1
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Mehta P, Liu CSC, Sinha S, Mohite R, Arora S, Chattopadhyay P, Budhiraja S, Tarai B, Pandey R. Reduced protein-coding transcript diversity in severe dengue emphasises the role of alternative splicing. Life Sci Alliance 2024; 7:e202402683. [PMID: 38830771 PMCID: PMC11147948 DOI: 10.26508/lsa.202402683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/22/2024] [Accepted: 05/22/2024] [Indexed: 06/05/2024] Open
Abstract
Dengue fever, a neglected tropical arboviral disease, has emerged as a global health concern in the past decade. Necessitating a nuanced comprehension of the intricate dynamics of host-virus interactions influencing disease severity, we analysed transcriptomic patterns using bulk RNA-seq from 112 age- and gender-matched NS1 antigen-confirmed hospital-admitted dengue patients with varying severity. Severe cases exhibited reduced platelet count, increased lymphocytosis, and neutropenia, indicating a dysregulated immune response. Using bulk RNA-seq, our analysis revealed a minimal overlap between the differentially expressed gene and transcript isoform, with a distinct expression pattern across the disease severity. Severe patients showed enrichment in retained intron and nonsense-mediated decay transcript biotypes, suggesting altered splicing efficiency. Furthermore, an up-regulated programmed cell death, a haemolytic response, and an impaired interferon and antiviral response at the transcript level were observed. We also identified the potential involvement of the RBM39 gene among others in the innate immune response during dengue viral pathogenesis, warranting further investigation. These findings provide valuable insights into potential therapeutic targets, underscoring the importance of exploring transcriptomic landscapes between different disease sub-phenotypes in infectious diseases.
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Affiliation(s)
- Priyanka Mehta
- https://ror.org/05ef28661 Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Chinky Shiu Chen Liu
- https://ror.org/05ef28661 Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
| | - Sristi Sinha
- https://ror.org/05ef28661 Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
| | - Ramakant Mohite
- https://ror.org/05ef28661 Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
| | - Smriti Arora
- https://ror.org/05ef28661 Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
| | - Partha Chattopadhyay
- https://ror.org/05ef28661 Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Sandeep Budhiraja
- https://ror.org/00e7r7m66 Max Super Speciality Hospital (A Unit of Devki Devi Foundation), Max Healthcare, Delhi, India
| | - Bansidhar Tarai
- https://ror.org/00e7r7m66 Max Super Speciality Hospital (A Unit of Devki Devi Foundation), Max Healthcare, Delhi, India
| | - Rajesh Pandey
- https://ror.org/05ef28661 Division of Immunology and Infectious Disease Biology, INtegrative GENomics of HOst-PathogEn (INGEN-HOPE) Laboratory, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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2
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Bonnet C, Dian AL, Espie-Caullet T, Fabbri L, Lagadec L, Pivron T, Dutertre M, Luco R, Navickas A, Vagner S, Verga D, Uguen P. Post-transcriptional gene regulation: From mechanisms to RNA chemistry and therapeutics. Bull Cancer 2024; 111:782-790. [PMID: 38824069 DOI: 10.1016/j.bulcan.2024.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/22/2024] [Accepted: 04/03/2024] [Indexed: 06/03/2024]
Abstract
A better understanding of the RNA biology and chemistry is necessary to then develop new RNA therapeutic strategies. This review is the synthesis of a series of conferences that took place during the 6th international course on post-transcriptional gene regulation at Institut Curie. This year, the course made a special focus on RNA chemistry.
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Affiliation(s)
- Clara Bonnet
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France
| | - Ana Luisa Dian
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France
| | - Tristan Espie-Caullet
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France
| | - Lucilla Fabbri
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France
| | - Lucie Lagadec
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France
| | - Thibaud Pivron
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France
| | - Martin Dutertre
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France
| | - Reini Luco
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France
| | - Albertas Navickas
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France
| | - Stephan Vagner
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France
| | - Daniela Verga
- CNRS UMR9187, Inserm U1196, Chemistry and Modelling for the Biology of Cancer, Institut Curie, université Paris-Saclay, 91405 Orsay, France
| | - Patricia Uguen
- CNRS UMR3348 Genome integrity, RNA and Cancer, Institut Curie, University Paris-Saclay, 91401 Orsay, France.
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3
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Shine M, Gordon J, Schärfen L, Zigackova D, Herzel L, Neugebauer KM. Co-transcriptional gene regulation in eukaryotes and prokaryotes. Nat Rev Mol Cell Biol 2024; 25:534-554. [PMID: 38509203 PMCID: PMC11199108 DOI: 10.1038/s41580-024-00706-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2024] [Indexed: 03/22/2024]
Abstract
Many steps of RNA processing occur during transcription by RNA polymerases. Co-transcriptional activities are deemed commonplace in prokaryotes, in which the lack of membrane barriers allows mixing of all gene expression steps, from transcription to translation. In the past decade, an extraordinary level of coordination between transcription and RNA processing has emerged in eukaryotes. In this Review, we discuss recent developments in our understanding of co-transcriptional gene regulation in both eukaryotes and prokaryotes, comparing methodologies and mechanisms, and highlight striking parallels in how RNA polymerases interact with the machineries that act on nascent RNA. The development of RNA sequencing and imaging techniques that detect transient transcription and RNA processing intermediates has facilitated discoveries of transcription coordination with splicing, 3'-end cleavage and dynamic RNA folding and revealed physical contacts between processing machineries and RNA polymerases. Such studies indicate that intron retention in a given nascent transcript can prevent 3'-end cleavage and cause transcriptional readthrough, which is a hallmark of eukaryotic cellular stress responses. We also discuss how coordination between nascent RNA biogenesis and transcription drives fundamental aspects of gene expression in both prokaryotes and eukaryotes.
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Affiliation(s)
- Morgan Shine
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Jackson Gordon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Leonard Schärfen
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Dagmar Zigackova
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Lydia Herzel
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Berlin, Germany.
