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Hien EDM, Chauvier A, St-Pierre P, Lafontaine DA. Structural Characterization of the Cotranscriptional Folding of the Thiamin Pyrophosphate Sensing thiC Riboswitch in Escherichia coli. Biochemistry 2024; 63:1608-1620. [PMID: 38864595 DOI: 10.1021/acs.biochem.3c00665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
Riboswitches are RNA-regulating elements that mostly rely on structural changes to modulate gene expression at various levels. Recent studies have revealed that riboswitches may control several regulatory mechanisms cotranscriptionally, i.e., during the transcription elongation of the riboswitch or early in the coding region of the regulated gene. Here, we study the structure of the nascent thiamin pyrophosphate (TPP)-sensing thiC riboswitch in Escherichia coli by using biochemical and enzymatic conventional probing approaches. Our chemical (in-line and lead probing) and enzymatic (nucleases S1, A, T1, and RNase H) probing data provide a comprehensive model of how TPP binding modulates the structure of the thiC riboswitch. Furthermore, by using transcriptional roadblocks along the riboswitch sequence, we find that a certain portion of nascent RNA is needed to sense TPP that coincides with the formation of the P5 stem loop. Together, our data suggest that conventional techniques may readily be used to study cotranscriptional folding of nascent RNAs.
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Affiliation(s)
- Elsa D M Hien
- Department of Biology, Faculty of Science, RNA Group, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
| | - Adrien Chauvier
- Department of Biology, Faculty of Science, RNA Group, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
| | - Patrick St-Pierre
- Department of Biology, Faculty of Science, RNA Group, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
| | - Daniel A Lafontaine
- Department of Biology, Faculty of Science, RNA Group, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
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2
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Giudice J, Jiang H. Splicing regulation through biomolecular condensates and membraneless organelles. Nat Rev Mol Cell Biol 2024:10.1038/s41580-024-00739-7. [PMID: 38773325 DOI: 10.1038/s41580-024-00739-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2024] [Indexed: 05/23/2024]
Abstract
Biomolecular condensates, sometimes also known as membraneless organelles (MLOs), can form through weak multivalent intermolecular interactions of proteins and nucleic acids, a process often associated with liquid-liquid phase separation. Biomolecular condensates are emerging as sites and regulatory platforms of vital cellular functions, including transcription and RNA processing. In the first part of this Review, we comprehensively discuss how alternative splicing regulates the formation and properties of condensates, and conversely the roles of biomolecular condensates in splicing regulation. In the second part, we focus on the spatial connection between splicing regulation and nuclear MLOs such as transcriptional condensates, splicing condensates and nuclear speckles. We then discuss key studies showing how splicing regulation through biomolecular condensates is implicated in human pathologies such as neurodegenerative diseases, different types of cancer, developmental disorders and cardiomyopathies, and conclude with a discussion of outstanding questions pertaining to the roles of condensates and MLOs in splicing regulation and how to experimentally study them.
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Affiliation(s)
- Jimena Giudice
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- McAllister Heart Institute, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Hao Jiang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA.
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3
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Kataoka N. The Nuclear Cap-Binding Complex, a multitasking binding partner of RNA polymerase II transcripts. J Biochem 2023; 175:9-15. [PMID: 37830942 PMCID: PMC10771035 DOI: 10.1093/jb/mvad081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/26/2023] [Accepted: 10/03/2023] [Indexed: 10/14/2023] Open
Abstract
In eukaryotic cells, RNAs transcribed by RNA polymerase-II receive the modification at the 5' end. This structure is called the cap structure. The cap structure has a fundamental role for translation initiation by recruiting eukaryotic translation initiation factor 4F (eIF4F). The other important mediator of the cap structure is a nuclear cap-binding protein complex (CBC). CBC consists of two proteins, which are renamed as NCBP1 and NCBP2 (previously called as CBP80/NCBP and CBP20/NIP1, respectively). This review article discusses the multiple roles CBC mediates and co-ordinates in several gene expression steps in eukaryotes.
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Affiliation(s)
- Naoyuki Kataoka
- Laboratory of Cellular Biochemistry, Department of Animal Resource Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Agriculture Bldg. 7A, Room 703, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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4
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Keller SH, Deng H, Lim B. Regulation of the dynamic RNA Pol II elongation rate in Drosophila embryos. Cell Rep 2023; 42:113225. [PMID: 37837623 PMCID: PMC10842316 DOI: 10.1016/j.celrep.2023.113225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/20/2023] [Accepted: 09/22/2023] [Indexed: 10/16/2023] Open
Abstract
An increasing number of studies have shown the key role that RNA polymerase II (RNA Pol II) elongation plays in gene regulation. We systematically examine how various enhancers, promoters, and gene body composition influence the RNA Pol II elongation rate through a single-cell-resolution live imaging assay. By using reporter constructs containing 5' MS2 and 3' PP7 repeating stem loops, we quantify the rate of RNA Pol II elongation in live Drosophila embryos. We find that promoters and exonic gene lengths have no effect on elongation rate, while enhancers and the presence of long introns may significantly change how quickly RNA Pol II moves across a gene. Furthermore, we observe in multiple constructs that the RNA Pol II elongation rate accelerates after the transcriptional onset of nuclear cycle 14 in Drosophila embryos. Our study provides a single-cell view of various mechanisms that affect the dynamic RNA Pol II elongation rate, ultimately affecting the rate of mRNA production.
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Affiliation(s)
- Samuel H Keller
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hao Deng
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bomyi Lim
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
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5
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Weaver JW, Proshkin S, Duan W, Epshtein V, Gowder M, Bharati BK, Afanaseva E, Mironov A, Serganov A, Nudler E. Control of transcription elongation and DNA repair by alarmone ppGpp. Nat Struct Mol Biol 2023; 30:600-607. [PMID: 36997761 PMCID: PMC10191844 DOI: 10.1038/s41594-023-00948-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/27/2023] [Indexed: 04/01/2023]
Abstract
Second messenger (p)ppGpp (collectively guanosine tetraphosphate and guanosine pentaphosphate) mediates bacterial adaptation to nutritional stress by modulating transcription initiation. More recently, ppGpp has been implicated in coupling transcription and DNA repair; however, the mechanism of ppGpp engagement remained elusive. Here we present structural, biochemical and genetic evidence that ppGpp controls Escherichia coli RNA polymerase (RNAP) during elongation via a specific site that is nonfunctional during initiation. Structure-guided mutagenesis renders the elongation (but not initiation) complex unresponsive to ppGpp and increases bacterial sensitivity to genotoxic agents and ultraviolet radiation. Thus, ppGpp binds RNAP at sites with distinct functions in initiation and elongation, with the latter being important for promoting DNA repair. Our data provide insights on the molecular mechanism of ppGpp-mediated adaptation during stress, and further highlight the intricate relationships between genome stability, stress responses and transcription.
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Affiliation(s)
- Jacob W Weaver
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Sergey Proshkin
- Engelhardt Institute of Molecular Biology, Russian Academy of Science, Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Moscow, Russia
| | - Wenqian Duan
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Vitaly Epshtein
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Manjunath Gowder
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY, USA
| | - Binod K Bharati
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY, USA
| | - Elena Afanaseva
- Engelhardt Institute of Molecular Biology, Russian Academy of Science, Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Moscow, Russia
| | - Alexander Mironov
- Engelhardt Institute of Molecular Biology, Russian Academy of Science, Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Moscow, Russia
| | - Alexander Serganov
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA.
| | - Evgeny Nudler
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA.
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY, USA.
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6
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Zhao F, Xue M, Zhang H, Li H, Zhao T, Jiang D. Coordinated histone variant H2A.Z eviction and H3.3 deposition control plant thermomorphogenesis. THE NEW PHYTOLOGIST 2023; 238:750-764. [PMID: 36647799 DOI: 10.1111/nph.18738] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 01/11/2023] [Indexed: 06/17/2023]
Abstract
Plants can sense temperature changes and adjust their development and morphology accordingly in a process called thermomorphogenesis. This phenotypic plasticity implies complex mechanisms regulating gene expression reprogramming in response to environmental alteration. Histone variants often associate with specific chromatin states; yet, how their deposition/eviction modulates transcriptional changes induced by environmental cues remains elusive. In Arabidopsis thaliana, temperature elevation-induced transcriptional activation at thermo-responsive genes entails the chromatin eviction of a histone variant H2A.Z by INO80, which is recruited to these loci via interacting with a key thermomorphogenesis regulator PIF4. Here, we show that both INO80 and the deposition chaperones of another histone variant H3.3 associate with ELF7, a critical component of the transcription elongator PAF1 complex. H3.3 promotes thermomorphogenesis and the high temperature-enhanced RNA Pol II transcription at PIF4 targets, and it is broadly required for the H2A.Z removal-induced gene activation. Reciprocally, INO80 and ELF7 regulate H3.3 deposition, and are necessary for the high temperature-induced H3.3 enrichment at PIF4 targets. Our findings demonstrate close coordination between H2A.Z eviction and H3.3 deposition in gene activation induced by high temperature, and pinpoint the importance of histone variants dynamics in transcriptional regulation.
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Affiliation(s)
- Fengyue Zhao
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Mande Xue
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Huairen Zhang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hui Li
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Ting Zhao
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Danhua Jiang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
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7
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Boumpas P, Merabet S, Carnesecchi J. Integrating transcription and splicing into cell fate: Transcription factors on the block. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1752. [PMID: 35899407 DOI: 10.1002/wrna.1752] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/22/2022] [Accepted: 07/01/2022] [Indexed: 11/10/2022]
Abstract
Transcription factors (TFs) are present in all life forms and conserved across great evolutionary distances in eukaryotes. From yeast to complex multicellular organisms, they are pivotal players of cell fate decision by orchestrating gene expression at diverse molecular layers. Notably, TFs fine-tune gene expression by coordinating RNA fate at both the expression and splicing levels. They regulate alternative splicing, an essential mechanism for cell plasticity, allowing the production of many mRNA and protein isoforms in precise cell and tissue contexts. Despite this apparent role in splicing, how TFs integrate transcription and splicing to ultimately orchestrate diverse cell functions and cell fate decisions remains puzzling. We depict substantial studies in various model organisms underlining the key role of TFs in alternative splicing for promoting tissue-specific functions and cell fate. Furthermore, we emphasize recent advances describing the molecular link between the transcriptional and splicing activities of TFs. As TFs can bind both DNA and/or RNA to regulate transcription and splicing, we further discuss their flexibility and compatibility for DNA and RNA substrates. Finally, we propose several models integrating transcription and splicing activities of TFs in the coordination and diversification of cell and tissue identities. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA Processing > Splicing Mechanisms.
