SEARCH · PubMed Health

Results for “SACCHAROMYCES CEREVISIAE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed2006

Natural hybrids from Saccharomyces cerevisiae, Saccharomyces bayanus and Saccharomyces kudriavzevii in wine fermentations.

Several wine isolates of Saccharomyces were analysed for six molecular markers, five nuclear and one mitochondrial, and new natural interspecific hybrids were identified. The molecular characterization of these Saccharomyces hybrids was performed based on the restriction analysis of five nuclear genes (CAT8, CYR1, GSY1, MET6 and OPY1, located in different chromosomes), the ribosomal region encompassing the 5.8S rRNA gene and the two internal transcribed spacers, and sequence analysis of the mitochondrial gene COX2. This method allowed us to identify and characterize new hybrids between Saccharomyces cerevisiae and Saccharomyces kudriavzevii, between S. cerevisiae and Saccharomyces bayanus, as well as a triple hybrid S. bayanusxS. cerevisiaexS. kudriavzevii. This is the first time that S. cerevisiaexS. kudriavzevii hybrids have been described which have been involved in wine fermentation.

DNA, Fungal↗

PubMed2004

Rapid identification and differentiation of Saccharomyces cerevisiae, Saccharomyces bayanus and their hybrids by multiplex PCR.

AIMS: To develop a multiplex PCR assay for the specific identification and differentiation of Saccharomyces cerevisiae, S. bayanus and their hybrids. METHODS AND RESULTS: Two sets of primers with sequences complementary to the region YBR033w were used. A single amplicon of 1710 bp or 329 bp was obtained with species S. cerevisiae and S. bayanus, respectively, while the presence of both bands was observed in S. pastorianus because of its hybrid nature. Both amplification products were also obtained after amplification from DNA of several laboratory S. cerevisiae x S. bayanus hybrid strains. CONCLUSIONS: Multiplex PCR was optimized for the rapid and reliable identification of S. cerevisiae, S. bayanus and their hybrids. SIGNIFICANCE AND IMPACT OF THE STUDY: The procedure may be used for routine detection of the most common Saccharomyces sensu stricto yeasts involved in industrial fermentation processes, overcoming the problems of conventional techniques.

DNA, Fungal↗

PubMedDate not supplied

[Component activity of the isoenzyme spectra of Saccharomyces cerevisiae, Saccharomyces carlsbergensis and their hybrids].

The object of this work was to study the activity and the isozyme spectra of hexokinase (the triggering enzyme of glycolysis), glucose-6-phosphate dehydrogenase (the key enzyme of the pentose-phosphate shunt), malate dehydrogenase and isocitrate dehydrogenase (the enzymes of the citric acid cycle) and alcohol dehydrogenase (the enzyme involved in the first steps of ethanol oxidation) in Saccharomyces cerevisiae, race Ya, S. carlsbergensis, race 4228, and their hybrid 67. The parent organisms and their hybrid were shown to differ from one another in the qualitative composition and the activity of the isozyme spectra of the above enzymes.

Alcohol Oxidoreductases↗

PubMed2003

Quantitative comparison of transient growth of Saccharomyces cerevisiae, Saccharomyces kluyveri, and Kluyveromyces lactis.

A multitude of metabolic regulations occur in yeast, particularly under dynamic process conditions, such as under sudden glucose excess. However, quantification of regulations and classification of yeast strains under these conditions have yet to be elucidated, which requires high-frequency and consistent quantification of the metabolic response. The present study aimed at quantifying the dynamic regulation of the central metabolism of strains Saccharomyces cerevisiae, S. kluyveri, and Kluyveromyces lactis upon sudden glucose excess, accomplished by a shift-up in dilution rate inside of the oxidative region using a small metabolic flux model. It was found that, under transient growth conditions, S. kluyveri behaved like K. lactis, while classification using steady-state conditions would position S. kluyveri close to S. cerevisiae. For transient conditions and based on the observation whether excess glucose is initially used for catabolism (energy) or anabolism (carbon), we propose to classify strains into energy-driven, such as S. cerevisiae, and carbon-driven, such as S. kluyveri and K. lactis, strains. Furthermore, it was found that the delayed onset of fermentative catabolism in carbon-driven strains is a consequence of low catabolic flux and the initial shunt of glucose in non-nitrogen-containing biomass constituents. The MFA model suggests that energy limitation forced the cell to ultimately increase catabolic flux, while the capacity of oxidative catabolism is not sufficient to process this flux oxidatively. The combination of transient experiments and its exploitation with reconciled intrinsic rates using a small metabolic model could corroborate earlier findings of metabolic regulations, such as tight glucose control in carbon-driven strains and transient changes in biomass composition, as well as explore new regulations, such as assimilation of ethanol before glucose. The benefit from using small metabolic flux models is the richness of information and the enhanced insight into intrinsic metabolic pathways without a priori knowledge of adaptation kinetics. Used in an online context, this approach serves as an efficient tool for strain characterization and physiological studies.