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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4
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Elvira-Blázquez D, Fernández-Justel JM, Arcas A, Statello L, Goñi E, González J, Ricci B, Zaccara S, Raimondi I, Huarte M. YTHDC1 m 6A-dependent and m 6A-independent functions converge to preserve the DNA damage response. EMBO J 2024:10.1038/s44318-024-00153-x. [PMID: 38951610 DOI: 10.1038/s44318-024-00153-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 05/07/2024] [Accepted: 06/05/2024] [Indexed: 07/03/2024] Open
Abstract
Cells have evolved a robust and highly regulated DNA damage response to preserve their genomic integrity. Although increasing evidence highlights the relevance of RNA regulation, our understanding of its impact on a fully efficient DNA damage response remains limited. Here, through a targeted CRISPR-knockout screen, we identify RNA-binding proteins and modifiers that participate in the p53 response. Among the top hits, we find the m6A reader YTHDC1 as a master regulator of p53 expression. YTHDC1 binds to the transcription start sites of TP53 and other genes involved in the DNA damage response, promoting their transcriptional elongation. YTHDC1 deficiency also causes the retention of introns and therefore aberrant protein production of key DNA damage factors. While YTHDC1-mediated intron retention requires m6A, TP53 transcriptional pause-release is promoted by YTHDC1 independently of m6A. Depletion of YTHDC1 causes genomic instability and aberrant cancer cell proliferation mediated by genes regulated by YTHDC1. Our results uncover YTHDC1 as an orchestrator of the DNA damage response through distinct mechanisms of co-transcriptional mRNA regulation.
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Affiliation(s)
- Daniel Elvira-Blázquez
- Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
- Institute of Health Research of Navarra (IdiSNA), Pamplona, Spain
| | - José Miguel Fernández-Justel
- Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
- Institute of Health Research of Navarra (IdiSNA), Pamplona, Spain
| | - Aida Arcas
- Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
- Institute of Health Research of Navarra (IdiSNA), Pamplona, Spain
- Clarivate, Barcelona, Spain
| | - Luisa Statello
- Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
- Institute of Health Research of Navarra (IdiSNA), Pamplona, Spain
| | - Enrique Goñi
- Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
- Institute of Health Research of Navarra (IdiSNA), Pamplona, Spain
| | - Jovanna González
- Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
- Institute of Health Research of Navarra (IdiSNA), Pamplona, Spain
| | - Benedetta Ricci
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Sara Zaccara
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Ivan Raimondi
- New York Genome Center, New York, NY, USA.
- Weill Cornell Medicine, New York, NY, USA.
| | - Maite Huarte
- Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.
- Institute of Health Research of Navarra (IdiSNA), Pamplona, Spain.
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5
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Tan CW, Sim DY, Zhen Y, Tian H, Koh J, Roca X. PRPF40A induces inclusion of exons in GC-rich regions important for human myeloid cell differentiation. Nucleic Acids Res 2024:gkae557. [PMID: 38943321 DOI: 10.1093/nar/gkae557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 06/07/2024] [Accepted: 06/19/2024] [Indexed: 07/01/2024] Open
Abstract
We characterized the regulatory mechanisms and role in human myeloid cell survival and differentiation of PRPF40A, a splicing factor lacking a canonical RNA Binding Domain. Upon PRPF40A knockdown, HL-60 cells displayed increased cell death, decreased proliferation and slight differentiation phenotype with upregulation of immune activation genes. Suggestive of both redundant and specific functions, cell death but not proliferation was rescued by overexpression of its paralog PRPF40B. Transcriptomic analysis revealed the predominant role of PRPF40A as an activator of cassette exon inclusion of functionally relevant splicing events. Mechanistically, the exons exclusively upregulated by PRPF40A are flanked by short and GC-rich introns which tend to localize to nuclear speckles in the nucleus center. These PRPF40A regulatory features are shared with other splicing regulators such as SRRM2, SON, PCBP1/2, and to a lesser extent TRA2B and SRSF2, as a part of a functional network that regulates splicing partly via co-localization in the nucleus.
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Affiliation(s)
- Cheryl Weiqi Tan
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Donald Yuhui Sim
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Yashu Zhen
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Haobo Tian
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Jace Koh
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Xavier Roca
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
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6
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Yustis JC, Devoucoux M, Côté J. The Functional Relationship Between RNA Splicing and the Chromatin Landscape. J Mol Biol 2024:168614. [PMID: 38762032 DOI: 10.1016/j.jmb.2024.168614] [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: 03/04/2024] [Revised: 04/27/2024] [Accepted: 05/13/2024] [Indexed: 05/20/2024]
Abstract
Chromatin is a highly regulated and dynamic structure that has been shown to play an essential role in transcriptional and co-transcriptional regulation. In the context of RNA splicing, early evidence suggested a loose connection between the chromatin landscape and splicing. More recently, it has been shown that splicing occurs in a co-transcriptional manner, meaning that the splicing process occurs in the context of chromatin. Experimental and computational evidence have also shown that chromatin dynamics can influence the splicing process and vice versa. However, much of this evidence provides mainly correlative relationships between chromatin and splicing with just a few concrete examples providing defined molecular mechanisms by which these two processes are functionally related. Nevertheless, it is clear that chromatin and RNA splicing are tightly interconnected to one another. In this review, we highlight the current state of knowledge of the relationship between chromatin and splicing.
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Affiliation(s)
- Juan-Carlos Yustis
- St-Patrick Research Group in Basic Oncology, Laval University Cancer Research Center, Oncology Division of the CHU de Québec-Université Laval Research Center, Quebec City, Quebec G1R 3S3, Canada
| | - Maëva Devoucoux
- St-Patrick Research Group in Basic Oncology, Laval University Cancer Research Center, Oncology Division of the CHU de Québec-Université Laval Research Center, Quebec City, Quebec G1R 3S3, Canada
| | - Jacques Côté
- St-Patrick Research Group in Basic Oncology, Laval University Cancer Research Center, Oncology Division of the CHU de Québec-Université Laval Research Center, Quebec City, Quebec G1R 3S3, Canada.
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7
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Bhat P, Chow A, Emert B, Ettlin O, Quinodoz SA, Strehle M, Takei Y, Burr A, Goronzy IN, Chen AW, Huang W, Ferrer JLM, Soehalim E, Goh ST, Chari T, Sullivan DK, Blanco MR, Guttman M. Genome organization around nuclear speckles drives mRNA splicing efficiency. Nature 2024; 629:1165-1173. [PMID: 38720076 PMCID: PMC11164319 DOI: 10.1038/s41586-024-07429-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 04/16/2024] [Indexed: 05/21/2024]
Abstract
The nucleus is highly organized, such that factors involved in the transcription and processing of distinct classes of RNA are confined within specific nuclear bodies1,2. One example is the nuclear speckle, which is defined by high concentrations of protein and noncoding RNA regulators of pre-mRNA splicing3. What functional role, if any, speckles might play in the process of mRNA splicing is unclear4,5. Here we show that genes localized near nuclear speckles display higher spliceosome concentrations, increased spliceosome binding to their pre-mRNAs and higher co-transcriptional splicing levels than genes that are located farther from nuclear speckles. Gene organization around nuclear speckles is dynamic between cell types, and changes in speckle proximity lead to differences in splicing efficiency. Finally, directed recruitment of a pre-mRNA to nuclear speckles is sufficient to increase mRNA splicing levels. Together, our results integrate the long-standing observations of nuclear speckles with the biochemistry of mRNA splicing and demonstrate a crucial role for dynamic three-dimensional spatial organization of genomic DNA in driving spliceosome concentrations and controlling the efficiency of mRNA splicing.
