Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Distinct Cdk9-phosphatase switches act on elongation factor Spt5 at the beginning and end of the RNA polymerase II transcription cycle

ABSTRACT: The Pol II transcription cycle is ordered by CDKs and phosphatases. In fission yeast, Cdk9 phosphorylates carboxy-terminal repeats (CTRs) of Spt5 while inhibiting PP1 during elongation. Transcription past the cleavage and polyadenylation signal (CPS) coincides with PP1-dependent Spt5 dephosphorylation and leads to Pol II pausing with phosphorylated CTD-Ser2 (pSer2). Here we show this switch is conserved in humans: Cdk9 inhibition decreases phosphorylation of both PP1g and Spt5-Thr806 (pThr806), and induces pSer2 upstream of the CPS, whereas PP1 depletion increases pThr806. Moreover, in unperturbed cells, pThr806 is diminished in 3’-paused complexes where pSer2 is maximal. Cdk9 also phosphorylates Spt5 on Ser666, a PP1-refractory site between conserved KOW4 and KOW5 motifs; pSer666 increases upon promoter-proximal pause release and, in contrast to pThr806, persists beyond the CPS. We identify PP4—another target of inhibitory phosphorylation by Cdk9—as a pSer666 phosphatase. PP4 and PP1g are enriched at 5’ and 3’ ends of genes, respectively, consistent with pSer666 and pThr806 distributions. Therefore, distinct Cdk9-phosphatase switches operate on Spt5 at different steps in transcription.

ORGANISM(S): Homo sapiens

PROVIDER: GSE138548 | GEO | 2020/08/04

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

A Cdk9-PP1 switch regulates the elongation-termination transition of RNA polymerase II

Project description:The end of the RNA polymerase II (Pol II) transcription cycle is strictly regulated to ensure proper mRNA maturation and prevent interference between neighboring genes. Pol II slowing downstream of the cleavage and polyadenylation signal (CPS) leads to recruitment of cleavage and polyadenylation factors and termination, but how this chain of events is initiated remains unclear. In a chemical-genetic screen we identified protein phosphatase 1 (PP1) isoforms as substrates of human positive transcription elongation factor b (P-TEFb), the cyclin-dependent kinase 9 (Cdk9)-cyclin T1 complex. Here we show that Cdk9 and PP1 govern phosphorylation of the conserved transcription factor Spt5 in the fission yeast Schizosaccharomyces pombe. Cdk9 phosphorylates both Spt5 and a negative regulatory site on the PP1 isoform Dis2. Sites phosphorylated by Cdk9 in the Spt5 carboxy-terminal domain (CTD) are dephosphorylated by Dis2 in vitro, and Cdk9 inhibition in vivo leads to rapid Spt5 dephosphorylation that is retarded by concurrent Dis2 inactivation. Chromatin immunoprecipitation and sequencing (ChIP-seq) analysis indicates that Spt5 is dephosphorylated as transcription complexes traverse the CPS, prior to or concomitant with Pol II pausing. A Dis2-inactivating mutation stabilizes Spt5 phosphorylation (pSpt5) on chromatin, promotes transcription beyond the normal termination zone detected by precision run-on transcription and sequencing (PRO-seq), and is suppressed by ablation of Cdk9 target sites in Spt5. These results support a model whereby the transition of Pol II from elongation to termination is regulated by opposing activities of Cdk9 and Dis2 towards their common substrate Spt5—a bistable switch analogous to a Cdk1-PP1 module that controls exit from mitosis.

2018-06-07 | GSE102590 | GEO

Elongation/termination factor exchange mediated by PP1 phosphatase orchestrates trancription termination

Project description:Termination of RNA polymerase II (Pol II) transcription is a key step, that is important for 3’end formation of functional mRNA, mRNA release and Pol II recycling. Even so, this underlying termination mechanism is not yet understood. Here, we demonstrate that the conserved and essential termination factor Seb1 interacts with Pol II near the end of the RNA exit channel and the Rpb4/7 stalk. Furthermore, the Seb1 interaction surface with Pol II largely overlaps with that of the elongation factor Spt5. Notably, Seb1 co-transcriptional recruitment is dependent on Spt5 de-phosphorylation by the conserved PP1 phosphatase Dis2, which also de-phosphorylates threonine 4 within the Pol II heptad repeated C-terminal domain. We propose that Dis2 orchestrates the transition from elongation to termination phase during the transcription cycle by mediating elongation to termination factor exchange and de-phosphorylation of Pol II C-terminal domain.

