1
|
Francette AM, Arndt KM. Multiple direct and indirect roles of the Paf1 complex in transcription elongation, splicing, and histone modifications. Cell Rep 2024; 43:114730. [PMID: 39244754 DOI: 10.1016/j.celrep.2024.114730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 07/17/2024] [Accepted: 08/23/2024] [Indexed: 09/10/2024] Open
Abstract
The polymerase-associated factor 1 (Paf1) complex (Paf1C) is a conserved protein complex with critical functions during eukaryotic transcription. Previous studies showed that Paf1C is multi-functional, controlling specific aspects of transcription ranging from RNA polymerase II (RNAPII) processivity to histone modifications. However, it is unclear how specific Paf1C subunits directly impact transcription and coupled processes. We have compared conditional depletion to steady-state deletion for each Paf1C subunit to determine the direct and indirect contributions to gene expression in Saccharomyces cerevisiae. Using nascent transcript sequencing, RNAPII profiling, and modeling of transcription elongation dynamics, we have demonstrated direct effects of Paf1C subunits on RNAPII processivity and elongation rate and indirect effects on transcript splicing and repression of antisense transcripts. Further, our results suggest that the direct transcriptional effects of Paf1C cannot be readily assigned to any particular histone modification. This work comprehensively analyzes both the immediate and the extended roles of each Paf1C subunit in transcription elongation and transcript regulation.
Collapse
Affiliation(s)
- Alex M Francette
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Karen M Arndt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| |
Collapse
|
2
|
Wang Q, Lin J. Homeostasis of mRNA concentrations through coupling transcription, export, and degradation. iScience 2024; 27:110531. [PMID: 39175768 PMCID: PMC11338957 DOI: 10.1016/j.isci.2024.110531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 04/16/2024] [Accepted: 07/15/2024] [Indexed: 08/24/2024] Open
Abstract
Many experiments showed that eukaryotic cells maintain a constant mRNA concentration upon various perturbations by actively regulating mRNA production and degradation rates, known as mRNA buffering. However, the underlying mechanism is still unknown. In this work, we unveil a mechanistic model of mRNA buffering: the releasing-shuttling (RS) model. The model incorporates two crucial proteins, X and Y, which play several roles, including transcription, decay, and export factors, in the different stages of mRNA metabolism. The RS model predicts the constant mRNA concentration under genome-wide genetic perturbations and cell volume changes, the slowed-down mRNA degradation after Pol II depletion, and the temporal transcription dynamics after exonuclease depletion, in agreement with multiple experiments. Finally, we present a list of X and Y candidates and propose an experimental method to identify X. Our work uncovers potentially universal pathways coupling transcription, export, and degradation that help cells maintain mRNA homeostasis.
Collapse
Affiliation(s)
- Qirun Wang
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Jie Lin
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| |
Collapse
|
3
|
Costanzo F, Paccosi E, Proietti-De-Santis L, Egly JM. CS proteins and ubiquitination: orchestrating DNA repair with transcription and cell division. Trends Cell Biol 2024:S0962-8924(24)00116-8. [PMID: 38910038 DOI: 10.1016/j.tcb.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 05/27/2024] [Accepted: 06/04/2024] [Indexed: 06/25/2024]
Abstract
To face genotoxic stress, eukaryotic cells evolved extremely refined mechanisms. Defects in counteracting the threat imposed by DNA damage underlie the rare disease Cockayne syndrome (CS), which arises from mutations in the CSA and CSB genes. Although initially defined as DNA repair proteins, recent work shows that CSA and CSB act instead as master regulators of the integrated response to genomic stress by coordinating DNA repair with transcription and cell division. CSA and CSB exert this function through the ubiquitination of target proteins, which are effectors/regulators of these processes. This review describes how the ubiquitination of target substrates is a common denominator by which CSA and CSB participate in different aspects of cellular life and how their mutation gives rise to the complex disease CS.
Collapse
Affiliation(s)
- Federico Costanzo
- Faculty of Biomedical Sciences, Institute of Oncology Research, USI, Bellinzona 6500, Switzerland; Department of Functional Genomics and Cancer, IGBMC, CNRS/INSERM/University of Strasbourg, Illkirch-Graffenstaden 67400, Strasbourg, France.
| | - Elena Paccosi
- Unit of Molecular Genetics of Aging, Department of Ecology and Biology, University of Tuscia, Viterbo 01100, Italy
| | - Luca Proietti-De-Santis
- Unit of Molecular Genetics of Aging, Department of Ecology and Biology, University of Tuscia, Viterbo 01100, Italy
| | - Jean Marc Egly
- Faculty of Biomedical Sciences, Institute of Oncology Research, USI, Bellinzona 6500, Switzerland; Department of Functional Genomics and Cancer, IGBMC, CNRS/INSERM/University of Strasbourg, Illkirch-Graffenstaden 67400, Strasbourg, France; College of Medicine, Centre for Genomics and Precision Medicine, National Taiwan University, Taipei City, Taiwan
| |
Collapse
|
4
|
Giordano G, Buratowski R, Jeronimo C, Poitras C, Robert F, Buratowski S. Uncoupling the TFIIH Core and Kinase Modules Leads To Misregulated RNA Polymerase II CTD Serine 5 Phosphorylation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.11.557269. [PMID: 37745343 PMCID: PMC10515806 DOI: 10.1101/2023.09.11.557269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
TFIIH is an essential transcription initiation factor for RNA polymerase II (RNApII). This multi-subunit complex comprises two modules that are physically linked by the subunit Tfb3 (MAT1 in metazoans). The TFIIH Core Module, with two DNA-dependent ATPases and several additional subunits, promotes DNA unwinding. The TFIIH Kinase Module phosphorylates Serine 5 of the C-terminal domain (CTD) of RNApII subunit Rpb1, a modification that coordinates exchange of initiation and early elongation factors. While it is not obvious why these two disparate activities are bundled into one factor, the connection may provide temporal coordination during early initiation. Here we show that Tfb3 can be split into two parts to uncouple the TFIIH modules. The resulting cells grow slower than normal, but are viable. Chromatin immunoprecipitation of the split TFIIH shows that the Core Module, but not the Kinase, is properly recruited to promoters. Instead of the normal promoter-proximal peak, high CTD Serine 5 phosphorylation is seen throughout transcribed regions. Therefore, coupling the TFIIH modules is necessary to localize and limit CTD kinase activity to early stages of transcription. These results are consistent with the idea that the two TFIIH modules began as independent functional entities that became connected by Tfb3 during early eukaryotic evolution.
Collapse
Affiliation(s)
- Gabriela Giordano
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA
| | - Robin Buratowski
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA
| | - Célia Jeronimo
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Québec, Canada
| | - Christian Poitras
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Québec, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Québec, Canada
- Département de Médecine, Université de Montréal, Montréal, Québec, Canada
- Division of Experimental Medicine, Medicine, McGill University, Montréal, Québec, Canada
| | - Stephen Buratowski
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA
| |
Collapse
|
5
|
Forouzanfar F, Plassard D, Furst A, Moreno D, Oliveira KA, Reina-San-Martin B, Tora L, Molina N, Mendoza M. Gene-specific RNA homeostasis revealed by perturbation of coactivator complexes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.30.577960. [PMID: 38352321 PMCID: PMC10862879 DOI: 10.1101/2024.01.30.577960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Transcript buffering entails the reciprocal modulation of mRNA synthesis and degradation rates to maintain stable RNA levels under varying cellular conditions. Current research supports a global, non-sequence-specific connection between mRNA synthesis and degradation, but the underlying mechanisms are still unclear. In this study, we investigated changes in RNA metabolism following acute depletion of TIP60/KAT5, the acetyltransferase subunit of the NuA4 transcriptional coactivator complex, in mouse embryonic stem cells. By combining RNA sequencing of nuclear, cytoplasmic, and newly synthesised transcript fractions with biophysical modelling, we demonstrate that TIP60 predominantly enhances transcription of numerous genes, while a smaller set of genes undergoes TIP60-dependent transcriptional repression. Surprisingly, transcription changes caused by TIP60 depletion were offset by corresponding changes in RNA nuclear export and cytoplasmic stability, indicating gene-specific buffering mechanisms. Similarly, disruption of the unrelated ATAC coactivator complex also resulted in gene-specific transcript buffering. These findings reveal that transcript buffering functions at a gene-specific level and suggest that cells dynamically adjust RNA splicing, export, and degradation in response to individual RNA synthesis alterations, thereby sustaining cellular homeostasis.
