Mechanistic studies of M and NP interactions of paramyxoviruses

与其他包膜病毒一样，副粘病毒可在细胞间和宿主之间传播感染。 以粒子的形式从受感染的细胞膜中萌发形成。副粘病毒基质 (M)蛋白质组织组装过程，将病毒糖蛋白和病毒连接在一起 核糖核蛋白(VRNPs)。M蛋白和核衣壳(NP)蛋白的相互作用是驱动因素 主动将vRNPs结合到病毒粒子中的力量，因此对 NsRNA病毒颗粒的传染性。 在这里，我们建议研究驱动vRNPs包装的副粘病毒M蛋白相互作用 变成了粒子。我们的第一个目标是操纵和抑制副粘病毒基因组包装的相互作用 以核衣壳蛋白为目标。我们将尝试实现对M-NP相互作用的竞争性抑制 使用外来蛋白质和多肽，它们通过相同的相互作用并入萌芽颗粒中 通常将vRNPs导向病毒粒子。我们还提出了一系列实验来定义参数， 控制副粘病毒之间的M-NP相互作用。 我们的第二个目标是通过靶向来定义和操纵副粘病毒基因组包装相互作用 基质蛋白。在第二位点突变和最近确定的M蛋白结构的指导下，我们 定义了可增强与NP相互作用的PIV5 M突变。增强的M-NP的后果 将使用微型基因组分析评估在转基因细胞中的相互作用，并在 重组病毒。我们假设在wt病毒中M-NP相互作用强度是谨慎平衡的。M-NP 太强的相互作用将有利于病毒组装，但也会导致不适当的M- 在感染的早期阶段结合vRNPs，从而损害病毒转录和/或基因组 复制。我们还将为M上的两个不同的第二位点突变簇定义单独的角色 蛋白质表面，假设C-末端表面间接影响病毒组装和NP 通过与宿主因子的相互作用而结合。

Like other enveloped viruses, paramyxoviruses spread infections from cell to cell and from host to host in the form of particles which are formed by budding from infected cell membranes. Paramyxovirus matrix (M) proteins organize the assembly process, linking together the viral glycoproteins and the viral ribonucleoproteins (vRNPs). Interactions between M proteins and nucleocapsid (NP) proteins are the driving force for active incorporation of vRNPs into virions, and hence are fundamentally important for the infectivity of nsRNA virus particles. Here, we propose to investigate paramyxovirus M protein interactions that drive the packaging of vRNPs into particles. Our first aim is to manipulate and inhibit paramyxovirus genome packaging interactions by targeting the nucleocapsid proteins. We will attempt to achieve competitive inhibition of M-NP interactions using foreign proteins and peptides that incorporate into budding particles using the same interactions that normally direct vRNPs into virions. We also propose a series of experiments to define parameters that govern M-NP interactions among the paramyxoviruses. Our second aim is to define and manipulate paramyxovirus genome packaging interactions by targeting the matrix proteins. Guided by second-site mutations and the recently-determined M protein structure, we have defined PIV5 M mutations that enhance interactions with NP. Consequences of enhanced M-NP interaction will be assessed both in transfected cells using mini-genome assays and in the context of recombinant virus. We hypothesize that M-NP interaction strength in wt virus is carefully balanced. M-NP interaction that is too strong will benefit virus assembly, but will also lead to inappropriate generation of M- bound vRNPs during the early phases of infection, thereby impairing viral transcription and/or genome replication. We will also define individual roles for two distinct clusters of second-site mutations on the M protein surface, with the hypothesis that the C-terminal surface indirectly influences virus assembly and NP binding through interactions with host factors.