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Rodríguez-García ME, Cotrina-Vinagre FJ, Bellusci M, Merino-López A, Chumilla-Calzada S, García-Silva MT, Martínez-Azorín F. New subtype of PCH1C caused by novel EXOSC8 variants in a 16-year-old Spanish patient. Neuromuscul Disord 2021; 31:773-782. [PMID: 34210538 DOI: 10.1016/j.nmd.2021.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 04/05/2021] [Accepted: 05/20/2021] [Indexed: 10/21/2022]
Abstract
We report the case of a 16-year-old Spanish boy with cerebellar and spinal muscular atrophy, spasticity, psychomotor retardation, nystagmus, ophthalmoparesis, epilepsy, and mitochondrial respiratory chain (MRC) deficiency. Whole exome sequencing (WES) uncovered three variants (two of them novel) in a compound heterozygous in EXOSC8 gene (NM_181503.3:c.[390+1delG];[628C>T;815G>C]) that encodes the exosome complex component RRP43 protein (EXOSC8). In order to assess the pathogenicity of these variants, expression experiments of RNA and protein for EXOSC8 were carried out. The c.[390+1delG] variant produces the elimination of exon 7 (r.[345_390del]; p.[Ser116LysfsTer27]) and a decrease of the RNA expression in relation to the other allele (p.[Pro210Ser;Ser272Thr]). Furthermore, total mRNA expression is reduced by 30% and the protein level by 65%. EXOSC8 is an essential protein of the exosome core, a ubiquitously expressed complex responsible for RNA processing and degradation. Recessive mutations in EXOSC8 cause pontocerebellar hypoplasia type 1C (PCH1C), and currently, only two homozygous variants in this gene have been described. However, unlike PCH1C-affected individuals with EXOSC8 variants, our patient presents a normal supratentorial cerebral tissue (neither corpus callosum hypoplasia nor hypomyelination) with a less severe phenotype and longer survival. In conclusion, our data expand both genetic and phenotypic spectrum associated with EXOSC8 variants.
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Affiliation(s)
- María Elena Rodríguez-García
- Grupo de Enfermedades Raras, Mitocondriales y Neuromusculares (ERMN). Instituto de Investigación Hospital 12 de Octubre (i+12), E-28041 Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U723, E-28041 Madrid, Spain.
| | - Francisco Javier Cotrina-Vinagre
- Grupo de Enfermedades Raras, Mitocondriales y Neuromusculares (ERMN). Instituto de Investigación Hospital 12 de Octubre (i+12), E-28041 Madrid, Spain
| | - Marcello Bellusci
- Unidad Pediátrica de Enfermedades Raras, Enfermedades Mitocondriales y Metabólicas Hereditarias, Hospital 12 de Octubre, E-28041, Madrid, Spain
| | - Abraham Merino-López
- Grupo de Enfermedades Raras, Mitocondriales y Neuromusculares (ERMN). Instituto de Investigación Hospital 12 de Octubre (i+12), E-28041 Madrid, Spain
| | - Silvia Chumilla-Calzada
- Unidad Pediátrica de Enfermedades Raras, Enfermedades Mitocondriales y Metabólicas Hereditarias, Hospital 12 de Octubre, E-28041, Madrid, Spain
| | - María Teresa García-Silva
- Unidad Pediátrica de Enfermedades Raras, Enfermedades Mitocondriales y Metabólicas Hereditarias, Hospital 12 de Octubre, E-28041, Madrid, Spain
| | - Francisco Martínez-Azorín
- Grupo de Enfermedades Raras, Mitocondriales y Neuromusculares (ERMN). Instituto de Investigación Hospital 12 de Octubre (i+12), E-28041 Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U723, E-28041 Madrid, Spain.
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52
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Wang C, Liu Y, DeMario SM, Mandric I, Gonzalez-Figueroa C, Chanfreau GF. Rrp6 Moonlights in an RNA Exosome-Independent Manner to Promote Cell Survival and Gene Expression during Stress. Cell Rep 2021; 31:107754. [PMID: 32521279 PMCID: PMC7587046 DOI: 10.1016/j.celrep.2020.107754] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 11/21/2019] [Accepted: 05/19/2020] [Indexed: 12/13/2022] Open
Abstract
The nuclear RNA exosome is essential for RNA processing and degradation. Here, we show that the exosome nuclear-specific subunit Rrp6p promotes cell survival during heat stress through the cell wall integrity (CWI) pathway, independently of its catalytic activity or association with the core exosome. Rrp6p exhibits negative genetic interactions with the Slt2/Mpk1p or Paf1p elongation factors required for expression of CWI genes during stress. Overexpression of Rrp6p or of its catalytically inactive or exosome-independent mutants can partially rescue the growth defect of the mpk1Δ mutant and stimulates expression of the Mpk1 p target gene FKS2. The rrp6Δ and mpk1Δ mutants show similarities in deficient expression of CWI genes during heat shock, and overexpression of the CWI gene HSP150 can rescue the stress-induced lethality of the mpk1Δrp6Δ mutant. These results demonstrate that Rrp6p moonlights independently from the exosome to ensure proper expression of CWI genes and to promote cell survival during stress. Wang et al. show that Rrp6 functions with the Slt2/Mpk1 and Paf1 elongation factors for the proper expression of CWI genes during heat stress. The role of Rrp6p in promoting heat-stress-induced gene expression does not require Rrp6 catalytic activity or interaction with the nuclear RNA exosome.
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Affiliation(s)
- Charles Wang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yanru Liu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Samuel M DeMario
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Igor Mandric
- Department of Computer Science, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Carlos Gonzalez-Figueroa
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Guillaume F Chanfreau
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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53
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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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54
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Somashekar PH, Kaur P, Stephen J, Guleria VS, Kadavigere R, Girisha KM, Bielas S, Upadhyai P, Shukla A. Bi-allelic missense variant, p.Ser35Leu in EXOSC1 is associated with pontocerebellar hypoplasia. Clin Genet 2021; 99:594-600. [PMID: 33463720 PMCID: PMC9990822 DOI: 10.1111/cge.13928] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 12/21/2020] [Accepted: 01/14/2021] [Indexed: 12/16/2022]
Abstract
RNA exosome is a highly conserved ribonuclease complex essential for RNA processing and degradation. Bi-allelic variants in exosome subunits EXOSC3, EXOSC8 and EXOSC9 have been reported to cause pontocerebellar hypoplasia type 1B, type 1C and type 1D, respectively, while those in EXOSC2 cause short stature, hearing loss, retinitis pigmentosa and distinctive facies. We ascertained an 8-months-old male with developmental delay, microcephaly, subtle dysmorphism and hypotonia. Pontocerebellar hypoplasia and delayed myelination were noted on neuroimaging. A similarly affected elder sibling succumbed at the age of 4-years 6-months. Chromosomal microarray returned normal results. Exome sequencing revealed a homozygous missense variant, c.104C > T p.(Ser35Leu) in EXOSC1 (NM_016046.5) as the possible candidate. In silico mutagenesis revealed loss of a polar contact with neighboring Leu37 residue. Quantitative real-time PCR indicated no appreciable differences in EXOSC1 transcript levels. Immunoblotting and blue native PAGE revealed reduction in the EXOSC1 protein levels and EXO9 complex in the proband, respectively. We herein report an individual with the bi-allelic variant c.104C>T p.(Ser35Leu) in EXOSC1 and clinical features of pontocerebellar hypoplasia type 1. Immunoblotting and blue native PAGE provide evidence for the pathogenicity of the variant. Thus, we propose EXOSC1 as a novel candidate gene for pontocerebellar hypoplasia.
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Affiliation(s)
- Puneeth H Somashekar
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Parneet Kaur
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Joshi Stephen
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Vishal Singh Guleria
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Rajagopal Kadavigere
- Department of Radiodiagnosis and Imaging, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Katta Mohan Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Stephanie Bielas
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Priyanka Upadhyai
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
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55
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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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56
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Moroz LL, Romanova DY, Kohn AB. Neural versus alternative integrative systems: molecular insights into origins of neurotransmitters. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190762. [PMID: 33550949 PMCID: PMC7935107 DOI: 10.1098/rstb.2019.0762] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Transmitter signalling is the universal chemical language of any nervous system, but little is known about its early evolution. Here, we summarize data about the distribution and functions of neurotransmitter systems in basal metazoans as well as outline hypotheses of their origins. We explore the scenario that neurons arose from genetically different populations of secretory cells capable of volume chemical transmission and integration of behaviours without canonical synapses. The closest representation of this primordial organization is currently found in Placozoa, disk-like animals with the simplest known cell composition but complex behaviours. We propose that injury-related signalling was the evolutionary predecessor for integrative functions of early transmitters such as nitric oxide, ATP, protons, glutamate and small peptides. By contrast, acetylcholine, dopamine, noradrenaline, octopamine, serotonin and histamine were recruited as canonical neurotransmitters relatively later in animal evolution, only in bilaterians. Ligand-gated ion channels often preceded the establishment of novel neurotransmitter systems. Moreover, lineage-specific diversification of neurotransmitter receptors occurred in parallel within Cnidaria and several bilaterian lineages, including acoels. In summary, ancestral diversification of secretory signal molecules provides unique chemical microenvironments for behaviour-driven innovations that pave the way to complex brain functions and elementary cognition. This article is part of the theme issue 'Basal cognition: multicellularity, neurons and the cognitive lens'.
