Many viruses are known to form cellular compartments, also called viral factories. Paramyxoviruses, including measles virus, colocalize their proteomic and genomic material in puncta in infected cells. We demonstrate that purified nucleoproteins (N) and phosphoproteins (P) of measles virus form liquid-like membraneless organelles upon mixing in vitro. We identify weak interactions involving intrinsically disordered domains of N and P that are implicated in this process, one of which is essential for phase separation. Fluorescence allows us to follow the modulation of the dynamics of N and P upon droplet formation, while NMR is used to investigate the thermodynamics of this process. RNA colocalizes to droplets, where it triggers assembly of N protomers into nucleocapsid-like particles that encapsidate the RNA. The rate of encapsidation within droplets is enhanced compared to the dilute phase, revealing one of the roles of liquid-liquid phase separation in measles virus replication.

中文翻译：

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麻疹病毒的核蛋白和磷蛋白形成液体状相分离的区室，促进了核衣壳的组装。

已知许多病毒会形成细胞区室，也称为病毒工厂。副粘病毒，包括麻疹病毒，将它们的蛋白质组和基因组物质共定位在感染细胞的点状体内。我们证明，在体外混合后，麻疹病毒的纯化核蛋白（N）和磷蛋白（P）形成液体样无膜细胞器。我们发现弱相互作用涉及此过程中牵涉的N和P的内在无序域，其中一个是相分离必不可少的。荧光使我们能够跟随液滴形成过程中N和P动力学的调节，而NMR用于研究该过程的热力学。RNA共定位到液滴上，在那里它触发N个启动子装配成核壳样颗粒，包裹了RNA。