scholarly journals Global Gene Expression Analysis of the Heat Shock Response in the Phytopathogen Xylella fastidiosa

2006 ◽  
Vol 188 (16) ◽  
pp. 5821-5830 ◽  
Author(s):  
Tie Koide ◽  
Ricardo Z. N. Vêncio ◽  
Suely L. Gomes
Keyword(s):  
Heat Shock ◽  
Stress Responses ◽  
Heat Shock Response ◽  
Time Course ◽  
Protein Biosynthesis ◽  
Xylella Fastidiosa ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Phytopathogenic Bacterium ◽  
Shock Response

ABSTRACT Xylella fastidiosa is a phytopathogenic bacterium that is responsible for diseases in many economically important crops. Although different strains have been studied, little is known about X. fastidiosa stress responses. One of the better characterized stress responses in bacteria is the heat shock response, which induces the expression of specific genes to prevent protein misfolding and aggregation and to promote degradation of the irreversibly denatured polypeptides. To investigate X. fastidiosa genes involved in the heat shock response, we performed a whole-genome microarray analysis in a time course experiment. Globally, 261 genes were induced (9.7%) and 222 genes were repressed (8.3%). The expression profiles of the differentially expressed genes were grouped, and their expression patterns were validated by quantitative reverse transcription-PCR experiments. We determined the transcription start sites of six heat shock-inducible genes and analyzed their promoter regions, which allowed us to propose a putative consensus for σ32 promoters in Xylella and to suggest additional genes as putative members of this regulon. Besides the induction of classical heat shock protein genes, we observed the up-regulation of virulence-associated genes such as vapD and of genes for hemagglutinins, hemolysin, and xylan-degrading enzymes, which may indicate the importance of heat stress to bacterial pathogenesis. In addition, we observed the repression of genes related to fimbriae, aerobic respiration, and protein biosynthesis and the induction of genes related to the extracytoplasmic stress response and some phage-related genes, revealing the complex network of genes that work together in response to heat shock.

scholarly journals Global Gene Expression Profiles of the Cyanobacterium Synechocystis sp. Strain PCC 6803 in Response to Irradiation with UV-B and White Light

2002 ◽  
Vol 184 (24) ◽  
pp. 6845-6858 ◽  
Author(s):  
Lixuan Huang ◽  
Michael P. McCluskey ◽  
Hao Ni ◽  
Robert A. LaRossa
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
White Light ◽  
Heat Shock Response ◽  
High Intensity ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Stringent Response ◽  
Shock Response ◽  
Pcc 6803

ABSTRACT We developed a transcript profiling methodology to elucidate expression patterns of the cyanobacterium Synechocystis sp. strain PCC 6803 and used the technology to investigate changes in gene expression caused by irradiation with either intermediate-wavelength UV light (UV-B) or high-intensity white light. Several families of transcripts were altered by UV-B treatment, including mRNAs specifying proteins involved in light harvesting, photosynthesis, photoprotection, and the heat shock response. In addition, UV-B light induced the stringent response in Synechocystis, as indicated by the repression of ribosomal protein transcripts and other mRNAs involved in translation. High-intensity white light- and UV-B-mediated expression profiles overlapped in the down-regulation of photosynthesis genes and induction of heat shock response but differed in several other transcriptional processes including those specifying carbon dioxide uptake and fixation, the stringent response, and the induction profile of the high-light-inducible proteins. These two profile comparisons not only corroborated known physiological changes but also suggested coordinated regulation of many pathways, including synchronized induction of D1 protein recycling and a coupling between decreased phycobilisome biosynthesis and increased phycobilisome degradation. Overall, the gene expression profile analysis generated new insights into the integrated network of genes that adapts rapidly to different wavelengths and intensities of light.

The efficacy of long-lasting residual drinking water disinfectants based on hydrogen peroxide and silver

2000 ◽  
Vol 42 (1-2) ◽  
pp. 293-298 ◽  
Author(s):  
R. Pedahzur ◽  
D. Katzenelson ◽  
N. Barnea ◽  
O. Lev ◽  
H.I. Shuval ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Heat Shock ◽  
Stress Responses ◽  
Heat Shock Response ◽  
Chemical Properties ◽  
Bactericidal Effect ◽  
Physiological Effects ◽  
Mechanisms Of Toxicity ◽  
E Coli ◽  
Shock Response

