酵母ENO2上游激活顺序对酵母LEU2表达的影响

THE EFFECT OF UPSTREAM ACTIVATION SEQUENCE OF SACCHAROMYCES CEREVISIAE ENO2 ON THE EXPRESSION OF YEAST LEU2

本文将酿酒酵母(Saccharomyces cerevisiae)中编码烯醇化酶的基因之一ENO2的上游激活顺序嵌入穿梭质粒YEp13上酵母LEU2基因上游-405Hpa Ⅰ的酶切部位。LEU2为编码β-异丙基苹果酸脱氢酶基因。从而研究了酵母ENO2的上游激活顺序对酵母LEU2表达的影响。实验结果表明ENO2上游激活顺序不论正向或反向嵌入都激活LEU2的表达达四倍左右。有亮氨酸存在的条件下,LEU2的表达受到抑制。ENO2上游激活顺序在对LEU2表达的激活上并不受葡萄糖的诱导。提出了用ENO2上游激活顺序组建高表达系统的可能性。

The upstream activation sequence of ENO2. one of the two genes coding for yeast enolase, was inserted into the upstream -405 Hpal site of LEU2, coding for β-isopropylmalate dehydrogenase(E.C. 1. 1. 1. 85) in shuttle plasmid YEp13. The effect of upstream activation sequence of ENO2 on the expression of yeast LEU2 was studied.The results show the upstream activation sequence of ENO2 activates the expression of LEU2 in both orientations by four times. Leucine represses the expression of LEU2. The effect of upstream activation sequence of ENO2 on the expression of LEU2 is not induced by glucose. It is possible to construct a high-level expression system in yeast with upstream activation sequence of ENO2.