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Affiliation(s)
- Panagiotis Boumpas
- Institut de Génomique Fonctionnelle de Lyon, UMR5242, Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard-Lyon 1, Lyon, France
| | - Samir Merabet
- Institut de Génomique Fonctionnelle de Lyon, UMR5242, Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard-Lyon 1, Lyon, France
| | - Julie Carnesecchi
- Institut de Génomique Fonctionnelle de Lyon, UMR5242, Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard-Lyon 1, Lyon, France
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8
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Mitra P, Banerjee S, Khandavalli C, Deshmukh AS. The role of Toxoplasma TFIIS-like protein in the early stages of mRNA transcription. Biochim Biophys Acta Gen Subj 2022; 1866:130240. [PMID: 36058424 DOI: 10.1016/j.bbagen.2022.130240] [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: 06/24/2022] [Revised: 08/25/2022] [Accepted: 08/28/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND The mRNA transcription is a multistep process involving distinct sets of proteins associated with RNA polymerase II (RNAPII) through various stages. Recent studies have highlighted the role of RNAPII-associated proteins in facilitating the assembly of functional complexes in a crowded nuclear milieu. RNAPII dynamics and gene expression regulation have been primarily studied in model eukaryotes like yeasts and mammals and remain largely unchartered in protozoan parasites like Toxoplasma gondii, where considerable gene expression changes accompany stage differentiations. Here we report a key modulator of RNAPII activity, TFIIS in Toxoplasma gondii (TgTFIIS). METHODS A Pull-down assay demonstrated that TgTFIIS binds to RNAPII subunit TgRPB1. Truncation mutants of TFIIS help us define the regions critical for its binding to TgRPB1. Co-immunoprecipitation analysis confirmed the interaction between the native TgTFIIS and TgRPB1. Confocal microscopy revealed a predominantly nuclear localization. Native TgTFIIS was able to bind promoter DNA which was consistent with the CHIP results. RESULTS TgTFIIS complements initiation defects in yeast mutants, and the regions implicated in RNAPII binding appeared essential for this function. Interestingly, the C-terminal zinc finger domain necessary for its potential elongation function is dispensable for TgRPB1 binding. TgTFIIS was found to be associated with the promoter region along with its association with the ORF on an RNAPII transcribed gene. CONCLUSION The observations were in line with the potential role of TgTFIIS in early events of RNAPII transcription in addition to elongation. GENERAL SIGNIFICANCE The study elucidates the potential role of RNAPII-associated proteins in multiple steps of transcription.
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Affiliation(s)
- Pallabi Mitra
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, India.
| | - Sneha Banerjee
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Chittiraju Khandavalli
- DBT-National Institute of Animal Biotechnology, Hyderabad, India; Dept. of Graduate Studies, Regional Centre for Biotechnology, Faridabad, Haryana, India
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9
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Zhang H, Li X, Song R, Zhan Z, Zhao F, Li Z, Jiang D. Cap-binding complex assists RNA polymerase II transcription in plant salt stress response. PLANT, CELL & ENVIRONMENT 2022; 45:2780-2793. [PMID: 35773782 DOI: 10.1111/pce.14388] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/14/2022] [Accepted: 06/17/2022] [Indexed: 06/15/2023]
Abstract
Adaptive response to stress involves an extensive reprogramming of gene expression. Under stressful conditions, the induction of efficient changes in messenger RNA (mRNA) production is crucial for maximized plant survival. Transcription and pre-mRNA processing are two closely related steps in mRNA biogenesis, yet how they are controlled in plant stress response remains elusive. Here, we show that the Arabidopsis nuclear cap-binding complex (CBC) component CBP20 directly interacts with ELF7, a subunit of the transcription elongation factor RNA Pol II-associated factor 1 complex (PAF1c) to promote RNA Pol II transcription in plant response to salt stress. CBP20 and ELF7 coregulate the expression of a large number of genes including those crucial for salt tolerance. Both CBP20 and ELF7 are required for enhanced RNA Pol II elongation at salt-activated genes. Though CBP20 also regulates intron splicing, this function is largely independent of ELF7. Our study reveals the function of an RNA processing regulator CBC in assisting efficient RNA Pol II transcription and pinpoints the complex roles of CBC on mRNA production in plant salt stress resistance.
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Affiliation(s)
- Huairen Zhang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Xiaoyi Li
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ruitian Song
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhenping Zhan
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Fengyue Zhao
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zicong Li
- Ministry of Education Key Laboratory of Plant Development and Environmental Adaption Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Danhua Jiang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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10
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The Role of RNA-Binding Proteins in Hematological Malignancies. Int J Mol Sci 2022; 23:ijms23179552. [PMID: 36076951 PMCID: PMC9455611 DOI: 10.3390/ijms23179552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/18/2022] [Accepted: 08/21/2022] [Indexed: 11/17/2022] Open
Abstract
Hematological malignancies comprise a plethora of different neoplasms, such as leukemia, lymphoma, and myeloma, plus a myriad of dysplasia, such as myelodysplastic syndromes or anemias. Despite all the advances in patient care and the development of new therapies, some of these malignancies remain incurable, mainly due to resistance and refractoriness to treatment. Therefore, there is an unmet clinical need to identify new biomarkers and potential therapeutic targets that play a role in treatment resistance and contribute to the poor outcomes of these tumors. RNA-binding proteins (RBPs) are a diverse class of proteins that interact with transcripts and noncoding RNAs and are involved in every step of the post-transcriptional processing of transcripts. Dysregulation of RBPs has been associated with the development of hematological malignancies, making them potential valuable biomarkers and potential therapeutic targets. Although a number of dysregulated RBPs have been identified in hematological malignancies, there is a critical need to understand the biology underlying their contribution to pathology, such as the spatiotemporal context and molecular mechanisms involved. In this review, we emphasize the importance of deciphering the regulatory mechanisms of RBPs to pinpoint novel therapeutic targets that could drive or contribute to hematological malignancy biology.
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11
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Transcription associated cyclin-dependent kinases as therapeutic targets for prostate cancer. Oncogene 2022; 41:3303-3315. [PMID: 35568739 PMCID: PMC9187515 DOI: 10.1038/s41388-022-02347-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/21/2022] [Accepted: 05/04/2022] [Indexed: 11/08/2022]
Abstract
Transcriptional deregulation has emerged as a hallmark of several cancer types. In metastatic castration-resistant prostate cancer, a stage in which systemic androgen deprivation therapies fail to show clinical benefit, transcriptional addiction to the androgen receptor is maintained in most patients. This has led to increased efforts to find novel therapies that prevent oncogenic transactivation of the androgen receptor. In this context, a group of druggable protein kinases, known as transcription associated cyclin-dependent kinases (tCDKs), show great potential as therapeutic targets. Despite initial reservations about targeting tCDKs due to their ubiquitous and prerequisite nature, preclinical studies showed that selectively inhibiting such kinases could provide sufficient therapeutic window to exert antitumour effects in the absence of systemic toxicity. As a result, several highly specific inhibitors are currently being trialled in solid tumours, including prostate cancer. This article summarises the roles of tCDKs in regulating gene transcription and highlights rationales for their targeting in prostate cancer. It provides an overview of the most recent developments in this therapeutic area, including the most recent clinical advances, and discusses the utility of tCDK inhibitors in combination with established cancer agents.
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12
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Kwon B, Fansler MM, Patel ND, Lee J, Ma W, Mayr C. Enhancers regulate 3' end processing activity to control expression of alternative 3'UTR isoforms. Nat Commun 2022; 13:2709. [PMID: 35581194 PMCID: PMC9114392 DOI: 10.1038/s41467-022-30525-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 05/02/2022] [Indexed: 12/12/2022] Open
Abstract
Multi-UTR genes are widely transcribed and express their alternative 3'UTR isoforms in a cell type-specific manner. As transcriptional enhancers regulate mRNA expression, we investigated if they also regulate 3'UTR isoform expression. Endogenous enhancer deletion of the multi-UTR gene PTEN did not impair transcript production but prevented 3'UTR isoform switching which was recapitulated by silencing of an enhancer-bound transcription factor. In reporter assays, enhancers increase transcript production when paired with single-UTR gene promoters. However, when combined with multi-UTR gene promoters, they change 3'UTR isoform expression by increasing 3' end processing activity of polyadenylation sites. Processing activity of polyadenylation sites is affected by transcription factors, including NF-κB and MYC, transcription elongation factors, chromatin remodelers, and histone acetyltransferases. As endogenous cell type-specific enhancers are associated with genes that increase their short 3'UTRs in a cell type-specific manner, our data suggest that transcriptional enhancers integrate cellular signals to regulate cell type-and condition-specific 3'UTR isoform expression.
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Affiliation(s)
- Buki Kwon
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Mervin M Fansler
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Tri-Institutional Training Program in Computational Biology and Medicine, Weill Cornell Graduate College, New York, NY, 10021, USA
| | - Neil D Patel
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Jihye Lee
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Weirui Ma
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Christine Mayr
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
- Tri-Institutional Training Program in Computational Biology and Medicine, Weill Cornell Graduate College, New York, NY, 10021, USA.
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13
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Co-transcriptional splicing efficiency is a gene-specific feature that can be regulated by TGFβ. Commun Biol 2022; 5:277. [PMID: 35347226 PMCID: PMC8960766 DOI: 10.1038/s42003-022-03224-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 03/03/2022] [Indexed: 11/26/2022] Open
Abstract
Differential splicing efficiency of specific introns is a mechanism that dramatically increases protein diversity, based on selection of alternative exons for the final mature mRNA. However, it is unclear whether splicing efficiency of introns within the same gene is coordinated and eventually regulated as a mechanism to control mature mRNA levels. Based on nascent chromatin-associated RNA-sequencing data, we now find that co-transcriptional splicing (CTS) efficiency tends to be similar between the different introns of a gene. We establish that two well-differentiated strategies for CTS efficiency exist, at the extremes of a gradient: short genes that produce high levels of pre-mRNA undergo inefficient splicing, while long genes with relatively low levels of pre-mRNA have an efficient splicing. Notably, we observe that genes with efficient CTS display a higher level of mature mRNA relative to their pre-mRNA levels. Further, we show that the TGFβ signal transduction pathway regulates the general CTS efficiency, causing changes in mature mRNA levels. Taken together, our data indicate that CTS efficiency is a gene-specific characteristic that can be regulated to control gene expression. Co-transcriptional splicing efficiency is a gene-specific characteristic that can be regulated by TGFβ to modulate gene expression.
