1
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Mars JC, Culjkovic-Kraljacic B, Borden KL. eIF4E orchestrates mRNA processing, RNA export and translation to modify specific protein production. Nucleus 2024; 15:2360196. [PMID: 38880976 PMCID: PMC11185188 DOI: 10.1080/19491034.2024.2360196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 05/22/2024] [Indexed: 06/18/2024] Open
Abstract
The eukaryotic translation initiation factor eIF4E acts as a multifunctional factor that simultaneously influences mRNA processing, export, and translation in many organisms. Its multifactorial effects are derived from its capacity to bind to the methyl-7-guanosine cap on the 5'end of mRNAs and thus can act as a cap chaperone for transcripts in the nucleus and cytoplasm. In this review, we describe the multifactorial roles of eIF4E in major mRNA-processing events including capping, splicing, cleavage and polyadenylation, nuclear export and translation. We discuss the evidence that eIF4E acts at two levels to generate widescale changes to processing, export and ultimately the protein produced. First, eIF4E alters the production of components of the mRNA processing machinery, supporting a widescale reprogramming of multiple mRNA processing events. In this way, eIF4E can modulate mRNA processing without physically interacting with target transcripts. Second, eIF4E also physically interacts with both capped mRNAs and components of the RNA processing or translation machineries. Further, specific mRNAs are sensitive to eIF4E only in particular mRNA processing events. This selectivity is governed by the presence of cis-acting elements within mRNAs known as USER codes that recruit relevant co-factors engaging the appropriate machinery. In all, we describe the molecular bases for eIF4E's multifactorial function and relevant regulatory pathways, discuss the basis for selectivity, present a compendium of ~80 eIF4E-interacting factors which play roles in these activities and provide an overview of the relevance of its functions to its oncogenic potential. Finally, we summarize early-stage clinical studies targeting eIF4E in cancer.
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Affiliation(s)
- Jean-Clément Mars
- Institute of Research in Immunology and Cancer, Department of Pathology and Cell Biology, Université de Montréal, Montréal, QC, Canada
| | - Biljana Culjkovic-Kraljacic
- Institute of Research in Immunology and Cancer, Department of Pathology and Cell Biology, Université de Montréal, Montréal, QC, Canada
| | - Katherine L.B. Borden
- Institute of Research in Immunology and Cancer, Department of Pathology and Cell Biology, Université de Montréal, Montréal, QC, Canada
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2
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Kim SY, Cheon J. Senescence-associated microvascular endothelial dysfunction: A focus on the blood-brain and blood-retinal barriers. Ageing Res Rev 2024; 100:102446. [PMID: 39111407 DOI: 10.1016/j.arr.2024.102446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 07/05/2024] [Accepted: 08/02/2024] [Indexed: 08/17/2024]
Abstract
The blood-brain barrier (BBB) and blood-retinal barrier (BRB) constitute critical physiochemical interfaces, precisely orchestrating the bidirectional communication between the brain/retina and blood. Increased permeability or leakage of these barriers has been demonstrably linked to age-related vascular and parenchymal damage. While it has been suggested that the gradual aging process may coincide with disruptions in these barriers, this phenomenon is significantly exacerbated in individuals with age-related neurodegenerative disorders (ARND). This review focuses on the microvascular endothelium, a key constituent of BBB and BRB, highlighting the impact of endothelial senescence on barrier dysfunction and exploring recent discoveries regarding core pathways implicated in its breakdown. Subsequently, we address the "vascular senescence hypothesis" for ARND, with a particular emphasis on Alzheimer's disease and age-related macular degeneration, centered on endothelial senescence. Finally, we discuss potential senotherapeutic strategies targeting barrier dysfunction.