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Affiliation(s)
- Leonid L. Moroz
- Department of Neuroscience, McKnight Brain Institute and Whitney laboratory, University of Florida, 9505 Ocean shore Blvd, St Augustine, FL 32080, USA
| | - Daria Y. Romanova
- Laboratory of Cellular Neurobiology of Learning, Institute of Higher Nervous Activity and Neurophysiology of RAS, 5A Butlerova Street, Moscow 117485, Russia
| | - Andrea B. Kohn
- Department of Neuroscience, McKnight Brain Institute and Whitney laboratory, University of Florida, 9505 Ocean shore Blvd, St Augustine, FL 32080, USA
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57
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Ulmke PA, Xie Y, Sokpor G, Pham L, Shomroni O, Berulava T, Rosenbusch J, Basu U, Fischer A, Nguyen HP, Staiger JF, Tuoc T. Post-transcriptional regulation by the exosome complex is required for cell survival and forebrain development via repression of P53 signaling. Development 2021; 148:dev.188276. [PMID: 33462115 DOI: 10.1242/dev.188276] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 12/29/2020] [Indexed: 12/15/2022]
Abstract
Fine-tuned gene expression is crucial for neurodevelopment. The gene expression program is tightly controlled at different levels, including RNA decay. N6-methyladenosine (m6A) methylation-mediated degradation of RNA is essential for brain development. However, m6A methylation impacts not only RNA stability, but also other RNA metabolism processes. How RNA decay contributes to brain development is largely unknown. Here, we show that Exosc10, a RNA exonuclease subunit of the RNA exosome complex, is indispensable for forebrain development. We report that cortical cells undergo overt apoptosis, culminating in cortical agenesis upon conditional deletion of Exosc10 in mouse cortex. Mechanistically, Exosc10 directly binds and degrades transcripts of the P53 signaling-related genes, such as Aen and Bbc3. Overall, our findings suggest a crucial role for Exosc10 in suppressing the P53 pathway, in which the rapid turnover of the apoptosis effectors Aen and Bbc3 mRNAs is essential for cell survival and normal cortical histogenesis.
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Affiliation(s)
- Pauline Antonie Ulmke
- University Medical Center, Georg-August- University Goettingen, Goettingen 37075, Germany
| | - Yuanbin Xie
- University Medical Center, Georg-August- University Goettingen, Goettingen 37075, Germany.,Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Gannan Medical University, 341000 Ganzhou, The People's Republic of China
| | - Godwin Sokpor
- University Medical Center, Georg-August- University Goettingen, Goettingen 37075, Germany.,Department of Human Genetics, Ruhr University of Bochum, Bochum 44801, Germany
| | - Linh Pham
- University Medical Center, Georg-August- University Goettingen, Goettingen 37075, Germany.,Department of Human Genetics, Ruhr University of Bochum, Bochum 44801, Germany
| | - Orr Shomroni
- Microarray and Deep-Sequencing Core Facility, Georg-August- University Goettingen, Goettingen 37075, Germany
| | - Tea Berulava
- German Center for Neurodegenerative Diseases, Goettingen 37075, Germany
| | - Joachim Rosenbusch
- University Medical Center, Georg-August- University Goettingen, Goettingen 37075, Germany
| | - Uttiya Basu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Andre Fischer
- German Center for Neurodegenerative Diseases, Goettingen 37075, Germany.,Department for Psychiatry and Psychotherapy, University Medical Center, Georg-August-University Goettingen, Goettingen 37075, Germany.,Cluster of Excellence 'Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells' (MBExC), University of Goettingen, Goettingen 37075, Germany
| | - Huu Phuc Nguyen
- Department of Human Genetics, Ruhr University of Bochum, Bochum 44801, Germany
| | - Jochen F Staiger
- University Medical Center, Georg-August- University Goettingen, Goettingen 37075, Germany
| | - Tran Tuoc
- University Medical Center, Georg-August- University Goettingen, Goettingen 37075, Germany .,Department of Human Genetics, Ruhr University of Bochum, Bochum 44801, Germany
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58
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Mu W, Heller T, Barañano KW. Two siblings with a novel variant of EXOSC3 extended phenotypic spectrum of pontocerebellar hypoplasia 1B to an exceptionally mild form. BMJ Case Rep 2021; 14:e236732. [PMID: 33462000 PMCID: PMC7813329 DOI: 10.1136/bcr-2020-236732] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2020] [Indexed: 01/21/2023] Open
Abstract
Pontocerebellar hypoplasia type 1B (PCH1B) describes an autosomal recessive neurological condition that involves hypoplasia or atrophy of the cerebellum and pons, resulting in neurocognitive impairments. Although there is phenotypic variability, this is often an infantile lethal condition, and most cases have been described to be congenital and neurodegenerative. PCH1B is caused by mutations in the gene EXOSC3, which encodes exosome component 3, a subunit of the human RNA exosome complex. A range of pathogenic variants with some correlation to phenotype have been reported. The most commonly reported pathogenic variant in EXOSC3 is c.395A>C, p.(Asp132Ala); homozygosity for this variant has been proposed to lead to milder phenotypes than compound heterozygosity. In this case, we report two siblings with extraordinarily mild presentations of PCH1B who are compound heterozygous for variants in EXOSC3 c.155delC and c.80T>G. These patients drastically expand the phenotypic variability of PCH1B and raise questions about genotype-phenotype associations.
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Affiliation(s)
- Weiyi Mu
- Institute of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Teresa Heller
- Department of Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Kristin W Barañano
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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59
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Out or decay: fate determination of nuclear RNAs. Essays Biochem 2020; 64:895-905. [DOI: 10.1042/ebc20200005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/12/2020] [Accepted: 08/24/2020] [Indexed: 02/08/2023]
Abstract
Abstract
In eukaryotes, RNAs newly synthesized by RNA polymerase II (RNAPII) undergo several processing steps prior to transport to the cytoplasm. It has long been known that RNAs with defects in processing or export are removed in the nucleus. Recent studies revealed that RNAs without apparent defects are also subjected to nuclear degradation, indicating that nuclear RNA fate is determined in a more complex and dynamic way than previously thought. Nuclear RNA sorting directly determines the quality and quantity of RNA pools for future translation and thus is of significant importance. In this essay, we will summarize recent studies on this topic, mainly focusing on findings in mammalian system, and discuss about important remaining questions and possible biological relevance for nuclear RNA fate determination.
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60
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Aguilar LC, Paul B, Reiter T, Gendron L, Arul Nambi Rajan A, Montpetit R, Trahan C, Pechmann S, Oeffinger M, Montpetit B. Altered rRNA processing disrupts nuclear RNA homeostasis via competition for the poly(A)-binding protein Nab2. Nucleic Acids Res 2020; 48:11675-11694. [PMID: 33137177 PMCID: PMC7672433 DOI: 10.1093/nar/gkaa964] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 10/06/2020] [Accepted: 10/12/2020] [Indexed: 12/13/2022] Open
Abstract
RNA-binding proteins (RBPs) are key mediators of RNA metabolism. Whereas some RBPs exhibit narrow transcript specificity, others function broadly across both coding and non-coding RNAs. Here, in Saccharomyces cerevisiae, we demonstrate that changes in RBP availability caused by disruptions to distinct cellular processes promote a common global breakdown in RNA metabolism and nuclear RNA homeostasis. Our data shows that stabilization of aberrant ribosomal RNA (rRNA) precursors in an enp1-1 mutant causes phenotypes similar to RNA exosome mutants due to nucleolar sequestration of the poly(A)-binding protein (PABP) Nab2. Decreased nuclear PABP availability is accompanied by genome-wide changes in RNA metabolism, including increased pervasive transcripts levels and snoRNA processing defects. These phenotypes are mitigated by overexpression of PABPs, inhibition of rDNA transcription, or alterations in TRAMP activity. Our results highlight the need for cells to maintain poly(A)-RNA levels in balance with PABPs and other RBPs with mutable substrate specificity across nucleoplasmic and nucleolar RNA processes.
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Affiliation(s)
- Lisbeth-Carolina Aguilar
- Department for Systems Biology, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC, Canada
| | - Biplab Paul
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | - Taylor Reiter
- Food Science Graduate Group, University of California Davis, Davis, CA, USA
| | - Louis Gendron
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Arvind Arul Nambi Rajan
- Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California Davis, Davis, CA, USA
| | - Rachel Montpetit
- Department of Viticulture and Enology, University of California Davis, Davis, CA, USA
| | - Christian Trahan
- Department for Systems Biology, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC, Canada
| | - Sebastian Pechmann
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Marlene Oeffinger
- Department for Systems Biology, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC, Canada
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
- Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Ben Montpetit
- Department of Cell Biology, University of Alberta, Edmonton, Canada
- Food Science Graduate Group, University of California Davis, Davis, CA, USA
- Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California Davis, Davis, CA, USA
- Department of Viticulture and Enology, University of California Davis, Davis, CA, USA
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61
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Xi PW, Zhang X, Zhu L, Dai XY, Cheng L, Hu Y, Shi L, Wei JF, Ding Q. Oncogenic action of the exosome cofactor RBM7 by stabilization of CDK1 mRNA in breast cancer. NPJ Breast Cancer 2020; 6:58. [PMID: 33145401 PMCID: PMC7603334 DOI: 10.1038/s41523-020-00200-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 10/01/2020] [Indexed: 12/22/2022] Open
Abstract
RNA exosome can target the specific RNAs for their processing/degradation by distinct exosome cofactors. As a key component in exosome cofactors, RNA binding motif protein 7 (RBM7) shows the binding specificity for uridine-rich sequences in mRNAs via its RNA recognition motifs. However, the specific function of RBM7 in human breast cancer remains unclear. In vitro, experiments revealed that knockdown of RBM7 dramatically inhibited breast cancer cell proliferation, while inducing G1 cell cycle arrest; the opposite was true when RBM7 was overexpressed. Meanwhile, experiments in vivo confirmed the oncogenic function of RBM7 in breast cancer. RNA sequencing and the following pathway analysis found that cyclin-dependent kinase1 (CDK1) was one of the main gene regulated by RBM7. Overexpression of RBM7 increased CDK1 expression, while RBM7 knockdown decreased it. RIP assays additionally found that RBM7 bound directly to CDK1 mRNA. It was also showed that RBM7 could directly bind to the AU-rich elements (AREs) in 3'-UTR of CDK1 mRNA, which contributed to the stability of CDK1 mRNA by lengthening its half-life. More importantly, the oncogenic activity reduced by knockdown of RBM7 could be rescued by overexpression of CDK1 both in vitro and in vivo, but mutant CDK1 failed. All the evidences implied RBM7 promoted breast cancer cell proliferation by stabilizing CDK1 mRNA via binding to AREs in its 3'-UTR. As we knew, it was the first attempt to connect the RNA exosome to the tumor development, providing new insights into the mechanisms of RNA exosome-linked diseases.
