Change in gene expression in Chlamydomonas reinhardtii upon heat shock
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ABSTRACT:
ORGANISM(S): Chlamydomonas reinhardtii
PROVIDER: GSE20859 | GEO | 2011/03/02
SECONDARY ACCESSION(S): PRJNA129623
REPOSITORIES: GEO
Similar Datasets
Project description:This was an accompanying experiment. Previously, the expression of genes hsp70A and hsp70B had been established as being tetrapyrrole-dependent (Kropat et al., 1997, 2000). Since both are well-known heat-shock proteins, we performed a one-step heat shock treatment by shifting the temperatures from 23M-BM-0C to 42M-BM-0C for 45 min. Moreover, this experiment served as an additional global control to further test the reliability of the microarray and our general conditions since the heat shock response in general is quite well investigated. 3988 responding genes were identified. Among them are 22 genes known to be regulated by HS, selected examples are: the heat shock proteins 22A, 22B and 22C, here leading the list of top-regulated genes on place 1 with a FC of 91297 (22A), place 3 with a FC of 45023 (22B) and place 5 with a FC of 6570 (22C). Other examples are several DnaJ-like proteins or the ClpB chaperone, from the Hsp100 family. In total the analysis comprises 8 samples. For heat shock, a 20 ml culture with ~4 M-CM-^W 106 cells per ml in a 100 ml Erlenmeyer flask was incubated at 42M-BM-0C for 45 min in the light with shaking. Control cultures were incubated in the light at 23M-BM-0C (von Gromoff et al., 1989; Kropat et al., 2000). For harvest, cultures were chilled immediately by pouring them onto crushed ice, centrifuged (5 min, 3000 g, 4M-BM-0C) and resuspended in 1 ml TAP. This procedure was repeated three times, resulting in 3 biological replicates.
2011-03-02 | E-GEOD-20859 | biostudies-arrayexpress
Project description:Proctor2005 - Actions of chaperones and their
role in ageing
This model is described in the article:
Modelling the actions of
chaperones and their role in ageing.
Proctor CJ, Soti C, Boys RJ,
Gillespie CS, Shanley DP, Wilkinson DJ, Kirkwood TB.
Mech. Ageing Dev. 2005 Jan; 126(1):
119-131
Abstract:
Many molecular chaperones are also known as heat shock
proteins because they are synthesised in increased amounts
after brief exposure of cells to elevated temperatures. They
have many cellular functions and are involved in the folding of
nascent proteins, the re-folding of denatured proteins, the
prevention of protein aggregation, and assisting the targeting
of proteins for degradation by the proteasome and lysosomes.
They also have a role in apoptosis and are involved in
modulating signals for immune and inflammatory responses.
Stress-induced transcription of heat shock proteins requires
the activation of heat shock factor (HSF). Under normal
conditions, HSF is bound to heat shock proteins resulting in
feedback repression. During stress, cellular proteins undergo
denaturation and sequester heat shock proteins bound to HSF,
which is then able to become transcriptionally active. The
induction of heat shock proteins is impaired with age and there
is also a decline in chaperone function. Aberrant/damaged
proteins accumulate with age and are implicated in several
important age-related conditions (e.g. Alzheimer's disease,
Parkinson's disease, and cataract). Therefore, the balance
between damaged proteins and available free chaperones may be
greatly disturbed during ageing. We have developed a
mathematical model to describe the heat shock system. The aim
of the model is two-fold: to explore the heat shock system and
its implications in ageing; and to demonstrate how to build a
model of a biological system using our simulation system
(biology of ageing e-science integration and simulation
(BASIS)).
This model is hosted on
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and identified by:
BIOMD0000000091.
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2024-09-02 | BIOMD0000000091 | BioModels
Project description:Microarray analysis of the global gene expression patterns of Tropheryma whipplei in response to thermal stresses showed unique transcription profiles. A few genes were regulated after 15 min exposure at 43°C, including the dnaK regulon composed of grpE, hspR, dnaK, clpB, cbpA as well as the TWT745 ORFan gene which might encode for another heat-shock protein. This operon is likely to be regulated by two HspR associated inverted repeats (HAIR motifs) found within its 5' region. Putative virulence factors like RibC and IspDF proteins were also up-regulated under such conditions. In contrast to the heat-shock response, T. whipplei transcriptome was strongly modified following cold shock at 4°C. From the 149 genes differentially transcribed, 9 regulons were evidenced, one of them being composed of 5 genes sharing similarities with ABC transporters. Up-regulation of the latter suggests an increase of nutrient uptake during cold stress. As evoked for several bacteria species, the major classes of differentially transcribed genes encode membrane proteins and enzymes involved in fatty acid biosynthesis, indicating that membrane modifications are essential. A most specific feature observed following T. whipplei in response to cold was the up-regulation of heat-shock proteins namely GroEL2 and ClpP1, as well as several genes involved in energy metabolism. All together, these data show that T. whipplei exhibits a specific adaptative response to thermic stresses which fits well to its putative environmental origin. Keywords: thermal stresses responses
2005-12-02 | GSE3693 | GEO
Project description:Environmental stress, such as oxidative or heat stress, induces the activation of the heat shock response
(HSR) and leads to an increase in the heat shock proteins (HSPs) level. These HSPs act as molecular
chaperones to maintain cellular proteostasis. Controlled by highly intricate regulatory mechanisms,
having stress-induced activation and feedback regulations with multiple partners, the HSR is still
incompletely understood. In this context, we propose a minimal molecular model for the gene
regulatory network of the HSR that reproduces quantitatively different heat shock experiments both
on heat shock factor 1 (HSF1) and HSPs activities. This model, which is based on chemical kinetics
laws, is kept with a low dimensionality without altering the biological interpretation of the model
dynamics. This simplistic model highlights the titration of HSF1 by chaperones as the guiding line of
the network. Moreover, by a steady states analysis of the network, three different temperature stress
regimes appear: normal, acute, and chronic, where normal stress corresponds to pseudo thermal
adaption. The protein triage that governs the fate of damaged proteins or the different stress regimes
are consequences of the titration mechanism. The simplicity of the present model is of interest in
order to study detailed modelling of cross regulation between the HSR and other major genetic
networks like the cell cycle or the circadian clock.
