类似于乌比奎的蛋白质参与了Mycobacterium tuberculosis的蛋白质酶路径
Michael J Pearce1, Julian Mintseris, Jessica Ferreyra
1Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA.
概括
科学家们在Mycobacterium tuberculosis中发现了一个类似于ubiquitin的 prokaryotic 蛋白质Pup. 化,一个需要PafA的过程,标记蛋白质降解,类似于eukaryotes的无处不在.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 乌比基 (一种蛋白质修饰剂) 在真核生物中传递蛋白质酶体介导的蛋白质降解信号.
- 人们认为,蛋白质酶载体的原核生物通过无素独立的途径降解蛋白质.
研究的目的:
- 研究 prokaryotes 中蛋白质降解的机制,特别是 Mycobacterium 结核病菌.
- 为了确定涉及 prokaryotic 蛋白质降解的潜在蛋白质修饰剂.
主要方法:
- 一种 prokaryotic 泛素类蛋白质 (Pup) 的识别和特征.
- 结合试验用于研究蛋白质酶基板上的pupylation.
- 对pafa突变的分析,以了解蛋白质酶辅助因子A (PafA) 在化和降解中的作用.
主要成果:
- 在Mycobacterium tuberculosis中发现了一种类似于ubiquitin的原生细胞蛋白,Pup (Rv2111c).
- Pup 特别与蛋白质酶基质结合,这一过程称为幼化.
- 幼发生在氨酸上,需要PafA;一个PafA突变体缺乏幼蛋白,并显示基质积累.
- 幼化,虽然类似于无处不在,但涉及不同的化学成分.
结论:
- 细菌,像真核生物一样,可以利用小蛋白修饰剂 (Pup) 调节蛋白质的稳定性.
- 幼化是一种与原核生物中蛋白质酶介导蛋白质降解相关的无素独立途径.
相关概念视频
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...
The Proteasome
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...
The Proteasome
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...
The Proteasome Structure
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...
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...
Export of Misfolded Proteins out of the ER
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...


