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

Abstract

In general, promoters have significant influence on recombinant protein production. Herein, we compared the performance of actin (p<i>ACT</i>), phosphoglycerate kinase (p<i>PGK</i>), and translational elongation factor (p<i>TEF</i>) promoters for driving the expression of fatty acid delta-6 (Δ6) desaturase from Nile tilapia (<i>Oreochromis niloticus</i>; <i>Oni-fads2</i>) in <i>Saccharomyces cerevisiae</i>. Our results showed that by applying real-time RT-PCR, the highest level of <i>Oni-fads2</i> mRNA was observed in <i>S. cerevisiae</i> carrying the expression vector driven by p<i>TEF</i> 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 p<i>TEF</i> as a promoter. Recombinant <i>S. cerevisia</i>e cells expressing <i>Oni-fads2</i> driven by p<i>TEF</i> 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 <i>S. cerevisia</i>e cells expressing <i>Oni-fads2</i> driven by the p<i>TEF</i> promoter have potential as a yeast factory for the sustainable production of long-chain polyunsaturated fatty acids.