Adaptation, Physiological↗

PubMed2003

Proteomic characterization of a wild-type wine strain of Saccharomyces cerevisiae.

Saccharomyces cerevisiae is the optimal eukaryotic model system to study mammalian biological responses. At the same time Saccharomyces cerevisiae is also widely utilized as a biotechnological tool in the food industry. Enological Saccharomyces cerevisiae strains have been so far routinely analyzed for their microbiological aspects. Nevertheless, wine yeasts are gaining an increasing interest in the last years since they strongly affect both the vinification process and the organoleptic properties of the final product wine. The protein repertoire is responsible of such features and, consequently, 2D-PAGE can be an useful tool to evaluate and select optimal wine yeast strains. We present here the first proteomic map of a wild-type wine Saccharomyces cerevisiae strain selected for the guided fermentation of very high quality wines.

Electrophoresis, Gel, Two-Dimensional↗

PubMed1999

Involvement of Spt7p in vacuolar polyphosphate level of Saccharomyces cerevisiae.

Saccharomyces cerevisiae became less sensitive to nickel by a defect of the SPT7 gene encoding a transcription factor. Initial rate of nickel uptake by whole cells of a SPT7-negative mutant FY963 was nearly equal to that of the parent strain FY61, and FY963 accumulated nickel about 1.7-fold of the value of FY61 when cultured in medium containing 0.1 mM NiCl2; most of which was sequestered into vacuoles. The pH gradient-driven nickel uptake by vacuolar membrane vesicles was not altered in FY963, but the amount of polyphosphate in vacuoles was highly elevated. Involvement of Spt7p in nickel detoxification through regulation of vacuolar polyphosphate level in S. cerevisiae was discussed.

Biological Transport↗

PubMed2000

Phosphatidylserine synthesis required for the maximal tryptophan transport activity in Saccharomyces cerevisiae.

Saccharomyces cerevisiae cho1/pss mutants, which are severely impaired in phosphatidylserine (PS) synthesis, do not have detectable amounts of PS in their lipid fractions. Their derivatives with mutations that cause defects in tryptophan synthesis grew poorly in a medium containing 5 micrograms/ml of L-tryptophan, a concentration that met the requirements of tryptophanauxotrophic CHO1/PSS strains. The rates of tryptophan uptake of trp1 cho1/pss mutants were low at low tryptophan concentrations. This defect in the use of tryptophan was restored either by expression of CHO1/PSS or by introduction of a gene encoding tryptophan transporter, TAT1 or TAT2. These results indicate that PS synthesis is required for the maximal tryptophan-transporting activity of S. cerevisiae at low tryptophan concentrations.

ATP-Binding Cassette Transporters↗

PubMed2000

Efflux-mediated resistance to fluconazole could be modulated by sterol homeostasis in Saccharomyces cerevisiae.

Saccharomyces cerevisiae has long been used as a model organism in the study of the ergosterol pathway and its inhibitors. The Pdr5 protein (Pdr5p), an ATP binding cassette transporter, plays an important role in active efflux of azole antifungals and therefore in azole sensitivity and resistance in S. cerevisiae. We have identified the Fluconazole Dominant Resistance-1 (FDR-1) mutant, which has a single dominant mutation conferring high-level resistance to fluconazole. FDR-1 has been found to be an activated allele of the Pleiotropic Drug Resistance-1 (PDR-1) gene (termed PDR1-100) and to upregulate PDR5 transcription. Resistance of PDR1-100 to fluconazole decreased in the background of mutations known to affect sterol homeostasis. Hence, the resistance to fluconazole of PDR1-100 was paradoxically decreased in an erg3 PDR1-100 double mutant. The erg3 mutants are resistant to azoles and accumulate 14-methyl-fecosterol instead of ergosterol in the presence of azoles. These results reinforce the emerging evidence in both S. cerevisiae and Candida albicans that sterols could serve as substrates for Pdr5p for transport across membranes.

ATP-Binding Cassette Transporters↗

PubMed1999

The Mre11-Rad50-Xrs2 protein complex facilitates homologous recombination-based double-strand break repair in Saccharomyces cerevisiae.

Saccharomyces cerevisiae mre11Delta mutants are profoundly deficient in double-strand break (DSB) repair, indicating that the Mre11-Rad50-Xrs2 protein complex plays a central role in the cellular response to DNA DSBs. In this study, we examined the role of the complex in homologous recombination, the primary mode of DSB repair in yeast. We measured survival in synchronous cultures following irradiation and scored sister chromatid and interhomologue recombination genetically. mre11Delta strains were profoundly sensitive to ionizing radiation (IR) throughout the cell cycle. Mutant strains exhibited decreased frequencies of IR-induced sister chromatid and interhomologue recombination, indicating a general deficiency in homologous recombination-based DSB repair. Since a nuclease-deficient mre11 mutant was not impaired in these assays, it appears that the role of the S. cerevisiae Mre11-Rad50-Xrs2 protein complex in facilitating homologous recombination is independent of its nuclease activities.