Collapse
|
6
|
Francette AM, Arndt KM. Multiple direct and indirect roles of Paf1C in elongation, splicing, and histone post-translational modifications. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.25.591159. [PMID: 38712269 PMCID: PMC11071476 DOI: 10.1101/2024.04.25.591159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Paf1C is a highly conserved protein complex with critical functions during eukaryotic transcription. Previous studies have shown that Paf1C is multi-functional, controlling specific aspects of transcription, ranging from RNAPII processivity to histone modifications. However, it is unclear how specific Paf1C subunits directly impact transcription and coupled processes. We have compared conditional depletion to steady-state deletion for each Paf1C subunit to determine the direct and indirect contributions to gene expression in Saccharomyces cerevisiae. Using nascent transcript sequencing, RNAPII profiling, and modeling of transcription elongation dynamics, we have demonstrated direct effects of Paf1C subunits on RNAPII processivity and elongation rate and indirect effects on transcript splicing and repression of antisense transcripts. Further, our results suggest that the direct transcriptional effects of Paf1C cannot be readily assigned to any particular histone modification. This work comprehensively analyzes both the immediate and extended roles of each Paf1C subunit in transcription elongation and transcript regulation.
Collapse
Affiliation(s)
- Alex M. Francette
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260, USA
| | - Karen M. Arndt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260, USA
- Lead contact
| |
Collapse
|
7
|
Swaffer MP, Marinov GK, Zheng H, Fuentes Valenzuela L, Tsui CY, Jones AW, Greenwood J, Kundaje A, Greenleaf WJ, Reyes-Lamothe R, Skotheim JM. RNA polymerase II dynamics and mRNA stability feedback scale mRNA amounts with cell size. Cell 2023; 186:5254-5268.e26. [PMID: 37944513 DOI: 10.1016/j.cell.2023.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 07/16/2023] [Accepted: 10/10/2023] [Indexed: 11/12/2023]
Abstract
A fundamental feature of cellular growth is that total protein and RNA amounts increase with cell size to keep concentrations approximately constant. A key component of this is that global transcription rates increase in larger cells. Here, we identify RNA polymerase II (RNAPII) as the limiting factor scaling mRNA transcription with cell size in budding yeast, as transcription is highly sensitive to the dosage of RNAPII but not to other components of the transcriptional machinery. Our experiments support a dynamic equilibrium model where global RNAPII transcription at a given size is set by the mass action recruitment kinetics of unengaged nucleoplasmic RNAPII to the genome. However, this only drives a sub-linear increase in transcription with size, which is then partially compensated for by a decrease in mRNA decay rates as cells enlarge. Thus, limiting RNAPII and feedback on mRNA stability work in concert to scale mRNA amounts with cell size.
Collapse
Affiliation(s)
| | - Georgi K Marinov
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Huan Zheng
- Department of Biology, McGill University, Montreal, QC H3G 0B1, Canada
| | | | - Crystal Yee Tsui
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | | | | | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | | | | | - Jan M Skotheim
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
| |
Collapse
|
8
|
Bryll AR, Peterson CL. The circular logic of mRNA homeostasis. Transcription 2023; 14:18-26. [PMID: 36843061 PMCID: PMC10353332 DOI: 10.1080/21541264.2023.2183684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/13/2023] [Accepted: 02/17/2023] [Indexed: 02/28/2023] Open
Abstract
Eukaryotic cells rely upon dynamic, multifaceted regulation at each step of RNA biogenesis to maintain mRNA pools and ensure normal protein synthesis. Studies in budding yeast indicate a buffering phenomenon that preserves global mRNA levels through the reciprocal balancing of RNA synthesis rates and mRNA decay. In short, changes in transcription impact the efficiency of mRNA degradation and defects in either nuclear or cytoplasmic mRNA degradation are somehow sensed and relayed to control a compensatory change in mRNA transcription rates. Here, we review current views on molecular mechanisms that might explain this apparent bidirectional sensing process that ensures homeostasis of the stable mRNA pool.
Collapse
Affiliation(s)
- Alysia R. Bryll
- Program of Molecular Medicine, University of Massachusetts Chan Medical School, Worcester
- Medical Scientist Training Program, University of Massachusetts Chan Medical School, Worcester
| | - Craig L. Peterson
- Program of Molecular Medicine, University of Massachusetts Chan Medical School, Worcester
| |
Collapse
|
9
|
Yague-Sanz C, Migeot V, Larochelle M, Bachand F, Wéry M, Morillon A, Hermand D. Chromatin remodeling by Pol II primes efficient Pol III transcription. Nat Commun 2023; 14:3587. [PMID: 37328480 PMCID: PMC10276017 DOI: 10.1038/s41467-023-39387-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 06/09/2023] [Indexed: 06/18/2023] Open
Abstract
The packaging of the genetic material into chromatin imposes the remodeling of this barrier to allow efficient transcription. RNA polymerase II activity is coupled with several histone modification complexes that enforce remodeling. How RNA polymerase III (Pol III) counteracts the inhibitory effect of chromatin is unknown. We report here a mechanism where RNA Polymerase II (Pol II) transcription is required to prime and maintain nucleosome depletion at Pol III loci and contributes to efficient Pol III recruitment upon re-initiation of growth from stationary phase in Fission yeast. The Pcr1 transcription factor participates in the recruitment of Pol II, which affects local histone occupancy through the associated SAGA complex and a Pol II phospho-S2 CTD / Mst2 pathway. These data expand the central role of Pol II in gene expression beyond mRNA synthesis.
Collapse
Affiliation(s)
- Carlo Yague-Sanz
- URPHYM-GEMO, The University of Namur, rue de Bruxelles, 61, Namur, 5000, Belgium
| | - Valérie Migeot
- URPHYM-GEMO, The University of Namur, rue de Bruxelles, 61, Namur, 5000, Belgium
| | - Marc Larochelle
- RNA Group, Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada
| | - François Bachand
- RNA Group, Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada
| | - Maxime Wéry
- ncRNA, Epigenetic and Genome Fluidity, Institut Curie, PSL Research University, Université Pierre et Marie Curie, CNRS UMR 3244, Paris, France
| | - Antonin Morillon
- ncRNA, Epigenetic and Genome Fluidity, Institut Curie, PSL Research University, Université Pierre et Marie Curie, CNRS UMR 3244, Paris, France
| | - Damien Hermand
- URPHYM-GEMO, The University of Namur, rue de Bruxelles, 61, Namur, 5000, Belgium.
| |
Collapse
|
10
|
Abstract
The most fundamental feature of cellular form is size, which sets the scale of all cell biological processes. Growth, form, and function are all necessarily linked in cell biology, but we often do not understand the underlying molecular mechanisms nor their specific functions. Here, we review progress toward determining the molecular mechanisms that regulate cell size in yeast, animals, and plants, as well as progress toward understanding the function of cell size regulation. It has become increasingly clear that the mechanism of cell size regulation is deeply intertwined with basic mechanisms of biosynthesis, and how biosynthesis can be scaled (or not) in proportion to cell size. Finally, we highlight recent findings causally linking aberrant cell size regulation to cellular senescence and their implications for cancer therapies.
Collapse
Affiliation(s)
- Shicong Xie
- Department of Biology, Stanford University, Stanford, California, USA;
| | - Matthew Swaffer
- Department of Biology, Stanford University, Stanford, California, USA;
| | - Jan M Skotheim
- Department of Biology, Stanford University, Stanford, California, USA;
- Chan Zuckerberg Biohub, San Francisco, California, USA
| |
Collapse
|
11
|
Chappleboim A, Joseph-Strauss D, Gershon O, Friedman N. Transcription feedback dynamics in the wake of cytoplasmic mRNA degradation shutdown. Nucleic Acids Res 2022; 50:5864-5880. [PMID: 35640599 PMCID: PMC9177992 DOI: 10.1093/nar/gkac411] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/02/2022] [Accepted: 05/09/2022] [Indexed: 01/02/2023] Open
Abstract
In the last decade, multiple studies demonstrated that cells maintain a balance of mRNA production and degradation, but the mechanisms by which cells implement this balance remain unknown. Here, we monitored cells' total and recently-transcribed mRNA profiles immediately following an acute depletion of Xrn1-the main 5'-3' mRNA exonuclease-which was previously implicated in balancing mRNA levels. We captured the detailed dynamics of the adaptation to rapid degradation of Xrn1 and observed a significant accumulation of mRNA, followed by a delayed global reduction in transcription and a gradual return to baseline mRNA levels. We found that this transcriptional response is not unique to Xrn1 depletion; rather, it is induced earlier when upstream factors in the 5'-3' degradation pathway are perturbed. Our data suggest that the mRNA feedback mechanism monitors the accumulation of inputs to the 5'-3' exonucleolytic pathway rather than its outputs.
