title: Specific binding sites in the alcR and alcA promoters of the ethanol regulon for the CREA repressor mediating carbon catabolite repression in Aspergillus nidulans.
abstract: 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 protein 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 alc 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.
authors: Institut de Génétique et Microbiologie, UPS, Orsay, France.
authors: P
authors: P
authors: Kulmburg
authors: M
authors: M
authors: Mathieu
authors: C
authors: C
authors: Dowzer
authors: J
authors: J
authors: Kelly
authors: B
authors: B
authors: Felenbok
mesh_terms: D000426:Alcohol Dehydrogenase / Q000235:genetics*; D001233:Aspergillus nidulans / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D000431:Ethanol / Q000494:pharmacology*; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005800:Genes, Fungal; D005947:Glucose / Q000494:pharmacology; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D016335:Zinc Fingers / Q000235:genetics*
chemical_list: C074202:ALCR protein, Aspergillus nidulans; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C071237:CreA protein, Aspergillus nidulans; D000431:Ethanol; D000426:Alcohol Dehydrogenase; D005947:Glucose