Integrator-PP2A complex dephosphorylates the C-terminal repeat domain of RNA Polymerase II
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE154093 | GEO | 2020/12/02
REPOSITORIES: GEO
Similar Datasets
Project description:Cyclin-dependent kinase 12 (CDK12) interacts with Cyclin K to form a functional nuclear kinase that promotes processive transcription elongation through phosphorylation of the RNA polymerase II (Pol II) C-terminal domain (CTD). To gain a broader understanding of CDK12 cellular function, we used chemical-genetic and phosphoproteomic screening to identify a landscape of nuclear human CDK12 substrates, including regulators of transcription, chromatin organization, and RNA splicing. We further validated LEO1, a subunit of the PAF1 complex (PAF1C), as a bona fide cellular substrate of CDK12. Acute depletion of LEO1, or substituting LEO1 phosphorylation sites with alanine, attenuated PAF1C association with elongating Pol II and impaired processive transcription elongation. We also found that LEO1 interacts with, and is dephosphorylated by, the Integrator-PP2A complex (INTAC) and that INTAC promotes the association of PAF1C with Pol II. Together, this study reveals a previously unknown role for CDK12 and INTAC in regulating LEO1 phosphorylation for transcriptional regulation, providing important insights into gene transcription and its regulation.
2023-06-08 | PXD038558 | Pride
Project description:Efficient release of promoter-proximally paused Pol II into productive elongation is essential for gene expression. Recently, we reported that the Integrator complex can bind paused Pol II and drive premature transcription termination, potently attenuating the activity of target genes. Premature termination requires RNA cleavage by the endonuclease subunit of Integrator, but the roles of other Integrator subunits in gene regulation have yet to be elucidated. Here, we report that Integrator subunit 8 (IntS8) is critical for transcription repression through its association with Protein Phosphatase 2A (PP2A). We find that Integrator-bound PP2A dephosphorylates the Pol II C-terminal domain and Spt5, and prevents the transition to productive elongation. Blocking PP2A association with Integrator thus stimulates pause release and gene activation. These results reveal a second catalytic function associated with Integrator-mediated transcription termination, and suggest a new model for the control of productive elongation involving active competition between transcriptional kinases and phosphatases.
2020-10-06 | GSE150844 | GEO
Project description:Integrator-PP2A complex dephosphorylates the C-terminal repeat domain of RNA Polymerase II
| PRJNA645103 | ENA
Project description:We evaluated the effects of suppressing MAP4K4 on transcriptome and YAP1 pathway based on the observation that partial suppression of MAP4K4 leads to transformation through activation of YAP1. Mutations and deletions involving subunits of the serine-threonine phosphatase PP2A occur in a broad range of human cancers, and partial loss of PP2A function contributes to cell transformation. In particular, displacement of regulatory B subunits by the viral oncoprotein SV40 small-t antigen (ST) or mutation or deletion of PP2A subunits alters the abundance and types of PP2A complexes in cells and induces cell transformation in human cells. Here we show that ST not only displaces common PP2A B subunits but also promotes PP2A A-C subunit interactions with a set of alternative B subunits (B’’’, striatins) that are components of the Striatin-interacting phosphatase and kinase (STRIPAK) complex. We found that members of the STRIPAK complex are required for ST-PP2A induced cell transformation. PP2A interacts with and dephosphorylates the STRIPAK-associated kinase MAP4K4, which induces cell transformation in part through the regulation of the Hippo pathway effector YAP1. These observations identify an unanticipated role of MAP4K4 in transformation and show that the STRIPAK complex plays a key role in defining PP2A specificity and activity.
2019-12-01 | GSE118272 | GEO
Project description:Gene expression by RNA Polymerase II (RNAPII) is tightly controlled by Cyclin-dependent kinases (CDKs) at discrete checkpoints during the transcription cycle. The RNAPII pausing checkpoint, engaged after transcription initiation, is controlled by CDK9 to regulate transcription in metazoans. We discovered that CDK9-mediated RNAPII pause-release is functionally opposed by a protein phosphatase 2A (PP2A) complex. PP2A dynamically competes for key CDK9 substrates, DSIF and RNAPII-CTD, and is recruited to transcription pausing sites by the Integrator complex subunit INTS6. INTS6 depletion confers resistance to CDK9 inhibition in a variety of normal and tumor cell lines. Loss of INTS6 abolishes the Integrator-PP2A association leading to unrestrained CDK9 activity, which amplifies transcriptional responses. Pharmacological PP2A activation synergizes with CDK9 inhibition to kill MLL-rearranged leukemias and solid tumors and provide therapeutic benefit in vivo. These data demonstrate that f inely-tuned gene expression relies on the balance of kinase and phosphatase activity at the pausing checkpoint.
