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Biochemistry. Biokhimiia Jul 2012The current view on phenoptosis and apoptosis as genetic programs aimed at eliminating potentially dangerous organisms and cells, respectively, is given. Special... (Review)
Review
The current view on phenoptosis and apoptosis as genetic programs aimed at eliminating potentially dangerous organisms and cells, respectively, is given. Special emphasis is placed on apoptosis (phenoptosis) in yeasts: intracellular defects and a plethora of external stimuli inducing apoptosis in yeasts; distinctive morphological and biochemical hallmarks accompanying apoptosis in yeasts; pro- and antiapoptotic factors involved in yeast apoptosis signaling; consecutive stages of apoptosis from external stimulus to the cell death; a prominent role of mitochondria and other organelles in yeast apoptosis; possible pathways for release of apoptotic factors from the intermembrane mitochondrial space into the cytosol are described. Using some concrete examples, the obvious physiological importance and expediency of altruistic death of yeast cells is shown. Poorly known aspects of yeast apoptosis and prospects for yeast apoptosis study are defined.
Topics: Apoptosis; Microbial Viability; Saccharomyces cerevisiae; Signal Transduction; Time Factors
PubMed: 22817540
DOI: 10.1134/S0006297912070097 -
Journal of Applied Microbiology Jul 2010Saccharomyces cerevisiae is traditionally used for alcoholic beverage and bioethanol production; however, its performance during fermentation is compromised by the... (Review)
Review
Saccharomyces cerevisiae is traditionally used for alcoholic beverage and bioethanol production; however, its performance during fermentation is compromised by the impact of ethanol accumulation on cell vitality. This article reviews studies into the molecular basis of the ethanol stress response and ethanol tolerance of S. cerevisiae; such knowledge can facilitate the development of genetic engineering strategies for improving cell performance during ethanol stress. Previous studies have used a variety of strains and conditions, which is problematic, because the impact of ethanol stress on gene expression is influenced by the environment. There is however some commonality in Gene Ontology categories affected by ethanol assault that suggests that the ethanol stress response of S. cerevisiae is compromised by constraints on energy production, leading to increased expression of genes associated with glycolysis and mitochondrial function, and decreased gene expression in energy-demanding growth-related processes. Studies using genome-wide screens suggest that the maintenance of vacuole function is important for ethanol tolerance, possibly because of the roles of this organelle in protein turnover and maintaining ion homoeostasis. Accumulation of Asr1 and Rat8 in the nucleus specifically during ethanol stress suggests S. cerevisiae has a specific response to ethanol stress although this supposition remains controversial.
Topics: Ethanol; Fermentation; Glycolysis; Saccharomyces cerevisiae; Stress, Physiological; Transcription, Genetic
PubMed: 20070446
DOI: 10.1111/j.1365-2672.2009.04657.x -
Yeast (Chichester, England) Aug 2014The identification and characterization of the molecular determinants governing ageing represents the key to counteracting age-related diseases and eventually prolonging... (Review)
Review
The identification and characterization of the molecular determinants governing ageing represents the key to counteracting age-related diseases and eventually prolonging our health span. A large number of fundamental insights into the ageing process have been provided by research into the budding yeast Saccharomyces cerevisiae, which couples a wide array of technical advantages with a high degree of genetic, proteomic and mechanistic conservation. Indeed, this unicellular organism harbours regulatory pathways, such as those related to programmed cell death or nutrient signalling, that are crucial for ageing control and are reminiscent of other eukaryotes, including mammals. Here, we summarize and discuss three different paradigms of yeast ageing: replicative, chronological and colony ageing. We address their physiological relevance as well as the specific and common characteristics and regulators involved, providing an overview of the network underlying ageing in one of the most important eukaryotic model organisms.
Topics: Gene Expression Regulation, Fungal; Gene Regulatory Networks; Microbial Viability; Saccharomyces cerevisiae
PubMed: 24842537
DOI: 10.1002/yea.3020 -
Advances in Experimental Medicine and... 2010Studies using Saccharomyces cerevisiae, the common baker's or brewer's yeast, have progressed over the past twenty years from knowing which sphingolipids are present in... (Review)
Review
Studies using Saccharomyces cerevisiae, the common baker's or brewer's yeast, have progressed over the past twenty years from knowing which sphingolipids are present in cells and a basic outline of how they are made to a complete or nearly complete directory of the genes that catalyze their anabolism and catabolism. In addition, cellular processes that depend upon sphingolipids have been identified including protein trafficking/exocytosis, endocytosis and actin cytoskeleton dynamics, membrane microdomains, calcium signaling, regulation of transcription and translation, cell cycle control, stress resistance, nutrient uptake and aging. These will be summarized here along with new data not previously reviewed. Advances in our knowledge of sphingolipids and their roles in yeast are impressive but molecular mechanisms remain elusive and are a primary challenge for further progress in understanding the specific functions of sphingolipids.
