Control of Retrovirus Assembly by Membrane Lipid Thermodynamic Activity.

通过膜脂质热力学活性控制逆转录病毒组装。

• 批准号: 8915268
• 负责人: GERALD William FEIGENSON
• 金额: $ 1.25万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-15 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8915268
• 关键词: Acquired Immunodeficiency Syndrome; Address; Affect; Affinity; Behavior; Binding; Cell membrane; Cells; Charge; Cholesterol; Coupled; Disease; Drug Combinations; Electrostatics; Fluorescence Microscopy; Gagging; HIV; HIV-1; Health; Heterogeneity; Human; In Vitro; Invaded; Life; Life Cycle Stages; Lipid Binding; Lipids; Liquid substance; Measurement; Measures; Membrane; Membrane Lipids; Modeling; Morphology; Phase; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylserines; Phospholipids; Play; Process; Protein Binding; Proteins; RNA; Retroviridae; Role; Rous sarcoma virus; Site; Staging; Structural Protein; Surface; System; Thermodynamics; Viral; Viral Load result; Viral Proteins; Virion; Virus; Virus Assembly; Work; base; gag Gene Products; in vitro Model; membrane activity; membrane model; nanoscale

DESCRIPTION (provided by applicant): Viruses invade all forms of life, causing diseases in humans including HIV-AIDS. Although the variety of viruses is daunting, all enveloped viruses including those studied here, HIV-1 and Rous Sarcoma Virus (RSV), must associate with the cytoplasmic leaflet of plasma membranes. One difficulty for in vitro studies is the lack of good models of the plasma membrane cytoplasmic leaflet. Another difficulty is that real cells can have membrane heterogeneities on the tens of nanometer size scale on the opposed, exoplasmic leaflet. Both of these experimental issues are addressed in these proposed studies, with a multicomponent model cytoplasmic mixture that can be coupled to a phase-separated lipid mixture in an asymmetric bilayer. This project will explore how three aspects of membrane lipid mixing behavior are related to viral Gag protein binding and assembly: (1) How is the thermodynamic activity of membrane-bound phosphatidylserine controlled by lipid composition, and how is this PS activity connected to Gag binding? (2) How is the thermodynamic activity of Gag's other binding partner, PI(4,5)P2 controlled by the other membrane lipids, and in particular, what factors control the formation of PI(4,5)P2 domains? Are these domains the sites of Gag assembly? (3) The plasma membrane is asymmetric. How does the presence of a phase-separated leaflet that is coupled to the cytoplasmic leaflet change Gag binding and assembly? A theme of this work is that the tendency of membrane lipids to bind or react is described by their thermodynamic activity, and this activity is controlled by all the components of the mixture. This approach provides predictive power to describe the associations of viral Gag structural proteins with their lipid binding partners: Which membrane factors exert control over the interactions among membrane-bound viral Gag proteins? The overall strategy is to combine measurements of lipid thermodynamic activity with measurement of virus protein binding and assembly. Fluorescence microscopy is used to visualize domains of PI(4,5)P2, and to correlate these domains with measured Gag binding and Gag-Gag assembly into its viral lattice.

描述（申请人提供）：病毒入侵了所有形式的生命，在包括艾滋病毒在内的人类中引起疾病​​。尽管多种病毒令人生畏，但所有包围病毒在这里研究的病毒，HIV-1和Rous肉瘤病毒（RSV）都必须与质膜的细胞质小叶相关。体外研究的一个困难是缺乏质膜细胞质小叶的良好模型。另一个困难是，真实细胞可以在相反的外质小叶上的数十个纳米尺寸尺度上具有膜异质性。这两个实验问题在这些提出的研究中都解决了，具有多组分模型的细胞质混合物，可以与非对称双层中的相分离脂质混合物耦合。该项目将探讨膜脂质混合行为的三个方面与病毒GAG蛋白的结合和组装如何有关：（1）如何通过脂质组成控制膜结合磷脂酰甲酯的热力学活性以及该PS活性如何连接到GAG结合？ （2）如何由其他膜脂质控制的其他结合伴侣PI（4,5）P2的热力学活性如何控制PI（4,5）P2域的形成哪些因素？这些域是堵嘴组件的位置吗？ （3）质膜是不对称的。与细胞质传单耦合的相位分离的传单的存在如何改变GAG结合和组装？这项工作的一个主题是，膜脂质结合或反应的趋势由其热力学活性描述，并且该活动受到所有成分的控制 混合物。这种方法提供了描述病毒堵嘴结构蛋白与其脂质结合伴侣的关联的预测能力：哪些膜因子对膜结合的病毒og蛋白之间的相互作用产生控制？总体策略是将脂质热力学活性的测量与病毒蛋白结合和组装的测量结合在一起。荧光显微镜用于可视化PI（4,5）P2的结构域，并将这些结构域与测得的GAG结合和GAG-GAG组件与其病毒晶格相关联。