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Jacobs RQ, Schneider DA. Transcription elongation mechanisms of RNA polymerases I, II, and III and their therapeutic implications. J Biol Chem 2024; 300:105737. [PMID: 38336292 PMCID: PMC10907179 DOI: 10.1016/j.jbc.2024.105737] [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: 11/10/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024] Open
Abstract
Transcription is a tightly regulated, complex, and essential cellular process in all living organisms. Transcription is comprised of three steps, transcription initiation, elongation, and termination. The distinct transcription initiation and termination mechanisms of eukaryotic RNA polymerases I, II, and III (Pols I, II, and III) have long been appreciated. Recent methodological advances have empowered high-resolution investigations of the Pols' transcription elongation mechanisms. Here, we review the kinetic similarities and differences in the individual steps of Pol I-, II-, and III-catalyzed transcription elongation, including NTP binding, bond formation, pyrophosphate release, and translocation. This review serves as an important summation of Saccharomyces cerevisiae (yeast) Pol I, II, and III kinetic investigations which reveal that transcription elongation by the Pols is governed by distinct mechanisms. Further, these studies illustrate how basic, biochemical investigations of the Pols can empower the development of chemotherapeutic compounds.
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Affiliation(s)
- Ruth Q Jacobs
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David A Schneider
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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2
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Boltengagen M, Verhagen D, Wolff MR, Oberbeckmann E, Hanke M, Gerland U, Korber P, Mueller-Planitz F. A single fiber view of the nucleosome organization in eukaryotic chromatin. Nucleic Acids Res 2024; 52:166-185. [PMID: 37994698 PMCID: PMC10783498 DOI: 10.1093/nar/gkad1098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 10/13/2023] [Accepted: 10/31/2023] [Indexed: 11/24/2023] Open
Abstract
Eukaryotic cells are thought to arrange nucleosomes into extended arrays with evenly spaced nucleosomes phased at genomic landmarks. Here we tested to what extent this stereotypic organization describes the nucleosome organization in Saccharomyces cerevisiae using Fiber-Seq, a long-read sequencing technique that maps entire nucleosome arrays on individual chromatin fibers in a high throughput manner. With each fiber coming from a different cell, Fiber-Seq uncovers cell-to-cell heterogeneity. The long reads reveal the nucleosome architecture even over repetitive DNA such as the ribosomal DNA repeats. The absolute nucleosome occupancy, a parameter that is difficult to obtain with conventional sequencing approaches, is a direct readout of Fiber-Seq. We document substantial deviations from the stereotypical nucleosome organization with unexpectedly long linker DNAs between nucleosomes, gene bodies missing entire nucleosomes, cell-to-cell heterogeneity in nucleosome occupancy, heterogeneous phasing of arrays and irregular nucleosome spacing. Nucleosome array structures are indistinguishable throughout the gene body and with respect to the direction of transcription arguing against transcription promoting array formation. Acute nucleosome depletion destroyed most of the array organization indicating that nucleosome remodelers cannot efficiently pack nucleosomes under those conditions. Given that nucleosomes are cis-regulatory elements, the cell-to-cell heterogeneity uncovered by Fiber-Seq provides much needed information to understand chromatin structure and function.
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Affiliation(s)
- Mark Boltengagen
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Daan Verhagen
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
- Molecular Biology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Michael Roland Wolff
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
- Physics of Complex Biosystems, Physics Department, Technical University of Munich, Garching, Germany
| | - Elisa Oberbeckmann
- Molecular Biology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Matthias Hanke
- Physics of Complex Biosystems, Physics Department, Technical University of Munich, Garching, Germany
| | - Ulrich Gerland
- Physics of Complex Biosystems, Physics Department, Technical University of Munich, Garching, Germany
| | - Philipp Korber
- Molecular Biology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Felix Mueller-Planitz
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
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Miyasaka S, Kitada R, Kokubo T. Taf1 N-terminal domain 2 (TAND2) of TFIID promotes formation of stable and mobile unstable TBP-TATA complexes. Gene 2023; 889:147800. [PMID: 37716588 DOI: 10.1016/j.gene.2023.147800] [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: 06/16/2023] [Revised: 09/05/2023] [Accepted: 09/12/2023] [Indexed: 09/18/2023]
Abstract
In eukaryotes, TATA-binding protein (TBP) occupancy of the core promoter globally correlates with transcriptional activity of class II genes. Elucidating how TBP is delivered to the TATA box or TATA-like element is crucial to understand the mechanisms of transcriptional regulation. A previous study demonstrated that the inhibitory DNA binding (IDB) surface of human TBP plays an indispensable role during the two-step formation of the TBP-TATA complex, first assuming an unstable and unbent intermediate conformation, and subsequently converting slowly to a stable and bent conformation. The DNA binding property of TBP is altered by physical contact of this surface with TBP regulators. In the present study, we examined whether the interaction between Taf1 N-terminal domain 2 (TAND2) and the IDB surface affected DNA binding property of yeast TBP by exploiting TAND2-fused TBP derivatives. TAND2 promoted formation of two distinct types of TBP-TATA complexes, which we arbitrarily designated as complex I and II. While complex I was stable and similar to the well-characterized original TBP-TATA complex, complex II was unstable and moved along DNA. Removal of TAND2 from TBP after complex formation revealed that continuous contact of TAND2 with the IDB surface was required for formation of complex II but not complex I. Further, TFIIA could be incorporated into the complex of TAND2-fused TBP and the TATA box, which was dependent on the amino-terminal non-conserved region of TBP, implying that this region could facilitate the exchange between TAND2 and TFIIA on the IDB surface. Collectively, these findings provide novel insights into the mechanism by which TBP is relieved from the interaction with TAND to bind the TATA box or TATA-like element within promoter-bound TFIID.
