Regulation of Viral Membrane Fusion

病毒膜融合的调控

• 批准号: 7174195
• 负责人: RICHARD W COMPANS
• 金额: $ 25.39万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7174195
• 关键词: Amino Acid Sequence; Animal Model; Appearance; Biology; Cell fusion; Cells; Cellular Membrane; Chimeric Proteins; Complex; Cultured Cells; Cytoplasmic Tail; DNA; Endosomes; Exhibits; Extracellular Domain; Genes; Glycoproteins; Goals; Human; Infection; Knowledge; Membrane Fusion; Membrane Fusion Activity; Modeling; Molecular Conformation; Nature; Nucleoproteins; Nucleotides; Other Genetics; Paramyxovirus; Pathway interactions; Phenotype; Play; Principal Investigator; Process; Property; Proteins; Regulation; Role; Serial Passage; Staging; Structure; Temperature; Testing; Variant; Viral; Viral Fusion Proteins; Virus; Virus Replication; Virus-Cell Membrane Interaction; base; cell type; inhibitor/antagonist; mouse model; mutant; novel; parainfluenza virus; recombinant virus

DESCRIPTION (provided by applicant): Fusion proteins of enveloped viruses play an essential role in the early stages of infection, enabling fusion of the viral envelope with a cellular membrane and release of the internal viral nucleoprotein complexes into cells to initiate the infection process. Although major advances have been made in our knowledge of the structure of viral fusion proteins, many aspects of the fusion process remain unknown. The present application is focused on extending our novel observations concerning the regulation of fusion activity by the cytoplasmic domain of the fusion (F) glycoprotein of a paramyxovirus. In the present application the mechanisms by which the cytoplasmic domain regulates cell fusion, and the consequences for virus-cell interaction, will be investigated. Studies will focus on a recently characterized paramyxovirus, designated SER virus, which is closely related to SV5 but exhibits no observable cell fusion activity in several cell types; this lack of fusion activity is the result of an extended cytoplasmic domain in the SER F protein. To investigate the possible mechanism involved in suppression of fusion activity, the hypothesis will be tested that the extended cytoplasmic domain stabilizes the metastable "pre-fusion" state of the SER F protein, thus increasing the activation energy required for conversion to a fusion-active state. It will be determined if the marked differences in fusion phenotypes between SV5 and SER viruses result in differences in virus-cell interaction, including whether SER virus entry into cells may differ from that of SV5 by involving a low PH-dependent process. It will also be determined whether serial passage of SER virus results in the appearance of fusogenic variants with a truncated cytoplasmic tail, and whether such viruses possess a replicative advantage. The effects of specific changes in the cytoplasmic domain on virus replication will also be investigated in the context of otherwise isogenic recombinant viruses. SER F genes with defined sequence changes will be used to replace the F gene of SV5 in an infectious DNA clone, and their effects on virus replication in cell culture as well as in a mouse model will be determined. The long term goal is to understand the interactions between the external and cytoplasmic domains which are involved in fusion, as well as the role of the fusion-inhibitory sequences in the biology of the virus.

描述（由申请人提供）：包膜病毒的融合蛋白在感染的早期阶段起着至关重要的作用，从而使病毒包膜与细胞膜融合并释放到细胞中内部病毒核蛋白复合物中启动感染过程。尽管我们对病毒融合蛋白的结构的了解已经取得了重大进展，但融合过程的许多方面仍然未知。本应用的重点是扩展我们的新观察结果，该观察结果是关于通过融合型（F）糖蛋白的胞质结构域调节融合活性的。在本应用中，将研究细胞质结构域调节细胞融合的机制，并研究病毒 - 细胞相互作用的后果。研究将重点放在最近表征的帕托马病毒，该病毒指定为SER病毒，该病毒与SV5密切相关，但在几种细胞类型中没有可观察到的细胞融合活性。缺乏融合活性是Ser f蛋白中扩展的细胞质结构域的结果。为了研究融合活性抑制的可能机制，将检验该假设，即扩展的细胞质结构域稳定了Ser f蛋白的可稳定的“前融合”状态，从而增加了转化为融合活性状态所需的激活能量。将确定SV5和SER病毒之间融合表型的明显差异是否会导致病毒 - 细胞相互作用的差异，包括通过涉及低pH依赖性过程而导致SER病毒进入细胞是否可能与SV5的融合型差异。还将确定SER病毒的系列通过是否导致具有截短的细胞质尾巴的融合型变体的出现，以及此类病毒是否具有复制优势。还将在其他等同基因的重组病毒的背景下研究细胞质结构域对病毒复制的特定变化对病毒复制的影响。具有定义序列变化的Ser F基因将用于替代传染性DNA克隆中SV5的F基因，并将确定它们对细胞培养物以及小鼠模型中病毒复制的影响。长期目标是了解涉及融合的外部和细胞质结构域之间的相互作用，以及融合抑制性序列在病毒生物学中的作用。