Whole-genome analysis of heat shock factor binding sites in Drosophila melanogaster
Ontology highlight
ABSTRACT:
ORGANISM(S): Drosophila melanogaster
SUBMITTER: Zak Razak
PROVIDER: E-GEOD-19744 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2011-01-05 | E-GEOD-19746 | biostudies-arrayexpress
Project description:DNA sequence and local chromatin landscape act jointly to determine transcription factor (TF) binding intensity profiles. To disentangle these influences, we developed an experimental approach, called protein/DNA binding and high-throughput sequencing (PB-seq), that allows the binding energy landscape to be characterized genome-wide in the absence of chromatin. We applied our methods to the Drosophila Heat Shock Factor (HSF), which inducibly binds a target DNA sequence element (HSE) following heat shock stress. PB-seq involves incubating sheared naked genomic DNA with recombinant HSF, partitioning the HSF-bound and HSF-free DNA, and then detecting HSF-bound DNA by high throughput sequencing. We compared PB-seq binding profiles with ones observed in vivo by ChIP-seq, and developed statistical models to predict the observed departures from idealized binding patterns based on covariates describing the local chromatin environment. We found that DNase I hypersensitivity and tetra-acetylation of H4 were the most influential covariates in predicting changes in HSF binding affinity. We also investigated the extent to which DNA accessibility, as measured by digital DNase I footprinting data, could be predicted from MNase-seq data and the ChIP-chip profiles for many histone modifications and TFs, and found GAGA element associated factor (GAF), tetra-acetylation of H4, and H4K16 acetylation to be the most predictive covariates. Lastly, we generated an unbiased model of HSF binding sequences, which revealed distinct biophysical properties of the HSF/HSE interaction and a previously unrecognized substructure within the HSE. These findings provide new insights into the interplay between the genomic sequence and the chromatin landscape in determining transcription factor binding intensity. We performed an in vitro binding experiment with purified HSF and naked, sheared genomic Drosophila S2 DNA (PB-seq), to derive an accurate set of potential HSF binding sites in the Drosophila genome. HSF-bound DNA was specifically eluted and detected by high throughput sequencing. Drosophila HSF was N-terminally tagged with glutathione s-transferase and a tobacco etch virus (TEV) protease cleavage site. The C-terminus of the recombinant HSF was fused to the 3xFLAG epitope. Recombinant HSF was purified from E. coli with glutathione resin as previously described (PMID: 20078429) , with the following modifications: HSF-3xFLAG elution was achieved by addition of 6xHistidine tagged TEV protease and TEV protease was cleared from the HSF preparation using a Nickel-NTA column. We incubated 600pM HSF and 2500ng genomic DNA (sonicated to 100-600bp fragment size as previously described in PMID: 20844575) in 1500μl final volume of 1xHSF binding buffer and let it come to equilibrium for an hour at room temperature. We added 20μl ANTI-FLAG M2 affinity gel for 10 minutes, washed 8 times with 1xHSF binding buffer to remove unbound DNA; 3xFLAG peptide was added to a final concentration of 200ng/μl to specifically elute HSF and HSF-bound DNA. The mock IP was done in the absence of recombinant HSF.
2012-02-06 | E-GEOD-32570 | biostudies-arrayexpress
Project description:Whole-genome analysis of heat shock factor binding sites in Drosophila melanogaster. Heat shock factor IP DNA or Mock IP DNA from heat shocked Kc 167 cells compared to whole cell extract on Agilent 2x244k tiling arrays.
2011-01-05 | GSE19744 | GEO
Project description:Whole-genome analysis of heat shock factor binding sites in Drosophila melanogaster. Heat shock factor IP DNA from non-shock (room temperature) Kc 167 cells compared to whole cell extract on Agilent 2x244k tiling arrays.
