Perturbation of mRNP biogenesis reveals a dynamic landscape of the Rrp6-dependent surveillance machinery trafficking along the yeast genome (ChIP-seq dataset)
ABSTRACT: In order to dissect the nuclear RNA quality control (QC) mechanisms, we used a powerful assay based on global perturbation of mRNP biogenesis in yeast Saccharomyces cerevisiae by the bacterial Rho helicase. We have monitored the global RNA levels upon Rho activation and compare it to basal RNA level in WT strain, which have revealed down-regulated transcripts. Then, the same experiment was performed but in a strain lacking Rrp47, giving us a precise overview of the QC targets (crosslinked dataset). We also followed some QC components (Nrd1, Nab3, Trf4 and Rrp6) along the yeast chromosomes by ChIP-seq before (NI) and after (I) perturbation of mRNP biogenesis by Rho.
Project description:In order to dissect the nuclear RNA quality control (QC) mechanisms, we used a powerful assay based on global perturbation of mRNP biogenesis in yeast Saccharomyces cerevisiae by the bacterial Rho helicase. We have monitored the global RNA levels upon Rho activation and compare it to basal RNA level in WT strain, which have revealed down-regulated transcripts. Then, the same experiment was performed but in a strain lacking Rrp47, giving us a precise overview of the QC targets. We also followed some QC components (Nrd1, Nab3, Trf4 and Rrp6) along the yeast chromosomes by ChIP-seq before and after perturbation of mRNP biogenesis by Rho (crosslinked dataset).
Project description:Biogenesis of eukaryotic messenger ribonucleoprotein complexes (mRNPs) involves the synthesis, splicing, and 3’-processing of pre-mRNA, and the assembly of mature mRNPs for nuclear export. We mapped 23 mRNP biogenesis factors onto the newly synthesized yeast transcriptome, providing ~10^5-10^6 high-confidence RNA interaction sites per factor. PAR-CLIP data of 23 mRNP biogenesis factors in Saccharomyces cerevisiae
Project description:The Microprocessor plays an essential role in canonical miRNA biogenesis by facilitating cleavage of stem-loop structures in primary transcripts to yield pre-miRNAs. Although miRNA biogenesis has been extensively studied through biochemical and molecular genetic approaches, it has yet to be addressed to what extent the current miRNA biogenesis models hold true in intact cells. To address the issues of in vivo recognition and cleavage by the Microprocessor, we investigate RNAs that are associated with DGCR8 and Drosha by using immunoprecipitation coupled with next-generation sequencing. Here, we present global protein-RNA interactions with unprecedented sensitivity and specificity. Our data indicate that precursors of canonical miRNAs and miRNA-like hairpins are the major substrates of the Microprocessor. As a result of specific enrichment of nascent cleavage products, we are able to pinpoint the Microprocessor-mediated cleavage sites per se at single-nucleotide resolution. Unexpectedly, a 2-nt 3’ overhang invariably exists at the ends of cleaved bases instead of nascent pre-miRNAs. Besides canonical miRNA precursors, we find that two novel miRNA-like structures embedded in mRNAs are cleaved to yield pre-miRNA-like hairpins, uncoupled from miRNA maturation. Our data provide a framework for in vivo Microprocessor-mediated cleavage and a foundation for experimental and computational studies on miRNA biogenesis in living cells. CLIP-seq for DGCR8 and Drosha, RIP-seq for DGCR8, sequencing of AGO2-assocated miRNA
Project description:Despite the prevalence of antisense transcripts in bacterial transcriptomes, little is known about how their synthesis is controlled. We report that a major function of the Escherichia coli termination factor Rho and its co-factor NusG is suppression of ubiquitous antisense transcription genome-wide. Rho binds C-rich unstructured nascent RNA (high C/G ratio) prior to its ATP-dependent dissociation of transcription complexes. NusG is required for efficient termination at minority subsets (~20%) of both antisense and sense Rho-dependent terminators with lower C/G ratio sequences. In contrast, a widely studied nusA deletion proposed to compromise Rho-dependent termination had no effect on antisense or sense Rho-dependent terminators in vivo. Global co-localization of the nucleoid-associated protein H-NS with Rho-dependent terminators and genetic interactions between hns and rho suggest that H-NS aids Rho in suppression of antisense transcription. The combined actions of Rho, NusG, and H-NS appear to be analogous to the Sen1-Nrd1-Nab3 and nucleosome systems that suppress antisense transcription in eukaryotes. Chromatin immunoprecipitation (ChIP) experiments were performed using antibodies against RNA polymerase (RNAP; Beta subunit) in wild-type cells or cells deleted for hns, nusG, or a partial deletion of nusA. Differentially labeled ChIP DNA and genomic DNA were competitively hybridized to an E. coli K-12 MG1655 tiling array with overlapping probes at ~12bp spacing across the entire genome. The series contains 12 datasets.
