Nile tilapia TRIM39 recruits I3K413 and I3KL45 as adaptors and is involved in the NF‐κB pathway

Abstract

Tripartite motif (TRIM) proteins play a regulatory function in cancer, cell apoptosis and innate immunity. To understand the role of TRIM39 in Nile tilapia (Oreochromis niloticus), TRIM39 cDNA was isolated. The total length of TRIM39 cDNA was 5025 bp. The deduced OnTRIM39 protein contains 549 amino acids and has conserved domains of the TRIM family, which are the RING, B‐box, coiled‐coil and PRY‐SPRY domains. OnTRIM39 mRNA was widely expressed in various tissues. After challenge with Streptococcus agalactiae and stimulation with polyinosinic polycytidylic acid [poly (I:C)] and lipopolysaccharides (LPS), the amount of OnTRIM39 transcript was changed in various tested tissues. OnTRIM39 overexpression increased NF‐κB activity. OnTRIM39 was present in the cytoplasm. Mass spectrometry of proteins pulled down with recombinant OnTRIM39 showed that 250 proteins potentially interact with OnTRIM39. The authors selected I3K4I3 from the 250 candidate proteins to verify its interaction with TRIM39. They also selected I3KL45, a member of the same 14‐3‐3 protein family, to verify its interaction with TRIM39. The results of pull‐down assays showed that OnTRIM39 interacted with both I3K413 and I3KL45. These results contribute to further study of the innate immune mechanism of tilapia.

Characterization of two tripartite motif‐containing genes from Asian Seabass Lates calcarifer and their expression in response to virus infection and microbial molecular motifs

“…Similar results were obtained from Orange‐spotted Grouper TRIM39 (Wang et al 2016) and TRIM21 (Zheng et al 2022). The TRIM39 fusion protein in green fluorescent protein‐tagged Nile Tilapia Oreochromis niloticus was reported to be localized in the cytoplasm (Gao et al 2022).…”

“…Expression of LcTRIM39 was higher in blood, followed by muscle, head kidney, and liver. In Nile Tilapia, the expression of TRIM39 was relatively high in the spleen, head kidney, gills, heart, brain, and muscle (Gao et al 2022). The higher expression of immune‐relevant genes in the peripheral blood could be because the peripheral blood is constantly exposed to various pathogens.…”

“…A similar upregulation of TRIM39 ‐like gene btr20 in Zebrafish kidney and spleen was reported during Aeromonas hydrophila infection (van der Aa et al 2012). A high level of TRIM39 induction was observed in the spleen tissue of Nile Tilapia injected with Streptococcus and lipopolysaccharides (Gao et al 2022). The amplitude and kinetics of innate antiviral response and the production of type I IFN and interferon‐stimulated genes varies among the cell type, and the TRIM proteins participate in a regional variation of IFN response (Pulverer et al 2010).…”