1
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Gao E, Brown JAR, Jung S, Howe LJ. A fluorescent assay for cryptic transcription in Saccharomyces cerevisiae reveals novel insights into factors that stabilize chromatin structure on newly replicated DNA. Genetics 2024; 226:iyae016. [PMID: 38407959 PMCID: PMC10990430 DOI: 10.1093/genetics/iyae016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/12/2024] [Indexed: 02/27/2024] Open
Abstract
The disruption of chromatin structure can result in transcription initiation from cryptic promoters within gene bodies. While the passage of RNA polymerase II is a well-characterized chromatin-disrupting force, numerous factors, including histone chaperones, normally stabilize chromatin on transcribed genes, thereby repressing cryptic transcription. DNA replication, which employs a partially overlapping set of histone chaperones, is also inherently disruptive to chromatin, but a role for DNA replication in cryptic transcription has never been examined. In this study, we tested the hypothesis that, in the absence of chromatin-stabilizing factors, DNA replication can promote cryptic transcription in Saccharomyces cerevisiae. Using a novel fluorescent reporter assay, we show that multiple factors, including Asf1, CAF-1, Rtt106, Spt6, and FACT, block transcription from a cryptic promoter, but are entirely or partially dispensable in G1-arrested cells, suggesting a requirement for DNA replication in chromatin disruption. Collectively, these results demonstrate that transcription fidelity is dependent on numerous factors that function to assemble chromatin on nascent DNA.
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Affiliation(s)
- Ellia Gao
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Joshua A R Brown
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Stephanie Jung
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - LeAnn J Howe
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
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2
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Robert F, Jeronimo C. Transcription-coupled nucleosome assembly. Trends Biochem Sci 2023; 48:978-992. [PMID: 37657993 DOI: 10.1016/j.tibs.2023.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/21/2023] [Accepted: 08/04/2023] [Indexed: 09/03/2023]
Abstract
Eukaryotic transcription occurs on chromatin, where RNA polymerase II encounters nucleosomes during elongation. These nucleosomes must unravel for the DNA to enter the active site. However, in most transcribed genes, nucleosomes remain intact due to transcription-coupled chromatin assembly mechanisms. These mechanisms primarily involve the local reassembly of displaced nucleosomes to prevent (epi)genomic instability and the emergence of cryptic transcription. As a fail-safe mechanism, cells can assemble nucleosomes de novo, particularly in highly transcribed genes, but this may result in the loss of epigenetic information. This review examines transcription-coupled chromatin assembly, with an emphasis on studies in yeast and recent structural studies. These studies shed light on how elongation factors and histone chaperones coordinate to enable nucleosome recycling during transcription.
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Affiliation(s)
- François Robert
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada; Département de Médecine, Faculté de Médecine, Université de Montréal, 2900 Boul. Édouard-Montpetit, Montréal, QC H3T 1J4, Canada; Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC H3A 1A3, Canada.
| | - Célia Jeronimo
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada
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3
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Li YM, Mei YC, Liu AH, Wang RX, Chen R, Du HN. Gcn5- and Bre1-mediated Set2 degradation promotes chronological aging of Saccharomyces cerevisiae. Cell Rep 2023; 42:113186. [PMID: 37796660 DOI: 10.1016/j.celrep.2023.113186] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 07/19/2023] [Accepted: 09/13/2023] [Indexed: 10/07/2023] Open
Abstract
Loss of transcription-coupled histone H3 lysine 36 trimethylation (H3K36me3) contributes to shorter lifespans in eukaryotes. However, the molecular mechanism of the decline of H3K36me3 during aging remains poorly understood. Here, we report that the degradation of the methyltransferase Set2 is the cause of decreased H3K36me3 levels during chronological aging in budding yeast. We show that Set2 protein degradation during cellular senescence and chronological aging is mainly mediated by the ubiquitin-conjugating E2 enzyme Ubc3 and the E3 ligase Bre1. Lack of Bre1 or abolishment of the ubiquitination stabilizes Set2 protein, sustains H3K36me3 levels at the aging-related gene loci, and upregulates their gene expression, thus leading to extended chronological lifespan. We further illustrate that Gcn5-mediated Set2 acetylation is a prerequisite for Bre1-catalyzed Set2 polyubiquitination and proteolysis during aging. We propose that two sequential post-translational modifications regulate Set2 homeostasis, suggesting a potential strategy to target the Gcn5-Bre1-Set2 axis for intervention of longevity.
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Affiliation(s)
- Yu-Min Li
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Hubei Clinical Research Center of Emergency and Resuscitation, Emergency Center of Zhongnan Hospital, RNA Institute, Wuhan University, Wuhan 430072, China
| | - Yu-Chao Mei
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Hubei Clinical Research Center of Emergency and Resuscitation, Emergency Center of Zhongnan Hospital, RNA Institute, Wuhan University, Wuhan 430072, China
| | - Ao-Hui Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Hubei Clinical Research Center of Emergency and Resuscitation, Emergency Center of Zhongnan Hospital, RNA Institute, Wuhan University, Wuhan 430072, China
| | - Ru-Xin Wang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Hubei Clinical Research Center of Emergency and Resuscitation, Emergency Center of Zhongnan Hospital, RNA Institute, Wuhan University, Wuhan 430072, China
| | - Runfa Chen
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Hubei Clinical Research Center of Emergency and Resuscitation, Emergency Center of Zhongnan Hospital, RNA Institute, Wuhan University, Wuhan 430072, China
| | - Hai-Ning Du
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Hubei Clinical Research Center of Emergency and Resuscitation, Emergency Center of Zhongnan Hospital, RNA Institute, Wuhan University, Wuhan 430072, China.
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4
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Barrientos-Moreno M, Maya-Miles D, Murillo-Pineda M, Fontalva S, Pérez-Alegre M, Andujar E, Prado F. Transcription and FACT facilitate the restoration of replication-coupled chromatin assembly defects. Sci Rep 2023; 13:11397. [PMID: 37452085 PMCID: PMC10349138 DOI: 10.1038/s41598-023-38280-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 07/06/2023] [Indexed: 07/18/2023] Open
Abstract
Genome duplication occurs through the coordinated action of DNA replication and nucleosome assembly at replication forks. Defective nucleosome assembly causes DNA lesions by fork breakage that need to be repaired. In addition, it causes a loss of chromatin integrity. These chromatin alterations can be restored, even though the mechanisms are unknown. Here, we show that the process of chromatin restoration can deal with highly severe chromatin defects induced by the absence of the chaperones CAF1 and Rtt106 or a strong reduction in the pool of available histones, and that this process can be followed by analyzing the topoisomer distribution of the 2µ plasmid. Using this assay, we demonstrate that chromatin restoration is slow and independent of checkpoint activation, whereas it requires the action of transcription and the FACT complex. Therefore, cells are able to "repair" not only DNA lesions but also chromatin alterations associated with defective nucleosome assembly.
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Affiliation(s)
- Marta Barrientos-Moreno
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine (CABIMER), CSIC‑University of Seville‑University Pablo de Olavide, Seville, Spain
| | - Douglas Maya-Miles
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine (CABIMER), CSIC‑University of Seville‑University Pablo de Olavide, Seville, Spain
| | - Marina Murillo-Pineda
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine (CABIMER), CSIC‑University of Seville‑University Pablo de Olavide, Seville, Spain
| | - Sara Fontalva
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine (CABIMER), CSIC‑University of Seville‑University Pablo de Olavide, Seville, Spain
| | - Mónica Pérez-Alegre
- Genomic Unit, Andalusian Molecular Biology and Regenerative Medicine Center (CABIMER), CSIC‑University of Seville‑University Pablo de Olavide, Seville, Spain
| | - Eloísa Andujar
- Genomic Unit, Andalusian Molecular Biology and Regenerative Medicine Center (CABIMER), CSIC‑University of Seville‑University Pablo de Olavide, Seville, Spain
| | - Félix Prado
- Department of Genome Biology, Andalusian Molecular Biology and Regenerative Medicine (CABIMER), CSIC‑University of Seville‑University Pablo de Olavide, Seville, Spain.
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5
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Al-Anzi BF, Khajah M, Fakhraldeen SA. Predicting and explaining the impact of genetic disruptions and interactions on organismal viability. Bioinformatics 2022; 38:4088-4099. [PMID: 35861390 PMCID: PMC9438956 DOI: 10.1093/bioinformatics/btac519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 06/30/2022] [Accepted: 07/20/2022] [Indexed: 12/24/2022] Open
Abstract
MOTIVATION Existing computational models can predict single- and double-mutant fitness but they do have limitations. First, they are often tested via evaluation metrics that are inappropriate for imbalanced datasets. Second, all of them only predict a binary outcome (viable or not, and negatively interacting or not). Third, most are uninterpretable black box machine learning models. RESULTS Budding yeast datasets were used to develop high-performance Multinomial Regression (MN) models capable of predicting the impact of single, double and triple genetic disruptions on viability. These models are interpretable and give realistic non-binary predictions and can predict negative genetic interactions (GIs) in triple-gene knockouts. They are based on a limited set of gene features and their predictions are influenced by the probability of target gene participating in molecular complexes or pathways. Furthermore, the MN models have utility in other organisms such as fission yeast, fruit flies and humans, with the single gene fitness MN model being able to distinguish essential genes necessary for cell-autonomous viability from those required for multicellular survival. Finally, our models exceed the performance of previous models, without sacrificing interpretability. AVAILABILITY AND IMPLEMENTATION All code and processed datasets used to generate results and figures in this manuscript are available at our Github repository at https://github.com/KISRDevelopment/cell_viability_paper. The repository also contains a link to the GI prediction website that lets users search for GIs using the MN models. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
| | | | - Saja A Fakhraldeen
- Ecosystem-based Management of Marine Resources Program, Kuwait Institute for Scientific Research, Safat, 13109, Kuwait
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6
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Li S, Edwards G, Radebaugh CA, Luger K, A Stargell L. Spn1 and its dynamic interactions with Spt6, histones and nucleosomes. J Mol Biol 2022; 434:167630. [PMID: 35595162 DOI: 10.1016/j.jmb.2022.167630] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 11/25/2022]
Abstract
Histone chaperones facilitate the assembly and disassembly of nucleosomes and regulate DNA accessibility for critical cellular processes. Spn1 is an essential, highly conserved histone chaperone that functions in transcription initiation and elongation in a chromatin context. Here we demonstrate that Spn1 binds H3-H4 with low nanomolar affinity, residues 85-99 within the acidic N-terminal region of Spn1 are required for H3-H4 binding, and Spn1 binding to H3-H4 dimers does not impede (H3-H4)2 tetramer formation. Previous work has shown the central region of Spn1 (residues 141-305) is important for interaction with Spt6, another conserved and essential histone chaperone. We show that the C-terminal region of Spn1 also contributes to Spt6 binding and is critical for Spn1 binding to nucleosomes. We also show Spt6 preferentially binds H3-H4 tetramers and Spt6 competes with nucleosomes for Spn1 binding. Combined with previous results, this indicates the Spn1-Spt6 complex does not bind nucleosomes. In contrast to nucleosome binding, we found that the Spn1-Spt6 complex can bind H3-H4 dimers and tetramers and H2A-H2B to form ternary complexes. These important results provide new information about the functions of Spn1, Spt6, and the Spn1-Spt6 complex, two essential and highly conserved histone chaperones.