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Affiliation(s)
- Prashant Bhat
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Amy Chow
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Benjamin Emert
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Olivia Ettlin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Sofia A Quinodoz
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA
| | - Mackenzie Strehle
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Yodai Takei
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Alex Burr
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Isabel N Goronzy
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Allen W Chen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Wesley Huang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Jose Lorenzo M Ferrer
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Elizabeth Soehalim
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Say-Tar Goh
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Tara Chari
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Delaney K Sullivan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Mario R Blanco
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Mitchell Guttman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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8
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Atkinson R, Georgiou M, Yang C, Szymanska K, Lahat A, Vasconcelos EJR, Ji Y, Moya Molina M, Collin J, Queen R, Dorgau B, Watson A, Kurzawa-Akanbi M, Laws R, Saxena A, Shyan Beh C, Siachisumo C, Goertler F, Karwatka M, Davey T, Inglehearn CF, McKibbin M, Lührmann R, Steel DH, Elliott DJ, Armstrong L, Urlaub H, Ali RR, Grellscheid SN, Johnson CA, Mozaffari-Jovin S, Lako M. PRPF8-mediated dysregulation of hBrr2 helicase disrupts human spliceosome kinetics and 5´-splice-site selection causing tissue-specific defects. Nat Commun 2024; 15:3138. [PMID: 38605034 PMCID: PMC11009313 DOI: 10.1038/s41467-024-47253-0] [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: 09/21/2023] [Accepted: 03/19/2024] [Indexed: 04/13/2024] Open
Abstract
The carboxy-terminus of the spliceosomal protein PRPF8, which regulates the RNA helicase Brr2, is a hotspot for mutations causing retinitis pigmentosa-type 13, with unclear role in human splicing and tissue-specificity mechanism. We used patient induced pluripotent stem cells-derived cells, carrying the heterozygous PRPF8 c.6926 A > C (p.H2309P) mutation to demonstrate retinal-specific endophenotypes comprising photoreceptor loss, apical-basal polarity and ciliary defects. Comprehensive molecular, transcriptomic, and proteomic analyses revealed a role of the PRPF8/Brr2 regulation in 5'-splice site (5'SS) selection by spliceosomes, for which disruption impaired alternative splicing and weak/suboptimal 5'SS selection, and enhanced cryptic splicing, predominantly in ciliary and retinal-specific transcripts. Altered splicing efficiency, nuclear speckles organisation, and PRPF8 interaction with U6 snRNA, caused accumulation of active spliceosomes and poly(A)+ mRNAs in unique splicing clusters located at the nuclear periphery of photoreceptors. Collectively these elucidate the role of PRPF8/Brr2 regulatory mechanisms in splicing and the molecular basis of retinal disease, informing therapeutic approaches.
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Affiliation(s)
| | - Maria Georgiou
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Chunbo Yang
- Biosciences Institute, Newcastle University, Newcastle, UK
| | | | - Albert Lahat
- Department of Biosciences, Durham University, Durham, UK
| | | | - Yanlong Ji
- Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
- Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Marina Moya Molina
- Biosciences Institute, Newcastle University, Newcastle, UK
- Newcells Biotech, Newcastle, UK
| | - Joseph Collin
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Rachel Queen
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Birthe Dorgau
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Avril Watson
- Biosciences Institute, Newcastle University, Newcastle, UK
- Newcells Biotech, Newcastle, UK
| | | | - Ross Laws
- Electron Microscopy Research Services, Newcastle University, Newcastle, UK
| | - Abhijit Saxena
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Chia Shyan Beh
- Biosciences Institute, Newcastle University, Newcastle, UK
| | | | | | | | - Tracey Davey
- Electron Microscopy Research Services, Newcastle University, Newcastle, UK
| | | | - Martin McKibbin
- Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Reinhard Lührmann
- Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - David H Steel
- Biosciences Institute, Newcastle University, Newcastle, UK
| | | | - Lyle Armstrong
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Henning Urlaub
- Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
- Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
- Göttingen Center for Molecular Biosciences, Georg August University of Göttingen, Göttingen, Germany
| | - Robin R Ali
- Centre for Cell and Gene Therapy, Kings College London, London, UK
| | - Sushma-Nagaraja Grellscheid
- Department of Biosciences, Durham University, Durham, UK
- Department of Informatics, University of Bergen, Bergen, Norway
| | - Colin A Johnson
- Leeds Institute of Medical Research, University of Leeds, Leeds, UK.
| | - Sina Mozaffari-Jovin
- Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany.
- Department of Medical Genetics and Medical Genetics Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Majlinda Lako
- Biosciences Institute, Newcastle University, Newcastle, UK.
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9
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Da Cunha D, Miro J, Van Goethem C, Notarnicola C, Hugon G, Carnac G, Cossée M, Koenig M, Tuffery-Giraud S. The exon junction complex is required for DMD gene splicing fidelity and myogenic differentiation. Cell Mol Life Sci 2024; 81:150. [PMID: 38512499 PMCID: PMC10957711 DOI: 10.1007/s00018-024-05188-1] [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: 09/10/2023] [Revised: 02/14/2024] [Accepted: 02/28/2024] [Indexed: 03/23/2024]
Abstract
Deposition of the exon junction complex (EJC) upstream of exon-exon junctions helps maintain transcriptome integrity by preventing spurious re-splicing events in already spliced mRNAs. Here we investigate the importance of EJC for the correct splicing of the 2.2-megabase-long human DMD pre-mRNA, which encodes dystrophin, an essential protein involved in cytoskeletal organization and cell signaling. Using targeted RNA-seq, we show that knock-down of the eIF4A3 and Y14 core components of EJC in a human muscle cell line causes an accumulation of mis-splicing events clustered towards the 3' end of the DMD transcript (Dp427m). This deregulation is conserved in the short Dp71 isoform expressed ubiquitously except in adult skeletal muscle and is rescued with wild-type eIF4A3 and Y14 proteins but not with an EJC assembly-defective mutant eIF4A3. MLN51 protein and EJC-associated ASAP/PSAP complexes independently modulate the inclusion of the regulated exons 71 and 78. Our data confirm the protective role of EJC in maintaining splicing fidelity, which in the DMD gene is necessary to preserve the function of the critical C-terminal protein-protein interaction domain of dystrophin present in all tissue-specific isoforms. Given the role of the EJC in maintaining the integrity of dystrophin, we asked whether the EJC could also be involved in the regulation of a mechanism as complex as skeletal muscle differentiation. We found that eIF4A3 knockdown impairs myogenic differentiation by blocking myotube formation. Collectively, our data provide new insights into the functional roles of EJC in human skeletal muscle.