Topics: Apoptosis; Genes, Fungal; Models, Biological; Saccharomyces cerevisiae; Signal Transduction; Sphingolipids
PubMed: 20919657
DOI: 10.1007/978-1-4419-6741-1_15 -
FEMS Yeast Research Sep 2018In the search for interventions against aging and age-related diseases, biological screening platforms are indispensable tools to identify anti-aging compounds among... (Review)
Review
In the search for interventions against aging and age-related diseases, biological screening platforms are indispensable tools to identify anti-aging compounds among large substance libraries. The budding yeast, Saccharomyces cerevisiae, has emerged as a powerful chemical and genetic screening platform, as it combines a rapid workflow with experimental amenability and the availability of a wide range of genetic mutant libraries. Given the amount of conserved genes and aging mechanisms between yeast and human, testing candidate anti-aging substances in yeast gene-deletion or overexpression collections, or de novo derived mutants, has proven highly successful in finding potential molecular targets. Yeast-based studies, for example, have led to the discovery of the polyphenol resveratrol and the natural polyamine spermidine as potential anti-aging agents. Here, we present strategies for pharmacological anti-aging screens in yeast, discuss common pitfalls and summarize studies that have used yeast for drug discovery and target identification.
Topics: Aging; Drug Discovery; Gene Library; Genetic Testing; Humans; Microbial Viability; Models, Biological; Phenotype; Saccharomyces cerevisiae; Small Molecule Libraries
PubMed: 29905792
DOI: 10.1093/femsyr/foy020 -
Brazilian Journal of Microbiology :... 2017Strains of Saccharomyces cerevisiae may display characteristics that are typical of rough-type colonies, made up of cells clustered in pseudohyphal structures and...
Strains of Saccharomyces cerevisiae may display characteristics that are typical of rough-type colonies, made up of cells clustered in pseudohyphal structures and comprised of daughter buds that do not separate from the mother cell post-mitosis. These strains are known to occur frequently in fermentation tanks with significant lower ethanol yield when compared to fermentations carried out by smooth strains of S. cerevisiae that are composed of dispersed cells. In an attempt to delineate genetic and phenotypic differences underlying the two phenotypes, this study analysed 10 microsatellite loci of 22 S. cerevisiae strains as well as stress resistance towards high concentrations of ethanol and glucose, low pH and cell sedimentation rates. The results obtained from the phenotypic tests by Principal-Component Analysis revealed that unlike the smooth colonies, the rough colonies of S. cerevisiae exhibit an enhanced resistance to stressful conditions resulting from the presence of excessive glucose and ethanol and high sedimentation rate. The microsatellite analysis was not successful to distinguish between the colony phenotypes as phenotypic assays. The relevant industrial strain PE-2 was observed in close genetic proximity to rough-colony although it does not display this colony morphology. A unique genetic pattern specific to a particular phenotype remains elusive.
Topics: Ethanol; Genetic Variation; Genotype; Glucose; Hydrogen-Ion Concentration; Microsatellite Repeats; Phenotype; Saccharomyces cerevisiae; Stress, Physiological
PubMed: 28057426
DOI: 10.1016/j.bjm.2016.09.017 -
FEMS Yeast Research Jan 2017One major challenge during genome duplication is the stalling of DNA replication forks by various forms of template blockages. As these barriers can lead to incomplete... (Review)
Review
One major challenge during genome duplication is the stalling of DNA replication forks by various forms of template blockages. As these barriers can lead to incomplete replication, multiple mechanisms have to act concertedly to correct and rescue stalled replication forks. Among these mechanisms, replication fork regression entails simultaneous annealing of nascent and template strands, which leads to regression of replication forks and formation of four-way DNA junctions. In principle, this process can lead to either positive outcomes, such as DNA repair and replication resumption, or less desirable outcomes, such as misalignment between nascent and template DNA and DNA cleavage. While our understanding of replication fork regression and its various possible outcomes is still at an early stage, recent studies using combinational approaches in multiple organisms have begun to identify the enzymes that catalyze this DNA transaction and how these enzymes are regulated, as well as the specific manners by which fork regression can influence replication. This review summarizes these recent progresses. In keeping with the theme of this series of reviews, we focus on studies in yeast and compare to findings in higher eukaryotes. It is anticipated that these findings will form the basis for future endeavors to further elucidate replication fork remodeling and its implications for genome maintenance.