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Affiliation(s)
- Sha Li
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1870, USA; Department of Biochemistry, University of Colorado, Boulder, CO, 80309, USA
| | - Garrett Edwards
- Department of Biochemistry, University of Colorado, Boulder, CO, 80309, USA
| | - Catherine A Radebaugh
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1870, USA
| | - Karolin Luger
- Department of Biochemistry, University of Colorado, Boulder, CO, 80309, USA; Howard Hughes Medical Institute, University of Colorado, Boulder, CO, 80309, USA
| | - Laurie A Stargell
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1870, USA
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7
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Jeronimo C, Robert F. The histone chaperone FACT: a guardian of chromatin structure integrity. Transcription 2022; 13:16-38. [PMID: 35485711 PMCID: PMC9467567 DOI: 10.1080/21541264.2022.2069995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The identification of FACT as a histone chaperone enabling transcription through chromatin in vitro has strongly shaped how its roles are envisioned. However, FACT has been implicated in essentially all aspects of chromatin biology, from transcription to DNA replication, DNA repair, and chromosome segregation. In this review, we focus on recent literature describing the role and mechanisms of FACT during transcription. We highlight the prime importance of FACT in preserving chromatin integrity during transcription and challenge its role as an elongation factor. We also review evidence for FACT's role as a cell-type/gene-specificregulator of gene expression and briefly summarize current efforts at using FACT inhibition as an anti-cancerstrategy.
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Affiliation(s)
- Célia Jeronimo
- Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal, Montréal, Québec, Canada.,Département de Médecine, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada.,Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec, Canada
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8
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Nikolov VN, Malavia D, Kubota T. SWI/SNF and the histone chaperone Rtt106 drive expression of the Pleiotropic Drug Resistance network genes. Nat Commun 2022; 13:1968. [PMID: 35413952 PMCID: PMC9005695 DOI: 10.1038/s41467-022-29591-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 03/23/2022] [Indexed: 12/13/2022] Open
Abstract
The Pleiotropic Drug Resistance (PDR) network is central to the drug response in fungi, and its overactivation is associated with drug resistance. However, gene regulation of the PDR network is not well understood. Here, we show that the histone chaperone Rtt106 and the chromatin remodeller SWI/SNF control expression of the PDR network genes and confer drug resistance. In Saccharomyces cerevisiae, Rtt106 specifically localises to PDR network gene promoters dependent on transcription factor Pdr3, but not Pdr1, and is essential for Pdr3-mediated basal expression of the PDR network genes, while SWI/SNF is essential for both basal and drug-induced expression. Also in the pathogenic fungus Candida glabrata, Rtt106 and SWI/SNF regulate drug-induced PDR gene expression. Consistently, loss of Rtt106 or SWI/SNF sensitises drug-resistant S. cerevisiae mutants and C. glabrata to antifungal drugs. Since they cooperatively drive PDR network gene expression, Rtt106 and SWI/SNF represent potential therapeutic targets to combat antifungal resistance.
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Affiliation(s)
- Vladislav N Nikolov
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Dhara Malavia
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
- MRC Centre for Medical Mycology, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Takashi Kubota
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
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9
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Trans-tail regulation-mediated suppression of cryptic transcription. Exp Mol Med 2021; 53:1683-1688. [PMID: 34845331 PMCID: PMC8639711 DOI: 10.1038/s12276-021-00711-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 01/08/2023] Open
Abstract
Crosstalk between post-translational modifications of histone proteins influences the regulation of chromatin structure and gene expression. Among such crosstalk pathways, the best-characterized example is H2B monoubiquitination-mediated H3K4 and H3K79 methylation, which is referred to as trans-tail regulation. Although many studies have investigated the fragmentary effects of this pathway on silencing and transcription, its ultimate contribution to transcriptional control has remained unclear. Recent advances in molecular techniques and genomics have, however, revealed that the trans-tail crosstalk is linked to a more diverse cascade of histone modifications and has various functions in cotranscriptional processes. Furthermore, H2B monoubiquitination sequentially facilitates H3K4 dimethylation and histone sumoylation, thereby providing a binding platform for recruiting Set3 complex proteins, including two histone deacetylases, to restrict cryptic transcription from gene bodies. The removal of both ubiquitin and SUMO, small ubiquitin-like modifier, modifications from histones also facilitates a change in the phosphorylation pattern of the RNA polymerase II C-terminal domain that is required for subsequent transcriptional elongation. Therefore, this review describes recent findings regarding trans-tail regulation-driven processes to elaborate on their contribution to maintaining transcriptional fidelity. Crosstalk between different DNA-winding proteins, or histones, is a mechanism of molecular fidelity that helps prevent the initiation of aberrant gene expression, which may contribute to cancer and neurodegenerative disease. A team from South Korea, led by Jungmin Choi from the Korea University College of Medicine in Seoul and Hong-Yeoul Ryu from Kyungpook National University in Daegu, review the ways in which different histone proteins chemically modify parts of each other’s structure to regulate their functions. These modifications affect how histones interact with DNA, which in turn alters the dynamics of other factors implicated in gene expression. The correct interaction of histones is necessary to prevent the gene expression machinery from starting RNA synthesis from the wrong sites. Accurate control of these mechanisms is essential for cellular wellbeing
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10
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The box C/D snoRNP assembly factor Bcd1 interacts with the histone chaperone Rtt106 and controls its transcription dependent activity. Nat Commun 2021; 12:1859. [PMID: 33767140 PMCID: PMC7994586 DOI: 10.1038/s41467-021-22077-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 02/26/2021] [Indexed: 12/25/2022] Open
Abstract
Biogenesis of eukaryotic box C/D small nucleolar ribonucleoproteins initiates co-transcriptionally and requires the action of the assembly machinery including the Hsp90/R2TP complex, the Rsa1p:Hit1p heterodimer and the Bcd1 protein. We present genetic interactions between the Rsa1p-encoding gene and genes involved in chromatin organization including RTT106 that codes for the H3-H4 histone chaperone Rtt106p controlling H3K56ac deposition. We show that Bcd1p binds Rtt106p and controls its transcription-dependent recruitment by reducing its association with RNA polymerase II, modulating H3K56ac levels at gene body. We reveal the 3D structures of the free and Rtt106p-bound forms of Bcd1p using nuclear magnetic resonance and X-ray crystallography. The interaction is also studied by a combination of biophysical and proteomic techniques. Bcd1p interacts with a region that is distinct from the interaction interface between the histone chaperone and histone H3. Our results are evidence for a protein interaction interface for Rtt106p that controls its transcription-associated activity. Biogenesis of small nucleolar RNAs ribonucleoproteins (snoRNPs) requires dedicated assembly machinery. Here, the authors show that a subset of snoRNP assembly factors interacts, genetically or directly, with factors modulating chromatin architecture, suggesting a link between ribosome formation and chromatin functions.
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11
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Young TJ, Cui Y, Pfeffer C, Hobbs E, Liu W, Irudayaraj J, Kirchmaier AL. CAF-1 and Rtt101p function within the replication-coupled chromatin assembly network to promote H4 K16ac, preventing ectopic silencing. PLoS Genet 2020; 16:e1009226. [PMID: 33284793 PMCID: PMC7746308 DOI: 10.1371/journal.pgen.1009226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 12/17/2020] [Accepted: 10/26/2020] [Indexed: 11/18/2022] Open
Abstract
Replication-coupled chromatin assembly is achieved by a network of alternate pathways containing different chromatin assembly factors and histone-modifying enzymes that coordinate deposition of nucleosomes at the replication fork. Here we describe the organization of a CAF-1-dependent pathway in Saccharomyces cerevisiae that regulates acetylation of histone H4 K16. We demonstrate factors that function in this CAF-1-dependent pathway are important for preventing establishment of silenced states at inappropriate genomic sites using a crippled HMR locus as a model, while factors specific to other assembly pathways do not. This CAF-1-dependent pathway required the cullin Rtt101p, but was functionally distinct from an alternate pathway involving Rtt101p-dependent ubiquitination of histone H3 and the chromatin assembly factor Rtt106p. A major implication from this work is that cells have the inherent ability to create different chromatin modification patterns during DNA replication via differential processing and deposition of histones by distinct chromatin assembly pathways within the network.
