1
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Bentley DL. Multiple Forms and Functions of Premature Termination by RNA Polymerase II. J Mol Biol 2024:168743. [PMID: 39127140 DOI: 10.1016/j.jmb.2024.168743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/05/2024] [Accepted: 08/06/2024] [Indexed: 08/12/2024]
Abstract
Eukaryotic genomes are widely transcribed by RNA polymerase II (pol II) both within genes and in intergenic regions. POL II elongation complexes comprising the polymerase, the DNA template and nascent RNA transcript must be extremely processive in order to transcribe the longest genes which are over 1 megabase long and take many hours to traverse. Dedicated termination mechanisms are required to disrupt these highly stable complexes. Transcription termination occurs not only at the 3' ends of genes once a full length transcript has been made, but also within genes and in promiscuously transcribed intergenic regions. Termination at these latter positions is termed "premature" because it is not triggered in response to a specific signal that marks the 3' end of a gene, like a polyA site. One purpose of premature termination is to remove polymerases from intergenic regions where they are "not wanted" because they may interfere with transcription of overlapping genes or the progress of replication forks. Premature termination has recently been appreciated to occur at surprisingly high rates within genes where it is speculated to serve regulatory or quality control functions. In this review I summarize current understanding of the different mechanisms of premature termination and its potential functions.
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Affiliation(s)
- David L Bentley
- Dept. Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA.
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2
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Lopez Martinez D, Svejstrup JQ. Mechanisms of RNA Polymerase II Termination at the 3'-End of Genes. J Mol Biol 2024:168735. [PMID: 39098594 DOI: 10.1016/j.jmb.2024.168735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 07/23/2024] [Accepted: 07/30/2024] [Indexed: 08/06/2024]
Abstract
RNA polymerase II (RNAPII) is responsible for the synthesis of a diverse set of RNA molecules, including protein-coding messenger RNAs (mRNAs) and many short non-coding RNAs (ncRNAs). For this purpose, RNAPII relies on a multitude of factors that regulate the transcription cycle, from initiation and promoter-proximal pausing, through elongation and finally termination. RNAPII transcription termination at the end of genes ensures the release of RNAPII from the DNA template and its efficient recycling for further rounds of transcription. Termination of RNAPII is tightly coupled to 3'-end mRNA processing, which constitutes an important trigger for the subsequent transcription termination event. In this review, we discuss the current understanding of RNAPII termination mechanisms, focusing on 'canonical' termination at the 3'-end of genes. We also integrate the allosteric and 'torpedo' models into a unified model of termination, and describe the different termination factors that have been identified to date, paying special attention to the human factors and their mechanism of action at the molecular level. Indeed, in recent years the development of novel approaches in structural biology, biochemistry and cell biology have together led to a more detailed comprehension of the different mechanisms of RNAPII termination, and a better understanding of their importance in regulating gene expression, especially under cellular stress and pathological situations.
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Affiliation(s)
- David Lopez Martinez
- Centre for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Jesper Q Svejstrup
- Centre for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.
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3
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Estell C, West S. ZC3H4/Restrictor Exerts a Stranglehold on Pervasive Transcription. J Mol Biol 2024:168707. [PMID: 39002716 DOI: 10.1016/j.jmb.2024.168707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 07/06/2024] [Accepted: 07/09/2024] [Indexed: 07/15/2024]
Abstract
The regulation of transcription by RNA polymerase II (RNAPII) underpins all cellular processes and is perturbed in thousands of diseases. In humans, RNAPII transcribes ∼20000 protein-coding genes and engages in apparently futile non-coding transcription at thousands of other sites. Despite being so ubiquitous, this transcription is usually attenuated soon after initiation and the resulting products are immediately degraded by the nuclear exosome. We and others have recently described a new complex, "Restrictor", which appears to control such unproductive transcription. Underpinned by the RNA binding protein, ZC3H4, Restrictor curtails unproductive/pervasive transcription genome-wide. Here, we discuss these recent discoveries and speculate on some of the many unknowns regarding Restrictor function and mechanism.
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Affiliation(s)
- Chris Estell
- The Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
| | - Steven West
- The Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
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4
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Kannan A, Gangadharan Leela S, Branzei D, Gangwani L. Role of senataxin in R-loop-mediated neurodegeneration. Brain Commun 2024; 6:fcae239. [PMID: 39070547 PMCID: PMC11277865 DOI: 10.1093/braincomms/fcae239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 06/14/2024] [Accepted: 07/13/2024] [Indexed: 07/30/2024] Open
Abstract
Senataxin is an RNA:DNA helicase that plays an important role in the resolution of RNA:DNA hybrids (R-loops) formed during transcription. R-loops are involved in the regulation of biological processes such as immunoglobulin class switching, gene expression and DNA repair. Excessive accumulation of R-loops results in DNA damage and loss of genomic integrity. Senataxin is critical for maintaining optimal levels of R-loops to prevent DNA damage and acts as a genome guardian. Within the nucleus, senataxin interacts with various RNA processing factors and DNA damage response and repair proteins. Senataxin interactors include survival motor neuron and zinc finger protein 1, with whom it co-localizes in sub-nuclear bodies. Despite its ubiquitous expression, mutations in senataxin specifically affect neurons and result in distinct neurodegenerative diseases such as amyotrophic lateral sclerosis type 4 and ataxia with oculomotor apraxia type 2, which are attributed to the gain-of-function and the loss-of-function mutations in senataxin, respectively. In addition, low levels of senataxin (loss-of-function) in spinal muscular atrophy result in the accumulation of R-loops causing DNA damage and motor neuron degeneration. Senataxin may play multiple functions in diverse cellular processes; however, its emerging role in R-loop resolution and maintenance of genomic integrity is gaining attention in the field of neurodegenerative diseases. In this review, we highlight the role of senataxin in R-loop resolution and its potential as a therapeutic target to treat neurodegenerative diseases.
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Affiliation(s)
| | - Shyni Gangadharan Leela
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| | - Dana Branzei
- The AIRC Institute of Molecular Oncology Foundation, IFOM ETS, Milan 20139, Italy
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche (IGM-CNR), Pavia 27100, Italy
| | - Laxman Gangwani
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
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5
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Wen X, Xu H, Woolley PR, Conway OM, Yao J, Matouschek A, Lambowitz AM, Paull TT. Senataxin deficiency disrupts proteostasis through nucleolar ncRNA-driven protein aggregation. J Cell Biol 2024; 223:e202309036. [PMID: 38717338 PMCID: PMC11080644 DOI: 10.1083/jcb.202309036] [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: 09/06/2023] [Revised: 01/19/2024] [Accepted: 03/13/2024] [Indexed: 05/12/2024] Open
Abstract
Senataxin is an evolutionarily conserved RNA-DNA helicase involved in DNA repair and transcription termination that is associated with human neurodegenerative disorders. Here, we investigated whether Senataxin loss affects protein homeostasis based on previous work showing R-loop-driven accumulation of DNA damage and protein aggregates in human cells. We find that Senataxin loss results in the accumulation of insoluble proteins, including many factors known to be prone to aggregation in neurodegenerative disorders. These aggregates are located primarily in the nucleolus and are promoted by upregulation of non-coding RNAs expressed from the intergenic spacer region of ribosomal DNA. We also map sites of R-loop accumulation in human cells lacking Senataxin and find higher RNA-DNA hybrids within the ribosomal DNA, peri-centromeric regions, and other intergenic sites but not at annotated protein-coding genes. These findings indicate that Senataxin loss affects the solubility of the proteome through the regulation of transcription-dependent lesions in the nucleus and the nucleolus.
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Affiliation(s)
- Xuemei Wen
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Hengyi Xu
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Phillip R. Woolley
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Olivia M. Conway
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Jun Yao
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Andreas Matouschek
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Alan M. Lambowitz
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
- Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, USA
| | - Tanya T. Paull
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
- Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, USA
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6
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Xiong Y, Han W, Xu C, Shi J, Wang L, Jin T, Jia Q, Lu Y, Hu S, Dou SX, Lin W, Strick TR, Wang S, Li M. Single-molecule reconstruction of eukaryotic factor-dependent transcription termination. Nat Commun 2024; 15:5113. [PMID: 38879529 PMCID: PMC11180205 DOI: 10.1038/s41467-024-49527-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 06/09/2024] [Indexed: 06/19/2024] Open
Abstract
Factor-dependent termination uses molecular motors to remodel transcription machineries, but the associated mechanisms, especially in eukaryotes, are poorly understood. Here we use single-molecule fluorescence assays to characterize in real time the composition and the catalytic states of Saccharomyces cerevisiae transcription termination complexes remodeled by Sen1 helicase. We confirm that Sen1 takes the RNA transcript as its substrate and translocates along it by hydrolyzing multiple ATPs to form an intermediate with a stalled RNA polymerase II (Pol II) transcription elongation complex (TEC). We show that this intermediate dissociates upon hydrolysis of a single ATP leading to dissociation of Sen1 and RNA, after which Sen1 remains bound to the RNA. We find that Pol II ends up in a variety of states: dissociating from the DNA substrate, which is facilitated by transcription bubble rewinding, being retained to the DNA substrate, or diffusing along the DNA substrate. Our results provide a complete quantitative framework for understanding the mechanism of Sen1-dependent transcription termination in eukaryotes.
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Affiliation(s)
- Ying Xiong
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
- School of Physics, University of Chinese Academy of Sciences, Beijing, China
| | - Weijing Han
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
| | - Chunhua Xu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Jing Shi
- Department of Pathogen Biology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
- Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lisha Wang
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
| | - Taoli Jin
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
| | - Qi Jia
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
| | - Ying Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Shuxin Hu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Shuo-Xing Dou
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physics, University of Chinese Academy of Sciences, Beijing, China
| | - Wei Lin
- Department of Pathogen Biology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China.
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing, China.
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
| | - Terence R Strick
- Institut de Biologie de l'Ecole Normale Supérieure, PSL Université, INSERM, CNRS, Paris, France.
