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Liu C, Dou X, Zhao Y, Zhang L, Zhang L, Dai Q, Liu J, Wu T, Xiao Y, He C. IGF2BP3 promotes mRNA degradation through internal m 7G modification. Nat Commun 2024; 15:7421. [PMID: 39198433 PMCID: PMC11358264 DOI: 10.1038/s41467-024-51634-w] [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: 08/24/2023] [Accepted: 08/11/2024] [Indexed: 09/01/2024] Open
Abstract
Recent studies have suggested that mRNA internal m7G and its writer protein METTL1 are closely related to cell metabolism and cancer regulation. Here, we identify that IGF2BP family proteins IGF2BP1-3 can preferentially bind internal mRNA m7G. Such interactions, especially IGF2BP3 with m7G, could promote the degradation of m7G target transcripts in cancer cells. IGF2BP3 is more responsive to changes of m7G modification, while IGF2BP1 prefers m6A to stabilize the bound transcripts. We also demonstrate that p53 transcript, TP53, is m7G-modified at its 3'UTR in cancer cells. In glioblastoma, the methylation level and the half lifetime of the modified transcript could be modulated by tuning IGF2BP3, or by site-specific targeting of m7G through a dCas13b-guided system, resulting in modulation of cancer progression and chemosensitivity.
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Affiliation(s)
- Chang Liu
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA
- Department of Genetics, School of Medicine, Stanford University, Stanford, CA, 94305, USA
| | - Xiaoyang Dou
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - Yutao Zhao
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - Linda Zhang
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - Lisheng Zhang
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
- Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Qing Dai
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - Jun Liu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
- Beijing Advanced Center of RNA Biology (BEACON), Peking University, Beijing, 100871, China
| | - Tong Wu
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - Yu Xiao
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - Chuan He
- Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA.
- Howard Hughes Medical Institute, The University of Chicago, Chicago, IL, 60637, USA.
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Fasken MB, Leung SW, Cureton LA, Al-Awadi M, Al-Kindy A, van Hoof A, Khoshnevis S, Ghalei H, Al-Maawali A, Corbett AH. A biallelic variant of the RNA exosome gene, EXOSC4, associated with neurodevelopmental defects impairs RNA exosome function and translation. J Biol Chem 2024; 300:107571. [PMID: 39009343 PMCID: PMC11357806 DOI: 10.1016/j.jbc.2024.107571] [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: 12/21/2023] [Revised: 06/15/2024] [Accepted: 07/01/2024] [Indexed: 07/17/2024] Open
Abstract
The RNA exosome is an evolutionarily conserved complex required for both precise RNA processing and decay. Pathogenic variants in EXOSC genes, which encode structural subunits of this complex, are linked to several autosomal recessive disorders. Here, we describe a missense allele of the EXOSC4 gene that causes a collection of clinical features in two affected siblings. This missense variant (NM_019037.3: exon3:c.560T>C) changes a leucine residue within a conserved region of EXOSC4 to proline (p.Leu187Pro). The two affected individuals show prenatal growth restriction, failure to thrive, global developmental delay, intracerebral and basal ganglia calcifications, and kidney failure. Homozygosity for the damaging variant was identified by exome sequencing with Sanger sequencing to confirm segregation. To explore the functional consequences of this amino acid change, we modeled EXOSC4-L187P in the corresponding budding yeast protein, Rrp41 (Rrp41-L187P). Cells that express Rrp41-L187P as the sole copy of the essential Rrp41 protein show growth defects. Steady-state levels of both Rrp41-L187P and EXOSC4-L187P are decreased compared to controls, and EXOSC4-L187P shows decreased copurification with other RNA exosome subunits. RNA exosome target transcripts accumulate in rrp41-L187P cells, including the 7S precursor of 5.8S rRNA. Polysome profiles show a decrease in actively translating ribosomes in rrp41-L187P cells as compared to control cells with the incorporation of 7S pre-rRNA into polysomes. This work adds EXOSC4 to the structural subunits of the RNA exosome that have been linked to human disease and defines foundational molecular defects that could contribute to the adverse phenotypes caused by EXOSC pathogenic variants.
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Affiliation(s)
- Milo B Fasken
- Department of Biology, Emory College of Arts and Sciences, Atlanta, Georgia USA.
| | - Sara W Leung
- Department of Biology, Emory College of Arts and Sciences, Atlanta, Georgia USA
| | - Lauryn A Cureton
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia USA; Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, Georgia, USA
| | - Maha Al-Awadi
- Sultan Qaboos Hospital, Ministry of Health, Salalah, Oman
| | - Adila Al-Kindy
- Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Sohail Khoshnevis
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia USA
| | - Homa Ghalei
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia USA.
| | - Almundher Al-Maawali
- Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman; Sultan Qaboos University Hospital, Sultan Qaboos University, Muscat, Oman.
| | - Anita H Corbett
- Department of Biology, Emory College of Arts and Sciences, Atlanta, Georgia USA.
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3
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King MR, Ruff KM, Lin AZ, Pant A, Farag M, Lalmansingh JM, Wu T, Fossat MJ, Ouyang W, Lew MD, Lundberg E, Vahey MD, Pappu RV. Macromolecular condensation organizes nucleolar sub-phases to set up a pH gradient. Cell 2024; 187:1889-1906.e24. [PMID: 38503281 DOI: 10.1016/j.cell.2024.02.029] [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: 07/18/2023] [Revised: 01/02/2024] [Accepted: 02/22/2024] [Indexed: 03/21/2024]
Abstract
Nucleoli are multicomponent condensates defined by coexisting sub-phases. We identified distinct intrinsically disordered regions (IDRs), including acidic (D/E) tracts and K-blocks interspersed by E-rich regions, as defining features of nucleolar proteins. We show that the localization preferences of nucleolar proteins are determined by their IDRs and the types of RNA or DNA binding domains they encompass. In vitro reconstitutions and studies in cells showed how condensation, which combines binding and complex coacervation of nucleolar components, contributes to nucleolar organization. D/E tracts of nucleolar proteins contribute to lowering the pH of co-condensates formed with nucleolar RNAs in vitro. In cells, this sets up a pH gradient between nucleoli and the nucleoplasm. By contrast, juxta-nucleolar bodies, which have different macromolecular compositions, featuring protein IDRs with very different charge profiles, have pH values that are equivalent to or higher than the nucleoplasm. Our findings show that distinct compositional specificities generate distinct physicochemical properties for condensates.
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Affiliation(s)
- Matthew R King
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Kiersten M Ruff
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Andrew Z Lin
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Avnika Pant
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Mina Farag
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jared M Lalmansingh
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Tingting Wu
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Department of Electrical and Systems Engineering, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Martin J Fossat
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Wei Ouyang
- Department of Bioengineering, Schools of Engineering and Medicine, Stanford University, Stanford, CA, USA; Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA; Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Stockholm, Sweden
| | - Matthew D Lew
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Department of Electrical and Systems Engineering, James F. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Emma Lundberg
- Department of Bioengineering, Schools of Engineering and Medicine, Stanford University, Stanford, CA, USA; Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA; Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Stockholm, Sweden
| | - Michael D Vahey
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Rohit V Pappu
- Department of Biomedical Engineering, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA; Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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4
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Ghasemi MR, Tehrani Fateh S, Moeinafshar A, Sadeghi H, Karimzadeh P, Mirfakhraie R, Rezaei M, Hashemi-Gorji F, Rezvani Kashani M, Fazeli Bavandpour F, Bagheri S, Moghimi P, Rostami M, Madannejad R, Roudgari H, Miryounesi M. Broadening the phenotype and genotype spectrum of novel mutations in pontocerebellar hypoplasia with a comprehensive molecular literature review. BMC Med Genomics 2024; 17:51. [PMID: 38347586 PMCID: PMC10863249 DOI: 10.1186/s12920-024-01810-0] [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: 04/26/2023] [Accepted: 01/16/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND Pontocerebellar hypoplasia is an umbrella term describing a heterogeneous group of prenatal neurodegenerative disorders mostly affecting the pons and cerebellum, with 17 types associated with 25 genes. However, some types of PCH lack sufficient information, which highlights the importance of investigating and introducing more cases to further elucidate the clinical, radiological, and biochemical features of these disorders. The aim of this study is to provide an in-depth review of PCH and to identify disease genes and their inheritance patterns in 12 distinct Iranian families with clinically confirmed PCH. METHODS Cases included in this study were selected based on their phenotypic and genetic information available at the Center for Comprehensive Genetic Services. Whole-exome sequencing (WES) was used to discover the underlying genetic etiology of participants' problems, and Sanger sequencing was utilized to confirm any suspected alterations. We also conducted a comprehensive molecular literature review to outline the genetic features of the various subtypes of PCH. RESULTS This study classified and described the underlying etiology of PCH into three categories based on the genes involved. Twelve patients also were included, eleven of whom were from consanguineous parents. Ten different variations in 8 genes were found, all of which related to different types of PCH. Six novel variations were reported, including SEPSECS, TSEN2, TSEN54, AMPD2, TOE1, and CLP1. Almost all patients presented with developmental delay, hypotonia, seizure, and microcephaly being common features. Strabismus and elevation in lactate levels in MR spectroscopy were novel phenotypes for the first time in PCH types 7 and 9. CONCLUSIONS This study merges previously documented phenotypes and genotypes with unique novel ones. Due to the diversity in PCH, we provided guidance for detecting and diagnosing these heterogeneous groups of disorders. Moreover, since certain critical conditions, such as spinal muscular atrophy, can be a differential diagnosis, providing cases with novel variations and clinical findings could further expand the genetic and clinical spectrum of these diseases and help in better diagnosis. Therefore, six novel genetic variants and novel clinical and paraclinical findings have been reported for the first time. Further studies are needed to elucidate the underlying mechanisms and potential therapeutic targets for PCH.