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Affiliation(s)
- Tiffany J. Young
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
- Purdue University Center for Cancer Research, West Lafayette, Indiana, United States of America
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
| | - Yi Cui
- Purdue University Center for Cancer Research, West Lafayette, Indiana, United States of America
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, United States of America
| | - Claire Pfeffer
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Emilie Hobbs
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Wenjie Liu
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, United States of America
- Department of Bioengineering, Cancer Center at Illinois, Micro and Nanotechnology Laboratory, University of Illinois at Urbana Champaign, Urbana, Illinois, United States of America
| | - Joseph Irudayaraj
- Purdue University Center for Cancer Research, West Lafayette, Indiana, United States of America
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, United States of America
- Department of Bioengineering, Cancer Center at Illinois, Micro and Nanotechnology Laboratory, University of Illinois at Urbana Champaign, Urbana, Illinois, United States of America
| | - Ann L. Kirchmaier
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
- Purdue University Center for Cancer Research, West Lafayette, Indiana, United States of America
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
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12
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Santos SM, Hartman JL. A yeast phenomic model for the influence of Warburg metabolism on genetic buffering of doxorubicin. Cancer Metab 2019; 7:9. [PMID: 31660150 PMCID: PMC6806529 DOI: 10.1186/s40170-019-0201-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 09/03/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The influence of the Warburg phenomenon on chemotherapy response is unknown. Saccharomyces cerevisiae mimics the Warburg effect, repressing respiration in the presence of adequate glucose. Yeast phenomic experiments were conducted to assess potential influences of Warburg metabolism on gene-drug interaction underlying the cellular response to doxorubicin. Homologous genes from yeast phenomic and cancer pharmacogenomics data were analyzed to infer evolutionary conservation of gene-drug interaction and predict therapeutic relevance. METHODS Cell proliferation phenotypes (CPPs) of the yeast gene knockout/knockdown library were measured by quantitative high-throughput cell array phenotyping (Q-HTCP), treating with escalating doxorubicin concentrations under conditions of respiratory or glycolytic metabolism. Doxorubicin-gene interaction was quantified by departure of CPPs observed for the doxorubicin-treated mutant strain from that expected based on an interaction model. Recursive expectation-maximization clustering (REMc) and Gene Ontology (GO)-based analyses of interactions identified functional biological modules that differentially buffer or promote doxorubicin cytotoxicity with respect to Warburg metabolism. Yeast phenomic and cancer pharmacogenomics data were integrated to predict differential gene expression causally influencing doxorubicin anti-tumor efficacy. RESULTS Yeast compromised for genes functioning in chromatin organization, and several other cellular processes are more resistant to doxorubicin under glycolytic conditions. Thus, the Warburg transition appears to alleviate requirements for cellular functions that buffer doxorubicin cytotoxicity in a respiratory context. We analyzed human homologs of yeast genes exhibiting gene-doxorubicin interaction in cancer pharmacogenomics data to predict causality for differential gene expression associated with doxorubicin cytotoxicity in cancer cells. This analysis suggested conserved cellular responses to doxorubicin due to influences of homologous recombination, sphingolipid homeostasis, telomere tethering at nuclear periphery, actin cortical patch localization, and other gene functions. CONCLUSIONS Warburg status alters the genetic network required for yeast to buffer doxorubicin toxicity. Integration of yeast phenomic and cancer pharmacogenomics data suggests evolutionary conservation of gene-drug interaction networks and provides a new experimental approach to model their influence on chemotherapy response. Thus, yeast phenomic models could aid the development of precision oncology algorithms to predict efficacious cytotoxic drugs for cancer, based on genetic and metabolic profiles of individual tumors.
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Affiliation(s)
- Sean M. Santos
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL USA
| | - John L. Hartman
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL USA
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13
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Li S, Almeida AR, Radebaugh CA, Zhang L, Chen X, Huang L, Thurston AK, Kalashnikova AA, Hansen JC, Luger K, Stargell LA. The elongation factor Spn1 is a multi-functional chromatin binding protein. Nucleic Acids Res 2019; 46:2321-2334. [PMID: 29300974 PMCID: PMC5861400 DOI: 10.1093/nar/gkx1305] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 12/19/2017] [Indexed: 12/17/2022] Open
Abstract
The process of transcriptional elongation by RNA polymerase II (RNAPII) in a chromatin context involves a large number of crucial factors. Spn1 is a highly conserved protein encoded by an essential gene and is known to interact with RNAPII and the histone chaperone Spt6. Spn1 negatively regulates the ability of Spt6 to interact with nucleosomes, but the chromatin binding properties of Spn1 are largely unknown. Here, we demonstrate that full length Spn1 (amino acids 1–410) binds DNA, histones H3–H4, mononucleosomes and nucleosomal arrays, and has weak nucleosome assembly activity. The core domain of Spn1 (amino acids 141–305), which is necessary and sufficient in Saccharomyces cerevisiae for growth under ideal growth conditions, is unable to optimally interact with histones, nucleosomes and/or DNA and fails to assemble nucleosomes in vitro. Although competent for binding with Spt6 and RNAPII, the core domain derivative is not stably recruited to the CYC1 promoter, indicating chromatin interactions are an important aspect of normal Spn1 functions in vivo. Moreover, strong synthetic genetic interactions are observed with Spn1 mutants and deletions of histone chaperone genes. Taken together, these results indicate that Spn1 is a histone binding factor with histone chaperone functions.
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Affiliation(s)
- Sha Li
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
| | - Adam R Almeida
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
| | - Catherine A Radebaugh
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
| | - Ling Zhang
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
| | - Xu Chen
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
| | - Liangqun Huang
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
| | - Alison K Thurston
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
| | - Anna A Kalashnikova
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
| | - Jeffrey C Hansen
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
| | - Karolin Luger
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO 80309, USA.,Howard Hughes Medical Institute
| | - Laurie A Stargell
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA.,Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO 80523-1870, USA
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14
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Vlaming H, McLean CM, Korthout T, Alemdehy MF, Hendriks S, Lancini C, Palit S, Klarenbeek S, Kwesi‐Maliepaard EM, Molenaar TM, Hoekman L, Schmidlin TT, Altelaar AFM, van Welsem T, Dannenberg J, Jacobs H, van Leeuwen F. Conserved crosstalk between histone deacetylation and H3K79 methylation generates DOT1L-dose dependency in HDAC1-deficient thymic lymphoma. EMBO J 2019; 38:e101564. [PMID: 31304633 PMCID: PMC6627229 DOI: 10.15252/embj.2019101564] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 05/20/2019] [Accepted: 05/24/2019] [Indexed: 12/12/2022] Open
Abstract
DOT1L methylates histone H3K79 and is aberrantly regulated in MLL-rearranged leukemia. Inhibitors have been developed to target DOT1L activity in leukemia, but cellular mechanisms that regulate DOT1L are still poorly understood. We have identified the histone deacetylase Rpd3 as a negative regulator of budding yeast Dot1. At its target genes, the transcriptional repressor Rpd3 restricts H3K79 methylation, explaining the absence of H3K79me3 at a subset of genes in the yeast genome. Similar to the crosstalk in yeast, inactivation of the murine Rpd3 homolog HDAC1 in thymocytes led to an increase in H3K79 methylation. Thymic lymphomas that arise upon genetic deletion of Hdac1 retained the increased H3K79 methylation and were sensitive to reduced DOT1L dosage. Furthermore, cell lines derived from Hdac1Δ/Δ thymic lymphomas were sensitive to a DOT1L inhibitor, which induced apoptosis. In summary, we identified an evolutionarily conserved crosstalk between HDAC1 and DOT1L with impact in murine thymic lymphoma development.
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Affiliation(s)
- Hanneke Vlaming
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
- Present address:
Department of Biological Chemistry and Molecular PharmacologyHarvard Medical SchoolBostonMAUSA
| | - Chelsea M McLean
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Tessy Korthout
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Mir Farshid Alemdehy
- Division of Tumor Biology & ImmunologyNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Sjoerd Hendriks
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Cesare Lancini
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Sander Palit
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Sjoerd Klarenbeek
- Experimental Animal PathologyNetherlands Cancer InstituteAmsterdamThe Netherlands
| | | | - Thom M Molenaar
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Liesbeth Hoekman
- Experimental Animal PathologyNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Thierry T Schmidlin
- Biomolecular Mass Spectrometry and ProteomicsBijvoet Center for Biomolecular ResearchUtrecht Institute for Pharmaceutical SciencesUtrecht University and Netherlands Proteomics CentreUtrechtThe Netherlands
| | - AF Maarten Altelaar
- Biomolecular Mass Spectrometry and ProteomicsBijvoet Center for Biomolecular ResearchUtrecht Institute for Pharmaceutical SciencesUtrecht University and Netherlands Proteomics CentreUtrechtThe Netherlands
- Proteomics FacilityNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Tibor van Welsem
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Jan‐Hermen Dannenberg
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
- Present address:
Genmab B.V.Antibody SciencesUtrechtThe Netherlands
| | - Heinz Jacobs
- Division of Tumor Biology & ImmunologyNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Fred van Leeuwen
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
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15
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Gali VK, Dickerson D, Katou Y, Fujiki K, Shirahige K, Owen-Hughes T, Kubota T, Donaldson AD. Identification of Elg1 interaction partners and effects on post-replication chromatin re-formation. PLoS Genet 2018; 14:e1007783. [PMID: 30418970 PMCID: PMC6258251 DOI: 10.1371/journal.pgen.1007783] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 11/26/2018] [Accepted: 10/23/2018] [Indexed: 12/04/2022] Open
Abstract
Elg1, the major subunit of a Replication Factor C-like complex, is critical to ensure genomic stability during DNA replication, and is implicated in controlling chromatin structure. We investigated the consequences of Elg1 loss for the dynamics of chromatin re-formation following DNA replication. Measurement of Okazaki fragment length and the micrococcal nuclease sensitivity of newly replicated DNA revealed a defect in nucleosome organization in the absence of Elg1. Using a proteomic approach to identify Elg1 binding partners, we discovered that Elg1 interacts with Rtt106, a histone chaperone implicated in replication-coupled nucleosome assembly that also regulates transcription. A central role for Elg1 is the unloading of PCNA from chromatin following DNA replication, so we examined the relative importance of Rtt106 and PCNA unloading for chromatin reassembly following DNA replication. We find that the major cause of the chromatin organization defects of an ELG1 mutant is PCNA retention on DNA following replication, with Rtt106-Elg1 interaction potentially playing a contributory role.
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Affiliation(s)
- Vamsi K. Gali
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, United Kingdom
| | - David Dickerson
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, Scotland, United Kingdom
| | - Yuki Katou
- Research Center for Epigenetic Disease, Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo, Japan
| | - Katsunori Fujiki
- Research Center for Epigenetic Disease, Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo, Japan
| | - Katsuhiko Shirahige
- Research Center for Epigenetic Disease, Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo, Japan
| | - Tom Owen-Hughes
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, Scotland, United Kingdom
| | - Takashi Kubota
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, United Kingdom
| | - Anne D. Donaldson
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, United Kingdom
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16
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Uwimana N, Collin P, Jeronimo C, Haibe-Kains B, Robert F. Bidirectional terminators in Saccharomyces cerevisiae prevent cryptic transcription from invading neighboring genes. Nucleic Acids Res 2017; 45:6417-6426. [PMID: 28383698 PMCID: PMC5499651 DOI: 10.1093/nar/gkx242] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 03/30/2017] [Indexed: 12/12/2022] Open
Abstract
Transcription can be quite disruptive for chromatin so cells have evolved mechanisms to preserve chromatin integrity during transcription, thereby preventing the emergence of cryptic transcripts from spurious promoter sequences. How these transcripts are regulated and processed remains poorly characterized. Notably, very little is known about the termination of cryptic transcripts. Here, we used RNA-Seq to identify and characterize cryptic transcripts in Spt6 mutant cells (spt6-1004) in Saccharomyces cerevisiae. We found polyadenylated cryptic transcripts running both sense and antisense relative to genes in this mutant. Cryptic promoters were enriched for TATA boxes, suggesting that the underlying DNA sequence defines the location of cryptic promoters. While intragenic sense cryptic transcripts terminate at the terminator of the genes that host them, we found that antisense cryptic transcripts preferentially terminate near the 3΄-end of the upstream gene. This finding led us to demonstrate that most terminators in yeast are bidirectional, leading to termination and polyadenylation of transcripts coming from both directions. We propose that S. cerevisiae has evolved this mechanism in order to prevent/attenuate spurious transcription from invading neighbouring genes, a feature that is particularly critical for organisms with small compact genomes.
