We report that in developing B cells individual enhancers of Igk make up super-enhancer cluster where contacts between its components rely on all constituents. Reduction of interaction frequency in enhancer knock-out cells is associated with deminished transcriptional output of enhancers and Igk locus. Moreover, we find that Igk enhancer MiEk has an effect on levels of CBFb enrichment on Tcrb enhancer, Eb afffecting Tcrb recombination and T cell development. Overall design: Examination of expression, chromatin accessibility, histone modifications and nuclear organization in developing wild-type and Igk and Tcrb enhancer deficient B and T lymphocytes.
Active and Inactive Enhancers Cooperate to Exert Localized and Long-Range Control of Gene Regulation.
Specimen part, Cell line, Subject
View SamplesTranscription termination and mRNA export from the nucleus are closely regulated and coordinated processes. Nuclear export factors are recruited to actively transcribed genes through their interactions with protein complexes associated with transcription and co-transcriptional pre-mRNA processing. We determine a new role for the kinase WNK1 in the cross-talk of transcription termination and mRNA export. WNK1 was previously attributed a cytoplasmic role as a regulator of ion transport. However, we now show a nuclear function for this kinase where it is required for efficient mRNA export along with the transcription termination factor PCF11. Finally, we identify the phosphorylation of the CID domain of PCF11 as an important step for the release of the mRNA from the transcription locus, thus allowing efficient mRNA export to the cytoplasm. Overall design: RNA from cytoplasmic and nuclear extracts of HeLa cells was obtained, upon depletion of WNK1 kinase or from control cells. Upon pA selection, libraries were generated and sequenced. A duplicate experiment was performed for each sample.
WNK1 kinase and the termination factor PCF11 connect nuclear mRNA export with transcription.
Cell line, Subject
View SamplesMicroRNA (miRNA) play a major role in the post-transcriptional regulation of gene expression. In mammals most miRNA derive from the introns of protein coding genes where they exist as hairpin structures in the primary gene transcript, synthesized by RNA polymerase II (Pol II). These are cleaved co-transcriptionally by the Microprocessor complex, comprising DGCR8 and the RNase III endonuclease Drosha, to release the precursor (pre-)miRNA hairpin, so generating both miRNA and spliced messenger RNA1-4. However, a substantial minority of miRNA originate from Pol II-synthesized long non coding (lnc) RNA where transcript processing is largely uncharacterized5. Here, we show that most lnc-pri-miRNA do not use the canonical cleavage and polyadenylation (CPA) transcription termination pathway6, but instead use Microprocessor cleavage both to release pre-miRNA and terminate transcription. We present a detailed characterization of one such lnc-pri-miRNA that generates the highly expressed liver-specific miR-1227. Genome-wide analysis then reveals that Microprocessor-mediated transcription termination is commonly used by lnc-pri-miRNA but not by protein coding miRNA genes. This identifies a fundamental difference between lncRNA and pre-mRNA processing. Remarkably, inactivation of the Microprocessor can lead to extensive transcriptional readthrough of lnc-pri-miRNA, resulting in inhibition of downstream genes by transcriptional interference. Consequently we define a novel RNase III-mediated, polyadenylation-independent mechanism of Pol II transcription termination in mammalian cells. Overall design: Chromatin associated RNA-seq from sicntrl,siDrosha,siDGCR8 treated Hela cells. Same for sicntrl and siDGCR8 from Huh7 cells. Nuclear polyA + and polyA- RNA-seq from sicntrl and siDGCR8 in HeLa cells. Chromatin associated RNA-seq from siDicer treated Hela cells.
Microprocessor mediates transcriptional termination of long noncoding RNA transcripts hosting microRNAs.
