通过CRL2识别C-degron的分子基础APPBP2 ubiquitin合酶
Shidong Zhao1, Diana Olmayev-Yaakobov2, Wenwen Ru1
1Ministry of Education Key Laboratory for Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Peoples Republic of China.
概括
这项研究揭示了基质受体APPPBP2如何使用低温电子显微镜识别蛋白质降解中的R-x-x-G/C降解子. 它揭示了对蛋白质循环至关重要的双重结合机制.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- E3 泛素酶通过降解控制蛋白质降解的特异性.
- 在C-终端残留物 (C-降解物) 被库林-RING酶 (CRL) 复合体中的基质受体 (SRs) 识别.
- APPBP2,CRL2的SR,识别R-x-x-G/C降解子,但其机制尚不清楚.
研究的目的:
- 阐明通过CRL2识别R-x-x-G/C降解子的分子机制.
- 为CRL2APPBP2复合体的组装提供结构性见解.
- 为基于结构的药物设计奠定基础,以蛋白质降解为目标.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于解决CRL2APPBP2-degron复合物的结构.
- 生物化学结合实验.生物化学结合实验.
- 基于细胞的测试,以在生物背景下验证发现.
主要成果:
- 确定了CRL2APPBP2二聚体和四聚体与R-x-x-G/C降解子结合的结构.
- 揭示了一种双重识别机制,其中氨酸和甘氨酸结合了不同的口袋.
- 证明APPBP2可以识别C端上游最多3个残留物的图案.
结论:
- APPBP2采用了一个特定的双方机制,用于R-x-x-G/C降级识别.
- 结构洞察力解释了CRL2APPBP2介导的蛋白质周转.
- 这些发现有助于设计用于向蛋白质降解的化学探针.
相关概念视频
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
GPCR Desensitization
6.1K
G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
6.1K
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
Covalently Linked Protein Regulators
6.8K
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....
6.8K
The Proteasome
857
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...
857