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Affiliation(s)
- Pei-Wen Xi
- Jiangsu Breast Disease Center, The First Affiliated Hospital with Nanjing Medical University (Jiangsu Province Hospital), 300 Guangzhou Road, 210029 Nanjing, China
| | - Xu Zhang
- Jiangsu Breast Disease Center, The First Affiliated Hospital with Nanjing Medical University (Jiangsu Province Hospital), 300 Guangzhou Road, 210029 Nanjing, China
| | - Lei Zhu
- Jiangsu Breast Disease Center, The First Affiliated Hospital with Nanjing Medical University (Jiangsu Province Hospital), 300 Guangzhou Road, 210029 Nanjing, China
| | - Xin-Yuan Dai
- Jiangsu Breast Disease Center, The First Affiliated Hospital with Nanjing Medical University (Jiangsu Province Hospital), 300 Guangzhou Road, 210029 Nanjing, China
| | - Lin Cheng
- Jiangsu Breast Disease Center, The First Affiliated Hospital with Nanjing Medical University (Jiangsu Province Hospital), 300 Guangzhou Road, 210029 Nanjing, China
| | - Yue Hu
- Jiangsu Breast Disease Center, The First Affiliated Hospital with Nanjing Medical University (Jiangsu Province Hospital), 300 Guangzhou Road, 210029 Nanjing, China
| | - Liang Shi
- Jiangsu Breast Disease Center, The First Affiliated Hospital with Nanjing Medical University (Jiangsu Province Hospital), 300 Guangzhou Road, 210029 Nanjing, China
| | - Ji-Fu Wei
- Research Division of Clinical Pharmacology, The First Affiliated Hospital with Nanjing Medical University (Jiangsu Province Hospital), 300 Guangzhou Road, 210029 Nanjing, China
| | - Qiang Ding
- Jiangsu Breast Disease Center, The First Affiliated Hospital with Nanjing Medical University (Jiangsu Province Hospital), 300 Guangzhou Road, 210029 Nanjing, China
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Yatsuka H, Hada K, Shiraishi H, Umeda R, Morisaki I, Urushibata H, Shimizu N, Sebastian WA, Hikida T, Ishitani T, Hanada R, Shimada T, Kimoto K, Kubota T, Hanada T. Exosc2 deficiency leads to developmental disorders by causing a nucleotide pool imbalance in zebrafish. Biochem Biophys Res Commun 2020; 533:1470-1476. [PMID: 33333712 DOI: 10.1016/j.bbrc.2020.10.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 10/17/2020] [Indexed: 02/07/2023]
Abstract
Exosc2 is one of the components of the exosome complex involved in RNA 3' end processing and degradation of various RNAs. Recently, EXOSC2 mutation has been reported in German families presenting short stature, hearing loss, retinitis pigmentosa, and premature aging. However, the in vivo function of EXOSC2 has been elusive. Herein, we generated Exosc2 knockout (exosc2-/-) zebrafish that showed larval lethality 13 days post fertilization, with microcephaly, loss of spinal motor neurons, myelin deficiency, and retinitis pigmentosa. Mechanistically, Exosc2 deficiency caused impaired mRNA turnover, resulting in a nucleotide pool imbalance. Rapamycin, which modulated mRNA turnover by inhibiting the mTOR pathway, improved nucleotide pool imbalance in exosc2-/- zebrafish, resulting in prolonged survival and partial rescue of neuronal defects. Taken together, our findings offer new insights into the disease pathogenesis caused by Exosc2 deficiency, and might help explain fundamental molecular mechanisms in neuronal diseases, such as Alzheimer's disease, amyotrophic lateral sclerosis, and spinal muscular atrophy.
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Affiliation(s)
- Hiroyuki Yatsuka
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan; Department of Ophthalmology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Kazumasa Hada
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Hiroshi Shiraishi
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Ryohei Umeda
- Department of Neurophysiology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Ikuko Morisaki
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Hirotaro Urushibata
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Nobuyuki Shimizu
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Wulan Apridita Sebastian
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan; Institute of Tropical Disease, Airlangga University, Surabaya, Indonesia
| | - Takatoshi Hikida
- Laboratory for Advanced Brain Functions, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Tohru Ishitani
- Department of Homeostatic Regulation, Division of Cellular and Molecular Biology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Reiko Hanada
- Department of Neurophysiology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Tatsuo Shimada
- Oita Medical Technology School, Japan College of Judo-Therapy, Acupuncture & Moxibustion Therapy, Oita, Japan
| | - Kenichi Kimoto
- Department of Ophthalmology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Toshiaki Kubota
- Department of Ophthalmology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Toshikatsu Hanada
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan.
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63
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Clayer E, Dalseno D, Kueh A, Lacey D, Tsai M, Arvell EH, Wimmer VC, Bouillet P. Severe Impairment of TNF Post-transcriptional Regulation Leads to Embryonic Death. iScience 2020; 23:101726. [PMID: 33210082 PMCID: PMC7658709 DOI: 10.1016/j.isci.2020.101726] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/08/2020] [Accepted: 10/20/2020] [Indexed: 02/07/2023] Open
Abstract
Post-transcriptional regulation mechanisms control mRNA stability or translational efficiency via ribosomes, and recent evidence indicates that it is a major determinant of the accurate levels of cytokine mRNAs. Transcriptional regulation of Tnf has been well studied and found to be important for the rapid induction of Tnf mRNA and regulation of the acute phase of inflammation, whereas study of its post-transcriptional regulation has been largely limited to the role of the AU-rich element (ARE), and to a lesser extent, to that of the constitutive decay element (CDE). We have identified another regulatory element (NRE) in the 3' UTR of Tnf and demonstrate that ARE, CDE, and NRE cooperate in vivo to efficiently downregulate Tnf expression and prevent autoimmune inflammatory diseases. We also show that excessive TNF may lead to embryonic death.
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Affiliation(s)
- Elise Clayer
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia,Department of Medical Biology, the University of Melbourne, Melbourne, VIC 3052, Australia
| | - Destiny Dalseno
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia,Department of Medical Biology, the University of Melbourne, Melbourne, VIC 3052, Australia
| | - Andrew Kueh
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia,Department of Medical Biology, the University of Melbourne, Melbourne, VIC 3052, Australia
| | - Derek Lacey
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia,Department of Medical Biology, the University of Melbourne, Melbourne, VIC 3052, Australia
| | - Minhsuang Tsai
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia,Department of Medical Biology, the University of Melbourne, Melbourne, VIC 3052, Australia
| | - Elyas H. Arvell
- Department of Medical Biology, the University of Melbourne, Melbourne, VIC 3052, Australia,The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3052, Australia
| | - Verena C. Wimmer
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia,Department of Medical Biology, the University of Melbourne, Melbourne, VIC 3052, Australia
| | - Philippe Bouillet
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia,Department of Medical Biology, the University of Melbourne, Melbourne, VIC 3052, Australia,Corresponding author
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64
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Sakamoto M, Iwama K, Sekiguchi F, Mashimo H, Kumada S, Ishigaki K, Okamoto N, Behnam M, Ghadami M, Koshimizu E, Miyatake S, Mitsuhashi S, Mizuguchi T, Takata A, Saitsu H, Miyake N, Matsumoto N. Novel EXOSC9 variants cause pontocerebellar hypoplasia type 1D with spinal motor neuronopathy and cerebellar atrophy. J Hum Genet 2020; 66:401-407. [PMID: 33040083 DOI: 10.1038/s10038-020-00853-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 12/11/2022]
Abstract
Pontocerebellar hypoplasia (PCH) is currently classified into 13 subgroups and many gene variants associated with PCH have been identified by next generation sequencing. PCH type 1 is a rare heterogeneous neurodegenerative disorder. The clinical presentation includes early-onset severe developmental delay, progressive motor neuronopathy, and cerebellar and pontine atrophy. Recently two variants in the EXOSC9 gene (MIM: 606180), NM_001034194.1: c.41T>C (p.Leu14Pro) and c.481C>T (p.Arg161*) were identified in four unrelated patients with PCH type 1D (PCH1D) (MIM: 618065). EXOSC9 encodes a component of the exosome complex, which is essential for correct processing and degradation of RNA. We report here two PCH1D families with biallelic EXOSC9 variants: c.239T>G (p.Leu80Arg) and c.484dupA (p.Arg162Lysfs*3) in one family and c.151G>C (p.Gly51Arg) in the other family. Although the patients studied here showed similar clinical features as previously described for PCH1D, relatively greater intellectual development (although still highly restricted) and normal pontine structure were recognized. Our findings expand the clinical consequences of biallelic EXOSC9 variants.
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Affiliation(s)
- Masamune Sakamoto
- Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan.,Department of Pediatrics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Kazuhiro Iwama
- Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan.,Department of Pediatrics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Futoshi Sekiguchi
- Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan
| | - Hideaki Mashimo
- Department of Neuropediatrics, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Satoko Kumada
- Department of Neuropediatrics, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Keiko Ishigaki
- Department of Pediatrics, Tokyo Women's Medical University, Tokyo, Japan
| | - Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Mahdiyeh Behnam
- Medical Genetics Research Center of Genome, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohsen Ghadami
- Department of Medical Genetics, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Cardiac Primary Research Center, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Eriko Koshimizu
- Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan
| | - Satoko Miyatake
- Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan.,Clinical Genetics Department, Yokohama City University Hospital, Yokohama, Japan
| | - Satomi Mitsuhashi
- Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan
| | - Takeshi Mizuguchi
- Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan
| | - Atsushi Takata
- Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan
| | - Hirotomo Saitsu
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Noriko Miyake
- Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan.
| | - Naomichi Matsumoto
- Department of Human Genetics, Graduate school of medicine, Yokohama City University, Yokohama, Japan.