Animals↗

PubMed2004

Proteomic response to amino acid starvation in Candida albicans and Saccharomyces cerevisiae.

Saccharomyces cerevisiae activates general amino acid control (GCN) in response to amino acid starvation. Some aspects of this response are known to be conserved in other fungi including Candida albicans, the major systemic fungal pathogen of humans. Here, we describe a proteomic comparison of the GCN responses in S. cerevisiae and C. albicans. We have used high-resolution two-dimensional (2-D) gel electrophoresis and peptide mass fingerprinting to develop a 2-D protein map of C. albicans. A total of 391 protein spots, representing 316 open reading frames, were identified. Fifty-five C. albicans and 65 S. cerevisiae proteins were identified that responded reproducibly to 3-aminotriazole (3AT) in a Gcn4p-dependent fashion. The changes in the S. cerevisiae proteome correlated with the response in the S. cerevisiae transcript profile to 3AT treatment (rank correlation coefficient = 0.59; Natarajan et al., Molec. Cell. Biol. 2001, 21, 4347-4368). Significant aspects of the GCN response were conserved in C. albicans and S. cerevisiae. In both fungi, amino acid biosynthetic enzymes on multiple metabolic pathways were induced by 3AT in a Gcn4p-dependent fashion. Carbon metabolism functions were also induced. However, subtle differences were observed between these fungi. For example, purine biosynthetic enzymes were induced in S. cerevisiae, but were not significantly induced in C. albicans. These differences presumably reflect the contrasting niches of these relatively benign and pathogenic yeasts, respectively.

Amino Acids↗

PubMed1992

ATP hydrolysis by initiation factor 4A is required for translation initiation in Saccharomyces cerevisiae.

Saccharomyces cerevisiae translation initiation factor eIF-4A, an RNA helicase of the Asp-Glu-Ala-Asp (DEAD) box protein family, was mutated in the putative ATP binding site and expressed in Escherichia coli. Mutant proteins with alanine at position 66 replaced by glycine [eIF-4A(A66G)] or valine [eIF-4A(A66V)] were purified from Escherichia coli extracts and analyzed in vitro for activity in ATP crosslinking, ATP hydrolysis, RNA helicase, and translation assays. The results show that in vitro ATP hydrolysis activity, RNA helicase activity, and translation activity of eIF-4A correlate with in vivo activity of the factor. Whereas eIF-4A(A66G) showed wild-type activity in all assays, eIF-4A(A66V) was active in ATP crosslinking but inactive in ATP hydrolysis and RNA helicase assays. In vitro translation was supported by wild-type eIF-4A and eIF-4A(A66G) but not by eIF-4A(A66V). The results show that, for their translation, the majority of mRNAs from Saccharomyces cerevisiae including an mRNA with the initiator AUG positioned 8 nucleotides downstream of the cap structure require eIF-4A that is able to hydrolyze ATP.

Adenosine Triphosphate↗

PubMed1993

A mutant allele skt5 affecting protoplast regeneration and killer toxin resistance has double mutations in its wild-type structural gene in Saccharomyces cerevisiae.

Saccharomyces cerevisiae strains carrying the mutant allele skt5 are resistant to the killer toxin of Kluyveromyces lactis and are defective in protoplast regeneration. The DNA sequence analysis of the cloned mutant skt5 gene showed a nucleotide substitution (causing a glycine-to-glutamic acid substitution) and also a nucleotide insertion (causing a frameshift at the extreme carboxyterminal region) in the structural region from its wild-type gene.

Alleles↗

PubMedDate not supplied

[Cross-effects of extracellular factors of adaptation to stress in Luteococcus casei and Saccharomyces cerevisiae].

Saccharomyces cerevisiae yeasts (lower eukaryotes) were shown to produce a protein exometabolite with reactivation activity. We demonstrated cross-effects of extracellular protein factors of adaptation to stress (heat and UV irradiation) in yeasts and Luteococcus casei bacteria. The possibility for isolation and partial purification of protein exometabolites from the culture liquid of yeasts and bacteria by similar methods, as well as the similarity of elution profiles for the active proteins in high-performance liquid chromatography, suggests that the proteins (or fragments thereot) of the organisms studied are homologous.

Adaptation, Physiological↗

PubMed2000

The Kluyver effect for trehalose in Saccharomyces cerevisiae.