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Affiliation(s)
- Nicole Uwimana
- Institut de recherches cliniques de Montréal, Montréal, Québec H2W 1R7, Canada
| | - Pierre Collin
- Institut de recherches cliniques de Montréal, Montréal, Québec H2W 1R7, Canada
| | - Célia Jeronimo
- Institut de recherches cliniques de Montréal, Montréal, Québec H2W 1R7, Canada
| | - Benjamin Haibe-Kains
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada.,Department of Computer Science, University of Toronto, Toronto, Ontario M5T 3A1, Canada.,Ontario Institute of Cancer Research, Toronto, Ontario M5G 1L7, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal, Montréal, Québec H2W 1R7, Canada.,Département de médecine, Faculté de médecine, Université de Montréal, Québec H3T 1J4, Canada
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17
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Robert F. Bidirectional terminators: an underestimated aspect of gene regulation. Curr Genet 2017; 64:389-391. [PMID: 29018946 DOI: 10.1007/s00294-017-0763-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 10/05/2017] [Accepted: 10/06/2017] [Indexed: 10/18/2022]
Abstract
Recent experimental and computational work revealed that transcriptional terminators in Saccharomyces cerevisiae can terminate transcription coming from both directions. This mechanism helps budding yeast cope with the pervasive nature of transcription by limiting aberrant transcription from invading neighboring genes.
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Affiliation(s)
- François Robert
- Institut de recherches cliniques de Montréal (IRCM), 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada.
- Département de Médecine, Faculté de Médecine, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada.
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18
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Histone exchange, chromatin structure and the regulation of transcription. Nat Rev Mol Cell Biol 2015; 16:178-89. [DOI: 10.1038/nrm3941] [Citation(s) in RCA: 650] [Impact Index Per Article: 72.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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19
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Abstract
The extent of chromatin compaction is a fundamental driver of nuclear metabolism . Yta7 is a chromatin-associated AAA-ATPase, the human ortholog of which, ANCCA/ATAD2 transcriptionally activates pathways of malignancy in a broad range of cancers. Yta7 directly binds histone H3, and bulk chromatin exhibits increased nucleosomal density in yta7Δ mutants. The suppression of yta7Δ mutant growth and transcriptional phenotypes in budding yeast by decreased dosage of histones H3 and H4 indicates the acute sensitivity of cells to deviations in nucleosome spacing. This study investigated the global changes in chromatin structure upon Yta7 loss or overexpression and determined which of these effects reflected direct Yta7 activity. Metagene analysis of Yta7's genome-wide localization indicated peak binding of Yta7 just downstream of the transcription start site. Cells lacking Yta7 exhibited increased nucleosome density within genes downstream of the +1 nucleosome, as defined by decreased internucleosomal distance, resulting in progressively 5'-shifted nucleosomes within the gene. In contrast, cells overexpressing Yta7 displayed profound 3'-shifts in nucleosome position and reduced nucleosome density within genes. Importantly, Yta7-bound regions were enriched for nucleosomal shifts, indicating that Yta7 acted locally to modulate nucleosome spacing. The phenotype of cells lacking both Yta7 and Rtt106, the histone H3/H4 chaperone, indicated that Yta7 functions in both Rtt106-dependent and Rtt106-independent ways to modulate nucleosome spacing within genes. This study suggested that Yta7 affected nucleosome density throughout the gene by both blocking Rtt106 from entering the gene, as shown previously at HTA1, and facilitating the loss of nucleosomes from the 5'-end.
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20
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Marquardt S, Escalante-Chong R, Pho N, Wang J, Churchman LS, Springer M, Buratowski S. A chromatin-based mechanism for limiting divergent noncoding transcription. Cell 2014; 157:1712-23. [PMID: 24949978 DOI: 10.1016/j.cell.2014.04.036] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 03/06/2014] [Accepted: 04/15/2014] [Indexed: 11/18/2022]
Abstract
In addition to their annotated transcript, many eukaryotic mRNA promoters produce divergent noncoding transcripts. To define determinants of divergent promoter directionality, we used genomic replacement experiments. Sequences within noncoding transcripts specified their degradation pathways, and functional protein-coding transcripts could be produced in the divergent direction. To screen for mutants affecting the ratio of transcription in each direction, a bidirectional fluorescent protein reporter construct was introduced into the yeast nonessential gene deletion collection. We identified chromatin assembly as an important regulator of divergent transcription. Mutations in the CAF-I complex caused genome-wide derepression of nascent divergent noncoding transcription. In opposition to the CAF-I chromatin assembly pathway, H3K56 hyperacetylation, together with the nucleosome remodeler SWI/SNF, facilitated divergent transcription by promoting rapid nucleosome turnover. We propose that these chromatin-mediated effects control divergent transcription initiation, complementing downstream pathways linked to early termination and degradation of the noncoding RNAs.
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Affiliation(s)
- Sebastian Marquardt
- Department of Biological Chemistry and Molecular Physiology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Renan Escalante-Chong
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
| | - Nam Pho
- Research Computing Group, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Jue Wang
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
| | - L Stirling Churchman
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Michael Springer
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
| | - Stephen Buratowski
- Department of Biological Chemistry and Molecular Physiology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
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21
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Mirón-García MC, Garrido-Godino AI, Martínez-Fernández V, Fernández-Pevida A, Cuevas-Bermúdez A, Martín-Expósito M, Chávez S, de la Cruz J, Navarro F. The yeast prefoldin-like URI-orthologue Bud27 associates with the RSC nucleosome remodeler and modulates transcription. Nucleic Acids Res 2014; 42:9666-76. [PMID: 25081216 PMCID: PMC4150788 DOI: 10.1093/nar/gku685] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Bud27, the yeast orthologue of human URI/RMP, is a member of the prefoldin-like family of ATP-independent molecular chaperones. It has recently been shown to mediate the assembly of the three RNA polymerases in an Rpb5-dependent manner. In this work, we present evidence of Bud27 modulating RNA pol II transcription elongation. We show that Bud27 associates with RNA pol II phosphorylated forms (CTD-Ser5P and CTD-Ser2P), and that its absence affects RNA pol II occupancy of transcribed genes. We also reveal that Bud27 associates in vivo with the Sth1 component of the chromatin remodeling complex RSC and mediates its association with RNA pol II. Our data suggest that Bud27, in addition of contributing to Rpb5 folding within the RNA polymerases, also participates in the correct assembly of other chromatin-associated protein complexes, such as RSC, thereby modulating their activity.
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Affiliation(s)
- María Carmen Mirón-García
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Paraje de las Lagunillas, s/n, 23071, Jaén, Spain
| | - Ana Isabel Garrido-Godino
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Paraje de las Lagunillas, s/n, 23071, Jaén, Spain
| | - Verónica Martínez-Fernández
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Paraje de las Lagunillas, s/n, 23071, Jaén, Spain
| | - Antonio Fernández-Pevida
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, E-41013 Sevilla, Spain Departamento de Genética, Universidad de Sevilla, E41012 Sevilla, Spain
| | - Abel Cuevas-Bermúdez
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Paraje de las Lagunillas, s/n, 23071, Jaén, Spain
| | - Manuel Martín-Expósito
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Paraje de las Lagunillas, s/n, 23071, Jaén, Spain
| | - Sebastián Chávez
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, E-41013 Sevilla, Spain Departamento de Genética, Universidad de Sevilla, E41012 Sevilla, Spain
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, E-41013 Sevilla, Spain Departamento de Genética, Universidad de Sevilla, E41012 Sevilla, Spain
| | - Francisco Navarro
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Paraje de las Lagunillas, s/n, 23071, Jaén, Spain
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22
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Amin AD, Vishnoi N, Prochasson P. A global requirement for the HIR complex in the assembly of chromatin. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1819:264-276. [PMID: 24459729 DOI: 10.1016/j.bbagrm.2011.07.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Due to its extensive length, DNA is packaged into a protective chromatin structure known as the nucleosome. In order to carry out various cellular functions, nucleosomes must be disassembled, allowing access to the underlying DNA, and subsequently reassembled on completion of these processes. The assembly and disassembly of nucleosomes is dependent on the function of histone modifiers, chromatin remodelers and histone chaperones. In this review, we discuss the roles of an evolutionarily conserved histone chaperone known as the HIR/HIRA complex. In S. cerevisiae, the HIR complex is made up of the proteins Hir1, Hir2, Hir3 and Hpc2, which collectively act in transcriptional regulation, elongation, gene silencing, cellular senescence and even aging. This review presents an overview of the role of the HIR complex, in yeast as well as other organisms, in each of these processes, in order to give a better understanding of how nucleosome assembly is imperative for cellular homeostasis and genomic integrity. This article is part of a Special Issue entitled: Histone chaperones and Chromatin assembly.
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23
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Kurat CF, Recht J, Radovani E, Durbic T, Andrews B, Fillingham J. Regulation of histone gene transcription in yeast. Cell Mol Life Sci 2014; 71:599-613. [PMID: 23974242 PMCID: PMC11113579 DOI: 10.1007/s00018-013-1443-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/10/2013] [Accepted: 07/29/2013] [Indexed: 12/11/2022]
Abstract
Histones are the primary protein component of chromatin, the mixture of DNA and proteins that packages the genetic material in eukaryotes. Large amounts of histones are required during the S phase of the cell cycle when genome replication occurs. However, ectopic expression of histones during other cell cycle phases is toxic; thus, histone expression is restricted to the S phase and is tightly regulated at multiple levels, including transcriptional, post-transcriptional, translational, and post-translational. In this review, we discuss mechanisms of regulation of histone gene expression with emphasis on the transcriptional regulation of the replication-dependent histone genes in the model yeast Saccharomyces cerevisiae.