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Affiliation(s)
- Sung Young Kim
- Department of Biochemistry, Konkuk University School of Medicine, Republic of Korea; Research Institute of Medical Science, Konkuk University, Republic of Korea; IBST, Konkuk University, Republic of Korea.
| | - Jaejoung Cheon
- Department of Biochemistry, Konkuk University School of Medicine, Republic of Korea
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3
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Rödel A, Weig I, Tiedemann S, Schwartz U, Längst G, Moehle C, Grasser M, Grasser KD. Arabidopsis mRNA export factor MOS11: molecular interactions and role in abiotic stress responses. THE NEW PHYTOLOGIST 2024; 243:180-194. [PMID: 38650347 DOI: 10.1111/nph.19773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 04/01/2024] [Indexed: 04/25/2024]
Abstract
Transcription and export (TREX) is a multi-subunit complex that links synthesis, processing and export of mRNAs. It interacts with the RNA helicase UAP56 and export factors such as MOS11 and ALYs to facilitate nucleocytosolic transport of mRNAs. Plant MOS11 is a conserved, but sparsely researched RNA-binding export factor, related to yeast Tho1 and mammalian CIP29/SARNP. Using biochemical approaches, the domains of Arabidopsis thaliana MOS11 required for interaction with UAP56 and RNA-binding were identified. Further analyses revealed marked genetic interactions between MOS11 and ALY genes. Cell fractionation in combination with transcript profiling demonstrated that MOS11 is required for export of a subset of mRNAs that are shorter and more GC-rich than MOS11-independent transcripts. The central α-helical domain of MOS11 proved essential for physical interaction with UAP56 and for RNA-binding. MOS11 is involved in the nucleocytosolic transport of mRNAs that are upregulated under stress conditions and accordingly mos11 mutant plants turned out to be sensitive to elevated NaCl concentrations and heat stress. Collectively, our analyses identify functional interaction domains of MOS11. In addition, the results establish that mRNA export is critically involved in the plant response to stress conditions and that MOS11 plays a prominent role at this.
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Affiliation(s)
- Amelie Rödel
- Cell Biology & Plant Biochemistry, Biochemistry Center, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Ina Weig
- Cell Biology & Plant Biochemistry, Biochemistry Center, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Sophie Tiedemann
- Cell Biology & Plant Biochemistry, Biochemistry Center, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Uwe Schwartz
- NGS Analysis Center, Biology and Pre-Clinical Medicine, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Gernot Längst
- Institute for Biochemistry III, Biochemistry Center, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Christoph Moehle
- Center of Excellence for Fluorescent Bioanalytics (KFB), University of Regensburg, Am Biopark 9, D-93053, Regensburg, Germany
| | - Marion Grasser
- Cell Biology & Plant Biochemistry, Biochemistry Center, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Klaus D Grasser
- Cell Biology & Plant Biochemistry, Biochemistry Center, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
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4
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Tsao N, Olabode J, Rodell R, Sun H, Brickner JR, Tsai MS, Pollina EA, Chen CK, Mosammaparast N. YTHDC1 cooperates with the THO complex to prevent RNA damage-induced DNA breaks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.14.585107. [PMID: 38559256 PMCID: PMC10979943 DOI: 10.1101/2024.03.14.585107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Certain environmental toxins are nucleic acid damaging agents, as are many chemotherapeutics used for cancer therapy. These agents induce various adducts in DNA as well as RNA. Indeed, most of the nucleic acid adducts (>90%) formed due to these chemicals, such as alkylating agents, occur in RNA 1 . However, compared to the well-studied mechanisms for DNA alkylation repair, the biological consequences of RNA damage are largely unexplored. Here, we demonstrate that RNA damage can directly result in loss of genome integrity. Specifically, we show that a human YTH domain-containing protein, YTHDC1, regulates alkylation damage responses in association with the THO complex (THOC) 2 . In addition to its established binding to N 6-methyladenosine (m6A)-containing RNAs, YTHDC1 binds to N 1-methyladenosine (m1A)-containing RNAs upon alkylation. In the absence of YTHDC1, alkylation damage results in increased alkylation damage sensitivity and DNA breaks. Such phenotypes are fully attributable to RNA damage, since an RNA-specific dealkylase can rescue these phenotypes. These R NA d amage-induced DNA b reaks (RDIBs) depend on R-loop formation, which in turn are processed by factors involved in transcription-coupled nucleotide excision repair. Strikingly, in the absence of YTHDC1 or THOC, an RNA m1A methyltransferase targeted to the nucleus is sufficient to induce DNA breaks. Our results uncover a unique role for YTHDC1-THOC in base damage responses by preventing RDIBs, providing definitive evidence for how damaged RNAs can impact genomic integrity.
