HSFA1s are a gene family of HSFA1 with four members, HSFA1a, HSFA1b, HSFA1d, and HSFA1e. HSFA1s are the master regulators of heat shock response. As a part of the heat shock response, HSFA2 can prolong the heat shock response and amplify the heat shock response in response to repeat heat shock. To identify the heat-shock-responsive genes differentially regulated by HSFA1s and HSFA2, we compared the transcriptomic differences of plants containing only constitutively expressed HSFA1s or HSFA2 after heat stress.
Common and distinct functions of Arabidopsis class A1 and A2 heat shock factors in diverse abiotic stress responses and development.
Age, Specimen part
View SamplesIn order to study the importance of HSFA1 in thermotolerance in Arabidopsis, we generated the HSFA1a, b, d and e quadruple mutant (QK). QK is very sensitive to heat. Therefore, we used microarray to study how many genes regulated by HSFA1 after heat shock.
The role of class A1 heat shock factors (HSFA1s) in response to heat and other stresses in Arabidopsis.
Age, Specimen part, Treatment
View SamplesSeveral lipocalin genes from higher plants were shown to be responsive to both high and low temperature stresses and have been named as temperature-induced lipocalin (Til). In this study, a reverse genetic approach was taken to elucidate the role of Arabidopsis Til1 (At5g58070) in thermotolerance. We showed that Til1 proteins was constitutively expressed and increased significantly after heat shock treatment. A T-DNA knockout line of Til1, designated as til1-1, could not produce Til1 and showed severe defects in basal and acquired thermotolerance. Introducing a wild type copy of Til1 gene into til1-1 complemented the mutant phenotype. Over-expression of Til1 in the wild type plant did not enhance thermotolerance. Til1 is peripherally associated with plasma membrane, suggesting a regulatory or protective role of this protein in membrane function. Transcriptomic analysis showed that the heat shock response in til1-1 was not altered as compared to the wild type plants. The temperature threshold for heat shock protein induction was not affected by the level of Til1. Ion leakage analysis revealed no significant difference in membrane stability between the wild type and til1-1 seedlings. These results suggested that Til1 is not involved in regulating membrane fluidity or stability. Nevertheless, the level of malondialdehyde was significantly higher in til1-1 than in the wild type after severe heat treatment. The mutant plants were also more sensitive than the wild type to tert-butyl hydroperoxide, a reagent that induces lipid peroxidation. Taken together, our data indicate that Til1 is an essential component for thermotolerance probably by acting against lipid peroxidation induced by severe heat stress.
Temperature-induced lipocalin is required for basal and acquired thermotolerance in Arabidopsis.
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View SamplesWe used microarrays to detail the global transcriptional response mediated by ERalpha or ERbeta to the phytoestrogen genistein in the MCF-7 human breast cancer cell model.
Estrogen Receptors alpha and beta as determinants of gene expression: influence of ligand, dose, and chromatin binding.
No sample metadata fields
View SamplesPlants 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.
Distinct heat shock factors and chromatin modifications mediate the organ-autonomous transcriptional memory of heat stress.
Age, Specimen part
View SamplesThe study demontrates differences in the transcriptome ( both of protein coding transcripts and long non-coding RNAs) in the unilateral ureteric obstruction model of renal fibrosis. Overall design: Renal tissue was studied from animals undergoing sham operation (as controls) or right ureteric ligation. Animals were sacrificed 2 and 8 days following ligation and the right kidney tissue was examined.
Whole-transcriptome analysis of UUO mouse model of renal fibrosis reveals new molecular players in kidney diseases.
Sex, Age, Specimen part, Cell line, Subject
View SamplesInflammatory breast cancer (IBC) is an aggressive form of BC poorly defined at the molecular level. We compared the molecular portraits of 63 IBC and 134 non-IBC (nIBC) clinical samples. Genomic imbalances of 49 IBCs and 124 nIBCs were determined using high-resolution array-comparative genomic hybridization, and mRNA expression profiles of 197 samples using whole-genome microarrays. Genomic profiles of IBCs were as heterogeneous as those of nIBCs, and globally relatively close. However, IBCs showed more frequent complex patterns and a higher percentage of genes with CNAs per sample. The number of altered regions was similar in both types, although some regions were altered more frequently and/or with higher amplitude in IBCs. Many genes were similarly altered in both types; however, more genes displayed recurrent amplifications in IBCs.
High-resolution comparative genomic hybridization of inflammatory breast cancer and identification of candidate genes.
Age
View SamplesThe nuclear receptor, estrogen receptor alpha (ER), controls the expression of hundreds of genes responsible for target cell phenotypic properties, but the relative importance of direct vs. tethering mechanisms of DNA binding has not been established. In this first report, we examine the genome-wide chromatin localization of an altered-specificity mutant ER with a DNA-binding domain deficient in binding to estrogen response element (ERE)-containing DNA (DBDmut ER) vs. wild type ER. Using high-throughput sequencing of ER chromatin immunoprecipitations (ChIP-Seq) and mRNA transcriptional profiling, we show that direct ERE binding is required for most (75%) estrogen-dependent gene regulation and 90% of hormone-dependent recruitment of ER to genomic binding sites. De novo motif analysis of the chromatin binding regions in MDA-MB-231 human breast cancer cells defined unique transcription factor profiles responsible for genes regulated through tethering vs. direct DNA (ERE) binding, with Runx motifs enriched in ER-tethered sites. We confirmed a role for Runx1 in mediating ERa genomic recruitment and regulation of tethering genes. Our findings delineate the contributions of ERE binding vs. binding through response elements for other transcription factors in chromatin localization and ER-dependent gene regulation, paradigms likely to underlie the gene regulatory actions of other nuclear receptors as well.
Genome-wide analysis of estrogen receptor alpha DNA binding and tethering mechanisms identifies Runx1 as a novel tethering factor in receptor-mediated transcriptional activation.
Specimen part, Time
View SamplesEstradiol Timecourse of MDA-MB-231ER+ cells containing a WT-ER and DBDmut-ER
Genome-wide analysis of estrogen receptor alpha DNA binding and tethering mechanisms identifies Runx1 as a novel tethering factor in receptor-mediated transcriptional activation.
Time
View SamplesAnalysis of the response to arginine of the Escherichia coli K-12 transcriptome by microarray hybridization and real-time quantitative PCR provides a first coherent quantitative picture of the ArgR-mediated repression of arginine biosynthesis and uptake genes. Transcriptional repression was shown to be the major control mechanism of the biosynthetic genes, leaving only limited room for additional transcriptional or post-transcriptional regulations. The art genes coding for the specific arginine uptake system are subject to ArgR-mediated repression,
The arginine regulon of Escherichia coli: whole-system transcriptome analysis discovers new genes and provides an integrated view of arginine regulation.
No sample metadata fields
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