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

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

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

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

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

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

scholarly journals High-Resolution Genome-Wide Occupancy in Candida spp. Using ChEC-seq

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Faiza Tebbji ◽  
Inès Khemiri ◽  
Adnane Sellam
Keyword(s):  
Public Health ◽  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
High Resolution ◽  
Transcriptional Regulator ◽  
Candida Auris ◽  
Content Type ◽  
Genome Wide ◽  
Public Health Threat

ABSTRACT To persist in their dynamic human host environments, fungal pathogens must sense and adapt by modulating their gene expression to fulfill their cellular needs. Understanding transcriptional regulation on a global scale would uncover cellular processes linked to persistence and virulence mechanisms that could be targeted for antifungal therapeutics. Infections associated with the yeast Candida albicans, a highly prevalent fungal pathogen, and the multiresistant related species Candida auris are becoming a serious public health threat. To define the set of a gene regulated by a transcriptional regulator in C. albicans, chromatin immunoprecipitation (ChIP)-based techniques, including ChIP with microarray technology (ChIP-chip) or ChIP-DNA sequencing (ChIP-seq), have been widely used. Here, we describe a new set of PCR-based micrococcal nuclease (MNase)-tagging plasmids for C. albicans and other Candida spp. to determine the genome-wide location of any transcriptional regulator of interest using chromatin endogenous cleavage (ChEC) coupled to high-throughput sequencing (ChEC-seq). The ChEC procedure does not require protein-DNA cross-linking or sonication, thus avoiding artifacts related to epitope masking or the hyper-ChIPable euchromatic phenomenon. In a proof-of-concept application of ChEC-seq, we provided a high-resolution binding map of the SWI/SNF chromatin remodeling complex, a master regulator of fungal fitness in C. albicans, in addition to the transcription factor Nsi1 that is an ortholog of the DNA-binding protein Reb1 for which genome-wide occupancy was previously established in Saccharomyces cerevisiae. The ChEC-seq procedure described here will allow a high-resolution genomic location definition which will enable a better understanding of transcriptional regulatory circuits that govern fungal fitness and drug resistance in these medically important fungi. IMPORTANCE Systemic fungal infections caused by Candida albicans and the “superbug” Candida auris are becoming a serious public health threat. The ability of these yeasts to cause disease is linked to their faculty to modulate the expression of genes that mediate their escape from the immune surveillance and their persistence in the different unfavorable niches within the host. Comprehensive knowledge on gene expression control of fungal fitness is consequently an interesting framework for the identification of essential infection processes that could be hindered by chemicals as potential therapeutics. Here, we expanded the use of ChEC-seq, a technique that was initially developed in the yeast model Saccharomyces cerevisiae to identify genes that are modulated by a transcriptional regulator, in pathogenic yeasts from the genus Candida. This robust technique will allow a better characterization of key gene expression regulators and their contribution to virulence and antifungal resistance in these pathogenic yeasts.

scholarly journals Anaerobic α-Amylase Production and Secretion with Fumarate as the Final Electron Acceptor in Saccharomyces cerevisiae

2013 ◽  
Vol 79 (9) ◽  
pp. 2962-2967 ◽  
Author(s):  
Zihe Liu ◽  
Tobias Österlund ◽  
Jin Hou ◽  
Dina Petranovic ◽  
Jens Nielsen
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Folding ◽  
Protein Secretion ◽  
Electron Acceptor ◽  
Anaerobic Growth ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Content Type ◽  
Final Electron ◽  
Final Electron Acceptor

ABSTRACTIn this study, we focus on production of heterologous α-amylase in the yeastSaccharomyces cerevisiaeunder anaerobic conditions. We compare the metabolic fluxes and transcriptional regulation under aerobic and anaerobic conditions, with the objective of identifying the final electron acceptor for protein folding under anaerobic conditions. We find that yeast produces more amylase under anaerobic conditions than under aerobic conditions, and we propose a model for electron transfer under anaerobic conditions. According to our model, during protein folding the electrons from the endoplasmic reticulum are transferred to fumarate as the final electron acceptor. This model is supported by findings that the addition of fumarate under anaerobic (but not aerobic) conditions improves cell growth, specifically in the α-amylase-producing strain, in which it is not used as a carbon source. Our results provide a model for the molecular mechanism of anaerobic protein secretion using fumarate as the final electron acceptor, which may allow for further engineering of yeast for improved protein secretion under anaerobic growth conditions.

