Promoter recognition by bacterial RNA polymerase is mediated by subunits, which assemble transiently to RNA polymerase core enzyme (E) during transcription initiation. subunits drive transcription of specific sets of genes by allowing RNA polymerase to interact with different promoter sequences. However, 70, the housekeeping subunit, and S, an alternative subunit mainly active during slow growth and in response to cellular stresses, appear to recognize almost identical promoter sequences, raising the question of how promoter selectivity is achieved in the bacterial cell. To identify sequence determinants for selective promoter recognition, we performed a run-off/microarray experiment (ROMA): in vitro transcription experiments were carried out with RNA polymerase saturated either with 70 (E70) or with S (ES) using the whole Escherichia coli genome as DNA template, and transcript levels were determined by microarray analysis. We found that several genes associated with bacterial growth (e.g., ribosomal operons) were transcribed more efficiently by E70. In contrast, ES transcribed preferentially genes involved in stress responses, secondary metabolism, as well as regulatory RNAs and intergenic regions with yet unknown function. Genes preferentially recognized in vitro by ES showed reduced expression in ES -deficient mutant strain of E. coli. Sequence comparison of E70- versus ES dependent promoters confirms that the presence of a -35 sequence and the relative location of UP elements affect promoter interaction with either form of RNA polymerase, and suggests that a G/C bias in the -2/+1 nucleotides would favour efficient promoter recognition by E70.
In vitro transcription profiling of the σS subunit of bacterial RNA polymerase: re-definition of the σS regulon and identification of σS-specific promoter sequence elements.
Disease
View SamplesAkt1, a serine-threonine protein kinase member of the PKB/Akt gene family, plays a critical role in the regulation of several cellular processes including cell proliferation and apoptosis. In this study, we utilized Akt1+/+ and Akt1-/- C57/Bl6 female mice to demonstrate that Akt1 is required for normal mammary gland postnatal development and homeostasis. Akt1 deficiency resulted in severely delayed postnatal mammary gland growth as well as a significant decrease in the number of terminal end buds during puberty. Adult Akt1-/- mammary glands exhibited significantly fewer alveolar buds coupled with a significant increase in epithelial cell apoptosis compared to their wild-type counterparts. Microarray analysis revealed that Akt1 deficiency resulted in several altered gene expression changes and biological processes in adult mammary glands, including organismal development, cell death, and tissue morphology. Of particular importance, a significant decrease in expression of Btn1a1, a gene involved in milk lipid secretion, was observed in Akt1-/- mammary glands by both microarray and RT-PCR validation.
Akt1 is essential for postnatal mammary gland development, function, and the expression of Btn1a1.
Sex
View SamplesWe sequenced mRNA extracted from heads of a D. melanogaster population that was sedated with a stream of ethanol saturated vapor, 30 minutes before RNA extraction; and from an age-matched untreated control group. Differential gene expression between the two groups was calculated and reported. Overall design: Examination of mRNA levels in heads of D. melanogaster adult females after ethanol exposure was performed using next generation sequencing (NGS) technology.
Alcohol resistance in Drosophila is modulated by the Toll innate immune pathway.
Cell line, Treatment, Subject
View SamplesDifferences between groups of children with obesity and healthy controls.
Looking for new diagnostic tools and biomarkers of hypertension in obese pediatric patients.
Specimen part, Disease
View SamplesBroilers were immunized with three variants of subunit vaccines, based on the hemagglutinin (HA) DNA and Pichia-produced HA protein from H5N1 virus, in comparison to the control group, which was administered an empty vector (pCI). Gene expression changes in the spleens of chickens were investigated at 7 day post booster dose.
Transcriptional response to a prime/boost vaccination of chickens with three vaccine variants based on HA DNA and Pichia-produced HA protein.