2018-12-26 | GSE111326 | GEO

Control of RNA pol II speed by PNUTS-PP1 and Spt5 dephosphorylation facilitates termination by a “sitting duck torpedo” mechanism

Project description:Control of transcription speed, which influences many co-transcriptional processes, is poorly understood. We report that PNUTS-PP1 phosphatase is a negative regulator of RNA pol II elongation rate. The PNUTS W401A mutation, which disrupts PP1 binding, causes genome-wide acceleration of transcription associated with hyper-phosphorylation of the Spt5 elongation factor. Immediately downstream of poly(A) sites, pol II decelerates from >2kb/min to <1 kb/min, which correlates with Spt5 dephosphorylation. Pol II deceleration and Spt5 dephosphorylation require poly(A) site recognition and the PNUTS-PP1 complex, which is in turn necessary for transcription termination. These results lead to a new model for termination, the “sitting duck torpedo” mechanism, where poly(A) site-dependent deceleration caused by PNUTS-PP1 and Spt5 dephosphorylation is required to convert pol II into a viable target for the Xrn2 terminator exonuclease. Spt5 and its bacterial homologue NusG therefore have related functions controlling kinetic competition between RNA polymerases and the termination factors that pursue them.

2019-10-30 | GSE134198 | GEO

Characterization of the SF3B1 interactome

Project description:CDK9 is a critical kinase required for the productive transcription of protein-coding genes by RNA polymerase II (pol II). As part of P-TEFb, CDK9 phosphorylates the carboxyl-terminal domain (CTD) of pol II and elongation factors, including SPT5, which allows pol II to elongate past the early elongation checkpoint (EEC) encountered soon after initiation. We show that, in addition to halting pol II at the EEC, loss of CDK9 activity causes premature termination of transcription across the last exon, loss of polyadenylation factors from chromatin, and loss of polyadenylation of nascent transcripts. Inhibition of the phosphatase PP2A abrogates the premature termination and loss of polyadenylation caused by CDK9 inhibition, indicating that this kinase/phosphatase pair regulates transcription elongation and RNA processing at the end of protein-coding genes. Our phosphoproteomic analyses after CDK9 inhibition, using either DRB or an analog-sensitive CDK9 cell line, confirm the splicing factor SF3B1 as an additional key target of this kinase. These results emphasize the important roles that CDK9 plays in coupling transcription elongation and termination to RNA maturation downstream of the EEC. As part of this project, we characterized the interactome of SF3B1 in HeLa cells in duplicate.

2022-08-22 | PXD033694 | Pride

Identification of CDK9 targets using DRB and quantitative phosphoproteomics

Project description:CDK9 is a critical kinase required for the productive transcription of protein-coding genes by RNA polymerase II (pol II) in higher eukaryotes. Phosphorylation of targets including the elongation factor SPT5 and the carboxyl-terminal domain (CTD) of RNA pol II allow the polymerase to pass an early elongation checkpoint (EEC), which is encountered soon after initiation. In addition to halting RNA polymerase II at the EEC, CDK9 inhibition also causes premature termination of transcription across the last exon, loss of polyadenylation factors from chromatin, and loss of polyadenylation of nascent transcripts. Inhibition of the phosphatase PP2A abrogates the premature termination and loss of polyadenylation caused by CDK9 inhibition, suggesting that CDK9 and PP2A, working together, regulate the coupling of elongation and transcription termination to RNA maturation. Our phosphoproteomic analyses, using either DRB or an analog-sensitive CDK9 cell line confirm the splicing factor SF3B1 as an additional key target of this kinase. CDK9 inhibition causes loss of interaction of splicing and export factors with SF3B1, suggesting that CDK9 also helps to co-ordinates coupling of splicing and export to transcription.