- Equipe Labellisée de la Ligue Nationale Contre le Cancer, Paris, France.
| | - Shuang Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China.
| | - Ming Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
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7
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Chaudhuri A, Paul S, Banerjea M, Das B. Polyadenylated versions of small non-coding RNAs in Saccharomyces cerevisiae are degraded by Rrp6p/Rrp47p independent of the core nuclear exosome. MICROBIAL CELL (GRAZ, AUSTRIA) 2024; 11:155-186. [PMID: 38783922 PMCID: PMC11115967 DOI: 10.15698/mic2024.05.823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/03/2024] [Accepted: 03/05/2024] [Indexed: 05/25/2024]
Abstract
In Saccharomyces cerevisiae, polyadenylated forms of mature (and not precursor) small non-coding RNAs (sncRNAs) those fail to undergo proper 3'-end maturation are subject to an active degradation by Rrp6p and Rrp47p, which does not require the involvement of core exosome and TRAMP components. In agreement with this finding, Rrp6p/Rrp47p is demonstrated to exist as an exosome-independent complex, which preferentially associates with mature polyadenylated forms of these sncRNAs. Consistent with this observation, a C-terminally truncated version of Rrp6p (Rrp6p-ΔC2) lacking physical association with the core nuclear exosome supports their decay just like its full-length version. Polyadenylation is catalyzed by both the canonical and non-canonical poly(A) polymerases, Pap1p and Trf4p. Analysis of the polyadenylation profiles in WT and rrp6-Δ strains revealed that the majority of the polyadenylation sites correspond to either one to three nucleotides upstream or downstream of their mature ends and their poly(A) tails ranges from 10-15 adenylate residues. Most interestingly, the accumulated polyadenylated snRNAs are functional in the rrp6-Δ strain and are assembled into spliceosomes. Thus, Rrp6p-Rrp47p defines a core nuclear exosome-independent novel RNA turnover system in baker's yeast targeting imperfectly processed polyadenylated sncRNAs that accumulate in the absence of Rrp6p.
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Affiliation(s)
- Anusha Chaudhuri
- Present Position: Zentrum fǜr Molekulare, Medizin, Institut fǜr Kardiovaskuläre Regeneration, Haus 25B, Goethe-Universität, Theodor-Stern-Kai 7, Universitätsklinikum, 60590 Frankfurt am Main, Germany
| | - Soumita Paul
- Department of Life Science and Biotechnology, Jadavpur University, 188 Raja S.C. Mullick Road, Kolkata – 700 032, West Bengal, India
| | - Mayukh Banerjea
- Department of Life Science and Biotechnology, Jadavpur University, 188 Raja S.C. Mullick Road, Kolkata – 700 032, West Bengal, India
| | - Biswadip Das
- Department of Life Science and Biotechnology, Jadavpur University, 188 Raja S.C. Mullick Road, Kolkata – 700 032, West Bengal, India
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8
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Song E, Han S, Hohng S, Kang C. Compatibility of termination mechanisms in bacterial transcription with inference on eukaryotic models. Biochem Soc Trans 2024; 52:887-897. [PMID: 38533838 DOI: 10.1042/bst20231229] [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: 01/19/2024] [Revised: 03/18/2024] [Accepted: 03/18/2024] [Indexed: 03/28/2024]
Abstract
Transcription termination has evolved to proceed through diverse mechanisms. For several classes of terminators, multiple models have been debatably proposed. Recent single-molecule studies on bacterial terminators have resolved several long-standing controversies. First, termination mode or outcome is twofold rather than single. RNA is released alone before DNA or together with DNA from RNA polymerase (RNAP), i.e. with RNA release for termination, RNAP retains on or dissociates off DNA, respectively. The concomitant release, described in textbooks, results in one-step decomposition of transcription complexes, and this 'decomposing termination' prevails at ρ factor-dependent terminators. Contrastingly, the sequential release was recently discovered abundantly from RNA hairpin-dependent intrinsic terminations. RNA-only release allows RNAP to diffuse on DNA in both directions and recycle for reinitiation. This 'recycling termination' enables one-dimensional reinitiation, which would be more expeditious than three-dimensional reinitiation by RNAP dissociated at decomposing termination. Second, while both recycling and decomposing terminations occur at a hairpin-dependent terminator, four termination mechanisms compatibly operate at a ρ-dependent terminator with ρ in alternative modes and even intrinsically without ρ. RNA-bound catch-up ρ mediates recycling termination first and decomposing termination later, while RNAP-prebound stand-by ρ invokes only decomposing termination slowly. Without ρ, decomposing termination occurs slightly and sluggishly. These four mechanisms operate on distinct timescales, providing orderly fail-safes. The stand-by mechanism is benefited by terminational pause prolongation and modulated by accompanying riboswitches more greatly than the catch-up mechanisms. Conclusively, any mechanism alone is insufficient to perfect termination, and multiple mechanisms operate compatibly to achieve maximum possible efficiency under separate controls.
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Affiliation(s)
- Eunho Song
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Sun Han
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Sungchul Hohng
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Changwon Kang
- Department of Biological Sciences, and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
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9
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Wang S, Han Z, Strick TR. Single-molecule characterization of Sen1 translocation properties provides insights into eukaryotic factor-dependent transcription termination. Nucleic Acids Res 2024; 52:3249-3261. [PMID: 38261990 PMCID: PMC11013386 DOI: 10.1093/nar/gkae026] [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: 08/09/2023] [Revised: 01/02/2024] [Accepted: 01/04/2024] [Indexed: 01/25/2024] Open
Abstract
Sen1 is an essential helicase for factor-dependent transcription termination in Saccharomyces cerevisiae, whose molecular-motor mechanism has not been well addressed. Here, we use single-molecule experimentation to better understand the molecular-motor determinants of its action on RNA polymerase II (Pol II) complex. We quantify Sen1 translocation activity on single-stranded DNA (ssDNA), finding elevated translocation rates, high levels of processivity and ATP affinities. Upon deleting the N- and C-terminal domains, or further deleting different parts of the prong subdomain, which is an essential element for transcription termination, Sen1 displays changes in its translocation properties, such as slightly reduced translocation processivities, enhanced translocation rates and statistically identical ATP affinities. Although these parameters fulfil the requirements for Sen1 translocating along the RNA transcript to catch up with a stalled Pol II complex, we observe significant reductions in the termination efficiencies as well as the factions of the formation of the previously described topological intermediate prior to termination, suggesting that the prong may preserve an interaction with Pol II complex during factor-dependent termination. Our results underscore a more detailed rho-like mechanism of Sen1 and a critical interaction between Sen1 and Pol II complex for factor-dependent transcription termination in eukaryotes.
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Affiliation(s)
- Shuang Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
- Songshan Lake Materials Laboratory, 523808 Dongguan, Guangdong, China
- Molecular Motors and Machines group, Ecole normale supérieure, Institut de Biologie de l’Ecole normale supérieure (IBENS), CNRS, INSERM, PSL Research University, 75005 Paris, France
| | - Zhong Han
- Metabolism and Function of RNA in the Nucleus, Institut Jacques Monod, CNRS, University Paris Diderot, Sorbonne Paris Cité F-75205 Paris, France
| | - Terence R Strick
- Molecular Motors and Machines group, Ecole normale supérieure, Institut de Biologie de l’Ecole normale supérieure (IBENS), CNRS, INSERM, PSL Research University, 75005 Paris, France
- Programme Equipe Labellisées, Ligue Contre le Cancer, 75013 Paris, France
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10
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Giannini M, Porrua O. Senataxin: A key actor in RNA metabolism, genome integrity and neurodegeneration. Biochimie 2024; 217:10-19. [PMID: 37558082 DOI: 10.1016/j.biochi.2023.08.001] [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: 05/08/2023] [Revised: 07/29/2023] [Accepted: 08/01/2023] [Indexed: 08/11/2023]
Abstract
The RNA/DNA helicase senataxin (SETX) has been involved in multiple crucial processes related to genome expression and integrity such us transcription termination, the regulation of transcription-replication conflicts and the resolution of R-loops. SETX has been the focus of numerous studies since the discovery that mutations in its coding gene are the root cause of two different neurodegenerative diseases: Ataxia with Oculomotor Apraxia type 2 (AOA2) and a juvenile form of Amyotrophic Lateral Sclerosis (ALS4). A plethora of cellular phenotypes have been described as the result of SETX deficiency, yet the precise molecular function of SETX as well as the molecular pathways leading from SETX mutations to AOA2 and ALS4 pathologies have remained unclear. However, recent data have shed light onto the biochemical activities and biological roles of SETX, thus providing new clues to understand the molecular consequences of SETX mutation. In this review we summarize near two decades of scientific effort to elucidate SETX function, we discuss strengths and limitations of the approaches and models used thus far to investigate SETX-associated diseases and suggest new possible research avenues for the study of AOA2 and ALS4 pathogenesis.
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Affiliation(s)
- Marta Giannini
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Odil Porrua
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France.
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11
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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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12
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Goguen EC, Brow DA. Domains and residues of the Saccharomyces cerevisiae hnRNP protein Hrp1 important for transcriptional autoregulation and noncoding RNA termination. Genetics 2023; 225:iyad134. [PMID: 37467478 PMCID: PMC10471224 DOI: 10.1093/genetics/iyad134] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/05/2023] [Accepted: 07/12/2023] [Indexed: 07/21/2023] Open
Abstract
Proteins that bind the nascent transcript exiting RNA polymerase II can regulate transcription elongation. The essential Saccharomyces cerevisiae hnRNP protein Hrp1 is one such protein and participates in both cleavage and polyadenylation-coupled and Nrd1-Nab3-Sen1-dependent RNA polymerase II termination. Prior evidence that Hrp1 is a positive RNA polymerase II elongation factor suggests that its release from the elongation complex promotes termination. Here we report the effects of deletions and substitutions in Hrp1 on its autoregulation via an Nrd1-Nab3-Sen1-dependent transcription attenuator in the 5'-UTR of its mRNA and on the function of an Hrp1-dependent Nrd1-Nab3-Sen1 terminator in the SNR82 snoRNA gene. Deletion of either of two central RNA recognition motifs or either of the flanking low-sequence complexity domains is lethal. Smaller, viable deletions in the amino-terminal low-sequence complexity domain cause readthrough of both the HRP1 attenuator and SNR82 terminator. Substitutions that cause readthrough localized mostly to the RNA recognition motifs, although not always to the RNA-binding face. We found that autoregulation of Hrp1 mRNA synthesis is surprisingly robust, overcoming the expected lethal effects of the start codon and frameshift mutations via overexpression of the mRNA up to 40-fold. Our results suggest a model in which binding of attenuator or terminator elements in the nascent transcript by RNA recognition motifs 1 and 2 disrupts interactions between RNA recognition motif 2 and the RNA polymerase II elongation complex, increasing its susceptibility to termination.
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Affiliation(s)
- Emma C Goguen
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - David A Brow
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
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13
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Rodríguez-Molina JB, West S, Passmore LA. Knowing when to stop: Transcription termination on protein-coding genes by eukaryotic RNAPII. Mol Cell 2023; 83:404-415. [PMID: 36634677 PMCID: PMC7614299 DOI: 10.1016/j.molcel.2022.12.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/12/2022] [Accepted: 12/20/2022] [Indexed: 01/13/2023]
Abstract
Gene expression is controlled in a dynamic and regulated manner to allow for the consistent and steady expression of some proteins as well as the rapidly changing production of other proteins. Transcription initiation has been a major focus of study because it is highly regulated. However, termination of transcription also plays an important role in controlling gene expression. Transcription termination on protein-coding genes is intimately linked with 3' end cleavage and polyadenylation of transcripts, and it generally results in the production of a mature mRNA that is exported from the nucleus. Termination on many non-coding genes can also result in the production of a mature transcript. Termination is dynamically regulated-premature termination and transcription readthrough occur in response to a number of cellular signals, and these can have varied consequences on gene expression. Here, we review eukaryotic transcription termination by RNA polymerase II (RNAPII), focusing on protein-coding genes.
