scholarly journals Transcriptional regulation of a sterol-biosynthetic enzyme by sterol levels in Saccharomyces cerevisiae.

1996 ◽  
Vol 16 (8) ◽  
pp. 3981-3989 ◽  
Author(s):  
D Dimster-Denk ◽  
J Rine
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Regulation ◽  
Feedback Control ◽  
Dna Sequences ◽  
Promoter Region ◽  
Mevalonate Pathway ◽  
Transcriptional Level ◽  
Biosynthetic Enzyme ◽  
Animal Cells ◽  
Regulatory Response

Sterols and all nonsterol isoprenoids are derived from the highly conserved mevalonate pathway. In animal cells, this pathway is regulated in part at the transcriptional level through the action of sterol response element-binding proteins acting at specific DNA sequences near promoters. Here we extend at least part of this regulatory paradigm to the ERG10 gene, which encodes a sterol-biosynthetic enzyme of Saccharomyces cerevisiae. Specifically, the discovery of sterol-mediated feedback control of ERG10 transcription is reported. Deletion analysis of the ERG10 promoter region identified sequences involved in the expression of ERG10. This regulatory axis appeared to involve sterol levels, as a late block in the pathway that depletes sterol, but not nonsterol isoprenoids, was able to elicit the regulatory response.

scholarly journals Regulation of gbpC Expression in Streptococcus mutans

2007 ◽  
Vol 189 (18) ◽  
pp. 6521-6531 ◽  
Author(s):  
Indranil Biswas ◽  
Laura Drake ◽  
Saswati Biswas
Keyword(s):  
Streptococcus Mutans ◽  
Dna Sequences ◽  
Promoter Region ◽  
Response Regulator ◽  
Surface Protein ◽  
Maximum Level ◽  
Stress Conditions ◽  
Pcr Analysis ◽  
Exponential Growth Phase ◽  
Transcriptional Level

ABSTRACT Streptococcus mutans, the principal causative agent of dental caries, produces four glucan-binding proteins (Gbp) that play major roles in bacterial adherence and pathogenesis. One of these proteins, GbpC, is an important cell surface protein involved in biofilm formation. GbpC is also important for cariogenesis, bacteremia, and infective endocarditis. In this study, we examined the regulation of gbpC expression in S. mutans strain UA159. We found that gbpC expression attains the maximum level at mid-exponential growth phase, and the half-life of the transcript is less than 2 min. Expression from PgbpC was measured using a PgbpC-gusA transcriptional fusion reporter and was analyzed under various stress conditions, including thermal, osmotic, and acid stresses. Expression of gbpC is induced under conditions of thermal stress but is repressed during growth at low pH, whereas osmotic stress had no effect on expression from PgbpC. The results from the expression analyses were further confirmed using semiquantitative reverse transcription-PCR analysis. Our results also reveal that CovR, a global response regulator in many Streptococcus spp., represses gbpC expression at the transcriptional level. We demonstrated that purified CovR protein binds directly to the promoter region of PgbpC to repress gbpC expression. Using a DNase I protection assay, we showed that CovR binds to DNA sequences surrounding PgbpC from bases −68 to 28 (where base 1 is the start of transcription). In summary, our results indicate that various stress conditions modulate the expression of gbpC and that CovR negatively regulates the expression of the gbpC gene by directly binding to the promoter region.

Elements involved in S-adenosylmethionine-mediated regulation of the Saccharomyces cerevisiae MET25 gene

1989 ◽  
Vol 9 (8) ◽  
pp. 3292-3298
Author(s):  
D Thomas ◽  
H Cherest ◽  
Y Surdin-Kerjan
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Transcriptional Regulation ◽  
Growth Medium ◽  
Posttranscriptional Regulation ◽  
Promoter Region ◽  
Regulatory Region ◽  
Cis Elements ◽  
Promoter Regions ◽  
Activation Site

In Saccharomyces cerevisiae, the MET25 gene encodes O-acetylhomoserine sulfhydrylase. Synthesis of this enzyme is repressed by the presence of S-adenosylmethionine (AdoMet) in the growth medium. We identified cis elements required for MET25 expression by analyzing small deletions in the MET25 promoter region. The results revealed a regulatory region, acting as an upstream activation site, that activated transcription of MET25 in the absence of methionine or AdoMet. We found that, for the most part, repression of MET25 expression was due to a lack of activation at this site, reinforced by an independent repression mechanism. The activation region contained a repeated dyad sequence that is also found in the promoter regions of other unlinked but coordinately regulated genes (MET3, MET2, and SAM2). We show that the presence of the two dyads is necessary for maximal gene expression. Moreover, we demonstrate that in addition to this transcriptional regulation, a posttranscriptional regulation, probably targeted at the 5' region of mRNA, is involved in MET25 expression.

scholarly journals Ash1 and Tup1 Dependent Repression of the Saccharomyces cerevisiae HO promoter Requires Activator-Dependent Nucleosome Eviction

2020 ◽  
Author(s):  
Emily J. Parnell ◽  
Timothy J. Parnell ◽  
Chao Yan ◽  
Lu Bai ◽  
David J. Stillman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Transcription Factor ◽  
Transcriptional Regulation ◽  
Dna Sequences ◽  
Binding Sites ◽  
Genome Wide ◽  
Intergenic Regions ◽  
Mother Cells ◽  
Activation Cycle

ABSTRACTTranscriptional regulation of the Saccharomyces cerevisiae HO gene is highly complex, requiring a balance of multiple activating and repressing factors to ensure that only a few transcripts are produced in mother cells within a narrow window of the cell cycle. Here, we show that the Ash1 repressor associates with two DNA sequences that are usually concealed within nucleosomes in the HO promoter and recruits the Tup1 corepressor and the Rpd3 histone deacetylase, both of which are required for full repression in daughters. Genome-wide ChIP identified greater than 200 additional sites of co-localization of these factors, primarily within large, intergenic regions from which they could regulate adjacent genes. Most Ash1 binding sites are in nucleosome depleted regions (NDRs), while a small number overlap nucleosomes, similar to HO. We demonstrate that Ash1 binding to the HO promoter does not occur in the absence of the Swi5 transcription factor, which recruits coactivators that evict nucleosomes, including the nucleosomes obscuring the Ash1 binding sites. In the absence of Swi5, artificial nucleosome depletion allowed Ash1 to bind, demonstrating that nucleosomes are inhibitory to Ash1 binding. The location of binding sites within nucleosomes may therefore be a mechanism for limiting repressive activity to periods of nucleosome eviction that are otherwise associated with activation of the promoter. Our results illustrate that activation and repression can be intricately connected, and events set in motion by an activator may also ensure the appropriate level of repression and reset the promoter for the next activation cycle.

scholarly journals Ash1 and Tup1 dependent repression of the Saccharomyces cerevisiae HO promoter requires activator-dependent nucleosome eviction

PLoS Genetics ◽  
2020 ◽  
Vol 16 (12) ◽  
pp. e1009133
Author(s):  
Emily J. Parnell ◽  
Timothy J. Parnell ◽  
Chao Yan ◽  
Lu Bai ◽  
David J. Stillman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Transcription Factor ◽  
Transcriptional Regulation ◽  
Dna Sequences ◽  
Binding Sites ◽  
Genome Wide ◽  
Intergenic Regions ◽  
Mother Cells ◽  
Activation Cycle

Transcriptional regulation of the Saccharomyces cerevisiae HO gene is highly complex, requiring a balance of multiple activating and repressing factors to ensure that only a few transcripts are produced in mother cells within a narrow window of the cell cycle. Here, we show that the Ash1 repressor associates with two DNA sequences that are usually concealed within nucleosomes in the HO promoter and recruits the Tup1 corepressor and the Rpd3 histone deacetylase, both of which are required for full repression in daughters. Genome-wide ChIP identified greater than 200 additional sites of co-localization of these factors, primarily within large, intergenic regions from which they could regulate adjacent genes. Most Ash1 binding sites are in nucleosome depleted regions (NDRs), while a small number overlap nucleosomes, similar to HO. We demonstrate that Ash1 binding to the HO promoter does not occur in the absence of the Swi5 transcription factor, which recruits coactivators that evict nucleosomes, including the nucleosomes obscuring the Ash1 binding sites. In the absence of Swi5, artificial nucleosome depletion allowed Ash1 to bind, demonstrating that nucleosomes are inhibitory to Ash1 binding. The location of binding sites within nucleosomes may therefore be a mechanism for limiting repressive activity to periods of nucleosome eviction that are otherwise associated with activation of the promoter. Our results illustrate that activation and repression can be intricately connected, and events set in motion by an activator may also ensure the appropriate level of repression and reset the promoter for the next activation cycle.

scholarly journals Regulation of Expression of GLT1, the Gene Encoding Glutamate Synthase in Saccharomyces cerevisiae

1998 ◽  
Vol 180 (14) ◽  
pp. 3533-3540 ◽  
Author(s):  
Lourdes Valenzuela ◽  
Paola Ballario ◽  
Cristina Aranda ◽  
Patrizia Filetici ◽  
Alicia González
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Regulation ◽  
Dna Sequences ◽  
Transcriptional Activation ◽  
Type Strain ◽  
Wild Type Strain ◽  
Glutamate Synthase ◽  
Nitrogen Sources ◽  
Wild Type ◽  
Regulation Of Expression