Collapse
Affiliation(s)
- Alon Chappleboim
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Daphna Joseph-Strauss
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Omer Gershon
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Nir Friedman
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| |
Collapse
|
12
|
Mechanisms of cellular mRNA transcript homeostasis. Trends Cell Biol 2022; 32:655-668. [PMID: 35660047 DOI: 10.1016/j.tcb.2022.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 05/08/2022] [Accepted: 05/09/2022] [Indexed: 11/20/2022]
Abstract
For most genes, mRNA transcript abundance scales with cell size to ensure a constant concentration. Scaling of mRNA synthesis rates with cell size plays an important role, with regulation of the activity and abundance of RNA polymerase II (Pol II) now emerging as a key point of control. However, there is also considerable evidence for feedback mechanisms that kinetically couple the rates of mRNA synthesis, nuclear export, and degradation to allow cells to compensate for changes in one by adjusting the others. Researchers are beginning to integrate results from these different fields to reveal the mechanisms underlying transcript homeostasis. This will be crucial for moving beyond our current understanding of relative gene expression towards an appreciation of how absolute transcript levels are linked to other aspects of the cellular phenotype.
Collapse
|
13
|
Berry S, Müller M, Rai A, Pelkmans L. Feedback from nuclear RNA on transcription promotes robust RNA concentration homeostasis in human cells. Cell Syst 2022; 13:454-470.e15. [PMID: 35613616 DOI: 10.1016/j.cels.2022.04.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 12/13/2021] [Accepted: 04/21/2022] [Indexed: 12/18/2022]
Abstract
RNA concentration homeostasis involves coordinating RNA abundance and synthesis rates with cell size. Here, we study this in human cells by combining genome-wide perturbations with quantitative single-cell measurements. Despite relative ease in perturbing RNA synthesis, we find that RNA concentrations generally remain highly constant. Perturbations that would be expected to increase nuclear mRNA levels, including those targeting nuclear mRNA degradation or export, result in downregulation of RNA synthesis. This is associated with reduced abundance of transcription-associated proteins and protein states that are normally coordinated with RNA production in single cells, including RNA polymerase II (RNA Pol II) itself. Acute perturbations, elevation of nuclear mRNA levels, and mathematical modeling indicate that mammalian cells achieve robust mRNA concentration homeostasis by the mRNA-based negative feedback on transcriptional activity in the nucleus. This ultimately acts to coordinate RNA Pol II abundance with nuclear mRNA degradation and export rates and may underpin the scaling of mRNA abundance with cell size.
Collapse
Affiliation(s)
- Scott Berry
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland; EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.
| | - Micha Müller
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Arpan Rai
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Lucas Pelkmans
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.
| |
Collapse
|
14
|
García-Martínez J, Medina DA, Bellvís P, Sun M, Cramer P, Chávez S, Pérez-Ortín JE. The total mRNA concentration buffering system in yeast is global rather than gene-specific. RNA (NEW YORK, N.Y.) 2021; 27:1281-1290. [PMID: 34272303 PMCID: PMC8456998 DOI: 10.1261/rna.078774.121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
Gene expression in eukaryotes does not follow a linear process from transcription to translation and mRNA degradation. Instead it follows a circular process in which cytoplasmic mRNA decay crosstalks with nuclear transcription. In many instances, this crosstalk contributes to buffer mRNA at a roughly constant concentration. Whether the mRNA buffering concept operates on the total mRNA concentration or at the gene-specific level, and if the mechanism to do so is a global or a specific one, remain unknown. Here we assessed changes in mRNA concentrations and their synthesis rates along the transcriptome of aneuploid strains of the yeast Saccharomyces cerevisiae We also assessed mRNA concentrations and their synthesis rates in nonsense-mediated decay (NMD) targets in euploid strains. We found that the altered synthesis rates in the genes from the aneuploid chromosome and the changes in their mRNA stabilities were not counterbalanced. In addition, the stability of NMD targets was not specifically compensated by the changes in synthesis rate. We conclude that there is no genetic compensation of NMD mRNA targets in yeast, and total mRNA buffering uses mostly a global system rather than a gene-specific one.
Collapse
Affiliation(s)
- José García-Martínez
- Instituto de Biotecnología y Biomedicina (BIOTECMED), Facultad de Biológicas, Universitat de València, E46100 Burjassot, Spain
| | - Daniel A Medina
- Instituto de Biotecnología y Biomedicina (BIOTECMED), Facultad de Biológicas, Universitat de València, E46100 Burjassot, Spain
| | - Pablo Bellvís
- Instituto de Biomedicina de Sevilla, Universidad de Sevilla-CSIC-Hospital Universitario V. del Rocío, Seville 41012, Spain
| | - Mai Sun
- Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, 37077 Göttingen, Germany
| | - Patrick Cramer
- Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, 37077 Göttingen, Germany
| | - Sebastián Chávez
- Instituto de Biomedicina de Sevilla, Universidad de Sevilla-CSIC-Hospital Universitario V. del Rocío, Seville 41012, Spain
- Dirección de Evaluación y Acreditación, Agencia Andaluza del Conocimiento, planta 3ª C.P. 14006 Córdoba, Spain
| | - José E Pérez-Ortín
- Instituto de Biotecnología y Biomedicina (BIOTECMED), Facultad de Biológicas, Universitat de València, E46100 Burjassot, Spain
| |
Collapse
|
15
|
Duncan-Lewis C, Hartenian E, King V, Glaunsinger BA. Cytoplasmic mRNA decay represses RNA polymerase II transcription during early apoptosis. eLife 2021; 10:e58342. [PMID: 34085923 PMCID: PMC8192121 DOI: 10.7554/elife.58342] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/03/2021] [Indexed: 12/22/2022] Open
Abstract
RNA abundance is generally sensitive to perturbations in decay and synthesis rates, but crosstalk between RNA polymerase II transcription and cytoplasmic mRNA degradation often leads to compensatory changes in gene expression. Here, we reveal that widespread mRNA decay during early apoptosis represses RNAPII transcription, indicative of positive (rather than compensatory) feedback. This repression requires active cytoplasmic mRNA degradation, which leads to impaired recruitment of components of the transcription preinitiation complex to promoter DNA. Importin α/β-mediated nuclear import is critical for this feedback signaling, suggesting that proteins translocating between the cytoplasm and nucleus connect mRNA decay to transcription. We also show that an analogous pathway activated by viral nucleases similarly depends on nuclear protein import. Collectively, these data demonstrate that accelerated mRNA decay leads to the repression of mRNA transcription, thereby amplifying the shutdown of gene expression. This highlights a conserved gene regulatory mechanism by which cells respond to threats.
Collapse
Affiliation(s)
- Christopher Duncan-Lewis
- Department of Molecular and Cell Biology; University of California, BerkeleyBerkeleyUnited States
| | - Ella Hartenian
- Department of Molecular and Cell Biology; University of California, BerkeleyBerkeleyUnited States
| | - Valeria King
- Department of Molecular and Cell Biology; University of California, BerkeleyBerkeleyUnited States
| | - Britt A Glaunsinger
- Department of Molecular and Cell Biology; University of California, BerkeleyBerkeleyUnited States
- Department of Plant and Microbial Biology; University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical Institute, BerkeleyBerkeleyUnited States
| |
Collapse
|
16
|
Ramani MKV, Escobar EE, Irani S, Mayfield JE, Moreno RY, Butalewicz JP, Cotham VC, Wu H, Tadros M, Brodbelt JS, Zhang YJ. Structural Motifs for CTD Kinase Specificity on RNA Polymerase II during Eukaryotic Transcription. ACS Chem Biol 2020; 15:2259-2272. [PMID: 32568517 DOI: 10.1021/acschembio.0c00474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The phosphorylation states of RNA polymerase II coordinate the process of eukaryotic transcription by recruitment of transcription regulators. The individual residues of the repetitive heptad of the C-terminal domain (CTD) of the biggest subunit of RNA polymerase II are phosphorylated temporally at different stages of transcription. Intriguingly, despite similar flanking residues, phosphorylation of Ser2 and Ser5 in CTD heptads play dramatically different roles. The mechanism of how the kinases place phosphorylation on the correct serine is not well understood. In this paper, we use biochemical assays, mass spectrometry, molecular modeling, and structural analysis to understand the structural elements determining which serine of the CTD heptad is subject to phosphorylation. We identified three motifs in the activation/P+1 loops differentiating the intrinsic specificity of CTD in various CTD kinases. We characterized the enzyme specificity of the CTD kinases-CDK7 as Ser5-specific, Erk2 with dual specificity for Ser2 and Ser5, and Dyrk1a as a Ser2-specific kinase. We also show that the specificities of kinases are malleable and can be modified by incorporating mutations in their activation/P+1 loops that alter the interactions of the three motifs. Our results provide an important clue to the understanding of post-translational modification of RNA polymerase II temporally during active transcription.
