Two mutually exclusive regulatory systems inhibit UASGATA, a cluster of 5′-GAT(A/T)A-3′ upstream from theUGA4gene ofSaccharomyces cerevisiae
| Autor: | Claudine Hein, David Coornaert, Saï Soussi Boudekou, Driss Talibi, Stephan Vissers, Bruno André |
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| Rok vydání: | 1995 |
| Předmět: |
GABA Plasma Membrane Transport Proteins
Saccharomyces cerevisiae Proteins Nitrogen Prions Glutamine Recombinant Fusion Proteins Molecular Sequence Data Saccharomyces cerevisiae Organic Anion Transporters Regulatory Sequences Nucleic Acid Mutually exclusive events GATA Transcription Factors Fungal Proteins Gene Expression Regulation Fungal Genetics Inducer Amino Acid Sequence DNA Fungal Psychological repression Gene Transcription factor gamma-Aminobutyric Acid Glutathione Peroxidase Base Sequence biology Permease Chromosome Mapping Membrane Transport Proteins Zinc Fingers biology.organism_classification Repressor Proteins Chromosomes Fungal |
| Zdroj: | Nucleic Acids Research. 23:558-564 |
| ISSN: | 1362-4962 0305-1048 |
| DOI: | 10.1093/nar/23.4.558 |
| Popis: | The S. cerevisiae Uga43(Dal80) protein down-regulates the expression of multiple nitrogen pathway genes. It contains a zinc-finger motif similar to the DNA-binding domain of the vertebrate GATA family of transcription factors; this domain is known to direct binding to 5'-GATA-3' core sequences. The inducible UGA4 gene, which encodes the specific gamma-aminobutyrate permease, undergoes strong repression by Uga43p. This study shows that the 5' region of UGA4 contains a UAS element made of four directly repeated 5'-CGAT(A/T) AG-3' sequences. This element, called UASGATA, can potentially confer to the UGA4 gene high-level expression in the absence of inducer, but this potential activity is inhibited by two distinct repression systems. One system is Uga43p-dependent; it operates in cells grown on a poor nitrogen source. The other is the nitrogen repression system, which relies on Ure2p and glutamine and operates when a good nitrogen source is present. Nitrogen repression also blocks the synthesis of Uga43p, making the two repression systems mutually exclusive. Previous studies have shown that expression supported by 5'-GATA-3'-containing UAS elements requires Gln3p, another global nitrogen regulatory factor containing a GATA zinc-finger domain. Although Gln3p contributes to UASGATA activity, evidence suggests that a second factor can potentially direct expression through UASGATA. Expression conferred by this putative factor is subject to both Uga43p- and Ure2p-mediated repression. The role of UASGATA in the expression of the UGA4 gene is discussed in relation to its sensitivity to the two distinct repression systems. |
| Databáze: | OpenAIRE |
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