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Affiliation(s)
- Christoph F. Kurat
- The Donnelly Center, University of Toronto, Toronto, ON M5S 3E1 Canada
- Banting and Best Department of Medical Research, University of Toronto, Toronto, ON M5S 3E1 Canada
| | | | - Ernest Radovani
- Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3 Canada
| | - Tanja Durbic
- Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3 Canada
| | - Brenda Andrews
- The Donnelly Center, University of Toronto, Toronto, ON M5S 3E1 Canada
- Banting and Best Department of Medical Research, University of Toronto, Toronto, ON M5S 3E1 Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3E1 Canada
| | - Jeffrey Fillingham
- Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3 Canada
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24
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Koster MJE, Yildirim AD, Weil PA, Holstege FCP, Timmers HTM. Suppression of intragenic transcription requires the MOT1 and NC2 regulators of TATA-binding protein. Nucleic Acids Res 2014; 42:4220-9. [PMID: 24459134 PMCID: PMC3985625 DOI: 10.1093/nar/gkt1398] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Chromatin structure in transcribed regions poses a barrier for intragenic transcription. In a comprehensive study of the yeast chromatin remodelers and the Mot1p-NC2 regulators of TATA-binding protein (TBP), we detected synthetic genetic interactions indicative of suppression of intragenic transcription. Conditional depletion of Mot1p or NC2 in absence of the ISW1 remodeler, but not in the absence of other chromatin remodelers, activated the cryptic FLO8 promoter. Likewise, conditional depletion of Mot1p or NC2 in deletion backgrounds of the H3K36 methyltransferase Set2p or the Asf1p-Rtt106p histone H3-H4 chaperones, important factors involved in maintaining a repressive chromatin environment, resulted in increased intragenic FLO8 transcripts. Activity of the cryptic FLO8 promoter is associated with reduced H3 levels, increased TBP binding and tri-methylation of H3K4 and is independent of Spt-Ada-Gcn5-acetyltransferase function. These data reveal cooperation of negative regulation of TBP with specific chromatin regulators to inhibit intragenic transcription.
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Affiliation(s)
- Maria J E Koster
- Department of Molecular Cancer Research, University Medical Center Utrecht, 3584 CG, Utrecht, The Netherlands and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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25
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Terweij M, van Leeuwen F. Histone exchange: sculpting the epigenome. FRONTIERS IN LIFE SCIENCE 2013. [DOI: 10.1080/21553769.2013.838193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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26
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A genetic screen for high copy number suppressors of the synthetic lethality between elg1Δ and srs2Δ in yeast. G3-GENES GENOMES GENETICS 2013; 3:917-26. [PMID: 23704284 PMCID: PMC3656737 DOI: 10.1534/g3.113.005561] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Elg1 and Srs2 are two proteins involved in maintaining genome stability in yeast. After DNA damage, the homotrimeric clamp PCNA, which provides stability and processivity to DNA polymerases and serves as a docking platform for DNA repair enzymes, undergoes modification by the ubiquitin-like molecule SUMO. PCNA SUMOylation helps recruit Srs2 and Elg1 to the replication fork. In the absence of Elg1, both SUMOylated PCNA and Srs2 accumulate at the chromatin fraction, indicating that Elg1 is required for removing SUMOylated PCNA and Srs2 from DNA. Despite this interaction, which suggests that the two proteins work together, double mutants elg1Δ srs2Δ have severely impaired growth as haploids and exhibit synergistic sensitivity to DNA damage and a synergistic increase in gene conversion. In addition, diploid elg1Δ srs2Δ double mutants are dead, which implies that an essential function in the cell requires at least one of the two gene products for survival. To gain information about this essential function, we have carried out a high copy number suppressor screen to search for genes that, when overexpressed, suppress the synthetic lethality between elg1Δ and srs2Δ. We report the identification of 36 such genes, which are enriched for functions related to DNA- and chromatin-binding, chromatin packaging and modification, and mRNA export from the nucleus.
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27
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Huh I, Zeng J, Park T, Yi SV. DNA methylation and transcriptional noise. Epigenetics Chromatin 2013; 6:9. [PMID: 23618007 PMCID: PMC3641963 DOI: 10.1186/1756-8935-6-9] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 04/05/2013] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND DNA methylation is one of the most phylogenetically widespread epigenetic modifications of genomic DNA. In particular, DNA methylation of transcription units ('gene bodies') is highly conserved across diverse taxa. However, the functional role of gene body methylation is not yet fully understood. A long-standing hypothesis posits that gene body methylation reduces transcriptional noise associated with spurious transcription of genes. Despite the plausibility of this hypothesis, an explicit test of this hypothesis has not been performed until now. RESULTS Using nucleotide-resolution data on genomic DNA methylation and abundant microarray data, here we investigate the relationship between DNA methylation and transcriptional noise. Transcriptional noise measured from microarrays scales down with expression abundance, confirming findings from single-cell studies. We show that gene body methylation is significantly negatively associated with transcriptional noise when examined in the context of other biological factors. CONCLUSIONS This finding supports the hypothesis that gene body methylation suppresses transcriptional noise. Heavy methylation of vertebrate genomes may have evolved as a global regulatory mechanism to control for transcriptional noise. In contrast, promoter methylation exhibits positive correlations with the level of transcriptional noise. We hypothesize that methylated promoters tend to undergo more frequent transcriptional bursts than those that avoid DNA methylation.
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Affiliation(s)
- Iksoo Huh
- School of Biology, Institute of Bioengineering and Biosciences, Georgia Institute of Technology, 310 Ferst Drive, Atlanta, GA, 30332, USA.
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Song Y, Seol JH, Yang JH, Kim HJ, Han JW, Youn HD, Cho EJ. Dissecting the roles of the histone chaperones reveals the evolutionary conserved mechanism of transcription-coupled deposition of H3.3. Nucleic Acids Res 2013; 41:5199-209. [PMID: 23563152 PMCID: PMC3664809 DOI: 10.1093/nar/gkt220] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The mammalian genome encodes multiple variants of histone H3 including H3.1/H3.2 and H3.3. In contrast to H3.1/H3.2, H3.3 is enriched in the actively transcribed euchromatin and the telomeric heterochromatins. However, the mechanism for H3.3 to incorporate into the different domains of chromatin is not known. Here, taking the advantage of well-defined transcription analysis system of yeast, we attempted to understand the molecular mechanism of selective deposition of human H3.3 into actively transcribed genes. We show that there are systemic H3 substrate-selection mechanisms operating even in yeasts, which encode a single type of H3. Yeast HIR complex mediated H3-specific recognition specificity for deposition of H3.3 in the transcribed genes. A critical component of this process was the H3 A-IG code composed of amino acids 87, 89 and 90. The preference toward H3.3 was completely lost when HIR subunits were absent and partially suppressed by human HIRA. Asf1 allows the influx of H3, regardless of H3 type. We propose that H3.3 is introduced into the active euchromatin by targeting the recycling pathway that is mediated by HIRA (or HIR), and this H3-selection mechanism is highly conserved through the evolution. These results also uncover an unexpected role of RI chaperones in evolution of variant H3s.
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Affiliation(s)
- Yunkyoung Song
- School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Republic of Korea
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Cell-cycle perturbations suppress the slow-growth defect of spt10Δ mutants in Saccharomyces cerevisiae. G3-GENES GENOMES GENETICS 2013; 3:573-83. [PMID: 23450643 PMCID: PMC3583463 DOI: 10.1534/g3.112.005389] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 01/17/2013] [Indexed: 01/05/2023]
Abstract
Spt10 is a putative acetyltransferase of Saccharomyces cerevisiae that directly activates the transcription of histone genes. Deletion of SPT10 causes a severe slow growth phenotype, showing that Spt10 is critical for normal cell division. To gain insight into the function of Spt10, we identified mutations that impair or improve the growth of spt10 null (spt10Δ) mutants. Mutations that cause lethality in combination with spt10Δ include particular components of the SAGA complex as well as asf1Δ and hir1Δ. Partial suppressors of the spt10Δ growth defect include mutations that perturb cell-cycle progression through the G1/S transition, S phase, and G2/M. Consistent with these results, slowing of cell-cycle progression by treatment with hydroxyurea or growth on medium containing glycerol as the carbon source also partially suppresses the spt10Δ slow-growth defect. In addition, mutations that impair the Lsm1-7-Pat1 complex, which regulates decapping of polyadenylated mRNAs, also partially suppress the spt10Δ growth defect. Interestingly, suppression of the spt10Δ growth defect is not accompanied by a restoration of normal histone mRNA levels. These findings suggest that Spt10 has multiple roles during cell division.
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Histone chaperones Nap1 and Vps75 regulate histone acetylation during transcription elongation. Mol Cell Biol 2013; 33:1645-56. [PMID: 23401858 DOI: 10.1128/mcb.01121-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Histone chaperones function in chromatin assembly and disassembly, suggesting they have important regulatory roles in transcription elongation. The Saccharomyces cerevisiae proteins Nap1 and Vps75 are structurally related, evolutionarily conserved histone chaperones. We showed that Nap1 genetically interacts with several transcription elongation factors and that both Nap1 and Vps75 interact with the RNA polymerase II kinase, CTK1. Loss of NAP1 or VPS75 suppressed cryptic transcription within the open reading frame (ORF) observed when strains are deleted for the kinase CTK1. Loss of the histone acetyltransferase Rtt109 also suppressed ctk1-dependent cryptic transcription. Vps75 regulates Rtt109 function, suggesting that they function together in this process. Histone H3 K9 was found to be the important lysine that is acetylated by Rtt109 during ctk1-dependent cryptic transcription. We showed that both Vps75 and Nap1 regulate the relative level of H3 K9 acetylation in the STE11 ORF. This supports a model in which Nap1, like Vps75, directly regulates Rtt109 activity or regulates the assembly of acetylated chromatin. Although Nap1 and Vps75 share many similarities, due to their distinct interactions with SET2, Nap1 and Vps75 may also play separate roles during transcription elongation. This work sheds further light on the importance of histone chaperones as general regulators of transcription elongation.