Collapse
|
17
|
Abstract
Type I IFN (IFN-I) is thought to be rapidly internalized and degraded following binding to its receptor and initiation of signaling. However, many studies report the persistent effects mediated by IFN-I for days or even weeks, both ex vivo and in vivo. These long-lasting effects are attributed to downstream signaling molecules or induced effectors having a long half-life, particularly in specific cell types. Here, we describe a mechanism explaining the long-term effects of IFN-I. Following receptor binding, IFN-I is siloed into endosomal compartments. These intracellular “IFN silos” persist for days and can be visualized by fluorescence and electron microscopy. However, they are largely dormant functionally, due to IFN-I−induced negative regulators. By contrast, in individuals lacking these negative regulators, such as ISG15 or USP18, this siloed IFN-I can continue to signal from within the endosome. This mechanism may underlie the long-term effects of IFN-I therapy and may contribute to the pathophysiology of type I interferonopathies.
Collapse
|
18
|
Niewiadomska-Cimicka A, Hache A, Trottier Y. Gene Deregulation and Underlying Mechanisms in Spinocerebellar Ataxias With Polyglutamine Expansion. Front Neurosci 2020; 14:571. [PMID: 32581696 PMCID: PMC7296114 DOI: 10.3389/fnins.2020.00571] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/11/2020] [Indexed: 12/14/2022] Open
Abstract
Polyglutamine spinocerebellar ataxias (polyQ SCAs) include SCA1, SCA2, SCA3, SCA6, SCA7, and SCA17 and constitute a group of adult onset neurodegenerative disorders caused by the expansion of a CAG repeat sequence located within the coding region of specific genes, which translates into polyglutamine tract in the corresponding proteins. PolyQ SCAs are characterized by degeneration of the cerebellum and its associated structures and lead to progressive ataxia and other diverse symptoms. In recent years, gene and epigenetic deregulations have been shown to play a critical role in the pathogenesis of polyQ SCAs. Here, we provide an overview of the functions of wild type and pathogenic polyQ SCA proteins in gene regulation, describe the extent and nature of gene expression changes and their pathological consequences in diseases, and discuss potential avenues to further investigate converging and distinct disease pathways and to develop therapeutic strategies.
Collapse
Affiliation(s)
- Anna Niewiadomska-Cimicka
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Strasbourg, France
| | - Antoine Hache
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Strasbourg, France
| | - Yvon Trottier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Strasbourg, France
| |
Collapse
|
19
|
Abdel-Azim H, Sun W, Wu L. Strategies to generate functionally normal neutrophils to reduce infection and infection-related mortality in cancer chemotherapy. Pharmacol Ther 2019; 204:107403. [PMID: 31470030 DOI: 10.1016/j.pharmthera.2019.107403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/19/2019] [Indexed: 02/08/2023]
Abstract
Neutrophils form an essential part of innate immunity against infection. Cancer chemotherapy-induced neutropenia (CCIN) is a condition in which the number of neutrophils in a patient's bloodstream is decreased, leading to increased susceptibility to infection. Granulocyte colony-stimulating factor (GCSF) has been the only approved treatment for CCIN over two decades. To date, CCIN-related infection and mortality remain a significant concern, as neutrophils generated in response to administered GCSF are functionally immature and cannot effectively fight infection. This review summarizes the molecular regulatory mechanisms of neutrophil granulocytic differentiation and innate immunity development, dissects the biology of GCSF in myeloid expansion, highlights the shortcomings of GCSF in CCIN treatment, updates the recent advance of a selective retinoid agonist that promotes neutrophil granulocytic differentiation, and evaluates the benefits of developing GCSF biosimilars to increase access to GCSF biologics versus seeking a new mode to fundamentally advance GCSF therapy for treatment of CCIN.
Collapse
Affiliation(s)
- Hisham Abdel-Azim
- Pediatric Hematology-Oncology, Blood and Marrow Transplantation, Children's Hospital Los Angeles Saban Research Institute, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Los Angeles, CA 90027, USA
| | - Weili Sun
- Pediatric Hematology-Oncology, City of Hope National Medical Center, 1500 E. Duarte road, Duarte, CA 91010, USA
| | - Lingtao Wu
- Research and Development, Therapeutic Approaches, 2712 San Gabriel Boulevard, Rosemead, CA 91770, USA.
| |
Collapse
|
20
|
Hartenian E, Glaunsinger BA. Feedback to the central dogma: cytoplasmic mRNA decay and transcription are interdependent processes. Crit Rev Biochem Mol Biol 2019; 54:385-398. [PMID: 31656086 PMCID: PMC6871655 DOI: 10.1080/10409238.2019.1679083] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/13/2019] [Accepted: 10/08/2019] [Indexed: 02/06/2023]
Abstract
Transcription and RNA decay are key determinants of gene expression; these processes are typically considered as the uncoupled beginning and end of the messenger RNA (mRNA) lifecycle. Here we describe the growing number of studies demonstrating interplay between these spatially disparate processes in eukaryotes. Specifically, cells can maintain mRNA levels by buffering against changes in mRNA stability or transcription, and can also respond to virally induced accelerated decay by reducing RNA polymerase II gene expression. In addition to these global responses, there is also evidence that mRNAs containing a premature stop codon can cause transcriptional upregulation of homologous genes in a targeted fashion. In each of these systems, RNA binding proteins (RBPs), particularly those involved in mRNA degradation, are critical for cytoplasmic to nuclear communication. Although their specific mechanistic contributions are yet to be fully elucidated, differential trafficking of RBPs between subcellular compartments are likely to play a central role in regulating this gene expression feedback pathway.
Collapse
Affiliation(s)
- Ella Hartenian
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Britt A. Glaunsinger
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Department of Plant & Microbial Biology, University of California, Berkeley, CA 94720
- Howard Hughes Medical Institute, Berkeley, CA 94720
| |
Collapse
|
21
|
Timmers HTM, Tora L. Transcript Buffering: A Balancing Act between mRNA Synthesis and mRNA Degradation. Mol Cell 2019; 72:10-17. [PMID: 30290147 DOI: 10.1016/j.molcel.2018.08.023] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/20/2018] [Accepted: 08/15/2018] [Indexed: 10/28/2022]
Abstract
Transcript buffering involves reciprocal adjustments between overall rates in mRNA synthesis and degradation to maintain similar cellular concentrations of mRNAs. This phenomenon was first discovered in yeast and encompasses coordination between the nuclear and cytoplasmic compartments. Transcript buffering was revealed by novel methods for pulse labeling of RNA to determine in vivo synthesis and degradation rates. In this Perspective, we discuss the current knowledge of transcript buffering. Emphasis is placed on the future challenges to determine the nature and directionality of the buffering signals, the generality of transcript buffering beyond yeast, and the molecular mechanisms responsible for this balancing.
Collapse
Affiliation(s)
- H Th Marc Timmers
- German Cancer Consortium (DKTK), partner site Freiburg, German Cancer Research Center (DKFZ) Zentrale Klinische Forschung (ZKF), and Medical Faculty-University of Freiburg, Breisacher Str. 66, 79106 Freiburg, Germany.
| | - László Tora
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, UMR7104, INSERM U1258 and Université de Strasbourg, 67404 Illkirch, France.
| |
Collapse
|
22
|
Baptista T, Devys D. Saccharomyces cerevisiae Metabolic Labeling with 4-thiouracil and the Quantification of Newly Synthesized mRNA As a Proxy for RNA Polymerase II Activity. J Vis Exp 2018. [PMID: 30394386 DOI: 10.3791/57982] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Global defects in RNA polymerase II transcription might be overlooked by transcriptomic studies analyzing steady-state RNA. Indeed, the global decrease in mRNA synthesis has been shown to be compensated by a simultaneous decrease in mRNA degradation to restore normal steady-state levels. Hence, the genome-wide quantification of mRNA synthesis, independently from mRNA decay, is the best direct reflection of RNA polymerase II transcriptional activity. Here, we discuss a method using non-perturbing metabolic labeling of nascent RNAs in Saccharomyces cerevisiae (S. cerevisiae). Specifically, the cells are cultured for 6 min with a uracil analog, 4-thiouracil, and the labeled newly transcribed RNAs are purified and quantified to determine the synthesis rates of all individual mRNA. Moreover, using labeled Schizosaccharomyces pombe cells as internal standard allows comparing mRNA synthesis in different S. cerevisiae strains. Using this protocol and fitting the data with a dynamic kinetic model, the corresponding mRNA decay rates can be determined.
