PDF(Pubmed)
Abstract：
Multi-segmented viruses often multimerize their genomic segments to ensure efficient and stoichiometric packaging of the correct genetic cargo. In the bipartite Nodaviridae family, genome heterodimerization is also observed and conserved among different species. However, the nucleotide composition and biological function for this heterodimer remain unclear. Using Flock House virus as a model system, we developed a next-generation sequencing approach (\"XL-ClickSeq\") to probe heterodimer site sequences. We identified an intermolecular base-pairing site which contributed to heterodimerization in both wild-type and defective virus particles. Mutagenic disruption of this heterodimer site exhibited significant deficiencies in genome packaging and encapsidation specificity to viral genomic RNAs. Furthermore, the disruption of this intermolecular interaction directly impacts the thermostability of the mature virions. These results demonstrate that the intermolecular RNA-RNA interactions within the encapsidated genome of an RNA virus have an important role on virus particle integrity and thus may impact its transmission to a new host.IMPORTANCEFlock House virus is a member of Nodaviridae family of viruses, which provides a well-studied model virus for non-enveloped RNA virus assembly, cell entry, and replication. The Flock House virus genome consists of two separate RNA molecules, which can form a heterodimer upon heating of virus particles. Although similar RNA dimerization is utilized by other viruses (such as retroviruses) as a packaging mechanism and is conserved among Nodaviruses, the role of heterodimerization in the Nodavirus replication cycle is unclear. In this research, we identified the RNA sequences contributing to Flock House virus genome heterodimerization and discovered that such RNA-RNA interaction plays an essential role in virus packaging efficiency and particle integrity. This provides significant insight into how the interaction of packaged viral RNA may have a broader impact on the structural and functional properties of virus particles.
摘要：
多节段病毒通常将其基因组片段多聚化，以确保正确的遗传货物的有效和化学计量包装。在二部Nodaviridae家族中，基因组异源二聚化在不同物种之间也被观察到和保守。然而,该异源二聚体的核苷酸组成和生物学功能尚不清楚。使用FlockHouse病毒作为模型系统，我们开发了一种下一代测序方法（“XL-ClickSeq”）来探测异源二聚体位点序列。我们确定了一个分子间碱基配对位点，该位点有助于野生型和缺陷病毒颗粒中的异二聚体化。该异二聚体位点的诱变破坏在基因组包装和对病毒基因组RNA的衣壳化特异性方面表现出明显的缺陷。此外，这种分子间相互作用的破坏直接影响成熟病毒体的热稳定性。这些结果表明，RNA病毒衣壳化基因组内的分子间RNA-RNA相互作用对病毒颗粒的完整性具有重要作用，因此可能影响其传播到新宿主。IMPORTANCEFlockHouse病毒是Nodaviridae病毒家族的成员，它为无包膜RNA病毒组装提供了一个经过充分研究的模型病毒，细胞输入,和复制。FlockHouse病毒基因组由两个独立的RNA分子组成，在加热病毒颗粒时可以形成异二聚体。尽管其他病毒（如逆转录病毒）利用类似的RNA二聚化作为包装机制，并且在诺达病毒之间是保守的，异二聚化在诺达病毒复制周期中的作用尚不清楚.在这项研究中,我们鉴定了有助于FlockHouse病毒基因组异源二聚化的RNA序列,并发现这种RNA-RNA相互作用在病毒包装效率和颗粒完整性中起着至关重要的作用.这提供了对包装的病毒RNA的相互作用如何对病毒颗粒的结构和功能特性具有更广泛影响的重要见解。
