Divergence of Transcription Regulation and the Function of a Conserved Elongation Factor in Budding and Fission Yeast
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PROVIDER: PRJNA306424 | ENA |
REPOSITORIES: ENA
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Project description:Complex regulation of gene expression in mammals has evolved from simpler eukaryotic systems, yet mechanistic details of this evolution remain elusive. By comparing the transcriptional landscape of distantly related budding and fission yeast, we catch a glimpse of divergence in gene regulation. Using an adapted Precision Run-On sequencing (PRO-seq) approach, we have mapped the positions of RNA polymerase (RNA Pol II) active sites genome-wide in S. pombe and S. cerevisiae at base-pair resolution. We further mapped preferred sites of transcription initiation in each organism, exposing the origins of nascent transcription. Performing PRO-seq in strains lacking Spt4, a highly conserved elongation factor subunit, results in globally elevated levels of transcribing Pol II within genes in both species. Messenger RNA abundance, however, does not reflect the increases in RNA Pol II density, indicating a possible global elongation rate defect. Unexpectedly, we identify a novel pause in early elongation, specific to S. pombe, which requires Spt4, suggesting regulatory potential similar to promoter-proximal pausing in mammals.
2016-04-16 | GSE76142 | GEO
Project description:Complex regulation of gene expression in mammals has evolved from simpler eukaryotic systems, yet the mechanistic features of this evolution remain elusive. Here, we compared the transcriptional landscapes of the distantly related budding and fission yeast. We adapted the Precision Run-On sequencing (PRO-seq) approach to map the positions of RNA polymerase active sites genome-wide in Schizosaccharomyces pombe and Saccharomyces cerevisiae. Additionally, we mapped preferred sites of transcription initiation in each organism using PRO-cap. Unexpectedly, we identify a pause in early elongation, specific to S. pombe, that requires the conserved elongation factor subunit Spt4 and resembles promoter-proximal pausing in metazoans. PRO-seq profiles in strains lacking Spt4 reveal globally elevated levels of transcribing RNA Polymerase II (Pol II) within genes in both species. Messenger RNA abundance, however, does not reflect the increases in Pol II density, indicating a global reduction in elongation rate. Together, our results provide the first base-pair resolution map of transcription elongation in S. pombe and identify divergent roles for Spt4 in controlling elongation in budding and fission yeast.
| S-EPMC4889974 | biostudies-literature
Project description:We have used micrococcal nuclease (MNase) digestion followed by deep sequencing in order to obtain a higher-resolution map than previously available of nucleosome positions in the fission yeast, Schizosaccharomyces pombe. Our data confirm an unusually short average nucleosome repeat length, ~152 bp, in fission yeast and that transcriptional start sites (TSSs) are associated with nucleosome-depleted regions (NDRs), ordered nucleosome arrays downstream and less regularly spaced upstream nucleosomes. In addition, we found enrichments for associated function in four of eight groups of genes clustered according to chromatin configurations near TSSs. At replication origins, our data revealed asymmetric localization of Pre-Replication Complex (pre-RC) proteins within large NDRs—a feature that is conserved in fission and budding yeast and is therefore likely to be conserved in other eukaryotic organisms.
2012-04-24 | GSE28071 | GEO
Project description:We have used micrococcal nuclease (MNase) digestion followed by deep sequencing in order to obtain a higher-resolution map than previously available of nucleosome positions in the fission yeast, Schizosaccharomyces pombe. Our data confirm an unusually short average nucleosome repeat length, ~152 bp, in fission yeast and that transcriptional start sites (TSSs) are associated with nucleosome-depleted regions (NDRs), ordered nucleosome arrays downstream and less regularly spaced upstream nucleosomes. In addition, we found enrichments for associated function in four of eight groups of genes clustered according to chromatin configurations near TSSs. At replication origins, our data revealed asymmetric localization of Pre-Replication Complex (pre-RC) proteins within large NDRsM-bM-^@M-^Ta feature that is conserved in fission and budding yeast and is therefore likely to be conserved in other eukaryotic organisms. Examination of nucleosome positioning in Schizosaccharomyces pombe
2012-04-23 | E-GEOD-28071 | biostudies-arrayexpress
Project description:Recent studies in comparative genomics demonstrate that inter-species comparisons represent a powerful tool for revealing both conserved and specialized biological processes across large evolutionary distances. All cells need to adjust to environmental fluctuations in metal levels since both metal excess and deficit are detrimental. Here, we explore the conservation of metal homoeostasis in two distantly related yeasts, examining genome-wide gene expression responses to changing copper and iron levels in budding and fission yeast using DNA microarrays
2007-03-01 | E-TABM-120 | biostudies-arrayexpress
Project description:Retrograde response was widely studied in budding yeast but the main transcription factors that transmit it (RTG1,2 and 3) are not conserved in other organisms, thus it is interesting to study how communication between mitochondria and nucleus evolved in distantly related fission yeast, and which are the common aspects of this conserved pathway between yeast and higher organisms.To analyse any retrograde response in fission yeast, we inhibited the electron transport chain activity by antimycin A and studied cellular gene expression changes by microarrays. Cells treated with antimycin A in fermentative medium (YE with 3% glucose), showed the same growth rate as untreated cells, but they reached a lower biomass in stationary phase. Antimycin A treated cells consumed glucose at a faster rate and produced more ethanol, indicating that the energy metabolism was shifted even more towards fermentation. We analyzed the transcriptomes of antimycin A-treated cells to untreated control cells during early exponential growth phase (OD 0.5).
