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Fetian T, Grover A, Arndt KM. Histone H2B ubiquitylation: Connections to transcription and effects on chromatin structure. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2024; 1867:195018. [PMID: 38331024 PMCID: PMC11098702 DOI: 10.1016/j.bbagrm.2024.195018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 01/30/2024] [Accepted: 02/05/2024] [Indexed: 02/10/2024]
Abstract
Nucleosomes are major determinants of eukaryotic genome organization and regulation. Many studies, incorporating a diversity of experimental approaches, have been focused on identifying and discerning the contributions of histone post-translational modifications to DNA-centered processes. Among these, monoubiquitylation of H2B (H2Bub) on K120 in humans or K123 in budding yeast is a critical histone modification that has been implicated in a wide array of DNA transactions. H2B is co-transcriptionally ubiquitylated and deubiquitylated via the concerted action of an extensive network of proteins. In addition to altering the chemical and physical properties of the nucleosome, H2Bub is important for the proper control of gene expression and for the deposition of other histone modifications. In this review, we discuss the molecular mechanisms underlying the ubiquitylation cycle of H2B and how it connects to the regulation of transcription and chromatin structure.
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Affiliation(s)
- Tasniem Fetian
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States of America
| | - Aakash Grover
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States of America
| | - Karen M Arndt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States of America.
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2
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Chen JJ, Moy C, Pagé V, Monnin C, El-Hajj ZW, Avizonis DZ, Reyes-Lamothe R, Tanny JC. The Rtf1/Prf1-dependent histone modification axis counteracts multi-drug resistance in fission yeast. Life Sci Alliance 2024; 7:e202302494. [PMID: 38514187 PMCID: PMC10958104 DOI: 10.26508/lsa.202302494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 03/05/2024] [Accepted: 03/06/2024] [Indexed: 03/23/2024] Open
Abstract
RNA polymerase II transcription elongation directs an intricate pattern of histone modifications. This pattern includes a regulatory cascade initiated by the elongation factor Rtf1, leading to monoubiquitylation of histone H2B, and subsequent methylation of histone H3 on lysine 4. Previous studies have defined the molecular basis for these regulatory relationships, but it remains unclear how they regulate gene expression. To address this question, we investigated a drug resistance phenotype that characterizes defects in this axis in the model eukaryote Schizosaccharomyces pombe (fission yeast). The mutations caused resistance to the ribonucleotide reductase inhibitor hydroxyurea (HU) that correlated with a reduced effect of HU on dNTP pools, reduced requirement for the S-phase checkpoint, and blunting of the transcriptional response to HU treatment. Mutations in the C-terminal repeat domain of the RNA polymerase II large subunit Rpb1 led to similar phenotypes. Moreover, all the HU-resistant mutants also exhibited resistance to several azole-class antifungal agents. Our results suggest a novel, shared gene regulatory function of the Rtf1-H2Bub1-H3K4me axis and the Rpb1 C-terminal repeat domain in controlling fungal drug tolerance.
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Affiliation(s)
- Jennifer J Chen
- https://ror.org/01pxwe438 Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Calvin Moy
- https://ror.org/01pxwe438 Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Viviane Pagé
- https://ror.org/01pxwe438 Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Cian Monnin
- https://ror.org/01pxwe438 Metabolomics Innovation Resource, Goodman Cancer Institute, McGill University, Montreal, Canada
| | - Ziad W El-Hajj
- https://ror.org/01pxwe438 Department of Biology, McGill University, Montreal, Canada
| | - Daina Z Avizonis
- https://ror.org/01pxwe438 Metabolomics Innovation Resource, Goodman Cancer Institute, McGill University, Montreal, Canada
| | - Rodrigo Reyes-Lamothe
- https://ror.org/01pxwe438 Department of Biology, McGill University, Montreal, Canada
| | - Jason C Tanny
- https://ror.org/01pxwe438 Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
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3
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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.
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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
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4
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Reese JC. New roles for elongation factors in RNA polymerase II ubiquitylation and degradation. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194956. [PMID: 37331651 PMCID: PMC10527621 DOI: 10.1016/j.bbagrm.2023.194956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 06/07/2023] [Accepted: 06/13/2023] [Indexed: 06/20/2023]
Abstract
RNA polymerase II (RNAPII) encounters numerous impediments on its way to completing mRNA synthesis across a gene. Paused and arrested RNAPII are reactivated or rescued by elongation factors that travel with polymerase as it transcribes DNA. However, when RNAPII fails to resume transcription, such as when it encounters an unrepairable bulky DNA lesion, it is removed by the targeting of its largest subunit, Rpb1, for degradation by the ubiquitin-proteasome system (UPS). We are starting to understand this process better and how the UPS marks Rbp1 for degradation. This review will focus on the latest developments and describe new functions for elongation factors that were once thought to only promote elongation in unstressed conditions in the removal and degradation of RNAPII. I propose that in addition to changes in RNAPII structure, the composition and modification of elongation factors in the elongation complex determine whether to rescue or degrade RNAPII.
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Affiliation(s)
- Joseph C Reese
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA.
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5
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Ellison MA, Namjilsuren S, Shirra M, Blacksmith M, Schusteff R, Kerr E, Fang F, Xiang Y, Shi Y, Arndt K. Spt6 directly interacts with Cdc73 and is required for Paf1 complex occupancy at active genes in Saccharomyces cerevisiae. Nucleic Acids Res 2023; 51:4814-4830. [PMID: 36928138 PMCID: PMC10250246 DOI: 10.1093/nar/gkad180] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 02/21/2023] [Accepted: 02/28/2023] [Indexed: 03/18/2023] Open
Abstract
The Paf1 complex (Paf1C) is a conserved transcription elongation factor that regulates transcription elongation efficiency, facilitates co-transcriptional histone modifications, and impacts molecular processes linked to RNA synthesis, such as polyA site selection. Coupling of the activities of Paf1C to transcription elongation requires its association with RNA polymerase II (Pol II). Mutational studies in yeast identified Paf1C subunits Cdc73 and Rtf1 as important mediators of Paf1C association with Pol II on active genes. While the interaction between Rtf1 and the general elongation factor Spt5 is relatively well-understood, the interactions involving Cdc73 have not been fully elucidated. Using a site-specific protein cross-linking strategy in yeast cells, we identified direct interactions between Cdc73 and two components of the Pol II elongation complex, the elongation factor Spt6 and the largest subunit of Pol II. Both of these interactions require the tandem SH2 domain of Spt6. We also show that Cdc73 and Spt6 can interact in vitro and that rapid depletion of Spt6 dissociates Paf1 from chromatin, altering patterns of Paf1C-dependent histone modifications genome-wide. These results reveal interactions between Cdc73 and the Pol II elongation complex and identify Spt6 as a key factor contributing to the occupancy of Paf1C at active genes in Saccharomyces cerevisiae.
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Affiliation(s)
- Mitchell A Ellison
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | | | - Margaret K Shirra
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Matthew S Blacksmith
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Rachel A Schusteff
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Eleanor M Kerr
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Fei Fang
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Yufei Xiang
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Yi Shi
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Karen M Arndt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
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Escobedo SE, McGovern SE, Jauregui-Lozano JP, Stanhope SC, Anik P, Singhal K, DeBernardis R, Weake VM. Targeted RNAi screen identifies transcriptional mechanisms that prevent premature degeneration of adult photoreceptors. FRONTIERS IN EPIGENETICS AND EPIGENOMICS 2023; 1:1187980. [PMID: 37901602 PMCID: PMC10603763 DOI: 10.3389/freae.2023.1187980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
Aging is associated with a decline in visual function and increased prevalence of ocular disease, correlating with changes in the transcriptome and epigenome of cells in the eye. Here, we sought to identify the transcriptional mechanisms that are necessary to maintain photoreceptor viability and function during aging. To do this, we performed a targeted photoreceptor-specific RNAi screen in Drosophila to identify transcriptional regulators whose knockdown results in premature, age-dependent retinal degeneration. From an initial set of 155 RNAi lines each targeting a unique gene and spanning a diverse set of transcription factors, chromatin remodelers, and histone modifiers, we identified 18 high-confidence target genes whose decreased expression in adult photoreceptors leads to premature and progressive retinal degeneration. These 18 target genes were enriched for factors involved in the regulation of transcription initiation, pausing, and elongation, suggesting that these processes are essential for maintaining the health of aging photoreceptors. To identify the genes regulated by these factors, we profiled the photoreceptor transcriptome in a subset of lines. Strikingly, two of the 18 target genes, Spt5 and domino, show similar changes in gene expression to those observed in photoreceptors with advanced age. Together, our data suggest that dysregulation of factors involved in transcription initiation and elongation plays a key role in shaping the transcriptome of aging photoreceptors. Further, our findings indicate that the age-dependent changes in gene expression not only correlate but might also contribute to an increased risk of retinal degeneration.
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Affiliation(s)
- Spencer E. Escobedo
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Sarah E. McGovern
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | | | - Sarah C. Stanhope
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Paul Anik
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Kratika Singhal
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Ryan DeBernardis
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Vikki M. Weake
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, United States
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7
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Park J, Park S, Lee JS. Role of the Paf1 complex in the maintenance of stem cell pluripotency and development. FEBS J 2023; 290:951-961. [PMID: 35869661 DOI: 10.1111/febs.16582] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 06/26/2022] [Accepted: 07/21/2022] [Indexed: 11/30/2022]
Abstract
Cell identity is determined by the transcriptional regulation of a cell-type-specific gene group. The Paf1 complex (Paf1C), an RNA polymerase II-associating factor, is an important transcriptional regulator that not only participates in transcription elongation and termination but also affects transcription-coupled histone modifications and chromatin organisation. Recent studies have shown that Paf1C is involved in the expression of genes required for self-renewal and pluripotency in stem cells and tumorigenesis. In this review, we focused on the role of Paf1C as a critical transcriptional regulator in cell fate decisions. Paf1C affects the pluripotency of stem cells by regulating the expression of core transcription factors such as Oct4 and Nanog. In addition, Paf1C directly binds to the promoters or distant elements of target genes, thereby maintaining the pluripotency in embryonic stem cells derived from an early stage of the mammalian embryo. Paf1C is upregulated in cancer stem cells, as compared with that in cancer cells, suggesting that Paf1C may be a target for cancer therapy. Interestingly, Paf1C is involved in multiple developmental stages in Drosophila, zebrafish, mice and even humans, thereby displaying a trend for the correlation between Paf1C and cell fate. Thus, we propose that Paf1C is a critical contributor to cell differentiation, cell specification and its characteristics and could be employed as a therapeutic target in developmental diseases.