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Affiliation(s)
- Shinji Miyasaka
- Molecular and Cellular Biology Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Ryota Kitada
- Molecular and Cellular Biology Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Tetsuro Kokubo
- Molecular and Cellular Biology Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa, Japan.
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Schwank K, Schmid C, Fremter T, Engel C, Milkereit P, Griesenbeck J, Tschochner H. Features of yeast RNA polymerase I with special consideration of the lobe binding subunits. Biol Chem 2023; 404:979-1002. [PMID: 37823775 DOI: 10.1515/hsz-2023-0184] [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: 04/14/2023] [Accepted: 07/13/2023] [Indexed: 10/13/2023]
Abstract
Ribosomal RNAs (rRNAs) are structural components of ribosomes and represent the most abundant cellular RNA fraction. In the yeast Saccharomyces cerevisiae, they account for more than 60 % of the RNA content in a growing cell. The major amount of rRNA is synthesized by RNA polymerase I (Pol I). This enzyme transcribes exclusively the rRNA gene which is tandemly repeated in about 150 copies on chromosome XII. The high number of transcribed rRNA genes, the efficient recruitment of the transcription machinery and the dense packaging of elongating Pol I molecules on the gene ensure that enough rRNA is generated. Specific features of Pol I and of associated factors confer promoter selectivity and both elongation and termination competence. Many excellent reviews exist about the state of research about function and regulation of Pol I and how Pol I initiation complexes are assembled. In this report we focus on the Pol I specific lobe binding subunits which support efficient, error-free, and correctly terminated rRNA synthesis.
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Affiliation(s)
- Katrin Schwank
- Regensburg Center of Biochemistry (RCB), Universität Regensburg, D-93053 Regensburg, Germany
| | - Catharina Schmid
- Regensburg Center of Biochemistry (RCB), Universität Regensburg, D-93053 Regensburg, Germany
| | - Tobias Fremter
- Regensburg Center of Biochemistry (RCB), Universität Regensburg, D-93053 Regensburg, Germany
| | - Christoph Engel
- Regensburg Center of Biochemistry (RCB), Universität Regensburg, D-93053 Regensburg, Germany
| | - Philipp Milkereit
- Regensburg Center of Biochemistry (RCB), Universität Regensburg, D-93053 Regensburg, Germany
| | - Joachim Griesenbeck
- Regensburg Center of Biochemistry (RCB), Universität Regensburg, D-93053 Regensburg, Germany
| | - Herbert Tschochner
- Regensburg Center of Biochemistry (RCB), Universität Regensburg, D-93053 Regensburg, Germany
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Daiß JL, Griesenbeck J, Tschochner H, Engel C. Synthesis of the ribosomal RNA precursor in human cells: mechanisms, factors and regulation. Biol Chem 2023; 404:1003-1023. [PMID: 37454246 DOI: 10.1515/hsz-2023-0214] [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: 05/12/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023]
Abstract
The ribosomal RNA precursor (pre-rRNA) comprises three of the four ribosomal RNAs and is synthesized by RNA polymerase (Pol) I. Here, we describe the mechanisms of Pol I transcription in human cells with a focus on recent insights gained from structure-function analyses. The comparison of Pol I-specific structural and functional features with those of other Pols and with the excessively studied yeast system distinguishes organism-specific from general traits. We explain the organization of the genomic rDNA loci in human cells, describe the Pol I transcription cycle regarding structural changes in the enzyme and the roles of human Pol I subunits, and depict human rDNA transcription factors and their function on a mechanistic level. We disentangle information gained by direct investigation from what had apparently been deduced from studies of the yeast enzymes. Finally, we provide information about how Pol I mutations may contribute to developmental diseases, and why Pol I is a target for new cancer treatment strategies, since increased rRNA synthesis was correlated with rapidly expanding cell populations.
