猪流行性腹泻病毒S蛋白诱导内质网应激的研究

Spike protein of porcine epidemic diarrhea virus mediates virus induced endoplasmic reticulum stress

内质网应激(ERS)在病毒感染中发挥着重要作用,S蛋白是猪流行性腹泻病毒(PEDV)最大的结构蛋白,在病毒感染过程中最有可能诱导ERS。为探究PEDV S蛋白是否诱导ERS和激活非折叠蛋白反应,本研究构建了PEDV S蛋白全长的重组真核表达载体pcDNA-S,将其通过脂质体转染Vero-E6细胞检测ERS标志蛋白和相关信号通路的变化情况。结果表明,S蛋白诱导了ERS标志蛋白Grp78的表达增加并且二者之间具有共定位,进一步研究显示其主要激活非折叠蛋白反应的PERK通路,药物Salubrinal特异性增强PERK通路后抑制了病毒的复制。本研究揭示PEDV S蛋白在病毒感染诱导的ERS中具有重要作用,将有助于深入了解PEDV致病的分子机制。

The endoplasmic reticulum stress(ERS)plays an important role in viral infection.The spike protein (S)of porcine epidemic diarrhea virus (PEDV)is the largest structural protein and is most likely to induce ERS.To investigate whether the S protein of PEDV induces ERS and activates the unfolded protein response (UPR),the pcDNA-S recombinant plasmid was constructed and transfected into Vero-E6cells by cationic liposome method.Biomarkers of ERS and activation of the UPR were detected,respectively.The results showed that S protein increased the expression of ERS marker protein Grp78and was colocalized with Grp78protein.We also found that S protein mainly activated the PERK signaling pathway of UPR and the activated PERK pathway suppressed PEDV replication in turn.In conclusion,These data suggested that S protein played an important role for activation of ERS in PEDV infected cells and would be very useful in understanding the molecular mechanisms responsible for PEDV pathogenesis.