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Affiliation(s)
- Jiyeon Park
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon-si, Korea
| | - Shinae Park
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon-si, Korea
| | - Jung-Shin Lee
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon-si, Korea
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8
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The Paf1 complex is required for RNA polymerase II removal in response to DNA damage. Proc Natl Acad Sci U S A 2022; 119:e2207332119. [PMID: 36161924 DOI: 10.1073/pnas.2207332119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rpb1, the largest subunit of RNA polymerase II (RNAPII), is rapidly polyubiquitinated and degraded in response to DNA damage; this process is considered to be a "mechanism of last resort'' employed by cells. The underlying mechanism of this process remains elusive. Here, we uncovered a previously uncharacterized multistep pathway in which the polymerase-associated factor 1 (Paf1) complex (PAF1C, composed of the subunits Ctr9, Paf1, Leo1, Cdc73, and Rtf1) is involved in regulating the RNAPII pool by stimulating Elongin-Cullin E3 ligase complex-mediated Rpb1 polyubiquitination and subsequent degradation by the proteasome following DNA damage. Mechanistically, Spt5 is dephosphorylated following DNA damage, thereby weakening the interaction between the Rtf1 subunit and Spt5, which might be a key step in initiating Rpb1 degradation. Next, Rad26 is loaded onto stalled RNAPII to replace the Spt4/Spt5 complex in an RNAPII-dependent manner and, in turn, recruits more PAF1C to DNA lesions via the binding of Rad26 to the Leo1 subunit. Importantly, the PAF1C, assembled in a Ctr9-mediated manner, coordinates with Rad26 to localize the Elongin-Cullin complex on stalled RNAPII, thereby inducing RNAPII removal, in which the heterodimer Paf1/Leo1 and the subunit Cdc73 play important roles. Together, our results clearly revealed a new role of the intact PAF1C in regulating the RNAPII pool in response to DNA damage.
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9
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Song A, Chen FX. The pleiotropic roles of SPT5 in transcription. Transcription 2022; 13:53-69. [PMID: 35876486 PMCID: PMC9467590 DOI: 10.1080/21541264.2022.2103366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Initially discovered by genetic screens in budding yeast, SPT5 and its partner SPT4 form a stable complex known as DSIF in metazoa, which plays pleiotropic roles in multiple steps of transcription. SPT5 is the most conserved transcription elongation factor, being found in all three domains of life; however, its structure has evolved to include new domains and associated posttranslational modifications. These gained features have expanded transcriptional functions of SPT5, likely to meet the demand for increasingly complex regulation of transcription in higher organisms. This review discusses the pleiotropic roles of SPT5 in transcription, including RNA polymerase II (Pol II) stabilization, enhancer activation, Pol II pausing and its release, elongation, and termination, with a focus on the most recent progress of SPT5 functions in regulating metazoan transcription.
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Affiliation(s)
- Aixia Song
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, Province 200032, China
| | - Fei Xavier Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, Province 200032, China
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10
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Chan J, Kumar A, Kono H. RNAPII driven post-translational modifications of nucleosomal histones. Trends Genet 2022; 38:1076-1095. [PMID: 35618507 DOI: 10.1016/j.tig.2022.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 04/08/2022] [Accepted: 04/22/2022] [Indexed: 12/12/2022]
Abstract
The current understanding of how specific distributions of histone post-translational modifications (PTMs) are achieved throughout the chromatin remains incomplete. This review focuses on the role of RNA polymerase II (RNAPII) in establishing H2BK120/K123 ubiquitination and H3K4/K36 methylation distribution. The rate of RNAPII transcription is mainly a function of the RNAPII elongation and recruitment rates. Two major mechanisms link RNAPII's transcription rate to the distribution of PTMs. First, the phosphorylation patterns of Ser2P/Ser5P in the C-terminal domain of RNAPII change as a function of time, since the start of elongation, linking them to the elongation rate. Ser2P/Ser5P recruits specific histone PTM enzymes/activators to the nucleosome. Second, multiple rounds of binding and catalysis by the enzymes are required to establish higher methylations (H3K4/36me3). Thus, methylation states are determined by the transcription rate. In summary, the first mechanism determines the location of methylations in the gene, while the second mechanism determines the methylation state.
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Affiliation(s)
- Justin Chan
- Molecular Modelling and Simulation (MMS) Team, Institute for Quantum Life Science (iQLS), National Institutes for Quantum Science and Technology (QST), 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Amarjeet Kumar
- Molecular Modelling and Simulation (MMS) Team, Institute for Quantum Life Science (iQLS), National Institutes for Quantum Science and Technology (QST), 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Hidetoshi Kono
- Molecular Modelling and Simulation (MMS) Team, Institute for Quantum Life Science (iQLS), National Institutes for Quantum Science and Technology (QST), 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan.
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11
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Wang Z, Song A, Xu H, Hu S, Tao B, Peng L, Wang J, Li J, Yu J, Wang L, Li Z, Chen X, Wang M, Chi Y, Wu J, Xu Y, Zheng H, Chen FX. Coordinated regulation of RNA polymerase II pausing and elongation progression by PAF1. SCIENCE ADVANCES 2022; 8:eabm5504. [PMID: 35363521 PMCID: PMC11093130 DOI: 10.1126/sciadv.abm5504] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
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 use 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, most destabilized polymerase undergoes 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.
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Affiliation(s)
- Zhenning Wang
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Aixia Song
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Hao Xu
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Shibin Hu
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Bolin Tao
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Linna Peng
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jingwen Wang
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Radiation Oncology, Shanghai, China
| | - Jiabei Li
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jiali Yu
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Li Wang
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Ze Li
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xizi Chen
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Mengyun Wang
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Radiation Oncology, Shanghai, China
| | - Yayun Chi
- Department of Breast Surgery, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Jiong Wu
- Department of Breast Surgery, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Hai Zheng
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Fei Xavier Chen
- Fudan University Shanghai Cancer Center, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Radiation Oncology, Shanghai, China
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12
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Liu Y, Fu L, Wu J, Liu M, Wang G, Liu B, Zhang L. Transcriptional cyclin-dependent kinases: Potential drug targets in cancer therapy. Eur J Med Chem 2021; 229:114056. [PMID: 34942431 DOI: 10.1016/j.ejmech.2021.114056] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 02/08/2023]
Abstract
In the wake of the development of the concept of cell cycle and its limiting points, cyclin-dependent kinases (CDKs) are considered to play a central role in regulating cell cycle progression. Recent studies have strongly demonstrated that CDKs also has multiple functions, especially in response to extracellular and intracellular signals by interfering with transcriptional events. Consequently, how to inhibit their function has been a hot research topic. It is worth noting that the key role of CDKs in regulating transcription has been explored in recent years, but its related pharmacological targets are less developed, and most inhibitors have not entered the clinical stage. Accordingly, this perspective focus on the biological functions of transcription related CDKs and their complexes, some key upstream and downstream signals, and inhibitors for cancer treatment in recent years. In addition, some corresponding combined treatment strategies will provide a more novel perspective for future cancer remedy.
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Affiliation(s)
- Yi Liu
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, 610031, Chengdu, China
| | - Leilei Fu
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, 610031, Chengdu, China
| | - Junhao Wu
- Department of Otolaryngology, Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Ming Liu
- Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, 610041, China.
| | - Guan Wang
- State Key Laboratory of Biotherapy and Cancer Center, Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, West China Hospital, and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, 610041, China.
| | - Bo Liu
- State Key Laboratory of Biotherapy and Cancer Center, Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, West China Hospital, and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Lan Zhang
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, 610031, Chengdu, China.
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13
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Shirra MK, Kocik RA, Ellison MA, Arndt KM. Opposing functions of the Hda1 complex and histone H2B mono-ubiquitylation in regulating cryptic transcription in Saccharomyces cerevisiae. G3-GENES GENOMES GENETICS 2021; 11:6360461. [PMID: 34499735 PMCID: PMC8527469 DOI: 10.1093/g3journal/jkab298] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 08/17/2021] [Indexed: 11/13/2022]
Abstract
Maintenance of chromatin structure under the disruptive force of transcription requires cooperation among numerous regulatory factors. Histone post-translational modifications can regulate nucleosome stability and influence the disassembly and reassembly of nucleosomes during transcription elongation. The Paf1 transcription elongation complex, Paf1C, is required for several transcription-coupled histone modifications, including the mono-ubiquitylation of H2B. In Saccharomyces cerevisiae, amino acid substitutions in the Rtf1 subunit of Paf1C greatly diminish H2B ubiquitylation and cause transcription to initiate at a cryptic promoter within the coding region of the FLO8 gene, an indicator of chromatin disruption. In a genetic screen to identify factors that functionally interact with Paf1C, we identified mutations in HDA3, a gene encoding a subunit of the Hda1C histone deacetylase (HDAC), as suppressors of an rtf1 mutation. Absence of Hda1C also suppresses the cryptic initiation phenotype of other mutants defective in H2B ubiquitylation. The genetic interactions between Hda1C and the H2B ubiquitylation pathway appear specific: loss of Hda1C does not suppress the cryptic initiation phenotypes of other chromatin mutants and absence of other HDACs does not suppress the absence of H2B ubiquitylation. Providing further support for an appropriate balance of histone acetylation in regulating cryptic initiation, absence of the Sas3 histone acetyltransferase elevates cryptic initiation in rtf1 mutants. Our data suggest that the H2B ubiquitylation pathway and Hda1C coordinately regulate chromatin structure during transcription elongation and point to a potential role for a HDAC in supporting chromatin accessibility.