Collapse
Affiliation(s)
- Tiago Baptista
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France; Centre National de la Recherche Scientifique, Illkirch, France; Institut National de la Santé et de la Recherche Médicale, Illkirch, France; Université de Strasbourg
| | - Didier Devys
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France; Centre National de la Recherche Scientifique, Illkirch, France; Institut National de la Santé et de la Recherche Médicale, Illkirch, France; Université de Strasbourg;
| |
Collapse
|
23
|
Rimel JK, Taatjes DJ. The essential and multifunctional TFIIH complex. Protein Sci 2018; 27:1018-1037. [PMID: 29664212 PMCID: PMC5980561 DOI: 10.1002/pro.3424] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 12/19/2022]
Abstract
TFIIH is a 10‐subunit complex that regulates RNA polymerase II (pol II) transcription but also serves other important biological roles. Although much remains unknown about TFIIH function in eukaryotic cells, much progress has been made even in just the past few years, due in part to technological advances (e.g. cryoEM and single molecule methods) and the development of chemical inhibitors of TFIIH enzymes. This review focuses on the major cellular roles for TFIIH, with an emphasis on TFIIH function as a regulator of pol II transcription. We describe the structure of TFIIH and its roles in pol II initiation, promoter‐proximal pausing, elongation, and termination. We also discuss cellular roles for TFIIH beyond transcription (e.g. DNA repair, cell cycle regulation) and summarize small molecule inhibitors of TFIIH and diseases associated with defects in TFIIH structure and function.
Collapse
Affiliation(s)
- Jenna K Rimel
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado, 80303
| | - Dylan J Taatjes
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado, 80303
| |
Collapse
|
24
|
Xu H, Bai X, Yu S, Liu Q, Pestell RG, Wu K. MAT1 correlates with molecular subtypes and predicts poor survival in breast cancer. Chin J Cancer Res 2018; 30:351-363. [PMID: 30046229 DOI: 10.21147/j.issn.1000-9604.2018.03.07] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Objective Menage a trois 1 (MAT1) is a targeting subunit of cyclin-dependent kinase-activating kinase and general transcription factor IIH kinase, which modulates cell cycle, transcription and DNA repair. Its dysregulation is responsible for diseases including cancers. To further explore the role of MAT1 in breast cancer, we investigated the pathways in which MAT1 might be involved, the association between MAT1 and molecular subtypes, and the role of MAT1 in clinical outcomes of breast cancer patients. Methods We conducted immunohistochemistry staining on tissue microarray and immunofluorescence staining on sections of MAT1 stable breast cancer cells. Also, we performed Kyoto Encyclopedia of Genes and Genomes pathway analysis, correlation analysis and prognosis analysis on public databases. Results MAT1 was involved in multiple pathways including normal physiology signaling and disease-related signaling. Furthermore, MAT1 positively correlated with the protein status of estrogen receptor and progesterone receptor, and was enriched in luminal-type and human epidermal growth factor receptor 2-enriched breast cancer in comparison with basal-like subtype at both mRNA and protein levels. Correlation analysis revealed significant association between MAT1 mRNA amount and epithelial markers, mesenchymal markers, cancer stem cell markers, apoptosis markers, transcription markers and oncogenes. Consistently, the results of immunofluorescence stain indicated that MAT1 overexpression enhanced the protein abundance of epidermal growth factor receptor, vimentin, sex determining region Y-box 2 and sine oculis homeobox homolog 1. Importantly, Kaplan-Meier Plotter analysis reflected that MAT1 could serve as a prognostic biomarker predicting worse relapse-free survival and metastasis-free survival. Conclusions MAT1 is correlated with molecular subtypes and is associated with unfavorable prognosis for breast cancer patients.
Collapse
Affiliation(s)
- Hanxiao Xu
- Department of Oncology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xianguang Bai
- Medical School of Pingdingshan University, Pingdingshan 467000, China
| | - Shengnan Yu
- Department of Oncology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Qian Liu
- Department of Oncology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Richard G Pestell
- Pennsylvania Center for Cancer and Regenerative Medicine, Wynnewood, PA 19096, USA
| | - Kongming Wu
- Department of Oncology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| |
Collapse
|
25
|
Engineered Covalent Inactivation of TFIIH-Kinase Reveals an Elongation Checkpoint and Results in Widespread mRNA Stabilization. Mol Cell 2016; 63:433-44. [PMID: 27477907 DOI: 10.1016/j.molcel.2016.06.036] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 05/09/2016] [Accepted: 06/23/2016] [Indexed: 12/25/2022]
Abstract
During transcription initiation, the TFIIH-kinase Kin28/Cdk7 marks RNA polymerase II (Pol II) by phosphorylating the C-terminal domain (CTD) of its largest subunit. Here we describe a structure-guided chemical approach to covalently and specifically inactivate Kin28 kinase activity in vivo. This method of irreversible inactivation recapitulates both the lethal phenotype and the key molecular signatures that result from genetically disrupting Kin28 function in vivo. Inactivating Kin28 impacts promoter release to differing degrees and reveals a "checkpoint" during the transition to productive elongation. While promoter-proximal pausing is not observed in budding yeast, inhibition of Kin28 attenuates elongation-licensing signals, resulting in Pol II accumulation at the +2 nucleosome and reduced transition to productive elongation. Furthermore, upon inhibition, global stabilization of mRNA masks different degrees of reduction in nascent transcription. This study resolves long-standing controversies on the role of Kin28 in transcription and provides a rational approach to irreversibly inhibit other kinases in vivo.
Collapse
|
26
|
Jeronimo C, Collin P, Robert F. The RNA Polymerase II CTD: The Increasing Complexity of a Low-Complexity Protein Domain. J Mol Biol 2016; 428:2607-2622. [DOI: 10.1016/j.jmb.2016.02.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 01/27/2016] [Accepted: 02/02/2016] [Indexed: 01/18/2023]
|
27
|
True JD, Muldoon JJ, Carver MN, Poorey K, Shetty SJ, Bekiranov S, Auble DT. The Modifier of Transcription 1 (Mot1) ATPase and Spt16 Histone Chaperone Co-regulate Transcription through Preinitiation Complex Assembly and Nucleosome Organization. J Biol Chem 2016; 291:15307-19. [PMID: 27226635 DOI: 10.1074/jbc.m116.735134] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Indexed: 11/06/2022] Open
Abstract
Modifier of transcription 1 (Mot1) is a conserved and essential Swi2/Snf2 ATPase that can remove TATA-binding protein (TBP) from DNA using ATP hydrolysis and in so doing exerts global effects on transcription. Spt16 is also essential and functions globally in transcriptional regulation as a component of the facilitates chromatin transcription (FACT) histone chaperone complex. Here we demonstrate that Mot1 and Spt16 regulate a largely overlapping set of genes in Saccharomyces cerevisiae. As expected, Mot1 was found to control TBP levels at co-regulated promoters. In contrast, Spt16 did not affect TBP recruitment. On a global scale, Spt16 was required for Mot1 promoter localization, and Mot1 also affected Spt16 localization to genes. Interestingly, we found that Mot1 has an unanticipated role in establishing or maintaining the occupancy and positioning of nucleosomes at the 5' ends of genes. Spt16 has a broad role in regulating chromatin organization in gene bodies, including those nucleosomes affected by Mot1. These results suggest that the large scale overlap in Mot1 and Spt16 function arises from a combination of both their unique and shared functions in transcription complex assembly and chromatin structure regulation.
Collapse
Affiliation(s)
- Jason D True
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Joseph J Muldoon
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Melissa N Carver
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Kunal Poorey
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Savera J Shetty
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Stefan Bekiranov
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - David T Auble
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| |
Collapse
|
28
|
Luo J, Cimermancic P, Viswanath S, Ebmeier CC, Kim B, Dehecq M, Raman V, Greenberg CH, Pellarin R, Sali A, Taatjes DJ, Hahn S, Ranish J. Architecture of the Human and Yeast General Transcription and DNA Repair Factor TFIIH. Mol Cell 2015; 59:794-806. [PMID: 26340423 DOI: 10.1016/j.molcel.2015.07.016] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/10/2015] [Accepted: 07/17/2015] [Indexed: 10/23/2022]
Abstract
TFIIH is essential for both RNA polymerase II transcription and DNA repair, and mutations in TFIIH can result in human disease. Here, we determine the molecular architecture of human and yeast TFIIH by an integrative approach using chemical crosslinking/mass spectrometry (CXMS) data, biochemical analyses, and previously published electron microscopy maps. We identified four new conserved "topological regions" that function as hubs for TFIIH assembly and more than 35 conserved topological features within TFIIH, illuminating a network of interactions involved in TFIIH assembly and regulation of its activities. We show that one of these conserved regions, the p62/Tfb1 Anchor region, directly interacts with the DNA helicase subunit XPD/Rad3 in native TFIIH and is required for the integrity and function of TFIIH. We also reveal the structural basis for defects in patients with xeroderma pigmentosum and trichothiodystrophy, with mutations found at the interface between the p62 Anchor region and the XPD subunit.
