scholarly journals Intracellular Maltose Is Sufficient To Induce MAL Gene Expression in Saccharomyces cerevisiae

2002 ◽  
Vol 1 (5) ◽  
pp. 696-703 ◽  
Author(s):  
Xin Wang ◽  
Mehtap Bali ◽  
Igor Medintz ◽  
Corinne A. Michels
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Plantago Major ◽  
Null Mutant ◽  
Transport Activity ◽  
Maltose Permease ◽  
Maltose Transport ◽  
Constitutive Overexpression ◽  
Reduced Rate

ABSTRACT The presence of maltose induces MAL gene expression in Saccharomyces cells, but little is known about how maltose is sensed. Strains with all maltose permease genes deleted are unable to induce MAL gene expression. In this study, we examined the role of maltose permease in maltose sensing by substituting a heterologous transporter for the native maltose permease. PmSUC2 encodes a sucrose transporter from the dicot plant Plantago major that exhibits no significant sequence homology to maltose permease. When expressed in Saccharomyces cerevisiae, PmSUC2 is capable of transporting maltose, albeit at a reduced rate. We showed that introduction of PmSUC2 restores maltose-inducible MAL gene expression to a maltose permease-null mutant and that this induction requires the MAL activator. These data indicate that intracellular maltose is sufficient to induce MAL gene expression independently of the mechanism of maltose transport. By using strains expressing defective mal61 mutant alleles, we demonstrated a correlation between the rate of maltose transport and the level of the induction, which is particularly evident in medium containing very limiting concentrations of maltose. Moreover, our results indicate that a rather low concentration of intracellular maltose is needed to trigger MAL gene expression. We also showed that constitutive overexpression of either MAL61 maltose permease or PmSUC2 suppresses the noninducible phenotype of a defective mal13 MAL-activator allele, suggesting that this suppression is solely a function of maltose transport activity and is not specific to the sequence of the permease. Our studies indicate that maltose permease does not function as the maltose sensor in S. cerevisiae.

Inactivation of maltose permease and maltase in sporulatingSaccharomyces cerevisiae

2000 ◽  
Vol 46 (4) ◽  
pp. 383-386 ◽  
Author(s):  
Julio C Ferreira ◽  
Anita D Panek ◽  
Pedro S de Araujo
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Yeast Strain ◽  
Cell Concentration ◽  
Alternative Mechanism ◽  
Sporulation Medium ◽  
Maltose Permease ◽  
Maltose Transport ◽  
Maltase Activity ◽  
Acetate Medium

Maltose transport and maltase activities were inactivated during sporulation of a MAL constitutive yeast strain harboring different MAL loci. Both activities were reduced to almost zero after 5 h of incubation in sporulation medium. The inactivation of maltase and maltose permease seems to be related to optimal sporulation conditions such as a suitable supply of oxygen and cell concentration in the sporulating cultures, and occurs in the fully derepressed conditions of incubation in the sporulation acetate medium. The inactivation of maltase and maltose permease under sporulation conditions in MAL constitutive strains suggests an alternative mechanism for the regulation of the MAL gene expression during the sporulation process.Key words: maltase activity, maltose permease activity, sporulation, Saccharomyces cerevisiae.

Regulation of mitochondrial gene expression in Saccharomyces cerevisiae: the role of RNA-binding enzymes

2001 ◽  
Vol 1 (S1) ◽  
Author(s):  
H van der Spek ◽  
M Siep ◽  
L de Jong ◽  
SDJ Elzinga ◽  
K van Oosterum ◽  
...  
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Rna Binding ◽  
Mitochondrial Gene ◽  
Mitochondrial Gene Expression

scholarly journals Role of HSP90 in Salt Stress Tolerance via Stabilization and Regulation of Calcineurin

2000 ◽  
Vol 20 (24) ◽  
pp. 9262-9270 ◽  
Author(s):  
Jun Imai ◽  
Ichiro Yahara
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Salt Stress ◽  
Stress Tolerance ◽  
Normal Level ◽  
Immune Complexes ◽  
Salt Stress Tolerance ◽  
Stressed Cells ◽  
Calcineurin Activity

ABSTRACT The role of HSP90 in stress tolerance was investigated inSaccharomyces cerevisiae. Cells showing 20-fold overexpression of Hsc82, an HSP90 homologue in yeast, were hypersensitive to high-NaCl or H-LiCl stresses. Hsc82-overexpressing cells appeared similar to calcineurin-defective cells in salt sensitivity and showed reduced levels of calcineurin-dependent gene expression. Co-overexpression of Cna2, the catalytic subunit of calcineurin, suppressed the hypersensitivity. Cna2 and Hsc82 coimmunoprecipitated from control cells grown under normal conditions but not from stressed cells. In contrast, coimmunoprecipitation was detected with Hsc82-overexpressing cells even after exposure to stresses. Cna2 immune complexes from stressed control cells showed a significant level of calcineurin activity, whereas those from stressed Hsc82-overexpressing cells did not. Treatment of extracts from Hsc82-overexpressing cells with Ca2+-calmodulin increased the calcineurin activity associated with Cna2 immune complexes. Geldanamycin, an inhibitor of HSP90 abolished the coimmunoprecipitation but did not activate calcineurin. When the expression level of Hsc82 decreased to below 30% of the normal level, cells also became hypersensitive to salt stress. In these cells, the amount of Cna2 was reduced, likely as a result of degradation. The present results showed that Hsc82 binds to and stabilizes Cna2 and that dissociation of Cna2 from Hsc82 is necessary for its activation.

