Soltes-Rak E, Kushner D J, Williams D D, Coleman J R
Department of Botany, University of Toronto, Ontario, Canada.
Appl Environ Microbiol. 1993 Aug;59(8):2404-10. doi: 10.1128/aem.59.8.2404-2410.1993.
The impact of promoter modification on the expression of the mosquitocidal Bacillus thuringiensis subsp. israelensis cryIVB gene when used to transform the cyanobacterium Synechococcus sp. strain PCC 7942 has been examined. Maximal transcript and protein abundances were achieved by the addition of the lacZ promoter upstream of the cryIVB sequence. Replacement of the endogenous corresponding Bacillus sequences with the Synechococcus petF1 promoter, ribosome binding site, and initiation codon also resulted in increased expression of the cryIVB gene relative to the expression obtained with the Bacillus promoter alone but decreased expression relative to the expression achieved with the tandem array of the Bacillus and lacZ promoters. Synechococcus cells carrying plasmids in which the expression of the cryIVB gene was regulated by either the lacZ or the petF1 promoter were readily consumed by first-instar Culex restuans larvae and proved to be toxic for these organisms.
研究了启动子修饰对苏云金芽孢杆菌以色列亚种cryIVB杀蚊基因在转化蓝藻聚球藻属PCC 7942菌株时表达的影响。通过在cryIVB序列上游添加lacZ启动子，实现了最大转录本和蛋白质丰度。用聚球藻petF1启动子、核糖体结合位点和起始密码子取代内源性相应芽孢杆菌序列，相对于仅用芽孢杆菌启动子获得的表达，cryIVB基因的表达也有所增加，但相对于用芽孢杆菌和lacZ启动子串联阵列获得的表达则有所降低。携带由lacZ或petF1启动子调控cryIVB基因表达的质粒的聚球藻细胞很容易被一龄致倦库蚊幼虫消耗，并被证明对这些生物体有毒。
