Characterization of TRIM16, a member of the fish-specific finTRIM family, in olive flounder Paralichthys olivaceus

Tripartite motif-containing (TRIM) proteins are conserved throughout the metazoan kingdom, and the TRIM subset finTRIM is highly diversified in fish. We isolated TRIM16 cDNA, a member of the finTRIM family, from the olive flounder Paralichthys olivaceus (PoTRIM16). PoTRIM16 contained a 1,725-bp coding sequence encoding a 574-amino acid polypeptide, which in turn contained a really interesting new gene (RING) finger domain, B-box-type zinc finger (B-BOX), nuclease SbcCD subunit C (SbcC), structural maintenance of chromosome (SMC prok B), and stonustoxin (SNTX) subunit alpha (SPRY-PRY-SNTX). Multiple alignment of related sequences revealed that PoTRIM16 showed 86.63-97.40% identity with fish orthologues, and a phylogenetic tree was constructed of vertebrates. PoTRIM16 mRNA was detected in all tissues examined; levels were highest in the eye and ovary. PoTRIM16 mRNA expression was investigated during early development. Under VHSV infection, PoTRIM16 mRNA was downregulated in the liver of P. olivaceus. This is the first study to characterize fish-specific finTRIM in P. olivaceus, which may play a role in the immune response against virus infection.