Paramyxovirus Membrane Fusion

描述(由申请人提供)：我们学习的目的是了解 新城疫病毒副粘病毒膜融合的分子机制 以疾病病毒为原型。与大多数副粘病毒系统一样，膜融合 需要HN和F两种蛋白质。我们的研究集中在F蛋白是如何 介导膜融合和HN蛋白在这一过程中的作用。我们有 最近提出了四个与未解决的问题有直接关系的观察结果 关于副粘病毒融合的问题。首先，我们发现了一个特定的 F蛋白的结构域与HN蛋白的一个结构域相互作用 来自两个蛋白质的序列之间相互作用的直接证据 确定所涉及的F蛋白的特定结构域。第二，使用抗血清 针对F蛋白的HR1和HR2结构域，我们已经证明了构象 依赖于HN蛋白表达的F蛋白和F蛋白的差异 乳沟。第三，使用针对HN短序列的多肽抗血清 蛋白质，我们已经证明了HN蛋白相关的构象差异 到F蛋白的表达和切割。第四，我们提出了一个突变点 F蛋白消除了对HN蛋白的绝对需求 合胞体的形成，这一发现引发了对HN作用的质疑 融合中的蛋白质附着。为了解决这些发现提出的问题 我们提出了四个具体的目标：1)描述特定的 HN蛋白和F蛋白的结构域，2)表征构象变化 在与HN蛋白表达和F蛋白切割相关的F蛋白中，3) HN蛋白与HN蛋白相关的构象变化特征 附着和F蛋白表达及卵裂。4)探索 在融合开始时的依附。

DESCRIPTION (Provided by applicant): The goal of our studies is to understand the molecular mechanisms of paramyxovirus membrane fusion using Newcastle disease virus as a prototype. As in most paramyxovirus systems, membrane fusion requires both HN and F proteins. Our studies have focused on how F protein mediates membrane fusion and the role of HN protein in that process. We have recently made four observations that have a direct bearing on unresolved questions about paramyxovirus fusion. First, we have found that a specific domain of the F protein interacts with a domains of the HN protein providing direct evidence for an interaction between sequences from the two proteins and identifying specific domains of the F protein involved. Second, using antisera specific for F protein HR1 and HR2 domains, we have demonstrated conformational differences in F protein dependent upon HN protein expression and F protein cleavage. Third, using peptide antisera specific for a short sequence of the HN protein, we have demonstrated conformational differences in HN protein related to F protein expression and cleavage. Fourth, we have made a point mutant in the F protein that eliminates the absolute requirement for HN protein in syncytia formation, a finding that raises questions about the role of HN protein attachment in fusion. To address the questions raised by these findings we propose four specific aims: 1) characterize interactions between specific domains of the HN protein and F protein, 2) characterize conformational changes in the F protein related to HN protein expression and F protein cleavage, 3) characterize conformational changes in the HN protein related to HN protein attachment and F protein expression and cleavage. 4) explore the role of attachment in initiation of fusion.