ACR1, a yeast ATF/CREB repressor.
Members of the mammalian ATF/CREB family of transcription factors, which are associated with regulation by cyclic AMP and viral oncogenes, bind common DNA sequences (consensus TGACGTCA) via a bZIP domain. In the yeast Saccharomyces cerevisiae, ATF/CREB-like sequences confer either repression or activation of transcription, depending on the promoter context. By isolating mutations that alleviate the repression mediated by ATF/CREB sites, we define a new yeast gene, ACR1, which encodes an ATF/CREB transcriptional repressor. ACR1 contains a bZIP domain that is necessary for homodimer formation and specific DNA binding to an ATF/CREB site. Within the bZIP domain, ACR1 most strongly resembles the mammalian cyclic AMP-responsive transcriptional regulators CREB and CREM; it is less similar to GCN4 and YAP1, two previously described yeast bZIP transcriptional activators that recognize the related AP-1 sequence (consensus TGACTCA). Interestingly, deletion of the ACR1 gene causes increased transcription through ATF/CREB sites that does not depend on GCN4 or YAP1. Moreover, extracts from acr1 deletion strains contain one or more ATF/CREB-like DNA-binding activities. These genetic and biochemical observations suggest that S. cerevisiae contains a family of ATF/CREB proteins that function as transcriptional repressors or activators.
Vincent
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AC
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115.
Struhl
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K
D000595:Amino Acid Sequence; D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D003001:Cloning, Molecular; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism*; D004271:DNA, Fungal; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005800:Genes, Fungal; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D016296:Mutagenesis; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D050976:Basic-Leucine Zipper Transcription Factors; D017362:Cyclic AMP Response Element-Binding Protein; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; C077832:SKO1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins