Expression of yeast cytochrome c1 is controlled at the transcriptional level by glucose, oxygen and haem

Mol Gen Genet. 1992 Apr;232(3):447-59. doi: 10.1007/BF00266250.


The nuclear gene for cytochrome c1 in Saccharomyces cerevisiae (CYT1) was localized on chromosome XV. Its upstream region was identified by functional complementation. Fusion to the lacZ reporter gene on a CEN plasmid allowed study of the effect of carbon sources and of specific deletion mutations on expression of the gene in yeast transformants. Detailed promoter analysis combined with expression studies in recipient strains defective in regulatory genes identified cis-acting sites and transcription factors involved in the regulated expression of the cytochrome c1 gene. These analyses showed that, in the presence of glucose, transcription of CYT1 is positively controlled by oxygen, presumably through the haem signal, and mediated by the HAP1-encoded transactivator. It is additionally regulated by the HAP2/3/4 complex which mediates gene activation mainly under glucose-free conditions. Basal transcription is, in part, effected by CPF1, a centromere and promoter-binding factor.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • Chromosome Deletion
  • Chromosome Mapping
  • Chromosomes, Fungal
  • Cloning, Molecular
  • Cytochromes c1 / genetics*
  • Cytochromes c1 / metabolism
  • DNA, Fungal / genetics
  • DNA, Fungal / isolation & purification
  • Gene Expression Regulation, Fungal / drug effects*
  • Genes, Fungal*
  • Genes, Regulator*
  • Glucose / pharmacology*
  • Heme / pharmacology*
  • Molecular Sequence Data
  • Oxygen / pharmacology*
  • Promoter Regions, Genetic*
  • Recombinant Fusion Proteins / metabolism
  • Regulatory Sequences, Nucleic Acid
  • Saccharomyces cerevisiae / drug effects
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Sequence Homology, Nucleic Acid
  • Transcription Factors / metabolism
  • Transcription, Genetic / drug effects*
  • Transcriptional Activation
  • beta-Galactosidase / genetics
  • beta-Galactosidase / metabolism


  • DNA, Fungal
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Heme
  • Cytochromes c1
  • beta-Galactosidase
  • Glucose
  • Oxygen