Foot-and-mouth disease virus capsid protein VP2 activates the cellular EIF2S1-ATF4 pathway and induces autophagy via HSPB1

• Published in: Autophagy 2018-02, Vol.14 (2), p.336-346
• Main Authors: Sun, Peng, Zhang, Shumin, Qin, Xiaodong, Chang, Xingni, Cui, Xiaorui, Li, Haitao, Zhang, Shuaijun, Gao, Huanhuan, Wang, Penghua, Zhang, Zhidong, Luo, Jianxun, Li, Zhiyong
• Format: Article
• Language: English
• Subjects: Activating Transcription Factor 4 - metabolism; AKT; Animals; ATF4; Autophagy; Capsid Proteins - metabolism; Cell Line; EIF2S1; Eukaryotic Initiation Factor-2 - metabolism; FMDV; HSP27 Heat-Shock Proteins - genetics; HSP27 Heat-Shock Proteins - metabolism; HSPB1; Humans; Huntingtin Protein - metabolism; Mice; MTOR; Protein Aggregation, Pathological - metabolism; replication; Research Papers - Basic Science; Signal Transduction; Swine; TOR Serine-Threonine Kinases - metabolism; Virus Replication; VP2
• ISSN: 1554-8627; 1554-8635
• DOI: 10.1080/15548627.2017.1405187

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.