Shp1被确定为由Cdc48-UN复合体展开的蛋白质的刺激剂.
结论:
- 建立了一个最小的复制系统来研究Cdc48依赖的蛋白质降解.
- 证明了Rad23,Ubx5和Shp1在促进具有挑战性的蛋白质基质降解方面的合作作用.
- 在体内证实了26S蛋白酶和Cdc48之间的双向基质穿,突出了动态降解路径.
相关概念视频
The Proteasome
8.6K
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...
8.6K
The Proteasome Structure
752
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...
752
Regulated Protein Degradation
7.3K
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...
7.3K
Export of Misfolded Proteins out of the ER
3.6K
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...
3.6K
Anaphase Promoting Complex
2.9K
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...
2.9K
Post-translational Translocation of Proteins to the RER
5.7K
A sizable fraction of proteins destined for ER are first synthesized in the cell cytosol and then transported across the ER membrane–a process called post-translational translocation. Similar to cotranslationally translocated proteins, these proteins also use the Sec translocon complex to enter the ER lumen.
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
5.7K