2021-05-23 | GSE163804 | GEO
Project description:Gene expression by RNA Polymerase II (RNAPII) is tightly controlled by Cyclin-dependent kinases (CDKs) at discrete checkpoints during the transcription cycle. The RNAPII pausing checkpoint, engaged after transcription initiation, is controlled by CDK9 to regulate transcription in metazoans. We discovered that CDK9-mediated RNAPII pause-release is functionally opposed by a protein phosphatase 2A (PP2A) complex. PP2A dynamically competes for key CDK9 substrates, DSIF and RNAPII-CTD, and is recruited to transcription pausing sites by the Integrator complex subunit INTS6. INTS6 depletion confers resistance to CDK9 inhibition in a variety of normal and tumor cell lines. Loss of INTS6 abolishes the Integrator-PP2A association leading to unrestrained CDK9 activity, which amplifies transcriptional responses. Pharmacological PP2A activation synergizes with CDK9 inhibition to kill MLL-rearranged leukemias and solid tumors and provide therapeutic benefit in vivo. These data demonstrate that f inely-tuned gene expression relies on the balance of kinase and phosphatase activity at the pausing checkpoint.
2021-05-23 | GSE163803 | GEO
Project description:Gene expression by RNA Polymerase II (RNAPII) is tightly controlled by Cyclin-dependent kinases (CDKs) at discrete checkpoints during the transcription cycle. The RNAPII pausing checkpoint, engaged after transcription initiation, is controlled by CDK9 to regulate transcription in metazoans. We discovered that CDK9-mediated RNAPII pause-release is functionally opposed by a protein phosphatase 2A (PP2A) complex. PP2A dynamically competes for key CDK9 substrates, DSIF and RNAPII-CTD, and is recruited to transcription pausing sites by the Integrator complex subunit INTS6. INTS6 depletion confers resistance to CDK9 inhibition in a variety of normal and tumor cell lines. Loss of INTS6 abolishes the Integrator-PP2A association leading to unrestrained CDK9 activity, which amplifies transcriptional responses. Pharmacological PP2A activation synergizes with CDK9 inhibition to kill MLL-rearranged leukemias and solid tumors and provide therapeutic benefit in vivo. These data demonstrate that f inely-tuned gene expression relies on the balance of kinase and phosphatase activity at the pausing checkpoint.
2021-05-23 | GSE163802 | GEO
Project description:Cyclin-dependent kinase 12 (CDK12) interacts with Cyclin K to form a a functional nuclear kinase complex, which has been reported to phosphorylate the carboxyl-terminal domain (CTD) of RNA polymerase II (Pol II) for transcriptional regulation and co-transcriptional RNA processing. However, the precise mechanisms and targets of CDK12 action remain largely unknown. Here, we combined a chemical genetic screen and phosphoproteomic strategies and identified a landscape of nuclear CDK12 substrates, which included proteins that regulate transcription, chromatin organization, and RNA splicing. Next, we confirmed that the LEO1 subunit of the transcription elongation factor PAF1 complex (PAF1C) is a bona fide substrate of CDK12. Acute depletion of LEO1 reduces Pol II occupancy on the chromatin, while mutations of LEO1 phosphorylation sites to non-phosphorylatable alanine residues attenuated the association of PAF1C with elongating Pol II and chromatin, resulting in impaired processive transcription elongation. Furthermore, LEO1 C-terminus could interact with and be dephosphorylated by the Integrator-PP2A complex (INTAC), while acute depletion of INTAC in cells promotes the association between PAF1C and elongating Pol II on the chromatin. Together, this study provides a novel transcriptional regulatory mechanism that the CDK12-INTAC axis fine-tunes LEO1 phosphorylation for processive transcription elongation.
2023-05-19 | GSE217544 | GEO
Project description:Pleiotropic transcription regulator RNA polymerase II (Pol II)-associated factor 1 (PAF1) governs multiple transcriptional steps and the deposition of several epigenetic marks. However, it remains unclear how ultimate transcriptional outcome is determined by PAF1 and whether it relates to PAF1-controlled epigenetic marks. We utilize rapid degradation systems and reveal direct PAF1 functions in governing pausing partially by recruiting Integrator-PP2A (INTAC), in addition to ensuring elongation. Following acute PAF1 degradation, destabilized polymerase undergoes early termination or effective release, which presumably relies on skewed balance between INTAC and P-TEFb resulting in hyperphosphorylated substrates including SPT5. Impaired Pol II progression during elongation, along with altered pause release frequency, determines the final transcriptional outputs. Moreover, PAF1 degradation causes a cumulative decline in histone modifications. These epigenetic alterations in chromatin likely further influence the production of transcripts from PAF1 target genes.
2022-01-30 | GSE192848 | GEO
Project description:Transcription machinery progression is governed by multitasking regulators including SPT5, an evolutionarily conserved factor implicated in virtually all transcriptional steps from enhancer activation to termination. Yet its mechanistic understanding in human cells remains incomplete. Here we utilize rapid degradation system and reveal crucial function of SPT5 in maintaining cellular and chromatin Pol II levels. Rapid SPT5 depletion causes a pronounced reduction of paused Pol II at promoters and enhancers, distinct from NELF degradation resulting in short-distance paused Pol II redistribution. Most of genes exhibit down- but not upregulation, accompanied by greatly impaired transcription activation and altered chromatin landscape at enhancers, and severe Pol II processivity defects at gene bodies. Phosphorylation of KOWx-4/5- linker potentiates pause release and is antagonized by Integrator-PP2A (INTAC) targeting SPT5 and Pol II. Our findings position SPT5 as an essential positive regulator of global transcription by controlling cellular Pol II levels, enhancer activation and landscape, paused Pol II stability, elongation processivity and termination in human.
2021-09-29 | GSE180843 | GEO