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5
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Tian Y, Yu F, Yun E, Lin JW, Man HY. mRNA nuclear retention reduces AMPAR expression and promotes autistic behavior in UBE3A-overexpressing mice. EMBO Rep 2024; 25:1282-1309. [PMID: 38316900 PMCID: PMC10933332 DOI: 10.1038/s44319-024-00073-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 01/07/2024] [Accepted: 01/16/2024] [Indexed: 02/07/2024] Open
Abstract
UBE3A is a common genetic factor in ASD etiology, and transgenic mice overexpressing UBE3A exhibit typical autistic-like behaviors. Because AMPA receptors (AMPARs) mediate most of the excitatory synaptic transmission in the brain, and synaptic dysregulation is considered one of the primary cellular mechanisms in ASD pathology, we investigate here the involvement of AMPARs in UBE3A-dependent ASD. We show that expression of the AMPAR GluA1 subunit is decreased in UBE3A-overexpressing mice, and that AMPAR-mediated neuronal activity is reduced. GluA1 mRNA is trapped in the nucleus of UBE3A-overexpressing neurons, suppressing GluA1 protein synthesis. Also, SARNP, an mRNA nuclear export protein, is downregulated in UBE3A-overexpressing neurons, causing GluA1 mRNA nuclear retention. Restoring SARNP levels not only rescues GluA1 mRNA localization and protein expression, but also normalizes neuronal activity and autistic behaviors in mice overexpressing UBE3A. These findings indicate that SARNP plays a crucial role in the cellular and behavioral phenotypes of UBE3A-induced ASD by regulating nuclear mRNA trafficking and protein translation of a key AMPAR subunit.
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Affiliation(s)
- Yuan Tian
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA, 02215, USA
| | - Feiyuan Yu
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA, 02215, USA
| | - Eunice Yun
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA, 02215, USA
| | - Jen-Wei Lin
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA, 02215, USA
| | - Heng-Ye Man
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA, 02215, USA.
- Department of Pharmacology, Physiology & Biophysics, Boston University School of Medicine, 72 East Concord Street, Boston, MA, 02118, USA.
- Center for Systems Neuroscience, Boston University, 610 Commonwealth Avenue, Boston, MA, 02215, USA.
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6
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Lizcano-Perret B, Vertommen D, Herinckx G, Calabrese V, Gatto L, Roux PP, Michiels T. Identification of RSK substrates using an analog-sensitive kinase approach. J Biol Chem 2024; 300:105739. [PMID: 38342435 PMCID: PMC10945272 DOI: 10.1016/j.jbc.2024.105739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/28/2024] [Accepted: 02/02/2024] [Indexed: 02/13/2024] Open
Abstract
The p90 ribosomal S6 kinases (RSK) family of serine/threonine kinases comprises four isoforms (RSK1-4) that lie downstream of the ERK1/2 mitogen-activated protein kinase pathway. RSKs are implicated in fine tuning of cellular processes such as translation, transcription, proliferation, and motility. Previous work showed that pathogens such as Cardioviruses could hijack any of the four RSK isoforms to inhibit PKR activation or to disrupt cellular nucleocytoplasmic trafficking. In contrast, some reports suggest nonredundant functions for distinct RSK isoforms, whereas Coffin-Lowry syndrome has only been associated with mutations in the gene encoding RSK2. In this work, we used the analog-sensitive kinase strategy to ask whether the cellular substrates of distinct RSK isoforms differ. We compared the substrates of two of the most distant RSK isoforms: RSK1 and RSK4. We identified a series of potential substrates for both RSKs in cells and validated RanBP3, PDCD4, IRS2, and ZC3H11A as substrates of both RSK1 and RSK4, and SORBS2 as an RSK1 substrate. In addition, using mutagenesis and inhibitors, we confirmed analog-sensitive kinase data showing that endogenous RSKs phosphorylate TRIM33 at S1119. Our data thus identify a series of potential RSK substrates and suggest that the substrates of RSK1 and RSK4 largely overlap and that the specificity of the various RSK isoforms likely depends on their cell- or tissue-specific expression pattern.
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Affiliation(s)
- Belén Lizcano-Perret
- Molecular Virology Unit, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Didier Vertommen
- MASSPROT Platform, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Gaëtan Herinckx
- MASSPROT Platform, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Viviane Calabrese
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, Quebec, Canada
| | - Laurent Gatto
- Computational Biology and Bioinformatics Unit, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Philippe P Roux
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, Quebec, Canada; Faculty of Medicine, Department of Pathology and Cell Biology, Université de Montréal, Montreal, Quebec, Canada
| | - Thomas Michiels
- Molecular Virology Unit, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium.