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65
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Wermuth PJ, Jimenez SA. Molecular characteristics and functional differences of anti-PM/Scl autoantibodies and two other distinct and unique supramolecular structures known as "EXOSOMES". Autoimmun Rev 2020; 19:102644. [PMID: 32801042 DOI: 10.1016/j.autrev.2020.102644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 04/10/2020] [Indexed: 02/06/2023]
Abstract
The term "exosome" has been applied to three distinct supramolecular entities, namely the PM/Scl autoantibodies or "RNA exosomes", transforming DNA fragments termed "DNA exosomes", and small size extracellular vesicles knows as "exosomes". Some of the molecular components of the "PM/Scl exosome complex" or "RNA exosome" are recognized by specific autoantibodies present in the serum from some Systemic Sclerosis (SSc), polymyositis (PM) and polymyositis SSc (PM/Scl) overlap syndrome patients. On the other hand, one of the most active focuses of laboratory investigation in the last decade has been the biogenesis and role of extracellular vesicles known as "exosomes". The remarkable ability of these "exosome" vesicles to alter the cellular phenotype following fusion with target cells and the release of their macromolecular cargo has revealed a possible role in the pathogenesis of numerous diseases, including malignant, inflammatory, and autoimmune disorders and may allow them to serve as theranostic agents for personalized and precision medicine. The indiscriminate use of the term "exosome" to refer to these three distinct molecular entities has engendered great confusion in the scientific literature. Here, we review the molecular characteristics and functional differences between the three molecular structures identified as "exosomes". Given the rapidly growing scientific interest in extravesicular exosomes, unless a solution is found the confusion in the literature resulting from the use of the term "exosomes" will markedly increase.
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Affiliation(s)
- Peter J Wermuth
- Jefferson Institute of Molecular Medicine and Scleroderma Center, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| | - Sergio A Jimenez
- Jefferson Institute of Molecular Medicine and Scleroderma Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
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66
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67
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Morton DJ, Jalloh B, Kim L, Kremsky I, Nair RJ, Nguyen KB, Rounds JC, Sterrett MC, Brown B, Le T, Karkare MC, McGaughey KD, Sheng S, Leung SW, Fasken MB, Moberg KH, Corbett AH. A Drosophila model of Pontocerebellar Hypoplasia reveals a critical role for the RNA exosome in neurons. PLoS Genet 2020; 16:e1008901. [PMID: 32645003 PMCID: PMC7373318 DOI: 10.1371/journal.pgen.1008901] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 07/21/2020] [Accepted: 06/01/2020] [Indexed: 12/27/2022] Open
Abstract
The RNA exosome is an evolutionarily-conserved ribonuclease complex critically important for precise processing and/or complete degradation of a variety of cellular RNAs. The recent discovery that mutations in genes encoding structural RNA exosome subunits cause tissue-specific diseases makes defining the role of this complex within specific tissues critically important. Mutations in the RNA exosome component 3 (EXOSC3) gene cause Pontocerebellar Hypoplasia Type 1b (PCH1b), an autosomal recessive neurologic disorder. The majority of disease-linked mutations are missense mutations that alter evolutionarily-conserved regions of EXOSC3. The tissue-specific defects caused by these amino acid changes in EXOSC3 are challenging to understand based on current models of RNA exosome function with only limited analysis of the complex in any multicellular model in vivo. The goal of this study is to provide insight into how mutations in EXOSC3 impact the function of the RNA exosome. To assess the tissue-specific roles and requirements for the Drosophila ortholog of EXOSC3 termed Rrp40, we utilized tissue-specific RNAi drivers. Depletion of Rrp40 in different tissues reveals a general requirement for Rrp40 in the development of many tissues including the brain, but also highlight an age-dependent requirement for Rrp40 in neurons. To assess the functional consequences of the specific amino acid substitutions in EXOSC3 that cause PCH1b, we used CRISPR/Cas9 gene editing technology to generate flies that model this RNA exosome-linked disease. These flies show reduced viability; however, the surviving animals exhibit a spectrum of behavioral and morphological phenotypes. RNA-seq analysis of these Drosophila Rrp40 mutants reveals increases in the steady-state levels of specific mRNAs and ncRNAs, some of which are central to neuronal function. In particular, Arc1 mRNA, which encodes a key regulator of synaptic plasticity, is increased in the Drosophila Rrp40 mutants. Taken together, this study defines a requirement for the RNA exosome in specific tissues/cell types and provides insight into how defects in RNA exosome function caused by specific amino acid substitutions that occur in PCH1b can contribute to neuronal dysfunction.
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Affiliation(s)
- Derrick J. Morton
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - Binta Jalloh
- Genetics and Molecular Biology Graduate Program, Emory University, NE, Atlanta, Georgia, United States of America
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Lily Kim
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - Isaac Kremsky
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - Rishi J. Nair
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - Khuong B. Nguyen
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - J. Christopher Rounds
- Genetics and Molecular Biology Graduate Program, Emory University, NE, Atlanta, Georgia, United States of America
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Maria C. Sterrett
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
- Biochemistry, Cell and Developmental Biology Graduate Program, Emory University, NE, Atlanta, Georgia, United States of America
| | - Brianna Brown
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Thalia Le
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - Maya C. Karkare
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - Kathryn D. McGaughey
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - Shaoyi Sheng
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - Sara W. Leung
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - Milo B. Fasken
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
| | - Kenneth H. Moberg
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Anita H. Corbett
- Department of Biology, RRC 1021, Emory University, NE, Atlanta, Georgia, United States of America
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68
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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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69
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Müller JS, Burns DT, Griffin H, Wells GR, Zendah RA, Munro B, Schneider C, Horvath R. RNA exosome mutations in pontocerebellar hypoplasia alter ribosome biogenesis and p53 levels. Life Sci Alliance 2020; 3:3/8/e202000678. [PMID: 32527837 PMCID: PMC7295610 DOI: 10.26508/lsa.202000678] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 06/01/2020] [Accepted: 06/03/2020] [Indexed: 12/12/2022] Open
Abstract
The RNA exosome is a ubiquitously expressed complex of nine core proteins (EXOSC1-9) and associated nucleases responsible for RNA processing and degradation. Mutations in EXOSC3, EXOSC8, EXOSC9, and the exosome cofactor RBM7 cause pontocerebellar hypoplasia and motor neuronopathy. We investigated the consequences of exosome mutations on RNA metabolism and cellular survival in zebrafish and human cell models. We observed that levels of mRNAs encoding p53 and ribosome biogenesis factors are increased in zebrafish lines with homozygous mutations of exosc8 or exosc9, respectively. Consistent with higher p53 levels, mutant zebrafish have a reduced head size, smaller brain, and cerebellum caused by an increased number of apoptotic cells during development. Down-regulation of EXOSC8 and EXOSC9 in human cells leads to p53 protein stabilisation and G2/M cell cycle arrest. Increased p53 transcript levels were also observed in muscle samples from patients with EXOSC9 mutations. Our work provides explanation for the pathogenesis of exosome-related disorders and highlights the link between exosome function, ribosome biogenesis, and p53-dependent signalling. We suggest that exosome-related disorders could be classified as ribosomopathies.
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Affiliation(s)
- Juliane S Müller
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.,Department of Clinical Neurosciences, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - David T Burns
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.,Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Helen Griffin
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Graeme R Wells
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Romance A Zendah
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Benjamin Munro
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.,Department of Clinical Neurosciences, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Claudia Schneider
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Rita Horvath
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK .,Department of Clinical Neurosciences, University of Cambridge School of Clinical Medicine, Cambridge, UK
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70
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EXOSC9 depletion attenuates P-body formation, stress resistance, and tumorigenicity of cancer cells. Sci Rep 2020; 10:9275. [PMID: 32518284 PMCID: PMC7283315 DOI: 10.1038/s41598-020-66455-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 05/21/2020] [Indexed: 01/16/2023] Open
Abstract
Cancer cells adapt to various stress conditions by optimizing gene expression profiles via transcriptional and translational regulation. However, whether and how EXOSC9, a component of the RNA exosome complex, regulates adaptation to stress conditions and tumorigenicity in cancer cells remain unclear. Here, we examined the effects of EXOSC9 depletion on cancer cell growth under various stress conditions. EXOSC9 depletion attenuated growth and survival under various stress conditions in cancer cells. Interestingly, this also decreased the number of P-bodies, which are messenger ribonucleoprotein particles (mRNPs) required for stress adaptation. Meanwhile, EXOSC2/EXOSC4 depletion also attenuated P-body formation and stress resistance with decreased EXOSC9 protein. EXOSC9-mediated stress resistance and P-body formation were found to depend on the intact RNA-binding motif of this protein. Further, RNA-seq analyses identified 343 EXOSC9-target genes, among which, APOBEC3G contributed to defects in stress resistance and P-body formation in MDA-MB-231 cells. Finally, EXOSC9 also promoted xenografted tumor growth of MDA-MB-231 cells in an intact RNA-binding motif-dependent manner. Database analyses further showed that higher EXOSC9 activity, estimated based on the expression of 343 target genes, was correlated with poorer prognosis in some cancer patients. Thus, drugs targeting activity of the RNA exosome complex or EXOSC9 might be useful for cancer treatment.
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71
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Gao C, Wang Y. mRNA Metabolism in Cardiac Development and Disease: Life After Transcription. Physiol Rev 2020; 100:673-694. [PMID: 31751167 PMCID: PMC7327233 DOI: 10.1152/physrev.00007.2019] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 09/06/2019] [Accepted: 10/30/2019] [Indexed: 02/06/2023] Open
Abstract
The central dogma of molecular biology illustrates the importance of mRNAs as critical mediators between genetic information encoded at the DNA level and proteomes/metabolomes that determine the diverse functional outcome at the cellular and organ levels. Although the total number of protein-producing (coding) genes in the mammalian genome is ~20,000, it is evident that the intricate processes of cardiac development and the highly regulated physiological regulation in the normal heart, as well as the complex manifestation of pathological remodeling in a diseased heart, would require a much higher degree of complexity at the transcriptome level and beyond. Indeed, in addition to an extensive regulatory scheme implemented at the level of transcription, the complexity of transcript processing following transcription is dramatically increased. RNA processing includes post-transcriptional modification, alternative splicing, editing and transportation, ribosomal loading, and degradation. While transcriptional control of cardiac genes has been a major focus of investigation in recent decades, a great deal of progress has recently been made in our understanding of how post-transcriptional regulation of mRNA contributes to transcriptome complexity. In this review, we highlight some of the key molecular processes and major players in RNA maturation and post-transcriptional regulation. In addition, we provide an update to the recent progress made in the discovery of RNA processing regulators implicated in cardiac development and disease. While post-transcriptional modulation is a complex and challenging problem to study, recent technological advancements are paving the way for a new era of exciting discoveries and potential clinical translation in the context of cardiac biology and heart disease.
