Using the ATH1 Affymetrix microarrays consisting of about 23,000 genes, we examined the response of Arabidopsis seedlings to chito-tetramers, chito-octamers and hydrolyzed chitin after 30 min of treatment.
Loss-of-function mutations in chitin responsive genes show increased susceptibility to the powdery mildew pathogen Erysiphe cichoracearum.
No sample metadata fields
View SamplesAffymetrix expression arrays were used to compare expression patterns upon knockdown of PARP-1, PARG, SIRT1, or macroH2A in comparison to Luciferase control.
Global analysis of transcriptional regulation by poly(ADP-ribose) polymerase-1 and poly(ADP-ribose) glycohydrolase in MCF-7 human breast cancer cells.
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View SamplesPoly(ADP-ribose) polymerase-1 (PARP-1) and poly(ADP-ribose) glycohydrolase (PARG) are enzymes that modify target proteins in the nucleus by the addition and removal, respectively, of ADP-ribose polymers. Although a role for PARP-1 in gene regulation has been well established, the role of PARG is less clear. To investigate how PARP-1 and PARG coordinately regulate global patterns of gene expression, we used short hairpin RNAs (shRNAs) to stably knockdown PARP-1 or PARG in MCF-7 cells, followed by expression microarray analyses.
Global analysis of transcriptional regulation by poly(ADP-ribose) polymerase-1 and poly(ADP-ribose) glycohydrolase in MCF-7 human breast cancer cells.
No sample metadata fields
View SamplesIn mammals, nicotinamide phosphoribosyltransferase (NAMPT) and nicotinamide mononucleotide adenylyltransferase 1 (NMNAT-1) constitute a nuclear NAD+ salvage pathway, regulating cellular functions of the NAD+-dependent deacetylase SIRT1. However, little is known about the molecular mechanisms by which NAD+ biosynthesis controls gene transcription in the nucleus. In this study, we show that stable knockdown of NAMPT or NMNAT-1 in MCF-7 breast cancer cells significantly reduced total cellular NAD+ levels. Expression microarray analyses demonstrate that both enzymes have broad and overlapping functions in gene regulation. SIRT1 is a key mediator of NAMPT- and NMNAT-1-dependent gene regulation, and is found at promoters of many of the target genes. Furthermore, SIRT1 deacetylase activity at these promoters is regulated by NAMPT and NMNAT-1. Most significantly, NMNAT-1 interacts with SIRT1 and is recruited to target gene promoters by SIRT1. Our results reveal an unexpected mechanism for the direct control of SIRT1 deacetylase activity at target gene promoters by NMNAT-1. Interactions between NMNAT-1 and SIRT1 at gene promoters may provide a platform for integration of multiple signaling pathways that regulate transcription.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
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View SamplesNMNAT1 is a nuclear enzyme in the mammalian NAD+ salvage pathway. Expression microarray analysis was used to study the effect of NMNAT1 knockdown on gene expression in MCF-7 breast cancer cells.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
No sample metadata fields
View SamplesSIRT1 is a nuclear NAD+-dependent protein deacetylase. Expression microarray analysis was used to study the effect of SIRT1 knockdown on gene expression in MCF-7 breast cancer cells.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
No sample metadata fields
View SamplesNAMPT is an enzyme in the mammalian NAD+ salvage pathway. Expression microarray analysis was used to study the effect of NAMPT knockdown on gene expression in MCF-7 breast cancer cells.
Enzymes in the NAD+ salvage pathway regulate SIRT1 activity at target gene promoters.
No sample metadata fields
View SamplesAn RNA-seq dataset obtained from neural fold-stage chicken (Gallus gallus, strain Special Black) embryos that were exposed to a pharmacologically-relevant alcohol concentration (52 mM for 90 min) or isotonic saline. The cranial headfolds were isolated 6 hours following the initial alcohol exposure. Following RNA isolation, cDNA synthesis, and quality assurance (20), paired-end reads (75 bp) were generated on an Illumina Genome Analyzer IIx (University of Wisconsin Biotechnology Center). Overall design: Paired end runs with 2 replicate ethanol exposed samples (pool of 23 individual neural folds) and 2 saline control samples (pool of 23 individual neural folds).
Exon level machine learning analyses elucidate novel candidate miRNA targets in an avian model of fetal alcohol spectrum disorder.
Specimen part, Cell line, Subject
View SamplesMultiple regulatory regions have the potential to regulate a single gene, yet how these elements combine to impact gene expression remains unclear. To uncover the combinatorial relationships between enhancers, we developed Enhancer-interference (Enhancer-i), a CRISPR interference-based approach that can prevent enhancer activation simultaneously at multiple regulatory regions. We applied Enhancer-i to promoter-distal estrogen receptor a binding sites (ERBS), which cluster around estradiol-responsive genes and therefore may collaborate to regulate gene expression. Targeting individual sites revealed predominant ERBS that are completely required for the transcriptional response, indicating a lack of redundancy. Simultaneous interference of different ERBS combinations identified supportive ERBS that contribute only when predominant sites are active. Using mathematical modeling, we find strong evidence for collaboration between predominant and supportive ERBS. Overall, our findings expose a complex functional hierarchy of enhancers, where multiple loci bound by the same transcription factor combine to fine tune the expression of target genes. Overall design: The effects of Enhancer interference (Enhancer-i) and control guide RNA treatment on the transcriptome before and after estrogen treatment, with 2 replicates per condition.
Multiplex Enhancer Interference Reveals Collaborative Control of Gene Regulation by Estrogen Receptor α-Bound Enhancers.
Specimen part, Treatment, Subject
View SamplesEstrogen receptor alpha (ESR1) mutations have been identified in hormone therapy resistant breast cancer and primary endometrial cancer. Analyses in breast cancer suggests that mutant ESR1 exhibits estrogen independent activity. In endometrial cancer, ESR1 mutations are associated with worse outcomes and less obesity, however experimental investigation of these mutations has not been performed. Using a unique CRISPR/Cas9 strategy, we introduced the D538G mutation, a common endometrial cancer mutation that alters the ligand binding domain of ESR1, while epitope tagging the endogenous locus. We discovered estrogen-independent mutant ESR1 genomic binding that is significantly altered from wildtype ESR1. The D538G mutation impacted expression, including a large set of non-estrogen regulated genes, and chromatin accessibility, with most affected loci bound by mutant ESR1. Mutant ESR1 is unique from constitutive ESR1 activity as mutant-specific changes are not recapitulated with prolonged estrogen exposure. Overall, D538G mutant ESR1 confers estrogen-independent activity while causing additional regulatory changes in endometrial cancer cells that are distinct from breast cancer cells. Overall design: RNA-seq was used to study the effects of the D538G mutation on gene expression
Estrogen-independent molecular actions of mutant estrogen receptor 1 in endometrial cancer.
Cell line, Treatment, Subject, Time
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