scholarly journals Regulatory circuit for responses of nitrogen catabolic gene expression to the GLN3 and DAL80 proteins and nitrogen catabolite repression in Saccharomyces cerevisiae.

1993 ◽  
Vol 175 (1) ◽  
pp. 64-73 ◽  
Author(s):  
J R Daugherty ◽  
R Rai ◽  
H M el Berry ◽  
T G Cooper
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Catabolite Repression ◽  
Catabolic Gene ◽  
Nitrogen Catabolite Repression ◽  
Regulatory Circuit

scholarly journals cis-Dominant mutations which dramatically enhance DUR1,2 gene expression without affecting its normal regulation.

1984 ◽  
Vol 4 (5) ◽  
pp. 947-955 ◽  
Author(s):  
G Chisholm ◽  
T Cooper
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Control System ◽  
Normal Control ◽  
Chromatin Structure ◽  
Catabolite Repression ◽  
Mutant Phenotype ◽  
Nitrogen Catabolite Repression ◽  
Upstream Control ◽  
Affect Gene Expression

We have isolated three cis-dominant mutations which dramatically enhance DUR1 ,2 gene expression in Saccharomyces cerevisiae. The mutant phenotype, which is expressed both in haploid and MATa/MAT alpha diploid strains, does not appear to be an alteration of the normal control system for this gene because its expression remained fully inducible and sensitive to nitrogen catabolite repression. Instead, we found much higher levels of DUR1 ,2-specific RNA under both uninduced and induced conditions, i.e., the overproduction trait was superimposed on normal regulation of the gene. The mutations seemed to affect gene expression in a unidirectional manner or to be specific for DUR1 ,2 gene expression, because other genes in proximity to the mutations were not affected. We feel that these mutations may alter the chromatin structure in the vicinity of the DUR1 ,2 upstream control sequences or, alternatively, may be Ty insertions which no longer possess the ROAM characteristics reported by others and ourselves.

scholarly journals The Level of DAL80 Expression Down-Regulates GATA Factor-Mediated Transcription inSaccharomyces cerevisiae

2000 ◽  
Vol 182 (23) ◽  
pp. 6584-6591 ◽  
Author(s):  
Thomas S. Cunningham ◽  
Rajendra Rai ◽  
Terrance G. Cooper
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Binding Sites ◽  
Nitrogen Availability ◽  
Transport Proteins ◽  
Catabolic Gene ◽  
Nitrogen Catabolite Repression ◽  
Gata Factor ◽  
Regulatory Circuit ◽  
Gata Family

ABSTRACT Nitrogen-catabolic gene expression in Saccharomyces cerevisiae is regulated by the action of four GATA family transcription factors: Gln3p and Gat1p/Nil1p are transcriptional activators, and Dal80 and Deh1p/Gzf3p are repressors. In addition to the GATA sequences situated upstream of all nitrogen catabolite repression-sensitive genes that encode enzyme and transport proteins, the promoters of the GAT1, DAL80, andDEH1 genes all contain multiple GATA sequences as well. These GATA sequences are the binding sites of the GATA family transcription factors and are hypothesized to mediate their autogenous and cross regulation. Here we show, using DAL80 fused to the carbon-regulated GAL1,10 or copper-regulated CUP1 promoter, that GAT1expression is inversely regulated by the level of DAL80expression, i.e., as DAL80 expression increases,GAT1 expression decreases. The amount of DAL80expression also dictates the level at which DAL3, a gene activated almost exclusively by Gln3p, is transcribed. Gat1p was found to partially substitute for Gln3p in transcription. These data support the contention that regulation of GATA-factor gene expression is tightly and dynamically coupled. Finally, we suggest that the complicated regulatory circuit in which the GATA family transcription factors participate is probably most beneficial as cells make the transition from excess to limited nitrogen availability.

scholarly journals Gat1p, a GATA family protein whose production is sensitive to nitrogen catabolite repression, participates in transcriptional activation of nitrogen-catabolic genes in Saccharomyces cerevisiae.

1996 ◽  
Vol 16 (3) ◽  
pp. 847-858 ◽  
Author(s):  
J A Coffman ◽  
R Rai ◽  
T Cunningham ◽  
V Svetlov ◽  
T G Cooper
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Catabolite Repression ◽  
Nitrogen Sources ◽  
Nitrogen Catabolite Repression ◽  
Triple Mutant ◽  
Regulatory Circuit ◽  
Catabolic Genes ◽  
Family Protein ◽  
Sequence Elements

Saccharomyces cerevisiae cells selectively use nitrogen sources in their environment. Nitrogen catabolite repression (NCR) is the basis of this selectivity. Until recently NCR was thought to be accomplished exclusively through the negative regulation of Gln3p function by Ure2p. The demonstration that NCR-sensitive expression of multiple nitrogen-catabolic genes occurs in a gln3 delta ure2 delta dal80::hisG triple mutant indicated that the prevailing view of the nitrogen regulatory circuit was in need of revision; additional components clearly existed. Here we demonstrate that another positive regulator, designated Gat1p, participates in the transcription of NCR-sensitive genes and is able to weakly activate transcription when tethered upstream of a reporter gene devoid of upstream activation sequence elements. Expression of GAT1 is shown to be NCR sensitive, partially Gln3p dependent, and Dal80p regulated. In agreement with this pattern of regulation, we also demonstrate the existence of Gln3p and Dal80p binding sites upstream of GAT1.

cis-Dominant mutations which dramatically enhance DUR1,2 gene expression without affecting its normal regulation

1984 ◽  
Vol 4 (5) ◽  
pp. 947-955
Author(s):  
G Chisholm ◽  
T Cooper
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Control System ◽  
Normal Control ◽  
Chromatin Structure ◽  
Catabolite Repression ◽  
Mutant Phenotype ◽  
Nitrogen Catabolite Repression ◽  
Upstream Control ◽  
Affect Gene Expression

We have isolated three cis-dominant mutations which dramatically enhance DUR1 ,2 gene expression in Saccharomyces cerevisiae. The mutant phenotype, which is expressed both in haploid and MATa/MAT alpha diploid strains, does not appear to be an alteration of the normal control system for this gene because its expression remained fully inducible and sensitive to nitrogen catabolite repression. Instead, we found much higher levels of DUR1 ,2-specific RNA under both uninduced and induced conditions, i.e., the overproduction trait was superimposed on normal regulation of the gene. The mutations seemed to affect gene expression in a unidirectional manner or to be specific for DUR1 ,2 gene expression, because other genes in proximity to the mutations were not affected. We feel that these mutations may alter the chromatin structure in the vicinity of the DUR1 ,2 upstream control sequences or, alternatively, may be Ty insertions which no longer possess the ROAM characteristics reported by others and ourselves.

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