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Affiliation(s)
- Mohammad-Reza Ghasemi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, , Tehran, Iran
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Aysan Moeinafshar
- School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Hossein Sadeghi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, , Tehran, Iran
| | - Parvaneh Karimzadeh
- Pediatric Neurology Department, Mofid Children's Hospital, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Mirfakhraie
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, , Tehran, Iran
| | - Mitra Rezaei
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Farzad Hashemi-Gorji
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Morteza Rezvani Kashani
- Pediatric Neurology Department, Mofid Children's Hospital, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Saman Bagheri
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- School of Medicine, Islamic Azad University Tehran Medical Sciences, Tehran, Iran
| | - Parinaz Moghimi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- School of Medicine, Islamic Azad University Tehran Medical Sciences, Tehran, Iran
| | - Masoumeh Rostami
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Rasoul Madannejad
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hassan Roudgari
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Miryounesi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, , Tehran, Iran.
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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de Amorim JL, Leung SW, Haji-Seyed-Javadi R, Hou Y, Yu DS, Ghalei H, Khoshnevis S, Yao B, Corbett AH. The putative RNA helicase DDX1 associates with the nuclear RNA exosome and modulates RNA/DNA hybrids (R-loops). J Biol Chem 2024; 300:105646. [PMID: 38219817 PMCID: PMC10875230 DOI: 10.1016/j.jbc.2024.105646] [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: 04/21/2023] [Revised: 12/19/2023] [Accepted: 12/23/2023] [Indexed: 01/16/2024] Open
Abstract
The RNA exosome is a ribonuclease complex that mediates both RNA processing and degradation. This complex is evolutionarily conserved, ubiquitously expressed, and required for fundamental cellular functions, including rRNA processing. The RNA exosome plays roles in regulating gene expression and protecting the genome, including modulating the accumulation of RNA-DNA hybrids (R-loops). The function of the RNA exosome is facilitated by cofactors, such as the RNA helicase MTR4, which binds/remodels RNAs. Recently, missense mutations in RNA exosome subunit genes have been linked to neurological diseases. One possibility to explain why missense mutations in genes encoding RNA exosome subunits lead to neurological diseases is that the complex may interact with cell- or tissue-specific cofactors that are impacted by these changes. To begin addressing this question, we performed immunoprecipitation of the RNA exosome subunit, EXOSC3, in a neuronal cell line (N2A), followed by proteomic analyses to identify novel interactors. We identified the putative RNA helicase, DDX1, as an interactor. DDX1 plays roles in double-strand break repair, rRNA processing, and R-loop modulation. To explore the functional connections between EXOSC3 and DDX1, we examined the interaction following double-strand breaks and analyzed changes in R-loops in N2A cells depleted for EXOSC3 or DDX1 by DNA/RNA immunoprecipitation followed by sequencing. We find that EXOSC3 interaction with DDX1 is decreased in the presence of DNA damage and that loss of EXOSC3 or DDX1 alters R-loops. These results suggest EXOSC3 and DDX1 interact during events of cellular homeostasis and potentially suppress unscrupulous expression of genes promoting neuronal projection.
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Affiliation(s)
- Julia L de Amorim
- Department of Biology, Emory College of Arts and Sciences, Atlanta, Georgia, USA; Graduate Program in Biochemistry, Cell, and Development Biology, Emory University, Atlanta, Georgia, USA
| | - Sara W Leung
- Department of Biology, Emory College of Arts and Sciences, Atlanta, Georgia, USA
| | - Ramona Haji-Seyed-Javadi
- Department of Radiation Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia, USA; Graduate Program in Genetics and Molecular Biology Graduate Program, Emory University, Atlanta, Georgia, USA
| | - Yingzi Hou
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - David S Yu
- Department of Radiation Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Homa Ghalei
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Sohail Khoshnevis
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Bing Yao
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Anita H Corbett
- Department of Biology, Emory College of Arts and Sciences, Atlanta, Georgia, USA.
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6
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Keidel A, Kögel A, Reichelt P, Kowalinski E, Schäfer IB, Conti E. Concerted structural rearrangements enable RNA channeling into the cytoplasmic Ski238-Ski7-exosome assembly. Mol Cell 2023; 83:4093-4105.e7. [PMID: 37879335 PMCID: PMC10659929 DOI: 10.1016/j.molcel.2023.09.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/25/2023] [Accepted: 09/29/2023] [Indexed: 10/27/2023]
Abstract
The Ski2-Ski3-Ski8 (Ski238) helicase complex directs cytoplasmic mRNAs toward the nucleolytic exosome complex for degradation. In yeast, the interaction between Ski238 and exosome requires the adaptor protein Ski7. We determined different cryo-EM structures of the Ski238 complex depicting the transition from a rigid autoinhibited closed conformation to a flexible active open conformation in which the Ski2 helicase module has detached from the rest of Ski238. The open conformation favors the interaction of the Ski3 subunit with exosome-bound Ski7, leading to the recruitment of the exosome. In the Ski238-Ski7-exosome holocomplex, the Ski2 helicase module binds the exosome cap, enabling the RNA to traverse from the helicase through the internal exosome channel to the Rrp44 exoribonuclease. Our study pinpoints how conformational changes within the Ski238 complex regulate exosome recruitment for RNA degradation. We also reveal the remarkable conservation of helicase-exosome RNA channeling mechanisms throughout eukaryotic nuclear and cytoplasmic exosome complexes.
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Affiliation(s)
- Achim Keidel
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152 Munich, Germany
| | - Alexander Kögel
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152 Munich, Germany
| | - Peter Reichelt
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152 Munich, Germany
| | - Eva Kowalinski
- EMBL Grenoble, 71 Avenue des Martyrs, 38072 Grenoble, France
| | - Ingmar B Schäfer
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152 Munich, Germany
| | - Elena Conti
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152 Munich, Germany.
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7
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Fasken MB, Leung SW, Cureton LA, Al-Awadi M, Al-Kindy A, Khoshnevis S, Ghalei H, Al-Maawali A, Corbett AH. A Biallelic Variant of the RNA Exosome Gene EXOSC4 Causes Translational Defects Associated with a Neurodevelopmental Disorder. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.10.24.23297197. [PMID: 37961665 PMCID: PMC10635191 DOI: 10.1101/2023.10.24.23297197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The RNA exosome is an evolutionarily conserved complex required for both precise RNA processing and decay. Mutations in EXOSC genes encoding structural subunits of the complex are linked to several autosomal recessive disorders. Here, we describe a missense allele of the EXOSC4 gene, which causes a collection of clinical features in two affected siblings. This missense mutation (NM_019037.3: exon3:c.560T>C), changes a leucine residue within a highly conserved region of EXOSC4 to proline (p.Leu187Pro). The two affected individuals presented with prenatal growth restriction, failure to thrive, global developmental delay, intracerebral and basal ganglia calcifications, and kidney failure. Homozygosity for the damaging variant was identified through exome sequencing and Sanger sequencing confirmed segregation. To explore the functional consequences of this amino acid change, we modeled EXOSC4-L187P in the corresponding budding yeast protein, Rrp41 (Rrp41-L187P). Cells that express Rrp41-L187P as the sole copy of the essential Rrp41 protein show significant growth defects. The steady-state level of both the Rrp41-L187P and the EXOSC4-L187P proteins is significantly decreased compared to control Rrp41/EXOSC4. Consistent with this observation, targets of the RNA exosome accumulate in rrp41-L187P cells, including the 7S precursor of 5.8S rRNA. Polysome profiles show a significant decrease in translation in rrp41-L187P cells as compared to control cells with apparent incorporation of 7S pre-rRNA into polysomes. Taken together, this work adds the EXOSC4 subunit of the RNA exosome to the structural subunits of this complex that have been linked to human disease and defines foundational molecular defects that could contribute to the adverse growth phenotypes caused by this novel EXOSC4 pathogenic variant.
