Structural Basis for HIV-1 Gag Interactions with Cellular Constituents

HIV-1 Gag 与细胞成分相互作用的结构基础

• 批准号: 9340233
• 负责人: Jamil Subhi Saad
• 金额: $ 36.75万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9340233
• 关键词: Acquired Immunodeficiency Syndrome; Address; Affinity; Antiviral Agents; Avian Sarcoma Viruses; Binding; Binding Proteins; Biochemical; Biophysics; Capsid; Cell membrane; Cholesterol; Cytoplasm; Cytoplasmic Tail; Data; Development; Drug Design; Elements; Engineering; Genetic; HIV; HIV-1; Human; Hydrophobicity; Infection; Knowledge; Lead; Life; Light; Lipids; Masks; Mediating; Membrane; Membrane Proteins; Molecular; Molecular Conformation; Molecular Models; N-terminal; Nucleocapsid; Outcome; Penetration; Phase; Physiological; Process; Production; Proteins; Public Health; RNA; Recruitment Activity; Retroviridae; Role; Safety; Site; Structural Protein; Structure; Suggestion; Surface Tension; Techniques; Therapeutic Agents; Virion; Virus; biophysical techniques; combat; env Gene Products; gag Gene Products; in vivo; innovation; insight; mimetics; molecular modeling; novel; novel strategies; novel therapeutic intervention; particle; pathogen; protein complex; public health relevance; reconstitution; tool

 DESCRIPTION (provided by applicant): During the late phase of HIV-1 infection, the Gag protein is synthesized and folds in the cytoplasm into an assembly inactive form in which not only the nucleocapsid (NC) domain but also the matrix (MA) domain interacts with RNA. As a consequence of this "folded" conformation, the capsid (CA) domain becomes incapable of assembling. During or upon transport to the plasma membrane (PM) site of assembly, a conformational switch occurs in which the interaction of MA with NC is exchanged for an interaction of MA with PM components. This switch liberates the CA domains for assembly and this conformational rearrangement, essential for activation of Gag, is driven by the binding affinity of specific PM components for MA. To understand this essential switch, it is fundamentally important to elucidate at the molecular level the interaction of MA with PM components. Interestingly, the Gag proteins of closely related retroviruses such as avian sarcoma virus (ASV) contain structural domains with functions essentially identical to those of HIV-1 Gag; however, the mechanisms for Gag assembly on the PM appear to be different. Understanding the molecular basis of this switch will not only shed light on the assembly of HIV-1 but is likely to provide insight into the control of assembly in other retroviruses that assemble at the PM. Subsequent to assembly on the PM, the Gag proteins recruit the envelope (Env) protein for incorporation into virus particles. There is mounting evidence that incorporation of th Env protein in nascent virions is mediated by interactions between the MA domain of Gag and the cytoplasmic tail (CT) of gp41. The mechanism by which Gag mediates Env incorporation is not known. In this proposal, we will employ NMR, biophysical, biochemical and in vivo tools to provide a macromolecular picture of how the Gag protein binds to the PM, and to determine the molecular elements for Gag-gp41 interactions that mediate Env incorporation into virus particles. In Aim 1, we will determine the precise molecular mechanism for HIV-1 Gag binding to the PM. We have devised innovative approaches to characterize interactions between MA and membrane mimetics. In Aim 2, we will identify the molecular elements of ASV Gag assembly on the PM. We present evidence for a novel molecular switch in ASV MA upon binding to PM components. In Aim 3, we will characterize the interactions between HIV-1 MA and gp41 CT. We devised a new strategy to reconstitute and mimic the physiologically relevant conditions for interactions. These studies will provide details on the molecular switches that activate Gag assembly on the PM and help in the recruitment of the Env protein to assembly sites. We hope that the outcome of this proposal will help in the development of new antiviral therapeutic agents that inhibit assembly and virus production.

 描述（由适用提供）：在HIV-1感染的后期，GAG蛋白是合成的，并在细胞质中折叠成组装不活动形式，其中不仅核OCAPSID（NC）结构域，而且矩阵（MA）结构域与RNA相互作用。由于这种“折叠”构象的结果，衣壳（CA）域变得无能组装。在传输到组装的质膜（PM）位点期间，发生了一个构象开关，其中MA与NC的相互作用与MA与PM组件的相互作用交换。该开关解放了用于组装的CA域，而这种咨询重排（对于激活GAG）至关重要，这是由MA的特定PM组件的结合亲密关系驱动的。为了理解这种基本开关，在分子水平上阐明MA与PM成分的相互作用至关重要。有趣的是，诸如禽肉瘤病毒（ASV）的密切相关逆转录病毒的GAG蛋白包含具有与HIV-1 GAG基本相同的功能的结构结构域；但是，PM上的插科打组件的机制似乎不同。了解这种开关的分子基础不仅会阐明HIV-1的组装，而且很可能可以洞悉组装中的其他逆转录病毒的控制 在下午。在PM组装后，GAG蛋白将保险蛋白募集到病毒颗粒中。有越来越多的证据表明，在新生病毒中掺入的Env蛋白是由GAG的MA结构域与GP41的细胞质尾巴（CT）之间的相互作用介导的。 GAG介导ENV收入的机制尚不清楚。在此提案中，我们将采用NMR，生物物理，生化和体内工具来提供大分子的图面，以了解GAG蛋白如何与PM结合，并确定GAG-GP41相互作用的分子元素，这些相互作用介导了介导于病毒颗粒中的NMR，并确定介导融合到病毒颗粒中的NMR。在AIM 1中，我们将确定HIV-1 GAG与PM结合的精确分子机制。我们设计了创新的方法来表征MA和膜模拟物之间的相互作用。在AIM 2中，我们将确定PM上ASV GAG组件的分子元件。我们提供了与PM成分结合后ASV MA中新型分子转换的证据。在AIM 3中，我们将表征HIV-1 MA和GP41 CT之间的相互作用。我们制定了一种新的策略，以重新建立和模仿与物理相关的互动条件。这些研究将提供有关激活PM上GAG组装的分子开关的详细信息，并有助于将ENV蛋白募集到组装位点。我们希望该提案的结果将有助于开发抑制组装和病毒生产的新抗病毒治疗剂。