Collapse
Affiliation(s)
- Jie Luo
- Institute for Systems Biology, 401 Terry Avenue North, Seattle, WA 98109, USA
| | - Peter Cimermancic
- Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biomedical Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Shruthi Viswanath
- Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biomedical Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Christopher C Ebmeier
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80303, USA
| | - Bong Kim
- Institute for Systems Biology, 401 Terry Avenue North, Seattle, WA 98109, USA
| | - Marine Dehecq
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, PO Box 19024, Mailstop A1-162, Seattle, WA 98109, USA; Génétique des Interactions Macromoléculaires, Institut Pasteur, CNRS UMR3525, 25-28 rue du docteur Roux, 75015 Paris, France
| | - Vishnu Raman
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80303, USA
| | - Charles H Greenberg
- Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biomedical Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Riccardo Pellarin
- Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biomedical Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Andrej Sali
- Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biomedical Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Dylan J Taatjes
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80303, USA
| | - Steven Hahn
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, PO Box 19024, Mailstop A1-162, Seattle, WA 98109, USA
| | - Jeff Ranish
- Institute for Systems Biology, 401 Terry Avenue North, Seattle, WA 98109, USA.
| |
Collapse
|
29
|
Ravens S, Yu C, Ye T, Stierle M, Tora L. Tip60 complex binds to active Pol II promoters and a subset of enhancers and co-regulates the c-Myc network in mouse embryonic stem cells. Epigenetics Chromatin 2015; 8:45. [PMID: 26550034 PMCID: PMC4636812 DOI: 10.1186/s13072-015-0039-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/29/2015] [Indexed: 01/24/2023] Open
Abstract
Background Tip60 (KAT5) is the histone acetyltransferase (HAT) of the mammalian Tip60/NuA4 complex. While Tip60 is important for early mouse development and mouse embryonic stem cell (mESC) pluripotency, the function of Tip60 as reflected in a genome-wide context is not yet well understood. Results Gel filtration of nuclear mESCs extracts indicate incorporation of Tip60 into large molecular complexes and exclude the existence of large quantities of “free” Tip60 within the nuclei of ESCs. Thus, monitoring of Tip60 binding to the genome should reflect the behaviour of Tip60-containing complexes. The genome-wide mapping of Tip60 binding in mESCs by chromatin immunoprecipitation (ChIP) coupled with high-throughput sequencing (ChIP-seq) shows that the Tip60 complex is present at promoter regions of predominantly active genes that are bound by RNA polymerase II (Pol II) and contain the H3K4me3 histone mark. The coactivator HAT complexes, Tip60- and Mof (KAT8)-containing (NSL and MSL), show a global overlap at promoters, whereas distinct binding profiles at enhancers suggest different regulatory functions of each essential HAT complex. Interestingly, Tip60 enrichment peaks at about 200 bp downstream of the transcription start sites suggesting a function for the Tip60 complexes in addition to histone acetylation. The comparison of genome-wide binding profiles of Tip60 and c-Myc, a somatic cell reprogramming factor that binds predominantly to active genes in mESCs, demonstrate that Tip60 and c-Myc co-bind at 50–60 % of their binding sites. We also show that the Tip60 complex binds to a subset of bivalent developmental genes and defines a set of mESC-specific enhancer as well as super-enhancer regions. Conclusions Our study suggests that the Tip60 complex functions as a global transcriptional co-activator at most active Pol II promoters, co-regulates the ESC-specific c-Myc network, important for ESC self-renewal and cell metabolism and acts at a subset of active distal regulatory elements, or super enhancers, in mESCs. Electronic supplementary material The online version of this article (doi:10.1186/s13072-015-0039-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sarina Ravens
- Cellular Signalling and Nuclear Dynamics Programme, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U964, Université de Strasbourg (UdS), BP 10142, 1 Rue Laurent Fries, CU de Strasbourg, 67404 Illkirch Cedex, France
| | - Changwei Yu
- Cellular Signalling and Nuclear Dynamics Programme, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U964, Université de Strasbourg (UdS), BP 10142, 1 Rue Laurent Fries, CU de Strasbourg, 67404 Illkirch Cedex, France
| | - Tao Ye
- Microarrays and Deep Sequencing Platform, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U964, UdS, BP 10142, CU de Strasbourg, 67404 Illkirch Cedex, France
| | - Matthieu Stierle
- Cellular Signalling and Nuclear Dynamics Programme, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U964, Université de Strasbourg (UdS), BP 10142, 1 Rue Laurent Fries, CU de Strasbourg, 67404 Illkirch Cedex, France
| | - Laszlo Tora
- Cellular Signalling and Nuclear Dynamics Programme, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U964, Université de Strasbourg (UdS), BP 10142, 1 Rue Laurent Fries, CU de Strasbourg, 67404 Illkirch Cedex, France
| |
Collapse
|
30
|
Medler S, Ansari A. Gene looping facilitates TFIIH kinase-mediated termination of transcription. Sci Rep 2015; 5:12586. [PMID: 26286112 PMCID: PMC4541409 DOI: 10.1038/srep12586] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 06/08/2015] [Indexed: 12/14/2022] Open
Abstract
TFIIH is a general transcription factor with kinase and helicase activities. The kinase activity resides in the Kin28 subunit of TFIIH. The role of Kin28 kinase in the early steps of transcription is well established. Here we report a novel role of Kin28 in the termination of transcription. We show that RNAPII reads through a termination signal upon kinase inhibition. Furthermore, the recruitment of termination factors towards the 3′ end of a gene was compromised in the kinase mutant, thus confirming the termination defect. A concomitant decrease in crosslinking of termination factors near the 5′ end of genes was also observed in the kinase-defective mutant. Simultaneous presence of termination factors towards both the ends of a gene is indicative of gene looping; while the loss of termination factor occupancy from the distal ends suggest the abolition of a looped gene conformation. Accordingly, CCC analysis revealed that the looped architecture of genes was severely compromised in the Kin28 kinase mutant. In a looping defective sua7-1 mutant, even the enzymatically active Kin28 kinase could not rescue the termination defect. These results strongly suggest a crucial role of Kin28 kinase-dependent gene looping in the termination of transcription in budding yeast.
Collapse
Affiliation(s)
- Scott Medler
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall Detroit, MI 48202
| | - Athar Ansari
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall Detroit, MI 48202
| |
Collapse
|
31
|
Genome-wide targeting of the epigenetic regulatory protein CTCF to gene promoters by the transcription factor TFII-I. Proc Natl Acad Sci U S A 2015; 112:E677-86. [PMID: 25646466 DOI: 10.1073/pnas.1416674112] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
CCCTC-binding factor (CTCF) is a key regulator of nuclear chromatin structure and gene regulation. The impact of CTCF on transcriptional output is highly varied, ranging from repression to transcriptional pausing and transactivation. The multifunctional nature of CTCF may be directed solely through remodeling chromatin architecture. However, another hypothesis is that the multifunctional nature of CTCF is mediated, in part, through differential association with protein partners having unique functions. Consistent with this hypothesis, our mass spectrometry analyses of CTCF interacting partners reveal a previously undefined association with the transcription factor general transcription factor II-I (TFII-I). Biochemical fractionation of CTCF indicates that a distinct CTCF complex incorporating TFII-I is assembled on DNA. Unexpectedly, we found that the interaction between CTCF and TFII-I is essential for directing CTCF to the promoter proximal regulatory regions of target genes across the genome, particularly at genes involved in metabolism. At genes coregulated by CTCF and TFII-I, we find knockdown of TFII-I results in diminished CTCF binding, lack of cyclin-dependent kinase 8 (CDK8) recruitment, and an attenuation of RNA polymerase II phosphorylation at serine 5. Phenotypically, knockdown of TFII-I alters the cellular response to metabolic stress. Our data indicate that TFII-I directs CTCF binding to target genes, and in turn the two proteins cooperate to recruit CDK8 and enhance transcription initiation.