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Affiliation(s)
- Milo B. Fasken
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA USA 30322
| | - Sara W. Leung
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA USA 30322
| | - Lauryn A. Cureton
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA USA 30322
- Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, GA 30322
| | - Maha Al-Awadi
- Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Adila Al-Kindy
- Sultan Qaboos University Hospital, Sultan Qaboos University, Muscat, Oman
| | - Sohail Khoshnevis
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA USA 30322
| | - Homa Ghalei
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA USA 30322
| | - Almundher Al-Maawali
- Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
- Sultan Qaboos University Hospital, Sultan Qaboos University, Muscat, Oman
| | - Anita H. Corbett
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA USA 30322
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8
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Krempl C, Lazzaretti D, Sprangers R. A structural biology view on the enzymes involved in eukaryotic mRNA turnover. Biol Chem 2023; 404:1101-1121. [PMID: 37709756 DOI: 10.1515/hsz-2023-0182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 08/24/2023] [Indexed: 09/16/2023]
Abstract
The cellular environment contains numerous ribonucleases that are dedicated to process mRNA transcripts that have been targeted for degradation. Here, we review the three dimensional structures of the ribonuclease complexes (Pan2-Pan3, Ccr4-Not, Xrn1, exosome) and the mRNA decapping enzymes (Dcp2, DcpS) that are involved in mRNA turnover. Structures of major parts of these proteins have been experimentally determined. These enzymes and factors do not act in isolation, but are embedded in interaction networks which regulate enzyme activity and ensure that the appropriate substrates are recruited. The structural details of the higher order complexes that form can, in part, be accurately deduced from known structural data of sub-complexes. Interestingly, many of the ribonuclease and decapping enzymes have been observed in structurally different conformations. Together with experimental data, this highlights that structural changes are often important for enzyme function. We conclude that the known structural data of mRNA decay factors provide important functional insights, but that static structural data needs to be complemented with information regarding protein motions to complete the picture of how transcripts are turned over. In addition, we highlight multiple aspects that influence mRNA turnover rates, but that have not been structurally characterized so far.
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Affiliation(s)
- Christina Krempl
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Daniela Lazzaretti
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Remco Sprangers
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
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9
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Schneider C, Bohnsack KE. Caught in the act-Visualizing ribonucleases during eukaryotic ribosome assembly. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1766. [PMID: 36254602 DOI: 10.1002/wrna.1766] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/22/2022] [Accepted: 09/24/2022] [Indexed: 07/20/2023]
Abstract
Ribosomes are essential macromolecular machines responsible for translating the genetic information encoded in mRNAs into proteins. Ribosomes are composed of ribosomal RNAs and proteins (rRNAs and RPs) and the rRNAs fulfill both catalytic and architectural functions. Excision of the mature eukaryotic rRNAs from their precursor transcript is achieved through a complex series of endoribonucleolytic cleavages and exoribonucleolytic processing steps that are precisely coordinated with other aspects of ribosome assembly. Many ribonucleases involved in pre-rRNA processing have been identified and pre-rRNA processing pathways are relatively well defined. However, momentous advances in cryo-electron microscopy have recently enabled structural snapshots of various pre-ribosomal particles from budding yeast (Saccharomyces cerevisiae) and human cells to be captured and, excitingly, these structures not only allow pre-rRNAs to be observed before and after cleavage events, but also enable ribonucleases to be visualized on their target RNAs. These structural views of pre-rRNA processing in action allow a new layer of understanding of rRNA maturation and how it is coordinated with other aspects of ribosome assembly. They illuminate mechanisms of target recognition by the diverse ribonucleases involved and reveal how the cleavage/processing activities of these enzymes are regulated. In this review, we discuss the new insights into pre-rRNA processing gained by structural analyses and the growing understanding of the mechanisms of ribonuclease regulation. This article is categorized under: Translation > Ribosome Biogenesis RNA Processing > rRNA Processing.
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Affiliation(s)
- Claudia Schneider
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
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10
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de Amorim JL, Asafu-Adjaye D, Corbett AH. Analysis of RNA Exosome Subunit Transcript Abundance Across Tissues: Implications for Neurological Disease Pathogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.544082. [PMID: 37333323 PMCID: PMC10274776 DOI: 10.1101/2023.06.07.544082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Exosomopathies are a collection of rare diseases caused by mutations in genes that encode structural subunits of a ribonuclease complex termed the RNA exosome. The RNA exosome mediates both RNA processing and degradation of multiple classes of RNA. This complex is evolutionarily conserved and required for fundamental cellular functions, including rRNA processing. Recently, missense mutations in genes encoding structural subunits of the RNA exosome complex have been linked to a variety of distinct neurological diseases, many of them childhood neuronopathies with at least some cerebellar atrophy. Understanding how these missense mutations lead to the disparate clinical presentations that have been reported for this class of diseases necessitates investigation of how these specific changes alter cell-specific RNA exosome function. Although the RNA exosome complex is routinely referred to as ubiquitously expressed, little is known about the tissue- or cell-specific expression of the RNA exosome complex or any individual subunit. Here, we leverage publicly available RNA-sequencing data to analyze RNA exosome subunit transcript levels in healthy human tissues, focusing on those tissues that are impacted in exosomopathy patients described in clinical reports. This analysis provides evidence to support the characterization of the RNA exosome as ubiquitously expressed with transcript levels for the individual subunits that vary in different tissues. However, the cerebellar hemisphere and cerebellum have high levels of nearly all RNA exosome subunit transcripts. These findings could suggest that the cerebellum has a high requirement for RNA exosome function and potentially explain why cerebellar pathology is common in RNA exosomopathies.
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11
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de Amorim JL, Leung SW, Haji-Seyed-Javadi R, Hou Y, Yu DS, Ghalei H, Khoshnevis S, Yao B, Corbett AH. The RNA helicase DDX1 associates with the nuclear RNA exosome and modulates R-loops. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.17.537228. [PMID: 37131662 PMCID: PMC10153151 DOI: 10.1101/2023.04.17.537228] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The RNA exosome is a ribonuclease complex that mediates both RNA processing and degradation. This complex is evolutionarily conserved, ubiquitously expressed, and required for fundamental cellular functions, including rRNA processing. The RNA exosome plays roles in regulating gene expression and protecting the genome, including modulating the accumulation of RNA-DNA hybrids (R-loops). The function of the RNA exosome is facilitated by cofactors, such as the RNA helicase MTR4, which binds/remodels RNAs. Recently, missense mutations in RNA exosome subunit genes have been linked to neurological diseases. One possibility to explain why missense mutations in genes encoding RNA exosome subunits lead to neurological diseases is that the complex may interact with cell- or tissue-specific cofactors that are impacted by these changes. To begin addressing this question, we performed immunoprecipitation of the RNA exosome subunit, EXOSC3, in a neuronal cell line (N2A) followed by proteomic analyses to identify novel interactors. We identified the putative RNA helicase, DDX1, as an interactor. DDX1 plays roles in double-strand break repair, rRNA processing, and R-loop modulation. To explore the functional connections between EXOSC3 and DDX1, we examined the interaction following double-strand breaks, and analyzed changes in R-loops in N2A cells depleted for EXOSC3 or DDX1 by DNA/RNA immunoprecipitation followed by sequencing (DRIP-Seq). We find that EXOSC3 interaction with DDX1 is decreased in the presence of DNA damage and that loss of EXOSC3 or DDX1 alters R-loops. These results suggest EXOSC3 and DDX1 interact during events of cellular homeostasis and potentially suppress unscrupulous expression of genes promoting neuronal projection.
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12
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Cesaro G, da Soler HT, Guerra-Slompo E, Haouz A, Legrand P, Zanchin N, Guimaraes B. Trypanosoma brucei RRP44: a versatile enzyme for processing structured and non-structured RNA substrates. Nucleic Acids Res 2022; 51:380-395. [PMID: 36583334 PMCID: PMC9841401 DOI: 10.1093/nar/gkac1199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 11/25/2022] [Accepted: 12/21/2022] [Indexed: 12/31/2022] Open
Abstract
Rrp44/Dis3 is a conserved eukaryotic ribonuclease that acts on processing and degradation of nearly all types of RNA. It contains an endo- (PIN) and an exonucleolytic (RNB) domain and, its depletion in model organisms supports its essential function for cell viability. In Trypanosoma brucei, depletion of Rrp44 (TbRRP44) blocks maturation of ribosomal RNA, leading to disruption of ribosome synthesis and inhibition of cell proliferation. We have determined the crystal structure of the exoribonucleolytic module of TbRRP44 in an active conformation, revealing novel details of the catalytic mechanism of the RNB domain. For the first time, the position of the second magnesium involved in the two-metal-ion mechanism was determined for a member of the RNase II family. In vitro, TbRRP44 acts preferentially on non-structured uridine-rich RNA substrates. However, we demonstrated for the first time that both TbRRP44 and its homologue from Saccharomyces cerevisiae can also degrade structured substrates without 3'-end overhang, suggesting that Rrp44/Dis3 ribonucleases may be involved in degradation of a wider panel of RNA than has been assumed. Interestingly, deletion of TbRRP44 PIN domain impairs RNA binding to different extents, depending on the type of substrate.