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Affiliation(s)
- Julia L Daiß
- Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Joachim Griesenbeck
- Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Herbert Tschochner
- Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Christoph Engel
- Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
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Yang DL, Huang K, Deng D, Zeng Y, Wang Z, Zhang Y. DNA-dependent RNA polymerases in plants. THE PLANT CELL 2023; 35:3641-3661. [PMID: 37453082 PMCID: PMC10533338 DOI: 10.1093/plcell/koad195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 06/09/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
DNA-dependent RNA polymerases (Pols) transfer the genetic information stored in genomic DNA to RNA in all organisms. In eukaryotes, the typical products of nuclear Pol I, Pol II, and Pol III are ribosomal RNAs, mRNAs, and transfer RNAs, respectively. Intriguingly, plants possess two additional Pols, Pol IV and Pol V, which produce small RNAs and long noncoding RNAs, respectively, mainly for silencing transposable elements. The five plant Pols share some subunits, but their distinct functions stem from unique subunits that interact with specific regulatory factors in their transcription cycles. Here, we summarize recent advances in our understanding of plant nucleus-localized Pols, including their evolution, function, structures, and transcription cycles.
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Affiliation(s)
- Dong-Lei Yang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Kun Huang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Deyin Deng
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Lin’an, Hangzhou 311300, China
| | - Yuan Zeng
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhenxing Wang
- College of Horticulture, National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
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Dörner K, Ruggeri C, Zemp I, Kutay U. Ribosome biogenesis factors-from names to functions. EMBO J 2023; 42:e112699. [PMID: 36762427 PMCID: PMC10068337 DOI: 10.15252/embj.2022112699] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/13/2022] [Accepted: 01/19/2023] [Indexed: 02/11/2023] Open
Abstract
The assembly of ribosomal subunits is a highly orchestrated process that involves a huge cohort of accessory factors. Most eukaryotic ribosome biogenesis factors were first identified by genetic screens and proteomic approaches of pre-ribosomal particles in Saccharomyces cerevisiae. Later, research on human ribosome synthesis not only demonstrated that the requirement for many of these factors is conserved in evolution, but also revealed the involvement of additional players, reflecting a more complex assembly pathway in mammalian cells. Yet, it remained a challenge for the field to assign a function to many of the identified factors and to reveal their molecular mode of action. Over the past decade, structural, biochemical, and cellular studies have largely filled this gap in knowledge and led to a detailed understanding of the molecular role that many of the players have during the stepwise process of ribosome maturation. Such detailed knowledge of the function of ribosome biogenesis factors will be key to further understand and better treat diseases linked to disturbed ribosome assembly, including ribosomopathies, as well as different types of cancer.
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Affiliation(s)
- Kerstin Dörner
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, Zurich, Switzerland
| | - Chiara Ruggeri
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.,RNA Biology Ph.D. Program, Zurich, Switzerland
| | - Ivo Zemp
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Ulrike Kutay
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
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Regulation of ribosomal RNA gene copy number, transcription and nucleolus organization in eukaryotes. Nat Rev Mol Cell Biol 2023; 24:414-429. [PMID: 36732602 DOI: 10.1038/s41580-022-00573-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2022] [Indexed: 02/04/2023]
Abstract
One of the first biological machineries to be created seems to have been the ribosome. Since then, organisms have dedicated great efforts to optimize this apparatus. The ribosomal RNA (rRNA) contained within ribosomes is crucial for protein synthesis and maintenance of cellular function in all known organisms. In eukaryotic cells, rRNA is produced from ribosomal DNA clusters of tandem rRNA genes, whose organization in the nucleolus, maintenance and transcription are strictly regulated to satisfy the substantial demand for rRNA required for ribosome biogenesis. Recent studies have elucidated mechanisms underlying the integrity of ribosomal DNA and regulation of its transcription, including epigenetic mechanisms and a unique recombination and copy-number control system to stably maintain high rRNA gene copy number. In this Review, we disucss how the crucial maintenance of rRNA gene copy number through control of gene amplification and of rRNA production by RNA polymerase I are orchestrated. We also discuss how liquid-liquid phase separation controls the architecture and function of the nucleolus and the relationship between rRNA production, cell senescence and disease.
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