2016-11-01 | E-MTAB-4520 | biostudies-arrayexpress
Project description:Post-translational modifications of the transcription elongation complex provide mechanisms to fine-tune gene expression, yet their specific impacts on RNA polymerase II regulation remain difficult to ascertain. Here, in Schizosaccharomyces pombe, we examine the role of Cdk9, and related Mcs6/Cdk7 and Lsk1/Cdk12 kinases, on transcription at base-pair resolution with Precision Run-On sequencing (PRO-seq). Within a minute of Cdk9 inhibition, phosphorylation of Pol II-associated factor, Spt5 is undetectable. The effects of Cdk9 inhibition are more severe than inhibition of Cdk7 and Cdk12, resulting in a shift of Pol II towards the transcription start site (TSS). A time course of Cdk9 inhibition reveals that early transcribing Pol II can escape promoter-proximal regions, but with a severely reduced rate of only ~400 bp/min. Our results in fission yeast suggest the existence of a conserved global regulatory checkpoint that requires Cdk9 kinase activity.
2018-01-04 | GSE102308 | GEO
Project description:Transcript elongation by RNA polymerase II (RNAPII) is accompanied by conserved patterns of histone modification within transcribed regions, but it remains uncertain how these modifications influence, or are influenced by, properties of the elongation complex. Here we establish an intimate link between Cdk9, the kinase component of positive transcription elongation factor b (P-TEFb), and mono-ubiquitylation of histone H2B (H2Bub1), in the fission yeast Schizosaccharomyces pombe. Mutations that impair Cdk9 function reduce H2Bub1 levels in vivo. Conversely, mutations that prevent H2Bub1 decrease phosphorylation of elongation factor subunit Spt5, a sensitive and specific indicator of Cdk9 activity. Chromatin immunoprecipitation (ChIP) analysis suggests this is due to impaired Cdk9 recruitment to H2Bub1-deficient chromatin. P-TEFb and H2Bub1 pathways also interact genetically: mutation of the histone H2B ubiquitin-acceptor residue decreases the requirement for Cdk9 activity in vivo, and multiple cdk9 mutations suppress morphological defects of H2Bub1-deficient strains. Moreover, H2Bub1 loss causes redistribution of transcribing RNAPII on chromatin that is corrected by a hypomorphic cdk9 mutation. Therefore, whereas mutual dependence of Spt5 phosphorylation and H2Bub1 suggests positive feedback between P-TEFb and the ubiquitylation machinery, mutual suppression by cdk9 and H2Bub1-pathway mutations indicates an antagonistic relationship, whereby the activities must be balanced to properly regulate elongation.
2012-12-01 | GSE31070 | GEO
Project description:Transcript elongation by RNA polymerase II (RNAPII) is accompanied by conserved patterns of histone modification within transcribed regions, but it remains uncertain how these modifications influence, or are influenced by, properties of the elongation complex. Here we establish an intimate link between Cdk9, the kinase component of positive transcription elongation factor b (P-TEFb), and mono-ubiquitylation of histone H2B (H2Bub1), in the fission yeast Schizosaccharomyces pombe. Mutations that impair Cdk9 function reduce H2Bub1 levels in vivo. Conversely, mutations that prevent H2Bub1 decrease phosphorylation of elongation factor subunit Spt5, a sensitive and specific indicator of Cdk9 activity. Chromatin immunoprecipitation (ChIP) analysis suggests this is due to impaired Cdk9 recruitment to H2Bub1-deficient chromatin. P-TEFb and H2Bub1 pathways also interact genetically: mutation of the histone H2B ubiquitin-acceptor residue decreases the requirement for Cdk9 activity in vivo, and multiple cdk9 mutations suppress morphological defects of H2Bub1-deficient strains. Moreover, H2Bub1 loss causes redistribution of transcribing RNAPII on chromatin that is corrected by a hypomorphic cdk9 mutation. Therefore, whereas mutual dependence of Spt5 phosphorylation and H2Bub1 suggests positive feedback between P-TEFb and the ubiquitylation machinery, mutual suppression by cdk9 and H2Bub1-pathway mutations indicates an antagonistic relationship, whereby the activities must be balanced to properly regulate elongation. In order to study the genome-wide localization of H2Bub1 in Schizosaccharomyces pombe, H2Bub1, H2B-Flag as well as RNAPII (along with associated DNA sequences) were immunoprecipitated using repectively anti-H2Bub1, anti-Flag and anti-8WG16 antibodies. The ChIPs were performed in duplicate from WT cells as well as in the H2B-K119R mutant. The extracted DNA was hybridized to a DNA microarray containing an average of 4 probes per kilobase across the whole yeast genome. The combined datasets are available in the supplemental files of the related publication.
2012-12-01 | E-GEOD-31070 | biostudies-arrayexpress
Project description:Termination of RNA polymerase II (RNAPII) transcription is a fundamental step of gene expression that is critical for determining the borders between genes. In budding yeast, termination at protein-coding genes is initiated by the cleavage/polyadenylation machinery, whereas termination of most noncoding RNA (ncRNA) genes occurs via the Nrd1-Nab3-Sen1 (NNS) pathway. Unexpectedly, we show here that NNS-like transcription termination is not conserved in fission yeast. Instead, genome-wide location analyses show global recruitment of mRNA 3’ end processing factors at the end of ncRNA genes, including snoRNAs and snRNAs, and that this recruitment coincides with high levels of Ser2 and Tyr1 phosphorylation on the RNAPII C-terminal domain. We further show that termination of mRNA and ncRNA transcription requires the conserved Ysh1/CPSF-73 and Dhp1/XRN2 nucleases, supporting widespread cleavage-dependent transcription termination in fission yeast. Our findings thus reveal that a common mode of transcription termination can produce functionally and structurally distinct types of polyadenylated and non-polyadenylated RNAs.
2018-08-10 | GSE115595 | GEO