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Affiliation(s)
- Giovanna Cesaro
- Carlos Chagas Institute, Oswaldo Cruz Foundation, FIOCRUZ, Curitiba-PR, Brazil,Biochemistry Postgraduate Program, Federal University of Paraná, Curitiba-PR, Brazil
| | | | | | - Ahmed Haouz
- Institut Pasteur, Plate-forme de cristallographie-C2RT, UMR-3528 CNRS, Paris, France
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13
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Fujiwara N, Shigemoto M, Hirayama M, Fujita KI, Seno S, Matsuda H, Nagahama M, Masuda S. MPP6 stimulates both RRP6 and DIS3 to degrade a specified subset of MTR4-sensitive substrates in the human nucleus. Nucleic Acids Res 2022; 50:8779-8806. [PMID: 35902094 PMCID: PMC9410898 DOI: 10.1093/nar/gkac559] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 06/10/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
Recent in vitro reconstitution analyses have proven that the physical interaction between the exosome core and MTR4 helicase, which promotes the exosome activity, is maintained by either MPP6 or RRP6. However, knowledge regarding the function of MPP6 with respect to in vivo exosome activity remains scarce. Here, we demonstrate a facilitative function of MPP6 that composes a specific part of MTR4-dependent substrate decay by the human exosome. Using RNA polymerase II-transcribed poly(A)+ substrate accumulation as an indicator of a perturbed exosome, we found functional redundancy between RRP6 and MPP6 in the decay of these poly(A)+ transcripts. MTR4 binding to the exosome core via MPP6 was essential for MPP6 to exert its redundancy with RRP6. However, at least for the decay of our identified exosome substrates, MTR4 recruitment by MPP6 was not functionally equivalent to recruitment by RRP6. Genome-wide classification of substrates based on their sensitivity to each exosome component revealed that MPP6 deals with a specific range of substrates and highlights the importance of MTR4 for their decay. Considering recent findings of competitive binding to the exosome between auxiliary complexes, our results suggest that the MPP6-incorporated MTR4-exosome complex is one of the multiple alternative complexes rather than the prevailing one.
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Affiliation(s)
- Naoko Fujiwara
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Maki Shigemoto
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Mizuki Hirayama
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Ken-Ichi Fujita
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan.,Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Shigeto Seno
- Graduate School of Information Science and Technology, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hideo Matsuda
- Graduate School of Information Science and Technology, Osaka University, Suita, Osaka 565-0871, Japan
| | - Masami Nagahama
- Laboratory of Molecular and Cellular Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan
| | - Seiji Masuda
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan.,Department of Food Science and Nutrition, Faculty of Agriculture Kindai University, Nara, Nara 631-8505, Japan.,Agricultural Technology and Innovation Research Institute, Kindai University, Nara, Nara 631-8505, Japan.,Antiaging center, Kindai University, Higashiosaka, Osaka 577-8502, Japan
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14
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Mitchell MI, Ma J, Carter CL, Loudig O. Circulating Exosome Cargoes Contain Functionally Diverse Cancer Biomarkers: From Biogenesis and Function to Purification and Potential Translational Utility. Cancers (Basel) 2022; 14:3350. [PMID: 35884411 PMCID: PMC9318395 DOI: 10.3390/cancers14143350] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/01/2022] [Accepted: 07/07/2022] [Indexed: 12/12/2022] Open
Abstract
Although diagnostic and therapeutic treatments of cancer have tremendously improved over the past two decades, the indolent nature of its symptoms has made early detection challenging. Thus, inter-disciplinary (genomic, transcriptomic, proteomic, and lipidomic) research efforts have been focused on the non-invasive identification of unique "silver bullet" cancer biomarkers for the design of ultra-sensitive molecular diagnostic assays. Circulating tumor biomarkers, such as CTCs and ctDNAs, which are released by tumors in the circulation, have already demonstrated their clinical utility for the non-invasive detection of certain solid tumors. Considering that exosomes are actively produced by all cells, including tumor cells, and can be found in the circulation, they have been extensively assessed for their potential as a source of circulating cell-specific biomarkers. Exosomes are particularly appealing because they represent a stable and encapsulated reservoir of active biological compounds that may be useful for the non-invasive detection of cancer. T biogenesis of these extracellular vesicles is profoundly altered during carcinogenesis, but because they harbor unique or uniquely combined surface proteins, cancer biomarker studies have been focused on their purification from biofluids, for the analysis of their RNA, DNA, protein, and lipid cargoes. In this review, we evaluate the biogenesis of normal and cancer exosomes, provide extensive information on the state of the art, the current purification methods, and the technologies employed for genomic, transcriptomic, proteomic, and lipidomic evaluation of their cargoes. Our thorough examination of the literature highlights the current limitations and promising future of exosomes as a liquid biopsy for the identification of circulating tumor biomarkers.
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Affiliation(s)
- Megan I Mitchell
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA
| | - Junfeng Ma
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20007, USA
| | - Claire L Carter
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA
| | - Olivier Loudig
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA
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15
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Puno MR, Lima CD. Structural basis for RNA surveillance by the human nuclear exosome targeting (NEXT) complex. Cell 2022; 185:2132-2147.e26. [PMID: 35688134 PMCID: PMC9210550 DOI: 10.1016/j.cell.2022.04.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 03/04/2022] [Accepted: 04/08/2022] [Indexed: 02/07/2023]
Abstract
RNA quality control relies on co-factors and adaptors to identify and prepare substrates for degradation by ribonucleases such as the 3' to 5' ribonucleolytic RNA exosome. Here, we determined cryogenic electron microscopy structures of human nuclear exosome targeting (NEXT) complexes bound to RNA that reveal mechanistic insights to substrate recognition and early steps that precede RNA handover to the exosome. The structures illuminate ZCCHC8 as a scaffold, mediating homodimerization while embracing the MTR4 helicase and flexibly anchoring RBM7 to the helicase core. All three subunits collaborate to bind the RNA, with RBM7 and ZCCHC8 surveying sequences upstream of the 3' end to facilitate RNA capture by MTR4. ZCCHC8 obscures MTR4 surfaces important for RNA binding and extrusion as well as MPP6-dependent recruitment and docking onto the RNA exosome core, interactions that contribute to RNA surveillance by coordinating RNA capture, translocation, and extrusion from the helicase to the exosome for decay.
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Affiliation(s)
- M Rhyan Puno
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Christopher D Lima
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Howard Hughes Medical Institute, 1275 York Avenue, New York, NY 10065, USA.
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16
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Villa T, Porrua O. Pervasive transcription: a controlled risk. FEBS J 2022. [PMID: 35587776 DOI: 10.1111/febs.16530] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/26/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022]
Abstract
Transcriptome-wide interrogation of eukaryotic genomes has unveiled the pervasive nature of RNA polymerase II transcription. Virtually, any DNA region with an accessible chromatin structure can be transcribed, resulting in a mass production of noncoding RNAs (ncRNAs) with the potential of interfering with gene expression programs. Budding yeast has proved to be a powerful model organism to understand the mechanisms at play to control pervasive transcription and overcome the risks of hazardous disruption of cellular functions. In this review, we focus on the actors and strategies yeasts employ to govern ncRNA production, and we discuss recent findings highlighting the dangers of losing control over pervasive transcription.
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Affiliation(s)
- Tommaso Villa
- Institut Jacques Monod CNRS, Université de Paris Cité France
| | - Odil Porrua
- Institut Jacques Monod CNRS, Université de Paris Cité France
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17
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Gerlach P, Garland W, Lingaraju M, Salerno-Kochan A, Bonneau F, Basquin J, Jensen TH, Conti E. Structure and regulation of the nuclear exosome targeting complex guides RNA substrates to the exosome. Mol Cell 2022; 82:2505-2518.e7. [PMID: 35688157 PMCID: PMC9278407 DOI: 10.1016/j.molcel.2022.04.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 03/07/2022] [Accepted: 04/08/2022] [Indexed: 11/30/2022]
Abstract
In mammalian cells, spurious transcription results in a vast repertoire of unproductive non-coding RNAs, whose deleterious accumulation is prevented by rapid decay. The nuclear exosome targeting (NEXT) complex plays a central role in directing non-functional transcripts to exosome-mediated degradation, but the structural and molecular mechanisms remain enigmatic. Here, we elucidated the architecture of the human NEXT complex, showing that it exists as a dimer of MTR4-ZCCHC8-RBM7 heterotrimers. Dimerization preconfigures the major MTR4-binding region of ZCCHC8 and arranges the two MTR4 helicases opposite to each other, with each protomer able to function on many types of RNAs. In the inactive state of the complex, the 3′ end of an RNA substrate is enclosed in the MTR4 helicase channel by a ZCCHC8 C-terminal gatekeeping domain. The architecture of a NEXT-exosome assembly points to the molecular and regulatory mechanisms with which the NEXT complex guides RNA substrates to the exosome. NEXT homodimerizes through two intertwined ZCCHC8 subunits ZCCHC8 binds MTR4 with both constitutive and regulatory interactions Stable MTR4 arch interactions orient the two helicases in opposite directions Regulatory interactions at the MTR4 helicase domain guide RNA to the exosome
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Affiliation(s)
- Piotr Gerlach
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, Munich, Germany.
| | - William Garland
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Mahesh Lingaraju
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, Munich, Germany
| | - Anna Salerno-Kochan
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, Munich, Germany
| | - Fabien Bonneau
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, Munich, Germany
| | - Jérôme Basquin
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, Munich, Germany
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Elena Conti
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, Munich, Germany.
