Sample records for saccharomyces sun gene

  1. Organization of the SUC gene family in Saccharomyces.

    PubMed Central

    Carlson, M; Botstein, D

    1983-01-01

    The SUC gene family of yeast (Saccharomyces) includes six structural genes for invertase (SUC1 through SUC5 and SUC7) found at unlinked chromosomal loci. A given yeast strain does not usually carry SUC+ alleles at all six loci; the natural negative alleles are called suc0 alleles. Cloned SUC2 DNA probes were used to investigate the physical structure of the SUC gene family in laboratory strains, commercial wine strains, and different Saccharomyces species. The active SUC+ genes are homologous. The suc0 allele at the SUC2 locus (suc2(0) in some strains is a silent gene or pseudogene. Other SUC loci carrying suc0 alleles appear to lack SUC DNA sequences. These findings imply that SUC genes have transposed to different chromosomal locations in closely related Saccharomyces strains. Images PMID:6843548

  2. [High gene conversion frequency between genes encoding 2-deoxyglucose-6-phosphate phosphatase in 3 Saccharomyces species].

    PubMed

    Piscopo, Sara-Pier; Drouin, Guy

    2014-05-01

    Gene conversions are nonreciprocal sequence exchanges between genes. They are relatively common in Saccharomyces cerevisiae, but few studies have investigated the evolutionary fate of gene conversions or their functional impacts. Here, we analyze the evolution and impact of gene conversions between the two genes encoding 2-deoxyglucose-6-phosphate phosphatase in S. cerevisiae, Saccharomyces paradoxus and Saccharomyces mikatae. Our results demonstrate that the last half of these genes are subject to gene conversions among these three species. The greater similarity and the greater percentage of GC nucleotides in the converted regions, as well as the absence of long regions of adjacent common converted sites, suggest that these gene conversions are frequent and occur independently in all three species. The high frequency of these conversions probably result from the fact that they have little impact on the protein sequences encoded by these genes.

  3. Gene expression cross-profiling in genetically modified industrial Saccharomyces cerevisiae strains during high-temperature ethanol production from xylose.

    PubMed

    Ismail, Ku Syahidah Ku; Sakamoto, Takatoshi; Hatanaka, Haruyo; Hasunuma, Tomohisa; Kondo, Akihiko

    2013-01-10

    Production of ethanol from xylose at high temperature would be an economical approach since it reduces risk of contamination and allows both the saccharification and fermentation steps in SSF to be running at elevated temperature. Eight recombinant xylose-utilizing Saccharomyces cerevisiae strains developed from industrial strains were constructed and subjected to high-temperature fermentation at 38 °C. The best performing strain was sun049T, which produced up to 15.2 g/L ethanol (63% of the theoretical production), followed by sun048T and sun588T, both with 14.1 g/L ethanol produced. Via transcriptomic analysis, expression profiling of the top three best ethanol producing strains compared to a negative control strain, sun473T, led to the discovery of genes in common that were regulated in the same direction. Identification of the 20 most highly up-regulated and the 20 most highly down-regulated genes indicated that the cells regulate their central metabolism and maintain the integrity of the cell walls in response to high temperature. We also speculate that cross-protection in the cells occurs, allowing them to maintain ethanol production at higher concentration under heat stress than the negative controls. This report provides further transcriptomics information in the interest of producing a robust microorganism for high-temperature ethanol production utilizing xylose. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Local Adaptation of Sun-Exposure-Dependent Gene Expression Regulation in Human Skin.

    PubMed

    Kita, Ryosuke; Fraser, Hunter B

    2016-10-01

    Sun-exposure is a key environmental variable in the study of human evolution. Several skin-pigmentation genes serve as classical examples of positive selection, suggesting that sun-exposure has significantly shaped worldwide genomic variation. Here we investigate the interaction between genetic variation and sun-exposure, and how this impacts gene expression regulation. Using RNA-Seq data from 607 human skin samples, we identified thousands of transcripts that are differentially expressed between sun-exposed skin and non-sun-exposed skin. We then tested whether genetic variants may influence each individual's gene expression response to sun-exposure. Our analysis revealed 10 sun-exposure-dependent gene expression quantitative trait loci (se-eQTLs), including genes involved in skin pigmentation (SLC45A2) and epidermal differentiation (RASSF9). The allele frequencies of the RASSF9 se-eQTL across diverse populations correlate with the magnitude of solar radiation experienced by these populations, suggesting local adaptation to varying levels of sunlight. These results provide the first examples of sun-exposure-dependent regulatory variation and suggest that this variation has contributed to recent human adaptation.

  5. PRIMARY STRUCTURE OF THE P450 LANOSTEROL DEMETHYLASE GENE FROM SACCHAROMYCES CEREVISIAE

    EPA Science Inventory

    We have sequenced the structural gene and flanking regions for lanosterol 14 alpha-demethylase (14DM) from Saccharomyces cerevisiae. An open reading frame of 530 codons encodes a 60.7-kDa protein. When this gene is disrupted by integrative transformation, the resulting strain req...

  6. Loss of lager specific genes and subtelomeric regions define two different Saccharomyces cerevisiae lineages for Saccharomyces pastorianus Group I and II strains.

    PubMed

    Monerawela, Chandre; James, Tharappel C; Wolfe, Kenneth H; Bond, Ursula

    2015-03-01

    Lager yeasts, Saccharomyces pastorianus, are interspecies hybrids between S. cerevisiae and S. eubayanus and are classified into Group I and Group II clades. The genome of the Group II strain, Weihenstephan 34/70, contains eight so-called 'lager-specific' genes that are located in subtelomeric regions. We evaluated the origins of these genes through bioinformatic and PCR analyses of Saccharomyces genomes. We determined that four are of cerevisiae origin while four originate from S. eubayanus. The Group I yeasts contain all four S. eubayanus genes but individual strains contain only a subset of the cerevisiae genes. We identified S. cerevisiae strains that contain all four cerevisiae 'lager-specific' genes, and distinct patterns of loss of these genes in other strains. Analysis of the subtelomeric regions uncovered patterns of loss in different S. cerevisiae strains. We identify two classes of S. cerevisiae strains: ale yeasts (Foster O) and stout yeasts with patterns of 'lager-specific' genes and subtelomeric regions identical to Group I and II S. pastorianus yeasts, respectively. These findings lead us to propose that Group I and II S. pastorianus strains originate from separate hybridization events involving different S. cerevisiae lineages. Using the combined bioinformatic and PCR data, we describe a potential classification map for industrial yeasts. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  7. New family of pectinase genes PGU1b-PGU3b of the pectinolytic yeast Saccharomyces bayanus var. uvarum.

    PubMed

    Naumov, G I; Shalamitskiy, M Yu; Naumova, E S

    2016-03-01

    Using yeast genome databases and literature data, we have conducted a phylogenetic analysis of pectinase PGU genes from Saccharomyces strains assigned to the biological species S. arboricola, S. bayanus (var. uvarum), S. cariocanus, S. cerevisiae, S. kudriavzevii, S. mikatae, S. paradoxus, and hybrid taxon S. pastorianus (syn. S. carlsbergensis). Single PGU genes were observed in all Saccharomyces species, except S. bayanus. The superfamily of divergent PGU genes has been documented in S. bayanus var. uvarum for the first time. Chromosomal localization of new PGU1b, PGU2b, and PGU3b genes in the yeast S. bayanus var. uvarum has been determined by molecular karyotyping and Southern hybridization.

  8. Three gene expression vector sets for concurrently expressing multiple genes in Saccharomyces cerevisiae.

    PubMed

    Ishii, Jun; Kondo, Takashi; Makino, Harumi; Ogura, Akira; Matsuda, Fumio; Kondo, Akihiko

    2014-05-01

    Yeast has the potential to be used in bulk-scale fermentative production of fuels and chemicals due to its tolerance for low pH and robustness for autolysis. However, expression of multiple external genes in one host yeast strain is considerably labor-intensive due to the lack of polycistronic transcription. To promote the metabolic engineering of yeast, we generated systematic and convenient genetic engineering tools to express multiple genes in Saccharomyces cerevisiae. We constructed a series of multi-copy and integration vector sets for concurrently expressing two or three genes in S. cerevisiae by embedding three classical promoters. The comparative expression capabilities of the constructed vectors were monitored with green fluorescent protein, and the concurrent expression of genes was monitored with three different fluorescent proteins. Our multiple gene expression tool will be helpful to the advanced construction of genetically engineered yeast strains in a variety of research fields other than metabolic engineering. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  9. Genes Required for Vacuolar Acidity in Saccharomyces Cerevisiae

    PubMed Central

    Preston, R. A.; Reinagel, P. S.; Jones, E. W.

    1992-01-01

    Mutations that cause loss of acidity in the vacuole (lysosome) of Saccharomyces cerevisiae were identified by screening colonies labeled with the fluorescent, pH-sensitive, vacuolar labeling agent, 6-carboxyfluorescein. Thirty nine vacuolar pH (Vph(-)) mutants were identified. Four of these contained mutant alleles of the previously described PEP3, PEP5, PEP6 and PEP7 genes. The remaining mutants defined eight complementation groups of vph mutations. No alleles of the VAT2 or TFP1 genes (known to encode subunits of the vacuolar H(+)-ATPase) were identified in the Vph(-) screen. Strains bearing mutations in any of six of the VPH genes failed to grow on medium buffered at neutral pH; otherwise, none of the vph mutations caused notable growth inhibition on standard yeast media. Expression of the vacuolar protease, carboxypeptidase Y, was defective in strains bearing vph4 mutations but was apparently normal in strains bearing any of the other vph mutations. Defects in vacuolar morphology at the light microscope level were evident in all Vph(-) mutants. Strains that contained representative mutant alleles of the 17 previously described PEP genes were assayed for vacuolar pH; mutations in seven of the PEP genes (including PEP3, PEP5, PEP6 and PEP7) caused loss of vacuolar acidity. PMID:1628805

  10. Time-based comparative transcriptomics in engineered xylose-utilizing Saccharomyces cerevisiae identifies temperature-responsive genes during ethanol production.

    PubMed

    Ismail, Ku Syahidah Ku; Sakamoto, Takatoshi; Hasunuma, Tomohisa; Kondo, Akihiko

    2013-09-01

    Agricultural residues comprising lignocellulosic materials are excellent sources of pentose sugar, which can be converted to ethanol as fuel. Ethanol production via consolidated bioprocessing requires a suitable microorganism to withstand the harsh fermentation environment of high temperature, high ethanol concentration, and exposure to inhibitors. We genetically enhanced an industrial Saccharomyces cerevisiae strain, sun049, enabling it to uptake xylose as the sole carbon source at high fermentation temperature. This strain was able to produce 13.9 g/l ethanol from 50 g/l xylose at 38 °C. To better understand the xylose consumption ability during long-term, high-temperature conditions, we compared by transcriptomics two fermentation conditions: high temperature (38 °C) and control temperature (30 °C) during the first 12 h of fermentation. This is the first long-term, time-based transcriptomics approach, and it allowed us to discover the role of heat-responsive genes when xylose is the sole carbon source. The results suggest that genes related to amino acid, cell wall, and ribosomal protein synthesis are down-regulated under heat stress. To allow cell stability and continuous xylose uptake in order to produce ethanol, hexose transporter HXT5, heat shock proteins, ubiquitin proteins, and proteolysis were all induced at high temperature. We also speculate that the strong relationship between high temperature and increased xylitol accumulation represents the cell's mechanism to protect itself from heat degradation.

  11. The histidine permease gene (HIP1) of Saccharomyces cerevisiae.

    PubMed

    Tanaka, J; Fink, G R

    1985-01-01

    The histidine-specific permease gene (HIP1) of Saccharomyces cerevisiae has been mapped, cloned, and sequenced. The HIP1 gene maps to the right arm of chromosome VII, approx. 11 cM distal to the ADE3 gene. The gene was isolated as an 8.6-kb BamHI-Sau3A fragment by complementation of the histidine-specific permease deficiency in recipient yeast cells. We sequenced a 2.4-kb subfragment of this BamHI-Sau3A fragment containing the HIP1 gene and identified a 1596-bp open reading frame (ORF). We confirmed the assignment of the 1596-bp ORF as the HIP1 coding sequence by sequencing a hip1 nonsense mutation. Analysis of the amino acid (aa) sequence of the HIP1 gene reveals several hydrophobic stretches, but shows no obvious N-terminal signal peptide. We have constructed a deletion of the HIP1 gene in vitro and replaced the wild-type copy of the gene with this deletion. The hip1 deletion mutant can grow when it is supplemented with 30 mM histidine, 50 times the amount required for the growth of HIP1 cells. Revertants of this deletion mutant able to grow on a normal level of histidine arise by mutation in unlinked genes. Both these observations suggest that there are additional, low-affinity pathways for histidine uptake.

  12. From Saccharomyces cerevisiae to human: The important gene co-expression modules.

    PubMed

    Liu, Wei; Li, Li; Ye, Hua; Chen, Haiwei; Shen, Weibiao; Zhong, Yuexian; Tian, Tian; He, Huaqin

    2017-08-01

    Network-based systems biology has become an important method for analyzing high-throughput gene expression data and gene function mining. Yeast has long been a popular model organism for biomedical research. In the current study, a weighted gene co-expression network analysis algorithm was applied to construct a gene co-expression network in Saccharomyces cerevisiae . Seventeen stable gene co-expression modules were detected from 2,814 S. cerevisiae microarray data. Further characterization of these modules with the Database for Annotation, Visualization and Integrated Discovery tool indicated that these modules were associated with certain biological processes, such as heat response, cell cycle, translational regulation, mitochondrion oxidative phosphorylation, amino acid metabolism and autophagy. Hub genes were also screened by intra-modular connectivity. Finally, the module conservation was evaluated in a human disease microarray dataset. Functional modules were identified in budding yeast, some of which are associated with patient survival. The current study provided a paradigm for single cell microorganisms and potentially other organisms.

  13. Molecular cloning and expression in Saccharomyces cerevisiae of two Aspergillus nidulans xylanase genes.

    PubMed Central

    Pérez-Gonzalez, J A; De Graaff, L H; Visser, J; Ramón, D

    1996-01-01

    Two Aspergillus nidulans genes, xlnA and xlnB, encoding the X22 and X24 xylanases from this fungus, respectively, have been cloned and sequenced. Their cDNAs have been expressed in a laboratory Saccharomyces cerevisiae strain under the control of a constitutive yeast promoter, resulting in the construction of recombinant xylanolytic yeast strains. PMID:8787417

  14. Expression variability of co-regulated genes differentiates Saccharomyces cerevisiae strains

    PubMed Central

    2011-01-01

    Background Saccharomyces cerevisiae (Baker's yeast) is found in diverse ecological niches and is characterized by high adaptive potential under challenging environments. In spite of recent advances on the study of yeast genome diversity, little is known about the underlying gene expression plasticity. In order to shed new light onto this biological question, we have compared transcriptome profiles of five environmental isolates, clinical and laboratorial strains at different time points of fermentation in synthetic must medium, during exponential and stationary growth phases. Results Our data unveiled diversity in both intensity and timing of gene expression. Genes involved in glucose metabolism and in the stress response elicited during fermentation were among the most variable. This gene expression diversity increased at the onset of stationary phase (diauxic shift). Environmental isolates showed lower average transcript abundance of genes involved in the stress response, assimilation of nitrogen and vitamins, and sulphur metabolism, than other strains. Nitrogen metabolism genes showed significant variation in expression among the environmental isolates. Conclusions Wild type yeast strains respond differentially to the stress imposed by nutrient depletion, ethanol accumulation and cell density increase, during fermentation of glucose in synthetic must medium. Our results support previous data showing that gene expression variability is a source of phenotypic diversity among closely related organisms. PMID:21507216

  15. Direct conversion of starch to ethanol using recombınant Saccharomyces cerevisiae containing glucoamylase gene

    NASA Astrophysics Data System (ADS)

    Purkan, P.; Baktir, A.; Puspaningsih, N. N. T.; Ni'mah, M.

    2017-09-01

    Saccharomyces cerevisiae is known for its high fermentative capacity, high ethanol yield and its high ethanol tolerance. The yeast is inability converting starch (relatively inexpensive substrate) into biofuel ethanol. Insertion of glucoamylase gene in yeast cell of Saccharomyces cerevisiae had been done to increase the yeast function in ethanol fermentation from starch. Transformation of yeast of S. cerevisiae with recombinant plasmid yEP-GLO1 carrying gene encoding glucoamylase (GLO1) produced the recombinant yeast which enable to degrade starch. Optimizing of bioconversion process of starch into ethanol by the yeast of recombinant Saccharomyces cerevisiae [yEP-GLO1] had been also done. Starch concentration which could be digested by recombinant yeast of S. cerevisiae [yEP-GLO1] was 10% (w/v). Bioconversion of starch having concentration 10% (b/v) using recombinant yeast of S. cerevisiae BY5207 [yEP-GLO1] could result ethanol as 20% (v/v) to alcoholmeter and 19,5% (v/v) to gas of chromatography. Otherwise, using recombinant yeast S. cerevisiae S. cerevisiae AS3324 [yEP-GLO1] resulted ethanol as 17% (v/v) to alcoholmeter and 17,5% (v/v) to gas of chromatography. The highest ethanol in starch bioconversion using both recombinant yeasts BY5207 and AS3324 could be resulted on 144 hours of fermentation time as well as in pH 5.

  16. Saccharomyces cerevisiae gene expression changes during rotating wall vessel suspension culture

    NASA Technical Reports Server (NTRS)

    Johanson, Kelly; Allen, Patricia L.; Lewis, Fawn; Cubano, Luis A.; Hyman, Linda E.; Hammond, Timothy G.

    2002-01-01

    This study utilizes Saccharomyces cerevisiae to study genetic responses to suspension culture. The suspension culture system used in this study is the high-aspect-ratio vessel, one type of the rotating wall vessel, that provides a high rate of gas exchange necessary for rapidly dividing cells. Cells were grown in the high-aspect-ratio vessel, and DNA microarray and metabolic analyses were used to determine the resulting changes in yeast gene expression. A significant number of genes were found to be up- or downregulated by at least twofold as a result of rotational growth. By using Gibbs promoter alignment, clusters of genes were examined for promoter elements mediating these genetic changes. Candidate binding motifs similar to the Rap1p binding site and the stress-responsive element were identified in the promoter regions of differentially regulated genes. This study shows that, as in higher order organisms, S. cerevisiae changes gene expression in response to rotational culture and also provides clues for investigations into the signaling pathways involved in gravitational response.

  17. Evidence for multiple interspecific hybridization in Saccharomyces sensu stricto species.

    PubMed

    de Barros Lopes, Miguel; Bellon, Jennifer R; Shirley, Neil J; Ganter, Philip F

    2002-01-01

    Fluorescent amplified fragment length polymorphism analysis demonstrates a high level of gene exchange between Saccharomyces sensu stricto species, with some strains having undergone multiple interspecific hybridization events with subsequent changes in genome complexity. Two lager strains were shown to be hybrids between Saccharomyces cerevisiae and the alloploid species Saccharomyces pastorianus. The genome structure of CBS 380(T), the type strain of Saccharomyces bayanus, is also consistent with S. pastorianus gene transfer. The results indicate that the cider yeast, CID1, possesses nuclear DNA from three separate species. Mating experiments show that there are no barriers to interspecific conjugation of haploid cells. Furthermore, the allopolyploid strains were able to undergo further hybridizations with other Saccharomyces sensu stricto yeasts. These results demonstrate that introgression between the Saccharomyces sensu stricto species is likely.

  18. Introduction and expression of genes for metabolic engineering applications in Saccharomyces cerevisiae.

    PubMed

    Da Silva, Nancy A; Srikrishnan, Sneha

    2012-03-01

    Metabolic pathway engineering in the yeast Saccharomyces cerevisiae leads to improved production of a wide range of compounds, ranging from ethanol (from biomass) to natural products such as sesquiterpenes. The introduction of multienzyme pathways requires precise control over the level and timing of expression of the associated genes. Gene number and promoter strength/regulation are two critical control points, and multiple studies have focused on modulating these in yeast. This MiniReview focuses on methods for introducing genes and controlling their copy number and on the many promoters (both constitutive and inducible) that have been successfully employed. The advantages and disadvantages of the methods will be presented, and applications to pathway engineering will be highlighted. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  19. Global gene response in Saccharomyces cerevisiae exposed to silver nanoparticles.

    PubMed

    Niazi, Javed H; Sang, Byoung-In; Kim, Yeon Seok; Gu, Man Bock

    2011-08-01

    Silver nanoparticles (AgNPs), exhibiting a broad size range and morphologies with highly reactive facets, which are widely applicable in real-life but not fully verified for biosafety and ecotoxicity, were subjected to report transcriptome profile in yeast Saccharomyces cerevisiae. A large number of genes accounted for ∼3% and ∼5% of the genome affected by AgNPs and Ag-ions, respectively. Principal component and cluster analysis suggest that the different physical forms of Ag were the major cause in differential expression profile. Among 90 genes affected by both AgNPs and Ag-ions, metalloprotein mediating high resistance to copper (CUP1-1 and CUP1-2) were strongly induced by AgNPs (∼45-folds) and Ag-ions (∼22-folds), respectively. A total of 17 genes, responsive to chemical stimuli, stress, and transport processes, were differentially induced by AgNPs. The differential expression was also seen with Ag-ions that affected 73 up- and 161 down-regulating genes, and most of these were involved in ion transport and homeostasis. This study provides new information on the knowledge for impact of nanoparticles on living microorganisms that can be extended to other nanoparticles.

  20. Gains and Losses of Transcription Factor Binding Sites in Saccharomyces cerevisiae and Saccharomyces paradoxus

    PubMed Central

    Schaefke, Bernhard; Wang, Tzi-Yuan; Wang, Chuen-Yi; Li, Wen-Hsiung

    2015-01-01

    Gene expression evolution occurs through changes in cis- or trans-regulatory elements or both. Interactions between transcription factors (TFs) and their binding sites (TFBSs) constitute one of the most important points where these two regulatory components intersect. In this study, we investigated the evolution of TFBSs in the promoter regions of different Saccharomyces strains and species. We divided the promoter of a gene into the proximal region and the distal region, which are defined, respectively, as the 200-bp region upstream of the transcription starting site and as the 200-bp region upstream of the proximal region. We found that the predicted TFBSs in the proximal promoter regions tend to be evolutionarily more conserved than those in the distal promoter regions. Additionally, Saccharomyces cerevisiae strains used in the fermentation of alcoholic drinks have experienced more TFBS losses than gains compared with strains from other environments (wild strains, laboratory strains, and clinical strains). We also showed that differences in TFBSs correlate with the cis component of gene expression evolution between species (comparing S. cerevisiae and its sister species Saccharomyces paradoxus) and within species (comparing two closely related S. cerevisiae strains). PMID:26220934

  1. DISRUPTION OF THE SACCHAROMYCES CEREVISIAE GENE FOR NADPH-CYTOCHROME P450-REDUCTASE CAUSES INCREASED SENSITIVITY TO KETOCONAZOLE

    EPA Science Inventory

    Strains of Saccharomyces cerevisiae deleted in the NADPH-cytochrome P450 reductase gene by transplacement are 200-fold more sensitive to ketoconazole, an inhibitor of the cytochrome P450 lanosterol 14-demethylase. Resistance is restored through complementation by the plasmid-born...

  2. A Minimal Set of Glycolytic Genes Reveals Strong Redundancies in Saccharomyces cerevisiae Central Metabolism

    PubMed Central

    Solis-Escalante, Daniel; Kuijpers, Niels G. A.; Barrajon-Simancas, Nuria; van den Broek, Marcel; Pronk, Jack T.

    2015-01-01

    As a result of ancestral whole-genome and small-scale duplication events, the genomes of Saccharomyces cerevisiae and many eukaryotes still contain a substantial fraction of duplicated genes. In all investigated organisms, metabolic pathways, and more particularly glycolysis, are specifically enriched for functionally redundant paralogs. In ancestors of the Saccharomyces lineage, the duplication of glycolytic genes is purported to have played an important role leading to S. cerevisiae's current lifestyle favoring fermentative metabolism even in the presence of oxygen and characterized by a high glycolytic capacity. In modern S. cerevisiae strains, the 12 glycolytic reactions leading to the biochemical conversion from glucose to ethanol are encoded by 27 paralogs. In order to experimentally explore the physiological role of this genetic redundancy, a yeast strain with a minimal set of 14 paralogs was constructed (the “minimal glycolysis” [MG] strain). Remarkably, a combination of a quantitative systems approach and semiquantitative analysis in a wide array of growth environments revealed the absence of a phenotypic response to the cumulative deletion of 13 glycolytic paralogs. This observation indicates that duplication of glycolytic genes is not a prerequisite for achieving the high glycolytic fluxes and fermentative capacities that are characteristic of S. cerevisiae and essential for many of its industrial applications and argues against gene dosage effects as a means of fixing minor glycolytic paralogs in the yeast genome. The MG strain was carefully designed and constructed to provide a robust prototrophic platform for quantitative studies and has been made available to the scientific community. PMID:26071034

  3. Salt tolerance and methionine biosynthesis in Saccharomyces cerevisiae involve a putative phosphatase gene.

    PubMed Central

    Gläser, H U; Thomas, D; Gaxiola, R; Montrichard, F; Surdin-Kerjan, Y; Serrano, R

    1993-01-01

    The progressive salinization of irrigated land poses a threat to the future of agriculture in arid regions. The identification of crucial metabolic steps in salt tolerance is important for the understanding of stress physiology and may provide the tools for its genetic engineering. In the yeast Saccharomyces cerevisiae we have isolated a gene, HAL2, which upon increase in gene dosage improves growth under NaCl and LiCl stresses. The HAL2 protein is homologous to inositol phosphatases, enzymes known to be inhibited by lithium salts. Complementation analysis demonstrated that HAL2 is identical to MET22, a gene involved in methionine biosynthesis. Accordingly, methionine supplementation improves the tolerance of yeast to NaCl and LiCl. These results demonstrate an unsuspected interplay between methionine biosynthesis and salt tolerance. Images PMID:8393782

  4. Abundant Gene-by-Environment Interactions in Gene Expression Reaction Norms to Copper within Saccharomyces cerevisiae

    PubMed Central

    Hodgins-Davis, Andrea; Adomas, Aleksandra B.; Warringer, Jonas; Townsend, Jeffrey P.

    2012-01-01

    Genetic variation for plastic phenotypes potentially contributes phenotypic variation to populations that can be selected during adaptation to novel ecological contexts. However, the basis and extent of plastic variation that manifests in diverse environments remains elusive. Here, we characterize copper reaction norms for mRNA abundance among five Saccharomyces cerevisiae strains to 1) describe population variation across the full range of ecologically relevant copper concentrations, from starvation to toxicity, and 2) to test the hypothesis that plastic networks exhibit increased population variation for gene expression. We find that although the vast majority of the variation is small in magnitude (considerably <2-fold), not just some, but most genes demonstrate variable expression across environments, across genetic backgrounds, or both. Plastically expressed genes included both genes regulated directly by copper-binding transcription factors Mac1 and Ace1 and genes indirectly responding to the downstream metabolic consequences of the copper gradient, particularly genes involved in copper, iron, and sulfur homeostasis. Copper-regulated gene networks exhibited more similar behavior within the population in environments where those networks have a large impact on fitness. Nevertheless, expression variation in genes like Cup1, important to surviving copper stress, was linked with variation in mitotic fitness and in the breadth of differential expression across the genome. By revealing a broader and deeper range of population variation, our results provide further evidence for the interconnectedness of genome-wide mRNA levels, their dependence on environmental context and genetic background, and the abundance of variation in gene expression that can contribute to future evolution. PMID:23019066

  5. Gains and Losses of Transcription Factor Binding Sites in Saccharomyces cerevisiae and Saccharomyces paradoxus.

    PubMed

    Schaefke, Bernhard; Wang, Tzi-Yuan; Wang, Chuen-Yi; Li, Wen-Hsiung

    2015-07-27

    Gene expression evolution occurs through changes in cis- or trans-regulatory elements or both. Interactions between transcription factors (TFs) and their binding sites (TFBSs) constitute one of the most important points where these two regulatory components intersect. In this study, we investigated the evolution of TFBSs in the promoter regions of different Saccharomyces strains and species. We divided the promoter of a gene into the proximal region and the distal region, which are defined, respectively, as the 200-bp region upstream of the transcription starting site and as the 200-bp region upstream of the proximal region. We found that the predicted TFBSs in the proximal promoter regions tend to be evolutionarily more conserved than those in the distal promoter regions. Additionally, Saccharomyces cerevisiae strains used in the fermentation of alcoholic drinks have experienced more TFBS losses than gains compared with strains from other environments (wild strains, laboratory strains, and clinical strains). We also showed that differences in TFBSs correlate with the cis component of gene expression evolution between species (comparing S. cerevisiae and its sister species Saccharomyces paradoxus) and within species (comparing two closely related S. cerevisiae strains). © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  6. Sequence analysis of three mitochondrial DNA molecules reveals interesting differences among Saccharomyces yeasts

    PubMed Central

    Langkjær, R. B.; Casaregola, S.; Ussery, D. W.; Gaillardin, C.; Piškur, J.

    2003-01-01

    The complete sequences of mitochondrial DNA (mtDNA) from the two budding yeasts Saccharomyces castellii and Saccharomyces servazzii, consisting of 25 753 and 30 782 bp, respectively, were analysed and compared to Saccharomyces cerevisiae mtDNA. While some of the traits are very similar among Saccharomyces yeasts, others have highly diverged. The two mtDNAs are much more compact than that of S.cerevisiae and contain fewer introns and intergenic sequences, although they have almost the same coding potential. A few genes contain group I introns, but group II introns, otherwise found in S.cerevisiae mtDNA, are not present. Surprisingly, four genes (ATP6, COX2, COX3 and COB) in the mtDNA of S.servazzii contain, in total, five +1 frameshifts. mtDNAs of S.castellii, S.servazzii and S.cerevisiae contain all genes on the same strand, except for one tRNA gene. On the other hand, the gene order is very different. Several gene rearrangements have taken place upon separation of the Saccharomyces lineages, and even a part of the transcription units have not been preserved. It seems that the mechanism(s) involved in the generation of the rearrangements has had to ensure that all genes stayed encoded by the same DNA strand. PMID:12799436

  7. Characterization of maltotriose transporters from the Saccharomyces eubayanus subgenome of the hybrid Saccharomyces pastorianus lager brewing yeast strain Weihenstephan 34/70.

    PubMed

    Cousseau, F E M; Alves, S L; Trichez, D; Stambuk, B U

    2013-01-01

    The genome from the Saccharomyces pastorianus industrial lager brewing strain Weihenstephan 34/70, a natural Saccharomyces cerevisiae/Saccharomyces eubayanus hybrid, indicated the presence of two different maltotriose transporter genes: a new gene in the S. eubayanus subgenome with 81% of homology to the AGT1 permease from S. cerevisiae, and an amplification of the S. eubayanus MTY1 maltotriose permease previously identified in S. pastorianus yeasts. To characterize these S. eubayanus transporter genes, we used a S. cerevisiae strain deleted in the AGT1 permease and introduced the desired permease gene(s) into this locus through homologous recombination. Our results indicate that both the MTY1 and AGT1 genes from the S. eubayanus subgenome encode functional maltotriose transporters that allow fermentation of this sugar by yeast cells, despite their apparent differences in the kinetics of maltotriose-H(+) symport activity. The presence of two maltotriose transporters in the S. eubayanus subgenome not only highlights the importance of sugar transport for efficient maltotriose utilization by industrial yeasts, but these new genes can be used in breeding and/or selection programs aimed at increasing yeast fitness for the efficient fermentation of brewer's wort. © 2012 The Society for Applied Microbiology.

  8. Determination of the core promoter regions of the Saccharomyces cerevisiae RPS3 gene.

    PubMed

    Joo, Yoo Jin; Kim, Jin-Ha; Baek, Joung Hee; Seong, Ki Moon; Lee, Jae Yung; Kim, Joon

    2009-01-01

    Ribosomal protein genes (RPG), which are scattered throughout the genomes of all eukaryotes, are subjected to coordinated expression. In yeast, the expression of RPGs is highly regulated, mainly at the transcriptional level. Recent research has found that many ribosomal proteins (RPs) function in multiple processes in addition to protein synthesis. Therefore, detailed knowledge of promoter architecture as well as gene regulation is important in understanding the multiple cellular processes mediated by RPGs. In this study, we investigated the functional architecture of the yeast RPS3 promoter and identified many putative cis-elements. Using beta-galactosidase reporter analysis and EMSA, the core promoter of RPS3 containing UASrpg and T-rich regions was corroborated. Moreover, the promoter occupancy of RPS3 by three transcription factors was confirmed. Taken together, our results further the current understanding of the promoter architecture and trans-elements of the Saccharomyces cerevisiae RPS3 gene.

  9. Effects of gene orientation and use of multiple promoters on the expression of XYL1 and XYL2 in Saccharomyces cerevisiae

    Treesearch

    Ju Yun Bae; Jose Laplaza; Thomas W. Jeffries

    2008-01-01

    Orientation of adjacent genes has been reported to affect their expression in eukaryotic systems, and metabolic engineering also often makes repeated use of a few promoters to obtain high expression. To improve transcriptional control in heterologous expression, we examined how these factors affect gene expression and enzymatic activity in Saccharomyces cerevisiae. We...

  10. [Characteristics of extracellular invertase of Saccharomyces cerevisiae in Heterologous expression of the suc2 gene in Solarium Tuberosum plants].

    PubMed

    Deriabin, A N; Berdichevets, I N; Burakhanova, E A; Trunova, T I

    2014-01-01

    Some properties and activity of extracellular invertase in the Saccharomyces cerevisiae yeasts encoded by the suc2 gene in heterologous expression were described. It was shown that the target suc2 gene is actively expressed in the genome of the transformed potato plants and S. cerevisiae invertase synthesized by this gene is transported into the apoplast due to the signal peptide of the proteinase II inhibitor. This enzyme is present in the apoplast in a soluble form and absorbed into the cell wall.

  11. A Comprehensive Analysis of Transcript-Supported De Novo Genes in Saccharomyces sensu stricto Yeasts

    PubMed Central

    Lu, Tzu-Chiao; Leu, Jun-Yi; Lin, Wen-Chang

    2017-01-01

    Abstract Novel genes arising from random DNA sequences (de novo genes) have been suggested to be widespread in the genomes of different organisms. However, our knowledge about the origin and evolution of de novo genes is still limited. To systematically understand the general features of de novo genes, we established a robust pipeline to analyze >20,000 transcript-supported coding sequences (CDSs) from the budding yeast Saccharomyces cerevisiae. Our analysis pipeline combined phylogeny, synteny, and sequence alignment information to identify possible orthologs across 20 Saccharomycetaceae yeasts and discovered 4,340 S. cerevisiae-specific de novo genes and 8,871 S. sensu stricto-specific de novo genes. We further combine information on CDS positions and transcript structures to show that >65% of de novo genes arose from transcript isoforms of ancient genes, especially in the upstream and internal regions of ancient genes. Fourteen identified de novo genes with high transcript levels were chosen to verify their protein expressions. Ten of them, including eight transcript isoform-associated CDSs, showed translation signals and five proteins exhibited specific cytosolic localizations. Our results suggest that de novo genes frequently arise in the S. sensu stricto complex and have the potential to be quickly integrated into ancient cellular network. PMID:28981695

  12. Molecular genetic diversity of the Saccharomyces yeasts in Taiwan: Saccharomyces arboricola, Saccharomyces cerevisiae and Saccharomyces kudriavzevii.

    PubMed

    Naumov, Gennadi I; Lee, Ching-Fu; Naumova, Elena S

    2013-01-01

    Genetic hybridization, sequence and karyotypic analyses of natural Saccharomyces yeasts isolated in different regions of Taiwan revealed three biological species: Saccharomyces arboricola, Saccharomyces cerevisiae and Saccharomyces kudriavzevii. Intraspecies variability of the D1/D2 and ITS1 rDNA sequences was detected among S. cerevisiae and S. kudriavzevii isolates. According to molecular and genetic analyses, the cosmopolitan species S. cerevisiae and S. kudriavzevii contain local divergent populations in Taiwan, Malaysia and Japan. Six of the seven known Saccharomyces species are documented in East Asia: S. arboricola, S. bayanus, S. cerevisiae, S. kudriavzevii, S. mikatae, and S. paradoxus.

  13. Expression in Escherichia coli of the Saccharomyces cerevisiae CCT gene encoding cholinephosphate cytidylyltransferase.

    PubMed Central

    Tsukagoshi, Y; Nikawa, J; Hosaka, K; Yamashita, S

    1991-01-01

    The coding region of the CCT gene from the yeast Saccharomyces cerevisiae was cloned into the pUC18 expression vector. The plasmid directed the synthesis of an active cholinephosphate cytidylyltransferase in Escherichia coli, confirming that CCT is the structural gene for this enzyme. The enzyme produced in E. coli efficiently utilized cholinephosphate and N,N-dimethylethanolaminephosphate, but N-methylethanolamine-phosphate and ethanolaminephosphate were poor substrates. Consistently, disruption of the CCT locus in the wild-type yeast cells resulted in a drastic decrease in activities with respect to the former two substrates. When activity was expressed in E. coli, over 90% was recovered in the cytosol, whereas most of the activity of yeast cells was associated with membranes, suggesting that yeast cells possess a mechanism that promotes membrane association of cytidylyltransferase. Images PMID:1848222

  14. Genetic Approaches to Study Meiosis and Meiosis-Specific Gene Expression in Saccharomyces cerevisiae.

    PubMed

    Kassir, Yona; Stuart, David T

    2017-01-01

    The budding yeast Saccharomyces cerevisiae has a long history as a model organism for studies of meiosis and the cell cycle. The popularity of this yeast as a model is in large part due to the variety of genetic and cytological approaches that can be effectively performed with the cells. Cultures of the cells can be induced to synchronously progress through meiosis and sporulation allowing large-scale gene expression and biochemical studies to be performed. Additionally, the spore tetrads resulting from meiosis make it possible to characterize the haploid products of meiosis allowing investigation of meiotic recombination and chromosome segregation. Here we describe genetic methods for analysis progression of S. cerevisiae through meiosis and sporulation with an emphasis on strategies for the genetic analysis of regulators of meiosis-specific genes.

  15. Design and engineering of intracellular-metabolite-sensing/regulation gene circuits in Saccharomyces cerevisiae.

    PubMed

    Wang, Meng; Li, Sijin; Zhao, Huimin

    2016-01-01

    The development of high-throughput phenotyping tools is lagging far behind the rapid advances of genotype generation methods. To bridge this gap, we report a new strategy for design, construction, and fine-tuning of intracellular-metabolite-sensing/regulation gene circuits by repurposing bacterial transcription factors and eukaryotic promoters. As proof of concept, we systematically investigated the design and engineering of bacterial repressor-based xylose-sensing/regulation gene circuits in Saccharomyces cerevisiae. We demonstrated that numerous properties, such as induction ratio and dose-response curve, can be fine-tuned at three different nodes, including repressor expression level, operator position, and operator sequence. By applying these gene circuits, we developed a cell sorting based, rapid and robust high-throughput screening method for xylose transporter engineering and obtained a sugar transporter HXT14 mutant with 6.5-fold improvement in xylose transportation capacity. This strategy should be generally applicable and highly useful for evolutionary engineering of proteins, pathways, and genomes in S. cerevisiae. © 2015 Wiley Periodicals, Inc.

  16. High-Throughput Screening to Identify Regulators of Meiosis-Specific Gene Expression in Saccharomyces cerevisiae.

    PubMed

    Kassir, Yona

    2017-01-01

    Meiosis and gamete formation are processes that are essential for sexual reproduction in all eukaryotic organisms. Multiple intracellular and extracellular signals feed into pathways that converge on transcription factors that induce the expression of meiosis-specific genes. Once triggered the meiosis-specific gene expression program proceeds in a cascade that drives progress through the events of meiosis and gamete formation. Meiosis-specific gene expression is tightly controlled by a balance of positive and negative regulatory factors that respond to a plethora of signaling pathways. The budding yeast Saccharomyces cerevisiae has proven to be an outstanding model for the dissection of gametogenesis owing to the sophisticated genetic manipulations that can be performed with the cells. It is possible to use a variety selection and screening methods to identify genes and their functions. High-throughput screening technology has been developed to allow an array of all viable yeast gene deletion mutants to be screened for phenotypes and for regulators of gene expression. This chapter describes a protocol that has been used to screen a library of homozygous diploid yeast deletion strains to identify regulators of the meiosis-specific IME1 gene.

  17. Multiplexed CRISPR/Cas9 Genome Editing and Gene Regulation Using Csy4 in Saccharomyces cerevisiae.

    PubMed

    Ferreira, Raphael; Skrekas, Christos; Nielsen, Jens; David, Florian

    2018-01-19

    Clustered regularly interspaced short palindromic repeats (CRISPR) technology has greatly accelerated the field of strain engineering. However, insufficient efforts have been made toward developing robust multiplexing tools in Saccharomyces cerevisiae. Here, we exploit the RNA processing capacity of the bacterial endoribonuclease Csy4 from Pseudomonas aeruginosa, to generate multiple gRNAs from a single transcript for genome editing and gene interference applications in S. cerevisiae. In regards to genome editing, we performed a quadruple deletion of FAA1, FAA4, POX1 and TES1 reaching 96% efficiency out of 24 colonies tested. Then, we used this system to efficiently transcriptionally regulate the three genes, OLE1, HMG1 and ACS1. Thus, we demonstrate that multiplexed genome editing and gene regulation can be performed in a fast and effective manner using Csy4.

  18. Time-Course Analysis of Gene Expression During the Saccharomyces cerevisiae Hypoxic Response.

    PubMed

    Bendjilali, Nasrine; MacLeon, Samuel; Kalra, Gurmannat; Willis, Stephen D; Hossian, A K M Nawshad; Avery, Erica; Wojtowicz, Olivia; Hickman, Mark J

    2017-01-05

    Many cells experience hypoxia, or low oxygen, and respond by dramatically altering gene expression. In the yeast Saccharomyces cerevisiae, genes that respond are required for many oxygen-dependent cellular processes, such as respiration, biosynthesis, and redox regulation. To more fully characterize the global response to hypoxia, we exposed yeast to hypoxic conditions, extracted RNA at different times, and performed RNA sequencing (RNA-seq) analysis. Time-course statistical analysis revealed hundreds of genes that changed expression by up to 550-fold. The genes responded with varying kinetics suggesting that multiple regulatory pathways are involved. We identified most known oxygen-regulated genes and also uncovered new regulated genes. Reverse transcription-quantitative PCR (RT-qPCR) analysis confirmed that the lysine methyltransferase EFM6 and the recombinase DMC1, both conserved in humans, are indeed oxygen-responsive. Looking more broadly, oxygen-regulated genes participate in expected processes like respiration and lipid metabolism, but also in unexpected processes like amino acid and vitamin metabolism. Using principle component analysis, we discovered that the hypoxic response largely occurs during the first 2 hr and then a new steady-state expression state is achieved. Moreover, we show that the oxygen-dependent genes are not part of the previously described environmental stress response (ESR) consisting of genes that respond to diverse types of stress. While hypoxia appears to cause a transient stress, the hypoxic response is mostly characterized by a transition to a new state of gene expression. In summary, our results reveal that hypoxia causes widespread and complex changes in gene expression to prepare the cell to function with little or no oxygen. Copyright © 2017 Bendjilali et al.

  19. Combining guilt-by-association and guilt-by-profiling to predict Saccharomyces cerevisiae gene function

    PubMed Central

    Tian, Weidong; Zhang, Lan V; Taşan, Murat; Gibbons, Francis D; King, Oliver D; Park, Julie; Wunderlich, Zeba; Cherry, J Michael; Roth, Frederick P

    2008-01-01

    Background: Learning the function of genes is a major goal of computational genomics. Methods for inferring gene function have typically fallen into two categories: 'guilt-by-profiling', which exploits correlation between function and other gene characteristics; and 'guilt-by-association', which transfers function from one gene to another via biological relationships. Results: We have developed a strategy ('Funckenstein') that performs guilt-by-profiling and guilt-by-association and combines the results. Using a benchmark set of functional categories and input data for protein-coding genes in Saccharomyces cerevisiae, Funckenstein was compared with a previous combined strategy. Subsequently, we applied Funckenstein to 2,455 Gene Ontology terms. In the process, we developed 2,455 guilt-by-profiling classifiers based on 8,848 gene characteristics and 12 functional linkage graphs based on 23 biological relationships. Conclusion: Funckenstein outperforms a previous combined strategy using a common benchmark dataset. The combination of 'guilt-by-profiling' and 'guilt-by-association' gave significant improvement over the component classifiers, showing the greatest synergy for the most specific functions. Performance was evaluated by cross-validation and by literature examination of the top-scoring novel predictions. These quantitative predictions should help prioritize experimental study of yeast gene functions. PMID:18613951

  20. Genomewide screening for genes involved in biofilm formation and miconazole susceptibility in Saccharomyces cerevisiae.

    PubMed

    Vandenbosch, Davy; De Canck, Evelien; Dhondt, Inne; Rigole, Petra; Nelis, Hans J; Coenye, Tom

    2013-12-01

    Infections related to fungal biofilms are difficult to treat due to the reduced susceptibility of sessile cells to most antifungal agents. Previous research has shown that 1-10% of sessile Candida cells survive treatment with high doses of miconazole (a fungicidal imidazole). The aim of this study was to identify genes involved in fungal biofilm formation and to unravel the mechanisms of resistance of these biofilms to miconazole. To this end, a screening of a Saccharomyces cerevisiae deletion mutant bank was carried out. Our results revealed that genes involved in peroxisomal transport and the biogenesis of the respiratory chain complex IV play an essential role in biofilm formation. On the other hand, genes involved in transcription and peroxisomal and mitochondrial organization seem to highly influence the susceptibility to miconazole of yeast biofilms. Additionally, our data confirm previous findings on genes involved in biofilm formation and in general stress responses. Our data suggest the involvement of peroxisomes in biofilm formation and miconazole resistance in fungal biofilms. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  1. Plasmid-encoded hygromycin B resistance: the sequence of hygromycin B phosphotransferase gene and its expression in Escherichia coli and Saccharomyces cerevisiae.

    PubMed

    Gritz, L; Davies, J

    1983-11-01

    The plasmid-borne gene hph coding for hygromycin B phosphotransferase (HPH) in Escherichia coli has been identified and its nucleotide sequence determined. The hph gene is 1026 nucleotides long, coding for a protein with a predicted Mr of 39 000. The hph gene was placed in a shuttle plasmid vector, downstream from the promoter region of the cyc 1 gene of Saccharomyces cerevisiae, and an hph construction containing a single AUG in the 5' noncoding region allowed direct selection following transformation in yeast and in E. coli. Thus the hph gene can be used in cloning vectors for both pro- and eukaryotes.

  2. Evolution of the dispersed SUC gene family of Saccharomyces by rearrangements of chromosome telomeres.

    PubMed Central

    Carlson, M; Celenza, J L; Eng, F J

    1985-01-01

    The SUC gene family of Saccharomyces contains six structural genes for invertase (SUC1 through SUC5 and SUC7) which are located on different chromosomes. Most yeast strains do not carry all six SUC genes and instead carry natural negative (suc0) alleles at some or all SUC loci. We determined the physical structures of SUC and suc0 loci. Except for SUC2, which is an unusual member of the family, all of the SUC genes are located very close to telomeres and are flanked by homologous sequences. On the centromere-proximal side of the gene, the conserved region contains X sequences, which are sequences found adjacent to telomeres (C. S. M. Chan and B.-K. Tye, Cell 33:563-573, 1983). On the other side of the gene, the homology includes about 4 kilobases of flanking sequence and then extends into a Y' element, which is an element often found distal to the X sequence at telomeres (Chan and Tye, Cell 33:563-573, 1983). Thus, these SUC genes and flanking sequences are embedded in telomere-adjacent sequences. Chromosomes carrying suc0 alleles (except suc20) lack SUC structural genes and portions of the conserved flanking sequences. The results indicate that the dispersal of SUC genes to different chromosomes occurred by rearrangements of chromosome telomeres. Images PMID:3018485

  3. Detection of maltose fermentation genes in the baking yeast strains of Saccharomyces cerevisiae.

    PubMed

    Oda, Y; Tonomura, K

    1996-10-01

    The presence of any one of the five unlinked MAL loci (MAL1, MAL2, MAL3, MAL4 and MAL6) confers the ability to ferment maltose on the yeast Saccharomyces cerevisiae. Each locus is composed of three genes encoding maltose permease, alpha-glucosidase and MAL activator. Chromosomal DNA of seven representative baking strains has been separated by pulse-field gel electrophoresis and probed with three genes in MAL6 locus. The DNA bands to which all of the three MAL-derived probes simultaneously hybridized were chromosome VII carrying MAL1 in all of the strains tested, chromosome XI carrying MAL4 in six strains, chromosome III carrying MAL2 in three strains and chromosomes II and VIII carrying MAL3 and MAL6, respectively, in the one strain. The number of MAL loci in baking strains was comparable to those of brewing strains.

  4. Identification and Characterization of a Novel Biotin Biosynthesis Gene in Saccharomyces cerevisiae

    PubMed Central

    Wu, Hong; Ito, Kiyoshi; Shimoi, Hitoshi

    2005-01-01

    Yeast Saccharomyces cerevisiae cells generally cannot synthesize biotin, a vitamin required for many carboxylation reactions. Although sake yeasts, which are used for Japanese sake brewing, are classified as S. cerevisiae, they do not require biotin for their growth. In this study, we identified a novel open reading frame (ORF) in the genome of one strain of sake yeast that we speculated to be involved in biotin synthesis. Homologs of this gene are widely distributed in the genomes of sake yeasts. However, they are not found in many laboratory strains and strains used for wine making and beer brewing. This ORF was named BIO6 because it has 52% identity with BIO3, a biotin biosynthesis gene of a laboratory strain. Further research showed that yeasts without the BIO6 gene are auxotrophic for biotin, whereas yeasts holding the BIO6 gene are prototrophic for biotin. The BIO6 gene was disrupted in strain A364A, which is a laboratory strain with one copy of the BIO6 gene. Although strain A364A is prototrophic for biotin, a BIO6 disrupted mutant was found to be auxotrophic for biotin. The BIO6 disruptant was able to grow in biotin-deficient medium supplemented with 7-keto-8-amino-pelargonic acid (KAPA), while the bio3 disruptant was not able to grow in this medium. These results suggest that Bio6p acts in an unknown step of biotin synthesis before KAPA synthesis. Furthermore, we demonstrated that expression of the BIO6 gene, like that of other biotin synthesis genes, was upregulated by depletion of biotin. We conclude that the BIO6 gene is a novel biotin biosynthesis gene of S. cerevisiae. PMID:16269718

  5. Roles of the 2 microns gene products in stable maintenance of the 2 microns plasmid of Saccharomyces cerevisiae.

    PubMed Central

    Reynolds, A E; Murray, A W; Szostak, J W

    1987-01-01

    We have examined the replication and segregation of the Saccharomyces cerevisiae 2 microns circle. The amplification of the plasmid at low copy numbers requires site-specific recombination between the 2 microns inverted repeat sequences catalyzed by the plasmid-encoded FLP gene. No other 2 microns gene products are required. The overexpression of FLP in a strain carrying endogenous 2 microns leads to uncontrolled plasmid replication, longer cell cycles, and cell death. Two different assays show that the level of Flp activity decreases with increasing 2 microns copy number. This regulation requires the products of the REP1 and REP2 genes. These gene products also act together to ensure that 2 microns molecules are randomly segregated between mother and daughter cells at cell division. Images PMID:3316982

  6. Saccharomyces cerevisiae possesses a stress-inducible glycyl-tRNA synthetase gene.

    PubMed

    Chen, Shun-Jia; Wu, Yi-Hua; Huang, Hsiao-Yun; Wang, Chien-Chia

    2012-01-01

    Aminoacyl-tRNA synthetases are a large family of housekeeping enzymes that are pivotal in protein translation and other vital cellular processes. Saccharomyces cerevisiae possesses two distinct nuclear glycyl-tRNA synthetase (GlyRS) genes, GRS1 and GRS2. GRS1 encodes both cytoplasmic and mitochondrial activities, while GRS2 is essentially silent and dispensable under normal conditions. We herein present evidence that expression of GRS2 was drastically induced upon heat shock, ethanol or hydrogen peroxide addition, and high pH, while expression of GRS1 was somewhat repressed under those conditions. In addition, GlyRS2 (the enzyme encoded by GRS2) had a higher protein stability and a lower K(M) value for yeast tRNA(Gly) under heat shock conditions than under normal conditions. Moreover, GRS2 rescued the growth defect of a GRS1 knockout strain when highly expressed by a strong promoter at 37 °C, but not at the optimal temperature of 30 °C. These results suggest that GRS2 is actually an inducible gene that may function to rescue the activity of GRS1 under stress conditions.

  7. Overexpression of the gene encoding HMG-CoA reductase in Saccharomyces cerevisiae for production of prenyl alcohols.

    PubMed

    Ohto, Chikara; Muramatsu, Masayoshi; Obata, Shusei; Sakuradani, Eiji; Shimizu, Sakayu

    2009-04-01

    To develop microbial production method for prenyl alcohols (e.g., (E,E)-farnesol (FOH), (E)-nerolidol (NOH), and (E,E,E)-geranylgeraniol (GGOH)), the genes encoding enzymes in the mevalonate and prenyl diphosphate pathways were overexpressed in Saccharomyces cerevisiae, and the resultant transformants were evaluated as to the production of these alcohols. Overexpression of the gene encoding hydroxymethylglutaryl (HMG)-CoA reductase was most effective among the genes tested. A derivative of S. cerevisiae ATCC 200589, which was selected through screening, was found to be the most suitable host for the production. On cultivation of the resultant transformant, in which the HMG-CoA reductase gene was overexpressed, in a 5-liter bench-scale jar fermenter for 7 d, the production of FOH, NOH, and GGOH reached 145.7, 98.8, and 2.46 mg/l, respectively.

  8. The pso4-1 mutation reduces spontaneous mitotic gene conversion and reciprocal recombination in Saccharomyces cerevisiae.

    PubMed

    Meira, L B; Fonseca, M B; Averbeck, D; Schenberg, A C; Henriques, J A

    1992-11-01

    Spontaneous mitotic recombination was examined in the haploid pso4-1 mutant of Saccharomyces cerevisiae and in the corresponding wild-type strain. Using a genetic system involving a duplication of the his4 gene it was shown that the pso4-1 mutation decreases at least fourfold the spontaneous rate of mitotic recombination. The frequency of spontaneous recombination was reduced tenfold in pso4-1 strains, as previously observed in the rad52-1 mutant. However, whereas the rad52-1 mutation specifically reduces gene conversion, the pso4-1 mutation reduces both gene conversion and reciprocal recombination. Induced mitotic recombination was also studied in pso4-1 mutant and wild-type strains after treatment with 8-methoxypsoralen plus UVA and 254 nm UV irradiation. Consistent with previous results, the pso4-1 mutation was found strongly to affect recombination induction.

  9. Cloning of the Pichia anomala SEC61 gene and its expression in a Saccharomyces cerevisiae sec61 mutant.

    PubMed

    Ruíz, Teresa; De la Rosa, José M; Domínguez, Angel; Rodríguez, Luis

    2003-05-01

    In several organisms, including Saccharomyces cerevisiae and other yeast species, the product encoded by the SEC61 gene is considered to be the core element of the translocation apparatus within the endoplasmic reticulum membrane through which translocation of secretory and membrane proteins occurs. In this study, we have cloned and characterized the homolog of the SEC61 gene from the yeast Pichia anomala. The cloned gene includes an ORF, interrupted after the first ten nucleotides by an intron of 131 bp, encoding a 479-amino acid putative polypeptide exhibiting homology to the products encoded by different eukaryotic SEC61 genes, particularly to those from other yeast species. We show that the P. anomala SEC61 gene is correctly processed (intron splicing) when expressed in S. cerevisiae and that it is able to complement the thermosensitive phenotype associated with a mutation in the S. cerevisiae SEC61 gene.

  10. Novel Sfp1 Transcriptional Regulation of Saccharomyces cerevisiae Gene Expression Changes During Spaceflight

    NASA Astrophysics Data System (ADS)

    Coleman, Chasity B.; Allen, Patricia L.; Rupert, Mark; Goulart, Carla; Hoehn, Alexander; Stodieck, Louis S.; Hammond, Timothy G.

    2008-12-01

    This study identifies transcriptional regulation of stress response element (STRE) genes in space in the model eukaryotic organism, Saccharomyces cerevisiae. To determine transcription-factor dependence, gene expression changes in space were examined in strains bearing green fluorescent protein tagged (GFP-tagged) reporters for YIL052C (Sfp1 dependent with stress), YST-2 (Sfp1/Rap1 dependent with stress), or SSA4 (Msn4 dependent with stress), along with strains of SSA4-GFP and YIL052C-GFP with individual deletions of the Msn4 or Sfp1. When compared to parallel ground controls, spaceflight induces significant gene expression changes in SSA4 (35% decrease) and YIL052C (45% decrease), while expression of YST-2 (0.08% decrease) did not change. In space, deletion of Sfp1 reversed the SSA4 gene expression effect (0.00% change), but Msn4 deletion yielded a similar decrease in SSA4 expression (34% change), which indicates that SSA4 gene expression is dependent on the Sfp1 transcription factor in space, unlike other stresses. For YIL052C, deletion of Sfp1 reversed the effect (0.01% change), and the Msn4 deletion maintained the decrease in expression (30% change), which indicates that expression of YIL052C is also dependent on Sfp1 in space. Spaceflight has selective and specific effects on SSA4 and YIL052C gene expression, indicated by novel dependence on Sfp1.

  11. The Saccharomyces cerevisiae enolase-related regions encode proteins that are active enolases.

    PubMed

    Kornblatt, M J; Richard Albert, J; Mattie, S; Zakaib, J; Dayanandan, S; Hanic-Joyce, P J; Joyce, P B M

    2013-02-01

    In addition to two genes (ENO1 and ENO2) known to code for enolase (EC4.2.1.11), the Saccharomyces cerevisiae genome contains three enolase-related regions (ERR1, ERR2 and ERR3) which could potentially encode proteins with enolase function. Here, we show that products of these genes (Err2p and Err3p) have secondary and quaternary structures similar to those of yeast enolase (Eno1p). In addition, Err2p and Err3p can convert 2-phosphoglycerate to phosphoenolpyruvate, with kinetic parameters similar to those of Eno1p, suggesting that these proteins could function as enolases in vivo. To address this possibility, we overexpressed the ERR2 and ERR3 genes individually in a double-null yeast strain lacking ENO1 and ENO2, and showed that either ERR2 or ERR3 could complement the growth defect in this strain when cells are grown in medium with glucose as the carbon source. Taken together, these data suggest that the ERR genes in Saccharomyces cerevisiae encode a protein that could function in glycolysis as enolase. The presence of these enolase-related regions in Saccharomyces cerevisiae and their absence in other related yeasts suggests that these genes may play some unique role in Saccharomyces cerevisiae. Further experiments will be required to determine whether these functions are related to glycolysis or other cellular processes. Copyright © 2012 John Wiley & Sons, Ltd.

  12. A tetO Toolkit To Alter Expression of Genes in Saccharomyces cerevisiae.

    PubMed

    Cuperus, Josh T; Lo, Russell S; Shumaker, Lucia; Proctor, Julia; Fields, Stanley

    2015-07-17

    Strategies to optimize a metabolic pathway often involve building a large collection of strains, each containing different versions of sequences that regulate the expression of pathway genes. Here, we develop reagents and methods to carry out this process at high efficiency in the yeast Saccharomyces cerevisiae. We identify variants of the Escherichia coli tet operator (tetO) sequence that bind a TetR-VP16 activator with differential affinity and therefore result in different TetR-VP16 activator-driven expression. By recombining these variants upstream of the genes of a pathway, we generate unique combinations of expression levels. Here, we built a tetO toolkit, which includes the I-OnuI homing endonuclease to create double-strand breaks, which increases homologous recombination by 10(5); a plasmid carrying six variant tetO sequences flanked by I-OnuI sites, uncoupling transformation and recombination steps; an S. cerevisiae-optimized TetR-VP16 activator; and a vector to integrate constructs into the yeast genome. We introduce into the S. cerevisiae genome the three crt genes from Erwinia herbicola required for yeast to synthesize lycopene and carry out the recombination process to produce a population of cells with permutations of tetO variants regulating the three genes. We identify 0.7% of this population as making detectable lycopene, of which the vast majority have undergone recombination at all three crt genes. We estimate a rate of ∼20% recombination per targeted site, much higher than that obtained in other studies. Application of this toolkit to medically or industrially important end products could reduce the time and labor required to optimize the expression of a set of metabolic genes.

  13. Application of the FLP/FRT system for conditional gene deletion in yeast Saccharomyces cerevisiae.

    PubMed

    Park, Yang-Nim; Masison, Daniel; Eisenberg, Evan; Greene, Lois E

    2011-09-01

    The yeast Saccharomyces cerevisiae has proved to be an excellent model organism to study the function of proteins. One of the many advantages of yeast is the many genetic tools available to manipulate gene expression, but there are still limitations. To complement the many methods used to control gene expression in yeast, we have established a conditional gene deletion system by using the FLP/FRT system on yeast vectors to conditionally delete specific yeast genes. Expression of Flp recombinase, which is under the control of the GAL1 promoter, was induced by galactose, which in turn excised FRT sites flanked genes. The efficacy of this system was examined using the FRT site-flanked genes HSP104, URA3 and GFP. The pre-excision frequency of this system, which might be caused by the basal activity of the GAL1 promoter or by spontaneous recombination between FRT sites, was detected ca. 2% under the non-selecting condition. After inducing expression of Flp recombinase, the deletion efficiency achieved ca. 96% of cells in a population within 9 h. After conditional deletion of the specific gene, protein degradation and cell division then diluted out protein that was expressed from this gene prior to its excision. Most importantly, the specific protein to be deleted could be expressed under its own promoter, so that endogenous levels of protein expression were maintained prior to excision by the Flp recombinase. Therefore, this system provides a useful tool for the conditional deletion of genes in yeast. Published in 2011 by John Wiley & Sons, Ltd.

  14. Mating-Type Genes and MAT Switching in Saccharomyces cerevisiae

    PubMed Central

    Haber, James E.

    2012-01-01

    Mating type in Saccharomyces cerevisiae is determined by two nonhomologous alleles, MATa and MATα. These sequences encode regulators of the two different haploid mating types and of the diploids formed by their conjugation. Analysis of the MATa1, MATα1, and MATα2 alleles provided one of the earliest models of cell-type specification by transcriptional activators and repressors. Remarkably, homothallic yeast cells can switch their mating type as often as every generation by a highly choreographed, site-specific homologous recombination event that replaces one MAT allele with different DNA sequences encoding the opposite MAT allele. This replacement process involves the participation of two intact but unexpressed copies of mating-type information at the heterochromatic loci, HMLα and HMRa, which are located at opposite ends of the same chromosome-encoding MAT. The study of MAT switching has yielded important insights into the control of cell lineage, the silencing of gene expression, the formation of heterochromatin, and the regulation of accessibility of the donor sequences. Real-time analysis of MAT switching has provided the most detailed description of the molecular events that occur during the homologous recombinational repair of a programmed double-strand chromosome break. PMID:22555442

  15. SUC1 gene of Saccharomyces: a structural gene for the large (glycoprotein) and small (carbohydrate-free) forms of invertase.

    PubMed Central

    Rodriguez, L; Lampen, J O; MacKay, V L

    1981-01-01

    Saccharomyces cerevisiae revertant strain D10-ER1 has been shown to contain thermosensitive forms of the large (glycoprotein) and small (carbohydrate-free) invertases and a very low level of the small enzyme, along with a wild-type level of the large form (T. Mizunaga et al., Mol. Cell. Biol. 1:460-468, 1981). These characteristics cosegregated in crosses of the revertant strain with wild-type sucrose-fermenting (SUC1) or nonfermenting (suc0) strains. In addition, there is tight linkage between sucrose and maltose fermentation in revertant D10-ER1 (characteristic of the SUC1 and MAL1 genes). From this we infer that a single reversion event is responsible for the several changes observed in D10-ER1, and that this mutation maps within or very close to the SUC1 gene present in the ancestor strain 4059-358D. The revertant SUC1 allele in D10-ER1 (termed SUC1-R1) was expressed independently of the wild-type SUC1 gene when both were present in diploid cells. Diploids carrying only the wild-type or the mutant genes synthesized invertases with the characteristics of the parental Suc+ haploids. The possibility that a modifier gene was responsible for the alterations in the invertases of revertant D10-ER1 was ruled out by appropriate crosses. We conclude that SUC1 is a structural gene that codes for both the large and the small forms of invertase and suggest that SUC2 through SUC5 are structural genes as well. PMID:6765604

  16. [Identification of new genes that affect [PSI^(+)] prion toxicity in Saccharomyces cerevisiae yeast].

    PubMed

    Matveenko, A G; Belousov, M V; Bondarev, S A; Moskalenko, S E; Zhouravleva, G A

    2016-01-01

    Translation termination is an important step in gene expression. Its correct processing is governed by eRF1 (Sup45) and eRF3 (Sup35) proteins. In Saccharomyces cerevisiae, mutations in the corresponding genes, as well as Sup35 aggregation in [PSI^(+)] cells that propagate the prion form of Sup35 lead to inaccurate stop codon recognition and, consequently, nonsense suppression. The presence of stronger prion variants results in the more efficient suppression of nonsense mutations. Previously, we proposed a synthetic lethality test that enables the identification of genes that may influence either translation termination factors or [PSI^(+)] manifestation. This is based on the fact that the combination of sup45 mutations with the strong [PSI^(+)] prion variant in diploids is lethal. In this work, a set of genes that were previously shown to enhance nonsense suppression was analyzed. It was found that ABF1, FKH2, and REB1 overexpression decreased the growth of strains in a prion-dependent manner and, thus, might influence [PSI^(+)] prion toxicity. It was also shown that the synthetic lethality of [PSI^(+)] and sup45 mutations increased with the overexpression of GLN3 and MOT3 that encode Q/N-rich transcription factors. An analysis of the effects of their expression on the transcription of the release factors genes revealed an increase in SUP35 transcription in both cases. Since SUP35 overexpression is known to be toxic in [PSI^(+)] strains, these genes apparently enhance [PSI^(+)] toxicity via the regulation of SUP35 transcription.

  17. Dual Luciferase Assay System for Rapid Assessment of Gene Expression in Saccharomyces cerevisiae

    PubMed Central

    McNabb, David S.; Reed, Robin; Marciniak, Robert A.

    2005-01-01

    A new reporter system has been developed for quantifying gene expression in the yeast Saccharomyces cerevisiae. The system relies on two different reporter genes, Renilla and firefly luciferase, to evaluate regulated gene expression. The gene encoding Renilla luciferase is fused to a constitutive promoter (PGK1 or SPT15) and integrated into the yeast genome at the CAN1 locus as a control for normalizing the assay. The firefly luciferase gene is fused to the test promoter and integrated into the yeast genome at the ura3 or leu2 locus. The dual luciferase assay is performed by sequentially measuring the firefly and Renilla luciferase activities of the same sample, with the results expressed as the ratio of firefly to Renilla luciferase activity (Fluc/Rluc). The yeast dual luciferase reporter (DLR) was characterized and shown to be very efficient, requiring approximately 1 minute to complete each assay, and has proven to yield data that accurately and reproducibly reflect promoter activity. A series of integrating plasmids were generated that contain either the firefly or Renilla luciferase gene preceded by a multicloning region in two different orientations and the three reading frames to make possible the generation of translational fusions. Additionally, each set of plasmids contains either the URA3 or LEU2 marker for genetic selection in yeast. A series of S288C-based yeast strains, including a two-hybrid strain, were developed to facilitate the use of the yeast DLR assay. This assay can be readily adapted to a high-throughput platform for studies requiring numerous measurements. PMID:16151247

  18. Saccharomyces cerevisiae and non-Saccharomyces yeasts in grape varieties of the São Francisco Valley

    PubMed Central

    de Ponzzes-Gomes, Camila M.P.B.S.; de Mélo, Dângelly L.F.M.; Santana, Caroline A.; Pereira, Giuliano E.; Mendonça, Michelle O.C.; Gomes, Fátima C.O.; Oliveira, Evelyn S.; Barbosa, Antonio M.; Trindade, Rita C.; Rosa, Carlos A.

    2014-01-01

    The aims of this work was to characterise indigenous Saccharomyces cerevisiae strains in the naturally fermented juice of grape varieties Cabernet Sauvignon, Grenache, Tempranillo, Sauvignon Blanc and Verdejo used in the São Francisco River Valley, northeastern Brazil. In this study, 155 S. cerevisiae and 60 non-Saccharomyces yeasts were isolated and identified using physiological tests and sequencing of the D1/D2 domains of the large subunit of the rRNA gene. Among the non-Saccharomyces species, Rhodotorula mucilaginosa was the most common species, followed by Pichia kudriavzevii, Candida parapsilosis, Meyerozyma guilliermondii, Wickerhamomyces anomalus, Kloeckera apis, P. manshurica, C. orthopsilosis and C. zemplinina. The population counts of these yeasts ranged among 1.0 to 19 × 105 cfu/mL. A total of 155 isolates of S. cerevisiae were compared by mitochondrial DNA restriction analysis, and five molecular mitochondrial DNA restriction profiles were detected. Indigenous strains of S. cerevisiae isolated from grapes of the São Francisco Valley can be further tested as potential starters for wine production. PMID:25242923

  19. Saccharomyces cerevisiae and non-Saccharomyces yeasts in grape varieties of the São Francisco Valley.

    PubMed

    de Ponzzes-Gomes, Camila M P B S; de Mélo, Dângelly L F M; Santana, Caroline A; Pereira, Giuliano E; Mendonça, Michelle O C; Gomes, Fátima C O; Oliveira, Evelyn S; Barbosa, Antonio M; Trindade, Rita C; Rosa, Carlos A

    2014-01-01

    The aims of this work was to characterise indigenous Saccharomyces cerevisiae strains in the naturally fermented juice of grape varieties Cabernet Sauvignon, Grenache, Tempranillo, Sauvignon Blanc and Verdejo used in the São Francisco River Valley, northeastern Brazil. In this study, 155 S. cerevisiae and 60 non-Saccharomyces yeasts were isolated and identified using physiological tests and sequencing of the D1/D2 domains of the large subunit of the rRNA gene. Among the non-Saccharomyces species, Rhodotorula mucilaginosa was the most common species, followed by Pichia kudriavzevii, Candida parapsilosis, Meyerozyma guilliermondii, Wickerhamomyces anomalus, Kloeckera apis, P. manshurica, C. orthopsilosis and C. zemplinina. The population counts of these yeasts ranged among 1.0 to 19 × 10(5) cfu/mL. A total of 155 isolates of S. cerevisiae were compared by mitochondrial DNA restriction analysis, and five molecular mitochondrial DNA restriction profiles were detected. Indigenous strains of S. cerevisiae isolated from grapes of the São Francisco Valley can be further tested as potential starters for wine production.

  20. Expression of an Aspergillus niger Phytase Gene (phyA) in Saccharomyces cerevisiae

    PubMed Central

    Han, Yanming; Wilson, David B.; Lei, Xin gen

    1999-01-01

    Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals and reduces phosphorus pollution of animal waste. Our objectives were to express an Aspergillus niger phytase gene (phyA) in Saccharomyces cerevisiae and to determine the effects of glycosylation on the phytase’s activity and thermostability. A 1.4-kb DNA fragment containing the coding region of the phyA gene was inserted into the expression vector pYES2 and was expressed in S. cerevisiae as an active, extracellular phytase. The yield of total extracellular phytase activity was affected by the signal peptide and the medium composition. The expressed phytase had two pH optima (2 to 2.5 and 5 to 5.5) and a temperature optimum between 55 and 60°C, and it cross-reacted with a rabbit polyclonal antibody against the wild-type enzyme. Due to the heavy glycosylation, the expressed phytase had a molecular size of approximately 120 kDa and appeared to be more thermostable than the commercial enzyme. Deglycosylation of the phytase resulted in losses of 9% of its activity and 40% of its thermostability. The recombinant phytase was effective in hydrolyzing phytate phosphorus from corn or soybean meal in vitro. In conclusion, the phyA gene was expressed as an active, extracellular phytase in S. cerevisiae, and its thermostability was affected by glycosylation. PMID:10223979

  1. Saccharomyces genome database informs human biology

    PubMed Central

    Skrzypek, Marek S; Nash, Robert S; Wong, Edith D; MacPherson, Kevin A; Karra, Kalpana; Binkley, Gail; Simison, Matt; Miyasato, Stuart R

    2018-01-01

    Abstract The Saccharomyces Genome Database (SGD; http://www.yeastgenome.org) is an expertly curated database of literature-derived functional information for the model organism budding yeast, Saccharomyces cerevisiae. SGD constantly strives to synergize new types of experimental data and bioinformatics predictions with existing data, and to organize them into a comprehensive and up-to-date information resource. The primary mission of SGD is to facilitate research into the biology of yeast and to provide this wealth of information to advance, in many ways, research on other organisms, even those as evolutionarily distant as humans. To build such a bridge between biological kingdoms, SGD is curating data regarding yeast-human complementation, in which a human gene can successfully replace the function of a yeast gene, and/or vice versa. These data are manually curated from published literature, made available for download, and incorporated into a variety of analysis tools provided by SGD. PMID:29140510

  2. Saccharomyces genome database informs human biology.

    PubMed

    Skrzypek, Marek S; Nash, Robert S; Wong, Edith D; MacPherson, Kevin A; Hellerstedt, Sage T; Engel, Stacia R; Karra, Kalpana; Weng, Shuai; Sheppard, Travis K; Binkley, Gail; Simison, Matt; Miyasato, Stuart R; Cherry, J Michael

    2018-01-04

    The Saccharomyces Genome Database (SGD; http://www.yeastgenome.org) is an expertly curated database of literature-derived functional information for the model organism budding yeast, Saccharomyces cerevisiae. SGD constantly strives to synergize new types of experimental data and bioinformatics predictions with existing data, and to organize them into a comprehensive and up-to-date information resource. The primary mission of SGD is to facilitate research into the biology of yeast and to provide this wealth of information to advance, in many ways, research on other organisms, even those as evolutionarily distant as humans. To build such a bridge between biological kingdoms, SGD is curating data regarding yeast-human complementation, in which a human gene can successfully replace the function of a yeast gene, and/or vice versa. These data are manually curated from published literature, made available for download, and incorporated into a variety of analysis tools provided by SGD. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. [Molecular evolution of the sulphite efflux gene SSU1 in Saccharomyces cerevisiae].

    PubMed

    Peng, Li-Xin; Sun, Fei-Fei; Huang, Yan-Yan; Li, Zhen-Chong

    2013-11-01

    The SSU1 gene encoding a membrane sulfite pump is a main facilitator invovled in sulfite efflux. In Saccharomyce cerevisiae, various range of resistance to sulfite was observed among strains. To explore the evolution traits of SSU1 gene, the population data of S. cerevisiae were collected and analyzed. The phylogenetic analysis indicated that S. cerevisiae population can be classified into three sub-populations, and the positive selection was detected in population by McDonald-Kreitman test. The anaylsis of Ka/Ks ratios further showed that S. cerevisiae sub-population was undergoing positive selection. This finding was also supported by PAML branch model. Nine potential positive selection sites were predicted by branch-site model, and four sites exclusively belong to the sub-population under positive seletion. The data from ssulp protein structure demonstrated that three sites are substitutions between polar and hydrophobic amino acids, and only one site of substitutaion from basic amino acid to basic amino acid (345R/K). Because amino acid pKa values are crucial for sulfite pump to maintain their routine function, positive selection of these amino acid substitutions might affect sulfite efflux efficient.

  4. A condition-specific codon optimization approach for improved heterologous gene expression in Saccharomyces cerevisiae

    PubMed Central

    2014-01-01

    Background Heterologous gene expression is an important tool for synthetic biology that enables metabolic engineering and the production of non-natural biologics in a variety of host organisms. The translational efficiency of heterologous genes can often be improved by optimizing synonymous codon usage to better match the host organism. However, traditional approaches for optimization neglect to take into account many factors known to influence synonymous codon distributions. Results Here we define an alternative approach for codon optimization that utilizes systems level information and codon context for the condition under which heterologous genes are being expressed. Furthermore, we utilize a probabilistic algorithm to generate multiple variants of a given gene. We demonstrate improved translational efficiency using this condition-specific codon optimization approach with two heterologous genes, the fluorescent protein-encoding eGFP and the catechol 1,2-dioxygenase gene CatA, expressed in S. cerevisiae. For the latter case, optimization for stationary phase production resulted in nearly 2.9-fold improvements over commercial gene optimization algorithms. Conclusions Codon optimization is now often a standard tool for protein expression, and while a variety of tools and approaches have been developed, they do not guarantee improved performance for all hosts of applications. Here, we suggest an alternative method for condition-specific codon optimization and demonstrate its utility in Saccharomyces cerevisiae as a proof of concept. However, this technique should be applicable to any organism for which gene expression data can be generated and is thus of potential interest for a variety of applications in metabolic and cellular engineering. PMID:24636000

  5. Hsf1p and Msn2/4p cooperate in the expression of Saccharomyces cerevisiae genes HSP26 and HSP104 in a gene- and stress type-dependent manner.

    PubMed

    Amorós, M; Estruch, F

    2001-03-01

    Saccharomyces cerevisiae possesses several transcription factors involved in the transcriptional activation of stress-induced genes. Among them, the heat shock factor (Hsf1p) and the zinc finger proteins of the general stress response (Msn2p and Msn4p) have been shown to play a major role in stress protection. Some heat shock protein (HSP) genes contain both heat shock elements (HSEs) and stress response elements (STREs), suggesting the involvement of both transcription factors in their regulation. Analysis of the stress-induced expression of two of these genes, HSP26 and HSP104, reveals that the contribution of Hsf1p and Msn2/4p is different depending on the gene and the stress condition.

  6. Purification of FKBP-70, a novel immunophilin from Saccharomyces cerevisiae, and cloning of its structural gene, FPR3.

    PubMed

    Manning-Krieg, U C; Henríquez, R; Cammas, F; Graff, P; Gavériaux, S; Movva, N R

    1994-09-19

    A novel protein, belonging to the yeast family of FKBPs (FK-binding proteins), FKBP-70, was isolated from Saccharomyces cerevisiae by its interaction with the immunosuppressive agent FK-520. Its structural gene, FPR3, was cloned and the protein expressed and purified from Escherichia coli. This third member of the FKBP family in yeast is homologous to the other FKBPs at its carboxy terminus, showing conserved ligand binding and proline isomerase regions. It is, however, a longer acidic protein with several potential nuclear targeting sequences and a region of homology to nucleolins. Yeast strains deleted for FPR3, as well as a triple deletion mutant of this family of genes, FPR1, FPR2 and FPR3, are viable under normal conditions of growth, indicating that the FPR genes are not essential for life.

  7. Regulation of SNM1, an inducible Saccharomyces cerevisiae gene required for repair of DNA cross-links.

    PubMed

    Wolter, R; Siede, W; Brendel, M

    1996-02-05

    The interstrand cross-link repair gene SNM1 of Saccharomyces cerevisiae was examined for regulation in response to DNA-damaging agents. Induction of SNM1-lacZ fusions was detected in response to nitrogen mustard, cis-platinum (II) diamine dichloride, UV light, and 8-methoxypsoralen + UVA, but not after heat-shock treatment or incubation with 2-dimethylaminoethylchloride, methylmethane sulfonate or 4-nitroquinoline-N-oxide. The promoter of SNM1 contains a 15 bp motif, which shows homology to the DRE2 box of the RAD2 promoter. Similar motifs have been found in promoter regions of other damage-inducible DNA repair genes. Deletion of this motif results in loss of inducibility of SNM1. Also, a putative negative upstream regulation sequence was found to be responsible for repression of constitutive transcription of SNM1. Surprisingly, no inducibility of SNM1 was found after treatment with DNA-damaging agents in strains without an intact DUN1 gene, while regulation seems unchanged in sad1 mutants.

