Structure of HIV-1 envelope spike in the context of membrane

膜背景下 HIV-1 包膜刺突的结构

• 批准号: 10322988
• 负责人: Bing Chen
• 金额: $ 71.03万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-16 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10322988
• 关键词: Adopted; Antibodies; Antigens; Binding; Biochemical; CCR5 gene; CD4 Antigens; CXCR4 gene; Cells; Complex; Cryoelectron Microscopy; Cytoplasmic Tail; Environment; Genetic; Genetic Variation; Glycoproteins; Goals; HIV; HIV Envelope Protein gp120; HIV-1; HIV-1 vaccine; Infection; Lead; Length; Lipid Bilayers; Lipids; Mediating; Membrane; Membrane Fusion; Membrane Proteins; Molecular; Molecular Conformation; Play; Process; Proteins; Protocols documentation; Reporting; Resistance; Resolution; Role; Sampling; Series; Structure; Technology; Transmembrane Domain; Vaccine Design; Variant; Viral; Virus; base; chemokine receptor; env Gene Products; gag Gene Products; gp160; matrix protein, Human immunodeficiency virus type 1; nanodisc technology; nanodisk; novel; particle; protein structure; receptor binding; reconstitution; structural biology; vaccine development

Project Summary Membrane fusion, mediated by HIV-1 envelope glycoprotein [Env; trimeric (gp160)3 cleaved to (gp120/gp41)3], is the first critical step for the virus to enter host cells and establish infection. A mature Env spike contains three copies each of noncovalently-associated receptor-binding subunit gp120 and fusion subunit gp41. A general picture of viral membrane fusion has emerged from extensive biochemical and structural studies. Sequential binding of gp120 to the primary receptor CD4 and a coreceptor leads to large, irreversible structural rearrangements in gp41, which drive the membrane fusion process. Despite tremendous progress in our understanding of the structure of HIV-1 Env over the last two decades, largely based on studies of its soluble fragments, we still lack an atomic picture of the full-length Env in a membrane environment. In a series of recent studies, we have determined the structures of the transmembrane domain, membrane proximal external region, as well as a portion of the cytoplasmic tail of HIV-1 Env in bicelles that mimic lipid bilayers by NMR. Unexpectedly, we find that these regions all form well-ordered trimeric clusters in the presence of a lipid bilayer and that disruption of any of them reduces membrane fusion efficiency and alters the antigenic structure of the entire Env, suggesting that they play critical structural and functional roles. These new findings provide a strong scientific premise to determine the structure of the full-length HIV-1 Env reconstituted in lipid nanodiscs by cryo-electron microscopy (cryoEM). We hypothesize that the transmembrane and membrane- proximal regions of HIV-1 Env all adopt defined oligomeric structures that are critical for the stability, function and antigenicity of the full-length protein in membrane. We will capitalize on the recent advances in cryoEM and nanodisc technology and plan to determine structures of the full-length Env proteins, reconstituted in lipid bilayers, both alone or in complex with the matrix protein. Our goal is to visualize novel structural features of the intact Env proteins in the context of membrane, to gain a full understanding of their structure-function and to facilitate Env-based immunogen design for vaccine development. We will purse the following specific aims: 1) we will determine the structure of a full-length HIV-1 Env in the context of membrane, 2) we will determine the structural basis for antigenic differences of the intact Env in membrane among HIV-1 isolates with different antibody sensitivity, and 3) we will determine the structure of a full-length HIV-1 Env in complex with matrix protein.

项目摘要 膜融合，由HIV-1包膜糖蛋白介导[Env;三聚体（GP160）3裂解至（gp120/gp41）3]，3]， 是病毒进入宿主细胞并建立感染的第一步。成熟的Env Spike包含 分别三个副本分别与非共价相关的受体结合亚基GP120和融合亚基GP41。一个 病毒膜融合的一般图像来自广泛的生化和结构研究。 GP120与初级受体CD4的顺序结合和cocector导致大型，不可逆的结构 GP41中的重排，这驱动了膜融合过程。尽管我们的进步很大 在过去的二十年中，了解HIV-1 Env的结构，主要基于对其可溶性的研究 碎片，我们仍然缺乏膜环境中全长ENV的原子图。一系列 最近的研究，我们确定了跨膜结构域，膜近端外部的结构 区域以及HIV-1 Env中的一部分在双层中的HIV-1 Env的区域，它们通过NMR模仿脂质双层。 出乎意料的是，我们发现在脂质双层存在下，这些区域均形成有序的三聚体簇 它们中的任何一个都会降低膜融合效率，并改变 整个Env，表明它们扮演着关键的结构和功能角色。这些新发现提供了 强大的科学前提来确定脂质中重构的全长HIV-1 env的结构 冷冻电子显微镜（冷冻）的纳米散发。我们假设跨膜和膜 - HIV-1 Env的近端区域所有采用定义的寡聚结构，这对于稳定性至关重要， 膜中全长蛋白的功能和抗原性。我们将利用最近的进步 在冷冻和纳米轴技术中，计划确定全长Env蛋白的结构， 单独或与基质蛋白复杂的脂质双层中重构。我们的目标是可视化小说 完整的Env蛋白在膜上的结构特征，以充分了解其 结构功能并促进基于ENV的免疫原设计，以进行疫苗开发。我们将钱包 以下具体目的：1）我们将在 膜，2）我们将确定膜中完整ENV的抗原差异的结构基础 在具有不同抗体敏感性的HIV-1分离株中，3）我们将确定全长的结构 与基质蛋白复合物中的HIV-1 env。