Background The RNA steady-state levels in the cell are a balance between synthesis and degradation rates. Although transcription is important, RNA processing and turnover are also key factors in the regulation of gene expression. In Escherichia coli there are three main exoribonucleases (RNase II, RNase R and PNPase) involved in RNA degradation. Although there are many studies about these exoribonucleases not much is known about their global effect in the transcriptome. Results In order to study the effects of the exoribonucleases on the transcriptome, we sequenced the total RNA (RNA-Seq) from wild-type cells and from mutants for each of the exoribonucleases (?rnb, ?rnr and ?pnp). We compared each of the mutant transcriptome with the wild-type to determine the global effects of the deletion of each exoribonucleases in exponential phase. We determined that the deletion of RNase II significantly affected 187 transcripts, while deletion of RNase R affects 202 transcripts and deletion of PNPase affected 226 transcripts. Surprisingly, many of the transcripts are actually down-regulated in the exoribonuclease mutants when compared to the wild-type control. The results obtained from the transcriptomic analysis pointed to the fact that these enzymes were changing the expression of genes related with flagellum assembly, motility and biofilm formation. The three exoribonucleases affected some stable RNAs, but PNPase was the main exoribonuclease affecting this class of RNAs. We confirmed by qPCR some fold-change values obtained from the RNA-Seq data, we also observed that all the exoribonuclease mutants were significantly less motile than the wild-type cells. Additionally, RNase II and RNase R mutants were shown to produce more biofilm than the wild-type control while the PNPase mutant did not form biofilms. Conclusions In this work we demonstrate how deep sequencing can be used to discover new and relevant functions of the exoribonucleases. We were able to obtain valuable information about the transcripts affected by each of the exoribonucleases and compare the roles of the three enzymes. Our results show that the three exoribonucleases affect cell motility and biofilm formation that are two very important factors for cell survival, especially for pathogenic cells. Overall design: RNA-Seq of E. coli K-12 MG1693 wild-type(wt) and three exoribonucleases mutants was done with Illumina Hi-Seq platform.
PNPase is involved in the coordination of mRNA degradation and expression in stationary phase cells of Escherichia coli.
Cell line, Subject
View SamplesComparison of emphysema vs non emphysema COPD lung tissue expression
Network Analysis of Lung Transcriptomics Reveals a Distinct B-Cell Signature in Emphysema.
Specimen part
View SamplesHuman embryonic stem cells (hESC) display substantial heterogeneity in gene expression, implying the existence of discrete substates within the stem cell compartment. To determine whether these substates impact fate decisions of hESC we used a GFP reporter line to investigate the properties of fractions of putative undifferentiated cells defined by their differential expression of the endoderm transcription factor, GATA6, together with the hESC surface marker, SSEA3. By single cell cloning, we confirmed that substates characterized by expression of GATA6 and SSEA3 include pluripotent stem cells capable of long term self-renewal. When clonal stem cell colonies were formed from GATA6-positive and GATA6-negative cells, more of those derived from GATA6-positive cells contained spontaneously differentiated endoderm cells than similar colonies derived from the GATA6-negative cells. We characterized these discrete cellular states using single cell transcriptomic analysis, identifying a potential role for SOX17 in the establishment of the endoderm biased stem cell state. Overall design: Examination of 4 different cell substates within one human embryonic stem cell line as determine by the expression status of GATA6 and SSEA3
Identification and Single-Cell Functional Characterization of an Endodermally Biased Pluripotent Substate in Human Embryonic Stem Cells.
Specimen part, Subject
View SamplesUsing a mimic miR-200c was restored to an aggressive, Type 2 endometrial cancer cell line, Hec50
MicroRNA-200c mitigates invasiveness and restores sensitivity to microtubule-targeting chemotherapeutic agents.
Specimen part, Cell line
View SamplesCdc34 is an essential E2 ubiquitin conjugating enzyme found in nearly all eukaryotes. It contains a highly conserved motif composed of S73/S97/12 amino acid insert near the active site cysteine. This motif is unique to Cdc34/Ubc7 type E2s while other E2s contain K/D/no insert at these positions. To better understand the function of this motif we mutated Cdc34 S73/S97/insert to be K/D/no insert and observed changes in transcript levels in mid-log phase yeast cells. ABSTRACT [Cdc34 is a ubiquitin conjugating enzyme necessary for the ubiquitylation of substrates by the SCF family of ubiquitin ligases. Previous work has shown that the Cdc34 protein is phosphorylated in vivo on serine residues. Cdc34 contains two serines within its catalytic domain, S73 and S97, that together with a 12 amino acid acidic loop, constitute a highly conserved motif (serine, serine, insert) among all members of the Cdc34 family of E2 enzymes. Using phosphospecific antibodies, we show that the essential serine S97 is indeed phosphorylated in vivo. Furthermore, this phosphorylation event is regulated by treatment with pheromone in yeast. Consistently, expression of a Cdc34 mutant lacking this motif (serine, serine, insert) leads to misregulation of the SCF substrates, Sic1, Far1, Cln1 and Cln2 and suppresses the cell cycle arrest brought about by an activated mating pathway. We further explored the function of this motif by microarray analysis and show that the transcripts of nearly the entire Sic1 cluster of co-transcribed genes is altered in a strain the expresses Cdc34 lacking this motif. Our data reveals that this highly conserved motif in Cdc34 and its phosphorylation are important for modulating SCF substrate abundance both transcriptionally and post-transcriptionally.]