No sample metadata fields
View SamplesNumerous long intervening non-coding RNA (lincRNA) are generated from the mammalian genome by RNA polymerase II (Pol II) transcription. Although multiple functions have been ascribed to lincRNA, their synthesis and turnover remain poorly characterised. Here we define systematic differences in transcription and RNA processing between protein-coding and lincRNA genes in human HeLa cells. This is based on a range of nascent transcriptomic approaches applied to different nuclear fractions, including mammalian native elongating transcript sequencing (mNET-seq). Notably mNET-seq patterns specific for different Pol II CTD phosphorylation states reveal weak co-transcriptional splicing and poly(A) signal independent Pol II termination on lincRNA as compared to pre-mRNA. In addition, lincRNA are mostly restricted to chromatin where they are co-transcriptionally degraded by the RNA exosome. We also show that a lincRNA specific co-transcriptional RNA cleavage mechanism acts to induce premature termination. In effect functional lincRNA must escape from this targeted nuclear surveillance process. Overall design: We employed CTD phospho specific mNET-Seq with pla-B splicing inhibitor and RNA processing factors knockdown (DGCR8, Dicer1, EXOSC3 and CPSF73 proteins). mNET-seq experiments with 1% Empigen detergent treatment were performed to separate Pol II-associated complex from Pol II. We also analyzed subcellur RNA and pA+ and pA- nucleoplasm RNA libraries for RNA processing efficiency and the turnover. There are 4 raw files come from an illumina experiment (per sample), produced in 2 lanes. They were all mapped together.
Distinctive Patterns of Transcription and RNA Processing for Human lincRNAs.
Cell line, Subject
View SamplesThe Drosha-DGCR8 complex (Microprocessor) is required for microRNA (miRNA) biogenesis. DGCR8 contains two double-stranded RNA binding motifs that recognize the RNA substrate, whereas Drosha functions as the endonuclease. We have used high-throughput sequencing of RNAs isolated by crosslinking immunoprecipitation (HITS-CLIP) to identify endogenous RNA targets of DGCR8 in mammalian cells. Unexpectedly, miRNAs were not the most abundant targets. DGCR8-bound RNAs comprised several hundred mRNAs as well as snoRNAs and long non-coding RNAs. We found that DGCR8 together with Drosha controls the abundance of several mRNAs, as well as long non-coding RNAs, such as MALAT-1. By contrast, the DGCR8-mediated cleavage of snoRNAs is independent of Drosha, suggesting the involvement of DGCR8 in cellular complexes with other endonucleases. Interestingly, binding of DGCR8 to cassette exons, acts as a novel mechanism to regulate the relative abundance of alternatively spliced isoforms. Collectively, these data provide new insights in the complex role of DGCR8 in controlling the fate of several classes of RNAs. Overall design: Comparison of RNAs associated to both endogenous (D8) and overexpressed (T7) DGCR8 in HEK293T cells
Drosha regulates gene expression independently of RNA cleavage function.
Cell line, Subject
View SamplesDuring S-phase of the cell cycle production of the core histone proteins is precisely balanced with DNA replication. Metazoan mRNAs encoding replication dependent (RD) histones lack polyA tail normally formed by 3' end cleavage and coupled polyadenylation of the pre-mRNA. Instead, they undergoes to endonucleolytic cleavage on the 3' side of an RNA hairpin (stem loop) producing mRNA with a 3´-stem loop (SL), which is exported from the nucleus for use in translation. The same endonuclease that is involved in normal protein-coding pre-mRNA cleavage, i.e. cleavage and poyladenylation specificity factor 73 (CPSF73), is proposed to catalyse RD pre-histone mRNA cleavage. Additional factors specific to RD pre-histone mRNA processing, including stem loop binding protein (SLBP) and the U7 small nuclear ribonucleoprotein (U7snRNP) that binds to a histone downstream element (HDE) are thought to be involved in CPSF73 targeting to RD pre-histone mRNA. We report that a different histone specific endonuclease (HSE), which like CPSF73 is a metallo ß lactamase (MBL) fold protein, is specific for RD pre-histone mRNA cleavage10,11. Crystallographic and biochemical studies reveal HSE has a di-zinc ion containing active site related to that of CPSF73, but which has distinct overall fold. Notably HSE depletion from cells leads to the production of unprocessed RD pre-histone mRNA due to inefficient 3' end processing. The consequent depletion of core histone proteins correlates with a cell cycle defect due to a delay in entering/progressing through S-phase. HSE thus may represent a new type of S-phase specific cancer target. Overall design: Examination of chromatin mRNA profiles in HeLa cells after depletion of HSE or CPSF73 by siRNA treatment.
Biosynthesis of histone messenger RNA employs a specific 3' end endonuclease.
