ERA, a novel cis-acting element required for autoregulation and ethanol repression of PDC1 transcription in Saccharomyces cerevisiae.
Yeast pyruvate decarboxylase (Pdc) catalyses the reaction at the branch-point of fermentation and respiration. In this work we have investigated the mechanisms of its transcriptional regulation in response to glucose and the non-fermentable carbon source ethanol. For this purpose we studied the function of different promoter fragments of PDC1, encoding the major pyruvate decarboxylase enzyme in wild-type cells, in the basal CYC1 promoter context. Thus, we identified a sequence mediating the response to ethanol and provide evidence showing that transcription of PDC1 is controlled by ethanol repression rather than by glucose induction. Furthermore, we showed that the same sequence is responsible for an autoregulatory process, leading to increased transcription from both the PDC1 and the PDC5 promoters, in strains in which the genomic copy of PDC1 is deleted. In addition, we have confirmed the role of Rap1 binding and have demonstrated that the Gcr1 protein also acts in transcriptional activation. DNA-protein interactions at the consensus Rap1-binding site and the newly identified ethanol-repression sequence (5'-AAATGCATA-3', termed 'ERA') were investigated by gel-shift and footprint analyses. Both DNA-binding activities were found in extracts from cells grown in media containing glucose or ethanol as the carbon source, indicating that the capacity to bind is not altered by the carbon source used.
Liesen
T
T
Institut für Mikrobiologie, Hainrich-Heine-Universität Düsseldorf, Germany.
Hollenberg
C P
CP
Heinisch
J J
JJ
D018983:DNA Footprinting; D004268:DNA-Binding Proteins / Q000235:genetics; D000431:Ethanol / Q000494:pharmacology*; D005656:Fungal Proteins / Q000235:genetics*; D019204:GTP-Binding Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D011401:Promoter Regions, Genetic; D011767:Pyruvate Decarboxylase / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014158:Transcription, Genetic; D020668:rap GTP-Binding Proteins
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C076227:GCR1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000431:Ethanol; D019204:GTP-Binding Proteins; D020668:rap GTP-Binding Proteins; C101504:PDC1 protein, S cerevisiae; D011767:Pyruvate Decarboxylase