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Affiliation(s)
| | - Steven West
- The Living Systems Institute, University of Exeter, Exeter, UK.
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14
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Webster SF, Ghalei H. Maturation of small nucleolar RNAs: from production to function. RNA Biol 2023; 20:715-736. [PMID: 37796118 PMCID: PMC10557570 DOI: 10.1080/15476286.2023.2254540] [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] [Accepted: 08/28/2023] [Indexed: 10/06/2023] Open
Abstract
Small Nucleolar RNAs (snoRNAs) are an abundant group of non-coding RNAs with well-defined roles in ribosomal RNA processing, folding and chemical modification. Besides their classic roles in ribosome biogenesis, snoRNAs are also implicated in several other cellular activities including regulation of splicing, transcription, RNA editing, cellular trafficking, and miRNA-like functions. Mature snoRNAs must undergo a series of processing steps tightly regulated by transiently associating factors and coordinated with other cellular processes including transcription and splicing. In addition to their mature forms, snoRNAs can contribute to gene expression regulation through their derivatives and degradation products. Here, we review the current knowledge on mechanisms of snoRNA maturation, including the different pathways of processing, and the regulatory mechanisms that control snoRNA levels and complex assembly. We also discuss the significance of studying snoRNA maturation, highlight the gaps in the current knowledge and suggest directions for future research in this area.
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Affiliation(s)
- Sarah F. Webster
- Biochemistry, Cell, and Developmental Biology Graduate Program, Emory University, Atlanta, Georgia, USA
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Homa Ghalei
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
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15
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Xie J, Libri D, Porrua O. Mechanisms of eukaryotic transcription termination at a glance. J Cell Sci 2023; 136:286227. [PMID: 36594557 DOI: 10.1242/jcs.259873] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Transcription termination is the final step of a transcription cycle, which induces the release of the transcript at the termination site and allows the recycling of the polymerase for the next round of transcription. Timely transcription termination is critical for avoiding interferences between neighbouring transcription units as well as conflicts between transcribing RNA polymerases (RNAPs) and other DNA-associated processes, such as replication or DNA repair. Understanding the mechanisms by which the very stable transcription elongation complex is dismantled is essential for appreciating how physiological gene expression is maintained and also how concurrent processes that occur synchronously on the DNA are coordinated. Although the strategies employed by the different classes of eukaryotic RNAPs are traditionally considered to be different, novel findings point to interesting commonalities. In this Cell Science at a Glance and the accompanying poster, we review the current understanding about the mechanisms of transcription termination by the three eukaryotic RNAPs.
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Affiliation(s)
- Juanjuan Xie
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Domenico Libri
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Odil Porrua
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
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16
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Xie J, Aiello U, Clement Y, Haidara N, Girbig M, Schmitzova J, Pena V, Müller CW, Libri D, Porrua O. An integrated model for termination of RNA polymerase III transcription. SCIENCE ADVANCES 2022; 8:eabm9875. [PMID: 35857496 PMCID: PMC9278858 DOI: 10.1126/sciadv.abm9875] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
RNA polymerase III (RNAPIII) synthesizes essential and abundant noncoding RNAs such as transfer RNAs. Controlling RNAPIII span of activity by accurate and efficient termination is a challenging necessity to ensure robust gene expression and to prevent conflicts with other DNA-associated machineries. The mechanism of RNAPIII termination is believed to be simpler than that of other eukaryotic RNA polymerases, solely relying on the recognition of a T-tract in the nontemplate strand. Here, we combine high-resolution genome-wide analyses and in vitro transcription termination assays to revisit the mechanism of RNAPIII transcription termination in budding yeast. We show that T-tracts are necessary but not always sufficient for termination and that secondary structures of the nascent RNAs are important auxiliary cis-acting elements. Moreover, we show that the helicase Sen1 plays a key role in a fail-safe termination pathway. Our results provide a comprehensive model illustrating how multiple mechanisms cooperate to ensure efficient RNAPIII transcription termination.
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Affiliation(s)
- Juanjuan Xie
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Umberto Aiello
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Yves Clement
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Nouhou Haidara
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Mathias Girbig
- European Molecular Biology Laboratory (EMBL), Structural and Computational Biology Unit, 69117 Heidelberg, Germany
- Joint PhD degree from EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Jana Schmitzova
- Max Planck Institute for Biophysical Chemistry, Macromolecular Crystallography, Am Fassberg 11, 37077 Goettingen, Germany
| | - Vladimir Pena
- Max Planck Institute for Biophysical Chemistry, Macromolecular Crystallography, Am Fassberg 11, 37077 Goettingen, Germany
| | - Christoph W. Müller
- European Molecular Biology Laboratory (EMBL), Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Domenico Libri
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Corresponding author. (D.L.); (O.P.)
| | - Odil Porrua
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Corresponding author. (D.L.); (O.P.)
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17
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Aiello U, Challal D, Wentzinger G, Lengronne A, Appanah R, Pasero P, Palancade B, Libri D. Sen1 is a key regulator of transcription-driven conflicts. Mol Cell 2022; 82:2952-2966.e6. [PMID: 35839782 DOI: 10.1016/j.molcel.2022.06.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 05/04/2022] [Accepted: 06/13/2022] [Indexed: 10/17/2022]
Abstract
Cellular homeostasis requires the coordination of several machineries concurrently engaged in the DNA. Wide-spread transcription can interfere with other processes, and transcription-replication conflicts (TRCs) threaten genome stability. The conserved Sen1 helicase not only terminates non-coding transcription but also interacts with the replisome and reportedly resolves genotoxic R-loops. Sen1 prevents genomic instability, but how this relates to its molecular functions remains unclear. We generated high-resolution, genome-wide maps of transcription-dependent conflicts and R-loops using a Sen1 mutant that has lost interaction with the replisome but is termination proficient. We show that, under physiological conditions, Sen1 removes RNA polymerase II at TRCs within genes and the rDNA and at sites of transcription-transcription conflicts, thus qualifying as a "key regulator of conflicts." We demonstrate that genomic stability is affected by Sen1 mutation only when in addition to its role at the replisome, the termination of non-coding transcription or R-loop removal are additionally compromised.
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Affiliation(s)
- Umberto Aiello
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013 Paris, France
| | - Drice Challal
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013 Paris, France
| | | | - Armelle Lengronne
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Montpellier, France
| | - Rowin Appanah
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Philippe Pasero
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Montpellier, France
| | - Benoit Palancade
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013 Paris, France
| | - Domenico Libri
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013 Paris, France.
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18
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Villa T, Porrua O. Pervasive transcription: a controlled risk. FEBS J 2022. [PMID: 35587776 DOI: 10.1111/febs.16530] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/26/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022]
Abstract
Transcriptome-wide interrogation of eukaryotic genomes has unveiled the pervasive nature of RNA polymerase II transcription. Virtually, any DNA region with an accessible chromatin structure can be transcribed, resulting in a mass production of noncoding RNAs (ncRNAs) with the potential of interfering with gene expression programs. Budding yeast has proved to be a powerful model organism to understand the mechanisms at play to control pervasive transcription and overcome the risks of hazardous disruption of cellular functions. In this review, we focus on the actors and strategies yeasts employ to govern ncRNA production, and we discuss recent findings highlighting the dangers of losing control over pervasive transcription.
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Affiliation(s)
- Tommaso Villa
- Institut Jacques Monod CNRS, Université de Paris Cité France
| | - Odil Porrua
- Institut Jacques Monod CNRS, Université de Paris Cité France
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19
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Structural insights into nuclear transcription by eukaryotic DNA-dependent RNA polymerases. Nat Rev Mol Cell Biol 2022; 23:603-622. [PMID: 35505252 DOI: 10.1038/s41580-022-00476-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2022] [Indexed: 02/07/2023]
Abstract
The eukaryotic transcription apparatus synthesizes a staggering diversity of RNA molecules. The labour of nuclear gene transcription is, therefore, divided among multiple DNA-dependent RNA polymerases. RNA polymerase I (Pol I) transcribes ribosomal RNA, Pol II synthesizes messenger RNAs and various non-coding RNAs (including long non-coding RNAs, microRNAs and small nuclear RNAs) and Pol III produces transfer RNAs and other short RNA molecules. Pol I, Pol II and Pol III are large, multisubunit protein complexes that associate with a multitude of additional factors to synthesize transcripts that largely differ in size, structure and abundance. The three transcription machineries share common characteristics, but differ widely in various aspects, such as numbers of RNA polymerase subunits, regulatory elements and accessory factors, which allows them to specialize in transcribing their specific RNAs. Common to the three RNA polymerases is that the transcription process consists of three major steps: transcription initiation, transcript elongation and transcription termination. In this Review, we outline the common principles and differences between the Pol I, Pol II and Pol III transcription machineries and discuss key structural and functional insights obtained into the three stages of their transcription processes.
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20
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Kanagaraj R, Mitter R, Kantidakis T, Edwards MM, Benitez A, Chakravarty P, Fu B, Becherel O, Yang F, Lavin MF, Koren A, Stewart A, West SC. Integrated genome and transcriptome analyses reveal the mechanism of genome instability in ataxia with oculomotor apraxia 2. Proc Natl Acad Sci U S A 2022; 119:e2114314119. [PMID: 35042798 PMCID: PMC8795503 DOI: 10.1073/pnas.2114314119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 12/14/2021] [Indexed: 12/21/2022] Open
Abstract
Mutations in the SETX gene, which encodes Senataxin, are associated with the progressive neurodegenerative diseases ataxia with oculomotor apraxia 2 (AOA2) and amyotrophic lateral sclerosis 4 (ALS4). To identify the causal defect in AOA2, patient-derived cells and SETX knockouts (human and mouse) were analyzed using integrated genomic and transcriptomic approaches. A genome-wide increase in chromosome instability (gains and losses) within genes and at chromosome fragile sites was observed, resulting in changes to gene-expression profiles. Transcription stress near promoters correlated with high GCskew and the accumulation of R-loops at promoter-proximal regions, which localized with chromosomal regions where gains and losses were observed. In the absence of Senataxin, the Cockayne syndrome protein CSB was required for the recruitment of the transcription-coupled repair endonucleases (XPG and XPF) and RAD52 recombination protein to target and resolve transcription bubbles containing R-loops, leading to genomic instability. These results show that transcription stress is an important contributor to SETX mutation-associated chromosome fragility and AOA2.
