Transcriptional profiles of Escherichia coli MG1655 in mixed culture with Pseudomonas aeruginosa PAO1 showed a number of E. coli genes to be upregulated including purA-F and other genes associated with purine synthesis. In contrast, genes associated with pyrimidine synthesis were unaffected. Competition experiments in both planktonic and biofilm cultures, using three purine synthesis mutants, purD, purH, and purT showed little difference in E. coli survival from the parent strain. As purines are components of the cell signals, cAMP and c-di-GMP, we conducted competition experiments with E. coli mutants lacking adenylate cyclase (cyaA), cAMP phosphodiesterase (cpdA), and the catabolite receptor protein (crp), as well as ydeH, an uncharacterized gene that has been associated with c-di-GMP synthesis. Survival of the cyaA and crp mutants during co-culture were significantly less than the parent strain. Supplementation of the media with 1mM cAMP could restore survival of the cyaA mutant but not the crp mutant. In contrast, survival of the cpdA mutant was similar to the parent strain. Survival of the ydeH mutant was moderately less than the parent, suggesting that cAMP has more impact on E. coli mixed culture growth than c-di-GMP. Addition of 1 mM indole restored the survival of both the cyaA and crp mutations. Mutants in genes for tryptophan synthesis (trpE) and indole production (tnaA) showed a loss of competition and recovery through indole supplementation, comparable to the cyaA and crp mutants. Overall, these results suggest indole and cAMP as major contributing factors to E. coli growth in mixed culture.
Indole production promotes Escherichia coli mixed-culture growth with Pseudomonas aeruginosa by inhibiting quorum signaling.
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View SamplesTranscriptional profiles of Escherichia coli MG1655 in mixed culture with Pseudomonas aeruginosa PAO1 showed a number of E. coli genes to be upregulated including purA-F and other genes associated with purine synthesis. In contrast, genes associated with pyrimidine synthesis were unaffected. Competition experiments in both planktonic and biofilm cultures, using three purine synthesis mutants, purD, purH, and purT showed little difference in E. coli survival from the parent strain. As purines are components of the cell signals, cAMP and c-di-GMP, we conducted competition experiments with E. coli mutants lacking adenylate cyclase (cyaA), cAMP phosphodiesterase (cpdA), and the catabolite receptor protein (crp), as well as ydeH, an uncharacterized gene that has been associated with c-di-GMP synthesis. Survival of the cyaA and crp mutants during co-culture were significantly less than the parent strain. Supplementation of the media with 1mM cAMP could restore survival of the cyaA mutant but not the crp mutant. In contrast, survival of the cpdA mutant was similar to the parent strain. Survival of the ydeH mutant was moderately less than the parent, suggesting that cAMP has more impact on E. coli mixed culture growth than c-di-GMP. Addition of 1 mM indole restored the survival of both the cyaA and crp mutations. Mutants in genes for tryptophan synthesis (trpE) and indole production (tnaA) showed a loss of competition and recovery through indole supplementation, comparable to the cyaA and crp mutants. Overall, these results suggest indole and cAMP as major contributing factors to E. coli growth in mixed culture.
Indole production promotes Escherichia coli mixed-culture growth with Pseudomonas aeruginosa by inhibiting quorum signaling.
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View SamplesPofut1 is an essential gene that glycosylates proteins containing EGF-like repeats, including Notch Receptors (NotchRs). Work in mice and in Drosophila has shown that O-fucosylation by Pofut1 is required for NotchR ligands to bind to and activate NotchRs. As such, Pofut1 deletion in skeletal myofibers allows for an analysis of potential functions and molecular changes of Pofut1 in skeletal muscle that derive from its expression in skeletal myofibers. In this study we compared gene expression profiles between quadriceps muscles in mice where Protein O-fucosyltransferase 1 (Pofut1) was deleted specifically in skeletal myofibers via use of a human skeletal alpha actin Cre transgene (Scre) and a loxP flanked Pofut1 gene (SCreFF) and mice which bore the only the Scre transgene but did not have floxed Pofut1 alleles (SCre++).
Deletion of <i>Pofut1</i> in Mouse Skeletal Myofibers Induces Muscle Aging-Related Phenotypes in <i>cis</i> and in <i>trans</i>.
Age, Specimen part
View SamplesDeregulated intracellular Ca2+ homeostasis underlies synaptic dysfunction and is a common feature in neurodegenerative processes, including Huntington's disease (HD). DREAM/calsenilin/KChIP-3 is a multifunctional Ca2+ binding protein that controls the expression level and/or the activity of several proteins related to Ca2+ homeostasis, neuronal excitability and neuronal survival. We found that expression of endogenous DREAM (DRE antagonist modulator) is reduced in the striatum of R6 mice, in STHdh-Q111/111 knock in striatal neurons and in HD patients. DREAM down regulation in R6 striatum occurs early after birth, well before the onset of motor coordination impairment, and could be part of an endogenous mechanism of neuroprotection, since i) R6/2 mice hemizygous for the DREAM gene (R6/2xDREAM+/-) showed delayed onset of locomotor impairment and prolonged lifespan, ii) motor impairment after chronic administration of 3-NPA was reduced in DREAM knockout mice and enhanced in daDREAM transgenic mice and, iii) lentiviral-mediated DREAM expression in STHdh-Q111/111 knock in cells sensitizes them to oxidative stress. Transcriptomic analysis showed that changes in gene expression in R6/2 striatum were notably reduced in R6/2xDREAM+/- striatum. Chronic administration of repaglinide, a molecule able to bind to DREAM in vitro and to accelerate its clearance in vivo, delayed the onset of motor dysfunction, reduced striatal loss and prolonged the lifespan in R6/2 mice. Furthermore, exposure to repaglinide protected STHdh-Q111/111 knock in striatal neurons sensitized to oxidative stress by lentiviral-mediated DREAM overexpression. Thus, genetic and pharmacological evidences disclose a role for DREAM silencing in early neuroprotective mechanisms in HD.