Specimen part, Treatment
View SamplesIn our studies we were searching for the new factors engaged in mitochondrial nucleic acids metabolism under stress conditions in humans. Quantitative proteomic approach revealed C6orf203 protein as a potential new factor engaged in response to perturbed mitochondrial gene expression. We showed that C6orf203 is a mitochondrial RNA binding protein which is able to rescue diminished mitochondrial transcription in stress conditions. Overall design: The dataset corresponds to RNAseq studies and comprises experiment performed in triplicate. The aim of this study was to examine the influence of C6orf203 silencing on mitochondrial transcriptome. To this end we engineered two stable cell lines with the use of human 293 Flp-In T-Rex cells as parental. First cell line inducible expressed miRNAs silencing endogenous copy of C6orf203 gene while second one expressed additionally transgenic version of FLAG-tagged C6orf203 which contained silent mutations causing insensitivity to miRNA. We also analyzed RNA isolated from parental 293 Flp-In T-Rex cells. RNAseq libraries were prepared with the use of strand-specific library preparation procedures. RNAs were random fragmented and reverse transcribed using random oligomers as primers (dUTP-based protocol, see PMID: 29590189, PMID: 22609201; this pipeline enables analysis of RNAs (> ~100 nucleotides)). RNA was isolated from unfractionated cells using TRI-Reagent. Before preparation of the libraries total RNA was subjected to depletion of nuclear-encoded rRNAs (Ribo-Zero rRNA Removal Kit (Human/Mouse/Rat), Epicenter). Libraries were sequenced with the help of Illumina sequencing platform.
Quantitative proteomics revealed C6orf203/MTRES1 as a factor preventing stress-induced transcription deficiency in human mitochondria.
Specimen part, Subject
View SamplesMicroarray was used to identify differential gene expression pattern in Barrett's esophagus (BE), compared to the normal adjacent epithelia gastric cardia (GC) and normal squamous esophagus (NE)
Evidence for a functional role of epigenetically regulated midcluster HOXB genes in the development of Barrett esophagus.
Specimen part
View SamplesA multi-subunit exosome complex is a major eukaryotic exoribonuclease that in the cytoplasm requires the SKI complex for activity. In yeast, SKI forms a heterotetramer and delivers RNA substrates directly into the exosome channel. Such cooperation requires Ski7 protein, which links the exosome and SKI complexes. However, since the human genome does not encode an orthologue of the yeast Ski7, the factor mediating SKI and exosome linkage in human cells is unknown. Proteomic analysis revealed that the human cytoplasmic exosome interacts with HBS1LV3, a protein encoded by a newly discovered short splicing isoform of HBS1L. HBS1LV3 recruits the SKI complex to the exosome. In contrast, the canonical HBS1L variant, HBS1LV1, acting as a ribosome dissociation factor, does not associate with the exosome and instead interacts with the mRNA surveillance factor PELOTA. HBS1LV3 contains a new domain of unknown structure with the short linear motif RxxxFxxxL, which is responsible for exosome binding, and may interact with the exosome core subunit RRP43 in way that resembles the association between Rrp6 RNase and Rrp43 in yeast. Depletion of HBS1LV3 and the SKI complex helicase SKI2W similarly affected the transcriptome by strongly upregulating a large number of genes. Moreover, following HBS1LV3 or SKI2W depletion the half-lives of representative upregulated mRNAs were increased, thus supporting the involvement of HBS1LV3 and SKI2W in the same mRNA degradation pathway. In contrast, HBS1LV1 depletion had little effect on transcriptome homeostasis. Our data indicate that human HBS1LV3 is the long-sought factor that links the exosome and SKI complexes to regulate cytoplasmic mRNA decay. Overall design: Examination of siRNA-mediated silencing in HEK293 cell lines. To identify transcripts that are degraded by cytoplasmic SKI/HBS1LV3/exosome supercomplexes, we used specific siRNAs to knock down HBS1LV1, HBS1LV3 or SKIV2L gene expression in (i) WT HEK293 cells and (ii) HEK293 cells rescued with siRNA insensitive protein. Analyses were performed in triplicate.
A short splicing isoform of HBS1L links the cytoplasmic exosome and SKI complexes in humans.
No sample metadata fields
View SamplesA prospective study was conducted in the Neonatal Intensive Care Unit of the University Children's hospital between September 1, 2008 and November 30, 2010. The entry criteria were (1) preterm birth below 32 weeks gestational age, (2) birthweight<1500g (VLBW). During the follow-up period, bronchopulmonary dysplasia (BPD) was diagnosed in 68 (61%) infants, including 40 (36%) children with mild disease, 13 (12%) with moderate and 15 (13%) with severe BPD. Forty-three babies served as a control group (no BPD).
Gene expression profiling in preterm infants: new aspects of bronchopulmonary dysplasia development.
Sex, Specimen part
View SamplesDifferencies between groups between pre and post haematopoietic stem cell transplantation children
Genetic Background of Immune Complications after Allogeneic Hematopoietic Stem Cell Transplantation in Children.
Specimen part, Disease stage
View Samples