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Affiliation(s)
- Radhakrishnan Kanagaraj
- DNA Recombination and Repair Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom;
| | - Richard Mitter
- Bioinformatics and Biostatistics, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | | | - Matthew M Edwards
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Anaid Benitez
- DNA Recombination and Repair Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Probir Chakravarty
- Bioinformatics and Biostatistics, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Beiyuan Fu
- Wellcome Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, United Kingdom
| | - Olivier Becherel
- Center for Clinical Research, University of Queensland, Herston, QLD 4029, Australia
| | - Fengtang Yang
- Wellcome Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, United Kingdom
| | - Martin F Lavin
- Center for Clinical Research, University of Queensland, Herston, QLD 4029, Australia
| | - Amnon Koren
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Aengus Stewart
- Bioinformatics and Biostatistics, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Stephen C West
- DNA Recombination and Repair Laboratory, The Francis Crick Institute, London NW1 1AT, United Kingdom;
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21
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Haidara N, Giannini M, Porrua O. Modulated termination of non-coding transcription partakes in the regulation of gene expression. Nucleic Acids Res 2022; 50:1430-1448. [PMID: 35037029 PMCID: PMC8860598 DOI: 10.1093/nar/gkab1304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 12/17/2021] [Accepted: 12/27/2021] [Indexed: 12/25/2022] Open
Abstract
Pervasive transcription is a universal phenomenon leading to the production of a plethora of non-coding RNAs. If left uncontrolled, pervasive transcription can be harmful for genome expression and stability. However, non-coding transcription can also play important regulatory roles, for instance by promoting the repression of specific genes by a mechanism of transcriptional interference. The efficiency of transcription termination can strongly influence the regulatory capacity of non-coding transcription events, yet very little is known about the mechanisms modulating the termination of non-coding transcription in response to environmental cues. Here, we address this question by investigating the mechanisms that regulate the activity of the main actor in termination of non-coding transcription in budding yeast, the helicase Sen1. We identify a phosphorylation at a conserved threonine of the catalytic domain of Sen1 and we provide evidence that phosphorylation at this site reduces the efficiency of Sen1-mediated termination. Interestingly, we find that this phosphorylation impairs termination at an unannotated non-coding gene, thus repressing the expression of a downstream gene encoding the master regulator of Zn homeostasis, Zap1. Consequently, many additional genes exhibit an expression pattern mimicking conditions of Zn excess, where ZAP1 is naturally repressed. Our findings provide a novel paradigm of gene regulatory mechanism relying on the direct modulation of non-coding transcription termination.
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Affiliation(s)
- Nouhou Haidara
- Université de Paris, CNRS, Institut Jacques Monod, F-75013 Paris, France.,Université Paris-Saclay, Gif sur Yvette, France
| | - Marta Giannini
- Université de Paris, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Odil Porrua
- Université de Paris, CNRS, Institut Jacques Monod, F-75013 Paris, France
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22
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Singh P, Chaudhuri A, Banerjea M, Marathe N, Das B. Nrd1p identifies aberrant and natural exosomal target messages during the nuclear mRNA surveillance in Saccharomyces cerevisiae. Nucleic Acids Res 2021; 49:11512-11536. [PMID: 34664673 PMCID: PMC8599857 DOI: 10.1093/nar/gkab930] [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: 08/27/2021] [Accepted: 10/16/2021] [Indexed: 12/24/2022] Open
Abstract
Nuclear degradation of aberrant mRNAs in Saccharomyces cerevisiae is accomplished by the nuclear exosome and its cofactors TRAMP/CTEXT. Evidence from this investigation establishes a universal role of the Nrd1p-Nab3p-Sen1p (NNS) complex in the nuclear decay of all categories of aberrant mRNAs. In agreement with this, both nrd1-1 and nrd1-2 mutations impaired the decay of all classes of aberrant messages. This phenotype is similar to that displayed by GAL::RRP41 and rrp6-Δ mutant yeast strains. Remarkably, however, nrd1ΔCID mutation (lacking the C-terminal domain required for interaction of Nrd1p with RNAPII) only diminished the decay of aberrant messages with defects occurring during the early stage of mRNP biogenesis, without affecting other messages with defects generated later in the process. Co-transcriptional recruitment of Nrd1p on the aberrant mRNAs was vital for their concomitant decay. Strikingly, this recruitment on to mRNAs defective in the early phases of biogenesis is solely dependent upon RNAPII. In contrast, Nrd1p recruitment onto export-defective transcripts with defects occurring in the later stage of biogenesis is independent of RNAPII and dependent on the CF1A component, Pcf11p, which explains the observed characteristic phenotype of nrd1ΔCID mutation. Consistently, pcf11-2 mutation displayed a selective impairment in the degradation of only the export-defective messages.
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Affiliation(s)
- Pragyan Singh
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata - 700032, West Bengal, India
| | - Anusha Chaudhuri
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata - 700032, West Bengal, India
| | - Mayukh Banerjea
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata - 700032, West Bengal, India
| | - Neeraja Marathe
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata - 700032, West Bengal, India
| | - Biswadip Das
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata - 700032, West Bengal, India
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23
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Transcription recycling assays identify PAF1 as a driver for RNA Pol II recycling. Nat Commun 2021; 12:6318. [PMID: 34732721 PMCID: PMC8566496 DOI: 10.1038/s41467-021-26604-1] [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: 02/19/2020] [Accepted: 10/17/2021] [Indexed: 11/20/2022] Open
Abstract
RNA Polymerase II (Pol II) transcriptional recycling is a mechanism for which the required factors and contributions to overall gene expression levels are poorly understood. We describe an in vitro methodology facilitating unbiased identification of putative RNA Pol II transcriptional recycling factors and quantitative measurement of transcriptional output from recycled transcriptional components. Proof-of-principle experiments identified PAF1 complex components among recycling factors and detected defective transcriptional output from Pol II recycling following PAF1 depletion. Dynamic ChIP-seq confirmed PAF1 silencing triggered defective Pol II recycling in human cells. Prostate tumors exhibited enhanced transcriptional recycling, which was attenuated by antibody-based PAF1 depletion. These findings identify Pol II recycling as a potential target in cancer and demonstrate the applicability of in vitro and cellular transcription assays to characterize Pol II recycling in other disease states. RNA Polymerase II (Pol II) recycling can influence transcription efficiency. Here the authors describe an approach aimed at facilitating the identification of factors involved in Pol II recycling and identify PAF1 complex components as mediators of recycling.
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24
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Villa T, Barucco M, Martin-Niclos MJ, Jacquier A, Libri D. Degradation of Non-coding RNAs Promotes Recycling of Termination Factors at Sites of Transcription. Cell Rep 2021; 32:107942. [PMID: 32698007 DOI: 10.1016/j.celrep.2020.107942] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 05/08/2020] [Accepted: 06/30/2020] [Indexed: 12/27/2022] Open
Abstract
A large share of the non-coding transcriptome in yeast is controlled by the Nrd1-Nab3-Sen1 (NNS) complex, which promotes transcription termination of non-coding RNA (ncRNA) genes, and by the nuclear exosome, which limits the steady-state levels of the transcripts produced. How unconstrained ncRNA levels affect RNA metabolism and gene expression are long-standing and important questions. Here, we show that degradation of ncRNAs by the exosome is required for freeing Nrd1 and Nab3 from the released transcript after termination. In exosome mutants, these factors are sequestered by ncRNAs and cannot be efficiently recycled to sites of transcription, inducing termination defects at NNS targets. ncRNA-dependent, genome-wide termination defects can be recapitulated by the expression of a degradation-resistant, circular RNA containing a natural NNS target in exosome-proficient cells. Our results have important implications for the mechanism of termination, the general impact of ncRNAs abundance, and the importance of nuclear ncRNA degradation.
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Affiliation(s)
- Tommaso Villa
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France.
| | - Mara Barucco
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France
| | | | - Alain Jacquier
- Institut Pasteur, Centre National de la Recherche Scientifique, UMR3525 Paris, France
| | - Domenico Libri
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France.
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25
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Hildreth AE, Ellison MA, Francette AM, Seraly JM, Lotka LM, Arndt KM. The nucleosome DNA entry-exit site is important for transcription termination and prevention of pervasive transcription. eLife 2020; 9:e57757. [PMID: 32845241 PMCID: PMC7449698 DOI: 10.7554/elife.57757] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 08/09/2020] [Indexed: 12/21/2022] Open
Abstract
Compared to other stages in the RNA polymerase II transcription cycle, the role of chromatin in transcription termination is poorly understood. We performed a genetic screen in Saccharomyces cerevisiae to identify histone mutants that exhibit transcriptional readthrough of terminators. Amino acid substitutions identified by the screen map to the nucleosome DNA entry-exit site. The strongest H3 mutants revealed widespread genomic changes, including increased sense-strand transcription upstream and downstream of genes, increased antisense transcription overlapping gene bodies, and reduced nucleosome occupancy particularly at the 3' ends of genes. Replacement of the native sequence downstream of a gene with a sequence that increases nucleosome occupancy in vivo reduced readthrough transcription and suppressed the effect of a DNA entry-exit site substitution. Our results suggest that nucleosomes can facilitate termination by serving as a barrier to transcription and highlight the importance of the DNA entry-exit site in broadly maintaining the integrity of the transcriptome.
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Affiliation(s)
- A Elizabeth Hildreth
- Department of Biological Sciences, University of PittsburghPittsburghUnited States
| | - Mitchell A Ellison
- Department of Biological Sciences, University of PittsburghPittsburghUnited States
| | - Alex M Francette
- Department of Biological Sciences, University of PittsburghPittsburghUnited States
| | - Julia M Seraly
- Department of Biological Sciences, University of PittsburghPittsburghUnited States
| | - Lauren M Lotka
- Department of Biological Sciences, University of PittsburghPittsburghUnited States
| | - Karen M Arndt
- Department of Biological Sciences, University of PittsburghPittsburghUnited States
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26
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Lee KY, Chopra A, Burke GL, Chen Z, Greenblatt JF, Biggar KK, Meneghini MD. A crucial RNA-binding lysine residue in the Nab3 RRM domain undergoes SET1 and SET3-responsive methylation. Nucleic Acids Res 2020; 48:2897-2911. [PMID: 31960028 PMCID: PMC7102954 DOI: 10.1093/nar/gkaa029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 01/07/2020] [Accepted: 01/18/2020] [Indexed: 11/13/2022] Open
Abstract
The Nrd1-Nab3-Sen1 (NNS) complex integrates molecular cues to direct termination of noncoding transcription in budding yeast. NNS is positively regulated by histone methylation as well as through Nrd1 binding to the initiating form of RNA PolII. These cues collaborate with Nrd1 and Nab3 binding to target RNA sequences in nascent transcripts through their RRM RNA recognition motifs. In this study, we identify nine lysine residues distributed amongst Nrd1, Nab3 and Sen1 that are methylated, suggesting novel molecular inputs for NNS regulation. We identify mono-methylation of one these residues (Nab3-K363me1) as being partly dependent on the H3K4 methyltransferase, Set1, a known regulator of NNS function. Moreover, the accumulation of Nab3-K363me1 is essentially abolished in strains lacking SET3, a SET domain containing protein that is positively regulated by H3K4 methylation. Nab3-K363 resides within its RRM and physically contacts target RNA. Mutation of Nab3-K363 to arginine (Nab3-K363R) decreases RNA binding of the Nab3 RRM in vitro and causes transcription termination defects and slow growth. These findings identify SET3 as a potential contextual regulator of Nab3 function through its role in methylation of Nab3-K363. Consistent with this hypothesis, we report that SET3 exhibits genetic activation of NAB3 that is observed in a sensitized context.