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Affiliation(s)
- Margaret K Shirra
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Rachel A Kocik
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Mitchell A Ellison
- 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
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14
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Francette AM, Tripplehorn SA, Arndt KM. The Paf1 Complex: A Keystone of Nuclear Regulation Operating at the Interface of Transcription and Chromatin. J Mol Biol 2021; 433:166979. [PMID: 33811920 PMCID: PMC8184591 DOI: 10.1016/j.jmb.2021.166979] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/21/2021] [Accepted: 03/24/2021] [Indexed: 12/14/2022]
Abstract
The regulation of transcription by RNA polymerase II is closely intertwined with the regulation of chromatin structure. A host of proteins required for the disassembly, reassembly, and modification of nucleosomes interacts with Pol II to aid its movement and counteract its disruptive effects on chromatin. The highly conserved Polymerase Associated Factor 1 Complex, Paf1C, travels with Pol II and exerts control over transcription elongation and chromatin structure, while broadly impacting the transcriptome in both single cell and multicellular eukaryotes. Recent studies have yielded exciting new insights into the mechanisms by which Paf1C regulates transcription elongation, epigenetic modifications, and post-transcriptional steps in eukaryotic gene expression. Importantly, these functional studies are now supported by an extensive foundation of high-resolution structural information, providing intimate views of Paf1C and its integration into the larger Pol II elongation complex. As a global regulatory factor operating at the interface between chromatin and transcription, the impact of Paf1C is broad and its influence reverberates into other domains of nuclear regulation, including genome stability, telomere maintenance, and DNA replication.
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Affiliation(s)
- Alex M Francette
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Sarah A Tripplehorn
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Karen M Arndt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States.
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15
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Pinto D, Pagé V, Fisher RP, Tanny JC. New connections between ubiquitylation and methylation in the co-transcriptional histone modification network. Curr Genet 2021; 67:695-705. [PMID: 34089069 DOI: 10.1007/s00294-021-01196-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/27/2021] [Accepted: 05/29/2021] [Indexed: 01/01/2023]
Abstract
Co-transcriptional histone modifications are a ubiquitous feature of RNA polymerase II (RNAPII) transcription, with profound but incompletely understood effects on gene expression. Unlike the covalent marks found at promoters, which are thought to be instructive for transcriptional activation, these modifications occur in gene bodies as a result of transcription, which has made elucidation of their functions challenging. Here we review recent insights into the regulation and roles of two such modifications: monoubiquitylation of histone H2B at lysine 120 (H2Bub1) and methylation of histone H3 at lysine 36 (H3K36me). Both H2Bub1 and H3K36me are enriched in the coding regions of transcribed genes, with highly overlapping distributions, but they were thought to work largely independently. We highlight our recent demonstration that, as was previously shown for H3K36me, H2Bub1 signals to the histone deacetylase (HDAC) complex Rpd3S/Clr6-CII, and that Rpd3S/Clr6-CII and H2Bub1 function in the same pathway to repress aberrant antisense transcription initiating within gene coding regions. Moreover, both of these histone modification pathways are influenced by protein phosphorylation catalyzed by the cyclin-dependent kinases (CDKs) that regulate RNAPII elongation, chiefly Cdk9. Therefore, H2Bub1 and H3K36me are more tightly linked than previously thought, sharing both upstream regulatory inputs and downstream effectors. Moreover, these newfound connections suggest extensive, bidirectional signaling between RNAPII elongation complexes and chromatin-modifying enzymes, which helps to determine transcriptional outputs and should be a focus for future investigation.
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Affiliation(s)
- Daniel Pinto
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Vivane Pagé
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada.
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16
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Abstract
Unlike most other eukaryotes, Leishmania and other trypanosomatid protozoa have largely eschewed transcriptional control of gene expression, relying instead on posttranscriptional regulation of mRNAs derived from polycistronic transcription units (PTUs). In these parasites, a novel modified nucleotide base (β-d-glucopyranosyloxymethyluracil) known as J plays a critical role in ensuring that transcription termination occurs only at the end of each PTU, rather than at the polyadenylation sites of individual genes. To further understand the biology of J-associated processes, we used tandem affinity purification (TAP) tagging and mass spectrometry to reveal proteins that interact with the glucosyltransferase performing the final step in J synthesis. These studies identified four proteins reminiscent of subunits in the PTW/PP1 complex that controls transcription termination in higher eukaryotes. Moreover, bioinformatic analyses identified the DNA-binding subunit of Leishmania PTW/PP1 as a novel J-binding protein (JBP3), which is also part of another complex containing proteins with domains suggestive of a role in chromatin modification/remodeling. Additionally, JBP3 associates (albeit transiently and/or indirectly) with the trypanosomatid equivalent of the PAF1 complex involved in the regulation of transcription in other eukaryotes. The downregulation of JBP3 expression levels in Leishmania resulted in a substantial increase in transcriptional readthrough at the 3′ end of most PTUs. We propose that JBP3 recruits one or more of these complexes to the J-containing regions at the end of PTUs, where they halt the progression of the RNA polymerase. This decoupling of transcription termination from the splicing of individual genes enables the parasites’ unique reliance on polycistronic transcription and posttranscriptional regulation of gene expression. IMPORTANCELeishmania parasites cause a variety of serious human diseases, with no effective vaccine and emerging resistance to current drug therapy. We have previously shown that a novel DNA base called J is critical for transcription termination at the ends of the polycistronic gene clusters that are a hallmark of Leishmania and related trypanosomatids. Here, we describe a new J-binding protein (JBP3) associated with three different protein complexes that are reminiscent of those involved in the control of transcription in other eukaryotes. However, the parasite complexes have been reprogrammed to regulate transcription and gene expression in trypanosomatids differently than in the mammalian hosts, providing new opportunities to develop novel chemotherapeutic treatments against these important pathogens.
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17
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Sansó M, Parua PK, Pinto D, Svensson JP, Pagé V, Bitton DA, MacKinnon S, Garcia P, Hidalgo E, Bähler J, Tanny JC, Fisher RP. Cdk9 and H2Bub1 signal to Clr6-CII/Rpd3S to suppress aberrant antisense transcription. Nucleic Acids Res 2020; 48:7154-7168. [PMID: 32496538 PMCID: PMC7367204 DOI: 10.1093/nar/gkaa474] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/26/2020] [Indexed: 12/13/2022] Open
Abstract
Mono-ubiquitylation of histone H2B (H2Bub1) and phosphorylation of elongation factor Spt5 by cyclin-dependent kinase 9 (Cdk9) occur during transcription by RNA polymerase II (RNAPII), and are mutually dependent in fission yeast. It remained unclear whether Cdk9 and H2Bub1 cooperate to regulate the expression of individual genes. Here, we show that Cdk9 inhibition or H2Bub1 loss induces intragenic antisense transcription of ∼10% of fission yeast genes, with each perturbation affecting largely distinct subsets; ablation of both pathways de-represses antisense transcription of over half the genome. H2Bub1 and phospho-Spt5 have similar genome-wide distributions; both modifications are enriched, and directly proportional to each other, in coding regions, and decrease abruptly around the cleavage and polyadenylation signal (CPS). Cdk9-dependence of antisense suppression at specific genes correlates with high H2Bub1 occupancy, and with promoter-proximal RNAPII pausing. Genetic interactions link Cdk9, H2Bub1 and the histone deacetylase Clr6-CII, while combined Cdk9 inhibition and H2Bub1 loss impair Clr6-CII recruitment to chromatin and lead to decreased occupancy and increased acetylation of histones within gene coding regions. These results uncover novel interactions between co-transcriptional histone modification pathways, which link regulation of RNAPII transcription elongation to suppression of aberrant initiation.
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Affiliation(s)
- Miriam Sansó
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Cancer Genomics Group, Vall d'Hebron Institute of Oncology, Barcelona, Spain
| | - Pabitra K Parua
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Daniel Pinto
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - J Peter Svensson
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Viviane Pagé
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Danny A Bitton
- Research Department of Genetics, Evolution & Environment, University College, London, UK
| | - Sarah MacKinnon
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Patricia Garcia
- Departament de Ciènces Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Elena Hidalgo
- Departament de Ciènces Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Jürg Bähler
- Research Department of Genetics, Evolution & Environment, University College, London, UK
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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18
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Piątkowski J, Golik P. Yeast pentatricopeptide protein Dmr1 (Ccm1) binds a repetitive AU-rich motif in the small subunit mitochondrial ribosomal RNA. RNA (NEW YORK, N.Y.) 2020; 26:1268-1282. [PMID: 32467310 PMCID: PMC7430664 DOI: 10.1261/rna.074880.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 05/23/2020] [Indexed: 06/11/2023]
Abstract
PPR proteins are a diverse family of RNA binding factors found in all Eukaryotic lineages. They perform multiple functions in the expression of organellar genes, mostly on the post-transcriptional level. PPR proteins are also significant determinants of evolutionary nucleo-organellar compatibility. Plant PPR proteins recognize their RNA substrates using a simple modular code. No target sequences recognized by animal or yeast PPR proteins were identified prior to the present study, making it impossible to assess whether this plant PPR code is conserved in other organisms. Dmr1p (Ccm1p, Ygr150cp) is a S. cerevisiae PPR protein essential for mitochondrial gene expression and involved in the stability of 15S ribosomal RNA. We demonstrate that in vitro Dmr1p specifically binds a motif composed of multiple AUA repeats occurring twice in the 15S rRNA sequence as the minimal 14 nt (AUA)4AU or longer (AUA)7 variant. Short RNA fragments containing this motif are protected by Dmr1p from exoribonucleolytic activity in vitro. Presence of the identified motif in mtDNA of different yeast species correlates with the compatibility between their Dmr1p orthologs and S. cerevisiae mtDNA. RNA recognition by Dmr1p is likely based on a rudimentary form of a PPR code specifying U at every third position, and depends on other factors, like RNA structure.