Project description:Under continuous, glucose-limited conditions, budding yeast exhibit robust metabolic cycles associated with major oscillations of gene expression and metabolic state. However, how such fluctuations might be coordinately linked to changes in chromatin status is less well understood. Here, we examine the correlated genome-wide transcription and chromatin states across the yeast metabolic cycle (YMC) at unprecedented temporal resolution, revealing a "just in time supply chain" by which specific cellular processes such as ribosome biogenesis are coordinated in time with remarkable precision. We identify distinct chromatin and splicing patterns associated with different gene categories and determine the relative timing of chromatin modifications to maximal transcription. Additionally, we interrogate chromatin modifier occupancy and observe subtly distinct spatial and temporal patterns compared to the modifications themselves. Furthermore, we identify multiple lysine mutants in H3 or H4 tails that disrupt metabolic cycling, supporting a potentially cooperative role of histone modifications in the YMC. 16 time points RNA-seq and ChIP-seq of 8 histone marks over one metabolic cycle, 14 time points ChIP-seq of 3 chromatin modifiers over one metabolic cycle
Project description:This SuperSeries is composed of the following subset Series: GSE41936: Rho and NusG suppress pervasive antisense transcription in Escherichia coli [ChIP-chip]. GSE41938: Rho and NusG suppress pervasive antisense transcription in Escherichia coli [tiling array]. GSE41939: Rho and NusG suppress pervasive antisense transcription in Escherichia coli [RNA-seq]. Refer to individual Series
Project description:The transcription termination factor Rho is a global regulator of RNA polymerase (RNAP). Although individual Rho-dependent terminators have been studied extensively, less is known about the sites of RNAP regulation by Rho on a genome-wide scale. Using chromatin immunoprecipitation and microarrays (ChIP-chip), we examined changes in the distribution of Escherichia coli RNAP in response to the Rho-specific inhibitor bicyclomycin (BCM). We found ~200 Rho-terminated loci that were divided evenly into two classes: intergenic (at the ends of genes) and intragenic (within genes). The intergenic class contained noncoding RNAs such as small RNAs (sRNAs) and transfer RNAs (tRNAs), establishing a previously unappreciated role of Rho in termination of stable RNA synthesis. The intragenic class of terminators included a novel set of short antisense transcripts, as judged by a shift in the distribution of RNAP in BCM-treated cells that was opposite to the direction of the corresponding gene. These Rho-terminated antisense transcripts point to a novel role of noncoding transcription in E. coli gene regulation that may resemble the ubiquitous noncoding transcription recently found to play myriad roles in eukaryotic gene regulation. Chromatin immunoprecipitation (ChIP) experiments were performed using antibodies against RNA polymerase (Beta or Beta' subunit) in cells treated with 20ug/ml bicyclomycin or untreated cells. Differentially labeled ChIP DNA and genomic DNA were competitively hybridized to an E. coli K-12 MG1655 tiling array with overlapping probes at ~12bp spacing across the entire genome. The series contains 4 datasets.
Project description:The in vivo trafficking patterns on DNA by the bacterial regulators of transcript elongation Sigma70, Rho, NusA, and NusG and the explanation for high promoter-proximal levels or peaks of RNA polymerase (RNAP) are unknown. Genome-wide ChIP-chip on E. coli revealed distinct association patterns of regulators as RNAP transcribes away from promoters (Rho first, then NusA, and then NusG). However, the interactions of elongating complexes with these regulators, including a weak interaction with Sigma70, did not differ significantly among most transcription units. A modest variation of NusG signal among genes reflected increased NusG interaction as transcription progresses, rather than functional specialization of elongating complexes. Promoter-proximal RNAP peaks were offset from Sigma70 peaks in the direction of transcription and co-occurred with NusA and Rho peaks, suggesting that the RNAP peaks reflected elongating, rather than initiating, complexes. However, inhibition of Rho did not increase RNAP levels within genes downstream of the RNAP peaks, suggesting the peaks are caused by a mechanism other than simple Rho-dependent attenuation. Chromatin immunoprecipitation (ChIP) experiments were performed using antibodies against RNA polymerase (Beta' subunit), Sigma70, NusA, NusG, or Rho. Differentially labeled ChIP DNA and genomic DNA were competitively hybridized to an E. coli K-12 MG1655 tiling array with overlapping probes at ~24bp spacing across the entire genome. The series contains 17 total datasets.
Project description:Translational regulation can be studied on a global scale by integrating polysome fractionation of mRNAs with microarray hybridization. This approach is based on the fact that translationally quiescent mRNAs are sequestered within messenger ribonucleoprotein (mRNP) particles or associated with single ribosomes (monosomes), whereas actively translated mRNAs are associated with multiple ribosomes (polysomes). The mRNAs associated within these fractions are then used to interrogate microarrays, providing insight into how the translational state of individual mRNAs is modified by environmental cues. In this study, we coupled polysome fractionation with microarray detection in order to identify changes in the translation state of the A. fumigatus transcriptome under conditions that perturb ER homeostasis such as chemical stress (DTT, tunicamycin) or thermal stress (shift from 25 degrees celsius to 37 degrees celsius).
Project description:Function and fate of mRNAs is controlled by RNA binding proteins (RBPs) but determining the proteome of a specific mRNA in vivo is still challenging. RNA proximity biotinylation on the transported β-actin mRNA tagged with MS2 aptamers (RNA-BioID) is used to characterize the dynamic proteome of the β-actin mRNP in mouse embryonic fibroblasts (MEFs). We have identified > 60 β-actin associated RBPs including all six previously known as well as novel interactors. By investigating the dynamics of the β-actin mRNP in MEFs, we expand the set of β-actin mRNA associated RBPs and characterize the changes of the interacting proteome upon serum-induced mRNA localization. We report that the KH-domain containing protein FUBP3 represents a new β-actin associated RBP that binds to its 3’-untranslated region outside the known RNA localization element but is required for β-actin RNA localization. RNA-BioID will allow to obtain a dynamic view on the composition of endogenous mRNPs.