Animal defence toward viruses are distinct compared to the bacterial or other pathogenic defences. Understanding of molecular mechanisms behind these defence mechanisms holds paramount importance when improving solutions for the virus diseases. This study describes the transcription factor Akirin-2 and its involvement in the virus defence which was identified from the ornamental fish Amphiprion clarkii. An immune challenge was conducted to disclose potential immune stimulants and responses for Akirin-2. Involvement in the NF-?B transcription factor complex was analysed with a luciferase promoter assay and an antiviral gene expression assay.
Bioinformatics analysis revealed that the A. clarkii Akirin-2 (AcAk-2) as a highly conserved protein with two nuclear localization signals. Localization analysis with florescent tagged AcAk-2 was observed in the nucleus regardless of poly I:C stimulation. Expression analysis revealed the strongest expression with the presence of poly I:C. Overexpression of AcAk-2 solely unable to enhance the luciferase activity, but overexpression in the presence of poly I:C significantly enhanced the luciferase activity. In-vitro viperin expression was significantly enhanced after 24 h post-transfection of AcAk-2 gene. These results provide evidence for the role of AcAk-2 plays during the RNA virus infections.