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.

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.

The heat shock response: A case study of chromatin dynamics in gene regulation

2013 ◽  
Vol 91 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Sheila S. Teves ◽  
Steven Henikoff
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Control Of Gene Expression ◽  
Pol Ii ◽  
Chromatin Dynamics ◽  
Regulatory Processes ◽  
Shock Response ◽  
Rate Limiting

Recent studies in transcriptional regulation using the Drosophila heat shock response system have elucidated many of the dynamic regulatory processes that govern transcriptional activation and repression. The classic view that the control of gene expression occurs at the point of RNA polymerase II (Pol II) recruitment is now giving way to a more complex outlook of gene regulation. Promoter chromatin dynamics coordinate with transcription factor binding to maintain the promoters of active genes accessible. For a large number of genes, the rate-limiting step in Pol II progression occurs during its initial elongation, where Pol II transcribes 30–50 bp and pauses for further signals. These paused genes have unique genic chromatin architecture and dynamics compared with genes where Pol II recruitment is rate limiting for expression. Further elongation of Pol II along the gene causes nucleosome turnover, a continuous process of eviction and replacement, which suggests a potential mechanism for Pol II transit along a nucleosomal template. In this review, we highlight recent insights into transcription regulation of the heat shock response and discuss how the dynamic regulatory processes involved at each transcriptional stage help to generate faithful yet highly responsive gene expression.

Ubiquitin gene expression in Dictyostelium is induced by heat and cold shock, cadmium, and inhibitors of protein synthesis

1988 ◽  
Vol 90 (1) ◽  
pp. 51-58 ◽  
Author(s):  
A. Muller-Taubenberger ◽  
J. Hagmann ◽  
A. Noegel ◽  
G. Gerisch
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Heat Shock ◽  
Differential Expression ◽  
Dictyostelium Discoideum ◽  
Heat Shock Response ◽  
Cold Shock ◽  
Multifunctional Protein ◽  
Cadmium Treatment ◽  
Shock Response

Ubiquitin is a highly conserved, multifunctional protein, which is implicated in the heat-shock response of eukaryotes. The differential expression of the multiple ubiquitin genes in Dictyostelium discoideum was investigated under various stress conditions. Growing D. discoideum cells express four major ubiquitin transcripts of sizes varying from 0.6 to 1.9 kb. Upon heat shock three additional ubiquitin mRNAs of 0.9, 1.2 and 1.4 kb accumulate within 30 min. The same three transcripts are expressed in response to cold shock or cadmium treatment. Inhibition of protein synthesis by cycloheximide leads to a particularly strong accumulation of the larger ubiquitin transcripts, which code for polyubiquitins. Possible mechanisms regulating the expression of ubiquitin transcripts upon heat shock and other stresses are discussed.

Thermal acclimation changes DNA-binding activity of heat shock factor 1(HSF1) in the gobyGillichthys mirabilis: implications for plasticity in the heat-shock response in natural populations

2002 ◽  
Vol 205 (20) ◽  
pp. 3231-3240 ◽  
Author(s):  
Bradley A. Buckley ◽  
Gretchen E. Hofmann
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Environmental Control ◽  
Heat Shock Factor ◽  
Thermal Acclimation ◽  
Model Systems ◽  
Threshold Temperature ◽  
Heat Shock Factor 1 ◽  
Shock Response

SUMMARYThe intracellular build-up of thermally damaged proteins following exposure to heat stress results in the synthesis of a family of evolutionarily conserved proteins called heat shock proteins (Hsps) that act as molecular chaperones, protecting the cell against the aggregation of denatured proteins. The transcriptional regulation of heat shock genes by heat shock factor 1(HSF1) has been extensively studied in model systems, but little research has focused on the role HSF1 plays in Hsp gene expression in eurythermal organisms from broadly fluctuating thermal environments. The threshold temperature for Hsp induction in these organisms shifts with the recent thermal history of the individual but the mechanism by which this plasticity in Hsp induction temperature is achieved is unknown. We examined the effect of thermal acclimation on the heat-activation of HSF1 in the eurythermal teleost Gillichthys mirabilis. After a 5-week acclimation period (at 13, 21 or 28°C) the temperature of HSF1 activation was positively correlated with acclimation temperature. HSF1 activation peaked at 27°C in fish acclimated to 13°C, at 33°C in the 21°C group, and at 36°C in the 28°C group. Concentrations of both HSF1 and Hsp70 in the 28°C group were significantly higher than in the colder acclimated fish. Plasticity in HSF1 activation may be important to the adjustable nature of the heat shock response in eurythermal organisms and the environmental control of Hsp gene expression.

THE HEAT SHOCK RESPONSE INHIBITS RANTES GENE EXPRESSION

1998 ◽  
Vol 26 (Supplement) ◽  
pp. 39A ◽  
Author(s):  
Onsy Ayad ◽  
James Stark ◽  
Hector R. Wong
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Shock Response
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