Search results for "Heat-shock response"
showing 10 items of 37 documents
Isolation and characterization of a Paracentrotus lividus cDNA encoding a stress-inducible chaperonin
2001
Chaperonins are ubiquitous proteins that facilitate protein folding in an adenosine triphosphate–dependent manner. Here we report the isolation of a sea urchin cDNA (Plhsp60) coding for mitochondrial chaperonin (Cpn60), whose basal expression is further enhanced by heat shock. The described cDNA corresponds to a full-length mRNA encoding a protein of 582 amino acids, the first 32 of which constitute a putative mitochondrial targeting leader sequence. Comparative analysis has demonstrated that this protein is highly conserved in evolution.
Exploring new roles for the rpoS gene in the survival and virulence of the fire blight pathogen Erwinia amylovora
2014
Erwinia amylovora causes fire blight in economically important plants of the family Rosaceae. This bacterial pathogen spends part of its life cycle coping with starvation and other fluctuating environmental conditions. In many Gram-negative bacteria, starvation and other stress responses are regulated by the sigma factor RpoS. We obtained an E. amylovora rpoS mutant to explore the role of this gene in starvation responses and its potential implication in other processes not yet studied in this pathogen. Results showed that E. amylovora needs rpoS to develop normal starvation survival and viable but nonculturable (VBNC) responses. Furthermore, this gene contributed to stationary phase cross-…
MDMA Administration and Heat Shock Proteins Response: Foreseeing a Molecular Link
2010
Molecular and cellular mechanisms of MDMA-induced toxicity have been extensively studied in a number of experimental models. Nevertheless, only few studies investigated the involvement of HSPs ("molecular chaperones") in MDMA organs toxicity. In the present minireview we highlight this subject analysing the results of these studies conducted especially on brain tissue. Despite of it seems obvious that HSPs overexpression is a protective reaction against MDMA treatment, the molecular mechanisms for exerting their action are far to be undiscovered. At the same time, we need of comprehensive studies concerning the whole range of Hsps/chaperones expressions in all organs after acute and chronic…
Induction of stress proteins in human endothelial cells by heavy metal ions and heat shock.
1999
In the present study, we compared the induction of heat shock proteins (HSPs) by heat and heavy metal ions in three different endothelial cell types, namely, human umbilical vein endothelial cells, human pulmonary microvascular endothelial cells, and the cell line EA.hy 926. Our results show that especially Zn2+and Cd2+are inducers of 70-kDa (HSP70), 60-kDa (HSP60), 32-kDa (HSP32), and 27-kDa (HSP27) HSPs. The strength of inducibility is specific for each HSP. Ni2+and Co2+only show an inducible effect at very high concentrations, that is, in the clearly cytotoxic range. Furthermore, we investigated the time course of HSP expression and the involvement of heat shock factor-1. Our study demon…
Chromatin-associated RNA interference components contribute to transcriptional regulation in Drosophila
2009
RNA interference (RNAi) pathways have evolved as important modulators of gene expression that operate in the cytoplasm by degrading RNA target molecules through the activity of short (21-30 nucleotide) RNAs1-6. RNAi components have been reported to have a role in the nucleus, as they are involved in epigenetic regulation and heterochromatin formation(7-10). However, although RNAi-mediated post-transcriptional gene silencing is well documented, the mechanisms of RNAi-mediated transcriptional gene silencing and, in particular, the role of RNAi components in chromatin dynamics, especially in animal multicellular organisms, are elusive. Here we show that the key RNAi components Dicer 2 (DCR2) a…
Btn2p is involved in ethanol tolerance and biofilm formation in flor yeast
2008
Flor yeasts are a particular kind of Saccharomyces cerevisiae strains involved in Sherry wine biological ageing. During this process, yeasts form a film on the wine surface and use ethanol as a carbon source, producing acetaldehyde as a by-product. Acetaldehyde induces BTN2 transcription in laboratory strains. Btn2p is involved in the control of the subcellular localization of different proteins. The BTN2 gene shows a complex expression pattern in wine yeast, increasing its expression by acetaldehyde, but repressing it by ethanol. A flor yeast strain transcribes more BTN2 than a first fermentation yeast during growth, but less under different stress conditions. BTN2 deletion decreases flor …
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 …
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…
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 …