Abstract:Astakine (AST) is a cytokine that promotes cell differentiation and proliferation of hemocytes in the hematopoietic tissue, which plays important roles in crustacean immune responses. Evidence from our previous studies showed that WSSV may compete with AST for a common receptor. By rapid amplification of cDNA ends (RACE) PCR, the full-length gene of Litopenaeus vannamei astakine gene (lvast) was obtained, which consisted of 1,846 bp with a 372 bp ORF, encoding 124 amino acids with the predicted molecular mass of 13.3kDa. The deduced protein contained a prokineticin (PK) domain. Homological comparison among LvAST and other species showed that the homogeneities were higher in comparison with those of Penaeus monodon and Pacifastacus leniusculus, and lower in comparison with those of vertebrates.The recombinant protein of LvAST was successfully expressed with the constructed recombined vector pBAD/g IIIA-lvast containing the lvast ORF. The results laid a theoretical basis for further functional studies of astakine.
