Measles Virus Forms Inclusion Bodies with Properties of Liquid Organelles
Measles Virus Forms Inclusion Bodies with Properties of Liquid Organelles
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DOI：
10.1128/jvi.00948-19
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发表时间：
2019-08
影响因子：
5.4
通讯作者：
Yu-Qin Zhou;Justin M Su;C. E. Samuel;Dzwokai Ma
中科院分区：
文献类型：
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作者：
Yu-Qin Zhou;Justin M Su;C. E. Samuel;Dzwokai Ma
麻疹病毒仍然是全球严重关切的病原体。尽管有有效的疫苗，但疫情仍在继续发生，全球每年有10万人死于麻疹。了解影响病毒复制效率的病毒-宿主相互作用的分子基础对于进一步开发预防和治疗策略至关重要。麻疹病毒复制发生在细胞质中与离散体，虽然很少知道的包涵体结构的性质。我们最近确定，细胞蛋白WD重复包含蛋白5（WDR 5）增强MeV的增长，并在细胞质病毒包涵体，包括负责RNA复制的病毒蛋白富集。在这里，我们表明，MeV的N和P蛋白足以触发形成的WDR 5包含的包涵体，这些结构显示相分离的液体细胞器的特性，和P磷酸化与主机动力蛋白电机一起影响的液-液相分离过程的效率。摘要非分节段负链RNA病毒，包括副粘病毒科成员麻疹病毒（MeV），被认为在胞质包涵体中复制。这些细胞质病毒工厂不是膜结合的，它们用于集中病毒RNA复制机制。虽然包涵体是一个突出的特点，在MeV感染的细胞，他们的生物起源和调节还没有得到很好的理解。在这里，我们表明，感染MeV触发包涵体形成通过液-液相分离（LLPS），一个过程的基础上形成无膜细胞器。我们发现，病毒的核蛋白（N）和磷蛋白（P）是足以触发MeV相分离，与病毒的N和P蛋白的C-末端结构域在相变中发挥关键作用。我们提供的证据表明，磷酸化的P和动力蛋白介导的运输促进这些细胞器的生长，这意味着他们可能有关键的调节作用，在生物物理组装过程中。此外，我们的研究结果支持了这样一种观点，即这些内含物在感染后随着时间的推移从液体变为凝胶状结构，这使得这些细胞器的动力学在感染过程中可以调整，以最佳地适应病毒复制周期中不断变化的需求。我们的研究为病毒包涵体工厂的形成过程提供了新的见解，并与早期的研究一起表明，单负基因病毒目已广泛进化为利用LLPS作为在感染细胞中组装细胞质复制工厂的常见策略。麻疹病毒仍然是全球关注的重要病原体。尽管有有效的疫苗，但疫情仍在继续发生，全球每年有10万人死于麻疹。了解影响病毒复制效率的病毒-宿主相互作用的分子基础对于进一步开发预防和治疗策略至关重要。麻疹病毒复制发生在细胞质中与离散体，虽然很少知道的包涵体结构的性质。我们最近确定，细胞蛋白WD重复包含蛋白5（WDR 5）增强MeV的增长，并在细胞质病毒包涵体，包括负责RNA复制的病毒蛋白富集。在这里，我们表明，MeV的N和P蛋白足以触发形成的WDR 5包含的包涵体，这些结构显示相分离的液体细胞器的特性，和P磷酸化与主机动力蛋白电机一起影响的液-液相分离过程的效率。
Measles virus remains a pathogen of significant global concern. Despite an effective vaccine, outbreaks continue to occur, and globally ∼100,000 measles-related deaths are seen annually. Understanding the molecular basis of virus-host interactions that impact the efficiency of virus replication is essential for the further development of prophylactic and therapeutic strategies. Measles virus replication occurs in the cytoplasm in association with discrete bodies, though little is known of the nature of the inclusion body structures. We recently established that the cellular protein WD repeat-containing protein 5 (WDR5) enhances MeV growth and is enriched in cytoplasmic viral inclusion bodies that include viral proteins responsible for RNA replication. Here, we show that MeV N and P proteins are sufficient to trigger the formation of WDR5-containing inclusion bodies, that these structures display properties characteristic of phase-separated liquid organelles, and that P phosphorylation together with the host dynein motor affect the efficiency of the liquid-liquid phase separation process. ABSTRACT Nonsegmented negative-strand RNA viruses, including measles virus (MeV), a member of the Paramyxoviridae family, are assumed to replicate in cytoplasmic inclusion bodies. These cytoplasmic viral factories are not membrane bound, and they serve to concentrate the viral RNA replication machinery. Although inclusion bodies are a prominent feature in MeV-infected cells, their biogenesis and regulation are not well understood. Here, we show that infection with MeV triggers inclusion body formation via liquid-liquid phase separation (LLPS), a process underlying the formation of membraneless organelles. We find that the viral nucleoprotein (N) and phosphoprotein (P) are sufficient to trigger MeV phase separation, with the C-terminal domains of the viral N and P proteins playing a critical role in the phase transition. We provide evidence suggesting that the phosphorylation of P and dynein-mediated transport facilitate the growth of these organelles, implying that they may have key regulatory roles in the biophysical assembly process. In addition, our findings support the notion that these inclusions change from liquid to gel-like structures as a function of time after infection, leaving open the intriguing possibility that the dynamics of these organelles can be tuned during infection to optimally suit the changing needs during the viral replication cycle. Our study provides novel insight into the process of formation of viral inclusion factories, and taken together with earlier studies, suggests that Mononegavirales have broadly evolved to utilize LLPS as a common strategy to assemble cytoplasmic replication factories in infected cells. IMPORTANCE Measles virus remains a pathogen of significant global concern. Despite an effective vaccine, outbreaks continue to occur, and globally ∼100,000 measles-related deaths are seen annually. Understanding the molecular basis of virus-host interactions that impact the efficiency of virus replication is essential for the further development of prophylactic and therapeutic strategies. Measles virus replication occurs in the cytoplasm in association with discrete bodies, though little is known of the nature of the inclusion body structures. We recently established that the cellular protein WD repeat-containing protein 5 (WDR5) enhances MeV growth and is enriched in cytoplasmic viral inclusion bodies that include viral proteins responsible for RNA replication. Here, we show that MeV N and P proteins are sufficient to trigger the formation of WDR5-containing inclusion bodies, that these structures display properties characteristic of phase-separated liquid organelles, and that P phosphorylation together with the host dynein motor affect the efficiency of the liquid-liquid phase separation process.