Sivéry, A., Courtade, E., Thommen, Q. (2016). A minimal titration model of the mammalian dynamical heat shock response. Physical biology, 13(6), 066008.
2022-01-25 | MODEL2201210001 | BioModels
Project description:Heat shock response (HSR) is a cellular defense mechanism against various stresses. Both heat shock and proteasome inhibitor MG132 cause the induction of heat shock proteins, a distinct feature of HSR. To better understand the molecular basis of HSR, we subjected the mouse fibrosarcoma cell line, RIF-1, and its thermotolerant variant, TR-RIF-1 cells, to heat shock and MG132. We compared mRNA expressions using microarray analysis during recovery after heat shock and MG132 treatment. This study led us to group the 3,245 up-regulated genes by heat shock and MG132 into three families: genes regulated 1) by both heat shock and MG132 (e.g. chaperones); 2) by heat shock (e.g. DNA-binding proteins including histones); and 3) by MG132 (e.g. innate immunity and defense-related molecules).
2011-11-09 | GSE24197 | GEO
Project description:Background: The aim of this study is to improve our understanding of the mechanisms underlying the sparing of masticatory muscles in ICU patients with acute quadriplegic myopathy (AQM) by using a unique porcine ICU model, i.e., 5-day longitudinal experiments where animals are sedated, mechanically ventilated and exposed to factors triggering AQM, such as muscle unloading, endotoxin-induced sepsis, and systemic exposure to CS and NMBA. Results: An increased expression was notably observed in atrogin-1, cathepsins, FoxO1a, runx1 and heat-shock proteins genes. A decreased expression in some sarcomeric proteins and myostatin genes was also noticed. Hence, modifications in heat-shock proteins and myostatin genes are in sharp contrast to alterations in the limb muscles and it is postulated that elevated heat-shock proteins and decreased myostatin genes play a protective role in the masticatory muscle in ICU patients with AQM. Conclusions: We have observed a general down-regulation of muscle proteins and myostatin. Genes involved in the UPS system, cathepsins, RUNX1, TBX1, TIMP2 and transcripts of heat-shock proteins were up-regulated. However, we have neither observed a decrease in fiber CSA or force generation, suggesting that the expected atrophic changes have been countered by a protective mechanism and myostatin downregulation. Five female domestic piglets were treated with non-depolarizing neuromuscular blocking agents (NMBA), corticosteroids(CS) and sepsis. Five female piglets were untreated.
2010-09-21 | E-GEOD-24239 | biostudies-arrayexpress
Project description:Heat shock response (HSR) is a cellular defense mechanism against various stresses. Both heat shock and proteasome inhibitor MG132 cause the induction of heat shock proteins, a distinct feature of HSR. To better understand the molecular basis of HSR, we subjected the mouse fibrosarcoma cell line, RIF-1, and its thermotolerant variant, TR-RIF-1 cells, to heat shock and MG132. We compared mRNA expressions using microarray analysis during recovery after heat shock and MG132 treatment. This study led us to group the 3,245 up-regulated genes by heat shock and MG132 into three families: genes regulated 1) by both heat shock and MG132 (e.g. chaperones); 2) by heat shock (e.g. DNA-binding proteins including histones); and 3) by MG132 (e.g. innate immunity and defense-related molecules). RIF-1 and TR cells were heat shock treated or MG132 treated and harvested after various times of recovery. mRNA expressions were compared to untreated samples. Biological replication was done.
2011-11-09 | E-GEOD-24197 | biostudies-arrayexpress
Project description:Anoxia induces several heat shock proteins and a heat pre-treatment can acclimatize Arabidopsis seedlings to a subsequent anoxic treatment. In this work we analyzed the response of Arabidopsis seedlings to anoxia, heat and a combined heat+anoxia stress. A significant overlapping between the anoxic and heat shock responses has been observed by whole-genome microarray analysis.
2009-05-30 | GSE16222 | GEO
Project description:In Drosophila larvae, acquired synaptic thermotolerance following heat shock has previously been shown to correlate with the induction of heat shock proteins (Hsps) including HSP70. We tested the hypothesis that synaptic thermotolerance would be significantly diminished in a temperature-sensitive strain (hsf4) which has been reported not to be able to produce inducible Hsps in response to heat shock. Contrary to our hypothesis, considerable thermoprotection was still observed at hsf4 larval synapses following heat shock. To investigate the cause of this thermoprotection, we conducted DNA microarray experiments to identify heat-induced transcript changes in these organisms. Transcripts of the hsp83, dnaJ-1(hsp40) and gstE1 genes were significantly up-regulated in hsf4 larvae after heat shock. In addition, increases in the levels of Hsp83 and DnaJ-1 proteins but not in the inducible form of Hsp70 were detected by Western blotting. The mode of heat shock administration differentially affected the relative transcript and translational changes for these chaperones. These results indicate that the compensatory up-regulation of constitutively expressed Hsps, in the absence of the synthesis of inducible Hsps including HSP70, could still provide substantial thermoprotection to both synapses and the whole organism. Keywords: heat shock response
2005-12-01 | GSE2998 | GEO