  8. Saccharomyces cerevisiae sigma 1278b has novel genes of the N-acetyltransferase gene superfamily required for L-proline analogue resistance.

    PubMed

    Takagi, H; Shichiri, M; Takemura, M; Mohri, M; Nakamori, S

    2000-08-01

    We discovered on the chromosome of Saccharomyces cerevisiae Sigma 1278b novel genes involved in L-proline analogue L-azetidine-2-carboxylic acid resistance which are not present in the standard laboratory strains. The 5.4 kb-DNA fragment was cloned from the genomic library of the L-azetidine-2-carboxylic acid-resistant mutant derived from a cross between S. cerevisiae strains S288C and Sigma 1278b. The nucleotide sequence of a 4.5-kb segment exhibited no identity with the sequence in the genome project involving strain S288C. Deletion analysis indicated that one open reading frame encoding a predicted protein of 229 amino acids is indispensable for L-azetidine-2-carboxylic acid resistance. The protein sequence was found to be a member of the N-acetyltransferase superfamily. Genomic Southern analysis and gene disruption showed that two copies of the novel gene with one amino acid change at position 85 required for L-azetidine-2-carboxylic acid resistance were present on chromosomes X and XIV of Sigma 1278b background strains. When this novel MPR1 or MPR2 gene (sigma 1278b gene for L-proline analogue resistance) was introduced into the other S. cerevisiae strains, all of the recombinants were resistant to L-azetidine-2-carboxylic acid, indicating that both MPR1 and MPR2 are expressed and have a global function in S. cerevisiae.

  9. Multiway real-time PCR gene expression profiling in yeast Saccharomyces cerevisiae reveals altered transcriptional response of ADH-genes to glucose stimuli.

    PubMed

    Ståhlberg, Anders; Elbing, Karin; Andrade-Garda, José Manuel; Sjögreen, Björn; Forootan, Amin; Kubista, Mikael

    2008-04-16

    The large sensitivity, high reproducibility and essentially unlimited dynamic range of real-time PCR to measure gene expression in complex samples provides the opportunity for powerful multivariate and multiway studies of biological phenomena. In multiway studies samples are characterized by their expression profiles to monitor changes over time, effect of treatment, drug dosage etc. Here we perform a multiway study of the temporal response of four yeast Saccharomyces cerevisiae strains with different glucose uptake rates upon altered metabolic conditions. We measured the expression of 18 genes as function of time after addition of glucose to four strains of yeast grown in ethanol. The data are analyzed by matrix-augmented PCA, which is a generalization of PCA for 3-way data, and the results are confirmed by hierarchical clustering and clustering by Kohonen self-organizing map. Our approach identifies gene groups that respond similarly to the change of nutrient, and genes that behave differently in mutant strains. Of particular interest is our finding that ADH4 and ADH6 show a behavior typical of glucose-induced genes, while ADH3 and ADH5 are repressed after glucose addition. Multiway real-time PCR gene expression profiling is a powerful technique which can be utilized to characterize functions of new genes by, for example, comparing their temporal response after perturbation in different genetic variants of the studied subject. The technique also identifies genes that show perturbed expression in specific strains.

  10. Multiway real-time PCR gene expression profiling in yeast Saccharomyces cerevisiae reveals altered transcriptional response of ADH-genes to glucose stimuli

    PubMed Central

    Ståhlberg, Anders; Elbing, Karin; Andrade-Garda, José Manuel; Sjögreen, Björn; Forootan, Amin; Kubista, Mikael

    2008-01-01

    Background The large sensitivity, high reproducibility and essentially unlimited dynamic range of real-time PCR to measure gene expression in complex samples provides the opportunity for powerful multivariate and multiway studies of biological phenomena. In multiway studies samples are characterized by their expression profiles to monitor changes over time, effect of treatment, drug dosage etc. Here we perform a multiway study of the temporal response of four yeast Saccharomyces cerevisiae strains with different glucose uptake rates upon altered metabolic conditions. Results We measured the expression of 18 genes as function of time after addition of glucose to four strains of yeast grown in ethanol. The data are analyzed by matrix-augmented PCA, which is a generalization of PCA for 3-way data, and the results are confirmed by hierarchical clustering and clustering by Kohonen self-organizing map. Our approach identifies gene groups that respond similarly to the change of nutrient, and genes that behave differently in mutant strains. Of particular interest is our finding that ADH4 and ADH6 show a behavior typical of glucose-induced genes, while ADH3 and ADH5 are repressed after glucose addition. Conclusion Multiway real-time PCR gene expression profiling is a powerful technique which can be utilized to characterize functions of new genes by, for example, comparing their temporal response after perturbation in different genetic variants of the studied subject. The technique also identifies genes that show perturbed expression in specific strains. PMID:18412983

  11. Expression of TPS1 gene from Saccharomycopsis fibuligera A11 in Saccharomyces sp. W0 enhances trehalose accumulation, ethanol tolerance, and ethanol production.

    PubMed

    Cao, Tian-Shu; Chi, Zhe; Liu, Guang-Lei; Chi, Zhen-Ming

    2014-01-01

    It has been reported that trehalose plays an important role in stress tolerance in yeasts. Therefore, in order to construct a stably recombinant Saccharomyces sp. W0 with higher ethanol tolerance, the TPS1 gene encoding 6-phosphate-trehalose synthase cloned from Saccharomycopsis fibuligera A11 was ligated into the 18S rDNA integration vector pMIRSC11 and integrated into chromosomal DNA of Saccharomyces sp. W0. The transformant Z8 obtained had the content of 6.23 g of trehalose/100 g of cell dry weight, while Saccharomyces sp. W0 only contained 4.05 g of trehalose/100 g of cell dry weight. The transformant Z8 also had higher ethanol tolerance (cell survival was 25.1 % at 18 ml of ethanol/100 ml of solution) and trehalose-6-phosphate synthase (Tps1) activity (1.3 U/mg) and produced more ethanol (16.4 ml of ethanol/100 ml of medium) than Saccharomyces sp. W0 (cell survival was 12.1 % at 18 ml of ethanol/100 ml of solution, Tps1 activity was 0.8 U/mg and the produced ethanol concentration was 14.2 ml of ethanol/100 ml of medium) under the same conditions. The results show that trehalose indeed can play an important role in ethanol tolerance and ethanol production by Saccharomyces sp. W0.

  12. In-silico identification and characterization of organic and inorganic chemical stress responding genes in yeast (Saccharomyces cerevisiae).

    PubMed

    Barozai, Muhammad Younas Khan; Bashir, Farrukh; Muzaffar, Shafia; Afzal, Saba; Behlil, Farida; Khan, Muzaffar

    2014-10-15

    To study the life processes of all eukaryotes, yeast (Saccharomyces cerevisiae) is a significant model organism. It is also one of the best models to study the responses of genes at transcriptional level. In a living organism, gene expression is changed by chemical stresses. The genes that give response to chemical stresses will provide good source for the strategies in engineering and formulating mechanisms which are chemical stress resistant in the eukaryotic organisms. The data available through microarray under the chemical stresses like lithium chloride, lactic acid, weak organic acids and tomatidine were studied by using computational tools. Out of 9335 yeast genes, 388 chemical stress responding genes were identified and characterized under different chemical stresses. Some of these are: Enolases 1 and 2, heat shock protein-82, Yeast Elongation Factor 3, Beta Glucanase Protein, Histone H2A1 and Histone H2A2 Proteins, Benign Prostatic Hyperplasia, ras GTPase activating protein, Establishes Silent Chromatin protein, Mei5 Protein, Nondisjunction Protein and Specific Mitogen Activated Protein Kinase. Characterization of these genes was also made on the basis of their molecular functions, biological processes and cellular components. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Aym1, a mouse meiotic gene identified by virtue of its ability to activate early meiotic genes in the yeast Saccharomyces cerevisiae.

    PubMed

    Malcov, Mira; Cesarkas, Karen; Stelzer, Gil; Shalom, Sarah; Dicken, Yosef; Naor, Yaniv; Goldstein, Ronald S; Sagee, Shira; Kassir, Yona; Don, Jeremy

    2004-12-01

    Our understanding of the molecular mechanisms that operate during differentiation of mitotically dividing spermatogonia cells into spermatocytes lags way behind what is known about other differentiating systems. Given the evolutionary conservation of the meiotic process, we screened for mouse proteins that could specifically activate early meiotic promoters in Saccharomyces cerevisiae yeast cells, when fused to the Gal4 activation domain (Gal4AD). Our screen yielded the Aym1 gene that encodes a short peptide of 45 amino acids. We show that a Gal4AD-AYM1 fusion protein activates expression of reporter genes through the promoters of the early meiosis-specific genes IME2 and HOP1, and that this activation is dependent on the DNA-binding protein Ume6. Aym1 is transcribed predominantly in mouse primary spermatocytes and in gonads of female embryos undergoing the corresponding meiotic divisions. Aym1 immunolocalized to nuclei of primary spermatocytes and oocytes and to specific type A spermatogonia cells, suggesting it might play a role in the processes leading to meiotic competence. The potential functional relationship between AYM1 and yeast proteins that regulate expression of early meiotic genes is discussed.

  14. Identification of Genes in Saccharomyces cerevisiae that Are Haploinsufficient for Overcoming Amino Acid Starvation

    PubMed Central

    Bae, Nancy S.; Seberg, Andrew P.; Carroll, Leslie P.; Swanson, Mark J.

    2017-01-01

    The yeast Saccharomyces cerevisiae responds to amino acid deprivation by activating a pathway conserved in eukaryotes to overcome the starvation stress. We have screened the entire yeast heterozygous deletion collection to identify strains haploinsufficient for growth in the presence of sulfometuron methyl, which causes starvation for isoleucine and valine. We have discovered that cells devoid of MET15 are sensitive to sulfometuron methyl, and loss of heterozygosity at the MET15 locus can complicate screening the heterozygous deletion collection. We identified 138 cases of loss of heterozygosity in this screen. After eliminating the issues of the MET15 loss of heterozygosity, strains isolated from the collection were retested on sulfometuron methyl. To determine the general effect of the mutations for a starvation response, SMM-sensitive strains were tested for the ability to grow in the presence of canavanine, which induces arginine starvation, and strains that were MET15 were also tested for growth in the presence of ethionine, which causes methionine starvation. Many of the genes identified in our study were not previously identified as starvation-responsive genes, including a number of essential genes that are not easily screened in a systematic way. The genes identified span a broad range of biological functions, including many involved in some level of gene expression. Several unnamed proteins have also been identified, giving a clue as to possible functions of the encoded proteins. PMID:28209762

  15. Switch between life history strategies due to changes in glycolytic enzyme gene dosage in Saccharomyces cerevisiae.

    PubMed

    Wang, Shaoxiao; Spor, Aymé; Nidelet, Thibault; Montalent, Pierre; Dillmann, Christine; de Vienne, Dominique; Sicard, Delphine

    2011-01-01

    Adaptation is the process whereby a population or species becomes better fitted to its habitat through modifications of various life history traits which can be positively or negatively correlated. The molecular factors underlying these covariations remain to be elucidated. Using Saccharomyces cerevisiae as a model system, we have investigated the effects on life history traits of varying the dosage of genes involved in the transformation of resources into energy. Changing gene dosage for each of three glycolytic enzyme genes (hexokinase 2, phosphoglucose isomerase, and fructose-1,6-bisphosphate aldolase) resulted in variation in enzyme activities, glucose consumption rate, and life history traits (growth rate, carrying capacity, and cell size). However, the range of effects depended on which enzyme was expressed differently. Most interestingly, these changes revealed a genetic trade-off between carrying capacity and cell size, supporting the discovery of two extreme life history strategies already described in yeast populations: the "ants," which have lower glycolytic gene dosage, take up glucose slowly, and have a small cell size but reach a high carrying capacity, and the "grasshoppers," which have higher glycolytic gene dosage, consume glucose more rapidly, and allocate it to a larger cell size but reach a lower carrying capacity. These results demonstrate antagonist pleiotropy for glycolytic genes and show that altered dosage of a single gene drives a switch between two life history strategies in yeast.

  16. Identification of autophagy genes participating in zinc-induced necrotic cell death in Saccharomyces cerevisiae.

    PubMed

    Dziedzic, Slawomir A; Caplan, Allan B

    2011-05-01

    Eukaryotes use a common set of genes to perform two mechanistically similar autophagic processes. Bulk autophagy harvests proteins nonselectively and reuses their constitutents when nutrients are scarce. In contrast, different forms of selective autophagy target protein aggregates or damaged organelles that threaten to interfere with growth. Yeast uses one form of selective autophagy, called cytoplasm-to-vacuole targeting (Cvt), to engulf two vacuolar enzymes in Cvt vesicles ("CVT-somes") within which they are transported to vacuoles for maturation. While both are dispensable normally, bulk and selective autophagy help sustain life under stressful conditions. Consistent with this view, knocking out several genes participating in Cvt and specialized autophagic pathways heightened the sensitivity of Saccharomyces cerevisiae to inhibitory levels of Zn(2+). The loss of other autophagic genes, and genes responsible for apoptotic cell death, had no such effect. Unexpectedly, the loss of members of a third set of autophagy genes heightened cellular resistance to zinc as if they encoded proteins that actively contributed to zinc-induced cell death. Further studies showed that both sensitive and resistant strains accumulated similar amounts of H2O2 during zinc treatments, but that more sensitive strains showed signs of necrosis sooner. Although zinc lethality depended on autophagic proteins, studies with several reporter genes failed to reveal increased autophagic activity. In fact, microscopy analysis indicated that Zn(2+) partially inhibited fusion of Cvt vesicles with vacuoles. Further studies into how the loss of autophagic processes suppressed necrosis in yeast might reveal whether a similar process could occur in plants and animals.

  17. Functional Genomics Using the Saccharomyces cerevisiae Yeast Deletion Collections.

    PubMed

    Nislow, Corey; Wong, Lai Hong; Lee, Amy Huei-Yi; Giaever, Guri

    2016-09-01

    Constructed by a consortium of 16 laboratories, the Saccharomyces genome-wide deletion collections have, for the past decade, provided a powerful, rapid, and inexpensive approach for functional profiling of the yeast genome. Loss-of-function deletion mutants were systematically created using a polymerase chain reaction (PCR)-based gene deletion strategy to generate a start-to-stop codon replacement of each open reading frame by homologous recombination. Each strain carries two molecular barcodes that serve as unique strain identifiers, enabling their growth to be analyzed in parallel and the fitness contribution of each gene to be quantitatively assessed by hybridization to high-density oligonucleotide arrays or through the use of next-generation sequencing technologies. Functional profiling of the deletion collections, using either strain-by-strain or parallel assays, provides an unbiased approach to systematically survey the yeast genome. The Saccharomyces yeast deletion collections have proved immensely powerful in contributing to the understanding of gene function, including functional relationships between genes and genetic pathways in response to diverse genetic and environmental perturbations. © 2016 Cold Spring Harbor Laboratory Press.

  18. Saccharomyces cerevisiae: gene annotation and genome variability, state of the art through comparative genomics.

    PubMed

    Louis, Ed

    2011-01-01

    In the early days of the yeast genome sequencing project, gene annotation was in its infancy and suffered the problem of many false positive annotations as well as missed genes. The lack of other sequences for comparison also prevented the annotation of conserved, functional sequences that were not coding. We are now in an era of comparative genomics where many closely related as well as more distantly related genomes are available for direct sequence and synteny comparisons allowing for more probable predictions of genes and other functional sequences due to conservation. We also have a plethora of functional genomics data which helps inform gene annotation for previously uncharacterised open reading frames (ORFs)/genes. For Saccharomyces cerevisiae this has resulted in a continuous updating of the gene and functional sequence annotations in the reference genome helping it retain its position as the best characterized eukaryotic organism's genome. A single reference genome for a species does not accurately describe the species and this is quite clear in the case of S. cerevisiae where the reference strain is not ideal for brewing or baking due to missing genes. Recent surveys of numerous isolates, from a variety of sources, using a variety of technologies have revealed a great deal of variation amongst isolates with genome sequence surveys providing information on novel genes, undetectable by other means. We now have a better understanding of the extant variation in S. cerevisiae as a species as well as some idea of how much we are missing from this understanding. As with gene annotation, comparative genomics enhances the discovery and description of genome variation and is providing us with the tools for understanding genome evolution, adaptation and selection, and underlying genetics of complex traits.

  19. Stoichiometric network constraints on xylose metabolism by recombinant Saccharomyces cerevisiae

    Treesearch

    Yong-Su Jin; Thomas W. Jeffries

    2004-01-01

    Metabolic pathway engineering is constrained by the thermodynamic and stoichiometric feasibility of enzymatic activities of introduced genes. Engineering of xylose metabolism in Saccharomyces cerevisiae has focused on introducing genes for the initial xylose assimilation steps from Pichia stipitis, a xylose-fermenting yeast, into S. cerevisiae, a yeast raditionally...

  20. Repressors Nrg1 and Nrg2 Regulate a Set of Stress-Responsive Genes in Saccharomyces cerevisiae§

    PubMed Central

    Vyas, Valmik K.; Berkey, Cristin D.; Miyao, Takenori; Carlson, Marian

    2005-01-01

    The yeast Saccharomyces cerevisiae responds to environmental stress by rapidly altering the expression of large sets of genes. We report evidence that the transcriptional repressors Nrg1 and Nrg2 (Nrg1/Nrg2), which were previously implicated in glucose repression, regulate a set of stress-responsive genes. Genome-wide expression analysis identified 150 genes that were upregulated in nrg1Δ nrg2Δ double mutant cells, relative to wild-type cells, during growth in glucose. We found that many of these genes are regulated by glucose repression. Stress response elements (STREs) and STRE-like elements are overrepresented in the promoters of these genes, and a search of available expression data sets showed that many are regulated in response to a variety of environmental stress signals. In accord with these findings, mutation of NRG1 and NRG2 enhanced the resistance of cells to salt and oxidative stress and decreased tolerance to freezing. We present evidence that Nrg1/Nrg2 not only contribute to repression of target genes in the absence of stress but also limit induction in response to salt stress. We suggest that Nrg1/Nrg2 fine-tune the regulation of a set of stress-responsive genes. PMID:16278455

  1. Production of geranylgeraniol on overexpression of a prenyl diphosphate synthase fusion gene in Saccharomyces cerevisiae.

    PubMed

    Ohto, Chikara; Muramatsu, Masayoshi; Obata, Shusei; Sakuradani, Eiji; Shimizu, Sakayu

    2010-07-01

    An acyclic diterpene alcohol, (E,E,E)-geranylgeraniol (GGOH), is one of the important compounds used as perfume and pharmacological agents. A deficiency of squalene (SQ) synthase activity allows yeasts to accumulate an acyclic sesquiterpene alcohol, (E,E)-farnesol, in their cells. Since sterols are essential for the growth of yeasts, a deficiency of SQ synthase activity makes the addition of supplemental sterols to the culture media necessary. To develop a GGOH production method not requiring any supplemental sterols, we overexpressed HMG1 encoding hydroxymethylglutaryl-CoA reductase and the genes of two prenyl diphosphate synthases, ERG20 and BTS1, in Saccharomyces cerevisiae. A prototrophic diploid coexpressing HMG1 and the ERG20-BTS1 fusion accumulated GGOH with neither disruption of the SQ synthase gene nor the addition of any supplemental sterols. The GGOH content on the diploid cultivation in a 5-l jar fermenter reached 138.8 mg/l under optimal conditions.

  2. Gateway Vectors for Efficient Artificial Gene Assembly In Vitro and Expression in Yeast Saccharomyces cerevisiae

    PubMed Central

    Giuraniuc, Claudiu V.; MacPherson, Murray; Saka, Yasushi

    2013-01-01

    Construction of synthetic genetic networks requires the assembly of DNA fragments encoding functional biological parts in a defined order. Yet this may become a time-consuming procedure. To address this technical bottleneck, we have created a series of Gateway shuttle vectors and an integration vector, which facilitate the assembly of artificial genes and their expression in the budding yeast Saccharomyces cerevisiae. Our method enables the rapid construction of an artificial gene from a promoter and an open reading frame (ORF) cassette by one-step recombination reaction in vitro. Furthermore, the plasmid thus created can readily be introduced into yeast cells to test the assembled gene’s functionality. As flexible regulatory components of a synthetic genetic network, we also created new versions of the tetracycline-regulated transactivators tTA and rtTA by fusing them to the auxin-inducible degron (AID). Using our gene assembly approach, we made yeast expression vectors of these engineered transactivators, AIDtTA and AIDrtTA and then tested their functions in yeast. We showed that these factors can be regulated by doxycycline and degraded rapidly after addition of auxin to the medium. Taken together, the method for combinatorial gene assembly described here is versatile and would be a valuable tool for yeast synthetic biology. PMID:23675537

  3. Fast-acting and nearly gratuitous induction of gene expression and protein depletion in Saccharomyces cerevisiae

    PubMed Central

    McIsaac, R. Scott; Silverman, Sanford J.; McClean, Megan N.; Gibney, Patrick A.; Macinskas, Joanna; Hickman, Mark J.; Petti, Allegra A.; Botstein, David

    2011-01-01

    We describe the development and characterization of a system that allows the rapid and specific induction of individual genes in the yeast Saccharomyces cerevisiae without changes in nutrients or temperature. The system is based on the chimeric transcriptional activator Gal4dbd.ER.VP16 (GEV). Upon addition of the hormone β-estradiol, cytoplasmic GEV localizes to the nucleus and binds to promoters containing Gal4p consensus binding sequences to activate transcription. With galactokinase Gal1p and transcriptional activator Gal4p absent, the system is fast-acting, resulting in readily detectable transcription within 5 min after addition of the inducer. β-Estradiol is nearly a gratuitous inducer, as indicated by genome-wide profiling that shows unintended induction (by GEV) of only a few dozen genes. Response to inducer is graded: intermediate concentrations of inducer result in production of intermediate levels of product protein in all cells. We present data illustrating several applications of this system, including a modification of the regulated degron method, which allows rapid and specific degradation of a specific protein upon addition of β-estradiol. These gene induction and protein degradation systems provide important tools for studying the dynamics and functional relationships of genes and their respective regulatory networks. PMID:21965290

  4. Updated regulation curation model at the Saccharomyces Genome Database

    PubMed Central

    Engel, Stacia R; Skrzypek, Marek S; Hellerstedt, Sage T; Wong, Edith D; Nash, Robert S; Weng, Shuai; Binkley, Gail; Sheppard, Travis K; Karra, Kalpana; Cherry, J Michael

    2018-01-01

    Abstract The Saccharomyces Genome Database (SGD) provides comprehensive, integrated biological information for the budding yeast Saccharomyces cerevisiae, along with search and analysis tools to explore these data, enabling the discovery of functional relationships between sequence and gene products in fungi and higher organisms. We have recently expanded our data model for regulation curation to address regulation at the protein level in addition to transcription, and are presenting the expanded data on the ‘Regulation’ pages at SGD. These pages include a summary describing the context under which the regulator acts, manually curated and high-throughput annotations showing the regulatory relationships for that gene and a graphical visualization of its regulatory network and connected networks. For genes whose products regulate other genes or proteins, the Regulation page includes Gene Ontology enrichment analysis of the biological processes in which those targets participate. For DNA-binding transcription factors, we also provide other information relevant to their regulatory function, such as DNA binding site motifs and protein domains. As with other data types at SGD, all regulatory relationships and accompanying data are available through YeastMine, SGD’s data warehouse based on InterMine. Database URL: http://www.yeastgenome.org PMID:29688362

  5. Transcriptome analysis identifies genes involved in ethanol response of Saccharomyces cerevisiae in Agave tequilana juice.

    PubMed

    Ramirez-Córdova, Jesús; Drnevich, Jenny; Madrigal-Pulido, Jaime Alberto; Arrizon, Javier; Allen, Kirk; Martínez-Velázquez, Moisés; Alvarez-Maya, Ikuri

    2012-08-01

    During ethanol fermentation, yeast cells are exposed to stress due to the accumulation of ethanol, cell growth is altered and the output of the target product is reduced. For Agave beverages, like tequila, no reports have been published on the global gene expression under ethanol stress. In this work, we used microarray analysis to identify Saccharomyces cerevisiae genes involved in the ethanol response. Gene expression of a tequila yeast strain of S. cerevisiae (AR5) was explored by comparing global gene expression with that of laboratory strain S288C, both after ethanol exposure. Additionally, we used two different culture conditions, cells grown in Agave tequilana juice as a natural fermentation media or grown in yeast-extract peptone dextrose as artificial media. Of the 6368 S. cerevisiae genes in the microarray, 657 genes were identified that had different expression responses to ethanol stress due to strain and/or media. A cluster of 28 genes was found over-expressed specifically in the AR5 tequila strain that could be involved in the adaptation to tequila yeast fermentation, 14 of which are unknown such as yor343c, ylr162w, ygr182c, ymr265c, yer053c-a or ydr415c. These could be the most suitable genes for transforming tequila yeast to increase ethanol tolerance in the tequila fermentation process. Other genes involved in response to stress (RFC4, TSA1, MLH1, PAU3, RAD53) or transport (CYB2, TIP20, QCR9) were expressed in the same cluster. Unknown genes could be good candidates for the development of recombinant yeasts with ethanol tolerance for use in industrial tequila fermentation.

  6. An Improved, Bias-Reduced Probabilistic Functional Gene Network of Baker's Yeast, Saccharomyces cerevisiae

    PubMed Central

    Lee, Insuk; Li, Zhihua; Marcotte, Edward M.

    2007-01-01

    Background Probabilistic functional gene networks are powerful theoretical frameworks for integrating heterogeneous functional genomics and proteomics data into objective models of cellular systems. Such networks provide syntheses of millions of discrete experimental observations, spanning DNA microarray experiments, physical protein interactions, genetic interactions, and comparative genomics; the resulting networks can then be easily applied to generate testable hypotheses regarding specific gene functions and associations. Methodology/Principal Findings We report a significantly improved version (v. 2) of a probabilistic functional gene network [1] of the baker's yeast, Saccharomyces cerevisiae. We describe our optimization methods and illustrate their effects in three major areas: the reduction of functional bias in network training reference sets, the application of a probabilistic model for calculating confidences in pair-wise protein physical or genetic interactions, and the introduction of simple thresholds that eliminate many false positive mRNA co-expression relationships. Using the network, we predict and experimentally verify the function of the yeast RNA binding protein Puf6 in 60S ribosomal subunit biogenesis. Conclusions/Significance YeastNet v. 2, constructed using these optimizations together with additional data, shows significant reduction in bias and improvements in precision and recall, in total covering 102,803 linkages among 5,483 yeast proteins (95% of the validated proteome). YeastNet is available from http://www.yeastnet.org. PMID:17912365

  7. Deciphering the Origin, Evolution, and Physiological Function of the Subtelomeric Aryl-Alcohol Dehydrogenase Gene Family in the Yeast Saccharomyces cerevisiae.

    PubMed

    Yang, Dong-Dong; de Billerbeck, Gustavo M; Zhang, Jin-Jing; Rosenzweig, Frank; Francois, Jean-Marie

    2018-01-01

    Homology searches indicate that Saccharomyces cerevisiae strain BY4741 contains seven redundant genes that encode putative aryl-alcohol dehydrogenases (AAD). Yeast AAD genes are located in subtelomeric regions of different chromosomes, and their functional role(s) remain enigmatic. Here, we show that two of these genes, AAD4 and AAD14 , encode functional enzymes that reduce aliphatic and aryl-aldehydes concomitant with the oxidation of cofactor NADPH, and that Aad4p and Aad14p exhibit different substrate preference patterns. Other yeast AAD genes are undergoing pseudogenization. The 5' sequence of AAD15 has been deleted from the genome. Repair of an AAD3 missense mutation at the catalytically essential Tyr 73 residue did not result in a functional enzyme. However, ancestral-state reconstruction by fusing Aad6 with Aad16 and by N-terminal repair of Aad10 restores NADPH-dependent aryl-alcohol dehydrogenase activities. Phylogenetic analysis indicates that AAD genes are narrowly distributed in wood-saprophyte fungi and in yeast that occupy lignocellulosic niches. Because yeast AAD genes exhibit activity on veratraldehyde, cinnamaldehyde, and vanillin, they could serve to detoxify aryl-aldehydes released during lignin degradation. However, none of these compounds induce yeast AAD gene expression, and Aad activities do not relieve aryl-aldehyde growth inhibition. Our data suggest an ancestral role for AAD genes in lignin degradation that is degenerating as a result of yeast's domestication and use in brewing, baking, and other industrial applications. IMPORTANCE Functional characterization of hypothetical genes remains one of the chief tasks of the postgenomic era. Although the first Saccharomyces cerevisiae genome sequence was published over 20 years ago, 22% of its estimated 6,603 open reading frames (ORFs) remain unverified. One outstanding example of this category of genes is the enigmatic seven-member AAD family. Here, we demonstrate that proteins encoded by two

  8. Deciphering the Origin, Evolution, and Physiological Function of the Subtelomeric Aryl-Alcohol Dehydrogenase Gene Family in the Yeast Saccharomyces cerevisiae

    PubMed Central

    de Billerbeck, Gustavo M.; Zhang, Jin-jing; Rosenzweig, Frank

    2017-01-01

    ABSTRACT Homology searches indicate that Saccharomyces cerevisiae strain BY4741 contains seven redundant genes that encode putative aryl-alcohol dehydrogenases (AAD). Yeast AAD genes are located in subtelomeric regions of different chromosomes, and their functional role(s) remain enigmatic. Here, we show that two of these genes, AAD4 and AAD14, encode functional enzymes that reduce aliphatic and aryl-aldehydes concomitant with the oxidation of cofactor NADPH, and that Aad4p and Aad14p exhibit different substrate preference patterns. Other yeast AAD genes are undergoing pseudogenization. The 5′ sequence of AAD15 has been deleted from the genome. Repair of an AAD3 missense mutation at the catalytically essential Tyr73 residue did not result in a functional enzyme. However, ancestral-state reconstruction by fusing Aad6 with Aad16 and by N-terminal repair of Aad10 restores NADPH-dependent aryl-alcohol dehydrogenase activities. Phylogenetic analysis indicates that AAD genes are narrowly distributed in wood-saprophyte fungi and in yeast that occupy lignocellulosic niches. Because yeast AAD genes exhibit activity on veratraldehyde, cinnamaldehyde, and vanillin, they could serve to detoxify aryl-aldehydes released during lignin degradation. However, none of these compounds induce yeast AAD gene expression, and Aad activities do not relieve aryl-aldehyde growth inhibition. Our data suggest an ancestral role for AAD genes in lignin degradation that is degenerating as a result of yeast's domestication and use in brewing, baking, and other industrial applications. IMPORTANCE Functional characterization of hypothetical genes remains one of the chief tasks of the postgenomic era. Although the first Saccharomyces cerevisiae genome sequence was published over 20 years ago, 22% of its estimated 6,603 open reading frames (ORFs) remain unverified. One outstanding example of this category of genes is the enigmatic seven-member AAD family. Here, we demonstrate that proteins encoded

  9. IMP2, a nuclear gene controlling the mitochondrial dependence of galactose, maltose and raffinose utilization in Saccharomyces cerevisiae.

    PubMed

    Donnini, C; Lodi, T; Ferrero, I; Puglisi, P P

    1992-02-01

    The IMP2 gene of Saccharomyces cerevisiae is involved in the nucleo-mitochondrial control of maltose, galactose and raffinose utilization as shown by the inability of imp2 mutants to grow on these carbon sources in respiratory-deficient conditions or in the presence of ethidium bromide and erythromycin. The negative phenotype cannot be scored in the presence of inhibitors of respiration and oxidative phosphorylation, indicating that the role of the mitochondria in the utilization of the above-mentioned carbon sources in imp2 mutants is not at the energetical level. Mutations in the IMP2 gene also confer many phenotypic alterations in respiratory-sufficient conditions, e.g. leaky phenotype on oxidizable carbon sources, sensitivity to heat shock and sporulation deficiency. The IMP2 gene has been cloned, sequenced and disrupted. The phenotype of null imp2 mutants is indistinguishable from that of the originally isolated mutant.

  10. Molecular cloning and expression in Saccharomyces cerevisiae and Neurospora crassa of the invertase gene from Neurospora crassa.

    PubMed

    Carú, M; Cifuentes, V; Pincheira, G; Jiménez, A

    1989-10-01

    A plasmid (named pCN2) carrying a 7.6 kb BamHI DNA insert was isolated from a Neurospora crassa genomic library raised in the yeast vector YRp7. Saccharomyces cerevisiae suco and N. crassa inv strains transformed with pNC2 were able to grow on sucrose-based media and expressed invertase activity. Saccharomyces cerevisiae suco (pNC2) expressed a product which immunoreacted with antibody raised against purified invertase from wild type N. crassa, although S. cerevisiae suc+ did not. The cloned DNA hybridized with a 7.6 kb DNA fragment from BamHI-restricted wild type N. crassa DNA. Plasmid pNC2 transformed N. crassa Inv- to Inv+ by integration either near to the endogenous inv locus (40% events) or at other genomic sites (60% events). It appears therefore that the cloned DNA piece encodes the N. crassa invertase enzyme. A 3.8 kb XhoI DNA fragment, derived from pNC2, inserted in YRp7, in both orientation, was able to express invertase activity in yeast, suggesting that it contains an intact invertase gene which is not expressed from a vector promoter.

  11. The ASP3 locus in Saccharomyces cerevisiae originated by horizontal gene transfer from Wickerhamomyces.

    PubMed

    League, Garrett P; Slot, Jason C; Rokas, Antonis

    2012-11-01

    The asparagine degradation pathway in the S288c laboratory strain of Saccharomyces cerevisiae is comprised of genes located at two separate loci. ASP1 is located on chromosome IV and encodes for cytosolic l-asparaginase I, whereas ASP3 contains a gene cluster located on chromosome XII comprised of four identical genes, ASP3-1, ASP3-2, ASP3-3, and ASP3-4, which encode for cell wall-associated l-asparaginase II. Interestingly, the ASP3 locus appears to be only present, in variable copy number, in S. cerevisiae strains isolated from laboratory or industrial environments and is completely absent from the genomes of 128 diverse fungal species. Investigation of the evolutionary history of ASP3 across these 128 genomes as well as across the genomes of 43 S. cerevisiae strains shows that ASP3 likely arose in a S. cerevisiae strain via horizontal gene transfer (HGT) from, or a close relative of, the wine yeast Wickerhamomyces anomalus, which co-occurs with S. cerevisiae in several biotechnological processes. Thus, because the ASP3 present in the S288c laboratory strain of S. cerevisiae is induced in response to nitrogen starvation, its acquisition may have aided yeast adaptation to artificial environments. Our finding that the ASP3 locus in S. cerevisiae originated via HGT further highlights the importance of gene sharing between yeasts in the evolution of their remarkable metabolic diversity. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  12. Expression of three Trichoderma reesei cellulase genes in Saccharomyces pastorianus for the development of a two-step process of hydrolysis and fermentation of cellulose.

    PubMed

    Fitzpatrick, J; Kricka, W; James, T C; Bond, U

    2014-07-01

    To compare the production of recombinant cellulase enzymes in two Saccharomyces species so as to ascertain the most suitable heterologous host for the degradation of cellulose-based biomass and its conversion into bioethanol. cDNA copies of genes representing the three major classes of cellulases (Endoglucanases, Cellobiohydrolases and β-glucosidases) from Trichoderma reesei were expressed in Saccharomyces pastorianus and Saccharomyces cerevisiae. The recombinant enzymes were secreted by the yeast hosts into the medium and were shown to act in synergy to hydrolyse cellulose. The conditions required to achieve maximum release of glucose from cellulose by the recombinant enzymes were defined and the activity of the recombinant enzymes was compared to a commercial cocktail of T. reesei cellulases. We demonstrate that significantly higher levels of cellulase activity were achieved by expression of the genes in S. pastorianus compared to S. cerevisiae. Hydrolysis of cellulose by the combined activity of the recombinant enzymes was significantly better at 50°C than at 30°C, the temperature used for mesophilic yeast fermentations, reflecting the known temperature profiles of the native enzymes. The results demonstrate that host choice is important for the heterologous production of cellulases. On the basis of the low activity of the T. reesei recombinant enzymes at fermentation temperatures, we propose a two-step process for the hydrolysis of cellulose and its fermentation into alcohol using cellulases produced in situ. © 2014 The Society for Applied Microbiology.

  13. The evolutionary history of Saccharomyces species inferred from completed mitochondrial genomes and revision in the ‘yeast mitochondrial genetic code’

    PubMed Central

    Szabóová, Dana; Bielik, Peter; Poláková, Silvia; Šoltys, Katarína; Jatzová, Katarína; Szemes, Tomáš

    2017-01-01

    Abstract The yeast Saccharomyces are widely used to test ecological and evolutionary hypotheses. A large number of nuclear genomic DNA sequences are available, but mitochondrial genomic data are insufficient. We completed mitochondrial DNA (mtDNA) sequencing from Illumina MiSeq reads for all Saccharomyces species. All are circularly mapped molecules decreasing in size with phylogenetic distance from Saccharomyces cerevisiae but with similar gene content including regulatory and selfish elements like origins of replication, introns, free-standing open reading frames or GC clusters. Their most profound feature is species-specific alteration in gene order. The genetic code slightly differs from well-established yeast mitochondrial code as GUG is used rarely as the translation start and CGA and CGC code for arginine. The multilocus phylogeny, inferred from mtDNA, does not correlate with the trees derived from nuclear genes. mtDNA data demonstrate that Saccharomyces cariocanus should be assigned as a separate species and Saccharomyces bayanus CBS 380T should not be considered as a distinct species due to mtDNA nearly identical to Saccharomyces uvarum mtDNA. Apparently, comparison of mtDNAs should not be neglected in genomic studies as it is an important tool to understand the origin and evolutionary history of some yeast species. PMID:28992063

  14. High hydrostatic pressure activates gene expression that leads to ethanol production enhancement in a Saccharomyces cerevisiae distillery strain

    PubMed Central

    Bravim, Fernanda; Lippman, Soyeon I.; da Silva, Lucas F.; Souza, Diego T.; Fernandes, A. Alberto R.; Masuda, Claudio A.; Broach, James R.

    2016-01-01

    High hydrostatic pressure (HHP) is a stress that exerts broad effects on microorganisms with characteristics similar to those of common environmental stresses. In this study, we aimed to identify genetic mechanisms that can enhance alcoholic fermentation of wild Saccharomyces cerevisiae isolated from Brazilian spirit fermentation vats. Accordingly, we performed a time course microarray analysis on a S. cerevisiae strain submitted to mild sublethal pressure treatment of 50 MPa for 30 min at room temperature, followed by incubation for 5, 10 and 15 min without pressure treatment. The obtained transcriptional profiles demonstrate the importance of post-pressurisation period on the activation of several genes related to cell recovery and stress tolerance. Based on these results, we over-expressed genes strongly induced by HHP in the same wild yeast strain and identified genes, particularly SYM1, whose over-expression results in enhanced ethanol production and stress tolerance upon fermentation. The present study validates the use of HHP as a biotechnological tool for the fermentative industries. PMID:22915193

  15. Extensive Copy Number Variation in Fermentation-Related Genes Among Saccharomyces cerevisiae Wine Strains.

    PubMed

    Steenwyk, Jacob; Rokas, Antonis

    2017-05-05

    Due to the importance of Saccharomyces cerevisiae in wine-making, the genomic variation of wine yeast strains has been extensively studied. One of the major insights stemming from these studies is that wine yeast strains harbor low levels of genetic diversity in the form of single nucleotide polymorphisms (SNPs). Genomic structural variants, such as copy number (CN) variants, are another major type of variation segregating in natural populations. To test whether genetic diversity in CN variation is also low across wine yeast strains, we examined genome-wide levels of CN variation in 132 whole-genome sequences of S. cerevisiae wine strains. We found an average of 97.8 CN variable regions (CNVRs) affecting ∼4% of the genome per strain. Using two different measures of CN diversity, we found that gene families involved in fermentation-related processes such as copper resistance ( CUP ), flocculation ( FLO ), and glucose metabolism ( HXT ), as well as the SNO gene family whose members are expressed before or during the diauxic shift, showed substantial CN diversity across the 132 strains examined. Importantly, these same gene families have been shown, through comparative transcriptomic and functional assays, to be associated with adaptation to the wine fermentation environment. Our results suggest that CN variation is a substantial contributor to the genomic diversity of wine yeast strains, and identify several candidate loci whose levels of CN variation may affect the adaptation and performance of wine yeast strains during fermentation. Copyright © 2017 Steenwyk and Rokas.

  16. How did Saccharomyces evolve to become a good brewer?

    PubMed

    Piskur, Jure; Rozpedowska, Elzbieta; Polakova, Silvia; Merico, Annamaria; Compagno, Concetta

    2006-04-01

    Brewing and wine production are among the oldest technologies and their products are almost indispensable in our lives. The central biological agents of beer and wine fermentation are yeasts belonging to the genus Saccharomyces, which can accumulate ethanol. Recent advances in comparative genomics and bioinformatics have made it possible to elucidate when and why yeasts produce ethanol in high concentrations, and how this remarkable trait originated and developed during their evolutionary history. Two research groups have shed light on the origin of the genes encoding alcohol dehydrogenase and the process of ethanol accumulation in Saccharomyces cerevisiae.

  17. Cloning and characterization of LOS1, a Saccharomyces cerevisiae gene that affects tRNA splicing.

    PubMed

    Hurt, D J; Wang, S S; Lin, Y H; Hopper, A K

    1987-03-01

    Saccharomyces cerevisiae strains carrying los1-1 mutations are defective in tRNA processing; at 37 degrees C, such strains accumulate tRNA precursors which have mature 5' and 3' ends but contain intervening sequences. Strains bearing los1-1 and an intron-containing ochre-suppressing tRNA gene, SUP4(0), also fail to suppress the ochre mutations ade2-1(0) and can1-100(0) at 34 degrees C. To understand the role of the LOS1 product in tRNA splicing, we initiated a molecular study of the LOS1 gene. Two plasmids, YEpLOS1 and YCpLOS1, that complement the los1-1 phenotype were isolated from the YEp24 and YCp50 libraries, respectively. YEpLOS1 and YCpLOS1 had overlapping restriction maps, indicating that the DNA in the overlapping segment could complement los1-1 when present in multiple or single copy. Integration of plasmid DNA at the LOS1 locus confirmed that these clones contained authentic LOS1 sequences. Southern analyses showed that LOS1 is a single copy gene. The locations of the LOS1 gene within YEpLOS1 and YCpLOS1 were determined by deletion and gamma-delta mapping. Two genomic disruptions of the LOS1 gene were constructed, i.e., an insertion of a 1.2-kilobase fragment carrying the yeast URA3 gene, los1::URA3, and a 2.4-kilobase deletion from the LOS1 gene, los1-delta V. Disruption or deletion of most of the LOS1 gene was not lethal; cells carrying the disrupted los1 alleles were viable and had phenotypes similar to those of cells carrying the los1-1 allele. Thus, it appears that the los1 gene product expedites tRNA splicing at elevated temperatures but is not essential for this process.

  18. Cytotoxicity and gene induction by some essential oils in the yeast Saccharomyces cerevisiae.

    PubMed

    Bakkali, F; Averbeck, S; Averbeck, D; Zhiri, A; Idaomar, M

    2005-08-01

    In order to get an insight into the possible genotoxicity of essential oils (EOs) used in traditional pharmacological applications we tested five different oils extracted from the medicinal plants Origanum compactum, Coriandrum sativum, Artemisia herba alba, Cinnamomum camphora (Ravintsara aromatica) and Helichrysum italicum (Calendula officinalis) for genotoxic effects using the yeast Saccharomyces cerevisiae. Clear cytotoxic effects were observed in the diploid yeast strain D7, with the cells being more sensitive to EOs in exponential than in stationary growth phase. The cytotoxicity decreased in the following order: Origanum compactum>Coriandrum sativum>Artemisia herba alba>Cinnamomum camphora>Helichrysum italicum. In the same order, all EOs, except that derived from Helichrysum italicum, clearly induced cytoplasmic petite mutations indicating damage to mitochondrial DNA. However, no nuclear genetic events such as point mutations or mitotic intragenic or intergenic recombination were induced. The capacity of EOs to induce nuclear DNA damage-responsive genes was tested using suitable Lac-Z fusion strains for RNR3 and RAD51, which are genes involved in DNA metabolism and DNA repair, respectively. At equitoxic doses, all EOs demonstrated significant gene induction, approximately the same as that caused by hydrogen peroxide, but much lower than that caused by methyl methanesulfonate (MMS). EOs affect mitochondrial structure and function and can stimulate the transcriptional expression of DNA damage-responsive genes. The induction of mitochondrial damage by EOs appears to be closely linked to overall cellular cytotoxicity and appears to mask the occurrence of nuclear genetic events. EO-induced cytotoxicity involves oxidative stress, as is evident from the protection observed in the presence of ROS inhibitors such as glutathione, catalase or the iron-chelating agent deferoxamine.

  19. [Expression of the Drosophila melanogaster limk1 gene 3'-UTRs mRNA in Yeast Saccharomyces cerevisiae].

    PubMed

    Rumyantsev, A M; Zakharov, G A; Zhuravlev, A V; Padkina, M V; Savvateeva-Popova, E V; Sambuk, E V

    2014-06-01

    The stability of mRNA and its translation efficacy in higher eukaryotes are influenced by the interaction of 3'-untranscribed regions (3'-UTRs) with microRNAs and RNA-binding proteins. Since Saccharomyces cerevisiae lack microRNAs, it is possible to evaluate the contribution of only 3'-UTRs' and RNA-binding proteins' interaction in post-transcriptional regulation. For this, the post-transcriptional regulation of Drosophila limk1 gene encoding for the key enzyme of actin remodeling was studied in yeast. Analysis of limkl mRNA 3'-UTRs revealed the potential sites of yeast transcriptional termination. Computer remodeling demonstrated the possibility of secondary structure formation in limkl mRNA 3'-UTRs. For an evaluation of the functional activity of Drosophila 3'-UTRs in yeast, the reporter gene PHO5 encoding for yeast acid phosphatase (AP) fused to different variants of Drosophila limk1 mRNA 3'-UTRs (513, 1075, 1554 bp) was used. Assessments of AP activity and RT-PCR demonstrated that Drosophila limkl gene 3'-UTRs were functionally active and recognized in yeast. Therefore, yeast might be used as an appropriate model system for studies of 3'-UTR's role in post-transcriptional regulation.

  20. Plant-Derived Transcription Factors for Orthologous Regulation of Gene Expression in the Yeast Saccharomyces cerevisiae.

    PubMed

    Naseri, Gita; Balazadeh, Salma; Machens, Fabian; Kamranfar, Iman; Messerschmidt, Katrin; Mueller-Roeber, Bernd

    2017-09-15

    Control of gene expression by transcription factors (TFs) is central in many synthetic biology projects for which a tailored expression of one or multiple genes is often needed. As TFs from evolutionary distant organisms are unlikely to affect gene expression in a host of choice, they represent excellent candidates for establishing orthogonal control systems. To establish orthogonal regulators for use in yeast (Saccharomyces cerevisiae), we chose TFs from the plant Arabidopsis thaliana. We established a library of 106 different combinations of chromosomally integrated TFs, activation domains (yeast GAL4 AD, herpes simplex virus VP64, and plant EDLL) and synthetic promoters harboring cognate cis-regulatory motifs driving a yEGFP reporter. Transcriptional output of the different driver/reporter combinations varied over a wide spectrum, with EDLL being a considerably stronger transcription activation domain in yeast than the GAL4 activation domain, in particular when fused to Arabidopsis NAC TFs. Notably, the strength of several NAC-EDLL fusions exceeded that of the strong yeast TDH3 promoter by 6- to 10-fold. We furthermore show that plant TFs can be used to build regulatory systems encoded by centromeric or episomal plasmids. Our library of TF-DNA binding site combinations offers an excellent tool for diverse synthetic biology applications in yeast.

  1. Transcriptional Regulatory Networks in Saccharomyces cerevisiae

    NASA Astrophysics Data System (ADS)

    Lee, Tong Ihn; Rinaldi, Nicola J.; Robert, François; Odom, Duncan T.; Bar-Joseph, Ziv; Gerber, Georg K.; Hannett, Nancy M.; Harbison, Christopher T.; Thompson, Craig M.; Simon, Itamar; Zeitlinger, Julia; Jennings, Ezra G.; Murray, Heather L.; Gordon, D. Benjamin; Ren, Bing; Wyrick, John J.; Tagne, Jean-Bosco; Volkert, Thomas L.; Fraenkel, Ernest; Gifford, David K.; Young, Richard A.

    2002-10-01

    We have determined how most of the transcriptional regulators encoded in the eukaryote Saccharomyces cerevisiae associate with genes across the genome in living cells. Just as maps of metabolic networks describe the potential pathways that may be used by a cell to accomplish metabolic processes, this network of regulator-gene interactions describes potential pathways yeast cells can use to regulate global gene expression programs. We use this information to identify network motifs, the simplest units of network architecture, and demonstrate that an automated process can use motifs to assemble a transcriptional regulatory network structure. Our results reveal that eukaryotic cellular functions are highly connected through networks of transcriptional regulators that regulate other transcriptional regulators.

  2. Genetic diversity of FLO1 and FLO5 genes in wine flocculent Saccharomyces cerevisiae strains.

    PubMed

    Tofalo, Rosanna; Perpetuini, Giorgia; Di Gianvito, Paola; Schirone, Maria; Corsetti, Aldo; Suzzi, Giovanna

    2014-11-17

    Twenty-eight flocculent wine strains were tested for adhesion and flocculation phenotypic variability. Moreover, the expression patterns of the main genes involved in flocculation (FLO1, FLO5 and FLO8) were studied both in synthetic medium and in presence of ethanol stress. Molecular identification and typing were achieved by PCR-RFLP of the 5.8S ITS rRNA region and microsatellite PCR fingerprinting, respectively. All isolates belong to Saccharomyces cerevisiae species. The analysis of microsatellites highlighted the intraspecific genetic diversity of flocculent wine S. cerevisiae strains allowing obtaining strain-specific profiles. Moreover, strains were characterized on the basis of adhesive properties. A wide biodiversity was observed even if none of the tested strains were able to form biofilms (or 'mats'), or to adhere to polystyrene. Moreover, genetic diversity of FLO1 and FLO5 flocculating genes was determined by PCR. Genetic diversity was detected for both genes, but a relationship with the flocculation degree was not found. So, the expression patterns of FLO1, FLO5 and FLO8 genes was investigated in a synthetic medium and a relationship between the expression of FLO5 gene and the flocculation capacity was established. To study the expression of FLO1, FLO5 and FLO8 genes in floc formation and ethanol stress resistance qRT-PCR was carried out and also in this case strains with flocculent capacity showed higher levels of FLO5 gene expression. This study confirmed the diversity of flocculation phenotype and genotype in wine yeasts. Moreover, the importance of FLO5 gene in development of high flocculent characteristic of wine yeasts was highlighted. The obtained collection of S. cerevisiae flocculent wine strains could be useful to study the relationship between the genetic variation and flocculation phenotype in wine yeasts. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. The Awesome Power of Yeast Evolutionary Genetics: New Genome Sequences and Strain Resources for the Saccharomyces sensu stricto Genus

    PubMed Central

    Scannell, Devin R.; Zill, Oliver A.; Rokas, Antonis; Payen, Celia; Dunham, Maitreya J.; Eisen, Michael B.; Rine, Jasper; Johnston, Mark; Hittinger, Chris Todd

    2011-01-01

    High-quality, well-annotated genome sequences and standardized laboratory strains fuel experimental and evolutionary research. We present improved genome sequences of three species of Saccharomyces sensu stricto yeasts: S. bayanus var. uvarum (CBS 7001), S. kudriavzevii (IFO 1802T and ZP 591), and S. mikatae (IFO 1815T), and describe their comparison to the genomes of S. cerevisiae and S. paradoxus. The new sequences, derived by assembling millions of short DNA sequence reads together with previously published Sanger shotgun reads, have vastly greater long-range continuity and far fewer gaps than the previously available genome sequences. New gene predictions defined a set of 5261 protein-coding orthologs across the five most commonly studied Saccharomyces yeasts, enabling a re-examination of the tempo and mode of yeast gene evolution and improved inferences of species-specific gains and losses. To facilitate experimental investigations, we generated genetically marked, stable haploid strains for all three of these Saccharomyces species. These nearly complete genome sequences and the collection of genetically marked strains provide a valuable toolset for comparative studies of gene function, metabolism, and evolution, and render Saccharomyces sensu stricto the most experimentally tractable model genus. These resources are freely available and accessible through www.SaccharomycesSensuStricto.org. PMID:22384314

  4. The YeastGenome app: the Saccharomyces Genome Database at your fingertips.

    PubMed

    Wong, Edith D; Karra, Kalpana; Hitz, Benjamin C; Hong, Eurie L; Cherry, J Michael

    2013-01-01

    The Saccharomyces Genome Database (SGD) is a scientific database that provides researchers with high-quality curated data about the genes and gene products of Saccharomyces cerevisiae. To provide instant and easy access to this information on mobile devices, we have developed YeastGenome, a native application for the Apple iPhone and iPad. YeastGenome can be used to quickly find basic information about S. cerevisiae genes and chromosomal features regardless of internet connectivity. With or without network access, you can view basic information and Gene Ontology annotations about a gene of interest by searching gene names and gene descriptions or by browsing the database within the app to find the gene of interest. With internet access, the app provides more detailed information about the gene, including mutant phenotypes, references and protein and genetic interactions, as well as provides hyperlinks to retrieve detailed information by showing SGD pages and views of the genome browser. SGD provides online help describing basic ways to navigate the mobile version of SGD, highlights key features and answers frequently asked questions related to the app. The app is available from iTunes (http://itunes.com/apps/yeastgenome). The YeastGenome app is provided freely as a service to our community, as part of SGD's mission to provide free and open access to all its data and annotations.

  5. Microarray data and gene expression statistics for Saccharomyces cerevisiae exposed to simulated asbestos mine drainage.

    PubMed

    Driscoll, Heather E; Murray, Janet M; English, Erika L; Hunter, Timothy C; Pivarski, Kara; Dolci, Elizabeth D

    2017-08-01

    Here we describe microarray expression data (raw and normalized), experimental metadata, and gene-level data with expression statistics from Saccharomyces cerevisiae exposed to simulated asbestos mine drainage from the Vermont Asbestos Group (VAG) Mine on Belvidere Mountain in northern Vermont, USA. For nearly 100 years (between the late 1890s and 1993), chrysotile asbestos fibers were extracted from serpentinized ultramafic rock at the VAG Mine for use in construction and manufacturing industries. Studies have shown that water courses and streambeds nearby have become contaminated with asbestos mine tailings runoff, including elevated levels of magnesium, nickel, chromium, and arsenic, elevated pH, and chrysotile asbestos-laden mine tailings, due to leaching and gradual erosion of massive piles of mine waste covering approximately 9 km 2 . We exposed yeast to simulated VAG Mine tailings leachate to help gain insight on how eukaryotic cells exposed to VAG Mine drainage may respond in the mine environment. Affymetrix GeneChip® Yeast Genome 2.0 Arrays were utilized to assess gene expression after 24-h exposure to simulated VAG Mine tailings runoff. The chemistry of mine-tailings leachate, mine-tailings leachate plus yeast extract peptone dextrose media, and control yeast extract peptone dextrose media is also reported. To our knowledge this is the first dataset to assess global gene expression patterns in a eukaryotic model system simulating asbestos mine tailings runoff exposure. Raw and normalized gene expression data are accessible through the National Center for Biotechnology Information Gene Expression Omnibus (NCBI GEO) Database Series GSE89875 (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE89875).

  6. Role of UME6 in transcriptional regulation of a DNA repair gene in Saccharomyces cerevisiae.

    PubMed

    Sweet, D H; Jang, Y K; Sancar, G B

    1997-11-01

    In Saccharomyces cerevisiae UV radiation and a variety of chemical DNA-damaging agents induce the transcription of specific genes, including several involved in DNA repair. One of the best characterized of these genes is PHR1, which encodes the apoenzyme for DNA photolyase. Basal-level and damage-induced expression of PHR1 require an upstream activation sequence, UAS(PHR1), which has homology with DRC elements found upstream of at least 19 other DNA repair and DNA metabolism genes in yeast. Here we report the identification of the UME6 gene of S. cerevisiae as a regulator of UAS(PHR1) activity. Multiple copies of UME6 stimulate expression from UAS(PHR1) and the intact PHR1 gene. Surprisingly, the effect of deletion of UME6 is growth phase dependent. In wild-type cells PHR1 is induced in late exponential phase, concomitant with the initiation of glycogen accumulation that precedes the diauxic shift. Deletion of UME6 abolishes this induction, decreases the steady-state concentration of photolyase molecules and PHR1 mRNA, and increases the UV sensitivity of a rad2 mutant. Despite the fact that UAS(PHR1) does not contain the URS1 sequence, which has been previously implicated in UME6-mediated transcriptional regulation, we find that Ume6p binds to UAS(PHR1) with an affinity and a specificity similar to those seen for a URS1 site. Similar binding is also seen for DRC elements from RAD2, RAD7, and RAD53, suggesting that UME6 contributes to the regulated expression of a subset of damage-responsive genes in yeast.

  7. 3' Untranslated regions mediate transcriptional interference between convergent genes both locally and ectopically in Saccharomyces cerevisiae.

    PubMed

    Wang, Luwen; Jiang, Ning; Wang, Lin; Fang, Ou; Leach, Lindsey J; Hu, Xiaohua; Luo, Zewei

    2014-01-01

    Paired sense and antisense (S/AS) genes located in cis represent a structural feature common to the genomes of both prokaryotes and eukaryotes, and produce partially complementary transcripts. We used published genome and transcriptome sequence data and found that over 20% of genes (645 pairs) in the budding yeast Saccharomyces cerevisiae genome are arranged in convergent pairs with overlapping 3'-UTRs. Using published microarray transcriptome data from the standard laboratory strain of S. cerevisiae, our analysis revealed that expression levels of convergent pairs are significantly negatively correlated across a broad range of environments. This implies an important role for convergent genes in the regulation of gene expression, which may compensate for the absence of RNA-dependent mechanisms such as micro RNAs in budding yeast. We selected four representative convergent gene pairs and used expression assays in wild type yeast and its genetically modified strains to explore the underlying patterns of gene expression. Results showed that convergent genes are reciprocally regulated in yeast populations and in single cells, whereby an increase in expression of one gene produces a decrease in the expression of the other, and vice-versa. Time course analysis of the cell cycle illustrated the functional significance of this relationship for the three pairs with relevant functional roles. Furthermore, a series of genetic modifications revealed that the 3'-UTR sequence plays an essential causal role in mediating transcriptional interference, which requires neither the sequence of the open reading frame nor the translation of fully functional proteins. More importantly, transcriptional interference persisted even when one of the convergent genes was expressed ectopically (in trans) and therefore does not depend on the cis arrangement of convergent genes; we conclude that the mechanism of transcriptional interference cannot be explained by the transcriptional collision

  8. Evidence for Divergent Evolution of Growth Temperature Preference in Sympatric Saccharomyces Species

    PubMed Central

    Gonçalves, Paula; Valério, Elisabete; Correia, Cláudia; de Almeida, João M. G. C. F.; Sampaio, José Paulo

    2011-01-01

    The genus Saccharomyces currently includes eight species in addition to the model yeast Saccharomyces cerevisiae, most of which can be consistently isolated from tree bark and soil. We recently found sympatric pairs of Saccharomyces species, composed of one cryotolerant and one thermotolerant species in oak bark samples of various geographic origins. In order to contribute to explain the occurrence in sympatry of Saccharomyces species, we screened Saccharomyces genomic data for protein divergence that might be correlated to distinct growth temperature preferences of the species, using the dN/dS ratio as a measure of protein evolution rates and pair-wise species comparisons. In addition to proteins previously implicated in growth at suboptimal temperatures, we found that glycolytic enzymes were among the proteins exhibiting higher than expected divergence when one cryotolerant and one thermotolerant species are compared. By measuring glycolytic fluxes and glycolytic enzymatic activities in different species and at different temperatures, we subsequently show that the unusual divergence of glycolytic genes may be related to divergent evolution of the glycolytic pathway aligning its performance to the growth temperature profiles of the different species. In general, our results support the view that growth temperature preference is a trait that may have undergone divergent selection in the course of ecological speciation in Saccharomyces. PMID:21674061

  9. Enrichment of Circular Code Motifs in the Genes of the Yeast Saccharomyces cerevisiae.

    PubMed

    Michel, Christian J; Ngoune, Viviane Nguefack; Poch, Olivier; Ripp, Raymond; Thompson, Julie D

    2017-12-03

    A set X of 20 trinucleotides has been found to have the highest average occurrence in the reading frame, compared to the two shifted frames, of genes of bacteria, archaea, eukaryotes, plasmids and viruses. This set X has an interesting mathematical property, since X is a maximal C3 self-complementary trinucleotide circular code. Furthermore, any motif obtained from this circular code X has the capacity to retrieve, maintain and synchronize the original (reading) frame. Since 1996, the theory of circular codes in genes has mainly been developed by analysing the properties of the 20 trinucleotides of X, using combinatorics and statistical approaches. For the first time, we test this theory by analysing the X motifs, i.e., motifs from the circular code X, in the complete genome of the yeast Saccharomyces cerevisiae . Several properties of X motifs are identified by basic statistics (at the frequency level), and evaluated by comparison to R motifs, i.e., random motifs generated from 30 different random codes R. We first show that the frequency of X motifs is significantly greater than that of R motifs in the genome of S. cerevisiae . We then verify that no significant difference is observed between the frequencies of X and R motifs in the non-coding regions of S. cerevisiae , but that the occurrence number of X motifs is significantly higher than R motifs in the genes (protein-coding regions). This property is true for all cardinalities of X motifs (from 4 to 20) and for all 16 chromosomes. We further investigate the distribution of X motifs in the three frames of S. cerevisiae genes and show that they occur more frequently in the reading frame, regardless of their cardinality or their length. Finally, the ratio of X genes, i.e., genes with at least one X motif, to non-X genes, in the set of verified genes is significantly different to that observed in the set of putative or dubious genes with no experimental evidence. These results, taken together, represent the first

  10. Mitochondrial genome evolution in the Saccharomyces sensu stricto complex.

    PubMed

    Ruan, Jiangxing; Cheng, Jian; Zhang, Tongcun; Jiang, Huifeng

    2017-01-01

    Exploring the evolutionary patterns of mitochondrial genomes is important for our understanding of the Saccharomyces sensu stricto (SSS) group, which is a model system for genomic evolution and ecological analysis. In this study, we first obtained the complete mitochondrial sequences of two important species, Saccharomyces mikatae and Saccharomyces kudriavzevii. We then compared the mitochondrial genomes in the SSS group with those of close relatives, and found that the non-coding regions evolved rapidly, including dramatic expansion of intergenic regions, fast evolution of introns and almost 20-fold higher rearrangement rates than those of the nuclear genomes. However, the coding regions, and especially the protein-coding genes, are more conserved than those in the nuclear genomes of the SSS group. The different evolutionary patterns of coding and non-coding regions in the mitochondrial and nuclear genomes may be related to the origin of the aerobic fermentation lifestyle in this group. Our analysis thus provides novel insights into the evolution of mitochondrial genomes.

  11. Regulatory regions in the promoters of the Saccharomyces cerevisiae PYC1 and PYC2 genes encoding isoenzymes of pyruvate carboxylase.

    PubMed

    Menéndez, J; Gancedo, C

    1998-07-15

    We have identified regions in the promoters of the PYC1 and PYC2 genes from Saccharomyces cerevisiae involved in their regulation in different culture conditions. In the case of PYC1, a UAS in the region between -330/-297 and three repressing sequences with the common central core CCGCC at positions -457, -432 and -399 were identified. Specific binding of nuclear proteins to the -330/-214 DNA fragment was abolished in rtg mutants suggesting a role for the RTG genes in the control of PYC1 expression. In the case of the PYC2 promoter, elimination of a fragment from -417 to -291 brings about a two-fold decrease in the expression in repressed conditions and a similar increase in derepression.

  12. ISOLATION OF A CYTOCHROME P-450 STRUCTURAL GENE FROM SACCHAROMYCES CEREVISIAE

    EPA Science Inventory

    We have transformed a Saccharomyces cerevisiae host with an S. cerevisiae genomic library contained in the shuttle vector YEp24 and screened the resultant transformants for resistance to ketoconazole (Kc), an inhibitor of the cytochrome P-450 (P-450) enzyme lanosterol 14-demethyl...

  13. Promoter engineering of the Saccharomyces cerevisiae RIM15 gene for improvement of alcoholic fermentation rates under stress conditions.

    PubMed

    Watanabe, Daisuke; Kaneko, Akie; Sugimoto, Yukiko; Ohnuki, Shinsuke; Takagi, Hiroshi; Ohya, Yoshikazu

    2017-02-01

    A loss-of-function mutation in the RIM15 gene, which encodes a Greatwall-like protein kinase, is one of the major causes of the high alcoholic fermentation rates in Saccharomyces cerevisiae sake strains closely related to Kyokai no. 7 (K7). However, impairment of Rim15p may not be beneficial under more severe fermentation conditions, such as in the late fermentation stage, as it negatively affects stress responses. To balance stress tolerance and fermentation performance, we inserted the promoter of a gluconeogenic gene, PCK1, into the 5'-untranslated region (5'-UTR) of the RIM15 gene in a laboratory strain to achieve repression of RIM15 gene expression in the glucose-rich early stage with its induction in the stressful late stage of alcoholic fermentation. The promoter-engineered strain exhibited a fermentation rate comparable to that of the RIM15-deleted strain with no decrease in cell viability. The engineered strain achieved better alcoholic fermentation performance than the RIM15-deleted strain under repetitive and high-glucose fermentation conditions. These data demonstrated the validity of promoter engineering of the RIM15 gene that governs inhibitory control of alcoholic fermentation. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Enhancing expression of SSU1 genes in Saccharomyces uvarum leads to an increase in sulfite tolerance and a transcriptome profile change.

    PubMed

    Liu, X Z; Sang, M; Zhang, X A; Zhang, T K; Zhang, H Y; He, X; Li, S X; Sun, X D; Zhang, Z M

    2017-05-01

    Saccharomyces uvarum is a good wine yeast species that may have great potential for the future. However, sulfur tolerance of most S. uvarum strains is very poor. In addition there is still little information about the SSU1 gene of S. uvarum, which encodes a putative transporter conferring sulfite tolerance. In order to analyze the function of the SSU1 gene, two expression vectors that contained different SSU1 genes were constructed and transferred into a sulfite-tolerant S. uvarum strain, A9. Then sulfite tolerance, SO2 production, and PCR, sequencing, RT-qPCR and transcriptome analyses were used to access the function of the S. uvarum SSU1 gene. Our results illustrated that enhancing expression of the SSU1 gene can promote sulfite resistance in S. uvarum, and an insertion fragment ahead of the additional SSU1 gene, as seen in some alleles, could affect the expression of other genes and the sulfite tolerance level of S. uvarum. This is the first report on enhancing the expression of the SSU1 gene of S. uvarum. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Regulation of cation transport in Saccharomyces cerevisiae by the salt tolerance gene HAL3.

    PubMed Central

    Ferrando, A; Kron, S J; Rios, G; Fink, G R; Serrano, R

    1995-01-01

    Dynamic regulation of ion transport is essential for homeostasis as cells confront changes in their environment. The gene HAL3 encodes a novel component of this regulatory circuit in the yeast Saccharomyces cerevisiae. Overexpression of HAL3 improves growth of wild-type cells exposed to toxic concentrations of sodium and lithium and suppresses the salt sensitivity conferred by mutation of the calcium-dependent protein phosphatase calcineurin. Null mutants of HAL3 display salt sensitivity. The sequence of HAL3 gives little clue to its function. However, alterations in intracellular cation concentrations associated with changes in HAL3 expression suggest that HAL3 activity may directly increase cytoplasmic K+ and decrease Na+ and Li+. Cation efflux in S. cerevisiae is mediated by the P-type ATPase encoded by the ENA1/PMR24 gene, a putative plasma membrane Na+ pump whose expression is salt induced. Acting in concert with calcineurin, HAL3 is necessary for full activation of ENA1 expression. This functional complementarity is also reflected in the participation of both proteins in recovery from alpha-factor-induced growth arrest. Recently, HAL3 was isolated as a gene (named SIS2) which when overexpressed partially relieves loss of transcription of G1 cyclins in mutants lacking the protein phosphatase Sit4p. Therefore, HAL3 influences cell cycle control and ion homeostasis, acting in parallel to the protein phosphatases Sit4p and calcineurin. PMID:7565698

  16. Omics analysis of acetic acid tolerance in Saccharomyces cerevisiae.

    PubMed

    Geng, Peng; Zhang, Liang; Shi, Gui Yang

    2017-05-01

    Acetic acid is an inhibitor in industrial processes such as wine making and bioethanol production from cellulosic hydrolysate. It causes energy depletion, inhibition of metabolic enzyme activity, growth arrest and ethanol productivity losses in Saccharomyces cerevisiae. Therefore, understanding the mechanisms of the yeast responses to acetic acid stress is essential for improving acetic acid tolerance and ethanol production. Although 329 genes associated with acetic acid tolerance have been identified in the Saccharomyces genome and included in the database ( http://www.yeastgenome.org/observable/resistance_to_acetic_acid/overview ), the cellular mechanistic responses to acetic acid remain unclear in this organism. Post-genomic approaches such as transcriptomics, proteomics, metabolomics and chemogenomics are being applied to yeast and are providing insight into the mechanisms and interactions of genes, proteins and other components that together determine complex quantitative phenotypic traits such as acetic acid tolerance. This review focuses on these omics approaches in the response to acetic acid in S. cerevisiae. Additionally, several novel strains with improved acetic acid tolerance have been engineered by modifying key genes, and the application of these strains and recently acquired knowledge to industrial processes is also discussed.

  17. Screening of Genes Involved in Isooctane Tolerance in Saccharomyces cerevisiae by Using mRNA Differential Display

    PubMed Central

    Miura, Shigenori; Zou, Wen; Ueda, Mitsuyoshi; Tanaka, Atsuo

    2000-01-01

    A Saccharomyces cerevisiae strain, KK-211, isolated by the long-term bioprocess of stereoselective reduction in isooctane, showed extremely high tolerance to the solvent, which is toxic to yeast cells, but, in comparison with its wild-type parent, DY-1, showed low tolerance to hydrophilic organic solvents, such as dimethyl sulfoxide and ethanol. In order to detect the isooctane tolerance-associated genes, mRNA differential display (DD) was employed using mRNAs isolated from strains DY-1 and KK-211 cultivated without isooctane, and from strain KK-211 cultivated with isooctane. Thirty genes were identified as being differentially expressed in these three types of cells and were classified into three groups according to their expression patterns. These patterns were further confirmed and quantified by Northern blot analysis. On the DD fingerprints, the expression of 14 genes, including MUQ1, PRY2, HAC1, AGT1, GAC1, and ICT1 (YLR099c) was induced, while the expression of the remaining 16 genes, including JEN1, PRY1, PRY3, and KRE1, was decreased, in strain KK-211 cultivated with isooctane. The genes represented by HAC1, PRY1, and ICT1 have been reported to be associated with cell stress, and AGT1 and GAC1 have been reported to be involved in the uptake of trehalose and the production of glycogen, respectively. MUQ1 and KRE1, encoding proteins associated with cell surface maintenance, were also detected. Based on these results, we concluded that alteration of expression levels of multiple genes, not of a single gene, might be the critical determinant for isooctane tolerance in strain KK-211. PMID:11055939

  18. Cloning and characterization of LOS1, a Saccharomyces cerevisiae gene that affects tRNA splicing.

    PubMed Central

    Hurt, D J; Wang, S S; Lin, Y H; Hopper, A K

    1987-01-01

    Saccharomyces cerevisiae strains carrying los1-1 mutations are defective in tRNA processing; at 37 degrees C, such strains accumulate tRNA precursors which have mature 5' and 3' ends but contain intervening sequences. Strains bearing los1-1 and an intron-containing ochre-suppressing tRNA gene, SUP4(0), also fail to suppress the ochre mutations ade2-1(0) and can1-100(0) at 34 degrees C. To understand the role of the LOS1 product in tRNA splicing, we initiated a molecular study of the LOS1 gene. Two plasmids, YEpLOS1 and YCpLOS1, that complement the los1-1 phenotype were isolated from the YEp24 and YCp50 libraries, respectively. YEpLOS1 and YCpLOS1 had overlapping restriction maps, indicating that the DNA in the overlapping segment could complement los1-1 when present in multiple or single copy. Integration of plasmid DNA at the LOS1 locus confirmed that these clones contained authentic LOS1 sequences. Southern analyses showed that LOS1 is a single copy gene. The locations of the LOS1 gene within YEpLOS1 and YCpLOS1 were determined by deletion and gamma-delta mapping. Two genomic disruptions of the LOS1 gene were constructed, i.e., an insertion of a 1.2-kilobase fragment carrying the yeast URA3 gene, los1::URA3, and a 2.4-kilobase deletion from the LOS1 gene, los1-delta V. Disruption or deletion of most of the LOS1 gene was not lethal; cells carrying the disrupted los1 alleles were viable and had phenotypes similar to those of cells carrying the los1-1 allele. Thus, it appears that the los1 gene product expedites tRNA splicing at elevated temperatures but is not essential for this process. Images PMID:3031485

  19. The RAD24 (= Rs1) Gene Product of Saccharomyces cerevisiae Participates in Two Different Pathways of DNA Repair

    PubMed Central

    Eckardt-Schupp, Friederike; Siede, Wolfram; Game, John C.

    1987-01-01

    The moderately UV- and X-ray-sensitive mutant of Saccharomyces cerevisiae originally designated rs1 complements all rad and mms mutants available. Therefore, the new nomination rad24-1 according to the RAD nomenclature is suggested. RAD24 maps on chromosome V, close to RAD3 (1.3 cM). In order to associate the RAD24 gene with one of the three repair pathways, double mutants of rad24 and various representative genes of each pathway were constructed. The UV and X-ray sensitivities of the double mutants compared to the single mutants indicate that RAD24 is involved in excision repair of UV damage (RAD3 epistasis group), as well as in recombination repair of UV and X-ray damage (RAD52 epistasis group). Properties of the mutant are discussed which hint at the control of late steps in the pathways. PMID:3549445

  20. Parallel evolution of the make–accumulate–consume strategy in Saccharomyces and Dekkera yeasts

    PubMed Central

    Rozpędowska, Elżbieta; Hellborg, Linda; Ishchuk, Olena P.; Orhan, Furkan; Galafassi, Silvia; Merico, Annamaria; Woolfit, Megan; Compagno, Concetta; Piškur, Jure

    2011-01-01

    Saccharomyces yeasts degrade sugars to two-carbon components, in particular ethanol, even in the presence of excess oxygen. This characteristic is called the Crabtree effect and is the background for the 'make–accumulate–consume' life strategy, which in natural habitats helps Saccharomyces yeasts to out-compete other microorganisms. A global promoter rewiring in the Saccharomyces cerevisiae lineage, which occurred around 100 mya, was one of the main molecular events providing the background for evolution of this strategy. Here we show that the Dekkera bruxellensis lineage, which separated from the Saccharomyces yeasts more than 200 mya, also efficiently makes, accumulates and consumes ethanol and acetic acid. Analysis of promoter sequences indicates that both lineages independently underwent a massive loss of a specific cis-regulatory element from dozens of genes associated with respiration, and we show that also in D. bruxellensis this promoter rewiring contributes to the observed Crabtree effect. PMID:21556056

  1. Assessment of the Toxicity of CuO Nanoparticles by Using Saccharomyces cerevisiae Mutants with Multiple Genes Deleted

    PubMed Central

    Bao, Shaopan; Lu, Qicong; Dai, Heping; Zhang, Chao

    2015-01-01

    To develop applicable and susceptible models to evaluate the toxicity of nanoparticles, the antimicrobial effects of CuO nanoparticles (CuO-NPs) on various Saccharomyces cerevisiae (S. cerevisiae) strains (wild type, single-gene-deleted mutants, and multiple-gene-deleted mutants) were determined and compared. Further experiments were also conducted to analyze the mechanisms associated with toxicity using copper salt, bulk CuO (bCuO), carbon-shelled copper nanoparticles (C/Cu-NPs), and carbon nanoparticles (C-NPs) for comparisons. The results indicated that the growth inhibition rates of CuO-NPs for the wild-type and the single-gene-deleted strains were comparable, while for the multiple-gene deletion mutant, significantly higher toxicity was observed (P < 0.05). When the toxicity of the CuO-NPs to yeast cells was compared with the toxicities of copper salt and bCuO, we concluded that the toxicity of CuO-NPs should be attributed to soluble copper rather than to the nanoparticles. The striking difference in adverse effects of C-NPs and C/Cu-NPs with equivalent surface areas also proved this. A toxicity assay revealed that the multiple-gene-deleted mutant was significantly more sensitive to CuO-NPs than the wild type. Specifically, compared with the wild-type strain, copper was readily taken up by mutant strains when cell permeability genes were knocked out, and the mutants with deletions of genes regulated under oxidative stress (OS) were likely producing more reactive oxygen species (ROS). Hence, as mechanism-based gene inactivation could increase the susceptibility of yeast, the multiple-gene-deleted mutants should be improved model organisms to investigate the toxicity of nanoparticles. PMID:26386067

  2. Relative importance of summer sun exposure, vitamin D intake, and genes to vitamin D status in Dutch older adults: The B-PROOF study.

    PubMed

    Brouwer-Brolsma, Elske M; Vaes, Anouk M M; van der Zwaluw, Nikita L; van Wijngaarden, Janneke P; Swart, Karin M A; Ham, Annelies C; van Dijk, Suzanne C; Enneman, Anke W; Sohl, Evelien; van Schoor, Natasja M; van der Velde, Nathalie; Uitterlinden, Andre G; Lips, Paul; Feskens, Edith J M; Dhonukshe-Rutten, Rosalie A M; de Groot, Lisette C P G M

    2016-11-01

    The prevalence of vitamin D deficiency among seniors is high. Whereas sun exposure, vitamin D intake, genes, demographics, and lifestyle have been identified as being important determinants of vitamin D status, the impact of these factors is expected to differ across populations. To improve current prevention and treatment strategies, this study aimed to explore the main determinants of vitamin D status and its relative importance in a population of community-dwelling Dutch older adults. Serum 25-hydroxyvitamin D (25(OH)D) was measured in 2857 adults aged ≥65 years. Sun exposure was assessed with a structured questionnaire (n=1012), vitamin D intake using a Food Frequency Questionnaire (n=596), and data on genetic variation that may affect 25(OH)D status was obtained for 4 genes, DHCR7 (rs12785878), CYP2R1 (rs10741657), GC (rs2282679), and CYP24A1 (rs6013897) (n=2530). Serum 25(OH)D concentrations <50nmol/L were observed in 45% of the population; only 6% of these participants used vitamin D supplements. Sun exposure (being outside daily during summer: 66±25nmol/L vs not being outside daily during summer: 58±27nmol/L, P=0.02) and vitamin D intake (per unit μg/day during winter/spring: 3.1±0.75nmol/L, P<0.0001) were associated with higher 25(OH)D concentrations. Major allele carriers of SNPs related to DHCR7, CYP24A1, and GC, as well as CYP2R1 minor allele carriers had the highest 25(OH)D concentrations. Together, sun (R 2 =0.29), vitamin D intake (R 2 =0.24), and genes (R 2 =0.28) explained 35% (R 2 =0.35) of the variation in 25(OH)D concentrations during summer/autumn period, when adjusted for age, sex, BMI, education, alcohol consumption, smoking, physical activity, and self-rated health status (n=185). The investigated determinants explained 35% of 25(OH)D status. Of the three main determinants under study, sun exposure still appeared to be an important determinant of serum 25(OH)D in older individuals, closely followed by genes, and vitamin D intake. Given

  3. Comparative characterization of endo-polygalacturonase (Pgu1) from Saccharomyces cerevisiae and Saccharomyces paradoxus under winemaking conditions.

