Molecular identification and function characterization of four alternative splice variants of trim25 in Japanese...

Area of Science:

• * Molecular Biology
• * Immunology
• * Aquaculture

Background:

• * Tripartite Motif containing 25 (Trim25) is a key regulator of innate antiviral immunity, known to activate RIG-I.
• * Alternative splicing (AS) generates diverse protein isoforms with potentially distinct functions.
• * Understanding Trim25's AS variants is crucial for fish antiviral defense mechanisms.

Purpose of the Study:

• * To investigate the alternative splicing variants (X1-X4) of Japanese flounder trim25.
• * To analyze the expression patterns and subcellular localization of these variants.
• * To elucidate the role of trim25 AS variants in modulating the RIG-I signaling pathway and innate immunity in Japanese flounder.

Main Methods:

• * Identification and sequencing of four alternative splicing variants (X1-X4) of Japanese flounder trim25.
• * In vitro and in vivo expression analysis following poly I:C stimulation.
• * Subcellular localization studies and overexpression experiments in flounder cells.
• * Quantitative PCR to analyze the expression of RIG-I pathway genes (dhx58, traf6, traf2, nfkbia, il-8).

Main Results:

• * The four AS variants (X1-X4) of Japanese flounder trim25 showed high sequence conservation.
• * Expression of trim25 X1-X4 variants was significantly upregulated in vitro and in vivo after poly I:C treatment.
• * Trim25 X1-X4 variants exhibited distinct subcellular localizations.
• * Overexpression of trim25 variants and poly I:C treatment modulated the expression of key RIG-I pathway genes.

Conclusions:

• * Alternative splicing of trim25 generates functionally distinct variants in Japanese flounder.
• * These AS variants play a significant role in conferring antiviral activity by modulating the innate immune response.
• * The findings contribute to understanding fish antiviral mechanisms and potential applications in aquaculture.