Identification and characterization of 16 tripartite motif-containing proteins from Takifugu obscurus

Tripartite motif-containing (TRIM) proteins play important roles in apoptosis, development, autophagy, and innate immunity in vertebrates. In this study, a total of 16 TRIM genes were cloned and identified from obscure puffer Takifugu obscurus. Multiple alignment results showed that most of the deduced ToTRIM proteins contained three typical motifs, a really interesting new gene (RING) zinc-finger domain, one B-box, and a coiled-coil domain, which together formed the TRIM motif found in this large family of proteins. The carboxyl terminus of ToTRIMs is architecturally unique, with frequent examples being the ADP ribosylation factor-like domain, the B30.2 (PRY-SPRY) domain, the fibronectin type III domain, and the pleckstrin homology domain. Phylogenetic analysis revealed that 16 ToTRIMs were evolutionarily closely related to their counterparts in other selected vertebrates. Tissue distribution analysis showed that the mRNA transcripts of most ToTRIM genes were constitutively expressed in all tissues examined, with relatively high expression in immune tissues. After infection with Vibrio harveyi, the expression levels of 16 ToTRIM genes in the kidney and liver were significantly upregulated, and their responses over time varied. Taken together, our results suggested that ToTRIM genes are involved in the antibacterial immune responses of T. obscurus, which is expected to provide new insights into the functional characteristics of TRIMs in teleost fish.