    PubMed

    Eschstruth, Alexis; Divol, Benoit

    2011-08-01

    Wine strains of Saccharomyces cerevisiae have no to weak natural pectinase activity, despite their genetic ability to secrete an endo-polygalacturonase. The addition of external pectinase of fungal origin has therefore become a common step of winemaking in order to enhance the extraction of compounds located in the grape berry skins during maceration and to ease wine clarification after maturation. Recently, the strong pectinase activity of a wine strain of Saccharomyces paradoxus has been reported. In this study, the endo-polygalacturonase-encoding gene of S. paradoxus was sequenced and its activity was characterised, compared with that of S. cerevisiae and tested under winemaking conditions through overexpression of both genes individually in S. cerevisiae. A few differences in the amino acids sequences between the two proteins were revealed and the activity of the Pgu1 enzyme of S. paradoxus was shown to be weaker under winemaking conditions. Clear indicators of extracellular activity were observed in the wines made with both recombinant strains (i.e. enzyme activity in cell-free wine, higher methanol concentration and higher free-run wine), but the actual composition of the wines fermented with the mutants was only sparingly altered. Although unexpectedly found in lower concentrations in the latter wines, phenolic compounds were shown to be the most discriminatory components. Overexpressing the PGU1 gene of S. paradoxus or that of S. cerevisiae did not make much difference, showing that the higher activity of S. paradoxus strains under laboratory conditions could be due to a different regulation mechanism rather than to a different sequence of PGU1.

  4. Effects of Inner Nuclear Membrane Proteins SUN1/UNC-84A and SUN2/UNC-84B on the Early Steps of HIV-1 Infection.

    PubMed

    Schaller, Torsten; Bulli, Lorenzo; Pollpeter, Darja; Betancor, Gilberto; Kutzner, Juliane; Apolonia, Luis; Herold, Nikolas; Burk, Robin; Malim, Michael H

    2017-10-01

    Human immunodeficiency virus type 1 (HIV-1) infection of dividing and nondividing cells involves regulatory interactions with the nuclear pore complex (NPC), followed by translocation to the nucleus and preferential integration into genomic areas in proximity to the inner nuclear membrane (INM). To identify host proteins that may contribute to these processes, we performed an overexpression screen of known membrane-associated NE proteins. We found that the integral transmembrane proteins SUN1/UNC84A and SUN2/UNC84B are potent or modest inhibitors of HIV-1 infection, respectively, and that suppression corresponds to defects in the accumulation of viral cDNA in the nucleus. While laboratory strains (HIV-1 NL4.3 and HIV-1 IIIB ) are sensitive to SUN1-mediated inhibition, the transmitted founder viruses RHPA and ZM247 are largely resistant. Using chimeric viruses, we identified the HIV-1 capsid (CA) protein as a major determinant of sensitivity to SUN1, and in vitro -assembled capsid-nucleocapsid (CANC) nanotubes captured SUN1 and SUN2 from cell lysates. Finally, we generated SUN1 -/- and SUN2 -/- cells by using CRISPR/Cas9 and found that the loss of SUN1 had no effect on HIV-1 infectivity, whereas the loss of SUN2 had a modest suppressive effect. Taken together, these observations suggest that SUN1 and SUN2 may function redundantly to modulate postentry, nuclear-associated steps of HIV-1 infection. IMPORTANCE HIV-1 causes more than 1 million deaths per year. The life cycle of HIV-1 has been studied extensively, yet important steps that occur between viral capsid release into the cytoplasm and the expression of viral genes remain elusive. We propose here that the INM components SUN1 and SUN2, two members of the linker of nucleoskeleton and cytoskeleton (LINC) complex, may interact with incoming HIV-1 replication complexes and affect key steps of infection. While overexpression of these proteins reduces HIV-1 infection, disruption of the individual SUN2 and SUN1 genes

  5. Sun Radio Interferometer Space Experiment (SunRISE)

    NASA Astrophysics Data System (ADS)

    Kasper, Justin C.; SunRISE Team

    2018-06-01

    The Sun Radio Interferometer Space Experiment (SunRISE) is a NASA Heliophysics Explorer Mission of Opportunity currently in Phase A. SunRISE is a constellation of spacecraft flying in a 10-km diameter formation and operating as the first imaging radio interferometer in space. The purpose of SunRISE is to reveal critical aspects of solar energetic particle (SEP) acceleration at coronal mass ejections (CMEs) and transport into space by making the first spatially resolved observations of coherent Type II and III radio bursts produced by electrons accelerated at CMEs or released from flares. SunRISE will focus on solar Decametric-Hectometric (DH, 0.1 < f < 15 MHz) radio bursts that always are detected from space before major SEP events, but cannot be seen on Earth due to ionospheric absorption. This talk will describe SunRISE objectives and implementation. Presented on behalf of the entire SunRISE team.

  6. Sun sensitivity and sun protective behaviors during sun exposure among indoor office workers in the American Midwest.

    PubMed

    Jung, Alesia M; Dennis, Leslie K; Jacobs, Elizabeth T; Wondrak, Georg T

    2018-06-11

    Sun sensitivity, a confounder between sun exposure and sun protection, is often overlooked. We examined how sun exposure and sun protection behaviors among indoor workers varied by sun sensitivity. Sun exposure and sun protection diaries over a 45-day period from Midwestern United States indoor workers were examined. We categorized sun sensitivity (fair and non-fair complexion) using tanning inability and sunburn tendency. Total exposure (sunrise to sunset) and peak exposure (10 am and 4 pm) lasting at least 60 minutes were examined. Percentages of time using sun protection were reported. We determined associations between fair complexion, mean sun exposure and mean sun protection times with logistic regression. Fair individuals spent less time in the sun than non-fair individuals, but a greater proportion of time using sun protection behaviors, including sunscreen with SPF 30+ (odds ratio (OR)=1.36; 95% confidence interval (95% CI) =0.98, 1.87)), or wearing long-sleeved shirts (OR=2.89; 95% CI=1.24, 6.73). Fair individuals spent less time in the sun and practiced more sun protective behaviors than non-fair individuals. This complex association between sun sensitivity, sun protection and sun exposure has not consistently been addressed in studies of skin cancer. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. 3′ Untranslated Regions Mediate Transcriptional Interference between Convergent Genes Both Locally and Ectopically in Saccharomyces cerevisiae

    PubMed Central

    Wang, Luwen; Jiang, Ning; Wang, Lin; Fang, Ou; Leach, Lindsey J.; Hu, Xiaohua; Luo, Zewei

    2014-01-01

    Paired sense and antisense (S/AS) genes located in cis represent a structural feature common to the genomes of both prokaryotes and eukaryotes, and produce partially complementary transcripts. We used published genome and transcriptome sequence data and found that over 20% of genes (645 pairs) in the budding yeast Saccharomyces cerevisiae genome are arranged in convergent pairs with overlapping 3′-UTRs. Using published microarray transcriptome data from the standard laboratory strain of S. cerevisiae, our analysis revealed that expression levels of convergent pairs are significantly negatively correlated across a broad range of environments. This implies an important role for convergent genes in the regulation of gene expression, which may compensate for the absence of RNA-dependent mechanisms such as micro RNAs in budding yeast. We selected four representative convergent gene pairs and used expression assays in wild type yeast and its genetically modified strains to explore the underlying patterns of gene expression. Results showed that convergent genes are reciprocally regulated in yeast populations and in single cells, whereby an increase in expression of one gene produces a decrease in the expression of the other, and vice-versa. Time course analysis of the cell cycle illustrated the functional significance of this relationship for the three pairs with relevant functional roles. Furthermore, a series of genetic modifications revealed that the 3′-UTR sequence plays an essential causal role in mediating transcriptional interference, which requires neither the sequence of the open reading frame nor the translation of fully functional proteins. More importantly, transcriptional interference persisted even when one of the convergent genes was expressed ectopically (in trans) and therefore does not depend on the cis arrangement of convergent genes; we conclude that the mechanism of transcriptional interference cannot be explained by the transcriptional collision

  8. A Cas9-based toolkit to program gene expression in Saccharomyces cerevisiae

    DOE PAGES

    Reider Apel, Amanda; d'Espaux, Leo; Wehrs, Maren; ...

    2016-11-28

    Despite the extensive use of Saccharomyces cerevisiae as a platform for synthetic biology, strain engineering remains slow and laborious. Here, we employ CRISPR/Cas9 technology to build a cloning-free toolkit that addresses commonly encountered obstacles in metabolic engineering, including chromosomal integration locus and promoter selection, as well as protein localization and solubility. The toolkit includes 23 Cas9-sgRNA plasmids, 37 promoters of various strengths and temporal expression profiles, and 10 protein-localization, degradation and solubility tags. We facilitated the use of these parts via a web-based tool, that automates the generation of DNA fragments for integration. Our system builds upon existing gene editingmore » methods in the thoroughness with which the parts are standardized and characterized, the types and number of parts available and the ease with which our methodology can be used to perform genetic edits in yeast. We demonstrated the applicability of this toolkit by optimizing the expression of a challenging but industrially important enzyme, taxadiene synthase (TXS). This approach enabled us to diagnose an issue with TXS solubility, the resolution of which yielded a 25-fold improvement in taxadiene production.« less

  9. A Cas9-based toolkit to program gene expression in Saccharomyces cerevisiae

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reider Apel, Amanda; d'Espaux, Leo; Wehrs, Maren

    Despite the extensive use of Saccharomyces cerevisiae as a platform for synthetic biology, strain engineering remains slow and laborious. Here, we employ CRISPR/Cas9 technology to build a cloning-free toolkit that addresses commonly encountered obstacles in metabolic engineering, including chromosomal integration locus and promoter selection, as well as protein localization and solubility. The toolkit includes 23 Cas9-sgRNA plasmids, 37 promoters of various strengths and temporal expression profiles, and 10 protein-localization, degradation and solubility tags. We facilitated the use of these parts via a web-based tool, that automates the generation of DNA fragments for integration. Our system builds upon existing gene editingmore » methods in the thoroughness with which the parts are standardized and characterized, the types and number of parts available and the ease with which our methodology can be used to perform genetic edits in yeast. We demonstrated the applicability of this toolkit by optimizing the expression of a challenging but industrially important enzyme, taxadiene synthase (TXS). This approach enabled us to diagnose an issue with TXS solubility, the resolution of which yielded a 25-fold improvement in taxadiene production.« less

  10. Saccharomyces cerevisiae mutants with enhanced induced mutation and altered mitotic gene conversion.

    PubMed

    Ivanov, E L; Kovaltzova, S V; Korolev, V G

    1989-08-01

    We have developed a method to isolate yeast (Saccharomyces cerevisiae) mutants with enhanced induced mutagenesis based on nitrous acid-induced reversion of the ade2-42 allele. Six mutants have been isolated and designated him (high induced mutagenesis), and 4 of them were studied in more detail. The him mutants displayed enhanced reversion of the ade2-42 allele, either spontaneous or induced by nitrous acid, UV light, and the base analog 6-N-hydroxylaminopurine, but not by gamma-irradiation. It is worth noting that the him mutants turned out not to be sensitive to the lethal effects of the mutagens used. The enhancement in mutation induced by nitrous acid, UV light, and 6-N-hydroxylaminopurine has been confirmed in a forward-mutation assay (induction of mutations in the ADE1, ADE2 genes). The latter agent revealed the most apparent differences between the him mutants and the wild-type strain and was, therefore, chosen for the genetic analysis of mutants, him mutations analyzed behaved as a single Mendelian trait; complementation tests indicated 3 complementation groups (HIM1, HIM2, and HIM3), each containing 1 mutant allele. Uracil-DNA glycosylase activity was determined in crude cell extracts, and no significant differences between the wild-type and him strains were detected. Spontaneous mitotic gene conversion at the ADE2 locus is altered in him1 strains, either increased or decreased, depending on the particular heteroallelic combination. Genetic evidence strongly suggests him mutations to be involved in a process of mismatch correction of molecular heteroduplexes.

  11. Adaptation of yeasts Saccharomyces cerevisiae and Brettanomyces bruxellensis to winemaking conditions: a comparative study of stress genes expression.

    PubMed

    Nardi, Tiziana; Remize, Fabienne; Alexandre, Hervé

    2010-10-01

    Brettanomyces is the major microbial cause for wine spoilage worldwide and causes significant economic losses. Like Saccharomyces cerevisiae, it is well adapted to winemaking, but molecular pathways involved in this acclimatization are still unknown. In this work, we report a time-scale comparison between the two yeasts coping with alcoholic fermentation. Orthologs of some well-characterized stress genes of S. cerevisiae were searched by sequence alignment in the Dekkera/Brettanomyces partial genome; nine genes were finally selected on the basis on their similarity and involvement in adaptation to wine. Transcript analysis during a model grape juice fermentation indicates that a subset of genes (i.e., ATP1, ERG6, VPS34) shows peculiar expression patterns in Brettanomyces bruxellensis but also that some common regulations of stress response exist between the two yeasts, although with different timing (i.e., for MSN4, SNF1, HSP82, NTH1). This suggests that B. bruxellensis efficient survival in such challenging conditions is due to mechanisms unique to it, together with a conserved yeast stress response. This study, although limited by the poor genetic data available on B. bruxellensis, provides first insights into its gene expression remodeling in winemaking and opens new frames for further investigations.

  12. Identification of target genes to control acetate yield during aerobic fermentation with Saccharomyces cerevisiae.

    PubMed

    Curiel, José Antonio; Salvadó, Zoel; Tronchoni, Jordi; Morales, Pilar; Rodrigues, Alda Joao; Quirós, Manuel; Gonzalez, Ramón

    2016-09-15

    Aerobic fermentation of grape must, leading to respiro-fermentative metabolism of sugars, has been proposed as way of reducing alcohol content in wines. Two factors limit the usefulness of Saccharomyces cerevisiae for this application, the Crabtree effect, and excess volatile acidity under aerobic conditions. This work aimed to explore the impact on ethanol acetate production of different S. cerevisiae strains deleted for genes previously related with the Crabtree phenotype. Recombinant strains were constructed on a wine industrial genetic background, FX10. All yeast strains, including FX10, showed respiro-fermentative metabolism in natural grape must under aerobic conditions, as well as a concomitant reduction in ethanol yield. This indicates that the Crabtree effect is not a major constrain for reaching relevant respiration levels in grape must. Indeed, only minor differences in ethanol yield were observed between the original and some of the recombinant strains. In contrast, some yeast strains showed a relevant reduction of acetic acid production. This was identified as a positive feature for the feasibility of alcohol level reduction by respiration. Reduced acetic acid production was confirmed by a thorough analysis of these and some additional deletion strains (involving genes HXK2, PYK1, REG1, PDE2 and PDC1). Some recombinant yeasts showed altered production of glycerol and pyruvate derived metabolites. REG1 and PDC1 deletion strains showed a strong reduction of acetic acid yield in aerobic fermentations. Since REG1 defective strains may be obtained by non-GMO approaches, these gene modifications show good promise to help reducing ethanol content in wines.

  13. Altered Phenotypes in Saccharomyces cerevisiae by Heterologous Expression of Basidiomycete Moniliophthora perniciosa SOD2 Gene.

    PubMed

    Melo, Sônia C; Santos, Regineide X; Melgaço, Ana C; Pereira, Alanna C F; Pungartnik, Cristina; Brendel, Martin

    2015-06-01

    Heterologous expression of a putative manganese superoxide dismutase gene (SOD2) of the basidiomycete Moniliophthora perniciosa complemented the phenotypes of a Saccharomyces cerevisiae sod2Δ mutant. Sequence analysis of the cloned M. perniciosa cDNA revealed an open reading frame (ORF) coding for a 176 amino acid polypeptide with the typical metal-binding motifs of a SOD2 gene, named MpSOD2. Phylogenetic comparison with known manganese superoxide dismutases (MnSODs) located the protein of M. perniciosa (MpSod2p) in a clade with the basidiomycete fungi Coprinopsis cinerea and Laccaria bicolor. Haploid wild-type yeast transformants containing a single copy of MpSOD2 showed increased resistance phenotypes against oxidative stress-inducing hydrogen peroxide and paraquat, but had unaltered phenotype against ultraviolet-C (UVC) radiation. The same transformants exhibited high sensitivity against treatment with the pro-mutagen diethylnitrosamine (DEN) that requires oxidation to become an active mutagen/carcinogen. Absence of MpSOD2 in the yeast sod2Δ mutant led to DEN hyper-resistance while introduction of a single copy of this gene restored the yeast wild-type phenotype. The haploid yeast wild-type transformant containing two SOD2 gene copies, one from M. perniciosa and one from its own, exhibited DEN super-sensitivity. This transformant also showed enhanced growth at 37 °C on the non-fermentable carbon source lactate, indicating functional expression of MpSod2p. The pro-mutagen dihydroethidium (DHE)-based fluorescence assay monitored basal level of yeast cell oxidative stress. Compared to the wild type, the yeast sod2Δ mutant had a much higher level of intrinsic oxidative stress, which was reduced to wild type (WT) level by introduction of one copy of the MpSOD2 gene. Taken together our data indicates functional expression of MpSod2 protein in the yeast S. cerevisiae.

  14. Altered Phenotypes in Saccharomyces cerevisiae by Heterologous Expression of Basidiomycete Moniliophthora perniciosa SOD2 Gene

    PubMed Central

    Melo, Sônia C.; Santos, Regineide X.; Melgaço, Ana C.; Pereira, Alanna C. F.; Pungartnik, Cristina; Brendel, Martin

    2015-01-01

    Heterologous expression of a putative manganese superoxide dismutase gene (SOD2) of the basidiomycete Moniliophthora perniciosa complemented the phenotypes of a Saccharomyces cerevisiae sod2Δ mutant. Sequence analysis of the cloned M. perniciosa cDNA revealed an open reading frame (ORF) coding for a 176 amino acid polypeptide with the typical metal-binding motifs of a SOD2 gene, named MpSOD2. Phylogenetic comparison with known manganese superoxide dismutases (MnSODs) located the protein of M. perniciosa (MpSod2p) in a clade with the basidiomycete fungi Coprinopsis cinerea and Laccaria bicolor. Haploid wild-type yeast transformants containing a single copy of MpSOD2 showed increased resistance phenotypes against oxidative stress-inducing hydrogen peroxide and paraquat, but had unaltered phenotype against ultraviolet–C (UVC) radiation. The same transformants exhibited high sensitivity against treatment with the pro-mutagen diethylnitrosamine (DEN) that requires oxidation to become an active mutagen/carcinogen. Absence of MpSOD2 in the yeast sod2Δ mutant led to DEN hyper-resistance while introduction of a single copy of this gene restored the yeast wild-type phenotype. The haploid yeast wild-type transformant containing two SOD2 gene copies, one from M. perniciosa and one from its own, exhibited DEN super-sensitivity. This transformant also showed enhanced growth at 37 °C on the non-fermentable carbon source lactate, indicating functional expression of MpSod2p. The pro-mutagen dihydroethidium (DHE)-based fluorescence assay monitored basal level of yeast cell oxidative stress. Compared to the wild type, the yeast sod2Δ mutant had a much higher level of intrinsic oxidative stress, which was reduced to wild type (WT) level by introduction of one copy of the MpSOD2 gene. Taken together our data indicates functional expression of MpSod2 protein in the yeast S. cerevisiae. PMID:26039235

  15. Increased xylose affinity of Hxt2 through gene shuffling of hexose transporters in Saccharomyces cerevisiae.

    PubMed

    Nijland, J G; Shin, H Y; de Waal, P P; Klaassen, P; Driessen, A J M

    2018-02-01

    Optimizing D-xylose transport in Saccharomyces cerevisiae is essential for efficient bioethanol production from cellulosic materials. We have used a gene shuffling approach of hexose (Hxt) transporters in order to increase the affinity for D-xylose. Various libraries were transformed to a hexose transporter deletion strain, and shuffled genes were selected via growth on low concentrations of D-xylose. This screening yielded two homologous fusion proteins (fusions 9,4 and 9,6), both consisting of the major central part of Hxt2 and various smaller parts of other Hxt proteins. Both chimeric proteins showed the same increase in D-xylose affinity (8·1 ± 3·0 mmol l -1 ) compared with Hxt2 (23·7 ± 2·1 mmol l -1 ). The increased D-xylose affinity could be related to the C terminus, more specifically to a cysteine to proline mutation at position 505 in Hxt2. The Hxt2 C505P mutation increased the affinity for D-xylose for Hxt2, thus providing a way to increase D-xylose transport flux at low D-xylose concentration. The gene shuffling protocol using the highly homologues hexose transporters family provides a powerful tool to enhance the D-xylose affinity of Hxt transporters in S. cerevisiae, thus providing a means to increase the D-xylose uptake flux at low D-xylose concentrations. © 2017 The Society for Applied Microbiology.

  16. Validation of reference genes for quantitative expression analysis by real-time RT-PCR in Saccharomyces cerevisiae

    PubMed Central

    Teste, Marie-Ange; Duquenne, Manon; François, Jean M; Parrou, Jean-Luc

    2009-01-01

    Background Real-time RT-PCR is the recommended method for quantitative gene expression analysis. A compulsory step is the selection of good reference genes for normalization. A few genes often referred to as HouseKeeping Genes (HSK), such as ACT1, RDN18 or PDA1 are among the most commonly used, as their expression is assumed to remain unchanged over a wide range of conditions. Since this assumption is very unlikely, a geometric averaging of multiple, carefully selected internal control genes is now strongly recommended for normalization to avoid this problem of expression variation of single reference genes. The aim of this work was to search for a set of reference genes for reliable gene expression analysis in Saccharomyces cerevisiae. Results From public microarray datasets, we selected potential reference genes whose expression remained apparently invariable during long-term growth on glucose. Using the algorithm geNorm, ALG9, TAF10, TFC1 and UBC6 turned out to be genes whose expression remained stable, independent of the growth conditions and the strain backgrounds tested in this study. We then showed that the geometric averaging of any subset of three genes among the six most stable genes resulted in very similar normalized data, which contrasted with inconsistent results among various biological samples when the normalization was performed with ACT1. Normalization with multiple selected genes was therefore applied to transcriptional analysis of genes involved in glycogen metabolism. We determined an induction ratio of 100-fold for GPH1 and 20-fold for GSY2 between the exponential phase and the diauxic shift on glucose. There was no induction of these two genes at this transition phase on galactose, although in both cases, the kinetics of glycogen accumulation was similar. In contrast, SGA1 expression was independent of the carbon source and increased by 3-fold in stationary phase. Conclusion In this work, we provided a set of genes that are suitable reference

  17. Validation of reference genes for quantitative expression analysis by real-time RT-PCR in Saccharomyces cerevisiae.

    PubMed

    Teste, Marie-Ange; Duquenne, Manon; François, Jean M; Parrou, Jean-Luc

    2009-10-30

    Real-time RT-PCR is the recommended method for quantitative gene expression analysis. A compulsory step is the selection of good reference genes for normalization. A few genes often referred to as HouseKeeping Genes (HSK), such as ACT1, RDN18 or PDA1 are among the most commonly used, as their expression is assumed to remain unchanged over a wide range of conditions. Since this assumption is very unlikely, a geometric averaging of multiple, carefully selected internal control genes is now strongly recommended for normalization to avoid this problem of expression variation of single reference genes. The aim of this work was to search for a set of reference genes for reliable gene expression analysis in Saccharomyces cerevisiae. From public microarray datasets, we selected potential reference genes whose expression remained apparently invariable during long-term growth on glucose. Using the algorithm geNorm, ALG9, TAF10, TFC1 and UBC6 turned out to be genes whose expression remained stable, independent of the growth conditions and the strain backgrounds tested in this study. We then showed that the geometric averaging of any subset of three genes among the six most stable genes resulted in very similar normalized data, which contrasted with inconsistent results among various biological samples when the normalization was performed with ACT1. Normalization with multiple selected genes was therefore applied to transcriptional analysis of genes involved in glycogen metabolism. We determined an induction ratio of 100-fold for GPH1 and 20-fold for GSY2 between the exponential phase and the diauxic shift on glucose. There was no induction of these two genes at this transition phase on galactose, although in both cases, the kinetics of glycogen accumulation was similar. In contrast, SGA1 expression was independent of the carbon source and increased by 3-fold in stationary phase. In this work, we provided a set of genes that are suitable reference genes for quantitative gene

  18. Sun Safety

    MedlinePlus

    ... the Sun? Are There Benefits to Spending Time Outdoors? Statistics Behavior Rates Sun Safety Tips for Men ... and yourself from skin cancer. Stay sun-safe outdoors and discourage indoor and outdoor tanning. Sun Safety ...

  19. Sun Exposure, Sun-Related Symptoms, and Sun Protection Practices in an African Informal Traditional Medicines Market.

    PubMed

    Wright, Caradee Y; Reddy, Tarylee; Mathee, Angela; Street, Renée A

    2017-09-28

    Informal workers in African market trade have little formal protection against sun exposure. We aimed to examine sun exposure, sun-related symptoms, and sun protection practices in an informal occupational setting. Trained fieldworkers asked 236 workers in the Warwick Junction market about their workplace, skin and eye sensitivity and skin colour, symptoms faced at work during the summer due to heat, and preventive measures. Data were analyzed using univariate logistic regression to assess the effect of gender and the risk of experiencing symptoms to sun exposure in relation to pre-existing diseases and perception of sun exposure as a hazard. Of the 236 participants, 234 were Black African and 141 (59.7%) were female. Portable shade was the most commonly used form of sun protection (69.9%). Glare from the sun (59.7%) and excessive sweating (57.6%) were commonly reported sun-related health symptoms. The use of protective clothing was more prevalent among those who perceived sun exposure as a hazard ( p = 0.003). In an informal occupational setting, sun exposure was high. Protective clothing and portable shade to eliminate heat and bright light were self-implemented. Action by local authorities to protect informal workers should consider sun exposure to support workers in their efforts to cope in hot weather.

  20. The PSO4 gene is responsible for an error-prone recombinational DNA repair pathway in Saccharomyces cerevisiae.

    PubMed

    de Andrade, H H; Marques, E K; Schenberg, A C; Henriques, J A

    1989-06-01

    The induction of mitotic gene conversion and crossing-over in Saccharomyces cerevisiae diploid cells homozygous for the pso4-1 mutation was examined in comparison to the corresponding wild-type strain. The pso4-1 mutant strain was found to be completely blocked in mitotic recombination induced by photoaddition of mono- and bifunctional psoralen derivatives as well as by mono- (HN1) and bifunctional (HN2) nitrogen mustards or 254 nm UV radiation in both stationary and exponential phases of growth. Concerning the lethal effect, diploids homozygous for the pso4-1 mutation are more sensitive to all agents tested in any growth phase. However, this effect is more pronounced in the G2 phase of the cell cycle. These results imply that the ploidy effect and the resistance of budding cells are under the control of the PSO4 gene. On the other hand, the pso4-1 mutant is mutationally defective for all agents used. Therefore, the pso4-1 mutant has a generalized block in both recombination and mutation ability. This indicates that the PSO4 gene is involved in an error-prone repair pathway which relies on a recombinational mechanism, strongly suggesting an analogy between the pso4-1 mutation and the RecA or LexA mutation of Escherichia coli.

  1. Abolishment of N-glycan mannosylphosphorylation in glyco-engineered Saccharomyces cerevisiae by double disruption of MNN4 and MNN14 genes.

    PubMed

    Kim, Yeong Hun; Kang, Ji-Yeon; Gil, Jin Young; Kim, Sang-Yoon; Shin, Keun Koo; Kang, Hyun Ah; Kim, Jeong-Yoon; Kwon, Ohsuk; Oh, Doo-Byoung

    2017-04-01

    Mannosylphosphorylated glycans are found only in fungi, including yeast, and the elimination of mannosylphosphates from glycans is a prerequisite for yeast glyco-engineering to produce human-compatible glycoproteins. In Saccharomyces cerevisiae, MNN4 and MNN6 genes are known to play roles in mannosylphosphorylation, but disruption of these genes does not completely remove the mannosylphosphates in N-glycans. This study was performed to find unknown key gene(s) involved in N-glycan mannosylphosphorylation in S. cerevisiae. For this purpose, each of one MNN4 and five MNN6 homologous genes were deleted from the och1Δmnn1Δmnn4Δmnn6Δ strain, which lacks yeast-specific hyper-mannosylation and the immunogenic α(1,3)-mannose structure. N-glycan profile analysis of cell wall mannoproteins and a secretory recombinant protein produced in mutants showed that the MNN14 gene, an MNN4 paralog with unknown function, is essential for N-glycan mannosylphosphorylation. Double disruption of MNN4 and MNN14 genes was enough to eliminate N-glycan mannosylphosphorylation. Our results suggest that the S. cerevisiae och1Δmnn1Δmnn4Δmnn14Δ strain, in which all yeast-specific N-glycan structures including mannosylphosphorylation are abolished, may have promise as a useful platform for glyco-engineering to produce therapeutic glycoproteins with human-compatible N-glycans.

  2. Overexpression of ADH1 and HXT1 genes in the yeast Saccharomyces cerevisiae improves the fermentative efficiency during tequila elaboration.

    PubMed

    Gutiérrez-Lomelí, Melesio; Torres-Guzmán, Juan Carlos; González-Hernández, Gloria Angélica; Cira-Chávez, Luis Alberto; Pelayo-Ortiz, Carlos; Ramírez-Córdova, Jose de Jesús

    2008-05-01

    This work assessed the effect of the overexpression of ADH1 and HXT1 genes in the Saccharomyces cerevisiae AR5 strain during fermentation of Agave tequilana Weber blue variety must. Both genes were cloned individually and simultaneously into a yeast centromere plasmid. Two transformant strains overexpressing ADH1 and HXT1 individually and one strain overexpressing both genes were randomly selected and named A1, A3 and A5 respectively. Overexpression effect on growth and ethanol production of the A1, A3 and A5 strains was evaluated in fermentative conditions in A. tequilana Weber blue variety must and YPD medium. During growth in YPD and Agave media, all the recombinant strains showed lower cell mass formation than the wild type AR5 strain. Adh enzymatic activity in the recombinant strains A1 and A5 cultivated in A. tequilana and YPD medium was higher than in the wild type. The overexpression of both genes individually and simultaneously had no significant effect on ethanol formation; however, the fermentative efficiency of the A5 strain increased from 80.33% to 84.57% and 89.40% to 94.29% in YPD and Agave medium respectively.

  3. Genome-wide identification of Saccharomyces cerevisiae genes required for tolerance to acetic acid.

    PubMed

    Mira, Nuno P; Palma, Margarida; Guerreiro, Joana F; Sá-Correia, Isabel

    2010-10-25

    Acetic acid is a byproduct of Saccharomyces cerevisiae alcoholic fermentation. Together with high concentrations of ethanol and other toxic metabolites, acetic acid may contribute to fermentation arrest and reduced ethanol productivity. This weak acid is also a present in lignocellulosic hydrolysates, a highly interesting non-feedstock substrate in industrial biotechnology. Therefore, the better understanding of the molecular mechanisms underlying S. cerevisiae tolerance to acetic acid is essential for the rational selection of optimal fermentation conditions and the engineering of more robust industrial strains to be used in processes in which yeast is explored as cell factory. The yeast genes conferring protection against acetic acid were identified in this study at a genome-wide scale, based on the screening of the EUROSCARF haploid mutant collection for susceptibility phenotypes to this weak acid (concentrations in the range 70-110 mM, at pH 4.5). Approximately 650 determinants of tolerance to acetic acid were identified. Clustering of these acetic acid-resistance genes based on their biological function indicated an enrichment of genes involved in transcription, internal pH homeostasis, carbohydrate metabolism, cell wall assembly, biogenesis of mitochondria, ribosome and vacuole, and in the sensing, signalling and uptake of various nutrients in particular iron, potassium, glucose and amino acids. A correlation between increased resistance to acetic acid and the level of potassium in the growth medium was found. The activation of the Snf1p signalling pathway, involved in yeast response to glucose starvation, is demonstrated to occur in response to acetic acid stress but no evidence was obtained supporting the acetic acid-induced inhibition of glucose uptake. Approximately 490 of the 650 determinants of tolerance to acetic acid identified in this work are implicated, for the first time, in tolerance to this weak acid. These are novel candidate genes for genetic

  4. Comparative study of Saccharomyces cerevisiae wine strains to identify potential marker genes correlated to desiccation stress tolerance.

    PubMed

    Capece, Angela; Votta, Sonia; Guaragnella, Nicoletta; Zambuto, Marianna; Romaniello, Rossana; Romano, Patrizia

    2016-05-01

    The most diffused formulation of starter for winemaking is active dry yeast (ADY). ADYs production process is essentially characterized by air-drying stress, a combination of several stresses, including thermal, hyperosmotic and oxidative and cell capacity to counteract such multiple stresses will determine its survival. The molecular mechanisms underlying cell stress response to desiccation have been mostly studied in laboratory and commercial yeast strains, but a growing interest is currently developing for indigenous yeast strains which represent a valuable and alternative source of genetic and molecular biodiversity to be exploited. In this work, a comparative study of different Saccharomyces cerevisiae indigenous wine strains, previously selected for their technological traits, has been carried out to identify potentially relevant genes involved in desiccation stress tolerance. Cell viability was evaluated along desiccation treatment and gene expression was analyzed by real-time PCR before and during the stress. Our data show that the observed differences in individual strain sensitivity to desiccation stress could be associated to specific gene expression over time. In particular, either the basal or the stress-induced mRNA levels of certain genes, such as HSP12, SSA3, TPS1, TPS2, CTT1 and SOD1, result tightly correlated to the strain survival advantage. This study provides a reliable and sensitive method to predict desiccation stress tolerance of indigenous wine yeast strains which could be preliminary to biotechnological applications. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Sun and Sun Worship in Different Cultures

    NASA Astrophysics Data System (ADS)

    Farmanyan, S. V.; Mickaelian, A. M.

    2014-10-01

    The Sun symbol is found in many cultures throughout history, it has played an important role in shaping our life on Earth since the dawn of time. Since the beginning of human existence, civilisations have established religious beliefs that involved the Sun's significance to some extent. As new civilisations and religions developed, many spiritual beliefs were based on those from the past so that there has been an evolution of the Sun's significance throughout cultural development. For comparing and finding the origin of the Sun we made a table of 66 languages and compared the roots of the words. For finding out from where these roots came from, we also made a table of 21 Sun Gods and Goddesses and proved the direct crossing of language and mythology.

  6. Transcription regulation of the Saccharomyces cerevisiae PIS1 gene by inositol and the pleiotropic regulator, Ume6p.

    PubMed

    Jani, Niketa M; Lopes, John M

    2008-12-01

    In Saccharomyces cerevisiae, transcription of most of the phospholipid biosynthetic genes (e.g. INO1, CHO1, CHO2 and OPI3) is repressed by growth in the presence of inositol and choline and derepressed in their absence. This regulation requires the Ino2p and Ino4p activators and the Opi1p repressor. The PIS1 structural gene is required for the synthesis of the essential lipid phosphatidylinositol. Previous reports show that PIS1 expression is uncoupled from inositol/choline regulation, but is regulated by carbon source, hypoxia and zinc. However, in this study we found that the expression of PIS1 is induced twofold by inositol. This regulation did not require Ino2p and Ino4p, although Ino4p was required for full expression. Ino4p is a basic helix-loop-helix protein that requires a binding partner. Curiously, none of the other basic helix-loop-helix proteins affected PIS1 expression. Inositol induction did require another general regulator of phospholipid biosynthesis, Ume6p. Ume6p was found to be a positive regulator of PIS1 gene expression. Ume6p, and several associated factors, were required for inositol-mediated induction and chromatin immunoprecipitation analysis showed that Ume6p directly regulates PIS1 expression. Thus, we demonstrate novel regulation of the PIS1 gene by Ume6p.

  7. Biocuration at the Saccharomyces Genome Database

    PubMed Central

    Skrzypek, Marek S.; Nash, Robert S.

    2015-01-01

    Saccharomyces Genome Database is an online resource dedicated to managing information about the biology and genetics of the model organism, yeast (Saccharomyces cerevisiae). This information is derived primarily from scientific publications through a process of human curation that involves manual extraction of data and their organization into a comprehensive system of knowledge. This system provides a foundation for further analysis of experimental data coming from research on yeast as well as other organisms. In this review we will demonstrate how biocuration and biocurators add a key component, the biological context, to our understanding of how genes, proteins, genomes and cells function and interact. We will explain the role biocurators play in sifting through the wealth of biological data to incorporate and connect key information. We will also discuss the many ways we assist researchers with their various research needs. We hope to convince the reader that manual curation is vital in converting the flood of data into organized and interconnected knowledge, and that biocurators play an essential role in the integration of scientific information into a coherent model of the cell. PMID:25997651

  8. Skin Tone Dissatisfaction, Sun Exposure, and Sun Protection in Australian Adolescents.

    PubMed

    Hutchinson, Amanda D; Prichard, Ivanka; Ettridge, Kerry; Wilson, Carlene

    2015-08-01

    This study aimed to assess the adoption of sun protection and sun exposure behaviors, the extent to which these behaviors group together, and the relationship between skin tone dissatisfaction and sun-related behaviors in South Australian adolescents (aged 12-17). A total of 2,875 secondary school students (1,461 male and 1,414 female) completed a questionnaire including questions about sun protection and sun exposure behaviors and skin tone dissatisfaction. Regular adoption of sun protection behaviors was low and ranged from 20% (wearing protective clothing) to 44% (sunscreen use). A principal components analysis identified four subgroups of sun-related behaviors: sun protection, appearance enhancement, sun avoidance, and sun exposure. Females had significantly higher skin tone dissatisfaction than males. Skin tone dissatisfaction was associated with decreased sun protection and avoidance and increased appearance enhancement and sun exposure in both males and females. Skin tone dissatisfaction plays an important role in Australian adolescents' sun-related behavior. Appearance-based interventions may be effective in reducing skin cancer risk through reduced sun exposure.

  9. Transposon mutagenesis to improve the growth of recombinant Saccharomyces cerevisiae on D-xylose

    Treesearch

    Haiying Ni; Jose M. Laplaza; Thomas W. Jeffries

    2007-01-01

    Saccharomyces cerevisiae L2612 transformed with genes for xylose reductase and xylitol dehydrogenase (XYL1 and XYL2) grows well on glucose but very poorly on D-xylose. When a gene for D-xylulokinase (XYL3 or XKS1) is overexpressed, growth on glucose is unaffected, but growth on xylose is blocked. Spontaneous or chemically induced mutants of this engineered yeast that...

  10. Saccharomyces kudriavzevii and Saccharomyces uvarum differ from Saccharomyces cerevisiae during the production of aroma-active higher alcohols and acetate esters using their amino acidic precursors.

    PubMed

    Stribny, Jiri; Gamero, Amparo; Pérez-Torrado, Roberto; Querol, Amparo

    2015-07-16

    Higher alcohols and acetate esters are important flavour and aroma components in the food industry. In alcoholic beverages these compounds are produced by yeast during fermentation. Although Saccharomyces cerevisiae is one of the most extensively used species, other species of the Saccharomyces genus have become common in fermentation processes. This study analyses and compares the production of higher alcohols and acetate esters from their amino acidic precursors in three Saccharomyces species: Saccharomyces kudriavzevii, Saccharomyces uvarum and S. cerevisiae. The global volatile compound analysis revealed that S. kudriavzevii produced large amounts of higher alcohols, whereas S. uvarum excelled in the production of acetate esters. Particularly from phenylalanine, S. uvarum produced the largest amounts of 2-phenylethyl acetate, while S. kudriavzevii obtained the greatest 2-phenylethanol formation from this precursor. The present data indicate differences in the amino acid metabolism and subsequent production of flavour-active higher alcohols and acetate esters among the closely related Saccharomyces species. This knowledge will prove useful for developing new enhanced processes in fragrance, flavour, and food industries. Copyright © 2015. Published by Elsevier B.V.

  11. Regulation of glucose-dependent gene expression by the RNA helicase Dbp2 in Saccharomyces cerevisiae.

    PubMed

    Beck, Zachary T; Cloutier, Sara C; Schipma, Matthew J; Petell, Christopher J; Ma, Wai Kit; Tran, Elizabeth J

    2014-11-01

    Cellular homeostasis requires a fine balance between energy uptake, utilization, and growth. Dbp2 is a member of the DEAD-box protein family in Saccharomyces cerevisiae with characterized ATPase and helicase activity in vitro. DEAD-box RNA helicases are a class of enzymes that utilize ATP hydrolysis to remodel RNA and/or RNA-protein (RNP) composition. Dbp2 has been proposed to utilize its helicase activity in vivo to promote RNA-protein complex assembly of both messenger (m)RNAs and long noncoding (lnc)RNAs. Previous work from our laboratory demonstrated that loss of DBP2 enhances the lncRNA-dependent transcriptional induction of the GAL genes by abolishing glucose-dependent repression. Herein, we report that either a carbon source switch or glucose deprivation results in rapid export of Dbp2 to the cytoplasm. Genome-wide RNA sequencing identified a new class of antisense hexose transporter transcripts that are specifically upregulated upon loss of DBP2. Further investigation revealed that both sense and antisense hexose transporter (HXT) transcripts are aberrantly expressed in DBP2-deficient cells and that this expression pathway can be partially mimicked in wild-type cells by glucose depletion. We also find that Dbp2 promotes ribosome biogenesis and represses alternative ATP-producing pathways, as loss of DBP2 alters the transcript levels of ribosome biosynthesis (snoRNAs and associated proteins) and respiration gene products. This suggests that Dbp2 is a key integrator of nutritional status and gene expression programs required for energy homeostasis. Copyright © 2014 by the Genetics Society of America.

  12. Metabolic Engineering of Probiotic Saccharomyces boulardii

    PubMed Central

    Liu, Jing-Jing; Kong, In Iok; Zhang, Guo-Chang; Jayakody, Lahiru N.; Kim, Heejin; Xia, Peng-Fei; Kwak, Suryang; Sung, Bong Hyun; Sohn, Jung-Hoon; Walukiewicz, Hanna E.; Rao, Christopher V.

    2016-01-01

    Saccharomyces boulardii is a probiotic yeast that has been used for promoting gut health as well as preventing diarrheal diseases. This yeast not only exhibits beneficial phenotypes for gut health but also can stay longer in the gut than Saccharomyces cerevisiae. Therefore, S. boulardii is an attractive host for metabolic engineering to produce biomolecules of interest in the gut. However, the lack of auxotrophic strains with defined genetic backgrounds has hampered the use of this strain for metabolic engineering. Here, we report the development of well-defined auxotrophic mutants (leu2, ura3, his3, and trp1) through clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9-based genome editing. The resulting auxotrophic mutants can be used as a host for introducing various genetic perturbations, such as overexpression or deletion of a target gene, using existing genetic tools for S. cerevisiae. We demonstrated the overexpression of a heterologous gene (lacZ), the correct localization of a target protein (red fluorescent protein) into mitochondria by using a protein localization signal, and the introduction of a heterologous metabolic pathway (xylose-assimilating pathway) in the genome of S. boulardii. We further demonstrated that human lysozyme, which is beneficial for human gut health, could be secreted by S. boulardii. Our results suggest that more sophisticated genetic perturbations to improve S. boulardii can be performed without using a drug resistance marker, which is a prerequisite for in vivo applications using engineered S. boulardii. PMID:26850302

  13. Metabolic Engineering of Probiotic Saccharomyces boulardii.

    PubMed

    Liu, Jing-Jing; Kong, In Iok; Zhang, Guo-Chang; Jayakody, Lahiru N; Kim, Heejin; Xia, Peng-Fei; Kwak, Suryang; Sung, Bong Hyun; Sohn, Jung-Hoon; Walukiewicz, Hanna E; Rao, Christopher V; Jin, Yong-Su

    2016-04-01

    Saccharomyces boulardiiis a probiotic yeast that has been used for promoting gut health as well as preventing diarrheal diseases. This yeast not only exhibits beneficial phenotypes for gut health but also can stay longer in the gut than Saccharomyces cerevisiae Therefore, S. boulardiiis an attractive host for metabolic engineering to produce biomolecules of interest in the gut. However, the lack of auxotrophic strains with defined genetic backgrounds has hampered the use of this strain for metabolic engineering. Here, we report the development of well-defined auxotrophic mutants (leu2,ura3,his3, and trp1) through clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9-based genome editing. The resulting auxotrophic mutants can be used as a host for introducing various genetic perturbations, such as overexpression or deletion of a target gene, using existing genetic tools forS. cerevisiae We demonstrated the overexpression of a heterologous gene (lacZ), the correct localization of a target protein (red fluorescent protein) into mitochondria by using a protein localization signal, and the introduction of a heterologous metabolic pathway (xylose-assimilating pathway) in the genome ofS. boulardii We further demonstrated that human lysozyme, which is beneficial for human gut health, could be secreted by S. boulardii Our results suggest that more sophisticated genetic perturbations to improveS. boulardii can be performed without using a drug resistance marker, which is a prerequisite for in vivo applications using engineeredS. boulardii. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  14. SIR2 and other genes are abundantly expressed in long-lived natural segregants for replicative aging of the budding yeast Saccharomyces cerevisiae.

    PubMed

    Guo, Zhenhua; Adomas, Aleksandra B; Jackson, Erin D; Qin, Hong; Townsend, Jeffrey P

    2011-06-01

    We investigated the mechanism underlying the natural variation in longevity within natural populations using the model budding yeast, Saccharomyces cerevisiae. We analyzed whole-genome gene expression in four progeny of a natural S. cerevisiae strain that display differential replicative aging. Genes with different expression levels in short- and long-lived strains were classified disproportionately into metabolism, transport, development, transcription or cell cycle, and organelle organization (mitochondrial, chromosomal, and cytoskeletal). With several independent validating experiments, we detected 15 genes with consistent differential expression levels between the long- and the short-lived progeny. Among those 15, SIR2, HSP30, and TIM17 were upregulated in long-lived strains, which is consistent with the known effects of gene silencing, stress response, and mitochondrial function on aging. The link between SIR2 and yeast natural life span variation offers some intriguing ties to the allelic association of the human homolog SIRT1 to visceral obesity and metabolic response to lifestyle intervention. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  15. Mutations in a gene encoding the. cap alpha. subunit of a Saccharomyces cerevisiae G protein indicate a role in mating pheromone signaling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jahng, K.Y.; Ferguson, J.; Reed, S.I.

    1988-06-01

    Mutations which allowed conjugation by Saccharomyces cerevisiae cells lacking a mating pheromone receptor gene were selected. One of the genes defined by such mutations was isolated from a yeast genomic library by complementation of a temperature-sensitive mutation and is identically to the gene GPA1 (also known as SCG1), recently shown to be highly homologous to gene encoding the ..cap alpha.. subunits of mammalian G proteins. Physiological analysis of temperature-sensitive gpal mutations suggests that the encoded G protein is involved in signaling in response to mating pheromones. Mutational disruption of G-protein activity causes cell-cycle arrest in G/sub 1/, deposition of mating-specificmore » cell surface aggultinins, and induction of pheromone-specific mRNa, all of which are responses to pheromone in wild-type cells. In addition, mutants can conjugate without the benefit of mating pheromone or pheromone receptor. A model is presented where the activated G protein has a negative impact on a constitutive signal which normally keeps the pheromone response repressed.« less

  16. Integration of tomato reproductive developmental landmarks and expression profiles, and the effect of SUN on fruit shape

    PubMed Central

    Xiao, Han; Radovich, Cheryll; Welty, Nicholas; Hsu, Jason; Li, Dongmei; Meulia, Tea; van der Knaap, Esther

    2009-01-01

    Background Universally accepted landmark stages are necessary to highlight key events in plant reproductive development and to facilitate comparisons among species. Domestication and selection of tomato resulted in many varieties that differ in fruit shape and size. This diversity is useful to unravel underlying molecular and developmental mechanisms that control organ morphology and patterning. The tomato fruit shape gene SUN controls fruit elongation. The most dramatic effect of SUN on fruit shape occurs after pollination and fertilization although a detailed investigation into the timing of the fruit shape change as well as gene expression profiles during critical developmental stages has not been conducted. Results We provide a description of floral and fruit development in a red-fruited closely related wild relative of tomato, Solanum pimpinellifolium accession LA1589. We use established and propose new floral and fruit landmarks to present a framework for tomato developmental studies. In addition, gene expression profiles of three key stages in floral and fruit development are presented, namely floral buds 10 days before anthesis (floral landmark 7), anthesis-stage flowers (floral landmark 10 and fruit landmark 1), and 5 days post anthesis fruit (fruit landmark 3). To demonstrate the utility of the landmarks, we characterize the tomato shape gene SUN in fruit development. SUN controls fruit shape predominantly after fertilization and its effect reaches a maximum at 8 days post-anthesis coinciding with fruit landmark 4 representing the globular embryo stage of seed development. The expression profiles of the NILs that differ at sun show that only 34 genes were differentially expressed and most of them at a less than 2-fold difference. Conclusion The landmarks for flower and fruit development in tomato were outlined and integrated with the effect of SUN on fruit shape. Although we did not identify many genes differentially expressed in the NILs that differ at

  17. Random phenotypic variation of yeast (Saccharomyces cerevisiae) single-gene knockouts fits a double pareto-lognormal distribution.

    PubMed

    Graham, John H; Robb, Daniel T; Poe, Amy R

    2012-01-01

    Distributed robustness is thought to influence the buffering of random phenotypic variation through the scale-free topology of gene regulatory, metabolic, and protein-protein interaction networks. If this hypothesis is true, then the phenotypic response to the perturbation of particular nodes in such a network should be proportional to the number of links those nodes make with neighboring nodes. This suggests a probability distribution approximating an inverse power-law of random phenotypic variation. Zero phenotypic variation, however, is impossible, because random molecular and cellular processes are essential to normal development. Consequently, a more realistic distribution should have a y-intercept close to zero in the lower tail, a mode greater than zero, and a long (fat) upper tail. The double Pareto-lognormal (DPLN) distribution is an ideal candidate distribution. It consists of a mixture of a lognormal body and upper and lower power-law tails. If our assumptions are true, the DPLN distribution should provide a better fit to random phenotypic variation in a large series of single-gene knockout lines than other skewed or symmetrical distributions. We fit a large published data set of single-gene knockout lines in Saccharomyces cerevisiae to seven different probability distributions: DPLN, right Pareto-lognormal (RPLN), left Pareto-lognormal (LPLN), normal, lognormal, exponential, and Pareto. The best model was judged by the Akaike Information Criterion (AIC). Phenotypic variation among gene knockouts in S. cerevisiae fits a double Pareto-lognormal (DPLN) distribution better than any of the alternative distributions, including the right Pareto-lognormal and lognormal distributions. A DPLN distribution is consistent with the hypothesis that developmental stability is mediated, in part, by distributed robustness, the resilience of gene regulatory, metabolic, and protein-protein interaction networks. Alternatively, multiplicative cell growth, and the mixing of

  18. Saccharomyces cerevisiae engineered for xylose metabolism exhibits a respiratory response

    Treesearch

    Yong-Su Jin; Jose M. Laplaza; Thomas W. Jeffries

    2004-01-01

    Native strains of Saccharomyces cerevisiae do not assimilate xylose. S. cerevisiae engineered for D-xylose utilization through the heterologous expression of genes for aldose reductase ( XYL1), xylitol dehydrogenase (XYL2), and D-xylulokinase ( XYL3 or XKS1) produce only limited amounts of ethanol in xylose medium. In recombinant S. cerevisiae expressing XYL1, XYL2,...

  19. Stress-tolerance of baker's-yeast (Saccharomyces cerevisiae) cells: stress-protective molecules and genes involved in stress tolerance.

    PubMed

    Shima, Jun; Takagi, Hiroshi

    2009-05-29

    During the fermentation of dough and the production of baker's yeast (Saccharomyces cerevisiae), cells are exposed to numerous environmental stresses (baking-associated stresses) such as freeze-thaw, high sugar concentrations, air-drying and oxidative stresses. Cellular macromolecules, including proteins, nucleic acids and membranes, are seriously damaged under stress conditions, leading to the inhibition of cell growth, cell viability and fermentation. To avoid lethal damage, yeast cells need to acquire a variety of stress-tolerant mechanisms, for example the induction of stress proteins, the accumulation of stress protectants, changes in membrane composition and repression of translation, and by regulating the corresponding gene expression via stress-triggered signal-transduction pathways. Trehalose and proline are considered to be critical stress protectants, as is glycerol. It is known that these molecules are effective for providing protection against various types of environmental stresses. Modifications of the metabolic pathways of trehalose and proline by self-cloning methods have significantly increased tolerance to baking-associated stresses. To clarify which genes are required for stress tolerance, both a comprehensive phenomics analysis and a functional genomics analysis were carried out under stress conditions that simulated those occurring during the commercial baking process. These analyses indicated that many genes are involved in stress tolerance in yeast. In particular, it was suggested that vacuolar H+-ATPase plays important roles in yeast cells under stress conditions.

  20. Influence of maternal and own genotype at tanning dependence-related SNPs on sun exposure in childhood.

    PubMed

    Khouja, Jasmine; Lewis, Sarah J; Bonilla, Carolina

    2018-04-12

    Research suggests there may be a genetic influence on the likelihood of becoming tanning dependent (TD). The way in which mothers regulate their children's sun exposure may be affected by being TD. We investigated the associations between single nucleotide polymorphisms (SNPs) related to being TD and early sun exposure. Data from the Avon Longitudinal Study of Parents and Children (ALSPAC) were used. Associations between 17 TD related SNPs in children and their mothers and 10 sun exposure variables in children (assessed via questionnaire at age 8) were analyzed in logistic and ordinal logistic regressions. Analyses were adjusted for principal components of population structure and age (at time of questionnaire response). Models with additional adjustment for maternal or offspring genotypes were also tested. Secondary analyses included adjustment for sex and skin pigmentation. Among ALSPAC children, the rs29132 SNP in the Vesicle-associated membrane protein-associated protein A (VAPA) gene was associated with five sun exposure variables whilst the rs650662 SNP in the Opioid Receptor Mu 1 (OPRM1) gene was associated with three. The remaining SNPs did not show associations beyond what was expected by chance. After Bonferroni correction one SNP in the children was associated with an increased likelihood of using sun cream whilst in the sun at 8 years old (rs60050811 in the Spermatogenesis and Centriole Associated 1 (SPATC1) gene, OR per C allele = 1.34, 95% CI 1.11-1.62, p = .003). In the mothers, rs650662 in OPRM1 was associated with the use of a lower factor of sun cream in their children, (OR per A allele = 0.89, 95% CI 0.82-0.96, p = .002). Whilst rs2073478 in the Aldehyde Dehydrogenase 1 Family Member B1 (ALDH1B1) gene was associated with a reduced odds of their child using a sun block or cream with a 4 star rating (OR per T allele = 0.68, 95% CI 0.53-0.88, p = .003). Similar but weaker associations were observed for the main findings in

  1. Genome-wide screen in Saccharomyces cerevisiae identifies vacuolar protein sorting, autophagy, biosynthetic, and tRNA methylation genes involved in life span regulation.

    PubMed

    Fabrizio, Paola; Hoon, Shawn; Shamalnasab, Mehrnaz; Galbani, Abdulaye; Wei, Min; Giaever, Guri; Nislow, Corey; Longo, Valter D

    2010-07-15

    The study of the chronological life span of Saccharomyces cerevisiae, which measures the survival of populations of non-dividing yeast, has resulted in the identification of homologous genes and pathways that promote aging in organisms ranging from yeast to mammals. Using a competitive genome-wide approach, we performed a screen of a complete set of approximately 4,800 viable deletion mutants to identify genes that either increase or decrease chronological life span. Half of the putative short-/long-lived mutants retested from the primary screen were confirmed, demonstrating the utility of our approach. Deletion of genes involved in vacuolar protein sorting, autophagy, and mitochondrial function shortened life span, confirming that respiration and degradation processes are essential for long-term survival. Among the genes whose deletion significantly extended life span are ACB1, CKA2, and TRM9, implicated in fatty acid transport and biosynthesis, cell signaling, and tRNA methylation, respectively. Deletion of these genes conferred heat-shock resistance, supporting the link between life span extension and cellular protection observed in several model organisms. The high degree of conservation of these novel yeast longevity determinants in other species raises the possibility that their role in senescence might be conserved.

  2. Nucleotide sequencing analysis of a LEU gene of Candida maltosa which complements leuB mutation of Escherichia coli and leu2 mutation of Saccharomyces cerevisiae.

    PubMed

    Takagi, M; Kobayashi, N; Sugimoto, M; Fujii, T; Watari, J; Yano, K

    1987-01-01

    The expression of a LEU gene from Candida maltosa (designated as C-LEU2) isolated previously (Kawamura et al. 1983) was shown to be regulated, when transferred into Saccharomyces cerevisiae, by leucine and threonine in the medium, as in the case of LEU2 gene of S. cerevisiae. The coding region together with the regulatory region was subcloned and the nucleotide sequence was determined. When the sequence of the coding region was compared with that of LEU2, the homology was 72% for base pairs and 76% for deduced amino acids. Comparison of the regulatory region of C-LEU2 with those of LEU1 and LEU2 suggested a few short consensus sequences which are involved in regulation of gene expression by leucine and threonine in the medium.

  3. High quality de novo sequencing and assembly of the Saccharomyces arboricolus genome

    PubMed Central

    2013-01-01

    Background Comparative genomics is a formidable tool to identify functional elements throughout a genome. In the past ten years, studies in the budding yeast Saccharomyces cerevisiae and a set of closely related species have been instrumental in showing the benefit of analyzing patterns of sequence conservation. Increasing the number of closely related genome sequences makes the comparative genomics approach more powerful and accurate. Results Here, we report the genome sequence and analysis of Saccharomyces arboricolus, a yeast species recently isolated in China, that is closely related to S. cerevisiae. We obtained high quality de novo sequence and assemblies using a combination of next generation sequencing technologies, established the phylogenetic position of this species and considered its phenotypic profile under multiple environmental conditions in the light of its gene content and phylogeny. Conclusions We suggest that the genome of S. arboricolus will be useful in future comparative genomics analysis of the Saccharomyces sensu stricto yeasts. PMID:23368932

  4. Genome-wide identification of genes involved in growth and fermentation activity at low temperature in Saccharomyces cerevisiae.

    PubMed

    Salvadó, Zoel; Ramos-Alonso, Lucía; Tronchoni, Jordi; Penacho, Vanessa; García-Ríos, Estéfani; Morales, Pilar; Gonzalez, Ramon; Guillamón, José Manuel

    2016-11-07

    Fermentation at low temperatures is one of the most popular current winemaking practices because of its reported positive impact on the aromatic profile of wines. However, low temperature is an additional hurdle to develop Saccharomyces cerevisiae wine yeasts, which are already stressed by high osmotic pressure, low pH and poor availability of nitrogen sources in grape must. Understanding the mechanisms of adaptation of S. cerevisiae to fermentation at low temperature would help to design strategies for process management, and to select and improve wine yeast strains specifically adapted to this winemaking practice. The problem has been addressed by several approaches in recent years, including transcriptomic and other high-throughput strategies. In this work we used a genome-wide screening of S. cerevisiae diploid mutant strain collections to identify genes that potentially contribute to adaptation to low temperature fermentation conditions. Candidate genes, impaired for growth at low temperatures (12°C and 18°C), but not at a permissive temperature (28°C), were deleted in an industrial homozygous genetic background, wine yeast strain FX10, in both heterozygosis and homozygosis. Some candidate genes were required for growth at low temperatures only in the laboratory yeast genetic background, but not in FX10 (namely the genes involved in aromatic amino acid biosynthesis). Other genes related to ribosome biosynthesis (SNU66 and PAP2) were required for low-temperature fermentation of synthetic must (SM) in the industrial genetic background. This result coincides with our previous findings about translation efficiency with the fitness of different wine yeast strains at low temperature. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Cloning, sequence, and disruption of the Saccharomyces diastaticus DAR1 gene encoding a glycerol-3-phosphate dehydrogenase.

    PubMed

    Wang, H T; Rahaim, P; Robbins, P; Yocum, R R

    1994-11-01

    The Saccharomyces diastaticus DAR1 gene was cloned by complementation in an Escherichia coli strain auxogrophic for glycerol-3-phosphate. DAR1 encodes an NADH-dependent dihydroxyacetone phosphate reductase (sn-glycerol-3-phosphate dehydrogenase [G3PDase; EC 1.1.1.8]) homologous to several other eukaryotic G3PDases. DAR1 is distinct from GUT2, which encodes a glucose-repressed mitochondrial G3PDase, but is identical to GPD1 from S. cerevisiae, a close relative of S. diastaticus. The level of DAR1-encoded G3PDase was increased about threefold in a medium of high osmolarity. Disruption of DAR1 in a haploid S. cerevisiae was not lethal but led to a decrease in cytoplasmic NADH-dependent G3PDase activity, an increase in osmotic sensitivity, and a 25% reduction in glycerol secretion from cells grown anaerobically on glucose.

  6. Complementation of Saccharomyces cerevisiae mutations in genes involved in translation and protein folding (EFB1 and SSB1) with Candida albicans cloned genes.

    PubMed

    Maneu, V; Roig, P; Gozalbo, D

    2000-11-01

    We have demonstrated that the expression of Candida albicans genes involved in translation and protein folding (EFB1 and SSB1) complements the phenotype of Saccharomyces cerevisiae mutants. The elongation factor 1beta (EF-1beta) is essential for growth and efb1 S. cerevisiae null mutant cells are not viable; however, viable haploid cells, carrying the disrupted chromosomal allele of the S. cerevisiae EFB1 gene and pEFB1, were isolated upon sporulation of a diploid strain which was heterozygous at the EFB1 locus and transformed with pEFB1 (a pEMBLYe23 derivative plasmid containing an 8-kb DNA fragment from the C. albicans genome which contains the EFB1 gene). This indicates that the C. albicans EFB1 gene encodes a functional EF-1beta. Expression of the SSB1 gene from C. albicans, which codes for a member of the 70-kDa heat shock protein family, in S. cerevisiae ssb1 ssb2 double mutant complements the mutant phenotype (poor growth particularly at low temperature, and sensitivity to certain protein synthesis inhibitors, such as paromomycin). This complementation indicates that C. albicans Ssbl may function as a molecular chaperone on the translating ribosomes, as described in S. cerevisiae. Northern blot analysis showed that SSB mRNA levels increased after mild cold shift (28 degrees C to 23 degrees C) and rapidly decreased after mild heat shift (from 28 degrees C to 37 degrees C, and particularly to 42 degrees C), indicating that SSB1 expression is regulated by temperature. Therefore, Ssb1 may be considered as a molecular chaperone whose pattern of expression is similar to that found in ribosomal proteins, according to its common role in translation.

  7. Efficient screening of environmental isolates for Saccharomyces cerevisiae strains that are suitable for brewing.

    PubMed

    Fujihara, Hidehiko; Hino, Mika; Takashita, Hideharu; Kajiwara, Yasuhiro; Okamoto, Keiko; Furukawa, Kensuke

    2014-01-01

    We developed an efficient screening method for Saccharomyces cerevisiae strains from environmental isolates. MultiPlex PCR was performed targeting four brewing S. cerevisiae genes (SSU1, AWA1, BIO6, and FLO1). At least three genes among the four were amplified from all S. cerevisiae strains. The use of this method allowed us to successfully obtain S. cerevisiae strains.

  8. Identification and classification of genes required for tolerance to freeze-thaw stress revealed by genome-wide screening of Saccharomyces cerevisiae deletion strains.

    PubMed

    Ando, Akira; Nakamura, Toshihide; Murata, Yoshinori; Takagi, Hiroshi; Shima, Jun

    2007-03-01

    Yeasts used in bread making are exposed to freeze-thaw stress during frozen-dough baking. To clarify the genes required for freeze-thaw tolerance, genome-wide screening was performed using the complete deletion strain collection of diploid Saccharomyces cerevisiae. The screening identified 58 gene deletions that conferred freeze-thaw sensitivity. These genes were then classified based on their cellular function and on the localization of their products. The results showed that the genes required for freeze-thaw tolerance were frequently involved in vacuole functions and cell wall biogenesis. The highest numbers of gene products were components of vacuolar H(+)-ATPase. Next, the cross-sensitivity of the freeze-thaw-sensitive mutants to oxidative stress and to cell wall stress was studied; both of these are environmental stresses closely related to freeze-thaw stress. The results showed that defects in the functions of vacuolar H(+)-ATPase conferred sensitivity to oxidative stress and to cell wall stress. In contrast, defects in gene products involved in cell wall assembly conferred sensitivity to cell wall stress but not to oxidative stress. Our results suggest the presence of at least two different mechanisms of freeze-thaw injury: oxidative stress generated during the freeze-thaw process, and defects in cell wall assembly.

  9. The gene ICS3 from the yeast Saccharomyces cerevisiae is involved in copper homeostasis dependent on extracellular pH.

    PubMed

    Alesso, C A; Discola, K F; Monteiro, G

    2015-09-01

    In the yeast Saccharomyces cerevisiae, many genes are involved in the uptake, transport, storage and detoxification of copper. Large scale studies have noted that deletion of the gene ICS3 increases sensitivity to copper, Sortin 2 and acid exposure. Here, we report a study on the Δics3 strain, in which ICS3 is related to copper homeostasis, affecting the intracellular accumulation of this metal. This strain is sensitive to hydrogen peroxide and copper exposure, but not to other tested transition metals. At pH 6.0, the Δics3 strain accumulates a larger amount of intracellular copper than the wild-type strain, explaining the sensitivity to oxidants in this condition. Unexpectedly, sensitivity to copper exposure only occurs in acidic conditions. This can be explained by the fact that the exposure of Δics3 cells to high copper concentrations at pH 4.0 results in over-accumulation of copper and iron. Moreover, the expression of ICS3 increases in acidic pH, and this is correlated with CCC2 gene expression, since both genes are regulated by Rim101 from the pH regulon. CCC2 is also upregulated in Δics3 in acidic pH. Together, these data indicate that ICS3 is involved in copper homeostasis and is dependent on extracellular pH. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Gene engineering in yeast for biodegradation: Immunological cross-reactivity among cytochrome p-450 system proteins of saccharomyces cerevisiae and candida tropicalis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Loper, J.C.; Chen, C.; Dey, C.R.

    1993-01-01

    Yeasts are eukaryotic microorganisms whose cytochrome P-450 monooxygenase systems may be amenable to genetic engineering for the hydroxylation and detoxication of polychlorinated aromatic hydrocarbons. The molecular genetic properties of strains of bakers yeast, Saccharomyces cerevisiae, and an n-alkane utilizing yeast, Candida tropicalis ATCC750 are examined. Standard methods were used to purify cytochrome P-450 and NADPH-cytochrome c (P-450) reductase proteins from cells cultured by semi-anaerobic glucose fermentation (S. cerevisiae, C. tropicalis) and by growth on tetradecane (C. tropicalis). Polyvalent antisera prepared in rabbits to some of these proteins were used in tests of immunological relatedness among the purified proteins using sodiummore » dodecyl sulfate-polyacrylamide gel electrophoresis and nitrocellulose filter immunoblots. The results provide evidence for gene relationships which should prove useful in gene isolation and subsequent engineering of P-450 enzyme systems in yeast.« less

  11. Spotless Sun

    NASA Image and Video Library

    2017-03-22

    The sun has been virtually spotless, as in no sunspots, over the past 11 days, a spotless stretch that we have not seen since the last solar minimum many years ago. The videos shows the past four days (Mar. 14-17, 2017) with a combination of an extreme ultraviolet image blended with just the filtered sun. If we just showed the filtered sun with no spots for reference points, any viewer would have a hard time telling that the sun was even rotating. The sun is trending again towards the solar minimum period of its 11 year cycle, which is predicted to be around 2020. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA21569

  12. Sun protection

    MedlinePlus

    ... age spots are caused by exposure to the sun. This is because the damage caused by the sun is permanent. ... The two types of sun rays that can injure the skin are ultraviolet A (UVA) and ultraviolet B (UVB). UVA affects the deep layers of ...

  13. Biocuration at the Saccharomyces genome database.

    PubMed

    Skrzypek, Marek S; Nash, Robert S

    2015-08-01

    Saccharomyces Genome Database is an online resource dedicated to managing information about the biology and genetics of the model organism, yeast (Saccharomyces cerevisiae). This information is derived primarily from scientific publications through a process of human curation that involves manual extraction of data and their organization into a comprehensive system of knowledge. This system provides a foundation for further analysis of experimental data coming from research on yeast as well as other organisms. In this review we will demonstrate how biocuration and biocurators add a key component, the biological context, to our understanding of how genes, proteins, genomes and cells function and interact. We will explain the role biocurators play in sifting through the wealth of biological data to incorporate and connect key information. We will also discuss the many ways we assist researchers with their various research needs. We hope to convince the reader that manual curation is vital in converting the flood of data into organized and interconnected knowledge, and that biocurators play an essential role in the integration of scientific information into a coherent model of the cell. © 2015 Wiley Periodicals, Inc.

  14. Epigenetics in Saccharomyces cerevisiae

    PubMed Central

    Grunstein, Michael; Gasser, Susan M.

    2013-01-01

    Saccharomyces cerevisiae provides a well-studied model system for heritable silent chromatin, in which a nonhistone protein complex—the SIR complex—represses genes by spreading in a sequence-independent manner, much like heterochromatin in higher eukaryotes. The ability to study mutations in histones and to screen genome-wide for mutations that impair silencing has yielded an unparalleled depth of detail about this system. Recent advances in the biochemistry and structural biology of the SIR-chromatin complex bring us much closer to a molecular understanding of how Sir3 selectively recognizes the deacetylated histone H4 tail and demethylated histone H3 core. The existence of appropriate mutants has also shown how components of the silencing machinery affect physiological processes beyond transcriptional repression. PMID:23818500

  15. Agaricus brasiliensis (sun mushroom) affects the expression of genes related to cholesterol homeostasis.

    PubMed

    de Miranda, Aline Mayrink; Rossoni Júnior, Joamyr Victor; Souza E Silva, Lorena; Dos Santos, Rinaldo Cardoso; Silva, Marcelo Eustáquio; Pedrosa, Maria Lúcia

    2017-06-01

    The sun mushroom (Agaricus brasiliensis) is considered a major source of bioactive compounds with potential health benefits. Mushrooms typically act as lipid-lowering agents; however, little is known about the mechanisms of action of A. brasiliensis in biological systems. This study aimed to determine the underlying mechanism involved in the cholesterol-lowering effect of A. brasiliensis through the assessment of fecal and serum lipid profiles in addition to gene expression analysis of specific transcription factors, enzymes, and transporters involved in cholesterol homeostasis. Twenty-four albino Fischer rats approximately 90 days old, with an average weight of 205 g, were divided into four groups of 6 each and fed a standard AIN-93 M diet (C), hypercholesterolemic diet (H), hypercholesterolemic diet +1 % A. brasiliensis (HAb), or hypercholesterolemic diet +0.008 % simvastatin (HS) for 6 weeks. Simvastatin was used as a positive control, as it is a typical drug prescribed for lipid disorders. Subsequently, blood, liver, and feces samples were collected for lipid profile and quantitative real-time polymerase chain reaction gene expression analyses. Diet supplementation with A. brasiliensis significantly improved serum lipid profiles, comparable to the effect observed for simvastatin. In addition, A. brasiliensis dietary supplementation markedly promoted fecal cholesterol excretion. Increased expression of 7α-hydroxylase (CYP7A1), ATP-binding cassette subfamily G-transporters (ABCG5/G8), and low-density lipoprotein receptor (LDLR) was observed following A. brasiliensis administration. Our results suggest that consumption of A. brasiliensis improves the serum lipid profile in hypercholesterolemic rats by modulating the expression of key genes involved in hepatic cholesterol metabolism.

  16. Flor yeasts of Saccharomyces cerevisiae--their ecology, genetics and metabolism.

    PubMed

    Alexandre, Hervé

    2013-10-15

    The aging of certain white wines is dependent on the presence of yeast strains that develop a biofilm on the wine surface after the alcoholic fermentation. These strains belong to the genus Saccharomyces and are called flor yeasts. These strains possess distinctive characteristics compared with Saccharomyces cerevisiae fermenting strain. The most important one is their capacity to form a biofilm on the air-liquid interface of the wine. The major gene involved in this phenotype is FLO11, however other genes are also involved in velum formation by these yeast and will be detailed. Other striking features presented in this review are their aneuploidy, and their mitochondrial DNA polymorphism which seems to reflect adaptive evolution of the yeast to a stressful environment where acetaldehyde and ethanol are present at elevated concentration. The biofilm assures access to oxygen and therefore permits continued growth on non-fermentable ethanol. This specific metabolism explains the peculiar organoleptic profile of these wines, especially their content in acetaldehyde and sotolon. This review deals with these different specificities of flor yeasts and will also underline the existing gaps regarding these astonishing yeasts. © 2013.

  17. Cloning, sequence, and disruption of the Saccharomyces diastaticus DAR1 gene encoding a glycerol-3-phosphate dehydrogenase.

    PubMed Central

    Wang, H T; Rahaim, P; Robbins, P; Yocum, R R

    1994-01-01

    The Saccharomyces diastaticus DAR1 gene was cloned by complementation in an Escherichia coli strain auxogrophic for glycerol-3-phosphate. DAR1 encodes an NADH-dependent dihydroxyacetone phosphate reductase (sn-glycerol-3-phosphate dehydrogenase [G3PDase; EC 1.1.1.8]) homologous to several other eukaryotic G3PDases. DAR1 is distinct from GUT2, which encodes a glucose-repressed mitochondrial G3PDase, but is identical to GPD1 from S. cerevisiae, a close relative of S. diastaticus. The level of DAR1-encoded G3PDase was increased about threefold in a medium of high osmolarity. Disruption of DAR1 in a haploid S. cerevisiae was not lethal but led to a decrease in cytoplasmic NADH-dependent G3PDase activity, an increase in osmotic sensitivity, and a 25% reduction in glycerol secretion from cells grown anaerobically on glucose. PMID:7961476

  18. iTRAQ-based proteome profiling of Saccharomyces cerevisiae and cryotolerant species Saccharomyces uvarum and Saccharomyces kudriavzevii during low-temperature wine fermentation.

    PubMed

    García-Ríos, Estéfani; Querol, Amparo; Guillamón, José Manuel

    2016-09-02

    Temperature is one of the most important parameters to affect the duration and rate of alcoholic fermentation and final wine quality. Some species of the Saccharomyces genus have shown better adaptation at low temperature than Saccharomyces cerevisiae, which was the case of cryotolerant yeasts Saccharomyces uvarum and Saccharomyces kudriavzevii. In an attempt to detect inter-specific metabolic differences, we characterized the proteomic landscape of these cryotolerant species grown at 12°C and 28°C, which we compared with the proteome of S. cerevisiae (poorly adapted at low temperature). Our results showed that the main differences among the proteomic profiling of the three Saccharomyces strains grown at 12°C and 28°C lay in translation, glycolysis and amino acid metabolism. Our data corroborate previous transcriptomic results, which suggest that S. kudriavzevii is better adapted to grow at low temperature as a result of enhanced more efficient translation. Fitter amino acid biosynthetic pathways can also be mechanisms that better explain biomass yield in cryotolerant strains. Yet even at low temperature, S. cerevisiae is the most fermentative competitive species. A higher concentration of glycolytic and alcoholic fermentation enzymes in the S. cerevisiae strain might explain such greater fermentation activity. Temperature is one of the main relevant environmental variables that microorganisms have to cope with and it is also a key factor in some industrial processes that involve microorganisms. However, we are still far from understanding the molecular and physiological mechanisms of adaptation at low temperatures. The results obtained in this study provided a global atlas of the proteome changes triggered by temperature in three different species of the genus Saccharomyces with different degree of cryotolerance. These results would facilitate a better understanding of mechanisms for how yeast could adapt at the low temperature of growth. Copyright © 2016

  19. Truncation of Gal4p explains the inactivation of the GAL/MEL regulon in both Saccharomyces bayanus and some Saccharomyces cerevisiae wine strains.

    PubMed

    Dulermo, Rémi; Legras, Jean-Luc; Brunel, François; Devillers, Hugo; Sarilar, Véronique; Neuvéglise, Cécile; Nguyen, Huu-Vang

    2016-09-01

    In the past, the galactose-negative (Gal(-)) phenotype was a key physiological character used to distinguish Saccharomyces bayanus from S. cerevisiae In this work, we investigated the inactivation of GAL gene networks in S. bayanus, which is an S. uvarum/S. eubayanus hybrid, and in S. cerevisiae wine strains erroneously labelled 'S. bayanus'. We made an inventory of their GAL genes using genomes that were either available publicly, re-sequenced by us, or assembled from public data and completed with targeted sequencing. In the S. eubayanus/S. uvarum CBS 380(T) hybrid, the GAL/MEL network is composed of genes from both parents: from S. uvarum, an otherwise complete set that lacks GAL4, and from S. eubayanus, a truncated version of GAL4 and an additional copy of GAL3 and GAL80 Similarly, two different truncated GAL4 alleles were found in S. cerevisiae wine strains EC1118 and LalvinQA23. The lack of GAL4 activity in these strains was corrected by introducing a full-length copy of S. cerevisiae GAL4 on a CEN4/ARS plasmid. Transformation with this plasmid restored galactose utilisation in Gal(-) strains, and melibiose fermentation in strain CBS 380(T) The melibiose fermentation phenotype, formerly regarded as characteristic of S. uvarum, turned out to be widespread among Saccharomyces species. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Enzymatic activities produced by mixed Saccharomyces and non-Saccharomyces cultures: relationship with wine volatile composition.

    PubMed

    Maturano, Yolanda Paola; Assof, Mariela; Fabani, María Paula; Nally, María Cristina; Jofré, Viviana; Rodríguez Assaf, Leticia Anahí; Toro, María Eugenia; Castellanos de Figueroa, Lucía Inés; Vazquez, Fabio

    2015-11-01

    During certain wine fermentation processes, yeasts, and mainly non-Saccharomyces strains, produce and secrete enzymes such as β-glucosidases, proteases, pectinases, xylanases and amylases. The effects of enzyme activity on the aromatic quality of wines during grape juice fermentation, using different co-inoculation strategies of non-Saccharomyces and Saccharomyces cerevisiae yeasts, were assessed in the current study. Three strains with appropriate enological performance and high enzymatic activities, BSc562 (S. cerevisiae), BDv566 (Debaryomyces vanrijiae) and BCs403 (Candida sake), were assayed in pure and mixed Saccharomyces/non-Saccharomyces cultures. β-Glucosidase, pectinase, protease, xylanase and amylase activities were quantified during fermentations. The aromatic profile of pure and mixed cultures was determined at the end of each fermentation. In mixed cultures, non-Saccharomyces species were detected until day 4-5 of the fermentation process, and highest populations were observed in MSD2 (10% S. cerevisiae/90% D. vanrijiae) and MSC1 (1% S. cerevisiae/99% C. sake). According to correlation and multivariate analysis, MSD2 presented the highest concentrations of terpenes and higher alcohols which were associated with pectinase, amylase and xylanase activities. On the other hand, MSC1 high levels of β-glucosidase, proteolytic and xylanolytic activities were correlated to esters and fatty acids. Our study contributes to a better understanding of the effect of enzymatic activities by yeasts on compound transformations that occur during wine fermentation.

