Cloning,sequence analysis of Chinese white rabbit IL-15 gene and its expression in E.coli

Chinese white rabbit IL-15 gene was amplified by RT-PCR method from the PMBC stimulated by ConA.Then the positive PCR product was purified and ligatured with pMD18-T.The positive recombinant was used for sequencing.The complete length of white rabbit IL-15 gene was 489 bp,encoding 162 amino acids.Compared with the IL-15 genes of other species,there were some differences in the nucleotide sequence and deduced amino acid sequence.There were four N-glycosylation sites and 6 conservative Cys in the deduced amino acid sequence.Meanwhile,the IL-15 gene was subcloned into the prokaryotic expressing vector pET28a and transformed into host E.coli strain BL21(DE3) for expression under the induction of IPTG.The expression of IL-15 protein was detected by SDS-PAGE.The results revealed that it had a molecular weight of 20 500,amounting to 13.6% in the total protein of the induced bacteria by the assaying of gel scanning.