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14
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Vaasjo LO. LncRNAs and Chromatin Modifications Pattern m6A Methylation at the Untranslated Regions of mRNAs. Front Genet 2022; 13:866772. [PMID: 35368653 PMCID: PMC8968631 DOI: 10.3389/fgene.2022.866772] [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: 01/31/2022] [Accepted: 02/28/2022] [Indexed: 12/16/2022] Open
Abstract
New roles for RNA in mediating gene expression are being discovered at an alarming rate. A broad array of pathways control patterning of N6-methyladenosine (m6A) methylation on RNA transcripts. This review comprehensively discusses long non-coding RNAs (lncRNAs) as an additional dynamic regulator of m6A methylation, with a focus on the untranslated regions (UTRs) of mRNAs. Although there is extensive literature describing m6A modification of lncRNA, the function of lncRNA in guiding m6A writers has not been thoroughly explored. The independent control of lncRNA expression, its heterogeneous roles in RNA metabolism, and its interactions with epigenetic machinery, alludes to their potential in dynamic patterning of m6A methylation. While epigenetic regulation by histone modification of H3K36me3 has been demonstrated to pattern RNA m6A methylation, these modifications were specific to the coding and 3′UTR regions. However, there are observations that 5′UTR m6A is distinct from that of the coding and 3′UTR regions, and substantial evidence supports the active regulation of 5′UTR m6A methylation. Consequently, two potential mechanisms in patterning the UTRs m6A methylation are discussed; (1) Anti-sense lncRNA (AS-lncRNA) can either bind directly to the UTR, or (2) act indirectly via recruitment of chromatin-modifying complexes to pattern m6A. Both pathways can guide the m6A writer complex, facilitate m6A methylation and modulate protein translation. Findings in the lncRNA-histone-m6A axis could potentially contribute to the discovery of new functions of lncRNAs and clarify lncRNA-m6A findings in translational medicine.
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Affiliation(s)
- Lee O. Vaasjo
- Cellular and Molecular Biology, Tulane University, New Orleans, LA, United States
- Neuroscience Program, Brain Institute, Tulane University, New Orleans, LA, United States
- *Correspondence: Lee O. Vaasjo,
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15
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Control of non-productive RNA polymerase II transcription via its early termination in metazoans. Biochem Soc Trans 2022; 50:283-295. [PMID: 35166324 DOI: 10.1042/bst20201140] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/11/2022] [Accepted: 01/24/2022] [Indexed: 11/17/2022]
Abstract
Transcription establishes the universal first step of gene expression where RNA is produced by a DNA-dependent RNA polymerase. The most versatile of eukaryotic RNA polymerases, RNA polymerase II (Pol II), transcribes a broad range of DNA including protein-coding and a variety of non-coding transcription units. Although Pol II can be configured as a durable enzyme capable of transcribing hundreds of kilobases, there is reliable evidence of widespread abortive Pol II transcription termination shortly after initiation, which is often followed by rapid degradation of the associated RNA. The molecular details underlying this phenomenon are still vague but likely reflect the action of quality control mechanisms on the early Pol II complex. Here, we summarize current knowledge of how and when such promoter-proximal quality control is asserted on metazoan Pol II.
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16
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Maudlin IE, Beggs JD. Conditional depletion of transcriptional kinases Ctk1 and Bur1 and effects on co-transcriptional spliceosome assembly and pre-mRNA splicing. RNA Biol 2021; 18:782-793. [PMID: 34705599 PMCID: PMC8782173 DOI: 10.1080/15476286.2021.1991673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 09/21/2021] [Indexed: 11/28/2022] Open
Abstract
From yeast to humans, pre-mRNA splicing occurs mainly co-transcriptionally, with splicing and transcription functionally coupled such that they influence one another. The recruitment model of co-transcriptional splicing proposes that core members of the transcription elongation machinery have the potential to influence co-transcriptional spliceosome assembly and pre-mRNA splicing. Here, we tested whether the transcription elongation kinases Bur1 and Ctk1 affect co-transcriptional spliceosome assembly and pre-mRNA splicing in the budding yeast Saccharomyces cerevisiae. In S. cerevisiae, Ctk1 is the major kinase that phosphorylates serine 2 of the carboxy-terminal domain of the largest subunit of RNA polymerase II, whilst Bur1 augments the kinase activity of Ctk1 and is the major kinase for elongation factor Spt5. We used the auxin-inducible degron system to conditionally deplete Bur1 and Ctk1 kinases, and investigated the effects on co-transcriptional spliceosome assembly and pre-mRNA splicing. Depletion of Ctk1 effectively reduced phosphorylation of serine 2 of the carboxy-terminal domain but did not impact co-transcriptional spliceosome assembly or pre-mRNA splicing. In striking contrast, depletion of Bur1 did not reduce phosphorylation of serine 2 of the carboxy-terminal domain, but reduced Spt5 phosphorylation and enhanced co-transcriptional spliceosome assembly and pre-mRNA splicing, suggesting a role for this kinase in modulating co-transcriptional splicing.
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Affiliation(s)
- Isabella E. Maudlin
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Jean D. Beggs
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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17
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Abstract
Transcription of DNA into RNA is crucial to life, and understanding RNA polymerase (RNAP) function has received considerable attention. In contrast, how the nascent RNA folds into structures that impact transcription itself and regulate gene expression remains poorly understood. Here, we combine single-molecule Förster resonance energy transfer and site-specific fluorescent labelling of transcripts within native complexes to enable real-time cotranscriptional folding studies of a metabolite-sensing riboswitch from Escherichia coli. By monitoring the folding of riboswitches stalled at RNAP pausing sites and during active elongation, we reveal a crucial role for RNAP, which directs RNA folding to allow thiamin pyrophosphate sensing within a precise, transcriptional hotspot. Our approach offers a unique opportunity to unveil cotranscriptional processes in eukaryotic and bacterial systems. Cotranscriptional RNA folding is crucial for the timely control of biological processes, but because of its transient nature, its study has remained challenging. While single-molecule Förster resonance energy transfer (smFRET) is unique to investigate transient RNA structures, its application to cotranscriptional studies has been limited to nonnative systems lacking RNA polymerase (RNAP)–dependent features, which are crucial for gene regulation. Here, we present an approach that enables site-specific labeling and smFRET studies of kilobase-length transcripts within native bacterial complexes. By monitoring Escherichia coli nascent riboswitches, we reveal an inverse relationship between elongation speed and metabolite-sensing efficiency and show that pause sites upstream of the translation start codon delimit a sequence hotspot for metabolite sensing during transcription. Furthermore, we demonstrate a crucial role of the bacterial RNAP actively delaying the formation, within the hotspot sequence, of competing structures precluding metabolite binding. Our approach allows the investigation of cotranscriptional regulatory mechanisms in bacterial and eukaryotic elongation complexes.
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18
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Naro C, Bielli P, Sette C. Oncogenic dysregulation of pre-mRNA processing by protein kinases: challenges and therapeutic opportunities. FEBS J 2021; 288:6250-6272. [PMID: 34092037 PMCID: PMC8596628 DOI: 10.1111/febs.16057] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/13/2021] [Accepted: 06/04/2021] [Indexed: 12/12/2022]
Abstract
Alternative splicing and polyadenylation represent two major steps in pre-mRNA-processing, which ensure proper gene expression and diversification of human transcriptomes. Deregulation of these processes contributes to oncogenic programmes involved in the onset, progression and evolution of human cancers, which often result in the acquisition of resistance to existing therapies. On the other hand, cancer cells frequently increase their transcriptional rate and develop a transcriptional addiction, which imposes a high stress on the pre-mRNA-processing machinery and establishes a therapeutically exploitable vulnerability. A prominent role in fine-tuning pre-mRNA-processing mechanisms is played by three main families of protein kinases: serine arginine protein kinase (SRPK), CDC-like kinase (CLK) and cyclin-dependent kinase (CDK). These kinases phosphorylate the RNA polymerase, splicing factors and regulatory proteins involved in cleavage and polyadenylation of the nascent transcripts. The activity of SRPKs, CLKs and CDKs can be altered in cancer cells, and their inhibition was shown to exert anticancer effects. In this review, we describe key findings that have been reported on these topics and discuss challenges and opportunities of developing therapeutic approaches targeting splicing factor kinases.
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Affiliation(s)
- Chiara Naro
- Department of NeuroscienceSection of Human AnatomyCatholic University of the Sacred HeartRomeItaly
- Fondazione Policlinico Universitario A. GemelliIRCCSRomeItaly
| | - Pamela Bielli
- Department of Biomedicine and PreventionUniversity of Rome Tor VergataItaly
- Fondazione Santa LuciaIRCCSRomeItaly
| | - Claudio Sette
- Department of NeuroscienceSection of Human AnatomyCatholic University of the Sacred HeartRomeItaly
- Fondazione Santa LuciaIRCCSRomeItaly
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19
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DeJong CS, Dichmann DS, Exner CRT, Xu Y, Harland RM. The atypical RNA-binding protein Taf15 regulates dorsoanterior neural development through diverse mechanisms in Xenopus tropicalis. Development 2021; 148:271175. [PMID: 34345915 DOI: 10.1242/dev.191619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/08/2021] [Indexed: 11/20/2022]
Abstract
The FET family of atypical RNA-binding proteins includes Fused in sarcoma (FUS), Ewing's sarcoma (EWS) and the TATA-binding protein-associate factor 15 (TAF15). FET proteins are highly conserved, suggesting specialized requirements for each protein. Fus regulates splicing of transcripts required for mesoderm differentiation and cell adhesion in Xenopus, but the roles of Ews and Taf15 remain unknown. Here, we analyze the roles of maternally deposited and zygotically transcribed Taf15, which is essential for the correct development of dorsoanterior neural tissues. By measuring changes in exon usage and transcript abundance from Taf15-depleted embryos, we found that Taf15 may regulate dorsoanterior neural development through fgfr4 and ventx2.1. Taf15 uses distinct mechanisms to downregulate Fgfr4 expression, namely retention of a single intron within fgfr4 when maternal and zygotic Taf15 is depleted, and reduction in the total fgfr4 transcript when zygotic Taf15 alone is depleted. The two mechanisms of gene regulation (post-transcriptional versus transcriptional) suggest that Taf15-mediated gene regulation is target and co-factor dependent, contingent on the milieu of factors that are present at different stages of development.
