通过抑制PKR介导的抗病毒应激颗粒的形成,TRBP调节RLR信号
Koji Onomoto1, Monami Sakai1, Miyu Watanabe1
1Division of Molecular Immunology, Medical Mycology Research Center, Chiba University, Chiba, 260-8673, Japan.
Scientific reports
|July 1, 2025
概括
TAR-RNA结合蛋白 (TRBP) 抑制了抗病毒应激颗粒 (avSG) 的形成,抑制了I型干扰素 (IFN) 的表达. TRBP通过抑制PKR激活来负面调节RLR信号,这是avSG组装的一个关键步骤.
科学领域:
- 细胞生物学 细胞生物学
- 免疫学 免疫学 免疫学
- 病毒学 病毒学
背景情况:
- 压力颗粒 (SG) 是在细胞压力下形成的动态RNA-蛋白聚合物.
- 抗病毒应激颗粒 (avSG) 对视网膜酸诱导基因I类受体 (RLR) 介导的对病毒的先天免疫非常重要.
- 对于avSG形成的准确规则仍然不完全理解.
研究的目的:
- 研究TAR-RNA结合蛋白 (TRBP) 在调节抗病毒应激颗粒 (avSG) 形成和I型干扰素 (IFN) 表达中的作用.
- 阐明TRBP影响RLR介导抗病毒信号的分子机制.
主要方法:
- 在细胞模型中对TRBP的过度表达和淘汰研究.
- 评估IFN-β促进体活性和mRNA表达.
- 对IRF-3酸化和激活的分析.
- 耗尽G3BP1和G3BP2以研究SG的形成.
- 同免疫沉试验用于研究TRBP和PKR之间的蛋白质相互作用.
主要成果:
- 过度表达TRBP抑制了AVSG的形成和I型IFN的产生病毒感染或多种I:C) 转染后.
- TRBP淘汰细胞显示增强的IRF-3激活和IFN-β表达.
- TRBP通过其dRNA结合域与PKR相互作用,并抑制PKR的激活.
- G3BP1/G3BP2的耗尽取消了TRBP对IRF-3酸化的抑制作用.
结论:
- TRBP作为RLR介导的抗病毒免疫的负调节剂.
- 通过PKR依赖的机制,TRBP抑制了avSG的形成.
- TRBP的新功能提供了关于先天抗病毒反应复杂调节的见解.
相关概念视频
Regulation of the Unfolded Protein Response
2.6K
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
2.6K
The Unfolded Protein Response
5.1K
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...
5.1K
PI3K/mTOR/AKT Signaling Pathway
4.0K
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a...
4.0K
LTR Retrotransposons
17.9K
LTR retrotransposons are class I transposable elements with long terminal repeats flanking an internal coding region. These elements are less abundant in mammals compared to other class I transposable elements. About 8 percent of human genomic DNA comprises LTR retrotransposons. Some of the common examples of LTR retrotransposons are Ty elements in yeast and Copia elements in Drosophila.
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
17.9K
Receptor Tyrosine Kinases
14.3K
Receptor tyrosine kinases or RTKs are membrane-bound receptors that phosphorylate specific tyrosine on protein substrates. RTKs regulate cellular growth, differentiation, survival, and migration. They contain an extracellular ligand binding domain, a transmembrane domain, and a cytosolic tail with intrinsic kinase activity. Several extracellular signaling molecules activate RTKs in one or more ways and relay the signal downstream. Ligands such as platelet-derived growth factor (PDGF) or...
14.3K
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


