Cloning and expression of the preS1 gene of hepatitis B virus in yeast cells

Objective: To investigate the complex functions ofHBV preS1 protein, we constructed HBV preS1 geneexpression vector and expressed it in yeast cells.Methods: Polymerase chain reaction (PCR) was per-formed to amplify the gene of HBV preS1 from theplasmid pCP10 containing the whole DNA fragmentof HBV ayw subtype as template and the PCR prod-uct was cloned into the pGEM-T vector for sequen-cing. After being identified, the HBV preSl genewas cut from the pGEM-T vector by EcoR I and PstI restriction enzymes, and cloned into yeast expres-sive plasmid pGBKT7 to constructe pGBKT7-preS1recombinant expressive plasmid. This plasmid wastransformed into yeast cell AH109 and expressed init. The yeast protein was isolated and analyzed withsodium dodecyl suifate-polyacrylamide gel electro-phoresis(SDS-PAGE) and Western blotting.Results: The HBV preS1 gene was amplified success-fully and identified by DNA sequencing. The PCRproducts were coincided completely with the reportedsequence. The digested fragments were cloned intothe pGBKT7 vector and transformed into yeast cellAH109. The results of SDS-PAGE and Western blot-ting assay showed: (1) The HBV preS1 protein wasexpressed and existed in yeast cells; (2) The molecu-lar weight of the expression product was about 30 000D.Conclusion: The HBV preS1 gene was successfullycloned and expressed in yeast cells.