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Affiliation(s)
- Caitlin S DeJong
- Molecular and Cell Biology Department, Genetics, Genomics and Development Division, University of California, Berkeley, CA 94720, USA
| | - Darwin S Dichmann
- Molecular and Cell Biology Department, Genetics, Genomics and Development Division, University of California, Berkeley, CA 94720, USA
| | - Cameron R T Exner
- Department of Psychiatry, Weill Institute for Neurosciences, Quantitative Biosciences Institute, University of California San Francisco, San Francisco, CA 94143, USA
| | - Yuxiao Xu
- Department of Psychiatry, Weill Institute for Neurosciences, Quantitative Biosciences Institute, University of California San Francisco, San Francisco, CA 94143, USA
| | - Richard M Harland
- Molecular and Cell Biology Department, Genetics, Genomics and Development Division, University of California, Berkeley, CA 94720, USA
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20
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González-Jiménez A, Campos A, Navarro F, Clemente-Blanco A, Calvo O. Regulation of Eukaryotic RNAPs Activities by Phosphorylation. Front Mol Biosci 2021; 8:681865. [PMID: 34250017 PMCID: PMC8268151 DOI: 10.3389/fmolb.2021.681865] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/07/2021] [Indexed: 01/11/2023] Open
Abstract
Evolutionarily conserved kinases and phosphatases regulate RNA polymerase II (RNAPII) transcript synthesis by modifying the phosphorylation status of the carboxyl-terminal domain (CTD) of Rpb1, the largest subunit of RNAPII. Proper levels of Rpb1-CTD phosphorylation are required for RNA co-transcriptional processing and to coordinate transcription with other nuclear processes, such as chromatin remodeling and histone modification. Whether other RNAPII subunits are phosphorylated and influences their role in gene expression is still an unanswered question. Much less is known about RNAPI and RNAPIII phosphorylation, whose subunits do not contain functional CTDs. However, diverse studies have reported that several RNAPI and RNAPIII subunits are susceptible to phosphorylation. Some of these phosphorylation sites are distributed within subunits common to all three RNAPs whereas others are only shared between RNAPI and RNAPIII. This suggests that the activities of all RNAPs might be finely modulated by phosphorylation events and raises the idea of a tight coordination between the three RNAPs. Supporting this view, the transcription by all RNAPs is regulated by signaling pathways that sense different environmental cues to adapt a global RNA transcriptional response. This review focuses on how the phosphorylation of RNAPs might regulate their function and we comment on the regulation by phosphorylation of some key transcription factors in the case of RNAPI and RNAPIII. Finally, we discuss the existence of possible common mechanisms that could coordinate their activities.
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Affiliation(s)
- Araceli González-Jiménez
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Adrián Campos
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Francisco Navarro
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Jaén, Spain.,Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Jaén, Spain
| | - Andrés Clemente-Blanco
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Olga Calvo
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
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21
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PBRM1 Cooperates with YTHDF2 to Control HIF-1α Protein Translation. Cells 2021; 10:cells10061425. [PMID: 34200988 PMCID: PMC8228889 DOI: 10.3390/cells10061425] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/27/2021] [Accepted: 06/04/2021] [Indexed: 11/16/2022] Open
Abstract
PBRM1, a component of the chromatin remodeller SWI/SNF, is often deleted or mutated in human cancers, most prominently in renal cancers. Core components of the SWI/SNF complex have been shown to be important for the cellular response to hypoxia. Here, we investigated how PBRM1 controls HIF-1α activity. We found that PBRM1 is required for HIF-1α transcriptional activity and protein levels. Mechanistically, PBRM1 is important for HIF-1α mRNA translation, as absence of PBRM1 results in reduced actively translating HIF-1α mRNA. Interestingly, we found that PBRM1, but not BRG1, interacts with the m6A reader protein YTHDF2. HIF-1α mRNA is m6A-modified, bound by PBRM1 and YTHDF2. PBRM1 is necessary for YTHDF2 binding to HIF-1α mRNA and reduction of YTHDF2 results in reduced HIF-1α protein expression in cells. Our results identify a SWI/SNF-independent function for PBRM1, interacting with HIF-1α mRNA and the epitranscriptome machinery. Furthermore, our results suggest that the epitranscriptome-associated proteins play a role in the control of hypoxia signalling pathways.
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22
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Schärfen L, Neugebauer KM. Transcription Regulation Through Nascent RNA Folding. J Mol Biol 2021; 433:166975. [PMID: 33811916 DOI: 10.1016/j.jmb.2021.166975] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/14/2022]
Abstract
Folding of RNA into secondary structures through intramolecular base pairing determines an RNA's three-dimensional architecture and associated function. Simple RNA structures like stem loops can provide specialized functions independent of coding capacity, such as protein binding, regulation of RNA processing and stability, stimulation or inhibition of translation. RNA catalysis is dependent on tertiary structures found in the ribosome, tRNAs and group I and II introns. While the extent to which non-coding RNAs contribute to cellular maintenance is generally appreciated, the fact that both non-coding and coding RNA can assume relevant structural states has only recently gained attention. In particular, the co-transcriptional folding of nascent RNA of all classes has the potential to regulate co-transcriptional processing, RNP (ribonucleoprotein particle) formation, and transcription itself. Riboswitches are established examples of co-transcriptionally folded coding RNAs that directly regulate transcription, mainly in prokaryotes. Here we discuss recent studies in both prokaryotes and eukaryotes showing that structure formation may carry a more widespread regulatory logic during RNA synthesis. Local structures forming close to the catalytic center of RNA polymerases have the potential to regulate transcription by reducing backtracking. In addition, stem loops or more complex structures may alter co-transcriptional RNA processing or its efficiency. Several examples of functional structures have been identified to date, and this review provides an overview of physiologically distinct processes where co-transcriptionally folded RNA plays a role. Experimental approaches such as single-molecule FRET and in vivo structural probing to further advance our insight into the significance of co-transcriptional structure formation are discussed.
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Affiliation(s)
- Leonard Schärfen
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
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23
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Interplay of mRNA capping and transcription machineries. Biosci Rep 2021; 40:221784. [PMID: 31904821 PMCID: PMC6981093 DOI: 10.1042/bsr20192825] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/02/2020] [Accepted: 01/06/2020] [Indexed: 12/31/2022] Open
Abstract
Early stages of transcription from eukaryotic promoters include two principal events: the capping of newly synthesized mRNA and the transition of RNA polymerase II from the preinitiation complex to the productive elongation state. The capping checkpoint model implies that these events are tightly coupled, which is necessary for ensuring the proper capping of newly synthesized mRNA. Recent findings also show that the capping machinery has a wider effect on transcription and the entire gene expression process. The molecular basis of these phenomena is discussed.
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24
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Bertero A. RNA Biogenesis Instructs Functional Inter-Chromosomal Genome Architecture. Front Genet 2021; 12:645863. [PMID: 33732290 PMCID: PMC7957078 DOI: 10.3389/fgene.2021.645863] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 02/08/2021] [Indexed: 12/12/2022] Open
Abstract
Three-dimensional (3D) genome organization has emerged as an important layer of gene regulation in development and disease. The functional properties of chromatin folding within individual chromosomes (i.e., intra-chromosomal or in cis) have been studied extensively. On the other hand, interactions across different chromosomes (i.e., inter-chromosomal or in trans) have received less attention, being often regarded as background noise or technical artifacts. This viewpoint has been challenged by emerging evidence of functional relationships between specific trans chromatin interactions and epigenetic control, transcription, and splicing. Therefore, it is an intriguing possibility that the key processes involved in the biogenesis of RNAs may both shape and be in turn influenced by inter-chromosomal genome architecture. Here I present the rationale behind this hypothesis, and discuss a potential experimental framework aimed at its formal testing. I present a specific example in the cardiac myocyte, a well-studied post-mitotic cell whose development and response to stress are associated with marked rearrangements of chromatin topology both in cis and in trans. I argue that RNA polymerase II clusters (i.e., transcription factories) and foci of the cardiac-specific splicing regulator RBM20 (i.e., splicing factories) exemplify the existence of trans-interacting chromatin domains (TIDs) with important roles in cellular homeostasis. Overall, I propose that inter-molecular 3D proximity between co-regulated nucleic acids may be a pervasive functional mechanism in biology.
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Affiliation(s)
- Alessandro Bertero
- Department of Laboratory Medicine and Pathology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, United States
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25
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Palazzo AF, Kang YM. GC-content biases in protein-coding genes act as an "mRNA identity" feature for nuclear export. Bioessays 2020; 43:e2000197. [PMID: 33165929 DOI: 10.1002/bies.202000197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/30/2020] [Accepted: 10/01/2020] [Indexed: 01/11/2023]
Abstract
It has long been observed that human protein-coding genes have a particular distribution of GC-content: the 5' end of these genes has high GC-content while the 3' end has low GC-content. In 2012, it was proposed that this pattern of GC-content could act as an mRNA identity feature that would lead to it being better recognized by the cellular machinery to promote its nuclear export. In contrast, junk RNA, which largely lacks this feature, would be retained in the nucleus and targeted for decay. Now two recent papers have provided evidence that GC-content does promote the nuclear export of many mRNAs in human cells.
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Affiliation(s)
- Alexander F Palazzo
- Department of Biochemistry, University of Toronto, Toronto, ON, M5G 1M1, Canada
| | - Yoon Mo Kang
- Department of Biochemistry, University of Toronto, Toronto, ON, M5G 1M1, Canada
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26
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Palazzo AF, Koonin EV. Functional Long Non-coding RNAs Evolve from Junk Transcripts. Cell 2020; 183:1151-1161. [PMID: 33068526 DOI: 10.1016/j.cell.2020.09.047] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/20/2020] [Accepted: 09/17/2020] [Indexed: 12/30/2022]
Abstract
Transcriptome studies reveal pervasive transcription of complex genomes, such as those of mammals. Despite popular arguments for functionality of most, if not all, of these transcripts, genome-wide analysis of selective constraints indicates that most of the produced RNA are junk. However, junk is not garbage. On the contrary, junk transcripts provide the raw material for the evolution of diverse long non-coding (lnc) RNAs by non-adaptive mechanisms, such as constructive neutral evolution. The generation of many novel functional entities, such as lncRNAs, that fuels organismal complexity does not seem to be driven by strong positive selection. Rather, the weak selection regime that dominates the evolution of most multicellular eukaryotes provides ample material for functional innovation with relatively little adaptation involved.
