酵母ADH2—SUC2融合启动子的构建及其对基因表达的调控

将ＡＤＨ２基因的ＵＡＳ与带有不同长度缺失上游区的ＳＵＣ３基因融合，构建成４种具有不同融合启动子的ＳＵＣ２基因的表达质粒ＹＲＤ１１０１．ＹＦＤ１１０△９．ＹＦＤ１１０△１７、ＹＦＤ１１０△１１。将这些质粒及对照表达质粒ＹＦＤ２６△１．ＹＦＤ２５转化酵母菌Ｙ３３，在阻遏与去阻遏培养条件下，对各种转化子所产生的蔗糖酶进行了活性测定和组分分析。结果表明：在葡萄糖去阻遏生长条件下，ＹＦＤ１１０△１的启动子组合中ＵＡＳｓｕｃ２和ＵＡＳＡＤＨ２对ＳＵＣ２基因的表达有协同激活作用。在阻遏条件下Ｙ３３／ＹＦＤ１１０△１与Ｙ３３／ＹＦＤ１１０△９、Ｙ３３／ＹＦＤ２６△１、Ｙ３３／ＹＦＤ２５一样，均表达很低的糖基化蔗糖酶，３种去阻遏培养条件比较说明，在低糖培养基中对糖基化蔗糖酶表达的去阻遏效果最佳

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 YFD1110#1, YFD110#9, YFD110#17 and YFD110#11 were constructed. They contained different hybrid promoters for transciption of SUC2 gene. After transforming them together with two control plasmids YFD26#1 . YFD25 into yeast S. cerevisiae Y33 respectively, the transfonmants 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 followis: ( 1 ) UASSUC2 and UASADH2 in the hybrid plasmid YFD11O#1 worked synergically under derepression condition. Under repression condition, Y33 / YFD110#1 produced very low level of glycosylation inverbue. (2) Compared with three different derepression media, the medium containing low concentration glucose gave higher derepression effeciency of glycosylated invertase than the media containing glycerol and ethanol.