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31
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Shim YS, Choi Y, Kang K, Cho K, Oh S, Lee J, Grewal SIS, Lee D. Hrp3 controls nucleosome positioning to suppress non-coding transcription in eu- and heterochromatin. EMBO J 2012; 31:4375-87. [PMID: 22990236 DOI: 10.1038/emboj.2012.267] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 09/03/2012] [Indexed: 11/09/2022] Open
Abstract
The positioning of the nucleosome by ATP-dependent remodellers provides the fundamental chromatin environment for the regulation of diverse cellular processes acting on the underlying DNA. Recently, genome-wide nucleosome mapping has revealed more detailed information on the chromatin-remodelling factors. Here, we report that the Schizosaccharomyces pombe CHD remodeller, Hrp3, is a global regulator that drives proper nucleosome positioning and nucleosome stability. The loss of Hrp3 resulted in nucleosome perturbation across the chromosome, and the production of antisense transcripts in the hrp3Δ cells emphasized the importance of nucleosome architecture for proper transcription. Notably, perturbation of the nucleosome in hrp3 deletion mutant was also associated with destabilization of the DNA-histone interaction and cell cycle-dependent alleviation of heterochromatin silencing. Furthermore, the effect of Hrp3 in the pericentric region was found to be accomplished via a physical interaction with Swi6, and appeared to cooperate with other heterochromatin factors for gene silencing. Taken together, our data indicate that a well-positioned nucleosome by Hrp3 is important for the spatial-temporal control of transcription-associated processes.
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Affiliation(s)
- Young Sam Shim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
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32
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Smolle M, Workman JL. Transcription-associated histone modifications and cryptic transcription. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1829:84-97. [PMID: 22982198 DOI: 10.1016/j.bbagrm.2012.08.008] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 08/14/2012] [Accepted: 08/29/2012] [Indexed: 12/21/2022]
Abstract
Eukaryotic genomes are packaged into chromatin, a highly organized structure consisting of DNA and histone proteins. All nuclear processes take place in the context of chromatin. Modifications of either DNA or histone proteins have fundamental effects on chromatin structure and function, and thus influence processes such as transcription, replication or recombination. In this review we highlight histone modifications specifically associated with gene transcription by RNA polymerase II and summarize their genomic distributions. Finally, we discuss how (mis-)regulation of these histone modifications perturbs chromatin organization over coding regions and results in the appearance of aberrant, intragenic transcription. This article is part of a Special Issue entitled: RNA polymerase II Transcript Elongation.
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Affiliation(s)
- Michaela Smolle
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
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Direct interplay among histones, histone chaperones, and a chromatin boundary protein in the control of histone gene expression. Mol Cell Biol 2012; 32:4337-49. [PMID: 22907759 DOI: 10.1128/mcb.00871-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Saccharomyces cerevisiae, the histone chaperone Rtt106 binds newly synthesized histone proteins and mediates their delivery into chromatin during transcription, replication, and silencing. Rtt106 is also recruited to histone gene regulatory regions by the HIR histone chaperone complex to ensure S-phase-specific expression. Here we showed that this Rtt106:HIR complex included Asf1 and histone proteins. Mutations in Rtt106 that reduced histone binding reduced Rtt106 enrichment at histone genes, leading to their increased transcription. Deletion of the chromatin boundary element Yta7 led to increased Rtt106:H3 binding, increased Rtt106 enrichment at histone gene regulatory regions, and decreased histone gene transcription at the HTA1-HTB1 locus. These results suggested a unique regulatory mechanism in which Rtt106 sensed the level of histone proteins to maintain the proper level of histone gene transcription. The role of these histone chaperones and Yta7 differed markedly among the histone gene loci, including the two H3-H4 histone gene pairs. Defects in silencing in rtt106 mutants could be partially accounted for by Rtt106-mediated changes in histone gene repression. These studies suggested that feedback mediated by histone chaperone complexes plays a pivotal role in regulating histone gene transcription.
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Weiner A, Chen HV, Liu CL, Rahat A, Klien A, Soares L, Gudipati M, Pfeffner J, Regev A, Buratowski S, Pleiss JA, Friedman N, Rando OJ. Systematic dissection of roles for chromatin regulators in a yeast stress response. PLoS Biol 2012; 10:e1001369. [PMID: 22912562 PMCID: PMC3416867 DOI: 10.1371/journal.pbio.1001369] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 06/20/2012] [Indexed: 01/05/2023] Open
Abstract
Systematic functional and mapping studies of histone modifications in yeast show that most chromatin regulators are more important for dynamic transcriptional reprogramming than for steady-state gene expression. Packaging of eukaryotic genomes into chromatin has wide-ranging effects on gene transcription. Curiously, it is commonly observed that deletion of a global chromatin regulator affects expression of only a limited subset of genes bound to or modified by the regulator in question. However, in many single-gene studies it has become clear that chromatin regulators often do not affect steady-state transcription, but instead are required for normal transcriptional reprogramming by environmental cues. We therefore have systematically investigated the effects of 83 histone mutants, and 119 gene deletion mutants, on induction/repression dynamics of 170 transcripts in response to diamide stress in yeast. Importantly, we find that chromatin regulators play far more pronounced roles during gene induction/repression than they do in steady-state expression. Furthermore, by jointly analyzing the substrates (histone mutants) and enzymes (chromatin modifier deletions) we identify specific interactions between histone modifications and their regulators. Combining these functional results with genome-wide mapping of several histone marks in the same time course, we systematically investigated the correspondence between histone modification occurrence and function. We followed up on one pathway, finding that Set1-dependent H3K4 methylation primarily acts as a gene repressor during multiple stresses, specifically at genes involved in ribosome biosynthesis. Set1-dependent repression of ribosomal genes occurs via distinct pathways for ribosomal protein genes and ribosomal biogenesis genes, which can be separated based on genetic requirements for repression and based on chromatin changes during gene repression. Together, our dynamic studies provide a rich resource for investigating chromatin regulation, and identify a significant role for the “activating” mark H3K4me3 in gene repression. Chromatin packaging of eukaryotic genomes has wideranging, yet poorly understood, effects on gene regulation. Curiously, many histone modifications occur on the majority of genes, yet their loss typically affects a small subset of those genes. Here, we examine gene expression defects in 200 chromatin-related mutants during a stress response, finding that chromatin regulators have far greater effects on the dynamics of gene expression than on the steady-state transcription. By grouping mutants according to their shared defects in the stress response, we systematically recover known chromatin-related complexes and pathways, and predict several novel pathways. Finally, by integrating genome-wide changes in the locations of five prominent histone modifications during the stress response with our functional data, we uncover a novel role for the “activating” histone modification H3K4me3 in gene repression. Surprisingly, H3K4 methylation appears to act in conjunction with H3S10 phosphorylation in the repression of ribosomal biosynthesis genes. Repression of ribosomal protein genes and ribosomal RNA maturation genes occur via distinct pathways. Our results show that steady-state studies miss a great deal of important chromatin biology, and identify a surprising role for H3K4 methylation in ribosomal gene repression in yeast.
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Affiliation(s)
- Assaf Weiner
- School of Computer Science and Engineering, The Hebrew University, Jerusalem, Israel
- Alexander Silberman Institute of Life Sciences, The Hebrew University, Jerusalem, Israel
| | - Hsiuyi V. Chen
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Chih Long Liu
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Ayelet Rahat
- School of Computer Science and Engineering, The Hebrew University, Jerusalem, Israel
- Alexander Silberman Institute of Life Sciences, The Hebrew University, Jerusalem, Israel
| | - Avital Klien
- School of Computer Science and Engineering, The Hebrew University, Jerusalem, Israel
- Alexander Silberman Institute of Life Sciences, The Hebrew University, Jerusalem, Israel
| | - Luis Soares
- Department of Biochemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Mohanram Gudipati
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Jenna Pfeffner
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Aviv Regev
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Stephen Buratowski
- Department of Biochemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jeffrey A. Pleiss
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Nir Friedman
- School of Computer Science and Engineering, The Hebrew University, Jerusalem, Israel
- Alexander Silberman Institute of Life Sciences, The Hebrew University, Jerusalem, Israel
- * E-mail: (NF); (OJR)
| | - Oliver J. Rando
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail: (NF); (OJR)
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Abstract
Understanding the mechanisms by which chromatin structure controls eukaryotic transcription has been an intense area of investigation for the past 25 years. Many of the key discoveries that created the foundation for this field came from studies of Saccharomyces cerevisiae, including the discovery of the role of chromatin in transcriptional silencing, as well as the discovery of chromatin-remodeling factors and histone modification activities. Since that time, studies in yeast have continued to contribute in leading ways. This review article summarizes the large body of yeast studies in this field.
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Giri S, Prasanth SG. Replicating and transcribing on twisted roads of chromatin. Brief Funct Genomics 2012; 11:188-204. [PMID: 22267489 DOI: 10.1093/bfgp/elr047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Chromatin, a complex of DNA and proteins in the eukaryotic cell nucleus governs various cellular processes including DNA replication, DNA repair and transcription. Chromatin architecture and dynamics dictates the timing of cellular events by regulating proteins' accessibility to DNA as well as by acting as a scaffold for protein-protein interactions. Nucleosome, the basic unit of chromatin consists of a histone octamer comprised of (H3-H4)2 tetramer and two H2A-H2B dimers on which 146 bp of DNA is wrapped around ~1.6 times. Chromatin changes brought about by histone modifications, histone-modifying enzymes, chromatin remodeling factors, histone chaperones, histone variants and chromatin dynamics influence the regulation and timing of gene expression. Similarly, the timing of DNA replication is dependent on the chromatin context that in turn dictates origin selection. Further, during the process of DNA replication, not only does an organism's DNA have to be accurately replicated but also the chromatin structure and the epigenetic marks have to be faithfully transmitted to the daughter cells. Active transcription has been shown to repress replication while at the same time it has been shown that when origins are located at promoters, because of enhanced chromatin accessibility, they fire efficiently. In this review, we focus on how chromatin modulates two fundamental processes, DNA replication and transcription.