  1. Metabolic Adaptation to Nutrients Involves Coregulation of Gene Expression by the RNA Helicase Dbp2 and the Cyc8 Corepressor in Saccharomyces cerevisiae.

    PubMed

    Wang, Siwen; Xing, Zheng; Pascuzzi, Pete E; Tran, Elizabeth J

    2017-07-05

    Cells fine-tune their metabolic programs according to nutrient availability in order to maintain homeostasis. This is achieved largely through integrating signaling pathways and the gene expression program, allowing cells to adapt to nutritional change. Dbp2, a member of the DEAD-box RNA helicase family in Saccharomyces cerevisiae , has been proposed to integrate gene expression with cellular metabolism. Prior work from our laboratory has reported the necessity of DBP2 in proper gene expression, particularly for genes involved in glucose-dependent regulation. Here, by comparing differentially expressed genes in dbp2 ∆ to those of 700 other deletion strains from other studies, we find that CYC8 and TUP1 , which form a complex and inhibit transcription of numerous genes, corepress a common set of genes with DBP2 Gene ontology (GO) annotations reveal that these corepressed genes are related to cellular metabolism, including respiration, gluconeogenesis, and alternative carbon-source utilization genes. Consistent with a direct role in metabolic gene regulation, loss of either DBP2 or CYC8 results in increased cellular respiration rates. Furthermore, we find that corepressed genes have a propensity to be associated with overlapping long noncoding RNAs and that upregulation of these genes in the absence of DBP2 correlates with decreased binding of Cyc8 to these gene promoters. Taken together, this suggests that Dbp2 integrates nutrient availability with energy homeostasis by maintaining repression of glucose-repressed, Cyc8-targeted genes across the genome. Copyright © 2017 Wang et al.

  2. The YPR153W gene is essential for the pressure tolerance of tryptophan permease Tat2 in the yeast Saccharomyces cerevisiae

    NASA Astrophysics Data System (ADS)

    Kurosaka, Goyu; Abe, Fumiyoshi

    2018-01-01

    In the yeast Saccharomyces cerevisiae, hydrostatic pressure at 25 MPa is known to be nonlethal but significantly impairs the uptake of tryptophan by the permease Tat2, thereby inhibiting the growth of strains that require tryptophan from the medium. Here, we found that the lack of the YPR153W gene, so far poorly characterized for its role in yeast, caused a serious adverse effect on the growth at 10-25 MPa in the strain that required tryptophan. Deletion for YPR153W resulted in an increased rate of pressure-induced degradation of Tat2, suggesting that Tat2 is destabilized in the YPR153W deletion mutant at 25 MPa. Overexpression of the TAT2 gene enabled the deletion mutant to grow at 25 MPa. These results suggest that Ypr153w is essential for the stability and proper transport function of Tat2 under pressure at 10-25 MPa.

  3. Saccharomyces cerevisiae and metabolic activators: HXT3 gene expression and fructose/glucose discrepancy in sluggish fermentation conditions.

    PubMed

    Díaz-Hellín, Patricia; Naranjo, Victoria; Úbeda, Juan; Briones, Ana

    2016-12-01

    When exposed to mixtures of glucose and fructose, as occurs during the fermentation of grape juice into wine, Saccharomyces cerevisiae uses these sugars at different rates. Moreover, glucose and fructose are transported by the same hexose transporters (HXT), which present a greater affinity for glucose, so that late in fermentation, fructose becomes the predominant sugar. Only a few commercial fermentation activators are available to optimally solve the problems this entails. The aim of this study was to investigate the relation between HXT3 gene expression and fructose/glucose discrepancy in two different media inoculated with a commercial wine strain of S. cerevisiae in the presence of three metabolic activators. Fermentation kinetics, vitality and major metabolites were also measured. Rehydration with ergosterol improved the area under the curve and the growth rate (µ max ) in both studied media. Also, the fructose/glucose discrepancy values were improved with all activator treatments, highlighting rehydration in the presence of ascorbic acid. The yeast rehydration process was demonstrated to influence HXT3 expression under the studied conditions. Tetrahydrofolic acid treatment greatly influenced HXT3 gene expression, especially on the 12th day of the fermentation process. To a lesser extent, ergosterol and ascorbic acid also improved this parameter.

  4. Glucose-free fructose production from Jerusalem artichoke using a recombinant inulinase-secreting Saccharomyces cerevisiae strain.

    PubMed

    Yu, Jing; Jiang, Jiaxi; Ji, Wangming; Li, Yuyang; Liu, Jianping

    2011-01-01

    Using inulin (polyfructose) obtained from Jerusalen artichokes, we have produced fructose free of residual glucose using a recombinant inulinase-secreting strain of Saccharomyces cerevisiae in a one-step fermentation of Jerusalem artichoke tubers. For producing fructose from inulin, a recombinant inulinase-producing Saccharomyce cerevisiae strain was constructed with a deficiency in fructose uptake by disruption of two hexokinase genes hxk1 and hxk2. The inulinase gene introduced into S. cerevisiae was cloned from Kluyveromyces cicerisporus. Extracellular inulinase activity of the recombinant hxk-mutated S. cerevisiae strain reached 31 U ml(-1) after 96 h growth. When grown in a medium containing Jerusalem artichoke tubers as the sole component without any additives, the recombinant yeast accumulated fructose up to 9.2% (w/v) in the fermentation broth with only 0.1% (w/v) glucose left after 24 h.

  5. Changes of trehalose content and expression of relative genes during the bioethanol fermentation by Saccharomyces cerevisiae.

    PubMed

    Yi, Chenfeng; Wang, Fenglian; Dong, Shijun; Li, Hao

    2016-10-01

    Traditionally, trehalose is considered as a protectant to improve the ethanol tolerance of Saccharomyces cerevisiae. In this study, to clarify the changes and roles of trehalose during the bioethanol fermentation, trehalose content and expression of related genes at lag, exponential, and stationary phases (i.e., 2, 8, and 16 h of batch fermentation process) were determined. Although yeast cells at exponential and stationary phase had higher trehalose content than cells at lag phase (P < 0.01), there was no significant difference in trehalose content between exponential and stationary phases (P > 0.05). Moreover, expression of the trehalose degradation-related genes NTH1 and NTH2 decreased at exponential phase in comparison with that at lag phase; compared with cells at lag phase, cells at stationary phase had higher expression of TPS1, ATH1, NTH1, and NTH2 but lower expression of TPS2. During the lag-exponential phase transition, downregulation of NTH1 and NTH2 promoted accumulation of trehalose, and to some extent, trehalose might confer ethanol tolerance to S. cerevisiae before stationary phase. During the exponential-stationary phase transition, upregulation of TPS1 contributed to accumulation of trehalose, and Tps1 protein might be indispensable in yeast cells to withstand ethanol stress at the stationary phase. Moreover, trehalose would be degraded to supply carbon source at stationary phase.

  6. Finding functional features in Saccharomyces genomes by phylogenetic footprinting.

    PubMed

    Cliften, Paul; Sudarsanam, Priya; Desikan, Ashwin; Fulton, Lucinda; Fulton, Bob; Majors, John; Waterston, Robert; Cohen, Barak A; Johnston, Mark

    2003-07-04

    The sifting and winnowing of DNA sequence that occur during evolution cause nonfunctional sequences to diverge, leaving phylogenetic footprints of functional sequence elements in comparisons of genome sequences. We searched for such footprints among the genome sequences of six Saccharomyces species and identified potentially functional sequences. Comparison of these sequences allowed us to revise the catalog of yeast genes and identify sequence motifs that may be targets of transcriptional regulatory proteins. Some of these conserved sequence motifs reside upstream of genes with similar functional annotations or similar expression patterns or those bound by the same transcription factor and are thus good candidates for functional regulatory sequences.

  7. Mixing of vineyard and oak-tree ecotypes of Saccharomyces cerevisiae in North American vineyards.

    PubMed

    Hyma, Katie E; Fay, Justin C

    2013-06-01

    Humans have had a significant impact on the distribution and abundance of Saccharomyces cerevisiae through its widespread use in beer, bread and wine production. Yet, similar to other Saccharomyces species, S. cerevisiae has also been isolated from habitats unrelated to fermentations. Strains of S. cerevisiae isolated from grapes, wine must and vineyards worldwide are genetically differentiated from strains isolated from oak-tree bark, exudate and associated soil in North America. However, the causes and consequences of this differentiation have not yet been resolved. Historical differentiation of these two groups may have been influenced by geographic, ecological or human-associated barriers to gene flow. Here, we make use of the relatively recent establishment of vineyards across North America to identify and characterize any active barriers to gene flow between these two groups. We examined S. cerevisiae strains isolated from grapes and oak trees within three North American vineyards and compared them to those isolated from oak trees outside of vineyards. Within vineyards, we found evidence of migration between grapes and oak trees and potential gene flow between the divergent oak-tree and vineyard groups. Yet, we found no vineyard genotypes on oak trees outside of vineyards. In contrast, Saccharomyces paradoxus isolated from the same sources showed population structure characterized by isolation by distance. The apparent absence of ecological or genetic barriers between sympatric vineyard and oak-tree populations of S. cerevisiae implies that vineyards play an important role in the mixing between these two groups. © 2013 John Wiley & Sons Ltd.

  8. A synthetic hybrid promoter for xylose-regulated control of gene expression in Saccharomyces yeasts

    USDA-ARS?s Scientific Manuscript database

    Metabolism of non-glucose carbon sources is often highly regulated at the transcriptional and post-translational levels. This level of regulation is lacking in Saccharomyces cerevisiae strains engineered to metabolize xylose. To better control transcription in S. cerevisiae, the xylose-dependent, DN...

  9. Identification and classification of genes required for tolerance to high-sucrose stress revealed by genome-wide screening of Saccharomyces cerevisiae.

    PubMed

    Ando, Akira; Tanaka, Fumiko; Murata, Yoshinori; Takagi, Hiroshi; Shima, Jun

    2006-03-01

    Yeasts used in bread making are exposed to high concentrations of sucrose during sweet dough fermentation. Despite its importance, tolerance to high-sucrose stress is poorly understood at the gene level. To clarify the genes required for tolerance to high-sucrose stress, genome-wide screening was undertaken using the complete deletion strain collection of diploid Saccharomyces cerevisiae. The screening identified 273 deletions that yielded high sucrose sensitivity, approximately 20 of which were previously uncharacterized. These 273 deleted genes were classified based on their cellular function and localization of their gene products. Cross-sensitivity of the high-sucrose-sensitive mutants to high concentrations of NaCl and sorbitol was studied. Among the 273 sucrose-sensitive deletion mutants, 269 showed cross-sensitivities to sorbitol or NaCl, and four (i.e. ade5,7, ade6, ade8, and pde2) were specifically sensitive to high sucrose. The general stress response pathways via high-osmolarity glycerol and stress response element pathways and the function of the invertase in the ade mutants were similar to those in the wild-type strain. In the presence of high-sucrose stress, intracellular contents of ATP in ade mutants were at least twofold lower than that of the wild-type cells, suggesting that depletion of ATP is a factor in sensitivity to high-sucrose stress. The genes identified in this study might be important for tolerance to high-sucrose stress, and therefore should be target genes in future research into molecular modification for breeding of yeast tolerant to high-sucrose stress.

  10. Enhanced enzymatic activity of glycerol-3-phosphate dehydrogenase from the cryophilic Saccharomyces kudriavzevii.

    PubMed

    Oliveira, Bruno M; Barrio, Eladio; Querol, Amparo; Pérez-Torrado, Roberto

    2014-01-01

    During the evolution of the different species classified within the Saccharomyces genus, each one has adapted to live in different environments. One of the most important parameters that have influenced the evolution of Saccharomyces species is the temperature. Here we have focused on the study of the ability of certain species as Saccharomyces kudriavzevii to grow at low temperatures, in contrast to Saccharomyces cerevisiae. We observed that S. kudriavzevii strains isolated from several regions are able to synthesize higher amounts of glycerol, a molecule that has been shown to accumulate in response to freeze and cold stress. To explain this observation at the molecular level we studied the expression of glycerol biosynthetic pathway genes and we observed a higher expression of GPD1 gene in S. kudriavzevii compared to S. cerevisiae in micro-vinification conditions. We observed higher enzymatic activity of Gpd1p in S. kudriavzevii in response to osmotic and cold stress. Also, we determined that S. kudriavzevii Gpd1p enzyme presents increased catalytic properties that will contribute to increase glycerol production. Finally, we evaluated the glycerol production with S. cerevisiae, S. kudriavzevii or a recombinant Gpd1p variant in the same background and observed that the S. kudriavzevii enzyme produced increased glycerol levels at 12 or 28°C. This suggests that glycerol is increased in S. kudriavzevii mainly due to increased V max of the Gpd1p enzyme. All these differences indicate that S. kudriavzevii has changed the metabolism to promote the branch of the glycolytic pathway involved in glycerol production to adapt to low temperature environments and maintain the NAD(+)/NADH ratio in alcoholic fermentations. This knowledge is industrially relevant due to the potential use, for example, of S. cerevisiae-S. kudriavzevii hybrids in the wine industry where glycerol content is an important quality parameter.

  11. Steady-state and dynamic gene expression programs in Saccharomyces cerevisiae in response to variation in environmental nitrogen

    PubMed Central

    Airoldi, Edoardo M.; Miller, Darach; Athanasiadou, Rodoniki; Brandt, Nathan; Abdul-Rahman, Farah; Neymotin, Benjamin; Hashimoto, Tatsu; Bahmani, Tayebeh; Gresham, David

    2016-01-01

    Cell growth rate is regulated in response to the abundance and molecular form of essential nutrients. In Saccharomyces cerevisiae (budding yeast), the molecular form of environmental nitrogen is a major determinant of cell growth rate, supporting growth rates that vary at least threefold. Transcriptional control of nitrogen use is mediated in large part by nitrogen catabolite repression (NCR), which results in the repression of specific transcripts in the presence of a preferred nitrogen source that supports a fast growth rate, such as glutamine, that are otherwise expressed in the presence of a nonpreferred nitrogen source, such as proline, which supports a slower growth rate. Differential expression of the NCR regulon and additional nitrogen-responsive genes results in >500 transcripts that are differentially expressed in cells growing in the presence of different nitrogen sources in batch cultures. Here we find that in growth rate–controlled cultures using nitrogen-limited chemostats, gene expression programs are strikingly similar regardless of nitrogen source. NCR expression is derepressed in all nitrogen-limiting chemostat conditions regardless of nitrogen source, and in these conditions, only 34 transcripts exhibit nitrogen source–specific differential gene expression. Addition of either the preferred nitrogen source, glutamine, or the nonpreferred nitrogen source, proline, to cells growing in nitrogen-limited chemostats results in rapid, dose-dependent repression of the NCR regulon. Using a novel means of computational normalization to compare global gene expression programs in steady-state and dynamic conditions, we find evidence that the addition of nitrogen to nitrogen-limited cells results in the transient overproduction of transcripts required for protein translation. Simultaneously, we find that that accelerated mRNA degradation underlies the rapid clearing of a subset of transcripts, which is most pronounced for the highly expressed NCR

  12. Saccharomyces and non-Saccharomyces Competition during Microvinification under Different Sugar and Nitrogen Conditions

    PubMed Central

    Lleixà, Jessica; Manzano, Maria; Mas, Albert; Portillo, María del C.

    2016-01-01

    The inoculation of wines with autochthonous yeast allows obtaining complex wines with a peculiar microbial footprint characteristic from a wine region. Mixed inoculation of non-Saccharomyces yeasts and S. cerevisiae is of interest for the wine industry for technological and sensory reasons. However, the interactions between these yeasts are not well understood, especially those regarding the availability of nutrients. The aim of the present study was to analyze the effect of nitrogen and sugar concentration on the evolution of mixed yeast populations on controlled laboratory-scale fermentations monitored by density, plate culturing, PCR-DGGE and sugar and nitrogen consumption. Furthermore, the effect of the time of inoculation of Saccharomyces cerevisiae respect the initial co-inoculation of three non-Saccharomyces yeasts was evaluated over the evolution of fermentation. Our results have shown that S. cerevisiae inoculation during the first 48 h conferred a stabilizing effect over the fermentations with non-Saccharomyces strains tested and, generally, reduced yeast diversity at the end of the fermentation. On the other hand, nitrogen limitation increased the time of fermentation and also the proportion of non-Saccharomyces yeasts at mid and final fermentation. High sugar concentration resulted in different proportions of the inoculated yeast depending on the time of S. cerevisiae inoculation. This work emphasizes the importance of the concentration of nutrients on the evolution of mixed fermentations and points to the optimal conditions for a stable fermentation in which the inoculated yeasts survived until the end. PMID:27994585

  13. Many Saccharomyces cerevisiae Cell Wall Protein Encoding Genes Are Coregulated by Mss11, but Cellular Adhesion Phenotypes Appear Only Flo Protein Dependent.

    PubMed

    Bester, Michael C; Jacobson, Dan; Bauer, Florian F

    2012-01-01

    The outer cell wall of the yeast Saccharomyces cerevisiae serves as the interface with the surrounding environment and directly affects cell-cell and cell-surface interactions. Many of these interactions are facilitated by specific adhesins that belong to the Flo protein family. Flo mannoproteins have been implicated in phenotypes such as flocculation, substrate adhesion, biofilm formation, and pseudohyphal growth. Genetic data strongly suggest that individual Flo proteins are responsible for many specific cellular adhesion phenotypes. However, it remains unclear whether such phenotypes are determined solely by the nature of the expressed FLO genes or rather as the result of a combination of FLO gene expression and other cell wall properties and cell wall proteins. Mss11 has been shown to be a central element of FLO1 and FLO11 gene regulation and acts together with the cAMP-PKA-dependent transcription factor Flo8. Here we use genome-wide transcription analysis to identify genes that are directly or indirectly regulated by Mss11. Interestingly, many of these genes encode cell wall mannoproteins, in particular, members of the TIR and DAN families. To examine whether these genes play a role in the adhesion properties associated with Mss11 expression, we assessed deletion mutants of these genes in wild-type and flo11Δ genetic backgrounds. This analysis shows that only FLO genes, in particular FLO1/10/11, appear to significantly impact on such phenotypes. Thus adhesion-related phenotypes are primarily dependent on the balance of FLO gene expression.

  14. Formation of AAV Single Stranded DNA Genome from a Circular Plasmid in Saccharomyces cerevisiae

    PubMed Central

    Cervelli, Tiziana; Backovic, Ana; Galli, Alvaro

    2011-01-01

    Adeno-associated virus (AAV)-based vectors are promising tools for targeted transfer in gene therapy studies. Many efforts have been accomplished to improve production and purification methods. We thought to develop a simple eukaryotic system allowing AAV replication which could provide an excellent opportunity for studying AAV biology and, more importantly, for AAV vector production. It has been shown that yeast Saccharomyces cerevisiae is able to replicate and form the capsid of many viruses. We investigated the ability of the yeast Saccharomyces cerevisiae to carry out the replication of a recombinant AAV (rAAV). When a plasmid containing a rAAV genome in which the cap gene was replaced with the S. cerevisiae URA3 gene, was co-transformed in yeast with a plasmid expressing Rep68, a significant number of URA3+ clones were scored (more than 30-fold over controls). Molecular analysis of low molecular weight DNA by Southern blotting revealed that single stranded DNA is formed and that the plasmid is entirely replicated. The ssDNA contains the ITRs, URA3 gene and also vector sequences suggesting the presence of two distinct molecules. Its formation was dependent on Rep68 expression and ITR. These data indicate that DNA is not obtained by the canonical AAV replication pathway. PMID:21853137

  15. Formation of AAV single stranded DNA genome from a circular plasmid in Saccharomyces cerevisiae.

    PubMed

    Cervelli, Tiziana; Backovic, Ana; Galli, Alvaro

    2011-01-01

    Adeno-associated virus (AAV)-based vectors are promising tools for targeted transfer in gene therapy studies. Many efforts have been accomplished to improve production and purification methods. We thought to develop a simple eukaryotic system allowing AAV replication which could provide an excellent opportunity for studying AAV biology and, more importantly, for AAV vector production. It has been shown that yeast Saccharomyces cerevisiae is able to replicate and form the capsid of many viruses. We investigated the ability of the yeast Saccharomyces cerevisiae to carry out the replication of a recombinant AAV (rAAV). When a plasmid containing a rAAV genome in which the cap gene was replaced with the S. cerevisiae URA3 gene, was co-transformed in yeast with a plasmid expressing Rep68, a significant number of URA3(+) clones were scored (more than 30-fold over controls). Molecular analysis of low molecular weight DNA by Southern blotting revealed that single stranded DNA is formed and that the plasmid is entirely replicated. The ssDNA contains the ITRs, URA3 gene and also vector sequences suggesting the presence of two distinct molecules. Its formation was dependent on Rep68 expression and ITR. These data indicate that DNA is not obtained by the canonical AAV replication pathway.

  16. The new modern era of yeast genomics: community sequencing and the resulting annotation of multiple Saccharomyces cerevisiae strains at the Saccharomyces Genome Database

    PubMed Central

    Engel, Stacia R.; Cherry, J. Michael

    2013-01-01

    The first completed eukaryotic genome sequence was that of the yeast Saccharomyces cerevisiae, and the Saccharomyces Genome Database (SGD; http://www.yeastgenome.org/) is the original model organism database. SGD remains the authoritative community resource for the S. cerevisiae reference genome sequence and its annotation, and continues to provide comprehensive biological information correlated with S. cerevisiae genes and their products. A diverse set of yeast strains have been sequenced to explore commercial and laboratory applications, and a brief history of those strains is provided. The publication of these new genomes has motivated the creation of new tools, and SGD will annotate and provide comparative analyses of these sequences, correlating changes with variations in strain phenotypes and protein function. We are entering a new era at SGD, as we incorporate these new sequences and make them accessible to the scientific community, all in an effort to continue in our mission of educating researchers and facilitating discovery. Database URL: http://www.yeastgenome.org/ PMID:23487186

  17. Sun-Earth Day: Exposing the Public to Sun-Earth Connection Science

    NASA Astrophysics Data System (ADS)

    Thieman, J. R.; Lewis, E.; Cline, T.

    2001-12-01

    The year 2001 marked the first observance of Sun-Earth Day as an event to celebrate the strong interconnection of the life we have on Earth and the dependence of it on the dynamic influence of the Sun. The science of the Sun-Earth Connection has grown dramatically with new satellite and ground-based studies of the Sun and the Sun's extended "atmosphere" in which we live. Space weather is becoming a more common concept that people know can affect their lives. An understanding of the importance of the Sun's dynamic behavior and how this shapes the solar system and especially the Earth is the aim of Sun-Earth Day. The first Sun-Earth event actually took place over two days, April 27 and 28, 2001, in order to accommodate all the events which were planned both in the classroom on Friday the 27th and in more informal settings on Saturday the 28th. The Sun-Earth Connection Education Forum (SECEF) organized the creation of ten thousand packets of educational materials about Sun-Earth Day and distributed them mostly to teachers who were trained to use them in the classroom. Many packets, however, went to science centers, museums, and planetariums as resource materials for programs associated with Sun-Earth Day. Over a hundred scientists used the event as an opportunity to communicate their love of science to audiences in these informal settings. Sun-Earth Day was also greatly assisted by the Amateur Astronomical Society which used the event as a theme for their annual promotion of astronomy in programs given around the country. The Solar and Heliospheric Observatory (SOHO), a satellite mission jointly sponsored by NASA and the European Space Agency (ESA), used Sun-Earth Day in conjunction with the fifth anniversary celebration of SOHO as a basis for many programs and events, especially a large number of happenings in Europe. These included observing parties, art exhibits, demonstrations, etc. Examples of some of the innovative ways that Sun-Earth Day was brought into people

  18. Mitochondrial DNA deletion percentage in sun exposed and non sun exposed skin.

    PubMed

    Powers, Julia M; Murphy, Gillian; Ralph, Nikki; O'Gorman, Susan M; Murphy, James E J

    2016-12-01

    The percentages of mitochondrial genomes carrying the mtDNA 3895 and the mtDNA 4977 (common) deletion were quantified in sun exposed and non sun exposed skin biopsies, for five cohorts of patients varying either in sun exposure profile, age or skin cancer status. Non-melanoma skin cancer diagnoses are rising in Ireland and worldwide [12] but most risk prediction is based on subjective visual estimations of sun exposure history. A quantitative objective test for pre-neoplastic markers may result in better adherence to sun protective behaviours. Mitochondrial DNA (mtDNA) is known to be subject to the loss of a significant proportion of specific sections of genetic code due to exposure to ultraviolet light in sunlight. Although one such deletion has been deemed more sensitive, another, called the mtDNA 4977 or common deletion, has proved to be a more useful indicator of possible risk in this study. Quantitative molecular analysis was carried out to determine the percentage of genomes carrying the deletion using non sun exposed and sun exposed skin biopsies in cohorts of patients with high or low sun exposure profiles and two high exposure groups undergoing treatment for NMSC. Results indicate that mtDNA deletions correlate to sun exposure; in groups with high sun exposure habits a significant increase in deletion number in exposed over non sun exposed skin occurred. An increase in deletion percentage was also seen in older cohorts compared to the younger group. The mtDNA 3895 deletion was detected in small amounts in exposed skin of many patients, the mtDNA 4977 common deletion, although present to some extent in non sun exposed skin, is suggested to be the more reliable and easily detected marker. In all cohorts except the younger group with relatively lower sun exposure, the mtDNA 4977 deletion was more frequent in sun exposed skin samples compared to non-sun exposed skin. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Sun Savvy Students: Free Teaching Resources from EPA's SunWise Program

    ERIC Educational Resources Information Center

    Hall-Jordan, Luke

    2008-01-01

    With summer in full swing and the sun is naturally on our minds, what better time to take advantage of a host of free materials provided by the U.S. Environmental Protection Agency's Sun Wise program. Sun Wise aims to teach students and teachers about the stratospheric ozone layer, ultraviolet (UV) radiation, and how to be safe while in the Sun.…

  20. A Gondwanan imprint on global diversity and domestication of wine and cider yeast Saccharomyces uvarum

    NASA Astrophysics Data System (ADS)

    Almeida, Pedro; Gonçalves, Carla; Teixeira, Sara; Libkind, Diego; Bontrager, Martin; Masneuf-Pomarède, Isabelle; Albertin, Warren; Durrens, Pascal; Sherman, David James; Marullo, Philippe; Todd Hittinger, Chris; Gonçalves, Paula; Sampaio, José Paulo

    2014-06-01

    In addition to Saccharomyces cerevisiae, the cryotolerant yeast species S. uvarum is also used for wine and cider fermentation but nothing is known about its natural history. Here we use a population genomics approach to investigate its global phylogeography and domestication fingerprints using a collection of isolates obtained from fermented beverages and from natural environments on five continents. South American isolates contain more genetic diversity than that found in the Northern Hemisphere. Moreover, coalescence analyses suggest that a Patagonian sub-population gave rise to the Holarctic population through a recent bottleneck. Holarctic strains display multiple introgressions from other Saccharomyces species, those from S. eubayanus being prevalent in European strains associated with human-driven fermentations. These introgressions are absent in the large majority of wild strains and gene ontology analyses indicate that several gene categories relevant for wine fermentation are overrepresented. Such findings constitute a first indication of domestication in S. uvarum.

  1. Global mapping of DNA conformational flexibility on Saccharomyces cerevisiae.

    PubMed

    Menconi, Giulia; Bedini, Andrea; Barale, Roberto; Sbrana, Isabella

    2015-04-01

    In this study we provide the first comprehensive map of DNA conformational flexibility in Saccharomyces cerevisiae complete genome. Flexibility plays a key role in DNA supercoiling and DNA/protein binding, regulating DNA transcription, replication or repair. Specific interest in flexibility analysis concerns its relationship with human genome instability. Enrichment in flexible sequences has been detected in unstable regions of human genome defined fragile sites, where genes map and carry frequent deletions and rearrangements in cancer. Flexible sequences have been suggested to be the determinants of fragile gene proneness to breakage; however, their actual role and properties remain elusive. Our in silico analysis carried out genome-wide via the StabFlex algorithm, shows the conserved presence of highly flexible regions in budding yeast genome as well as in genomes of other Saccharomyces sensu stricto species. Flexibile peaks in S. cerevisiae identify 175 ORFs mapping on their 3'UTR, a region affecting mRNA translation, localization and stability. (TA)n repeats of different extension shape the central structure of peaks and co-localize with polyadenylation efficiency element (EE) signals. ORFs with flexible peaks share common features. Transcripts are characterized by decreased half-life: this is considered peculiar of genes involved in regulatory systems with high turnover; consistently, their function affects biological processes such as cell cycle regulation or stress response. Our findings support the functional importance of flexibility peaks, suggesting that the flexible sequence may be derived by an expansion of canonical TAYRTA polyadenylation efficiency element. The flexible (TA)n repeat amplification could be the outcome of an evolutionary neofunctionalization leading to a differential 3'-end processing and expression regulation in genes with peculiar function. Our study provides a new support to the functional role of flexibility in genomes and a

  2. Global Mapping of DNA Conformational Flexibility on Saccharomyces cerevisiae

    PubMed Central

    Menconi, Giulia; Bedini, Andrea; Barale, Roberto; Sbrana, Isabella

    2015-01-01

    In this study we provide the first comprehensive map of DNA conformational flexibility in Saccharomyces cerevisiae complete genome. Flexibility plays a key role in DNA supercoiling and DNA/protein binding, regulating DNA transcription, replication or repair. Specific interest in flexibility analysis concerns its relationship with human genome instability. Enrichment in flexible sequences has been detected in unstable regions of human genome defined fragile sites, where genes map and carry frequent deletions and rearrangements in cancer. Flexible sequences have been suggested to be the determinants of fragile gene proneness to breakage; however, their actual role and properties remain elusive. Our in silico analysis carried out genome-wide via the StabFlex algorithm, shows the conserved presence of highly flexible regions in budding yeast genome as well as in genomes of other Saccharomyces sensu stricto species. Flexibile peaks in S. cerevisiae identify 175 ORFs mapping on their 3’UTR, a region affecting mRNA translation, localization and stability. (TA)n repeats of different extension shape the central structure of peaks and co-localize with polyadenylation efficiency element (EE) signals. ORFs with flexible peaks share common features. Transcripts are characterized by decreased half-life: this is considered peculiar of genes involved in regulatory systems with high turnover; consistently, their function affects biological processes such as cell cycle regulation or stress response. Our findings support the functional importance of flexibility peaks, suggesting that the flexible sequence may be derived by an expansion of canonical TAYRTA polyadenylation efficiency element. The flexible (TA)n repeat amplification could be the outcome of an evolutionary neofunctionalization leading to a differential 3’-end processing and expression regulation in genes with peculiar function. Our study provides a new support to the functional role of flexibility in genomes and a

  3. A mutated ARO4 gene for feedback-resistant DAHP synthase which causes both o-fluoro-DL-phenylalanine resistance and beta-phenethyl-alcohol overproduction in Saccharomyces cerevisiae.

    PubMed

    Fukuda, K; Watanabe, M; Asano, K; Ouchi, K; Takasawa, S

    1991-12-01

    o-Fluoro-DL-phenylalanine (OFP)-resistant mutants which overproduce beta-phenethyl-alcohol were isolated from a laboratory strain of Saccharomyces cerevisiae. Cells of one of the mutants accumulated tyrosine and phenylalanine 1.5-3 fold more than did wild-type cells. Its 3-deoxy-D-arabino-hepturosonate-7-phosphate (DAHP) synthase (EC 4.1.2.15), encoded by ARO4, was free from feedback inhibition by tyrosine. Genetic analysis revealed that the mutation was controlled by a single dominant gene, ARO4-OFP, encoding feedback-resistant DAHP synthase by tyrosine, and that this gene caused both the OFP resistance and beta-phenethyl-alcohol overproduction. This was supported by molecular genetic studies using cloned ARO4 both from the wild-type and its mutant strain.

  4. Sun behaviour in Canadian children: results of the 2006 National Sun Survey.

    PubMed

    Pichora, Erin C; Marrett, Loraine D

    2010-01-01

    Childhood sun exposure is a particularly important determinant of skin cancer, yet little data are available for children. This paper describes sun behaviour among Canadian children for the summer of 2006. As part of the Second National Sun Survey (NSS2), 1,437 parents reported on the time spent in the sun, and the frequency of sun protection behaviours and sunburning for one of their children aged 1 to 12 years. Analysis was carried out using complex survey procedures in SAS and STATA. The majority of children (94%) spend at least 30 minutes in the sun on a typical summer day; however, regular sun protection is only commonly reported for young children (1 to 5 years) and involves covering their heads and wearing sunscreen (85%). The frequency of other protective behaviours is much lower, and sun protection decreases with age. Older children are also twice as likely to spend extended time in the sun and to get a sunburn. Among older children, boys are more likely to cover their heads and girls are more likely to wear sunscreen. Regular sun protection among Canadian children is low, given their sun exposure. Heavy reliance on sunscreen is consistent with previous reports and indicates that other measures, such as seeking shade and wearing protective clothing, need to be promoted. Riskier sun behaviour among older children may reflect decreased parental control, as well as changing attitudes and peer pressure, and highlights the importance of adult role models and targeted interventions for this age group.

  5. Impact of oxygenation on the performance of three non-Saccharomyces yeasts in co-fermentation with Saccharomyces cerevisiae.

    PubMed

    Shekhawat, Kirti; Bauer, Florian F; Setati, Mathabatha E

    2017-03-01

    The sequential or co-inoculation of grape must with non-Saccharomyces yeast species and Saccharomyces cerevisiae wine yeast strains has recently become a common practice in winemaking. The procedure intends to enhance unique aroma and flavor profiles of wine. The extent of the impact of non-Saccharomyces strains depends on their ability to produce biomass and to remain metabolically active for a sufficiently long period. However, mixed-culture wine fermentations tend to become rapidly dominated by S. cerevisiae, reducing or eliminating the non-Saccharomyces yeast contribution. For an efficient application of these yeasts, it is therefore essential to understand the environmental factors that modulate the population dynamics of such ecosystems. Several environmental parameters have been shown to influence population dynamics, but their specific effect remains largely uncharacterized. In this study, the population dynamics in co-fermentations of S. cerevisiae and three non-Saccharomyces yeast species: Torulaspora delbrueckii, Lachancea thermotolerans, and Metschnikowia pulcherrima, was investigated as a function of oxygen availability. In all cases, oxygen availability strongly influenced population dynamics, but clear species-dependent differences were observed. Our data show that L. thermotolerans required the least oxygen, followed by T. delbrueckii and M. pulcherrima. Distinct species-specific chemical volatile profiles correlated in all cases with increased persistence of non-Saccharomyces yeasts, in particular increases in some higher alcohols and medium chain fatty acids. The results highlight the role of oxygen in regulating the succession of yeasts during wine fermentations and suggests that more stringent aeration strategies would be necessary to support the persistence of non-Saccharomyces yeasts in real must fermentations.

  6. Saccharomyces Boulardii

    MedlinePlus

    ... blisters. High cholesterol. Hives. Lactose intolerance. Lyme disease. Urinary tract infections (UTIs). Yeast infections. Other conditions. More evidence is needed to rate Saccharomyces boulardii for these uses.

  7. Vitamin D Beliefs and Associations with Sunburns, Sun Exposure, and Sun Protection

    PubMed Central

    Kim, Bang Hyun; Glanz, Karen; Nehl, Eric J.

    2012-01-01

    The main objective of this study was to examine certain beliefs about vitamin D and associations with sun exposure, sun protection behaviors, and sunburns. A total of 3,922 lifeguards, pool managers, and parents completed a survey in 2006 about beliefs regarding vitamin D and sun-related behaviors. Multivariate ordinal regression analyses and linear regression analysis were used to examine associations of beliefs and other variables. Results revealed that Non-Caucasian lifeguards and pool managers were less likely to agree that they needed to go out in the sun to get enough vitamin D. Lifeguards and parents who were non-Caucasian were less likely to report that sunlight helped the body to produce vitamin D. A stronger belief about the need to go out in the sun to get enough vitamin D predicted more sun exposure for lifeguards. For parents, a stronger belief that they can get enough vitamin D from foods predicted greater sun protection and a stronger belief that sunlight helps the body produce vitamin D predicted lower sun exposure. This study provides information regarding vitamin D beliefs and their association with certain sun related behaviors across different demographic groups that can inform education efforts about vitamin D and sun protection. PMID:22851950

  8. Mitochondrial introgression suggests extensive ancestral hybridization events among Saccharomyces species.

    PubMed

    Peris, David; Arias, Armando; Orlić, Sandi; Belloch, Carmela; Pérez-Través, Laura; Querol, Amparo; Barrio, Eladio

    2017-03-01

    Horizontal gene transfer (HGT) in eukaryotic plastids and mitochondrial genomes is common, and plays an important role in organism evolution. In yeasts, recent mitochondrial HGT has been suggested between S. cerevisiae and S. paradoxus. However, few strains have been explored given the lack of accurate mitochondrial genome annotations. Mitochondrial genome sequences are important to understand how frequent these introgressions occur, and their role in cytonuclear incompatibilities and fitness. Indeed, most of the Bateson-Dobzhansky-Muller genetic incompatibilities described in yeasts are driven by cytonuclear incompatibilities. We herein explored the mitochondrial inheritance of several worldwide distributed wild Saccharomyces species and their hybrids isolated from different sources and geographic origins. We demonstrated the existence of several recombination points in mitochondrial region COX2-ORF1, likely mediated by either the activity of the protein encoded by the ORF1 (F-SceIII) gene, a free-standing homing endonuclease, or mostly facilitated by A+T tandem repeats and regions of integration of GC clusters. These introgressions were shown to occur among strains of the same species and among strains of different species, which suggests a complex model of Saccharomyces evolution that involves several ancestral hybridization events in wild environments. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Sun exposure, sun protection and sunburn among Canadian adults.

    PubMed

    Pinault, Lauren; Fioletov, Vitali

    2017-05-17

    Ultraviolet radiation (UVR) exposure and a history of sunburn are important risk factors for skin cancer. Sunburn is more common among men, younger age groups, and people in higher income households. Sun protection measures also vary by sex, age, and socioeconomic characteristics. Associations between ambient UVR and sunburn and sun safety measures have not been quantified. A total of 53,130 respondents aged 18 or older answered a Canadian Community Health Survey (CCHS) module on sun safety, which was administered in six provinces from 2005 to 2014. The module contained questions about sunburn, time in the sun, and sun protection. These respondents were linked to an ambient erythemal UVR dataset representing the June-to-August mean. Descriptive statistics and logistic regression were used to examine associations between population characteristics, sunburn, sun safety, time in the sun, and ambient UVR. Sunburn was reported by 33% of respondents and was more common among men, younger age groups, people who were not members of visible minorities, residents of higher income households, and individuals who were employed. On a typical summer day, a larger percentage of women than men sought shade and wore sunscreen, whereas a larger percentage of men wore a hat or long pants. As ambient summer UVR increased, women were more likely to apply sunscreen to their face, seek shade, or wear a hat (OR~1.02 to 1.09 per increase of 187 J/m² of erythemally-weighted UVR, or 5.4% of the mean); these associations were not observed among men. Findings related to sunburn and sun protection were similar to those of previous studies. The association between ambient UVR and women's precautionary measures suggests that information about UVR may influence their decision to protect their skin.

  10. Using the Saccharomyces Genome Database (SGD) for analysis of genomic information

    PubMed Central

    Skrzypek, Marek S.; Hirschman, Jodi

    2011-01-01

    Analysis of genomic data requires access to software tools that place the sequence-derived information in the context of biology. The Saccharomyces Genome Database (SGD) integrates functional information about budding yeast genes and their products with a set of analysis tools that facilitate exploring their biological details. This unit describes how the various types of functional data available at SGD can be searched, retrieved, and analyzed. Starting with the guided tour of the SGD Home page and Locus Summary page, this unit highlights how to retrieve data using YeastMine, how to visualize genomic information with GBrowse, how to explore gene expression patterns with SPELL, and how to use Gene Ontology tools to characterize large-scale datasets. PMID:21901739

  11. Microaerobic glycerol formation in Saccharomyces cerevisiae.

    PubMed

    Costenoble, R; Valadi, H; Gustafsson, L; Niklasson, C; Franzén, C J

    2000-12-01

    The yeast Saccharomyces cerevisiae produces large amounts of glycerol as an osmoregulator during hyperosmotic stress and as a redox sink at low oxygen availability. NAD(+)-dependent glycerol-3-phosphate dehydrogenase in S. cerevisiae is present in two isoforms, coded for by two different genes, GPD1 and GPD2. Mutants for either one or both of these genes were investigated under carefully controlled static and dynamic conditions in continuous cultures at low oxygen transfer rates. Our results show that S. cerevisiae controls the production of glycerol in response to hypoxic conditions by regulating the expression of several genes. At high demand for NADH reoxidation, a strong induction was seen not only of the GPD2 gene, but also of GPP1, encoding one of the molecular forms of glycerol-3-phosphatase. Induction of the GPP1 gene appears to play a decisive role at elevated growth rates. At low demand for NADH reoxidation via glycerol formation, the GPD1, GPD2, GPP1, and GPP2 genes were all expressed at basal levels. The dynamics of the gene induction and the glycerol formation at low demand for NADH reoxidation point to an important role of the Gpd1p; deletion of the GPD1 gene strongly altered the expression patterns of the GPD2 and GPP1 genes under such conditions. Furthermore, our results indicate that GCY1 and DAK1, tentatively encoding glycerol dehydrogenase and dihydroxyacetone kinase, respectively, may be involved in the redox regulation of S. cerevisiae. Copyright 2000 John Wiley & Sons, Ltd.

  12. Promoter architecture and transcriptional regulation of Abf1-dependent ribosomal protein genes in Saccharomyces cerevisiae

    PubMed Central

    Fermi, Beatrice; Bosio, Maria Cristina; Dieci, Giorgio

    2016-01-01

    In Saccharomyces cerevisiae, ribosomal protein gene (RPG) promoters display binding sites for either Rap1 or Abf1 transcription factors. Unlike Rap1-associated promoters, the small cohort of Abf1-dependent RPGs (Abf1-RPGs) has not been extensively investigated. We show that RPL3, RPL4B, RPP1A, RPS22B and RPS28A/B share a common promoter architecture, with an Abf1 site upstream of a conserved element matching the sequence recognized by Fhl1, a transcription factor which together with Ifh1 orchestrates Rap1-associated RPG regulation. Abf1 and Fhl1 promoter association was confirmed by ChIP and/or gel retardation assays. Mutational analysis revealed a more severe requirement of Abf1 than Fhl1 binding sites for RPG transcription. In the case of RPS22B an unusual Tbf1 binding site promoted both RPS22B and intron-hosted SNR44 expression. Abf1-RPG down-regulation upon TOR pathway inhibition was much attenuated at defective mutant promoters unable to bind Abf1. TORC1 inactivation caused the expected reduction of Ifh1 occupancy at RPS22B and RPL3 promoters, but unexpectedly it entailed largely increased Abf1 association with Abf1-RPG promoters. We present evidence that Abf1 recruitment upon nutritional stress, also observed for representative ribosome biogenesis genes, favours RPG transcriptional rescue upon nutrient replenishment, thus pointing to nutrient-regulated Abf1 dynamics at promoters as a novel mechanism in ribosome biogenesis control. PMID:27016735

  13. Engineering Saccharomyces cerevisiae to produce feruloyl esterase for the release of ferulic acid from switchgrass

    USDA-ARS?s Scientific Manuscript database

    The Aspergillus niger ferulic acid esterase gene (faeA) was cloned into Saccharomyces cerevisiae via a yeast expression vector, resulting in efficient expression and secretion of the enzyme in the medium. The recombinant enzyme was purified to homogeneity by anion-exchange and hydrophobic interactio...

  14. Trichoderma virens β-glucosidase I (BGLI) gene; expression in Saccharomyces cerevisiae including docking and molecular dynamics studies.

    PubMed

    Wickramasinghe, Gammadde Hewa Ishan Maduka; Rathnayake, Pilimathalawe Panditharathna Attanayake Mudiyanselage Samith Indika; Chandrasekharan, Naduviladath Vishvanath; Weerasinghe, Mahindagoda Siril Samantha; Wijesundera, Ravindra Lakshman Chundananda; Wijesundera, Wijepurage Sandhya Sulochana

    2017-06-21

    Cellulose, a linear polymer of β 1-4, linked glucose, is the most abundant renewable fraction of plant biomass (lignocellulose). It is synergistically converted to glucose by endoglucanase (EG) cellobiohydrolase (CBH) and β-glucosidase (BGL) of the cellulase complex. BGL plays a major role in the conversion of randomly cleaved cellooligosaccharides into glucose. As it is well known, Saccharomyces cerevisiae can efficiently convert glucose into ethanol under anaerobic conditions. Therefore, S.cerevisiae was genetically modified with the objective of heterologous extracellular expression of the BGLI gene of Trichoderma virens making it capable of utilizing cellobiose to produce ethanol. The cDNA and a genomic sequence of the BGLI gene of Trichoderma virens was cloned in the yeast expression vector pGAPZα and separately transformed to Saccharomyces cerevisiae. The size of the BGLI cDNA clone was 1363 bp and the genomic DNA clone contained an additional 76 bp single intron following the first exon. The gene was 90% similar to the DNA sequence and 99% similar to the deduced amino acid sequence of 1,4-β-D-glucosidase of T. atroviride (AC237343.1). The BGLI activity expressed by the recombinant genomic clone was 3.4 times greater (1.7 x 10 -3  IU ml -1 ) than that observed for the cDNA clone (5 x 10 -4  IU ml -1 ). Furthermore, the activity was similar to the activity of locally isolated Trichoderma virens (1.5 x 10 -3  IU ml -1 ). The estimated size of the protein was 52 kDA. In fermentation studies, the maximum ethanol production by the genomic and the cDNA clones were 0.36 g and 0.06 g /g of cellobiose respectively. Molecular docking results indicated that the bare protein and cellobiose-protein complex behave in a similar manner with considerable stability in aqueous medium. The deduced binding site and the binding affinity of the constructed homology model appeared to be reasonable. Moreover, it was identified that the five hydrogen bonds formed

  15. Metabolic gene products have evolved to interact with the cell wall integrity pathway in Saccharomyces cerevisiae.

    PubMed

    Ugbogu, Eziuche A; Wang, Ke; Schweizer, Lilian M; Schweizer, Michael

    2016-12-01

    Two of the five unlinked genes theoretically capable of encoding 5-phosphoribosyl-1(α)-pyrophosphate (PRPP) synthetase (Prs) in Saccharomyces cerevisiae, PRS1 and PRS5, contain in-frame insertions which separate the cation- and PRPP-binding sites, diagnostic of Prs polypeptides. The impairment of cell wall integrity (CWI) mitogen-activated protein kinase (MAPK) cascade in strains lacking PRS1 and the synthetic lethality associated with loss of PRS1 and PRS5 imply that these insertions are not gratuitous. Coimmunoprecipitation revealed that Prs1 interacts with the CWI MAPK pathway, only when Slt2 has been phosphorylated by Mkk1/2. Three serine residues identified by phosphoproteome analysis (Ficarro et al 2002) are located in one of the insertions of PRS5 thereby defining Prs5 as one of the 11 triply phosphorylated proteins in yeast. Mutation of these phosphosites compromised the transcriptional readout of one endpoint of the CWI pathway, Rlm1, as well as the expression of the gene encoding the stress-activated 1,3 β-glucan synthase, Fks2, regulated by a second endpoint of the CWI pathway, Swi4/Swi6 (SBF transcription factor). Therefore, the unexpected impairment of the CWI phenotype encountered in yeast strains either mutated or deleted for PRS1 or PRS5 can be explained by disruption of the communication between primary cell metabolism and CWI signalling. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Effects of Gene Orientation and Use of Multiple Promoters on the Expression of XYL1 and XYL2 in Saccharomyces cerevisiae

    NASA Astrophysics Data System (ADS)

    Bae, Ju Yun; Laplaza, José; Jeffries, Thomas W.

    Orientation of adjacent genes has been reported to affect their expression in eukaryotic systems, and metabolic engineering also often makes repeated use of a few promoters to obtain high expression. To improve transcriptional control in heterologous expression, we examined how these factors affect gene expression and enzymatic activity in Saccharomyces cerevisiae. We assembled d-xylose reductase (XYL1) and d-xylitol dehydrogenase (XYL2) in four ways. Each pair of genes was placed in two different tandem (l→2→ or √1√2), convergent (1→√2), and divergent (√1 2→) orientations in autonomous plasmids. The TEF1 promoter was used to drive XYL1 and the TDH3 promoter to drive XYL2 in each of the constructs. The effects of gene orientation on growth, transcription, and enzyme activity were analyzed. The transcription level as measured by quantitative PCR (q-PCR) correlated with enzyme activities, but our data did not show a significant effect of gene orientation. To test the possible dilution of promoter strength due to multiple use of the same promoter, we examined the level of expression of XYL1 driven by either the TEF1 or TDH3 promoter when carried on a single copy plasmid. We then coexpressed XYL2 from either a single or multicopy plasmid, which was also driven by the same promoter. XYL2 transcript and enzyme expression increased with plasmid copy number, while the expression of XYLl was constant regardless of the number of other TEF1 or TDH3 promoters present in the cell. According to our data, there is no significant effect of gene orientation or multiple promoter use on gene transcription and translation when genes are expressed from plasmids; however, other factors could affect expression of adjacent genes in chromosomes.

  17. The expression of the Saccharomyces cerevisiae HAL1 gene increases salt tolerance in transgenic watermelon [Citrullus lanatus (Thunb.) Matsun. & Nakai.].

    PubMed

    Ellul, P; Ríos, G; Atarés, A; Roig, L A; Serrano, R; Moreno, V

    2003-08-01

    An optimised Agrobacterium-mediated gene transfer protocol was developed in order to obtain watermelon transgenic plants [Citrullus lanatus (Thunb.) Matsun. & Nakai.]. Transformation efficiencies ranged from 2.8% to 5.3%, depending on the cultivar. The method was applied to obtain genetically engineered watermelon plants expressing the Saccharomyces cerevisiae HAL1 gene related to salt tolerance. In order to enhance its constitutive expression in plants, the HAL1 gene was cloned in a pBiN19 plasmid under control of the 35S promoter with a double enhancer sequence from the cauliflower mosaic virus and the RNA4 leader sequence of the alfalfa mosaic virus. This vector was introduced into Agrobacterium tumefaciens strain LBA4404 for further inoculation of watermelon half-cotyledon explants. The introduction of both the neomycin phosphotransferase II and HAL1 genes was assessed in primary transformants (TG1) by polymerase chain reaction analysis and Southern hybridisation. The expression of the HAL1 gene was determined by Northern analysis, and the diploid level of transgenic plants was confirmed by flow cytometry. The presence of the selectable marker gene in the expected Mendelian ratios was demonstrated in TG2 progenies. The TG2 kanamycin-resistant plantlets elongated better and produced new roots and leaves in culture media supplemented with NaCl compared with the control. Salt tolerance was confirmed in a semi-hydroponic system (EC=6 dS m(-1)) on the basis of the higher growth performance of homozygous TG3 lines with respect to their respective azygous control lines without the transgene. The halotolerance observed confirmed the inheritance of the trait and supports the potential usefulness of the HAL1 gene of S. cerevisiae as a molecular tool for genetic engineering of salt-stress protection in other crop species.

  18. RNAseq-based transcriptome comparison of Saccharomyces cerevisiae strains isolated from diverse fermentative environments.

    PubMed

    Ibáñez, Clara; Pérez-Torrado, Roberto; Morard, Miguel; Toft, Christina; Barrio, Eladio; Querol, Amparo

    2017-09-18

    Transcriptome analyses play a central role in unraveling the complexity of gene expression regulation in Saccharomyces cerevisiae. This species, one of the most important microorganisms for humans given its industrial applications, shows an astonishing degree of genetic and phenotypic variability among different strains adapted to specific environments. In order to gain novel insights into the Saccharomyces cerevisiae biology of strains adapted to different fermentative environments, we analyzed the whole transcriptome of three strains isolated from wine, flor wine or mezcal fermentations. An RNA-seq transcriptome comparison of the different yeasts in the samples obtained during synthetic must fermentation highlighted the differences observed in the genes that encode mannoproteins, and in those involved in aroma, sugar transport, glycerol and alcohol metabolism, which are important under alcoholic fermentation conditions. These differences were also observed in the physiology of the strains after mannoprotein and aroma determinations. This study offers an essential foundation for understanding how gene expression variations contribute to the fermentation differences of the strains adapted to unequal fermentative environments. Such knowledge is crucial to make improvements in fermentation processes and to define targets for the genetic improvement or selection of wine yeasts. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Studying Functions of All Yeast Genes Simultaneously

    NASA Technical Reports Server (NTRS)

    Stolc, Viktor; Eason, Robert G.; Poumand, Nader; Herman, Zelek S.; Davis, Ronald W.; Anthony Kevin; Jejelowo, Olufisayo

    2006-01-01

    A method of studying the functions of all the genes of a given species of microorganism simultaneously has been developed in experiments on Saccharomyces cerevisiae (commonly known as baker's or brewer's yeast). It is already known that many yeast genes perform functions similar to those of corresponding human genes; therefore, by facilitating understanding of yeast genes, the method may ultimately also contribute to the knowledge needed to treat some diseases in humans. Because of the complexity of the method and the highly specialized nature of the underlying knowledge, it is possible to give only a brief and sketchy summary here. The method involves the use of unique synthetic deoxyribonucleic acid (DNA) sequences that are denoted as DNA bar codes because of their utility as molecular labels. The method also involves the disruption of gene functions through deletion of genes. Saccharomyces cerevisiae is a particularly powerful experimental system in that multiple deletion strains easily can be pooled for parallel growth assays. Individual deletion strains recently have been created for 5,918 open reading frames, representing nearly all of the estimated 6,000 genetic loci of Saccharomyces cerevisiae. Tagging of each deletion strain with one or two unique 20-nucleotide sequences enables identification of genes affected by specific growth conditions, without prior knowledge of gene functions. Hybridization of bar-code DNA to oligonucleotide arrays can be used to measure the growth rate of each strain over several cell-division generations. The growth rate thus measured serves as an index of the fitness of the strain.

  20. Ninety-six haploid yeast strains with individual disruptions of open reading frames between YOR097C and YOR192C, constructed for the Saccharomyces genome deletion project, have an additional mutation in the mismatch repair gene MSH3.

    PubMed

    Lehner, Kevin R; Stone, Megan M; Farber, Rosann A; Petes, Thomas D

    2007-11-01

    As part of the Saccharomyces Genome Deletion Project, sets of presumably isogenic haploid and diploid strains that differed only by single gene deletions were constructed. We found that one set of 96 strains (containing deletions of ORFs located between YOR097C and YOR192C) in the collection, which was derived from the haploid BY4741, has an additional mutation in the MSH3 mismatch repair gene.

  1. A Gondwanan Imprint on Global Diversity and Domestication of Wine and Cider Yeast Saccharomyces uvarum

    PubMed Central

    Almeida, Pedro; Gonçalves, Carla; Teixeira, Sara; Libkind, Diego; Bontrager, Martin; Masneuf-Pomarède, Isabelle; Albertin, Warren; Durrens, Pascal; Sherman, David; Marullo, Philippe; Hittinger, Chris Todd; Gonçalves, Paula; Sampaio, José Paulo

    2016-01-01

    In addition to Saccharomyces cerevisiae, the cryotolerant yeast species S. uvarum is also used for wine and cider fermentation but nothing is known about its natural history. Here we use a population genomics approach to investigate its global phylogeography and domestication fingerprints using a collection of isolates obtained from fermented beverages and from natural environments on five continents. South American isolates contain more genetic diversity than that found in the Northern Hemisphere. Moreover, coalescence analyses suggest that a Patagonian sub-population gave rise to the Holarctic population through a recent bottleneck. Holarctic strains display multiple introgressions from other Saccharomyces species, those from S. eubayanus being prevalent in European strains associated with human-driven fermentations. These introgressions are absent in the large majority of wild strains and gene ontology analyses indicate that several gene categories relevant for wine fermentation are overrepresented. Such findings constitute a first indication of domestication in S. uvarum. PMID:24887054

  2. Sun: Friend and Foe.

    ERIC Educational Resources Information Center

    Froschauer, Linda K.; Boudrot, Barbara

    1986-01-01

    Reviews the benefits and hazards that the sun provides. Describes activities which focus on the power of the sun and on the development of "Sun-sensible" behavior. Also included is a poster which contains puzzles and additional information and activities on safe sunning. (ML)

  3. Saccharomyces eubayanus and Saccharomyces arboricola reside in North Island native New Zealand forests.

    PubMed

    Gayevskiy, Velimir; Goddard, Matthew R

    2016-04-01

    Saccharomyces is one of the best-studied microbial genera, but our understanding of the global distributions and evolutionary histories of its members is relatively poor. Recent studies have altered our view of Saccharomyces' origin, but a lack of sampling from the vast majority of the world precludes a holistic perspective. We evaluate alternate Gondwanan and Far East Asian hypotheses concerning the origin of these yeasts. Being part of Gondwana, and only colonized by humans in the last ∼1000 years, New Zealand represents a unique environment for testing these ideas. Genotyping and ribosomal sequencing of samples from North Island native forest parks identified a widespread population of Saccharomyces. Whole genome sequencing identified the presence of S. arboricola and S. eubayanus in New Zealand, which is the first report of S. arboricola outside Far East Asia, and also expands S. eubayanus' known distribution to include the Oceanic region. Phylogenomic approaches place the S. arboricola population as significantly diverged from the only other sequenced Chinese isolate but indicate that S. eubayanus might be a recent migrant from South America. These data tend to support the Far East Asian origin of the Saccharomyces, but the history of this group is still far from clear. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Genetic characterization of strains of Saccharomyces uvarum from New Zealand wineries.

    PubMed

    Zhang, Hanyao; Richards, Keith D; Wilson, Sandra; Lee, Soon A; Sheehan, Hester; Roncoroni, Miguel; Gardner, Richard C

    2015-04-01

    We present a genetic characterization of 65 isolates of Saccharomyces uvarum isolated from wineries in New Zealand, along with the complete nucleotide sequence of a single sulfite-tolerant isolate. The genome of the New Zealand isolate averaged 99.85% nucleotide identity to CBS7001, the previously sequenced strain of S. uvarum. However, three genomic segments (37-87 kb) showed 10% nucleotide divergence from CBS7001 but 99% identity to Saccharomyces eubayanus. We conclude that these three segments appear to have been introgressed from that species. The nucleotide sequence of the internal transcribed spacer (ITS) region from other New Zealand isolates were also very similar to that of CBS7001, and hybrids showed complete genetic compatibility for some strains, with tetrads giving four viable progeny that showed 2:2 segregations of marker genes. Some strains showed high tolerance to sulfite, with genetic analysis indicating linkage of this trait to the transcription factor FZF1, but not to SSU1, the sulfite efflux pump that it regulates in order to confer sulfite tolerance in Saccharomyces cerevisiae. The fermentation characteristics of selected strains of S. uvarum showed exceptionally good cold fermentation characteristics, superior to the best commercially available strains of S. cerevisiae. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Mutations in Ran system affected telomere silencing in Saccharomyces cerevisiae

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hayashi, Naoyuki; Department of Molecular Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-0934; Kobayashi, Masahiko

    The Ran GTPase system regulates the direction and timing of several cellular events, such as nuclear-cytosolic transport, centrosome formation, and nuclear envelope assembly in telophase. To gain insight into the Ran system's involvement in chromatin formation, we investigated gene silencing at the telomere in several mutants of the budding yeast Saccharomyces cerevisiae, which had defects in genes involved in the Ran system. A mutation of the RanGAP gene, rna1-1, caused reduced silencing at the telomere, and partial disruption of the nuclear Ran binding factor, yrb2-{delta}2, increased this silencing. The reduced telomere silencing in rna1-1 cells was suppressed by a highmore » dosage of the SIR3 gene or the SIT4 gene. Furthermore, hyperphosphorylated Sir3 protein accumulated in the rna1-1 mutant. These results suggest that RanGAP is required for the heterochromatin structure at the telomere in budding yeast.« less

  6. TPS1 terminator increases mRNA and protein yield in a Saccharomyces cerevisiae expression system.

    PubMed

    Yamanishi, Mamoru; Katahira, Satoshi; Matsuyama, Takashi

    2011-01-01

    Both terminators and promoters regulate gene expression. In Saccharomyces cerevisiae, the TPS1 terminator (TPS1t), coupled to a gene encoding a fluorescent protein, produced more transgenic mRNA and protein than did similar constructs containing other terminators, such as CYC1t, TDH3t, and PGK1t. This suggests that TPS1t can be used as a general terminator in the development of metabolically engineered yeast in high-yield systems.

  7. The mammalian AMP-activated protein kinase complex mediates glucose regulation of gene expression in the yeast Saccharomyces cerevisiae.

    PubMed

    Ye, Tian; Bendrioua, Loubna; Carmena, David; García-Salcedo, Raúl; Dahl, Peter; Carling, David; Hohmann, Stefan

    2014-06-05

    The AMP-activated protein kinase (AMPK) controls energy homeostasis in eukaryotic cells. Here we expressed hetero-trimeric mammalian AMPK complexes in a Saccharomyces cerevisiae mutant lacking all five genes encoding yeast AMPK/SNF1 components. Certain mammalian complexes complemented the growth defect of the yeast mutant on non-fermentable carbon sources. Phosphorylation of the AMPK α1-subunit was glucose-regulated, albeit not by the Glc7-Reg1/2 phosphatase, which performs this function on yeast AMPK/SNF1. AMPK could take over SNF1 function in glucose derepression. While indirectly acting anti-diabetic drugs had no effect on AMPK in yeast, compound 991 stimulated α1-subunit phosphorylation. Our results demonstrate a remarkable functional conservation of AMPK and that glucose regulation of AMPK may not be mediated by regulatory features of a specific phosphatase. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  8. Simultaneous and Sequential Integration by Cre/loxP Site-Specific Recombination in Saccharomyces cerevisiae.

    PubMed

    Choi, Ho-Jung; Kim, Yeon-Hee

    2018-05-28

    A Cre/ loxP -δ-integration system was developed to allow sequential and simultaneous integration of a multiple gene expression cassette in Saccharomyces cerevisiae . To allow repeated integrations, the reusable Candida glabrata MARKER ( CgMARKER ) carrying loxP sequences was used, and the integrated CgMARKER was efficiently removed by inducing Cre recombinase. The XYLP and XYLB genes encoding endoxylanase and β-xylosidase, respectively, were used as model genes for xylan metabolism in this system, and the copy number of these genes was increased to 15.8 and 16.9 copies/cell, respectively, by repeated integration. This integration system is a promising approach for the easy construction of yeast strains with enhanced metabolic pathways through multicopy gene expression.

  9. Personal, Seasonal Suns

    ERIC Educational Resources Information Center

    Sutley, Jane

    2010-01-01

    This article presents an art project designed for upper-elementary students to (1) imagine visual differences in the sun's appearance during the four seasons; (2) develop ideas for visually translating their personal experiences regarding the seasons to their sun drawings; (3) create four distinctive seasonal suns using colors and imagery to…

  10. Overexpression of ACC gene from oleaginous yeast Lipomyces starkeyi enhanced the lipid accumulation in Saccharomyces cerevisiae with increased levels of glycerol 3-phosphate substrates.

    PubMed

    Wang, Jiancai; Xu, Ronghua; Wang, Ruling; Haque, Mohammad Enamul; Liu, Aizhong

    2016-06-01

    The conversion of acetyl-CoA to malonyl-CoA by acetyl-CoA carboxylase (ACC) is the rate-limiting step in fatty acid biosynthesis. In this study, a gene coding for ACC was isolated and characterized from an oleaginous yeast, Lipomyces starkeyi. Real-time quantitative PCR (qPCR) analysis of L. starkeyi acetyl-CoA carboxylase gene (LsACC1) showed that the expression levels were upregulated with the fast accumulation of lipids. The LsACC1 was co-overexpressed with the glycerol 3-phosphate dehydrogenase gene (GPD1), which regulates lipids biosynthesis by supplying another substrates glycerol 3-phosphate for storage lipid assembly, in the non-oleaginous yeast Saccharomyces cerevisiae. Further, the S. cerevisiae acetyl-CoA carboxylase (ScACC1) was transferred with GPD1 and its function was analyzed in comparison with LsACC1. The results showed that overexpressed LsACC1 and GPD1 resulted in a 63% increase in S. cerevisiae. This study gives new data in understanding of the molecular mechanisms underlying the regulation of fatty acids and lipid biosynthesis in yeasts.

  11. Novel insights in genetic transformation of the probiotic yeast Saccharomyces boulardii

    PubMed Central

    Douradinha, Bruno; Reis, Viviane CB; Rogers, Matthew B; Torres, Fernando AG; Evans, Jared D; Marques Jr, Ernesto TA

    2014-01-01

    Saccharomyces boulardii (S. boulardii) is a probiotic yeast related to Saccharomyces cerevisiae (S. cerevisiae) but with distinct genetic, taxonomic and metabolic properties. S. cerevisiae has been used extensively in biotechnological applications. Currently, many strains are available, and multiple genetic tools have been developed, which allow the expression of several exogenous proteins of interest with applications in the fields of medicine, biofuels, the food industry, and scientific research, among others. Although S. boulardii has been widely studied due to its probiotic properties against several gastrointestinal tract disorders, very few studies addressed the use of this yeast as a vector for expression of foreign genes of interest with biotechnological applications. Here we show that, despite the similarity of the two yeasts, not all genetic tools used in S. cerevisiae can be applied in S. boulardii. While transformation of the latter could be obtained using a commercial kit developed for the former, consequent screening of successful transformants had to be optimized. We also show that several genes frequently used in genetic manipulation of S. cerevisiae (e.g., promoters and resistance markers) are present in S. boulardii. Sequencing revealed a high rate of homology (>96%) between the orthologs of the two yeasts. However, we also observed some of them are not eligible to be targeted for transformation of S. boulardii. This work has important applications toward the potential of this probiotic yeast as an expression system for genes of interest. PMID:24013355

  12. Novel insights in genetic transformation of the probiotic yeast Saccharomyces boulardii.

    PubMed

    Douradinha, Bruno; Reis, Viviane C B; Rogers, Matthew B; Torres, Fernando A G; Evans, Jared D; Marques, Ernesto T A

    2014-01-01

    Saccharomyces boulardii (S. boulardii) is a probiotic yeast related to Saccharomyces cerevisiae (S. cerevisiae) but with distinct genetic, taxonomic and metabolic properties. S. cerevisiae has been used extensively in biotechnological applications. Currently, many strains are available, and multiple genetic tools have been developed, which allow the expression of several exogenous proteins of interest with applications in the fields of medicine, biofuels, the food industry, and scientific research, among others. Although S. boulardii has been widely studied due to its probiotic properties against several gastrointestinal tract disorders, very few studies addressed the use of this yeast as a vector for expression of foreign genes of interest with biotechnological applications. Here we show that, despite the similarity of the two yeasts, not all genetic tools used in S. cerevisiae can be applied in S. boulardii. While transformation of the latter could be obtained using a commercial kit developed for the former, consequent screening of successful transformants had to be optimized. We also show that several genes frequently used in genetic manipulation of S. cerevisiae (e.g., promoters and resistance markers) are present in S. boulardii. Sequencing revealed a high rate of homology (> 96%) between the orthologs of the two yeasts. However, we also observed some of them are not eligible to be targeted for transformation of S. boulardii. This work has important applications toward the potential of this probiotic yeast as an expression system for genes of interest.

  13. Sun and Skin: The Dark Side of Sun Exposure

    MedlinePlus

    ... 2014 Print this issue Sun and Skin The Dark Side of Sun Exposure En español Send us ... says. Several factors—like cloudy days or having dark-colored skin—can reduce the amount of vitamin ...

  14. The ecology and evolution of non-domesticated Saccharomyces species.

    PubMed

    Boynton, Primrose J; Greig, Duncan

    2014-12-01

    Yeast researchers need model systems for ecology and evolution, but the model yeast Saccharomyces cerevisiae is not ideal because its evolution has been affected by domestication. Instead, ecologists and evolutionary biologists are focusing on close relatives of S. cerevisiae, the seven species in the genus Saccharomyces. The best-studied Saccharomyces yeast, after S. cerevisiae, is S. paradoxus, an oak tree resident throughout the northern hemisphere. In addition, several more members of the genus Saccharomyces have recently been discovered. Some Saccharomyces species are only found in nature, while others include both wild and domesticated strains. Comparisons between domesticated and wild yeasts have pinpointed hybridization, introgression and high phenotypic diversity as signatures of domestication. But studies of wild Saccharomyces natural history, biogeography and ecology are only beginning. Much remains to be understood about wild yeasts' ecological interactions and life cycles in nature. We encourage researchers to continue to investigate Saccharomyces yeasts in nature, both to place S. cerevisiae biology into its ecological context and to develop the genus Saccharomyces as a model clade for ecology and evolution. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd.

  15. The ecology and evolution of non-domesticated Saccharomyces species

    PubMed Central

    Boynton, Primrose J; Greig, Duncan

    2014-01-01

    Yeast researchers need model systems for ecology and evolution, but the model yeast Saccharomyces cerevisiae is not ideal because its evolution has been affected by domestication. Instead, ecologists and evolutionary biologists are focusing on close relatives of S. cerevisiae, the seven species in the genus Saccharomyces. The best-studied Saccharomyces yeast, after S. cerevisiae, is S. paradoxus, an oak tree resident throughout the northern hemisphere. In addition, several more members of the genus Saccharomyces have recently been discovered. Some Saccharomyces species are only found in nature, while others include both wild and domesticated strains. Comparisons between domesticated and wild yeasts have pinpointed hybridization, introgression and high phenotypic diversity as signatures of domestication. But studies of wild Saccharomyces natural history, biogeography and ecology are only beginning. Much remains to be understood about wild yeasts' ecological interactions and life cycles in nature. We encourage researchers to continue to investigate Saccharomyces yeasts in nature, both to place S. cerevisiae biology into its ecological context and to develop the genus Saccharomyces as a model clade for ecology and evolution. © 2014 The Authors. Yeast published by John Wiley & Sons Ltd. PMID:25242436

  16. Draft Genome Sequence of Saccharomyces cerevisiae Barra Grande (BG-1), a Brazilian Industrial Bioethanol-Producing Strain

    PubMed Central

    Coutouné, Natalia; Mulato, Aline Tieppo Nogueira

    2017-01-01

    ABSTRACT Here, we present the draft genome sequence of Saccharomyces cerevisiae BG-1, a Brazilian industrial strain widely used for bioethanol production from sugarcane. The 11.7-Mb genome sequence consists of 216 scaffolds and harbors 5,607 predicted protein-coding genes. PMID:28360170

  17. Improved Acetic Acid Resistance in Saccharomyces cerevisiae by Overexpression of the WHI2 Gene Identified through Inverse Metabolic Engineering

    PubMed Central

    Chen, Yingying; Stabryla, Lisa

    2016-01-01

    Development of acetic acid-resistant Saccharomyces cerevisiae is important for economically viable production of biofuels from lignocellulosic biomass, but the goal remains a critical challenge due to limited information on effective genetic perturbation targets for improving acetic acid resistance in the yeast. This study employed a genomic-library-based inverse metabolic engineering approach to successfully identify a novel gene target, WHI2 (encoding a cytoplasmatic globular scaffold protein), which elicited improved acetic acid resistance in S. cerevisiae. Overexpression of WHI2 significantly improved glucose and/or xylose fermentation under acetic acid stress in engineered yeast. The WHI2-overexpressing strain had 5-times-higher specific ethanol productivity than the control in glucose fermentation with acetic acid. Analysis of the expression of WHI2 gene products (including protein and transcript) determined that acetic acid induced endogenous expression of Whi2 in S. cerevisiae. Meanwhile, the whi2Δ mutant strain had substantially higher susceptibility to acetic acid than the wild type, suggesting the important role of Whi2 in the acetic acid response in S. cerevisiae. Additionally, overexpression of WHI2 and of a cognate phosphatase gene, PSR1, had a synergistic effect in improving acetic acid resistance, suggesting that Whi2 might function in combination with Psr1 to elicit the acetic acid resistance mechanism. These results improve our understanding of the yeast response to acetic acid stress and provide a new strategy to breed acetic acid-resistant yeast strains for renewable biofuel production. PMID:26826231

  18. Genome Mutational and Transcriptional Hotspots Are Traps for Duplicated Genes and Sources of Adaptations.

    PubMed

    Fares, Mario A; Sabater-Muñoz, Beatriz; Toft, Christina

    2017-05-01

    Gene duplication generates new genetic material, which has been shown to lead to major innovations in unicellular and multicellular organisms. A whole-genome duplication occurred in the ancestor of Saccharomyces yeast species but 92% of duplicates returned to single-copy genes shortly after duplication. The persisting duplicated genes in Saccharomyces led to the origin of major metabolic innovations, which have been the source of the unique biotechnological capabilities in the Baker's yeast Saccharomyces cerevisiae. What factors have determined the fate of duplicated genes remains unknown. Here, we report the first demonstration that the local genome mutation and transcription rates determine the fate of duplicates. We show, for the first time, a preferential location of duplicated genes in the mutational and transcriptional hotspots of S. cerevisiae genome. The mechanism of duplication matters, with whole-genome duplicates exhibiting different preservation trends compared to small-scale duplicates. Genome mutational and transcriptional hotspots are rich in duplicates with large repetitive promoter elements. Saccharomyces cerevisiae shows more tolerance to deleterious mutations in duplicates with repetitive promoter elements, which in turn exhibit higher transcriptional plasticity against environmental perturbations. Our data demonstrate that the genome traps duplicates through the accelerated regulatory and functional divergence of their gene copies providing a source of novel adaptations in yeast. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  19. Identification of auxotrophic mutants of the yeast Kluyveromyces marxianus by non-homologous end joining-mediated integrative transformation with genes from Saccharomyces cerevisiae.

    PubMed

    Yarimizu, Tohru; Nonklang, Sanom; Nakamura, Junpei; Tokuda, Shuya; Nakagawa, Takaaki; Lorreungsil, Sasithorn; Sutthikhumpha, Surasit; Pukahuta, Charida; Kitagawa, Takao; Nakamura, Mikiko; Cha-Aim, Kamonchai; Limtong, Savitree; Hoshida, Hisashi; Akada, Rinji

    2013-12-01

    The isolation and application of auxotrophic mutants for gene manipulations, such as genetic transformation, mating selection and tetrad analysis, form the basis of yeast genetics. For the development of these genetic methods in the thermotolerant fermentative yeast Kluyveromyces marxianus, we isolated a series of auxotrophic mutants with defects in amino acid or nucleic acid metabolism. To identify the mutated genes, linear DNA fragments of nutrient biosynthetic pathway genes were amplified from Saccharomyces cerevisiae chromosomal DNA and used to directly transform the K. marxianus auxotrophic mutants by random integration into chromosomes through non-homologous end joining (NHEJ). The appearance of transformant colonies indicated that the specific S. cerevisiae gene complemented the K. marxianus mutant. Using this interspecific complementation approach with linear PCR-amplified DNA, we identified auxotrophic mutations of ADE2, ADE5,7, ADE6, HIS2, HIS3, HIS4, HIS5, HIS6, HIS7, LYS1, LYS2, LYS4, LYS9, LEU1, LEU2, MET2, MET6, MET17, TRP3, TRP4 and TRP5 without the labour-intensive requirement of plasmid construction. Mating, sporulation and tetrad analysis techniques for K. marxianus were also established. With the identified auxotrophic mutant strains and S. cerevisiae genes as selective markers, NHEJ-mediated integrative transformation with PCR-amplified DNA is an attractive system for facilitating genetic analyses in the yeast K. marxianus. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Promoter architecture and transcriptional regulation of Abf1-dependent ribosomal protein genes in Saccharomyces cerevisiae.

    PubMed

    Fermi, Beatrice; Bosio, Maria Cristina; Dieci, Giorgio

    2016-07-27

    In Saccharomyces cerevisiae, ribosomal protein gene (RPG) promoters display binding sites for either Rap1 or Abf1 transcription factors. Unlike Rap1-associated promoters, the small cohort of Abf1-dependent RPGs (Abf1-RPGs) has not been extensively investigated. We show that RPL3, RPL4B, RPP1A, RPS22B and RPS28A/B share a common promoter architecture, with an Abf1 site upstream of a conserved element matching the sequence recognized by Fhl1, a transcription factor which together with Ifh1 orchestrates Rap1-associated RPG regulation. Abf1 and Fhl1 promoter association was confirmed by ChIP and/or gel retardation assays. Mutational analysis revealed a more severe requirement of Abf1 than Fhl1 binding sites for RPG transcription. In the case of RPS22B an unusual Tbf1 binding site promoted both RPS22B and intron-hosted SNR44 expression. Abf1-RPG down-regulation upon TOR pathway inhibition was much attenuated at defective mutant promoters unable to bind Abf1. TORC1 inactivation caused the expected reduction of Ifh1 occupancy at RPS22B and RPL3 promoters, but unexpectedly it entailed largely increased Abf1 association with Abf1-RPG promoters. We present evidence that Abf1 recruitment upon nutritional stress, also observed for representative ribosome biogenesis genes, favours RPG transcriptional rescue upon nutrient replenishment, thus pointing to nutrient-regulated Abf1 dynamics at promoters as a novel mechanism in ribosome biogenesis control. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  1. No evidence for extrinsic post-zygotic isolation in a wild Saccharomyces yeast system.

    PubMed

    Charron, Guillaume; Landry, Christian R

    2017-06-01

    Although microorganisms account for the largest fraction of Earth's biodiversity, we know little about how their reproductive barriers evolve. Sexual microorganisms such as Saccharomyces yeasts rapidly develop strong intrinsic post-zygotic isolation, but the role of extrinsic isolation in the early speciation process remains to be investigated. We measured the growth of F 1 hybrids between two incipient species of Saccharomyces paradoxus to assess the presence of extrinsic post-zygotic isolation across 32 environments. More than 80% of hybrids showed either partial dominance of the best parent or over-dominance for growth, revealing no fitness defects in F 1 hybrids. Extrinsic reproductive isolation therefore likely plays little role in limiting gene flow between incipient yeast species and is not a requirement for speciation. © 2017 The Author(s).

  2. Sun Protection Practices and Sun Exposure among Children with a Parental History of Melanoma

    PubMed Central

    Glenn, Beth A.; Lin, Tiffany; Chang, L. Cindy; Okada, Ashley; Wong, Weng Kee; Glanz, Karen; Bastani, Roshan

    2014-01-01

    Background First-degree relatives of melanoma survivors have a substantially higher lifetime risk for melanoma than individuals with no family history. Exposure to ultraviolet radiation is the primary modifiable risk factor for the disease. Reducing UV exposure through sun protection may be particularly important for children with a parental history of melanoma. Nonetheless, limited prior research has investigated sun protection practices and sun exposure among these children. Methods The California Cancer Registry was used to identify melanoma survivors eligible to participate in a survey to assess their children's sun protection practices and sun exposure. The survey was administered by mail, telephone, or web to Latino and non-Latino white melanoma survivors with at least one child (0–17 years; N = 324). Results Sun exposure was high and the rate of sunburn was equivalent to or higher than estimates from average risk populations. Use of sun protection was suboptimal. Latino children were less likely to wear sunscreen and hats and more likely to wear sunglasses, although these differences disappeared in adjusted analyses. Increasing age of the child was associated with lower sun protection and higher risk for sunburn whereas higher objective risk for melanoma predicted improved sun protection and a higher risk for sunburns. Perception of high barriers to sun protection was the strongest modifiable correlate of sun protection. Conclusions Interventions to improve sun protection and reduce sun exposure and sunburns in high risk children are needed. Impact Intervening in high risk populations may help reduce the burden of melanoma in the U.S. PMID:25587110

  3. Patterns of Variation for the Sun and Sun-like Stars

    NASA Astrophysics Data System (ADS)

    Radick, Richard R.; Lockwood, G. Wesley; Henry, Gregory W.; Hall, Jeffrey C.; Pevtsov, Alexei A.

