Department of Microbiology & Immunology, Stanford University SOM, Stanford, California, United Sates of America.
Stanford ChEM-H, Stanford, California, United States of America.
PLoS Pathog. 2022 Apr 28;18(4):e1010163. doi: 10.1371/journal.ppat.1010163. eCollection 2022 Apr.
Arthropod-borne viruses infect both mosquito and mammalian hosts. While much is known about virus-host interactions that modulate viral gene expression in their mammalian host, much less is known about the interactions that involve inhibition, subversion or avoidance strategies in the mosquito host. A novel RNA-Protein interaction detection assay was used to detect proteins that directly or indirectly bind to dengue viral genomes in infected mosquito cells. Membrane-associated mosquito proteins Sec61A1 and Loquacious (Loqs) were found to be in complex with the viral RNA. Depletion analysis demonstrated that both Sec61A1 and Loqs have pro-viral functions in the dengue viral infectious cycle. Co-localization and pull-down assays showed that Loqs interacts with viral protein NS3 and both full-length and subgenomic viral RNAs. While Loqs coats the entire positive-stranded viral RNA, it binds selectively to the 3' end of the negative-strand of the viral genome. In-depth analyses showed that the absence of Loqs did not affect translation or turnover of the viral RNA but modulated viral replication. Loqs also displayed pro-viral functions for several flaviviruses in infected mosquito cells, suggesting a conserved role for Loqs in flavivirus-infected mosquito cells.
节肢动物传播的病毒感染蚊子和哺乳动物宿主。虽然人们对调节其哺乳动物宿主中病毒基因表达的病毒-宿主相互作用了解很多，但对涉及蚊子宿主中抑制、颠覆或回避策略的相互作用知之甚少。使用一种新型的 RNA-蛋白相互作用检测分析来检测在感染蚊子细胞中直接或间接与登革热病毒基因组结合的蛋白。发现膜相关的蚊子蛋白 Sec61A1 和喋喋不休（Loqs）与病毒 RNA 形成复合物。耗尽分析表明，Sec61A1 和 Loqs 都在登革热病毒感染周期中具有促进病毒的功能。共定位和下拉实验表明，Loqs 与病毒蛋白 NS3 以及全长和亚基因组病毒 RNA 相互作用。虽然 Loqs 包裹整个正链病毒 RNA，但它选择性地结合病毒基因组负链的 3' 端。深入分析表明，Loqs 的缺失不影响病毒 RNA 的翻译或周转，但调节病毒复制。Loqs 在感染蚊子细胞的几种黄病毒中也显示出促进病毒的功能，这表明 Loqs 在黄病毒感染的蚊子细胞中具有保守作用。