Saccharomyces cerevisiae cells are able to grow using trehalose as a sole source of carbon and energy. However, the biomass yield obtained with trehalose was higher, and the specific growth rate lower, than that obtained with glucose or maltose. The respiratory inhibitor antimycin A prevented cell growth on trehalose, and no ethanol or glycerol was formed during batch growth on this carbon source. Thus, S. cerevisiae exhibits the KLUYVER effect for trehalose: this disaccharide is assimilated and respired, but, in contrast to glucose or maltose, it cannot be fermented. The high-affinity trehalose-H+ symporter encoded by the AGT1 gene is required for growth on trehalose. Analysis of the differences in the metabolism of maltose and trehalose (both disaccharides of glucose transported by active transport systems) indicated that the absence of trehalose fermentation is a consequence of low sugar influx into the cells during growth on this carbon source.

Antifungal Agents↗

PubMed1995

Effects of cadmium and of YAP1 and CAD1/YAP2 genes on iron metabolism in the yeast Saccharomyces cerevisiae.

Saccharomyces cerevisiae was more resistant to cadmium when the growth medium contained excess iron. Cadmium reduced the amount of iron taken up by cells during growth, and the cell ferrireductase activity was also strongly inhibited. These effects depended on the YAP1 and CAD1/YAP2 gene dosage. The growth rate of cells in iron-deficient conditions and their ferrireductase activity in the absence of added cadmium were also strongly affected by the dosage of YAP1 and CAD1/YAP2 genes. Our results suggest an indirect influence of these genes on iron metabolism, possibly via modification of the cell redox status.

Alcohol Oxidoreductases↗

PubMed1999

Molecular characterization of Vig4/Vrg4 GDP-mannose transporter of the yeast Saccharomyces cerevisiae.

Saccharomyces cerevisiae Vig4/Vrg4 protein is a Golgi membrane protein which has multiple transmembrane domains and is essential for transport of GDP-mannose across the Golgi membrane. By immunoprecipitation of detergent-solubilized tagged protein, we found that this protein exists as oligomer. Two mutants vig4-1 and vig4-2 had amino acid substitutions in the C-terminal region, Ala286Val and Ser278Cys, respectively. In accord with these mutations, trimming of the C-terminal hydrophobic part close to the region impaired the function and traffic of the proteins from the endoplasmic reticulum to the Golgi compartments.

Amino Acid Sequence↗

PubMed1999

Pathways of As(III) detoxification in Saccharomyces cerevisiae.

Saccharomyces cerevisiae has two independent transport systems for the removal of arsenite from the cytosol. Acr3p is a plasma membrane transporter that confers resistance to arsenite, presumably by arsenite extrusion from the cells. Ycf1p, a member of the ABC transporter superfamily, catalyzes the ATP-driven uptake of As(III) into the vacuole, also producing resistance to arsenite. Vacuolar accumulation requires a reductant such as glutathione, suggesting that the substrate is the glutathione conjugate, As(GS)3. Disruption of either the ACR3 or YCF1 gene results in sensitivity to arsenite and disruption of both genes produces additive hypersensitivity. Thus, Acr3p and Ycf1p represent separate pathways for the detoxification of arsenite in yeast.

ATP-Binding Cassette Transporters↗

PubMed1997

Coregulation of starch degradation and dimorphism in the yeast Saccharomyces cerevisiae.

Saccharomyces cerevisiae, the exemplar unicellular eukaryote, can only survive and proliferate in its natural habitats through constant adaptation within the constraints of a dynamic ecosystem. In every cell cycle of S. cerevisiae, there is a short period in the G1 phase of the cell cycle where "sensing" transpires; if a sufficient amount of fermentable sugars is available, the cells will initiate another round of vegetative cell division. When fermentable sugars become limiting, the yeast can execute the diauxic shift, where it reprograms its metabolism to utilize nonfermentable carbon sources. S. cerevisiae can also initiate the developmental program of pseudohyphal formation and invasive growth response, when essential nutrients become limiting. S. cerevisiae shares this growth form-switching ability with important pathogens such as the human pathogen, Candida albicans, and the corn smut pathogen Ustilago maydis. The pseudohyphal growth response of S. cerevisiae has mainly been implicated as a means for the yeast to search for nutrients. An important observation made was that starch-degrading S. cerevisiae strains have the added ability to form pseudohyphae and grow invasively into a starch-containing medium. More significantly, it was also shown that the STA1-3 genes encoding three glucoamylase isozymes responsible for starch hydrolysis in S. cerevisiae are coregulated with a gene, MUC1, essential for pseudohyphal and invasive growth. At least two putative transcriptional activators, Mss10p and Mss11p, are involved in this regulation. The Muc1p is a putative integral membrane-bound protein similar to mammalian mucin-like proteins that have been implicated in the ability of cancer cells to invade other tissues. This provided us with an excellent example of integrative control between nutrient sensing, signaling, and differential development.

Adaptation, Physiological↗