scholarly journals A Hyperactive Form of the Zinc Cluster Transcription Factor Stb5 CausesYOR1Overexpression and Beauvericin Resistance inCandida albicans

2018 ◽  
Vol 62 (12) ◽  
Author(s):  
Bernardo Ramírez-Zavala ◽  
Hannah Manz ◽  
Frank Englert ◽  
P. David Rogers ◽  
Joachim Morschhäuser
Keyword(s):  
Transcription Factor ◽  
Target Genes ◽  
Efflux Pump ◽  
Hyphal Growth ◽  
Pathogenic Yeast ◽  
Fluconazole Resistance ◽  
Content Type ◽  
Activating Mutations ◽  
Zinc Cluster ◽  
Constitutive Overexpression

ABSTRACTGain-of-function mutations in the zinc cluster transcription factors Mrr1, Tac1, and Upc2, which result in constitutive overexpression of their target genes, are a frequent cause of fluconazole resistance in the pathogenic yeastCandida albicans. In this study, we show that an activated form of another zinc cluster transcription factor, Stb5, confers resistance to the natural compound beauvericin via the overexpression ofYOR1, encoding an efflux pump of the ATP-binding cassette transporter superfamily. Beauvericin was recently shown to potentiate the activity of azole drugs againstC. albicans. Although Yor1 did not contribute to fluconazole resistance whenC. albicanscells were treated with the drug alone, Stb5-mediatedYOR1overexpression diminished the synergistic effect of the fluconazole-beauvericin combination, thereby enhancing fluconazole resistance in beauvericin-treatedC. albicanscells. Stb5-mediatedYOR1overexpression also suppressed the inhibition of hyphal growth, an important virulence trait ofC. albicans, by beauvericin. Therefore, activating mutations in Stb5, which result in constitutiveYOR1overexpression, may enableC. albicansto acquire resistance to beauvericin and thereby overcome both the sensitization to azole drugs and the inhibition of morphogenesis caused by this compound.

The zinc cluster transcriptional regulator Asg1 transcriptionally coordinates oleate utilization and lipid accumulation in Saccharomyces cerevisiae

2016 ◽  
Vol 100 (10) ◽  
pp. 4549-4560 ◽  
Author(s):  
Siripat Jansuriyakul ◽  
Pichayada Somboon ◽  
Napachai Rodboon ◽  
Olena Kurylenko ◽  
Andriy Sibirny ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lipid Accumulation ◽  
Transcriptional Regulator ◽  
Zinc Cluster

scholarly journals Mutual Cross Talk between the Regulators Hac1 of the Unfolded Protein Response and Gcn4 of the General Amino Acid Control of Saccharomyces cerevisiae

2013 ◽  
Vol 12 (8) ◽  
pp. 1142-1154 ◽  
Author(s):  
Britta Herzog ◽  
Blagovesta Popova ◽  
Antonia Jakobshagen ◽  
Hedieh Shahpasandzadeh ◽  
Gerhard H. Braus
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Cross Talk ◽  
Cellular Response ◽  
Promoter Regions ◽  
Content Type ◽  
General Amino Acid Control ◽  
Acid Control ◽  
The Unfolded Protein Response ◽  
Diploid Cells

ABSTRACTHac1 is the activator of the cellular response to the accumulation of unfolded proteins in the endoplasmic reticulum. Hac1 function requires the activity of Gcn4, which mainly acts as a regulator of the general amino acid control network providingSaccharomyces cerevisiaecells with amino acids. Here, we demonstrate novel functions of Hac1 and describe a mutual connection between Hac1 and Gcn4. Hac1 is required for induction of Gcn4-responsive promoter elements in haploid as well as diploid cells and therefore participates in the cellular amino acid supply. Furthermore, Hac1 and Gcn4 mutually influence their mRNA expression levels. Hac1 is also involved inFLO11expression and adhesion upon amino acid starvation. Hac1 and Gcn4 act through the same promoter regions of theFLO11flocculin. The results indicate an indirect effect of both transcription factors onFLO11expression. Our data suggest a complex mutual cross talk between the Hac1- and Gcn4-controlled networks.

scholarly journals Nuclear Localization of Haa1, Which Is Linked to Its Phosphorylation Status, Mediates Lactic Acid Tolerance in Saccharomyces cerevisiae