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Affiliation(s)
- Dylan Da Cunha
- PhyMedExp, Univ Montpellier, CNRS, INSERM, Montpellier, France
| | - Julie Miro
- PhyMedExp, Univ Montpellier, CNRS, INSERM, Montpellier, France
| | - Charles Van Goethem
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Montpellier, France
- Montpellier BioInformatique Pour Le Diagnostic Clinique (MOBIDIC), Plateau de Médecine Moléculaire Et Génomique (PMMG), CHU Montpellier, 34295, Montpellier, France
| | | | - Gérald Hugon
- PhyMedExp, Univ Montpellier, CNRS, INSERM, Montpellier, France
| | - Gilles Carnac
- PhyMedExp, Univ Montpellier, CNRS, INSERM, Montpellier, France
| | - Mireille Cossée
- PhyMedExp, Univ Montpellier, CNRS, INSERM, Montpellier, France
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Montpellier, France
| | - Michel Koenig
- PhyMedExp, Univ Montpellier, CNRS, INSERM, Montpellier, France
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Montpellier, France
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10
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Marie P, Bazire M, Ladet J, Ameur LB, Chahar S, Fontrodona N, Sexton T, Auboeuf D, Bourgeois CF, Mortreux F. Gene-to-gene coordinated regulation of transcription and alternative splicing by 3D chromatin remodeling upon NF-κB activation. Nucleic Acids Res 2024; 52:1527-1543. [PMID: 38272542 PMCID: PMC10899780 DOI: 10.1093/nar/gkae015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 12/13/2023] [Accepted: 01/05/2024] [Indexed: 01/27/2024] Open
Abstract
The NF-κB protein p65/RelA plays a pivotal role in coordinating gene expression in response to diverse stimuli, including viral infections. At the chromatin level, p65/RelA regulates gene transcription and alternative splicing through promoter enrichment and genomic exon occupancy, respectively. The intricate ways in which p65/RelA simultaneously governs these functions across various genes remain to be fully elucidated. In this study, we employed the HTLV-1 Tax oncoprotein, a potent activator of NF-κB, to investigate its influence on the three-dimensional organization of the genome, a key factor in gene regulation. We discovered that Tax restructures the 3D genomic landscape, bringing together genes based on their regulation and splicing patterns. Notably, we found that the Tax-induced gene-gene contact between the two master genes NFKBIA and RELA is associated with their respective changes in gene expression and alternative splicing. Through dCas9-mediated approaches, we demonstrated that NFKBIA-RELA interaction is required for alternative splicing regulation and is caused by an intragenic enrichment of p65/RelA on RELA. Our findings shed light on new regulatory mechanisms upon HTLV-1 Tax and underscore the integral role of p65/RelA in coordinated regulation of NF-κB-responsive genes at both transcriptional and splicing levels in the context of the 3D genome.
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Affiliation(s)
- Paul Marie
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Matéo Bazire
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Julien Ladet
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Lamya Ben Ameur
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Sanjay Chahar
- Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Nicolas Fontrodona
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Tom Sexton
- Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Didier Auboeuf
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Cyril F Bourgeois
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Franck Mortreux
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d’Italie Site Jacques Monod, F-69007 Lyon, France
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11
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Naro C, Antonioni A, Medici V, Caggiano C, Jolly A, de la Grange P, Bielli P, Paronetto MP, Sette C. Splicing targeting drugs highlight intron retention as an actionable vulnerability in advanced prostate cancer. J Exp Clin Cancer Res 2024; 43:58. [PMID: 38413979 PMCID: PMC10898177 DOI: 10.1186/s13046-024-02986-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/15/2024] [Indexed: 02/29/2024] Open
Abstract
BACKGROUND Advanced prostate cancer (PC) is characterized by insensitivity to androgen deprivation therapy and chemotherapy, resulting in poor outcome for most patients. Thus, advanced PC urgently needs novel therapeutic strategies. Mounting evidence points to splicing dysregulation as a hallmark of advanced PC. Moreover, pharmacologic inhibition of the splicing process is emerging as a promising option for this disease. METHOD By using a representative androgen-insensitive PC cell line (22Rv1), we have investigated the genome-wide transcriptomic effects underlying the cytotoxic effects exerted by three splicing-targeting drugs: Pladienolide B, indisulam and THZ531. Bioinformatic analyses were performed to uncover the gene structural features underlying sensitivity to transcriptional and splicing regulation by these treatments. Biological pathways altered by these treatments were annotated by gene ontology analyses and validated by functional experiments in cell models. RESULTS Although eliciting similar cytotoxic effects on advanced PC cells, Pladienolide B, indisulam and THZ531 modulate specific transcriptional and splicing signatures. Drug sensitivity is associated with distinct gene structural features, expression levels and cis-acting sequence elements in the regulated exons and introns. Importantly, we identified PC-relevant genes (i.e. EZH2, MDM4) whose drug-induced splicing alteration exerts an impact on cell survival. Moreover, computational analyses uncovered a widespread impact of splicing-targeting drugs on intron retention, with enrichment in genes implicated in pre-mRNA 3'-end processing (i.e. CSTF3, PCF11). Coherently, advanced PC cells displayed high sensitivity to a specific inhibitor of the cleavage and polyadenylation complex, which enhances the effects of chemotherapeutic drugs that are already in use for this cancer. CONCLUSIONS Our study uncovers intron retention as an actionable vulnerability for advanced PC, which may be exploited to improve therapeutic management of this currently incurable disease.
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Affiliation(s)
- Chiara Naro
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168, Rome, Italy
- GSTeP Organoids Research Core Facility, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168, Rome, Italy
| | - Ambra Antonioni
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168, Rome, Italy
| | - Vanessa Medici
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168, Rome, Italy
| | - Cinzia Caggiano
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168, Rome, Italy
- GSTeP Organoids Research Core Facility, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168, Rome, Italy
| | | | | | - Pamela Bielli
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133, Rome, Italy
| | - Maria Paola Paronetto
- Laboratory of Molecular and Cellular Neurobiology, IRCCS Fondazione Santa Lucia, 00143, Rome, Italy
- University of Rome Foro Italico, 00135, Rome, Italy
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168, Rome, Italy.
- GSTeP Organoids Research Core Facility, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168, Rome, Italy.