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Affiliation(s)
- Kwan Yin Lee
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Anand Chopra
- Institute of Biochemistry, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Giovanni L Burke
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada.,Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Ziyan Chen
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Jack F Greenblatt
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada.,Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Kyle K Biggar
- Institute of Biochemistry, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Marc D Meneghini
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
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27
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Han Z, Jasnovidova O, Haidara N, Tudek A, Kubicek K, Libri D, Stefl R, Porrua O. Termination of non-coding transcription in yeast relies on both an RNA Pol II CTD interaction domain and a CTD-mimicking region in Sen1. EMBO J 2020; 39:e101548. [PMID: 32107786 PMCID: PMC7110113 DOI: 10.15252/embj.2019101548] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 01/23/2020] [Accepted: 01/31/2020] [Indexed: 12/12/2022] Open
Abstract
Pervasive transcription is a widespread phenomenon leading to the production of a plethora of non‐coding RNAs (ncRNAs) without apparent function. Pervasive transcription poses a threat to proper gene expression that needs to be controlled. In yeast, the highly conserved helicase Sen1 restricts pervasive transcription by inducing termination of non‐coding transcription. However, the mechanisms underlying the specific function of Sen1 at ncRNAs are poorly understood. Here, we identify a motif in an intrinsically disordered region of Sen1 that mimics the phosphorylated carboxy‐terminal domain (CTD) of RNA polymerase II, and structurally characterize its recognition by the CTD‐interacting domain of Nrd1, an RNA‐binding protein that binds specific sequences in ncRNAs. In addition, we show that Sen1‐dependent termination strictly requires CTD recognition by the N‐terminal domain of Sen1. We provide evidence that the Sen1‐CTD interaction does not promote initial Sen1 recruitment, but rather enhances Sen1 capacity to induce the release of paused RNAPII from the DNA. Our results shed light on the network of protein–protein interactions that control termination of non‐coding transcription by Sen1.
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Affiliation(s)
- Zhong Han
- Université de Paris, CNRS, Institut Jacques Monod, Paris, France.,Université Paris-Saclay, Yvette, France
| | - Olga Jasnovidova
- CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Nouhou Haidara
- Université de Paris, CNRS, Institut Jacques Monod, Paris, France.,Université Paris-Saclay, Yvette, France
| | - Agnieszka Tudek
- Université de Paris, CNRS, Institut Jacques Monod, Paris, France
| | - Karel Kubicek
- CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Domenico Libri
- Université de Paris, CNRS, Institut Jacques Monod, Paris, France
| | - Richard Stefl
- CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Odil Porrua
- Université de Paris, CNRS, Institut Jacques Monod, Paris, France
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28
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Appanah R, Lones EC, Aiello U, Libri D, De Piccoli G. Sen1 Is Recruited to Replication Forks via Ctf4 and Mrc1 and Promotes Genome Stability. Cell Rep 2020; 30:2094-2105.e9. [PMID: 32075754 PMCID: PMC7034062 DOI: 10.1016/j.celrep.2020.01.087] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 09/06/2019] [Accepted: 01/24/2020] [Indexed: 01/21/2023] Open
Abstract
DNA replication and RNA transcription compete for the same substrate during S phase. Cells have evolved several mechanisms to minimize such conflicts. Here, we identify the mechanism by which the transcription termination helicase Sen1 associates with replisomes. We show that the N terminus of Sen1 is both sufficient and necessary for replisome association and that it binds to the replisome via the components Ctf4 and Mrc1. We generated a separation of function mutant, sen1-3, which abolishes replisome binding without affecting transcription termination. We observe that the sen1-3 mutants show increased genome instability and recombination levels. Moreover, sen1-3 is synthetically defective with mutations in genes involved in RNA metabolism and the S phase checkpoint. RNH1 overexpression suppresses defects in the former, but not the latter. These findings illustrate how Sen1 plays a key function at replication forks during DNA replication to promote fork progression and chromosome stability.
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Affiliation(s)
- Rowin Appanah
- Warwick Medical School, University of Warwick, CV4 7AL Coventry, UK
| | | | - Umberto Aiello
- Institut Jacques Monod, CNRS, UMR7592, Université Paris Diderot, Paris Sorbonne Cité, Paris, France
| | - Domenico Libri
- Institut Jacques Monod, CNRS, UMR7592, Université Paris Diderot, Paris Sorbonne Cité, Paris, France
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29
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Directed RNase H Cleavage of Nascent Transcripts Causes Transcription Termination. Mol Cell 2020; 77:1032-1043.e4. [PMID: 31924447 DOI: 10.1016/j.molcel.2019.12.029] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/20/2019] [Accepted: 12/25/2019] [Indexed: 11/22/2022]
Abstract
An attractive approach to reduce gene expression is via the use of antisense oligonucleotides (ASOs) that harness the RNase H1 mechanism. Here we show that RNase H ASOs targeted to introns or exons robustly reduce the level of spliced RNA associated with chromatin. Surprisingly, intron-targeted ASOs reduce the level of pre-mRNA associated with chromatin to a greater extent than exon-targeted ASOs. This indicates that exon-targeted ASOs achieve full activity after the pre-mRNA has undergone splicing, but before the mRNA is released from chromatin. Even though RNase H ASOs can reduce the level of RNA associated with chromatin, the effect of ASO-directed RNA degradation on transcription has never been documented. Here we show that intron-targeted ASOs and, to a lesser extent, exon-targeted ASOs cause RNA polymerase II (Pol II) transcription termination in cultured cells and mice. Furthermore, ASO-directed transcription termination is mediated by the nuclear exonuclease XRN2.
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30
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Porrua O. Purification and In Vitro Analysis of the Exosome Cofactors Nrd1-Nab3 and Trf4-Air2. Methods Mol Biol 2020; 2062:277-289. [PMID: 31768982 DOI: 10.1007/978-1-4939-9822-7_14] [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] [Indexed: 06/10/2023]
Abstract
In many eukaryotic organisms from yeast to human, the exosome plays an important role in the control of pervasive transcription and in non-coding RNA (ncRNA) processing and quality control by trimming precursor RNAs and degrading aberrant transcripts. In Saccharomyces cerevisiae this function is enabled by the interaction of the exosome with several cofactors: the Nrd1-Nab3 heterodimer and the Trf4-Air2-Mtr4 (TRAMP4) complex. Nrd1 and Nab3 are RNA binding proteins that recognize specific motifs enriched in the target ncRNAs, whereas TRAMP4 adds polyA tails at the 3' end of transcripts and stimulates RNA degradation by the exosome. This chapter provides protocols for the purification of recombinant forms of these exosome cofactors and for the in vitro assessment of their activity.
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Affiliation(s)
- Odil Porrua
- Institut Jacques Monod-UMR7592, CNRS, Université de Paris, Paris, France.
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31
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Rivosecchi J, Larochelle M, Teste C, Grenier F, Malapert A, Ricci EP, Bernard P, Bachand F, Vanoosthuyse V. Senataxin homologue Sen1 is required for efficient termination of RNA polymerase III transcription. EMBO J 2019; 38:e101955. [PMID: 31294478 DOI: 10.15252/embj.2019101955] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/03/2019] [Accepted: 06/11/2019] [Indexed: 01/13/2023] Open
Abstract
R-loop disassembly by the human helicase Senataxin contributes to genome integrity and to proper transcription termination at a subset of RNA polymerase II genes. Whether Senataxin also contributes to transcription termination at other classes of genes has remained unclear. Here, we show that Sen1, one of two fission yeast homologues of Senataxin, promotes efficient termination of RNA polymerase III (RNAP3) transcription in vivo. In the absence of Sen1, RNAP3 accumulates downstream of RNAP3-transcribed genes and produces long exosome-sensitive 3'-extended transcripts. Importantly, neither of these defects was affected by the removal of R-loops. The finding that Sen1 acts as an ancillary factor for RNAP3 transcription termination in vivo challenges the pre-existing view that RNAP3 terminates transcription autonomously. We propose that Sen1 is a cofactor for transcription termination that has been co-opted by different RNA polymerases in the course of evolution.
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Affiliation(s)
- Julieta Rivosecchi
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, CNRS, UMR 5239, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Marc Larochelle
- Département de Biochimie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Camille Teste
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, CNRS, UMR 5239, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Frédéric Grenier
- Département de Biochimie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Amélie Malapert
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, CNRS, UMR 5239, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Emiliano P Ricci
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, CNRS, UMR 5239, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Pascal Bernard
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, CNRS, UMR 5239, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - François Bachand
- Département de Biochimie, Université de Sherbrooke, Sherbrooke, QC, Canada.,Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Vincent Vanoosthuyse
- Laboratoire de Biologie et Modélisation de la Cellule, Université de Lyon, CNRS, UMR 5239, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
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32
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Wang S, Han Z, Libri D, Porrua O, Strick TR. Single-molecule characterization of extrinsic transcription termination by Sen1 helicase. Nat Commun 2019; 10:1545. [PMID: 30948716 PMCID: PMC6449345 DOI: 10.1038/s41467-019-09560-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 03/11/2019] [Indexed: 01/08/2023] Open
Abstract
Extrinsic transcription termination typically involves remodeling of RNA polymerase by an accessory helicase. In yeast this is accomplished by the Sen1 helicase homologous to human senataxin (SETX). To gain insight into these processes we develop a DNA scaffold construct compatible with magnetic-trapping assays and from which S. cerevisiae RNA polymerase II (Pol II), as well as E. coli RNA polymerase (ecRNAP), can efficiently initiate transcription without transcription factors, elongate, and undergo extrinsic termination. By stalling Pol II TECs on the construct we can monitor Sen1-induced termination in real-time, revealing the formation of an intermediate in which the Pol II transcription bubble appears half-rewound. This intermediate requires ~40 sec to form and lasts ~20 sec prior to final dissociation of the stalled Pol II. The experiments enabled by the scaffold construct permit detailed statistical and kinetic analysis of Pol II interactions with a range of cofactors in a multi-round, high-throughput fashion. Yeast’s Sen1 helicase is involved in the suppression of antisense transcription from bidirectional eukaryotic promoters. Here authors develop and utilize a quantitative single-molecule assay reporting on the kinetics of extrinsic eukaryotic transcription termination by the Sen1 helicase and a reaction intermediate in which the Pol II transcription bubble appears half-rewound.
