在CRL5-SPSB3无酸酶的核cGAS降解目标
Pengbiao Xu1, Ying Liu1,2, Chong Liu1
1Global Health Institute, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
Nature
|February 28, 2024
概括
在循环细胞中,ubiquitin蛋白质体系统降解核循环GMP-AMP合成酶 (cGAS). 这种由SPSB3蛋白调节维持平衡,并可作为增强抗病毒防御的目标.
科学领域:
- 免疫学
- 分子生物学
- 细胞生物学
背景情况:
- 循环GMP-AMP合成酶 (cGAS) 是异常DNA的关键传感器,可以启动先天免疫反应.
- 严格调节cGAS对于维持平衡至关重要,因为它的不分青红白的DNA传感可能是有害的.
- 核cGAS在正常细胞生理中的命运和功能尚不清楚.
研究的目的:
- 研究循环细胞中核cGAS的调节和命运.
- 确定控制核cGAS蛋白质稳定的机制.
- 探索针对核cGAS降解的治疗潜力.
主要方法:
- 使用冷电子显微镜确定核体结合cGAS及其相互作用蛋白的结构.
- 采用全方位蛋白酶系统 (UPS) 测试来研究cGAS降解.
- 研究了SPSB3作为cGAS无处不在的基质受体的作用.
主要成果:
- 证明UPS可以在循环电池中降解核cGAS.
- 确定了SPSB3作为招募CRL5复合体到核cGAS的基质受体.
- 在cGAS上发现了一种保存的Asn-Asn (NN) 基因,该基因调解SPSB3结合和无处不在.
- 显示抑制SPSB3介导的降解增强了I型干扰素的信号传递和抗病毒保护.
结论:
- 通过UPS降解蛋白质是核cGAS的关键调节机制.
- SPSB3针对核cGAS进行降解,控制其稳定性和细胞功能.
- 对cGAS-SPSB3相互作用的结构见解为免疫调节和抗病毒策略提供了治疗途径.
相关概念视频
Regulated Protein Degradation
7.2K
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...
7.2K
Regulation of Nuclear Protein Sorting
2.4K
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
2.4K
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
Nuclear Export of mRNA
7.7K
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
7.7K
Nuclear Localization Signals and Import
5.7K
Proteins targeted to the nucleus carry short stretches of amino acid sequences called the nuclear localization signal or NLS. Classical nuclear localization signals are of two types: monopartite and bipartite NLS. Monopartite classical NLS (cNLS) consists of a single cluster of 4-8 amino acids. Bipartite cNLS consists of two clusters of 2-3 amino acids and a 9-12 residue long proline-rich linker bridging the two clusters. Signal clusters are rich in positively charged amino acids such as...
5.7K
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


