The network interactions between the porcine deltacoronavirus nucleocapsid protein and host cellular proteins.

Porcine deltacoronavirus (PDCoV) is an emerging swine coronavirus that can cause diarrhea in pigs of all ages with varying severity. Host-virus protein interactions are critical for intracellular viral replication. Elucidating the interactions between cellular and viral proteins can help us to design antiviral strategies. PDCoV N protein is the most abundant and vital regulator in virus replication. In this study, 604 host proteins were identified to interact with PDCoV N protein by Co-IP combined with LC-MS, of which 243 proteins were specifically bound to N protein. PPI analysis revealed that the N-interacting host proteins are categorized into three groups: ribonucleoprotein complex biogenesis modulation, cellular nitrogen compound metabolism, and nucleic acid binding. GO and KEGG analyses showed that the host proteins are primarily involved in mRNA splicing, stress granule assembly, spliceosomal snRNP assembly. Additionally, four host proteins-TRIM25, HNRNPUL1, RPS27A, and SLC3A2-were selected to validate the interactome data through Co-IP and Confocal assays. This study can help in designing anti-PDCoV strategies and understanding the replication mechanism of PDCoV.