在ER相关蛋白质降解过程中基质加工的机制
John C Christianson1, Ernst Jarosch2, Thomas Sommer3,4
1Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK. john.christianson@ndorms.ox.ac.uk.
Nature reviews. Molecular cell biology
|August 1, 2023
概括
维持蛋白质完整性对于生物的生存至关重要. 细胞内膜网关联蛋白质降解 (ERAD) 使用膜结合的机械来通过ubiquitin-proteasome系统消除错误折叠的蛋白质.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 蛋白质组的完整性对生物体的生存至关重要,通过质量控制机制来维持.
- 细胞内膜网膜 (ER) 对于蛋白质质量控制来说是一个挑战,因为它与细胞质降解机器的空间分离.
- 与ER相关的蛋白质降解 (ERAD) 是一个进化保守的系统,它解决了这一挑战.
研究的目的:
- 审查ER相关蛋白降解 (ERAD) 中基质加工的机制.
- 突出ERAD途径在管理缺陷或多余蛋白质方面的多样性.
- 在ERAD中强调ER-膜嵌入式泛素酶 (ER-E3s) 的核心作用.
主要方法:
- 对ERAD途径和基质降解的现有文献的审查.
- 分析乌比奎丁-蛋白酶体系统在ER中的作用.
- 专注于ER-膜嵌入式泛素酶 (ER-E3s) 的功能.
主要成果:
- ERAD包括多个独立的过程,具有不同的基质选择性.
- 结合ER膜的无处不在化机制针对错误折叠或多余的ER蛋白进行蛋白质体降解.
- 在各种ERAD路线上,ER-E3s协调基质识别,传输和无处不在.
结论:
- ERAD是一个多方面的质量控制系统,对于维持蛋白质稳定至关重要.
- ER-E3s是关键的调节器,整合了各种因素,以确保有效地处置异常蛋白质.
- 了解ERAD途径为细胞健康和疾病提供了洞察力.
相关概念视频
Export of Misfolded Proteins out of the ER
3.7K
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...
3.7K
The Unfolded Protein Response
4.7K
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...
4.7K
Protein Modifications in the RER
5.3K
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
5.3K
Directing Proteins to the Rough Endoplasmic Reticulum
7.3K
The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes, etc. Some of the proteins directed to ER are then trafficked via vesicles to other organelles within the cell or the extracellular environment through the Golgi complex. For example, the rough ER synthesizes soluble proteins for transportation to the lysosomes or secretion out of the cell. It can also synthesize transmembrane proteins that can...
7.3K
Post-translational Translocation of Proteins to the RER
5.8K
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...
5.8K
ER Retrieval Pathway
3.9K
In the secretory pathway, vesicles transport proteins from one cellular compartment to another in forward transport to deliver the protein to its correct location. Occasionally, misfolded proteins and incorrect proteins escape their original compartments, and a retrieval pathway is used to return the escaped proteins to their original compartment.
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
3.9K


