scholarly journals Growth Temperature Exerts Differential Physiological and Transcriptional Responses in Laboratory and Wine Strains of Saccharomyces cerevisiae

2008 ◽  
Vol 74 (20) ◽  
pp. 6358-6368 ◽  
Author(s):  
Francisco J. Pizarro ◽  
Michael C. Jewett ◽  
Jens Nielsen ◽  
Eduardo Agosin

ABSTRACT Laboratory strains of Saccharomyces cerevisiae have been widely used as a model for studying eukaryotic cells and mapping the molecular mechanisms of many different human diseases. Industrial wine yeasts, on the other hand, have been selected on the basis of their adaptation to stringent environmental conditions and the organoleptic properties that they confer to wine. Here, we used a two-factor design to study the responses of a standard laboratory strain, CEN.PK113-7D, and an industrial wine yeast strain, EC1118, to growth temperatures of 15°C and 30°C in nitrogen-limited, anaerobic, steady-state chemostat cultures. Physiological characterization revealed that the growth temperature strongly impacted the biomass yield of both strains. Moreover, we found that the wine yeast was better adapted to mobilizing resources for biomass production and that the laboratory yeast exhibited higher fermentation rates. To elucidate mechanistic differences controlling the growth temperature response and underlying adaptive mechanisms between the strains, DNA microarrays and targeted metabolome analysis were used. We identified 1,007 temperature-dependent genes and 473 strain-dependent genes. The transcriptional response was used to identify highly correlated gene expression subnetworks within yeast metabolism. We showed that temperature differences most strongly affect nitrogen metabolism and the heat shock response. A lack of stress response element-mediated gene induction, coupled with reduced trehalose levels, indicated that there was a decreased general stress response at 15°C compared to that at 30°C. Differential responses among strains were centered on sugar uptake, nitrogen metabolism, and expression of genes related to organoleptic properties. Our study provides global insight into how growth temperature affects differential physiological and transcriptional responses in laboratory and wine strains of S. cerevisiae.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Marlous van Dijk ◽  
Peter Rugbjerg ◽  
Yvonne Nygård ◽  
Lisbeth Olsson

Abstract Background The limited tolerance of Saccharomyces cerevisiae to inhibitors is a major challenge in second-generation bioethanol production, and our understanding of the molecular mechanisms providing tolerance to inhibitor-rich lignocellulosic hydrolysates is incomplete. Short-term adaptation of the yeast in the presence of dilute hydrolysate can improve its robustness and productivity during subsequent fermentation. Results We utilized RNA sequencing to investigate differential gene expression in the industrial yeast strain CR01 during short-term adaptation, mimicking industrial conditions for cell propagation. In this first transcriptomic study of short-term adaption of S. cerevisiae to lignocellulosic hydrolysate, we found that cultures respond by fine-tuned up- and down-regulation of a subset of general stress response genes. Furthermore, time-resolved RNA sequencing allowed for identification of genes that were differentially expressed at 2 or more sampling points, revealing the importance of oxidative stress response, thiamin and biotin biosynthesis. furan-aldehyde reductases and specific drug:H+ antiporters, as well as the down-regulation of certain transporter genes. Conclusions These findings provide a better understanding of the molecular mechanisms governing short-term adaptation of S. cerevisiae to lignocellulosic hydrolysate, and suggest new genetic targets for improving fermentation robustness.


2015 ◽  
Vol 65 (6) ◽  
pp. 444
Author(s):  
Ramesh C. Meena ◽  
Amitabha Chakrabarti

<p>The versatility of the yeast experimental model has aided in innumerable ways in the understanding of fundamental cellular functions and has also contributed towards the elucidation of molecular mechanisms underlying several pathological conditions in humans. Genome-wide expression, functional, localization and interaction studies on the yeast Saccharomyces cerevisiae exposed to various stressors have made profound contributions towards the understanding of stress response pathways. Analysis of gene expression data from S. cerevisiae cells indicate that the expression of a common set of genes is altered upon exposure to all the stress conditions examined. This common response to multiple stressors is known as the Environmental stress response. Knowledge gained from studies on the yeast model has now become helpful in understanding stress response pathways and associated disease conditions in humans. Cross-species microarray experiments and analysis of data with ever improving computational methods has led to a better comparison of gene expression data between diverse organisms that include yeast and humans.</p>


2005 ◽  
Vol 71 (11) ◽  
pp. 6831-6837 ◽  
Author(s):  
Roberto Pérez-Torrado ◽  
Jose M. Bruno-Bárcena ◽  
Emilia Matallana

ABSTRACT Physiological capabilities and fermentation performance of Saccharomyces cerevisiae strains to be employed during industrial wine fermentations are critical for the quality of the final product. During the process of biomass propagation, yeast cells are dynamically exposed to a mixed and interrelated group of known stresses such as osmotic, oxidative, thermic, and/or starvation. These stressing conditions can dramatically affect the parameters of the fermentation process and the technological abilities of the yeast, e.g., the biomass yield and its fermentative capacity. Although a good knowledge exists of the behavior of S. cerevisiae under laboratory conditions, insufficient knowledge is available about yeast stress responses under the specific media and growth conditions during industrial processes. We performed growth experiments using bench-top fermentors and employed a molecular marker approach (changes in expression levels of five stress-related genes) to investigate how the cells respond to environmental changes during the process of yeast biomass production. The data show that in addition to the general stress response pathway, using the HSP12 gene as a marker, other specific stress response pathways were induced, as indicated by the changes detected in the mRNA levels of two stress-related genes, GPD1 and TRX2. These results suggest that the cells were affected by osmotic and oxidative stresses, demonstrating that these are the major causes of the stress response throughout the process of wine yeast biomass production.


Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3754-3761 ◽  
Author(s):  
Virginie Galeote ◽  
Maïté Novo ◽  
Madalena Salema-Oom ◽  
Christian Brion ◽  
Elisabete Valério ◽  
...  

Transport of glucose and fructose in the yeast Saccharomyces cerevisiae plays a crucial role in controlling the rate of wine fermentation. In S. cerevisiae, hexoses are transported by facilitated diffusion via hexose carriers (Hxt), which prefer glucose to fructose. However, utilization of fructose by wine yeast is critically important at the end of fermentation. Here, we report the characterization of a fructose transporter recently identified by sequencing the genome of the commercial wine yeast strain EC1118 and found in many other wine yeasts. This transporter is designated Fsy1p because of its homology with the Saccharomyces pastorianus fructose/H+ symporter Fsy1p. A strain obtained by transformation of the V5 hxt1-7Δ mutant with FSY1 grew well on fructose, but to a much lesser extent on glucose as the sole carbon source. Sugar uptake and symport experiments showed that FSY1 encodes a proton-coupled symporter with high affinity for fructose (K m 0.24±0.04 mM). Using real-time RT-PCR, we also investigated the expression pattern of FSY1 in EC1118 growing on various carbon sources. FSY1 was repressed by high concentrations of glucose or fructose and was highly expressed on ethanol as the sole carbon source. The characteristics of this transporter indicate that its acquisition could confer a significant advantage to S. cerevisiae during the wine fermentation process. This transporter is a good example of acquisition of a new function in yeast by horizontal gene transfer.


2010 ◽  
Vol 77 (3) ◽  
pp. 934-941 ◽  
Author(s):  
Daisuke Watanabe ◽  
Hong Wu ◽  
Chiemi Noguchi ◽  
Yan Zhou ◽  
Takeshi Akao ◽  
...  

ABSTRACTSake yeasts (strains ofSaccharomyces cerevisiae) produce high concentrations of ethanol in sake fermentation. To investigate the molecular mechanisms underlying this brewing property, we compared gene expression of sake and laboratory yeasts in sake mash. DNA microarray and reporter gene analyses revealed defects of sake yeasts in environmental stress responses mediated by transcription factors Msn2p and/or Msn4p (Msn2/4p) and stress response elements (STRE). Furthermore, we found that dysfunction ofMSN2and/orMSN4contributes to the higher initial rate of ethanol fermentation in both sake and laboratory yeasts. These results provide novel insights into yeast stress responses as major impediments of effective ethanol fermentation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nelson Martínez-Matías ◽  
Nataliya Chorna ◽  
Sahily González-Crespo ◽  
Lilliam Villanueva ◽  
Ingrid Montes-Rodríguez ◽  
...  

AbstractFunctional analysis of the Mtl1 protein in Saccharomyces cerevisiae has revealed that this transmembrane sensor endows yeast cells with resistance to oxidative stress through a signaling mechanism called the cell wall integrity pathway (CWI). We observed upregulation of multiple heat shock proteins (HSPs), proteins associated with the formation of stress granules, and the phosphatase subunit of trehalose 6-phosphate synthase which suggests that mtl1Δ strains undergo intrinsic activation of a non-lethal heat stress response. Furthermore, quantitative global proteomic analysis conducted on TMT-labeled proteins combined with metabolome analysis revealed that mtl1Δ strains exhibit decreased levels of metabolites of carboxylic acid metabolism, decreased expression of anabolic enzymes and increased expression of catabolic enzymes involved in the metabolism of amino acids, with enhanced expression of mitochondrial respirasome proteins. These observations support the idea that Mtl1 protein controls the suppression of a non-lethal heat stress response under normal conditions while it plays an important role in metabolic regulatory mechanisms linked to TORC1 signaling that are required to maintain cellular homeostasis and optimal mitochondrial function.


2020 ◽  
Vol 17 ◽  
Author(s):  
Asma Babar ◽  
Kifayatullah Mengal ◽  
Abdul Hanan Babar ◽  
Shixin Wu ◽  
Mujahid Ali Shah ◽  
...  

