Potassium is one of the essential macronutrients required for plant growth and development. It plays a major role in different physiological processes like cell elongation, stomatal movement, turgor regulation, osmotic adjustment, and signal transduction by acting as a major osmolyte and component of the ionic environment in the cytosol and subcellular organelles.
Gene expression analysis of rice seedling under potassium deprivation reveals major changes in metabolism and signaling components.
Specimen part, Treatment, Time
View SamplesFull title: Altered levels of MOF (member of MYST family histone acetyl transferase) and decreased levels of H4K16ac correlate with a defective DNA damage response (DDR).
MOF and histone H4 acetylation at lysine 16 are critical for DNA damage response and double-strand break repair.
Specimen part, Cell line
View SamplesTargeted differentiation of human induced pluripotent stem cells (hiPSCs) using only chemicals is proclaimed to have value-added clinical potential in the regeneration of complex cell types like cardiomyocytes. Despite the availability of several small molecule inhibitors capable of modulating specific receptor-ligand interaction or enzymatic activity, no bioactive synthetic DNA-binding inhibitor targeting key cell fate-controlling gene like SOX2 is available yet. Herein, we demonstrate a novel DNA-based chemical approach to guide hiPSCs differentiation using pyrrole-imidazole polyamides (PIPs), which are sequence-selective DNA-binding synthetic molecules. Harnessing the knowledge about key transcriptional changes associated with cardiomyocyte induction, we developed a PIP termed SOX-L targeting 5-CTTTGTT-3 sequence and demonstrate the inhibition of SOX2-DNA interaction and mesoderm induction of hiPSCs. Genome-wide gene analyses revealed that SOX-L remarkably specified cardiac mesoderm by triggering targeted alteration in SOX2-associated gene regulatory networks. Also, employment of SOX-L along with a Wnt inhibitor successfully generated spontaneously contracting cardiomyocytes to validate our concept that DNA-binding inhibitors like PIPs could be used for directed differentiation of hiPSCs. Because PIPs could be fine-tuned to target specific DNA sequences, our DNA-based approach could be expanded to directly target and distinctively regulate key transcription factor associated with the desired cell type.
A synthetic DNA-binding inhibitor of SOX2 guides human induced pluripotent stem cells to differentiate into mesoderm.
Specimen part, Cell line, Treatment, Time
View SamplesPyrrole-imidazole polyamides (PIPs) have been shown to inhibit gene expression by interrupting the DNA-protein interface. Human Ectopic viral integration site 1 (EVI1) is an oncogenic transcription factor which plays a key role in many aggressive forms of cancer. We have developed a novel pyrroleimidazole polyamide, PIP1 targeting the REL/ELK1 binding site in the EVI1 minimal promoter that can significantly repress the expression of EVI1 in MDA-MB-231 cells. Whole-transcriptome analysis revealed that a fraction of EVI1-driven genes were modulated by PIP1.
Targeted suppression of EVI1 oncogene expression by sequence-specific pyrrole-imidazole polyamide.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Promoter-proximal transcription factor binding is transcriptionally active when coupled with nucleosome repositioning in immediate vicinity.
Specimen part, Disease, Cell line
View SamplesNon-metastatic 2 (NME2) is an established metastases suppressor in multiple human cancer types. However, the molecular mechanisms of NME2 action remain insufficiently resolved. We recently validated the transcription regulatory activity of NME2 with respect to control of proto-oncogene c-MYC expression. We hypothesized that large scale transcriptional potential of NME2 may be at the core of metastases suppression by NME2. Using a combination of high throughput genomic assays such as chromatin immunoprecipitation coupled to promoter array hybridization (ChIP-chip) and gene expression profiling, we characterized the transcriptional roles of NME2. Specifically, we found a set of NME2 target genes which changed expression upon selective depletion of NME2 in a lung cancer cell line, A549. The analysis of gene expression suggested control of various biological pathways esp. cell adhesion and apoptosis by NME2 target genes which could be important in regulation of metastases.
Promoter-proximal transcription factor binding is transcriptionally active when coupled with nucleosome repositioning in immediate vicinity.
Specimen part, Cell line
View SamplesIt is widely believed that reorganization of nucleosomes result in availability of binding sites that engage transcription factors during eukaryotic gene regulation. Recent findings, on the other hand, suggest that transcription factors induced as a result of physiological perturbations directly (or in association with chromatin modifiers) may alter nucleosome occupancy to facilitate DNA binding. Although, together these suggest a close relationship between transcription factor binding and nucleosome reorganization, the nature of the inter-dependency, or to what extent it influences regulatory transcription is not clear. Moreover, since most studies used physiolgical pertubations that induced multiple transcription factor chromatin modifiers, the relatively local (or direct) effect of transcription factor binding on nucleosome occupancy remains unclear. With these in mind, we used a single transcription factor to induce physiological changes, representing metastatic (aggressive cancer) and the corresponding non-metastatic state, in human cancer cells. Following characterization of the two states (before and after induction of the transcription factor) we determined: (a) genome wide binding sites of the transcription factor, (b) promoter nucleosome occupancy and (c) transcriptome profiles, independently in both conditions. Interestingly, we find only ~20% of TF binding results from nucleosome reorganization - however, almost all corresponding genes were transcriptionally altered. Whereas, in cases where TF-occupancy was independent of nucleosome repositioning (in close vicinity), or co-occurred with nucleosomes, only a small fraction of the corresponding genes were expressed/repressed. Together, these indicate a model where TF occupancy only when coupled with nucleosome repositioning in close proximity is transcriptionally active. This, to our knowledge, for the first time also helps explain why genome wide TF occupancy (e.g., from ChIP-seq) is typically associated with only a small fraction of genes that change expression.
Promoter-proximal transcription factor binding is transcriptionally active when coupled with nucleosome repositioning in immediate vicinity.
Specimen part, Cell line
View SamplesTo gain insights into the mechanism responsible for the protumorigenic actions of NRG we performed gene expression analyses of MCF7 cells treated with soluble NRG for 3, 6, 12 and 24 hours.
Breast cancer dissemination promoted by a neuregulin-collagenase 3 signalling node.
Age, Specimen part, Disease, Cell line, Treatment, Time
View SamplesInterleukin 9 (IL-9) producing helper T (Th9) cells play a crucial role in allergic inflammation, autoimmunity, immunity to extracellular pathogens and anti-tumor immune response. In addition to Th9, Th2, Th17 and Foxp3+ Treg cells produce IL-9. Transcription factor that is critical for IL-9 induction in Th2, Th9 and Th17 cells has not been identified. Here we show that Foxo1, a forkhead family transcription factor, requires for IL-9 induction in Th9 and Th17 cells. We further show that inhibition of AKT enhances IL-9 induction in Th9 cells while it reciprocally regulates IL-9 and IL-17 in Th17 cells via Foxo1. Mechanistically, Foxo1 binds and transactivates IL-9 and IRF4 promoters in Th9, Th17 and iTregs. Furthermore, loss of Foxo1 attenuates IL-9 in mouse and human Th9 and Th17 cells, and ameliorates allergic inflammation in asthma. Our findings thus identify that Foxo1 is essential for IL-9 induction in Th9 and Th17 cells. Overall design: Transcriptional analysis of Th0 and TGF-beta 1 + IL-4 induced Th9 cells
Transcription factor Foxo1 is essential for IL-9 induction in T helper cells.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Distinct DNA-based epigenetic switches trigger transcriptional activation of silent genes in human dermal fibroblasts.
Sex, Treatment
View Samples