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Affiliation(s)
- Chen Gao
- Departments of Anesthesiology, Medicine, and Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
| | - Yibin Wang
- Departments of Anesthesiology, Medicine, and Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
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Tuck AC, Rankova A, Arpat AB, Liechti LA, Hess D, Iesmantavicius V, Castelo-Szekely V, Gatfield D, Bühler M. Mammalian RNA Decay Pathways Are Highly Specialized and Widely Linked to Translation. Mol Cell 2020; 77:1222-1236.e13. [PMID: 32048998 PMCID: PMC7083229 DOI: 10.1016/j.molcel.2020.01.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 11/11/2019] [Accepted: 01/07/2020] [Indexed: 12/24/2022]
Abstract
RNA decay is crucial for mRNA turnover and surveillance and misregulated in many diseases. This complex system is challenging to study, particularly in mammals, where it remains unclear whether decay pathways perform specialized versus redundant roles. Cytoplasmic pathways and links to translation are particularly enigmatic. By directly profiling decay factor targets and normal versus aberrant translation in mouse embryonic stem cells (mESCs), we uncovered extensive decay pathway specialization and crosstalk with translation. XRN1 (5'-3') mediates cytoplasmic bulk mRNA turnover whereas SKIV2L (3'-5') is universally recruited by ribosomes, tackling aberrant translation and sometimes modulating mRNA abundance. Further exploring translation surveillance revealed AVEN and FOCAD as SKIV2L interactors. AVEN prevents ribosome stalls at structured regions, which otherwise require SKIV2L for clearance. This pathway is crucial for histone translation, upstream open reading frame (uORF) regulation, and counteracting ribosome arrest on small ORFs. In summary, we uncovered key targets, components, and functions of mammalian RNA decay pathways and extensive coupling to translation.
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Affiliation(s)
- Alex Charles Tuck
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Aneliya Rankova
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Alaaddin Bulak Arpat
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Luz Angelica Liechti
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Daniel Hess
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Vytautas Iesmantavicius
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | | | - David Gatfield
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Marc Bühler
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; University of Basel, Petersplatz 10, 4003 Basel, Switzerland.
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73
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Regulation of long non-coding RNAs and genome dynamics by the RNA surveillance machinery. Nat Rev Mol Cell Biol 2020; 21:123-136. [PMID: 32020081 DOI: 10.1038/s41580-019-0209-0] [Citation(s) in RCA: 131] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2019] [Indexed: 02/07/2023]
Abstract
Much of the mammalian genome is transcribed, generating long non-coding RNAs (lncRNAs) that can undergo post-transcriptional surveillance whereby only a subset of the non-coding transcripts is allowed to attain sufficient stability to persist in the cellular milieu and control various cellular functions. Paralleling protein turnover by the proteasome complex, lncRNAs are also likely to exist in a dynamic equilibrium that is maintained through constant monitoring by the RNA surveillance machinery. In this Review, we describe the RNA surveillance factors and discuss the vital role of lncRNA surveillance in orchestrating various biological processes, including the protection of genome integrity, maintenance of pluripotency of embryonic stem cells, antibody-gene diversification, coordination of immune cell activation and regulation of heterochromatin formation. We also discuss examples of human diseases and developmental defects associated with the failure of RNA surveillance mechanisms, further highlighting the importance of lncRNA surveillance in maintaining cell and organism functions and health.
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74
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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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75
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Bizzari S, Hamzeh AR, Mohamed M, Al-Ali MT, Bastaki F. Expanded PCH1D phenotype linked to EXOSC9 mutation. Eur J Med Genet 2020; 63:103622. [DOI: 10.1016/j.ejmg.2019.01.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 01/13/2019] [Accepted: 01/20/2019] [Indexed: 12/11/2022]
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76
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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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77
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Abstract
The numerous quality control pathways that target defective ribonucleic acids (RNAs) for degradation play key roles in shaping mammalian transcriptomes and preventing disease. These pathways monitor most steps in the biogenesis of both noncoding RNAs (ncRNAs) and protein-coding messenger RNAs (mRNAs), degrading ncRNAs that fail to form functional complexes with one or more proteins and eliminating mRNAs that encode abnormal, potentially toxic proteins. Mutations in components of diverse RNA surveillance pathways manifest as disease. Some mutations are characterized by increased interferon production, suggesting that a major role of these pathways is to prevent aberrant cellular RNAs from being recognized as "non-self." Other mutations are common in cancer, or result in developmental defects, revealing the importance of RNA surveillance to cell and organismal function.
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Affiliation(s)
- Sandra L Wolin
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| | - Lynne E Maquat
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.
- Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
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78
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Chang NW, Huang YP. The RNA degradation pathway is involved in PPARα-modulated anti-oral tumorigenesis. Biomedicine (Taipei) 2019; 9:27. [PMID: 31724941 PMCID: PMC6855187 DOI: 10.1051/bmdcn/2019090427] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 10/02/2019] [Indexed: 12/15/2022] Open
Abstract
Background: The activation of peroxisome proliferator-activated receptor alpha (PPARα) has been shown to reprogram tumor metabolism and exhibits great potential for treating anti-oral tumorigenesis. Methods: In this study, we used a pathway-based strategy to explore possible functional pathways involved in the anticancer activity of PPARα in oral cancer cells through next-generation sequencing (NGS) and bioinformatic approaches. Results: We found that 3919 genes were upregulated and 1060 genes were downregulated through PPARα activation. These genes were mainly involved in the proteasomal, mRNA surveillance, spliceosomal, RNA transport, and RNA degradation pathways, as indicated by GO and KEGG enrichment analysis. Importantly, a total of 13 upregulated genes in the RNA degradation pathway were identified including 3 core exosome factor genes (RRP43, RRP42, and CSL4), 2 TRAMP complex genes (TRF4 and Mtr4), 2 exosome cofactor genes (RRP6 and MPP6), 2 CCR4-NOT complex genes (CNOT2 and CNOT3), 2 Ski complex genes (SKI2 and Ski3), 1 decapping complex gene (EDC4), and 1 gene involved in 5’ exoribonuclease activity (XRN1). Conclusion: Our findings suggest that the activation of PPARα to upregulate the RNA degradation pathway might provide a new strategy for oral cancer treatment.
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Affiliation(s)
- Nai-Wen Chang
- Department of Biochemistry, College of Medicine, China Medical University, Taichung 404, Taiwan
| | - Yi-Ping Huang
- Department of Physiology, College of Medicine, China Medical University, Taichung 404, Taiwan
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79
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Pillon MC, Lo YH, Stanley RE. IT'S 2 for the price of 1: Multifaceted ITS2 processing machines in RNA and DNA maintenance. DNA Repair (Amst) 2019; 81:102653. [PMID: 31324529 PMCID: PMC6764878 DOI: 10.1016/j.dnarep.2019.102653] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cells utilize sophisticated RNA processing machines to ensure the quality of RNA. Many RNA processing machines have been further implicated in regulating the DNA damage response signifying a strong link between RNA processing and genome maintenance. One of the most intricate and highly regulated RNA processing pathways is the processing of the precursor ribosomal RNA (pre-rRNA), which is paramount for the production of ribosomes. Removal of the Internal Transcribed Spacer 2 (ITS2), located between the 5.8S and 25S rRNA, is one of the most complex steps of ribosome assembly. Processing of the ITS2 is initiated by the newly discovered endoribonuclease Las1, which cleaves at the C2 site within the ITS2, generating products that are further processed by the polynucleotide kinase Grc3, the 5'→3' exonuclease Rat1, and the 3'→5' RNA exosome complex. In addition to their defined roles in ITS2 processing, these critical cellular machines participate in other stages of ribosome assembly, turnover of numerous cellular RNAs, and genome maintenance. Here we summarize recent work defining the molecular mechanisms of ITS2 processing by these essential RNA processing machines and highlight their emerging roles in transcription termination, heterochromatin function, telomere maintenance, and DNA repair.
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Affiliation(s)
- 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
| | - Yu-Hua Lo
- 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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80
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Belair C, Sim S, Kim KY, Tanaka Y, Park IH, Wolin SL. The RNA exosome nuclease complex regulates human embryonic stem cell differentiation. J Cell Biol 2019; 218:2564-2582. [PMID: 31308215 PMCID: PMC6683745 DOI: 10.1083/jcb.201811148] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 05/21/2019] [Accepted: 06/12/2019] [Indexed: 01/09/2023] Open
Abstract
This work shows that the exosome modulates the levels of LINE-1 retrotransposons and specific miRNAs, lncRNAs, and mRNAs that encode developmental regulators or affect their expression. The exosome restrains stem cell differentiation in part by degrading transcripts encoding FOXH1, a transcription factor crucial for mesendoderm formation. A defining feature of embryonic stem cells (ESCs) is the ability to differentiate into all three germ layers. Pluripotency is maintained in part by a unique transcription network that maintains expression of pluripotency-specific transcription factors and represses developmental genes. While the mechanisms that establish this transcription network are well studied, little is known of the posttranscriptional surveillance pathways that degrade differentiation-related RNAs. We report that the surveillance pathway mediated by the RNA exosome nuclease complex represses ESC differentiation. Depletion of the exosome expedites differentiation of human ESCs into all three germ layers. LINE-1 retrotransposons and specific miRNAs, lncRNAs, and mRNAs that encode developmental regulators or affect their expression are all bound by the exosome and increase in level upon exosome depletion. The exosome restrains differentiation in part by degrading transcripts encoding FOXH1, a transcription factor crucial for mesendoderm formation. Our studies establish the exosome as a regulator of human ESC differentiation and reveal the importance of RNA decay in maintaining pluripotency.
