Molecular identification and function characterization of four alternative splice variants of trim25 in Japanese flounder (Paralichthys olivaceus).

ABSTRACT

Trim25 is a member of Tripartite Motif (TRIM) family. Previous studies report that trim25 modulates antiviral activity by activating RIG-I. In this study we explored the four alternative splicing (AS) variants X1-X4 of Japanese flounder trim25. The sequences of the AS variants were highly conserved. Expression levels of trim25 X1-X4 were increased after 12 h of poly IC treatment in vitro. In vivo expression of X2-X4 in liver, kidney (except X2) and blood was significantly up-regulated in early stages of poly IC treatment. Subcellular localization analysis showed that Trim25 X1-X4 were distributed in different cellular organelles. The recombinant vector pcDNA3.1-Trim25 X1-X4 were successfully overexpressed in Flounder cells and the samples were collected. Expression patterns of RIG-I pathway genes dhx58, traf6, traf2, nfkbia and il-8 were explored in vitro and in vivo after poly IC treatment, as well as overexpressed samples. The findings of this study imply that AS variants of trim25 confer antiviral activity in Japanese flounder by modulating innate immune response.