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Affiliation(s)
- Jakub Piątkowski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, 02-106, Poland
| | - Paweł Golik
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, 02-106, Poland
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, 02-106, Poland
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19
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Ólafsson G, Thorpe PH. Polo kinase recruitment via the constitutive centromere-associated network at the kinetochore elevates centromeric RNA. PLoS Genet 2020; 16:e1008990. [PMID: 32810142 PMCID: PMC7455000 DOI: 10.1371/journal.pgen.1008990] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/28/2020] [Accepted: 07/13/2020] [Indexed: 12/23/2022] Open
Abstract
The kinetochore, a multi-protein complex assembled on centromeres, is essential to segregate chromosomes during cell division. Deficiencies in kinetochore function can lead to chromosomal instability and aneuploidy-a hallmark of cancer cells. Kinetochore function is controlled by recruitment of regulatory proteins, many of which have been documented, however their function often remains uncharacterized and many are yet to be identified. To identify candidates of kinetochore regulation we used a proteome-wide protein association strategy in budding yeast and detected many proteins that are involved in post-translational modifications such as kinases, phosphatases and histone modifiers. We focused on the Polo-like kinase, Cdc5, and interrogated which cellular components were sensitive to constitutive Cdc5 localization. The kinetochore is particularly sensitive to constitutive Cdc5 kinase activity. Targeting Cdc5 to different kinetochore subcomplexes produced diverse phenotypes, consistent with multiple distinct functions at the kinetochore. We show that targeting Cdc5 to the inner kinetochore, the constitutive centromere-associated network (CCAN), increases the levels of centromeric RNA via an SPT4 dependent mechanism.
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Affiliation(s)
- Guðjón Ólafsson
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
| | - Peter H. Thorpe
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
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20
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Spt5 Phosphorylation and the Rtf1 Plus3 Domain Promote Rtf1 Function through Distinct Mechanisms. Mol Cell Biol 2020; 40:MCB.00150-20. [PMID: 32366382 DOI: 10.1128/mcb.00150-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 04/28/2020] [Indexed: 11/20/2022] Open
Abstract
Rtf1 is a conserved RNA polymerase II (RNAPII) elongation factor that promotes cotranscriptional histone modification, RNAPII transcript elongation, and mRNA processing. Rtf1 function requires the phosphorylation of Spt5, an essential RNAPII processivity factor. Spt5 is phosphorylated within its C-terminal domain (CTD) by cyclin-dependent kinase 9 (Cdk9), the catalytic component of positive transcription elongation factor b (P-TEFb). Rtf1 recognizes phosphorylated Spt5 (pSpt5) through its Plus3 domain. Since Spt5 is a unique target of Cdk9 and Rtf1 is the only known pSpt5-binding factor, the Plus3/pSpt5 interaction is thought to be a key Cdk9-dependent event regulating RNAPII elongation. Here, we dissect Rtf1 regulation by pSpt5 in the fission yeast Schizosaccharomyces pombe We demonstrate that the Plus3 domain of Rtf1 (Prf1 in S. pombe) and pSpt5 are functionally distinct and that they act in parallel to promote Prf1 function. This alternate Plus3 domain function involves an interface that overlaps the pSpt5-binding site and that can interact with single-stranded nucleic acid or with the polymerase-associated factor (PAF) complex in vitro We further show that the C-terminal region of Prf1, which also interacts with PAF, has a similar parallel function with pSpt5. Our results elucidate unexpected complexity underlying Cdk9-dependent pathways that regulate transcription elongation.
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21
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Structure of complete Pol II-DSIF-PAF-SPT6 transcription complex reveals RTF1 allosteric activation. Nat Struct Mol Biol 2020; 27:668-677. [PMID: 32541898 DOI: 10.1038/s41594-020-0437-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 04/22/2020] [Indexed: 12/20/2022]
Abstract
Transcription by RNA polymerase II (Pol II) is carried out by an elongation complex. We previously reported an activated porcine Pol II elongation complex, EC*, encompassing the human elongation factors DSIF, PAF1 complex (PAF) and SPT6. Here we report the cryo-EM structure of the complete EC* that contains RTF1, a dissociable PAF subunit critical for chromatin transcription. The RTF1 Plus3 domain associates with Pol II subunit RPB12 and the phosphorylated C-terminal region of DSIF subunit SPT5. RTF1 also forms four α-helices that extend from the Plus3 domain along the Pol II protrusion and RPB10 to the polymerase funnel. The C-terminal 'fastener' helix retains PAF and is followed by a 'latch' that reaches the end of the bridge helix, a flexible element of the Pol II active site. RTF1 strongly stimulates Pol II elongation, and this requires the latch, possibly suggesting that RTF1 activates transcription allosterically by influencing Pol II translocation.
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22
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Cucinotta CE, Hildreth AE, McShane BM, Shirra MK, Arndt KM. The nucleosome acidic patch directly interacts with subunits of the Paf1 and FACT complexes and controls chromatin architecture in vivo. Nucleic Acids Res 2019; 47:8410-8423. [PMID: 31226204 PMCID: PMC6895269 DOI: 10.1093/nar/gkz549] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 06/07/2019] [Accepted: 06/11/2019] [Indexed: 12/12/2022] Open
Abstract
The nucleosome core regulates DNA-templated processes through the highly conserved nucleosome acidic patch. While structural and biochemical studies have shown that the acidic patch controls chromatin factor binding and activity, few studies have elucidated its functions in vivo. We employed site-specific crosslinking to identify proteins that directly bind the acidic patch in Saccharomyces cerevisiae and demonstrated crosslinking of histone H2A to Paf1 complex subunit Rtf1 and FACT subunit Spt16. Rtf1 bound to nucleosomes through its histone modification domain, supporting its role as a cofactor in H2B K123 ubiquitylation. An acidic patch mutant showed defects in nucleosome positioning and occupancy genome-wide. Our results provide new information on the chromatin engagement of two central players in transcription elongation and emphasize the importance of the nucleosome core as a hub for proteins that regulate chromatin during transcription.
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Affiliation(s)
- Christine E Cucinotta
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - A Elizabeth Hildreth
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Brendan M McShane
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Margaret K Shirra
- 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
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23
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Liu Q, Hobbs HA, Domier LL. Genome-wide association study of the seed transmission rate of soybean mosaic virus and associated traits using two diverse population panels. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2019; 132:3413-3424. [PMID: 31630210 DOI: 10.1007/s00122-019-03434-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
KEY MESSAGE Genome-wide association analyses identified candidates for genes involved in restricting virus movement into embryonic tissues, suppressing virus-induced seed coat mottling and preserving yield in soybean plants infected with soybean mosaic virus. Soybean mosaic virus (SMV) causes significant reductions in soybean yield and seed quality. Because seedborne infections can serve as primary sources of inoculum for SMV infections, resistance to SMV seed transmission provides a means to limit the impacts of SMV. In this study, two diverse population panels, Pop1 and Pop2, composed of 409 and 199 soybean plant introductions, respectively, were evaluated for SMV seed transmission rate, seed coat mottling, and seed yield from SMV-infected plants. The phenotypic data and genotypic data from the SoySNP50K dataset were analyzed using GAPIT and rrBLUP. For SMV seed transmission rate, a single locus was identified on chromosome 9 in Pop1. For SMV-induced seed coat mottling, loci were identified on chromosome 9 in Pop1 and on chromosome 3 in Pop2. For seed yield from SMV-infected plants, a single locus was identified on chromosome 3 in Pop2 that was within the map interval of a previously described quantitative trait locus for seed number. The high linkage disequilibrium regions surrounding the markers on chromosomes 3 and 9 contained a predicted nonsense-mediated RNA decay gene, multiple pectin methylesterase inhibitor genes (involved in restricting virus movement), two chalcone synthase genes, and a homolog of the yeast Rtf1 gene (involved in RNA-mediated transcriptional gene silencing). The results of this study provided additional insight into the genetic architecture of these three important traits, suggested candidate genes for downstream functional validation, and suggested that genomic prediction would outperform marker-assisted selection for two of the four trait-marker associations.
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Affiliation(s)
- Qiong Liu
- Department of Crop Sciences, University of Illinois, Urbana, IL, 61801, USA
| | - Houston A Hobbs
- Department of Crop Sciences, University of Illinois, Urbana, IL, 61801, USA
| | - Leslie L Domier
- Soybean/Maize Germplasm, Pathology, and Genetics Research Unit, United States Department of Agriculture-Agricultural Research Service, Urbana, IL, 61801, USA.
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24
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Yeast PAF1 complex counters the pol III accumulation and replication stress on the tRNA genes. Sci Rep 2019; 9:12892. [PMID: 31501524 PMCID: PMC6733944 DOI: 10.1038/s41598-019-49316-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 08/21/2019] [Indexed: 12/13/2022] Open
Abstract
The RNA polymerase (pol) III transcribes mostly short, house-keeping genes, which produce stable, non-coding RNAs. The tRNAs genes, highly transcribed by pol III in vivo are known replication fork barriers. One of the transcription factors, the PAF1C (RNA polymerase II associated factor 1 complex) is reported to associate with pol I and pol II and influence their transcription. We found low level PAF1C occupancy on the yeast pol III-transcribed genes, which is not correlated with nucleosome positions, pol III occupancy and transcription. PAF1C interacts with the pol III transcription complex and causes pol III loss from the genes under replication stress. Genotoxin exposure causes pol III but not Paf1 loss from the genes. In comparison, Paf1 deletion leads to increased occupancy of pol III, γ-H2A and DNA pol2 in gene-specific manner. Paf1 restricts the accumulation of pol III by influencing the pol III pause on the genes, which reduces the pol III barrier to the replication fork progression.
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25
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Goodman LD, Prudencio M, Kramer NJ, Martinez-Ramirez LF, Srinivasan AR, Lan M, Parisi MJ, Zhu Y, Chew J, Cook CN, Berson A, Gitler AD, Petrucelli L, Bonini NM. Toxic expanded GGGGCC repeat transcription is mediated by the PAF1 complex in C9orf72-associated FTD. Nat Neurosci 2019; 22:863-874. [PMID: 31110321 PMCID: PMC6535128 DOI: 10.1038/s41593-019-0396-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 03/26/2019] [Indexed: 02/06/2023]
Abstract
An expanded GGGGCC hexanucleotide of more than 30 repeats (termed (G4C2)30+) within C9orf72 is the most prominent mutation in familial frontotemporal degeneration (FTD) and amyotrophic lateral sclerosis (ALS) (termed C9+). Through an unbiased large-scale screen of (G4C2)49-expressing Drosophila we identify the CDC73/PAF1 complex (PAF1C), a transcriptional regulator of RNA polymerase II, as a suppressor of G4C2-associated toxicity when knocked-down. Depletion of PAF1C reduces RNA and GR dipeptide production from (G4C2)30+ transgenes. Notably, in Drosophila, the PAF1C components Paf1 and Leo1 appear to be selective for the transcription of long, toxic repeat expansions, but not shorter, nontoxic expansions. In yeast, PAF1C components regulate the expression of both sense and antisense repeats. PAF1C is upregulated following (G4C2)30+ expression in flies and mice. In humans, PAF1 is also upregulated in C9+-derived cells, and its heterodimer partner, LEO1, binds C9+ repeat chromatin. In C9+ FTD, PAF1 and LEO1 are upregulated and their expression positively correlates with the expression of repeat-containing C9orf72 transcripts. These data indicate that PAF1C activity is an important factor for transcription of the long, toxic repeat in C9+ FTD.