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18
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Prasai A, Jay JW, Jupiter D, Wolf SE, El Ayadi A. Role of Exosomes in Dermal Wound Healing: A Systematic Review. J Invest Dermatol 2022; 142:662-678.e8. [PMID: 34461128 PMCID: PMC9400548 DOI: 10.1016/j.jid.2021.07.167] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/08/2021] [Accepted: 07/27/2021] [Indexed: 12/22/2022]
Abstract
Cell-based therapy imparts its therapeutic effects through soluble GFs and vesicular bodies such as exosomes. A systematic review with a meta-analysis of preclinical studies was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the modified Stroke Therapy Academic Industry Roundtable guidelines to identify exosomes as an archetype biological therapy for dermal wound healing and to provide guidelines for the concentrations to be used in preclinical studies. A total of 51 rodent studies were included in the systematic review and 9 were included in the meta-analysis section. Three independent reviewers cross-screened eligibility and selected studies for quality assessment from 3,064 published studies on exosomes and wound healing. The mean quality scores for all studies were 5.08 ± 0.752 and 5.11 ± 1.13 for systematic review and meta-analysis, respectively. Exosome effects were reported to have the highest efficacy at 7 days (OR = 1.82, 95% confidence interval = 0.69‒2.95) than at 14 days (OR = 2.29, 95% confidence interval = 0.01‒4.56) after administration. Exosomes were reported to regulate all phases of skin wound healing, mostly by the actions of circulating microRNA. The outcome of this review may be used to guide preclinical and clinical studies on the role of exosomes in wound healing.
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Affiliation(s)
- Anesh Prasai
- Department of Surgery, University of Texas Medical Branch, Galveston, Texas, USA.
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19
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Gaubitz C, Liu X, Pajak J, Stone NP, Hayes JA, Demo G, Kelch BA. Cryo-EM structures reveal high-resolution mechanism of a DNA polymerase sliding clamp loader. eLife 2022; 11:e74175. [PMID: 35179493 PMCID: PMC8893722 DOI: 10.7554/elife.74175] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 02/01/2022] [Indexed: 11/13/2022] Open
Abstract
Sliding clamps are ring-shaped protein complexes that are integral to the DNA replication machinery of all life. Sliding clamps are opened and installed onto DNA by clamp loader AAA+ ATPase complexes. However, how a clamp loader opens and closes the sliding clamp around DNA is still unknown. Here, we describe structures of the Saccharomyces cerevisiae clamp loader Replication Factor C (RFC) bound to its cognate sliding clamp Proliferating Cell Nuclear Antigen (PCNA) en route to successful loading. RFC first binds to PCNA in a dynamic, closed conformation that blocks both ATPase activity and DNA binding. RFC then opens the PCNA ring through a large-scale 'crab-claw' expansion of both RFC and PCNA that explains how RFC prefers initial binding of PCNA over DNA. Next, the open RFC:PCNA complex binds DNA and interrogates the primer-template junction using a surprising base-flipping mechanism. Our structures indicate that initial PCNA opening and subsequent closure around DNA do not require ATP hydrolysis, but are driven by binding energy. ATP hydrolysis, which is necessary for RFC release, is triggered by interactions with both PCNA and DNA, explaining RFC's switch-like ATPase activity. Our work reveals how a AAA+ machine undergoes dramatic conformational changes for achieving binding preference and substrate remodeling.
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Affiliation(s)
- Christl Gaubitz
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical SchoolWorcesterUnited States
| | - Xingchen Liu
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical SchoolWorcesterUnited States
| | - Joshua Pajak
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical SchoolWorcesterUnited States
| | - Nicholas P Stone
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical SchoolWorcesterUnited States
| | - Janelle A Hayes
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical SchoolWorcesterUnited States
| | - Gabriel Demo
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester MA & Central European Institute of Technology, Masaryk UniversityBrnoCzech Republic
| | - Brian A Kelch
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical SchoolWorcesterUnited States
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20
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Kögel A, Keidel A, Bonneau F, Schäfer IB, Conti E. The human SKI complex regulates channeling of ribosome-bound RNA to the exosome via an intrinsic gatekeeping mechanism. Mol Cell 2022; 82:756-769.e8. [PMID: 35120588 PMCID: PMC8860381 DOI: 10.1016/j.molcel.2022.01.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/01/2021] [Accepted: 01/07/2022] [Indexed: 12/31/2022]
Abstract
The superkiller (SKI) complex is the cytoplasmic co-factor and regulator of the RNA-degrading exosome. In human cells, the SKI complex functions mainly in co-translational surveillance-decay pathways, and its malfunction is linked to a severe congenital disorder, the trichohepatoenteric syndrome. To obtain insights into the molecular mechanisms regulating the human SKI (hSKI) complex, we structurally characterized several of its functional states in the context of 80S ribosomes and substrate RNA. In a prehydrolytic ATP form, the hSKI complex exhibits a closed conformation with an inherent gating system that effectively traps the 80S-bound RNA into the hSKI2 helicase subunit. When active, hSKI switches to an open conformation in which the gating is released and the RNA 3′ end exits the helicase. The emerging picture is that the gatekeeping mechanism and architectural remodeling of hSKI underpin a regulated RNA channeling system that is mechanistically conserved among the cytoplasmic and nuclear helicase-exosome complexes. hSKI has closed and open states connected to different helicase conformations The intrinsic closed state traps the RNA 3′ end and blocks the RNA exit path ATP induces the open state of hSKI, allowing 80S ribosome-bound RNA extraction The hSKI open state primes hSKI2 for channeling RNA to the cytosolic exosome
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Affiliation(s)
- Alexander Kögel
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Munich, Germany
| | - Achim Keidel
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Munich, Germany
| | - Fabien Bonneau
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Munich, Germany
| | - Ingmar B Schäfer
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Munich, Germany.
| | - Elena Conti
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Munich, Germany.
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21
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Puno MR, Lima CD. Methods to assess helicase and translocation activities of human nuclear RNA exosome and RNA adaptor complexes. Methods Enzymol 2022; 673:453-473. [PMID: 35965016 PMCID: PMC9382703 DOI: 10.1016/bs.mie.2022.03.060] [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] [Indexed: 11/02/2022]
Abstract
The nuclear RNA exosome collaborates with the MTR4 helicase and RNA adaptor complexes to process, surveil, and degrade RNA. Here we outline methods to characterize RNA translocation and strand displacement by exosome-associated helicases and adaptor complexes using fluorescence-based strand displacement assays. The design and preparation of substrates suitable for analysis of helicase and decay activities of reconstituted MTR4–exosome complexes are described. To aid structural and biophysical studies, we present strategies for engineering substrates that can stall helicases during translocation, providing a means to capture snapshots of interactions and molecular steps involved in substrate translocation and delivery to the exosome.
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22
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Ogami K, Suzuki HI. Nuclear RNA Exosome and Pervasive Transcription: Dual Sculptors of Genome Function. Int J Mol Sci 2021; 22:13401. [PMID: 34948199 PMCID: PMC8707817 DOI: 10.3390/ijms222413401] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/10/2021] [Accepted: 12/10/2021] [Indexed: 01/14/2023] Open
Abstract
The genome is pervasively transcribed across various species, yielding numerous non-coding RNAs. As a counterbalance for pervasive transcription, various organisms have a nuclear RNA exosome complex, whose structure is well conserved between yeast and mammalian cells. The RNA exosome not only regulates the processing of stable RNA species, such as rRNAs, tRNAs, small nucleolar RNAs, and small nuclear RNAs, but also plays a central role in RNA surveillance by degrading many unstable RNAs and misprocessed pre-mRNAs. In addition, associated cofactors of RNA exosome direct the exosome to distinct classes of RNA substrates, suggesting divergent and/or multi-layer control of RNA quality in the cell. While the RNA exosome is essential for cell viability and influences various cellular processes, mutations and alterations in the RNA exosome components are linked to the collection of rare diseases and various diseases including cancer, respectively. The present review summarizes the relationships between pervasive transcription and RNA exosome, including evolutionary crosstalk, mechanisms of RNA exosome-mediated RNA surveillance, and physiopathological effects of perturbation of RNA exosome.
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Affiliation(s)
- Koichi Ogami
- Division of Molecular Oncology, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan;
| | - Hiroshi I. Suzuki
- Division of Molecular Oncology, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan;
- Institute for Glyco-core Research (iGCORE), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
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23
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Slavotinek A, Misceo D, Htun S, Mathisen L, Frengen E, Foreman M, Hurtig JE, Enyenihi L, Sterrett MC, Leung SW, Schneidman-Duhovny D, Estrada-Veras J, Duncan JL, Haaxma CA, Kamsteeg EJ, Xia V, Beleford D, Si Y, Douglas G, Treidene HE, van Hoof A, Fasken MB, Corbett AH. Biallelic variants in the RNA exosome gene EXOSC5 are associated with developmental delays, short stature, cerebellar hypoplasia and motor weakness. Hum Mol Genet 2021; 29:2218-2239. [PMID: 32504085 DOI: 10.1093/hmg/ddaa108] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/10/2020] [Accepted: 05/28/2020] [Indexed: 12/15/2022] Open
Abstract
The RNA exosome is an essential ribonuclease complex required for processing and/or degradation of both coding and non-coding RNAs. We identified five patients with biallelic variants in EXOSC5, which encodes a structural subunit of the RNA exosome. The clinical features of these patients include failure to thrive, short stature, feeding difficulties, developmental delays that affect motor skills, hypotonia and esotropia. Brain MRI revealed cerebellar hypoplasia and ventriculomegaly. While we ascertained five patients, three patients with distinct variants of EXOSC5 were studied in detail. The first patient had a deletion involving exons 5-6 of EXOSC5 and a missense variant, p.Thr114Ile, that were inherited in trans, the second patient was homozygous for p.Leu206His and the third patient had paternal isodisomy for chromosome 19 and was homozygous for p.Met148Thr. The additional two patients ascertained are siblings who had an early frameshift mutation in EXOSC5 and the p.Thr114Ile missense variant that were inherited in trans. We employed three complementary approaches to explore the requirement for EXOSC5 in brain development and assess consequences of pathogenic EXOSC5 variants. Loss of function for exosc5 in zebrafish results in shortened and curved tails/bodies, reduced eye/head size and edema. We modeled pathogenic EXOSC5 variants in both budding yeast and mammalian cells. Some of these variants cause defects in RNA exosome function as well as altered interactions with other RNA exosome subunits. These findings expand the number of genes encoding RNA exosome subunits linked to human disease while also suggesting that disease mechanism varies depending on the specific pathogenic variant.