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Affiliation(s)
- Alexander F Palazzo
- Department of Biochemistry, University of Toronto, Toronto, ON M5G 1M1, Canada.
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
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27
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Sansó M, Parua PK, Pinto D, Svensson JP, Pagé V, Bitton DA, MacKinnon S, Garcia P, Hidalgo E, Bähler J, Tanny JC, Fisher RP. Cdk9 and H2Bub1 signal to Clr6-CII/Rpd3S to suppress aberrant antisense transcription. Nucleic Acids Res 2020; 48:7154-7168. [PMID: 32496538 PMCID: PMC7367204 DOI: 10.1093/nar/gkaa474] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/26/2020] [Indexed: 12/13/2022] Open
Abstract
Mono-ubiquitylation of histone H2B (H2Bub1) and phosphorylation of elongation factor Spt5 by cyclin-dependent kinase 9 (Cdk9) occur during transcription by RNA polymerase II (RNAPII), and are mutually dependent in fission yeast. It remained unclear whether Cdk9 and H2Bub1 cooperate to regulate the expression of individual genes. Here, we show that Cdk9 inhibition or H2Bub1 loss induces intragenic antisense transcription of ∼10% of fission yeast genes, with each perturbation affecting largely distinct subsets; ablation of both pathways de-represses antisense transcription of over half the genome. H2Bub1 and phospho-Spt5 have similar genome-wide distributions; both modifications are enriched, and directly proportional to each other, in coding regions, and decrease abruptly around the cleavage and polyadenylation signal (CPS). Cdk9-dependence of antisense suppression at specific genes correlates with high H2Bub1 occupancy, and with promoter-proximal RNAPII pausing. Genetic interactions link Cdk9, H2Bub1 and the histone deacetylase Clr6-CII, while combined Cdk9 inhibition and H2Bub1 loss impair Clr6-CII recruitment to chromatin and lead to decreased occupancy and increased acetylation of histones within gene coding regions. These results uncover novel interactions between co-transcriptional histone modification pathways, which link regulation of RNAPII transcription elongation to suppression of aberrant initiation.
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Affiliation(s)
- Miriam Sansó
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Cancer Genomics Group, Vall d'Hebron Institute of Oncology, Barcelona, Spain
| | - Pabitra K Parua
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Daniel Pinto
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - J Peter Svensson
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Viviane Pagé
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Danny A Bitton
- Research Department of Genetics, Evolution & Environment, University College, London, UK
| | - Sarah MacKinnon
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Patricia Garcia
- Departament de Ciènces Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Elena Hidalgo
- Departament de Ciènces Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Jürg Bähler
- Research Department of Genetics, Evolution & Environment, University College, London, UK
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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28
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Tellier M, Maudlin I, Murphy S. Transcription and splicing: A two-way street. WILEY INTERDISCIPLINARY REVIEWS. RNA 2020; 11:e1593. [PMID: 32128990 DOI: 10.1002/wrna.1593] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/18/2019] [Accepted: 02/12/2020] [Indexed: 12/11/2022]
Abstract
RNA synthesis by RNA polymerase II and RNA processing are closely coupled during the transcription cycle of protein-coding genes. This coupling affords opportunities for quality control and regulation of gene expression and the effects can go in both directions. For example, polymerase speed can affect splice site selection and splicing can increase transcription and affect the chromatin landscape. Here we review the many ways that transcription and splicing influence one another, including how splicing "talks back" to transcription. We will also place the connections between transcription and splicing in the context of other RNA processing events that define the exons that will make up the final mRNA. This article is categorized under: RNA Processing > Splicing Mechanisms RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
- Michael Tellier
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Isabella Maudlin
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Shona Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
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29
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30
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Tognacca RS, Kubaczka MG, Servi L, Rodríguez FS, Godoy Herz MA, Petrillo E. Light in the transcription landscape: chromatin, RNA polymerase II and splicing throughout Arabidopsis thaliana's life cycle. Transcription 2020; 11:117-133. [PMID: 32748694 DOI: 10.1080/21541264.2020.1796473] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Plants have a high level of developmental plasticity that allows them to respond and adapt to changes in the environment. Among the environmental cues, light controls almost every aspect of A. thaliana's life cycle, including seed maturation, seed germination, seedling de-etiolation and flowering time. Light signals induce massive reprogramming of gene expression, producing changes in RNA polymerase II transcription, alternative splicing, and chromatin state. Since splicing reactions occur mainly while transcription takes place, the regulation of RNAPII transcription has repercussions in the splicing outcomes. This cotranscriptional nature allows a functional coupling between transcription and splicing, in which properties of the splicing reactions are affected by the transcriptional process. Chromatin landscapes influence both transcription and splicing. In this review, we highlight, summarize and discuss recent progress in the field to gain a comprehensive insight on the cross-regulation between chromatin state, RNAPII transcription and splicing decisions in plants, with a special focus on light-triggered responses. We also introduce several examples of transcription and splicing factors that could be acting as coupling factors in plants. Unravelling how these connected regulatory networks operate, can help in the design of better crops with higher productivity and tolerance.
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Affiliation(s)
- Rocío S Tognacca
- Departamento De Fisiología, Biología Molecular Y Celular, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires , Buenos Aires, Argentina.,Instituto De Fisiología, Biología Molecular Y Neurociencias (IFIBYNE), CONICET-Universidad De Buenos Aires , Buenos Aires, Argentina
| | - M Guillermina Kubaczka
- Departamento De Fisiología, Biología Molecular Y Celular, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires , Buenos Aires, Argentina.,Instituto De Fisiología, Biología Molecular Y Neurociencias (IFIBYNE), CONICET-Universidad De Buenos Aires , Buenos Aires, Argentina
| | - Lucas Servi
- Departamento De Fisiología, Biología Molecular Y Celular, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires , Buenos Aires, Argentina.,Instituto De Fisiología, Biología Molecular Y Neurociencias (IFIBYNE), CONICET-Universidad De Buenos Aires , Buenos Aires, Argentina
| | - Florencia S Rodríguez
- Departamento De Fisiología, Biología Molecular Y Celular, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires , Buenos Aires, Argentina.,Instituto De Fisiología, Biología Molecular Y Neurociencias (IFIBYNE), CONICET-Universidad De Buenos Aires , Buenos Aires, Argentina.,Departamento De Biodiversidad Y Biología Experimental, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires , Buenos Aires, Argentina
| | - Micaela A Godoy Herz
- Departamento De Fisiología, Biología Molecular Y Celular, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires , Buenos Aires, Argentina.,Instituto De Fisiología, Biología Molecular Y Neurociencias (IFIBYNE), CONICET-Universidad De Buenos Aires , Buenos Aires, Argentina
| | - Ezequiel Petrillo
- Departamento De Fisiología, Biología Molecular Y Celular, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires , Buenos Aires, Argentina.,Instituto De Fisiología, Biología Molecular Y Neurociencias (IFIBYNE), CONICET-Universidad De Buenos Aires , Buenos Aires, Argentina
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31
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Ntini E, Marsico A. Functional impacts of non-coding RNA processing on enhancer activity and target gene expression. J Mol Cell Biol 2020; 11:868-879. [PMID: 31169884 PMCID: PMC6884709 DOI: 10.1093/jmcb/mjz047] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 04/03/2019] [Accepted: 04/04/2019] [Indexed: 01/06/2023] Open
Abstract
Tight regulation of gene expression is orchestrated by enhancers. Through recent research advancements, it is becoming clear that enhancers are not solely distal regulatory elements harboring transcription factor binding sites and decorated with specific histone marks, but they rather display signatures of active transcription, showing distinct degrees of transcription unit organization. Thereby, a substantial fraction of enhancers give rise to different species of non-coding RNA transcripts with an unprecedented range of potential functions. In this review, we bring together data from recent studies indicating that non-coding RNA transcription from active enhancers, as well as enhancer-produced long non-coding RNA transcripts, may modulate or define the functional regulatory potential of the cognate enhancer. In addition, we summarize supporting evidence that RNA processing of the enhancer-associated long non-coding RNA transcripts may constitute an additional layer of regulation of enhancer activity, which contributes to the control and final outcome of enhancer-targeted gene expression.
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Affiliation(s)
- Evgenia Ntini
- Max Planck Institute for Molecular Genetics, Berlin, Germany.,Free University Berlin, Berlin, Germany
| | - Annalisa Marsico
- Max Planck Institute for Molecular Genetics, Berlin, Germany.,Free University Berlin, Berlin, Germany.,Institute of Computational Biology, Helmholtz Zentrum München, München, Germany
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32
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Calvo O. RNA polymerase II phosphorylation and gene looping: new roles for the Rpb4/7 heterodimer in regulating gene expression. Curr Genet 2020; 66:927-937. [PMID: 32508001 DOI: 10.1007/s00294-020-01084-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 12/22/2022]
Abstract
In eukaryotes, cellular RNAs are produced by three nuclear RNA polymerases (RNAPI, II, and III), which are multisubunit complexes. They share structural and functional features, although they are specialized in the synthesis of specific RNAs. RNAPII transcribes the vast majority of cellular RNAs, including mRNAs and a large number of noncoding RNAs. The structure of RNAPII is highly conserved in all eukaryotes, consisting of 12 subunits (Rpb1-12) organized into five structural modules, among which the Rpb4 and Rpb7 subunits form the stalk. Early studies suggested an accessory role for Rpb4, because is required for specific gene transcription pathways. Far from this initial hypothesis, it is now well established that the Rpb4/7 heterodimer plays much wider roles in gene expression regulation. It participates in nuclear and cytosolic processes ranging from transcription to translation and mRNA degradation in a cyclical process. For this reason, Rpb4/7 is considered a coordinator of gene expression. New functions have been added to the list of stalk functions during transcription, which will be reviewed herein: first, a role in the maintenance of proper RNAPII phosphorylation levels, and second, a role in the establishment of a looped gene architecture in actively transcribed genes.
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Affiliation(s)
- Olga Calvo
- Instituto de Biología Funcional y Genómica (IBFG), CSIC-USAL, C/ Zacarías González 2, Salamanca, 37007, España.