New insight into the role of the Cdc34 ubiquitin-conjugating enzyme in cell cycle regulation via Ace2 and Sic1.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Phenotypic, transcriptomic, and genomic features of clonal plasma cells in light-chain amyloidosis.
Specimen part, Disease
View SamplesImmunoglobulin light-chain amyloidosis (AL) is a rare clonal plasma cell (PC) disorder that remains largely incurable. AL and multiple myeloma (MM) share the same cellular origin, but while knowledge about MM PC biology has improved significantly, the same does not apply for AL. Here, we undertook an integrative phenotypic, molecular, and genomic approach to study clonal PCs from 22 newly-diagnosed AL patients. Through principal-component-analysis, we demonstrated highly overlapping phenotypic profiles between AL and MGUS or MM patients. However, in contrast to MM, highly-purified FACSs-sorted clonal PCs in AL (n=9/22) show virtually normal transcriptomes with only 68 deregulated genes as compared to normal PCs, including a few tumor suppressor (CDH1, RCAN) and pro-apoptotic (GLIPR1, FAS) genes. Notwithstanding, clonal PCs in AL (n=11/22) were genomically unstable with a median of 9 copy-number-abnormities (CNAs) per case; many of which similar to those found in MM. Whole-exome sequencing (WES) was performed in three AL patients and revealed a median of 10 non-recurrent mutations per case. Altogether, we showed that although clonal PCs in AL display phenotypic and CNA profiles similar to MM, their transcriptome is remarkably similar to that of normal PCs. First-ever WES revealed the lack of a unifying mutation in AL
Phenotypic, transcriptomic, and genomic features of clonal plasma cells in light-chain amyloidosis.
Specimen part, Disease
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A dichotomy of gene regulatory associations during the activated B-cell to plasmablast transition.
Specimen part, Cell line, Treatment
View SamplesThe activated B-cell (ABC) to plasmablast transition is the cusp of antibody secreting cell (ASC) differentiation but is incompletely defined. We apply expression time-courses, parsimonious gene correlation network analysis, and ChIP-seq to explore this in human cells. The transition initiates with input signal loss leading within hours from cell growth dominant programs to enhanced proliferation, accompanied from 24h by ER-stress response, secretory optimization and upregulation of ASC features. Clustering of genomic occupancy for ASC transcription factors (TFs) IRF4, BLIMP1 and XBP1 with CTCF and histone marks defines distinct patterns for each factor in plasmablasts. Integrating TF-associated clusters and modular gene expression identifies a dichotomy: XBP1 and IRF4 significantly link to gene modules induced in plasmablasts, but not to modules of repressed genes, while BLIMP1 links to modules of ABC genes repressed in plasmablasts but is not significantly associated with modules induced in plasmablasts. Pharmacological inhibition of the G9A (EHMT2) histone-methytransferase, a BLIMP1 co-factor that catalyzes repressive H3K9me2 marks, leaves functional ASC differentiation intact but de-represses ABC-state genes. Thus, in human plasmablasts IRF4 and XBP1 emerge as the dominant association with ASC gene expression, while BLIMP1 links to repressed modules with particular focus in repression of the B-cell activation state.
A dichotomy of gene regulatory associations during the activated B-cell to plasmablast transition.
Specimen part
View SamplesPolycomb repressive complex 2 (PRC2-EZH2) methylates histone H3 at lysine 27 (H3K27) and is required to maintain gene repression during development. Misregulation of PRC2 is linked to a range of neoplastic malignancies, which is believed to involve methylation of H3K27. However, the full spectrum of non-histone substrates of PRC2 that might also contribute to PRC2 function is not known. We characterized the target recognition specificity of PRC2 and used the resultant data to screen for novel potential targets. The RNA polymerase II (Pol II) transcription factor, Elongin A (EloA), is methylated by PRC2 in vivo. Mutation of the methylated EloA residue decreased repression of many, but not all, PRC2 target genes as measured by both steady state and nascent RNA levels. We propose that PRC2 regulates transcription of a subset of target genes in part via methylation of EloA. Overall design: We examined the transcripitonal profile of EEDnull, EloAnull, EloA mutant, and parental mouse embryonic stem cells by RNAseq. Please note that the .bw processed data file was generated from the *mESC replicate samples together and linked to the corresponding *rep1 sample records.
Polycomb Repressive Complex 2 Methylates Elongin A to Regulate Transcription.
Specimen part, Subject
View Samples