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12
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Palazzo AF, Qiu Y, Kang YM. mRNA nuclear export: how mRNA identity features distinguish functional RNAs from junk transcripts. RNA Biol 2024; 21:1-12. [PMID: 38091265 PMCID: PMC10732640 DOI: 10.1080/15476286.2023.2293339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2023] [Indexed: 12/18/2023] Open
Abstract
The division of the cellular space into nucleoplasm and cytoplasm promotes quality control mechanisms that prevent misprocessed mRNAs and junk RNAs from gaining access to the translational machinery. Here, we explore how properly processed mRNAs are distinguished from both misprocessed mRNAs and junk RNAs by the presence or absence of various 'identity features'.
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Affiliation(s)
| | - Yi Qiu
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Yoon Mo Kang
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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13
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Wang C, Xu L, Du C, Yun H, Wang K, Liu H, Ye M, Fan J, Zhou Y, Cheng H. CDK11 requires a critical activator SAP30BP to regulate pre-mRNA splicing. EMBO J 2023; 42:e114051. [PMID: 38059508 PMCID: PMC10711644 DOI: 10.15252/embj.2023114051] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 12/08/2023] Open
Abstract
CDK11 is an emerging druggable target for cancer therapy due to its prevalent roles in phosphorylating critical transcription and splicing factors and in facilitating cell cycle progression in cancer cells. Like other cyclin-dependent kinases, CDK11 requires its cognate cyclin, cyclin L1 or cyclin L2, for activation. However, little is known about how CDK11 activities might be modulated by other regulators. In this study, we show that CDK11 forms a tight complex with cyclins L1/L2 and SAP30BP, the latter of which is a poorly characterized factor. Acute degradation of SAP30BP mirrors that of CDK11 in causing widespread and strong defects in pre-mRNA splicing. Furthermore, we demonstrate that SAP30BP facilitates CDK11 kinase activities in vitro and in vivo, through ensuring the stabilities and the assembly of cyclins L1/L2 with CDK11. Together, these findings uncover SAP30BP as a critical CDK11 activator that regulates global pre-mRNA splicing.
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Affiliation(s)
- Changshou Wang
- Key Laboratory of RNA Science and Engineering, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell ScienceChinese Academy of Sciences, University of Chinese Academy of SciencesShanghaiChina
| | - Lin Xu
- Key Laboratory of RNA Science and Engineering, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell ScienceChinese Academy of Sciences, University of Chinese Academy of SciencesShanghaiChina
| | - Chen Du
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA Institute, Hubei Key Laboratory of Cell HomeostasisWuhan UniversityWuhanChina§
| | - Hao Yun
- Key Laboratory of RNA Science and Engineering, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell ScienceChinese Academy of Sciences, University of Chinese Academy of SciencesShanghaiChina
| | - Keyun Wang
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianChina
| | - Hui Liu
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhouChina
| | - Mingliang Ye
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianChina
| | - Jing Fan
- Key Laboratory of RNA Science and Engineering, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell ScienceChinese Academy of Sciences, University of Chinese Academy of SciencesShanghaiChina
| | - Yu Zhou
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA Institute, Hubei Key Laboratory of Cell HomeostasisWuhan UniversityWuhanChina§
| | - Hong Cheng
- Key Laboratory of RNA Science and Engineering, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell ScienceChinese Academy of Sciences, University of Chinese Academy of SciencesShanghaiChina
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhouChina
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14
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Pascal C, Zonszain J, Hameiri O, Gargi-Levi C, Lev-Maor G, Tammer L, Levy T, Tarabeih A, Roy VR, Ben-Salmon S, Elbaz L, Eid M, Hakim T, Abu Rabe'a S, Shalev N, Jordan A, Meshorer E, Ast G. Human histone H1 variants impact splicing outcome by controlling RNA polymerase II elongation. Mol Cell 2023; 83:3801-3817.e8. [PMID: 37922872 DOI: 10.1016/j.molcel.2023.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 08/17/2023] [Accepted: 10/05/2023] [Indexed: 11/07/2023]
Abstract
Histones shape chromatin structure and the epigenetic landscape. H1, the most diverse histone in the human genome, has 11 variants. Due to the high structural similarity between the H1s, their unique functions in transferring information from the chromatin to mRNA-processing machineries have remained elusive. Here, we generated human cell lines lacking up to five H1 subtypes, allowing us to characterize the genomic binding profiles of six H1 variants. Most H1s bind to specific sites, and binding depends on multiple factors, including GC content. The highly expressed H1.2 has a high affinity for exons, whereas H1.3 binds intronic sequences. H1s are major splicing regulators, especially of exon skipping and intron retention events, through their effects on the elongation of RNA polymerase II (RNAPII). Thus, H1 variants determine splicing fate by modulating RNAPII elongation.
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Affiliation(s)
- Corina Pascal
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Jonathan Zonszain
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ofir Hameiri
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Chen Gargi-Levi
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Galit Lev-Maor
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Luna Tammer
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Tamar Levy
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Anan Tarabeih
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Vanessa Rachel Roy
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Stav Ben-Salmon
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Liraz Elbaz
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Mireille Eid
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Tamar Hakim
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Salima Abu Rabe'a
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nana Shalev
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Albert Jordan
- Instituto de Biologia Molecular de Barcelona (IBMB-CSIC), Carrer de Baldiri Reixac, 15, 08028 Barcelona, Spain
| | - Eran Meshorer
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, Jerusalem 91904, Israel; Edmond and Lily Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Gil Ast
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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15
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Schmit JD, Dundr M. Keeping membraneless organelles apart. Nat Cell Biol 2023; 25:1566-1567. [PMID: 37932454 DOI: 10.1038/s41556-023-01265-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Affiliation(s)
- Jeremy D Schmit
- Department of Physics, Kansas State University, Manhattan, KS, USA
| | - Miroslav Dundr
- Center for Cancer Cell Biology, Rosalind Franklin University of Medicine & Science, Chicago Medical School, North Chicago, IL, USA.
