Antiviral radical SAM enzyme viperin homologue from Asian seabass (Lates calcarifer): Molecular characterisation and expression analysis

Abstract

The host response to virus infection is mediated by the interferon system and its workhorse effector proteins like Interferon-stimulated genes (ISGs). Viperin is an interferon-inducible antiviral protein. In the present study, an antiviral radical SAM enzyme, viperin homologue, was cloned and characterised from teleost, Asian seabass (Lates calcarifer). This cloned viperin cDNA encodes 351 amino acid protein with predicted N-terminal amphipathic alpha-helix, conserved radical S-adenosyl l-methionine (SAM) domain with CxxxCxxC motif and a highly conserved C-terminal domain. Lcviperin gene consists of six exons and five introns. The secondary structure contains nine alpha helices and beta sheets. Viperin from Lates is evolutionarily conserved and shares about 89% identity with Seriola dumerili and 70% identity with human orthologue. Poly(I:C) and RGNNV upregulated Lcviperin during in-vivo challenge studies, providing insight into its antiviral properties. Lates antiviral effector genes like viperin could help in elucidating the host-virus protein interactions and allow the development of improved antiviral strategies against pathogens like betanodavirus that devastate aquaculture of the species.