Table 1.
The functions of PEDV viral proteins.
| PEDV Proteins | The Biological Processes Involved | References |
|---|---|---|
| S (S1 and S2) | receptor binding and subsequent membrane fusion; replication cycle and propagation; cell apoptosis induction | [48,49,50,128] |
| N | viral replication, transcription, and assembly; extension of S-phase of cell cycle; endoplasmic reticulum (ER) stress formation; innate immunity antagonist; interaction with host protein NPM1 | [44,56,57,129] |
| M | virion assembly and virus budding; induction of PEDV neutralizing antibodies; cell growth retardation in S-phase; IFN antagonist with unknown mechanism | [62,63,64,65] |
| E | virus packaging and budding; stimulation of ER stress and activation of NF-κB pathway | [66,67] |
| ORF3 | detention of cells at S-phase; facilitating vesicle formation; promoting PEDV replication | [69,70] |
| nsp1 | type I IFNs and type III IFN antagonists; inducing the degradation of CBP; suppression of phosphorylation and degradation of IκBα, as well as p65 nuclear translocation; blocking nuclear translocation of IRF1 | [65,78,130] |
| nsp2 | Unknown | |
| nsp3,4,6 | nsp3, 4, and 6 are all involved in viral replication process; nsp3 also acts as a viral deubiquitinase (DUB) that deubiquitinates RIG-I and STING and negatively regulates type I IFN signaling | [80,94,99] |
| nsp5 | 3CLpro; processing replicase polyprotein during virus replication; blocking host innate immune responses by cleavage of NF-κB essential modulator (NEMO) | [99] |
| nsp7–10 | Nsp7 is an IFN antagonist; nsp8 inhibits type III IFN response; nsp9 is involved in nucleic acid binding; nsp10 enhances the inhibitory effect of nsp16 on IFN-β production. | [65,131,132,133] |
| nsp12 | encoding a RdRp; viral replication | [134] |
| nsp13 | a NTPase/helicase that is essential for viral replication | [111] |
| nsp14 | N-7-MTase; catalyzing N7-methylation of Gppp-RNA to form a cap-0 structure; 3′-5′ exoribonuclease activity involves in a replicative mismatch repair system during RNA synthesis; IFN antagonist | [42,65,112,113,119,133] |
| nsp15 | EndoU; IFN antagonist; inhibition of the type I IFN and the type III IFN responses | [114,115,116,135] |
| nsp16 | 2′-O-MTase that catalyzes methylation of the 5’ cap; IFN antagonist | [112,123,124,125,126,132] |