    2018-03-01

    We compare patterns of variation for the Sun and 72 Sun-like stars by combining total and spectral solar irradiance measurements between 2003 and 2017 from the SORCE satellite, Strömgren b, y stellar photometry between 1993 and 2017 from Fairborn Observatory, and solar and stellar chromospheric Ca II H+K emission observations between 1992 and 2016 from Lowell Observatory. The new data and their analysis strengthen the relationships found previously between chromospheric and brightness variability on the decadal timescale of the solar activity cycle. Both chromospheric H+K and photometric b, y variability among Sun-like stars are related to average chromospheric activity by power laws on this timescale. Young active stars become fainter as their H+K emission increases, and older, less active, more Sun-age stars tend to show a pattern of direct correlation between photometric and chromospheric emission variations. The directly correlated pattern between total solar irradiance and chromospheric Ca II emission variations shown by the Sun appears to extend also to variations in the Strömgren b, y portion of the solar spectrum. Although the Sun does not differ strongly from its stellar age and spectral class mates in the activity and variability characteristics that we have now studied for over three decades, it may be somewhat unusual in two respects: (1) its comparatively smooth, regular activity cycle, and (2) its rather low photometric brightness variation relative to its chromospheric activity level and variation, perhaps indicating that facular emission and sunspot darkening are especially well-balanced on the Sun.

  4. Fermentative production of l-galactonate by using recombinant Saccharomyces cerevisiae containing the endogenous galacturonate reductase gene from Cryptococcus diffluens.

    PubMed

    Matsubara, Takeo; Hamada, Shohei; Wakabayashi, Ayaka; Kishida, Masao

    2016-11-01

    The GAR1 gene, encoding d-galacturonate reductase in Cryptococcus diffluens, was isolated, and the GAR1-expression plasmid was constructed by insertion of GAR1 downstream of the yeast constitutive promoter in the yeast-integrating vector. Recombinant Saccharomyces cerevisiae expressing C. diffluensd-galacturonate reductase from a genome integrated copy of the gene was cultured for use the conversion of d-galacturonic acid to l-galactonic acid. The optimum conditions for l-galactonic acid production were determined in terms of the initial concentration of d-galacturonic acid, fermentation pH, and mixed sugars. The following conditions yielded high efficiency in the conversion of d-galacturonic acid to l-galactonic acid in large-scale cultures: 0.1% initial d-galacturonic acid concentration, pH 3.5, and glucose as additional sugar. The aerobic condition was necessary for the conversion of d-galacturonic acid. Subculture of that recombinant was not showing to decrease of the d-galacturonic acid conversion rate even though it was repeated in ten generations. Culturing in scale-up, the conversion rate of d-galacturonic acid to l-galactonic acid was increased. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. ISC1-dependent metabolic adaptation reveals an indispensable role for mitochondria in induction of nuclear genes during the diauxic shift in Saccharomyces cerevisiae.

    PubMed

    Kitagaki, Hiroshi; Cowart, L Ashley; Matmati, Nabil; Montefusco, David; Gandy, Jason; de Avalos, Silvia Vaena; Novgorodov, Sergei A; Zheng, Jim; Obeid, Lina M; Hannun, Yusuf A

    2009-04-17

    Growth of Saccharomyces cerevisiae following glucose depletion (the diauxic shift) depends on a profound metabolic adaptation accompanied by a global reprogramming of gene expression. In this study, we provide evidence for a heretofore unsuspected role for Isc1p in mediating this reprogramming. Initial studies revealed that yeast cells deleted in ISC1, the gene encoding inositol sphingolipid phospholipase C, which resides in mitochondria in the post-diauxic phase, showed defective aerobic respiration in the post-diauxic phase but retained normal intrinsic mitochondrial functions, including intact mitochondrial DNA, normal oxygen consumption, and normal mitochondrial polarization. Microarray analysis revealed that the Deltaisc1 strain failed to up-regulate genes required for nonfermentable carbon source metabolism during the diauxic shift, thus suggesting a mechanism for the defective supply of respiratory substrates into mitochondria in the post-diauxic phase. This defect in regulating nuclear gene induction in response to a defect in a mitochondrial enzyme raised the possibility that mitochondria may initiate diauxic shift-associated regulation of nucleus-encoded genes. This was established by demonstrating that in respiratory-deficient petite cells these genes failed to be up-regulated across the diauxic shift in a manner similar to the Deltaisc1 strain. Isc1p- and mitochondrial function-dependent genes significantly overlapped with Adr1p-, Snf1p-, and Cat8p-dependent genes, suggesting some functional link among these factors. However, the retrograde response was not activated in Deltaisc1, suggesting that the response of Deltaisc1 cannot be simply attributed to mitochondrial dysfunction. These results suggest a novel role for Isc1p in allowing the reprogramming of gene expression during the transition from anaerobic to aerobic metabolism.

  6. Enhanced Iron Uptake of Saccharomyces cerevisiae by Heterologous Expression of a Tadpole Ferritin Gene

    PubMed Central

    Shin, Young-Mi; Kwon, Tae-Ho; Kim, Kyung-Suk; Chae, Keon-Sang; Kim, Dae-Hyuk; Kim, Jae-Ho; Yang, Moon-Sik

    2001-01-01

    We genetically engineered Saccharomyces cerevisiae to express ferritin, a ubiquitous iron storage protein, with the major heavy-chain subunit of tadpole ferritin. A 450-kDa ferritin complex can store up to 4,500 iron atoms in its central cavity. We cloned the tadpole ferritin heavy-chain gene (TFH) into the yeast shuttle vector YEp352 under the control of a hybrid alcohol dehydrogenase II and glyceraldehyde-3-phosphate dehydrogenase promoter. We confirmed transformation and expression by Northern blot analysis of the recombinant yeast, by Western blot analysis using an antibody against Escherichia coli-expressed TFH, and with Prussian blue staining that indicated that the yeast-expressed tadpole ferritin was assembled into a complex that could bind iron. The recombinant yeast was more iron tolerant in that 95% of transformed cells, but none of the recipient strain cells, could form colonies on plates containing 30 mM ferric citrate. The cell-associated concentration of iron was 500 μg per gram (dry cell weight) of the recombinant yeast but was 210 μg per gram (dry cell weight) in the wild type. These findings indicate that the iron-carrying capacity of yeast is improved by heterologous expression of tadpole ferritin and suggests that this approach may help relieve dietary iron deficiencies in domesticated animals by the use of the engineered yeast as a feed and food supplement. PMID:11229922

  7. Replicative age induces mitotic recombination in the ribosomal RNA gene cluster of Saccharomyces cerevisiae.

    PubMed

    Lindstrom, Derek L; Leverich, Christina K; Henderson, Kiersten A; Gottschling, Daniel E

    2011-03-01

    Somatic mutations contribute to the development of age-associated disease. In earlier work, we found that, at high frequency, aging Saccharomyces cerevisiae diploid cells produce daughters without mitochondrial DNA, leading to loss of respiration competence and increased loss of heterozygosity (LOH) in the nuclear genome. Here we used the recently developed Mother Enrichment Program to ask whether aging cells that maintain the ability to produce respiration-competent daughters also experience increased genomic instability. We discovered that this population exhibits a distinct genomic instability phenotype that primarily affects the repeated ribosomal RNA gene array (rDNA array). As diploid cells passed their median replicative life span, recombination rates between rDNA arrays on homologous chromosomes progressively increased, resulting in mutational events that generated LOH at >300 contiguous open reading frames on the right arm of chromosome XII. We show that, while these recombination events were dependent on the replication fork block protein Fob1, the aging process that underlies this phenotype is Fob1-independent. Furthermore, we provide evidence that this aging process is not driven by mechanisms that modulate rDNA recombination in young cells, including loss of cohesion within the rDNA array or loss of Sir2 function. Instead, we suggest that the age-associated increase in rDNA recombination is a response to increasing DNA replication stress generated in aging cells.

  8. SUNBURN, SUN EXPOSURE, AND SUN SENSITIVITY IN THE STUDY OF NEVI IN CHILDREN

    PubMed Central

    Satagopan, Jaya M; Oliveria, Susan A; Arora, Arshi; Marchetti, Michael A; Orlow, Irene; Dusza, Stephen W; Weinstock, Martin A; Scope, Alon; Geller, Alan C; Marghoob, Ashfaq A; Halpern, Allan C

    2015-01-01

    Purpose To examine the joint effect of sun exposure and sunburn on nevus counts (on the natural logarithm scale; log nevi) and the role of sun sensitivity. Methods We describe an analysis of cross-sectional data from 443 children enrolled in the prospective study of nevi in children. To evaluate the joint effect, we partitioned the sum of squares due to interaction between sunburn and sun exposure into orthogonal components representing: (i) monotonic increase in log nevi with increasing sun exposure (rate of increase of log nevi depends upon sunburn), and (ii) non-monotonic pattern. Results In unadjusted analyses, there was a marginally significant monotonic pattern of interaction (p-value = 0.08). In adjusted analyses, sun exposure was associated with higher log nevi among those without sunburn (p < 0.001), but not among those with sunburn (p = 0.14). Sunburn was independently associated with log nevi (p = 0.02), even though sun sensitivity explained 29% (95% CI: 2%-56%, p = 0.04) of its effect. Children with high sun sensitivity and sunburn had more nevi, regardless of sun exposure. Conclusions A program of increasing sun protection in early childhood as a strategy for reducing nevi, when applied to the general population, may not equally benefit everyone. PMID:26096189

  9. Sunburn, sun exposure, and sun sensitivity in the Study of Nevi in Children.

    PubMed

    Satagopan, Jaya M; Oliveria, Susan A; Arora, Arshi; Marchetti, Michael A; Orlow, Irene; Dusza, Stephen W; Weinstock, Martin A; Scope, Alon; Geller, Alan C; Marghoob, Ashfaq A; Halpern, Allan C

    2015-11-01

    To examine the joint effect of sun exposure and sunburn on nevus counts (on the natural logarithm scale; log nevi) and the role of sun sensitivity. We describe an analysis of cross-sectional data from 443 children enrolled in the prospective Study of Nevi in Children. To evaluate the joint effect, we partitioned the sum of squares because of interaction between sunburn and sun exposure into orthogonal components representing (1) monotonic increase in log nevi with increasing sun exposure (rate of increase of log nevi depends on sunburn), and (2) nonmonotonic pattern. In unadjusted analyses, there was a marginally significant monotonic pattern of interaction (P = .08). In adjusted analyses, sun exposure was associated with higher log nevi among those without sunburn (P < .001), but not among those with sunburn (P = .14). Sunburn was independently associated with log nevi (P = .02), even though sun sensitivity explained 29% (95% confidence interval: 2%-56%, P = .04) of its effect. Children with high sun sensitivity and sunburn had more nevi, regardless of sun exposure. A program of increasing sun protection in early childhood as a strategy for reducing nevi, when applied to the general population, may not equally benefit everyone. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. A systematic genetic screen for genes involved in sensing inorganic phosphate availability in Saccharomyces cerevisiae

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Choi, Joonhyuk; Rajagopal, Abbhirami; Xu, Yi -Fan

    Saccharomyces cerevisiae responds to changes in extracellular inorganic phosphate (Pi) availability by regulating the activity of the phosphate-responsive (PHO) signaling pathway, enabling cells to maintain intracellular levels of the essential nutrient P i. P i-limitation induces upregulation of inositol heptakisphosphate (IP 7) synthesized by the inositol hexakisphosphate kinase Vip1, triggering inhibition of the Pho80/Pho85 cyclin-cyclin dependent kinase (CDK) complex by the CDK inhibitor Pho81, which upregulates the PHO regulon through the CDK target and transcription factor Pho4. To identify genes that are involved in signaling upstream of the Pho80/Pho85/Pho81 complex and how they interact with each other to regulate themore » PHO pathway, we performed genome-wide screens with the synthetic genetic array method. We identified more than 300 mutants with defects in signaling upstream of the Pho80/Pho85/Pho81 complex, including AAH1, which encodes an adenine deaminase that negatively regulates the PHO pathway in a Vip1-dependent manner. Moreover, we showed that even in the absence of VIP1, the PHO pathway can be activated under prolonged periods of P i starvation, suggesting complexity in the mechanisms by which the PHO pathway is regulated.« less

  11. The Saccharomyces cerevisiae MLH3 gene functions in MSH3-dependent suppression of frameshift mutations.

    PubMed

    Flores-Rozas, H; Kolodner, R D

    1998-10-13

    The Saccharomyces cerevisiae genome encodes four MutL homologs. Of these, MLH1 and PMS1 are known to act in the MSH2-dependent pathway that repairs DNA mismatches. We have investigated the role of MLH3 in mismatch repair. Mutations in MLH3 increased the rate of reversion of the hom3-10 allele by increasing the rate of deletion of a single T in a run of 7 Ts. Combination of mutations in MLH3 and MSH6 caused a synergistic increase in the hom3-10 reversion rate, whereas the hom3-10 reversion rate in an mlh3 msh3 double mutant was the same as in the respective single mutants. Similar results were observed when the accumulation of mutations at frameshift hot spots in the LYS2 gene was analyzed, although mutation of MLH3 did not cause the same extent of affect at every LYS2 frameshift hot spot. MLH3 interacted with MLH1 in a two-hybrid system. These data are consistent with the idea that a proportion of the repair of specific insertion/deletion mispairs by the MSH3-dependent mismatch repair pathway uses a heterodimeric MLH1-MLH3 complex in place of the MLH1-PMS1 complex.

  12. A systematic genetic screen for genes involved in sensing inorganic phosphate availability in Saccharomyces cerevisiae

    DOE PAGES

    Choi, Joonhyuk; Rajagopal, Abbhirami; Xu, Yi -Fan; ...

    2017-05-17

    Saccharomyces cerevisiae responds to changes in extracellular inorganic phosphate (Pi) availability by regulating the activity of the phosphate-responsive (PHO) signaling pathway, enabling cells to maintain intracellular levels of the essential nutrient P i. P i-limitation induces upregulation of inositol heptakisphosphate (IP 7) synthesized by the inositol hexakisphosphate kinase Vip1, triggering inhibition of the Pho80/Pho85 cyclin-cyclin dependent kinase (CDK) complex by the CDK inhibitor Pho81, which upregulates the PHO regulon through the CDK target and transcription factor Pho4. To identify genes that are involved in signaling upstream of the Pho80/Pho85/Pho81 complex and how they interact with each other to regulate themore » PHO pathway, we performed genome-wide screens with the synthetic genetic array method. We identified more than 300 mutants with defects in signaling upstream of the Pho80/Pho85/Pho81 complex, including AAH1, which encodes an adenine deaminase that negatively regulates the PHO pathway in a Vip1-dependent manner. Moreover, we showed that even in the absence of VIP1, the PHO pathway can be activated under prolonged periods of P i starvation, suggesting complexity in the mechanisms by which the PHO pathway is regulated.« less

  13. Global study of holistic morphological effectors in the budding yeast Saccharomyces cerevisiae.

    PubMed

    Suzuki, Godai; Wang, Yang; Kubo, Karen; Hirata, Eri; Ohnuki, Shinsuke; Ohya, Yoshikazu

    2018-02-20

    The size of the phenotypic effect of a gene has been thoroughly investigated in terms of fitness and specific morphological traits in the budding yeast Saccharomyces cerevisiae, but little is known about gross morphological abnormalities. We identified 1126 holistic morphological effectors that cause severe gross morphological abnormality when deleted, and 2241 specific morphological effectors with weak holistic effects but distinctive effects on yeast morphology. Holistic effectors fell into many gene function categories and acted as network hubs, affecting a large number of morphological traits, interacting with a large number of genes, and facilitating high protein expression. Holistic morphological abnormality was useful for estimating the importance of a gene to morphology. The contribution of gene importance to fitness and morphology could be used to efficiently classify genes into functional groups. Holistic morphological abnormality can be used as a reproducible and reliable gene feature for high-dimensional morphological phenotyping. It can be used in many functional genomic applications.

  14. Creating a Sun-Safe Camp.

    ERIC Educational Resources Information Center

    Landrey, Ann

    1996-01-01

    Strategies for minimizing sun exposure of campers and staff include educating campers about the sun's effect on their skin, scheduling activities when the sun is less intense, creating shade at the camp site, incorporating sun protection into camp dress code, and training staff regarding sun protection. Addresses OSHA and liability issues. (LP)

  15. Properties of promoters cloned randomly from the Saccharomyces cerevisiae genome.

    PubMed Central

    Santangelo, G M; Tornow, J; McLaughlin, C S; Moldave, K

    1988-01-01

    Promoters were isolated at random from the genome of Saccharomyces cerevisiae by using a plasmid that contains a divergently arrayed pair of promoterless reporter genes. A comprehensive library was constructed by inserting random (DNase I-generated) fragments into the intergenic region upstream from the reporter genes. Simple in vivo assays for either reporter gene product (alcohol dehydrogenase or beta-galactosidase) allowed the rapid identification of promoters from among these random fragments. Poly(dA-dT) homopolymer tracts were present in three of five randomly cloned promoters. With two exceptions, each RNA start site detected was 40 to 100 base pairs downstream from a TATA element. All of the randomly cloned promoters were capable of activating reporter gene transcription bidirectionally. Interestingly, one of the promoter fragments originated in a region of the S. cerevisiae rDNA spacer; regulated divergent transcription (presumably by RNA polymerase II) initiated in the same region. Images PMID:2847031

  16. Dominant suppressor mutation bypasses the sphingolipid requirement for growth of Saccharomyces cells at low pH: role of the CWP2 gene.

    PubMed

    Skrzypek, M; Lester, R L; Spielmann, P; Zingg, N; Shelling, J; Dickson, R C

    2000-11-01

    Strains of Saccharomyces cerevisiae termed sphingolipid compensatory (SLC) do not grow at low pH when the cells lack sphingolipids. To begin to understand why sphingolipids are required for growth at low pH, we isolated derivatives of SLC strains, termed low pH resistant (LprR), carrying the LPR suppressor gene that allows growth at pH 4.1 when cells lack sphingolipids. Suppression is due to mutation of a single nuclear gene. The LPR suppressor gene functions, at least in part, by enhancing the ability of cells lacking sphingolipids to generate a net efflux of protons in suspension fluid with a pH range of 4.0-6.0. The LPR suppressor gene also enables cells lacking sphingolipids to maintain their intracellular pH near neutrality when the pH of the suspension fluid is low, unlike cells lacking the suppressor gene, which cannot maintain their intracellular pH in the face of a low external pH. These results demonstrate that some functions(s) of sphingolipids necessary for growth at low pH can be bypassed by a suppressor mutation. Attempts to clone the LPR suppressor gene were not successful, but they led to the isolation of the CWP2 gene, which encodes a major mannoprotein component of the outer cell wall. It was isolated because an increased copy number has the unusual property of increasing the frequency at which LprR strains arise. As we show here, part of the reason for this effect is that the CWP2 gene is essential for generating a net efflux of protons and for controlling intracellular pH in LprR strains that lack sphingolipids. These results suggest new cellular functions for the Cwp2 protein.

  17. Producing human ceramide-NS by metabolic engineering using yeast Saccharomyces cerevisiae.

    PubMed

    Murakami, Suguru; Shimamoto, Toshi; Nagano, Hideaki; Tsuruno, Masahiro; Okuhara, Hiroaki; Hatanaka, Haruyo; Tojo, Hiromasa; Kodama, Yukiko; Funato, Kouichi

    2015-11-17

    Ceramide is one of the most important intercellular components responsible for the barrier and moisture retention functions of the skin. Because of the risks involved with using products of animal origin and the low productivity of plants, the availability of ceramides is currently limited. In this study, we successfully developed a system that produces sphingosine-containing human ceramide-NS in the yeast Saccharomyces cerevisiae by eliminating the genes for yeast sphingolipid hydroxylases (encoded by SUR2 and SCS7) and introducing the gene for a human sphingolipid desaturase (encoded by DES1). The inactivation of the ceramidase gene YDC1, overexpression of the inositol phosphosphingolipid phospholipase C gene ISC1, and endoplasmic reticulum localization of the DES1 gene product resulted in enhanced production of ceramide-NS. The engineered yeast strains can serve as hosts not only for providing a sustainable source of ceramide-NS but also for developing further systems to produce sphingosine-containing sphingolipids.

  18. VID22 is required for transcriptional activation of the PSD2 gene in the yeast Saccharomyces cerevisiae.

    PubMed

    Miyata, Non; Miyoshi, Takuya; Yamaguchi, Takanori; Nakazono, Toshimitsu; Tani, Motohiro; Kuge, Osamu

    2015-12-15

    Phosphatidylethanolamine (PE) in the yeast Saccharomyces cerevisiae is synthesized through decarboxylation of phosphatidylserine (PS), catalysed by PS decarboxylase 1 (Psd1p) and 2 (Psd2p) and the cytidine 5'-diphosphate (CDP)-ethanolamine (CDP-Etn) pathway. PSD1 null (psd1Δ) and PSD2 null (psd2Δ) mutants are viable in a synthetic minimal medium, but a psd1Δ psd2Δ double mutant exhibits Etn auxotrophy, which is incorporated into PE through the CDP-Etn pathway. We have previously shown that psd1Δ is synthetic lethal with deletion of VID22 (vid22Δ) [Kuroda et al. (2011) Mol. Microbiol. 80: , 248-265]. In the present study, we found that vid22Δ mutant exhibits Etn auxotrophy under PSD1-depressed conditions. Deletion of VID22 in wild-type and PSD1-depressed cells caused partial defects in PE formation through decarboxylation of PS. The enzyme activity of PS decarboxylase in an extract of vid22Δ cells was ∼70% of that in wild-type cells and similar to that in psd2Δ cells and the PS decarboxylase activity remaining in the PSD1-depressed cells became almost negligible with deletion of VID22. Thus, the vid22Δ mutation was suggested to cause a defect in the Psd2p activity. Furthermore, vid22Δ cells were shown to be defective in expression of the PSD2 gene tagged with 6×HA, the defect being ameliorated by replacement of the native promoter of the PSD2 gene with a CYC1 promoter. In addition, an α-galactosidase reporter assay revealed that the activity of the promoter of the PSD2 gene in vid22Δ cells was ∼5% of that in wild-type cells. These results showed that VID22 is required for transcriptional activation of the PSD2 gene. © 2015 Authors; published by Portland Press Limited.

  19. Functional equivalence of translation factor eIF5B from Candida albicans and Saccharomyces cerevisiae.

    PubMed

    Jun, Kyung Ok; Yang, Eun Ji; Lee, Byeong Jeong; Park, Jeong Ro; Lee, Joon H; Choi, Sang Ki

    2008-04-30

    Eukaryotic translation initiation factor 5B (eIF5B) plays a role in recognition of the AUG codon in conjunction with translation factor eIF2, and promotes joining of the 60S ribosomal subunit. To see whether the eIF5B proteins of other organisms function in Saccharomyces cerevisiae, we cloned the corresponding genes from Oryza sativa, Arabidopsis thaliana, Aspergillus nidulans and Candida albican and expressed them under the control of the galactose-inducible GAL promoter in the fun12Delta strain of Saccharomyces cerevisiae. Expression of Candida albicans eIF5B complemented the slow-growth phenotype of the fun12Delta strain, but that of Aspergillus nidulance did not, despite the fact that its protein was expressed better than that of Candida albicans. The Arabidopsis thaliana protein was also not functional in Saccharomyces. These results reveal that the eIF5B in Candida albicans has a close functional relationship with that of Sacharomyces cerevisiae, as also shown by a phylogenetic analysis based on the amino acid sequences of the eIF5Bs.

  20. SunBlock '99: Young Scientists Investigate the Sun

    NASA Astrophysics Data System (ADS)

    Walsh, R. W.; Pike, C. D.; Mason, H.; Young, P.; Ireland, J.; Galsgaard, K.

    1999-10-01

    SunBlock `99 is a Web-based Public Understanding of Science and educational project which seeks to present the very latest solar research as seen through the eyes of young British scientists. These ``solar guides'' discuss not only their scientific interests, but also their extra-curricular activities and the reasons they chose scientific careers; in other words the human face of scientific research. The SunBlock '99 pages gather a range of solar images and movies from current solar space observatories and discuss the underlying physics and its relationship to the school curriculum. The instructional level is pitched at UK secondary school children (aged 13-16 years). It is intended that the material should not only provide a visually appealing introduction to the study of the Sun, but that it should help bridge the often wide gap between classroom science lessons and the research scientist `out in the field'. SunBlock '99 is managed by a team from the Rutherford Appleton Laboratory and the Universities of St Andrews and Cambridge, together with educational consultants. The production has, in part, been sponsored by PPARC and the Millennium Mathematics Project. Web site addresss: http://www.sunblock99.org.uk

  1. Very low amounts of glucose cause repression of the stress-responsive gene HSP12 in Saccharomyces cerevisiae.

    PubMed

    de Groot, E; Bebelman, J P; Mager, W H; Planta, R J

    2000-02-01

    Changing the growth mode of Saccharomyces cerevisiae by adding fermentable amounts of glucose to cells growing on a non-fermentable carbon source leads to rapid repression of general stress-responsive genes like HSP12. Remarkably, glucose repression of HSP12 appeared to occur even at very low glucose concentrations, down to 0.005%. Although these low levels of glucose do not induce fermentative growth, they do act as a growth signal, since upon addition of glucose to a concentration of 0.02%, growth rate increased and ribosomal protein gene transcription was up-regulated. In an attempt to elucidate how this type of glucose signalling may operate, several signalling mutants were examined. Consistent with the low amounts of glucose that elicit HSP12 repression, neither the main glucose-repression pathway nor cAMP-dependent activation of protein kinase A appeared to play a role in this regulation. Using mutants involved in glucose metabolism, evidence was obtained suggesting that glucose 6-phosphate serves as a signalling molecule. To identify the target for glucose repression on the promoter of the HSP12 gene, a promoter deletion series was used. The major transcription factors governing (stress-induced) transcriptional activation of HSP12 are Msn2p and Msn4p, binding to the general stress-responsive promoter elements (STREs). Surprisingly, glucose repression of HSP12 appeared to be independent of Msn2/4p: HSP12 transcription in glycerol-grown cells was unaffected in a deltamsn2deltamsn4 strain. Nevertheless, evidence was obtained that STRE-mediated transcription is the target of repression by low amounts of glucose. These data suggest that an as yet unidentified factor is involved in STRE-mediated transcriptional regulation of HSP12.

  2. Evolutionary Analysis of Heterochromatin Protein Compatibility by Interspecies Complementation in Saccharomyces

    PubMed Central

    Zill, Oliver A.; Scannell, Devin R.; Kuei, Jeffrey; Sadhu, Meru; Rine, Jasper

    2012-01-01

    The genetic bases for species-specific traits are widely sought, but reliable experimental methods with which to identify functionally divergent genes are lacking. In the Saccharomyces genus, interspecies complementation tests can be used to evaluate functional conservation and divergence of biological pathways or networks. Silent information regulator (SIR) proteins in S. bayanus provide an ideal test case for this approach because they show remarkable divergence in sequence and paralog number from those found in the closely related S. cerevisiae. We identified genes required for silencing in S. bayanus using a genetic screen for silencing-defective mutants. Complementation tests in interspecies hybrids identified an evolutionarily conserved Sir-protein-based silencing machinery, as defined by two interspecies complementation groups (SIR2 and SIR3). However, recessive mutations in S. bayanus SIR4 isolated from this screen could not be complemented by S. cerevisiae SIR4, revealing species-specific functional divergence in the Sir4 protein despite conservation of the overall function of the Sir2/3/4 complex. A cladistic complementation series localized the occurrence of functional changes in SIR4 to the S. cerevisiae and S. paradoxus branches of the Saccharomyces phylogeny. Most of this functional divergence mapped to sequence changes in the Sir4 PAD. Finally, a hemizygosity modifier screen in the interspecies hybrids identified additional genes involved in S. bayanus silencing. Thus, interspecies complementation tests can be used to identify (1) mutations in genetically underexplored organisms, (2) loci that have functionally diverged between species, and (3) evolutionary events of functional consequence within a genus. PMID:22923378

  3. The HOG pathway controls osmotic regulation of transcription via the stress response element (STRE) of the Saccharomyces cerevisiae CTT1 gene.

    PubMed Central

    Schüller, C; Brewster, J L; Alexander, M R; Gustin, M C; Ruis, H

    1994-01-01

    The HOG signal pathway of the yeast Saccharomyces cerevisiae is defined by the PBS2 and HOG1 genes encoding members of the MAP kinase kinase and of the MAP kinase family, respectively. Mutations in this pathway (deletions of PBS2 or HOG1, or point mutations in HOG1) almost completely abolish the induction of transcription by osmotic stress that is mediated by stress response elements (STREs). We have demonstrated previously that STREs also mediate induction of transcription by heat shock, nitrogen starvation and oxidative stress. This study shows that they are also activated by low external pH, sorbate, benzoate or ethanol stress. Induction by these other stress signals appears to be HOG pathway independent. HOG1-dependent osmotic induction of transcription of the CTT1 gene encoding the cytosolic catalase T occurs in the presence of a protein synthesis inhibitor and can be detected rapidly after an increase of tyrosine phosphorylation of Hog1p triggered by high osmolarity. Consistent with a role of STREs in the induction of stress resistance, a number of other stress protein genes (e.g. HSP104) are regulated like CTT1. Furthermore, catalase T was shown to be important for viability under severe osmotic stress, and heat shock was demonstrated to provide cross-protection against osmotic stress. Images PMID:7523111

  4. The HOG pathway controls osmotic regulation of transcription via the stress response element (STRE) of the Saccharomyces cerevisiae CTT1 gene.

    PubMed

    Schüller, C; Brewster, J L; Alexander, M R; Gustin, M C; Ruis, H

    1994-09-15

    The HOG signal pathway of the yeast Saccharomyces cerevisiae is defined by the PBS2 and HOG1 genes encoding members of the MAP kinase kinase and of the MAP kinase family, respectively. Mutations in this pathway (deletions of PBS2 or HOG1, or point mutations in HOG1) almost completely abolish the induction of transcription by osmotic stress that is mediated by stress response elements (STREs). We have demonstrated previously that STREs also mediate induction of transcription by heat shock, nitrogen starvation and oxidative stress. This study shows that they are also activated by low external pH, sorbate, benzoate or ethanol stress. Induction by these other stress signals appears to be HOG pathway independent. HOG1-dependent osmotic induction of transcription of the CTT1 gene encoding the cytosolic catalase T occurs in the presence of a protein synthesis inhibitor and can be detected rapidly after an increase of tyrosine phosphorylation of Hog1p triggered by high osmolarity. Consistent with a role of STREs in the induction of stress resistance, a number of other stress protein genes (e.g. HSP104) are regulated like CTT1. Furthermore, catalase T was shown to be important for viability under severe osmotic stress, and heat shock was demonstrated to provide cross-protection against osmotic stress.

  5. Mechanisms and Regulation of Mitotic Recombination in Saccharomyces cerevisiae

    PubMed Central

    Symington, Lorraine S.; Rothstein, Rodney; Lisby, Michael

    2014-01-01

    Homology-dependent exchange of genetic information between DNA molecules has a profound impact on the maintenance of genome integrity by facilitating error-free DNA repair, replication, and chromosome segregation during cell division as well as programmed cell developmental events. This chapter will focus on homologous mitotic recombination in budding yeast Saccharomyces cerevisiae. However, there is an important link between mitotic and meiotic recombination (covered in the forthcoming chapter by Hunter et al. 2015) and many of the functions are evolutionarily conserved. Here we will discuss several models that have been proposed to explain the mechanism of mitotic recombination, the genes and proteins involved in various pathways, the genetic and physical assays used to discover and study these genes, and the roles of many of these proteins inside the cell. PMID:25381364

  6. Genomic diversity of Saccharomyces cerevisiae yeasts associated with alcoholic fermentation of bacanora produced by artisanal methods.

    PubMed

    Álvarez-Ainza, M L; Zamora-Quiñonez, K A; Moreno-Ibarra, G M; Acedo-Félix, E

    2015-03-01

    Bacanora is a spirituous beverage elaborated with Agave angustifolia Haw in an artisanal process. Natural fermentation is mostly performed with native yeasts and bacteria. In this study, 228 strains of yeast like Saccharomyces were isolated from the natural alcoholic fermentation on the production of bacanora. Restriction analysis of the amplified region ITS1-5.8S-ITS2 of the ribosomal DNA genes (RFLPr) were used to confirm the genus, and 182 strains were identified as Saccharomyces cerevisiae. These strains displayed high genomic variability in their chromosomes profiles by karyotyping. Electrophoretic profiles of the strains evaluated showed a large number of chromosomes the size of which ranged between 225 and 2200 kpb approximately.

  7. SPK1 is an essential S-phase-specific gene of Saccharomyces cerevisiae that encodes a nuclear serine/threonine/tyrosine kinase.

    PubMed

    Zheng, P; Fay, D S; Burton, J; Xiao, H; Pinkham, J L; Stern, D F

    1993-09-01

    SPK1 was originally discovered in an immunoscreen for tyrosine-protein kinases in Saccharomyces cerevisiae. We have used biochemical and genetic techniques to investigate the function of this gene and its encoded protein. Hybridization of an SPK1 probe to an ordered genomic library showed that SPK1 is adjacent to PEP4 (chromosome XVI L). Sporulation of spk1/+ heterozygotes gave rise to spk1 spores that grew into microcolonies but could not be further propagated. These colonies were greatly enriched for budded cells, especially those with large buds. Similarly, eviction of CEN plasmids bearing SPK1 from cells with a chromosomal SPK1 disruption yielded viable cells with only low frequency. Spk1 protein was identified by immunoprecipitation and immunoblotting. It was associated with protein-Ser, Thr, and Tyr kinase activity in immune complex kinase assays. Spk1 was localized to the nucleus by immunofluorescence. The nucleotide sequence of the SPK1 5' noncoding region revealed that SPK1 contains two MluI cell cycle box elements. These elements confer S-phase-specific transcription to many genes involved in DNA synthesis. Northern (RNA) blotting of synchronized cells verified that the SPK1 transcript is coregulated with other MluI box-regulated genes. The SPK1 upstream region also includes a domain highly homologous to sequences involved in induction of RAD2 and other excision repair genes by agents that induce DNA damage. spk1 strains were hypersensitive to UV irradiation. Taken together, these findings indicate that SPK1 is a dual-specificity (Ser/Thr and Tyr) protein kinase that is essential for viability. The cell cycle-dependent transcription, presence of DNA damage-related sequences, requirement for UV resistance, and nuclear localization of Spk1 all link this gene to a crucial S-phase-specific role, probably as a positive regulator of DNA synthesis.

  8. Improved Acetic Acid Resistance in Saccharomyces cerevisiae by Overexpression of the WHI2 Gene Identified through Inverse Metabolic Engineering.

    PubMed

    Chen, Yingying; Stabryla, Lisa; Wei, Na

    2016-01-29

    Development of acetic acid-resistant Saccharomyces cerevisiae is important for economically viable production of biofuels from lignocellulosic biomass, but the goal remains a critical challenge due to limited information on effective genetic perturbation targets for improving acetic acid resistance in the yeast. This study employed a genomic-library-based inverse metabolic engineering approach to successfully identify a novel gene target, WHI2 (encoding a cytoplasmatic globular scaffold protein), which elicited improved acetic acid resistance in S. cerevisiae. Overexpression of WHI2 significantly improved glucose and/or xylose fermentation under acetic acid stress in engineered yeast. The WHI2-overexpressing strain had 5-times-higher specific ethanol productivity than the control in glucose fermentation with acetic acid. Analysis of the expression of WHI2 gene products (including protein and transcript) determined that acetic acid induced endogenous expression of Whi2 in S. cerevisiae. Meanwhile, the whi2Δ mutant strain had substantially higher susceptibility to acetic acid than the wild type, suggesting the important role of Whi2 in the acetic acid response in S. cerevisiae. Additionally, overexpression of WHI2 and of a cognate phosphatase gene, PSR1, had a synergistic effect in improving acetic acid resistance, suggesting that Whi2 might function in combination with Psr1 to elicit the acetic acid resistance mechanism. These results improve our understanding of the yeast response to acetic acid stress and provide a new strategy to breed acetic acid-resistant yeast strains for renewable biofuel production. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  9. Gene Amplification on Demand Accelerates Cellobiose Utilization in Engineered Saccharomyces cerevisiae

    PubMed Central

    Oh, Eun Joong; Skerker, Jeffrey M.; Kim, Soo Rin; Wei, Na; Turner, Timothy L.; Maurer, Matthew J.; Arkin, Adam P.

    2016-01-01

    ABSTRACT Efficient microbial utilization of cellulosic sugars is essential for the economic production of biofuels and chemicals. Although the yeast Saccharomyces cerevisiae is a robust microbial platform widely used in ethanol plants using sugar cane and corn starch in large-scale operations, glucose repression is one of the significant barriers to the efficient fermentation of cellulosic sugar mixtures. A recent study demonstrated that intracellular utilization of cellobiose by engineered yeast expressing a cellobiose transporter (encoded by cdt-1) and an intracellular β-glucosidase (encoded by gh1-1) can alleviate glucose repression, resulting in the simultaneous cofermentation of cellobiose and nonglucose sugars. Here we report enhanced cellobiose fermentation by engineered yeast expressing cdt-1 and gh1-1 through laboratory evolution. When cdt-1 and gh1-1 were integrated into the genome of yeast, the single copy integrant showed a low cellobiose consumption rate. However, cellobiose fermentation rates by engineered yeast increased gradually during serial subcultures on cellobiose. Finally, an evolved strain exhibited a 15-fold-higher cellobiose fermentation rate. To identify the responsible mutations in the evolved strain, genome sequencing was performed. Interestingly, no mutations affecting cellobiose fermentation were identified, but the evolved strain contained 9 copies of cdt-1 and 23 copies of gh1-1. We also traced the copy numbers of cdt-1 and gh1-1 of mixed populations during the serial subcultures. The copy numbers of cdt-1 and gh1-1 in the cultures increased gradually with similar ratios as cellobiose fermentation rates of the cultures increased. These results suggest that the cellobiose assimilation pathway (transport and hydrolysis) might be a rate-limiting step in engineered yeast and copies of genes coding for metabolic enzymes might be amplified in yeast if there is a growth advantage. This study indicates that on-demand gene amplification

  10. Gene Amplification on Demand Accelerates Cellobiose Utilization in Engineered Saccharomyces cerevisiae.

    PubMed

    Oh, Eun Joong; Skerker, Jeffrey M; Kim, Soo Rin; Wei, Na; Turner, Timothy L; Maurer, Matthew J; Arkin, Adam P; Jin, Yong-Su

    2016-06-15

    Efficient microbial utilization of cellulosic sugars is essential for the economic production of biofuels and chemicals. Although the yeast Saccharomyces cerevisiae is a robust microbial platform widely used in ethanol plants using sugar cane and corn starch in large-scale operations, glucose repression is one of the significant barriers to the efficient fermentation of cellulosic sugar mixtures. A recent study demonstrated that intracellular utilization of cellobiose by engineered yeast expressing a cellobiose transporter (encoded by cdt-1) and an intracellular β-glucosidase (encoded by gh1-1) can alleviate glucose repression, resulting in the simultaneous cofermentation of cellobiose and nonglucose sugars. Here we report enhanced cellobiose fermentation by engineered yeast expressing cdt-1 and gh1-1 through laboratory evolution. When cdt-1 and gh1-1 were integrated into the genome of yeast, the single copy integrant showed a low cellobiose consumption rate. However, cellobiose fermentation rates by engineered yeast increased gradually during serial subcultures on cellobiose. Finally, an evolved strain exhibited a 15-fold-higher cellobiose fermentation rate. To identify the responsible mutations in the evolved strain, genome sequencing was performed. Interestingly, no mutations affecting cellobiose fermentation were identified, but the evolved strain contained 9 copies of cdt-1 and 23 copies of gh1-1 We also traced the copy numbers of cdt-1 and gh1-1 of mixed populations during the serial subcultures. The copy numbers of cdt-1 and gh1-1 in the cultures increased gradually with similar ratios as cellobiose fermentation rates of the cultures increased. These results suggest that the cellobiose assimilation pathway (transport and hydrolysis) might be a rate-limiting step in engineered yeast and copies of genes coding for metabolic enzymes might be amplified in yeast if there is a growth advantage. This study indicates that on-demand gene amplification might be an

  11. Saccharomyces cerevisiae × Saccharomyces uvarum hybrids generated under different conditions share similar winemaking features.

    PubMed

    Origone, Andrea Cecilia; Rodríguez, María Eugenia; Oteiza, Juan Martín; Querol, Amparo; Lopes, Christian Ariel

    2018-01-01

    Interspecific hybrids among species in the Saccharomyces genus are frequently detected in anthropic habitats and can also be obtained easily in the laboratory. This occurs because the most important genetic barriers among Saccharomyces species are post-zygotic. Depending on several factors, including the involved strains, the hybridization mechanism and stabilization conditions, hybrids that bear differential genomic constitutions, and hence phenotypic variability, can be obtained. In the present study, Saccharomyces cerevisiae × Saccharomyces uvarum hybrids were constructed using genetically and physiologically different S. uvarum parents at distinct temperatures (13 and 20°C). The effect of those variables on the main oenological features of the wines obtained with these hybrids was evaluated. Hybrids were successfully obtained in all cases. However, genetic stabilization based on successive fermentations in white wine at 13°C was significantly longer than that at 20°C. Our results demonstrated that, irrespective of the S. uvarum parent and temperature used for hybrid generation and stabilization, similar physicochemical and aromatic features were found in wines. The hybrids generated herein were characterized by low ethanol production, high glycerol synthesis and the capacity to grow at low temperature and to produce malic acid with particular aroma profiles. These features make these hybrids useful for the new winemaking industry within the climate change era frame. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Saccharomyces cerevisiae FLO1 Gene Demonstrates Genetic Linkage to Increased Fermentation Rate at Low Temperatures

    PubMed Central

    Deed, Rebecca C.; Fedrizzi, Bruno; Gardner, Richard C.

    2017-01-01

    Low fermentation temperatures are of importance to food and beverage industries working with Saccharomyces cerevisiae. Therefore, the identification of genes demonstrating a positive impact on fermentation kinetics is of significant interest. A set of 121 mapped F1 progeny, derived from a cross between haploid strains BY4716 (a derivative of the laboratory yeast S288C) and wine yeast RM11-1a, were fermented in New Zealand Sauvignon Blanc grape juice at 12.5°. Analyses of five key fermentation kinetic parameters among the F1 progeny identified a quantitative trait locus (QTL) on chromosome I with a significant degree of linkage to maximal fermentation rate (Vmax) at low temperature. Independent deletions of two candidate genes within the region, FLO1 and SWH1, were constructed in the parental strains (with S288C representing BY4716). Fermentation of wild-type and deletion strains at 12.5 and 25° confirmed that the genetic linkage to Vmax corresponds to the S288C version of the FLO1 allele, as the absence of this allele reduced Vmax by ∼50% at 12.5°, but not at 25°. Reciprocal hemizygosity analysis (RHA) between S288C and RM11-1a FLO1 alleles did not confirm the prediction that the S288C version of FLO1 was promoting more rapid fermentation in the opposing strain background, suggesting that the positive effect on Vmax derived from S288C FLO1 may only provide an advantage in haploids, or is dependent on strain-specific cis or trans effects. This research adds to the growing body of evidence demonstrating the role of FLO1 in providing stress tolerance to S. cerevisiae during fermentation. PMID:28143947

  13. Direct enzyme assay evidence confirms aldehyde reductase function of Ydr541cp and Ygl039wp from Saccharomyces cerevisiae

    USDA-ARS?s Scientific Manuscript database

    Aldehyde reductase gene ARI1 is a recently characterized member of intermediate subfamily under SDR (short-chain dehydrogenase/reductase) superfamily that revealed mechanisms of in situ detoxification of furfural and HMF for tolerance of Saccharomyces cerevisiae. Uncharacterized open reading frames ...

  14. Influence of genetic background of engineered xylose-fermenting industrial Saccharomyces cerevisiae strains for ethanol production from lignocellulosic hydrolysates

    USDA-ARS?s Scientific Manuscript database

    An industrial ethanol-producing Saccharomyces cerevisiae strain with genes needed for xylose-fermentation integrated into its genome was used to obtain haploids and diploid isogenic strains. The isogenic strains were more effective in metabolizing xylose than their parental strain (p < 0.05) and abl...

  15. Aztec Suns

    ERIC Educational Resources Information Center

    Petersen, Hugh

    2010-01-01

    The Aztec Sun Stone is a revered Mexican artifact. It is said to be perhaps the most famous symbol of Mexico, besides its flag. It primarily depicts the four great disasters that led to the migration of the Mexica people to modern-day Mexico City. The Aztec Sun Stone also contains pictographs depicting the way the Mexica measured time, and was…

  16. New insights into the Saccharomyces cerevisiae fermentation switch: Dynamic transcriptional response to anaerobicity and glucose-excess

    PubMed Central

    van den Brink, Joost; Daran-Lapujade, Pascale; Pronk, Jack T; de Winde, Johannes H

    2008-01-01

    Background The capacity of respiring cultures of Saccharomyces cerevisiae to immediately switch to fast alcoholic fermentation upon a transfer to anaerobic sugar-excess conditions is a key characteristic of Saccharomyces cerevisiae in many of its industrial applications. This transition was studied by exposing aerobic glucose-limited chemostat cultures grown at a low specific growth rate to two simultaneous perturbations: oxygen depletion and relief of glucose limitation. Results The shift towards fully fermentative conditions caused a massive transcriptional reprogramming, where one third of all genes within the genome were transcribed differentially. The changes in transcript levels were mostly driven by relief from glucose-limitation. After an initial strong response to the addition of glucose, the expression profile of most transcriptionally regulated genes displayed a clear switch at 30 minutes. In this respect, a striking difference was observed between the transcript profiles of genes encoding ribosomal proteins and those encoding ribosomal biogenesis components. Not all regulated genes responded with this binary profile. A group of 87 genes showed a delayed and steady increase in expression that specifically responded to anaerobiosis. Conclusion Our study demonstrated that, despite the complexity of this multiple-input perturbation, the transcriptional responses could be categorized and biologically interpreted. By comparing this study with public datasets representing dynamic and steady conditions, 14 up-regulated and 11 down-regulated genes were determined to be anaerobic specific. Therefore, these can be seen as true "signature" transcripts for anaerobicity under dynamic as well as under steady state conditions. PMID:18304306

  17. Sun protection counseling by pediatricians has little effect on parent and child sun protection behavior.

    PubMed

    Cohen, Liza; Brown, Judith; Haukness, Heather; Walsh, Lori; Robinson, June K

    2013-02-01

    To compare counseling concerning sun protection and outdoor exercise with the parent's report of the behavior of a child aged 9-16 years old. Structured interviews of medical personnel in 3 Chicago area practices elicited information about counseling methods and recommendations. In each practice, a convenience sample of parents completed a self-reported survey of their and their child's behavior. Sun protection counseling occurred more frequently than exercise counseling in all practices (P = .014). Sun protection counseling was associated with parental prompting (P = .004), performing a summer camp physical (P = .002), and the child having a sunburn (P = .003). After controlling for the child's age, sex, and skin tone, sun protection counseling was not associated with the child's use of sun protection. In multivariate analysis of the child's sun protection behavior, parental sunburns, indoor tanning in the last 12 months, perception of skin cancer risk, and sun protection self-efficacy were significant (P = .02). Children who pursued outdoor sports were twice as likely to use inadequate sun protection and sustain sunburns (CI 1.3-1.7). The child's sun protection behavior was influenced by parental sun protection, parental perception of skin cancer risk, and parental sun protection self-efficacy; therefore, sun protection for children needs to be aimed at parents as well as children. Communication with parents in a way that incorporates the principles of motivational interviewing may be more effective in promoting behavioral change than admonitions to use sunscreen. Copyright © 2013 Mosby, Inc. All rights reserved.

  18. Work-time sun behaviours among Canadian outdoor workers: results from the 2006 National Sun Survey.

    PubMed

    Marrett, Loraine D; Pichora, Erin C; Costa, Michelle L

    2010-01-01

    The objective of the study was to describe summer work-related sun behaviours among Canadian outdoor workers. Information on time in the sun and sun protection practices at work during the summer of 2006 were collected from 1,337 outdoor workers aged 16-64 years as part of the Second National Sun Survey. Proportions (and 95% confidence intervals) were estimated using procedures appropriate for complex survey designs. Twenty-six percent of all Canadians, 39% of males and 33% of those aged 16-24 years work outdoors during the summer. Although 41% spend four or more hours daily in the sun at work, just over half always or often protect themselves by covering their heads (58%), wearing protective clothing (56%) or wearing sunglasses (54%), and only 29% use sunscreen. Males and those aged 16-24 spend the most work time in the sun but are the least likely to use protection. The prevalence of outdoor work and sun behaviours varies among regions. Study findings confirm the need for strategies to reduce time in the sun and increase the use of sun protection among outdoor workers. In order to be effective, these strategies must include both enhanced workplace policies and practice, and increased individual use of sun protection.

  19. Deletion of acetate transporter gene ADY2 improved tolerance of Saccharomyces cerevisiae against multiple stresses and enhanced ethanol production in the presence of acetic acid.

    PubMed

    Zhang, Mingming; Zhang, Keyu; Mehmood, Muhammad Aamer; Zhao, Zongbao Kent; Bai, Fengwu; Zhao, Xinqing

    2017-12-01

    The aim of this work was to study the effects of deleting acetate transporter gene ADY2 on growth and fermentation of Saccharomyces cerevisiae in the presence of inhibitors. Comparative transcriptome analysis revealed that three genes encoding plasma membrane carboxylic acid transporters, especially ADY2, were significantly downregulated under the zinc sulfate addition condition in the presence of acetic acid stress, and the deletion of ADY2 improved growth of S. cerevisiae under acetic acid, ethanol and hydrogen peroxide stresses. Consistently, a concomitant increase in ethanol production by 14.7% in the presence of 3.6g/L acetic acid was observed in the ADY2 deletion mutant of S. cerevisiae BY4741. Decreased intracellular acetic acid, ROS accumulation, and plasma membrane permeability were observed in the ADY2 deletion mutant. These findings would be useful for developing robust yeast strains for efficient ethanol production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. The Saccharomyces cerevisiae LOS1 gene involved in pre-tRNA splicing encodes a nuclear protein that behaves as a component of the nuclear matrix.

    PubMed

    Shen, W C; Selvakumar, D; Stanford, D R; Hopper, A K

    1993-09-15

    Mutations of the Saccharomyces cerevisiae LOS1 gene cause the accumulation of end matured intron-containing pre-tRNAs at elevated temperatures. In an effort to decipher the role of the LOS1 protein in pre-tRNA splicing, we have analyzed the LOS1 gene and its protein product. The LOS1 gene is located on the left arm of chromosome XI and the order of genes in this area of the chromosome is .... URA1 ... SAC1 TRP3 UBA1 STE6 LOS1 .... FAS1..... The LOS1 open reading frame encodes a putative protein of 1100 amino acids that shows no significant homology to other genes. The LOS1 open reading frame was tagged with the influenza virus hemagglutinin epitope recognized by the 12CA5 antibody. The 12CA5 antibody recognizes an epitope-tagged protein of the size predicted by the LOS1 open reading frame. Using this antibody for indirect immunofluorescence and cell fractionation studies we show that the LOS1 protein is located in nuclei. Los1p cannot be extracted from nuclei by treatment with nucleases, salts, or Triton X-100. This insolubility suggests that Los1p is a component of the nucleoskeleton. We propose that LOS1 mutations may affect pre-tRNA processing via alteration of the nuclear matrix.

  1. The Yeast Saccharomyces cerevisiae Contains Two Glutaredoxin Genes That Are Required for Protection against Reactive Oxygen Species

    PubMed Central

    Luikenhuis, Sandra; Perrone, Gabriel; Dawes, Ian W.; Grant, Chris M.

    1998-01-01

    Glutaredoxins are small heat-stable proteins that act as glutathione-dependent disulfide oxidoreductases. Two genes, designated GRX1 and GRX2, which share 40–52% identity and 61–76% similarity with glutaredoxins from bacterial and mammalian species, were identified in the yeast Saccharomyces cerevisiae. Strains deleted for both GRX1 and GRX2 were viable but lacked heat-stable oxidoreductase activity using β-hydroxyethylene disulfide as a substrate. Surprisingly, despite the high degree of homology between Grx1 and Grx2 (64% identity), the grx1 mutant was unaffected in oxidoreductase activity, whereas the grx2 mutant displayed only 20% of the wild-type activity, indicating that Grx2 accounted for the majority of this activity in vivo. Expression analysis indicated that this difference in activity did not arise as a result of differential expression of GRX1 and GRX2. In addition, a grx1 mutant was sensitive to oxidative stress induced by the superoxide anion, whereas a strain that lacked GRX2 was sensitive to hydrogen peroxide. Sensitivity to oxidative stress was not attributable to altered glutathione metabolism or cellular redox state, which did not vary between these strains. The expression of both genes was similarly elevated under various stress conditions, including oxidative, osmotic, heat, and stationary phase growth. Thus, Grx1 and Grx2 function differently in the cell, and we suggest that glutaredoxins may act as one of the primary defenses against mixed disulfides formed following oxidative damage to proteins. PMID:9571241

  2. Engineering of ribozyme-based aminoglycoside switches of gene expression by in vivo genetic selection in Saccharomyces cerevisiae.

    PubMed

    Klauser, Benedikt; Rehm, Charlotte; Summerer, Daniel; Hartig, Jörg S

    2015-01-01

    Synthetic RNA-based switches are a growing class of genetic controllers applied in synthetic biology to engineer cellular functions. In this chapter, we detail a protocol for the selection of posttranscriptional controllers of gene expression in yeast using the Schistosoma mansoni hammerhead ribozyme as a central catalytic unit. Incorporation of a small molecule-sensing aptamer domain into the ribozyme renders its activity ligand-dependent. Aptazymes display numerous advantages over conventional protein-based transcriptional controllers, namely, the use of little genomic space for encryption, their modular architecture allowing for easy reprogramming to new inputs, the physical linkage to the message to be controlled, and the ability to function without protein cofactors. Herein, we describe the method to select ribozyme-based switches of gene expression in Saccharomyces cerevisiae that we successfully implemented to engineer neomycin- and theophylline-responsive switches. We also highlight how to adapt the protocol to screen for switches responsive to other ligands. Reprogramming of the sensor unit and incorporation into any RNA of interest enables the fulfillment of a variety of regulatory functions. However, proper functioning of the aptazyme is largely dependent on optimal connection between the aptamer and the catalytic core. We obtained functional switches from a pool of variants carrying randomized connection sequences by an in vivo selection in MaV203 yeast cells that allows screening of a large sequence space of up to 1×10(9) variants. The protocol given explains how to construct aptazyme libraries, carry out the in vivo selection and characterize novel ON- and OFF-switches. © 2015 Elsevier Inc. All rights reserved.

  3. Lactose/whey utilization and ethanol production by transformed Saccharomyces cerevisiae cells.

    PubMed

    Porro, D; Martegani, E; Ranzi, B M; Alberghina, L

    1992-04-05

    Strains of Saccharomyces cerevisiae transformed with a multicopy expression vector bearing both the Escherichia coli beta-galactosidase gene under the control of the upstream activating sequence of the GAL1-10 genes and the GAL4 activator gene release part of beta-galactosidase in the growth medium. This release is due to cell lysis of the older mother cells; the enzyme maintains its activity in buffered growth media. Fermentation studies with transformed yeast strains showed that the release of beta-galactosidase allowed an efficient growth on buffered media containing lactose as carbon source as well as on whey-based media. The transformed strains utilized up to 95% of the lactose and a high growth yield was obtained in rich media. High productions of ethanol were also observed in stationary phase after growth in lactose minimal media.

  4. System-level analysis of genes and functions affecting survival during nutrient starvation in Saccharomyces cerevisiae.

    PubMed

    Gresham, David; Boer, Viktor M; Caudy, Amy; Ziv, Naomi; Brandt, Nathan J; Storey, John D; Botstein, David

    2011-01-01

    An essential property of all cells is the ability to exit from active cell division and persist in a quiescent state. For single-celled microbes this primarily occurs in response to nutrient deprivation. We studied the genetic requirements for survival of Saccharomyces cerevisiae when starved for either of two nutrients: phosphate or leucine. We measured the survival of nearly all nonessential haploid null yeast mutants in mixed populations using a quantitative sequencing method that estimates the abundance of each mutant on the basis of frequency of unique molecular barcodes. Starvation for phosphate results in a population half-life of 337 hr whereas starvation for leucine results in a half-life of 27.7 hr. To measure survival of individual mutants in each population we developed a statistical framework that accounts for the multiple sources of experimental variation. From the identities of the genes in which mutations strongly affect survival, we identify genetic evidence for several cellular processes affecting survival during nutrient starvation, including autophagy, chromatin remodeling, mRNA processing, and cytoskeleton function. In addition, we found evidence that mitochondrial and peroxisome function is required for survival. Our experimental and analytical methods represent an efficient and quantitative approach to characterizing genetic functions and networks with unprecedented resolution and identified genotype-by-environment interactions that have important implications for interpretation of studies of aging and quiescence in yeast.

  5. The Sun in Time

    NASA Technical Reports Server (NTRS)

    Adams, Mitzi L.

    1998-01-01

    The presentation will include slides and documentation concerning archaeological sites where observations of the Sun may have taken place, as well as a discussion of the role the Sun played in the lives of the ancients. We will complete our discussion by contrasting ancient ideas of the Sun with those of the current era.

  6. Sun compensation by bees.

    PubMed

    Gould, J L

    1980-02-01

    In both their navigation and dance communication, bees are able to compensate for the sun's movement. When foragers are prevented from seeing the sun for 2 hours, they compensate by extrapolation, using the sun's rate of movement when last observed. These and other data suggest a time-averaging processing strategy in honey bee orientation.

  7. Functional expression of a heterologous nickel-dependent, ATP-independent urease in Saccharomyces cerevisiae.

    PubMed

    Milne, N; Luttik, M A H; Cueto Rojas, H F; Wahl, A; van Maris, A J A; Pronk, J T; Daran, J M

    2015-07-01

    In microbial processes for production of proteins, biomass and nitrogen-containing commodity chemicals, ATP requirements for nitrogen assimilation affect product yields on the energy producing substrate. In Saccharomyces cerevisiae, a current host for heterologous protein production and potential platform for production of nitrogen-containing chemicals, uptake and assimilation of ammonium requires 1 ATP per incorporated NH3. Urea assimilation by this yeast is more energy efficient but still requires 0.5 ATP per NH3 produced. To decrease ATP costs for nitrogen assimilation, the S. cerevisiae gene encoding ATP-dependent urease (DUR1,2) was replaced by a Schizosaccharomyces pombe gene encoding ATP-independent urease (ure2), along with its accessory genes ureD, ureF and ureG. Since S. pombe ure2 is a Ni(2+)-dependent enzyme and Saccharomyces cerevisiae does not express native Ni(2+)-dependent enzymes, the S. pombe high-affinity nickel-transporter gene (nic1) was also expressed. Expression of the S. pombe genes into dur1,2Δ S. cerevisiae yielded an in vitro ATP-independent urease activity of 0.44±0.01 µmol min(-1) mg protein(-1) and restored growth on urea as sole nitrogen source. Functional expression of the Nic1 transporter was essential for growth on urea at low Ni(2+) concentrations. The maximum specific growth rates of the engineered strain on urea and ammonium were lower than those of a DUR1,2 reference strain. In glucose-limited chemostat cultures with urea as nitrogen source, the engineered strain exhibited an increased release of ammonia and reduced nitrogen content of the biomass. Our results indicate a new strategy for improving yeast-based production of nitrogen-containing chemicals and demonstrate that Ni(2+)-dependent enzymes can be functionally expressed in S. cerevisiae. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  8. Immunomodulatory Effects of Saccharomyces cerevisiae Fermentation Product Supplementation on Immune Gene Expression and Lymphocyte Distribution in Immune Organs in Broilers.

    PubMed

    Chou, Wen K; Park, Jungwoo; Carey, John B; McIntyre, Don R; Berghman, Luc R

    2017-01-01

    A study was conducted to evaluate the molecular and cellular immunomodulatory effects of a Saccharomyces cerevisiae fermentation product (Original XPC, Diamond V) in broilers. Our lab has previously demonstrated that broilers fed XPC generate faster and stronger antigen-specific humoral immune responses to Newcastle disease virus (NDV) vaccination. This study aims at investigating the mechanism behind this increased immunocompetence. One-day-old broilers were randomly assigned to one of two treatments: 1.25 kg/ton S. cerevisiae fermentation product (XPC treatment group) or control diet. Birds were vaccinated against NDV on day 1 (B1 strain) and day 21 (LaSota strain) post-hatch. Innate and adaptive immune-related gene expression profiles in central (thymus and bursa of Fabricius) and peripheral (spleen) immune organs were investigated at 14 and 28 days of age by qPCR array. Fold changes larger than 1.2 ( P  < 0.05) between treated and control were considered significant. Lymphocyte subpopulations in central and peripheral immune organs and blood leukocytes were analyzed by flow cytometry at 14, 21, 28, and 42 days of age. In the spleen, Th1 immune responses and antiviral genes, such as IFN-γ, and its downstream genes signal transducer and activator of transcription (STAT4) and NFκB, were significantly upregulated in the treated group by 14 days of age. In the thymus, genes belonging to different functional groups were influenced at different time points. Cytokine genes associated with lymphocyte maturation, differentiation, and proliferation, such as IL-1R, IL-2, and IL-15 were significantly upregulated in the treated group by 28 days of age. Genes preferentially expressed in the medulla of the thymus and mature thymocytes, such as Myxovirus resistance gene 1, interferon regulatory factor-1, interferon regulatory factor-7, and STAT1, were upregulated in the birds supplemented with XPC. Birds supplemented with XPC had significantly higher percentages

  9. Enhancement of protein production via the strong DIT1 terminator and two RNA-binding proteins in Saccharomyces cerevisiae.

    PubMed

    Ito, Yoichiro; Kitagawa, Takao; Yamanishi, Mamoru; Katahira, Satoshi; Izawa, Shingo; Irie, Kenji; Furutani-Seiki, Makoto; Matsuyama, Takashi

    2016-11-15

    Post-transcriptional upregulation is an effective way to increase the expression of transgenes and thus maximize the yields of target chemicals from metabolically engineered organisms. Refractory elements in the 3' untranslated region (UTR) that increase mRNA half-life might be available. In Saccharomyces cerevisiae, several terminator regions have shown activity in increasing the production of proteins by upstream coding genes; among these terminators the DIT1 terminator has the highest activity. Here, we found in Saccharomyces cerevisiae that two resident trans-acting RNA-binding proteins (Nab6p and Pap1p) enhance the activity of the DIT1 terminator through the cis element GUUCG/U within the 3'-UTR. These two RNA-binding proteins could upregulate a battery of cell-wall-related genes. Mutagenesis of the DIT1 terminator improved its activity by a maximum of 500% of that of the standard PGK1 terminator. Further understanding and improvement of this system will facilitate inexpensive and stable production of complicated organism-derived drugs worldwide.

  10. Multi-targeted priming for genome-wide gene expression assays.

    PubMed

    Adomas, Aleksandra B; Lopez-Giraldez, Francesc; Clark, Travis A; Wang, Zheng; Townsend, Jeffrey P

    2010-08-17

    Complementary approaches to assaying global gene expression are needed to assess gene expression in regions that are poorly assayed by current methodologies. A key component of nearly all gene expression assays is the reverse transcription of transcribed sequences that has traditionally been performed by priming the poly-A tails on many of the transcribed genes in eukaryotes with oligo-dT, or by priming RNA indiscriminately with random hexamers. We designed an algorithm to find common sequence motifs that were present within most protein-coding genes of Saccharomyces cerevisiae and of Neurospora crassa, but that were not present within their ribosomal RNA or transfer RNA genes. We then experimentally tested whether degenerately priming these motifs with multi-targeted primers improved the accuracy and completeness of transcriptomic assays. We discovered two multi-targeted primers that would prime a preponderance of genes in the genomes of Saccharomyces cerevisiae and Neurospora crassa while avoiding priming ribosomal RNA or transfer RNA. Examining the response of Saccharomyces cerevisiae to nitrogen deficiency and profiling Neurospora crassa early sexual development, we demonstrated that using multi-targeted primers in reverse transcription led to superior performance of microarray profiling and next-generation RNA tag sequencing. Priming with multi-targeted primers in addition to oligo-dT resulted in higher sensitivity, a larger number of well-measured genes and greater power to detect differences in gene expression. Our results provide the most complete and detailed expression profiles of the yeast nitrogen starvation response and N. crassa early sexual development to date. Furthermore, our multi-targeting priming methodology for genome-wide gene expression assays provides selective targeting of multiple sequences and counter-selection against undesirable sequences, facilitating a more complete and precise assay of the transcribed sequences within the genome.

  11. Reduction of biogenic amines production by eliminating the PEP4 gene in Saccharomyces cerevisiae during fermentation of Chinese rice wine.

    PubMed

    Guo, Xuewu; Guan, Xiangyu; Wang, Yazhou; Li, Lina; Wu, Deguang; Chen, Yefu; Pei, Huadong; Xiao, Dongguang

    2015-07-01

    Biogenic amines in Chinese rice wine have a potential threat of toxicity to human health. In this study, PEP4 gene in Saccharomyces cerevisiae was knocked out in order to evaluate its effect on biogenic amines production; the enzyme encodes proteinase A (PrA), an enzyme that is responsible for the production of free amino acids. It was found that compared to the wild type strain, the PrA activity and amino acid concentration decreased significantly, and the production of biogenic amines in this knockout strain decreased by 25.5%, from 180.1mg/L to 134.2mg/L. Especially, tyramine, cadaverine and histamine concentrations were also decreased by 57.5%, 24.6% and 54.3%, respectively. The main reason for the decrease of biogenic amines may be due to the low concentration of free amino acids. Our results provide a new strategy to minimize the biogenic amine production during fermentation of Chinese rice wine. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Characterization of the Bacillus stearothermophilus manganese superoxide dismutase gene and its ability to complement copper/zinc superoxide dismutase deficiency in Saccharomyces cerevisiae

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bowler, C.; Inze, D.; Van Camp, W.

    1990-03-01

    Recombinant clones containing the manganese superoxide dismutase (MnSOD) gene of Bacillus stearothermophilus were isolated with an oligonucleotide probe designed to match a part of the previously determined amino acid sequence. Complementation analyses, performed by introducing each plasmid into a superoxide dismutase-deficient mutant of Escherichia coli, allowed us to define the region of DNA which encodes the MnSOD structural gene and to identify a promoter region immediately upstream from the gene. These data were subsequently confirmed by DNA sequencing. Since MnSOD is normally restricted to the mitochondria in eucaryotes, we were interested (i) in determining whether B. stearothermophilus MnSOD could functionmore » in eucaryotic cytosol and (ii) in determining whether MnSOD could replace the structurally unrelated copper/zinc superoxide dismutase (Cu/ZnSOD) which is normally found there. To test this, the sequence encoding bacterial MnSOD was cloned into a yeast expression vector and subsequently introduced into a Cu/ZnSOD-deficient mutant of the yeast Saccharomyces cerevisiae. Functional expression of the protein was demonstrated, and complementation tests revealed that the protein was able to provide tolerance at wild-type levels to conditions which are normally restrictive for this mutant. Thus, in spite of the evolutionary unrelatedness of these two enzymes, Cu/ZnSOD can be functionally replaced by MnSOD in yeast cytosol.« less

  13. The Saccharomyces cerevisiae MUM2 gene interacts with the DNA replication machinery and is required for meiotic levels of double strand breaks.

    PubMed Central

    Davis, L; Barbera, M; McDonnell, A; McIntyre, K; Sternglanz, R; Jin , Q; Loidl, J; Engebrecht, J

    2001-01-01

    The Saccharomyces cerevisiae MUM2 gene is essential for meiotic, but not mitotic, DNA replication and thus sporulation. Genetic interactions between MUM2 and a component of the origin recognition complex and polymerase alpha-primase suggest that MUM2 influences the function of the DNA replication machinery. Early meiotic gene expression is induced to a much greater extent in mum2 cells than in meiotic cells treated with the DNA synthesis inhibitor hydroxyurea. This result indicates that the mum2 meiotic arrest is downstream of the arrest induced by hydroxyurea and suggests that DNA synthesis is initiated in the mutant. Genetic analyses indicate that the recombination that occurs in mum2 mutants is dependent on the normal recombination machinery and on synaptonemal complex components and therefore is not a consequence of lesions created by incompletely replicated DNA. Both meiotic ectopic and allelic recombination are similarly reduced in the mum2 mutant, and the levels are consistent with the levels of meiosis-specific DSBs that are generated. Cytological analyses of mum2 mutants show that chromosome pairing and synapsis occur, although at reduced levels compared to wild type. Given the near-wild-type levels of meiotic gene expression, pairing, and synapsis, we suggest that the reduction in DNA replication is directly responsible for the reduced level of DSBs and meiotic recombination. PMID:11238403

  14. Experience with Saccharomyces boulardii Probiotic in Oncohaematological Patients.

    PubMed

    Sulik-Tyszka, Beata; Snarski, Emilian; Niedźwiedzka, Magda; Augustyniak, Małgorzata; Myhre, Thorvald Nilsen; Kacprzyk, Anna; Swoboda-Kopeć, Ewa; Roszkowska, Marta; Dwilewicz-Trojaczek, Jadwiga; Jędrzejczak, Wiesław Wiktor; Wróblewska, Marta

    2018-06-01

    Very few reports have been published to date on the bloodstream infections caused by Saccharomyces spp. in oncohaematological patients, and there are no guidelines on the use of this probiotic microorganism in this population. We describe the use of probiotic preparation containing Saccharomyces boulardii in a large group of oncohaematological patients. We retrospectively analysed the data from 32,000 patient hospitalisations at the haematological centre during 2011-2013 (including 196 haematopoietic stem cell transplant recipients) in a tertiary care university-affiliated hospital. During the study period, 2270 doses of Saccharomyces boulardii probiotic were administered to the oncohaematological patients. In total, 2816 mycological cultures were performed, out of which 772 (27.4%) were positive, with 52 indicating digestive tract colonisation by Saccharomyces spp., mainly in patients with acute myeloid leukaemia (AML), myelodysplastic syndrome (MDS) or multiple myeloma (MM). While colonised, they were hospitalised for 1683 days and 416 microbiological cultures of their clinical samples were performed. In the studied group of patients, there were six blood cultures positive for fungi; however, they comprised Candida species: two C. glabrata, one C. albicans, one C. krusei, one C. tropicalis and one C. parapsilosis. There was no blood culture positive for Saccharomyces spp. Our study indicates that despite colonisation of many oncohaematological patients with Saccharomyces spp., there were no cases of fungal sepsis caused by this species.

  15. Seasons by the Sun

    ERIC Educational Resources Information Center

    Stark, Meri-Lyn

    2005-01-01

    Understanding the Sun has challenged people since ancient times. Mythology from the Greek, Inuit, and Inca cultures attempted to explain the daily appearance and nightly disappearance of the Sun by relating it to a chariot being chased across the sky. While people no longer believe the Sun is a chariot racing across the sky, teachers are still…

  16. Saccharomyces eubayanus and Saccharomyces uvarum associated with the fermentation of Araucaria araucana seeds in Patagonia.

    PubMed

    Rodríguez, M Eugenia; Pérez-Través, Laura; Sangorrín, Marcela P; Barrio, Eladio; Lopes, Christian A

    2014-09-01

    Mudai is a traditional fermented beverage, made from the seeds of the Araucaria araucana tree by Mapuche communities. The main goal of the present study was to identify and characterize the yeast microbiota responsible of Mudai fermentation as well as from A. araucana seeds and bark from different locations in Northern Patagonia. Only Hanseniaspora uvarum and a commercial bakery strain of Saccharomyces cerevisiae were isolated from Mudai and all Saccharomyces isolates recovered from A. araucana seed and bark samples belonged to the cryotolerant species Saccharomyces eubayanus and Saccharomyces uvarum. These two species were already reported in Nothofagus trees from Patagonia; however, this is the first time that they were isolated from A. araucana, which extends their ecological distribution. The presence of these species in A. araucana seeds and bark samples, led us to postulate a potential role for them as the original yeasts responsible for the elaboration of Mudai before the introduction of commercial S. cerevisiae cultures. The molecular and genetic characterization of the S. uvarum and S. eubayanus isolates and their comparison with European S. uvarum strains and S. eubayanus hybrids (S. bayanus and S. pastorianus), allowed their ecology and evolution us to be examined. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  17. Genomic Insights into the Saccharomyces sensu stricto Complex

    PubMed Central

    Borneman, Anthony R.; Pretorius, Isak S.

    2015-01-01

    The Saccharomyces sensu stricto group encompasses species ranging from the industrially ubiquitous yeast Saccharomyces cerevisiae to those that are confined to geographically limited environmental niches. The wealth of genomic data that are now available for the Saccharomyces genus is providing unprecedented insights into the genomic processes that can drive speciation and evolution, both in the natural environment and in response to human-driven selective forces during the historical “domestication” of these yeasts for baking, brewing, and winemaking. PMID:25657346

  18. Sun-Earth Scientists and Native Americans Collaborate on Sun-Earth Day

    NASA Astrophysics Data System (ADS)

    Ng, C. Y.; Lopez, R. E.; Hawkins, I.

    2004-12-01

    Sun-Earth Connection scientists have established partnerships with several minority professional societies to reach out to the blacks, Hispanics and Native American students. Working with NSBP, SACNAS, AISES and NSHP, SEC scientists were able to speak in their board meetings and national conferences, to network with minority scientists, and to engage them in Sun-Earth Day. Through these opportunities and programs, scientists have introduced NASA research results as well indigenous views of science. They also serve as role models in various communities. Since the theme for Sun-Earth Day 2005 is Ancient Observatories: Timeless Knowledge, scientists and education specialists are hopeful to excite many with diverse backgrounds. Sun-Earth Day is a highly visible annual program since 2001 that touches millions of students and the general public. Interviews, classroom activities and other education resources are available on the web at sunearthday.nasa.gov.

  19. Gradient Sun [still

    NASA Image and Video Library

    2017-12-08

    To view a video of the Gradient Sun go to: www.flickr.com/photos/gsfc/8103212817 Looking at a particularly beautiful image of the sun helps show how the lines between science and art can sometimes blur. But there is more to the connection between the two disciplines: science and art techniques are often quite similar, indeed one may inform the other or be improved based on lessons from the other arena. One such case is a technique known as a "gradient filter" – recognizable to many people as an option available on a photo-editing program. Gradients are, in fact, a mathematical description that highlights the places of greatest physical change in space. A gradient filter, in turn, enhances places of contrast, making them all the more obviously different, a useful tool when adjusting photos. Scientists, too, use gradient filters to enhance contrast, using them to accentuate fine structures that might otherwise be lost in the background noise. On the sun, for example, scientists wish to study a phenomenon known as coronal loops, which are giant arcs of solar material constrained to travel along that particular path by the magnetic fields in the sun's atmosphere. Observations of the loops, which can be more or less tangled and complex during different phases of the sun's 11-year activity cycle, can help researchers understand what's happening with the sun's complex magnetic fields, fields that can also power great eruptions on the sun such as solar flares or coronal mass ejections. The still here shows an unfiltered image from the sun next to one that has been processed using a gradient filter. Note how the coronal loops are sharp and defined, making them all the more easy to study. On the other hand, gradients also make great art. NASA/Goddard Space Flight Center To download this video go to: svs.gsfc.nasa.gov/goto?11112 NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics

  20. Biotechnology of non-Saccharomyces yeasts-the basidiomycetes.

    PubMed

    Johnson, Eric A

    2013-09-01

    Yeasts are the major producer of biotechnology products worldwide, exceeding production in capacity and economic revenues of other groups of industrial microorganisms. Yeasts have wide-ranging fundamental and industrial importance in scientific, food, medical, and agricultural disciplines (Fig. 1). Saccharomyces is the most important genus of yeast from fundamental and applied perspectives and has been expansively studied. Non-Saccharomyces yeasts (non-conventional yeasts) including members of the Ascomycetes and Basidiomycetes also have substantial current utility and potential applicability in biotechnology. In an earlier mini-review, "Biotechnology of non-Saccharomyces yeasts-the ascomycetes" (Johnson Appl Microb Biotechnol 97: 503-517, 2013), the extensive biotechnological utility and potential of ascomycetous yeasts are described. Ascomycetous yeasts are particularly important in food and ethanol formation, production of single-cell protein, feeds and fodder, heterologous production of proteins and enzymes, and as model and fundamental organisms for the delineation of genes and their function in mammalian and human metabolism and disease processes. In contrast, the roles of basidiomycetous yeasts in biotechnology have mainly been evaluated only in the past few decades and compared to the ascomycetous yeasts and currently have limited industrial utility. From a biotechnology perspective, the basidiomycetous yeasts are known mainly for the production of enzymes used in pharmaceutical and chemical synthesis, for production of certain classes of primary and secondary metabolites such as terpenoids and carotenoids, for aerobic catabolism of complex carbon sources, and for bioremediation of environmental pollutants and xenotoxicants. Notwithstanding, the basidiomycetous yeasts appear to have considerable potential in biotechnology owing to their catabolic utilities, formation of enzymes acting on recalcitrant substrates, and through the production of unique primary

  1. Outlining a future for non-Saccharomyces yeasts: selection of putative spoilage wine strains to be used in association with Saccharomyces cerevisiae for grape juice fermentation.

    PubMed

    Domizio, Paola; Romani, Cristina; Lencioni, Livio; Comitini, Francesca; Gobbi, Mirko; Mannazzu, Ilaria; Ciani, Maurizio

    2011-06-30

    The use of non-Saccharomyces yeasts that are generally considered as spoilage yeasts, in association with Saccharomyces cerevisiae for grape must fermentation was here evaluated. Analysis of the main oenological characteristics of pure cultures of 55 yeasts belonging to the genera Hanseniaspora, Pichia, Saccharomycodes and Zygosaccharomyces revealed wide biodiversity within each genus. Moreover, many of these non-Saccharomyces strains had interesting oenological properties in terms of fermentation purity, and ethanol and secondary metabolite production. The use of four non-Saccharomyces yeasts (one per genus) in mixed cultures with a commercial S. cerevisiae strain at different S. cerevisiae/non-Saccharomyces inoculum ratios was investigated. This revealed that most of the compounds normally produced at high concentrations by pure cultures of non-Saccharomyces, and which are considered detrimental to wine quality, do not reach threshold taste levels in these mixed fermentations. On the other hand, the analytical profiles of the wines produced by these mixed cultures indicated that depending on the yeast species and the S. cerevisiae/non-Saccharomyces inoculum ratio, these non-Saccharomyces yeasts can be used to increase production of polysaccharides and to modulate the final concentrations of acetic acid and volatile compounds, such as ethyl acetate, phenyl-ethyl acetate, 2-phenyl ethanol, and 2-methyl 1-butanol. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Identification and Characterization of Mutations Affecting Sporulation in Saccharomyces Cerevisiae

    PubMed Central

    Smith, L. M.; Robbins, L. G.; Kennedy, A.; Magee, P. T.

