scholarly journals Regulation of Gluconeogenesis in Saccharomyces cerevisiae Is Mediated by Activator and Repressor Functions of Rds2

2007 ◽  
Vol 27 (22) ◽  
pp. 7895-7905 ◽  
Author(s):  
Nitnipa Soontorngun ◽  
Marc Larochelle ◽  
Simon Drouin ◽  
François Robert ◽  
Bernard Turcotte
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Target Genes ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Dual Function ◽  
Snf1 Kinase ◽  
Zinc Cluster ◽  
Chip Technology

ABSTRACT In Saccharomyces cerevisiae, RDS2 encodes a zinc cluster transcription factor with unknown function. Here, we unravel a key function of Rds2 in gluconeogenesis using chromatin immunoprecipitation-chip technology. While we observed that Rds2 binds to only a few promoters in glucose-containing medium, it binds many additional genes when the medium is shifted to ethanol, a nonfermentable carbon source. Interestingly, many of these genes are involved in gluconeogenesis, the tricarboxylic acid cycle, and the glyoxylate cycle. Importantly, we show that Rds2 has a dual function: it directly activates the expression of gluconeogenic structural genes while it represses the expression of negative regulators of this pathway. We also show that the purified DNA binding domain of Rds2 binds in vitro to carbon source response elements found in the promoters of target genes. Finally, we show that upon a shift to ethanol, Rds2 activation is correlated with its hyperphosphorylation by the Snf1 kinase. In summary, we have characterized Rds2 as a novel major regulator of gluconeogenesis.

scholarly journals Aca1 and Aca2, ATF/CREB Activators in Saccharomyces cerevisiae, Are Important for Carbon Source Utilization but Not the Response to Stress

2000 ◽  
Vol 20 (12) ◽  
pp. 4340-4349 ◽  
Author(s):  
M. Adelaida Garcia-Gimeno ◽  
Kevin Struhl
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Target Genes ◽  
Carbon Sources ◽  
Biological Functions ◽  
Carbon Source Utilization ◽  
The Family ◽  
Response To Stress

ABSTRACT In Saccharomyces cerevisiae, the family of ATF/CREB transcriptional regulators consists of a repressor, Acr1 (Sko1), and two activators, Aca1 and Aca2. The AP-1 factor Gen4 does not activate transcription through ATF/CREB sites in vivo even though it binds these sites in vitro. Unlike ATF/CREB activators in other species, Aca1- and Aca2-dependent transcription is not affected by protein kinase A or by stress, and Aca1 and Aca2 are not required for Hog1-dependent salt induction of transcription through an optimal ATF/CREB site. Aca2 is important for a variety of biological functions including growth on nonoptimal carbon sources, and Aca2-dependent activation is modestly regulated by carbon source. Strains lacking Aca1 are phenotypically normal, but overexpression of Aca1 suppresses some defects associated with the loss of Aca2, indicating a functional overlap between Aca1 and Aca2. Acr1 represses transcription both by recruiting the Cyc8-Tup1 corepressor and by directly competing with Aca1 and Aca2 for target sites. Acr1 does not fully account for osmotic regulation through ATF/CREB sites, and a novel Hog1-dependent activator(s) that is not a bZIP protein is required for ATF/CREB site activation in response to high salt. In addition, Acr1 does not affect a number of phenotypes that arise from loss of Aca2. Thus, members of the S. cerevisiae ATF/CREB family have overlapping, but distinct, biological functions and target genes.

scholarly journals Key Role of Ser562/661 in Snf1-Dependent Regulation of Cat8p in Saccharomyces cerevisiae and Kluyveromyces lactis

2004 ◽  
Vol 24 (10) ◽  
pp. 4083-4091 ◽  
Author(s):  
Godefroid Charbon ◽  
Karin D. Breunig ◽  
Ruddy Wattiez ◽  
Jean Vandenhaute ◽  
Isabelle Noël-Georis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Target Genes ◽  
Kluyveromyces Lactis ◽  
Active Form ◽  
Phosphorylation Site ◽  
Carbon Sources ◽  
Mutant Form ◽  
Zinc Cluster

