Takizawa Naoki, Higashi Koichi, Kawaguchi Risa Karakida, Gotoh Yasuhiro, Hayashi Tetsuya, Kurokawa Ken
Laboratory of Virology, Institute of Microbial Chemistry (BIKAKEN), Tokyo, Japan.
Genome Evolution Laboratory, National Institute of Genetics, Mishima, Japan.
iScience. 2025 Sep 22;28(10):113606. doi: 10.1016/j.isci.2025.113606. eCollection 2025 Oct 17.
The influenza A virus genome consists of eight RNA segments; each incorporated into a virion. It has been proposed that intersegment interactions bundle these segments, and viral inclusions, which contain viral ribonucleoproteins (vRNPs) and Rab11, facilitate this process. However, the spatial and mechanistic dynamics of intersegment interactions remain unclear. To investigate this, we identified comprehensive intersegment interactions in infected cells using the customized ligation of interacting RNA and high-throughput sequencing (LIGR-seq). We found that intersegment interactions overlapping with those in virions were present under viral inclusion-promoting conditions. In contrast, such interactions were diminished in the absence of viral inclusions. Moreover, artificially increasing vRNP concentrations in the nucleus, where intersegment interactions typically do not occur, induced intersegment interaction patterns resembling those in virions. These findings suggest that intersegment interaction networks form in a vRNP concentration-dependent manner within viral inclusions, providing a spatiotemporal basis for segment bundling.
甲型流感病毒基因组由八个RNA片段组成；每个片段都整合到一个病毒粒子中。有人提出，片段间相互作用将这些片段聚集在一起，而含有病毒核糖核蛋白（vRNP）和Rab11的病毒内含物促进了这一过程。然而，片段间相互作用的空间和机制动力学仍不清楚。为了研究这一点，我们使用定制的相互作用RNA连接和高通量测序（LIGR-seq）在受感染细胞中鉴定了全面的片段间相互作用。我们发现，在促进病毒内含物形成的条件下，存在与病毒粒子中重叠的片段间相互作用。相比之下，在没有病毒内含物的情况下，这种相互作用会减弱。此外，在通常不会发生片段间相互作用的细胞核中人为增加vRNP浓度，会诱导出类似于病毒粒子中的片段间相互作用模式。这些发现表明，片段间相互作用网络在病毒内含物中以vRNP浓度依赖的方式形成，为片段聚集提供了时空基础。
