JEV helicase targets host MTOC and participates in the organization of pericentriolar viroplasm

Flaviviruses contribute significantly to the global disease burden and are known to remodel host organelles to their advantage. Centrosomal microtubule-organizing centres (MTOCs) having established role in cell division and signalling are also targeted by viruses. However, it remains uncertain whether they act as bystanders or actively engage in viral processes. Here, we elucidate the centrosome and cytoskeletal involvement during Japanese Encephalitis Virus (JEV) infection. Our virus-free expression studies revealed a centrosome-targeting region within the C-terminal helicase domain that mediates the association of JEV-NS3 with host MTOCs. When expressed exogenously, JEV-NS3 formed pericentriolar aggresomes resembling the helicase-containing viroplasm distribution pattern of infected cells. These pericentriolar viroplasm appears in the non-neuronal cell types with centriolar consequences while the neuronal cell types fail to show such phenotypes. Centriole depletion assays revealed the proviral role of centrosome, where the viroplasm organization depends on centrosomal MTOCs, and vimentin cages. Additionally, microtubule disruption and dynarrestin blockade assays emphasized the roles of microtubules and dynein in concentrating NS3-containing vesicular packets towards centrosomes, highlighting the centrosome-cytoskeleton axis as a potential target for intervention.