ABSTRACT Utilization of nonfermentable carbon sources by Kluyveromyces lactis and Saccharomyces cerevisiae requires the Snf1p kinase and the Cat8p transcriptional activator, which binds to carbon source-responsive elements of target genes. We demonstrate that KlSnf1p and KlCat8p from K. lactis interact in a two-hybrid system and that the interaction is stronger with a kinase-dead mutant form of KlSnf1p. Of two putative phosphorylation sites in the KlCat8p sequence, serine 661 was identified as a key residue governing KlCat8p regulation. Serine 661 is located in the middle homology region, a regulatory domain conserved among zinc cluster transcription factors, and is part of an Snf1p consensus phosphorylation site. Single mutations at this site are sufficient to completely change the carbon source regulation of the KlCat8p transactivation activity observed. A serine-to-glutamate mutant form mimicking constitutive phosphorylation results in a nearly constitutively active form of KlCat8p, while a serine-to-alanine mutation has the reverse effect. Furthermore, it is shown that KlCat8p phosphorylation depends on KlSNF1. The Snf1-Cat8 connection is evolutionarily conserved: mutation of corresponding serine 562 of ScCat8p gave similar results in S. cerevisiae. The enhanced capacity of ScCat8S562E to suppress the phenotype caused by snf1 strengthens the hypothesis of direct phosphorylation of Cat8p by Snf1p. Unlike that of S. cerevisiae ScCAT8, KlCAT8 transcription is not carbon source regulated, illustrating the prominent role of posttranscriptional regulation of Cat8p in K. lactis.

Metabolic control in Acinetobacter sp. I. Effect of C4 versus C2 and C3 substrates on isocitrate lyase synthesis

1970 ◽  
Vol 16 (8) ◽  
pp. 769-774 ◽  
Author(s):  
Norma J. Herman ◽  
Emily J. Bell
Keyword(s):  
Carbon Source ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Specific Activity ◽  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Enzyme Synthesis ◽  
Synthetase Activity ◽  
The Glyoxylate Cycle

The comparative effects of various substrates serving as sole carbon and energy source or as a supplemental nutrient on the synthesis of isocitrate lyase by a species of Acinetobacter have been investigated. Previous work has shown that succinate, as carbon source, allows some late, limited induction of enzyme synthesis. No increase in synthesis is seen above the basal level, however, in cultures growing in a medium containing L-malate as a sole carbon source. The addition of acetate to cultures growing in media containing either of the C4 intermediates results in rapid enzyme induction. Further, Acinetobacter grows very well in pyruvate medium and isocitrate lyase is synthesized to a significant extent, indicating that the glyoxylate cycle is acting anaplerotically under these conditions. Phosphoenolpyruvate synthetase activity has been demonstrated in this organism; levels comparable to those observed in Escherichia coli have been detected; the levels of NAD- and NADP-linked "malic enzyme" and phosphoenolpyruvate carboxykinase, enzymes functioning in C4 to C3 conversion, do not fluctuate with the various carbon sources tested; i.e. no correlation between the in vitro specific activity of these enzymes and the levels of isocitrate lyase activity may be made. All of the data are consistent with the hypothesis that, in this aerobic organism, as opposed to the facultative E. coli, the C4 intermediates of the tricarboxylic acid cycle may be more direct "coarse" control metabolites regulating the rate of the glyoxylate cycle.

Saccharomyces cerevisiae contains two functional citrate synthase genes

1986 ◽  
Vol 6 (6) ◽  
pp. 1936-1942
Author(s):  
K S Kim ◽  
M S Rosenkrantz ◽  
L Guarente
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Nuclear Gene ◽  
Tricarboxylic Acid ◽  
Yeast Genome ◽  
Gene Encoding ◽  
Acid Cycle ◽  
Nonfermentable Carbon Source