scholarly journals Interplay of a Ligand Sensor and an Enzyme in Controlling Expression of the Saccharomyces cerevisiae GAL Genes

2011 ◽  
Vol 11 (3) ◽  
pp. 334-342 ◽  
Author(s):  
Dariusz Abramczyk ◽  
Stacey Holden ◽  
Christopher J. Page ◽  
Richard J. Reece
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Transcriptional Control ◽  
Transcriptional Response ◽  
Content Type ◽  
Considerable Debate ◽  
Active Transcription ◽  
Gal Genes ◽  
The Subject

ABSTRACT The regulation of the Saccharomyces cerevisiae GAL genes in response to galactose as a source of carbon has served as a paradigm for eukaryotic transcriptional control over the last 50 years. Three proteins—a transcriptional activator (Gal4p), an inhibitor (Gal80p), and a ligand sensor (Gal3p)—control the switch between inert and active gene expression. The molecular mechanism by which the recognition of galactose within the cell is converted into a transcriptional response has been the subject of considerable debate. In this study, using a novel and powerful method of localizing active transcription factors within the nuclei of cells, we show that a short-lived complex between Gal4p, Gal80p, and Gal3p occurs soon after the addition of galactose to cells to activate GAL gene expression. Gal3p is subsequently replaced in this complex by Gal1p, and a Gal4p-Gal80p-Gal1p complex is responsible for the continued expression of the GAL genes. The transient role of the ligand sensor indicates that current models for the induction and continued expression of the yeast GAL genes need to be reevaluated.

scholarly journals Intestinal DCs global gene expression dynamics affected by recombinant baker’s yeasts saccharomyces cerevisiae

2019 ◽  
Author(s):  
Baoquan Han ◽  
Tingting Zhang ◽  
Xinyi Li ◽  
Rui Zhao ◽  
Wei Ge ◽  
...  
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Inflammatory Response ◽  
Budding Yeast ◽  
Global Gene Expression ◽  
Transcriptome Profile ◽  
Delivery Vehicle ◽  
Gene Delivery Vehicle ◽  
Gene Expression Dynamics

Abstract Background The baker’s yeast, saccharomyces cerevisiae, has been widely used throughout our daily life in diverse aspects for thousands of years. The saccharomyces cerevisiae was found to specifically target the dendritic cells (DCs) in mammalian with a manner of antigen-receptor interaction as described previously. It is necessary to investigate the effect of the baker’s yeasts on global gene expression dynamics of intestinal DCs and explore the possibilities of using baker’s yeast as gene delivery vehicle to modulate animal’s immune functions Results with a murine oral delivery model in vivo, we confirmed the feasibility of using budding yeast as gene delivery vehicle to the intestinal DCs using the Western blots. We then examined the transcriptome profile of the mouse intestinal DCs upon yeast stimulus. The enrichment analysis of unique transcripts indicated the beneficial role of yeast in modulating the DC-mediated adaptive immunity. Compared with previous study, we also found that a large fraction of the regulated genes is coincident with the response induced by other fungus, suggesting that the budding yeast induces a similar tailored unique genetic re-programming of DCs. Another analysis of transcriptome profile indicated that expression of β-catenin gene significantly changes DCs gene expression related to inflammatory response and cell adhesion. Conclusions Here, we defined the role of budding yeast on global gene expression of intestinal DCs, and confirmed the important role of β-catenin gene on the DCs-related inflammatory response, which provides a framework for the development of mucosa yeast-based DNA vaccine.

scholarly journals Defects in Assembly of the Extracellular Matrix Are Responsible for Altered Morphogenesis of a Candida albicans phr1 Mutant

1998 ◽  
Vol 180 (1) ◽  
pp. 163-166 ◽  
Author(s):  
Laura Popolo ◽  
Marina Vai
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
Parental Strain ◽  
Germ Tube ◽  
Null Mutant ◽  
Yeast Form ◽  
Insoluble Glucan ◽  
Cross Linker ◽  
External Ph