    1988-01-01

    Mutations affecting the synthesis of the sporulation amyloglucosidase were isolated in a homothallic strain of Saccharomyces cerevisiae, SCMS7-1. Two were found, both of which were deficient in sporulation at 34°. One, SL484, sporulated to 50% normal levels at 30° but less than 5% at 34° or 22°. The other, SL641, failed to sporulate at any temperature. Both mutants were blocked before premeiotic DNA synthesis, and both complemented spo1, spo3, and spo7. Genetic analysis of the mutation in SL484 indicated linkage to TRP5 and placed the gene 10 map units from TRP5 on chromosome VII. A plasmid containing an insert which complements the mutation in SL484 fails to complement SL641. We therefore conclude that these two mutations are in separate genes and we propose to call these genes SPO17 and SPO18. These two genes are (with SPO7, SPO8, and SPO9) among the earliest identified in the sporulation pathway and may interact directly with the positive and negative regulators RME and IME. PMID:3147221

  3. Photometer Tracks The Sun

    NASA Technical Reports Server (NTRS)

    Matsumoto, Tak; Mina, Cesar; Russell, Philip; Van Ark, William

    1988-01-01

    Airborne Sun-tracking photometer enables observations of Sun during much greater portion of flights than previously possible, without special maneuvers of airplane. Instrument occupies dome atop airplane. Fiberglass dome protects photometer and rotates to aim photometer in azimuth and elevation to track Sun. Provides controlled environment for instrument, including mechanical and electronic parts. Instrument calibrated without removing it from airplane.

  4. Induction of homologous recombination in Saccharomyces cerevisiae.

    PubMed

    Simon, J R; Moore, P D

    1988-09-01

    We have investigated the effects of UV irradiation of Saccharomyces cerevisiae in order to distinguish whether UV-induced recombination results from the induction of enzymes required for homologous recombination, or the production of substrate sites for recombination containing regions of DNA damage. We utilized split-dose experiments to investigate the induction of proteins required for survival, gene conversion, and mutation in a diploid strain of S. cerevisiae. We demonstrate that inducing doses of UV irradiation followed by a 6 h period of incubation render the cells resistant to challenge doses of UV irradiation. The effects of inducing and challenge doses of UV irradiation upon interchromosomal gene conversion and mutation are strictly additive. Using the yeast URA3 gene cloned in non-replicating single- and double-stranded plasmid vectors that integrate into chromosomal genes upon transformation, we show that UV irradiation of haploid yeast cells and homologous plasmid DNA sequences each stimulate homologous recombination approximately two-fold, and that these effects are additive. Non-specific DNA damage has little effect on the stimulation of homologous recombination, as shown by studies in which UV-irradiated heterologous DNA was included in transformation/recombination experiments. We further demonstrate that the effect of competing single- and double-stranded heterologous DNA sequences differs in UV-irradiated and unirradiated cells, suggesting an induction of recombinational machinery in UV-irradiated S. cerevisiae cells.

  5. The development of bactericidal yeast strains by expressing the Pediococcus acidilactici pediocin gene (pedA) in Saccharomyces cerevisiae.

    PubMed

    Schoeman, H; Vivier, M A; Du Toit, M; Dicks, L M; Pretorius, I S

    1999-06-15

    The excessive use of sulphur dioxide and other chemical preservatives in wine, beer and other fermented food and beverage products to prevent the growth of unwanted microbes holds various disadvantages for the quality of the end-products and is confronted by mounting consumer resistance. The objective of this study was to investigate the feasibility of controlling spoilage bacteria during yeast-based fermentations by engineering bactericidal strains of Saccharomyces cerevisiae. To test this novel concept, we have successfully expressed a bacteriocin gene in yeast. The pediocin operon of Pediococcus acidilactici PAC1.0 consists of four clustered genes, namely pedA (encoding a 62 amino acid precursor of the PA-1 pediocin), pedB (encoding an immunity factor), pedC (encoding a PA-1 transport protein) and pedD (encoding a protein involved in the transport and processing of PA-1). The pedA gene was inserted into a yeast expression/secretion cassette and introduced as a multicopy episomal plasmid into a laboratory strain (Y294) of S. cerevisiae. Northern blot analysis confirmed that the pedA structural gene in this construct (ADH1P-MFa1S-pedA-ADH1T, designated PED1), was efficiently expressed under the control of the yeast alcohol dehydrogenase I gene promoter (ADH1P) and terminator (ADH1T). Secretion of the PED1-encoded pediocin PA-1 was directed by the yeast mating pheromone alpha-factor's secretion signal (MFa1S). The presence of biologically active antimicrobial peptides produced by the yeast transformants was indicated by agar diffusion assays against sensitive indicator bacteria (e.g. Listeria monocytogenes B73). Protein analysis indicated the secreted heterologous peptide to be approximately 4.6 kDa, which conforms to the expected size. The heterologous peptide was present at relatively low levels in the yeast supernatant but pediocin activity was readily detected when intact yeast colonies were used in sensitive strain overlays. This study could lead to the

  6. Genomic insights into the Saccharomyces sensu stricto complex.

    PubMed

    Borneman, Anthony R; Pretorius, Isak S

    2015-02-01

    The Saccharomyces sensu stricto group encompasses species ranging from the industrially ubiquitous yeast Saccharomyces cerevisiae to those that are confined to geographically limited environmental niches. The wealth of genomic data that are now available for the Saccharomyces genus is providing unprecedented insights into the genomic processes that can drive speciation and evolution, both in the natural environment and in response to human-driven selective forces during the historical "domestication" of these yeasts for baking, brewing, and winemaking. Copyright © 2015 by the Genetics Society of America.

  7. The Saccharomyces cerevisiae DPM1 gene encoding dolichol-phosphate-mannose synthase is able to complement a glycosylation-defective mammalian cell line.

    PubMed Central

    Beck, P J; Orlean, P; Albright, C; Robbins, P W; Gething, M J; Sambrook, J F

    1990-01-01

    The Saccharomyces cerevisiae DPM1 gene product, dolichol-phosphate-mannose (Dol-P-Man) synthase, is involved in the coupled processes of synthesis and membrane translocation of Dol-P-Man. Dol-P-Man is the lipid-linked sugar donor of the last four mannose residues that are added to the core oligosaccharide transferred to protein during N-linked glycosylation in the endoplasmic reticulum. We present evidence that the S. cerevisiae gene DPM1, when stably transfected into a mutant Chinese hamster ovary cell line, B4-2-1, is able to correct the glycosylation defect of the cells. Evidence for complementation includes (i) fluorescence-activated cell sorter analysis of differential lectin binding to cell surface glycoproteins, (ii) restoration of Dol-P-Man synthase enzymatic activity in crude cell lysates, (iii) isolation and high-performance liquid chromatography fractionation of the lipid-linked oligosaccharides synthesized in the transfected and control cell lines, and (iv) the restoration of endoglycosidase H sensitivity to the oligosaccharides transferred to a specific glycoprotein synthesized in the DPM1 CHO transfectants. Indirect immunofluorescence with a primary antibody directed against the DPM1 protein shows a reticular staining pattern of protein localization in transfected hamster and monkey cell lines. Images PMID:2201896

  8. A rapid method for differentiating Saccharomyces sensu stricto strains from other yeast species in an enological environment.

    PubMed

    Nardi, Tiziana; Carlot, Milena; De Bortoli, Elena; Corich, Viviana; Giacomini, Alessio

    2006-11-01

    During programs for the selection of enological yeasts, several hundred natural isolates are usually screened. The scope of these operations is to isolate strains possessing good fermentative properties without necessarily arriving at a precise species designation: in other words, to detect strains belonging to the Saccharomyces sensu stricto complex. In the present study, a pair of primers, designed within the variable D1/D2 region of the 26S subunit of ribosomal yeast RNA, have been constructed. These generate an amplification fragment of 471 bp that is specific for the seven Saccharomyces sensu stricto species, while no signal was obtained for Saccharomyces sensu lato strains (17 species) or for another 18 selected species commonly found in enological environments. A second pair of primers was also constructed, within the 18S rRNA gene, composed of perfectly conserved sequences common for all 42 yeast species examined, which generate a 900 bp (c.) band for all strains. This was used as a positive experimental control in multiplex PCR analysis using all four primers.

  9. Child sun protection: sun-related attitudes mediate the association between children's knowledge and behaviours.

    PubMed

    Wright, Caradee; Reeder, Anthony I; Gray, Andrew; Cox, Brian

    2008-12-01

    To describe and investigate the relationship among the sun-related knowledge, attitudes and behaviours of New Zealand primary schoolchildren and consider the roles of sex and school year level. A randomly selected, two-stage cluster sample of 488 children from 27 primary schools in five regions of New Zealand was surveyed regarding their sun-related knowledge, attitudes and behaviours. A scoring system was used to assign a knowledge, attitude and behaviour score to each child. Although knowledge increased with school year level, there was a decline in sun protective attitudes and behaviours. There was little variation in knowledge, attitudes and behaviour between boys and girls, but sex-year level interactions were found for knowledge and behaviour. When considering children's knowledge, attitudes and behaviours simultaneously, knowledge was only significantly associated with behaviours when mediated by attitudes. When targeting child sun protection and skin cancer prevention programmes, a focus on attitudes towards sun exposure and a suntan may prove beneficial in influencing sun-related behaviours.

  10. Disruption of the processing alpha-mannosidase gene does not prevent outer chain synthesis in Saccharomyces cerevisiae.

    PubMed Central

    Puccia, R; Grondin, B; Herscovics, A

    1993-01-01

    Processing of N-linked oligosaccharides in Saccharomyces cerevisiae begins with the removal of glucose and mannose residues from Glc3Man9GlcNAc2 to form a single isomer of Man8GlcNAc2. The importance of mannose removal for subsequent outer chain synthesis was examined in strains of S. cerevisiae disrupted in the MNS1 gene encoding a specific alpha 1,2-mannosidase responsible for Man8GlcNAc2 synthesis [Camirand, Heysen, Grondin and Herscovics (1991) J. Biol. Chem. 266, 15120-15127]. Both MNS1 transcripts of 1.85 kb and 1.7 kb were not observed in Northern blots of mns1 cells (i.e. cells containing the disrupted gene). Analysis on Bio-Gel P-6 of endo-beta-N-acetylglucosaminidase-H-sensitive oligosaccharides following a 10 min pulse with [2-3H]mannose revealed similar amounts of labelled outer chains excluded from the gel in both control and mns1 cells. H.p.l.c. of the included oligosaccharides showed that a Man9GlcNAc, rather than a Man8GlcNAc, intermediate was formed in mns1 cells. Analysis of [3H]mannose-labelled core oligosaccharides from immunoprecipitated CPY and invertase by h.p.l.c. showed a similar size distribution in mns1 and control cells. Invertase immunoprecipitated from [35S]methionine-labelled mns1 cells was highly glycosylated, but migrated slightly faster than that from control cells on denaturing PAGE, indicating a small difference in glycosylation. A similar difference in mobility was observed for invertase activity stain following non-denaturing gel electrophoresis. It is concluded that the alpha-mannosidase encoded by MNS1 is the only enzyme responsible for mannose removal in vivo, and that this processing step is not essential for outer chain synthesis. Images Figure 1 Figure 4 PMID:8439291

  11. Disruption of the processing alpha-mannosidase gene does not prevent outer chain synthesis in Saccharomyces cerevisiae.

    PubMed

    Puccia, R; Grondin, B; Herscovics, A

    1993-02-15

    Processing of N-linked oligosaccharides in Saccharomyces cerevisiae begins with the removal of glucose and mannose residues from Glc3Man9GlcNAc2 to form a single isomer of Man8GlcNAc2. The importance of mannose removal for subsequent outer chain synthesis was examined in strains of S. cerevisiae disrupted in the MNS1 gene encoding a specific alpha 1,2-mannosidase responsible for Man8GlcNAc2 synthesis [Camirand, Heysen, Grondin and Herscovics (1991) J. Biol. Chem. 266, 15120-15127]. Both MNS1 transcripts of 1.85 kb and 1.7 kb were not observed in Northern blots of mns1 cells (i.e. cells containing the disrupted gene). Analysis on Bio-Gel P-6 of endo-beta-N-acetylglucosaminidase-H-sensitive oligosaccharides following a 10 min pulse with [2-3H]mannose revealed similar amounts of labelled outer chains excluded from the gel in both control and mns1 cells. H.p.l.c. of the included oligosaccharides showed that a Man9GlcNAc, rather than a Man8GlcNAc, intermediate was formed in mns1 cells. Analysis of [3H]mannose-labelled core oligosaccharides from immunoprecipitated CPY and invertase by h.p.l.c. showed a similar size distribution in mns1 and control cells. Invertase immunoprecipitated from [35S]methionine-labelled mns1 cells was highly glycosylated, but migrated slightly faster than that from control cells on denaturing PAGE, indicating a small difference in glycosylation. A similar difference in mobility was observed for invertase activity stain following non-denaturing gel electrophoresis. It is concluded that the alpha-mannosidase encoded by MNS1 is the only enzyme responsible for mannose removal in vivo, and that this processing step is not essential for outer chain synthesis.

  12. Requirement of the Saccharomyces cerevisiae APN1 Gene for the Repair of Mitochondrial DNA Alkylation Damage

    PubMed Central

    Acevedo-Torres, Karina; Fonseca-Williams, Sharon; Ayala-Torres, Sylvette; Torres-Ramos, Carlos A.

    2010-01-01

    The Saccharomyces cerevisiae APN1 gene that participates in base excision repair has been localized both in the nucleus and the mitochondria. APN1 deficient cells (apn1Δ) show increased mutation frequencies in mitochondrial DNA (mtDNA) suggesting that APN1 is also important for mtDNA stability. To understand APN1-dependent mtDNA repair processes we studied the formation and repair of mtDNA lesions in cells exposed to methyl methanesulfonate (MMS). We show that MMS induces mtDNA damage in a dose-dependent fashion and that deletion of the APN1 gene enhances the susceptibility of mtDNA to MMS. Repair kinetic experiments demonstrate that in wild-type cells (WT) it takes 4 hr to repair the damage induced by 0.1% MMS, whereas in the apn1Δ strain there is a lag in mtDNA repair that results in significant differences in the repair capacity between the two yeast strains. Analysis of lesions in nuclear DNA (nDNA) after treatment with 0.1% MMS shows a significant difference in the amount of nDNA lesions between WT and apn1Δ cells. Interestingly, comparisons between nDNA and mtDNA damage show that nDNA is more sensitive to the effects of MMS treatment. However, both strains are able to repair the nDNA lesions, contrary to mtDNA repair, which is compromised in the apn1Δ mutant strain. Therefore, although nDNA is more sensitive than mtDNA to the effects of MMS, deletion of APN1 has a stronger phenotype in mtDNA repair than in nDNA. These results highlight the prominent role of APN1 in the repair of environmentally induced mtDNA damage. PMID:19197988

  13. Mutation in the peroxin-coding gene PEX22 contributing to high malate production in Saccharomyces cerevisiae.

    PubMed

    Negoro, Hiroaki; Sakamoto, Mitsuru; Kotaka, Atsushi; Matsumura, Kengo; Hata, Yoji

    2018-02-01

    Saccharomyces cerevisiae produces organic acids such as succinate, acetate, and malate during alcoholic fermentation. Since malate contributes to the pleasant taste of sake (a Japanese alcoholic beverage), various methods for breeding high-malate-producing yeast strains have been developed. Here, a high-malate-producing yeast strain F-701H was isolated. This mutant was sensitive to dimethyl succinate (DMS) and harbored a nonsense mutation in the peroxin gene PEX22, which was identified as the cause of high malate production by comparative genome analysis. This mutation, which appeared to cause Pex22p dysfunction, was sufficient to confer increased malate productivity and DMS sensitivity to yeast cells. Next, we investigated the mechanism by which this mutation led to high malate production in yeast cells. Peroxins, such as Pex22p, maintain peroxisomal biogenesis. Analysis of 29 PEX disruptants revealed an increased malate production by deletion of the genes encoding peroxins responsible for importing proteins (containing peroxisomal targeting signal 1, PTS1) into the peroxisomal matrix, and those responsible for the assembly of peroxins themselves in the peroxisomal membrane. A defect in peroxisomal malate dehydrogenase (Mdh3p), harboring endogenous PTS1, inhibited the high malate-producing phenotype in the PEX22 mutant. Moreover, Mdh3p, which was normally sorted to the peroxisomal matrix, was potentially mislocalized to the cytosol in the PEX22 mutant. This suggested that an increase in malate production resulted from the mislocalization of Mdh3p from the peroxisome to the cytoplasm due to the loss of peroxin-mediated transportation. Thus, the present study revealed a novel mechanism for organic acid productions in yeast during sake brewing. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Overproduction of Geranylgeraniol by Metabolically Engineered Saccharomyces cerevisiae▿

    PubMed Central

    Tokuhiro, Kenro; Muramatsu, Masayoshi; Ohto, Chikara; Kawaguchi, Toshiya; Obata, Shusei; Muramoto, Nobuhiko; Hirai, Masana; Takahashi, Haruo; Kondo, Akihiko; Sakuradani, Eiji; Shimizu, Sakayu

    2009-01-01

    (E, E, E)-Geranylgeraniol (GGOH) is a valuable starting material for perfumes and pharmaceutical products. In the yeast Saccharomyces cerevisiae, GGOH is synthesized from the end products of the mevalonate pathway through the sequential reactions of farnesyl diphosphate synthetase (encoded by the ERG20 gene), geranylgeranyl diphosphate synthase (the BTS1 gene), and some endogenous phosphatases. We demonstrated that overexpression of the diacylglycerol diphosphate phosphatase (DPP1) gene could promote GGOH production. We also found that overexpression of a BTS1-DPP1 fusion gene was more efficient for producing GGOH than coexpression of these genes separately. Overexpression of the hydroxymethylglutaryl-coenzyme A reductase (HMG1) gene, which encodes the major rate-limiting enzyme of the mevalonate pathway, resulted in overproduction of squalene (191.9 mg liter−1) rather than GGOH (0.2 mg liter−1) in test tube cultures. Coexpression of the BTS1-DPP1 fusion gene along with the HMG1 gene partially redirected the metabolic flux from squalene to GGOH. Additional expression of a BTS1-ERG20 fusion gene resulted in an almost complete shift of the flux to GGOH production (228.8 mg liter−1 GGOH and 6.5 mg liter−1 squalene). Finally, we constructed a diploid prototrophic strain coexpressing the HMG1, BTS1-DPP1, and BTS1-ERG20 genes from multicopy integration vectors. This strain attained 3.31 g liter−1 GGOH production in a 10-liter jar fermentor with gradual feeding of a mixed glucose and ethanol solution. The use of bifunctional fusion genes such as the BTS1-DPP1 and ERG20-BTS1 genes that code sequential enzymes in the metabolic pathway was an effective method for metabolic engineering. PMID:19592534

  15. Screening for hydrolytic enzymes reveals Ayr1p as a novel triacylglycerol lipase in Saccharomyces cerevisiae.

    PubMed

    Ploier, Birgit; Scharwey, Melanie; Koch, Barbara; Schmidt, Claudia; Schatte, Jessica; Rechberger, Gerald; Kollroser, Manfred; Hermetter, Albin; Daum, Günther

    2013-12-13

    Saccharomyces cerevisiae, as well as other eukaryotes, preserves fatty acids and sterols in a biologically inert form, as triacylglycerols and steryl esters. The major triacylglycerol lipases of the yeast S. cerevisiae identified so far are Tgl3p, Tgl4p, and Tgl5p (Athenstaedt, K., and Daum, G. (2003) YMR313c/TGL3 encodes a novel triacylglycerol lipase located in lipid particles of Saccharomyces cerevisiae. J. Biol. Chem. 278, 23317-23323; Athenstaedt, K., and Daum, G. (2005) Tgl4p and Tgl5p, two triacylglycerol lipases of the yeast Saccharomyces cerevisiae, are localized to lipid particles. J. Biol. Chem. 280, 37301-37309). We observed that upon cultivation on oleic acid, triacylglycerol mobilization did not come to a halt in a yeast strain deficient in all currently known triacylglycerol lipases, indicating the presence of additional not yet characterized lipases/esterases. Functional proteome analysis using lipase and esterase inhibitors revealed a subset of candidate genes for yet unknown hydrolytic enzymes on peroxisomes and lipid droplets. Based on the conserved GXSXG lipase motif, putative functions, and subcellular localizations, a selected number of candidates were characterized by enzyme assays in vitro, gene expression analysis, non-polar lipid analysis, and in vivo triacylglycerol mobilization assays. These investigations led to the identification of Ayr1p as a novel triacylglycerol lipase of yeast lipid droplets and confirmed the hydrolytic potential of the peroxisomal Lpx1p in vivo. Based on these results, we discuss a possible link between lipid storage, lipid mobilization, and peroxisomal utilization of fatty acids as a carbon source.

  16. 'Yeast mail': a novel Saccharomyces application (NSA) to encrypt messages.

    PubMed

    Rosemeyer, Helmut; Paululat, Achim; Heinisch, Jürgen J

    2014-09-01

    The universal genetic code is used by all life forms to encode biological information. It can also be used to encrypt semantic messages and convey them within organisms without anyone but the sender and recipient knowing, i.e., as a means of steganography. Several theoretical, but comparatively few experimental, approaches have been dedicated to this subject, so far. Here, we describe an experimental system to stably integrate encrypted messages within the yeast genome using a polymerase chain reaction (PCR)-based, one-step homologous recombination system. Thus, DNA sequences encoding alphabetical and/or numerical information will be inherited by yeast propagation and can be sent in the form of dried yeast. Moreover, due to the availability of triple shuttle vectors, Saccharomyces cerevisiae can also be used as an intermediate construction device for transfer of information to either Drosophila or mammalian cells as steganographic containers. Besides its classical use in alcoholic fermentation and its modern use for heterologous gene expression, we here show that baker's yeast can thus be employed in a novel Saccharomyces application (NSA) as a simple steganographic container to hide and convey messages. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

  17. Mercury Transit Across the Sun

    NASA Image and Video Library

    2016-05-09

    On May 9, 2016, Mercury passed directly between the Sun and Earth, making a transit of the Sun. Mercury transits happen about 13 times each century. NASA SDO studies the Sun 24/7 and captured the eight-hour event.

  18. Mixing of vineyard and oak-tree ecotypes of Saccharomyces cerevisiae in North American vineyards

    PubMed Central

    Hyma, Katie E.; Fay, Justin C.

    2012-01-01

    Humans have had a significant impact on the distribution and abundance of Saccharomyces cerevisiae through its widespread use in beer, bread and wine production. Yet, similar to other Saccharomyces species, S. cerevisiae has also been isolated from habitats unrelated to fermentations. Strains of S. cerevisiae isolated from grapes, wine must and vineyards worldwide are genetically differentiated from strains isolated from oak-tree bark, exudate and associated soil in North America. However, the causes and consequences of this differentiation have not yet been resolved. Historical differentiation of these two groups may have been influenced by geographic, ecological or human-associated barriers to gene flow. Here, we make use of the relatively recent establishment of vineyards across North America to identify and characterize any active barriers to gene flow between these two groups. We examined S. cerevisiae strains isolated from grapes and oak-trees within three North American vineyards and compared them to those isolated from oak-trees outside of vineyards. Within vineyards we found evidence of migration between grapes and oak-trees and potential gene flow between the divergent oak-tree and vineyard groups. Yet, we found no vineyard genotypes on oak-trees outside of vineyards. In contrast, S. paradoxus isolated from the same sources showed population structure characterized by isolation by distance. The apparent absence of ecological or genetic barriers between sympatric vineyard and oak-tree populations of S. cerevisiae implies that vineyards play an important role in the mixing between these two groups. PMID:23286354

  19. Engineering industrial Saccharomyces cerevisiae strains for xylose fermentation and comparison for switchgrass conversion.

    PubMed

    Hector, Ronald E; Dien, Bruce S; Cotta, Michael A; Qureshi, Nasib

    2011-09-01

    Saccharomyces' physiology and fermentation-related properties vary broadly among industrial strains used to ferment glucose. How genetic background affects xylose metabolism in recombinant Saccharomyces strains has not been adequately explored. In this study, six industrial strains of varied genetic background were engineered to ferment xylose by stable integration of the xylose reductase, xylitol dehydrogenase, and xylulokinase genes. Aerobic growth rates on xylose were 0.04-0.17 h(-1). Fermentation of xylose and glucose/xylose mixtures also showed a wide range of performance between strains. During xylose fermentation, xylose consumption rates were 0.17-0.31 g/l/h, with ethanol yields 0.18-0.27 g/g. Yields of ethanol and the metabolite xylitol were positively correlated, indicating that all of the strains had downstream limitations to xylose metabolism. The better-performing engineered and parental strains were compared for conversion of alkaline pretreated switchgrass to ethanol. The engineered strains produced 13-17% more ethanol than the parental control strains because of their ability to ferment xylose.

  20. Distribution and regulation of stochasticity and plasticity in Saccharomyces cerevisiae

    DOE PAGES

    Dar, R. D.; Karig, D. K.; Cooke, J. F.; ...

    2010-09-01

    Stochasticity is an inherent feature of complex systems with nanoscale structure. In such systems information is represented by small collections of elements (e.g. a few electrons on a quantum dot), and small variations in the populations of these elements may lead to big uncertainties in the information. Unfortunately, little is known about how to work within this inherently noisy environment to design robust functionality into complex nanoscale systems. Here, we look to the biological cell as an intriguing model system where evolution has mediated the trade-offs between fluctuations and function, and in particular we look at the relationships and trade-offsmore » between stochastic and deterministic responses in the gene expression of budding yeast (Saccharomyces cerevisiae). We find gene regulatory arrangements that control the stochastic and deterministic components of expression, and show that genes that have evolved to respond to stimuli (stress) in the most strongly deterministic way exhibit the most noise in the absence of the stimuli. We show that this relationship is consistent with a bursty 2-state model of gene expression, and demonstrate that this regulatory motif generates the most uncertainty in gene expression when there is the greatest uncertainty in the optimal level of gene expression.« less

  1. Advancing Metabolic Engineering of Saccharomyces cerevisiae Using the CRISPR/Cas System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lian, Jiazhang; HamediRad, Mohammad; Zhao, Huimin

    Thanks to its ease of use, modularity, and scalability, the clustered regularly interspaced short palindromic repeats (CRISPR) system has been increasingly used in the design and engineering of Saccharomyces cerevisiae, one of the most popular hosts for industrial biotechnology. This review summarizes the recent development of this disruptive technology for metabolic engineering applications, including CRISPR-mediated gene knock-out and knock-in as well as transcriptional activation and interference. More importantly, multi-functional CRISPR systems that combine both gain- and loss-of-function modulations for combinatorial metabolic engineering are highlighted.

  2. Advancing Metabolic Engineering of Saccharomyces cerevisiae Using the CRISPR/Cas System

    DOE PAGES

    Lian, Jiazhang; HamediRad, Mohammad; Zhao, Huimin

    2018-04-18

    Thanks to its ease of use, modularity, and scalability, the clustered regularly interspaced short palindromic repeats (CRISPR) system has been increasingly used in the design and engineering of Saccharomyces cerevisiae, one of the most popular hosts for industrial biotechnology. This review summarizes the recent development of this disruptive technology for metabolic engineering applications, including CRISPR-mediated gene knock-out and knock-in as well as transcriptional activation and interference. More importantly, multi-functional CRISPR systems that combine both gain- and loss-of-function modulations for combinatorial metabolic engineering are highlighted.

  3. Orbit-attitude coupled motion around small bodies: Sun-synchronous orbits with Sun-tracking attitude motion

    NASA Astrophysics Data System (ADS)

    Kikuchi, Shota; Howell, Kathleen C.; Tsuda, Yuichi; Kawaguchi, Jun'ichiro

    2017-11-01

    The motion of a spacecraft in proximity to a small body is significantly perturbed due to its irregular gravity field and solar radiation pressure. In such a strongly perturbed environment, the coupling effect of the orbital and attitude motions exerts a large influence that cannot be neglected. However, natural orbit-attitude coupled dynamics around small bodies that are stationary in both orbital and attitude motions have yet to be observed. The present study therefore investigates natural coupled motion that involves both a Sun-synchronous orbit and Sun-tracking attitude motion. This orbit-attitude coupled motion enables a spacecraft to maintain its orbital geometry and attitude state with respect to the Sun without requiring active control. Therefore, the proposed method can reduce the use of an orbit and attitude control system. This paper first presents analytical conditions to achieve Sun-synchronous orbits and Sun-tracking attitude motion. These analytical solutions are then numerically propagated based on non-linear coupled orbit-attitude equations of motion. Consequently, the possibility of implementing Sun-synchronous orbits with Sun-tracking attitude motion is demonstrated.

  4. SunSmart: evaluation of a pilot school-based sun protection intervention in Hispanic early adolescents

    PubMed Central

    Miller, K. A.; Langholz, B. M.; Ly, T.; Harris, S. C.; Richardson, J. L.; Peng, D. H.; Cockburn, M. G.

    2015-01-01

    The incidence of melanoma is rising among Hispanic populations in the United States. The purpose of this study is to evaluate the impact of a pilot sun safety educational intervention conducted from 2006 to 2012 on Hispanic early adolescents in a high ultraviolet environment. Nineteen schools with high Hispanic enrollment were recruited from urban neighborhoods in Los Angeles. The analytic sample was restricted to students identifying as Hispanic or Latino (n = 777). A mixed effects linear model was used to test mean changes from pre- to posttest on students’ sun protection knowledge, attitudes and behaviors. Significant improvements were observed across several cognitive outcomes related to sun protection, including knowledge of and attitudes toward sun protection and self-efficacy to wear sunscreen. However, changes in sun protective behaviors were not achieved. Although some improvements were observed, future studies should identify the factors that motivate sun protection in this population and develop tailored prevention strategies, as improving the sun safe behaviors of Hispanic youths may aid in reducing the risk of melanoma in adulthood in this population. PMID:25801103

  5. Improved ethanol production in the presence of cadmium ions by a Saccharomyces cerevisiae transformed with a novel cadmium-resistance gene DvCRP1.

    PubMed

    Hu, Jiajun; Xu, Qingyun; Wu, Mengnan; Meng, Xiangzong; Song, Rentao; Gao, Mintian

    2016-11-01

    The DvCRP1 gene obtained from Dunaliella viridis is a cadmium-resistance gene that induces cadmium accumulation in microbial and plant cells. In the present study, Saccharomyces cerevisiae was used as a model system to investigate the effect of DvCRP1 on both cadmium detoxification and ethanol production. Inhibitory effects of cadmium (50-300 µmol/L) on growth (29-92%), glucose consumption (23-89%), and ethanol production (17-92%) were observed at 24 h by S. cerevisiae. DvCRP1 alleviated the inhibitory effect of cadmium, with increase in the ethanol production. The established mathematical model showed that the initial inoculation concentration, cadmium concentration, and transformation of DvCRP1 were the most important factors for cell growth, glucose consumption, and ethanol production. Cadmium detoxification of yeast was also enhanced by increasing the initial concentration of yeast cells. Transforming with DvCRP1 further enhanced detoxification, especially at high cadmium concentrations. Transforming with DvCRP1 further enhanced detoxification, especially at high cadmium concentrations (200 µmol/L). The present results evidenced the potential of the insertion of the DvCRP1 gene into yeast for use in bio-refineries during fermentation of heavy metals-contaminated substrates. In addition, this is a promising method for phytoremediation of agricultural soils highly contaminated by heavy metals.

  6. Genomic and transcriptome analyses reveal that MAPK- and phosphatidylinositol-signaling pathways mediate tolerance to 5-hydroxymethyl-2-furaldehyde for industrial yeast Saccharomyces cerevisiae

    PubMed Central

    Zhou, Qian; Liu, Z. Lewis; Ning, Kang; Wang, Anhui; Zeng, Xiaowei; Xu, Jian

    2014-01-01

    The industrial yeast Saccharomyces cerevisiae is a traditional ethanologenic agent and a promising biocatalyst for advanced biofuels production using lignocellulose mateials. Here we present the genomic background of type strain NRRL Y-12632 and its transcriptomic response to 5-hydroxymethyl-2-furaldehyde (HMF), a commonly encountered toxic compound liberated from lignocellulosic-biomass pretreatment, in dissecting the genomic mechanisms of yeast tolerance. Compared with the genome of laboratory model strain S288C, we identified more than 32,000 SNPs in Y-12632 with 23,000 missense and nonsense SNPs. Enriched sequence mutations occurred for genes involved in MAPK- and phosphatidylinositol (PI)- signaling pathways in strain Y-12632, with 41 and 13 genes containing non-synonymous SNPs, respectively. Many of these mutated genes displayed consistent up-regulated signature expressions in response to challenges of 30 mM HMF. Analogous single-gene deletion mutations of these genes showed significantly sensitive growth response on a synthetic medium containing 20 mM HMF. Our results suggest at least three MAPK-signaling pathways, especially for the cell-wall integrity pathway, and PI-signaling pathways to be involved in mediation of yeast tolerance against HMF in industrial yeast Saccharomyces cerevisiae. Higher levels of sequence variations were also observed for genes involved in purine and pyrimidine metabolism pathways. PMID:25296911

  7. Requirement of mismatch repair genes MSH2 and MSH3 in the RAD1-RAD10 pathway of mitotic recombination in Saccharomyces cerevisiae.

    PubMed

    Saparbaev, M; Prakash, L; Prakash, S

    1996-03-01

    The RAD1 and RAD10 genes of Saccharomyces cerevisiae are required for nucleotide excision repair and they also act in mitotic recombination. The Rad1-Rad10 complex has a single-stranded DNA endonuclease activity. Here, we show that the mismatch repair genes MSH2 and MSH3 function in mitotic recombination. For both his3 and his4 duplications, and for homologous integration of a linear DNA fragment into the genome, the msh3 delta mutation has an effect on recombination similar to that of the rad1 delta and rad10 delta mutations. The msh2 delta mutation also reduces the rate of recombination of the his3 duplication and lowers the incidence of homologous integration of a linear DNA fragment. Epistasis analyses indicate that MSH2 and MSH3 function in the RAD1-RAD10 recombination pathway, and studies presented here suggest an involvement of the RAD1-RAD10 pathway in reciprocal recombination. The possible roles of Msh2, Msh3, Rad1, and Rad10 proteins in genetic recombination are discussed. Coupling of mismatch binding proteins with the recombinational machinery could be important for ensuring genetic fidelity in the recombination process.

  8. Biotechnology of non-Saccharomyces yeasts--the ascomycetes.

    PubMed

    Johnson, Eric A

    2013-01-01

    Saccharomyces cerevisiae and several other yeast species are among the most important groups of biotechnological organisms. S. cerevisiae and closely related ascomycetous yeasts are the major producer of biotechnology products worldwide, exceeding other groups of industrial microorganisms in productivity and economic revenues. Traditional industrial attributes of the S. cerevisiae group include their primary roles in food fermentations such as beers, cider, wines, sake, distilled spirits, bakery products, cheese, sausages, and other fermented foods. Other long-standing industrial processes involving S. cerevisae yeasts are production of fuel ethanol, single-cell protein (SCP), feeds and fodder, industrial enzymes, and small molecular weight metabolites. More recently, non-Saccharomyces yeasts (non-conventional yeasts) have been utilized as industrial organisms for a variety of biotechnological roles. Non-Saccharomyces yeasts are increasingly being used as hosts for expression of proteins, biocatalysts and multi-enzyme pathways for the synthesis of fine chemicals and small molecular weight compounds of medicinal and nutritional importance. Non-Saccharomyces yeasts also have important roles in agriculture as agents of biocontrol, bioremediation, and as indicators of environmental quality. Several of these products and processes have reached commercial utility, while others are in advanced development. The objective of this mini-review is to describe processes currently used by industry and those in developmental stages and close to commercialization primarily from non-Saccharomyces yeasts with an emphasis on new opportunities. The utility of S. cerevisiae in heterologous production of selected products is also described.

  9. Autonomous Sun-Direction Estimation Using Partially Underdetermined Coarse Sun Sensor Configurations

    NASA Astrophysics Data System (ADS)

    O'Keefe, Stephen A.

    In recent years there has been a significant increase in interest in smaller satellites as lower cost alternatives to traditional satellites, particularly with the rise in popularity of the CubeSat. Due to stringent mass, size, and often budget constraints, these small satellites rely on making the most of inexpensive hardware components and sensors, such as coarse sun sensors (CSS) and magnetometers. More expensive high-accuracy sun sensors often combine multiple measurements, and use specialized electronics, to deterministically solve for the direction of the Sun. Alternatively, cosine-type CSS output a voltage relative to the input light and are attractive due to their very low cost, simplicity to manufacture, small size, and minimal power consumption. This research investigates using coarse sun sensors for performing robust attitude estimation in order to point a spacecraft at the Sun after deployment from a launch vehicle, or following a system fault. As an alternative to using a large number of sensors, this thesis explores sun-direction estimation techniques with low computational costs that function well with underdetermined sets of CSS. Single-point estimators are coupled with simultaneous nonlinear control to achieve sun-pointing within a small percentage of a single orbit despite the partially underdetermined nature of the sensor suite. Leveraging an extensive analysis of the sensor models involved, sequential filtering techniques are shown to be capable of estimating the sun-direction to within a few degrees, with no a priori attitude information and using only CSS, despite the significant noise and biases present in the system. Detailed numerical simulations are used to compare and contrast the performance of the five different estimation techniques, with and without rate gyro measurements, their sensitivity to rate gyro accuracy, and their computation time. One of the key concerns with reducing the number of CSS is sensor degradation and failure. In

  10. ATG18 and FAB1 are involved in dehydration stress tolerance in Saccharomyces cerevisiae.

    PubMed

    López-Martínez, Gema; Margalef-Català, Mar; Salinas, Francisco; Liti, Gianni; Cordero-Otero, Ricardo

    2015-01-01

    Recently, different dehydration-based technologies have been evaluated for the purpose of cell and tissue preservation. Although some early results have been promising, they have not satisfied the requirements for large-scale applications. The long experience of using quantitative trait loci (QTLs) with the yeast Saccharomyces cerevisiae has proven to be a good model organism for studying the link between complex phenotypes and DNA variations. Here, we use QTL analysis as a tool for identifying the specific yeast traits involved in dehydration stress tolerance. Three hybrids obtained from stable haploids and sequenced in the Saccharomyces Genome Resequencing Project showed intermediate dehydration tolerance in most cases. The dehydration resistance trait of 96 segregants from each hybrid was quantified. A smooth, continuous distribution of the anhydrobiosis tolerance trait was found, suggesting that this trait is determined by multiple QTLs. Therefore, we carried out a QTL analysis to identify the determinants of this dehydration tolerance trait at the genomic level. Among the genes identified after reciprocal hemizygosity assays, RSM22, ATG18 and DBR1 had not been referenced in previous studies. We report new phenotypes for these genes using a previously validated test. Finally, our data illustrates the power of this approach in the investigation of the complex cell dehydration phenotype.

  11. ATG18 and FAB1 Are Involved in Dehydration Stress Tolerance in Saccharomyces cerevisiae

    PubMed Central

    López-Martínez, Gema; Margalef-Català, Mar; Salinas, Francisco; Liti, Gianni; Cordero-Otero, Ricardo

    2015-01-01

    Recently, different dehydration-based technologies have been evaluated for the purpose of cell and tissue preservation. Although some early results have been promising, they have not satisfied the requirements for large-scale applications. The long experience of using quantitative trait loci (QTLs) with the yeast Saccharomyces cerevisiae has proven to be a good model organism for studying the link between complex phenotypes and DNA variations. Here, we use QTL analysis as a tool for identifying the specific yeast traits involved in dehydration stress tolerance. Three hybrids obtained from stable haploids and sequenced in the Saccharomyces Genome Resequencing Project showed intermediate dehydration tolerance in most cases. The dehydration resistance trait of 96 segregants from each hybrid was quantified. A smooth, continuous distribution of the anhydrobiosis tolerance trait was found, suggesting that this trait is determined by multiple QTLs. Therefore, we carried out a QTL analysis to identify the determinants of this dehydration tolerance trait at the genomic level. Among the genes identified after reciprocal hemizygosity assays, RSM22, ATG18 and DBR1 had not been referenced in previous studies. We report new phenotypes for these genes using a previously validated test. Finally, our data illustrates the power of this approach in the investigation of the complex cell dehydration phenotype. PMID:25803831

  12. Saccharomyces cerevisiae engineered for xylose metabolism requires gluconeogenesis and the oxidative branch of the pentose phosphate pathway for aerobic xylose assimilation

    USDA-ARS?s Scientific Manuscript database

    Saccharomyces strains engineered to ferment xylose using Scheffersomyces stipitis xylose reductase (XR) and xylitol dehydrogenase (XDH) genes appear to be limited by metabolic imbalances due to differing cofactor specificities of XR and XDH. The S. stipitis XR, which uses nicotinamide adenine dinucl...

  13. Identification of genes that function in the biogenesis and localization of small nucleolar RNAs in Saccharomyces cerevisiae.

    PubMed

    Qiu, Hui; Eifert, Julia; Wacheul, Ludivine; Thiry, Marc; Berger, Adam C; Jakovljevic, Jelena; Woolford, John L; Corbett, Anita H; Lafontaine, Denis L J; Terns, Rebecca M; Terns, Michael P

    2008-06-01

    Small nucleolar RNAs (snoRNAs) orchestrate the modification and cleavage of pre-rRNA and are essential for ribosome biogenesis. Recent data suggest that after nucleoplasmic synthesis, snoRNAs transiently localize to the Cajal body (in plant and animal cells) or the homologous nucleolar body (in budding yeast) for maturation and assembly into snoRNPs prior to accumulation in their primary functional site, the nucleolus. However, little is known about the trans-acting factors important for the intranuclear trafficking and nucleolar localization of snoRNAs. Here, we describe a large-scale genetic screen to identify proteins important for snoRNA transport in Saccharomyces cerevisiae. We performed fluorescence in situ hybridization analysis to visualize U3 snoRNA localization in a collection of temperature-sensitive yeast mutants. We have identified Nop4, Prp21, Tao3, Sec14, and Htl1 as proteins important for the proper localization of U3 snoRNA. Mutations in genes encoding these proteins lead to specific defects in the targeting or retention of the snoRNA to either the nucleolar body or the nucleolus. Additional characterization of the mutants revealed impairment in specific steps of U3 snoRNA processing, demonstrating that snoRNA maturation and trafficking are linked processes.

  14. An Examination of Coarse Sun Sensor Contingencies in Attitude Determination and the Sun Vector Calculation

    NASA Technical Reports Server (NTRS)

    Coffey, Brenman; Welch, Ray; Burt, Brad

    2012-01-01

    Satellite pointing is vital to the success of a mission. One element of that entails describing the position of the sun relative to the frame of the satellite. Coarse Sun Sensors (CSS) are typically used to provide the information to calculate the sun's position in Safe Modes or contingency operations. In the OCO-2 configuration there are 13 CSS total, which provide redundant 4 celestial coverage. Failures of the individual CSS elements can introduce holes in the celestial coverage resulting in potential loss of sun knowledge. These failures must be analyzed to determine if the contingency plan is sufficient to assure mission success. First the static case was looked at and determined that at a maximum, 3 CSS failures can be sustained on the body and 1 on the array without causing coverage holes. Also array sensors are more important to mission success. The Sun Vector calculation has been transcribed to MATLAB code and failure scenarios are being examined to determine the maximum error given a set of failure scenarios. This activity indicated that if there is a loss of the sun, the sun-searching algorithm could be modified to use XZ rotation as that is guaranteed to find it whereas the design using the YZ rotation misses the sun if it is at the + or - Y orientation.

  15. High-resolution genome-wide scan of genes, gene-networks and cellular systems impacting the yeast ionome

    USDA-ARS?s Scientific Manuscript database

    To balance the demand for uptake of essential elements with their potential toxicity living cells have complex regulatory mechanisms. Here, we describe a genome-wide screen to identify genes that impact the elemental composition (‘ionome’) of yeast Saccharomyces cerevisiae. Using inductively coupled...

  16. Skin Cancer-Sun Knowledge and Sun Protection Behaviors of Liver Transplant Recipients in Turkey.

    PubMed

    Haney, Meryem Ozturk; Ordin, Yaprak Sarigol; Arkan, Gulcihan

    2017-09-08

    The aim of this study was to compare liver transplant recipients (LTRs) with the general population regarding their knowledge of skin cancer, sun health, sun protection behaviors, and affecting factors. This cross-sectional study was conducted in Turkey between March 2016 and September 2016 with 104 LTRs and 100 participants from the general population group (GPG). The mean age of the LTRs was 53.2 ± 11.8 and that of the GPG was 42.7 ± 14.5. The LTRs' skin cancer and sun knowledge were significantly lower than in the GPG, but there was no difference between the two groups in terms of their sun protection behavior scores. The most commonly used sun protection behaviors of LTRs were not being outside and not sunbathing between 10 a.m. and 4 p.m., wearing clothing that covers the skin, and avoiding the solarium. Behaviors commonly practiced by the GPG were wearing sunglasses, wearing sunscreen with a sun protection factor of 15 or higher before going outside, wearing sunscreen at the beach, while swimming or doing physical activity outside, and reapplying it every 2 h. Results of our study will contribute to the development of education and training programs for LTRs on skin cancer. The results also demonstrated the importance of practicing adequate sun protection behaviors which will certainly impact their future health.

  17. Solar tracking control system Sun Chaser

    NASA Technical Reports Server (NTRS)

    Scott, D. R.; White, P. R.

    1978-01-01

    The solar tracking control system, Sun Chaser, a method of tracking the Sun in all types of weather conditions is described. The Sun Chaser follows the Sun from east to west in clear or cloudy weather, and resets itself to the east position after sundown in readiness for the next sunrise.

  18. SunSmart: evaluation of a pilot school-based sun protection intervention in Hispanic early adolescents.

    PubMed

    Miller, K A; Langholz, B M; Ly, T; Harris, S C; Richardson, J L; Peng, D H; Cockburn, M G

    2015-06-01

    The incidence of melanoma is rising among Hispanic populations in the United States. The purpose of this study is to evaluate the impact of a pilot sun safety educational intervention conducted from 2006 to 2012 on Hispanic early adolescents in a high ultraviolet environment. Nineteen schools with high Hispanic enrollment were recruited from urban neighborhoods in Los Angeles. The analytic sample was restricted to students identifying as Hispanic or Latino (n = 777). A mixed effects linear model was used to test mean changes from pre- to posttest on students' sun protection knowledge, attitudes and behaviors. Significant improvements were observed across several cognitive outcomes related to sun protection, including knowledge of and attitudes toward sun protection and self-efficacy to wear sunscreen. However, changes in sun protective behaviors were not achieved. Although some improvements were observed, future studies should identify the factors that motivate sun protection in this population and develop tailored prevention strategies, as improving the sun safe behaviors of Hispanic youths may aid in reducing the risk of melanoma in adulthood in this population. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  19. Expression of a mutated SPT15 gene in Saccharomyces cerevisiae enhances both cell growth and ethanol production in microaerobic batch, fed-batch, and simultaneous saccharification and fermentations.

    PubMed

    Seong, Yeong-Je; Park, Haeseong; Yang, Jungwoo; Kim, Soo-Jung; Choi, Wonja; Kim, Kyoung Heon; Park, Yong-Cheol

    2017-05-01

    The SPT15 gene encodes a Saccharomyces cerevisiae TATA-binding protein, which is able to globally control the transcription levels of various metabolic and regulatory genes. In this study, a SPT15 gene mutant (S42N, S78R, S163P, and I212N) was expressed in S. cerevisiae BY4741 (BSPT15-M3), of which effects on fermentative yeast properties were evaluated in a series of culture types. By applying different nitrogen sources and air supply conditions in batch culture, organic nitrogen sources and microaerobic condition were decided to be more favorable for both cell growth and ethanol production of the BSPT15-M3 strain than the control S. cerevisiae BY4741 strain expressing the SPT15 gene (BSPT15wt). Microaerobic fed-batch cultures of BSPT15-M3 with glucose shock in the presence of high ethanol content resulted in a 9.5-13.4% higher glucose consumption rate and ethanol productivity than those for the BSPT15wt strain. In addition, BSPT15-M3 showed 4.5 and 3.9% increases in ethanol productivity from cassava hydrolysates and corn starch in simultaneous saccharification and fermentation processes, respectively. It was concluded that overexpression of the mutated SPT15 gene would be a potent strategy to develop robust S. cerevisiae strains with enhanced cell growth and ethanol production abilities.

  20. A genetic network that suppresses genome rearrangements in Saccharomyces cerevisiae and contains defects in cancers

    PubMed Central

    Putnam, Christopher D.; Srivatsan, Anjana; Nene, Rahul V.; Martinez, Sandra L.; Clotfelter, Sarah P.; Bell, Sara N.; Somach, Steven B.; E.S. de Souza, Jorge; Fonseca, André F.; de Souza, Sandro J.; Kolodner, Richard D.

    2016-01-01

    Gross chromosomal rearrangements (GCRs) play an important role in human diseases, including cancer. The identity of all Genome Instability Suppressing (GIS) genes is not currently known. Here multiple Saccharomyces cerevisiae GCR assays and query mutations were crossed into arrays of mutants to identify progeny with increased GCR rates. One hundred eighty two GIS genes were identified that suppressed GCR formation. Another 438 cooperatively acting GIS genes were identified that were not GIS genes, but suppressed the increased genome instability caused by individual query mutations. Analysis of TCGA data using the human genes predicted to act in GIS pathways revealed that a minimum of 93% of ovarian and 66% of colorectal cancer cases had defects affecting one or more predicted GIS gene. These defects included loss-of-function mutations, copy-number changes associated with reduced expression, and silencing. In contrast, acute myeloid leukaemia cases did not appear to have defects affecting the predicted GIS genes. PMID:27071721

  1. FLO11 Gene Is Involved in the Interaction of Flor Strains of Saccharomyces cerevisiae with a Biofilm-Promoting Synthetic Hexapeptide

    PubMed Central

    Bou Zeidan, Marc; Carmona, Lourdes

    2013-01-01

    Saccharomyces cerevisiae “flor” yeasts have the ability to form a buoyant biofilm at the air-liquid interface of wine. The formation of biofilm, also called velum, depends on FLO11 gene length and expression. FLO11 encodes a cell wall mucin-like glycoprotein with a highly O-glycosylated central domain and an N-terminal domain that mediates homotypic adhesion between cells. In the present study, we tested previously known antimicrobial peptides with different mechanisms of antimicrobial action for their effect on the viability and ability to form biofilm of S. cerevisiae flor strains. We found that PAF26, a synthetic tryptophan-rich cationic hexapeptide that belongs to the class of antimicrobial peptides with cell-penetrating properties, but not other antimicrobial peptides, enhanced biofilm formation without affecting cell viability in ethanol-rich medium. The PAF26 biofilm enhancement required a functional FLO11 but was not accompanied by increased FLO11 expression. Moreover, fluorescence microscopy and flow cytometry analyses showed that the PAF26 peptide binds flor yeast cells and that a flo11 gene knockout mutant lost the ability to bind PAF26 but not P113, a different cell-penetrating antifungal peptide, demonstrating that the FLO11 gene is selectively involved in the interaction of PAF26 with cells. Taken together, our data suggest that the cationic and hydrophobic PAF26 hexapeptide interacts with the hydrophobic and negatively charged cell wall, favoring Flo11p-mediated cell-to-cell adhesion and thus increasing biofilm biomass formation. The results are consistent with previous data that point to glycosylated mucin-like proteins at the fungal cell wall as potential interacting partners for antifungal peptides. PMID:23892742

  2. Sun compass error model

    NASA Technical Reports Server (NTRS)

    Blucker, T. J.; Ferry, W. W.

    1971-01-01

    An error model is described for the Apollo 15 sun compass, a contingency navigational device. Field test data are presented along with significant results of the test. The errors reported include a random error resulting from tilt in leveling the sun compass, a random error because of observer sighting inaccuracies, a bias error because of mean tilt in compass leveling, a bias error in the sun compass itself, and a bias error because the device is leveled to the local terrain slope.

  3. SunShot Initiative Portfolio Book 2014

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Solar Energy Technologies Office

    2014-05-01

    The 2014 SunShot Initiative Portfolio Book outlines the progress towards the goals outlined in the SunShot Vision Study. Contents include overviews of each of SunShot’s five subprogram areas, as well as a description of every active project in the SunShot’s project portfolio as of May 2014.

  4. Weekend sun protection and sunburn in Australia trends (1987-2002) and association with SunSmart television advertising.

    PubMed

    Dobbinson, Suzanne J; Wakefield, Melanie A; Jamsen, Kris M; Herd, Natalie L; Spittal, Matthew J; Lipscomb, John E; Hill, David J

    2008-02-01

    The Australian state of Victoria has run a population-based skin cancer prevention program called SunSmart since 1988, incorporating substantial public education efforts and environmental change strategies. Trends over 15 years in behavioral risk factors for skin cancer were examined in a population exposed to the SunSmart program. Whether outcomes were associated with extent of SunSmart television advertising was then assessed. In nine cross-sectional surveys from 1987 to 2002, 11,589 adults were interviewed by telephone about their sun exposure and sun protection during outdoor activities on summer weekends. Analyses completed in 2007 adjusted for ambient temperature and ultraviolet radiation. Sun protection and sunburn show substantial general improvement over time, but have stalled in recent years. Use of hats and sunscreens significantly increased over time and peaked during the mid to late 1990s, compared with the pre-SunSmart baseline. The mean proportion of unprotected skin was reduced and was lowest in the summer of 1997-1998. Summer sunburn incidence declined over time and was 9.1% in 2002, almost half baseline (OR=0.53; 95% CI=0.39-0.73). Higher exposure to SunSmart advertising in the 4 weeks before the interview increased: (1) preference for no tan, (2) hat and sunscreen use, and (3) proportion of body surface protected from the sun. The general improvement in sun-protective behaviors over time highlight that a population's sun-protective behaviors are amenable to change. Population-based prevention programs incorporating substantial television advertising campaigns into the mix of strategies may be highly effective in improving a population's sun-protective behaviors.

  5. Enhancement of protein production via the strong DIT1 terminator and two RNA-binding proteins in Saccharomyces cerevisiae

    PubMed Central

    Ito, Yoichiro; Kitagawa, Takao; Yamanishi, Mamoru; Katahira, Satoshi; Izawa, Shingo; Irie, Kenji; Furutani-Seiki, Makoto; Matsuyama, Takashi

    2016-01-01

    Post-transcriptional upregulation is an effective way to increase the expression of transgenes and thus maximize the yields of target chemicals from metabolically engineered organisms. Refractory elements in the 3′ untranslated region (UTR) that increase mRNA half-life might be available. In Saccharomyces cerevisiae, several terminator regions have shown activity in increasing the production of proteins by upstream coding genes; among these terminators the DIT1 terminator has the highest activity. Here, we found in Saccharomyces cerevisiae that two resident trans-acting RNA-binding proteins (Nab6p and Pap1p) enhance the activity of the DIT1 terminator through the cis element GUUCG/U within the 3′-UTR. These two RNA-binding proteins could upregulate a battery of cell-wall–related genes. Mutagenesis of the DIT1 terminator improved its activity by a maximum of 500% of that of the standard PGK1 terminator. Further understanding and improvement of this system will facilitate inexpensive and stable production of complicated organism-derived drugs worldwide. PMID:27845367

  6. Ecological Success of a Group of Saccharomyces cerevisiae/Saccharomyces kudriavzevii Hybrids in the Northern European Wine-Making Environment

    PubMed Central

    Erny, C.; Raoult, P.; Alais, A.; Butterlin, G.; Delobel, P.; Matei-Radoi, F.; Casaregola, S.

    2012-01-01

    The hybrid nature of lager-brewing yeast strains has been known for 25 years; however, yeast hybrids have only recently been described in cider and wine fermentations. In this study, we characterized the hybrid genomes and the relatedness of the Eg8 industrial yeast strain and of 24 Saccharomyces cerevisiae/Saccharomyces kudriavzevii hybrid yeast strains used for wine making in France (Alsace), Germany, Hungary, and the United States. An array-based comparative genome hybridization (aCGH) profile of the Eg8 genome revealed a typical chimeric profile. Measurement of hybrids DNA content per cell by flow cytometry revealed multiple ploidy levels (2n, 3n, or 4n), and restriction fragment length polymorphism analysis of 22 genes indicated variable amounts of S. kudriavzevii genetic content in three representative strains. We developed microsatellite markers for S. kudriavzevii and used them to analyze the diversity of a population isolated from oaks in Ardèche (France). This analysis revealed new insights into the diversity of this species. We then analyzed the diversity of the wine hybrids for 12 S. cerevisiae and 7 S. kudriavzevii microsatellite loci and found that these strains are the products of multiple hybridization events between several S. cerevisiae wine yeast isolates and various S. kudriavzevii strains. The Eg8 lineage appeared remarkable, since it harbors strains found over a wide geographic area, and the interstrain divergence measured with a (δμ)2 genetic distance indicates an ancient origin. These findings reflect the specific adaptations made by S. cerevisiae/S. kudriavzevii cryophilic hybrids to winery environments in cool climates. PMID:22344648

  7. School Sun-Protection Policies--Does Being SunSmart Make a Difference?

    ERIC Educational Resources Information Center

    Turner, Denise; Harrison, Simone L.; Buettner, Petra; Nowak, Madeleine

    2014-01-01

    Evaluate the comprehensiveness of primary school sun-protection policies in tropical North Queensland, Australia. Pre-determined criteria were used to assess publicly available sun-protection policies from primary schools in Townsville (latitude 19.3°S; n = 43), Cairns (16.9°S; n = 46) and the Atherton Tablelands (17.3°S; n = 23) during 2009-2012.…

  8. Discordant timing between antennae disrupts sun compass orientation in migratory monarch butterflies

    PubMed Central

    Guerra, Patrick A; Merlin, Christine; Gegear, Robert J; Reppert, Steven M

    2014-01-01

    To navigate during their long-distance migration, monarch butterflies (Danaus plexippus) use a time-compensated sun compass. The sun compass timing elements reside in light-entrained circadian clocks in the antennae. Here we show that either antenna is sufficient for proper time compensation. However, migrants with either antenna painted black (to block light entrainment) and the other painted clear (to permit light entrainment) display disoriented group flight. Remarkably, when the black-painted antenna is removed, re-flown migrants with a single, clear-painted antenna exhibit proper orientation behaviour. Molecular correlates of clock function reveal that period and timeless expression is highly rhythmic in brains and clear-painted antennae, while rhythmic clock gene expression is disrupted in black-painted antennae. Our work shows that clock outputs from each antenna are processed and integrated together in the monarch time-compensated sun compass circuit. This dual timing system is a novel example of the regulation of a brain-driven behaviour by paired organs. PMID:22805565

  9. Sun-Direction Estimation Using a Partially Underdetermined Set of Coarse Sun Sensors

    NASA Astrophysics Data System (ADS)

    O'Keefe, Stephen A.; Schaub, Hanspeter

    2015-09-01

    A comparison of different methods to estimate the sun-direction vector using a partially underdetermined set of cosine-type coarse sun sensors (CSS), while simultaneously controlling the attitude towards a power-positive orientation, is presented. CSS are commonly used in performing power-positive sun-pointing and are attractive due to their relative inexpensiveness, small size, and reduced power consumption. For this study only CSS and rate gyro measurements are available, and the sensor configuration does not provide global triple coverage required for a unique sun-direction calculation. The methods investigated include a vector average method, a combination of least squares and minimum norm criteria, and an extended Kalman filter approach. All cases are formulated such that precise ground calibration of the CSS is not required. Despite significant biases in the state dynamics and measurement models, Monte Carlo simulations show that an extended Kalman filter approach, despite the underdetermined sensor coverage, can provide degree-level accuracy of the sun-direction vector both with and without a control algorithm running simultaneously. If no rate gyro measurements are available, and rates are partially estimated from CSS, the EKF performance degrades as expected, but is still able to achieve better than 10∘ accuracy using only CSS measurements.

  10. Transcriptomic analysis of Saccharomyces cerevisiae upon honokiol treatment.

    PubMed

    Zhu, Xiaolong; Zou, Shenshen; Li, Youbin; Liang, Yongheng

    2017-09-01

    Honokiol (HNK), one of the main medicinal components in Magnolia officinalis, possesses antimicrobial activity against a variety of pathogenic bacteria and fungi. However, little is known of the molecular mechanisms underpinning the antimicrobial activity. To explore the molecular mechanism of its antifungal activity, we determined the effects of HNK on the mRNA expression profile of Saccharomyces cerevisiae using a DNA microarray approach. HNK markedly induced the expression of genes related to iron uptake and homeostasis. Conversely, genes associated with respiratory electron transport were downregulated, mirroring the effects of iron starvation. Meanwhile, HNK-induced growth deficiency was partly rescued by iron supplementation and HNK reacted with iron, producing iron complexes that depleted iron. These results suggest that HNK treatment induced iron starvation. Additionally, HNK treatment resulted in the upregulation of genes involved in protein synthesis and drug resistance networks. Furthermore, the deletion of PDR5, a gene encoding the plasma membrane ATP binding cassette (ABC) transporter, conferred sensitivity to HNK. Overexpression of PDR5 enhanced resistance of WT and pdr5Δ strains to HNK. Taken together, these findings suggest that HNK, which can be excluded by overexpression of Pdr5, functions in multiple cellular processes in S. cerevisiae, particularly in inducing iron starvation to inhibit cell growth. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  11. Genetic dissection of acetic acid tolerance in Saccharomyces cerevisiae.

    PubMed

    Geng, Peng; Xiao, Yin; Hu, Yun; Sun, Haiye; Xue, Wei; Zhang, Liang; Shi, Gui-Yang

    2016-09-01

    Dissection of the hereditary architecture underlying Saccharomyces cerevisiae tolerance to acetic acid is essential for ethanol fermentation. In this work, a genomics approach was used to dissect hereditary variations in acetic acid tolerance between two phenotypically different strains. A total of 160 segregants derived from these two strains were obtained. Phenotypic analysis indicated that the acetic acid tolerance displayed a normal distribution in these segregants, and suggested that the acetic acid tolerant traits were controlled by multiple quantitative trait loci (QTLs). Thus, 220 SSR markers covering the whole genome were used to detect QTLs of acetic acid tolerant traits. As a result, three QTLs were located on chromosomes 9, 12, and 16, respectively, which explained 38.8-65.9 % of the range of phenotypic variation. Furthermore, twelve genes of the candidates fell into the three QTL regions by integrating the QTL analysis with candidates of acetic acid tolerant genes. These results provided a novel avenue to obtain more robust strains.

  12. [The ABC transporters of Saccharomyces cerevisiae].

    PubMed

    Wawrzycka, Donata

    2011-01-01

    The ABC transporters (ATP Binding Cassette) compose one of the bigest protein family with the great medical, industrial and economical impact. They are found in all organism from bacteria to man. ABC proteins are responsible for resistance of microorganism to antibiotics and fungicides and multidrug resistance of cancer cells. Mutations in ABC transporters genes cause seriuos deseases like cystic fibrosis, adrenoleucodystrophy or ataxia. Transport catalized by ABC proteins is charged with energy from the ATP hydrolysis. The ABC superfamily contains transporters, canals, receptors. Analysis of the Saccharomyces cerevisiae genome allowed to distinguish 30 potential ABC proteins which are classified into 6 subfamilies. The structural and functional similarity of the yeast and human ABC proteins allowes to use the S. cerevisiae as a model organism for ABC transporters characterisation. In this work the present state of knowleadge on yeast S. cerevisiae ABC proteins was summarised.

  13. Screening for Hydrolytic Enzymes Reveals Ayr1p as a Novel Triacylglycerol Lipase in Saccharomyces cerevisiae*

    PubMed Central

    Ploier, Birgit; Scharwey, Melanie; Koch, Barbara; Schmidt, Claudia; Schatte, Jessica; Rechberger, Gerald; Kollroser, Manfred; Hermetter, Albin; Daum, Günther

    2013-01-01

    Saccharomyces cerevisiae, as well as other eukaryotes, preserves fatty acids and sterols in a biologically inert form, as triacylglycerols and steryl esters. The major triacylglycerol lipases of the yeast S. cerevisiae identified so far are Tgl3p, Tgl4p, and Tgl5p (Athenstaedt, K., and Daum, G. (2003) YMR313c/TGL3 encodes a novel triacylglycerol lipase located in lipid particles of Saccharomyces cerevisiae. J. Biol. Chem. 278, 23317–23323; Athenstaedt, K., and Daum, G. (2005) Tgl4p and Tgl5p, two triacylglycerol lipases of the yeast Saccharomyces cerevisiae, are localized to lipid particles. J. Biol. Chem. 280, 37301–37309). We observed that upon cultivation on oleic acid, triacylglycerol mobilization did not come to a halt in a yeast strain deficient in all currently known triacylglycerol lipases, indicating the presence of additional not yet characterized lipases/esterases. Functional proteome analysis using lipase and esterase inhibitors revealed a subset of candidate genes for yet unknown hydrolytic enzymes on peroxisomes and lipid droplets. Based on the conserved GXSXG lipase motif, putative functions, and subcellular localizations, a selected number of candidates were characterized by enzyme assays in vitro, gene expression analysis, non-polar lipid analysis, and in vivo triacylglycerol mobilization assays. These investigations led to the identification of Ayr1p as a novel triacylglycerol lipase of yeast lipid droplets and confirmed the hydrolytic potential of the peroxisomal Lpx1p in vivo. Based on these results, we discuss a possible link between lipid storage, lipid mobilization, and peroxisomal utilization of fatty acids as a carbon source. PMID:24187129

  14. Changing flux of xylose metabolites by altering expression of xylose reductase and xylitol dehydrogenase in recombinant Saccharomyces cerevisiae

    Treesearch

    Yong-Su Jin; Thomas W. Jeffries

    2003-01-01

    We changed the fluxes of xylose metabolites in recombinant Saccharomyces cerevisiae by manipulating expression of Pichia stipitis genes(XYL1 and XYL2) coding for xylose reductase (XR) and xylitol dehydrogenase (XDH), respectively. XYL1 copy number was kept constant by integrating it into the chromosome. Copy numbers of XYL2 were varied either by integrating XYL2 into...

  15. High-efficiency genome editing and allele replacement in prototrophic and wild strains of Saccharomyces.

    PubMed

    Alexander, William G; Doering, Drew T; Hittinger, Chris Todd

    2014-11-01

    Current genome editing techniques available for Saccharomyces yeast species rely on auxotrophic markers, limiting their use in wild and industrial strains and species. Taking advantage of the ancient loss of thymidine kinase in the fungal kingdom, we have developed the herpes simplex virus thymidine kinase gene as a selectable and counterselectable marker that forms the core of novel genome engineering tools called the H: aploid E: ngineering and R: eplacement P: rotocol (HERP) cassettes. Here we show that these cassettes allow a researcher to rapidly generate heterogeneous populations of cells with thousands of independent chromosomal allele replacements using mixed PCR products. We further show that the high efficiency of this approach enables the simultaneous replacement of both alleles in diploid cells. Using these new techniques, many of the most powerful yeast genetic manipulation strategies are now available in wild, industrial, and other prototrophic strains from across the diverse Saccharomyces genus. Copyright © 2014 by the Genetics Society of America.

  16. A comprehensive comparison of RNA-Seq-based transcriptome analysis from reads to differential gene expression and cross-comparison with microarrays: a case study in Saccharomyces cerevisiae

    PubMed Central

    Nookaew, Intawat; Papini, Marta; Pornputtapong, Natapol; Scalcinati, Gionata; Fagerberg, Linn; Uhlén, Matthias; Nielsen, Jens

    2012-01-01

    RNA-seq, has recently become an attractive method of choice in the studies of transcriptomes, promising several advantages compared with microarrays. In this study, we sought to assess the contribution of the different analytical steps involved in the analysis of RNA-seq data generated with the Illumina platform, and to perform a cross-platform comparison based on the results obtained through Affymetrix microarray. As a case study for our work we, used the Saccharomyces cerevisiae strain CEN.PK 113-7D, grown under two different conditions (batch and chemostat). Here, we asses the influence of genetic variation on the estimation of gene expression level using three different aligners for read-mapping (Gsnap, Stampy and TopHat) on S288c genome, the capabilities of five different statistical methods to detect differential gene expression (baySeq, Cuffdiff, DESeq, edgeR and NOISeq) and we explored the consistency between RNA-seq analysis using reference genome and de novo assembly approach. High reproducibility among biological replicates (correlation ≥0.99) and high consistency between the two platforms for analysis of gene expression levels (correlation ≥0.91) are reported. The results from differential gene expression identification derived from the different statistical methods, as well as their integrated analysis results based on gene ontology annotation are in good agreement. Overall, our study provides a useful and comprehensive comparison between the two platforms (RNA-seq and microrrays) for gene expression analysis and addresses the contribution of the different steps involved in the analysis of RNA-seq data. PMID:22965124

  17. LISTA, a comprehensive compilation of nucleotide sequences encoding proteins from the yeast Saccharomyces.

    PubMed Central

    Linder, P; Dölz, R; Mossé, M O; Lazowska, J; Slonimski, P P

    1993-01-01

    The amount of nucleotide sequence data is increasing exponentially. We therefore made an effort to make a comprehensive database (LISTA) for the yeast Saccharomyces cerevisiae. Each sequence has been attributed a single genetic name and in the case of allelic duplicated sequences, synonyms are given, if necessary. For the nomenclature we have introduced a standard principle for naming gene sequences based on priority rules. We have also applied a simple method to distinguish duplicated sequences of one and the same gene from non-allelic sequences of duplicated genes. By using these principles we have sorted out a lot of confusion in the literature and databanks. Along with the genetic name, the mnemonic from the EMBL databank, the codon bias, reference of the publication of the sequence and the EMBL accession numbers are included in each entry. PMID:8332521

  18. Study of. lambda. parameters and crossover phenomena in SU(N) x SU(N) sigma models in two dimensions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shigemitsu, J; Kogut, J B

    1981-01-01

    The spin system analogues of recent studies of the string tension and ..lambda.. parameters of SU(N) gauge theories in 4 dimensions are carried out for the SU(N) x SU(N) and O(N) models in 2 dimensions. The relations between the ..lambda.. parameters of both the Euclidean and Hamiltonian formulation of the lattice models and the ..lambda.. parameter of the continuum models are obtained. The one loop finite renormalization of the speed of light in the lattice Hamiltonian formulations of the O(N) and SU(N) x SU(N) models is calculated. Strong coupling calculations of the mass gaps of these spin models are donemore » for all N and the constants of proportionality between the gap and the ..lambda.. parameter of the continuum models are obtained. These results are contrasted with similar calculations for the SU(N) gauge models in 3+1 dimensions. Identifying suitable coupling constants for discussing the N ..-->.. infinity limits, the numerical results suggest that the crossover from weak to strong coupling in the lattice O(N) models becomes less abrupt as N increases while the crossover for the SU(N) x SU(N) models becomes more abrupt. The crossover in SU(N) gauge theories also becomes more abrupt with increasing N, however, at an even greater rate than in the SU(N) x SU(N) spin models.« less

  19. Cell Surface Display of Four Types of Solanum nigrum Metallothionein on Saccharomyces cerevisiae for Biosorption of Cadmium.

    PubMed

    Wei, Qinguo; Zhang, Honghai; Guo, Dongge; Ma, Shisheng

    2016-05-28

    We displayed four types of Solanum nigrum metallothionein (SMT) for the first time on the surface of Saccharomyces cerevisiae using an α-agglutinin-based display system. The SMT genes were amplified by RT-PCR. The plasmid pYES2 was used to construct the expression vector. Transformed yeast strains were confirmed by PCR amplification and custom sequencing. Surface-expressed metallothioneins were indirectly indicated by the enhanced cadmium sorption capacity. Flame atomic absorption spectrophotometry was used to examine the concentration of Cd(2+) in this study. The transformed yeast strains showed much higher resistance ability to Cd(2+) compared with the control. Strikingly, their Cd(2+) accumulation was almost twice as much as that of the wild-type yeast cells. Furthermore, surface-engineered yeast strains could effectively adsorb ultra-trace cadmium and accumulate Cd(2+) under a wide range of pH levels, from 3 to 7, without disturbing the Cu(2+) and Hg(2+). Four types of surfaceengineered Saccharomyces cerevisiae strains were constructed and they could be used to purify Cd(2+)-contaminated water and adsorb ultra-trace cadmium effectively. The surface-engineered Saccharomyces cerevisiae strains would be useful tools for the bioremediation and biosorption of environmental cadmium contaminants.

  20. Increasing Sun Protection in Winter Outdoor Recreation

    PubMed Central

    Walkosz, Barbara J.; Buller, David B.; Andersen, Peter A.; Scott, Michael D.; Dignan, Mark B.; Cutter, Gary R.; Maloy, Julie A.

    2009-01-01

    Background Unprotected and excessive exposure to ultraviolet radiation (UVR) is the primary risk factor for skin cancer. Design A pair-matched, group-randomized, pre-test/post-test, quasi-experimental design, with ski resorts as the unit of randomization, tested the effectiveness of Go Sun Smart, a multi-channel skin cancer prevention program. Independent samples of guests were taken at baseline (2001) and follow-up (2002); data were analyzed in 2006. Setting and Participants A total of 6516 adult guests at 26 ski resorts in the western U.S. and Canada were recruited, consented, and interviewed on chairlifts. This study was nested within an occupational intervention for ski resort workers. Intervention Ski resorts were pair-matched and randomized to receive Go Sun Smart, which consisted of print, electronic, visual, and interpersonal skin cancer prevention messages. Main Outcome Measures Sun-protection behaviors, sunburning, recall of sun-protection messages, and the association of message exposure to sun protection. Results The difference in recall of all sun-protection messages, messages on signs and posters, and the Go Sun Smart logo was significant between the intervention and control resorts. Reported use of sun-protection practices was higher by guests at intervention ski areas using more (a higher dose of) Go Sun Smart materials. Intervention-group guests who recalled a sun-safety message were more likely to practice sun safety than intervention-group guests who did not recall a message and control-group guests. Conclusions While the mere implementation of Go Sun Smart did not produce sun-safety improvements, Go Sun Smart appeared to be effective for guests who encountered and remembered it. Many factors can work against message exposure. Signage seemed to produce the greatest increase in exposure to sun-safety messages. PMID:18471586

  1. Homozygous diploid deletion strains of Saccharomyces cerevisiae that determine lag phase and dehydration tolerance.

    PubMed

    D'Elia, Riccardo; Allen, Patricia L; Johanson, Kelly; Nickerson, Cheryl A; Hammond, Timothy G

    2005-06-01

    This study identifies genes that determine length of lag phase, using the model eukaryotic organism, Saccharomyces cerevisiae. We report growth of a yeast deletion series following variations in the lag phase induced by variable storage times after drying-down yeast on filters. Using a homozygous diploid deletion pool, lag times ranging from 0 h to 90 h were associated with increased drop-out of mitochondrial genes and increased survival of nuclear genes. Simple linear regression (R2 analysis) shows that there are over 500 genes for which > 70% of the variation can be explained by lag alone. In the genes with a positive correlation, such that the gene abundance increases with lag and hence the deletion strain is suitable for survival during prolonged storage, there is a strong predominance of nucleonic genes. In the genes with a negative correlation, such that the gene abundance decreases with lag and hence the strain may be critical for getting yeast out of the lag phase, there is a strong predominance of glycoproteins and transmembrane proteins. This study identifies yeast deletion strains with survival advantage on prolonged storage and amplifies our understanding of the genes critical for getting out of the lag phase.

  2. Homozygous diploid deletion strains of Saccharomyces cerevisiae that determine lag phase and dehydration tolerance

    NASA Technical Reports Server (NTRS)

    D'Elia, Riccardo; Allen, Patricia L.; Johanson, Kelly; Nickerson, Cheryl A.; Hammond, Timothy G.

    2005-01-01

    This study identifies genes that determine length of lag phase, using the model eukaryotic organism, Saccharomyces cerevisiae. We report growth of a yeast deletion series following variations in the lag phase induced by variable storage times after drying-down yeast on filters. Using a homozygous diploid deletion pool, lag times ranging from 0 h to 90 h were associated with increased drop-out of mitochondrial genes and increased survival of nuclear genes. Simple linear regression (R2 analysis) shows that there are over 500 genes for which > 70% of the variation can be explained by lag alone. In the genes with a positive correlation, such that the gene abundance increases with lag and hence the deletion strain is suitable for survival during prolonged storage, there is a strong predominance of nucleonic genes. In the genes with a negative correlation, such that the gene abundance decreases with lag and hence the strain may be critical for getting yeast out of the lag phase, there is a strong predominance of glycoproteins and transmembrane proteins. This study identifies yeast deletion strains with survival advantage on prolonged storage and amplifies our understanding of the genes critical for getting out of the lag phase.

  3. Characterization of insertion mutations in the Saccharomyces cerevisiae MSH1 and MSH2 genes: evidence for separate mitochondrial and nuclear functions.

    PubMed

    Reenan, R A; Kolodner, R D

    1992-12-01

    The MSH1 and MSH2 genes of Saccharomyces cerevisiae are predicted to encode proteins that are homologous to the Escherichia coli MutS and Streptococcus pneumoniae HexA proteins and their homologs. Disruption of the MSH1 gene caused a petite phenotype which was established rapidly. A functional MSH1 gene present on a single-copy centromere plasmid was incapable of rescuing the established msh1 petite phenotype. Analysis of msh1 strains demonstrated that mutagenesis and large-scale rearrangement of mitochondrial DNA had occurred. 4',6-Diamidino-2-phenylindole (DAPI) staining of msh1 yeast revealed an aberrant distribution of mtDNA. Haploid msh2 mutants displayed an increase of 85-fold in the rate of spontaneous mutation to canavanine resistance. Sporulation of homozygous msh2/msh2 diploids gave rise to a high level of lethality which was compounded during increased vegetative growth prior to sporulation. msh2 mutations also affected gene conversion of two HIS4 alleles. The his4x mutation, lying near the 5' end of the gene, was converted with equal frequency in both wild-type and msh2 strains. However, many of the events in the msh2 background were post-meiotic segregation (PMS) events (46.4%) while none (< 0.25%) of the aberrant segregations in wild type were PMS events. The his4b allele, lying 1.6 kb downstream of his4x, was converted at a 10-fold higher frequency in the msh2 background than in the corresponding wild-type strain. Like the his4x allele, his4b showed a high level of PMS (30%) in the msh2 background compared to the corresponding wild-type strain where no (< 0.26%) PMS events were observed. These results indicate that MSH1 plays a role in repair or stability of mtDNA and MSH2 plays a role in repair of 4-bp insertion/deletion mispairs in the nucleus.

  4. Tolerance to winemaking stress conditions of Patagonian strains of Saccharomyces eubayanus and Saccharomyces uvarum.

    PubMed

    Origone, A C; Del Mónaco, S M; Ávila, J R; González Flores, M; Rodríguez, M E; Lopes, C A

    2017-08-01

    Evaluating the winemaking stress tolerance of a set of both Saccharomyces eubayanus and Saccharomyces uvarum strains from diverse Patagonian habitats. Yeast strains growth was analysed under increasing ethanol concentrations; all of them were able to grow until 8% v/v ethanol. The effect of different temperature and pH conditions as well as at SO 2 and hexose concentrations was evaluated by means of a central composite experimental design. Only two S. uvarum strains (NPCC 1289 and 1321) were able to grow in most stress conditions. Kinetic parameters analysed (μ max and λ) were statistically affected by temperature, pH and SO 2 , but not influenced by sugar concentration. The obtained growth model was used for predicting optimal growth conditions for both strains: 20°C, 0% w/v SO 2 and pH 4·5. Strains from human-associated environments (chichas) presented the highest diversity in the response to different stress factors. Two S. uvarum strains from chichas demonstrated to be the most tolerant to winemaking conditions. This work evidenced the potential use of two S. uvarum yeast strains as starter cultures in wines fermented at low temperatures. Saccharomyces eubayanus was significantly affected by winemaking stress conditions, limiting its use in this industry. © 2017 The Society for Applied Microbiology.

  5. Nucleotide sequence of the Saccharomyces cerevisiae PUT4 proline-permease-encoding gene: similarities between CAN1, HIP1 and PUT4 permeases.

