Heat shock protein 70 on Neuro2a cells is a putative receptor for Japanese encephalitis virus

Abstract

Japanese encephalitis virus (JEV) envelope (E) protein has been shown to play a critical role in attachment to cells. However, the receptor interacting with envelope protein has not been conclusively identified. Using mouse neuroblastoma (Neuro2a) cells and purified JEV-E protein in ‘Virus Overlay Protein Binding Assay’ followed by MALDI-TOF analysis, we identified ‘heat shock protein 70’ (Hsp70) as a possible receptor for JEV. Indirect immunofluorescence and flow-cytometry analysis demonstrated localization of Hsp70 on Neuro2a cell surface. Co-immunoprecipitation followed by Western blot analysis reconfirmed the interaction between Hsp70 and JEV-E protein. Further, anti-Hsp70 polyclonal-antibodies were able to block JEV entry into Neuro2a cells. Additionally, using the bioinformatic tool — FTDOCK, docking between the proteins was performed. Amongst six interacting structural poses studied one pose involving RGD motif on JEV-E and leucine 539 on Hsp70 displayed stable interaction. These observations indicate that Hsp70 serves as putative receptor for JEV in Neuro2A cells.