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7
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Goswami N, Singh A, Bharadwaj S, Sahoo AK, Singh IK. Targeting neuroblastoma by small-molecule inhibitors of human ALYREF protein: mechanistic insights using molecular dynamics simulations. J Biomol Struct Dyn 2024; 42:1352-1367. [PMID: 37158061 DOI: 10.1080/07391102.2023.2204376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 03/30/2023] [Indexed: 05/10/2023]
Abstract
Neuroblastoma is a tumour of the sympathetic nervous system mainly prevalent in children. Many strategies have been employed to target several drug-targetable proteins for the clinical management of neuroblastoma. However, the heterogeneous nature of neuroblastoma presents serious challenges in drug development for its treatment. Albeit numerous medications have been developed to target various signalling pathways in neuroblastoma, the redundant nature of the tumour pathways makes its suppression unsuccessful. Recently, the quest for neuroblastoma therapy resulted in the identification of human ALYREF, a nuclear protein that plays an essential role in tumour growth and progression. Therefore, this study used the structure-based drug discovery method to identify the putative inhibitors targeting ALYREF for the Neuroblastoma treatment. Herein, a library of 119 blood-brain barrier crossing small molecules from the ChEMBL database was downloaded and docked against the predicted binding pocket of the human ALYREF protein. Based on docking scores, the top four compounds were considered for intermolecular interactions and molecular dynamics simulation analysis, which revealed CHEMBL3752986 and CHEMBL3753744 with substantial affinity and stability with the ALYREF. These results were further supported by binding free energies and essential dynamics analysis of the respective complexes. Hence, this study advocates the sorted compounds targeting ALYREF for further in vitro and in vivo assessment to develop a drug against neuroblastoma.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Nidhi Goswami
- Molecular Biology Research Lab, Department of Zoology, Deshbandhu College, University of Delhi, Delhi, India
- Neuropharmacology and Drug Delivery Laboratory, Department of Zoology, Daulat Ram College, University of Delhi, Delhi, India
| | - Archana Singh
- Department of Botany, Hansraj College, University of Delhi, Delhi, India
| | - Shiv Bharadwaj
- Department of Biotechnology, Institute of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan, Gyeongbuk, Republic of Korea
| | - Amaresh Kumar Sahoo
- Department of Applied Sciences, Indian Institute of Information Technology Allahabad, Allahabad, Uttar Pradesh, India
| | - Indrakant K Singh
- Molecular Biology Research Lab, Department of Zoology, Deshbandhu College, University of Delhi, Delhi, India
- Delhi School of Public Health, Institute of Eminence, University of Delhi, Delhi, India
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8
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Heinrich S, Hondele M, Marchand D, Derrer CP, Zedan M, Oswald A, Malinovska L, Uliana F, Khawaja S, Mancini R, Grunwald D, Weis K. Glucose stress causes mRNA retention in nuclear Nab2 condensates. Cell Rep 2024; 43:113593. [PMID: 38113140 DOI: 10.1016/j.celrep.2023.113593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 10/12/2023] [Accepted: 11/30/2023] [Indexed: 12/21/2023] Open
Abstract
Nuclear mRNA export via nuclear pore complexes is an essential step in eukaryotic gene expression. Although factors involved in mRNA transport have been characterized, a comprehensive mechanistic understanding of this process and its regulation is lacking. Here, we use single-RNA imaging in yeast to show that cells use mRNA retention to control mRNA export during stress. We demonstrate that, upon glucose withdrawal, the essential RNA-binding factor Nab2 forms RNA-dependent condensate-like structures in the nucleus. This coincides with a reduced abundance of the DEAD-box ATPase Dbp5 at the nuclear pore. Depleting Dbp5, and consequently blocking mRNA export, is necessary and sufficient to trigger Nab2 condensation. The state of Nab2 condensation influences the extent of nuclear mRNA accumulation and can be recapitulated in vitro, where Nab2 forms RNA-dependent liquid droplets. We hypothesize that cells use condensation to regulate mRNA export and control gene expression during stress.