2014 ◽  
Vol 80 (11) ◽  
pp. 3488-3495 ◽  
Author(s):  
Minetaka Sugiyama ◽  
Shin-Pei Akase ◽  
Ryota Nakanishi ◽  
Hitoshi Horie ◽  
Yoshinobu Kaneko ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactic Acid ◽  
Subcellular Localization ◽  
Target Genes ◽  
Acid Stress ◽  
Acid Tolerance ◽  
Acid Resistance ◽  
Nuclear Accumulation ◽  
Content Type ◽  
Adaptation Response

ABSTRACTImprovement of the lactic acid resistance of the yeastSaccharomyces cerevisiaeis important for the application of the yeast in industrial production of lactic acid from renewable resources. However, we still do not know the precise mechanisms of the lactic acid adaptation response in yeast and, consequently, lack effective approaches for improving its lactic acid tolerance. To enhance our understanding of the adaptation response, we screened forS. cerevisiaegenes that confer enhanced lactic acid resistance when present in multiple copies and identified the transcriptional factor Haa1 as conferring resistance to toxic levels of lactic acid when overexpressed. The enhanced tolerance probably results from increased expression of its target genes. When cells that expressed Haa1 only from the endogenous promoter were exposed to lactic acid stress, the main subcellular localization of Haa1 changed from the cytoplasm to the nucleus within 5 min. This nuclear accumulation induced upregulation of the Haa1 target genesYGP1,GPG1, andSPI1, while the degree of Haa1 phosphorylation observed under lactic acid-free conditions decreased. Disruption of the exportin geneMSN5led to accumulation of Haa1 in the nucleus even when no lactic acid was present. Since Msn5 was reported to interact with Haa1 and preferentially exports phosphorylated cargo proteins, our results suggest that regulation of the subcellular localization of Haa1, together with alteration of its phosphorylation status, mediates the adaptation to lactic acid stress in yeast.

scholarly journals Comparison of Sterol Import under Aerobic and Anaerobic Conditions in Three Fungal Species, Candida albicans, Candida glabrata, and Saccharomyces cerevisiae

2013 ◽  
Vol 12 (5) ◽  
pp. 725-738 ◽  
Author(s):  
Martin Zavrel ◽  
Sam J. Hoot ◽  
Theodore C. White
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
Exponential Growth ◽  
Candida Glabrata ◽  
Fungal Species ◽  
Growth Phases ◽  
Anaerobic Conditions ◽  
Content Type ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

ABSTRACTSterol import has been characterized under various conditions in three distinct fungal species, the model organismSaccharomyces cerevisiaeand two human fungal pathogensCandida glabrataandCandida albicans, employing cholesterol, the sterol of higher eukaryotes, as well as its fungal equivalent, ergosterol. Import was confirmed by the detection of esterified cholesterol within the cells. Comparing the three fungal species, we observe sterol import under three different conditions. First, as previously well characterized, we observe sterol import under low oxygen levels inS. cerevisiaeandC. glabrata, which is dependent on the transcription factor Upc2 and/or its orthologs or paralogs. Second, we observe sterol import under aerobic conditions exclusively in the two pathogenic fungiC. glabrataandC. albicans. Uptake emerges during post-exponential-growth phases, is independent of the characterized Upc2-pathway and is slower compared to the anaerobic uptake inS. cerevisiaeandC. glabrata. Third, we observe under normoxic conditions inC. glabratathat Upc2-dependent sterol import can be induced in the presence of fetal bovine serum together with fluconazole. In summary,C. glabrataimports sterols both in aerobic and anaerobic conditions, and the limited aerobic uptake can be further stimulated by the presence of serum together with fluconazole.S. cerevisiaeimports sterols only in anaerobic conditions, demonstrating aerobic sterol exclusion. Finally,C. albicansimports sterols exclusively aerobically in post-exponential-growth phases, independent of Upc2. For the first time, we provide direct evidence of sterol import into the human fungal pathogenC. albicans, which until now was believed to be incapable of active sterol import.

scholarly journals Adjustment of Trehalose Metabolism in Wine Saccharomyces cerevisiae Strains To Modify Ethanol Yields

2013 ◽  
Vol 79 (17) ◽  
pp. 5197-5207 ◽  
Author(s):  
D. Rossouw ◽  
E. H. Heyns ◽  
M. E. Setati ◽  
S. Bosch ◽  
F. F. Bauer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Modification ◽  
Target Genes ◽  
Tca Cycle ◽  
Pentose Phosphate ◽  
Systematic Screening ◽  
Content Type ◽  
Genes Encoding ◽  
Ethanol Yields ◽  
Trehalose Biosynthesis