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Affiliation(s)
- Anne Slavotinek
- Department of Pediatrics, University of California, San Francisco, CA 94143, USA
| | - Doriana Misceo
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo 0450, Norway
| | - Stephanie Htun
- Department of Pediatrics, University of California, San Francisco, CA 94143, USA
| | - Linda Mathisen
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo 0450, Norway
| | - Eirik Frengen
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo 0450, Norway
| | - Michelle Foreman
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
| | - Jennifer E Hurtig
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
| | - Liz Enyenihi
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | | | - Sara W Leung
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Dina Schneidman-Duhovny
- School of Computer Science and Engineering and the Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Juvianee Estrada-Veras
- Department of Pediatrics-Medical Genetics and Metabolism, Uniformed Services University/Walter Reed NMMC Bethesda, MD 20889, USA
| | - Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, CA 94143, USA
| | - Charlotte A Haaxma
- Department of Pediatric Neurology, Amalia Children's Hospital and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen 6500 HB, The Netherlands
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen 6500 HB, The Netherlands
| | - Vivian Xia
- Department of Pediatrics, University of California, San Francisco, CA 94143, USA
| | - Daniah Beleford
- Department of Pediatrics, University of California, San Francisco, CA 94143, USA
| | - Yue Si
- GeneDx Inc., MD 20877, USA
| | | | - Hans Einar Treidene
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo 0450, Norway
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
| | - Milo B Fasken
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, GA 30322, USA
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24
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Das M, Zattas D, Zinder JC, Wasmuth EV, Henri J, Lima CD. Substrate discrimination and quality control require each catalytic activity of TRAMP and the nuclear RNA exosome. Proc Natl Acad Sci U S A 2021; 118:e2024846118. [PMID: 33782132 PMCID: PMC8040639 DOI: 10.1073/pnas.2024846118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Quality control requires discrimination between functional and aberrant species to selectively target aberrant substrates for destruction. Nuclear RNA quality control in Saccharomyces cerevisiae includes the TRAMP complex that marks RNA for decay via polyadenylation followed by helicase-dependent 3' to 5' degradation by the RNA exosome. Using reconstitution biochemistry, we show that polyadenylation and helicase activities of TRAMP cooperate with processive and distributive exoribonuclease activities of the nuclear RNA exosome to protect stable RNA from degradation while selectively targeting and degrading less stable RNA. Substrate discrimination is lost when the distributive exoribonuclease activity of Rrp6 is inactivated, leading to degradation of stable and unstable RNA species. These data support a proofreading mechanism in which deadenylation by Rrp6 competes with Mtr4-dependent degradation to protect stable RNA while selectively targeting and degrading unstable RNA.
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Affiliation(s)
- Mom Das
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Dimitrios Zattas
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - John C Zinder
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Tri-Institutional Training Program in Chemical Biology, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Elizabeth V Wasmuth
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Julien Henri
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Christopher D Lima
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065;
- HHMI, Memorial Sloan Kettering Cancer Center, New York, NY 10065
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25
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Frazier MN, Pillon MC, Kocaman S, Gordon J, Stanley RE. Structural overview of macromolecular machines involved in ribosome biogenesis. Curr Opin Struct Biol 2021; 67:51-60. [PMID: 33099228 PMCID: PMC8058114 DOI: 10.1016/j.sbi.2020.09.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/04/2020] [Accepted: 09/08/2020] [Indexed: 12/17/2022]
Abstract
The production of ribosomes is essential for ensuring the translational capacity of cells. Because of its high energy demand ribosome production is subject to stringent cellular controls. Hundreds of ribosome assembly factors are required to facilitate assembly of nascent ribosome particles with high fidelity. Many ribosome assembly factors organize into macromolecular machines that drive complex steps of the production pathway. Recent advances in structural biology, in particular cryo-EM, have provided detailed information about the structure and function of these higher order enzymatic assemblies. Here, we summarize recent structures revealing molecular insight into these macromolecular machines with an emphasis on the interplay between discrete active sites.
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Affiliation(s)
- Meredith N Frazier
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Monica C Pillon
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Seda Kocaman
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Jacob Gordon
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Robin E Stanley
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA.
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26
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Fraga de Andrade I, Mehta C, Bresnick EH. Post-transcriptional control of cellular differentiation by the RNA exosome complex. Nucleic Acids Res 2020; 48:11913-11928. [PMID: 33119769 PMCID: PMC7708067 DOI: 10.1093/nar/gkaa883] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/21/2020] [Accepted: 09/30/2020] [Indexed: 12/12/2022] Open
Abstract
Given the complexity of intracellular RNA ensembles and vast phenotypic remodeling intrinsic to cellular differentiation, it is instructive to consider the role of RNA regulatory machinery in controlling differentiation. Dynamic post-transcriptional regulation of protein-coding and non-coding transcripts is vital for establishing and maintaining proteomes that enable or oppose differentiation. By contrast to extensively studied transcriptional mechanisms governing differentiation, many questions remain unanswered regarding the involvement of post-transcriptional mechanisms. Through its catalytic activity to selectively process or degrade RNAs, the RNA exosome complex dictates the levels of RNAs comprising multiple RNA classes, thereby regulating chromatin structure, gene expression and differentiation. Although the RNA exosome would be expected to control diverse biological processes, studies to elucidate its biological functions and how it integrates into, or functions in parallel with, cell type-specific transcriptional mechanisms are in their infancy. Mechanistic analyses have demonstrated that the RNA exosome confers expression of a differentiation regulatory receptor tyrosine kinase, downregulates the telomerase RNA component TERC, confers genomic stability and promotes DNA repair, which have considerable physiological and pathological implications. In this review, we address how a broadly operational RNA regulatory complex interfaces with cell type-specific machinery to control cellular differentiation.
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Affiliation(s)
- Isabela Fraga de Andrade
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, 4009 WIMR, Madison, WI 53705, USA
| | - Charu Mehta
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, 4009 WIMR, Madison, WI 53705, USA
| | - Emery H Bresnick
- Wisconsin Blood Cancer Research Institute, Department of Cell and Regenerative Biology, Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, 4009 WIMR, Madison, WI 53705, USA
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27
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Weick EM, Lima CD. RNA helicases are hubs that orchestrate exosome-dependent 3'-5' decay. Curr Opin Struct Biol 2020; 67:86-94. [PMID: 33147539 DOI: 10.1016/j.sbi.2020.09.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/14/2020] [Accepted: 09/20/2020] [Indexed: 01/10/2023]
Abstract
The RNA exosome is a conserved complex of proteins that mediates 3'-5' RNA processing and decay. Its functions range from processing of non-coding RNAs such as ribosomal RNAs and decay of aberrant transcripts in the nucleus to cytoplasmic mRNA turnover and quality control. Ski2-like RNA helicases translocate substrates to exosome-associated ribonucleases and interact with the RNA exosome either directly or as part of multi-subunit helicase-containing complexes that identify and target RNA substrates for decay. Recent structures of these helicases with their RNA-binding partners or the RNA exosome have advanced our understanding of a system of modular and mutually exclusive contacts between the exosome and exosome-associated helicase complexes that shape the transcriptome by orchestrating exosome-dependent 3'-5' decay.
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Affiliation(s)
- Eva-Maria Weick
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Christopher D Lima
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Howard Hughes Medical Institute, 1275 York Avenue, New York, NY 10065, USA.
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28
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Structure of the human clamp loader reveals an autoinhibited conformation of a substrate-bound AAA+ switch. Proc Natl Acad Sci U S A 2020; 117:23571-23580. [PMID: 32907938 DOI: 10.1073/pnas.2007437117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
DNA replication requires the sliding clamp, a ring-shaped protein complex that encircles DNA, where it acts as an essential cofactor for DNA polymerases and other proteins. The sliding clamp needs to be opened and installed onto DNA by a clamp loader ATPase of the AAA+ family. The human clamp loader replication factor C (RFC) and sliding clamp proliferating cell nuclear antigen (PCNA) are both essential and play critical roles in several diseases. Despite decades of study, no structure of human RFC has been resolved. Here, we report the structure of human RFC bound to PCNA by cryogenic electron microscopy to an overall resolution of ∼3.4 Å. The active sites of RFC are fully bound to adenosine 5'-triphosphate (ATP) analogs, which is expected to induce opening of the sliding clamp. However, we observe the complex in a conformation before PCNA opening, with the clamp loader ATPase modules forming an overtwisted spiral that is incapable of binding DNA or hydrolyzing ATP. The autoinhibited conformation observed here has many similarities to a previous yeast RFC:PCNA crystal structure, suggesting that eukaryotic clamp loaders adopt a similar autoinhibited state early on in clamp loading. Our results point to a "limited change/induced fit" mechanism in which the clamp first opens, followed by DNA binding, inducing opening of the loader to release autoinhibition. The proposed change from an overtwisted to an active conformation reveals an additional regulatory mechanism for AAA+ ATPases. Finally, our structural analysis of disease mutations leads to a mechanistic explanation for the role of RFC in human health.