2011-01-05 | GSE22335 | GEO
Project description:Mutants of the Mnn1 gene are hyper-sensitive to several stresses and display increased genome instability when subjected to conditions, such as heat shock, generally regarded as non-genotoxic. We describe a role for Menin as a global regulator of heat shock gene expression and critical factor in the maintenance of genome integrity 2-colour microarray design using 36 microarrays testing shock vs non shock in Drosophila melanogaster. Using a test of loss-of-heterozygosity, we show that Drosophila strains lacking a functional Mnn1 gene or expressing a Mnn1 dsRNAi are characterized by increased genome instability in response to short, repeated but non-lethal heat shock or hypoxia treatments. The same was true for strains lacking all Hsp70 genes.
2010-10-25 | E-GEOD-20497 | biostudies-arrayexpress
Project description:In HuntingtonM-bM-^@M-^Ys disease (HD), polyglutamine expansions in the huntingtin (Htt) protein cause subtle changes in cellular functions that, over-time, lead to neurodegeneration and death. Studies have indicated that activation of the heat shock response can reduce many of the effects of mutant Htt in disease models, suggesting that the heat shock response is impaired in the disease. To understand the basis for this impairment, we have used genome-wide chromatin immunoprecipitation followed by massively parallel sequencing (ChIP-Seq) to examine the effects of mutant Htt on the master regulator of the heat shock response, HSF1. We find that, under normal conditions, HSF1 function is highly similar in cells carrying either wild-type or mutant Htt. However, polyQ-expanded Htt severely blunts the HSF1-mediated stress response. Surprisingly, we find that the HSF1 targets most affected upon stress are not directly associated with proteostasis, but with cytoskeletal binding, focal adhesion and GTPase activity. Our data raise the intriguing hypothesis that the accumulated damage from life-long impairment in these stress responses may contribute significantly to the etiology of Huntington's disease. ChIP-Seq experiments for HSF-1 were performed in striatal cells that express either wild-type or mutant Htt using ChIP-Seq technology under normal (33M-BM-0C) and heat shock (42M-BM-0C for six hours) conditions. The cells were crosslinked with 1% formaldehyde and immunoprecipitated using antibody sc-9144 (Santa Cruz Biotech) for HSF-1. Sequencing was performed using the Illumina Genome Analyzer II.
2012-06-19 | E-GEOD-38000 | biostudies-arrayexpress
Project description:Total H4 and acetyl H4 IP, time course Total H4 and acetyl H4 occupancy, Snf2 occupancy, gene expression analysis Keywords: stress response, time course S cerevisiae were subjected to heat shock and stationary phase stress. The histone occupancy and H4 acetylation levels were monitored in parallel with gene expression studies, and Snf2 occupancy before and after stress.
2010-05-26 | E-GEOD-7665 | 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
BioModels Database
and identified by:
BIOMD0000000091.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
2007-02-26 | BIOMD0000000091 | BioModels
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:Sequence-specific transcription factors (TFs) are critical for specifying patterns and levels of gene expression, but the DNA elements to which they can bind are not always sufficient to specify their binding in vivo. In eukaryotes, the binding of a TF is in competition with a constellation of other proteins, including histones which package DNA into nucleosomes. Here, we examine using the ChIP-seq assay, the genome-wide distribution of Drosophila Heat Shock Factor (HSF), a TF whose binding activity is mediated by heat shock-induced trimerization. We detect HSF binding to 464 sites, the vast majority of which contain HSF Sequence-binding Elements (HSEs) in Drosophila S2 cells, but these HSF-bound sites represent only a small fraction of HSEs present in the genome. We find a strong correlation of bound HSEs to active chromatin marks present prior to HSF binding, indicating an HSEM-bM-^@M-^Ys residence in open chromatin is a primary determinant of whether HSF can bind following heat shock. A single mock immunoprecipitation (IP) using the pre-innoculated animal serum was used as a background dataset for this study. For each condition (NHS and 20minute HS), we performed two independent HSF-ChIP-seq experiments. In addition, we performed two independent HSF-ChIP-seq experiments for each condition (NHS and 20minute HS) in cells that were highly depleted of HSF by RNAi.
2010-09-02 | E-GEOD-19025 | biostudies-arrayexpress