Collapse
|
32
|
Perner J, Lasserre J, Kinkley S, Vingron M, Chung HR. Inference of interactions between chromatin modifiers and histone modifications: from ChIP-Seq data to chromatin-signaling. Nucleic Acids Res 2014; 42:13689-95. [PMID: 25414326 PMCID: PMC4267652 DOI: 10.1093/nar/gku1234] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Chromatin modifiers and histone modifications are components of a chromatin-signaling network involved in transcription and its regulation. The interactions between chromatin modifiers and histone modifications are often unknown, are based on the analysis of few genes or are studied in vitro. Here, we apply computational methods to recover interactions between chromatin modifiers and histone modifications from genome-wide ChIP-Seq data. These interactions provide a high-confidence backbone of the chromatin-signaling network. Many recovered interactions have literature support; others provide hypotheses about yet unknown interactions. We experimentally verified two of these predicted interactions, leading to a link between H4K20me1 and members of the Polycomb Repressive Complexes 1 and 2. Our results suggest that our computationally derived interactions are likely to lead to novel biological insights required to establish the connectivity of the chromatin-signaling network involved in transcription and its regulation.
Collapse
Affiliation(s)
- Juliane Perner
- Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Julia Lasserre
- Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Sarah Kinkley
- Otto-Warburg-Laboratories Epigenomics, Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Martin Vingron
- Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Ho-Ryun Chung
- Otto-Warburg-Laboratories Epigenomics, Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| |
Collapse
|
33
|
Bonnet J, Wang CY, Baptista T, Vincent SD, Hsiao WC, Stierle M, Kao CF, Tora L, Devys D. The SAGA coactivator complex acts on the whole transcribed genome and is required for RNA polymerase II transcription. Genes Dev 2014; 28:1999-2012. [PMID: 25228644 PMCID: PMC4173158 DOI: 10.1101/gad.250225.114] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The SAGA coactivator complex contains distinct chromatin-modifying activities and is recruited by DNA-bound activators to regulate the expression of a subset of genes. Bonnet et al. discovered that SAGA acetylates the promoters and deubiquitinates the transcribed region of all expressed genes. SAGA also plays a critical role for RNA polymerase II recruitment at all expressed genes. This study uncovers a new function for SAGA as a bona fide cofactor for all RNA polymerase II transcription. The SAGA (Spt–Ada–Gcn5 acetyltransferase) coactivator complex contains distinct chromatin-modifying activities and is recruited by DNA-bound activators to regulate the expression of a subset of genes. Surprisingly, recent studies revealed little overlap between genome-wide SAGA-binding profiles and changes in gene expression upon depletion of subunits of the complex. As indicators of SAGA recruitment on chromatin, we monitored in yeast and human cells the genome-wide distribution of histone H3K9 acetylation and H2B ubiquitination, which are respectively deposited or removed by SAGA. Changes in these modifications after inactivation of the corresponding enzyme revealed that SAGA acetylates the promoters and deubiquitinates the transcribed region of all expressed genes. In agreement with this broad distribution, we show that SAGA plays a critical role for RNA polymerase II recruitment at all expressed genes. In addition, through quantification of newly synthesized RNA, we demonstrated that SAGA inactivation induced a strong decrease of mRNA synthesis at all tested genes. Analysis of the SAGA deubiquitination activity further revealed that SAGA acts on the whole transcribed genome in a very fast manner, indicating a highly dynamic association of the complex with chromatin. Thus, our study uncovers a new function for SAGA as a bone fide cofactor for all RNA polymerase II transcription.
Collapse
Affiliation(s)
- Jacques Bonnet
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France
| | - Chen-Yi Wang
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Tiago Baptista
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France
| | - Stéphane D Vincent
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France
| | - Wei-Chun Hsiao
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Matthieu Stierle
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France
| | - Cheng-Fu Kao
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - László Tora
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France
| | - Didier Devys
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France;
| |
Collapse
|
34
|
Abstract
What has been will be again, what has been done will be done again; there is nothing new under the sun. -Ecclesiastes 1:9 (New International Version) Posttranscriptional regulation of gene expression has an important role in defining the phenotypic characteristics of an organism. Well-defined steps in mRNA metabolism that occur in the nucleus-capping, splicing, and polyadenylation-are mechanistically linked to the process of transcription. Recent evidence suggests another link between RNA polymerase II (Pol II) and a posttranscriptional process that occurs in the cytoplasm-mRNA decay. This conclusion appears to represent a conundrum. How could mRNA synthesis in the nucleus and mRNA decay in the cytoplasm be mechanistically linked? After a brief overview of mRNA processing, we will review the recent evidence for transcription-coupled mRNA decay and the possible involvement of Snf1, the Saccharomyces cerevisiae ortholog of AMP-activated protein kinase, in this process.
Collapse
|
35
|
Cyclin-dependent kinase 7 controls mRNA synthesis by affecting stability of preinitiation complexes, leading to altered gene expression, cell cycle progression, and survival of tumor cells. Mol Cell Biol 2014; 34:3675-88. [PMID: 25047832 DOI: 10.1128/mcb.00595-14] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyclin-dependent kinase 7 (CDK7) activates cell cycle CDKs and is a member of the general transcription factor TFIIH. Although there is substantial evidence for an active role of CDK7 in mRNA synthesis and associated processes, the degree of its influence on global and gene-specific transcription in mammalian species is unclear. In the current study, we utilize two novel inhibitors with high specificity for CDK7 to demonstrate a restricted but robust impact of CDK7 on gene transcription in vivo and in in vitro-reconstituted reactions. We distinguish between relative low- and high-dose responses and relate them to distinct molecular mechanisms and altered physiological responses. Low inhibitor doses cause rapid clearance of paused RNA polymerase II (RNAPII) molecules and sufficed to cause genome-wide alterations in gene expression, delays in cell cycle progression at both the G1/S and G2/M checkpoints, and diminished survival of human tumor cells. Higher doses and prolonged inhibition led to strong reductions in RNAPII carboxyl-terminal domain (CTD) phosphorylation, eventual activation of the p53 program, and increased cell death. Together, our data reason for a quantitative contribution of CDK7 to mRNA synthesis, which is critical for cellular homeostasis.
Collapse
|
36
|
Lou S, Liu G, Shimada H, Yang X, He Q, Wu L. The lost intrinsic fragmentation of MAT1 protein during granulopoiesis promotes the growth and metastasis of leukemic myeloblasts. Stem Cells 2014; 31:1942-53. [PMID: 23765726 DOI: 10.1002/stem.1444] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 04/17/2013] [Accepted: 05/02/2013] [Indexed: 01/15/2023]
Abstract
MAT1, an assembly factor and targeting subunit of both cyclin-dependent kinase-activating kinase (CAK) and general transcription factor IIH (TFIIH) kinase, regulates cell cycle and transcription. Previous studies show that expression of intact MAT1 protein is associated with expansion of human hematopoietic stem cells (HSC), whereas intrinsically programmed or retinoic acid (RA)-induced MAT1 fragmentation accompanies granulocytic differentiation of HSC or leukemic myeloblasts. Here we determined that, in humanized mouse microenvironment, MAT1 overexpression resisted intrinsic MAT1 fragmentation to sustain hematopoietic CD34+ cell expansion while preventing granulopoiesis. Conversely, we mimicked MAT1 fragmentation in vitro and in a mouse model by overexpressing a fragmented 81-aa MAT1 polypeptide (pM9) that retains the domain for assembling CAK but cannot affix CAK to TFIIH-core. Our results showed that pM9 formed ΔCAK by competing with MAT1 for CAK assembly to mimic MAT1 fragmentation-depletion of CAK. This resulting ΔCAK acted as a dominant negative to inhibit the growth and metastasis of different leukemic myeloblasts, with or without RA resistance, by concurrently suppressing CAK and TFIIH kinase activities to inhibit cell cycle and gene transcription. These findings suggest that the intrinsically programmed MAT1 expression and fragmentation regulate granulopoiesis by inversely coordinating CAK and TFIIH activities, whereas pM9 shares a mechanistic resemblance with MAT1 fragmentation in suppressing myeloid leukemogenesis.