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Affiliation(s)
- Cedric Belair
- Department of Cell Biology, Yale School of Medicine, New Haven, CT.,RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD
| | - Soyeong Sim
- Department of Cell Biology, Yale School of Medicine, New Haven, CT.,RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD
| | - Kun-Yong Kim
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, CT
| | - Yoshiaki Tanaka
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, CT
| | - In-Hyun Park
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, CT
| | | | - Sandra L Wolin
- Department of Cell Biology, Yale School of Medicine, New Haven, CT .,RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD
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81
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Mendez AS, Vogt C, Bohne J, Glaunsinger BA. Site specific target binding controls RNA cleavage efficiency by the Kaposi's sarcoma-associated herpesvirus endonuclease SOX. Nucleic Acids Res 2019; 46:11968-11979. [PMID: 30321376 PMCID: PMC6294519 DOI: 10.1093/nar/gky932] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 10/04/2018] [Indexed: 12/24/2022] Open
Abstract
A number of viruses remodel the cellular gene expression landscape by globally accelerating messenger RNA (mRNA) degradation. Unlike the mammalian basal mRNA decay enzymes, which largely target mRNA from the 5′ and 3′ end, viruses instead use endonucleases that cleave their targets internally. This is hypothesized to more rapidly inactivate mRNA while maintaining selective power, potentially though the use of a targeting motif(s). Yet, how mRNA endonuclease specificity is achieved in mammalian cells remains largely unresolved. Here, we reveal key features underlying the biochemical mechanism of target recognition and cleavage by the SOX endonuclease encoded by Kaposi's sarcoma-associated herpesvirus (KSHV). Using purified KSHV SOX protein, we reconstituted the cleavage reaction in vitro and reveal that SOX displays robust, sequence-specific RNA binding to residues proximal to the cleavage site, which must be presented in a particular structural context. The strength of SOX binding dictates cleavage efficiency, providing an explanation for the breadth of mRNA susceptibility observed in cells. Importantly, we establish that cleavage site specificity does not require additional cellular cofactors, as had been previously proposed. Thus, viral endonucleases may use a combination of RNA sequence and structure to capture a broad set of mRNA targets while still preserving selectivity.
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Affiliation(s)
- Aaron S Mendez
- Department of Plant & Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Carolin Vogt
- Department of Plant & Microbial Biology, University of California Berkeley, Berkeley, CA, USA
- Hannover Medical School Institute of Virology, Hannover, Germany
| | - Jens Bohne
- Hannover Medical School Institute of Virology, Hannover, Germany
| | - Britt A Glaunsinger
- Department of Plant & Microbial Biology, University of California Berkeley, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
- To whom correspondence should be addressed. Tel: +1 510 642 5427;
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82
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Tang S, Zheng K, Tang Y, Li Z, Zou T, Liu D. Overexpression of serum exosomal HOTAIR is correlated with poor survival and poor response to chemotherapy in breast cancer patients. J Biosci 2019; 44:37. [PMID: 31180050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
To investigate the source of serum exosomal HOTAIR, to uncover the diagnostic and prognostic values of serum exosomal HOTAIR, and to discern the expression of serum exosomal HOTAIR between neoadjuvant chemotherapy and response to tamoxifen therapy. Samples were collected from the Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan. Exosomes were isolated from serum, cell culture medium and tumor tissues. We used transmission electron microscopy and western immunoblotting assay to characterize exosomes, and real-time PCR (qPCR) to assess HOTAIR expression. Neoadjuvant chemotherapy and tamoxifen therapy were carried out according to established guidelines. Breast cancer patients expressed higher serum exosomal HOTAIR than did healthy individuals (P\0.001). Serum exosomal HOTAIR levels 3 months after surgery were markedly decreased compared with levels before surgery (P\0.001), and the expression level of exosomal HOTAIR in cell culture medium increased with time in both breast cancer cell lines (72 h greater than 48 h greater than 24 h, 48 h vs 24 h [ [P less than 0.05]; 72 h vs 24 h [P less than 0.01]. Expression of serum exosomal HOTAIR in nude mice was notably greater than in the mock control group (P less than 0.001). The results of the ROC analysis revealed an AUC for serum exosomal HOTAIR of 0.9178 with a 95% CI of 0.8407-1.017 (P less than 0.01). The AUC for the CA15-3 cell line was 0.7378 (95% CI, 0.5585-0.9170; P = 0.03). High expression of exosomal HOTAIR led to a worse disease-free survival (P = 0.0481) and overall survival (P = 0.0463). In the high-expression chemotherapy group, six patients achieved a partial response (PR) and eight demonstrated stable disease (SD) and nine patients achieved PR and two SD in the low-expression group (P = 0.048). In the low-expression tamoxifen group, one patient had a recurrence of breast cancer and another 10 patients exhibited no recurrence, while six showed recurrence, and seven had none in the highexpression group (P = 0.035). We isolated exosomes successfully, and demonstrated that serum exosomal HOTAIR originated from primary breast cancer tissue. We conclude that serum exosomal HOTAIR exhibits the potential to be a diagnostic and prognostic biomarker. High expression of serum exosomal HOTAIR was also correlated with poor neoadjuvant chemotherapy and response to tamoxifen therapy.
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MESH Headings
- Adult
- Aged
- Animals
- Antineoplastic Agents/therapeutic use
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Breast Neoplasms/blood
- Breast Neoplasms/drug therapy
- Breast Neoplasms/genetics
- Breast Neoplasms/mortality
- Carcinoma, Ductal, Breast/blood
- Carcinoma, Ductal, Breast/drug therapy
- Carcinoma, Ductal, Breast/genetics
- Carcinoma, Ductal, Breast/mortality
- Carcinoma, Lobular/blood
- Carcinoma, Lobular/drug therapy
- Carcinoma, Lobular/genetics
- Carcinoma, Lobular/mortality
- Cell Differentiation/drug effects
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Exosomes/chemistry
- Exosomes/metabolism
- Female
- Gene Expression Regulation, Neoplastic
- Humans
- Mice
- Mice, Nude
- Middle Aged
- RNA, Long Noncoding/genetics
- RNA, Long Noncoding/metabolism
- Signal Transduction
- Survival Analysis
- Tamoxifen/therapeutic use
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Shicong Tang
- Department of Breast Surgery, The Third Affiliated Hospital of Kunming Medical University, Tumor Hospital of Yunnan, Kunming, Yunnan, People's Republic of China
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83
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Beheshtian M, Fattahi Z, Fadaee M, Vazehan R, Jamali P, Parsimehr E, Kamgar M, Zonooz MF, Mahdavi SS, Kalhor Z, Arzhangi S, Abedini SS, Kermani FS, Mojahedi F, Kalscheuer VM, Ropers HH, Kariminejad A, Najmabadi H, Kahrizi K. Identification of disease-causing variants in the EXOSC gene family underlying autosomal recessive intellectual disability in Iranian families. Clin Genet 2019; 95:718-725. [PMID: 30950035 DOI: 10.1111/cge.13549] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 03/29/2019] [Accepted: 04/03/2019] [Indexed: 11/29/2022]
Abstract
Neurodevelopmental delay and intellectual disability (ID) can arise from numerous genetic defects. To date, variants in the EXOSC gene family have been associated with such disorders. Using next-generation sequencing (NGS), known and novel variants in this gene family causing autosomal recessive ID (ARID) have been identified in five Iranian families. By collecting clinical information on these families and comparing their phenotypes with previously reported patients, we further describe the clinical variability of ARID resulting from alterations in the EXOSC gene family, and emphasize the role of RNA processing dysregulation in ARID.
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Affiliation(s)
- Maryam Beheshtian
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.,Kariminejad - Najmabadi Pathology & Genetics Center, Tehran, Islamic Republic of Iran.,Student Research Committee, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Zohreh Fattahi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.,Kariminejad - Najmabadi Pathology & Genetics Center, Tehran, Islamic Republic of Iran
| | - Mahsa Fadaee
- Kariminejad - Najmabadi Pathology & Genetics Center, Tehran, Islamic Republic of Iran
| | - Raheleh Vazehan
- Kariminejad - Najmabadi Pathology & Genetics Center, Tehran, Islamic Republic of Iran
| | | | - Elham Parsimehr
- Kariminejad - Najmabadi Pathology & Genetics Center, Tehran, Islamic Republic of Iran
| | - Mahboubeh Kamgar
- Comprehensive Medical Genetics Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | | | - Zahra Kalhor
- Kariminejad - Najmabadi Pathology & Genetics Center, Tehran, Islamic Republic of Iran
| | - Sanaz Arzhangi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Seyedeh Sedigheh Abedini
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Farahnaz Sabbagh Kermani
- Clinical Research Unit, Afzalipour Hospital, Kerman, University of Medical Sciences, Kerman, Iran
| | | | - Vera M Kalscheuer
- Research Group Development and Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Hans-Hilger Ropers
- Department of Human Molecular Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Ariana Kariminejad
- Kariminejad - Najmabadi Pathology & Genetics Center, Tehran, Islamic Republic of Iran
| | - Hossein Najmabadi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.,Kariminejad - Najmabadi Pathology & Genetics Center, Tehran, Islamic Republic of Iran
| | - Kimia Kahrizi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
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84
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Overexpression of serum exosomal HOTAIR is correlated with poor survival and poor response to chemotherapy in breast cancer patients. J Biosci 2019. [DOI: 10.1007/s12038-019-9861-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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85
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Helicase-Dependent RNA Decay Illuminated by a Cryo-EM Structure of a Human Nuclear RNA Exosome-MTR4 Complex. Cell 2019; 173:1663-1677.e21. [PMID: 29906447 DOI: 10.1016/j.cell.2018.05.041] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 04/26/2018] [Accepted: 05/17/2018] [Indexed: 01/08/2023]
Abstract
The ribonucleolytic RNA exosome interacts with RNA helicases to degrade RNA. To understand how the 3' to 5' Mtr4 helicase engages RNA and the nuclear exosome, we reconstituted 14-subunit Mtr4-containing RNA exosomes from Saccharomyces cerevisiae, Schizosaccharomyces pombe, and human and show that they unwind structured substrates to promote degradation. We loaded a human exosome with an optimized DNA-RNA chimera that stalls MTR4 during unwinding and determined its structure to an overall resolution of 3.45 Å by cryoelectron microscopy (cryo-EM). The structure reveals an RNA-engaged helicase atop the non-catalytic core, with RNA captured within the central channel and DIS3 exoribonuclease active site. MPP6 tethers MTR4 to the exosome through contacts to the RecA domains of MTR4. EXOSC10 remains bound to the core, but its catalytic module and cofactor C1D are displaced by RNA-engaged MTR4. Competition for the exosome core may ensure that RNA is committed to degradation by DIS3 when engaged by MTR4.