    PubMed

    Vandenbol, M; Jauniaux, J C; Grenson, M

    1989-11-15

    The complete nucleotide (nt) sequence of the PUT4 gene, whose product is required for high-affinity proline active transport in the yeast Saccharomyces cerevisiae, is presented. The sequence contains a single long open reading frame of 1881 nt, encoding a polypeptide with a calculated Mr of 68,795. The predicted protein is strongly hydrophobic and exhibits six potential glycosylation sites. Its hydropathy profile suggests the presence of twelve membrane-spanning regions flanked by hydrophilic N- and C-terminal domains. The N terminus does not resemble signal sequences found in secreted proteins. These features are characteristic of integral membrane proteins catalyzing translocation of ligands across cellular membranes. Protein sequence comparisons indicate strong resemblance to the arginine and histidine permeases of S. cerevisiae, but no marked sequence similarity to the proline permease of Escherichia coli or to other known prokaryotic or eukaryotic transport proteins. The strong similarity between the three yeast amino acid permeases suggests a common ancestor for the three proteins.

  6. Physiologically Shrinking the Solution Space of a Saccharomyces cerevisiae Genome-Scale Model Suggests the Role of the Metabolic Network in Shaping Gene Expression Noise.

    PubMed

    Chi, Baofang; Tao, Shiheng; Liu, Yanlin

    2015-01-01

    Sampling the solution space of genome-scale models is generally conducted to determine the feasible region for metabolic flux distribution. Because the region for actual metabolic states resides only in a small fraction of the entire space, it is necessary to shrink the solution space to improve the predictive power of a model. A common strategy is to constrain models by integrating extra datasets such as high-throughput datasets and C13-labeled flux datasets. However, studies refining these approaches by performing a meta-analysis of massive experimental metabolic flux measurements, which are closely linked to cellular phenotypes, are limited. In the present study, experimentally identified metabolic flux data from 96 published reports were systematically reviewed. Several strong associations among metabolic flux phenotypes were observed. These phenotype-phenotype associations at the flux level were quantified and integrated into a Saccharomyces cerevisiae genome-scale model as extra physiological constraints. By sampling the shrunken solution space of the model, the metabolic flux fluctuation level, which is an intrinsic trait of metabolic reactions determined by the network, was estimated and utilized to explore its relationship to gene expression noise. Although no correlation was observed in all enzyme-coding genes, a relationship between metabolic flux fluctuation and expression noise of genes associated with enzyme-dosage sensitive reactions was detected, suggesting that the metabolic network plays a role in shaping gene expression noise. Such correlation was mainly attributed to the genes corresponding to non-essential reactions, rather than essential ones. This was at least partially, due to regulations underlying the flux phenotype-phenotype associations. Altogether, this study proposes a new approach in shrinking the solution space of a genome-scale model, of which sampling provides new insights into gene expression noise.

  7. The Sun Sense Study: An Intervention to Improve Sun Protection in Children

    ERIC Educational Resources Information Center

    Glasser, Alice; Shaheen, Magda; Glenn, Beth A.; Bastani, Roshan

    2010-01-01

    Objectives: To assess the effect of a multicomponent intervention on parental knowledge, sun avoidance behaviors, and sun protection practices in children 3-10 years. Methods: A randomized trial at a pediatric clinic recruited 197 caregiver-child pairs (90% parents). Intervention included a brief presentation and brochure for the parent and…

  8. Tolerant industrial yeast Saccharomyces cerevisiae posses a more robust cell wall integrity signaling pathway against 2-furaldehyde and 5-(hydroxymethyl)-2-furaldehyde

    USDA-ARS?s Scientific Manuscript database

    Cell wall integrity signaling pathway in Saccharomyces cerevisiae is a conserved function for detecting and responding to cell stress conditions but less understood for industrial yeast. We dissected gene expression dynamics for a tolerant industrial yeast strain NRRL Y-50049 in response to challeng...

  9. 77 FR 34122 - Application of Sun Air Express, LLC, d/b/a Sun Air International for Commuter Authority

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-08

    ... DEPARTMENT OF TRANSPORTATION Office of the Secretary [Docket DOT-OST-2011-0169] Application of Sun Air Express, LLC, d/b/a Sun Air International for Commuter Authority AGENCY: Department of... order finding Sun Air Express, LLC d/b/a Sun Air International fit, willing, and able, and awarding it...

  10. The Sun and Earth

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Natchimuthuk

    2012-01-01

    Thus the Sun forms the basis for life on Earth via the black body radiation it emits. The Sun also emits mass in the form of the solar wind and the coronal mass ejections (CMEs). Mass emission also occurs in the form of solar energetic particles (SEPs), which happens during CMEs and solar flares. Both the mass and electromagnetic energy output of the Sun vary over a wide range of time scales, thus introducing disturbances on the space environment that extends from the Sun through the entire heliosphere including the magnetospheres and ionospheres of planets and moons of the solar system. Although our habitat is located in the neutral atmosphere of Earth, we are intimately connected to the non-neutral space environment starting from the ionosphere to the magnetosphere and to the vast interplanetary space. The variability of the solar mass emissions results in the interaction between the solar wind plasma and the magnetospheric plasma leading to huge disturbances in the geospace. The Sun ionizes our atmosphere and creates the ionosphere. The ionosphere can be severely disturbed by the transient energy input from solar flares and the solar wind during geomagnetic storms. The complex interplay between Earth's magnetic field and the solar magnetic field carried by the solar wind presents varying conditions that are both beneficial and hazardous to life on earth. This seminar presents some of the key aspects of this Sun-Earth connection that we have learned since the birth of space science as a scientific discipline some half a century ago.

  11. The effect of Saccharomyces boulardii on human colon cells and inflammation in rats with trinitrobenzene sulfonic acid-induced colitis.

    PubMed

    Lee, Sang Kil; Kim, Youn Wha; Chi, Sung-Gil; Joo, Yeong-Shil; Kim, Hyo Jong

    2009-02-01

    Saccharomyces boulardii (S. boulardii) has beneficial effects in the treatment of intestinal inflammation; however, little is known about the mechanisms by which these effects occur. We investigated the effects of S. boulardii on the expression of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and interleukin-8 (IL-8), using human HT-29 colonocytes and a rat model of trinitrobenzene sulfonic acid (TNBS)-induced colitis. The effect of S. boulardii on gene expression was assessed by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), and Northern blot and Western blot assays. Pharmacological inhibitors for various signaling pathways were used to determine the signaling pathways implicated in the S. boulardii regulation of PPAR-gamma and IL-8. We found that S. boulardii up-regulated and down-regulated PPAR-gamma and IL-8 expression at the transcription level, both in vitro and in vivo (P < 0.05, respectively). Saccharomyces boulardii blocked tumor necrosis factor-alpha (TNF-alpha) regulation of PPAR-gamma and IL-8 through disruption of TNF-alpha-mediated nuclear factor kappa B (NF-kappaB) activation. Furthermore, S. boulardii suppressed colitis and expression of pro-inflammatory cytokine genes in vivo (P < 0.05, respectively). Our study demonstrated that S. boulardii reduces colonic inflammation and regulates inflammatory gene expression.

  12. The Sun Magnetic Field

    NASA Image and Video Library

    2011-12-16

    This frame from an animation shows how the magnetic field lines emanating from our sun spiral out into the solar system as the sun rotates. NASA Voyager 1 is in an area scientists are calling the stagnation region, at the outer layer of the heliosphere.

  13. Activity of the Baby Sun

    NASA Astrophysics Data System (ADS)

    Katsova, M. M.; Livshits, M. A.; Mishenina, T. V.; Nizamov, B. A.

    2017-05-01

    An analysis of the X-ray radiation of G-stars shows that the youngest fast rotating stars are characterized by saturation of activity, but part of stars demonstrate the solar-type activity, starting from rotational periods of 1.4 days. This type of activity, the level of which is determined by the rate of axial rotation, includes the formation of spots, flares and etc; first, activity is irregular, and only then there are conditions for the formation of cycles. The Kepler data show that stars of the same spectral type demonstrate two activity levels. This bimodality of different distributions of stars, change in a character of cycles and a level of Жiзнь i Bceлeннaya flare activity are evidences for an evolution of activity versus the age. By the nature of activity, we call conditionally G-dwarfs with rotation periods from 1 day to 5-6 days by the term "the Baby Sun" (the maximal number of these stars has Prot = 3 d), and we refer G-stars with Prot from 10 to 18 days to "the Young Suns". Ages of the main amount of the Baby Sun are around 200-600 Myr and the Young Sun are of about 1-2 Gyr. The Baby Suns are characterized by enhanced lithium content. We estimate the quasi-stationary X-ray and farultraviolet radiation of the outer atmosphere of the Baby Sun. From the GALEX data we obtain the FUV flux in the range 1350-1750 A for this kind of stars at the distance of 1 AU is 12.8 ± 4.2 erg/(cm^2 c), that exceeds the FUV-flux of the contemporary Sun by more than 6 times. The Kepler data demonstrate that the superflares happen more often namely on the Baby Suns. Our estimate is that superflares of the total energies 10^35 erg occur on the Baby Sun of about one per year.

  14. Sun-Earth Day, 2001

    NASA Technical Reports Server (NTRS)

    Adams, Mitzi L.; Mortfield, P.; Hathaway, D. H.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    To promote awareness of the Sun-Earth connection, NASA's Marshall Space Flight Center, in collaboration with the Stanford SOLAR Center, sponsored a one-day Sun-Earth Day event on April 27, 2001. Although "celebrated" on only one day, teachers and students from across the nation, prepared for over a month in advance. Workshops were held in March to train teachers. Students performed experiments, results of which were shared through video clips and an internet web cast. Our poster includes highlights from student experiments (grades 2 - 12), lessons learned from the teacher workshops and the event itself, and plans for Sun-Earth Day 2002.

  15. The Sun in STEREO

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Parallax gives depth to life. Simultaneous viewing from slightly different vantage points makes binocular humans superior to monocular cyclopes, and fixes us in the third dimension of the Universe. We've been stunned by 3-d images of Venus and Mars (along with more familiar views of earth). Now astronomers plan to give us the best view of all, 3-d images of the dynamic Sun. That's one of the prime goals of NASA's Solar Terrestrial Relations Observatories, also known as STEREO. STEREO is a pair of spacecraft observatories, one placed in orbit in front of earth, and one to be placed in an earth-trailing orbit. Simultaneous observations of the Sun with the two STEREO spacecraft will provide extraordinary 3-d views of all types of solar activity, especially the dramatic events called coronal mass ejections which send high energy particles from the outer solar atmosphere hurtling towards earth. The image above the first image of the sun by the two STEREO spacecraft, an extreme ultraviolet shot of the Sun's million-degree corona, taken by the Extreme Ultraviolet Imager on the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument package. STEREO's first 3-d solar images should be available in April if all goes well. Put on your red and blue glasses!

  16. Zymogram profiling of superoxide dismutase and catalase activities allows Saccharomyces and non-Saccharomyces species differentiation and correlates to their fermentation performance.

    PubMed

    Gamero-Sandemetrio, Esther; Gómez-Pastor, Rocío; Matallana, Emilia

    2013-05-01

    Aerobic organisms have devised several enzymatic and non-enzymatic antioxidant defenses to deal with reactive oxygen species (ROS) produced by cellular metabolism. To combat such stress, cells induce ROS scavenging enzymes such as catalase, peroxidase, superoxide dismutase (SOD) and glutathione reductase. In the present research, we have used a double staining technique of SOD and catalase enzymes in the same polyacrylamide gel to analyze the different antioxidant enzymatic activities and protein isoforms present in Saccharomyces and non-Saccharomyces yeast species. Moreover, we used a technique to differentially detect Sod1p and Sod2p on gel by immersion in NaCN, which specifically inhibits the Sod1p isoform. We observed unique SOD and catalase zymogram profiles for all the analyzed yeasts and we propose this technique as a new approach for Saccharomyces and non-Saccharomyces yeast strains differentiation. In addition, we observed functional correlations between SOD and catalase enzyme activities, accumulation of essential metabolites, such as glutathione and trehalose, and the fermentative performance of different yeasts strains with industrial relevance.

  17. Secretory Expression and Characterization of an Acidic Endo-Polygalacturonase Gene from Aspergillus niger SC323 in Saccharomyces cerevisiae.

    PubMed

    Zhou, Huoxiang; Li, Xi; Guo, Mingyue; Xu, Qingrui; Cao, Yu; Qiao, Dairong; Cao, Yi; Xu, Hui

    2015-07-01

    The endo-polygalacturonase gene (endo-pgaA) was cloned from DNA of Aspergillus niger SC323 using the cDNA synthesized by overlapping PCR, and successfully expressed in Saccharomyces cerevisiae EBY100 through fusing the α-factor signal peptide of yeast. The full-length cDNA consists of 1,113 bp and encodes a protein of 370 amino acids with a calculated molecular mass of 38.8 kDa. After induction by galactose for 48 h, the activity of recombinant endo-PgaA in the culture supernatant can reach up to 1,448.48 U/mg. The recombinant protein was purified to homogeneity by ammonium sulfate precipitation and gel filtration column chromatography and subsequently characterized. The optimal pH and temperature of the purified recombinant enzyme were 5.0 and 50°C, respectively. The Michaelis-Menten constant (Km) and maximal velocity (Vmax) of the enzyme for pectin were 88.54 μmol/ml and 175.44 μmol/mg/min, respectively. The enzyme activity was enhanced by Ca(2+), Cu(2+), and Na(+), and strongly inhibited by Pb(2+) and Mn(2+). The pectin hydrolysates were mainly galacturonic acid and other oligo-galacturonates. Therefore, these characteristics suggest that the recombinant endo-PgaA may be of potential use in the food and feed industries.

  18. Relationship factors and couples' engagement in sun protection.

    PubMed

    Manne, S L; Coups, E J; Kashy, D A

    2016-08-01

    Individuals may be more motivated to adopt health practices if they consider the benefits of these behaviors for their close relationships. The goal of this study was to examine couple concordance with sun protection and use the interdependence and communal coping theory to evaluate the role of relationship factors in sun protection. One hundred and eighty-four married couples aged 50 years and older completed measures of objective skin cancer risk, perceived risk, sun protection benefits, relationship-centered motivations for sun protection, discussions about sun protection, and sun protection. A mediational model was evaluated. Results indicated a high level of couple concordance. Partners who adopted a relationship-centered motivation for sun protection were more likely to discuss sun protection with one another, and partners who discussed sun protection together were more likely to engage in sun protection. One partner's attitude about personal risk and sun protection benefits was associated with the other partner's sun protection. Wives had higher relationship-centered motivation and discussed sun protection more with their husbands. Behavioral interventions may benefit from encouraging couples to discuss sun protection and encouraging married individuals to consider the benefits of sun protection for their relationship and for their spouse's health. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  19. Gene Ontology annotations at SGD: new data sources and annotation methods

    PubMed Central

    Hong, Eurie L.; Balakrishnan, Rama; Dong, Qing; Christie, Karen R.; Park, Julie; Binkley, Gail; Costanzo, Maria C.; Dwight, Selina S.; Engel, Stacia R.; Fisk, Dianna G.; Hirschman, Jodi E.; Hitz, Benjamin C.; Krieger, Cynthia J.; Livstone, Michael S.; Miyasato, Stuart R.; Nash, Robert S.; Oughtred, Rose; Skrzypek, Marek S.; Weng, Shuai; Wong, Edith D.; Zhu, Kathy K.; Dolinski, Kara; Botstein, David; Cherry, J. Michael

    2008-01-01

    The Saccharomyces Genome Database (SGD; http://www.yeastgenome.org/) collects and organizes biological information about the chromosomal features and gene products of the budding yeast Saccharomyces cerevisiae. Although published data from traditional experimental methods are the primary sources of evidence supporting Gene Ontology (GO) annotations for a gene product, high-throughput experiments and computational predictions can also provide valuable insights in the absence of an extensive body of literature. Therefore, GO annotations available at SGD now include high-throughput data as well as computational predictions provided by the GO Annotation Project (GOA UniProt; http://www.ebi.ac.uk/GOA/). Because the annotation method used to assign GO annotations varies by data source, GO resources at SGD have been modified to distinguish data sources and annotation methods. In addition to providing information for genes that have not been experimentally characterized, GO annotations from independent sources can be compared to those made by SGD to help keep the literature-based GO annotations current. PMID:17982175

  20. Multi-gene phylogenetic analysis reveals that shochu-fermenting Saccharomyces cerevisiae strains form a distinct sub-clade of the Japanese sake cluster.

    PubMed

    Futagami, Taiki; Kadooka, Chihiro; Ando, Yoshinori; Okutsu, Kayu; Yoshizaki, Yumiko; Setoguchi, Shinji; Takamine, Kazunori; Kawai, Mikihiko; Tamaki, Hisanori

    2017-10-01

    Shochu is a traditional Japanese distilled spirit. The formation of the distinguishing flavour of shochu produced in individual distilleries is attributed to putative indigenous yeast strains. In this study, we performed the first (to our knowledge) phylogenetic classification of shochu strains based on nucleotide gene sequences. We performed phylogenetic classification of 21 putative indigenous shochu yeast strains isolated from 11 distilleries. All of these strains were shown or confirmed to be Saccharomyces cerevisiae, sharing species identification with 34 known S. cerevisiae strains (including commonly used shochu, sake, ale, whisky, bakery, bioethanol and laboratory yeast strains and clinical isolate) that were tested in parallel. Our analysis used five genes that reflect genome-level phylogeny for the strain-level classification. In a first step, we demonstrated that partial regions of the ZAP1, THI7, PXL1, YRR1 and GLG1 genes were sufficient to reproduce previous sub-species classifications. In a second step, these five analysed regions from each of 25 strains (four commonly used shochu strains and the 21 putative indigenous shochu strains) were concatenated and used to generate a phylogenetic tree. Further analysis revealed that the putative indigenous shochu yeast strains form a monophyletic group that includes both the shochu yeasts and a subset of the sake group strains; this cluster is a sister group to other sake yeast strains, together comprising a sake-shochu group. Differences among shochu strains were small, suggesting that it may be possible to correlate subtle phenotypic differences among shochu flavours with specific differences in genome sequences. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Requirement of mismatch repair genes MSH2 and MSH3 in the RAD1-RAD10 pathway of mitotic recombination in Saccharomyces cerevisiae

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Saparbaev, M.; Prakash, L.; Prakash, S.

    1996-03-01

    The RAD1 and RAD10 genes of Saccharomyces cerevisiae are required for nucleotide excision repair and they also act in mitotic recombination. The Rad1-Rad10 complex has a single-stranded DNA endonuclease activity. Here, we show that the mismatch repair genes MSH2 and MSH3 function in mitotic recombination. For both his3 and his4 duplications, and for homologous integration of a linear DNA fragment into the genome, the msh3-A mutation has an effect on recombination similar to that of the rad1{Delta} and rad10{Delta} mutations. The msh2{Delta} mutation also reduces the rate of recombination of the his3 duplication and lowers the incidence of homologous integrationmore » of a linear DNA fragment. Epistasis analyses indicate that MSH2 and MSH3 function in the RAD1-RAD10 recombination pathway, and studies presented here suggest an involvement of the RAM-RAD10 pathway in reciprocal recombination. The possible roles of Msh2, Msh3, Rad1, and Rad10 proteins in genetic recombination are discussed. Coupling of mismatch binding proteins with the recombinational machinery could be important for ensuring genetic fidelity in the recombination process. 59 refs., 2 figs., 7 tabs.« less

  2. Overexpressing enzymes of the Ehrlich pathway and deleting genes of the competing pathway in Saccharomyces cerevisiae for increasing 2-phenylethanol production from glucose.

    PubMed

    Shen, Li; Nishimura, Yuya; Matsuda, Fumio; Ishii, Jun; Kondo, Akihiko

    2016-07-01

    2-Phenylethanol (2-PE) is a higher aromatic alcohol that is used in the cosmetics and food industries. The budding yeast Saccharomyces cerevisiae is considered to be a suitable host for the industrial production of higher alcohols, including 2-PE. To produce 2-PE from glucose in S. cerevisiae, we searched for suitable 2-keto acid decarboxylase (KDC) and alcohol dehydrogenase (ADH) enzymes of the Ehrlich pathway for overexpression in strain YPH499, and found that overexpression of the ARO10 and/or ADH1 genes increased 2-PE production from glucose. Further, we screened ten BY4741 single-deletion mutants of genes involved in the competing pathways for 2-PE production, and found that strains aro8Δ and aat2Δ displayed increased 2-PE production. Based on these results, we engineered a BY4741 strain that overexpressed ARO10 and contained an aro8Δ deletion, and demonstrated that the strain produced 96 mg/L 2-PE from glucose as the sole carbon source. As this engineered S. cerevisiae strain showed a significant increase in 2-PE production from glucose without the addition of an intermediate carbon substrate, it is a promising candidate for the large-scale production of 2-PE. Copyright © 2016. Published by Elsevier B.V.

  3. [Improvement of acetic acid tolerance and fermentation performance of industrial Saccharomyces cerevisiae by overexpression of flocculent gene FLO1 and FLO1c].

    PubMed

    Du, Zhaoli; Cheng, Yanfei; Zhu, Hui; He, Xiuping; Zhang, Borun

    2015-02-01

    Flocculent gene FLO1 and its truncated form FLO1c with complete deletion of repeat unit C were expressed in a non-flocculent industrial strain Saccharomyces cerevisiae CE6 to generate recombinant flocculent strains 6-AF1 and 6-AF1c respectively. Both strains of 6-AF1 and 6-AF1c displayed strong flocculation and better cell growth than the control strain CE6-V carrying the empty vector under acetic acid stress. Moreover, the flocculent strains converted glucose to ethanol at much higher rates than the control strain CE6-V under acetic acid stress. In the presence of 0.6% (V/V) acetic acid, the average ethanol production rates of 6-AF1 and 6-AF1c were 1.56 and 1.62 times of that of strain CE6-V, while the ethanol production rates of 6-AF1 and 6-AF1c were 1.21 and 1.78 times of that of strain CE6-V under 1.0% acetic acid stress. Results in this study indicate that acetic acid tolerance and fermentation performance of industrial S. cerevisiae under acetic acid stress can be improved largely by flocculation endowed by expression of flocculent genes, especially FLO1c.

  4. Differential roles of transcriptional mediator subunits in regulation of multidrug resistance gene expression in Saccharomyces cerevisiae.

    PubMed

    Shahi, Puja; Gulshan, Kailash; Näär, Anders M; Moye-Rowley, W Scott

    2010-07-15

    The multiprotein transcriptional Mediator complex provides a key link between RNA polymerase II and upstream transcriptional activator proteins. Previous work has established that the multidrug resistance transcription factors Pdr1 and Pdr3 interact with the Mediator component Med15/Gal11 to drive normal levels of expression of the ATP-binding cassette transporter-encoding gene PDR5 in Saccharomyces cerevisiae. PDR5 transcription is induced upon loss of the mitochondrial genome (rho(0) cells) and here we provide evidence that this rho(0) induction is Med15 independent. A search through other known Mediator components determined that Med12/Srb8, a member of the CDK8 Mediator submodule, is required for rho(0) activation of PDR5 transcription. The CDK8 submodule contains the cyclin C homologue (CycC/Srb11), cyclin-dependent kinase Cdk8/Srb10, and the large Med13/Srb9 protein. Loss of these other proteins did not lead to the same block in PDR5 induction. Chromatin immunoprecipitation analyses demonstrated that Med15 is associated with the PDR5 promoter in both rho(+) and rho(0), whereas Med12 recruitment to this target promoter is highly responsive to loss of the mitochondrial genome. Coimmunoprecipitation experiments revealed that association of Pdr3 with Med12 can only be detected in rho(0) cells. These experiments uncover the unique importance of Med12 in activated transcription of PDR5 seen in rho(0) cells.

  5. Directed alteration of Saccharomyces cerevisiae mitochondrial DNA by biolistic transformation and homologous recombination.

    PubMed

    Bonnefoy, Nathalie; Fox, Thomas D

    2007-01-01

    Saccharomyces cerevisiae is currently the only species in which genetic transformation of mitochondria can be used to generate a wide variety of defined alterations in mitochondrial deoxyribonucleic acid (mtDNA). DNA sequences can be delivered into yeast mitochondria by microprojectile bombardment (biolistic transformation) and subsequently incorporated into mtDNA by the highly active homologous recombination machinery present in the organelle. Although transformation frequencies are relatively low, the availability of strong mitochondrial selectable markers for the yeast system, both natural and synthetic, makes the isolation of transformants routine. The strategies and procedures reviewed here allow the researcher to insert defined mutations into endogenous mitochondrial genes and to insert new genes into mtDNA. These methods provide powerful in vivo tools for the study of mitochondrial biology.

  6. Functional expression of amine oxidase from Aspergillus niger (AO-I) in Saccharomyces cerevisiae.

    PubMed

    Kolaríková, Katerina; Galuszka, Petr; Sedlárová, Iva; Sebela, Marek; Frébort, Ivo

    2009-01-01

    The aim of this work was to prepare recombinant amine oxidase from Aspergillus niger after overexpressing in yeast. The yeast expression vector pDR197 that includes a constitutive PMA1 promoter was used for the expression in Saccharomyces cerevisiae. Recombinant amine oxidase was extracted from the growth medium of the yeast, purified to homogeneity and identified by activity assay and MALDI-TOF peptide mass fingerprinting. Similarity search in the newly published A. niger genome identified six genes coding for copper amine oxidase, two of them corresponding to the previously described enzymes AO-I a methylamine oxidase and three other genes coding for FAD amine oxidases. Thus, A. niger possesses an enormous metabolic gear to grow on amine compounds and thus support its saprophytic lifestyle.

  7. Educating preschoolers about sun safety.

    PubMed Central

    Loescher, L J; Emerson, J; Taylor, A; Christensen, D H; McKinney, M

    1995-01-01

    OBJECTIVES. This feasibility study examined whether a sun safety curriculum designed for and administered to preschoolers affects their cognition (knowledge, comprehension, application) regarding sun safety. METHODS. Twelve classes of 4- to 5-year-olds were recruited from local preschools and randomly assigned to an intervention group or a control group. The intervention group received an investigator-developed sun safety curriculum; the control group did not. Children in both groups were tested at the beginning of the study about their cognition related to sun safety. They then received posttests 2 and 7 weeks following the pretest. RESULTS. The curriculum had a significant effect on the knowledge (P = .01) and comprehension (P = .006) components of cognition. The application component of cognition was not significantly changed by the curriculum. CONCLUSIONS. A structured curriculum was found to be an efficacious means of enhancing knowledge and comprehension of sun safety in preschool children. At the preoperational developmental stage, however, children may not be able to apply such knowledge and comprehension. PMID:7604917

  8. Characterization of vacuolar amino acid transporter from Fusarium oxysporum in Saccharomyces cerevisiae.

    PubMed

    Lunprom, Siriporn; Pongcharoen, Pongsanat; Sekito, Takayuki; Kawano-Kawada, Miyuki; Kakinuma, Yoshimi; Akiyama, Koichi

    2015-01-01

    Fusarium oxysporum causes wilt disease in many plant families, and many genes are involved in its development or growth in host plants. A recent study revealed that vacuolar amino acid transporters play an important role in spore formation in Schizosaccharomyces pombe and Saccharomyces cerevisiae. To investigate the role of vacuolar amino acid transporters of this phytopathogenic fungus, the FOXG_11334 (FoAVT3) gene from F. oxysporum was isolated and its function was characterized. Transcription of FoAVT3 was upregulated after rapamycin treatment. A green fluorescent protein fusion of FoAvt3p was localized to vacuolar membranes in both S. cerevisiae and F. oxysporum. Analysis of the amino acid content of the vacuolar fraction and amino acid transport activities using vacuolar membrane vesicles from S. cerevisiae cells heterologously expressing FoAVT3 revealed that FoAvt3p functions as a vacuolar amino acid transporter, exporting neutral amino acids. We conclude that the FoAVT3 gene encodes a vacuolar neutral amino acid transporter.

  9. Allelic variants of hexose transporter Hxt3p and hexokinases Hxk1p/Hxk2p in strains of Saccharomyces cerevisiae and interspecies hybrids.

    PubMed

    Zuchowska, Magdalena; Jaenicke, Elmar; König, Helmut; Claus, Harald

    2015-11-01

    The transport of sugars across the plasma membrane is a critical step in the utilization of glucose and fructose by Saccharomyces cerevisiae during must fermentations. Variations in the molecular structure of hexose transporters and kinases may affect the ability of wine yeast strains to finish sugar fermentation, even under stressful wine conditions. In this context, we sequenced and compared genes encoding the hexose transporter Hxt3p and the kinases Hxk1p/Hxk2p of Saccharomyces strains and interspecies hybrids with different industrial usages and regional backgrounds. The Hxt3p primary structure varied in a small set of amino acids, which characterized robust yeast strains used for the production of sparkling wine or to restart stuck fermentations. In addition, interspecies hybrid strains, previously isolated at the end of spontaneous fermentations, revealed a common amino acid signature. The location and potential influence of the amino acids exchanges is discussed by means of a first modelled Hxt3p structure. In comparison, hexokinase genes were more conserved in different Saccharomyces strains and hybrids. Thus, molecular variants of the hexose carrier Hxt3p, but not of kinases, correlate with different fermentation performances of yeast. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Antigenic validation of recombinant hemagglutinin-neuraminidase protein of Newcastle disease virus expressed in Saccharomyces cerevisiae.

    PubMed

    Khulape, S A; Maity, H K; Pathak, D C; Mohan, C Madhan; Dey, S

    2015-09-01

    The outer membrane glycoprotein, hemagglutinin-neuraminidase (HN) of Newcastle disease virus (NDV) is important for virus infection and subsequent immune response by host, and offers target for development of recombinant antigen-based immunoassays and subunit vaccines. In this study, the expression of HN protein of NDV is attempted in yeast expression system. Yeast offers eukaryotic environment for protein processing and posttranslational modifications like glycosylation, in addition to higher growth rate and easy genetic manipulation. Saccharomyces cerevisiae was found to be better expression system for HN protein than Pichia pastoris as determined by codon usage analysis. The complete coding  sequence of HN gene was amplified with the histidine tag, cloned in pESC-URA under GAL10 promotor and transformed in Saccharomyces cerevisiae. The recombinant HN (rHN) protein was characterized by western blot, showing glycosylation heterogeneity as observed with other eukaryotic expression systems. The recombinant protein was purified by affinity column purification. The protein could be further used as subunit vaccine.

  11. The resistance of the yeast Saccharomyces cerevisiae to the biocide polyhexamethylene biguanide: involvement of cell wall integrity pathway and emerging role for YAP1.

    PubMed

    Elsztein, Carolina; de Lucena, Rodrigo M; de Morais, Marcos A

    2011-08-19

    Polyhexamethylene biguanide (PHMB) is an antiseptic polymer that is mainly used for cleaning hospitals and pools and combating Acantamoeba infection. Its fungicide activity was recently shown by its lethal effect on yeasts that contaminate the industrial ethanol process, and on the PE-2 strain of Saccharomyces cerevisiae, one of the main fermenting yeasts in Brazil. This pointed to the need to know the molecular mechanism that lay behind the cell resistance to this compound. In this study, we examined the factors involved in PHMB-cell interaction and the mechanisms that respond to the damage caused by this interaction. To achieve this, two research strategies were employed: the expression of some genes by RT-qPCR and the analysis of mutant strains. Cell Wall integrity (CWI) genes were induced in the PHMB-resistant Saccharomyces cerevisiae strain JP-1, although they are poorly expressed in the PHMB-sensitive Saccharomyces cerevisiae PE2 strain. This suggested that PHMB damages the glucan structure on the yeast cell wall. It was also confirmed by the observed sensitivity of the yeast deletion strains, Δslg1, Δrom2, Δmkk2, Δslt2, Δknr4, Δswi4 and Δswi4, which showed that the protein kinase C (PKC) regulatory mechanism is involved in the response and resistance to PHMB. The sensitivity of the Δhog1 mutant was also observed. Furthermore, the cytotoxicity assay and gene expression analysis showed that the part played by YAP1 and CTT1 genes in cell resistance to PHMB is unrelated to oxidative stress response. Thus, we suggested that Yap1p can play a role in cell wall maintenance by controlling the expression of the CWI genes. The PHMB treatment of the yeast cells activates the PKC1/Slt2 (CWI) pathway. In addition, it is suggested that HOG1 and YAP1 can play a role in the regulation of CWI genes.

  12. The resistance of the yeast Saccharomyces cerevisiae to the biocide polyhexamethylene biguanide: involvement of cell wall integrity pathway and emerging role for YAP1

    PubMed Central

    2011-01-01

    Background Polyhexamethylene biguanide (PHMB) is an antiseptic polymer that is mainly used for cleaning hospitals and pools and combating Acantamoeba infection. Its fungicide activity was recently shown by its lethal effect on yeasts that contaminate the industrial ethanol process, and on the PE-2 strain of Saccharomyces cerevisiae, one of the main fermenting yeasts in Brazil. This pointed to the need to know the molecular mechanism that lay behind the cell resistance to this compound. In this study, we examined the factors involved in PHMB-cell interaction and the mechanisms that respond to the damage caused by this interaction. To achieve this, two research strategies were employed: the expression of some genes by RT-qPCR and the analysis of mutant strains. Results Cell Wall integrity (CWI) genes were induced in the PHMB-resistant Saccharomyces cerevisiae strain JP-1, although they are poorly expressed in the PHMB-sensitive Saccharomyces cerevisiae PE2 strain. This suggested that PHMB damages the glucan structure on the yeast cell wall. It was also confirmed by the observed sensitivity of the yeast deletion strains, Δslg1, Δrom2, Δmkk2, Δslt2, Δknr4, Δswi4 and Δswi4, which showed that the protein kinase C (PKC) regulatory mechanism is involved in the response and resistance to PHMB. The sensitivity of the Δhog1 mutant was also observed. Furthermore, the cytotoxicity assay and gene expression analysis showed that the part played by YAP1 and CTT1 genes in cell resistance to PHMB is unrelated to oxidative stress response. Thus, we suggested that Yap1p can play a role in cell wall maintenance by controlling the expression of the CWI genes. Conclusion The PHMB treatment of the yeast cells activates the PKC1/Slt2 (CWI) pathway. In addition, it is suggested that HOG1 and YAP1 can play a role in the regulation of CWI genes. PMID:21854579

  13. Increased copper toxicity in Saccharomyces cerevisiae lacking VPS35, a component of the retromer and monogenic Parkinson disease gene in humans.

    PubMed

    Sowada, Nadine; Stiller, Barbara; Kubisch, Christian

    2016-08-05

    The Saccharomyces cerevisiae gene VPS35 encodes a component of the retromer complex which is involved in vesicle transport from endosomes to the trans-Golgi network. Yeast and human VPS35 orthologs are highly conserved and mutations in human VPS35 cause an autosomal dominant form of late-onset Parkinson disease (PD). We now show that deletion of VPS35 in yeast (vps35Δ) leads to a dose-dependent growth defect towards copper. This increased sensitivity could be rescued by transformation with yeast wild-type VPS35 but not by the expression of a construct harboring the yeast equivalent (i.e. D686N) of the most commonly identified VPS35-associated PD mutation, p.D620N. In addition, we show that expression of one copy of α-synuclein, which is known to directly interact with copper, leads to a pronounced aggravation of copper toxicity in vps35Δ cells, thereby linking the regulation of copper homeostasis by Vps35p in yeast to one of the key molecules in PD pathophysiology. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Deletion of JJJ1 improves acetic acid tolerance and bioethanol fermentation performance of Saccharomyces cerevisiae strains.

    PubMed

    Wu, Xuechang; Zhang, Lijie; Jin, Xinna; Fang, Yahong; Zhang, Ke; Qi, Lei; Zheng, Daoqiong

    2016-07-01

    To improve tolerance to acetic acid that is present in lignocellulosic hydrolysates and affects bioethanol production by Saccharomyces cerevisiae. Saccharomyces cerevisiae strains with improved tolerance to acetic acid were obtained through deletion of the JJJ1 gene. The lag phase of the JJJ1 deletion mutant BYΔJJJ1 was ~16 h shorter than that of the parent strain, BY4741, when the fermentation medium contained 4.5 g acetic acid/l. Additionally, the specific ethanol production rate of BYΔJJJ1 was increased (0.057 g/g h) compared to that of the parent strain (0.051 g/g h). Comparative transcription and physiological analyses revealed higher long chain fatty acid, trehalose, and catalase contents might be critical factors responsible for the acetic acid resistance of JJJ1 knockout strains. JJJ1 deletion improves acetic acid tolerance and ethanol fermentation performance of S. cerevisiae.

  15. Sun burn incidence and knowledge of greek elementary and high school children about sun protection.

    PubMed

    Saridi, Maria Ioannis; Toska, Aikaterini George; Rekleiti, Maria Dimitrios; Tsironi, Maria; Geitona, Maria; Souliotis, Kyriakos

    2015-01-01

    Overexposure to sun radiation and particularly its accumulation during childhood and adolescence is a significant risk factor for skin cancer development. The sun burn is particularly important. To estimate sun burn incidence in young pupils in a coastal area of Greece. Two surveys were conducted in a school population in the same district in Greece, over different periods of time, in young people 9 to 18 years old (n=2 977). Anonymous questionnaires were completed. Levels of significance were two- tailed and statistical significance was set at p=0.05. SPSS 17.0 software was used for statistical analysis. From the individual characteristics of the participants it was shown that the majority of them had dark hair and fair skin, whereas a significant percentage reported the existence of moles on face and their body (83.4% vs 68.1%). The sun burn incidence was high in adolescents and the younger pupils (41.9% vs 55.6%). The younger aged children who were living in an urban area had significantly higher rates of sun burn than those living in semi-urban areas (33.8% vs 24.8%, p=0.020). As far as the knowledge of pupils about the risks of sun radiation it was shown that the elementary school pupils had better knowledge than those at high school. Finally, those with better knowledge had the fewer sun burns (Mean 2.83 SD 0.87, p<0.001). The contribution of knowledge to the decrease of sun burn incidence is important as long as this is continuous. Therefore, the education should concern not only children but also teachers and parents in the context of continuous and systematic programs of health education.

  16. Earth Eclipses the Sun

    NASA Image and Video Library

    2017-02-21

    Several times a day for a few days the Earth completely blocked the Sun for about an hour due to NASA's Solar Dynamics Observatory's orbital path (Feb. 15, 2017). The edge of the Earth is not crisp, but kind of fuzzy due to Earth's atmosphere. This frame from a video shows the ending of one such eclipse over -- just seven minutes. The sun is shown in a wavelength of extreme ultraviolet light. These eclipses re-occur about every six months. The Moon blocks SDO's view of the sun on occasion as well. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA21461

  17. 7 CFR 3201.97 - Sun care products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Sun care products. 3201.97 Section 3201.97... Designated Items § 3201.97 Sun care products. (a) Definition. Products including sunscreens, sun blocks, and suntan lotions that are topical products that absorb or reflect the sun's ultraviolet radiation to...

  18. 7 CFR 3201.97 - Sun care products.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Sun care products. 3201.97 Section 3201.97... Designated Items § 3201.97 Sun care products. (a) Definition. Products including sunscreens, sun blocks, and suntan lotions that are topical products that absorb or reflect the sun's ultraviolet radiation to...

  19. Pulses from the Sun

    NASA Image and Video Library

    2014-02-11

    The dark region seen on the face of the sun at the end of March 2013 is a coronal hole just above and to the right of the middle of the picture, which is a source of fast solar wind leaving the sun in this image from NASA Solar Dynamic Observatory.

  20. Genome shuffling of Saccharomyces cerevisiae for enhanced glutathione yield and relative gene expression analysis using fluorescent quantitation reverse transcription polymerase chain reaction.

    PubMed

    Yin, Hua; Ma, Yanlin; Deng, Yang; Xu, Zhenbo; Liu, Junyan; Zhao, Junfeng; Dong, Jianjun; Yu, Junhong; Chang, Zongming

    2016-08-01

    Genome shuffling is an efficient and promising approach for the rapid improvement of microbial phenotypes. In this study, genome shuffling was applied to enhance the yield of glutathione produced by Saccharomyces cerevisiae YS86. Six isolates with subtle improvements in glutathione yield were obtained from populations generated by ultraviolet (UV) irradiation and nitrosoguanidine (NTG) mutagenesis. These yeast strains were then subjected to recursive pool-wise protoplast fusion. A strain library that was likely to yield positive colonies was created by fusing the lethal protoplasts obtained from both UV irradiation and heat treatments. After two rounds of genome shuffling, a high-yield recombinant YSF2-19 strain that exhibited 3.2- and 3.3-fold increases in glutathione production in shake flask and fermenter respectively was obtained. Comparative analysis of synthetase gene expression was conducted between the initial and shuffled strains using FQ (fluorescent quantitation) RT-PCR (reverse transcription polymerase chain reaction). Delta CT (threshold cycle) relative quantitation analysis revealed that glutathione synthetase gene (GSH-I) expression at the transcriptional level in the YSF2-19 strain was 9.9-fold greater than in the initial YS86. The shuffled yeast strain has a potential application in brewing, other food, and pharmaceutical industries. Simultaneously, the analysis of improved phenotypes will provide more valuable data for inverse metabolic engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Associations between authoritative parenting and the sun exposure and sun protective behaviours of adolescents and their friends.

    PubMed

    Mewse, Avril J; Lea, Stephen E G; Ntala, Eleni; Eiser, J Richard

    2011-05-01

    Associations between the sun exposure and sun protective behaviours of adolescents and their friends were examined along with the role played by authoritative parenting and other family and peer socialisation factors. Four hundred and two adolescents (198 males, 204 females) participated in the research. It was found that these adolescents and their friends shared similar sun exposure and sun protective behaviours and had similar parenting backgrounds. Parental authoritativeness was positively associated with the use of sun protection, even after the effects of other familial and peer variables were controlled, but not with the time spent sunbathing which was associated with friends' behaviours. The theoretical and practical implications of these findings are discussed.

  2. Purification and Characterization of Put1p from Saccharomyces cerevisiae

    PubMed Central

    Wanduragala, Srimevan; Sanyal, Nikhilesh; Liang, Xinwen; Becker, Donald F.

    2010-01-01

    In Saccharomyces cerevisiae, the PUT1 and PUT2 genes are required for the conversion of proline to glutamate. The PUT1 gene encodes Put1p, a proline dehydrogenase (PRODH)1 enzyme localized in the mitochondrion. Put1p was expressed and purified from Escherichia coli and shown to have a UV-visible absorption spectrum that is typical of a bound flavin cofactor. A Km value of 36 mM proline and a kcat = 27 s−1 were determined for Put1p using an artificial electron acceptor. Put1p also exhibited high activity using ubiquinone-1 (CoQ1) as an electron acceptor with a kcat = 9.6 s−1 and a Km of 33 µM for CoQ1. In addition, knockout strains of the electron transfer flavoprotein (ETF) homolog in S. cerevisiae were able to grow on proline as the sole nitrogen source demonstrating that ETF is not required for proline utilization in yeast. PMID:20450881

  3. Saccharomyces boulardii CNCM I-745 in different clinical conditions.

    PubMed

    Dinleyici, Ener Cagri; Kara, Ates; Ozen, Metehan; Vandenplas, Yvan

    2014-11-01

    Saccharomyces boulardii is a well-known probiotic worldwide, and there are numerous studies including experimental and clinical trials in children and adults by the use of S. boulardii. The objective of the present report is to provide an update on the evidence for the efficacy of S. boulardii CNCM I-745 in different clinical conditions. Saccharomyces boulardii is one of the best-studied probiotics in acute gastroenteritis (AGE) and is shown to be safe and to reduce the duration of diarrhea and hospitalization by about 1 day. Saccharomyces boulardii is one of the recommended probiotics for AGE in children by European Society of Paediatric Infectious Diseases and European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). Saccharomyces boulardii is also a recommended probiotic for the prevention of antibiotic-associated diarrhea (AAD), and a recent study showed promising results for the treatment of AAD in children. There is insufficient evidence to recommend the long-term use of S. boulardii in patients with irritable bowel syndrome. Although some clinical studies showed positive effects of S. boulardii on inflammation, there is no clinical evidence that S. boulardii is useful in inflammatory bowel disease. Saccharomyces boulardii could be used in patients needing Helicobacter pylori eradication because the S. boulardii improves compliance, decreases the side effects and moderately increases the eradication rate. There are new promising results (improving feeding tolerance, shorten the course of hyperbilirubinemia), but we do still not recommend the routine use of S. boulardii in newborns. Saccharomyces boulardii CNCM I-745 is a good example for the statement that each probiotic needs to be taxonomically characterized and its efficacy and safety should be documented individually in different clinical settings.

  4. If the Sun Were a Light Bulb.

    ERIC Educational Resources Information Center

    Adney, Kenneth J.

    1991-01-01

    An activity in which students compare the sun's brightness with that of a light bulb of known luminosity (in watts) to determine the luminosity of the sun is presented. As an extension, the luminosity value that the student obtains for the sun can also be used to estimate the sun's surface temperature. (KR)

  5. Dynamics of the Saccharomyces cerevisiae Transcriptome during Bread Dough Fermentation

    PubMed Central

    Aslankoohi, Elham; Zhu, Bo; Rezaei, Mohammad Naser; Voordeckers, Karin; De Maeyer, Dries; Marchal, Kathleen; Dornez, Emmie

    2013-01-01

    The behavior of yeast cells during industrial processes such as the production of beer, wine, and bioethanol has been extensively studied. In contrast, our knowledge about yeast physiology during solid-state processes, such as bread dough, cheese, or cocoa fermentation, remains limited. We investigated changes in the transcriptomes of three genetically distinct Saccharomyces cerevisiae strains during bread dough fermentation. Our results show that regardless of the genetic background, all three strains exhibit similar changes in expression patterns. At the onset of fermentation, expression of glucose-regulated genes changes dramatically, and the osmotic stress response is activated. The middle fermentation phase is characterized by the induction of genes involved in amino acid metabolism. Finally, at the latest time point, cells suffer from nutrient depletion and activate pathways associated with starvation and stress responses. Further analysis shows that genes regulated by the high-osmolarity glycerol (HOG) pathway, the major pathway involved in the response to osmotic stress and glycerol homeostasis, are among the most differentially expressed genes at the onset of fermentation. More importantly, deletion of HOG1 and other genes of this pathway significantly reduces the fermentation capacity. Together, our results demonstrate that cells embedded in a solid matrix such as bread dough suffer severe osmotic stress and that a proper induction of the HOG pathway is critical for optimal fermentation. PMID:24056467

  6. Dynamics of the Saccharomyces cerevisiae transcriptome during bread dough fermentation.

    PubMed

    Aslankoohi, Elham; Zhu, Bo; Rezaei, Mohammad Naser; Voordeckers, Karin; De Maeyer, Dries; Marchal, Kathleen; Dornez, Emmie; Courtin, Christophe M; Verstrepen, Kevin J

    2013-12-01

    The behavior of yeast cells during industrial processes such as the production of beer, wine, and bioethanol has been extensively studied. In contrast, our knowledge about yeast physiology during solid-state processes, such as bread dough, cheese, or cocoa fermentation, remains limited. We investigated changes in the transcriptomes of three genetically distinct Saccharomyces cerevisiae strains during bread dough fermentation. Our results show that regardless of the genetic background, all three strains exhibit similar changes in expression patterns. At the onset of fermentation, expression of glucose-regulated genes changes dramatically, and the osmotic stress response is activated. The middle fermentation phase is characterized by the induction of genes involved in amino acid metabolism. Finally, at the latest time point, cells suffer from nutrient depletion and activate pathways associated with starvation and stress responses. Further analysis shows that genes regulated by the high-osmolarity glycerol (HOG) pathway, the major pathway involved in the response to osmotic stress and glycerol homeostasis, are among the most differentially expressed genes at the onset of fermentation. More importantly, deletion of HOG1 and other genes of this pathway significantly reduces the fermentation capacity. Together, our results demonstrate that cells embedded in a solid matrix such as bread dough suffer severe osmotic stress and that a proper induction of the HOG pathway is critical for optimal fermentation.

  7. RPO41-independent maintenance of [rho-] mitochondrial DNA in Saccharomyces cerevisiae.

    PubMed

    Fangman, W L; Henly, J W; Brewer, B J

    1990-01-01

    A subset of promoters in the mitochondrial DNA (mtDNA) of the yeast Saccharomyces cerevisiae has been proposed to participate in replication initiation, giving rise to a primer through site-specific cleavage of an RNA transcript. To test whether transcription is essential for mtDNA maintenance, we examined two simple mtDNA deletion ([rho-]) genomes in yeast cells. One genome (HS3324) contains a consensus promoter (ATATAAGTA) for the mitochondrial RNA polymerase encoded by the nuclear gene RPO41, and the other genome (4a) does not. As anticipated, in RPO41 cells transcripts from the HS3324 genome were more abundant than were transcripts from the 4a genome. When the RPO41 gene was disrupted, both [rho-] genomes were efficiently maintained. The level of transcripts from HS3324 mtDNA was decreased greater than 400-fold in cells carrying the RPO41 disrupted gene; however, the low-level transcripts from 4a mtDNA were undiminished. These results indicate that replication of [rho-] genomes can be initiated in the absence of wild-type levels of the RPO41-encoded RNA polymerase.

  8. Mechanistic study on the nuclear modifier gene MSS1 mutation suppressing neomycin sensitivity of the mitochondrial 15S rRNA C1477G mutation in Saccharomyces cerevisiae.

    PubMed

    Zhou, Qiyin; Wang, Wei; He, Xiangyu; Zhu, Xiaoyu; Shen, Yaoyao; Yu, Zhe; Wang, Xuexiang; Qi, Xuchen; Zhang, Xuan; Fan, Mingjie; Dai, Yu; Yang, Shuxu; Yan, Qingfeng

    2014-01-01

    The phenotypic manifestation of mitochondrial DNA (mtDNA) mutations can be modulated by nuclear genes and environmental factors. However, neither the interaction among these factors nor their underlying mechanisms are well understood. The yeast Saccharomyces cerevisiae mtDNA 15S rRNA C1477G mutation (PR) corresponds to the human 12S rRNA A1555G mutation. Here we report that a nuclear modifier gene mss1 mutation suppresses the neomycin-sensitivity phenotype of a yeast C1477G mutant in fermentable YPD medium. Functional assays show that the mitochondrial function of the yeast C1477G mutant was impaired severely in YPD medium with neomycin. Moreover, the mss1 mutation led to a significant increase in the steady-state level of HAP5 (heme activated protein), which greatly up-regulated the expression of glycolytic transcription factors RAP1, GCR1, and GCR2 and thus stimulated glycolysis. Furthermore, the high expression of the key glycolytic enzyme genes HXK2, PFK1 and PYK1 indicated that enhanced glycolysis not only compensated for the ATP reduction from oxidative phosphorylation (OXPHOS) in mitochondria, but also ensured the growth of the mss1(PR) mutant in YPD medium with neomycin. This study advances our understanding of the phenotypic manifestation of mtDNA mutations.

  9. Improved Xylose Metabolism by a CYC8 Mutant of Saccharomyces cerevisiae.

    PubMed

    Nijland, Jeroen G; Shin, Hyun Yong; Boender, Leonie G M; de Waal, Paul P; Klaassen, Paul; Driessen, Arnold J M

    2017-06-01

    Engineering Saccharomyces cerevisiae for the utilization of pentose sugars is an important goal for the production of second-generation bioethanol and biochemicals. However, S. cerevisiae lacks specific pentose transporters, and in the presence of glucose, pentoses enter the cell inefficiently via endogenous hexose transporters (HXTs). By means of in vivo engineering, we have developed a quadruple hexokinase deletion mutant of S. cerevisiae that evolved into a strain that efficiently utilizes d-xylose in the presence of high d-glucose concentrations. A genome sequence analysis revealed a mutation (Y353C) in the general corepressor CYC8 , or SSN6 , which was found to be responsible for the phenotype when introduced individually in the nonevolved strain. A transcriptome analysis revealed altered expression of 95 genes in total, including genes involved in (i) hexose transport, (ii) maltose metabolism, (iii) cell wall function (mannoprotein family), and (iv) unknown functions (seripauperin multigene family). Of the 18 known HXTs, genes for 9 were upregulated, especially the low or nonexpressed HXT10 , HXT13 , HXT15 , and HXT16 Mutant cells showed increased uptake rates of d-xylose in the presence of d-glucose, as well as elevated maximum rates of metabolism ( V max ) for both d-glucose and d-xylose transport. The data suggest that the increased expression of multiple hexose transporters renders d-xylose metabolism less sensitive to d-glucose inhibition due to an elevated transport rate of d-xylose into the cell. IMPORTANCE The yeast Saccharomyces cerevisiae is used for second-generation bioethanol formation. However, growth on xylose is limited by pentose transport through the endogenous hexose transporters (HXTs), as uptake is outcompeted by the preferred substrate, glucose. Mutant strains were obtained with improved growth characteristics on xylose in the presence of glucose, and the mutations mapped to the regulator Cyc8. The inactivation of Cyc8 caused increased

  10. Trends in sunburns, sun protection practices, and attitudes toward sun exposure protection and tanning among US adolescents, 1998-2004.

    PubMed

    Cokkinides, Vilma; Weinstock, Martin; Glanz, Karen; Albano, Jessica; Ward, Elizabeth; Thun, Michael

    2006-09-01

    Sun exposure in childhood is an important risk factor for developing skin cancer as an adult. Despite extensive efforts to reduce sun exposure among the young, there are no population-based data on trends in sunburns and sun protection practices in the young. The aim of this study was to describe nationally representative trend data on sunburns, sun protection, and attitudes related to sun exposure among US youth. Cross-sectional telephone surveys of youth aged 11 to 18 years in 1998 (N = 1196) and in 2004 (N = 1613) were conducted using a 2-stage sampling process to draw population-based samples. The surveys asked identical questions about sun protection, number of sunburns experienced, and attitudes toward sun exposure. Time trends were evaluated using pooled logistic regression analysis. In 2004, 69% of subjects reported having been sunburned during the summer, not significantly less than in 1998 (72%). There was a significant decrease in the percentage of those aged 11 to 15 years who reported sunburns and a nonsignificant increase among the 16- to 18-year-olds. The proportion of youth who reported regular sunscreen use increased significantly from 31% to 39%. Little change occurred in other recommended sun protection practices. A small reduction in sunburn frequency and modest increases in sun protection practices were observed among youth between 1998 and 2004, despite widespread sun protection campaigns. Nevertheless, the decrease in sunburns among younger teens may be cause for optimism regarding future trends. Overall, there was rather limited progress in improving sun protection practices and reducing sunburns among US youth between 1998 and 2004.

  11. After the Bell: Developing Sun Sense--Learning about Protection from the Sun's Rays

    ERIC Educational Resources Information Center

    Farenga, Stephen J.; Ness, Daniel

    2008-01-01

    The American Academy of Dermatology (2008) reports that our students will experience 80% of their lifetime exposure to the Sun by the time they are 18. Further, research has demonstrated that continued exposure to the Sun's ultraviolet rays can lead to skin aging, sunburn, immune suppression, ocular melanoma, cataracts, corneal burns, and even…

  12. Acquisition of thermotolerant yeast Saccharomyces cerevisiae by breeding via stepwise adaptation.

    PubMed

    Satomura, Atsushi; Katsuyama, Yoshiaki; Miura, Natsuko; Kuroda, Kouichi; Tomio, Ayako; Bamba, Takeshi; Fukusaki, Eiichiro; Ueda, Mitsuyoshi

    2013-01-01

    A thermotolerant Saccharomyces cerevisiae yeast strain, YK60-1, was bred from a parental strain, MT8-1, via stepwise adaptation. YK60-1 grew at 40°C, a temperature at which MT8-1 could not grow at all. YK60-1 exhibited faster growth than MT8-1 at 30°C. To investigate the mechanisms how MT8-1 acquired thermotolerance, DNA microarray analysis was performed. The analysis revealed the induction of stress-responsive genes such as those encoding heat shock proteins and trehalose biosynthetic enzymes in YK60-1. Furthermore, nontargeting metabolome analysis showed that YK60-1 accumulated more trehalose, a metabolite that contributes to stress tolerance in yeast, than MT8-1. In conclusion, S. cerevisiae MT8-1 acquired thermotolerance by induction of specific stress-responsive genes and enhanced intracellular trehalose levels. © 2013 American Institute of Chemical Engineers.

  13. Transcriptional Regulation in Saccharomyces cerevisiae: Transcription Factor Regulation and Function, Mechanisms of Initiation, and Roles of Activators and Coactivators

    PubMed Central

    Hahn, Steven; Young, Elton T.

    2011-01-01

    Here we review recent advances in understanding the regulation of mRNA synthesis in Saccharomyces cerevisiae. Many fundamental gene regulatory mechanisms have been conserved in all eukaryotes, and budding yeast has been at the forefront in the discovery and dissection of these conserved mechanisms. Topics covered include upstream activation sequence and promoter structure, transcription factor classification, and examples of regulated transcription factor activity. We also examine advances in understanding the RNA polymerase II transcription machinery, conserved coactivator complexes, transcription activation domains, and the cooperation of these factors in gene regulatory mechanisms. PMID:22084422

  14. [Effects of non-saccharomyces albicans metabolic products on the proliferation of human umbilical vein endothelial cell ECV304].

    PubMed

    Chen, Bin; Che, Tuanjie; Bai, Decheng; He, Xiangyi

    2013-04-01

    To evaluate the effects of non-Saccharomyces albicans metabolic products on the cell cycle distribution and proliferation of human umbilical vein endothelial cell ECV304 cells in vitro. The parallel dilution supernatant of Saccharomyces tropicalis, Saccharomyces krusei and Saccharomyces glabrata were prepared, and 1, 4, 16-fold(s) diluted concentration and control group were set up. The line of human umbilical vein endothelial cell ECV304 was cultured in vitro and treated by non-Saccharomyces albicans supernatant. The proliferous effect of ECV304 induced by non-Saccharomyces albicans supernatant after 24, 48, 72 h was detected by the methods of MTT, and the changes of cell density and cycle after 48 h were investigated by inverted microscope and flow cytometry. At the 24th hour, all of the higher concentration (1-fold) of non-Saccharomyces albicans supernatant and the 4-folds diluted Saccharomyces krusei could promote ECV304 proliferation(P < 0.05). After adding various non-Saccharomyces albicans supernatant at 48h and 72th hour, Saccharomyces krusei supernatant and Saccharomyces glabrata supernatant significantly increased proliferation rate of ECV304, while Saccharomyces tropicalis supernatant group showed no significant change no matter which concentration was tested. At 48th hour after adding the non-Saccharomyces albicans supernatant, the ECV304 cells density treated by Saccharomyces krusei supernatant and Saccharomyces glabrata supernatant were significantly higher under the inverted microscope. The G0/G1 population of ECV304 cells decreased while cell proliferation index (PI) increased after incubated with Saccharomyces krusei supernatant and Saccharomyces glabrata supernatant for 48 hours (P < 0.05). Saccharomyces tropicalis group showed no significant change (P > 0.05). The metabolic products of Sacharoymces krusei and Saccharomyces glabrata could induce proliferation of ECV304 cell, which suggests non-Saccharomyces albicans should be undergone more

  15. RNAP-II transcribes two small RNAs at the promoter and terminator regions of the RNAP-I gene in Saccharomyces cerevisiae.

    PubMed

    Mayán, Maria D

    2013-01-01

    Three RNA polymerases coexist in the ribosomal DNA of Saccharomyces cerevisiae. RNAP-I transcribes the 35S rRNA, RNAP-III transcribes the 5S rRNA and RNAP-II is found in both intergenic non-coding regions. Previously, we demonstrated that RNAP-II molecules bound to the intergenic non-coding regions (IGS) of the ribosomal locus are mainly found in a stalled conformation, and the stalled polymerase mediates chromatin interactions, which isolate RNAP-I from the RNAP-III transcriptional domain. Besides, RNAP-II transcribes both IGS regions at low levels, using different cryptic promoters. This report demonstrates that RNAP-II also transcribes two sequences located in the 5'- and 3'-ends of the 35S rRNA gene that overlap with the sequences of the 35S rRNA precursor transcribed by RNAP-I. The sequence located at the promoter region of RNAP-I, called the p-RNA transcript, binds to the transcription termination-related protein, Reb1p, while the T-RNA sequence, located in the termination sites of RNAP-I gene, contains the stem-loop recognized by Rtn1p, which is necessary for proper termination of RNAP-I. Because of their location, these small RNAs may play a key role in the initiation and termination of RNAP-I transcription. To correctly synthesize proteins, eukaryotic cells may retain a mechanism that connects the three main polymerases. This report suggests that cryptic transcription by RNAP-II may be required for normal transcription by RNAP-I in the ribosomal locus of S. cerevisiae. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Three-Dimensional Encapsulation of Saccharomyces cerevisiae in Silicate Matrices Creates Distinct Metabolic States as Revealed by Gene Chip Analysis.

    PubMed

    Fazal, Zeeshan; Pelowitz, Jennifer; Johnson, Patrick E; Harper, Jason C; Brinker, C Jeffrey; Jakobsson, Eric

    2017-04-25

    In order to design hybrid cellular/synthetic devices such as sensors and vaccines, it is important to understand how the metabolic state of living cells changes upon physical confinement within three-dimensional (3D) matrices. We analyze the gene expression patterns of stationary phase Saccharomyces cerevisiae (S. cerevisiae) cells encapsulated within three distinct nanostructured silica matrices and relate those patterns to known naturally occurring metabolic states. Silica encapsulation methods employed were lipid-templated mesophase silica thin films formed by cell-directed assembly (CDA), lipid-templated mesophase silica particles formed by spray drying (SD), and glycerol-doped silica gel monoliths prepared from an aqueous silicate (AqS+g) precursor solution. It was found that the cells for all three-encapsulated methods enter quiescent states characteristic of response to stress, albeit to different degrees and with differences in detail. By the measure of enrichment of stress-related gene ontology categories, we find that the AqS+g encapsulation is more amenable to the cells than CDA and SD encapsulation. We hypothesize that this differential response in the AqS+g encapsulation is related to four properties of the encapsulating gel: (1) oxygen permeability, (2) relative softness of the material, (3) development of a protective sheath around individual cells (visible in TEM micrographs vide infra), and (4) the presence of glycerol in the gel, which has been previously noted to serve as a protectant for encapsulated cells and can serve as the sole carbon source for S. cerevisiae under aerobic conditions. This work represents a combination of experiment and analysis aimed at the design and development of 3D encapsulation procedures to induce, and perhaps control, well-defined physiological behaviors.

  17. Cloning and characterization of a Candida albicans maltase gene involved in sucrose utilization.

    PubMed Central

    Geber, A; Williamson, P R; Rex, J H; Sweeney, E C; Bennett, J E

    1992-01-01

    In order to isolate the structural gene involved in sucrose utilization, we screened a sucrose-induced Candida albicans cDNA library for clones expressing alpha-glucosidase activity. The C. albicans maltase structural gene (CAMAL2) was isolated. No other clones expressing alpha-glucosidase activity. were detected. A genomic CAMAL2 clone was obtained by screening a size-selected genomic library with the cDNA clone. DNA sequence analysis reveals that CAMAL2 encodes a 570-amino-acid protein which shares 50% identity with the maltase structural gene (MAL62) of Saccharomyces carlsbergensis. The substrate specificity of the recombinant protein purified from Escherichia coli identifies the enzyme as a maltase. Northern (RNA) analysis reveals that transcription of CAMAL2 is induced by maltose and sucrose and repressed by glucose. These results suggest that assimilation of sucrose in C. albicans relies on an inducible maltase enzyme. The family of genes controlling sucrose utilization in C. albicans shares similarities with the MAL gene family of Saccharomyces cerevisiae and provides a model system for studying gene regulation in this pathogenic yeast. Images PMID:1400249

  18. Vibration Based Sun Gear Damage Detection

    NASA Technical Reports Server (NTRS)

    Hood, Adrian; LaBerge, Kelsen; Lewicki, David; Pines, Darryll

    2013-01-01

    Seeded fault experiments were conducted on the planetary stage of an OH-58C helicopter transmission. Two vibration based methods are discussed that isolate the dynamics of the sun gear from that of the planet gears, bearings, input spiral bevel stage, and other components in and around the gearbox. Three damaged sun gears: two spalled and one cracked, serve as the focus of this current work. A non-sequential vibration separation algorithm was developed and the resulting signals analyzed. The second method uses only the time synchronously averaged data but takes advantage of the signal/source mapping required for vibration separation. Both algorithms were successful in identifying the spall damage. Sun gear damage was confirmed by the presence of sun mesh groups. The sun tooth crack condition was inconclusive.

  19. As reliable as the sun

    NASA Astrophysics Data System (ADS)

    Leijtens, J. A. P.

    2017-11-01

    Fortunately there is almost nothing as reliable as the sun which can consequently be utilized as a very reliable source of spacecraft power. In order to harvest this power, the solar panels have to be pointed towards the sun as accurately and reliably as possible. To this extend, sunsensors are available on almost every satellite to support vital sun-pointing capability throughout the mission, even in the deployment and save mode phases of the satellites life. Given the criticality of the application one would expect that after more than 50 years of sun sensor utilisation, such sensors would be fully matured and optimised. In actual fact though, the majority of sunsensors employed are still coarse sunsensors which have a proven extreme reliability but present major issues regarding albedo sensitivity and pointing accuracy.

  20. Cloning and expression of two chitin deacetylase genes of Saccharomyces cerevisiae.

    PubMed

    Mishra, C; Semino, C E; McCreath, K J; de la Vega, H; Jones, B J; Specht, C A; Robbins, P W

    1997-03-30

    Chitin deacetylase (EC 3.5.1.41), which hydrolyses the N-acetamido groups of N-acetyl-D-glucosamine residues in chitin, has been demonstrated in crude extracts from sporulating Saccharomyces cerevisiae. Two S. cerevisiae open reading frames (ORFs), identified by the Yeast Genome Project, have protein sequence homology to a chitin deacetylase from Mucor rouxii. Northern blot hybridizations show each ORF was transcribed in diploid cells after transfer to sporulation medium and prior to formation of asci. Each ORF was cloned in a vector under transcriptional control of the GAL 1, 10 promoter and introduced back into haploid strains of S. cerevisiae. Chitin deacetylase activity was detected by in vitro assays from vegetative cells grown in galactose. Chemical analysis of these cells also demonstrated the synthesis of chitosam in vivo. Both recombinant chitin deacetylases showed similar qualitative and quantitative activities toward chitooligosaccharides in vitro. A diploid strain deleted to both ORFs, when sporulated, did not show deacetylase activity. The mutant spores were hypersensitive to lytic enzymes (Glusulase or Zymolyase).

  1. The Sun Radio Imaging Space Experiment (SunRISE) Mission

    NASA Astrophysics Data System (ADS)

    Lazio, Joseph; Kasper, Justin; Maksimovic, Milan; Alibay, Farah; Amiri, Nikta; Bastian, Tim; Cohen, Christina; Landi, Enrico; Manchester, Ward; Reinard, Alysha; Schwadron, Nathan; Cecconi, Baptiste; Hallinan, Gregg; Hegedus, Alex; Krupar, Vratislav; Zaslavsky, Arnaud

    2017-04-01

    Radio emission from coronal mass ejections (CMEs) is a direct tracer of particle acceleration in the inner heliosphere and potential magnetic connections from the lower solar corona to the larger heliosphere. Energized electrons excite Langmuir waves, which then convert into intense radio emission at the local plasma frequency, with the most intense acceleration thought to occur within 20 RS. The radio emission from CMEs is quite strong such that only a relatively small number of antennas is required to detect and map it, but many aspects of this particle acceleration and transport remain poorly constrained. Ground-based arrays would be quite capable of tracking the radio emission associated with CMEs, but absorption by the Earth's ionosphere limits the frequency coverage of ground-based arrays (ν ≳ 15 MHz), which in turn limits the range of solar distances over which they can track the radio emission (≲ 3RS). The state-of-the-art for tracking such emission from space is defined by single antennas (Wind/WAVES, Stereo/SWAVES), in which the tracking is accomplished by assuming a frequency-to-density mapping; there has been some success in triangulating the emission between the spacecraft, but considerable uncertainties remain. We describe the Sun Radio Imaging Space Experiment (SunRISE) mission concept: A constellation of small spacecraft in a geostationary graveyard orbit designed to localize and track radio emissions in the inner heliosphere. Each spacecraft would carry a receiving system for observations below 25 MHz, and SunRISE would produce the first images of CMEs more than a few solar radii from the Sun. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  2. The Sun Radio Imaging Space Experiment (SunRISE) Mission

    NASA Astrophysics Data System (ADS)

    Kasper, J. C.; Lazio, J.; Alibay, F.; Amiri, N.; Bastian, T.; Cohen, C.; Landi, E.; Hegedus, A. M.; Maksimovic, M.; Manchester, W.; Reinard, A.; Schwadron, N.; Cecconi, B.; Hallinan, G.; Krupar, V.

    2017-12-01

    Radio emission from coronal mass ejections (CMEs) is a direct tracer of particle acceleration in the inner heliosphere and potential magnetic connections from the lower solar corona to the larger heliosphere. Energized electrons excite Langmuir waves, which then convert into intense radio emission at the local plasma frequency, with the most intense acceleration thought to occur within 20 R_S. The radio emission from CMEs is quite strong such that only a relatively small number of antennas is required to detect and map it, but many aspects of this particle acceleration and transport remain poorly constrained. Ground-based arrays would be quite capable of tracking the radio emission associated with CMEs, but absorption by the Earth's ionosphere limits the frequency coverage of ground-based arrays (nu > 15 MHz), which in turn limits the range of solar distances over which they can track the radio emission (< 3 R_S). The state-of-the-art for tracking such emission from space is defined by single antennas (Wind/WAVES, Stereo/SWAVES), in which the tracking is accomplished by assuming a frequency-to-density mapping; there has been some success in triangulating the emission between the spacecraft, but considerable uncertainties remain. We describe the Sun Radio Imaging Space Experiment (SunRISE) mission concept: A constellation of small spacecraft in a geostationary graveyard orbit designed to localize and track radio emissions in the inner heliosphere. Each spacecraft would carry a receiving system for observations below 25 MHz, and SunRISE would produce the first images of CMEs more than a few solar radii from the Sun. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  3. Comet ISON Approaching the Sun [still

    NASA Image and Video Library

    2013-11-27

    This movie from NASA’s STEREO spacecraft's Heliospheric Imager shows Comet ISON, Mercury, Comet Encke and Earth over a five-day period from Nov. 20 to Nov. 25, 2013. The sun sits right of the field of view of this camera. Comet ISON, which will round the sun on Nov. 28, is what's known as a sungrazing comet, due to its close approach. Foreshortening or the angle at which these images were obtained make Earth appear as if it is closer to the sun than Mercury. If you look closely you will also see a dimmer and smaller comet Encke near comet ISON. A comet’s journey through the solar system is perilous and violent. A giant ejection of solar material from the sun could rip its tail off. Before it reaches Mars -- at some 230 million miles away from the sun -- the radiation of the sun begins to boil its water, the first step toward breaking apart. And, if it survives all this, the intense radiation and pressure as it flies near the surface of the sun could destroy it altogether. Even if the comet does not survive, tracking its journey will help scientists understand what the comet is made of, how it reacts to its environment, and what this explains about the origins of the solar system. Closer to the sun, watching how the comet and its tail interact with the vast solar atmosphere can teach scientists more about the sun itself. Image Credit: NASA/STEREO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  4. Digital sun sensor multi-spot operation.

    PubMed

    Rufino, Giancarlo; Grassi, Michele

    2012-11-28

    The operation and test of a multi-spot digital sun sensor for precise sun-line determination is described. The image forming system consists of an opaque mask with multiple pinhole apertures producing multiple, simultaneous, spot-like images of the sun on the focal plane. The sun-line precision can be improved by averaging multiple simultaneous measures. Nevertheless, the sensor operation on a wide field of view requires acquiring and processing images in which the number of sun spots and the related intensity level are largely variable. To this end, a reliable and robust image acquisition procedure based on a variable shutter time has been considered as well as a calibration function exploiting also the knowledge of the sun-spot array size. Main focus of the present paper is the experimental validation of the wide field of view operation of the sensor by using a sensor prototype and a laboratory test facility. Results demonstrate that it is possible to keep high measurement precision also for large off-boresight angles.

  5. Orientation in birds. The sun compass.

    PubMed

    Schmidt-Koenig, K; Ganzhorn, J U; Ranvaud, R

    1991-01-01

    The sun compass was discovered by G. Kramer in caged birds showing migratory restlessness. Subsequent experiments with caged birds employing directional training and clock shifts, carried out by Hoffman and Schmidt-Koenig, showed that the sun azimuth is used, and the sun altitude ignored. In the laboratory, McDonald found the accuracy to be +/- 3 degrees(-)+/- 5 degrees. According to Hoffmann and Schmidt-Koenig, caged birds trained at medium northern latitudes were able to allow for the sun's apparent movement north of the arctic circle, but not in equatorial and trans-equatorial latitudes. In homing experiments, and employing clock shifts, Schmidt-Koenig demonstrated that the sun compass is used by homing pigeons during initial orientation. This finding is the principal evidence for the existence of a map-and-compass navigational system. Pigeons living in equatorial latitudes utilize the sun compass even under the extreme solar conditions of equinox, achieving angular resolution of about 3 degrees in homing experiments. According to preliminary analyses, the homing pigeons' ephemerides are retarded by several weeks (Ranvaud, Schmidt-Koenig, Ganzhorn et al.).

  6. Study on DNA Damage Induced by Neon Beam Irradiation in Saccharomyces Cerevisiae

    NASA Astrophysics Data System (ADS)

    Lu, Dong; Li, Wenjian; Wu, Xin; Wang, Jufang; Ma, Shuang; Liu, Qingfang; He, Jinyu; Jing, Xigang; Ding, Nan; Dai, Zhongying; Zhou, Jianping

    2010-12-01

    Yeast strain Saccharomyces cerevisiae was irradiated with different doses of 85 MeV/u 20Ne10+ to investigate DNA damage induced by heavy ion beam in eukaryotic microorganism. The survival rate, DNA double strand breaks (DSBs) and DNA polymorphic were tested after irradiation. The results showed that there were substantial differences in DNA between the control and irradiated samples. At the dose of 40 Gy, the yeast cell survival rate approached 50%, DNA double-strand breaks were barely detectable, and significant DNA polymorphism was observed. The alcohol dehydrogenase II gene was amplified and sequenced. It was observed that base changes in the mutant were mainly transversions of T→G and T→C. It can be concluded that heavy ion beam irradiation can lead to change in single gene and may be an effective way to induce mutation.

  7. The product of the Saccharomyces cerevisiae cell cycle gene DBF2 has homology with protein kinases and is periodically expressed in the cell cycle.

    PubMed Central

    Johnston, L H; Eberly, S L; Chapman, J W; Araki, H; Sugino, A

    1990-01-01

    Several Saccharomyces cerevisiae dbf mutants defective in DNA synthesis have been described previously. In this paper, one of them, dbf2, is characterized in detail. The DBF2 gene has been cloned and mapped, and its nucleotide sequence has been determined. This process has identified an open reading frame capable of encoding a protein of molecular weight 64,883 (561 amino acids). The deduced amino acid sequence contains all 11 conserved domains found in various protein kinases. DBF2 was periodically expressed in the cell cycle at a time that clearly differed from the time of expression of either the histone H2A or DNA polymerase I gene. Its first function was completed very near to initiation of DNA synthesis. However, DNA synthesis in the mutant was only delayed at 37 degrees C, and the cells blocked in nuclear division. Consistent with this finding, the execution point occurred about 1 h after DNA synthesis, and the nuclear morphology of the mutant at the restrictive temperature was that of cells blocked in late nuclear division. DBF2 is therefore likely to encode a protein kinase that may function in initiation of DNA synthesis and also in late nuclear division. Images PMID:2181271

  8. Isopentenyldiphosphate:dimethylallyldiphosphate isomerase: Construction of a high-level heterologous expression system for the gene from Saccharomyces cerevisiae and identification of an active-site nucleophile

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Street, I.P.; Poulter, C.D.

    1990-08-14

    Isopentenyldiphosphate:dimethylallyldiphosphate isomerase (IPP isomerase) is an enzyme in isoprene metabolism which catalyzes the interconversion of the fundamental five-carbon homoallylic and allylic diphosphate building blocks for the pathway. The gene encoding IPP isomerase has recently been isolated from Saccharomyces cerevisiae. A heterologous expression system was constructed for the gene and used to overexpress IPP isomerase in Escherichia coli. In transformants carrying the expression vector, IPP isomerase activity was increased by over 100,000-fold relative to that of the untransformed host strain. The overexpressed enzyme constitutes 30-35% of the total soluble cell protein and can be purified to homogeneity in two steps. Recombinantmore » IPP isomerase was indistinguishable from that purified from yeast. 3-(Fluoromethyl)-3-butenyl diphosphate (FIPP) is a specific active-site-directed inhibitor of IPP isomerase from Claviceps purpurea. Inactivation of yeast IPP isomerase by FIPP was active-site-directed, and inhibition resulted in formation of a stoichiometric enzyme-inhibitor complex. The site of covalent attachment in the enzyme-inhibitor complex was determined by inactivating IPP isomerase with (4-{sup 3}H)FIPP, followed by digestion of the labeled enzyme with trypsin and purification of the resulting radioactive peptides by reversed-phase high-performance liquid chromatography. The primary site of attachment was Cys-139.« less

  9. Sun Exposure and Sun Protection at Primary Schools in The Netherlands: A Cross-Sectional Study.

    PubMed

    Boog, Matthijs C; Nederend, Annelies; Ultee, Jetske

    2016-01-01

    In The Netherlands, skin cancer incidence rates have dramatically increased during the last decades. Exposure to ultraviolet radiation is the most important environmental risk factor for developing skin cancer. The present study aimed to determine the level of sun exposure and sun protection of children at Dutch primary schools. Registered members of an Internet panel of a private research company with a child 6 to 12 years of age completed a standardized questionnaire on sun exposure, sun protection and sunburn for their child on school days during the spring and summer. A total of 1103 parents completed the questionnaire. Most parents reported that their child spent 31 minutes to 1 hour (39.7%) or 1 hour to 1.5 hours (26.1%) outside at school during the spring and summer, 29.3% reported that sunscreen is always or often applied to the skin of their child in the morning on school days, 37% reported that they always or often paid attention to sun protection when selecting their child's outfit, 19.3% of the parents stated that their child could not play in the shade outside at school, and 19.9% of the parents reported that their child had ever had a sunburn at school. With most children, this consistent and repetitive pattern of sun exposure at school will probably lead to damage of exposed skin, because sun protection is insufficiently achieved among children during school days in the spring and summer. Future school-based interventions are necessary to alert and change behavior of parents, children, and primary school teachers. © 2015 Wiley Periodicals, Inc.

  10. Sir- and silencer-independent disruption of silencing in Saccharomyces by Sas10p.

    PubMed

    Kamakaka, R T; Rine, J

    1998-06-01

    A promoter fusion library of Saccharomyces cerevisiae genes was used to exploit phenotypes associated with altered protein dosage. We identified a novel gene, SAS10, by the ability of Sas10p, when overproduced, to disrupt silencing. The predicted Sas10p was 70,200 kD and strikingly rich in charged amino acids. Sas10p was exclusively nuclear in all stages of the cell cycle. Overproduction of Sas10p caused derepression of mating type genes at both HML and HMR, as well as of URA3, TRP1, and ADE2 when inserted near a telomere or at HMR or the rDNA locus. Repressed genes not associated with silenced chromatin were unaffected. Sas10p was essential for viability, and the termination point following Sas10p depletion was as large budded cells. Remarkably, Sas10p overproduction disrupted silencing even under conditions that bypassed the requirement for Sir proteins, ORC, and Rap1p in silencing. These data implied that Sas10p function was intimately connected with the structure of silenced chromatin.