Specimen part, Subject
View SamplesThe pervasive nature of RNA polymerase II (Pol II) transcription requires efficient termination. A key player in this process is the cleavage and polyadenylation (CPA) factor PCF11, which directly binds to the Pol II C-terminal domain and dismantles elongating Pol II from DNA in vitro. We demonstrate that PCF11-mediated termination is essential for vertebrate development. A range of genomic analyses, including: mNET-seq, 3' mRNA-seq, chromatin RNA-seq and ChIP-seq, reveals that PCF11 enhances transcription termination and stimulates early polyadenylation genome-wide. PCF11 binds preferentially between closely spaced genes, where it prevents transcriptional interference and downstream gene silencing. Notably, PCF11 is sub-stoichiometric to the CPA complex. Low levels of PCF11 are maintained by an auto-regulatory mechanism involving premature termination of its own transcript, and are important for normal development. Both in human cell culture and during zebrafish development, PCF11 selectively attenuates the expression of other transcriptional regulators by premature CPA and termination. Overall design: Semi-nascent transcriptome measured by chromatin-bound RNA-seq in HeLa cells. Control and PCF11 knock-down (2 biological replicates) and control and PCF11 PAS1 deletion (4 biological replicates).
Selective Roles of Vertebrate PCF11 in Premature and Full-Length Transcript Termination.
Specimen part, Subject
View SamplesThe pervasive nature of RNA polymerase II (Pol II) transcription requires efficient termination. A key player in this process is the cleavage and polyadenylation (CPA) factor PCF11, which directly binds to the Pol II C-terminal domain and dismantles elongating Pol II from DNA in vitro. We demonstrate that PCF11-mediated termination is essential for vertebrate development. A range of genomic analyses, including: mNET-seq, 3' mRNA-seq, chromatin RNA-seq and ChIP-seq, reveals that PCF11 enhances transcription termination and stimulates early polyadenylation genome-wide. PCF11 binds preferentially between closely spaced genes, where it prevents transcriptional interference and downstream gene silencing. Notably, PCF11 is sub-stoichiometric to the CPA complex. Low levels of PCF11 are maintained by an auto-regulatory mechanism involving premature termination of its own transcript, and are important for normal development. Both in human cell culture and during zebrafish development, PCF11 selectively attenuates the expression of other transcriptional regulators by premature CPA and termination. Overall design: 3' mRNA-seq in individual zebrafish embryo heads. Two types of mutants: zPCF11 null and zPCF11 with deletion of PAS1. Wild-type (wt, +/+), heterozygous (het, +/-) and homozygous mutant (hom, -/-) embryos were analyzed. Wild-type and heterozygous animals were phenotypically indistinguishable.
Selective Roles of Vertebrate PCF11 in Premature and Full-Length Transcript Termination.
Subject
View SamplesThe pervasive nature of RNA polymerase II (Pol II) transcription requires efficient termination. A key player in this process is the cleavage and polyadenylation (CPA) factor PCF11, which directly binds to the Pol II C-terminal domain and dismantles elongating Pol II from DNA in vitro. We demonstrate that PCF11-mediated termination is essential for vertebrate development. A range of genomic analyses, including: mNET-seq, 3' mRNA-seq, chromatin RNA-seq and ChIP-seq, reveals that PCF11 enhances transcription termination and stimulates early polyadenylation genome-wide. PCF11 binds preferentially between closely spaced genes, where it prevents transcriptional interference and downstream gene silencing. Notably, PCF11 is sub-stoichiometric to the CPA complex. Low levels of PCF11 are maintained by an auto-regulatory mechanism involving premature termination of its own transcript, and are important for normal development. Both in human cell culture and during zebrafish development, PCF11 selectively attenuates the expression of other transcriptional regulators by premature CPA and termination. Overall design: 3' mRNA-seq in HeLa cells. Control and PCF11 knock-down (4 biological replicates); control and PCF11 PAS1 deletion clones muA and muB (3 biological replicates); control and additional PCF11 PAS1 deletion clones muC and muD (1 replicate).
Selective Roles of Vertebrate PCF11 in Premature and Full-Length Transcript Termination.
Subject
View SamplesThis study was performed to test the hypothesis that cigarette smoke extract would alter the responses of primary cultures of human bronchial epithelial cells to infection with purified human rhinovirus 16.
Cigarette smoke modulates expression of human rhinovirus-induced airway epithelial host defense genes.
Specimen part, Subject
View Samples