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Affiliation(s)
- Lindsey D Goodman
- Neuroscience Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Nicholas J Kramer
- Neuroscience Graduate Program, Stanford University School of Medicine, Stanford, CA, USA
| | | | | | - Matthews Lan
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael J Parisi
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Yongqing Zhu
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jeannie Chew
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Casey N Cook
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Amit Berson
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Nancy M Bonini
- Neuroscience Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
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26
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Pontier D, Picart C, El Baidouri M, Roudier F, Xu T, Lahmy S, Llauro C, Azevedo J, Laudié M, Attina A, Hirtz C, Carpentier MC, Shen L, Lagrange T. The m 6A pathway protects the transcriptome integrity by restricting RNA chimera formation in plants. Life Sci Alliance 2019; 2:2/3/e201900393. [PMID: 31142640 PMCID: PMC6545605 DOI: 10.26508/lsa.201900393] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/20/2019] [Accepted: 05/20/2019] [Indexed: 11/24/2022] Open
Abstract
This study reveals that an m6A-assisted polyadenylation pathway comprising conserved m6A writer proteins and a plant-specific m6A reader contributes to transcriptome integrity in Arabidopsis thaliana by restricting RNA chimera formation at rearranged loci. Global, segmental, and gene duplication–related processes are driving genome size and complexity in plants. Despite their evolutionary potentials, those processes can also have adverse effects on genome regulation, thus implying the existence of specialized corrective mechanisms. Here, we report that an N6-methyladenosine (m6A)–assisted polyadenylation (m-ASP) pathway ensures transcriptome integrity in Arabidopsis thaliana. Efficient m-ASP pathway activity requires the m6A methyltransferase-associated factor FIP37 and CPSF30L, an m6A reader corresponding to an YT512-B Homology Domain-containing protein (YTHDC)-type domain containing isoform of the 30-kD subunit of cleavage and polyadenylation specificity factor. Targets of the m-ASP pathway are enriched in recently rearranged gene pairs, displayed an atypical chromatin signature, and showed transcriptional readthrough and mRNA chimera formation in FIP37- and CPSF30L-deficient plants. Furthermore, we showed that the m-ASP pathway can also restrict the formation of chimeric gene/transposable-element transcript, suggesting a possible implication of this pathway in the control of transposable elements at specific locus. Taken together, our results point to selective recognition of 3′-UTR m6A as a safeguard mechanism ensuring transcriptome integrity at rearranged genomic loci in plants.
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Affiliation(s)
- Dominique Pontier
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France.,Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Perpignan, France
| | - Claire Picart
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France.,Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Perpignan, France
| | - Moaine El Baidouri
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France.,Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Perpignan, France
| | - François Roudier
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon1, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Lyon, France
| | - Tao Xu
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Sylvie Lahmy
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France.,Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Perpignan, France
| | - Christel Llauro
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France.,Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Perpignan, France
| | - Jacinthe Azevedo
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France.,Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Perpignan, France
| | - Michèle Laudié
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France.,Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Perpignan, France
| | - Aurore Attina
- Platform SMART/Laboratoire de Biochimie et Protéomique Clinique/Plateforme de Protéomique Clinique, University of Montpellier, Institut de Médecine Régénérative et de Biothérapie , Centre Hospitalier Universitaire Montpellier, Institut national de la santé et de la Recherche Médicale, Montpeller, France
| | - Christophe Hirtz
- Platform SMART/Laboratoire de Biochimie et Protéomique Clinique/Plateforme de Protéomique Clinique, University of Montpellier, Institut de Médecine Régénérative et de Biothérapie , Centre Hospitalier Universitaire Montpellier, Institut national de la santé et de la Recherche Médicale, Montpeller, France
| | - Marie-Christine Carpentier
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France.,Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Perpignan, France
| | - Lisha Shen
- Temasek Life Sciences Laboratory, 1 Research Link, NUS, Singapore
| | - Thierry Lagrange
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, UMR 5096, Perpignan, France .,Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, Perpignan, France
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27
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Bhalla P, Vernekar DV, Gilquin B, Couté Y, Bhargava P. Interactome of the yeast RNA polymerase III transcription machinery constitutes several chromatin modifiers and regulators of the genes transcribed by RNA polymerase II. Gene 2018; 702:205-214. [PMID: 30593915 DOI: 10.1016/j.gene.2018.12.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/17/2018] [Accepted: 12/20/2018] [Indexed: 02/06/2023]
Abstract
Eukaryotic transcription is a highly regulated fundamental life process. A large number of regulatory proteins and complexes, many of them with sequence-specific DNA-binding activity are known to influence transcription by RNA polymerase (pol) II with a fine precision. In comparison, only a few regulatory proteins are known for pol III, which transcribes genes encoding small, stable, non-translated RNAs. The pol III transcription is precisely regulated under various stress conditions. We used pol III transcription complex (TC) components TFIIIC (Tfc6), pol III (Rpc128) and TFIIIB (Brf1) as baits and mass spectrometry to identify their potential interactors in vivo. A large interactome constituting chromatin modifiers, regulators and factors of transcription by pol I and pol II supports the possibility of a crosstalk between the three transcription machineries. The association of proteins and complexes involved in various basic life processes like ribogenesis, RNA processing, protein folding and degradation, DNA damage response, replication and transcription underscores the possibility of the pol III TC serving as a signaling hub for communication between the transcription and other cellular physiological activities under normal growth conditions. We also found an equally large number of proteins and complexes interacting with the TC under nutrient starvation condition, of which at least 25% were non-identical under the two conditions. The data reveal the possibility of a large number of signaling cues for pol III transcription against adverse conditions, necessary for an efficient co-ordination of various cellular functions.
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Affiliation(s)
- Pratibha Bhalla
- Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research), Hyderabad, India
| | - Dipti Vinayak Vernekar
- Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research), Hyderabad, India
| | - Benoit Gilquin
- Univ. Grenoble Alpes, CEA, INSERM, BIG-BGE, Grenoble, France
| | - Yohann Couté
- Univ. Grenoble Alpes, CEA, INSERM, BIG-BGE, Grenoble, France
| | - Purnima Bhargava
- Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research), Hyderabad, India.
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28
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Paf1 and Ctr9 subcomplex formation is essential for Paf1 complex assembly and functional regulation. Nat Commun 2018; 9:3795. [PMID: 30228257 PMCID: PMC6143631 DOI: 10.1038/s41467-018-06237-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 08/15/2018] [Indexed: 11/09/2022] Open
Abstract
The evolutionarily conserved multifunctional polymerase-associated factor 1 (Paf1) complex (Paf1C), which is composed of at least five subunits (Paf1, Leo1, Ctr9, Cdc73, and Rtf1), plays vital roles in gene regulation and has connections to development and human diseases. Here, we report two structures of each of the human and yeast Ctr9/Paf1 subcomplexes, which assemble into heterodimers with very similar conformations, revealing an interface between the tetratricopeptide repeat module in Ctr9 and Paf1. The structure of the Ctr9/Paf1 subcomplex may provide mechanistic explanations for disease-associated mutations in human PAF1 and CTR9. Our study reveals that the formation of the Ctr9/Paf1 heterodimer is required for the assembly of yeast Paf1C, and is essential for yeast viability. In addition, disruption of the interaction between Paf1 and Ctr9 greatly affects the level of histone H3 methylation in vivo. Collectively, our results shed light on Paf1C assembly and functional regulation.
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29
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Voichek Y, Mittelman K, Gordon Y, Bar-Ziv R, Lifshitz Smit D, Shenhav R, Barkai N. Epigenetic Control of Expression Homeostasis during Replication Is Stabilized by the Replication Checkpoint. Mol Cell 2018; 70:1121-1133.e9. [PMID: 29910110 DOI: 10.1016/j.molcel.2018.05.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 03/22/2018] [Accepted: 05/11/2018] [Indexed: 11/24/2022]
Abstract
DNA replication introduces a dosage imbalance between early and late replicating genes. In budding yeast, buffering gene expression against this imbalance depends on marking replicated DNA by H3K56 acetylation (H3K56ac). Whether additional processes are required for suppressing transcription from H3K56ac-labeled DNA remains unknown. Here, using a database-guided candidate screen, we find that COMPASS, the H3K4 methyltransferase, and its upstream effector, PAF1C, act downstream of H3K56ac to buffer expression. Replicated genes show reduced abundance of the transcription activating mark H3K4me3 and accumulate the transcription inhibitory mark H3K4me2 near transcription start sites. Notably, in hydroxyurea-exposed cells, the S phase checkpoint stabilizes H3K56ac and becomes essential for buffering. We suggest that H3K56ac suppresses transcription of replicated genes by interfering with post-replication recovery of epigenetic marks and assign a new function for the S phase checkpoint in stabilizing this mechanism during persistent dosage imbalance.