The aim of the present work was to evaluate the disinfectant capacity and the possible fields of application of a combined silver and hydrogen peroxide (HP) water disinfectant. The findings demonstrated the high bactericidal action of silver (on E. coli) and its relatively ineffective virucidal effect (on MS-2 phage). HP was found to have a small bactericidal effect and a mild virucidal one. When combined, silver and HP usually exhibited a synergistic action on the viability of E. coli and on the luminescence of recombinant luminescent E. coli. In some instances, the combined bactericidal effects were 1000-fold higher than the sum of the separate ones. No increased virucidal action was observed. The biocidal action of the combination generally increased with increasing temperature and pH, and decreased in secondary and tertiary effluents. The physiological effects and mechanisms of toxicity of HP, silver and their combinations, were assessed by monitoring the induction of stress promoters upon exposure to the active agents, and by assessing the sensitivity of E. coli mutated in major stress responses to HP, silver and their combinations. The results showed that HP induced a wide array of stress responses, that both silver and HP induced promoters regulated by the heat shock response, and that the dnaK promoter (regulated by the heat shock response) was synergistically induced. The mutant sensitivity tests showed that bacteria deficient in the ability to activate central cellular stress responses (SOS, heat shock, stationary phase, oxidative) were hypersensitive to both HP and silver. These results imply that cellular proteins, and possibly the DNA, are the cellular moieties chiefly affected. The above findings suggest that the potentiated effect of HP and silver is a metabolically dependant/related process that stems from a combination and/or accumulation of physiological effects exerted by the active ingredients. The physico-chemical properties of the combined disinfectant, and its disinfection capacity, points to its potential application as a long-term secondary residual disinfectant for water of relatively high quality.

Summer season induced changes in quantitative expression patterns of different heat shock response genes in Salem black goats

2020 ◽  
Vol 52 (5) ◽  
pp. 2725-2730 ◽  
Author(s):  
A. P. Madhusoodan ◽  
M. Bagath ◽  
V. Sejian ◽  
G. Krishnan ◽  
V. P. Rashamol ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Expression Patterns ◽  
Summer Season ◽  
Quantitative Expression ◽  
Shock Response ◽  
Induced Changes

scholarly journals Heat Shock Response of Archaeoglobus fulgidus

2005 ◽  
Vol 187 (17) ◽  
pp. 6046-6057 ◽  
Author(s):  
Lars Rohlin ◽  
Jonathan D. Trent ◽  
Kirsty Salmon ◽  
Unmi Kim ◽  
Robert P. Gunsalus ◽  
...  
Keyword(s):  
Heat Shock ◽  
Dna Binding ◽  
Heat Shock Response ◽  
Expression Profiles ◽  
Small Heat Shock Protein ◽  
Transcript Abundance ◽  
Archaeoglobus Fulgidus ◽  
Binding Motif ◽  
Cell Functions ◽  
Shock Response

ABSTRACT The heat shock response of the hyperthermophilic archaeon Archaeoglobus fulgidus strain VC-16 was studied using whole-genome microarrays. On the basis of the resulting expression profiles, approximately 350 of the 2,410 open reading frames (ORFs) (ca. 14%) exhibited increased or decreased transcript abundance. These span a range of cell functions, including energy production, amino acid metabolism, and signal transduction, where the majority are uncharacterized. One ORF called AF1298 was identified that contains a putative helix-turn-helix DNA binding motif. The gene product, HSR1, was expressed and purified from Escherichia coli and was used to characterize specific DNA recognition regions upstream of two A. fulgidus genes, AF1298 and AF1971. The results indicate that AF1298 is autoregulated and is part of an operon with two downstream genes that encode a small heat shock protein, Hsp20, and cdc48, an AAA+ ATPase. The DNase I footprints using HSR1 suggest the presence of a cis-binding motif upstream of AF1298 consisting of CTAAC-N5-GTTAG. Since AF1298 is negatively regulated in response to heat shock and encodes a protein only distantly related to the N-terminal DNA binding domain of Phr of Pyrococcus furiosus, these results suggest that HSR1 and Phr may belong to an evolutionarily diverse protein family involved in heat shock regulation in hyperthermophilic and mesophilic Archaea organisms.

Absence of Classical Heat Shock Response in the Citrus Pathogen Xylella fastidiosa

2007 ◽  
Vol 54 (2) ◽  
pp. 119-123 ◽  
Author(s):  
Daniel Martins ◽  
Gustavo Astua-Monge ◽  
Helvécio Della Coletta-Filho ◽  
Flavia Vischi Winck ◽  
Paulo Aparecido Baldasso ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Xylella Fastidiosa ◽  
Shock Response

scholarly journals The Heat Shock Response ofMycobacterium tuberculosis: Linking Gene Expression, Immunology and Pathogenesis