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16
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Papadaki V, Erpapazoglou Z, Kokkori M, Rogalska M, Potiri M, Birladeanu A, Tsakiri E, Ashktorab H, Smoot D, Papanikolopoulou K, Samiotaki M, Kafasla P. IQGAP1 mediates the communication between the nucleus and the mitochondria via NDUFS4 alternative splicing. NAR Cancer 2023; 5:zcad046. [PMID: 37636315 PMCID: PMC10448856 DOI: 10.1093/narcan/zcad046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 08/04/2023] [Accepted: 08/10/2023] [Indexed: 08/29/2023] Open
Abstract
Constant communication between mitochondria and nucleus ensures cellular homeostasis and adaptation to mitochondrial stress. Anterograde regulatory pathways involving a large number of nuclear-encoded proteins control mitochondrial biogenesis and functions. Such functions are deregulated in cancer cells, resulting in proliferative advantages, aggressive disease and therapeutic resistance. Transcriptional networks controlling the nuclear-encoded mitochondrial genes are known, however alternative splicing (AS) regulation has not been implicated in this communication. Here, we show that IQGAP1, a scaffold protein regulating AS of distinct gene subsets in gastric cancer cells, participates in AS regulation that strongly affects mitochondrial respiration. Combined proteomic and RNA-seq analyses of IQGAP1KO and parental cells show that IQGAP1KO alters an AS event of the mitochondrial respiratory chain complex I (CI) subunit NDUFS4 and downregulates a subset of CI subunits. In IQGAP1KO cells, CI intermediates accumulate, resembling assembly deficiencies observed in patients with Leigh syndrome bearing NDUFS4 mutations. Mitochondrial CI activity is significantly lower in KO compared to parental cells, while exogenous expression of IQGAP1 reverses mitochondrial defects of IQGAP1KO cells. Our work sheds light to a novel facet of IQGAP1 in mitochondrial quality control that involves fine-tuning of CI activity through AS regulation in gastric cancer cells relying highly on mitochondrial respiration.
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Affiliation(s)
- Vasiliki Papadaki
- Institute for Fundamental Biomedical Research, BSRC “Al. Fleming”, Vari 16672, Greece
| | - Zoi Erpapazoglou
- Institute for Fundamental Biomedical Research, BSRC “Al. Fleming”, Vari 16672, Greece
| | - Maria Kokkori
- Institute for Fundamental Biomedical Research, BSRC “Al. Fleming”, Vari 16672, Greece
| | - Malgorzata Ewa Rogalska
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Myrto Potiri
- Institute for Fundamental Biomedical Research, BSRC “Al. Fleming”, Vari 16672, Greece
| | - Andrada Birladeanu
- Institute for Fundamental Biomedical Research, BSRC “Al. Fleming”, Vari 16672, Greece
| | - Eleni N Tsakiri
- Institute for Fundamental Biomedical Research, BSRC “Al. Fleming”, Vari 16672, Greece
| | - Hassan Ashktorab
- Department of Medicine and Cancer Center, Howard University, Washington, DC, USA
| | - Duane T Smoot
- Department of Medicine, Meharry Medical Center, Nashville, TN, USA
| | | | | | - Panagiota Kafasla
- Institute for Fundamental Biomedical Research, BSRC “Al. Fleming”, Vari 16672, Greece
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17
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Ebersberger S, Hipp C, Mulorz MM, Buchbender A, Hubrich D, Kang HS, Martínez-Lumbreras S, Kristofori P, Sutandy FXR, Llacsahuanga Allcca L, Schönfeld J, Bakisoglu C, Busch A, Hänel H, Tretow K, Welzel M, Di Liddo A, Möckel MM, Zarnack K, Ebersberger I, Legewie S, Luck K, Sattler M, König J. FUBP1 is a general splicing factor facilitating 3' splice site recognition and splicing of long introns. Mol Cell 2023:S1097-2765(23)00516-6. [PMID: 37506698 DOI: 10.1016/j.molcel.2023.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 05/19/2023] [Accepted: 07/03/2023] [Indexed: 07/30/2023]
Abstract
Splicing of pre-mRNAs critically contributes to gene regulation and proteome expansion in eukaryotes, but our understanding of the recognition and pairing of splice sites during spliceosome assembly lacks detail. Here, we identify the multidomain RNA-binding protein FUBP1 as a key splicing factor that binds to a hitherto unknown cis-regulatory motif. By collecting NMR, structural, and in vivo interaction data, we demonstrate that FUBP1 stabilizes U2AF2 and SF1, key components at the 3' splice site, through multivalent binding interfaces located within its disordered regions. Transcriptional profiling and kinetic modeling reveal that FUBP1 is required for efficient splicing of long introns, which is impaired in cancer patients harboring FUBP1 mutations. Notably, FUBP1 interacts with numerous U1 snRNP-associated proteins, suggesting a unique role for FUBP1 in splice site bridging for long introns. We propose a compelling model for 3' splice site recognition of long introns, which represent 80% of all human introns.
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Affiliation(s)
| | - Clara Hipp
- Institute of Structural Biology, Helmholtz Center Munich, 85764 Neuherberg, Germany; Bavarian NMR Center, Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85747 Garching, Germany
| | - Miriam M Mulorz
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany
| | | | - Dalmira Hubrich
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany
| | - Hyun-Seo Kang
- Institute of Structural Biology, Helmholtz Center Munich, 85764 Neuherberg, Germany; Bavarian NMR Center, Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85747 Garching, Germany
| | - Santiago Martínez-Lumbreras
- Institute of Structural Biology, Helmholtz Center Munich, 85764 Neuherberg, Germany; Bavarian NMR Center, Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85747 Garching, Germany
| | - Panajot Kristofori
- Department of Systems Biology, Institute for Biomedical Genetics (IBMG), University of Stuttgart, 70569 Stuttgart, Germany
| | | | | | - Jonas Schönfeld
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany
| | - Cem Bakisoglu
- Buchmann Institute for Molecular Life Sciences & Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Anke Busch
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany
| | - Heike Hänel
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany
| | - Kerstin Tretow
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany
| | - Mareen Welzel
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany
| | | | - Martin M Möckel
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany
| | - Kathi Zarnack
- Buchmann Institute for Molecular Life Sciences & Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; CardioPulmonary Institute (CPI), 35392 Gießen, Germany
| | - Ingo Ebersberger
- Applied Bioinformatics Group, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; Senckenberg Biodiversity and Climate Research Center (S-BIK-F), 60325 Frankfurt am Main, Germany; LOEWE Center for Translational Biodiversity Genomics (TBG), 60325 Frankfurt am Main, Germany
| | - Stefan Legewie
- Department of Systems Biology, Institute for Biomedical Genetics (IBMG), University of Stuttgart, 70569 Stuttgart, Germany; Stuttgart Research Center for Systems Biology (SRCSB), University of Stuttgart, 70569 Stuttgart, Germany
| | - Katja Luck
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany.
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Center Munich, 85764 Neuherberg, Germany; Bavarian NMR Center, Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85747 Garching, Germany.
| | - Julian König
- Institute of Molecular Biology (IMB) gGmbH, 55128 Mainz, Germany.