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Affiliation(s)
- S Wang
- Molecular Motors and Machines group, Ecole normale supérieure, Institut de Biologie de l'Ecole normale supérieure (IBENS), CNRS, INSERM, PSL Research University, 75005, Paris, France.,Biomolecular Nanomanipulation group, Institut Jacques Monod, CNRS, University Paris Diderot, Sorbonne Paris Cité, F-75205, Paris, France
| | - Z Han
- Metabolism and Function of RNA in the Nucleus, Institut Jacques Monod, CNRS, University Paris Diderot, Sorbonne Paris Cité, F-75205, Paris, France
| | - D Libri
- Metabolism and Function of RNA in the Nucleus, Institut Jacques Monod, CNRS, University Paris Diderot, Sorbonne Paris Cité, F-75205, Paris, France
| | - O Porrua
- Metabolism and Function of RNA in the Nucleus, Institut Jacques Monod, CNRS, University Paris Diderot, Sorbonne Paris Cité, F-75205, Paris, France
| | - T R Strick
- Molecular Motors and Machines group, Ecole normale supérieure, Institut de Biologie de l'Ecole normale supérieure (IBENS), CNRS, INSERM, PSL Research University, 75005, Paris, France. .,Biomolecular Nanomanipulation group, Institut Jacques Monod, CNRS, University Paris Diderot, Sorbonne Paris Cité, F-75205, Paris, France. .,Programme Equipe Labellisées, Ligue Contre le Cancer, 75013, Paris, France.
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33
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Peck SA, Hughes KD, Victorino JF, Mosley AL. Writing a wrong: Coupled RNA polymerase II transcription and RNA quality control. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1529. [PMID: 30848101 PMCID: PMC6570551 DOI: 10.1002/wrna.1529] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 12/27/2018] [Accepted: 02/07/2019] [Indexed: 12/20/2022]
Abstract
Processing and maturation of precursor RNA species is coupled to RNA polymerase II transcription. Co-transcriptional RNA processing helps to ensure efficient and proper capping, splicing, and 3' end processing of different RNA species to help ensure quality control of the transcriptome. Many improperly processed transcripts are not exported from the nucleus, are restricted to the site of transcription, and are in some cases degraded, which helps to limit any possibility of aberrant RNA causing harm to cellular health. These critical quality control pathways are regulated by the highly dynamic protein-protein interaction network at the site of transcription. Recent work has further revealed the extent to which the processes of transcription and RNA processing and quality control are integrated, and how critically their coupling relies upon the dynamic protein interactions that take place co-transcriptionally. This review focuses specifically on the intricate balance between 3' end processing and RNA decay during transcription termination. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Processing > 3' End Processing RNA Processing > Splicing Mechanisms RNA Processing > Capping and 5' End Modifications.
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Affiliation(s)
- Sarah A Peck
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Katlyn D Hughes
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jose F Victorino
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
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34
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Collin P, Jeronimo C, Poitras C, Robert F. RNA Polymerase II CTD Tyrosine 1 Is Required for Efficient Termination by the Nrd1-Nab3-Sen1 Pathway. Mol Cell 2019; 73:655-669.e7. [PMID: 30639244 DOI: 10.1016/j.molcel.2018.12.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/09/2018] [Accepted: 11/29/2018] [Indexed: 12/15/2022]
Abstract
In Saccharomyces cerevisiae, transcription termination at protein-coding genes is coupled to the cleavage of the nascent transcript, whereas most non-coding RNA transcription relies on a cleavage-independent termination pathway involving Nrd1, Nab3, and Sen1 (NNS). Termination involves RNA polymerase II CTD phosphorylation, but a systematic analysis of the contribution of individual residues would improve our understanding of the role of the CTD in this process. Here we investigated the effect of mutating phosphorylation sites in the CTD on termination. We observed widespread termination defects at protein-coding genes in mutants for Ser2 or Thr4 but rare defects in Tyr1 mutants for this genes class. Instead, mutating Tyr1 led to widespread termination defects at non-coding genes terminating via NNS. Finally, we showed that Tyr1 is important for pausing in the 5' end of genes and that slowing down transcription suppresses termination defects. Our work highlights the importance of Tyr1-mediated pausing in NNS-dependent termination.
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Affiliation(s)
- Pierre Collin
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Célia Jeronimo
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Christian Poitras
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - 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 Boulevard Edouard-Montpetit, Montréal, QC H3T 1J4, Canada.
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35
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Schmid M, Jensen TH. The Nuclear RNA Exosome and Its Cofactors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:113-132. [PMID: 31811632 DOI: 10.1007/978-3-030-31434-7_4] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The RNA exosome is a highly conserved ribonuclease endowed with 3'-5' exonuclease and endonuclease activities. The multisubunit complex resides in both the nucleus and the cytoplasm, with varying compositions and activities between the two compartments. While the cytoplasmic exosome functions mostly in mRNA quality control pathways, the nuclear RNA exosome partakes in the 3'-end processing and complete decay of a wide variety of substrates, including virtually all types of noncoding (nc) RNAs. To handle these diverse tasks, the nuclear exosome engages with dedicated cofactors, some of which serve as activators by stimulating decay through oligoA addition and/or RNA helicase activities or, as adaptors, by recruiting RNA substrates through their RNA-binding capacities. Most nuclear exosome cofactors contain the essential RNA helicase Mtr4 (MTR4 in humans). However, apart from Mtr4, nuclear exosome cofactors have undergone significant evolutionary divergence. Here, we summarize biochemical and functional knowledge about the nuclear exosome and exemplify its cofactor variety by discussing the best understood model organisms-the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe, and human cells.
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Affiliation(s)
- Manfred Schmid
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark.
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36
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Nab3's localization to a nuclear granule in response to nutrient deprivation is determined by its essential prion-like domain. PLoS One 2018; 13:e0209195. [PMID: 30557374 PMCID: PMC6296506 DOI: 10.1371/journal.pone.0209195] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/30/2018] [Indexed: 12/20/2022] Open
Abstract
Ribonucleoprotein (RNP) granules are higher order assemblies of RNA, RNA-binding proteins, and other proteins, that regulate the transcriptome and protect RNAs from environmental challenge. There is a diverse range of RNP granules, many cytoplasmic, which provide various levels of regulation of RNA metabolism. Here we present evidence that the yeast transcription termination factor, Nab3, is targeted to intranuclear granules in response to glucose starvation by Nab3’s proline/glutamine-rich, prion-like domain (PrLD) which can assemble into amyloid in vitro. Localization to the granule is reversible and sensitive to the chemical probe 1,6 hexanediol suggesting condensation is driven by phase separation. Nab3’s RNA recognition motif is also required for localization as seen for other PrLD-containing RNA-binding proteins that phase separate. Although the PrLD is necessary, it is not sufficient to localize to the granule. A heterologous PrLD that functionally replaces Nab3’s essential PrLD, directed localization to the nuclear granule, however a chimeric Nab3 molecule with a heterologous PrLD that cannot restore termination function or viability, does not form granules. The Nab3 nuclear granule shows properties similar to well characterized cytoplasmic compartments formed by phase separation, suggesting that, as seen for other elements of the transcription machinery, termination factor condensation is functionally important.
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37
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Kufel J, Grzechnik P. Small Nucleolar RNAs Tell a Different Tale. Trends Genet 2018; 35:104-117. [PMID: 30563726 DOI: 10.1016/j.tig.2018.11.005] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 11/16/2018] [Accepted: 11/21/2018] [Indexed: 12/21/2022]
Abstract
Transcribing RNA Polymerase II interacts with multiple factors that orchestrate maturation and stabilisation of messenger RNA. For the majority of noncoding RNAs, the polymerase complex employs entirely different strategies, which usually direct the nascent transcript to ribonucleolytic degradation. However, some noncoding RNA classes use endo- and exonucleases to achieve functionality. Here we review processing of small nucleolar RNAs that are transcribed by RNA Polymerase II as precursors, and whose 5' and 3' ends undergo processing to release mature, functional molecules. The maturation strategies of these noncoding RNAs in various organisms follow a similar pattern but employ different factors and are strictly correlated with genomic organisation of their genes.
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Affiliation(s)
- Joanna Kufel
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Pawel Grzechnik
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
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38
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Ji D, Manavski N, Meurer J, Zhang L, Chi W. Regulated chloroplast transcription termination. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1860:69-77. [PMID: 30414934 DOI: 10.1016/j.bbabio.2018.11.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 10/15/2018] [Accepted: 11/07/2018] [Indexed: 11/16/2022]
Abstract
Transcription termination by the RNA polymerase (RNAP) is a fundamental step of gene expression that involves the release of the nascent transcript and dissociation of the RNAP from the DNA template. However, the functional importance of termination extends beyond the mere definition of the gene borders. Chloroplasts originate from cyanobacteria and possess their own gene expression system. Plastids have a unique hybrid transcription system consisting of two different types of RNAPs of dissimilar phylogenetic origin together with several additional nuclear encoded components. Although the basic components involved in chloroplast transcription have been identified, little attention has been paid to the chloroplast transcription termination. Recent identification and functional characterization of novel factors in regulating transcription termination in Arabidopsis chloroplasts via genetic and biochemical approaches have provided insights into the mechanisms and significance of transcription termination in chloroplast gene expression. This review provides an overview of the current knowledge of the transcription termination in chloroplasts.
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Affiliation(s)
- Daili Ji
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Nikolay Manavski
- Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Moleculaire des Plantes, 12 rue du General Zimmer, 67084 Strasbourg, France
| | - Jörg Meurer
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-University Munich, D-82152 Planegg-Martinsried, Germany
| | - Lixin Zhang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Wei Chi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
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39
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Larochelle M, Robert MA, Hébert JN, Liu X, Matteau D, Rodrigue S, Tian B, Jacques PÉ, Bachand F. Common mechanism of transcription termination at coding and noncoding RNA genes in fission yeast. Nat Commun 2018; 9:4364. [PMID: 30341288 PMCID: PMC6195540 DOI: 10.1038/s41467-018-06546-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 08/30/2018] [Indexed: 11/09/2022] Open
Abstract
Termination of RNA polymerase II (RNAPII) transcription is a fundamental step of gene expression that is critical for determining the borders between genes. In budding yeast, termination at protein-coding genes is initiated by the cleavage/polyadenylation machinery, whereas termination of most noncoding RNA (ncRNA) genes occurs via the Nrd1-Nab3-Sen1 (NNS) pathway. Here, we find that NNS-like transcription termination is not conserved in fission yeast. Rather, genome-wide analyses show global recruitment of mRNA 3' end processing factors at the end of ncRNA genes, including snoRNAs and snRNAs, and that this recruitment coincides with high levels of Ser2 and Tyr1 phosphorylation on the RNAPII C-terminal domain. We also find that termination of mRNA and ncRNA transcription requires the conserved Ysh1/CPSF-73 and Dhp1/XRN2 nucleases, supporting widespread cleavage-dependent transcription termination in fission yeast. Our findings thus reveal that a common mode of transcription termination can produce functionally and structurally distinct types of polyadenylated and non-polyadenylated RNAs.