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29
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Fazel E, Fattahpour S, Abdali H, Nasiri J, Sedghi M. Understanding the impact of DIS3 cancer-associated mutations by in silico structure modeling. GENE REPORTS 2020. [DOI: 10.1016/j.genrep.2020.100779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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30
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Kilchert C, Kecman T, Priest E, Hester S, Aydin E, Kus K, Rossbach O, Castello A, Mohammed S, Vasiljeva L. System-wide analyses of the fission yeast poly(A) + RNA interactome reveal insights into organization and function of RNA-protein complexes. Genome Res 2020; 30:1012-1026. [PMID: 32554781 PMCID: PMC7397868 DOI: 10.1101/gr.257006.119] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 05/18/2020] [Indexed: 01/12/2023]
Abstract
Large RNA-binding complexes play a central role in gene expression and orchestrate production, function, and turnover of mRNAs. The accuracy and dynamics of RNA–protein interactions within these molecular machines are essential for their function and are mediated by RNA-binding proteins (RBPs). Here, we show that fission yeast whole-cell poly(A)+ RNA–protein crosslinking data provide information on the organization of RNA–protein complexes. To evaluate the relative enrichment of cellular RBPs on poly(A)+ RNA, we combine poly(A)+ RNA interactome capture with a whole-cell extract normalization procedure. This approach yields estimates of in vivo RNA-binding activities that identify subunits within multiprotein complexes that directly contact RNA. As validation, we trace RNA interactions of different functional modules of the 3′ end processing machinery and reveal additional contacts. Extending our analysis to different mutants of the RNA exosome complex, we explore how substrate channeling through the complex is affected by mutation. Our data highlight the central role of the RNA helicase Mtl1 in regulation of the complex and provide insights into how different components contribute to engagement of the complex with substrate RNA. In addition, we characterize RNA-binding activities of novel RBPs that have been recurrently detected in the RNA interactomes of multiple species. We find that many of these, including cyclophilins and thioredoxins, are substoichiometric RNA interactors in vivo. Because RBPomes show very good overall agreement between species, we propose that the RNA-binding characteristics we observe in fission yeast are likely to apply to related proteins in higher eukaryotes as well.
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Affiliation(s)
- Cornelia Kilchert
- Institut für Biochemie, Justus-Liebig-Universität Gießen, 35392 Gießen, Germany
| | - Tea Kecman
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Emily Priest
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Svenja Hester
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Ebru Aydin
- Institut für Biochemie, Justus-Liebig-Universität Gießen, 35392 Gießen, Germany
| | - Krzysztof Kus
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Oliver Rossbach
- Institut für Biochemie, Justus-Liebig-Universität Gießen, 35392 Gießen, Germany
| | - Alfredo Castello
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Shabaz Mohammed
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom.,Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA, United Kingdom
| | - Lidia Vasiljeva
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
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31
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Davidson L, Francis L, Cordiner RA, Eaton JD, Estell C, Macias S, Cáceres JF, West S. Rapid Depletion of DIS3, EXOSC10, or XRN2 Reveals the Immediate Impact of Exoribonucleolysis on Nuclear RNA Metabolism and Transcriptional Control. Cell Rep 2020; 26:2779-2791.e5. [PMID: 30840897 PMCID: PMC6403362 DOI: 10.1016/j.celrep.2019.02.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 01/09/2019] [Accepted: 02/04/2019] [Indexed: 12/26/2022] Open
Abstract
Cell-based studies of human ribonucleases traditionally rely on methods that deplete proteins slowly. We engineered cells in which the 3′→5′ exoribonucleases of the exosome complex, DIS3 and EXOSC10, can be rapidly eliminated to assess their immediate roles in nuclear RNA biology. The loss of DIS3 has the greatest impact, causing the substantial accumulation of thousands of transcripts within 60 min. These transcripts include enhancer RNAs, promoter upstream transcripts (PROMPTs), and products of premature cleavage and polyadenylation (PCPA). These transcripts are unaffected by the rapid loss of EXOSC10, suggesting that they are rarely targeted to it. More direct detection of EXOSC10-bound transcripts revealed its substrates to prominently include short 3′ extended ribosomal and small nucleolar RNAs. Finally, the 5′→3′ exoribonuclease, XRN2, has little activity on exosome substrates, but its elimination uncovers different mechanisms for the early termination of transcription from protein-coding gene promoters. Engineered human cells for rapid inducible degradation of EXOSC10 and DIS3 DIS3 degrades the majority of nuclear exosome substrates Direct targets of EXOSC10 include ribosomal and small nucleolar RNAs XRN2 has little activity on exosome substrates
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Affiliation(s)
- Lee Davidson
- The Living Systems Institute, University of Exeter, Stocker Rd, Exeter EX4 4QD, UK
| | - Laura Francis
- The Living Systems Institute, University of Exeter, Stocker Rd, Exeter EX4 4QD, UK
| | - Ross A Cordiner
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Joshua D Eaton
- The Living Systems Institute, University of Exeter, Stocker Rd, Exeter EX4 4QD, UK
| | - Chris Estell
- The Living Systems Institute, University of Exeter, Stocker Rd, Exeter EX4 4QD, UK
| | - Sara Macias
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Javier F Cáceres
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Steven West
- The Living Systems Institute, University of Exeter, Stocker Rd, Exeter EX4 4QD, UK.
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32
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Lingaraju M, Schuller JM, Falk S, Gerlach P, Bonneau F, Basquin J, Benda C, Conti E. To Process or to Decay: A Mechanistic View of the Nuclear RNA Exosome. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2020; 84:155-163. [PMID: 32493762 DOI: 10.1101/sqb.2019.84.040295] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The RNA exosome was originally discovered in yeast as an RNA-processing complex required for the maturation of 5.8S ribosomal RNA (rRNA), one of the constituents of the large ribosomal subunit. The exosome is now known in eukaryotes as the major 3'-5' RNA degradation machine involved in numerous processing, turnover, and surveillance pathways, both in the nucleus and the cytoplasm. Yet its role in maturing the 5.8S rRNA in the pre-60S ribosomal particle remains probably the most intricate and emblematic among its functions, as it involves all the RNA unwinding, degradation, and trimming activities embedded in this macromolecular complex. Here, we propose a comprehensive mechanistic model, based on current biochemical and structural data, explaining the dual functions of the nuclear exosome-the constructive versus the destructive mode.
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Affiliation(s)
- Mahesh Lingaraju
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Jan M Schuller
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Sebastian Falk
- Max Perutz Labs, Department of Structural and Computational Biology, University of Vienna, 1030, Vienna, Austria
| | - Piotr Gerlach
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Fabien Bonneau
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Jérôme Basquin
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Christian Benda
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Elena Conti
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
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33
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Zinoviev A, Ayupov RK, Abaeva IS, Hellen CUT, Pestova TV. Extraction of mRNA from Stalled Ribosomes by the Ski Complex. Mol Cell 2020; 77:1340-1349.e6. [PMID: 32006463 DOI: 10.1016/j.molcel.2020.01.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 11/13/2019] [Accepted: 01/07/2020] [Indexed: 11/26/2022]
Abstract
The evolutionarily conserved Ski2-Ski3-Ski8 (Ski) complex containing the 3'→5' RNA helicase Ski2 binds to 80S ribosomes near the mRNA entrance and facilitates 3'→5' exosomal degradation of mRNA during ribosome-associated mRNA surveillance pathways. Here, we assayed Ski's activity using an in vitro reconstituted translation system and report that this complex efficiently extracts mRNA from 80S ribosomes in the 3'→5' direction in a nucleotide-by-nucleotide manner. The process is ATP dependent and can occur on pre- and post-translocation ribosomal complexes. The Ski complex can engage productively with mRNA and extract it from 80S complexes containing as few as 19 (but not 13) 3'-terminal mRNA nucleotides starting from the P site. The mRNA-extracting activity of the Ski complex suggests that its role in mRNA quality control pathways is not limited to acceleration of exosomal degradation and could include clearance of stalled ribosomes from mRNA, poising mRNA for degradation and rendering stalled ribosomes recyclable by Pelota/Hbs1/ABCE1.
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Affiliation(s)
- Alexandra Zinoviev
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Rustam K Ayupov
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Irina S Abaeva
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Christopher U T Hellen
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Tatyana V Pestova
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA.
