Cloning and characterization of prion protein coding genes of Japanese seabass (Lateolabrax japonicus) and Japanese flounder (Paralichthys olivaceus)

Complementary DNA (cDNA) sequences of Japanese seabass (Lateolabrax japonicus) and Japanese flounder (Paralichthys olivaceus) prion protein (PrP) encoding genes were cloned and characterized through RT-PCR approach. The PrPs of two fish species consist of 507 and 497 amino acid residues with an estimated molecular weight of about 54 and 52 kilodaltons, respectively. The deduced amino acid sequences of two sequences are about 65% similar to those of Japanese pufferfish (Fugu rubripes, stPrP-1) and Atlantic salmon (Salmo salar) in average, and bear the structural features of PrPs including a signal sequence, tandem repeats, a hydrophobic region, glycosylation sites, two cystein residues potentially involved in the formation of a disulphide bridge and a glycosyl phosphatidylinositol anchor site. The isolation of two PrP encoding genes will facilitate the exploration concerning the evolution, structure and function of PrPs and possible transmissible spongiform encephalopathies (TSE) in fish.