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86
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Laffleur B, Basu U. Biology of RNA Surveillance in Development and Disease. Trends Cell Biol 2019; 29:428-445. [PMID: 30755352 DOI: 10.1016/j.tcb.2019.01.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/03/2019] [Accepted: 01/10/2019] [Indexed: 01/09/2023]
Abstract
The 'RNA world', in which RNA molecules stored information and acquired enzymatic properties, has been proposed to have preceded organism life. RNA is now recognized for its central role in biology, with accumulating evidence implicating coding and noncoding (nc)RNAs in myriad mechanisms regulating cellular physiology and disequilibrium in transcriptomes resulting in pathological conditions. Nascently synthesized RNAs are subjected to stringent regulation by sophisticated RNA surveillance pathways. In this review, we integrate these pathways from a developmental viewpoint, proposing RNA surveillance as the convergence of mechanisms that ensure the exact titration of RNA molecules in a spatiotemporally controlled manner, leading to development without the onset of pathological conditions, including cancer.
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Affiliation(s)
- Brice Laffleur
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
| | - Uttiya Basu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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87
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Uggenti C, Lepelley A, Crow YJ. Self-Awareness: Nucleic Acid-Driven Inflammation and the Type I Interferonopathies. Annu Rev Immunol 2019; 37:247-267. [PMID: 30633609 DOI: 10.1146/annurev-immunol-042718-041257] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Recognition of foreign nucleic acids is the primary mechanism by which a type I interferon-mediated antiviral response is triggered. Given that human cells are replete with DNA and RNA, this evolutionary strategy poses an inherent biological challenge, i.e., the fundamental requirement to reliably differentiate self-nucleic acids from nonself nucleic acids. We suggest that the group of Mendelian inborn errors of immunity referred to as the type I interferonopathies relate to a breakdown of self/nonself discrimination, with the associated mutant genotypes involving molecules playing direct or indirect roles in nucleic acid signaling. This perspective begs the question as to the sources of self-derived nucleic acids that drive an inappropriate immune response. Resolving this question will provide fundamental insights into immune tolerance, antiviral signaling, and complex autoinflammatory disease states. Here we develop these ideas, discussing type I interferonopathies within the broader framework of nucleic acid-driven inflammation.
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Affiliation(s)
- Carolina Uggenti
- Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom;
| | - Alice Lepelley
- Laboratory of Neurogenetics and Neuroinflammation, Institut Imagine, Paris 75015, France
| | - Yanick J Crow
- Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom; .,Laboratory of Neurogenetics and Neuroinflammation, Institut Imagine, Paris 75015, France.,Paris Descartes University, Sorbonne-Paris-Cité, Paris 75006, France
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88
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Saramago M, da Costa PJ, Viegas SC, Arraiano CM. The Implication of mRNA Degradation Disorders on Human DISease: Focus on DIS3 and DIS3-Like Enzymes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1157:85-98. [PMID: 31342438 DOI: 10.1007/978-3-030-19966-1_4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
RNA degradation is considered a critical posttranscriptional regulatory checkpoint, maintaining the correct functioning of organisms. When a specific RNA transcript is no longer required in the cell, it is signaled for degradation through a number of highly regulated steps. Ribonucleases (or simply RNases) are key enzymes involved in the control of RNA stability. These enzymes can perform the RNA degradation alone or cooperate with other proteins in RNA degradation complexes. Important findings over the last years have shed light into eukaryotic RNA degradation by members of the RNase II/RNB family of enzymes. DIS3 enzyme belongs to this family and represents one of the catalytic subunits of the multiprotein complex exosome. This RNase has a diverse range of functions, mainly within nuclear RNA metabolism. Humans encode two other DIS3-like enzymes: DIS3L (DIS3L1) and DIS3L2. DIS3L1 also acts in association with the exosome but is strictly cytoplasmic. In contrast, DIS3L2 acts independently of the exosome and shows a distinctive preference for uridylated RNAs. These enzymes have been shown to be involved in important cellular processes, such as mitotic control, and associated with human disorders like cancer. This review shows how the impairment of function of each of these enzymes is implicated in human disease.
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Affiliation(s)
- Margarida Saramago
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Paulo J da Costa
- Department of Human Genetics, National Institute of Health Doutor Ricardo Jorge, Lisboa, Portugal.,Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisbon, Lisboa, Portugal
| | - Sandra C Viegas
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
| | - Cecília M Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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89
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Schmid M, Jensen TH. The Nuclear RNA Exosome and Its Cofactors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:113-132. [PMID: 31811632 DOI: 10.1007/978-3-030-31434-7_4] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The RNA exosome is a highly conserved ribonuclease endowed with 3'-5' exonuclease and endonuclease activities. The multisubunit complex resides in both the nucleus and the cytoplasm, with varying compositions and activities between the two compartments. While the cytoplasmic exosome functions mostly in mRNA quality control pathways, the nuclear RNA exosome partakes in the 3'-end processing and complete decay of a wide variety of substrates, including virtually all types of noncoding (nc) RNAs. To handle these diverse tasks, the nuclear exosome engages with dedicated cofactors, some of which serve as activators by stimulating decay through oligoA addition and/or RNA helicase activities or, as adaptors, by recruiting RNA substrates through their RNA-binding capacities. Most nuclear exosome cofactors contain the essential RNA helicase Mtr4 (MTR4 in humans). However, apart from Mtr4, nuclear exosome cofactors have undergone significant evolutionary divergence. Here, we summarize biochemical and functional knowledge about the nuclear exosome and exemplify its cofactor variety by discussing the best understood model organisms-the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe, and human cells.
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Affiliation(s)
- Manfred Schmid
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark.
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90
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Basler CF, Krogan NJ, Leung DW, Amarasinghe GK. Virus and host interactions critical for filoviral RNA synthesis as therapeutic targets. Antiviral Res 2018; 162:90-100. [PMID: 30550800 DOI: 10.1016/j.antiviral.2018.12.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/05/2018] [Accepted: 12/08/2018] [Indexed: 01/24/2023]
Abstract
Filoviruses, which include Ebola virus (EBOV) and Marburg virus, are negative-sense RNA viruses associated with sporadic outbreaks of severe viral hemorrhagic fever characterized by uncontrolled virus replication. The extreme virulence and emerging nature of these zoonotic pathogens make them a significant threat to human health. Replication of the filovirus genome and production of viral RNAs require the function of a complex of four viral proteins, the nucleoprotein (NP), viral protein 35 (VP35), viral protein 30 (VP30) and large protein (L). The latter performs the enzymatic activities required for production of viral RNAs and capping of viral mRNAs. Although it has been recognized that interactions between the virus-encoded components of the EBOV RNA polymerase complex are required for viral RNA synthesis reactions, specific molecular details have, until recently, been lacking. New efforts have combined structural biology and molecular virology to reveal in great detail the molecular basis for critical protein-protein interactions (PPIs) necessary for viral RNA synthesis. These efforts include recent studies that have identified a range of interacting host factors and in some instances demonstrated unique mechanisms by which they act. For a select number of these interactions, combined use of mutagenesis, over-expressing of peptides corresponding to PPI interfaces and identification of small molecules that disrupt PPIs have demonstrated the functional significance of virus-virus and virus-host PPIs and suggest several as potential targets for therapeutic intervention.
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Affiliation(s)
- Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA.
| | - Nevan J Krogan
- Quantitative Biosciences Institute (QBI), UCSF, San Francisco, CA, USA; Gladstone Institute of Data Science and Biotechnology, J. David Gladstone Institutes, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, CA, USA
| | - Daisy W Leung
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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91
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Aubert M, O'Donohue MF, Lebaron S, Gleizes PE. Pre-Ribosomal RNA Processing in Human Cells: From Mechanisms to Congenital Diseases. Biomolecules 2018; 8:biom8040123. [PMID: 30356013 PMCID: PMC6315592 DOI: 10.3390/biom8040123] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 10/19/2018] [Accepted: 10/19/2018] [Indexed: 12/15/2022] Open
Abstract
Ribosomal RNAs, the most abundant cellular RNA species, have evolved as the structural scaffold and the catalytic center of protein synthesis in every living organism. In eukaryotes, they are produced from a long primary transcript through an intricate sequence of processing steps that include RNA cleavage and folding and nucleotide modification. The mechanisms underlying this process in human cells have long been investigated, but technological advances have accelerated their study in the past decade. In addition, the association of congenital diseases to defects in ribosome synthesis has highlighted the central place of ribosomal RNA maturation in cell physiology regulation and broadened the interest in these mechanisms. Here, we give an overview of the current knowledge of pre-ribosomal RNA processing in human cells in light of recent progress and discuss how dysfunction of this pathway may contribute to the physiopathology of congenital diseases.
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Affiliation(s)
- Maxime Aubert
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France.
| | - Marie-Françoise O'Donohue
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France.
| | - Simon Lebaron
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France.
| | - Pierre-Emmanuel Gleizes
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000 Toulouse, France.
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92
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Roy D, Kahler DJ, Yun C, Hubbard EJA. Functional Interactions Between rsks-1/S6K, glp-1/Notch, and Regulators of Caenorhabditis elegans Fertility and Germline Stem Cell Maintenance. G3 (BETHESDA, MD.) 2018; 8:3293-3309. [PMID: 30126834 PMCID: PMC6169383 DOI: 10.1534/g3.118.200511] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/06/2018] [Indexed: 12/17/2022]
Abstract
The proper accumulation and maintenance of stem cells is critical for organ development and homeostasis. The Notch signaling pathway maintains stem cells in diverse organisms and organ systems. In Caenorhabditis elegans, GLP-1/Notch activity prevents germline stem cell (GSC) differentiation. Other signaling mechanisms also influence the maintenance of GSCs, including the highly-conserved TOR substrate ribosomal protein S6 kinase (S6K). Although C. elegans bearing either a null mutation in rsks-1/S6K or a reduction-of-function (rf) mutation in glp-1/Notch produce half the normal number of adult germline progenitors, virtually all these single mutant animals are fertile. However, glp-1(rf) rsks-1(null) double mutant animals are all sterile, and in about half of their gonads, all GSCs differentiate, a distinctive phenotype associated with a significant reduction or loss of GLP-1 signaling. How rsks-1/S6K promotes GSC fate is unknown. Here, we determine that rsks-1/S6K acts germline-autonomously to maintain GSCs, and that it does not act through Cyclin-E or MAP kinase in this role. We found that interfering with translation also enhances glp-1(rf), but that regulation through rsks-1 cannot fully account for this effect. In a genome-scale RNAi screen for genes that act similarly to rsks-1/S6K, we identified 56 RNAi enhancers of glp-1(rf) sterility, many of which were previously not known to interact functionally with Notch. Further investigation revealed at least six candidates that, by genetic criteria, act linearly with rsks-1/S6K. These include genes encoding translation-related proteins, cacn-1/Cactin, an RNA exosome component, and a Hedgehog-related ligand. We found that additional Hedgehog-related ligands may share functional relationships with glp-1/Notch and rsks-1/S6K in maintaining germline progenitors.
