OBJECTIVE; We cloned the promoter of glycerol-3-phosphate dehydrogenase gene(CgGPD) from the Candida glycerinogenes, and studied its functional regulation under high osmotic stress condition.
Methods: We amplified the 950 bp promoter of CgGPD from C. glycerinogenes and the green fluorescent protein gene (gfp) from pCAMBIA1302 vector by PCR and introduced them into a modified vector pYX212-zeocin simultaneously. The recombinant plasmid pYX212-zeocin harboring both the promoter of CgGPD and gene gfp was transformed into S. cerevisiae W303-1A by electroporation. In the medium containing glucose with different concentrations for culturing the recombinant strain S. cerevisiae W303-1A-GFP the green fluorescence was detected by fluorescent microscopy.
Results: The gene gfp was functionally expressed under the control of the promoter of CgGPD in S. cerevisiae. Furthermore, the expression of the gene gfp at different level was conducted by the different osmotic stress for the recombinant strain. The green fluorescence was less intensive when the concentration of glucose was low for culturing the recombinant strain, but it became much more intensive when the concentration of glucose increased.
Conclusion: The promoter of CgGPD is an inducible promoter that can be induced significantly by the high concentration of glucose. The promoter will facilitate further studies on the mechanism of glycerol synthesis from C. glycerinogenes WL2002-5 under osmotic stress conditions.