ABSTRACT Saccharomyces cerevisiae glutamate synthase (GOGAT) is an oligomeric enzyme composed of three 199-kDa identical subunits encoded by GLT1. In this work, we analyzed GLT1transcriptional regulation. GLT1-lacZ fusions were prepared and GLT1 expression was determined in a GDH1wild-type strain and in a gdh1 mutant derivative grown in the presence of various nitrogen sources. Null mutants impaired inGCN4, GLN3, GAT1/NIL1, orUGA43/DAL80 were transformed with a GLT1-lacZfusion to determine whether the above-mentioned transcriptional factors had a role in GLT1 expression. A collection of increasingly larger 5′ deletion derivatives of the GLT1 promoter was constructed to identify DNA sequences that could be involved inGLT1 transcriptional regulation. The effect of the lack ofGCN4, GLN3, or GAT1/NIL1 was also tested in the pertinent 5′ deletion derivatives. Our results indicate that (i) GLT1 expression is negatively modulated by glutamate-mediated repression and positively regulated by Gln3p- and Gcn4p-dependent transcriptional activation; (ii) twocis-acting elements, a CGGN15CCG palindrome and an imperfect poly(dA-dT), are present and could play a role inGLT1 transcriptional activation; and (iii) GLT1expression is moderately regulated by GCN4 under amino acid deprivation. Our results suggest that in a wild-type strain grown on ammonium, GOGAT constitutes an ancillary pathway for glutamate biosynthesis.

scholarly journals Elements involved in S-adenosylmethionine-mediated regulation of the Saccharomyces cerevisiae MET25 gene.

1989 ◽  
Vol 9 (8) ◽  
pp. 3292-3298 ◽  
Author(s):  
D Thomas ◽  
H Cherest ◽  
Y Surdin-Kerjan
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Transcriptional Regulation ◽  
Growth Medium ◽  
Posttranscriptional Regulation ◽  
Promoter Region ◽  
Regulatory Region ◽  
Cis Elements ◽  
Promoter Regions ◽  
Activation Site

In Saccharomyces cerevisiae, the MET25 gene encodes O-acetylhomoserine sulfhydrylase. Synthesis of this enzyme is repressed by the presence of S-adenosylmethionine (AdoMet) in the growth medium. We identified cis elements required for MET25 expression by analyzing small deletions in the MET25 promoter region. The results revealed a regulatory region, acting as an upstream activation site, that activated transcription of MET25 in the absence of methionine or AdoMet. We found that, for the most part, repression of MET25 expression was due to a lack of activation at this site, reinforced by an independent repression mechanism. The activation region contained a repeated dyad sequence that is also found in the promoter regions of other unlinked but coordinately regulated genes (MET3, MET2, and SAM2). We show that the presence of the two dyads is necessary for maximal gene expression. Moreover, we demonstrate that in addition to this transcriptional regulation, a posttranscriptional regulation, probably targeted at the 5' region of mRNA, is involved in MET25 expression.

scholarly journals Correlation of methylation status in MTHFR promoter region with recurrent pregnancy loss

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Mai Mahmoud Shaker ◽  
Taghreed Abdelmoniem shalabi ◽  
Khalda said Amr
Keyword(s):  
Dna Methylation ◽  
Dna Sequences ◽  
Promoter Region ◽  
Pregnancy Loss ◽  
Recurrent Pregnancy Loss ◽  
Methylation Status ◽  
Control Group ◽  
Case Group ◽  
Methyl Radical ◽  
Fertile Women

Abstract Background DNA methylation is an epigenetic process for modifying transcription factors in various genes. Methylenetetrahydrofolate reductase (MTHFR) stimulates synthesis of methyl radical in the homocysteine cycle and delivers methyl groups needed in DNA methylation. Furthermore, numerous studies have linked gene polymorphisms of this enzyme with a larger risk of recurrent pregnancy loss (RPL), yet scarce information is available concerning the association between epigenetic deviations in this gene and RPL. Hypermethylation at precise DNA sequences can function as biomarkers for a diversity of diseases. We aimed by this study to evaluate the methylation status of the promoter region of MTHFR gene in women with RPL compared to healthy fertile women. It is a case–control study. Hundred RPL patients and hundred healthy fertile women with no history of RPL as controls were recruited. MTHFR C677T was assessed by polymerase chain reaction-restriction fragment length polymorphism (RFLP). Quantitative evaluation of DNA methylation was performed by high-resolution melt analysis by real-time PCR. Results The median of percentage of MTHFR promoter methylation in RPL cases was 6.45 [0.74–100] vs. controls was 4.50 [0.60–91.7], P value < 0.001. In the case group, 57 hypermethylated and 43 normo-methylated among RPL patients vs. 40 hypermethylated and 60 normo-methylated among controls, P< 0.005. Frequency of T allele in C677T MTHFR gene among RPL patients was 29% vs. 23% among the control group; C allele vs. T allele: odds ratio (OR) = 1.367 (95% confidence interval (CI) 0.725–2.581). Conclusion Findings suggested a significant association between hypermethylation of the MTHFR promoter region in RPL patients compared to healthy fertile women.

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