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33
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An insight into structural plasticity and conformational transitions of transcriptional co-activator Sus1. PLoS One 2020; 15:e0229216. [PMID: 32134955 PMCID: PMC7058303 DOI: 10.1371/journal.pone.0229216] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 01/31/2020] [Indexed: 11/30/2022] Open
Abstract
RNA biogenesis and mRNA transport are an intricate process for every eukaryotic cell. SAGA, a transcriptional coactivator and TREX-2 are the two major complexes participate in this process. Sus1 is a transcription export factor and part of both the SAGA and the TREX-2 complex. The competitive exchange of Sus1 molecule between SAGA and TREX-2 complex modulates their function which is credited to structural plasticity of Sus1. Here, we portray the biophysical characterization of Sus1 from S. cerevisiae. The recombinant Sus1 is a α-helical structure which is stable at various pH conditions. We reported the α-helix to β-sheet transition at the low pH as well as at high pH. Sus1 showed 50% reduction in the fluorescence intensity at pH-2 as compared to native protein. The fluorescence studies demonstrated the unfolding of tertiary structure of the protein with variation in pH as compared to neutral pH. The same results were obtained in the ANS binding and acrylamide quenching studies. Similarly, the secondary structure of the Sus1 was found to be stable till 55% alcohol concentration while tertiary structure was stable up to 20% alcohol concentration. Further increase in the alcohol concentration destabilizes the secondary as well as tertiary structure. The 300 mM concentration of ammonium sulfate also stabilizes the secondary structure of the protein. The structural characterization of this protein is expected to unfold the process of the transportation of the mRNA with cooperation of different proteins.
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34
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Chaudhuri A, Das S, Das B. Localization elements and zip codes in the intracellular transport and localization of messenger RNAs in Saccharomyces cerevisiae. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 11:e1591. [PMID: 32101377 DOI: 10.1002/wrna.1591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/05/2020] [Accepted: 02/07/2020] [Indexed: 12/13/2022]
Abstract
Intracellular trafficking and localization of mRNAs provide a mechanism of regulation of expression of genes with excellent spatial control. mRNA localization followed by localized translation appears to be a mechanism of targeted protein sorting to a specific cell-compartment, which is linked to the establishment of cell polarity, cell asymmetry, embryonic axis determination, and neuronal plasticity in metazoans. However, the complexity of the mechanism and the components of mRNA localization in higher organisms prompted the use of the unicellular organism Saccharomyces cerevisiae as a simplified model organism to study this vital process. Current knowledge indicates that a variety of mRNAs are asymmetrically and selectively localized to the tip of the bud of the daughter cells, to the vicinity of endoplasmic reticulum, mitochondria, and nucleus in this organism, which are connected to diverse cellular processes. Interestingly, specific cis-acting RNA localization elements (LEs) or RNA zip codes play a crucial role in the localization and trafficking of these localized mRNAs by providing critical binding sites for the specific RNA-binding proteins (RBPs). In this review, we present a comprehensive account of mRNA localization in S. cerevisiae, various types of localization elements influencing the mRNA localization, and the RBPs, which bind to these LEs to implement a number of vital physiological processes. Finally, we emphasize the significance of this process by highlighting their connection to several neuropathological disorders and cancers. This article is categorized under: RNA Export and Localization > RNA Localization.
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Affiliation(s)
- Anusha Chaudhuri
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Subhadeep Das
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Biswadip Das
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
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35
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Achar YJ, Adhil M, Choudhary R, Gilbert N, Foiani M. Negative supercoil at gene boundaries modulates gene topology. Nature 2020; 577:701-705. [PMID: 31969709 DOI: 10.1038/s41586-020-1934-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 11/25/2019] [Indexed: 11/08/2022]
Abstract
Transcription challenges the integrity of replicating chromosomes by generating topological stress and conflicts with forks1,2. The DNA topoisomerases Top1 and Top2 and the HMGB family protein Hmo1 assist DNA replication and transcription3-6. Here we describe the topological architecture of genes in Saccharomyces cerevisiae during the G1 and S phases of the cell cycle. We found under-wound DNA at gene boundaries and over-wound DNA within coding regions. This arrangement does not depend on Pol II or S phase. Top2 and Hmo1 preserve negative supercoil at gene boundaries, while Top1 acts at coding regions. Transcription generates RNA-DNA hybrids within coding regions, independently of fork orientation. During S phase, Hmo1 protects under-wound DNA from Top2, while Top2 confines Pol II and Top1 at coding units, counteracting transcription leakage and aberrant hybrids at gene boundaries. Negative supercoil at gene boundaries prevents supercoil diffusion and nucleosome repositioning at coding regions. DNA looping occurs at Top2 clusters. We propose that Hmo1 locks gene boundaries in a cruciform conformation and, with Top2, modulates the architecture of genes that retain the memory of the topological arrangements even when transcription is repressed.
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MESH Headings
- Chromatin Assembly and Disassembly
- DNA Replication
- DNA Topoisomerases, Type I/metabolism
- DNA Topoisomerases, Type II/genetics
- DNA Topoisomerases, Type II/metabolism
- DNA, Cruciform/chemistry
- DNA, Cruciform/genetics
- DNA, Cruciform/metabolism
- DNA, Fungal/chemistry
- DNA, Fungal/genetics
- DNA, Fungal/metabolism
- DNA, Superhelical/chemistry
- DNA, Superhelical/genetics
- DNA, Superhelical/metabolism
- G1 Phase
- Gene Expression Regulation, Fungal
- Genes, Fungal
- High Mobility Group Proteins/metabolism
- Mutation
- Nucleic Acid Hybridization
- Nucleosomes/chemistry
- Nucleosomes/genetics
- Nucleosomes/metabolism
- Open Reading Frames/genetics
- RNA Polymerase II/genetics
- RNA Polymerase II/metabolism
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- S Phase
- Saccharomyces cerevisiae/cytology
- Saccharomyces cerevisiae/enzymology
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae Proteins/metabolism
- Transcription, Genetic
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Affiliation(s)
| | - Mohamood Adhil
- IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), Milan, Italy
| | - Ramveer Choudhary
- IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), Milan, Italy
| | - Nick Gilbert
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Marco Foiani
- IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), Milan, Italy.
- Università degli Studi di Milano, Milan, Italy.
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36
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Fukuda S, Yan S, Komi Y, Sun M, Gabizon R, Bustamante C. The Biogenesis of SRP RNA Is Modulated by an RNA Folding Intermediate Attained during Transcription. Mol Cell 2019; 77:241-250.e8. [PMID: 31706702 DOI: 10.1016/j.molcel.2019.10.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 08/29/2019] [Accepted: 10/04/2019] [Indexed: 11/16/2022]
Abstract
The signal recognition particle (SRP), responsible for co-translational protein targeting and delivery to cellular membranes, depends on the native long-hairpin fold of its RNA to confer functionality. Since RNA initiates folding during its synthesis, we used high-resolution optical tweezers to follow in real time the co-transcriptional folding of SRP RNA. Surprisingly, SRP RNA folding is robust to transcription rate changes and the presence or absence of its 5'-precursor sequence. The folding pathway also reveals the obligatory attainment of a non-native hairpin intermediate (H1) that eventually rearranges into the native fold. Furthermore, H1 provides a structural platform alternative to the native fold for RNase P to bind and mature SRP RNA co-transcriptionally. Delays in attaining the final native fold are detrimental to the cell, altogether showing that a co-transcriptional folding pathway underpins the proper biogenesis of function-essential SRP RNA.
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Affiliation(s)
- Shingo Fukuda
- Institute for Quantitative Biosciences-QB3, University of California, Berkeley, Berkeley, CA, USA; Okazaki Institute for Integrative Bioscience and Institute for Molecular Science, National Institutes of Natural Science, Tokyo, Japan; Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa 920-1192, Japan.
| | - Shannon Yan
- Institute for Quantitative Biosciences-QB3, University of California, Berkeley, Berkeley, CA, USA; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
| | - Yusuke Komi
- Institute for Quantitative Biosciences-QB3, University of California, Berkeley, Berkeley, CA, USA; Laboratory for Protein Conformation Diseases, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Mingxuan Sun
- Institute for Quantitative Biosciences-QB3, University of California, Berkeley, Berkeley, CA, USA; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Ronen Gabizon
- Institute for Quantitative Biosciences-QB3, University of California, Berkeley, Berkeley, CA, USA
| | - Carlos Bustamante
- Institute for Quantitative Biosciences-QB3, University of California, Berkeley, Berkeley, CA, USA; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA; Jason L. Choy Laboratory of Single-Molecule Biophysics, University of California, Berkeley, Berkeley, CA, USA; Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA, USA; Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA; Department of Physics, University of California, Berkeley, Berkeley, CA, USA; Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA; Kavli Energy Nanoscience Institute, University of California, Berkeley, Berkeley, CA, USA.
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37
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mRNA Cap Methyltransferase, RNMT-RAM, Promotes RNA Pol II-Dependent Transcription. Cell Rep 2019; 23:1530-1542. [PMID: 29719263 PMCID: PMC5946721 DOI: 10.1016/j.celrep.2018.04.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 01/11/2018] [Accepted: 03/30/2018] [Indexed: 11/20/2022] Open
Abstract
mRNA cap addition occurs early during RNA Pol II-dependent transcription, facilitating pre-mRNA processing and translation. We report that the mammalian mRNA cap methyltransferase, RNMT-RAM, promotes RNA Pol II transcription independent of mRNA capping and translation. In cells, sublethal suppression of RNMT-RAM reduces RNA Pol II occupancy, net mRNA synthesis, and pre-mRNA levels. Conversely, expression of RNMT-RAM increases transcription independent of cap methyltransferase activity. In isolated nuclei, recombinant RNMT-RAM stimulates transcriptional output; this requires the RAM RNA binding domain. RNMT-RAM interacts with nascent transcripts along their entire length and with transcription-associated factors including the RNA Pol II subunits SPT4, SPT6, and PAFc. Suppression of RNMT-RAM inhibits transcriptional markers including histone H2BK120 ubiquitination, H3K4 and H3K36 methylation, RNA Pol II CTD S5 and S2 phosphorylation, and PAFc recruitment. These findings suggest that multiple interactions among RNMT-RAM, RNA Pol II factors, and RNA along the transcription unit stimulate transcription. mRNA cap methyltransferase, RNMT-RAM, promotes RNA Pol II-dependent transcription RNMT-RAM-dependent transcription is independent of mRNA cap methylation RNMT-RAM binds to the entire length of pre-mRNA and to transcription-associated proteins Significant loss of RNA Pol II gene occupancy is observed on RNMT-RAM suppression
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38
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Maudlin IE, Beggs JD. Spt5 modulates cotranscriptional spliceosome assembly in Saccharomyces cerevisiae. RNA (NEW YORK, N.Y.) 2019; 25:1298-1310. [PMID: 31289129 PMCID: PMC6800482 DOI: 10.1261/rna.070425.119] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 05/29/2019] [Indexed: 06/09/2023]
Abstract
There is increasing evidence from yeast to humans that pre-mRNA splicing occurs mainly cotranscriptionally, such that splicing and transcription are functionally coupled. Currently, there is little insight into the contribution of the core transcription elongation machinery to cotranscriptional spliceosome assembly and pre-mRNA splicing. Spt5 is a member of the core transcription elongation machinery and an essential protein, whose absence in budding yeast causes defects in pre-mRNA splicing. To determine how Spt5 affects pre-mRNA splicing, we used the auxin-inducible degron system to conditionally deplete Spt5 in Saccharomyces cerevisiae and assayed effects on cotranscriptional spliceosome assembly and splicing. We show that Spt5 is needed for efficient splicing and for the accumulation of U5 snRNPs at intron-containing genes, and therefore for stable cotranscriptional assembly of spliceosomes. The defect in cotranscriptional spliceosome assembly can explain the relatively mild splicing defect as being a consequence of the failure of cotranscriptional splicing. Coimmunoprecipitation of Spt5 with core spliceosomal proteins and all spliceosomal snRNAs suggests a model whereby Spt5 promotes cotranscriptional pre-mRNA splicing by stabilizing the association of U5 snRNP with spliceosome complexes as they assemble on the nascent transcript. If this phenomenon is conserved in higher eukaryotes, it has the potential to be important for cotranscriptional regulation of alternative splicing.