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Affiliation(s)
- Sumanprava Giri
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, 601S Goodwin Avenue, Urbana, IL 61801, USA
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Zunder RM, Antczak AJ, Berger JM, Rine J. Two surfaces on the histone chaperone Rtt106 mediate histone binding, replication, and silencing. Proc Natl Acad Sci U S A 2012; 109:E144-53. [PMID: 22198837 PMCID: PMC3271894 DOI: 10.1073/pnas.1119095109] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The histone chaperone Rtt106 binds histone H3 acetylated at lysine 56 (H3K56ac) and facilitates nucleosome assembly during several molecular processes. Both the structural basis of this modification-specific recognition and how this recognition informs Rtt106 function are presently unclear. Guided by our crystal structure of Rtt106, we identified two regions on its double-pleckstrin homology domain architecture that mediated histone binding. When histone binding was compromised, Rtt106 localized properly to chromatin but failed to deliver H3K56ac, leading to replication and silencing defects. By mutating analogous regions in the structurally homologous chromatin-reorganizer Pob3, we revealed a conserved histone-binding function for a basic patch found on both proteins. In contrast, a loop connecting two β-strands was required for histone binding by Rtt106 but was dispensable for Pob3 function. Unlike Rtt106, Pob3 histone binding was modification-independent, implicating the loop of Rtt106 in H3K56ac-specific recognition in vivo. Our studies described the structural origins of Rtt106 function, identified a conserved histone-binding surface, and defined a critical role for Rtt106:H3K56ac-binding specificity in silencing and replication-coupled nucleosome turnover.
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Affiliation(s)
- Rachel M. Zunder
- Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | - Andrew J. Antczak
- Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | - James M. Berger
- Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | - Jasper Rine
- Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
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Silva AC, Xu X, Kim HS, Fillingham J, Kislinger T, Mennella TA, Keogh MC. The replication-independent histone H3-H4 chaperones HIR, ASF1, and RTT106 co-operate to maintain promoter fidelity. J Biol Chem 2011; 287:1709-18. [PMID: 22128187 DOI: 10.1074/jbc.m111.316489] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
RNA polymerase II initiates from low complexity sequences so cells must reliably distinguish "real" from "cryptic" promoters and maintain fidelity to the former. Further, this must be performed under a range of conditions, including those found within inactive and highly transcribed regions. Here, we used genome-scale screening to identify those factors that regulate the use of a specific cryptic promoter and how this is influenced by the degree of transcription over the element. We show that promoter fidelity is most reliant on histone gene transactivators (Spt10, Spt21) and H3-H4 chaperones (Asf1, HIR complex) from the replication-independent deposition pathway. Mutations of Rtt106 that abrogate its interactions with H3-H4 or dsDNA permit extensive cryptic transcription comparable with replication-independent deposition factor deletions. We propose that nucleosome shielding is the primary means to maintain promoter fidelity, and histone replacement is most efficiently mediated in yeast cells by a HIR/Asf1/H3-H4/Rtt106 pathway.
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Affiliation(s)
- Andrea C Silva
- Department of Cell Biology, Albert Einstein College of Medicine, New York, New York 10461, USA
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Stevens JR, O'Donnell AF, Perry TE, Benjamin JJR, Barnes CA, Johnston GC, Singer RA. FACT, the Bur kinase pathway, and the histone co-repressor HirC have overlapping nucleosome-related roles in yeast transcription elongation. PLoS One 2011; 6:e25644. [PMID: 22022426 PMCID: PMC3192111 DOI: 10.1371/journal.pone.0025644] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 09/06/2011] [Indexed: 02/03/2023] Open
Abstract
Gene transcription is constrained by the nucleosomal nature of chromosomal DNA. This nucleosomal barrier is modulated by FACT, a conserved histone-binding heterodimer. FACT mediates transcription-linked nucleosome disassembly and also nucleosome reassembly in the wake of the RNA polymerase II transcription complex, and in this way maintains the repression of ‘cryptic’ promoters found within some genes. Here we focus on a novel mutant version of the yeast FACT subunit Spt16 that supplies essential Spt16 activities but impairs transcription-linked nucleosome reassembly in dominant fashion. This Spt16 mutant protein also has genetic effects that are recessive, which we used to show that certain Spt16 activities collaborate with histone acetylation and the activities of a Bur-kinase/Spt4–Spt5/Paf1C pathway that facilitate transcription elongation. These collaborating activities were opposed by the actions of Rpd3S, a histone deacetylase that restores a repressive chromatin environment in a transcription-linked manner. Spt16 activity paralleling that of HirC, a co-repressor of histone gene expression, was also found to be opposed by Rpd3S. Our findings suggest that Spt16, the Bur/Spt4–Spt5/Paf1C pathway, and normal histone abundance and/or stoichiometry, in mutually cooperative fashion, facilitate nucleosome disassembly during transcription elongation. The recessive nature of these effects of the mutant Spt16 protein on transcription-linked nucleosome disassembly, contrasted to its dominant negative effect on transcription-linked nucleosome reassembly, indicate that mutant FACT harbouring the mutant Spt16 protein competes poorly with normal FACT at the stage of transcription-linked nucleosome disassembly, but effectively with normal FACT for transcription-linked nucleosome reassembly. This functional difference is consistent with the idea that FACT association with the transcription elongation complex depends on nucleosome disassembly, and that the same FACT molecule that associates with an elongation complex through nucleosome disassembly is retained for reassembly of the same nucleosome.
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Affiliation(s)
- Jennifer R. Stevens
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Allyson F. O'Donnell
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Troy E. Perry
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jeremy J. R. Benjamin
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Christine A. Barnes
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Gerald C. Johnston
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Richard A. Singer
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- * E-mail:
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Wan Y, Chen W, Xing J, Tan J, Li B, Chen H, Lin Z, Chiang JH, Ramsey S. Transcriptome profiling reveals a novel role for trichostatin A in antagonizing histone chaperone Chz1 mediated telomere anti-silencing. FEBS Lett 2011; 585:2519-25. [DOI: 10.1016/j.febslet.2011.06.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2011] [Revised: 06/12/2011] [Accepted: 06/20/2011] [Indexed: 01/06/2023]
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Ferreira ME, Flaherty K, Prochasson P. The Saccharomyces cerevisiae histone chaperone Rtt106 mediates the cell cycle recruitment of SWI/SNF and RSC to the HIR-dependent histone genes. PLoS One 2011; 6:e21113. [PMID: 21698254 PMCID: PMC3115976 DOI: 10.1371/journal.pone.0021113] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 05/19/2011] [Indexed: 11/18/2022] Open
Abstract
Background In Saccharomyces cerevisiae, three out of the four histone gene pairs (HTA1-HTB1, HHT1-HHF1, and HHT2-HHF2) are regulated by the HIR co-repressor complex. The histone chaperone Rtt106 has recently been shown to be present at these histone gene loci throughout the cell cycle in a HIR- and Asf1-dependent manner and involved in their transcriptional repression. The SWI/SNF and RSC chromatin remodeling complexes are both recruited to the HIR-dependent histone genes; SWI/SNF is required for their activation in S phase, whereas RSC is implicated in their repression outside of S phase. Even though their presence at the histone genes is dependent on the HIR complex, their specific recruitment has not been well characterized. In this study we focused on characterizing the role played by the histone chaperone Rtt106 in the cell cycle-dependent recruitment of SWI/SNF and RSC complexes to the histone genes. Methodology/Principal Findings Using GST pull-down and co-immunoprecipitation assays, we showed that Rtt106 physically interacts with both the SWI/SNF and RSC complexes in vitro and in vivo. We then investigated the function of this interaction with respect to the recruitment of these complexes to HIR-dependent histone genes. Using chromatin immunoprecipitation assays (ChIP), we found that Rtt106 is important for the recruitment of both SWI/SNF and RSC complexes to the HIR-dependent histone genes. Furthermore, using synchronized cell cultures, we showed by ChIP assays that the Rtt106-dependent SWI/SNF recruitment to these histone gene loci is cell cycle regulated and restricted to late G1 phase just before the peak of histone gene expression in S phase. Conclusions/Significance Overall, these data strongly suggest that the interaction between the histone chaperone Rtt106 and both the SWI/SNF and RSC chromatin remodeling complexes is important for the cell cycle regulated recruitment of these two complexes to the HIR-dependent histone genes.
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Affiliation(s)
- Monica E. Ferreira
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Kacie Flaherty
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Philippe Prochasson
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- * E-mail:
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42
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Abstract
Chromatin structure governs a number of cellular processes including DNA replication, transcription, and DNA repair. During DNA replication, chromatin structure including the basic repeating unit of chromatin, the nucleosome, is temporarily disrupted, and then reformed immediately after the passage of the replication fork. This coordinated process of nucleosome assembly during DNA replication is termed replication-coupled nucleosome assembly. Disruption of this process can lead to genome instability, a hallmark of cancer cells. Therefore, addressing how replication-coupled nucleosome assembly is regulated has been of great interest. Here, we review the current status of this growing field of interest, highlighting recent advances in understanding the regulation of this important process by the dynamic interplay of histone chaperones and histone modifications.
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Affiliation(s)
- Rebecca J Burgess
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
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Dermody JL, Buratowski S. Leo1 subunit of the yeast paf1 complex binds RNA and contributes to complex recruitment. J Biol Chem 2010; 285:33671-9. [PMID: 20732871 DOI: 10.1074/jbc.m110.140764] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The Paf1 complex (Paf1C) affects RNA polymerase II transcription by coordinating co-transcriptional chromatin modifications and helping recruit mRNA 3' end processing factors. Paf1C cross-links to transcribed genes, but not downstream of the cleavage and polyadenylation site, suggesting that it may interact with the nascent mRNA. Paf1C purified from Saccharomyces cerevisiae binds RNA in vitro, as do the purified Leo1 and Rtf1 subunits of the complex. In vivo cross-linking and immunoprecipitation of RNA associated with Paf1C (RNA-IP) show that Leo1, but not Rtf1, is necessary for the complex to bind RNA. Cells lacking Leo1 have reduced Paf1C recruitment as well as decreased levels of histone H3 and trimethylated H3 Lys(4) within transcribed chromatin. Together, these results suggest that association of Paf1C with RNA stabilizes its localization at actively transcribed regions where it influences chromatin structure.
