[Cloning and expression of human octamer-binding protein-4 (Oct4) cDNA in Escherichia coli and HEK293T cells].

OBJECTIVE: To clone and express human octamer-binding protein-4 (Oct4) cDNA in Escherichia coli and HEK293T cells. METHODS: Primers were designed based on the coding sequence for the human Oct4 cDNA. The fragment containing Oct4 gene, amplified by reverse transcription PCR (RT-PCR) from human HeLa cell cDNA as the template, was subcloned into pET-22b(+) and pcDNA3.1(+) vectors to construct the gene recombinant prokaryotic expression vector pET-22b(+)-Oct4 and eukaryotic expression vector pcDNA3.1(+)-his-Oct4, respectively. Thereafter, the double enzymes digestion and the target gene sequencing were performed for identification. The prokaryotic expression vector pET-22b(+)-Oct4 and eukaryotic expression vector pcDNA3.1(+)- his-Oct4 from the positive clones were respectively transformed into E.coli BL21 (DE3) and the embryo HEK293T cells for protein expression. RESULTS: DNA fragments (1100 bp) containing the coding region of Oct4 gene were obtained from RT-PCR. The recombinant expression plasmids were confirmed by enzymes digestion identification and sequencing analysis, proving both of the expression vectors were successfully constructed. SDS-PAGE analysis showed that the molecular mass of OCT4 expressed in the host E.coli BL21 (DE3) was 38 000, which was consistent with the theoretical prediction. Western blotting confirmed the expression of pcDNA3.1(+)-his-Oct4 transfected into HEK293T. CONCLUSION: Human Oct4 cDNA was cloned and its protein was successfully expressed in E.coli and HEK293T cells.