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Affiliation(s)
- Stephanie Heinrich
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland.
| | - Maria Hondele
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland; Biozentrum, Center for Molecular Life Sciences, University of Basel, 4056 Basel, Switzerland
| | - Désirée Marchand
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland
| | - Carina Patrizia Derrer
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland
| | - Mostafa Zedan
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland
| | - Alexandra Oswald
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland
| | - Liliana Malinovska
- Department of Biology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland
| | - Federico Uliana
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland
| | - Sarah Khawaja
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland
| | - Roberta Mancini
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland
| | - David Grunwald
- University of Massachusetts Chan Medical School, RNA Therapeutics Institute, Worcester, MA 01605, USA
| | - Karsten Weis
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland.
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9
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Palazzo AF, Qiu Y, Kang YM. mRNA nuclear export: how mRNA identity features distinguish functional RNAs from junk transcripts. RNA Biol 2024; 21:1-12. [PMID: 38091265 PMCID: PMC10732640 DOI: 10.1080/15476286.2023.2293339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2023] [Indexed: 12/18/2023] Open
Abstract
The division of the cellular space into nucleoplasm and cytoplasm promotes quality control mechanisms that prevent misprocessed mRNAs and junk RNAs from gaining access to the translational machinery. Here, we explore how properly processed mRNAs are distinguished from both misprocessed mRNAs and junk RNAs by the presence or absence of various 'identity features'.
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Affiliation(s)
| | - Yi Qiu
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Yoon Mo Kang
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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10
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Beauvais V, Moreau K, Žunar B, Hervouet-Coste N, Novačić A, Le Dantec A, Primig M, Mosrin-Huaman C, Stuparević I, Rahmouni AR. Tho2 is critical for the recruitment of Rrp6 to chromatin in response to perturbed mRNP biogenesis. RNA (NEW YORK, N.Y.) 2023; 30:89-98. [PMID: 37914399 PMCID: PMC10726162 DOI: 10.1261/rna.079707.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 10/24/2023] [Indexed: 11/03/2023]
Abstract
The eukaryotic THO complex coordinates the assembly of so-called messenger RNA-ribonucleoprotein particles (mRNPs), a process that involves cotranscriptional coating of nascent mRNAs with proteins. Once formed, mRNPs undergo a quality control step that marks them either for active transport to the cytoplasm, or Rrp6/RNA exosome-mediated degradation in the nucleus. However, the mechanism behind the quality control of nascent mRNPs is still unclear. We investigated the cotranscriptional quality control of mRNPs in budding yeast by expressing the bacterial Rho helicase, which globally perturbs yeast mRNP formation. We examined the genome-wide binding profiles of the THO complex subunits Tho2, Thp2, Hpr1, and Mft1 upon perturbation of the mRNP biogenesis, and found that Tho2 plays two roles. In addition to its function as a subunit of the THO complex, upon perturbation of mRNP biogenesis Tho2 targets Rrp6 to chromatin via its carboxy-terminal domain. Interestingly, other THO subunits are not enriched on chromatin upon perturbation of mRNP biogenesis and are not necessary for localizing Rrp6 at its target loci. Our study highlights the potential role of Tho2 in cotranscriptional mRNP quality control, which is independent of other THO subunits. Considering that both the THO complex and the RNA exosome are evolutionarily highly conserved, our findings are likely relevant for mRNP surveillance in mammals.
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Affiliation(s)
- Valentin Beauvais
- Centre de Biophysique Moléculaire, UPR 4301 du CNRS, 45071 Orléans, France
| | - Kévin Moreau
- Centre de Biophysique Moléculaire, UPR 4301 du CNRS, 45071 Orléans, France
| | - Bojan Žunar
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
| | | | - Ana Novačić
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
| | - Aurélia Le Dantec
- Centre de Biophysique Moléculaire, UPR 4301 du CNRS, 45071 Orléans, France
| | - Michael Primig
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S 1085, F-2 Rennes, France
| | | | - Igor Stuparević
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
| | - A Rachid Rahmouni
- Centre de Biophysique Moléculaire, UPR 4301 du CNRS, 45071 Orléans, France
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11
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Gambelli A, Ferrando A, Boncristiani C, Schoeftner S. Regulation and function of R-loops at repetitive elements. Biochimie 2023; 214:141-155. [PMID: 37619810 DOI: 10.1016/j.biochi.2023.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/13/2023] [Accepted: 08/19/2023] [Indexed: 08/26/2023]
Abstract
R-loops are atypical, three-stranded nucleic acid structures that contain a stretch of RNA:DNA hybrids and an unpaired, single stranded DNA loop. R-loops are physiological relevant and can act as regulators of gene expression, chromatin structure, DNA damage repair and DNA replication. However, unscheduled and persistent R-loops are mutagenic and can mediate replication-transcription conflicts, leading to DNA damage and genome instability if left unchecked. Detailed transcriptome analysis unveiled that 85% of the human genome, including repetitive regions, hold transcriptional activity. This anticipates that R-loops management plays a central role for the regulation and integrity of genomes. This function is expected to have a particular relevance for repetitive sequences that make up to 75% of the human genome. Here, we review the impact of R-loops on the function and stability of repetitive regions such as centromeres, telomeres, rDNA arrays, transposable elements and triplet repeat expansions and discuss their relevance for associated pathological conditions.