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18
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Girardini KN, Olthof AM, Kanadia RN. Introns: the "dark matter" of the eukaryotic genome. Front Genet 2023; 14:1150212. [PMID: 37260773 PMCID: PMC10228655 DOI: 10.3389/fgene.2023.1150212] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/28/2023] [Indexed: 06/02/2023] Open
Abstract
The emergence of introns was a significant evolutionary leap that is a major distinguishing feature between prokaryotic and eukaryotic genomes. While historically introns were regarded merely as the sequences that are removed to produce spliced transcripts encoding functional products, increasingly data suggests that introns play important roles in the regulation of gene expression. Here, we use an intron-centric lens to review the role of introns in eukaryotic gene expression. First, we focus on intron architecture and how it may influence mechanisms of splicing. Second, we focus on the implications of spliceosomal snRNAs and their variants on intron splicing. Finally, we discuss how the presence of introns and the need to splice them influences transcription regulation. Despite the abundance of introns in the eukaryotic genome and their emerging role regulating gene expression, a lot remains unexplored. Therefore, here we refer to introns as the "dark matter" of the eukaryotic genome and discuss some of the outstanding questions in the field.
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Affiliation(s)
- Kaitlin N. Girardini
- Physiology and Neurobiology Department, University of Connecticut, Storrs, CT, United States
| | - Anouk M. Olthof
- Physiology and Neurobiology Department, University of Connecticut, Storrs, CT, United States
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Rahul N. Kanadia
- Physiology and Neurobiology Department, University of Connecticut, Storrs, CT, United States
- Institute for Systems Genomics, University of Connecticut, Storrs, CT, United States
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19
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Guo X, Wang T, Jiang L, Qi H, Zhang Z. PlaASDB: a comprehensive database of plant alternative splicing events in response to stress. BMC PLANT BIOLOGY 2023; 23:225. [PMID: 37106367 PMCID: PMC10134664 DOI: 10.1186/s12870-023-04234-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 04/18/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUND Alternative splicing (AS) is a co-transcriptional regulatory mechanism of plants in response to environmental stress. However, the role of AS in biotic and abiotic stress responses remains largely unknown. To speed up our understanding of plant AS patterns under different stress responses, development of informative and comprehensive plant AS databases is highly demanded. DESCRIPTION In this study, we first collected 3,255 RNA-seq data under biotic and abiotic stresses from two important model plants (Arabidopsis and rice). Then, we conducted AS event detection and gene expression analysis, and established a user-friendly plant AS database termed PlaASDB. By using representative samples from this highly integrated database resource, we compared AS patterns between Arabidopsis and rice under abiotic and biotic stresses, and further investigated the corresponding difference between AS and gene expression. Specifically, we found that differentially spliced genes (DSGs) and differentially expressed genes (DEG) share very limited overlapping under all kinds of stresses, suggesting that gene expression regulation and AS seemed to play independent roles in response to stresses. Compared with gene expression, Arabidopsis and rice were more inclined to have conserved AS patterns under stress conditions. CONCLUSION PlaASDB is a comprehensive plant-specific AS database that mainly integrates the AS and gene expression data of Arabidopsis and rice in stress response. Through large-scale comparative analyses, the global landscape of AS events in Arabidopsis and rice was observed. We believe that PlaASDB could help researchers understand the regulatory mechanisms of AS in plants under stresses more conveniently. PlaASDB is freely accessible at http://zzdlab.com/PlaASDB/ASDB/index.html .
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Affiliation(s)
- Xiaokun Guo
- State Key Laboratory of Farm Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Tianpeng Wang
- State Key Laboratory of Farm Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
| | - Linyang Jiang
- State Key Laboratory of Farm Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Huan Qi
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ziding Zhang
- State Key Laboratory of Farm Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
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20
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Rogalska ME, Vivori C, Valcárcel J. Regulation of pre-mRNA splicing: roles in physiology and disease, and therapeutic prospects. Nat Rev Genet 2023; 24:251-269. [PMID: 36526860 DOI: 10.1038/s41576-022-00556-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2022] [Indexed: 12/23/2022]
Abstract
The removal of introns from mRNA precursors and its regulation by alternative splicing are key for eukaryotic gene expression and cellular function, as evidenced by the numerous pathologies induced or modified by splicing alterations. Major recent advances have been made in understanding the structures and functions of the splicing machinery, in the description and classification of physiological and pathological isoforms and in the development of the first therapies for genetic diseases based on modulation of splicing. Here, we review this progress and discuss important remaining challenges, including predicting splice sites from genomic sequences, understanding the variety of molecular mechanisms and logic of splicing regulation, and harnessing this knowledge for probing gene function and disease aetiology and for the design of novel therapeutic approaches.
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Affiliation(s)
- Malgorzata Ewa Rogalska
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Claudia Vivori
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain
- The Francis Crick Institute, London, UK
| | - Juan Valcárcel
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
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21
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Bouwman BA, Crosetto N, Bienko M. A GC-centered view of 3D genome organization. Curr Opin Genet Dev 2023; 78:102020. [PMID: 36610373 DOI: 10.1016/j.gde.2022.102020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/30/2022] [Accepted: 12/03/2022] [Indexed: 01/07/2023]
Abstract
In the past two decades, our understanding of how the genome of mammalian cells is spatially organized in the three-dimensional (3D) space of the nucleus and how key nuclear processes are orchestrated in this space has drastically expanded. While genome organization has been extensively studied at the nanoscale, the higher-order arrangement of individual portions of the genome with respect to their intranuclear as well as reciprocal placement is less thoroughly characterized. Emerging evidence points to the existence of a complex radial arrangement of chromatin in the nucleus. However, what shapes this radial organization and whether it has any functional implications remain elusive. In this mini review, we first summarize our current knowledge on this rather overlooked aspect of mammalian genome organization. We then present a theoretical framework for explaining how the genome might be radially organized, focusing on the role of the guanine and cytosine density along the linear genome. Last, we discuss outstanding questions, hoping to inspire future experiments and spark interest in this topic within the 3D genome community.
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Affiliation(s)
- Britta Am Bouwman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm SE-17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Solna SE-17165, Sweden
| | - Nicola Crosetto
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm SE-17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Solna SE-17165, Sweden; Human Technopole, Viale Rita Levi-Montalcini 1, 20157 Milan, Italy
| | - Magda Bienko
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm SE-17165, Sweden; Science for Life Laboratory, Tomtebodavägen 23A, Solna SE-17165, Sweden; Human Technopole, Viale Rita Levi-Montalcini 1, 20157 Milan, Italy.
