Arbovirus-vector protein interactomics identifies Loquacious as a co-factor for dengue virus replication in Aedes mosquitoes

• Published in: PLoS pathogens 2022-09, Vol.18 (9), p.e1010329
• Main Authors: Besson, Benoit, Lezcano, Oscar M, Overheul, Gijs J, Janssen, Kirsten, Spruijt, Cornelia G, Vermeulen, Michiel, Qu, Jieqiong, van Rij, Ronald P
• Format: Article
• Language: English
• Subjects: 3' Untranslated Regions; Aedes; Animals; Annotations; Arboviruses; Arboviruses - genetics; Biology and life sciences; Culicidae; Dengue; Dengue fever; Dengue Virus - genetics; Dengue viruses; Disease transmission; Double-stranded RNA; Gene expression; Genetic aspects; Genetic vectors; Genomes; Health aspects; Human populations; Humans; Interactomes; Intermediates; Mammals; Mass spectrometry; Mass spectroscopy; Medicine and Health Sciences; MicroRNAs; Mosquito Vectors; Mosquitoes; Oligosaccharyltransferase; Protein interaction; Proteins; Replication; Research and Analysis Methods; RNA polymerase; RNA, Double-Stranded - metabolism; RNA-mediated interference; Scientific imaging; Structural proteins; Vector-borne diseases; Vertebrates; Viral infections; Virus Replication - genetics; Viruses; Zika Virus - genetics; Zika Virus Infection
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1010329

Efficient virus replication in Aedes vector mosquitoes is essential for the transmission of arboviral diseases such as dengue virus (DENV) in human populations. Like in vertebrates, virus-host protein-protein interactions are essential for viral replication and immune evasion in the mosquito vector. Here, 79 mosquito host proteins interacting with DENV non-structural proteins NS1 and NS5 were identified by label-free mass spectrometry, followed by a functional screening. We confirmed interactions with host factors previously observed in mammals, such as the oligosaccharyltransferase complex, and we identified protein-protein interactions that seem to be specific for mosquitoes. Among the interactors, the double-stranded RNA (dsRNA) binding protein Loquacious (Loqs), an RNA interference (RNAi) cofactor, was found to be essential for efficient replication of DENV and Zika virus (ZIKV) in mosquito cells. Loqs did not affect viral RNA stability or translation of a DENV replicon and its proviral activity was independent of its RNAi regulatory activity. Interestingly, Loqs colocalized with DENV dsRNA replication intermediates in infected cells and directly interacted with high affinity with DENV RNA in the 3' untranslated region in vitro (KD = 48-62 nM). Our study provides an interactome for DENV NS1 and NS5 and identifies Loqs as a key proviral host factor in mosquitoes. We propose that DENV hijacks a factor of the RNAi mechanism for replication of its own RNA.