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Affiliation(s)
- Marc Larochelle
- Département de Biochimie, Université de Sherbrooke, Sherbrooke, QC, J1E4K8, Canada
| | - Marc-Antoine Robert
- Départment de Biologie, Université de Sherbrooke, Sherbrooke, QC, J1K2R1, Canada
| | - Jean-Nicolas Hébert
- Département de Biochimie, Université de Sherbrooke, Sherbrooke, QC, J1E4K8, Canada
| | - Xiaochuan Liu
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School and Rutgers Cancer Institute of New Jersey, Newark, NJ, 07103, USA
| | - Dominick Matteau
- Départment de Biologie, Université de Sherbrooke, Sherbrooke, QC, J1K2R1, Canada
| | - Sébastien Rodrigue
- Départment de Biologie, Université de Sherbrooke, Sherbrooke, QC, J1K2R1, Canada
| | - Bin Tian
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School and Rutgers Cancer Institute of New Jersey, Newark, NJ, 07103, USA
| | - Pierre-Étienne Jacques
- Départment de Biologie, Université de Sherbrooke, Sherbrooke, QC, J1K2R1, Canada.
- Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, QC, J1H5N4, Canada.
| | - François Bachand
- Département de Biochimie, Université de Sherbrooke, Sherbrooke, QC, J1E4K8, Canada.
- Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, QC, J1H5N4, Canada.
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40
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Erickson B, Sheridan RM, Cortazar M, Bentley DL. Dynamic turnover of paused Pol II complexes at human promoters. Genes Dev 2018; 32:1215-1225. [PMID: 30150253 PMCID: PMC6120720 DOI: 10.1101/gad.316810.118] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/11/2018] [Indexed: 12/30/2022]
Abstract
Paused RNA polymerase II (Pol II) that piles up near most human promoters is the target of mechanisms that control entry into productive elongation. Whether paused Pol II is a stable or dynamic target remains unresolved. We report that most 5' paused Pol II throughout the genome is turned over within 2 min. This process is revealed under hypertonic conditions that prevent Pol II recruitment to promoters. This turnover requires cell viability but is not prevented by inhibiting transcription elongation, suggesting that it is mediated at the level of termination. When initiation was prevented by triptolide during recovery from high salt, a novel preinitiated state of Pol II lacking the pausing factor Spt5 accumulated at transcription start sites. We propose that Pol II occupancy near 5' ends is governed by a cycle of ongoing assembly of preinitiated complexes that transition to pause sites followed by eviction from the DNA template. This model suggests that mechanisms regulating the transition to productive elongation at pause sites operate on a dynamic population of Pol II that is turning over at rates far higher than previously suspected. We suggest that a plausible alternative to elongation control via escape from a stable pause is by escape from premature termination.
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Affiliation(s)
- Benjamin Erickson
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Ryan M Sheridan
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Michael Cortazar
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - David L Bentley
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
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41
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Lawson MR, Ma W, Bellecourt MJ, Artsimovitch I, Martin A, Landick R, Schulten K, Berger JM. Mechanism for the Regulated Control of Bacterial Transcription Termination by a Universal Adaptor Protein. Mol Cell 2018; 71:911-922.e4. [PMID: 30122535 DOI: 10.1016/j.molcel.2018.07.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/21/2018] [Accepted: 07/13/2018] [Indexed: 12/14/2022]
Abstract
NusG/Spt5 proteins are the only transcription factors utilized by all cellular organisms. In enterobacteria, NusG antagonizes the transcription termination activity of Rho, a hexameric helicase, during the synthesis of ribosomal and actively translated mRNAs. Paradoxically, NusG helps Rho act on untranslated transcripts, including non-canonical antisense RNAs and those arising from translational stress; how NusG fulfills these disparate functions is unknown. Here, we demonstrate that NusG activates Rho by assisting helicase isomerization from an open-ring, RNA-loading state to a closed-ring, catalytically active translocase. A crystal structure of closed-ring Rho in complex with NusG reveals the physical basis for this activation and further explains how Rho is excluded from translationally competent RNAs. This study demonstrates how a universally conserved transcription factor acts to modulate the activity of a ring-shaped ATPase motor and establishes how the innate sequence bias of a termination factor can be modulated to silence pervasive, aberrant transcription.
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Affiliation(s)
- Michael R Lawson
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Wen Ma
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science Technology, Urbana, IL 61801, USA; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Michael J Bellecourt
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Irina Artsimovitch
- Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Andreas Martin
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Klaus Schulten
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science Technology, Urbana, IL 61801, USA; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - James M Berger
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA; Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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42
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RNA Polymerase II Transcription Attenuation at the Yeast DNA Repair Gene, DEF1, Involves Sen1-Dependent and Polyadenylation Site-Dependent Termination. G3-GENES GENOMES GENETICS 2018; 8:2043-2058. [PMID: 29686108 PMCID: PMC5982831 DOI: 10.1534/g3.118.200072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Termination of RNA Polymerase II (Pol II) activity serves a vital cellular role by separating ubiquitous transcription units and influencing RNA fate and function. In the yeast Saccharomyces cerevisiae, Pol II termination is carried out by cleavage and polyadenylation factor (CPF-CF) and Nrd1-Nab3-Sen1 (NNS) complexes, which operate primarily at mRNA and non-coding RNA genes, respectively. Premature Pol II termination (attenuation) contributes to gene regulation, but there is limited knowledge of its prevalence and biological significance. In particular, it is unclear how much crosstalk occurs between CPF-CF and NNS complexes and how Pol II attenuation is modulated during stress adaptation. In this study, we have identified an attenuator in the DEF1 DNA repair gene, which includes a portion of the 5′-untranslated region (UTR) and upstream open reading frame (ORF). Using a plasmid-based reporter gene system, we conducted a genetic screen of 14 termination mutants and their ability to confer Pol II read-through defects. The DEF1 attenuator behaved as a hybrid terminator, relying heavily on CPF-CF and Sen1 but without Nrd1 and Nab3 involvement. Our genetic selection identified 22 cis-acting point mutations that clustered into four regions, including a polyadenylation site efficiency element that genetically interacts with its cognate binding-protein Hrp1. Outside of the reporter gene context, a DEF1 attenuator mutant increased mRNA and protein expression, exacerbating the toxicity of a constitutively active Def1 protein. Overall, our data support a biologically significant role for transcription attenuation in regulating DEF1 expression, which can be modulated during the DNA damage response.
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43
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H3K4 Methylation Dependent and Independent Chromatin Regulation by JHD2 and SET1 in Budding Yeast. G3-GENES GENOMES GENETICS 2018; 8:1829-1839. [PMID: 29599176 PMCID: PMC5940172 DOI: 10.1534/g3.118.200151] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Set1 and Jhd2 regulate the methylation state of histone H3 lysine-4 (H3K4me) through their opposing methyltransferase and demethylase activities in the budding yeast Saccharomyces cerevisiae. H3K4me associates with actively transcribed genes and, like both SET1 and JHD2 themselves, is known to regulate gene expression diversely. It remains unclear, however, if Set1 and Jhd2 act solely through H3K4me. Relevantly, Set1 methylates lysine residues in the kinetochore protein Dam1 while genetic studies of the S. pombe SET1 ortholog suggest the existence of non-H3K4 Set1 targets relevant to gene regulation. We interrogated genetic interactions of JHD2 and SET1 with essential genes involved in varied aspects of the transcription cycle. Our findings implicate JHD2 in genetic inhibition of the histone chaperone complexes Spt16-Pob3 (FACT) and Spt6-Spn1. This targeted screen also revealed that JHD2 inhibits the Nrd1-Nab3-Sen1 (NNS) transcription termination complex. We find that while Jhd2’s impact on these transcription regulatory complexes likely acts via H3K4me, Set1 governs the roles of FACT and NNS through opposing H3K4-dependent and -independent functions. We also identify diametrically opposing consequences for mutation of H3K4 to alanine or arginine, illuminating that caution must be taken in interpreting histone mutation studies. Unlike FACT and NNS, detailed genetic studies suggest an H3K4me-centric mode of Spt6-Spn1 regulation by JHD2 and SET1. Chromatin immunoprecipitation and transcript quantification experiments show that Jhd2 opposes the positioning of a Spt6-deposited nucleosome near the transcription start site of SER3, a Spt6-Spn1 regulated gene, leading to hyper-induction of SER3. In addition to confirming and extending an emerging role for Jhd2 in the control of nucleosome occupancy near transcription start sites, our findings suggest some of the chromatin regulatory functions of Set1 are independent of H3K4 methylation.
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44
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Mischo HE, Chun Y, Harlen KM, Smalec BM, Dhir S, Churchman LS, Buratowski S. Cell-Cycle Modulation of Transcription Termination Factor Sen1. Mol Cell 2018; 70:312-326.e7. [PMID: 29656924 PMCID: PMC5919780 DOI: 10.1016/j.molcel.2018.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 06/26/2017] [Accepted: 03/08/2018] [Indexed: 01/14/2023]
Abstract
Many non-coding transcripts (ncRNA) generated by RNA polymerase II in S. cerevisiae are terminated by the Nrd1-Nab3-Sen1 complex. However, Sen1 helicase levels are surprisingly low compared with Nrd1 and Nab3, raising questions regarding how ncRNA can be terminated in an efficient and timely manner. We show that Sen1 levels increase during the S and G2 phases of the cell cycle, leading to increased termination activity of NNS. Overexpression of Sen1 or failure to modulate its abundance by ubiquitin-proteasome-mediated degradation greatly decreases cell fitness. Sen1 toxicity is suppressed by mutations in other termination factors, and NET-seq analysis shows that its overexpression leads to a decrease in ncRNA production and altered mRNA termination. We conclude that Sen1 levels are carefully regulated to prevent aberrant termination. We suggest that ncRNA levels and coding gene transcription termination are modulated by Sen1 to fulfill critical cell cycle-specific functions. Transcription termination factor Sen1 levels fluctuate throughout the cell cycle APC targets Sen1 for degradation during G1 Reduced Sen1 levels lower efficiency of Sen1-mediated termination Sen1 overexpression reduces cell viability because of excessive termination
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Affiliation(s)
- Hannah E Mischo
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Sir William Dunn School of Pathology, Oxford University, South Parks Road, Oxford OX1 3RE, UK; Mechanisms of Transcription Laboratory, Clare Hall Laboratories, Cancer Research UK London Research Institute, South Mimms EN6 3LD, UK.
| | - Yujin Chun
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Kevin M Harlen
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Brendan M Smalec
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Somdutta Dhir
- Sir William Dunn School of Pathology, Oxford University, South Parks Road, Oxford OX1 3RE, UK
| | | | - Stephen Buratowski
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
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45
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Abstract
The nuclear RNA exosome is an essential and versatile machinery that regulates maturation and degradation of a huge plethora of RNA species. The past two decades have witnessed remarkable progress in understanding the whole picture of its RNA substrates and the structural basis of its functions. In addition to the exosome itself, recent studies focusing on associated co-factors have been elucidating how the exosome is directed towards specific substrates. Moreover, it has been gradually realized that loss-of-function of exosome subunits affect multiple biological processes such as the DNA damage response, R-loop resolution, maintenance of genome integrity, RNA export, translation and cell differentiation. In this review, we summarize the current knowledge of the mechanisms of nuclear exosome-mediated RNA metabolism and discuss their physiological significance.