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Affiliation(s)
- Debasmita Roy
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016
| | - David J Kahler
- NYU High Throughput Biology Laboratory, NYU Langone Health, New York, NY 10016
| | - Chi Yun
- NYU High Throughput Biology Laboratory, NYU Langone Health, New York, NY 10016
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016
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93
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Garcia-Vaquero ML, Gama-Carvalho M, Rivas JDL, Pinto FR. Searching the overlap between network modules with specific betweeness (S2B) and its application to cross-disease analysis. Sci Rep 2018; 8:11555. [PMID: 30068933 PMCID: PMC6070533 DOI: 10.1038/s41598-018-29990-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 07/23/2018] [Indexed: 12/14/2022] Open
Abstract
Discovering disease-associated genes (DG) is strategic for understanding pathological mechanisms. DGs form modules in protein interaction networks and diseases with common phenotypes share more DGs or have more closely interacting DGs. This prompted the development of Specific Betweenness (S2B) to find genes associated with two related diseases. S2B prioritizes genes frequently and specifically present in shortest paths linking two disease modules. Top S2B scores identified genes in the overlap of artificial network modules more than 80% of the times, even with incomplete or noisy knowledge. Applied to Amyotrophic Lateral Sclerosis and Spinal Muscular Atrophy, S2B candidates were enriched in biological processes previously associated with motor neuron degeneration. Some S2B candidates closely interacted in network cliques, suggesting common molecular mechanisms for the two diseases. S2B is a valuable tool for DG prediction, bringing new insights into pathological mechanisms. More generally, S2B can be applied to infer the overlap between other types of network modules, such as functional modules or context-specific subnetworks. An R package implementing S2B is publicly available at https://github.com/frpinto/S2B .
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Affiliation(s)
- Marina L Garcia-Vaquero
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8 bdg, 1749-016, Lisboa, Portugal
| | - Margarida Gama-Carvalho
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8 bdg, 1749-016, Lisboa, Portugal
| | - Javier De Las Rivas
- Cancer Research Center (CiC-IBMCC, CSIC/USAL/IBSAL), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad de Salamanca (USAL), Salamanca, Spain
| | - Francisco R Pinto
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8 bdg, 1749-016, Lisboa, Portugal.
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94
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Gerlach P, Schuller JM, Bonneau F, Basquin J, Reichelt P, Falk S, Conti E. Distinct and evolutionary conserved structural features of the human nuclear exosome complex. eLife 2018; 7:38686. [PMID: 30047866 PMCID: PMC6072439 DOI: 10.7554/elife.38686] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 07/17/2018] [Indexed: 12/19/2022] Open
Abstract
The nuclear RNA exosome complex mediates the processing of structured RNAs and the decay of aberrant non-coding RNAs, an important function particularly in human cells. Most mechanistic studies to date have focused on the yeast system. Here, we reconstituted and studied the properties of a recombinant 14-subunit human nuclear exosome complex. In biochemical assays, the human exosome embeds a longer RNA channel than its yeast counterpart. The 3.8 Å resolution cryo-EM structure of the core complex bound to a single-stranded RNA reveals that the RNA channel path is formed by two distinct features of the hDIS3 exoribonuclease: an open conformation and a domain organization more similar to bacterial RNase II than to yeast Rrp44. The cryo-EM structure of the holo-complex shows how obligate nuclear cofactors position the hMTR4 helicase at the entrance of the core complex, suggesting a striking structural conservation from lower to higher eukaryotes.
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Affiliation(s)
- Piotr Gerlach
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Munich, Germany
| | - Jan M Schuller
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Munich, Germany
| | - Fabien Bonneau
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Munich, Germany
| | - Jérôme Basquin
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Munich, Germany
| | - Peter Reichelt
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Munich, Germany
| | - Sebastian Falk
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Munich, Germany
| | - Elena Conti
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Munich, Germany
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95
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Corbett AH. Post-transcriptional regulation of gene expression and human disease. Curr Opin Cell Biol 2018; 52:96-104. [PMID: 29518673 PMCID: PMC5988930 DOI: 10.1016/j.ceb.2018.02.011] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/08/2018] [Accepted: 02/15/2018] [Indexed: 12/18/2022]
Abstract
A large number of mutations in genes that encode RNA binding proteins cause human disease. Many of these RNA binding proteins mediate key steps in post-transcriptional regulation of gene expression from mRNA processing to eventual decay in the cytoplasm. Surprisingly, these RNA binding proteins, which are ubiquitously expressed and play fundamental roles in gene expression, are often altered in tissue-specific disease. Mutations linked to disease impact nearly every post-transcriptional processing step and cause diverse disease phenotypes in a variety of specific tissues. This review summarizes steps in post-transcriptional regulation of gene expression that have been linked to disease providing specific examples of some of the many genes affected. Finally, recent advances that hold promise for treatment of some of these diseases are presented.
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Affiliation(s)
- Anita H Corbett
- Department of Biology, RRC 1021, Emory University, 1510 Clifton Road, NE, Atlanta 30322, GA, United States.
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96
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Singh P, Saha U, Paira S, Das B. Nuclear mRNA Surveillance Mechanisms: Function and Links to Human Disease. J Mol Biol 2018; 430:1993-2013. [PMID: 29758258 DOI: 10.1016/j.jmb.2018.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/30/2018] [Accepted: 05/07/2018] [Indexed: 01/05/2023]
Abstract
Production of export-competent mRNAs involves transcription and a series of dynamic processing and modification events of pre-messenger RNAs in the nucleus. Mutations in the genes encoding the transcription and mRNP processing machinery and the complexities involved in the biogenesis events lead to the formation of aberrant messages. These faulty transcripts are promptly eliminated by the nuclear RNA exosome and its cofactors to safeguard the cells and organisms from genetic catastrophe. Mutations in the components of the core nuclear exosome and its cofactors lead to the tissue-specific dysfunction of exosomal activities, which are linked to diverse human diseases and disorders. In this article, we examine the structure and function of both the yeast and human RNA exosome complex and its cofactors, discuss the nature of the various altered amino acid residues implicated in these diseases with the speculative mechanisms of the mutation-induced disorders and project the frontier and prospective avenues of the future research in this field.
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Affiliation(s)
- Pragyan Singh
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Upasana Saha
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Sunirmal Paira
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Biswadip Das
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India.
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97
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98
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Abstract
The nuclear RNA exosome is an essential and versatile machinery that regulates maturation and degradation of a huge plethora of RNA species. The past two decades have witnessed remarkable progress in understanding the whole picture of its RNA substrates and the structural basis of its functions. In addition to the exosome itself, recent studies focusing on associated co-factors have been elucidating how the exosome is directed towards specific substrates. Moreover, it has been gradually realized that loss-of-function of exosome subunits affect multiple biological processes such as the DNA damage response, R-loop resolution, maintenance of genome integrity, RNA export, translation and cell differentiation. In this review, we summarize the current knowledge of the mechanisms of nuclear exosome-mediated RNA metabolism and discuss their physiological significance.
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99
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Abstract
Circular RNAs (circRNAs) are a novel family of non-coding endogenous RNAs discovered in all eukaryotic cells and generated through a particular mechanism of alternative splicing called "back-splicing". These molecules show multiple functions, by acting as modulators of gene and miRNA expression, and may have a role in several biological processes, such as cell proliferation and invasion with, tumour development and progression, and in several mechanisms underlying other diseases. Their presence has been shown to be abundant in several body fluids such as blood and saliva. Based on their biogenesis mechanism, circRNAs may be categorized into five classes: exonic circRNAs, intronic circRNAs, antisense circRNAs, sense overlapping circRNAs and intergenic circRNAs. Recently, the presence of circRNAs, in addition to that of miRNAs and long non-coding RNAs, has been detected also in small extracellular vesicles called exosomes. Investigating the presence and expression levels of serum exosomal circRNAs could allow us, in future, to discriminate cancer patients from healthy individuals, identifying new potential exosome-based cancer biomarkers.In this chapter, we briefly will describe the major features and functions of exosomal circRNAs, discussing their potential role as molecular biomarkers for diagnosis, prognosis and monitoring of complex diseases, including cancer.
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100
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Impact of Methods on the Measurement of mRNA Turnover. Int J Mol Sci 2017; 18:ijms18122723. [PMID: 29244760 PMCID: PMC5751324 DOI: 10.3390/ijms18122723] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/04/2017] [Accepted: 12/08/2017] [Indexed: 12/25/2022] Open
Abstract
The turnover of the RNA molecules is determined by the rates of transcription and RNA degradation. Several methods have been developed to study RNA turnover since the beginnings of molecular biology. Here we summarize the main methods to measure RNA half-life: transcription inhibition, gene control, and metabolic labelling. These methods were used to detect the cellular activity of the mRNAs degradation machinery, including the exo-ribonuclease Xrn1 and the exosome. On the other hand, the study of the differential stability of mature RNAs has been hampered by the fact that different methods have often yielded inconsistent results. Recent advances in the systematic comparison of different method variants in yeast have permitted the identification of the least invasive methodologies that reflect half-lives the most faithfully, which is expected to open the way for a consistent quantitative analysis of the determinants of mRNA stability.
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