SDS-PAGE (A) and Western blotting (B) results of the glutathione-S-transferase (GST) pulldown assay and CO-IP assay. The GST-S1 and His-UBXN1 fusion proteins were used in the GST pulldown assay to verify the interaction between S1 and UBXN1. Lanes 1 and 4: result of S1 and UBXN1 pulldown; lanes 2 and 5: His-UBXN1 fusion protein (42 kDa); lanes 3 and 6: GST-S1 fusion protein (97 kDa) and GST tag blank control (20 kDa). C Co-IP assay for the interaction between S1 and UBXN1 in vivo. IPEC-J2 cells were infected with TGEV Miller for 36 h and were then subjected to a Co-IP assay. The coimmunoprecipitated proteins were detected by SDS-PAGE (left) and Western blotting (right). +: virus-infected group; −: normal group.