2022-08-22 | PXD026720 | Pride

CDK9 and PP2A regulate RNA polymerase II transcription termination and coupled RNA maturation

Project description:CDK9 is a kinase critical for the productive transcription of protein-coding genes by RNA polymerase II (pol II). As part of P-TEFb, CDK9 phosphorylates the carboxyl-terminal domain (CTD) of pol II and elongation factors, which allows pol II to elongate past the early elongation checkpoint (EEC) encountered soon after initiation. We show that, in addition to halting pol II at the EEC, loss of CDK9 activity causes premature termination of transcription across the last exon, loss of polyadenylation factors from chromatin, and loss of polyadenylation of nascent transcripts. Inhibition of the phosphatase PP2A abrogates the premature termination and loss of polyadenylation caused by CDK9 inhibition, indicating that this kinase/phosphatase pair regulates transcription elongation and RNA processing at the end of protein-coding genes. We also confirm the splicing factor SF3B1 as a target of CDK9 and show that SF3B1 in complex with polyadenylation factors is lost from chromatin after CDK9 inhibition. These results emphasize the important roles that CDK9 plays in coupling transcription elongation and termination to RNA maturation downstream of the EEC.

2022-08-22 | GSE176541 | GEO

The Protein Phosphatase 4 Complex Promotes Transcription and Processing of Primary microRNAs in Arabidopsis [ncRNA-Seq]

Project description:Protein phosphatase 4 (PP4) is a highly conserved serine/threonine protein phosphatase in yeast, plants, and animals. The composition and functions of the plant PP4 are poorly understood. Here, we uncovered previously unsuspected complexity of Arabidopsis PP4 and identified the composition of one form of PP4 containing the regulatory subunit PP4R3A. We showed that PP4R3A, together with one of two redundant catalytic subunit genes PPX1 and PPX2, promotes the biogenesis of microRNAs. PP4R3A is a chromatin-associated protein, interacts with RNA polymerase II (Pol II), and recruits Pol II to the promoters of MIR genes to promote their transcription. PP4R3A probably also promotes the cotranscriptional processing of miRNA precursors as it recruits the microprocessor component HYPONASTIC LEAVES1 (HYL1) to MIR genes and nuclear dicing bodies. Moreover, we showed that hundreds of introns exhibit splicing defects in pp4r3a mutants. Together, this study revealed a role of Arabidopsis PP4 in transcription and nuclear RNA metabolism.

2019-02-08 | GSE121453 | GEO

The Protein Phosphatase 4 Complex Promotes Transcription and Processing of Primary microRNAs in Arabidopsis [RNA-Seq]

2019-02-08 | GSE121450 | GEO

Cdk9 regulates a promoter-proximal checkpoint to modulate RNA Polymerase II elongation rate in fission yeast

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

Pol II Ser7phospho ChIP-seq in mES cells

Project description:RNA Polymerase II transcribes protein-coding and many non-coding RNA genes in eukaryotes. The largest subunit of RNA Polymerase II, Rpb1, contains a hepta-peptide repeat on its C-terminal tail with three potential phosphorylation sites (Serine 2, Serine 5 and Serine 7). Mammalian Rpb1 contains 52 repeats. The phosphorylation events are catalyzed by specific protein kinases where the phosphorylation of specific residues is coupled to the transcription cycle. For example, the Cdk7 subunit of TFIIH phosphorylates both Serine 5 and Serine 7 during intiation and the Cdk9 subunit of P-TEFb phosphorylates Serine 2 during the transition into productive elongation. The dataset presented here is the genome-wide distribution of RNA Pol II with Serine 7 of the CTD phosphorylated in murine embryonic stem cells. This data, in addition to phospho-specific datasets generated in the same cell type in Rahl et al. Cell 2010 and Seila et al. Science 2008, represents the genome-wide distribution of multiple RNA Pol II isoforms in murine embryonic stem cells: total Pol II, hypophosphorylated CTD Pol II, Serine 2 phosphorylated CTD Pol II, Serine 5 phosphorylated CTD Pol II and Serine 7 phosphorylated CTD Pol II. An antibody specific to RNA Pol II Serine 7 phosphorylated CTD (gift of Dirk Eick; Chapman et al. Science 2008) was used to enrich for DNA fragments associated with this Pol II isoform in murine embryonic stem cells. DNA was purified and prepared for Illumina/Solexa sequencing following their standard protocol. This is a single dataset but together with datasets from Rahl et al. Cell 2010 and Seila et al. Science 2008, these datasets represent the genome-wide distribution of multiple RNA Pol II isoforms in murine embryonic stem cells: total Pol II, hypophosphorylated CTD Pol II, Serine 2 phosphorylated CTD Pol II, Serine 5 phosphorylated CTD Pol II and Serine 7 phosphorylated CTD Pol II.

2010-05-20 | E-GEOD-21917 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data