Foot-and-Mouth Disease Virus Capsid Protein VP2 Activates the Cellular EIF2S1-ATF4 Pathway and Induces Autophagy via HSPB1
Microbiology and Immunology
Foot-and-mouth disease virus (FMDV) can result in economical destruction of cloven-hoofed animals. FMDV infection has been reported to induce macroautophagy/autophagy; however, the precise molecular mechanisms of autophagy induction and effect of FMDV capsid protein on autophagy remain unknown. In the present study, we report that FMDV infection induced a complete autophagy process in the natural host cells of FMDV, and inhibition of autophagy significantly decreased FMDV production, suggesting that FMDV-induced autophagy facilitates viral replication. We found that the EIF2S1-ATF4 pathway was activated and the AKT-MTOR signaling pathway was inhibited by FMDV infection. We also observed that ultraviolet (UV)-inactivated FMDV can induce autophagy. Importantly, our work provides the first piece of evidence that expression of FMDV capsid protein VP2 can induce autophagy through the EIF2S1-ATF4-AKT-MTOR cascade, and we found that VP2 interacted with HSPB1 (heat shock protein family B [small] member 1) and activated the EIF2S1-ATF4 pathway, resulting in autophagy and enhanced FMDV replication. In addition, we show that VP2 induced autophagy in a variety of mammalian cell lines and decreased aggregates of a model mutant HTT (huntingtin) polyglutamine expansion protein (HTT103Q). Overall, our results demonstrate that FMDV capsid protein VP2 induces autophagy through interaction with HSPB1 and activation of the EIF2S1-ATF4 pathway.
Sun, P., Zhang, S., Qin, X., Chang, X., Cui, X., Li, H., Zhang, S., Gao, H., Wang, P., Zhang, Z., Luo, J., & Li, Z. (2018). Foot-and-Mouth Disease Virus Capsid Protein VP2 Activates the Cellular EIF2S1-ATF4 Pathway and Induces Autophagy via HSPB1. Autophagy, 14 (2), 336-346. https://doi.org/10.1080/15548627.2017.1405187