Ubiquitous Promoters Direct the Expression of Fatty Acid Delta-6 Desaturase from Nile Tilapia (Oreochromis niloticus) in Saccharomyces cerevisiae.

In general, promoters have significant influence on recombinant protein production. Herein, we compared the performance of actin (pACT), phosphoglycerate kinase (pPGK), and translational elongation factor (pTEF) promoters for driving the expression of fatty acid delta-6 (Δ6) desaturase from Nile tilapia (Oreochromis niloticus; Oni-fads2) in Saccharomyces cerevisiae. Our results showed that by applying real-time RT-PCR, the highest level of Oni-fads2 mRNA was observed in S. cerevisiae carrying the expression vector driven by pTEF promoters. Exogenous substrate C18:2n-6 was used to determine Δ6 activity by quantitatively determining the C18:3n-6 product. The results showed that highest Δ6 desaturation was observed when using pTEF as a promoter. Recombinant S. cerevisiae cells expressing Oni-fads2 driven by pTEF were tested with the substrate C18:3n-3, and Δ6 desaturation efficiently converted C18:3n-3 to C18:4n-3. Furthermore, crude extract of recombinant yeast also exhibited Δ6 activity. Thus, recombinant S. cerevisiae cells expressing Oni-fads2 driven by the pTEF promoter have potential as a yeast factory for the sustainable production of long-chain polyunsaturated fatty acids.