用MDA5激活dRNA识别,线程形成和抗病毒信号的结构基础
Bin Wu1, Alys Peisley, Claire Richards
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
Cell
|January 1, 2013
概括
病毒RNA受体MDA5与RIG-I不同,它与内部双链RNA (dsRNA) 不同地结合. 这种结构揭示了MDA5如何在dsRNA上形成细丝,从而触发抗病毒免疫信号.
科学领域:
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- MDA5 (黑色素分化相关蛋白5) 是一种关键的病毒双链RNA (dsRNA) 受体,参与天生的抗病毒免疫力.
- MDA5与RIG-I (Retinoic acid-inducible gene I) 有相似之处,但对病毒RNA具有明显的特异性,导致不同的免疫反应.
- 了解MDA5独特功能的分子基础对于理解病毒识别和免疫激活至关重要.
研究的目的:
- 阐明病毒RNA识别中MDA5和RIG-I之间的功能分歧背后的分子机制.
- 为了确定与dsRNA结合的MDA5的晶体结构.
- 研究MDA5如何利用其结构来识别病毒RNA并启动下游信号.
主要方法:
- 采用X射线晶体学来确定MDA5与dsRNA.complex的结构.
- 生物化学测试用于分析蛋白质与蛋白质相互作用和寡合化.
- 进行了功能测试,以评估信号适配器MAVS的激活.
主要成果:
- 晶体结构显示,MDA5识别了dsRNA的内部双重区域,与RIG-I对dsRNA终端的识别形成鲜明对比.
- 通过直接的蛋白质-蛋白质接触,MDA5沿着dsRNA形成一个从头到尾的丝.
- MDA5的双联CARD (卡斯帕斯激活和招募域) 信号域独立寡合化,促进MAVS激活.
结论:
- MDA5采用一种独特的dSRNA识别机制,利用长dSRNA作为线程组装平台.
- 对于强大的抗病毒信号传输,MDA5光纤的合作组合和随后的CARD域的随机寡合化至关重要.
- 这些发现为MDA5在抗病毒免疫力中的独特作用提供了分子基础,与RIG-I相比.
相关概念视频
Formation of Intermediate Filaments
4.0K
Intermediate filaments are cytoskeletal proteins with higher tensile strength and flexibility than microfilaments and microtubules. Unlike the other two cytoskeletal proteins, intermediate filament formation lacks the enzymatic activity to hydrolyze nucleotides like ATP and GTP to generate energy for polymerization. Therefore, the formation of intermediate filaments is multistep self-assembly. The involvement of any accessory proteins in intermediate filament formation has not yet been...
4.0K
Formation of Higher-order Actin Filaments
3.7K
The polymerization of G-actin monomers into filamentous F-actin is a multi-step process. Once the F-actins are formed, they can bundle together in different arrangements to form higher-order networks and regulate cellular functions. Common examples include the formation of lamellipodia and filopodia at the cell's leading edge by actin reorganization in a migrating cell. The microvilli on the brush border epithelial cells are also formed through the F-actin network.
The high-order actin...
The high-order actin...
3.7K
The Structure of Intermediate Filaments
5.8K
The intermediate filaments are one of three widely studied cytoskeletal filaments. They are so named as their diameter (10 nm) is in between that of microfilaments (7 nm) and the microtubules (25 nm). These filaments are highly stable and can remain intact when exposed to high salt concentrations and detergents. These filaments are responsible for providing stability and mechanical support to the cells. They also help in cell adhesion and maintaining tissue integrity.
Intermediate...
Intermediate...
5.8K
Structural Protein Function
30.1K
Structural proteins are a category of proteins responsible for functions ranging from cell shape and movement to providing support to major structures such as bones, cartilage, hair, and muscles. This group includes proteins such as collagen, actin, myosin, and keratin.
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to...
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to...
30.1K
Structure-Activity Relationships and Drug Design
1.8K
Drug design is a dynamic field that involves discovering and developing new medications based on specific biological targets. This process heavily relies on structure-activity relationships (SAR) and quantitative structure-activity relationships (QSAR) to guide the design and optimization of efficient drugs.
SAR studies the intricate relationship between a drug's chemical structure and biological activity. It focuses on understanding how modifications to a drug's structure can influence...
SAR studies the intricate relationship between a drug's chemical structure and biological activity. It focuses on understanding how modifications to a drug's structure can influence...
1.8K
Structures of Solids
18.6K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
18.6K