Topics: DNA Replication; DNA, Fungal; Eukaryotic Cells; Saccharomyces cerevisiae
PubMed: 28011905
DOI: 10.1093/femsyr/fow110 -
Trends in Genetics : TIG Nov 2019Global outbreaks of drug-resistant fungi such as Candida auris are thought to be due at least in part to excessive use of antifungal drugs. Baker's yeast Saccharomyces... (Review)
Review
Global outbreaks of drug-resistant fungi such as Candida auris are thought to be due at least in part to excessive use of antifungal drugs. Baker's yeast Saccharomyces cerevisiae has gained importance as an emerging opportunistic fungal pathogen that can cause infections in immunocompromised patients. Analyses of over 1000 S. cerevisiae isolates are providing rich resources to better understand how fungi can grow in human environments. A large percentage of clinical S. cerevisiae isolates are heterozygous across many nucleotide sites, and a significant proportion are of mixed ancestry and/or are aneuploid or polyploid. Such features potentially facilitate adaptation to new environments. These observations provide strong impetus for expanding genomic and molecular studies on clinical and wild isolates to understand the prevalence of genetic diversity and instability-generating mechanisms, and how they are selected for and maintained. Such work can also lead to the identification of new targets for antifungal drugs.
Topics: Adaptation, Biological; Candidiasis; Disease Susceptibility; Genetic Variation; Host-Pathogen Interactions; Humans; Mutation; Opportunistic Infections; Phenotype; Ploidies; Saccharomyces cerevisiae; Stress, Physiological; Virulence
PubMed: 31526615
DOI: 10.1016/j.tig.2019.08.002 -
Microbiology and Molecular Biology... Mar 2006Eukaryotic cells possess an exquisitely interwoven and fine-tuned series of signal transduction mechanisms with which to sense and respond to the ubiquitous fermentable... (Review)
Review
Eukaryotic cells possess an exquisitely interwoven and fine-tuned series of signal transduction mechanisms with which to sense and respond to the ubiquitous fermentable carbon source glucose. The budding yeast Saccharomyces cerevisiae has proven to be a fertile model system with which to identify glucose signaling factors, determine the relevant functional and physical interrelationships, and characterize the corresponding metabolic, transcriptomic, and proteomic readouts. The early events in glucose signaling appear to require both extracellular sensing by transmembrane proteins and intracellular sensing by G proteins. Intermediate steps involve cAMP-dependent stimulation of protein kinase A (PKA) as well as one or more redundant PKA-independent pathways. The final steps are mediated by a relatively small collection of transcriptional regulators that collaborate closely to maximize the cellular rates of energy generation and growth. Understanding the nuclear events in this process may necessitate the further elaboration of a new model for eukaryotic gene regulation, called "reverse recruitment." An essential feature of this idea is that fine-structure mapping of nuclear architecture will be required to understand the reception of regulatory signals that emanate from the plasma membrane and cytoplasm. Completion of this task should result in a much improved understanding of eukaryotic growth, differentiation, and carcinogenesis.
Topics: Gene Expression Regulation, Fungal; Glucose; Saccharomyces cerevisiae; Signal Transduction
PubMed: 16524925
DOI: 10.1128/MMBR.70.1.253-282.2006 -
PloS One 2009Saccharomyces cerevisiae has been associated with human life for millennia in the brewery and bakery. Recently it has been recognized as an emerging opportunistic...
BACKGROUND
Saccharomyces cerevisiae has been associated with human life for millennia in the brewery and bakery. Recently it has been recognized as an emerging opportunistic pathogen. To study the evolutionary history of S. cerevisiae, the origin of clinical isolates and the importance of a virulence-associated trait, population genetics and phenotypic assays have been applied to an ecologically diverse set of 103 strains isolated from clinics, breweries, vineyards, fruits, soil, commercial supplements and insect guts.
METHODOLOGY/PRINCIPAL FINDINGS
DNA sequence data from five nuclear DNA loci were analyzed for population structure and haplotype distribution. Additionally, all strains were tested for survival of oxidative stress, a trait associated with microbial pathogenicity. DNA sequence analyses identified three genetic subgroups within the recombining S. cerevisiae strains that are associated with ecology, geography and virulence. Shared alleles suggest that the clinical isolates contain genetic contribution from the fruit isolates. Clinical and fruit isolates exhibit high levels of recombination, unlike the genetically homogenous soil isolates in which no recombination was detected. However, clinical and soil isolates were more resistant to oxidative stress than any other population, suggesting a correlation between survival in oxidative stress and yeast pathogenicity.
CONCLUSIONS/SIGNIFICANCE
Population genetic analyses of S. cerevisiae delineated three distinct groups, comprising primarily the (i) human-associated brewery and vineyard strains, (ii) clinical and fruit isolates (iii) and wild soil isolates from eastern U.S. The interactions between S. cerevisiae and humans potentiate yeast evolution and the development of genetically, ecologically and geographically divergent groups.
Topics: Genetic Variation; Genetics, Population; Genome, Fungal; Haplotypes; Oxidative Stress; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins
PubMed: 19390633
DOI: 10.1371/journal.pone.0005317