PLoS Pathogens (Apr 2022)

Loquacious modulates flaviviral RNA replication in mosquito cells.

  • Shwetha Shivaprasad,
  • Kuo-Feng Weng,
  • Yaw Shin Ooi,
  • Julia Belk,
  • Jan E Carette,
  • Ryan Flynn,
  • Peter Sarnow

DOI
https://doi.org/10.1371/journal.ppat.1010163
Journal volume & issue
Vol. 18, no. 4
p. e1010163

Abstract

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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.