The tricarboxylic acid cycle occurs within the mitochondria of the yeast Saccharomyces cerevisiae. A nuclear gene encoding the tricarboxylic acid cycle enzyme citrate synthase has previously been isolated (M. Suissa, K. Suda, and G. Schatz, EMBO J. 3:1773-1781, 1984) and is referred to here as CIT1. We report here the isolation, by an immunological method, of a second nuclear gene encoding citrate synthase (CIT2). Disruption of both genes in the yeast genome was necessary to produce classical citrate synthase-deficient phenotypes: glutamate auxotrophy and poor growth on rich medium containing lactate, a nonfermentable carbon source. Therefore, the citrate synthase produced from either gene was sufficient for these metabolic roles. Transcription of both genes was maximally repressed in medium containing both glucose and glutamate. However, transcription of CIT1 but not of CIT2 was derepressed in medium containing a nonfermentable carbon source. The significance of the presence of two genes encoding citrate synthase in S. cerevisiae is discussed.

scholarly journals CAT8, a new zinc cluster-encoding gene necessary for derepression of gluconeogenic enzymes in the yeast Saccharomyces cerevisiae.

1995 ◽  
Vol 15 (4) ◽  
pp. 1915-1922 ◽  
Author(s):  
D Hedges ◽  
M Proft ◽  
K D Entian
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Carbon Source ◽  
Gene Activation ◽  
Carbon Sources ◽  
Source Analysis ◽  
Yeast Saccharomyces Cerevisiae ◽  
Gluconeogenic Enzymes ◽  
Zinc Cluster ◽  
Promoter Fusion

The expression of gluconeogenic fructose-1,6-bisphosphatase (encoded by the FBP1 gene) depends on the carbon source. Analysis of the FBP1 promoter revealed two upstream activating elements, UAS1FBP1 and UAS2FBP1, which confer carbon source-dependent regulation on a heterologous reporter gene. On glucose media neither element was activated, whereas after transfer to ethanol a 100-fold derepression was observed. This gene activation depended on the previously identified derepression genes CAT1 (SNF1) (encoding a protein kinase) and CAT3 (SNF4) (probably encoding a subunit of Cat1p [Snf1p]). Screening for mutations specifically involved in UAS1FBP1 derepression revealed the new recessive derepression mutation cat8. The cat8 mutants also failed to derepress UAS2FBP1, and these mutants were unable to grow on nonfermentable carbon sources. The CAT8 gene encodes a zinc cluster protein related to Saccharomyces cerevisiae Gal4p. Deletion of CAT8 caused a defect in glucose derepression which affected all key gluconeogenic enzymes. Derepression of glucose-repressible invertase and maltase was still normally regulated. A CAT8-lacZ promoter fusion revealed that the CAT8 gene itself is repressed by Cat4p (Mig1p). These results suggest that gluconeogenic genes are derepressed upon binding of Cat8p, whose synthesis depends on the release of Cat4p (Mig1p) from the CAT8 promoter. However, gluconeogenic promoters are still glucose repressed in cat4 mutants, which indicates that in addition to its transcription, the Cat8p protein needs further activation. The observation that multicopy expression of CAT8 reverses the inability of cat1 and cat3 mutants to grow on ethanol indicates that Cat8p might be the substrate of the Cat1p/Cat3p protein kinase.

scholarly journals Phosphorylation and Maximal Activity of Saccharomyces cerevisiae Meiosis-Specific Transcription Factor Ndt80 Is Dependent on Ime2

2002 ◽  
Vol 22 (20) ◽  
pp. 7024-7040 ◽  
Author(s):  
Richelle Sopko ◽  
Sheetal Raithatha ◽  
David Stuart
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factor ◽  
Target Genes ◽  
Meiotic Chromosome ◽  
Maximal Activity ◽  
Direct Role ◽  
Specific Transcription Factor ◽  
Mutant Strains ◽  
Sporulation Genes

