Heat shock protein 90ß in the Vero cell membrane binds Japanese encephalitis virus

Wang, Yuan; Li, Yan; Ding, Tianbing

To inititiate JEV pathogenesis, the JEV E protein and the cellular receptor on the surface of susceptible cells form an initial interaction (20) (21) (22) (23) (24) . Therefore, determining the cellular receptor is a prerequisite for future investigations into precise molecular events involved in JEV binding and entry into cells, which has always been an intriguing basic virology field. Research has advanced over the past few decades. Early in 1994, researchers discovered that a 74 kDa molecule from Vero (African green monkey kidney) cells can bind JEV without further characterization (20) . Later, researchers found that a 57 kDa protein from BHK-21 (baby hamster kidney) cells (21) and a GAG protein in Chinese hamster ovary (CHO) cells (22) may be involved in JEV attachment or entry. In previous studies from our laboratory, we generated several pieces of evidence and, thus, hypothesised that heat shock cognate protein 70 (HSC70) may act as a JEV binding receptor on mosquito C6/36 cells (23) . It has been reported that heat shock protein (HSP)70, which is present in the membrane fraction from mouse neuroblastoma cells (Neuro2a), is the putative receptor for JEV (24) . In addition, using a mouse microglial cell line, researchers have demonstrated that the extracellular matrix protein, laminin, and several other candidate receptor molecules, including HSP70, HSP90, GRP78, CD14 and CD4, are involved in JEV entry (25) . Nevertheless, these studies are limited to rodent or mosquito cells, and the interacting cellular proteins from human or at least primate cells are necessary to elucidate the functional role of E protein with interacting cellular proteins. Herein, we discovered that HSP90β in the monkey cell (Vero) membrane binds JEV particles.