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46
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Eaton JD, Davidson L, Bauer DLV, Natsume T, Kanemaki MT, West S. Xrn2 accelerates termination by RNA polymerase II, which is underpinned by CPSF73 activity. Genes Dev 2018; 32:127-139. [PMID: 29432121 PMCID: PMC5830926 DOI: 10.1101/gad.308528.117] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 01/05/2018] [Indexed: 12/31/2022]
Abstract
In this study, Eaton et al. use a new gene-editing approach to delineate the mechanism by which RNA polymerase II terminates. They generated human cell lines from which the 5′-to-3′ exoribonuclease Xrn2 or the poly(A) signal endoribonuclease CPSF73 can be rapidly controlled and show that efficient termination on most protein-coding genes involves CPSF73-mediated RNA cleavage and cotranscriptional degradation of polymerase-associated RNA by Xrn2. Termination is a ubiquitous phase in every transcription cycle but is incompletely understood and a subject of debate. We used gene editing as a new approach to address its mechanism through engineered conditional depletion of the 5′ → 3′ exonuclease Xrn2 or the polyadenylation signal (PAS) endonuclease CPSF73 (cleavage and polyadenylation specificity factor 73). The ability to rapidly control Xrn2 reveals a clear and general role for it in cotranscriptional degradation of 3′ flanking region RNA and transcriptional termination. This defect is characterized genome-wide at high resolution using mammalian native elongating transcript sequencing (mNET-seq). An Xrn2 effect on termination requires prior RNA cleavage, and we provide evidence for this by showing that catalytically inactive CPSF73 cannot restore termination to cells lacking functional CPSF73. Notably, Xrn2 plays no significant role in either Histone or small nuclear RNA (snRNA) gene termination even though both RNA classes undergo 3′ end cleavage. In sum, efficient termination on most protein-coding genes involves CPSF73-mediated RNA cleavage and cotranscriptional degradation of polymerase-associated RNA by Xrn2. However, as CPSF73 loss caused more extensive readthrough transcription than Xrn2 elimination, it likely plays a more underpinning role in termination.
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Affiliation(s)
- Joshua D Eaton
- The Living Systems Institute, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Lee Davidson
- The Living Systems Institute, University of Exeter, Exeter EX4 4QD, United Kingdom.,Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - David L V Bauer
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Toyoaki Natsume
- Division of Molecular Cell Engineering, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Mishima, Shizuoka 411-8540, Japan.,Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka 411-8540, Japan
| | - Masato T Kanemaki
- Division of Molecular Cell Engineering, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Mishima, Shizuoka 411-8540, Japan.,Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka 411-8540, Japan
| | - Steven West
- The Living Systems Institute, University of Exeter, Exeter EX4 4QD, United Kingdom
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47
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Candelli T, Challal D, Briand JB, Boulay J, Porrua O, Colin J, Libri D. High-resolution transcription maps reveal the widespread impact of roadblock termination in yeast. EMBO J 2018; 37:embj.201797490. [PMID: 29351914 DOI: 10.15252/embj.201797490] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 01/04/2023] Open
Abstract
Transcription termination delimits transcription units but also plays important roles in limiting pervasive transcription. We have previously shown that transcription termination occurs when elongating RNA polymerase II (RNAPII) collides with the DNA-bound general transcription factor Reb1. We demonstrate here that many different DNA-binding proteins can induce termination by a similar roadblock (RB) mechanism. We generated high-resolution transcription maps by the direct detection of RNAPII upon nuclear depletion of two essential RB factors or when the canonical termination pathways for coding and non-coding RNAs are defective. We show that RB termination occurs genomewide and functions independently of (and redundantly with) the main transcription termination pathways. We provide evidence that transcriptional readthrough at canonical terminators is a significant source of pervasive transcription, which is controlled to a large extent by RB termination. Finally, we demonstrate the occurrence of RB termination around centromeres and tRNA genes, which we suggest shields these regions from RNAPII to preserve their functional integrity.
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Affiliation(s)
- Tito Candelli
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Paris, France.,Ecole doctorale Structure et Dynamique des Systèmes Vivants, Université Paris Saclay, Gif sur Yvette, France
| | - Drice Challal
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Paris, France.,Ecole doctorale Structure et Dynamique des Systèmes Vivants, Université Paris Saclay, Gif sur Yvette, France
| | - Jean-Baptiste Briand
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Paris, France.,Ecole doctorale Structure et Dynamique des Systèmes Vivants, Université Paris Saclay, Gif sur Yvette, France
| | - Jocelyne Boulay
- Institut de Biologie Intégrative de la Cellule (I2BC), CNRS, UMR 9198, Univ Paris-Saclay, Centre Energie Atomique, Gif sur Yvette, France
| | - Odil Porrua
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Paris, France
| | - Jessie Colin
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Paris, France
| | - Domenico Libri
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Paris, France
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48
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Iasillo C, Schmid M, Yahia Y, Maqbool MA, Descostes N, Karadoulama E, Bertrand E, Andrau JC, Jensen TH. ARS2 is a general suppressor of pervasive transcription. Nucleic Acids Res 2017; 45:10229-10241. [PMID: 28973446 PMCID: PMC5622339 DOI: 10.1093/nar/gkx647] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 07/18/2017] [Indexed: 01/06/2023] Open
Abstract
Termination of transcription is important for establishing gene punctuation marks. It is also critical for suppressing many of the pervasive transcription events occurring throughout eukaryotic genomes and coupling their RNA products to efficient decay. In human cells, the ARS2 protein has been implicated in such function as its depletion causes transcriptional read-through of selected gene terminators and because it physically interacts with the ribonucleolytic nuclear RNA exosome. Here, we study the role of ARS2 on transcription and RNA metabolism genome wide. We show that ARS2 depletion negatively impacts levels of promoter-proximal RNA polymerase II at protein-coding (pc) genes. Moreover, our results reveal a general role of ARS2 in transcription termination-coupled RNA turnover at short transcription units like snRNA-, replication-dependent histone-, promoter upstream transcript- and enhancer RNA-loci. Depletion of the ARS2 interaction partner ZC3H18 mimics the ARS2 depletion, although to a milder extent, whereas depletion of the exosome core subunit RRP40 only impacts RNA abundance post-transcriptionally. Interestingly, ARS2 is also involved in transcription termination events within first introns of pc genes. Our work therefore establishes ARS2 as a general suppressor of pervasive transcription with the potential to regulate pc gene expression.
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Affiliation(s)
- Claudia Iasillo
- Department of Molecular Biology and Genetics, Aarhus University, C. F. M⊘llers Allé 3, Building 1130, DK-8000 Aarhus C, Denmark.,IGMM, CNRS, Univ. Montpellier, 34293 Montpellier, Cedex 5, France
| | - Manfred Schmid
- Department of Molecular Biology and Genetics, Aarhus University, C. F. M?llers Allé 3, Building 1130, DK-8000 Aarhus C, Denmark
| | - Yousra Yahia
- IGMM, CNRS, Univ. Montpellier, 34293 Montpellier, Cedex 5, France
| | | | - Nicolas Descostes
- IGMM, CNRS, Univ. Montpellier, 34293 Montpellier, Cedex 5, France.,Howard Hughes Medical Institute, New York, NY 10016, USA.,Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Evdoxia Karadoulama
- Department of Molecular Biology and Genetics, Aarhus University, C. F. M?llers Allé 3, Building 1130, DK-8000 Aarhus C, Denmark
| | - Edouard Bertrand
- IGMM, CNRS, Univ. Montpellier, 34293 Montpellier, Cedex 5, France
| | | | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, C. F. M?llers Allé 3, Building 1130, DK-8000 Aarhus C, Denmark
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49
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Abstract
Numerous surveillance pathways sculpt eukaryotic transcriptomes by degrading unneeded, defective, and potentially harmful noncoding RNAs (ncRNAs). Because aberrant and excess ncRNAs are largely degraded by exoribonucleases, a key characteristic of these RNAs is an accessible, protein-free 5' or 3' end. Most exoribonucleases function with cofactors that recognize ncRNAs with accessible 5' or 3' ends and/or increase the availability of these ends. Noncoding RNA surveillance pathways were first described in budding yeast, and there are now high-resolution structures of many components of the yeast pathways and significant mechanistic understanding as to how they function. Studies in human cells are revealing the ways in which these pathways both resemble and differ from their yeast counterparts, and are also uncovering numerous pathways that lack equivalents in budding yeast. In this review, we describe both the well-studied pathways uncovered in yeast and the new concepts that are emerging from studies in mammalian cells. We also discuss the ways in which surveillance pathways compete with chaperone proteins that transiently protect nascent ncRNA ends from exoribonucleases, with partner proteins that sequester these ends within RNPs, and with end modification pathways that protect the ends of some ncRNAs from nucleases.
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Affiliation(s)
- Cedric Belair
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute , National Institutes of Health , Frederick , Maryland 21702 , United States
| | - Soyeong Sim
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute , National Institutes of Health , Frederick , Maryland 21702 , United States
| | - Sandra L Wolin
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute , National Institutes of Health , Frederick , Maryland 21702 , United States
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50
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Han Z, Porrua O. Helicases as transcription termination factors: Different solutions for a common problem. Transcription 2017; 9:152-158. [PMID: 28886303 DOI: 10.1080/21541264.2017.1361503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Helicases are enzymes that remodel nucleic acids or protein-nucleic acid complexes in an ATP-dependent manner. They are ubiquitous and can play many diverse functions related to the metabolism of nucleic acids. A few helicases from both the prokaryotic and the eukaryotic worlds have the ability to induce transcription termination. Here we discuss how the same biological function is achieved by different helicases with quite divergent structures and mechanisms of action.
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Affiliation(s)
- Zhong Han
- a Institut Jacques Monod, Centre Nationale pour la Recherche Scientifique (CNRS), UMR 7592, Université Paris Diderot, Sorbonne Paris Cité , Paris , France.,b Université Paris-Saclay , Gif sur Yvette , France
| | - Odil Porrua
- a Institut Jacques Monod, Centre Nationale pour la Recherche Scientifique (CNRS), UMR 7592, Université Paris Diderot, Sorbonne Paris Cité , Paris , France
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