: The world highest and largest altitude area is called the Qinghai-Tibetan plateau (QTB), which harbors unique animal and plant species. Mammals that inhabit the higher altitude regions have adapted well to the hypoxic conditions. One of the main stressors at high altitude is hypoxia. Metabolic responses to hypoxia play important roles in cell survival strategies and some diseases. However, the homeostatic alterations that equilibrate variations in the demand and supply of energy to maintain organismal function in a prolonged low O2 environment persist partly understood, making it problematic to differentiate adaptive from maladaptive responses in hypoxia. Tibetans and yaks are two perfect examples innate to the plateau for high altitude adaptation. By the scan of the whole-genome, EPAS1 and EGLN1 were identified as key genes associated with sustained haemoglobin concentration in high altitude mammals for adaptation. The yak is a much more ancient mammal which has existed on QTB longer than humans, it is, therefore, possible that natural selection represented a diverse group of genes/pathways in yaks. Physiological characteristics are extremely informative in revealing molecular networks associated with inherited adaptation, in addition to the whole-genome adaptive changes at the DNA sequence level. Gene-expression can be changed by a variety of signals originating from the environment, and hypoxia is the main factor amongst them. The hypoxia-inducible factors (HIF-1α and EPAS1/HIF-2α) are the main regulators of oxygen in homeostasis which play a role as maestro regulators of adaptation in hypoxic reaction of molecular mechanisms. (Vague) The basis of this review is to present recent information regarding the molecular mechanism involved in hypoxia that regulates candidate genes and proteins. Many transcriptional responses toward hypoxia are facilitated by HIFs that change the number of gene expressions and help in angiogenesis, erythropoiesis, metabolic reprogramming and metastasis. HIFs also activate several signals highlighting a strong association between hypoxia, the misfolded proteins’ accumulation in the endoplasmic reticulum in stress and activation of unfolded protein response (UPR). It was observed that at high-altitude, pregnancies yield a low birth weight ∼100 g per1000 m of the climb. (Vague) It may involve variation in the events of energy-demanding, like protein synthesis. Prolonged hypobaric hypoxia causes placental ER stress, which in turn, moderates protein synthesis and reduces proliferation. Further, Cardiac hypertrophy by cytosolic Ca2+ raises and Ca2+/calmodulin, calcineurin stimulation, NF-AT3 pathway might be caused by an imbalance in Sarcoplasmic reticulum ER Ca2, might be adaptive in beginning but severe later.


2021 ◽  
Vol 22 (11) ◽  
pp. 5713
Author(s):  
Yiping Zhang ◽  
Li Zhang ◽  
Hai Ma ◽  
Yichu Zhang ◽  
Xiuming Zhang ◽  
...  

APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) transcription factors play important roles in plant development and stress response. Although AP2/ERF genes have been extensively investigated in model plants such as Arabidopsis thaliana, little is known about their role in biotic stress response in perennial fruit tree crops such as apple (Malus × domestica). Here, we investigated the role of MdERF100 in powdery mildew resistance in apple. MdERF100 localized to the nucleus but showed no transcriptional activation activity. The heterologous expression of MdERF100 in Arabidopsis not only enhanced powdery mildew resistance but also increased reactive oxygen species (ROS) accumulation and cell death. Furthermore, MdERF100-overexpressing Arabidopsis plants exhibited differential expressions of genes involved in jasmonic acid (JA) and salicylic acid (SA) signaling when infected with the powdery mildew pathogen. Additionally, yeast two-hybrid and bimolecular fluorescence complementation assays confirmed that MdERF100 physically interacts with the basic helix–loop–helix (bHLH) protein MdbHLH92. These results suggest that MdERF100 mediates powdery mildew resistance by regulating the JA and SA signaling pathways, and MdbHLH92 is involved in plant defense against powdery mildew. Overall, this study enhances our understanding of the role of MdERF genes in disease resistance, and provides novel insights into the molecular mechanisms of powdery mildew resistance in apple.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kirsten P. Stone ◽  
Sujoy Ghosh ◽  
Jean Paul Kovalik ◽  
Manda Orgeron ◽  
Desiree Wanders ◽  
...  

AbstractThe initial sensing of dietary methionine restriction (MR) occurs in the liver where it activates an integrated stress response (ISR) that quickly reduces methionine utilization. The ISR program is regulated in part by ATF4, but ATF4’s prototypical upstream regulator, eIF2α, is not acutely activated by MR. Bioinformatic analysis of RNAseq and metabolomics data from liver samples harvested 3 h and 6 h after initiating MR shows that general translation is inhibited at the level of ternary complex formation by an acute 50% reduction of hepatic methionine that limits formation of initiator methionine tRNA. The resulting ISR is induced by selective expression of ATF4 target genes that mediate adaptation to reduced methionine intake and return hepatic methionine to control levels within 4 days of starting the diet. Complementary in vitro experiments in HepG2 cells after knockdown of ATF4, or inhibition of mTOR or Erk1/2 support the conclusion that the early induction of genes by MR is partially dependent on ATF4 and regulated by both mTOR and Erk1/2. Taken together, these data show that initiation of dietary MR induces an mTOR- and Erk1/2-dependent stress response that is linked to ATF4 by the sharp, initial drop in hepatic methionine and resulting repression of translation pre-initiation.


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