ABSTRACTThe ability ofSaccharomyces cerevisiaeto efficiently produce high levels of ethanol through glycolysis has been the focus of much scientific and industrial activity. Despite the accumulated knowledge regarding glycolysis, the modification of flux through this pathway to modify ethanol yields has proved difficult. Here, we report on the systematic screening of 66 strains with deletion mutations of genes encoding enzymes involved in central carbohydrate metabolism for altered ethanol yields. Five of these strains showing the most prominent changes in carbon flux were selected for further investigation. The genes were representative of trehalose biosynthesis (TPS1, encoding trehalose-6-phosphate synthase), central glycolysis (TDH3, encoding glyceraldehyde-3-phosphate dehydrogenase), the oxidative pentose phosphate pathway (ZWF1, encoding glucose-6-phosphate dehydrogenase), and the tricarboxylic acid (TCA) cycle (ACO1andACO2, encoding aconitase isoforms 1 and 2). Two strains exhibited lower ethanol yields than the wild type (tps1Δ andtdh3Δ), while the remaining three showed higher ethanol yields. To validate these findings in an industrial yeast strain, theTPS1gene was selected as a good candidate for genetic modification to alter flux to ethanol during alcoholic fermentation in wine. Using low-strength promoters active at different stages of fermentation, the expression of theTPS1gene was slightly upregulated, resulting in a decrease in ethanol production and an increase in trehalose biosynthesis during fermentation. Thus, the mutant screening approach was successful in terms of identifying target genes for genetic modification in commercial yeast strains with the aim of producing lower-ethanol wines.

scholarly journals Aggregate Filamentous Growth Responses in Yeast

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Jacky Chow ◽  
Heather M. Dionne ◽  
Aditi Prabhakar ◽  
Amit Mehrotra ◽  
Jenn Somboonthum ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
Signaling Pathways ◽  
Budding Yeast ◽  
Filamentous Growth ◽  
Fungal Species ◽  
Fungal Pathogenesis ◽  
Invasive Growth ◽  
Content Type ◽  
Secreted Enzymes

ABSTRACTMany fungal species, including pathogens, undergo a morphogenetic response called filamentous growth, where cells differentiate into a specialized cell type to promote nutrient foraging and surface colonization. Despite the fact that filamentous growth is required for virulence in some plant and animal pathogens, certain aspects of this behavior remain poorly understood. By examining filamentous growth in the budding yeastSaccharomyces cerevisiaeand the opportunistic pathogenCandida albicans, we identify responses where cells undergo filamentous growth in groups of cells or aggregates. InS. cerevisiae, aggregate invasive growth was regulated by signaling pathways that control normal filamentous growth. These pathways promoted aggregation in part by fostering aspects of microbial cooperation. For example, aggregate invasive growth required cellular contacts mediated by the flocculin Flo11p, which was produced at higher levels in aggregates than cells undergoing regular invasive growth. Aggregate invasive growth was also stimulated by secreted enzymes, like invertase, which produce metabolites that are shared among cells. Aggregate invasive growth was also induced by alcohols that promote density-dependent filamentous growth in yeast. Aggregate invasive growth also required highly polarized cell morphologies, which may affect the packing or organization of cells. A directed selection experiment for aggregating phenotypes uncovered roles for the fMAPK and RAS pathways, which indicates that these pathways play a general role in regulating aggregate-based responses in yeast. Our study extends the range of responses controlled by filamentation regulatory pathways and has implications in understanding aspects of fungal biology that may be relevant to fungal pathogenesis.IMPORTANCEFilamentous growth is a fungal morphogenetic response that is critical for virulence in some fungal species. Many aspects of filamentous growth remain poorly understood. We have identified an aspect of filamentous growth in the budding yeastSaccharomyces cerevisiaeand the human pathogenCandida albicanswhere cells behave collectively to invade surfaces in aggregates. These responses may reflect an extension of normal filamentous growth, as they share the same signaling pathways and effector processes. Aggregate responses may involve cooperation among individual cells, because aggregation was stimulated by cell adhesion molecules, secreted enzymes, and diffusible molecules that promote quorum sensing. Our study may provide insights into the genetic basis of collective cellular responses in fungi. The study may have ramifications in fungal pathogenesis, in situations where collective responses occur to promote virulence.

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