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Affiliation(s)
- Isabella E Maudlin
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Jean D Beggs
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
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39
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Das S, Biswas S, Chaudhuri S, Bhattacharyya A, Das B. A Nuclear Zip Code in SKS1 mRNA Promotes Its Slow Export, Nuclear Retention, and Degradation by the Nuclear Exosome/DRN in Saccharomyces cerevisiae. J Mol Biol 2019; 431:3626-3646. [DOI: 10.1016/j.jmb.2019.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 06/26/2019] [Accepted: 07/01/2019] [Indexed: 01/12/2023]
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40
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Florini F, Naguleswaran A, Gharib WH, Bringaud F, Roditi I. Unexpected diversity in eukaryotic transcription revealed by the retrotransposon hotspot family of Trypanosoma brucei. Nucleic Acids Res 2019; 47:1725-1739. [PMID: 30544263 PMCID: PMC6393297 DOI: 10.1093/nar/gky1255] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/28/2018] [Accepted: 12/03/2018] [Indexed: 12/20/2022] Open
Abstract
The path from DNA to RNA to protein in eukaryotes is guided by a series of factors linking transcription, mRNA export and translation. Many of these are conserved from yeast to humans. Trypanosomatids, which diverged early in the eukaryotic lineage, exhibit unusual features such as polycistronic transcription and trans-splicing of all messenger RNAs. They possess basal transcription factors, but lack recognisable orthologues of many factors required for transcription elongation and mRNA export. We show that retrotransposon hotspot (RHS) proteins fulfil some of these functions and that their depletion globally impairs nascent RNA synthesis by RNA polymerase II. Three sub-families are part of a coordinated process in which RHS6 is most closely associated with chromatin, RHS4 is part of the Pol II complex and RHS2 connects transcription with the translation machinery. In summary, our results show that the components of eukaryotic transcription are far from being universal, and reveal unsuspected plasticity in the course of evolution.
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Affiliation(s)
- Francesca Florini
- Institute of Cell Biology, University of Bern, Bern, Switzerland.,Graduate School of Cellular and Biomedical Science, University of Bern, Bern, Switzerland
| | | | - Walid H Gharib
- Interfaculty Bioinformatics Unit, University of Bern, Switzerland
| | - Frédéric Bringaud
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234 CNRS, Université de Bordeaux, France
| | - Isabel Roditi
- Institute of Cell Biology, University of Bern, Bern, Switzerland
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41
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Fisher RP. Cdk7: a kinase at the core of transcription and in the crosshairs of cancer drug discovery. Transcription 2019; 10:47-56. [PMID: 30488763 PMCID: PMC6602562 DOI: 10.1080/21541264.2018.1553483] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/20/2018] [Accepted: 11/20/2018] [Indexed: 12/22/2022] Open
Abstract
The transcription cycle of RNA polymerase II (Pol II) is regulated by a set of cyclin-dependent kinases (CDKs). Cdk7, associated with the transcription initiation factor TFIIH, is both an effector CDK that phosphorylates Pol II and other targets within the transcriptional machinery, and a CDK-activating kinase (CAK) for at least one other essential CDK involved in transcription. Recent studies have illuminated Cdk7 functions that are executed throughout the Pol II transcription cycle, from promoter clearance and promoter-proximal pausing, to co-transcriptional chromatin modification in gene bodies, to mRNA 3´-end formation and termination. Cdk7 has also emerged as a target of small-molecule inhibitors that show promise in the treatment of cancer and inflammation. The challenges now are to identify the relevant targets of Cdk7 at each step of the transcription cycle, and to understand how heightened dependence on an essential CDK emerges in cancer, and might be exploited therapeutically.
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Affiliation(s)
- Robert P. Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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42
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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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43
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Zhao X, Xiong J, Mao F, Sheng Y, Chen X, Feng L, Dui W, Yang W, Kapusta A, Feschotte C, Coyne RS, Miao W, Gao S, Liu Y. RNAi-dependent Polycomb repression controls transposable elements in Tetrahymena. Genes Dev 2019; 33:348-364. [PMID: 30808657 PMCID: PMC6411011 DOI: 10.1101/gad.320796.118] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 01/02/2019] [Indexed: 12/30/2022]
Abstract
In this study, Zhao et al. show that in the protozoan Tetrahymena thermophila, germline-specific internally eliminated sequences (IESs) become transcriptionally activated in mutants deficient in the RNAi-dependent Polycomb repression pathway. Their findings suggest that the interplay between RNAi and Polycomb repression is a widely conserved phenomenon whose ancestral role is epigenetic silencing of TEs. RNAi and Polycomb repression play evolutionarily conserved and often coordinated roles in transcriptional silencing. Here, we show that, in the protozoan Tetrahymena thermophila, germline-specific internally eliminated sequences (IESs)—many related to transposable elements (TEs)—become transcriptionally activated in mutants deficient in the RNAi-dependent Polycomb repression pathway. Germline TE mobilization also dramatically increases in these mutants. The transition from noncoding RNA (ncRNA) to mRNA production accompanies transcriptional activation of TE-related sequences and vice versa for transcriptional silencing. The balance between ncRNA and mRNA production is potentially affected by cotranscriptional processing as well as RNAi and Polycomb repression. We posit that interplay between RNAi and Polycomb repression is a widely conserved phenomenon, whose ancestral role is epigenetic silencing of TEs.
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Affiliation(s)
- Xiaolu Zhao
- Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109, USA.,Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Jie Xiong
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Fengbiao Mao
- Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Yalan Sheng
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China
| | - Xiao Chen
- Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109, USA.,Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Lifang Feng
- Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Wen Dui
- Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Wentao Yang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Aurélie Kapusta
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA
| | - Cédric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850, USA
| | - Robert S Coyne
- J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | - Wei Miao
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Shan Gao
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China
| | - Yifan Liu
- Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109, USA
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44
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Bañuelos CP, Levy GV, Níttolo AG, Roser LG, Tekiel V, Sánchez DO. The Trypanosoma brucei RNA-Binding Protein TbRRM1 is Involved in the Transcription of a Subset of RNA Pol II-Dependent Genes. J Eukaryot Microbiol 2019; 66:719-729. [PMID: 30730083 DOI: 10.1111/jeu.12716] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/11/2019] [Accepted: 01/25/2019] [Indexed: 11/30/2022]
Abstract
It has been long thought that RNA Polymerase (Pol) II transcriptional regulation does not operate in trypanosomes. However, recent reports have suggested that these organisms could regulate RNA Pol II transcription by epigenetic mechanisms. In this paper, we investigated the role of TbRRM1 in transcriptional regulation of RNA Pol II-dependent genes by focusing both in genes located in a particular polycistronic transcription unit (PTU) and in the monocistronic units of the SL-RNA genes. We showed that TbRRM1 is recruited throughout the PTU, with a higher presence on genes than intergenic regions. However, its depletion leads both to the decrease of nascent RNA and to chromatin compaction only of regions located distal to the main transcription start site. These findings suggest that TbRRM1 facilitates the RNA Pol II transcriptional elongation step by collaborating to maintain an open chromatin state in particular regions of the genome. Interestingly, the SL-RNA genes do not recruit TbRRM1 and, after TbRRM1 knockdown, nascent SL-RNAs accumulate while the chromatin state of these regions remains unchanged. Although it was previously suggested that TbRRM1 could regulate RNA Pol II-driven genes, we provide here the first experimental evidence which involves TbRRM1 to transcriptional regulation.
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Affiliation(s)
- Carolina P Bañuelos
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia, San Martín, Buenos Aires, Argentina
| | - Gabriela V Levy
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia, San Martín, Buenos Aires, Argentina
| | - Analía G Níttolo
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia, San Martín, Buenos Aires, Argentina
| | - Leandro G Roser
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia, San Martín, Buenos Aires, Argentina
| | - Valeria Tekiel
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia, San Martín, Buenos Aires, Argentina
| | - Daniel O Sánchez
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia, San Martín, Buenos Aires, Argentina
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45
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Venters CC, Oh JM, Di C, So BR, Dreyfuss G. U1 snRNP Telescripting: Suppression of Premature Transcription Termination in Introns as a New Layer of Gene Regulation. Cold Spring Harb Perspect Biol 2019; 11:11/2/a032235. [PMID: 30709878 DOI: 10.1101/cshperspect.a032235] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent observations showed that nascent RNA polymerase II transcripts, pre-mRNAs, and noncoding RNAs are highly susceptible to premature 3'-end cleavage and polyadenylation (PCPA) from numerous intronic cryptic polyadenylation signals (PASs). The importance of this in gene regulation was not previously appreciated as PASs, despite their prevalence, were thought to be active in terminal exons at gene ends. Unexpectedly, antisense oligonucleotide interference with U1 snRNA base-pairing to 5' splice sites, which is necessary for U1 snRNP's (U1) function in splicing, caused widespread PCPA in metazoans. This uncovered U1's PCPA suppression activity, termed telescripting, as crucial for full-length transcription in thousands of vertebrate genes, providing a general role in transcription elongation control. Progressive intron-size expansion in metazoan evolution greatly increased PCPA vulnerability and dependence on U1 telescripting. We describe how these observations unfolded and discuss U1 telescripting's role in shaping the transcriptome.