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Affiliation(s)
- Yoav Voichek
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Karin Mittelman
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yulia Gordon
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Raz Bar-Ziv
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - David Lifshitz Smit
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Rom Shenhav
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Naama Barkai
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
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30
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Cdc73 suppresses genome instability by mediating telomere homeostasis. PLoS Genet 2018; 14:e1007170. [PMID: 29320491 PMCID: PMC5779705 DOI: 10.1371/journal.pgen.1007170] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 01/23/2018] [Accepted: 12/25/2017] [Indexed: 12/18/2022] Open
Abstract
Defects in the genes encoding the Paf1 complex can cause increased genome instability. Loss of Paf1, Cdc73, and Ctr9, but not Rtf1 or Leo1, caused increased accumulation of gross chromosomal rearrangements (GCRs). Combining the cdc73Δ mutation with individual deletions of 43 other genes, including TEL1 and YKU80, which are involved in telomere maintenance, resulted in synergistic increases in GCR rates. Whole genome sequence analysis of GCRs indicated that there were reduced relative rates of GCRs mediated by de novo telomere additions and increased rates of translocations and inverted duplications in cdc73Δ single and double mutants. Analysis of telomere lengths and telomeric gene silencing in strains containing different combinations of cdc73Δ, tel1Δ and yku80Δ mutations suggested that combinations of these mutations caused increased defects in telomere maintenance. A deletion analysis of Cdc73 revealed that a central 105 amino acid region was necessary and sufficient for suppressing the defects observed in cdc73Δ strains; this region was required for the binding of Cdc73 to the Paf1 complex through Ctr9 and for nuclear localization of Cdc73. Taken together, these data suggest that the increased GCR rate of cdc73Δ single and double mutants is due to partial telomere dysfunction and that Ctr9 and Paf1 play a central role in the Paf1 complex potentially by scaffolding the Paf1 complex subunits or by mediating recruitment of the Paf1 complex to the different processes it functions in. Maintaining a stable genome is crucial for all organisms, and loss of genome stability has been linked to multiple human diseases, including many cancers. Previously we found that defects in Cdc73, a component of the Paf1 transcriptional elongation complex, give rise to increased genome instability. Here, we explored the mechanism underlying this instability and found that Cdc73 defects give rise to partial defects in maintaining telomeres, which are the specialized ends of chromosomes, and interact with other mutations causing telomere defects. Remarkably, Cdc73 function is mediated through a short central region of the protein that is not a part of previously identified protein domains but targets Cdc73 to the Paf1 complex through interaction with the Ctr9 subunit. Analysis of the other components of the Paf1 complex provides a model in which the Paf1 subunit mediates recruitment of the other subunits to different processes they function in. Together, these data suggest that the mutations in CDC73 and CTR9 found in patients with hyperparathyroidism-jaw tumor syndrome and some patients with Wilms tumors, respectively, may contribute to cancer progression by contributing to genome instability.
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31
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Nilson KA, Lawson CK, Mullen NJ, Ball CB, Spector BM, Meier JL, Price DH. Oxidative stress rapidly stabilizes promoter-proximal paused Pol II across the human genome. Nucleic Acids Res 2017; 45:11088-11105. [PMID: 28977633 PMCID: PMC5737879 DOI: 10.1093/nar/gkx724] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/08/2017] [Indexed: 12/29/2022] Open
Abstract
Oxidative stress has pervasive effects on cells but how they respond transcriptionally upon the initial insult is incompletely understood. We developed a nuclear walk-on assay that semi-globally quantifies nascent transcripts in promoter-proximal paused RNA polymerase II (Pol II). Using this assay in conjunction with ChIP-Seq, in vitro transcription, and a chromatin retention assay, we show that within a minute, hydrogen peroxide causes accumulation of Pol II near promoters and enhancers that can best be explained by a rapid decrease in termination. Some of the accumulated polymerases slowly move or ‘creep’ downstream. This second effect is correlated with and probably results from loss of NELF association and function. Notably, both effects were independent of DNA damage and ADP-ribosylation. Our results demonstrate the unexpected speed at which a global transcriptional response can occur. The findings provide strong support for the residence time of paused Pol II elongation complexes being much shorter than estimated from previous studies.
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Affiliation(s)
- Kyle A Nilson
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA.,Molecular and Cellular Biology Program, University of Iowa, Iowa City, IA 52242, USA
| | - Christine K Lawson
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Nicholas J Mullen
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Christopher B Ball
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Benjamin M Spector
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Jeffery L Meier
- Department of Internal Medicine, University of Iowa and Veterans Affairs Health Care System, Iowa City, IA 52242, USA
| | - David H Price
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA.,Molecular and Cellular Biology Program, University of Iowa, Iowa City, IA 52242, USA
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32
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Crickard JB, Lee J, Lee TH, Reese JC. The elongation factor Spt4/5 regulates RNA polymerase II transcription through the nucleosome. Nucleic Acids Res 2017; 45:6362-6374. [PMID: 28379497 PMCID: PMC5499766 DOI: 10.1093/nar/gkx220] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 03/23/2017] [Indexed: 01/04/2023] Open
Abstract
RNA polymerase II (RNAPII) passes through the nucleosome in a coordinated manner, generating several intermediate nucleosomal states as it breaks and then reforms histone–DNA contacts ahead of and behind it, respectively. Several studies have defined transcription-induced nucleosome intermediates using only RNA Polymerase. However, RNAPII is decorated with elongation factors as it transcribes the genome. One such factor, Spt4/5, becomes an integral component of the elongation complex, making direct contact with the ‘jaws’ of RNAPII and nucleic acids in the transcription scaffold. We have characterized the effect of incorporating Spt4/5 into the elongation complex on transcription through the 601R nucleosome. Spt4/5 suppressed RNAPII pausing at the major H3/H4-induced arrest point, resulting in downstream re-positioning of RNAPII further into the nucleosome. Using a novel single molecule FRET system, we found that Spt4/5 affected the kinetics of DNA re-wrapping and stabilized a nucleosomal intermediate with partially unwrapped DNA behind RNAPII. Comparison of nucleosomes of different sequence polarities suggest that the strength of the DNA–histone interactions behind RNAPII specifies the Spt4/5 requirement. We propose that Spt4/5 may be important to coordinate the mechanical movement of RNAPII through the nucleosome with co-transcriptional chromatin modifications during transcription, which is affected by the strength of histone–DNA interactions.
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Affiliation(s)
- John B Crickard
- Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Penn State University, University Park, PA 16802, USA
| | - Jaehyoun Lee
- Department of Chemistry, Penn State University, University Park, PA 16802, USA
| | - Tae-Hee Lee
- Department of Chemistry, Penn State University, University Park, PA 16802, USA
| | - Joseph C Reese
- Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Penn State University, University Park, PA 16802, USA
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33
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Van Oss SB, Cucinotta CE, Arndt KM. Emerging Insights into the Roles of the Paf1 Complex in Gene Regulation. Trends Biochem Sci 2017; 42:788-798. [PMID: 28870425 PMCID: PMC5658044 DOI: 10.1016/j.tibs.2017.08.003] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/03/2017] [Accepted: 08/08/2017] [Indexed: 12/21/2022]
Abstract
The conserved, multifunctional Polymerase-Associated Factor 1 complex (Paf1C) regulates all stages of the RNA polymerase (Pol) II transcription cycle. In this review, we examine a diverse set of recent studies from various organisms that build on foundational studies in budding yeast. These studies identify new roles for Paf1C in the control of gene expression and the regulation of chromatin structure. In exploring these advances, we find that various functions of Paf1C, such as the regulation of promoter-proximal pausing and development in higher eukaryotes, are complex and context dependent. As more becomes known about the role of Paf1C in human disease, interest in the molecular mechanisms underpinning Paf1C function will continue to increase.
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Affiliation(s)
- S Branden Van Oss
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Christine E Cucinotta
- 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.
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34
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Xu Y, Bernecky C, Lee CT, Maier KC, Schwalb B, Tegunov D, Plitzko JM, Urlaub H, Cramer P. Architecture of the RNA polymerase II-Paf1C-TFIIS transcription elongation complex. Nat Commun 2017; 8:15741. [PMID: 28585565 PMCID: PMC5467213 DOI: 10.1038/ncomms15741] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 04/25/2017] [Indexed: 02/01/2023] Open
Abstract
The conserved polymerase-associated factor 1 complex (Paf1C) plays multiple roles in chromatin transcription and genomic regulation. Paf1C comprises the five subunits Paf1, Leo1, Ctr9, Cdc73 and Rtf1, and binds to the RNA polymerase II (Pol II) transcription elongation complex (EC). Here we report the reconstitution of Paf1C from Saccharomyces cerevisiae, and a structural analysis of Paf1C bound to a Pol II EC containing the elongation factor TFIIS. Cryo-electron microscopy and crosslinking data reveal that Paf1C is highly mobile and extends over the outer Pol II surface from the Rpb2 to the Rpb3 subunit. The Paf1-Leo1 heterodimer and Cdc73 form opposite ends of Paf1C, whereas Ctr9 bridges between them. Consistent with the structural observations, the initiation factor TFIIF impairs Paf1C binding to Pol II, whereas the elongation factor TFIIS enhances it. We further show that Paf1C is globally required for normal mRNA transcription in yeast. These results provide a three-dimensional framework for further analysis of Paf1C function in transcription through chromatin.