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34
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de Amorim J, Slavotinek A, Fasken MB, Corbett AH, Morton DJ. Modeling Pathogenic Variants in the RNA Exosome. RNA & DISEASE 2020; 7:e1166. [PMID: 34676290 PMCID: PMC8528344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023] Open
Abstract
Exosomopathies are a collection of rare diseases caused by mutations in genes that encode structural subunits of the RNA exosome complex (EXOSC). The RNA exosome is critical for both processing and degrading many RNA targets. Mutations in individual RNA exosome subunit genes (termed EXOSC genes) are linked to a variety of distinct diseases. These exosomopathies do not arise from homozygous loss-of-function or large deletions in the EXOSC genes likely because some level of RNA exosome activity is essential for viability. Thus, all patients described so far have at least one allele with a missense mutation encoding an RNA exosome subunit with a single pathogenic amino acid change linked to disease. Understanding how these changes lead to the disparate clinical presentations that have been reported for this class of diseases necessitates investigation of how individual pathogenic missense variants alter RNA exosome function. Such studies will require access to patient samples, a challenge for these very rare diseases, coupled with modeling the patient variants. Here, we highlight five recent studies that model pathogenic variants in EXOSC3, EXOSC2, and EXOSC5.
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Affiliation(s)
- Julia de Amorim
- Department of Biology, Emory University,1510 Clifton Rd., NE RRC 1021, Atlanta, GA 30322, United States
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University,1510 Clifton Rd., NE RRC 1021, Atlanta, GA 30322, United States
| | - Anne Slavotinek
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, United States
| | - Milo B. Fasken
- Department of Biology, Emory University,1510 Clifton Rd., NE RRC 1021, Atlanta, GA 30322, United States
| | - Anita H. Corbett
- Department of Biology, Emory University,1510 Clifton Rd., NE RRC 1021, Atlanta, GA 30322, United States
| | - Derrick J. Morton
- The Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, United States
- Department of Biomedical Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA 91101, United States
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Abstract
The evolutionarily conserved RNA exosome is a multisubunit ribonuclease complex that processes and/or degrades numerous RNAs. Recently, mutations in genes encoding both structural and catalytic subunits of the RNA exosome have been linked to human disease. Mutations in the structural exosome gene EXOSC2 cause a distinct syndrome that includes retinitis pigmentosa, hearing loss, and mild intellectual disability. In contrast, mutations in the structural exosome genes EXOSC3 and EXOSC8 cause pontocerebellar hypoplasia type 1b (PCH1b) and type 1c (PCH1c), respectively, which are related autosomal recessive, neurodegenerative diseases. In addition, mutations in the structural exosome gene EXOSC9 cause a PCH-like disease with cerebellar atrophy and spinal motor neuronopathy. Finally, mutations in the catalytic exosome gene DIS3 have been linked to multiple myeloma, a neoplasm of plasma B cells. How mutations in these RNA exosome genes lead to distinct, tissue-specific diseases is not currently well understood. In this chapter, we examine the role of the RNA exosome complex in human disease and discuss the mechanisms by which mutations in different exosome subunit genes could impair RNA exosome function and give rise to diverse diseases.
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Affiliation(s)
- Milo B Fasken
- Department of Biology, RRC 1021, Emory University, Atlanta, GA, USA.
| | - Derrick J Morton
- Department of Biology, RRC 1021, Emory University, Atlanta, GA, USA
| | - Emily G Kuiper
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Stephanie K Jones
- Department of Biology, RRC 1021, Emory University, Atlanta, GA, USA
- Genetics and Molecular Biology Graduate Program, Emory University, Atlanta, GA, USA
| | - Sara W Leung
- Department of Biology, RRC 1021, Emory University, Atlanta, GA, USA
| | - Anita H Corbett
- Department of Biology, RRC 1021, Emory University, Atlanta, GA, USA.
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Dendooven T, Luisi BF, Bandyra KJ. RNA lifetime control, from stereochemistry to gene expression. Curr Opin Struct Biol 2019; 61:59-70. [PMID: 31869589 DOI: 10.1016/j.sbi.2019.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/13/2019] [Accepted: 10/14/2019] [Indexed: 10/25/2022]
Abstract
Through the activities of various multi-component assemblies, protein-coding transcripts can be chaperoned toward protein synthesis or nudged into a funnel of rapid destruction. The capacity of these machine-like assemblies to tune RNA lifetime underpins the harmony of gene expression in all cells. Some of the molecular machines that mediate transcript turnover also contribute to on-the-fly surveillance of aberrant mRNAs and non-coding RNAs. How these dynamic assemblies distinguish functional RNAs from those that must be degraded is an intriguing puzzle for understanding the regulation of gene expression and dysfunction associated with disease. Recent data illuminate what the machines look like, and how they find, recognise and operate on transcripts to sculpt the dynamic regulatory landscape. This review captures current structural and mechanistic insights into the key enzymes and their effector assemblies that contribute to the fate-determining decision points for RNA in post-transcriptional control of genetic information.
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Affiliation(s)
- Tom Dendooven
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Ben F Luisi
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK.
| | - Katarzyna J Bandyra
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK.
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Mallam AL, Sae-Lee W, Schaub JM, Tu F, Battenhouse A, Jang YJ, Kim J, Wallingford JB, Finkelstein IJ, Marcotte EM, Drew K. Systematic Discovery of Endogenous Human Ribonucleoprotein Complexes. Cell Rep 2019; 29:1351-1368.e5. [PMID: 31665645 PMCID: PMC6873818 DOI: 10.1016/j.celrep.2019.09.060] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 08/30/2019] [Accepted: 09/18/2019] [Indexed: 12/16/2022] Open
Abstract
RNA-binding proteins (RBPs) play essential roles in biology and are frequently associated with human disease. Although recent studies have systematically identified individual RNA-binding proteins, their higher-order assembly into ribonucleoprotein (RNP) complexes has not been systematically investigated. Here, we describe a proteomics method for systematic identification of RNP complexes in human cells. We identify 1,428 protein complexes that associate with RNA, indicating that more than 20% of known human protein complexes contain RNA. To explore the role of RNA in the assembly of each complex, we identify complexes that dissociate, change composition, or form stable protein-only complexes in the absence of RNA. We use our method to systematically identify cell-type-specific RNA-associated proteins in mouse embryonic stem cells and finally, distribute our resource, rna.MAP, in an easy-to-use online interface (rna.proteincomplexes.org). Our system thus provides a methodology for explorations across human tissues, disease states, and throughout all domains of life.
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Affiliation(s)
- Anna L Mallam
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
| | - Wisath Sae-Lee
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Jeffrey M Schaub
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Fan Tu
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Anna Battenhouse
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Yu Jin Jang
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Jonghwan Kim
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Edward M Marcotte
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
| | - Kevin Drew
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
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Lingaraju M, Johnsen D, Schlundt A, Langer LM, Basquin J, Sattler M, Heick Jensen T, Falk S, Conti E. The MTR4 helicase recruits nuclear adaptors of the human RNA exosome using distinct arch-interacting motifs. Nat Commun 2019; 10:3393. [PMID: 31358741 PMCID: PMC6662825 DOI: 10.1038/s41467-019-11339-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 07/07/2019] [Indexed: 12/16/2022] Open
Abstract
The nuclear exosome and its essential co-factor, the RNA helicase MTR4, play crucial roles in several RNA degradation pathways. Besides unwinding RNA substrates for exosome-mediated degradation, MTR4 associates with RNA-binding proteins that function as adaptors in different RNA processing and decay pathways. Here, we identify and characterize the interactions of human MTR4 with a ribosome processing adaptor, NVL, and with ZCCHC8, an adaptor involved in the decay of small nuclear RNAs. We show that the unstructured regions of NVL and ZCCHC8 contain short linear motifs that bind the MTR4 arch domain in a mutually exclusive manner. These short sequences diverged from the arch-interacting motif (AIM) of yeast rRNA processing factors. Our results suggest that nuclear exosome adaptors have evolved canonical and non-canonical AIM sequences to target human MTR4 and demonstrate the versatility and specificity with which the MTR4 arch domain can recruit a repertoire of different RNA-binding proteins.
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Affiliation(s)
- Mahesh Lingaraju
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, D-82152, Martinsried, Germany
| | - Dennis Johnsen
- Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Alle 3, 8000, Aarhus C, Denmark
| | - Andreas Schlundt
- Center for Integrated Protein Science Munich (CIPSM) at Department of Chemistry, Technical University of Munich (TUM), 85747, Garching, Germany.,Institute of Structural Biology, Helmholtz-Zentrum München, 85764, Neuherberg, Germany.,Institute for Molecular Biosciences and Center for Biomolecular Magnetic Resonance (BMRZ) at Johann Wolfgang Goethe-University, Frankfurt am Main, 60438, Germany
| | - Lukas M Langer
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, D-82152, Martinsried, Germany
| | - Jérôme Basquin
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, D-82152, Martinsried, Germany
| | - Michael Sattler
- Center for Integrated Protein Science Munich (CIPSM) at Department of Chemistry, Technical University of Munich (TUM), 85747, Garching, Germany.,Institute of Structural Biology, Helmholtz-Zentrum München, 85764, Neuherberg, Germany
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Alle 3, 8000, Aarhus C, Denmark
| | - Sebastian Falk
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, D-82152, Martinsried, Germany. .,Max F. Perutz Laboratories, Department of Structural and Computational Biology, University of Vienna, Campus Vienna Biocenter 5, 1030, Vienna, Austria.
| | - Elena Conti
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, D-82152, Martinsried, Germany.
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