Efficient expression of genetically engineered hepatitis B virus surface antigen P31 proteins in yeast.
We have constructed plasmids that express modified hepatitis B virus surface antigen (HBsAg) P31-coding genes (M-P31c, d, e, f, and i) having various genetically engineered pre-S2 regions. The plasmids contain the GAPDH (gene coding for glyceraldehyde-3-phosphate dehydrogenase) promoter and the PGK (gene coding for 3-phosphoglycerate kinase) terminator, both isolated from sake brewing yeast, Saccharomyces cerevisiae Kyokai III. Expression levels of the modified HBsAg P31 proteins in yeast are greatly increased from 0.4% to 11.7% of total cell protein. However, the specific mRNAs are expressed at equal levels and the degradation rates of the modified P31 proteins do not vary significantly. Therefore, we considered that different expression levels of the modified P31 proteins are attributed to the changes of the post-translational efficiency. And it was suggested that the conformational stability of the N-terminal peptide (Met-1-Phe-46) in the endoplasmic reticulum membrane determines the expression level of modified P31 proteins.
Kuroda
S
S
Biotechnology Laboratories, Central Research Division, Takeda Chemical Industries, Ltd., Osaka, Japan.
Itoh
Y
Y
Miyazaki
T
T
Otaka-Imai
S
S
Fujisawa
Y
Y
D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport; D015153:Blotting, Western; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005786:Gene Expression Regulation; D005814:Genes, Viral; D006514:Hepatitis B Surface Antigens / Q000235:genetics* / Q000378:metabolism; D006515:Hepatitis B virus / Q000235:genetics*; D007425:Intracellular Membranes / Q000378:metabolism; D008969:Molecular Sequence Data; D010957:Plasmids; D011487:Protein Conformation; D021382:Protein Sorting Signals / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014170:Transformation, Genetic
D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D021382:Protein Sorting Signals; D012333:RNA, Messenger; C061034:hepatitis B virus surface antigen P31c