Regulation of Virus Capsid Assembly

病毒衣壳组装的调控

• 批准号: 7434710
• 负责人: Gillian M Air
• 金额: $ 28.58万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7434710
• 关键词: Affect; Allosteric Regulation; American; Antiviral Agents; Attenuated; Behavior; Binding; Biology; Capsid; Capsid Proteins; Cessation of life; Charge; Chronic; Cirrhosis; Complex; Core Protein; Cultured Cells; Data; Double Stranded DNA Virus; Escherichia coli; Family; Frequencies; Genome; Hepatitis B Virus; In Vitro; Individual; Infection; Integration Host Factors; Intervention; Investigation; Kinetics; Length; Link; Modeling; Molecular Conformation; Mutation; Nucleic Acid Binding; Nucleic Acids; Numbers; Phenotype; Phosphorylation; Play; Primary carcinoma of the liver cells; Production; Property; Proteins; RNA; RNA Binding; RNA Recognition Motif; RNA-Directed DNA Polymerase; Rate; Reaction; Regulation; Regulatory Element; Reverse Transcription; Role; Salts; Series; Signal Transduction; Simian B disease; Specificity; Structure; System; Testing; Therapeutic; Thermodynamics; Time; Viral; Viral Genome; Virion; Virus; Virus Assembly; Virus Replication; base; dimer; in vivo; interest; mutant; pgRNA; prevent; response; small molecule; stoichiometry; viral RNA

Hepatitis B virus (HBV) is an enveloped dsDNA virus with a ssRNA intermediate form. Correct assembly of the icosahedral core of HBV is required for replication. Reverse transcription of the RNA pre-genome (pgRNA) takes place within the completed capsid, the protein shell of the core. The HBV capsid is constructed from 120 capsid protein (Cp) dimers. In vitro, Cp assembles spontaneously. In vivo, pgRNA is selectively encapsidated in the presence of a great excess of host RNA, even when the Cp is expressed in trans. It is hard to imagine how there can be any selectivity, especially given the +17 charge on the RNAbinding domain of Cp. What prevents misassembly? Based on our in vitro studies, we have developed the hypothesis that HBV assembly is allosterically regulated: we suggest that Cp has assembly-active and - inactive conformations. We have identified different salts and small molecules that favor or inhibit assembly. We have also identified a number of mutations that inhibit and enhance assembly. In parallel, there are high frequency, naturally occurring mutations of the Cp that correlate with unexpected changes in the yield of virions; we hypothesize that these mutations affect assembly proficiency. In order to better understand regulation of HBV assembly, we propose to test our hypotheses that (i) in vitro assembly can be correlated with assembly in vivo and (ii) assembly is subject to allosteric regulation. Assembly of the common naturally occurring mutants will be correlated with phenotype. With assembly-defective Cp, we will describe structural differences between Cp dimers and Cp bound in capsids, a fundamental prediction of allostery. We will investigate how mutations at the dimer interface affect assembly; typically, interfaces between subunits are altered by allosteric transitions. We will examine the RNA-binding and specificity of Cp. Our preliminary data for allostery is strong but requires further investigation. Our results with HBV will advance the question of how assembly is regulated in other viruses. More than 350 million individuals suffer from chronic infection with hepatitis B virus (HBV), including more than 1.25 million Americans. Worldwide, HBV will contribute to 1 million deaths this year. By determining how HBV assembly is regulated, we will characterize a new target for antiviral intervention.

乙型肝炎病毒 (HBV) 是一种有包膜的 dsDNA 病毒，具有 ssRNA 中间形式。正确组装 乙型肝炎病毒的复制需要二十面体核心。 RNA前基因组的逆转录 (pgRNA) 发生在完整的衣壳内，即核心的蛋白质壳。乙肝病毒衣壳是 由 120 个衣壳蛋白 (Cp) 二聚体构建。在体外，Cp 自发组装。在体内，pgRNA 是 在存在大量宿主 RNA 的情况下选择性地包裹衣壳，即使 Cp 在 跨。很难想象怎么会有选择性，特别是考虑到 RNA 结合上的 +17 电荷 Cp 的域。什么可以防止误组装？基于我们的体外研究，我们开发了 假设 HBV 组装受到变构调节：我们认为 Cp 具有组装活性并且 - 非活性构象。我们已经确定了有利于或抑制组装的不同盐和小分子。 我们还发现了许多抑制和增强组装的突变。同时，还有高 频率，自然发生的 Cp 突变与产量的意外变化相关 病毒粒子；我们假设这些突变影响组装熟练程度。为了更好地理解 HBV 组装的调控，我们建议检验我们的假设：(i) 体外组装可以相关 体内组装并且（ii）组装受到变构调节。自然地共同组装 发生的突变体将与表型相关。对于装配缺陷 Cp，我们将描述结构 Cp 二聚体和衣壳中结合的 Cp 之间的差异，是变构的基本预测。我们将 研究二聚体界面的突变如何影响组装；通常，子单元之间的接口是 因变构转变而改变。我们将检查 Cp 的 RNA 结合和特异性。我们的初步数据 因为变构很强，但需要进一步研究。我们对乙肝病毒的研究结果将推进以下问题： 其他病毒中的组装是如何调节的。 超过 3.5 亿人患有乙型肝炎病毒 (HBV) 慢性感染，其中包括 超过 125 万美国人。今年，全球范围内，乙型肝炎将导致 100 万人死亡。通过确定 乙型肝炎病毒的组装是如何调控的，我们将确定抗病毒干预的新目标。