scholarly journals Saturation mutagenesis of the UASNTR (GATAA) responsible for nitrogen catabolite repression-sensitive transcriptional activation of the allantoin pathway genes in Saccharomyces cerevisiae.

1991 ◽  
Vol 173 (16) ◽  
pp. 4977-4982 ◽  
Author(s):  
N Bysani ◽  
J R Daugherty ◽  
T G Cooper
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Catabolite Repression ◽  
Saturation Mutagenesis ◽  
Nitrogen Catabolite Repression

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.

A gene product needed for induction of allantoin system genes in Saccharomyces cerevisiae but not for their transcriptional activation

1989 ◽  
Vol 9 (9) ◽  
pp. 3869-3877
Author(s):  
P A Bricmont ◽  
T G Cooper
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Product ◽  
Transcriptional Activation ◽  
Nitrogen Catabolite Repression ◽  
Wild Type ◽  
Product Analysis ◽  
Cis Acting ◽  
Induction Sequence ◽  
Basal Level Expression ◽  
Activation Sequence

The allantoin-degradative pathway of Saccharomyces cerevisiae consists of several genes whose expression is highly induced by the presence of allophanic acid. Induced expression requires a functional DAL81 gene product. Analysis of these genes has demonstrated the presence of three cis-acting elements in the upstream regions: (i) an upstream activation sequence (UAS) required for transcriptional activation in an inducer-independent fashion, (ii) an upstream repression sequence (URS) that mediates inhibition of this transcriptional activation, and (iii) an upstream induction sequence (UIS) needed for a response to inducer. The UIS element mediates inhibition of URS-mediated function when inducer is present. We cloned and characterized the DAL81 gene and identified the element with which it was associated. The gene was found to encode a rare 3.2-kilobase-pair mRNA. The amount of DAL81-specific RNA responded neither to induction nor to nitrogen catabolite repression. Deletion of the DAL81 gene resulted in loss of induction but did not significantly affect basal level expression of the DAL7 and DUR1,2 genes or the UAS and URS functions present in plasmid constructions. These data suggest that (i) transcriptional activation of the DAL genes and their responses to inducer are mediated by different factors and cis-acting sequences and (ii) the UIS functions only when a wild-type DAL81 gene product is available.

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.

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