Chicken TRIM25 protein promotes host antiviral innate immune response to avian influenza virus in chicken fibroblast cells

TRIM family proteins play an important role in antiviral innate immunity. However, the function of chicken TRIM25 (chTRIM25) protein remains unclear. In this study, we cloned the full-length of chTRIM25 gene and analyzed its function. Sequence analysis revealed that chicken TRIM25 contained a 1902-bp open-reading frame that probably encodes a 633-amino acid protein with a molecular weight of 71.42 kD. Structural analysis demonstrated that the chTRIM25 protein had a RING finger domain (amino acids 21–66), B-box1 (amino acids 110–146), B-box2 (amino acids 160–189), a coiled-coil region (amino acids 208–311) and B30.2 domain (amino acids 465–633). The homology analysis showed that the amino acid sequence homology of chicken TRIM25 with duck and goose TRIM25 was from 74% to 77%, while the amino acid sequence homology of chicken TRIM25 with human and mouse TRIM25 was about 46%. We further found that chTRIM25 promoted type I interferon-mediated immune response to avian influenza virus in chicken fibroblast cells. This study will help us to further understand the host antiviral innate immune response to avian influenza virus in chickens.