ABSTRACT Analysis of Candida albicans cells using antibodies directed against Gas1p/Ggp1p, Saccharomyces cerevisiaehomolog of Phr1p, revealed that Phr1p is a glycoprotein of about 88 kDa whose accumulation increases with the rise of external pH. This polypeptide is present both in the yeast form and during germ tube induction. In the Phr1− cells at pH 8 the solubility of glucans in alkali is greatly affected. In the parental strain the alkali-soluble/-insoluble glucan ratio shows a 50% decrease at pH 8 with respect to pH 4.5, whereas in the null mutant it is unchanged, indicating the lack of a polymer cross-linker activity induced by the rise of pH. The mutant has a sixfold increase in chitin level and is hypersensitive to calcofluor. Consistently with a role of chitin in strengthening the cell wall, Phr1− cells are more sensitive to nikkomycin Z than the parental strain.

scholarly journals Metabolic Signals Trigger Glucose-Induced Inactivation of Maltose Permease in Saccharomyces

2000 ◽  
Vol 182 (3) ◽  
pp. 647-654 ◽  
Author(s):  
Hua Jiang ◽  
Igor Medintz ◽  
Bin Zhang ◽  
Corinne A. Michels
Keyword(s):  
Glucose Transport ◽  
Mammalian Cells ◽  
Glucose Repression ◽  
Carbon Sources ◽  
Glucose Sensing ◽  
High Rate ◽  
Transport Activity ◽  
Maltose Permease ◽  
Maltose Transport ◽  
Rapid Inactivation

ABSTRACT Organisms such as Saccharomyces capable of utilizing several different sugars selectively ferment glucose when less desirable carbon sources are also available. This is achieved by several mechanisms. Glucose down-regulates the transcription of genes involved in utilization of these alternate carbon sources. Additionally, it causes posttranslational modifications of enzymes and transporters, leading to their inactivation and/or degradation. Two glucose sensing and signaling pathways stimulate glucose-induced inactivation of maltose permease. Pathway 1 uses Rgt2p as a sensor of extracellular glucose and causes degradation of maltose permease protein. Pathway 2 is dependent on glucose transport and stimulates degradation of permease protein and very rapid inactivation of maltose transport activity, more rapid than can be explained by loss of protein alone. In this report, we characterize signal generation through pathway 2 using the rapid inactivation of maltose transport activity as an assay of signaling activity. We find that pathway 2 is dependent onHXK2 and to a lesser extent HXK1. The correlation between pathway 2 signaling and glucose repression suggests that these pathways share common upstream components. We demonstrate that glucose transport via galactose permease is able to stimulate pathway 2. Moreover, rapid transport and fermentation of a number of fermentable sugars (including galactose and maltose, not just glucose) are sufficient to generate a pathway 2 signal. These results indicate that pathway 2 responds to a high rate of sugar fermentation and monitors an intracellular metabolic signal. Production of this signal is not specific to glucose, glucose catabolism, glucose transport by the Hxt transporters, or glucose phosphorylation by hexokinase 1 or 2. Similarities between this yeast glucose sensing pathway and glucose sensing mechanisms in mammalian cells are discussed.

The role of histone ubiquitylation and deubiquitylation in gene expression as determined by the analysis of an HTB1 K123R Saccharomyces cerevisiae strain

2007 ◽  
Vol 277 (5) ◽  
pp. 491-506 ◽  
Author(s):  
A. Irina Mutiu ◽  
Stephen M. T. Hoke ◽  
Julie Genereaux ◽  
Gaoyang Liang ◽  
Christopher J. Brandl
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Histone Ubiquitylation

scholarly journals Expression of the Mitochondrial ADP/ATP Carrier inEscherichia coli

2001 ◽  
Vol 276 (15) ◽  
pp. 11499-11506 ◽  
Author(s):  
Simone Heimpel ◽  
Gabriele Basset ◽  
Sabine Odoy ◽  
Martin Klingenberg
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Inclusion Bodies ◽  
Positive Charge ◽  
Inescherichia Coli ◽  
Transport Activity ◽  
E Coli ◽  
The Matrix ◽  
A Charge

Previously, the role of residues in the ADP/ATP carrier (AAC) fromSaccharomyces cerevisiaehas been studied by mutagenesis, but the dependence of mitochondrial biogenesis on functional AAC impedes segregation of the mutational effects on transport and biogenesis. Unlike other mitochondrial carriers, expression of the AAC from yeast or mammalians inEscherichia coliencountered difficulties because of disparate codon usage. Here we introduce the AAC fromNeurospora crassainE. coli, where it is accumulated in inclusion bodies and establish the reconstitution conditions. AAC expressed with heat shock vector gave higher activity than with pET-3a. Transport activity was absolutely dependent on cardiolipin. The 10 single mutations of intrahelical positive residues and of the matrix repeat (+X+) motif resulted in lower activity, except of R245A. R143A had decreased sensitivity toward carboxyatractylate. The ATP-linked exchange is generally more affected than ADP exchange. This reflects a charge network that propagates positive charge defects to ATP4−more strongly than to ADP3−transport. Comparison to the homologous mutants of yeast AAC2 permits attribution of the roles of these residues more to ADP/ATP transport or to AAC import into mitochondria.

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