ABSTRACT The Saccharomyces cerevisiae meiosis-specific transcription factor Ndt80 is responsible for the induction of a class of genes referred to as middle sporulation genes. Among the members of this family are the B-type cyclins and other genes whose products are required for meiotic chromosome division and spore morphogenesis. Inactivation of NDT80 leads to a failure to induce the middle sporulation genes and a subsequent arrest in pachytene. The expression of NDT80 is itself highly regulated. The initial transcription of NDT80 is dependent upon the protein kinase Ime2; once Ndt80 protein accumulates, it activates its own promoter, thus generating an autoactivation loop. In addition to being transcriptionally regulated, Ndt80 protein is posttranslationally regulated. Phosphorylation of Ndt80 occurs coincident with its activation as a transcription factor. If expressed prematurely in meiosis, Ndt80 accumulates initially in an unmodified form that is subsequently modified by phosphorylation. In contrast, Ndt80 expressed in ime2 mutant strains does not become modified and has a reduced ability to activate transcription of its target genes. Ime2 can also phosphorylate Ndt80 in vitro, further supporting a direct role for Ime2 in the phosphorylation of Ndt80. These data indicate that Ime2 plays a novel and previously unexpected role in promoting chromosome dissemination and progress through meiotic development by activating Ndt80.

scholarly journals Structure of glyoxysomal malate dehydrogenase (MDH3) from Saccharomyces cerevisiae

2018 ◽  
Vol 74 (10) ◽  
pp. 617-624 ◽  
Author(s):  
Shu Moriyama ◽  
Kazuya Nishio ◽  
Tsunehiro Mizushima
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Malate Dehydrogenase ◽  
Ternary Complex ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Tricarboxylic Acid ◽  
Mitochondrial Enzyme ◽  
Open Conformation ◽  
Metabolism Enzyme ◽  
The Glyoxylate Cycle

Malate dehydrogenase (MDH), a carbohydrate and energy metabolism enzyme in eukaryotes, catalyzes the interconversion of malate to oxaloacetate (OAA) in conjunction with that of nicotinamide adenine dinucleotide (NAD+) to NADH. Three isozymes of MDH have been reported in Saccharomyces cerevisiae: MDH1, MDH2 and MDH3. MDH1 is a mitochondrial enzyme and a member of the tricarboxylic acid cycle, whereas MDH2 is a cytosolic enzyme that functions in the glyoxylate cycle. MDH3 is a glyoxysomal enzyme that is involved in the reoxidation of NADH, which is produced during fatty-acid β-oxidation. The affinity of MDH3 for OAA is lower than those of MDH1 and MDH2. Here, the crystal structures of yeast apo MDH3, the MDH3–NAD+ complex and the MDH3–NAD+–OAA ternary complex were determined. The structure of the ternary complex suggests that the active-site loop is in the open conformation, differing from the closed conformations in mitochondrial and cytosolic malate dehydrogenases.

Yeast intragenic transcriptional control: activation and repression sites within the coding region of the Saccharomyces cerevisiae LPD1 gene

1994 ◽  
Vol 14 (1) ◽  
pp. 214-225
Author(s):  
D A Sinclair ◽  
G D Kornfeld ◽  
I W Dawes
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Rna Polymerase Ii ◽  
Mutational Analysis ◽  
Lacz Fusion ◽  
Dependent Manner ◽  
Coding Region ◽  
Coding Sequence

Though widely recognized in higher eukaryotes, the regulation of Saccharomyces cerevisiae genes transcribed by RNA polymerase II by proteins that bind within the coding sequence remains largely speculative. We have shown for the LPD1 gene, encoding lipoamide dehydrogenase, that the coding sequence between +13 and +469 activated gene expression of an LPD1::lacZ fusion by up to sixfold in the presence of the upstream promoter. This downstream region, inserted upstream of a promoterless CYC1::lacZ fusion, activated gene expression in a carbon source-dependent manner by a factor of 15 to 111, independent of orientation. Deletion and mutational analysis identified two downstream activation sites (DAS1 and DAS2) and two downstream repressor sites (DRS1 and DRS2) that influence the rate of LPD1 transcription rather than mRNA degradation or translation. Activation from the DAS1 region (positions +137 to +191), encompassing a CDEI-like element, is twofold under derepressive conditions. Activation from DAS2 (+291 to +296), a CRE-like motif, is 12-fold for both repressed and derepressed states. DRS1, a pair of adjacent and opposing ABF1 sites (+288 to +313), is responsible for a 1.3- to 2-fold repression of transcription, depending on the carbon source. DRS1 requires the concerted action of DRS2 (a RAP1 motif at position +406) for repression of transcription only when the gene is induced. Gel mobility shift analysis and in vitro footprinting have shown that proteins bind in vitro to these downstream elements.

scholarly journals Dosage-dependent modulation of glucose repression by MSN3 (STD1) in Saccharomyces cerevisiae.

