Project description:FBXW7 modulates stress response by post-translational modification of HSF1 HSF1 orchestrates the heat-shock response upon exposure to heat stress and activates a transcriptional program vital for cancer cells. In this study we assayed for genome-wide localization of HSF1 enrichment in the HCT116 FBXW7 KO colon cells and their wild type counterpart in untreated cells and upon heat shock. These results revealed that accumulation of nuclear HSF1 in FBXW7 KO cells results in rewiring of the HSF1 transcriptional program. Five million cells were used for the ChIP and precipitated using 5 micrograms of antibody (cell signaling, 4356) against human HSF1
Project description:FBXW7 modulates stress response by post-translational modification of HSF1 HSF1 orchestrates the heat-shock response upon exposure to heat stress and activates a transcriptional program vital for cancer cells. In this study we assayed for genome-wide localization of HSF1 enrichment in the HCT116 FBXW7 KO colon cells and their wild type counterpart in untreated cells and upon heat shock. These results revealed that accumulation of nuclear HSF1 in FBXW7 KO cells results in rewiring of the HSF1 transcriptional program.
2015-02-20 | GSE57398 | GEO
Project description:Transcriptional profiles of heat stress response in Yellowtail Kingfish
Project description:Plants can be primed by a stress cue to mount a faster and stronger activation of defense mechanisms upon a subsequent stress. A crucial component of such stress priming is the modified reactivation of genes upon recurring stress, a phenomenon known as transcriptional memory. The transcriptional memory in response to heat stress is not clear at the genome scale. We used microarrays to identify genes that showed transcriptional memory in response to recurring heat stress.
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.
Project description:During heat stress cyto-protective genes including heat shock proteins are transcriptionally up-regulated and post-transcriptional splicing is inhibited. In contrast, co-transcriptional mRNA-splicing is maintained. These factors closely resemble the proteotoxic stress response during tumor development. The bromodomain protein BRD4 has been identified as an integral member of the oxidative stress as well as of the inflammatory response. Furthermore, there is evidence for BRD4's role in splicing regulation; Using RNA-Seq analyses we indeed found a significant increase in splicing inhibition, in particular intron retentions, during heat treatment in BRD4-deficient cells, but not under normal conditions. Subsequent experiments revealed that heat stress leads to the recruitment of BRD4 to nuclear stress bodies, to the interaction with the heat shock factor 1 (HSF1) and to the transcriptional up-regulation of non-coding Sat III RNA transcripts. These findings implicate BRD4 as a central regulator of splicing during heat stress. Since BRD4 is a potent target for anti-cancer therapies, our data linking BRD4 to the splicing machinery and the heat stress response - give additional insight into the mode of action of BRD4 inhibitors.
Project description:Transcriptional profiles were compared between vector control and DPB3-1-overexpressing rice plants under control and heat stress conditions. Transcriptional changes of the vector control plants in response to heat stress were also studied.
Project description:SUMOylation, a post-translational protein modification, is dramatically upregulated and critically involved in heat stress response conservatively among species. Previous studies in Arabidopsis indicated that numerous chromatin associated proteins are SUMOylation substrates and most of heat-enhancing SUMOylation reactions occur in nucleus. However, the global functional connection between gene expression regulation and SUMOylation on chromatin is completely unknown in plant cells. Here we show a genome-wide relationship of chromatin-associated SUMOylation and transcription switches under room temperature, heat stress, and recovering conditions in Arabidopsis. The SUMO-associated chromatin sites, characterized via whole-genome ChIP-seq assays, are generally correlated with active chromatin markers. In response to heat stress, we found chromatin-associated SUMO signals increased at promoter-transcriptional start site regions and decreased in the gene bodies. Further RNA-seq analysis supported the role of chromatin-associated SUMOylation in activation of transcription during rapid responses to high temperature. Changing of SUMO signals on chromatin is correlated with upregulation of heat-responsive genes and downregulation of growth-related genes. Disruption of the SUMO ligase gene SIZ1 abolishes SUMO signals on chromatin and attenuates the rapid transcriptional responses to heat stress. Interestingly, the SUMO signal peaks are enriched in DNA elements recognized by distinguished groups of transcription factors under different temperature conditions. Collectively, our data provide evidence that SUMOylation on chromatin regulates transcription switches during development and heat stress response, improving our understanding on the precise roles of SUMOylation in plant cells.
Project description:During heat stress cyto-protective genes including heat shock proteins are transcriptionally up-regulated and post-transcriptional splicing is inhibited. In contrast, co-transcriptional mRNA-splicing is maintained. These factors closely resemble the proteotoxic stress response during tumor development. The bromodomain protein BRD4 has been identified as an integral member of the oxidative stress as well as of the inflammatory response. Furthermore, there is evidence for BRD4's role in splicing regulation; Using RNA-Seq analyses we indeed found a significant increase in splicing inhibition, in particular intron retentions, during heat treatment in BRD4-deficient cells, but not under normal conditions. Subsequent experiments revealed that heat stress leads to the recruitment of BRD4 to nuclear stress bodies, to the interaction with the heat shock factor 1 (HSF1) and to the transcriptional up-regulation of non-coding Sat III RNA transcripts. These findings implicate BRD4 as a central regulator of splicing during heat stress. Since BRD4 is a potent target for anti-cancer therapies, our data linking BRD4 to the splicing machinery and the heat stress response - give additional insight into the mode of action of BRD4 inhibitors. WI38 cells have been treated by heatshock and anti BRD4 siRNA and combination.