Search results for " EXPRESSION"
showing 10 items of 4731 documents
Functional distinction between Cln1p and Cln2p cyclins in the control of the Saccharomyces cerevisiae mitotic cycle.
2004
Abstract Cln1p and Cln2p are considered as equivalent cyclins on the basis of sequence homology, regulation, and functional studies. Here we describe a functional distinction between the Cln1p and Cln2p cyclins in the control of the G1/S transition. Inactivation of CLN2, but not of CLN1, leads to a larger-than-normal cell size, whereas overexpression of CLN2, but not of CLN1, results in smaller-than-normal cells. Furthermore, mild ectopic expression of CLN2, but not of CLN1, suppresses the lethality of swi4swi6 and cdc28 mutant strains. In the absence of Cln1p, the kinetics of budding, initiation of DNA replication, and activation of the Start-transcription program are not affected; by cont…
Molecular response of Saccharomyces cerevisiae wine and laboratory strains to high sugar stress conditions.
2010
One of the stress conditions that can affect Saccharomyces cerevisiae cells during their growth is osmotic stress. Under particular environments (for instance, during the production of alcoholic beverages) yeasts have to cope with osmotic stress caused by high sugar concentrations. Although the molecular changes and pathways involved in the response to saline or sorbitol stress are widely understood, less is known about how cells respond to high sugar concentrations. In this work we present a comprehensive study of the response to this form of stress which indicates important transcriptomic changes, especially in terms of the genes involved in both stress response and respiration, and the i…
Recruitment of Xrn1 to stress-induced genes allows efficient transcription by controlling RNA polymerase II backtracking
2020
A new paradigm has emerged proposing that the crosstalk between nuclear transcription and cytoplasmic mRNA stability keeps robust mRNA levels in cells under steady-state conditions. A key piece in this crosstalk is the highly conserved 5′–3′ RNA exonuclease Xrn1, which degrades most cytoplasmic mRNAs but also associates with nuclear chromatin to activate transcription by not well-understood mechanisms. Here, we investigated the role of Xrn1 in the transcriptional response of Saccharomyces cerevisiae cells to osmotic stress. We show that a lack of Xrn1 results in much lower transcriptional induction of the upregulated genes but in similar high levels of their transcripts because of parallel …
Protein Interactions within the Set1 Complex and Their Roles in the Regulation of Histone 3 Lysine 4 Methylation
2006
Set1 is the catalytic subunit and the central component of the evolutionarily conserved Set1 complex (Set1C) that methylates histone 3 lysine 4 (H3K4). Here we have determined protein/protein interactions within the complex and related the substructure to function. The loss of individual Set1C subunits differentially affects Set1 stability, complex integrity, global H3K4 methylation, and distribution of H3K4 methylation along active genes. The complex requires Set1, Swd1, and Swd3 for integrity, and Set1 amount is greatly reduced in the absence of the Swd1-Swd3 heterodimer. Bre2 and Sdc1 also form a heteromeric subunit, which requires the SET domain for interaction with the complex, and Sdc…
Transcriptomic and Proteomic Approach for Understanding the Molecular Basis of Adaptation of Saccharomyces cerevisiae to Wine Fermentation
2006
ABSTRACT Throughout alcoholic fermentation, Saccharomyces cerevisiae cells have to cope with several stress conditions that could affect their growth and viability. In addition, the metabolic activity of yeast cells during this process leads to the production of secondary compounds that contribute to the organoleptic properties of the resulting wine. Commercial strains have been selected during the last decades for inoculation into the must to carry out the alcoholic fermentation on the basis of physiological traits, but little is known about the molecular basis of the fermentative behavior of these strains. In this work, we present the first transcriptomic and proteomic comparison between …
The C-terminal region of the Hot1 transcription factor binds GGGACAAA-related sequences in the promoter of its target genes
2015
Response to hyperosmotic stress in the yeast Saccharomyces cerevisiae involves the participation of the general stress response mediated by Msn2/4 transcription factors and the HOG pathway. One of the transcription factors activated through this pathway is Hot1, which contributes to the control of the expression of several genes involved in glycerol synthesis and flux, or in other functions related to adaptation to adverse conditions. This work provides new data about the interaction mechanism of this transcription factor with DNA. By means of one-hybrid and electrophoretic mobility assays, we demonstrate that the C-terminal region, which corresponds to amino acids 610-719, is the DNA-bindi…
Monitoring Stress-Related Genes during the Process of Biomass Propagation of Saccharomyces cerevisiae Strains Used for Wine Making
2005
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 knowl…
Trx2p-dependent Regulation of Saccharomyces cerevisiae Oxidative Stress Response by the Skn7p Transcription Factor under Respiring Conditions
2013
The whole genome analysis has demonstrated that wine yeasts undergo changes in promoter regions and variations in gene copy number, which make them different to lab strains and help them better adapt to stressful conditions during winemaking, where oxidative stress plays a critical role. Since cytoplasmic thioredoxin II, a small protein with thiol-disulphide oxidoreductase activity, has been seen to perform important functions under biomass propagation conditions of wine yeasts, we studied the involvement of Trx2p in the molecular regulation of the oxidative stress transcriptional response on these strains. In this study, we analyzed the expression levels of several oxidative stress-related…
Differences in activation of MAP kinases and variability in the polyglutamine tract of Slt2 in clinical and non-clinical isolates of Saccharomyces ce…
2010
The concept of Saccharomyces cerevisiae as an emerging opportunistic pathogen is relatively new and it is due to an increasing number of human infections during the past 20 years. There are still few studies addressing the mechanisms of infection of this yeast species. Moreover, little is known about how S. cerevisiae cells sense and respond to the harsh conditions imposed by the host, and whether this response is different between clinical isolates and non-pathogenic strains. In this regard, mitogen-activated protein kinase (MAPK) pathways constitute one of the major mechanisms for controlling transcriptional responses and, in some cases, virulence in fungi. Here we show differences among …
Analysis of the stress resistance of commercial wine yeast strains
2001
Alcoholic fermentation is an essential step in wine production that is usually conducted by yeasts belonging to the species Saccharomyces cerevisiae. The ability to carry out vinification is largely influenced by the response of yeast cells to the stress conditions that affect them during this process. In this work, we present a systematic analysis of the resistance of 14 commercial S. cerevisiae wine yeast strains to heat shock, ethanol, oxidative, osmotic and glucose starvation stresses. Significant differences were found between these yeast strains under certain severe conditions, Vitilevure Pris Mouse and Lalvin T73 being the most resistant strains, while Fermiblanc arom SM102 and UCLM …