Membrane trafficking RNA interference screen identifies a crucial role of the clathrin endocytic pathway and ARP2/3 complex for Japanese encephalitis virus infection in HeLa cells.

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is one of the leading global causes of virus-induced encephalitis. The infectious life-cycle of viruses is heavily dependent on the host membrane trafficking network. Here, we have performed a RNA-interference-based screen using a siRNA panel targeting 136 membrane trafficking proteins to identify the key regulators of JEV infection in HeLa cells. We identified 35 proteins whose siRNA depletion restricts JEV replication by over twofold. We observe that JEV infection in HeLa cells is largely dependent on components of the clathrin-mediated endocytic (CME) pathway. Proteins involved in actin-filament-based processes, specifically CDC42 and members of the ARP2/3 complex are crucial for establishment of infection. Pharmacological pertubations of actin polymerization, a small molecule inhibitor of actin nucleation by the ARP2/3 complex - CK-548 - and the inhibitor of neural Wiskott-Aldrich syndrome proteins- Wiskostatin- inhibited JEV replication, highlighting the important role of the dynamic actin network. Other proteins involved in cargo-recognition for CME and endomembrane system organization were also validated as essential host factors for virus replication.