  11. Novel Gal3 proteins showing altered Gal80p binding cause constitutive transcription of Gal4p-activated genes in Saccharomyces cerevisiae.

    PubMed Central

    Blank, T E; Woods, M P; Lebo, C M; Xin, P; Hopper, J E

    1997-01-01

    Gal4p-mediated activation of galactose gene expression in Saccharomyces cerevisiae normally requires both galactose and the activity of Gal3p. Recent evidence suggests that in cells exposed to galactose, Gal3p binds to and inhibits Ga180p, an inhibitor of the transcriptional activator Gal4p. Here, we report on the isolation and characterization of novel mutant forms of Gal3p that can induce Gal4p activity independently of galactose. Five mutant GAL3(c) alleles were isolated by using a selection demanding constitutive expression of a GAL1 promoter-driven HIS3 gene. This constitutive effect is not due to overproduction of Gal3p. The level of constitutive GAL gene expression in cells bearing different GAL3(c) alleles varies over more than a fourfold range and increases in response to galactose. Utilizing glutathione S-transferase-Gal3p fusions, we determined that the mutant Gal3p proteins show altered Gal80p-binding characteristics. The Gal3p mutant proteins differ in their requirements for galactose and ATP for their Gal80p-binding ability. The behavior of the novel Gal3p proteins provides strong support for a model wherein galactose causes an alteration in Gal3p that increases either its ability to bind to Gal80p or its access to Gal80p. With the Gal3p-Gal80p interaction being a critical step in the induction process, the Gal3p proteins constitute an important new reagent for studying the induction mechanism through both in vivo and in vitro methods. PMID:9111326

  12. SunWise[R] Meteorologist Tool Kit

    ERIC Educational Resources Information Center

    US Environmental Protection Agency, 2007

    2007-01-01

    The SunWise Program is designed to help meteorologists raise sun safety awareness by addressing the science of the sun, the risk of overexposure to its ultraviolet (UV) radiation, and what students and their families can do to protect themselves from overexposure. This Tool Kit has been designed for use all over the United States and its…

  13. Identification of the gene for β-fructofuranosidase from Ceratocystis moniliformis CMW 10134 and characterization of the enzyme expressed in Saccharomyces cerevisiae

    PubMed Central

    2013-01-01

    Background β-Fructofuranosidases (or invertases) catalyse the commercially-important biotransformation of sucrose into short-chain fructooligosaccharides with wide-scale application as a prebiotic in the functional foods and pharmaceutical industries. Results We identified a β-fructofuranosidase gene (CmINV) from a Ceratocystis moniliformis genome sequence using protein homology and phylogenetic analysis. The predicted 615 amino acid protein, CmINV, grouped with an existing clade within the glycoside hydrolase (GH) family 32 and showed typical conserved motifs of this enzyme family. Heterologous expression of the CmINV gene in Saccharomyces cerevisiae BY4742∆suc2 provided further evidence that CmINV indeed functions as a β-fructofuranosidase. Firstly, expression of the CmINV gene complemented the inability of the ∆suc2 deletion mutant strain of S. cerevisiae to grow on sucrose as sole carbohydrate source. Secondly, the recombinant protein was capable of producing short-chain fructooligosaccharides (scFOS) when incubated in the presence of 10% sucrose. Purified deglycosylated CmINV protein showed a molecular weight of ca. 66 kDa and a Km and Vmax on sucrose of 7.50 mM and 986 μmol/min/mg protein, respectively. Its optimal pH and temperature conditions were determined to be 6.0 and 62.5°C, respectively. The addition of 50 mM LiCl led to a 186% increase in CmINV activity. Another striking feature was the relatively high volumetric production of this protein in S. cerevisiae as one mL of supernatant was calculated to contain 197 ± 6 International Units of enzyme. Conclusion The properties of the CmINV enzyme make it an attractive alternative to other invertases being used in industry. PMID:24225070

  14. 'My child did not like using sun protection': practices and perceptions of child sun protection among rural black African mothers.

    PubMed

    Kunene, Zamantimande; Albers, Patricia N; Lucas, Robyn M; Banwell, Cathy; Mathee, Angela; Wright, Caradee Y

    2017-08-25

    Photodamage is partially mitigated by darker skin pigmentation, but immune suppression, photoaging and cataracts occur among individuals with all skin types. To assess practices and acceptability to Black African mothers of sun protection equipment for their children living in a rural area, participants were recruited at the time of their child's 18-month vaccinations. Mothers completed a baseline questionnaire on usual sun behaviours and sun protection practices. They were then provided with sun protection equipment and advice. A follow-up questionnaire was administered two weeks later. Mothers reported that during the week prior to the baseline questionnaire, children spent on average less than 1 hour of time outdoors (most often spent in the shade). Most mothers (97%) liked the sun protection equipment. However, many (78 of 86) reported that their child did not like any of the sun protection equipment and two-thirds stated that the sun protection equipment was not easy to use. Among Black Africans in rural northern South Africa, we found a mismatch between parental preferences and child acceptance for using sun protection when outdoors. A better understanding of the health risks of incidental excess sun exposure and potential benefits of sun protection is required among Black Africans.

  15. Use of High Capacity Terminators in Saccharomyces cerevisiae to Increase mRNA half-life and Improve Gene Expression Control for Metabolic Engineering Applications

    PubMed Central

    Curran, Kathleen A.; Karim, Ashty S.; Gupta, Akash; Alper, Hal S.

    2013-01-01

    Control of gene and protein expression of both endogenous and heterologous genes is a key component of metabolic engineering. While a large amount of work has been published characterizing promoters for this purpose, less effort has been exerted to elucidate the role of terminators in yeast. In this study, we characterize over 30 terminators for use in metabolic engineering applications in Saccharomyces cerevisiae and determine mRNA half-life changes to be the major cause of the varied protein and transcript expression level. We demonstrate that the difference in transcript level can be over 6.5-fold even for high strength promoters. The influence of terminator selection is magnified when coupled with a low-expression promoter, with a maximum difference in protein expression of 11-fold between a high-capacity terminator and the parent plasmid terminator and over 35-fold difference when compared with a no-terminator baseline. This is the first time that terminators have been investigated in the context of multiple promoters spanning orders of magnitude in activity. Finally, we demonstrate the utility of terminator selection for metabolic engineering by using a mutant xylose isomerase gene as a proof-of-concept. Through pairing a high-capacity terminator with a low-expression promoter, we were able to achieve the same phenotypic result as with a promoter considerably higher in strength. Moreover, we can further boost the phenotype of the high-strength promoter by pairing it with a high-capacity terminator. This work highlights how terminator elements can be used to control metabolic pathways in the same way that promoters are traditionally used in yeast. Together, this work demonstrates that terminators will be an important part of heterologous gene expression and metabolic engineering for yeast in the future. PMID:23856240

  16. Co-consumption of sugars or ethanol and glucose in a Saccharomyces cerevisiae strain deleted in the HXK2 gene.

    PubMed

    Raamsdonk, L M; Diderich, J A; Kuiper, A; van Gaalen, M; Kruckeberg, A L; Berden, J A; Van Dam, K; Kruckberg, A L

    2001-08-01

    In previous studies it was shown that deletion of the HXK2 gene in Saccharomyces cerevisiae yields a strain that hardly produces ethanol and grows almost exclusively oxidatively in the presence of abundant glucose. This paper reports on physiological studies on the hxk2 deletion strain on mixtures of glucose/sucrose, glucose/galactose, glucose/maltose and glucose/ethanol in aerobic batch cultures. The hxk2 deletion strain co-consumed galactose and sucrose, together with glucose. In addition, co-consumption of glucose and ethanol was observed during the early exponential growth phase. In S.cerevisiae, co-consumption of ethanol and glucose (in the presence of abundant glucose) has never been reported before. The specific respiration rate of the hxk2 deletion strain growing on the glucose/ethanol mixture was 900 micromol.min(-1).(g protein)(-1), which is four to five times higher than that of the hxk2 deletion strain growing oxidatively on glucose, three times higher than its parent growing on ethanol (when respiration is fully derepressed) and is almost 10 times higher than its parent growing on glucose (when respiration is repressed). This indicates that the hxk2 deletion strain has a strongly enhanced oxidative capacity when grown on a mixture of glucose and ethanol. Copyright 2001 John Wiley & Sons, Ltd.

  17. Effects of a preschool staff intervention on children's sun protection: outcomes of sun protection is fun!

    PubMed

    Gritz, Ellen R; Tripp, Mary K; James, Aimee S; Harrist, Ronald B; Mueller, Nancy H; Chamberlain, Robert M; Parcel, Guy S

    2007-08-01

    The preschool is an important yet understudied setting for sun-protection interventions. This study evaluates the effects of Sun Protection is Fun! (SPF) on preschool staff behavioral and psychosocial outcomes related to protecting children from sun exposure. Twenty preschools participated in a 2-year, group-randomized trial to evaluate SPF, a behavioral intervention grounded in social cognitive theory and designed to be more extensive than previous preschool sun-protection interventions. The staff intervention included training, a video, newsletters, a curriculum, and sunscreen. Cross-sectional samples of staff completed surveys at baseline (N= 245), a 12 month intervention assessment (N = 192), and a 24-month intervention assessment (N = 225). At the 12-month and 24-month assessments, significant behavioral effects were seen for use of sunscreen, protective clothing, and shade. Knowledge, self-efficacy, and norms were among the psychosocial variables most affected by the intervention. This study demonstrates that the SPF intervention is effective in improving staff outcomes related to children's sun protection.

  18. Caddo Sun Accounts across Time and Place

    ERIC Educational Resources Information Center

    Gerona, Carla

    2012-01-01

    Billy Day, a Tunica/Biloxi, recently described the significance of the sun for Caddoan people. Day quoted an "old Caddo relative" of his who said: "I used to go outside and hold my hands up and bless myself with the sun--'a'hat.' Well, I can't do that anymore because they say we are sun worshipers. We didn't worship the sun. We worshiped what was…

  19. Population genetics of the wild yeast Saccharomyces paradoxus.

    PubMed Central

    Johnson, Louise J; Koufopanou, Vassiliki; Goddard, Matthew R; Hetherington, Richard; Schäfer, Stefanie M; Burt, Austin

    2004-01-01

    Saccharomyces paradoxus is the closest known relative of the well-known S. cerevisiae and an attractive model organism for population genetic and genomic studies. Here we characterize a set of 28 wild isolates from a 10-km(2) sampling area in southern England. All 28 isolates are homothallic (capable of mating-type switching) and wild type with respect to nutrient requirements. Nine wild isolates and two lab strains of S. paradoxus were surveyed for sequence variation at six loci totaling 7 kb, and all 28 wild isolates were then genotyped at seven polymorphic loci. These data were used to calculate nucleotide diversity and number of segregating sites in S. paradoxus and to investigate geographic differentiation, population structure, and linkage disequilibrium. Synonymous site diversity is approximately 0.3%. Extensive incompatibilities between gene genealogies indicate frequent recombination between unlinked loci, but there is no evidence of recombination within genes. Some localized clonal growth is apparent. The frequency of outcrossing relative to inbreeding is estimated at 1.1% on the basis of heterozygosity. Thus, all three modes of reproduction known in the lab (clonal replication, inbreeding, and outcrossing) have been important in molding genetic variation in this species. PMID:15020405

  20. Heterologous Expression of the Carrot Hsp17.7 gene Increased Growth, Cell Viability, and Protein Solubility in Transformed Yeast (Saccharomyces cerevisiae) under Heat, Cold, Acid, and Osmotic Stress Conditions.

    PubMed

    Ko, Eunhye; Kim, Minhye; Park, Yunho; Ahn, Yeh-Jin

    2017-08-01

    In industrial fermentation of yeast (Saccharomyces cerevisiae), culture conditions are often modified from the optimal growth conditions of the cells to maintain large-scale cultures and/or to increase recombinant protein production. However, altered growth conditions can be stressful to yeast cells resulting in reduced cell growth and viability. In this study, a small heat shock protein gene from carrot (Daucus carota L.), Hsp17.7, was inserted into the yeast genome via homologous recombination to increase tolerance to stress conditions that can occur during industrial culture. A DNA construct, Translational elongation factor gene promoter-carrot Hsp17.7 gene-Phosphoribosyl-anthranilate isomerase gene (an auxotrophic marker), was generated by a series of PCRs and introduced into the chromosome IV of the yeast genome. Immunoblot analysis showed that carrot Hsp17.7 accumulated in the transformed yeast cell lines. Growth rates and cell viability of these cell lines were higher than control cell lines under heat, cold, acid, and hyperosmotic stress conditions. Soluble protein levels were higher in the transgenic cell lines than control cell lines under heat and cold conditions, suggesting the molecular chaperone function of the recombinant Hsp17.7. This study showed that a recombinant DNA construct containing a HSP gene from carrot was successfully expressed in yeast by homologous recombination and increased tolerances to abiotic stress conditions.

  1. Expression of PEP carboxylase from Escherichia coli complements the phenotypic effects of pyruvate carboxylase mutations in Saccharomyces cerevisiae.

    PubMed

    Flores, C L; Gancedo, C

    1997-08-04

    We investigated the effects of the expression of the Escherichia coli ppc gene encoding PEP carboxylase in Saccharomyces cerevisiae mutants devoid of pyruvate carboxylase. Functional expression of the ppc gene restored the ability of the yeast mutants to grow in glucose-ammonium medium. Growth yield in this medium was the same in the transformed yeast than in the wild type although the growth rate of the transformed yeast was slower. Growth in pyruvate was slowed down in the transformed strain, likely due to a futile cycle produced by the simultaneous action of PEP carboxykinase and PEP carboxylase.

  2. Sun's influence on climate: Explored with SDO

    NASA Astrophysics Data System (ADS)

    Lundstedt, H.

    2010-09-01

    Stunning images and movies recorded of the Sun, with Solar Dynamics Observatory (SDO), makes one wonder: How would this change our view on the Sun-Earth climate coupling? SDO shows a much more variable Sun, on all spatial and temporal scales. Detailed pictures of solar storms are foreseen to improve our understanding of the direct Sun-Earth coupling. Dynamo models, described by dynamical systems using input from helioseismic observations, are foreseen to improve our knowledge of the the Sun's cyclic influence on climate. Both the direct-, and the cycle-influence will be discussed in view of the new SDO observations.

  3. Review of Saccharomyces boulardii as a treatment option in IBD.

    PubMed

    Sivananthan, Kavitha; Petersen, Andreas Munk

    2018-05-17

    Review of the yeast Saccharomyces boulardii as a treatment option for the inflammatory bowel diseases (IBD) ulcerative colitis and Crohn's disease. IBD is caused by an inappropriate immune response to gut microbiota. Treatment options could therefore be prebiotics, probiotics, antibiotics and/or fecal transplant. In this review, we have looked at the evidence for the yeast S. boulardii as a treatment option. Searches in PubMed and the Cochrane Library with the MeSH words 'Saccharomyces boulardii AND IBD', 'Saccharomyces boulardii AND Inflammatory Bowel Disease', 'Saccharomyces boulardii AND ulcerative colitis' and 'Saccharomyces boulardii AND Crohn's disease' gave total a total of 80 articles. After exclusions because of irrelevance, articles in other languages and some articles that were not available, 16 articles were included in this review. Three of the clinical trials showed a positive effect of S. boulardii in IBD patients (two Crohn's disease, one ulcerative colitis), while there was one trial that didn't prove any effect (Crohn's disease). Included Animal trials and cell assays describes different anti-inflammatory mechanisms of S. boulardii supporting a possible effect when treating IBD patients. The number of studies of S. boulardii as treatment for IBD is limited. Furthermore, the existing trials have small populations and short duration. We do not have enough evidence to prove the effect of S. boulardii in IBD. Saccharomyces boulardii is, however, a plausible treatment option in the future, but more placebo-controlled clinical studies on both patients with ulcerative colitis and Crohn's disease are needed.

  4. Expression of three mammalian cDNAs that interfere with RAS function in Saccharomyces cerevisiae.

    PubMed Central

    Colicelli, J; Nicolette, C; Birchmeier, C; Rodgers, L; Riggs, M; Wigler, M

    1991-01-01

    Saccharomyces cerevisiae strains expressing the activated RAS2Val19 gene or lacking both cAMP phosphodiesterase genes, PDE1 and PDE2, have impaired growth control and display an acute sensitivity to heat shock. We have isolated two classes of mammalian cDNAs from yeast expression libraries that suppress the heat shock-sensitive phenotype of RAS2Val19 strain. Members of the first class of cDNAs also suppress the heat shock-sensitive phenotype of pde1- pde2- strains and encode cAMP phosphodiesterases. Members of the second class fail to suppress the phenotype of pde1- pde2- strains and therefore are candidate cDNAs encoding proteins that interact with RAS proteins. We report the nucleotide sequence of three members of this class. Two of these cDNAs share considerable sequence similarity, but none are clearly similar to previously isolated genes. Images PMID:1849280

  5. Sun Tracking Systems: A Review

    PubMed Central

    Lee, Chia-Yen; Chou, Po-Cheng; Chiang, Che-Ming; Lin, Chiu-Feng

    2009-01-01

    The output power produced by high-concentration solar thermal and photovoltaic systems is directly related to the amount of solar energy acquired by the system, and it is therefore necessary to track the sun's position with a high degree of accuracy. Many systems have been proposed to facilitate this task over the past 20 years. Accordingly, this paper commences by providing a high level overview of the sun tracking system field and then describes some of the more significant proposals for closed-loop and open-loop types of sun tracking systems. PMID:22412341

  6. Mediation analysis of decisional balance, sun avoidance and sunscreen use in the precontemplation and preparation stages for sun protection.

    PubMed

    Santiago-Rivas, Marimer; Velicer, Wayne F; Redding, Colleen

    2015-01-01

    Mediation analyses of sun protection were conducted testing structural equation models using longitudinal data with three waves. An effect was said to be mediated if the standardised path between processes of change, decisional balance and sun protection outcomes was significant. Longitudinal models of sun protection using data from individuals in the precontemplation (N = 964) and preparation (N = 463) stages who participated of an expert system intervention. Nine processes of change for sun protection, decisional balance constructs of sun protection (pros and cons), sun avoidance behaviour and sunscreen use. With the exception of two processes in the preparation stage, processes of change predicted the pros (r = .126-.614), and the pros predicted the outcomes (r = .181-.272). Three models with the cons as mediator in the preparation stage, and none in the precontemplation stage, showed a mediated relationship between processes and outcomes. In general, mediation analyses found both the process of change-to-pros and pros-to-behaviour paths significant for both precontemplation and preparation stages, and for both sun avoidance and sunscreen use outcomes. Findings provide support for the importance of assessing the role of underlying risk cognitions in improving sun protection adherence.

  7. SWITCH: a dynamic CRISPR tool for genome engineering and metabolic pathway control for cell factory construction in Saccharomyces cerevisiae.

    PubMed

    Vanegas, Katherina García; Lehka, Beata Joanna; Mortensen, Uffe Hasbro

    2017-02-08

    The yeast Saccharomyces cerevisiae is increasingly used as a cell factory. However, cell factory construction time is a major obstacle towards using yeast for bio-production. Hence, tools to speed up cell factory construction are desirable. In this study, we have developed a new Cas9/dCas9 based system, SWITCH, which allows Saccharomyces cerevisiae strains to iteratively alternate between a genetic engineering state and a pathway control state. Since Cas9 induced recombination events are crucial for SWITCH efficiency, we first developed a technique TAPE, which we have successfully used to address protospacer efficiency. As proof of concept of the use of SWITCH in cell factory construction, we have exploited the genetic engineering state of a SWITCH strain to insert the five genes necessary for naringenin production. Next, the naringenin cell factory was switched to the pathway control state where production was optimized by downregulating an essential gene TSC13, hence, reducing formation of a byproduct. We have successfully integrated two CRISPR tools, one for genetic engineering and one for pathway control, into one system and successfully used it for cell factory construction.

  8. Targeted proteome analysis of single-gene deletion strains of Saccharomyces cerevisiae lacking enzymes in the central carbon metabolism.

    PubMed

    Matsuda, Fumio; Kinoshita, Syohei; Nishino, Shunsuke; Tomita, Atsumi; Shimizu, Hiroshi

    2017-01-01

    Central carbon metabolism is controlled by modulating the protein abundance profiles of enzymes that maintain the essential systems in living organisms. In this study, metabolic adaptation mechanisms in the model organism Saccharomyces cerevisiae were investigated by direct determination of enzyme abundance levels in 30 wild type and mutant strains. We performed a targeted proteome analysis using S. cerevisiae strains that lack genes encoding the enzymes responsible for central carbon metabolism. Our analysis revealed that at least 30% of the observed variations in enzyme abundance levels could be explained by global regulatory mechanisms. A enzyme-enzyme co-abundance analysis revealed that the abundances of enzyme proteins involved in the trehalose metabolism and glycolysis changed in a coordinated manner under the control of the transcription factors for global regulation. The remaining variations were derived from local mechanisms such as a mutant-specific increase in the abundances of remote enzymes. The proteome data also suggested that, although the functional compensation of the deficient enzyme was attained by using more resources for protein biosynthesis, available resources for the biosynthesis of the enzymes responsible for central metabolism were not abundant in S. cerevisiae cells. These results showed that global and local regulation of enzyme abundance levels shape central carbon metabolism in S. cerevisiae by using a limited resource for protein biosynthesis.

  9. Overproduction of isoprenoids by Saccharomyces cerevisiae in a synthetic grape juice medium in the absence of plant genes.

    PubMed

    Camesasca, L; Minteguiaga, M; Fariña, L; Salzman, V; Aguilar, P S; Gaggero, C; Carrau, F

    2018-06-06

    The objective of this work is to demonstrate if the hexaprenyl pyrophosphate synthetase Coq1p might be involved in monoterpenes synthesis in Saccharomyces cerevisiae, although its currently known function in yeast is to catalyze the first step in ubiquinone biosynthesis. However, in a BY4743 laboratory strain, the presence of an empty plasmid in a chemically defined grape juice medium results in a statistically significant increase of linalool, (E)-nerolidol and (E,E)-farnesol. When COQ1 is overexpressed from a plasmid, the levels of the volatile isoprenoids are further increased. Furthermore, overexpression of COQ1 in the same genetic context but with a mutated farnesyl pyrophosphate synthetase (erg20 mutation K197E), results in statistically significant higher levels of linalool (above 750 μg/L), geraniol, α-terpineol, and the sesquiterpenes, farnesol and nerolidol (total concentration of volatile isoprenoids surpasses 1300 μg/L). We show that the levels of monoterpenes and sesquiterpenes that S. cerevisiae can produce, in the absence of plant genes, depend on the composition of the medium and the genetic context. To the best of our knowledge, this is the highest level of linalool produced by S. cerevisiae up to now. Further research will be needed for understanding how COQ1 and the medium composition might interact to increase flavor complexity of fermented beverages. Copyright © 2018. Published by Elsevier B.V.

  10. Distribution patterns of Saccharomyces species in cultural landscapes of Germany.

    PubMed

    Brysch-Herzberg, Michael; Seidel, Martin

    2017-08-01

    The distribution patterns of the three Saccharomyces species, Saccharomyces paradoxus, S. uvarum and S. cerevisiae, were investigated by a culture-dependent approach in order to understand better how these species propagate in the cultural landscape of Germany. Saccharomyces paradoxus, the closest relative of S. cerevisiae, is shown to be a true woodland species. It was frequently found in the soil under conifers indicating that S. paradoxus is an autochthonous member of the microbial community in this habitat. Physiological characteristics of the species like the Crabtree effect and high tolerance against ethanol suggest that the species is adapted to regular supply with considerable amounts of sugars. Additionally, a high proportion of the S. paradoxus strains isolated in this study are shown to have the rare ability to ferment melezitose. For these reasons, it is hypothesized that S. paradoxus may be closely associated with the honeydew system in forests. Saccharomyces cerevisiae was rare in most habitats and only exceeded the frequency of S. paradoxus in habitats characterized by modern agricultural mass production of fruit. Both the landscape structure and the agricultural system heavily influence the frequencies of Saccharomyces species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. The Sun in Time

    NASA Technical Reports Server (NTRS)

    Adams, Mitzi L.; Bero, Elizabeth; Sever, Thomas L.

    1999-01-01

    Leveraging funds from NASA's Initiative to Develop Education through Astronomy and Space Science (IDEAS) program, we combined the expertise of an archaeoastronomer, a solar scientist, and a teacher to trace humankind's view of the Sun and how that has changed, from the time of Stonehenge in about 1800 B.C.E., to the time of the Maya in 700 C.E., up to the modem era. Our program was aimed at middle-school students in an attempt to explain not only how science is done today, but how science has evolved from the observations of ancient societies. From these varied cultures, we touched on methods of observing the Sun, ideas of the composition of the Sun, and the relationship of the Sun to everyday life. Further, using the von Braun Astronomical Society's Planetarium in Huntsville, Alabama as a test-bed for the program, we illustrated concepts such as solstices, equinoxes, and local noon with approximately 800 eighth grade students from the local area. Our presentation to SEPA will include a description of NASA's IDEAS program and how to go about partnering with a NASA astronomer, some slides from our planetarium program and web-site, and some hands-on activities.

  12. Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

    PubMed

    Bellon, Jennifer R; Schmid, Frank; Capone, Dimitra L; Dunn, Barbara L; Chambers, Paul J

    2013-01-01

    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

  13. Sun-care product advertising in parenting magazines: what information does it provide about sun protection?

    PubMed

    Kang, Hannah; Walsh-Childers, Kim

    2014-01-01

    This study analyzed the content of sun-care product advertisements in five major U.S. parenting magazines with high circulation: Family Circle, Parents, Family Fun, Parenting (Early Years), and Parenting (School Years). The study examined what information sun-care product advertisements tell parents about skin cancer prevention and about sunscreen use for themselves or for their children based on the Health Belief Model concepts of perceived benefits and perceived barriers. Results showed that the most commonly mentioned benefit of the product was that it blocks ultraviolet A (UVA) and ultraviolet B (UVB) rays. One-third of the ads promoted the product's effectiveness in overcoming four of the barriers that prevent people from using sunscreens: eye irritation, skin irritation, an unpleasant smell, and the need to reapply sunscreen too often or after physical activity. However, only a few of the ads provided information about the consequences of unprotected sun exposure or mentioned methods of sun protection or skin cancer prevention other than sunscreen use. We discuss the implications of these messages for parents' ability to understand correctly how to protect their children from damaging sun exposure.

  14. Zinc oxide and silver nanoparticles toxicity in the baker's yeast, Saccharomyces cerevisiae.

    PubMed

    Galván Márquez, Imelda; Ghiyasvand, Mergan; Massarsky, Andrey; Babu, Mohan; Samanfar, Bahram; Omidi, Katayoun; Moon, Thomas W; Smith, Myron L; Golshani, Ashkan

    2018-01-01

    Engineered nanomaterials (ENMs) are increasingly incorporated into a variety of commercial applications and consumer products; however, ENMs may possess cytotoxic properties due to their small size. This study assessed the effects of two commonly used ENMs, zinc oxide nanoparticles (ZnONPs) and silver nanoparticles (AgNPs), in the model eukaryote Saccharomyces cerevisiae. A collection of ≈4600 S. cerevisiae deletion mutant strains was used to deduce the genes, whose absence makes S. cerevisiae more prone to the cytotoxic effects of ZnONPs or AgNPs. We demonstrate that S. cerevisiae strains that lack genes involved in transmembrane and membrane transport, cellular ion homeostasis, and cell wall organization or biogenesis exhibited the highest sensitivity to ZnONPs. In contrast, strains that lack genes involved in transcription and RNA processing, cellular respiration, and endocytosis and vesicular transport exhibited the highest sensitivity to AgNPs. Secondary assays confirmed that ZnONPs affected cell wall function and integrity, whereas AgNPs exposure decreased transcription, reduced endocytosis, and led to a dysfunctional electron transport system. This study supports the use of S. cerevisiae Gene Deletion Array as an effective high-throughput technique to determine cellular targets of ENM toxicity.

  15. Deletion of a Single-Copy Trna Affects Microtubule Function in Saccharomyces Cerevisiae

    PubMed Central

    Reijo, R. A.; Cho, D. S.; Huffaker, T. C.

    1993-01-01

    rts1-1 was identified as an extragenic suppressor of tub2-104, a cold-sensitive allele of the sole gene encoding β-tubulin in the yeast, Saccharomyces cerevisiae. In addition, rts1-1 cells are heat sensitive and resistant to the microtubule-destabilizing drug, benomyl. The rts1-1 mutation is a deletion of approximately 5 kb of genomic DNA on chromosome X that includes one open reading frame and three tRNA genes. Dissection of this region shows that heat sensitivity is due to deletion of the open reading frame (HIT1). Suppression and benomyl resistance are caused by deletion of the gene encoding a tRNA(AGG)(Arg) (HSX1). Northern analysis of rts1-1 cells indicates that HSX1 is the only gene encoding this tRNA. Deletion of HSX1 does not suppress the tub2-104 mutation by misreading at the AGG codons in TUB2. It also does not suppress by interfering with the protein arginylation that targets certain proteins for degradation. These results leave open the prospect that this tRNA(AGG)(Arg) plays a novel role in the cell. PMID:8307335

  16. Comparison of fermentative capacities of industrial baking and wild-type yeasts of the species Saccharomyces cerevisiae in different sugar media.

    PubMed

    Bell, P J; Higgins, V J; Attfield, P V

    2001-04-01

    To compare the fermentative capacity of wild and domesticated isolates of the genus Saccharomyces. The fermentative capacity of yeasts from a variety of wild and domesticated sources was tested in synthetic dough media that mimic major bread dough types. Domesticated yeast strains were found to have better maltose-utilizing capacity than wild yeast strains. The capacity to ferment sugars under high osmotic stress was randomly distributed amongst wild and baking strains of Saccharomyces. The domestication of bakers' yeast has enhanced the ability of yeasts to ferment maltose, without a similar impact on the fermentative capacity under high osmotic conditions. This study, combined with molecular studies of both wild and domesticated yeast, showed that domestication of bakers' yeast has resulted in improved maltose utilization, apparently via the duplication and mutation of the MAL genes.

  17. Associations of cumulative sun exposure and phenotypic characteristics with histologic solar elastosis

    PubMed Central

    Thomas, Nancy E.; Kricker, Anne; From, Lynn; Busam, Klaus; Millikan, Robert C.; Ritchey, Mary E.; Armstrong, Bruce K.; Lee-Taylor, Julia; Marrett, Loraine D.; Anton-Culver, Hoda; Zanetti, Roberto; Rosso, Stefano; Gallagher, Richard P.; Dwyer, Terence; Goumas, Chris; Kanetsky, Peter A.; Begg, Colin B.; Orlow, Irene; Wilcox, Homer; Paine, Susan; Berwick, Marianne

    2010-01-01

    Background Solar elastosis adjacent to melanomas in histologic sections is regarded as an indicator of sun exposure although the associations of ultraviolet (UV) exposure and phenotype with solar elastosis are yet to be fully explored. Methods The study included 2,589 incident primary melanoma patients with assessment of histologic solar elastosis in the population-based Genes, Environment, and Melanoma study. Ambient erythemal UV (UVE) at places of residence and sun exposure hours, including body site-specific exposure, were collected. We examined the association of cumulative site-specific and non site-specific sun exposure hours and ambient UVE with solar elastosis in multivariable models adjusted for age, sex, center, pigmentary characteristics, nevi and, where relevant, body site. Results Solar elastosis was associated most strongly with site-specific UVE (OR for top exposure quartile, 5.20; 95% CI, 3.40-7.96; P for trend <0.001) and also with site-specific sun exposure (OR for top quartile, 5.12; 95% CI, 3.35-7.83; P for trend <0.001). Older age (OR at >70 years, 7.69; 95% CI, 5.14-11.52); P trend < 0.001) and having more than 10 back nevi (OR, 0.77; 95% CI, 0.61-0.97; P = 0.03) were independently associated with solar elastosis. Conclusion Solar elastosis had a strong association with higher site-specific UVE dose, older age and fewer nevi. Impact Solar elastosis could be a useful biomarker of lifetime site-specific UV. Future research is needed to explore whether age represents more than simple accumulation of sun exposure and the reason that people with more nevi may be less prone to solar elastosis. PMID:20802019

  18. Associations of cumulative sun exposure and phenotypic characteristics with histologic solar elastosis.

    PubMed

    Thomas, Nancy E; Kricker, Anne; From, Lynn; Busam, Klaus; Millikan, Robert C; Ritchey, Mary E; Armstrong, Bruce K; Lee-Taylor, Julia; Marrett, Loraine D; Anton-Culver, Hoda; Zanetti, Roberto; Rosso, Stefano; Gallagher, Richard P; Dwyer, Terence; Goumas, Chris; Kanetsky, Peter A; Begg, Colin B; Orlow, Irene; Wilcox, Homer; Paine, Susan; Berwick, Marianne

    2010-11-01

    Solar elastosis adjacent to melanomas in histologic sections is regarded as an indicator of sun exposure, although the associations of UV exposure and phenotype with solar elastosis are yet to be fully explored. The study included 2,589 incident primary melanoma patients with assessment of histologic solar elastosis in the population-based Genes, Environment, and Melanoma study. Ambient erythemal UV (UVE) at places of residence and sun exposure hours, including body site-specific exposure, were collected. We examined the association of cumulative site-specific and non-site-specific sun exposure hours and ambient UVE with solar elastosis in multivariable models adjusted for age, sex, center, pigmentary characteristics, nevi, and, where relevant, body site. Solar elastosis was associated most strongly with site-specific UVE [odds ratio (OR) for top exposure quartile, 5.20; 95% confidence interval (95% CI), 3.40-7.96; P for trend <0.001] and also with site-specific sun exposure (OR for top quartile, 5.12; 95% CI, 3.35-7.83; P for trend <0.001). Older age (OR at >70 years, 7.69; 95% CI, 5.14-11.52; P for trend < 0.001) and having more than 10 back nevi (OR, 0.77; 95% CI, 0.61-0.97; P = 0.03) were independently associated with solar elastosis. Solar elastosis had a strong association with higher site-specific UVE dose, older age, and fewer nevi. Solar elastosis could be a useful biomarker of lifetime site-specific UV. Future research is needed to explore whether age represents more than simple accumulation of sun exposure and to determine why people with more nevi may be less prone to solar elastosis. ©2010 AACR.

  19. The genetic architecture of low-temperature adaptation in the wine yeast Saccharomyces cerevisiae.

    PubMed

    García-Ríos, Estéfani; Morard, Miguel; Parts, Leopold; Liti, Gianni; Guillamón, José M

    2017-02-14

    Low-temperature growth and fermentation of wine yeast can enhance wine aroma and make them highly desirable traits for the industry. Elucidating response to cold in Saccharomyces cerevisiae is, therefore, of paramount importance to select or genetically improve new wine strains. As most enological traits of industrial importance in yeasts, adaptation to low temperature is a polygenic trait regulated by many interacting loci. In order to unravel the genetic determinants of low-temperature fermentation, we mapped quantitative trait loci (QTLs) by bulk segregant analyses in the F13 offspring of two Saccharomyces cerevisiae industrial strains with divergent performance at low temperature. We detected four genomic regions involved in the adaptation at low temperature, three of them located in the subtelomeric regions (chromosomes XIII, XV and XVI) and one in the chromosome XIV. The QTL analysis revealed that subtelomeric regions play a key role in defining individual variation, which emphasizes the importance of these regions' adaptive nature. The reciprocal hemizygosity analysis (RHA), run to validate the genes involved in low-temperature fermentation, showed that genetic variation in mitochondrial proteins, maintenance of correct asymmetry and distribution of phospholipid in the plasma membrane are key determinants of low-temperature adaptation.

  20. Sun Shines in High-Energy X-rays

    NASA Image and Video Library

    2014-12-22

    X-rays stream off the sun in this first picture of the sun, overlaid on a picture taken by NASA Solar Dynamics Observatory SDO, taken by NASA NuSTAR. The field of view covers the west limb of the sun.

  1. Cloning and characterization of an inulinase gene from the marine yeast Candida membranifaciens subsp. flavinogenie W14-3 and its expression in Saccharomyces sp. W0 for ethanol production.

    PubMed

    Zhang, Lin-Lin; Tan, Mei-Juan; Liu, Guang-Lei; Chi, Zhe; Wang, Guang-Yuan; Chi, Zhen-Ming

    2015-04-01

    The INU1 gene encoding an exo-inulinase from the marine-derived yeast Candida membranifaciens subsp. flavinogenie W14-3 was cloned and characterized. It had an open reading frame of 1,536 bp long encoding an inulinase. The coding region of it was not interrupted by any intron. The cloned gene encoded 512 amino acid residues of a protein with a putative signal peptide of 23 amino acids and a calculated molecular mass of 57.8 kDa. The protein sequence deduced from the inulinase gene contained the inulinase consensus sequences (WMNDPNGL), (RDP), ECP FS and Q. The protein also had six conserved putative N-glycosylation sites. The deduced inulinase from the yeast strain W14-3 was found to be closely related to that from Candida kutaonensis sp. nov. KRF1, Kluyveromyces marxianus, and Cryptococcus aureus G7a. The inulinase gene with its signal peptide encoding sequence was subcloned into the pMIRSC11 expression vector and expressed in Saccharomyces sp. W0. The recombinant yeast strain W14-3-INU-112 obtained could produce 16.8 U/ml of inulinase activity and 12.5 % (v/v) ethanol from 250 g/l of inulin within 168 h. The monosaccharides were detected after the hydrolysis of inulin with the crude inulinase (the yeast culture). All the results indicated that the cloned gene and the recombinant yeast strain W14-3-INU-112 had potential applications in biotechnology.

  2. Vba5p, a novel plasma membrane protein involved in amino acid uptake and drug sensitivity in Saccharomyces cerevisiae.

    PubMed

    Shimazu, Masamitsu; Itaya, Teruhiro; Pongcharoen, Pongsanat; Sekito, Takayuki; Kawano-Kawada, Miyuki; Kakinuma, Yoshimi

    2012-01-01

    Vba5p is closest to Vba3p in the vacuolar transporter for basic amino acids (VBA) family of Saccharomyces cerevisiae. We found that green fluorescence protein (GFP)-tagged Vba5p localized exclusively to the plasma membrane. The uptake of lysine and arginine by whole cells was little affected by deletion of the VBA5 gene, but was stimulated by overexpression of the VBA5 gene. The inhibitory effect of 4-nitroquinoline N-oxide on cell growth was accelerated by expression of the VBA5 gene, and was lessened by the addition of arginine. These results suggest that Vba5p is a plasma membrane protein involved in amino acid uptake and drug sensitivity.

  3. Mediation Analysis of Decisional Balance, Sun Avoidance, and Sunscreen Use in the Precontemplation and Preparation Stages for Sun Protection

    PubMed Central

    Velicer, Wayne F.; Redding, Colleen

    2015-01-01

    Objective Mediation analyses of sun protection were conducted testing structural equation models using longitudinal data with three waves. An effect was said to be mediated if the standardized path between processes of change, decisional balance, and sun protection outcomes were significant. Design Longitudinal models of sun protection using data from individuals in the precontemplation (N=964) and preparation (N =463) stages who participated of an expert system intervention. Main Outcome Measures Nine processes of change for sun protection, decisional balance constructs of sun protection (pros and cons), sun avoidance behavior, and sunscreen use. Results With the exception of two processes in the preparation stage, processes of change predicted the pros (r= .126 to .614), and the pros predicted the outcomes (r= .181 to .272). Three models with the cons as mediator in the preparation stage, and none in the precontemplation stage, showed a mediated relationship between processes and outcomes. Conclusion In general, mediation analyses found both the process of change-to-pros and pros-to-behavior paths significant for both precontemplation and preparation stages, and for both sun avoidance and sunscreen use outcomes. Findings provide support for the importance of assessing the role of underlying risk cognitions in improving sun protection adherence. PMID:26040293

  4. Haploid deletion strains of Saccharomyces cerevisiae that determine survival during space flight

    NASA Astrophysics Data System (ADS)

    Johanson, Kelly; Allen, Patricia L.; Gonzalez-Villalobos, Romer A.; Nesbit, Jacqueline; Nickerson, Cheryl A.; Höner zu Bentrup, Kerstin; Wilson, James W.; Ramamurthy, Rajee; D'Elia, Riccardo; Muse, Kenneth E.; Hammond, Jeffrey; Freeman, Jake; Stodieck, Louis S.; Hammond, Timothy G.

    2007-02-01

    This study identifies genes that determine survival during a space flight, using the model eukaryotic organism, Saccharomyces cerevisiae. Select strains of a haploid yeast deletion series grew during storage in distilled water in space, but not in ground based static or clinorotation controls. The survival advantages in space in distilled water include a 133-fold advantage for the deletion of PEX19, a chaperone and import receptor for newly- synthesized class I peroxisomal membrane proteins, to 77-40 fold for deletion strains lacking elements of aerobic respiration, isocitrate metabolism, and mitochondrial electron transport. Following automated addition of rich growth media, the space flight was associated with a marked survival advantage of strains with deletions in catalytically active genes including hydrolases, oxidoreductases and transferases. When compared to static controls, space flight was associated with a marked survival disadvantage of deletion strains lacking transporter, antioxidant and catalytic activity. This study identifies yeast deletion strains with a survival advantage during storage in distilled water and space flight, and amplifies our understanding of the genes critical for survival in space.

  5. Sun Exposure

    MedlinePlus

    ... pass through your skin and damage your skin cells. Sunburns are a sign of skin damage. Suntans ... after the sun's rays have already killed some cells and damaged others. UV rays can cause skin ...

  6. Sun Allergy

    MedlinePlus

    ... occurs on skin that has been exposed to sunlight. The most common form of sun allergy is ... have unusual, bothersome skin reactions after exposure to sunlight. For severe or persistent symptoms, you may need ...

  7. Signature gene expressions of cell wall integrity pathway concur with tolerance response of industrial yeast Saccharomyces cerevisiae against biomass pretreatment inhibitors

    USDA-ARS?s Scientific Manuscript database

    Traditional industrial ethanologenic yeast Saccharomyces cerevisiae has a robust performance under various environmental conditions and can be served as a candidate for the next-generation biocatalyst development for advanced biofuels production using lignocellulose mateials. Overcoming toxic compou...

  8. Investigation of Model Sunscreen Formulations Comparing the Sun Protection Factor, the Universal Sun Protection Factor and the Radical Formation Ratio.

    PubMed

    Syring, Felicia; Weigmann, Hans-Jürgen; Schanzer, Sabine; Meinke, Martina C; Knorr, Fanny; Lademann, Jürgen

    2016-01-01

    In view of globally rising skin cancer rates and harmful effects exerted by sunlight throughout the ultraviolet, visible and infrared ranges, an objective, safe and comprehensive method for determining sunscreen efficacy is required in order to warrant safe sun exposure. In this study, the influence of characteristic active ingredients (chemical filters, physical filters and antioxidants) on different sunscreen indicators, including the universal sun protection factor and the radical formation ratio, was determined and compared to their influence on sun protection factor values. Spectroscopic universal sun protection factor measurements were conducted ex vivo by analyzing tape strips taken from human skin, and radical formation ratio determination was performed via electron paramagnetic resonance spectroscopy using porcine ear skin ex vivo. The sun protection factor determination was conducted according to ISO standards (ISO 24444:2010). It was shown that chemical filters provide a protective effect which was measurable by all methods examined (spectroscopy, electron paramagnetic resonance spectroscopy and erythema formation). Physical filters, when used as single active ingredients, increased protective values in universal sun protection factor and sun protection factor measurements but exhibited no significant effect on universal sun protection factor measurements when used in combination with chemical filters or antioxidants. Antioxidants were shown to increase sun protection factor values. Radical formation ratio values were shown to be influenced merely by chemical filters, leading to the conclusion that the universal sun protection factor is the most suitable efficacy indicator for the ultraviolet range. © 2015 S. Karger AG, Basel.

  9. Identification of mitochondrial carriers in Saccharomyces cerevisiae by transport assay of reconstituted recombinant proteins.

    PubMed

    Palmieri, Ferdinando; Agrimi, Gennaro; Blanco, Emanuela; Castegna, Alessandra; Di Noia, Maria A; Iacobazzi, Vito; Lasorsa, Francesco M; Marobbio, Carlo M T; Palmieri, Luigi; Scarcia, Pasquale; Todisco, Simona; Vozza, Angelo; Walker, John

    2006-01-01

    The inner membranes of mitochondria contain a family of carrier proteins that are responsible for the transport in and out of the mitochondrial matrix of substrates, products, co-factors and biosynthetic precursors that are essential for the function and activities of the organelle. This family of proteins is characterized by containing three tandem homologous sequence repeats of approximately 100 amino acids, each folded into two transmembrane alpha-helices linked by an extensive polar loop. Each repeat contains a characteristic conserved sequence. These features have been used to determine the extent of the family in genome sequences. The genome of Saccharomyces cerevisiae contains 34 members of the family. The identity of five of them was known before the determination of the genome sequence, but the functions of the remaining family members were not. This review describes how the functions of 15 of these previously unknown transport proteins have been determined by a strategy that consists of expressing the genes in Escherichia coli or Saccharomyces cerevisiae, reconstituting the gene products into liposomes and establishing their functions by transport assay. Genetic and biochemical evidence as well as phylogenetic considerations have guided the choice of substrates that were tested in the transport assays. The physiological roles of these carriers have been verified by genetic experiments. Various pieces of evidence point to the functions of six additional members of the family, but these proposals await confirmation by transport assay. The sequences of many of the newly identified yeast carriers have been used to characterize orthologs in other species, and in man five diseases are presently known to be caused by defects in specific mitochondrial carrier genes. The roles of eight yeast mitochondrial carriers remain to be established.

  10. Dissemination of go sun smart in outdoor recreation: effect of program exposure on sun protection of guests at high-altitude ski areas.

    PubMed

    Walkosz, Barbara J; Buller, David B; Andersen, Peter A; Scott, Michael D; Dignan, Mark B; Cutter, Gary R; Liu, Xia; Maloy, Julie A

    2014-09-01

    Go Sun Smart is a theory-based health communication program designed to influence sun-protection behaviors of employees and guests at high-altitude ski areas to reduce skin cancer risk. The effects of Go Sun Smart, in a Phase IV dissemination randomized posttest-only trial, on sun-protection behaviors of ski area guests are reported. Program use was assessed by on-site observation and guest message exposure, and sun protection was measured in intercept surveys at ski areas. Dissemination strategy-enhanced versus basic-was not significantly related to sun safety practices. Additional analyses examined the relation between message exposure and guests' sun safety practices. Ski areas displaying at least 6 Go Sun Smart materials in guest-only areas and 9 Go Sun Smart materials throughout the area increased guests' message exposure. Higher message exposure within the high-use ski areas was associated with improved sun protection by guests but not within the low-use ski areas. The authors underscore the importance of program implementation and message exposure on the success of evidence-based health communication efforts applied industrywide.

  11. Sun meter

    DOEpatents

    Younskevicius, Robert E.

    1978-01-01

    A simple, inexpensive device for measuring the radiation energy of the sun impinging on the device. The measurement of the energy over an extended period of time is accomplished without moving parts or tracking mechanisms.

  12. Sun Safe Mode Controller Design for LADEE

    NASA Technical Reports Server (NTRS)

    Fusco, Jesse C.; Swei, Sean S. M.; Nakamura, Robert H.

    2015-01-01

    This paper presents the development of sun safe controllers which are designed to keep the spacecraft power positive and thermally balanced in the event an anomaly is detected. Employed by NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE), the controllers utilize the measured sun vector and the spacecraft body rates for feedback control. To improve the accuracy of sun vector estimation, the least square minimization approach is applied to process the sensor data, which is proven to be effective and accurate. To validate the controllers, the LADEE spacecraft model engaging the sun safe mode was first simulated and then compared with the actual LADEE orbital fight data. The results demonstrated the applicability of the proposed sun safe controllers.

  13. Sun tracker for clear or cloudy weather

    NASA Technical Reports Server (NTRS)

    Scott, D. R.; White, P. R.

    1979-01-01

    Sun tracker orients solar collector so that they absorb maximum possible sunlight without being fooled by bright clouds, holes in cloud cover, or other atmospheric conditions. Tracker follows sun within 0.25 deg arc and is accurate within + or - 5 deg when sun is hidden.

  14. The Award Winning Black Suns

    NASA Astrophysics Data System (ADS)

    Holbrook, Jarita

    2018-01-01

    Black Suns: An Astrophysics Adventure is a documentary film focusing on the annular and total solar eclipses of 2012. We made a different kind of astronomy documentary showing the human aspects rather than just focusing on pretty astronomy pictures. The film combines personal stories with science. Our heroes are Hakeem Oluseyi and Alphonse Sterling, who valiantly travel to study the solar corona during total solar eclipses. The goals of the film included presenting three dimensional scientists, to show their paths to becoming astrophysicists, and to show them as they collect data and work as scientists. Drama and tension surround taking data during the small window of time during totality. The Black Suns was filmed in Tokyo, Cairns, Tucson, and Melbourne Florida. Uniquely, the film began through a Kickstarter campaign to fund travel and filming in Tokyo. Many American Astronomical Society members donated to the film! Black Suns won the Jury Prize at the 2017 Art of Brooklyn Film Festival. Black Suns will be screening in full on ???.

  15. Prototype of sun projector device

    NASA Astrophysics Data System (ADS)

    Ihsan; Dermawan, B.

    2016-11-01

    One way to introduce astronomy to public, including students, can be handled by solar observation. The widely held device for this purpose is coelostat and heliostat. Besides using filter attached to a device such as telescope, it is safest to use indirect way for observing the Sun. The main principle of the indirect way is deflecting the sun light and projecting image of the sun on a screen. We design and build a simple and low-cost astronomical device, serving as a supplement to increase public service, especially for solar observation. Without using any digital and intricate supporting equipment, people can watch and relish image of the Sun in comfortable condition, i.e. in a sheltered or shady place. Here we describe a design and features of our prototype of the device, which still, of course, has some limitations. In the future, this prototype can be improved for more efficient and useful applications.

  16. Tuning CRISPR-Cas9 Gene Drives in Saccharomyces cerevisiae

    PubMed Central

    Roggenkamp, Emily; Giersch, Rachael M.; Schrock, Madison N.; Turnquist, Emily; Halloran, Megan; Finnigan, Gregory C.

    2018-01-01

    Control of biological populations is an ongoing challenge in many fields, including agriculture, biodiversity, ecological preservation, pest control, and the spread of disease. In some cases, such as insects that harbor human pathogens (e.g., malaria), elimination or reduction of a small number of species would have a dramatic impact across the globe. Given the recent discovery and development of the CRISPR-Cas9 gene editing technology, a unique arrangement of this system, a nuclease-based “gene drive,” allows for the super-Mendelian spread and forced propagation of a genetic element through a population. Recent studies have demonstrated the ability of a gene drive to rapidly spread within and nearly eliminate insect populations in a laboratory setting. While there are still ongoing technical challenges to design of a more optimal gene drive to be used in wild populations, there are still serious ecological and ethical concerns surrounding the nature of this powerful biological agent. Here, we use budding yeast as a safe and fully contained model system to explore mechanisms that might allow for programmed regulation of gene drive activity. We describe four conserved features of all CRISPR-based drives and demonstrate the ability of each drive component—Cas9 protein level, sgRNA identity, Cas9 nucleocytoplasmic shuttling, and novel Cas9-Cas9 tandem fusions—to modulate drive activity within a population. PMID:29348295

  17. Cloning and expression of Saccharomyces cerevisiae SUC2 gene in yeast platform and characterization of recombinant enzyme biochemical properties.

    PubMed

    Mohandesi, Nooshin; Siadat, Seyed Omid Ranaei; Haghbeen, Kamahldin; Hesampour, Ardeshir

    2016-12-01

    Invertase (EC.3.2.1.26) catalyzes the hydrolysis of sucrose to an equimolar mixture of D-glucose and D-fructose which is of interest for various industrial applications. In this research, Saccharomyces cerevisiae invertase gene (SUC2) was optimized based on Pichia pastoris codon preference. The synthetic gene was introduced into the methylotrophic yeast Pichia pastoris under the control of the inducible AOX1 promoter. High level of the extracellular recombinant invertase (R-inv) production was achieved via methanol induction for 4 days and purified by His-Tag affinity chromatography which appeared to be a mixture of glycosylated proteins with various sizes of 85-95 kDa on SDS-PAGE. Deglycosylation of the proteins by Endo-H resulted in the proteins with average molecular weight of 60 kDa. The purified recombinant invertase biochemical properties and kinetic parameters determined a pH and temperature optimum at 4.8 and 60 °C, respectively, which in comparison with native S. cerevisiae invertase, thermal stability of recombinant invertase is highly increased in different heating treatment experiments. The purification of recombinant invertase resulted in an enzyme with specific activity of 178.56 U/mg with 3.83-fold of purification and the kinetic constants for enzyme were Km value of 19 mM and Vmax value of 300 μmol min -1  mg -1 With kinetic efficiency (Kcat/Km) of 13.15 s -1  mmol -1 it can be concluded that recombinant P. pastoris invertase can be more effective for industrial quality criteria. We conclude that recombinant P. pastoris enzyme with broad pH stability, substrate specificity and proper thermal stability can fulfil a series of predefined industrial quality criteria to be used in food, pharmaceutical and bio ethanol production industries.

  18. Thermal resistance of Saccharomyces yeast ascospores in beers.

    PubMed

    Milani, Elham A; Gardner, Richard C; Silva, Filipa V M

    2015-08-03

    The industrial production of beer ends with a process of thermal pasteurization. Saccharomyces cerevisiae and Saccharomyces pastorianus are yeasts used to produce top and bottom fermenting beers, respectively. In this research, first the sporulation rate of 12 Saccharomyces strains was studied. Then, the thermal resistance of ascospores of three S. cerevisiae strains (DSMZ 1848, DSMZ 70487, Ethanol Red(®)) and one strain of S. pastorianus (ATCC 9080) was determined in 4% (v/v) ethanol lager beer. D60 °C-values of 11.2, 7.5, 4.6, and 6.0 min and z-values of 11.7, 14.3, 12.4, and 12.7 °C were determined for DSMZ 1848, DSMZ 70487, ATCC 9080, and Ethanol Red(®), respectively. Lastly, experiments with 0 and 7% (v/v) beers were carried out to investigate the effect of ethanol content on the thermal resistance of S. cerevisiae (DSMZ 1848). D55 °C-values of 34.2 and 15.3 min were obtained for 0 and 7% beers, respectively, indicating lower thermal resistance in the more alcoholic beer. These results demonstrate similar spore thermal resistance for different Saccharomyces strains and will assist in the design of appropriate thermal pasteurization conditions for preserving beers with different alcohol contents. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Enhanced expression of the DNA damage-inducible gene DIN7 results in increased mutagenesis of mitochondrial DNA in Saccharomyces cerevisiae.

    PubMed

    Koprowski, P; Fikus, M U; Dzierzbicki, P; Mieczkowski, P; Lazowska, J; Ciesla, Z

    2003-08-01

    We reported previously that the product of DIN7, a DNA damage-inducible gene of Saccharomyces cerevisiae, belongs to the XPG family of proteins, which are involved in DNA repair and replication. This family includes the S. cerevisiae protein Rad2p and its human homolog XPGC, Rad27p and its mammalian homolog FEN-1, and Exonuclease I (Exo I). Interestingly, Din7p is the only member of the XPG family which specifically functions in mitochondria. We reported previously that overexpression of DIN7 results in a mitochondrial mutator phenotype. In the present study we wished to test the hypothesis that this phenotype is dependent on the nuclease activity of Din7p. For this purpose, we constructed two alleles, din7-D78A and din7-D173A, which encode proteins in which highly conserved aspartates important for the nuclease activity of the XPG proteins have been replaced by alanines. Here, we report that overexpression of the mutant alleles, in contrast to DIN7, fails to increase the frequency of mitochondrial petite mutants or erythromycin-resistant (Er) mutants. Also, overproduction of din7-D78Ap does not result in destabilization of poly GT tracts in mitochondrial DNA (mtDNA), the phenotype observed in cells that overexpress Din7p. We also show that petite mutants induced by enhanced synthesis of wild-type Din7p exhibit gross rearrangements of mtDNA, and that this correlates with enhanced recombination within the mitochondrial cyt b gene. These results suggest that the stability of the mitochondrial genome of S. cerevisiae is modulated by the level of the nuclease Din7p.

  20. Alternative Saccharomyces interspecies hybrid combinations and their potential for low‐temperature wort fermentation

    PubMed Central

    Nikulin, Jarkko; Krogerus, Kristoffer

    2017-01-01

    Abstract The lager yeast hybrid (Saccharomyces cerevisiae × Saccharomyces eubayanus) possesses two key characteristics that are essential for lager brewing: efficient sugar utilization and cold tolerance. Here we explore the possibility that the lager yeast phenotype can be recreated by hybridizing S. cerevisiae ale yeast with a number of cold‐tolerant Saccharomyces species including Saccharomyces arboricola, Saccharomyces eubayanus, Saccharomyces mikatae and Saccharomyces uvarum. Interspecies hybrids performed better than parental strains in lager brewing conditions (12°C and 12°P wort), with the S. mikatae hybrid performing as well as the S. eubayanus hybrid. Where the S. cerevisiae parent was capable of utilizing maltotriose, this trait was inherited by the hybrids. A greater production of higher alcohols and esters by the hybrids resulted in the production of more aromatic beers relative to the parents. Strong fermentation performance relative to the parents was dependent on ploidy, with polyploid hybrids (3n, 4n) performing better than diploid hybrids. All hybrids produced 4‐vinyl guaiacol, a smoke/clove aroma generally considered an off flavour in lager beer. This characteristic could however be eliminated by isolating spore clones from a fertile hybrid of S. cerevisiae and S. mikatae. The results suggest that S. eubayanus is dispensable when constructing yeast hybrids that express the typical lager yeast phenotype. © 2017 The Authors. Yeast published by John Wiley & Sons, Ltd. PMID:28755430

  1. Physiological and Transcriptional Responses of Saccharomyces cerevisiae to Zinc Limitation in Chemostat Cultures †

    PubMed Central

    De Nicola, Raffaele; Hazelwood, Lucie A.; De Hulster, Erik A. F.; Walsh, Michael C.; Knijnenburg, Theo A.; Reinders, Marcel J. T.; Walker, Graeme M.; Pronk, Jack T.; Daran, Jean-Marc; Daran-Lapujade, Pascale

    2007-01-01

    Transcriptional responses of the yeast Saccharomyces cerevisiae to Zn availability were investigated at a fixed specific growth rate under limiting and abundant Zn concentrations in chemostat culture. To investigate the context dependency of this transcriptional response and eliminate growth rate-dependent variations in transcription, yeast was grown under several chemostat regimens, resulting in various carbon (glucose), nitrogen (ammonium), zinc, and oxygen supplies. A robust set of genes that responded consistently to Zn limitation was identified, and the set enabled the definition of the Zn-specific Zap1p regulon, comprised of 26 genes and characterized by a broader zinc-responsive element consensus (MHHAACCBYNMRGGT) than so far described. Most surprising was the Zn-dependent regulation of genes involved in storage carbohydrate metabolism. Their concerted down-regulation was physiologically relevant as revealed by a substantial decrease in glycogen and trehalose cellular content under Zn limitation. An unexpectedly large number of genes were synergistically or antagonistically regulated by oxygen and Zn availability. This combinatorial regulation suggested a more prominent involvement of Zn in mitochondrial biogenesis and function than hitherto identified. PMID:17933919

  2. Comet ISON Streaks Toward the Sun

    NASA Image and Video Library

    2013-11-22

    Date: 19 Nov 2013 Comet ISON shows off its tail in this three-minute exposure taken on 19 Nov. 2013 at 6:10 a.m. EST, using a 14-inch telescope located at the Marshall Space Flight Center. The comet is just nine days away from its close encounter with the sun; hopefully it will survive to put on a nice show during the first week of December. The star images are trailed because the telescope is tracking on the comet, which is now exhibiting obvious motion with respect to the background stars over a period of minutes. At the time of this image, Comet ISON was some 44 million miles from the sun -- and 80 million miles from Earth -- moving at a speed of 136,700 miles per hour. Credit: NASA/MSFC/Aaron Kingery -------- More details on Comet ISON: Comet ISON began its trip from the Oort cloud region of our solar system and is now travelling toward the sun. The comet will reach its closest approach to the sun on Thanksgiving Day -- 28 Nov 2013 -- skimming just 730,000 miles above the sun's surface. If it comes around the sun without breaking up, the comet will be visible in the Northern Hemisphere with the naked eye, and from what we see now, ISON is predicted to be a particularly bright and beautiful comet. Catalogued as C/2012 S1, Comet ISON was first spotted 585 million miles away in September 2012. This is ISON's very first trip around the sun, which means it is still made of pristine matter from the earliest days of the solar system’s formation, its top layers never having been lost by a trip near the sun. Comet ISON is, like all comets, a dirty snowball made up of dust and frozen gases like water, ammonia, methane and carbon dioxide -- some of the fundamental building blocks that scientists believe led to the formation of the planets 4.5 billion years ago. NASA has been using a vast fleet of spacecraft, instruments, and space- and Earth-based telescope, in order to learn more about this time capsule from when the solar system first formed. The journey along the way

  3. Homing at an extragenic locus mediated by VDE (PI-SceI) in Saccharomyces cerevisiae.

    PubMed

    Nogami, Satoru; Fukuda, Tomoyuki; Nagai, Yuri; Yabe, Shizu; Sugiura, Masako; Mizutani, Ryuta; Satow, Yoshinori; Anraku, Yasuhiro; Ohya, Yoshikazu

    2002-06-30

    PI-SceI (VDE), a homing endonuclease with protein splicing activity, is a genomic parasite in the VMA1 gene of Saccharomyces cerevisiae. In a heterozygous diploid of the VDE-less VMA1 allele and a VDE-containing VMA1 allele, VDE specifically cleaves its recognition sequence (VRS) in the VDE-less VMA1 allele at meiosis, followed by 'homing', i.e. a conversion to a VDE-containing allele. We found that upon VDE expression, homing of a marker gene at an extragenic locus occurs only when a 45 bp element containing the VRS is inserted at its allelic site, while mutants of VDE with no endonuclease activity lack authentic extragenic homing activity. Thus, both the VRS and VDE are required for homing. Insertion of the VRS in a homozygous diploid significantly lowered the spore germination ability, indicating that a template for gene repair at its allelic locus is essential for efficient homing and survival of yeast cells. Copyright 2002 John Wiley & Sons, Ltd.

  4. Introducing a New Breed of Wine Yeast: Interspecific Hybridisation between a Commercial Saccharomyces cerevisiae Wine Yeast and Saccharomyces mikatae

    PubMed Central

    Bellon, Jennifer R.; Schmid, Frank; Capone, Dimitra L.; Dunn, Barbara L.; Chambers, Paul J.

    2013-01-01

    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment. PMID:23614011

  5. Smart, passive sun facing surfaces

    DOEpatents

    Hively, Lee M.

    1996-01-01

    An article adapted for selectively utilizing solar radiation comprises an absorptive surface and a reflective surface, the absorptive surface and the reflective surface oriented to absorb solar radiation when the sun is in a relatively low position, and to reflect solar radiation when the sun is in a relatively high position.

  6. CME leaving the Sun [Video

    NASA Image and Video Library

    2017-12-08

    Animation of a CME leaving the Sun, slamming into our magnetosphere. Credit: NASA/GSFC/SOHO/ESA Sound: Juan Carlos Garcia To learn more go to the SOHO website: sohowww.nascom.nasa.gov/home.html To learn more about NASA's Sun Earth Day go here: sunearthday.nasa.gov/2010/index.php

  7. Anaerobic organic acid metabolism of Candida zemplinina in comparison with Saccharomyces wine yeasts.

    PubMed

    Magyar, Ildikó; Nyitrai-Sárdy, Diána; Leskó, Annamária; Pomázi, Andrea; Kállay, Miklós

    2014-05-16

    Organic acid production under oxygen-limited conditions has been thoroughly studied in the Saccharomyces species, but practically never investigated in Candida zemplinina, which seems to be an acidogenic species under oxidative laboratory conditions. In this study, several strains of C. zemplinina were tested for organic acid metabolism, in comparison with Saccharomyces cerevisiae, Saccharomyces uvarum and Candida stellata, under fermentative conditions. Only C. stellata produced significantly higher acidity in simple minimal media (SM) with low sugar content and two different nitrogen sources (ammonia or glutamic acid) at low level. However, the acid profile differed largely between the Saccharomyces and Candida species and showed inverse types of N-dependence in some cases. Succinic acid production was strongly enhanced on glutamic acid in Saccharomyces species, but not in Candida species. 2-oxoglutarate production was strongly supported on ammonium nitrogen in Candida species, but remained low in Saccharomyces. Candida species, C. stellata in particular, produced more pyruvic acid regardless of N-sources. From the results, we concluded that the anaerobic organic acid metabolisms of C. zemplinina and C. stellata are different from each other and also from that of the Saccharomyces species. In the formation of succinic acid, the oxidative pathway from glutamic acid seems to play little or no role in C. zemplinina. The reductive branch of the TCA cycle, however, produces acidic intermediates (malic, fumaric, and succinic acid) in a level comparable with the production of the Saccharomyces species. An unidentified organic acid, which was produced on glutamic acid only by the Candida species, needs further investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Knowledge and practice of sun protection in schools in South Africa where no national sun protection programme exists.

    PubMed

    Wright, Caradee Y; Reeder, Anthony I; Albers, Patricia N

    2016-04-01

    Interventions in primary schools that increase sun-protective behaviours and decrease ultraviolet radiation exposure, sunburn incidence and skin cancer risk can be effective. SunSmart School Accreditation Programmes (SSAP) are recommended. Prior to SSAP implementation in South Africa, we explored the feasibility of obtaining national baseline information and investigated possible associations between strategies regarding sun protection in schools and students' responses to a questionnaire. Principals from randomly selected urban government schools in all nine South African provinces completed a questionnaire and 679 students were surveyed. The mean sun-related knowledge and behaviour scores of students were 4 (range: 1-7) and 3 (range-0-8) out of 9, respectively. The mean school sun protection effort score was 4 out of 14. There were no statistically significant correlations between students' knowledge or behaviour scores and their school score. The World Health Organization recommends an SSAP to address policy, practice and curriculum changes to support sun protection of students. This cross-sectional study demonstrates the feasibility of, and need for, a larger baseline study with longitudinal, multi-variable follow-up which includes other influential factors, such as parent support. Such research could quantify the impact of the SSAP and identify which key factors influence the sun-related knowledge and behaviours of students. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. Genome Sequence of the Lager-Brewing Yeast Saccharomyces sp. Strain M14, Used in the High-Gravity Brewing Industry in China

    PubMed Central

    Liu, Chunfeng; Niu, Chengtuo; Zheng, Feiyun; Li, Yongxian; Zhao, Yun; Yin, Xiangsheng

    2017-01-01

    ABSTRACT Lager-brewing yeasts are mainly used for the production of lager beers. Illumina and PacBio-based sequence analyses revealed an approximate genome size of 22.8 Mb, with a GC content of 38.98%, for the Chinese lager-brewing yeast Saccharomyces sp. strain M14. Based on ab initio prediction, 9,970 coding genes were annotated. PMID:29074666

  10. Sun safety measures among construction workers in Britain.

    PubMed

    Madgwick, P; Houdmont, J; Randall, R

    2011-09-01

    Relative to other occupational groups in Britain, construction workers have a high incidence of skin cancer attributable to sun exposure. The importance of sun safety measures to minimize the risk of skin cancer is recognized in the literature; however, little is known about the factors associated with their use by construction workers. Knowledge in this area could help inform interventions to encourage sun safety behaviour within the sector. To investigate socio-demographic and occupational characteristics associated with the use of sun safety measures among construction workers in Britain. Data collection was by means of a self-administered questionnaire, which was sent to 360 construction workers. Information collected included socio-demographic and occupational characteristics and the use of sun safety measures. Participants worked outdoors for an average of 6.6 h/day. Three specific sun safety measures were used by the majority of respondents. Logistic regression analyses showed that certain socio-demographic and occupational factors were associated with the use of sun safety measures. In particular, receipt of sun safety training was positively associated with the wearing of long sleeved, loose fitting tops and trousers (OR, 1.69; 95% CI, 1.02-2.80) and sunglasses (OR, 1.85; 95% CI, 1.10-3.13). The results highlight the importance of employer-led sun safety interventions in the British construction industry. Interventions that take account of demographic and occupational characteristics are likely to have a positive impact in terms of improving workers' use of sun safety measures.

  11. Smart, passive sun facing surfaces

    DOEpatents

    Hively, L.M.

    1996-04-30

    An article adapted for selectively utilizing solar radiation comprises an absorptive surface and a reflective surface, the absorptive surface and the reflective surface oriented to absorb solar radiation when the sun is in a relatively low position, and to reflect solar radiation when the sun is in a relatively high position. 17 figs.

  12. Comet Plunge and CME on the Sun

    NASA Image and Video Library

    2017-12-08

    A small comet was streaking towards the Sun when the Sun blew out a "halo" coronal mass ejection (CME) Aug. 19-20, 2013). The CME originated from the far side of the Sun and did not have any interaction with the comet. The comet, only perhaps 30 meters across, was not seen after it went out of view, likely disintegrated by the heat and radiation from the Sun. We call this a "full halo" CME since the front edge of the CME is expanding in all directions around the Sun like a halo. The images were taken by SOHO's coronagraphs in which a disk (red) blocks the Sun and some of the area around it so we can see faint structures beyond that. Here we superimposed the Sun from NASA's SDO. The movie covers about five hours of activity and can be seen here: www.flickr.com/photos/gsfc/9601034896/ Credit: NASA/Goddard/SOHO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  13. Encouraging Sun Safety for Children and Adolescents

    ERIC Educational Resources Information Center

    Boe, Kathy; Tillotson, Elizabeth A.

    2006-01-01

    The rise in the number of cases of skin cancers, both melanomas and nonmelanomas, has prompted increased awareness and educational efforts to limit sun exposure. Because 80% of lifetime sun exposure occurs before the age of 18, educating parents and adolescents to incorporate sun-protective behaviors into daily routines is particularly important.…

  14. Transcriptome profiling of a Saccharomyces cerevisiae mutant with a constitutively activated Ras/cAMP pathway.

    PubMed

    Jones, D L; Petty, J; Hoyle, D C; Hayes, A; Ragni, E; Popolo, L; Oliver, S G; Stateva, L I

    2003-12-16

    Often changes in gene expression levels have been considered significant only when above/below some arbitrarily chosen threshold. We investigated the effect of applying a purely statistical approach to microarray analysis and demonstrated that small changes in gene expression have biological significance. Whole genome microarray analysis of a pde2Delta mutant, constructed in the Saccharomyces cerevisiae reference strain FY23, revealed altered expression of approximately 11% of protein encoding genes. The mutant, characterized by constitutive activation of the Ras/cAMP pathway, has increased sensitivity to stress, reduced ability to assimilate nonfermentable carbon sources, and some cell wall integrity defects. Applying the Munich Information Centre for Protein Sequences (MIPS) functional categories revealed increased expression of genes related to ribosome biogenesis and downregulation of genes in the cell rescue, defense, cell death and aging category, suggesting a decreased response to stress conditions. A reduced level of gene expression in the unfolded protein response pathway (UPR) was observed. Cell wall genes whose expression was affected by this mutation were also identified. Several of the cAMP-responsive orphan genes, upon further investigation, revealed cell wall functions; others had previously unidentified phenotypes assigned to them. This investigation provides a statistical global transcriptome analysis of the cellular response to constitutive activation of the Ras/cAMP pathway.

  15. Chemical Genomic Screening of a Saccharomyces cerevisiae Genomewide Mutant Collection Reveals Genes Required for Defense against Four Antimicrobial Peptides Derived from Proteins Found in Human Saliva

    PubMed Central

    Bhatt, Sanjay; Schoenly, Nathan E.; Lee, Anna Y.; Nislow, Corey; Bobek, Libuse A.

    2013-01-01

    To compare the effects of four antimicrobial peptides (MUC7 12-mer, histatin 12-mer, cathelicidin KR20, and a peptide containing lactoferricin amino acids 1 to 11) on the yeast Saccharomyces cerevisiae, we employed a genomewide fitness screen of combined collections of mutants with homozygous deletions of nonessential genes and heterozygous deletions of essential genes. When an arbitrary fitness score cutoffs of 1 (indicating a fitness defect, or hypersensitivity) and −1 (indicating a fitness gain, or resistance) was used, 425 of the 5,902 mutants tested exhibited altered fitness when treated with at least one peptide. Functional analysis of the 425 strains revealed enrichment among the identified deletions in gene groups associated with the Gene Ontology (GO) terms “ribosomal subunit,” “ribosome biogenesis,” “protein glycosylation,” “vacuolar transport,” “Golgi vesicle transport,” “negative regulation of transcription,” and others. Fitness profiles of all four tested peptides were highly similar, particularly among mutant strains exhibiting the greatest fitness defects. The latter group included deletions in several genes involved in induction of the RIM101 signaling pathway, including several components of the ESCRT sorting machinery. The RIM101 signaling regulates response of yeasts to alkaline and neutral pH and high salts, and our data indicate that this pathway also plays a prominent role in regulating protective measures against all four tested peptides. In summary, the results of the chemical genomic screens of S. cerevisiae mutant collection suggest that the four antimicrobial peptides, despite their differences in structure and physical properties, share many interactions with S. cerevisiae cells and consequently a high degree of similarity between their modes of action. PMID:23208710

  16. Cosmic Influence on the Sun-Earth Environment

    PubMed Central

    Mukherjee, Saumitra

    2008-01-01

    SOHO satellite data reveals geophysical changes before sudden changes in the Earth's Sun-Earth environment. The influence of extragalactic changes on the Sun as well as the Sun-Earth environment seems to be both periodic and episodic. The periodic changes in terms of solar maxima and minima occur every 11 years, whereas the episodic changes can happen at any time. Episodic changes can be monitored by cosmic ray detectors as a sudden increase or decrease of activity. During these solar and cosmic anomaly periods the environment of the Earth is affected. The Star-Sun-Earth connection has the potential to influence the thermosphere, atmosphere, ionosphere and lithosphere. Initial correlation of the cosmic and Sun-Earth connection has shown the possibility of predicting earthquakes, sudden changes in atmospheric temperatures and erratic rainfall/snowfall patterns. PMID:27873955

  17. Comet ISON Approaching the Sun [hd video

    NASA Image and Video Library

    2013-11-27

    This movie from NASA’s STEREO spacecraft's Heliospheric Imager shows Comet ISON, Mercury, Comet Encke and Earth over a five-day period from Nov. 20 to Nov. 25, 2013. The sun sits right of the field of view of this camera. Comet ISON, which will round the sun on Nov. 28, is what's known as a sungrazing comet, due to its close approach. Foreshortening or the angle at which these images were obtained make Earth appear as if it is closer to the sun than Mercury. If you look closely you will also see a dimmer and smaller comet Encke near comet ISON. A comet’s journey through the solar system is perilous and violent. A giant ejection of solar material from the sun could rip its tail off. Before it reaches Mars -- at some 230 million miles away from the sun -- the radiation of the sun begins to boil its water, the first step toward breaking apart. And, if it survives all this, the intense radiation and pressure as it flies near the surface of the sun could destroy it altogether. Even if the comet does not survive, tracking its journey will help scientists understand what the comet is made of, how it reacts to its environment, and what this explains about the origins of the solar system. Closer to the sun, watching how the comet and its tail interact with the vast solar atmosphere can teach scientists more about the sun itself. Image Credit: NASA/STEREO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  18. Influence of age, gender, educational level and self-estimation of skin type on sun exposure habits and readiness to increase sun protection.

    PubMed

    Falk, M; Anderson, C D

    2013-04-01

    Sun exposure habits and the propensity to undertake sun protection differ between individuals. Not least in primary prevention of skin cancer, aiming at reducing ultraviolet (UV) exposure, knowledge about these factors may be of importance. The aim of the present study was to investigate, in a primary health care (PHC) population, the relationship between sun exposure habits/sun protection behaviour/readiness to increase sun protection and gender, age, educational level and skin UV-sensitivity. The baseline data from a previously performed RCT on skin cancer prevention was used. 415 patients, aged > 18 years, visiting a PHC centre in southern Sweden, filled-out a questionnaire mapping sun exposure, readiness to increase sun protection according to the Transtheoretical Model of Behaviour Change (TTM), and the above mentioned factors. Female gender was associated with more frequent suntanning (p < 0.001) and sunbed use (p < 0.05), but also with more extensive sunscreen use (p < 0.001). High age was in general associated with low level of sun exposure and high level of protection. Subjects with low educational level reported less frequent sunscreen use than those with higher educational level, and also chose lower SPF (p < 0.001). For almost all parameters, high skin UV-sensitivity was associated with markedly lower sun exposure (p < 0.001) and more pronounced readiness to increase sun protection. Females and subjects with high educational level reported higher readiness to increase sunscreen use than males and subjects with lower educational level (p < 0.001). Gender, age, educational level and skin type appear to be important factors affecting sun exposure habits and sun protection behaviour, which supports the idea of appropriate mapping of these factors in patients in order to individualise sun protection advice according to the individual patient situation and capabilities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. A gene family for acidic ribosomal proteins in Schizosaccharomyces pombe: two essential and two nonessential genes.

    PubMed Central

    Beltrame, M; Bianchi, M E

    1990-01-01

    We have cloned the genes for small acidic ribosomal proteins (A-proteins) of the fission yeast Schizosaccharomyces pombe. S. pombe contains four transcribed genes for small A-proteins per haploid genome, as is the case for Saccharomyces cerevisiae. In contrast, multicellular eucaryotes contain two transcribed genes per haploid genome. The four proteins of S. pombe, besides sharing a high overall similarity, form two couples of nearly identical sequences. Their corresponding genes have a very conserved structure and are transcribed to a similar level. Surprisingly, of each couple of genes coding for nearly identical proteins, one is essential for cell growth, whereas the other is not. We suggest that the unequal importance of the four small A-proteins for cell survival is related to their physical organization in 60S ribosomal subunits. Images PMID:2325655

  20. Network Hubs Buffer Environmental Variation in Saccharomyces cerevisiae

    PubMed Central

    Levy, Sasha F; Siegal, Mark L

    2008-01-01

    Regulatory and developmental systems produce phenotypes that are robust to environmental and genetic variation. A gene product that normally contributes to this robustness is termed a phenotypic capacitor. When a phenotypic capacitor fails, for example when challenged by a harsh environment or mutation, the system becomes less robust and thus produces greater phenotypic variation. A functional phenotypic capacitor provides a mechanism by which hidden polymorphism can accumulate, whereas its failure provides a mechanism by which evolutionary change might be promoted. The primary example to date of a phenotypic capacitor is Hsp90, a molecular chaperone that targets a large set of signal transduction proteins. In both Drosophila and Arabidopsis, compromised Hsp90 function results in pleiotropic phenotypic effects dependent on the underlying genotype. For some traits, Hsp90 also appears to buffer stochastic variation, yet the relationship between environmental and genetic buffering remains an important unresolved question. We previously used simulations of knockout mutations in transcriptional networks to predict that many gene products would act as phenotypic capacitors. To test this prediction, we use high-throughput morphological phenotyping of individual yeast cells from single-gene deletion strains to identify gene products that buffer environmental variation in Saccharomyces cerevisiae. We find more than 300 gene products that, when absent, increase morphological variation. Overrepresented among these capacitors are gene products that control chromosome organization and DNA integrity, RNA elongation, protein modification, cell cycle, and response to stimuli such as stress. Capacitors have a high number of synthetic-lethal interactions but knockouts of these genes do not tend to cause severe decreases in growth rate. Each capacitor can be classified based on whether or not it is encoded by a gene with a paralog in the genome. Capacitors with a duplicate are highly