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Affiliation(s)
- Jessica L Dermody
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Aslam A, Logie C. Histone H3 serine 57 and lysine 56 interplay in transcription elongation and recovery from S-phase stress. PLoS One 2010; 5:e10851. [PMID: 20520775 PMCID: PMC2877106 DOI: 10.1371/journal.pone.0010851] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 05/05/2010] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Acetylation of lysine 56 of histone H3 plays an important role in the DNA damage response and it has been postulated to play an as yet undefined role in transcription, both in yeast and in higher eukaryotes. Because phosphorylated human histone H3 serine 57 peptides have been detected by mass spectrometry we examined whether H3-S57 phosphorylation interplays with H3-K56 acetylation in vivo. METHODOLOGY/PRINCIPAL FINDINGS To explore the physiological role of H3-S57, H3-K56 was mutated to mimic constitutively (un)acetylated forms of H3-K56 and these were combined with constitutively (un)phosphorylated mimics of H3-S57, in yeast. A phosphorylated serine mimic at position 57 lessened sensitivities to a DNA replication fork inhibitor and to a transcription elongation inhibitor that were caused by an acetylated lysine mimic at position 56, while the same substitution exacerbated sensitivities due to mimicking a constitutive non-acetylated lysine at position 56. Strikingly, opposite results were obtained in the context of a serine to alanine substitution at position 57 of histone H3. CONCLUSIONS/SIGNIFICANCE The phenotypes elicited and the context-dependent interplay of the H3-K56 and -S57 point mutations that mimic their respective modification states suggest that serine 57 phosphorylation promotes a nucleosomal transaction when lysine 56 is acetylated. We speculate that histone H3-S57 couples H3-K56 acetylation to histone quaternary structures involving arginine 40 on histone H4 helix 1.
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Affiliation(s)
- Aamir Aslam
- Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, The Netherlands
| | - Colin Logie
- Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, The Netherlands
- * E-mail:
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45
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The histone shuffle: histone chaperones in an energetic dance. Trends Biochem Sci 2010; 35:476-89. [PMID: 20444609 DOI: 10.1016/j.tibs.2010.04.001] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Revised: 03/30/2010] [Accepted: 04/05/2010] [Indexed: 11/22/2022]
Abstract
Our genetic information is tightly packaged into a rather ingenious nucleoprotein complex called chromatin in a manner that enables it to be rapidly accessed during genomic processes. Formation of the nucleosome, which is the fundamental unit of chromatin, occurs via a stepwise process that is reversed to enable the disassembly of nucleosomes. Histone chaperone proteins have prominent roles in facilitating these processes as well as in replacing old histones with new canonical histones or histone variants during the process of histone exchange. Recent structural, biophysical and biochemical studies have begun to shed light on the molecular mechanisms whereby histone chaperones promote chromatin assembly, disassembly and histone exchange to facilitate DNA replication, repair and transcription.
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Harrison BR, Yazgan O, Krebs JE. Life without RNAi: noncoding RNAs and their functions in Saccharomyces cerevisiae. Biochem Cell Biol 2010; 87:767-79. [PMID: 19898526 DOI: 10.1139/o09-043] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
There are a number of well-characterized and fundamental roles for noncoding RNAs (ncRNAs) in gene regulation in all kingdoms of life. ncRNAs, such as ribosomal RNAs, transfer RNAs, small nuclear RNAs, small nucleolar RNAs, and small interfering RNAs, can serve catalytic and scaffolding functions in transcription, messenger RNA processing, translation, and RNA degradation. Recently, our understanding of gene expression has been dramatically challenged by the identification of large and diverse populations of novel ncRNAs in the eukaryotic genomes surveyed thus far. Studies carried out using the budding yeast Saccharomyces cerevisiae indicate that at least some coding genes are regulated by these novel ncRNAs. S. cerevisiae lacks RNA interference (RNAi) and, thus, provides an ideal system for studying the RNAi-independent mechanisms of ncRNA-based gene regulation. The current picture of gene regulation is one of great unknowns, in which the transcriptional environment surrounding a given locus may have as much to do with its regulation as its DNA sequence or local chromatin structure. Drawing on the recent research in S. cerevisiae and other organisms, this review will discuss the identification of ncRNAs, their origins and processing, and several models that incorporate ncRNAs into the regulation of gene expression and chromatin structure.
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Affiliation(s)
- Benjamin R Harrison
- Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, AK 99508, USA
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Abstract
Until recently, it was generally assumed that essentially all regulation of transcription takes place via regions adjacent to the coding region of a gene--namely promoters and enhancers--and that, after recruitment to the promoter, the polymerase simply behaves like a machine, quickly "reading the gene." However, over the past decade a revolution in this thinking has occurred, culminating in the idea that transcript elongation is extremely complex and highly regulated and, moreover, that this process significantly affects both the organization and integrity of the genome. This review addresses basic aspects of transcript elongation by RNA polymerase II (RNAPII) and how it relates to other DNA-related processes.
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Affiliation(s)
- Luke A Selth
- Mechanisms of Transcription Laboratory, Clare Hall Laboratories, Cancer Research UK London Research Institute, South Mimms, Hertfordshire EN6 3LD, United Kingdom
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Liu Y, Huang H, Zhou BO, Wang SS, Hu Y, Li X, Liu J, Zang J, Niu L, Wu J, Zhou JQ, Teng M, Shi Y. Structural analysis of Rtt106p reveals a DNA binding role required for heterochromatin silencing. J Biol Chem 2009; 285:4251-4262. [PMID: 20007951 DOI: 10.1074/jbc.m109.055996] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Rtt106p is a Saccharomyces cerevisiae histone chaperone with roles in heterochromatin silencing and nucleosome assembly. The molecular mechanism by which Rtt106p engages in chromatin dynamics remains unclear. Here, we report the 2.5 A crystal structure of the core domain of Rtt106p, which adopts an unusual "double pleckstrin homology" domain architecture that represents a novel structural mode for histone chaperones. A histone H3-H4-binding region and a novel double-stranded DNA-binding region have been identified. Mutagenesis studies reveal that the histone and DNA binding activities of Rtt106p are involved in Sir protein-mediated heterochromatin formation. Our results uncover the structural basis of the diverse functions of Rtt106p and provide new insights into its cellular roles.
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Affiliation(s)
- Yiwei Liu
- From the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026 and
| | - Hongda Huang
- From the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026 and
| | - Bo O Zhou
- the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, the Graduate School, Chinese Academy of Sciences, Shanghai 200031, China
| | - Shan-Shan Wang
- the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, the Graduate School, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yingxia Hu
- From the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026 and
| | - Xu Li
- From the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026 and
| | - Jianping Liu
- From the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026 and
| | - Jianye Zang
- From the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026 and
| | - Liwen Niu
- From the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026 and
| | - Jihui Wu
- From the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026 and
| | - Jin-Qiu Zhou
- the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, the Graduate School, Chinese Academy of Sciences, Shanghai 200031, China
| | - Maikun Teng
- From the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026 and.
| | - Yunyu Shi
- From the Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026 and.
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Hardy S, Jacques PÉ, Gévry N, Forest A, Fortin MÈ, Laflamme L, Gaudreau L, Robert F. The euchromatic and heterochromatic landscapes are shaped by antagonizing effects of transcription on H2A.Z deposition. PLoS Genet 2009; 5:e1000687. [PMID: 19834540 PMCID: PMC2754525 DOI: 10.1371/journal.pgen.1000687] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Accepted: 09/16/2009] [Indexed: 01/14/2023] Open
Abstract
A role for variant histone H2A.Z in gene expression is now well established but little is known about the mechanisms by which it operates. Using a combination of ChIP–chip, knockdown and expression profiling experiments, we show that upon gene induction, human H2A.Z associates with gene promoters and helps in recruiting the transcriptional machinery. Surprisingly, we also found that H2A.Z is randomly incorporated in the genome at low levels and that active transcription antagonizes this incorporation in transcribed regions. After cessation of transcription, random H2A.Z quickly reappears on genes, demonstrating that this incorporation utilizes an active mechanism. Within facultative heterochromatin, we observe a hyper accumulation of the variant histone, which might be due to the lack of transcription in these regions. These results show how chromatin structure and transcription can antagonize each other, therefore shaping chromatin and controlling gene expression. DNA in living cells is packaged into chromatin by histones and non-histone proteins. This packaging is very dynamic, allowing the controlled access of regulatory proteins such as transcription factors to DNA. Most chromatin is packaged with so-called canonical histones; namely H2A, H2B, H3, and H4. In some regions, however, variant histones replace canonical histones, creating special chromatin regions. Here we show that the variant histone H2A.Z is dynamically recruited to promoter regions where it helps in the recruitment of RNA polymerase II, the enzyme responsible for the first step of gene expression. In addition, we show that H2A.Z also associates randomly in the genome, but these molecules are removed during the passage of RNA polymerase II. In non-transcribed regions, H2A.Z accumulates in large domains called heterochromatin. We propose that a battle between random H2A.Z deposition and RNAPII-dependent H2A.Z eviction shapes the chromatin landscape.
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Affiliation(s)
- Sara Hardy
- Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
| | | | - Nicolas Gévry
- Département de biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Audrey Forest
- Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
| | - Marie-Ève Fortin
- Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
| | - Liette Laflamme
- Département de biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Luc Gaudreau
- Département de biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
- Département de médecine, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
- * E-mail:
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50
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Acencio ML, Lemke N. Towards the prediction of essential genes by integration of network topology, cellular localization and biological process information. BMC Bioinformatics 2009; 10:290. [PMID: 19758426 PMCID: PMC2753850 DOI: 10.1186/1471-2105-10-290] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Accepted: 09/16/2009] [Indexed: 11/21/2022] Open
Abstract
Background The identification of essential genes is important for the understanding of the minimal requirements for cellular life and for practical purposes, such as drug design. However, the experimental techniques for essential genes discovery are labor-intensive and time-consuming. Considering these experimental constraints, a computational approach capable of accurately predicting essential genes would be of great value. We therefore present here a machine learning-based computational approach relying on network topological features, cellular localization and biological process information for prediction of essential genes. Results We constructed a decision tree-based meta-classifier and trained it on datasets with individual and grouped attributes-network topological features, cellular compartments and biological processes-to generate various predictors of essential genes. We showed that the predictors with better performances are those generated by datasets with integrated attributes. Using the predictor with all attributes, i.e., network topological features, cellular compartments and biological processes, we obtained the best predictor of essential genes that was then used to classify yeast genes with unknown essentiality status. Finally, we generated decision trees by training the J48 algorithm on datasets with all network topological features, cellular localization and biological process information to discover cellular rules for essentiality. We found that the number of protein physical interactions, the nuclear localization of proteins and the number of regulating transcription factors are the most important factors determining gene essentiality. Conclusion We were able to demonstrate that network topological features, cellular localization and biological process information are reliable predictors of essential genes. Moreover, by constructing decision trees based on these data, we could discover cellular rules governing essentiality.
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Affiliation(s)
- Marcio L Acencio
- Department of Physics and Biophysics, São Paulo State University, Botucatu, São Paulo, Brazil.
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