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22
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Zeng Y, Fair BJ, Zeng H, Krishnamohan A, Hou Y, Hall JM, Ruthenburg AJ, Li YI, Staley JP. Profiling lariat intermediates reveals genetic determinants of early and late co-transcriptional splicing. Mol Cell 2022; 82:4681-4699.e8. [PMID: 36435176 PMCID: PMC10448999 DOI: 10.1016/j.molcel.2022.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 09/10/2022] [Accepted: 11/02/2022] [Indexed: 11/27/2022]
Abstract
Long introns with short exons in vertebrate genes are thought to require spliceosome assembly across exons (exon definition), rather than introns, thereby requiring transcription of an exon to splice an upstream intron. Here, we developed CoLa-seq (co-transcriptional lariat sequencing) to investigate the timing and determinants of co-transcriptional splicing genome wide. Unexpectedly, 90% of all introns, including long introns, can splice before transcription of a downstream exon, indicating that exon definition is not obligatory for most human introns. Still, splicing timing varies dramatically across introns, and various genetic elements determine this variation. Strong U2AF2 binding to the polypyrimidine tract predicts early splicing, explaining exon definition-independent splicing. Together, our findings question the essentiality of exon definition and reveal features beyond intron and exon length that are determinative for splicing timing.
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Affiliation(s)
- Yi Zeng
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Benjamin J Fair
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Huilin Zeng
- 855 Jefferson Ave. Redwood City, CA 94063, USA
| | - Aiswarya Krishnamohan
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Yichen Hou
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Johnathon M Hall
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Alexander J Ruthenburg
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA; Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Yang I Li
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA; Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA.
| | - Jonathan P Staley
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA.
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23
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Faber GP, Nadav-Eliyahu S, Shav-Tal Y. Nuclear speckles - a driving force in gene expression. J Cell Sci 2022; 135:275909. [PMID: 35788677 DOI: 10.1242/jcs.259594] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Nuclear speckles are dynamic membraneless bodies located in the cell nucleus. They harbor RNAs and proteins, many of which are splicing factors, that together display complex biophysical properties dictating nuclear speckle formation and maintenance. Although these nuclear bodies were discovered decades ago, only recently has in-depth genomic analysis begun to unravel their essential functions in modulation of gene activity. Major advancements in genomic mapping techniques combined with microscopy approaches have enabled insights into the roles nuclear speckles may play in enhancing gene expression, and how gene positioning to specific nuclear landmarks can regulate gene expression and RNA processing. Some studies have drawn a link between nuclear speckles and disease. Certain maladies either involve nuclear speckles directly or dictate the localization and reorganization of many nuclear speckle factors. This is most striking during viral infection, as viruses alter the entire nuclear architecture and highjack host machinery. As discussed in this Review, nuclear speckles represent a fascinating target of study not only to reveal the links between gene positioning, genome subcompartments and gene activity, but also as a potential target for therapeutics.
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Affiliation(s)
- Gabriel P Faber
- The Mina and Everard Goodman Faculty of Life Sciences , Bar-Ilan University, Ramat Gan 5290002, Israel.,Institute of Nanotechnology , Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Shani Nadav-Eliyahu
- The Mina and Everard Goodman Faculty of Life Sciences , Bar-Ilan University, Ramat Gan 5290002, Israel.,Institute of Nanotechnology , Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Yaron Shav-Tal
- The Mina and Everard Goodman Faculty of Life Sciences , Bar-Ilan University, Ramat Gan 5290002, Israel.,Institute of Nanotechnology , Bar-Ilan University, Ramat Gan 5290002, Israel
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24
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Gutiérrez J, van Wely KHM, Martínez-A C. Hepatitis, testicular degeneration, and ataxia in DIDO3-deficient mice with altered mRNA processing. Cell Biosci 2022; 12:84. [PMID: 35672775 PMCID: PMC9172153 DOI: 10.1186/s13578-022-00804-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 04/26/2022] [Indexed: 11/15/2022] Open
Abstract
Background mRNA processing is an essential step of gene expression; its malfunction can lead to different degrees of physiological disorder from subclinical disease to death. We previously identified Dido1 as a stemness marker and a gene involved in embryonic stem cell differentiation. DIDO3, the largest protein encoded by the Dido1 gene, is necessary for accurate mRNA splicing and correct transcription termination. The deletion of Dido1 exon16, which encodes the carboxy-terminal half of DIDO3, results in early embryonic lethality in mouse. Results We obtained mice bearing a Cre-LoxP conditional version of that deletion and studied the effects of inducing it ubiquitously in adult stages. DIDO3-deficient mice survive the deletion but suffer mild hepatitis, testicular degeneration, and progressive ataxia, in association with systemic alterations in mRNA splicing and transcriptional readthrough. Conclusions These results offer insight into the distinct vulnerabilities in mouse organs following impairment of the mRNA processing machinery, and could aid understanding of human health dependence on accurate mRNA metabolism. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00804-8.
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25
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Systematic mapping of nuclear domain-associated transcripts reveals speckles and lamina as hubs of functionally distinct retained introns. Mol Cell 2022; 82:1035-1052.e9. [PMID: 35182477 DOI: 10.1016/j.molcel.2021.12.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 12/22/2022]
Abstract
The nucleus is highly compartmentalized through the formation of distinct classes of membraneless domains. However, the composition and function of many of these structures are not well understood. Using APEX2-mediated proximity labeling and RNA sequencing, we surveyed human transcripts associated with nuclear speckles, several additional domains, and the lamina. Remarkably, speckles and lamina are associated with distinct classes of retained introns enriched in genes that function in RNA processing, translation, and the cell cycle, among other processes. In contrast to the lamina-proximal introns, retained introns associated with speckles are relatively short, GC-rich, and enriched for functional sites of RNA-binding proteins that are concentrated in these domains. They are also highly differentially regulated across diverse cellular contexts, including the cell cycle. Thus, our study provides a resource of nuclear domain-associated transcripts and further reveals speckles and lamina as hubs of distinct populations of retained introns linked to gene regulation and cell cycle progression.
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26
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Abstract
Alternative splicing enables higher eukaryotes to expand mRNA diversity from a finite number of genes through highly combinatorial splice site selection mechanisms that are influenced by the sequence of competing splice sites, cis-regulatory elements binding trans-acting factors, the length of exons and introns harbouring alternative splice sites and RNA secondary structures at putative splice junctions. To test the hypothesis that the intron definition or exon definition modes of splice site recognition direct the selection of alternative splice patterns, we created a database of alternative splice site usage (ALTssDB). When alternative splice sites are embedded within short introns (intron definition), the 5' and 3' splice sites closest to each other across the intron preferentially pair, consistent with previous observations. However, when alternative splice sites are embedded within large flanking introns (exon definition), the 5' and 3' splice sites closest to each other across the exon are preferentially selected. Thus, alternative splicing decisions are influenced by the intron and exon definition modes of splice site recognition. The results demonstrate that the spliceosome pairs splice sites that are closest in proximity within the unit of initial splice site selection.
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Affiliation(s)
- Francisco Carranza
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, California, USA
| | - Hossein Shenasa
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, California, USA
| | - Klemens J Hertel
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, California, USA
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