SPECIFIC BINDING-SITES IN THE ALCR AND ALCA PROMOTERS OF THE ETHANOL REGULON FOR THE CREA REPRESSOR MEDIATING CARBON CATABOLITE REPRESSION IN ASPERGILLUS-NIDULANS
SPECIFIC BINDING-SITES IN THE ALCR AND ALCA PROMOTERS OF THE ETHANOL REGULON FOR THE CREA REPRESSOR MEDIATING CARBON CATABOLITE REPRESSION IN ASPERGILLUS-NIDULANS
复制标题
DOI：
10.1111/j.1365-2958.1993.tb01175.x
复制
发表时间：
1993-03-01
影响因子：
3.6
通讯作者：
FELENBOK, B
中科院分区：
文献类型：
--
作者：
KULMBURG, P;MATHIEU, M;FELENBOK, B
在构巢曲霉中负责碳分解代谢物阻遏的CREA阻遏物阻遏乙醇调节子的转录。CREA蛋白的N端部分包括两个锌指（C2 H2类家族）和富含丙氨酸的区域，在大肠杆菌中作为与谷胱甘肽-S-转移酶的融合蛋白表达。我们的研究结果表明，CREA是一种DNA结合蛋白，能够结合到特定的反式作用基因alcR和编码乙醇脱氢酶I的结构基因alcA的启动子上。DNA酶I保护足迹实验揭示了在具有共有序列5 ′-G/CP γ GGGG-3 ′的alcR和alcA启动子中的几个特异性结合位点。在与反式激活因子ALCR的诱导靶重叠的alcR启动子中的这些CREA结合位点之一的破坏导致部分去阻遏的ak表型和去阻遏的alcR转录，表明该结合位点在体内是功能性的。我们的数据表明，CREA抑制乙醇调节子的双锁机制抑制反式作用基因，alcR，和结构基因，alcA。
The CREA repressor responsible for carbon catabolite repression in Aspergillus nidulans represses the transcription of the ethanol regulon. The N-terminal part of the CREA protein encompassing the two zinc fingers (C2H2 class family) and an alanine-rich region was expressed in Escherichia coli as a fusion protei n with glutathione-S-transferase. Our results show that CREA is a DNA-binding protein able to bind to the promoters of both the specific trans-acting gene, alcR, and of the structural gene, alcA, encoding the alcohol dehydrogenase I. DNase I protection footprinting experiments revealed several specific binding sites in the alcR and in the alcA promoters having the consensus sequence 5'-G/CPyGGGG-3'. The disruption of one of these CREA-binding sites in the alcR promoter overlapping the induction target for the trans-activator ALCR results in a partially derepressed ak phenotype and derepressed alcR transcription, showing that this binding site is functional in vivo. Our data suggest that CREA represses the ethanol regulon by a double lock mechanism repressing both the trans-acting gene, alcR, and the structural gene, alcA.