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Affiliation(s)
- Christopher C Venters
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Jung-Min Oh
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Chao Di
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Byung Ran So
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Gideon Dreyfuss
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
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46
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Mitra P, Deshmukh AS, Gurupwar R, Kashyap P. Characterization of Toxoplasma gondii Spt5 like transcription elongation factor. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:184-197. [DOI: 10.1016/j.bbagrm.2019.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/26/2018] [Accepted: 01/06/2019] [Indexed: 12/14/2022]
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47
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Godoy Herz MA, Kornblihtt AR. Alternative Splicing and Transcription Elongation in Plants. FRONTIERS IN PLANT SCIENCE 2019; 10:309. [PMID: 30972082 PMCID: PMC6443983 DOI: 10.3389/fpls.2019.00309] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 02/26/2019] [Indexed: 05/19/2023]
Abstract
Alternative splicing and transcription elongation by RNA polymerase II (RNAPII) are two processes which are tightly connected. Splicing is a co-transcriptional process, and different experimental approaches show that splicing is coupled to transcription in Drosophila, yeast and mammals. However, little is known about coupling of transcription and alternative splicing in plants. The kinetic coupling explains how changes in RNAPII elongation rate influence alternative splicing choices. Recent work in Arabidopsis shows that expression of a dominant negative transcription elongation factor, TFIIS, enhances exon inclusion. Furthermore, the Arabidopsis transcription elongation complex has been recently described, providing new information about elongation factors that interact with elongating RNAPII. Light regulates alternative splicing in plants through a chloroplast retrograde signaling. We have recently shown that light promotes RNAPII elongation in the affected genes, while in darkness elongation is lower. These changes in transcription are consistent with elongation causing the observed changes in alternative splicing. Altogether, these findings provide evidence that coupling between transcription and alternative splicing is an important layer of gene expression regulation in plants.
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Affiliation(s)
- Micaela A. Godoy Herz
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-UBA, Buenos Aires, Argentina
| | - Alberto R. Kornblihtt
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-UBA, Buenos Aires, Argentina
- *Correspondence: Alberto R. Kornblihtt,
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48
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Hu X, Xu S, Chen Y, Gao Z, Li Y, Hu J, Huang X, Zhang Y, Jiang X, Li L, Yang C, Chen J, Gao N. Depletion of Ars2 inhibits cell proliferation and leukemogenesis in acute myeloid leukemia by modulating the miR-6734-3p/p27 axis. Leukemia 2018; 33:1090-1101. [PMID: 30518811 PMCID: PMC6756072 DOI: 10.1038/s41375-018-0301-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/03/2018] [Accepted: 09/20/2018] [Indexed: 01/16/2023]
Abstract
Ars2 is a component of the nuclear cap-binding complex (CBC) that contributes to microRNA biogenesis and is required for cellular proliferation. Little is known regarding the functional role of Ars2 in cell proliferation and leukemogenesis of acute myeloid leukemia. Here, we show that the elevated expression of Ars2 was observed in acute myeloid leukemia (AML) cell lines and bone marrow samples from AML patients and was correlated with poorer overall survival. Overexpression of Ars2 promoted cell proliferation and colony formation in AML cells, whereas depletion of Ars2 inhibited cell proliferation and colony formation. Mechanistic studies reveal that depletion of Ars2 suppressed the interaction of Ars2 with CBC and led to alterations in miRNA processing. Furthermore, Ars2 depletion reduced the levels of miR-6734-3p, resulting in upregulation of p27 and culminating in cell cycle arrest at the G1 phase. In vivo studies indicate that depletion of Ars2 significantly reduced leukemic cell burden and prolonged the survival time of the leukemia-bearing mice. These findings indicate that Ars2 may not only play a crucial role in the regulation of cell proliferation and leukemogenesis, but could also be identified as a critical therapeutic target for treatment of AML.
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Affiliation(s)
- Xiaoye Hu
- College of Pharmacy, Army Medical University, Chongqing, China
| | - Shuangnian Xu
- Department of Hematology, Southwest Hospital, Army Medical University, Chongqing, China
| | - Yibiao Chen
- College of Pharmacy, Army Medical University, Chongqing, China
| | - Ziyi Gao
- Greater Philadelphia Pharmacy, Philadelphia, PA, USA
| | - Yunong Li
- College of Pharmacy, Army Medical University, Chongqing, China
| | - Jinjiao Hu
- College of Pharmacy, Army Medical University, Chongqing, China
| | - Xiuning Huang
- College of Pharmacy, Army Medical University, Chongqing, China
| | - Yanhao Zhang
- College of Pharmacy, Army Medical University, Chongqing, China
| | - Xiuxing Jiang
- College of Pharmacy, Army Medical University, Chongqing, China
| | - Lirong Li
- College of Pharmacy, Army Medical University, Chongqing, China
| | - Chong Yang
- College of Pharmacy, Army Medical University, Chongqing, China
| | - Jieping Chen
- Department of Hematology, Southwest Hospital, Army Medical University, Chongqing, China.
| | - Ning Gao
- College of Pharmacy, Army Medical University, Chongqing, China. .,Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China.
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49
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Zhao N, Sebastiano V, Moshkina N, Mena N, Hultquist J, Jimenez-Morales D, Ma Y, Rialdi A, Albrecht R, Fenouil R, Sánchez-Aparicio MT, Ayllon J, Ravisankar S, Haddad B, Ho JSY, Low D, Jin J, Yurchenko V, Prinjha RK, Tarakhovsky A, Squatrito M, Pinto D, Allette K, Byun M, Smith ML, Sebra R, Guccione E, Tumpey T, Krogan N, Greenbaum B, van Bakel H, García-Sastre A, Marazzi I. Influenza virus infection causes global RNAPII termination defects. Nat Struct Mol Biol 2018; 25:885-893. [PMID: 30177761 PMCID: PMC10754036 DOI: 10.1038/s41594-018-0124-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 08/09/2018] [Indexed: 12/23/2022]
Abstract
Viral infection perturbs host cells and can be used to uncover regulatory mechanisms controlling cellular responses and susceptibility to infections. Using cell biological, biochemical, and genetic tools, we reveal that influenza A virus (IAV) infection induces global transcriptional defects at the 3' ends of active host genes and RNA polymerase II (RNAPII) run-through into extragenic regions. Deregulated RNAPII leads to expression of aberrant RNAs (3' extensions and host-gene fusions) that ultimately cause global transcriptional downregulation of physiological transcripts, an effect influencing antiviral response and virulence. This phenomenon occurs with multiple strains of IAV, is dependent on influenza NS1 protein, and can be modulated by SUMOylation of an intrinsically disordered region (IDR) of NS1 expressed by the 1918 pandemic IAV strain. Our data identify a strategy used by IAV to suppress host gene expression and indicate that polymorphisms in IDRs of viral proteins can affect the outcome of an infection.
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Affiliation(s)
- Nan Zhao
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Vittorio Sebastiano
- Department of Obstetrics and Gynecology, Stanford University, Stanford, CA, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA, USA
| | - Natasha Moshkina
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Nacho Mena
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Judd Hultquist
- Department of Medicine (Infectious Diseases), Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - David Jimenez-Morales
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
| | - Yixuan Ma
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Alex Rialdi
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Randy Albrecht
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Romain Fenouil
- Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Maria Teresa Sánchez-Aparicio
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Juan Ayllon
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sweta Ravisankar
- Department of Obstetrics and Gynecology, Stanford University, Stanford, CA, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA, USA
| | - Bahareh Haddad
- Department of Obstetrics and Gynecology, Stanford University, Stanford, CA, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University, Stanford, CA, USA
| | - Jessica Sook Yuin Ho
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Diana Low
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Jian Jin
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Rab K Prinjha
- Epinova Epigenetics Discovery Performance Unit, Immuno-Inflammation Therapy Area, GlaxoSmithKline, Medicines Research Centre, Stevenage, UK
| | - Alexander Tarakhovsky
- Laboratory of Immune Cell Epigenetics and Signaling, The Rockefeller University, New York, NY, USA
| | - Massimo Squatrito
- Cancer Cell Biology Programme, Centro Nacional de Investigaciones Oncológicas, CNIO, Madrid, Spain
| | - Dalila Pinto
- Department of Psychiatry, Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Kimaada Allette
- Department of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Minji Byun
- Department of Medicine, Clinical Immunology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Melissa Laird Smith
- Department of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Robert Sebra
- Department of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ernesto Guccione
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Terrence Tumpey
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Nevan Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
| | - Benjamin Greenbaum
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Division of Hematology and Oncology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Harm van Bakel
- Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Adolfo García-Sastre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ivan Marazzi
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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50
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Pegoraro M, Marshall H, Lonsdale ZN, Mallon EB. Do social insects support Haig's kin theory for the evolution of genomic imprinting? Epigenetics 2018; 12:725-742. [PMID: 28703654 PMCID: PMC5739101 DOI: 10.1080/15592294.2017.1348445] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Although numerous imprinted genes have been described in several lineages, the phenomenon of genomic imprinting presents a peculiar evolutionary problem. Several hypotheses have been proposed to explain gene imprinting, the most supported being Haig's kinship theory. This theory explains the observed pattern of imprinting and the resulting phenotypes as a competition for resources between related individuals, but despite its relevance it has not been independently tested. Haig's theory predicts that gene imprinting should be present in eusocial insects in many social scenarios. These lineages are therefore ideal for testing both the theory's predictions and the mechanism of gene imprinting. Here we review the behavioral evidence of genomic imprinting in eusocial insects, the evidence of a mechanism for genomic imprinting and finally we evaluate recent results showing parent of origin allele specific expression in honeybees in the light of Haig's theory.
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Affiliation(s)
- Mirko Pegoraro
- a Department of Genetics and Genome Biology , University of Leicester , UK
| | - Hollie Marshall
- a Department of Genetics and Genome Biology , University of Leicester , UK
| | - Zoë N Lonsdale
- a Department of Genetics and Genome Biology , University of Leicester , UK
| | - Eamonn B Mallon
- a Department of Genetics and Genome Biology , University of Leicester , UK
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