To study the physiological roles of polyamines, we have carried out a global microarray analysis on the effect of adding polyamines to an Escherichia coli mutant that lacks polyamines because of deletions in the genes in the polyamine biosynthetic pathway. Previously, we have reported that the earliest response to the polyamine addition is the increased expression of the genes for the glutamate dependent acid resistance system (GDAR). We also presented preliminary evidence for the involvement of rpoS and gadE regulators. In the current study further confirmation of the regulatory roles of rpoS and gadE is shown by a comparison of genome-wide expression profiling data from a series of microarrays comparing the genes induced by polyamine addition to polyamine-free rpoS+/gadE+ cells with genes induced by polyamine addition to polyamine-free rpoS and gadE cells. The results indicate that most of the genes in the E. coli GDAR system that are induced by polyamines require rpoS and gadE. Our data also show that, gadE is the main regulator of GDAR and other acid-fitness-island genes. Both polyamines and rpoS are necessary for the expression of gadE genes from the three promoters of gadE (P1, P2 and P3). The most important effect of polyamine addition is the very rapid post-transcriptional increase in the level of RpoS sigma factor. Our current hypothesis is that polyamines increase the level of RpoS protein, and that this increased RpoS level is responsible for the stimulation of gadE expression, which in turn induces the GDAR system in E. coli.
Polyamines Stimulate the Level of the σ38 Subunit (RpoS) of Escherichia coli RNA Polymerase, Resulting in the Induction of the Glutamate Decarboxylase-dependent Acid Response System via the gadE Regulon.
Treatment
View SamplesSingle O-GlcNAc modification orchestrate by O-GlcNAc Transferase (OGT) and O-GlcNAcase (OGA alias MGEA5) enzymes, affects signal transduction and gene expression by chromatin modulation. We developed Oga deleted MEF (mouse embryonic fibroblast) cells to investigate effects of O-GlcNAc modification in mice. RNA isolated from Mouse Embryonic Fibroblast cells generated from Oga Knock out (KO) Heterozygous (Het) and wild type (WT) cells and subjected to microarray analysis.
Conditional knock-out reveals a requirement for O-linked N-Acetylglucosaminase (O-GlcNAcase) in metabolic homeostasis.
Sex, Specimen part
View SamplesHepatitis C virus (HCV) infection induces interferon stimulated genes (ISGs) and downstream innate immune responses. This study investigated whether baseline and on-treatment differences in these responses predict response versus virological breakthrough during therapy with direct acting antivirals (DAA).
Baseline Intrahepatic and Peripheral Innate Immunity are Associated with Hepatitis C Virus Clearance During Direct-Acting Antiviral Therapy.
Sex, Age, Specimen part, Disease, Disease stage, Treatment, Race, Subject
View SamplesMedulloblastoma is the most common form of malignant paediatric brain tumour and is the leading cause of childhood cancer related mortality. The four molecular subgroups of medulloblastoma that have been identified WNT, SHH, Group 3 and Group 4 - have molecular and topographical characteristics suggestive of different cells of origin. Definitive identification of the cell(s) of origin of the medulloblastoma subgroups, particularly the poorer prognosis Group 3 and Group 4 medulloblastoma, is critical to understand the pathogenesis of the disease, and ultimately for the development of more effective treatment options.
Gene expression analyses of the spatio-temporal relationships of human medulloblastoma subgroups during early human neurogenesis.
Sex, Age
View SamplesWe compared the gene expression profile from a group of children with T-cell acute lymphoblastic leukamia who remained in continuous complete remission (CCR) (n = 7) with that from a group who relapsed (n = 5), using Affymetrix HG-U133A arrays. Using the decision-tree based supervised learning algorithm Random Forest (RF), genes were ranked with respect to their ability to discriminate between patients who remained in CCR and those who relapsed. From the 300 top-ranked probe sets 9 genes were selected for further investigation and validation in an independent cohort of 25 T-ALL patients using quantitative real time polymerase chain reaction.
Identification of novel molecular prognostic markers for paediatric T-cell acute lymphoblastic leukaemia.
Sex, Age, Specimen part, Disease, Subject
View SamplesWe evaluated changes in mRNA stability and transcription using 4sU metabolic pulse labeling across a four hour time course following activation of Jurkat T cells with PMA and PHA Overall design: Measurement of total mRNA (T) and 4sU labeled mRNA (IP) in three biological replicates at five time points: prior to activation (U) and the first four hours after activation (1-4)
Functional coordination and HuR-mediated regulation of mRNA stability during T cell activation.
No sample metadata fields
View SamplesTo identify transcriptional markers for beef traits related to meat tenderness and moisture, we measured the transcriptome of the Longissimus dorsi skeletal muscle in 10 Korean native cattle (KNC). We analyzed the correlation between the beef transcriptome and measurements of four different beef traits, shear force (SF), water holding capacity (WHC), cooking loss (CL), and loin eye area (LEA). We obtained non-overlapping and unique panels of genes showing strong correlations (|r| > 0.8) with SF, WHC, CL, and LEA, respectively. Functional studies of these genes indicated that SF was mainly related to energy metabolism, and LEA to rRNA processing. Interestingly, our data suggested that WHC is influenced by protein metabolism. Overall, the skeletal muscle transcriptome pointed to the importance of energy and protein metabolism in determining meat quality after the aging process. The panels of transcripts for beef traits may be useful for predicting meat tenderness and moisture.
Characterization of beef transcripts correlated with tenderness and moisture.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Combinatorial ETS1-dependent control of oncogenic NOTCH1 enhancers in T-cell leukemia.
Sex, Specimen part, Disease, Cell line
View SamplesTo formally address the biological activity of ETS1 in vitro, we measured the transcriptional effect of ETS1 knock down by transducing HPB-ALL leukemia cell lines with a plKO - shETS1 and plko shLUC control. Samples were hybridized to Affymetrix Human Genome U133 Plus 2.0 arrays. Log2 abundance estimates were obtained using gcrma package of Bioconductor, which is a version of the Robust Multi-Array Average (RMA) algorithm. We provide a supplementary file with gene annotation, which performs a two-sample T-test and computes an average fold-change.
Combinatorial ETS1-dependent control of oncogenic NOTCH1 enhancers in T-cell leukemia.
Sex, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Dominant negative PPARγ promotes atherosclerosis, vascular dysfunction, and hypertension through distinct effects in endothelium and vascular muscle.
Specimen part
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