title: Additive effect of calreticulin and translation initiation factor eIF4E on secreted protein production in the baculovirus expression system.
abstract: The baculovirus expression vector system is widely used for the production of recombinant proteins. However, the yield of membrane-bound or secreted proteins is relatively low when compared with intracellular or nuclear proteins. In a previous study, we had demonstrated that the co-expression of the human chaperones calreticulin (CALR) or β-synuclein (β-syn) increased the production of a secreted protein considerably. A similar effect was also seen when co-expressing insect translation initiation factor eIF4E. In this study, different combinations of the three genes were tested (CALR alone, β-syn + CALR, or β-syn + CALR + eIF4E) to further improve secretory protein production by assessing the expression level of a recombinant secreted alkaline phosphatase (SEFP). An additional 1.8-fold increment of SEFP production was obtained when cells co-expressed all the three "helper" genes, compared to cells, in which only CALR was co-produced with SEFP. Moreover, the duration of the SEFP production lasted much longer in cells that co-expressed these three "helper" genes, up to 10 dpi was observed. Utilization of this "triple-supporters" containing vector offers significant advantages when producing secreted proteins and is likely to have benefits for the production of viral vaccines and other pharmaceutical products.
authors.affiliation: Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li, 320, Taiwan, Republic of China.
authors.forename: Chao-Yi
authors.initials: CY
authors.lastname: Teng
authors.forename: Monique M
authors.initials: MM
authors.lastname: van Oers
authors.forename: Tzong-Yuan
authors.initials: TY
authors.lastname: Wu
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D016367:Baculoviridae / Q000235:genetics*; D037282:Calreticulin / Q000378:metabolism*; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D039561:Eukaryotic Initiation Factor-4E / Q000378:metabolism*; D015870:Gene Expression; D005822:Genetic Vectors; D006801:Humans; D007313:Insecta; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D051846:beta-Synuclein / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; C576483:CALR protein, human; D037282:Calreticulin; D039561:Eukaryotic Initiation Factor-4E; D011994:Recombinant Proteins; D051846:beta-Synuclein; D010450:Endopeptidases; C087822:alkaline protease