Activating transcription factor 6 derepression mediates neuroprotection in Huntington disease.
Specimen part
View SamplesHigh resolution transcriptional profiling of H1-derived human neuronal precursor cells over a timecourse of differentiation in vitro. Overall design: Human NPC differentiation timecourse covers Days 0,1,2,4,5,11, and 18 after induction of neuronal differentiation as described in manuscript. Each time point was assayed in triplicate cultures with the exception of Day 5, in which one outlier culture has been removed.
Multiple knockout mouse models reveal lincRNAs are required for life and brain development.
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View SamplesAnalysis of the expression profiles of MCF7 cells transduced with a control shRNA and an TSC2-targeted shRNA (leading to tuberin depletion).
Lymphangioleiomyomatosis Biomarkers Linked to Lung Metastatic Potential and Cell Stemness.
Cell line
View SamplesSadanandam et al. (2013) recently published a study based on the use of microarray data to classify colorectal cancer (CRC) samples. The classification claimed to have strong clinical implications, as reflected in the paper title: A colorectal cancer classification system that associates cellular phenotype and responses to therapy. They defined five subtypes: (i) inflammatory; (ii) goblet-like; (iii) enterocyte; (iv) transit-amplifying; and (v) stem-like. Based on drug sensitivity data from 21 patients, they also reported that the so-called stem-like subtype show differential sensitivity to FOLFIRI. This is the key result in their publication, since it implies a direct relation between the subtype and the choice of CRC therapy (i.e. FOLFIRI response). However, our analyses using the same drug sensitivity data and results from additional patients showed that the CRC classification reported by Sadanandam et al. is not predictive of FOLFIRI response.
Colorectal cancer classification based on gene expression is not associated with FOLFIRI response.
Specimen part
View SamplesLong non-coding RNAs (lncRNAs) comprise a diverse class of transcripts that structurally resemble mRNAs but do not encode proteins. Recent genome-wide studies in human and mouse have annotated lncRNAs expressed in cell lines and adult tissues, but a systematic analysis of lncRNAs expressed during vertebrate embryogenesis has been elusive. To identify lncRNAs with potential functions in vertebrate embryogenesis, we performed a time series of RNA-Seq experiments at eight stages during early zebrafish development. We reconstructed 56,535 high-confidence transcripts in 28,912 loci, recovering the vast majority of expressed RefSeq transcripts, while identifying thousands of novel isoforms and expressed loci. We defined a stringent set of 1,133 non-coding multi-exonic transcripts expressed during embryogenesis. These include long intergenic ncRNAs (lincRNAs), intronic overlapping lncRNAs, exonic antisense overlapping lncRNAs, and precursors for small RNAs (sRNAs). Zebrafish lncRNAs share many of the characteristics of their mammalian counterparts: relatively short length, low exon number, low expression, and conservation levels comparable to introns. Subsets of lncRNAs carry chromatin signatures characteristic of genes with developmental functions. The temporal expression profile of lncRNAs revealed two novel properties: lncRNAs are expressed in narrower time windows than protein-coding genes and are specifically enriched in early-stage embryos. In addition, several lncRNAs show tissue-specific expression and distinct subcellular localization patterns. Integrative computational analyses associated individual lncRNAs with specific pathways and functions, ranging from cell cycle regulation to morphogenesis. Our study provides the first comprehensive identification of lncRNAs in a vertebrate embryo and forms the foundation for future genetic, genomic and evolutionary studies. Overall design: RNA-Seq for 8 zebrafish developmental stages, 2 lanes for each stage (3 for shield).
Ribosome profiling reveals resemblance between long non-coding RNAs and 5' leaders of coding RNAs.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Novel targets of the CbrAB/Crc carbon catabolite control system revealed by transcript abundance in Pseudomonas aeruginosa.
No sample metadata fields
View SamplesWe previously identified the ZTRE in genes involved in zinc homeostasis and showed that it mediates transcriptional repression in response to zinc. We now report that ZNF658 acts at the ZTRE. ZNF658 was identified by MALDI-TOF mass spectrometry of a band excised after EMSA using a ZTRE probe. The protein contains a KRAB domain and 21 zinc fingers. It has similarity with ZAP1 from Saccharomyces cerevisiae, which regulates the response to zinc restriction, including a conserved DNA binding region we show to be functional also in ZNF658. siRNA targeted to ZNF658 abrogated the zinc-induced, ZTRE-dependent reduction in SLC30A5 (ZnT5), SLC30A10 (ZnT10) and CBWD transcripts in human Caco-2 cells and the ability of zinc to repress reporter gene expression from corresponding promoter-reporter constructs. Microarray analysis of the effect of reducing ZNF658 expression by siRNA uncovered large changes in rRNA. We find that ZTREs are clustered within the 45S rRNA precursor. We also saw effects on expression of multiple ribosomal proteins. ZNF658 thus links zinc homeostasis with ribosome biogenesis, the most active transcriptional, and hence zinc-demanding, process in the cell. ZNF658 is thus a novel transcriptional regulator that plays a fundamental role in the orchestrated cellular response to zinc availability.
The zinc finger protein ZNF658 regulates the transcription of genes involved in zinc homeostasis and affects ribosome biogenesis through the zinc transcriptional regulatory element.
Cell line
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