1994 ◽  
Vol 14 (3) ◽  
pp. 1972-1978 ◽  
Author(s):  
E J Hubbard ◽  
R Jiang ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Glucose Repression ◽  
Binding Studies ◽  
Glucose Limitation ◽  
Snf1 Kinase ◽  
Multicopy Suppressor ◽  
C Terminus ◽  
In The Wild

The SNF1 protein kinase of Saccharomyces cerevisiae is required to relieve glucose repression of transcription. To identify components of the SNF1 pathway, we isolated multicopy suppressors of defects caused by loss of SNF4, an activator of the SNF1 kinase. Increased dosage of the MSN3 gene restored invertase expression in snf4 mutants and also relieved glucose repression in the wild type. Deletion of MSN3 caused no substantial phenotype, and we identified a homolog, MTH1, encoding a protein 61% identical to MSN3. Both are also homologous to chicken fimbrin, human plastin, and yeast SAC6 over a 43-residue region. Deletion of MSN3 and MTH1 together impaired derepression of invertase in response to glucose limitation. Finally, MSN3 physically interacts with the SNF1 protein kinase, as assayed by a two-hybrid system and by in vitro binding studies. MSN3 is the same gene as STD1, a multicopy suppressor of defects caused by overexpression of the C terminus of TATA-binding protein (R. W. Ganster, W. Shen, and M. C. Schmidt, Mol. Cell. Biol. 13:3650-3659, 1993). Taken together, these data suggest that MSN3 modulates the regulatory response to glucose and may couple the SNF1 pathway to transcription.

scholarly journals The Zinc Cluster Protein Sut1 Contributes to Filamentation in Saccharomyces cerevisiae

2012 ◽  
Vol 12 (2) ◽  
pp. 244-253 ◽  
Author(s):  
Helen A. Foster ◽  
Mingfei Cui ◽  
Angel Naveenathayalan ◽  
Heike Unden ◽  
Ralf Schwanbeck ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nutrient Limitation ◽  
Target Genes ◽  
Transcriptional Regulator ◽  
Filamentous Growth ◽  
Anaerobic Conditions ◽  
Content Type ◽  
Zinc Cluster ◽  
Sterol Uptake ◽  
Diploid Cells

ABSTRACTSut1 is a transcriptional regulator of the Zn(II)2Cys6family in the budding yeastSaccharomyces cerevisiae. The only function that has been attributed to Sut1 is sterol uptake under anaerobic conditions. Here, we show that Sut1 is also expressed in the presence of oxygen, and we identify a novel function for Sut1.SUT1overexpression blocks filamentous growth, a response to nutrient limitation, in both haploid and diploid cells. This inhibition by Sut1 is independent of its function in sterol uptake. Sut1 downregulates the expression ofGAT2,HAP4,MGA1,MSN4,NCE102,PRR2,RHO3, andRHO5. Several of these Sut1 targets (GAT2,HAP4,MGA1,RHO3, andRHO5) are essential for filamentation in haploids and/or diploids. Furthermore, the expression of the Sut1 target genes, with the exception ofMGA1, is induced during filamentous growth. We also show thatSUT1expression is autoregulated and inhibited by Ste12, a key transcriptional regulator of filamentation. We propose that Sut1 partially represses the expression ofGAT2,HAP4,MGA1,MSN4,NCE102,PRR2,RHO3, andRHO5when nutrients are plentiful. Filamentation-inducing conditions relieve this repression by Sut1, and the increased expression of Sut1 targets triggers filamentous growth.

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