2002 ◽  
Vol 3 (4) ◽  
pp. 348-351 ◽  
Author(s):  
Graham R. Stewart ◽  
Lorenz Wernisch ◽  
Richard Stabler ◽  
Joseph A. Mangan ◽  
Jason Hinds ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Drug Targets ◽  
Expression Patterns ◽  
Transcriptional Regulators ◽  
Deletion Mutants ◽  
Immune Recognition ◽  
Physiological Conditions ◽  
Shock Response

The regulation of heat shock protein (HSP) expression is critically important to pathogens such asMycobacterium tuberculosisand dysregulation of the heat shock response results in increased immune recognition of the bacterium and reduced survival during chronic infection. In this study we use a whole genome spotted microarray to characterize the heat shock response ofM. tuberculosis. We also begin a dissection of this important stress response by generating deletion mutants that lack specific transcriptional regulators and examining their transcriptional profiles under different stresses. Understanding the stimuli and mechanisms that govern heat shock in mycobacteria will allow us to relate observedin vivoexpression patterns of HSPs to particular stresses and physiological conditions. The mechanisms controlling HSP expression also make attractive drug targets as part of a strategy designed to enhance immune recognition of the bacterium.

scholarly journals Large Organellar Changes Occur during Mild Heat Shock in Yeast

2021 ◽  
Author(s):  
Katharina Keuenhof ◽  
Lisa Larsson Berglund ◽  
Sandra Malmgren Hill ◽  
Kara L Schneider ◽  
Per O Widlund ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Time Course ◽  
Cellular Stress Response ◽  
Mild Heat ◽  
Cellular Environment ◽  
Shock Response ◽  
Summary Statement ◽  
Novel Structures ◽  
Continuous Heat

AbstractWhen the temperature is increased, the heat shock response is activated to protect the cellular environment. The transcriptomics and proteomics of this process are intensively studied, while information about how the cell responds structurally to heat stress is mostly lacking. Here, Saccharomyces cerevisiae were subjected to a mild continuous heat shock and intermittently cryo-immobilized for electron microscopy. Through measuring changes in all distinguishable organelle numbers, sizes, and morphologies in over 2400 electron micrographs a major restructuring of the cell’s internal architecture during the progressive heat shock was revealed. The cell grew larger but most organelles within it expanded even more. Organelles responded to heat shock at different times, both in terms of size and number, and adaptations of certain organelles’ morphology were observed. Multivesicular bodies grew to almost 170% in size, indicating a previously unknown involvement in the heat shock response. A previously undescribed electron translucent structure accumulated close to the plasma membrane during the entire time course. This all-encompassing approach provides a detailed chronological progression of organelle adaptation throughout the cellular stress response.Summary statementExposure to mild heat shock leads to large quantifiable changes in the cellular ultrastructure of yeast, shows involvement of MVBs in the heat shock response and the apparition of novel structures.

scholarly journals Absence of Classical Heat Shock Response in the Citrus Pathogen Xylella fastidiosa

2009 ◽  
Vol 59 (3) ◽  
pp. 362-362
Author(s):  
Daniel Martins-de-Souza ◽  
Gustavo Astua-Monge ◽  
Helvécio Della Coletta-Filho ◽  
Flavia Vischi Winck ◽  
Paulo Aparecido Baldasso ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Xylella Fastidiosa ◽  
Shock Response

Distinctive heat-shock response of bioleaching microorganismAcidithiobacillus ferrooxidansobserved using genome-wide microarray

2012 ◽  
Vol 58 (5) ◽  
pp. 628-636 ◽  
Author(s):  
Huaqun Yin ◽  
Min Tang ◽  
Zhijun Zhou ◽  
Xian Fu ◽  
Li Shen ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Heterotrophic Bacteria ◽  
Expression Profiles ◽  
Central Carbon Metabolism ◽  
Autotrophic Bacteria ◽  
Genome Wide ◽  
Shock Response ◽  
Shock Proteins ◽  
Genome Wide Expression

Temperature plays an important role in the heap bioleaching. The maldistribution of ventilation in the heap leads to local hyperthermia, which does exert a tremendous stress on bioleaching microbes. In this study, the genome-wide expression profiles of Acidithiobacillus ferrooxidans at 40 °C were detected using the microarray. The results showed that some classic proteases like Lon and small heat-shock proteins were not induced, and heat-inducible membrane proteins were suggested to be under the control of σE. Moreover, expression changes of energy metabolism are noteworthy, which is different from that in heterotrophic bacteria upon heat stress. The induced enzymes catalyzed the central carbon metabolism pathway that might mainly provide precursors of amino acids for protein synthesis. These results will deepen the understanding of the mechanisms of heat-shock response on autotrophic bacteria.

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