Collapse
Affiliation(s)
- Siyue Lou
- Department of Pathology, Children's Hospital Los Angeles, The Saban Research Institute, Los Angeles, California, USA
| | | | | | | | | | | |
Collapse
|
37
|
ARCH domain of XPD, an anchoring platform for CAK that conditions TFIIH DNA repair and transcription activities. Proc Natl Acad Sci U S A 2013; 110:E633-42. [PMID: 23382212 DOI: 10.1073/pnas.1213981110] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The xeroderma pigmentosum group D (XPD) helicase is a subunit of transcription/DNA repair factor, transcription factor II H (TFIIH) that catalyzes the unwinding of a damaged DNA duplex during nucleotide excision repair. Apart from two canonical helicase domains, XPD is composed of a 4Fe-S cluster domain involved in DNA damage recognition and a module of uncharacterized function termed the "ARCH domain." By investigating the consequences of a mutation found in a patient with trichothiodystrophy, we show that the ARCH domain is critical for the recruitment of the cyclin-dependent kinase (CDK)-activating kinase (CAK) complex. Indeed, this mutation not only affects the interaction with the MAT1 CAK subunit, thereby decreasing the in vitro basal transcription activity of TFIIH itself and impeding the efficient recruitment of the transcription machinery on the promoter of an activated gene, but also impairs the DNA unwinding activity of XPD and the nucleotide excision repair activity of TFIIH. We further demonstrate the role of CAK in downregulating the XPD helicase activity within TFIIH. Taken together, our results identify the ARCH domain of XPD as a platform for the recruitment of CAK and as a potential molecular switch that might control TFIIH composition and play a key role in the conversion of TFIIH from a factor active in transcription to a factor involved in DNA repair.
Collapse
|
38
|
The fate of the messenger is pre-determined: a new model for regulation of gene expression. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:643-53. [PMID: 23337853 DOI: 10.1016/j.bbagrm.2013.01.004] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/07/2013] [Accepted: 01/08/2013] [Indexed: 02/08/2023]
Abstract
Recent years have seen a rise in publications demonstrating coupling between transcription and mRNA decay. This coupling most often accompanies cellular processes that involve transitions in gene expression patterns, for example during mitotic division and cellular differentiation and in response to cellular stress. Transcription can affect the mRNA fate by multiple mechanisms. The most novel finding is the process of co-transcriptional imprinting of mRNAs with proteins, which in turn regulate cytoplasmic mRNA stability. Transcription therefore is not only a catalyst of mRNA synthesis but also provides a platform that enables imprinting, which coordinates between transcription and mRNA decay. Here we present an overview of the literature, which provides the evidence of coupling between transcription and decay, review the mechanisms and regulators by which the two processes are coupled, discuss why such coupling is beneficial and present a new model for regulation of gene expression. This article is part of a Special Issue entitled: RNA Decay mechanisms.
Collapse
|
39
|
Dori-Bachash M, Shalem O, Manor YS, Pilpel Y, Tirosh I. Widespread promoter-mediated coordination of transcription and mRNA degradation. Genome Biol 2012; 13:R114. [PMID: 23237624 PMCID: PMC4056365 DOI: 10.1186/gb-2012-13-12-r114] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 12/13/2012] [Indexed: 12/16/2022] Open
Abstract
Background Previous work showed that mRNA degradation is coordinated with transcription in yeast, and in several genes the control of mRNA degradation was linked to promoter elements through two different mechanisms. Here we show at the genomic scale that the coordination of transcription and mRNA degradation is promoter-dependent in yeast and is also observed in humans. Results We first demonstrate that swapping upstream cis-regulatory sequences between two yeast species affects both transcription and mRNA degradation and suggest that while some cis-regulatory elements control either transcription or degradation, multiple other elements enhance both processes. Second, we show that adjacent yeast genes that share a promoter (through divergent orientation) have increased similarity in their patterns of mRNA degradation, providing independent evidence for the promoter-mediated coupling of transcription to mRNA degradation. Finally, analysis of the differences in mRNA degradation rates between mammalian cell types or mammalian species suggests a similar coordination between transcription and mRNA degradation in humans. Conclusions Our results extend previous studies and suggest a pervasive promoter-mediated coordination between transcription and mRNA degradation in yeast. The diverse genes and regulatory elements associated with this coordination suggest that it is generated by a global mechanism of gene regulation and modulated by gene-specific mechanisms. The observation of a similar coupling in mammals raises the possibility that coupling of transcription and mRNA degradation may reflect an evolutionarily conserved phenomenon in gene regulation.
Collapse
|
40
|
Abstract
The transcription initiation factor TFIIH is a remarkable protein complex that has a fundamental role in the transcription of protein-coding genes as well as during the DNA nucleotide excision repair pathway. The detailed understanding of how TFIIH functions to coordinate these two processes is also providing an explanation for the phenotypes observed in patients who bear mutations in some of the TFIIH subunits. In this way, studies of TFIIH have revealed tight molecular connections between transcription and DNA repair and have helped to define the concept of 'transcription diseases'.
Collapse
Affiliation(s)
- Emmanuel Compe
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UdS, BP 163, 67404 Illkirch Cedex, C. U., Strasbourg, France.
| | | |
Collapse
|
41
|
Huang X, Tian C, Liu M, Wang Y, Tolmachev AV, Sharma S, Yu F, Fu K, Zheng J, Ding SJ. Quantitative proteomic analysis of mouse embryonic fibroblasts and induced pluripotent stem cells using 16O/18O labeling. J Proteome Res 2012; 11:2091-102. [PMID: 22375802 DOI: 10.1021/pr300155r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Induced pluripotent stem cells (iPSC) hold great promise for regenerative medicine as well as for investigations into the pathogenesis and treatment of various diseases. Understanding of key intracellular signaling pathways and protein targets that control development of iPSC from somatic cells is essential for designing new approaches to improve reprogramming efficiency. Here, we report the development and application of an integrated quantitative proteomics platform for investigating differences in protein expressions between mouse embryonic fibroblasts (MEF) and MEF-derived iPSC. This platform consists of 16O/18O labeling, multidimensional peptide separation coupled with tandem mass spectrometry, and data analysis with UNiquant software. With this platform, a total of 2481 proteins were identified and quantified from the 16O/18O-labeled MEF-iPSC proteome mixtures with a false discovery rate of 0.01. Among them, 218 proteins were significantly upregulated, while 247 proteins were significantly downregulated in iPSC compared to MEF. Many nuclear proteins, including Hdac1, Dnmt1, Pcna, Ccnd1, Smarcc1, and subunits in DNA replication and RNA polymerase II complex, were found to be enhanced in iPSC. Protein network analysis revealed that Pcna functions as a hub orchestrating complicated mechanisms including DNA replication, epigenetic inheritance (Dnmt1), and chromatin remodeling (Smarcc1) to reprogram MEF and maintain stemness of iPSC.
Collapse
Affiliation(s)
- Xin Huang
- Department of Pathology and Microbiology, Mass Spectrometry and Proteomics Core Facility, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Abstract
Mammalian preimplantation development is a process of dedifferentiation from the terminally differentiated eggs to the totipotent blastomeres at the cleavage stage, and then to the pluripotent cells at the blastocyst stage. Maternal factors that accumulate during oogenesis dominate early preimplantation development until the embryonic factors gain control after the activation of the embryonic genome. Recently, a handful of maternal factors that are encoded by the maternal-effect genes have been characterized in genetically modified mouse models. These factors are shown to participate in many aspects of preimplantation development, such as the degradation of maternal macromolecues, epigenetic modification, protein translation, cellular signaling transduction, and cell compaction. Even so, little is known about the interactions between different maternal factors. In this chapter, we have summarized the functions of known maternal factors and hopefully this will lead to a better understanding of the regulation of preimplantation embryogenesis by the maternal regulatory network.
Collapse
Affiliation(s)
- Wenjing Zheng
- Department of Cell and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
| | | |
Collapse
|
43
|
Transcription inhibition as a therapeutic target for cancer. Cancers (Basel) 2011; 3:4170-90. [PMID: 24213132 PMCID: PMC3763417 DOI: 10.3390/cancers3044170] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 11/14/2011] [Accepted: 11/16/2011] [Indexed: 01/10/2023] Open
Abstract
During tumorigenesis the transformed cells lose their normal growth control mechanisms and become dependent on oncogenes' products and pathways for survival. Treatments tailored to block the expression or function of transforming genes have shown efficacy in eliminating neoplastic cells. The mRNAs of many oncogenes, as well as regulators of other key processes such as cell proliferation, angiogenesis, and apoptosis, typically have shorter half-lives. Agents that impede mRNA synthesis are expected to selectively hinder the expression of these genes and, therefore, be detrimental to neoplastic cells that are physiologically dependent on them. In addition to exploiting the tumor cells' dependency on short-lived transcripts, RNA-directed agents also take advantage of the differential sensitivity between transformed and non-transformed cells, as the cytotoxic effects of inhibiting RNA synthesis have not been seen in non-transformed cells. The abrogation of the formation of oncotranscripts provides a new concept in cancer therapeutics and numerous agents have been developed which are able to target transcription. The focus of this review is to give an overview of transcription and the different inhibitory strategies that target various aspects of the transcriptional process.
Collapse
|