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Affiliation(s)
- Youwei Xu
- Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, Max Planck Society, Am Fassberg 11, Göttingen 37077, Germany
| | - Carrie Bernecky
- Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, Max Planck Society, Am Fassberg 11, Göttingen 37077, Germany
| | - Chung-Tien Lee
- Bioanalytical Mass Spectrometry, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany.,Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center, Göttingen, Robert-Koch-Strasse 40, Göttingen 37075, Germany
| | - Kerstin C Maier
- Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, Max Planck Society, Am Fassberg 11, Göttingen 37077, Germany
| | - Björn Schwalb
- Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, Max Planck Society, Am Fassberg 11, Göttingen 37077, Germany
| | - Dimitry Tegunov
- Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, Max Planck Society, Am Fassberg 11, Göttingen 37077, Germany
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max-Planck-Institute for Biochemistry, Am Klopferspitz 18, Martinsried 82152, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany.,Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center, Göttingen, Robert-Koch-Strasse 40, Göttingen 37075, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, Max Planck Society, Am Fassberg 11, Göttingen 37077, Germany
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35
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Battaglia S, Lidschreiber M, Baejen C, Torkler P, Vos SM, Cramer P. RNA-dependent chromatin association of transcription elongation factors and Pol II CTD kinases. eLife 2017; 6. [PMID: 28537551 PMCID: PMC5457138 DOI: 10.7554/elife.25637] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 05/22/2017] [Indexed: 11/13/2022] Open
Abstract
For transcription through chromatin, RNA polymerase (Pol) II associates with elongation factors (EFs). Here we show that many EFs crosslink to RNA emerging from transcribing Pol II in the yeast Saccharomyces cerevisiae. Most EFs crosslink preferentially to mRNAs, rather than unstable non-coding RNAs. RNA contributes to chromatin association of many EFs, including the Pol II serine 2 kinases Ctk1 and Bur1 and the histone H3 methyltransferases Set1 and Set2. The Ctk1 kinase complex binds RNA in vitro, consistent with direct EF-RNA interaction. Set1 recruitment to genes in vivo depends on its RNA recognition motifs (RRMs). These results strongly suggest that nascent RNA contributes to EF recruitment to transcribing Pol II. We propose that EF-RNA interactions facilitate assembly of the elongation complex on transcribed genes when RNA emerges from Pol II, and that loss of EF-RNA interactions upon RNA cleavage at the polyadenylation site triggers disassembly of the elongation complex. DOI:http://dx.doi.org/10.7554/eLife.25637.001
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Affiliation(s)
- Sofia Battaglia
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Michael Lidschreiber
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Biosciences and Nutrition, Center for Innovative Medicine and Science for Life Laboratory, Novum, Karolinska Institutet, Huddinge, Sweden
| | - Carlo Baejen
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Phillipp Torkler
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Seychelle M Vos
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Biosciences and Nutrition, Center for Innovative Medicine and Science for Life Laboratory, Novum, Karolinska Institutet, Huddinge, Sweden
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36
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Lu C, Tian Y, Wang S, Su Y, Mao T, Huang T, Chen Q, Xu Z, Ding Y. Phosphorylation of SPT5 by CDKD;2 Is Required for VIP5 Recruitment and Normal Flowering in Arabidopsis thaliana. THE PLANT CELL 2017; 29:277-291. [PMID: 28188267 PMCID: PMC5354186 DOI: 10.1105/tpc.16.00568] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 01/10/2017] [Accepted: 02/09/2017] [Indexed: 05/10/2023]
Abstract
The elongation factor suppressor of Ty 5 homolog (Spt5) is a regulator of transcription and histone methylation. In humans, phosphorylation of SPT5 by P-TEFb, a protein kinase composed of Cyclin-dependent kinase 9 (CDK9) and cyclin T, interacts with the RNA polymerase II-associated factor1 (PAF1) complex. However, the mechanism of SPT5 phosphorylation is not well understood in plants. Here, we examine the function of SPT5 in Arabidopsis thaliana and find that spt5 mutant flowers early under long-day and short-day conditions. SPT5 interacts with the CDK-activating kinase 4 (CAK4; CDKD;2) and is specifically phosphorylated by CDKD;2 at threonines. The phosphorylated SPT5 binds VERNALIZATION INDEPENDENCE5 (VIP5), a subunit of the PAF1 complex. Genetic analysis showed that VIP5 acts downstream of SPT5 and CDKD;2 Loss of SPT5 or CDKD;2 function results in early flowering because of decreased amounts of FLOWERING LOCUS C (FLC) transcript. Importantly, CDKD;2 and SPT5 are required for the deposition of VIP5 and the enhancement of trimethylation of histone 3 lysine 4 in the chromatin of the FLC locus. Together, our results provide insight into the mechanism by which the Arabidopsis elongation factor SPT5 recruits the PAF1 complex via the posttranslational modification of proteins and suggest that the phosphorylation of SPT5 by CDKD;2 enables it to recruit VIP5 to regulate chromatin and transcription in Arabidopsis.
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Affiliation(s)
- Chengyuan Lu
- CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, University of Science and Technology of China, Anhui, China 230027
| | - Yongke Tian
- CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, University of Science and Technology of China, Anhui, China 230027
| | - Shiliang Wang
- CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, University of Science and Technology of China, Anhui, China 230027
| | - Yanhua Su
- CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, University of Science and Technology of China, Anhui, China 230027
| | - Ting Mao
- CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, University of Science and Technology of China, Anhui, China 230027
| | - Tongtong Huang
- CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, University of Science and Technology of China, Anhui, China 230027
| | - Qingqing Chen
- CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, University of Science and Technology of China, Anhui, China 230027
| | - Zuntao Xu
- CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, University of Science and Technology of China, Anhui, China 230027
| | - Yong Ding
- CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, University of Science and Technology of China, Anhui, China 230027
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Van Oss SB, Shirra MK, Bataille AR, Wier AD, Yen K, Vinayachandran V, Byeon IJL, Cucinotta CE, Héroux A, Jeon J, Kim J, VanDemark AP, Pugh BF, Arndt KM. The Histone Modification Domain of Paf1 Complex Subunit Rtf1 Directly Stimulates H2B Ubiquitylation through an Interaction with Rad6. Mol Cell 2016; 64:815-825. [PMID: 27840029 DOI: 10.1016/j.molcel.2016.10.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 09/09/2016] [Accepted: 10/05/2016] [Indexed: 10/24/2022]
Abstract
The five-subunit yeast Paf1 complex (Paf1C) regulates all stages of transcription and is critical for the monoubiquitylation of histone H2B (H2Bub), a modification that broadly influences chromatin structure and eukaryotic transcription. Here, we show that the histone modification domain (HMD) of Paf1C subunit Rtf1 directly interacts with the ubiquitin conjugase Rad6 and stimulates H2Bub independently of transcription. We present the crystal structure of the Rtf1 HMD and use site-specific, in vivo crosslinking to identify a conserved Rad6 interaction surface. Utilizing ChIP-exo analysis, we define the localization patterns of the H2Bub machinery at high resolution and demonstrate the importance of Paf1C in targeting the Rtf1 HMD, and thereby H2Bub, to its appropriate genomic locations. Finally, we observe HMD-dependent stimulation of H2Bub in a transcription-free, reconstituted in vitro system. Taken together, our results argue for an active role for Paf1C in promoting H2Bub and ensuring its proper localization in vivo.
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Affiliation(s)
- S Branden Van Oss
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Margaret K Shirra
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Alain R Bataille
- Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, PA 16802, USA
| | - Adam D Wier
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Kuangyu Yen
- Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, PA 16802, USA; Department of Developmental Biology, Southern Medical University, Guangzhou 510515, China
| | - Vinesh Vinayachandran
- Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, PA 16802, USA
| | - In-Ja L Byeon
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Christine E Cucinotta
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Annie Héroux
- Department of Biology, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jongcheol Jeon
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
| | - Jaehoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
| | - Andrew P VanDemark
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - B Franklin Pugh
- Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, PA 16802, USA
| | - Karen M Arndt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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38
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Crickard JB, Fu J, Reese JC. Biochemical Analysis of Yeast Suppressor of Ty 4/5 (Spt4/5) Reveals the Importance of Nucleic Acid Interactions in the Prevention of RNA Polymerase II Arrest. J Biol Chem 2016; 291:9853-70. [PMID: 26945063 DOI: 10.1074/jbc.m116.716001] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Indexed: 11/06/2022] Open
Abstract
RNA polymerase II (RNAPII) undergoes structural changes during the transitions from initiation, elongation, and termination, which are aided by a collection of proteins called elongation factors. NusG/Spt5 is the only elongation factor conserved in all domains of life. Although much information exists about the interactions between NusG/Spt5 and RNA polymerase in prokaryotes, little is known about how the binding of eukaryotic Spt4/5 affects the biochemical activities of RNAPII. We characterized the activities of Spt4/5 and interrogated the structural features of Spt5 required for it to interact with elongation complexes, bind nucleic acids, and promote transcription elongation. The eukaryotic specific regions of Spt5 containing the Kyrpides, Ouzounis, Woese domains are involved in stabilizing the association with the RNAPII elongation complex, which also requires the presence of the nascent transcript. Interestingly, we identify a region within the conserved NusG N-terminal (NGN) domain of Spt5 that contacts the non-template strand of DNA both upstream of RNAPII and in the transcription bubble. Mutating charged residues in this region of Spt5 did not prevent Spt4/5 binding to elongation complexes, but abrogated the cross-linking of Spt5 to DNA and the anti-arrest properties of Spt4/5, thus suggesting that contact between Spt5 (NGN) and DNA is required for Spt4/5 to promote elongation. We propose that the mechanism of how Spt5/NGN promotes elongation is fundamentally conserved; however, the eukaryotic specific regions of the protein evolved so that it can serve as a platform for other elongation factors and maintain its association with RNAPII as it navigates genomes packaged into chromatin.
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Affiliation(s)
- J Brooks Crickard
- From the Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Penn State University, University Park, Pennsylvania 16802 and
| | - Jianhua Fu
- the Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Joseph C Reese
- From the Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Penn State University, University Park, Pennsylvania 16802 and
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39
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Verrier L, Taglini F, Barrales RR, Webb S, Urano T, Braun S, Bayne EH. Global regulation of heterochromatin spreading by Leo1. Open Biol 2016; 5:rsob.150045. [PMID: 25972440 PMCID: PMC4450266 DOI: 10.1098/rsob.150045] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Heterochromatin plays important roles in eukaryotic genome regulation. However, the repressive nature of heterochromatin combined with its propensity to self-propagate necessitates robust mechanisms to contain heterochromatin within defined boundaries and thus prevent silencing of expressed genes. Here we show that loss of the PAF complex (PAFc) component Leo1 compromises chromatin boundaries, resulting in invasion of heterochromatin into flanking euchromatin domains. Similar effects are seen upon deletion of other PAFc components, but not other factors with related functions in transcription-associated chromatin modification, indicating a specific role for PAFc in heterochromatin regulation. Loss of Leo1 results in reduced levels of H4K16 acetylation at boundary regions, while tethering of the H4K16 acetyltransferase Mst1 to boundary chromatin suppresses heterochromatin spreading in leo1Δ cells, suggesting that Leo1 antagonises heterochromatin spreading by promoting H4K16 acetylation. Our findings reveal a previously undescribed role for PAFc in regulating global heterochromatin distribution.
