[Construction of yeast ADH2-SUC2 hybrid promoter and its regulation in gene expression]

By fusing the upstream activation sequence (UAS) of ADH2 gene to the 5' end of a series of deletions in the upstream region of SUC2 gene, 4 expression plasmids YFD110 delta 1, YFD110 delta 9, YFD110 delta 17 and YFD110 delta 11 were constructed. They contained different hybrid promoters for transcription of SUC2 gene. After transforming them together with two control plasmids YFD26 delta 1, YFD25 into yeast. S. cerevisiae Y33 respectively, the transformants were grown in the repression or derepression media and the invertase produced by each transformants were analyzed by colormetry and gel electrophoresis. The results were as follow is: (1) UASSUC2 and UASADH2 in the hybrid plasmid YFD110 delta 1 worked synergically under derepression condition. Under repression condition, Y33/YFD110 delta 1 produced very low level of glycosylation invertase. (2) Compared with three different derepression media, the medium containing low concentration glucose gave higher derepression efficiency of glycosylated invertase than the media containing glycerol and ethanol.