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Affiliation(s)
- Laure Verrier
- Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | | | - Ramon R Barrales
- Butenandt Institute of Physiological Chemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Shaun Webb
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Takeshi Urano
- Department of Biochemistry, Faculty of Medicine, Shimane University, Izumo, Japan
| | - Sigurd Braun
- Butenandt Institute of Physiological Chemistry, Ludwig-Maximilians-Universität München, Munich, Germany
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40
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Mbogning J, Pagé V, Burston J, Schwenger E, Fisher RP, Schwer B, Shuman S, Tanny JC. Functional interaction of Rpb1 and Spt5 C-terminal domains in co-transcriptional histone modification. Nucleic Acids Res 2015; 43:9766-75. [PMID: 26275777 PMCID: PMC4787787 DOI: 10.1093/nar/gkv837] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 08/09/2015] [Indexed: 12/11/2022] Open
Abstract
Transcription by RNA polymerase II (RNAPII) is accompanied by a conserved pattern of histone modifications that plays important roles in regulating gene expression. The establishment of this pattern requires phosphorylation of both Rpb1 (the largest RNAPII subunit) and the elongation factor Spt5 on their respective C-terminal domains (CTDs). Here we interrogated the roles of individual Rpb1 and Spt5 CTD phospho-sites in directing co-transcriptional histone modifications in the fission yeast Schizosaccharomyces pombe. Steady-state levels of methylation at histone H3 lysines 4 (H3K4me) and 36 (H3K36me) were sensitive to multiple mutations of the Rpb1 CTD repeat motif (Y1S2P3T4S5P6S7). Ablation of the Spt5 CTD phospho-site Thr1 reduced H3K4me levels but had minimal effects on H3K36me. Nonetheless, Spt5 CTD mutations potentiated the effects of Rpb1 CTD mutations on H3K36me, suggesting overlapping functions. Phosphorylation of Rpb1 Ser2 by the Cdk12 orthologue Lsk1 positively regulated H3K36me but negatively regulated H3K4me. H3K36me and histone H2B monoubiquitylation required Rpb1 Ser5 but were maintained upon inactivation of Mcs6/Cdk7, the major kinase for Rpb1 Ser5 in vivo, implicating another Ser5 kinase in these regulatory pathways. Our results elaborate the CTD ‘code’ for co-transcriptional histone modifications.
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Affiliation(s)
- Jean Mbogning
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, H3G 1Y6, Canada
| | - Viviane Pagé
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, H3G 1Y6, Canada
| | - Jillian Burston
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, H3G 1Y6, Canada
| | - Emily Schwenger
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, H3G 1Y6, Canada
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Beate Schwer
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, H3G 1Y6, Canada
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41
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Cucinotta CE, Young AN, Klucevsek KM, Arndt KM. The Nucleosome Acidic Patch Regulates the H2B K123 Monoubiquitylation Cascade and Transcription Elongation in Saccharomyces cerevisiae. PLoS Genet 2015; 11:e1005420. [PMID: 26241481 PMCID: PMC4524731 DOI: 10.1371/journal.pgen.1005420] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 07/05/2015] [Indexed: 02/06/2023] Open
Abstract
Eukaryotes regulate gene expression and other nuclear processes through the posttranslational modification of histones. In S. cerevisiae, the mono-ubiquitylation of histone H2B on lysine 123 (H2B K123ub) affects nucleosome stability, broadly influences gene expression and other DNA-templated processes, and is a prerequisite for additional conserved histone modifications that are associated with active transcription, namely the methylation of lysine residues in H3. While the enzymes that promote these chromatin marks are known, regions of the nucleosome required for the recruitment of these enzymes are undefined. To identify histone residues required for H2B K123ub, we exploited a functional interaction between the ubiquitin-protein ligase, Rkr1/Ltn1, and H2B K123ub in S. cerevisiae. Specifically, we performed a synthetic lethal screen with cells lacking RKR1 and a comprehensive library of H2A and H2B residue substitutions, and identified H2A residues that are required for H2B K123ub. Many of these residues map to the nucleosome acidic patch. The substitutions in the acidic patch confer varying histone modification defects downstream of H2B K123ub, indicating that this region contributes differentially to multiple histone modifications. Interestingly, substitutions in the acidic patch result in decreased recruitment of H2B K123ub machinery to active genes and defects in transcription elongation and termination. Together, our findings reveal a role for the nucleosome acidic patch in recruitment of histone modification machinery and maintenance of transcriptional integrity. Chromatin, a complex of DNA wrapped around histone proteins, impacts all DNA-templated processes, including gene expression. Cells employ various strategies to alter chromatin structure and control access to the genetic material. Nucleosomes, the building blocks of chromatin, are subject to a myriad of modifications on their constituent histone proteins. One highly conserved modification with important connections to human health is the addition of ubiquitin to histone H2B. H2B ubiquitylation modulates chromatin structure during gene transcription and acts as a master regulator for downstream histone modifications. The proteins that promote H2B ubiquitylation have been identified; however, little is known about how these proteins interface with the nucleosome. Here, we exploited the genetic tools of budding yeast to reveal features of the nucleosome that are required for H2B ubiquitylation. Our genetic screen identified amino acids on the nucleosome acidic patch, a negatively charged region on the nucleosome surface, as being important for this process. The acidic patch is critical for regulating chromatin transactions, and, in our study, we identified roles for the acidic patch throughout transcription. Our data reveal that the acidic patch recruits histone modifiers, regulates histone modifications within the H2B ubiquitylation cascade, and maintains transcriptional fidelity.
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Affiliation(s)
- Christine E. Cucinotta
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Alexandria N. Young
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Kristin M. Klucevsek
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Karen M. Arndt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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42
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Characterization of the Human Transcription Elongation Factor Rtf1: Evidence for Nonoverlapping Functions of Rtf1 and the Paf1 Complex. Mol Cell Biol 2015. [PMID: 26217014 DOI: 10.1128/mcb.00601-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Restores TBP function 1 (Rtf1) is generally considered to be a subunit of the Paf1 complex (PAF1C), a multifunctional protein complex involved in histone modification and transcriptional or posttranscriptional regulation. Rtf1, however, is not stably associated with the PAF1C in most species except Saccharomyces cerevisiae, and its biochemical functions are not well understood. Here, we show that human Rtf1 is a transcription elongation factor that may function independently of the PAF1C. Rtf1 requires "Rtf1 coactivator" activity, which is most likely unrelated to the PAF1C or DSIF, for transcriptional activation in vitro. A mutational study revealed that the Plus3 domain of human Rtf1 is critical for its coactivator-dependent function. Transcriptome sequencing (RNA-seq) and chromatin immunoprecipitation studies in HeLa cells showed that Rtf1 and the PAF1C play distinct roles in regulating the expression of a subset of genes. Moreover, contrary to the finding in S. cerevisiae, the PAF1C was apparently recruited to the genes examined in an Rtf1-independent manner. The present study establishes a role for human Rtf1 as a transcription elongation factor and highlights the similarities and differences between the S. cerevisiae and human Rtf1 proteins.
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43
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Abstract
Transcription elongation by RNA polymerase II (RNAP II) involves the coordinated action of numerous regulatory factors. Among these are chromatin-modifying enzymes, which generate a stereotypic and conserved pattern of histone modifications along transcribed genes. This pattern implies a precise coordination between regulators of histone modification and the RNAP II elongation complex. Here I review the pathways and molecular events that regulate co-transcriptional histone modifications. Insight into these events will illuminate the assembly of functional RNAP II elongation complexes and how the chromatin landscape influences their composition and function.
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Affiliation(s)
- Jason C Tanny
- a Department of Pharmacology and Therapeutics ; McGill University ; Montreal , Canada
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44
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Deshpande SM, Sadhale PP, Vijayraghavan U. Involvement of S. cerevisiae Rpb4 in subset of pathways related to transcription elongation. Gene 2014; 545:126-31. [DOI: 10.1016/j.gene.2014.04.061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 04/10/2014] [Accepted: 04/25/2014] [Indexed: 11/28/2022]
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45
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Mbogning J, Nagy S, Pagé V, Schwer B, Shuman S, Fisher RP, Tanny JC. The PAF complex and Prf1/Rtf1 delineate distinct Cdk9-dependent pathways regulating transcription elongation in fission yeast. PLoS Genet 2013; 9:e1004029. [PMID: 24385927 PMCID: PMC3873232 DOI: 10.1371/journal.pgen.1004029] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 10/31/2013] [Indexed: 11/19/2022] Open
Abstract
Cyclin-dependent kinase 9 (Cdk9) promotes elongation by RNA polymerase II (RNAPII), mRNA processing, and co-transcriptional histone modification. Cdk9 phosphorylates multiple targets, including the conserved RNAPII elongation factor Spt5 and RNAPII itself, but how these different modifications mediate Cdk9 functions is not known. Here we describe two Cdk9-dependent pathways in the fission yeast Schizosaccharomyces pombe that involve distinct targets and elicit distinct biological outcomes. Phosphorylation of Spt5 by Cdk9 creates a direct binding site for Prf1/Rtf1, a transcription regulator with functional and physical links to the Polymerase Associated Factor (PAF) complex. PAF association with chromatin is also dependent on Cdk9 but involves alternate phosphoacceptor targets. Prf1 and PAF are biochemically separate in cell extracts, and genetic analyses show that Prf1 and PAF are functionally distinct and exert opposing effects on the RNAPII elongation complex. We propose that this opposition constitutes a Cdk9 auto-regulatory mechanism, such that a positive effect on elongation, driven by the PAF pathway, is kept in check by a negative effect of Prf1/Rtf1 and downstream mono-ubiquitylation of histone H2B. Thus, optimal RNAPII elongation may require balanced action of functionally distinct Cdk9 pathways.
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Affiliation(s)
- Jean Mbogning
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Stephen Nagy
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Viviane Pagé
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Beate Schwer
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Stewart Shuman
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Robert P. Fisher
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Jason C. Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
- * E-mail:
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46
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Structural basis for Spt5-mediated recruitment of the Paf1 complex to chromatin. Proc Natl Acad Sci U S A 2013; 110:17290-5. [PMID: 24101474 DOI: 10.1073/pnas.1314754110] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Polymerase associated factor 1 complex (Paf1C) broadly influences gene expression by regulating chromatin structure and the recruitment of RNA-processing factors during transcription elongation. The Plus3 domain of the Rtf1 subunit mediates Paf1C recruitment to genes by binding a repeating domain within the elongation factor Spt5 (suppressor of Ty). Here we provide a molecular description of this interaction by reporting the structure of human Rtf1 Plus3 in complex with a phosphorylated Spt5 repeat. We find that Spt5 binding is mediated by an extended surface containing phosphothreonine recognition and hydrophobic interfaces that interact with residues outside the Spt5 motif. Changes within these interfaces diminish binding of Spt5 in vitro and chromatin localization of Rtf1 in vivo. The structure reveals the basis for recognition of the repeat motif of Spt5, a key player in the recruitment of gene regulatory factors to RNA polymerase II.
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