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Affiliation(s)
- Alice Gambelli
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Via E. Weiss 2, 34127, Trieste, Italy
| | - Alessandro Ferrando
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Via E. Weiss 2, 34127, Trieste, Italy
| | - Chiara Boncristiani
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Via E. Weiss 2, 34127, Trieste, Italy
| | - Stefan Schoeftner
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Via E. Weiss 2, 34127, Trieste, Italy.
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12
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Alexander KA, Yu R, Skuli N, Coffey NJ, Nguyen S, Faunce C, Huang H, Dardani IP, Good AL, Lim J, Li C, Biddle N, Joyce EF, Raj A, Lee D, Keith B, Simon MC, Berger SL. Nuclear speckles regulate HIF-2α programs and correlate with patient survival in kidney cancer. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.14.557228. [PMID: 37745397 PMCID: PMC10515914 DOI: 10.1101/2023.09.14.557228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Nuclear speckles are membrane-less bodies within the cell nucleus enriched in RNA biogenesis, processing, and export factors. In this study we investigated speckle phenotype variation in human cancer, finding a reproducible speckle signature, based on RNA expression of speckle-resident proteins, across >20 cancer types. Of these, clear cell renal cell carcinoma (ccRCC) exhibited a clear correlation between the presence of this speckle expression signature, imaging-based speckle phenotype, and clinical outcomes. ccRCC is typified by hyperactivation of the HIF-2α transcription factor, and we demonstrate here that HIF-2α drives physical association of a select subset of its target genes with nuclear speckles. Disruption of HIF-2α-driven speckle association via deletion of its speckle targeting motifs (STMs)-defined in this study-led to defective induction of speckle-associating HIF-2α target genes without impacting non-speckle-associating HIF-2α target genes. We further identify the RNA export complex, TREX, as being specifically altered in speckle signature, and knockdown of key TREX component, ALYREF, also compromises speckle-associated gene expression. By integrating tissue culture functional studies with tumor genomic and imaging analysis, we show that HIF-2α gene regulatory programs are impacted by specific manipulation of speckle phenotype and by abrogation of speckle targeting abilities of HIF-2α. These findings suggest that, in ccRCC, a key biological function of nuclear speckles is to modulate expression of a specific subset of HIF-2α-regulated target genes that, in turn, influence patient outcomes. We also identify STMs in other transcription factors, suggesting that DNA-speckle targeting may be a general mechanism of gene regulation.
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Affiliation(s)
- Katherine A. Alexander
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ruofan Yu
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Nicolas Skuli
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
- Stem Cell and Xenograft Core, Department of Medicine – Division of Hematology and Oncology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nathan J. Coffey
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Son Nguyen
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christine Faunce
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Hua Huang
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ian P. Dardani
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Austin L. Good
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joan Lim
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Catherine Li
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Nicholas Biddle
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Eric F. Joyce
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Arjun Raj
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Daniel Lee
- Division of Urology, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Brian Keith
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - M. Celeste Simon
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shelley L. Berger
- Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
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13
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Jozwiak M, Bielewicz D, Szweykowska-Kulinska Z, Jarmolowski A, Bajczyk M. SERRATE: a key factor in coordinated RNA processing in plants. TRENDS IN PLANT SCIENCE 2023; 28:841-853. [PMID: 37019716 DOI: 10.1016/j.tplants.2023.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 02/17/2023] [Accepted: 03/09/2023] [Indexed: 06/17/2023]
Abstract
The SERRATE (SE) protein is involved in the processing of RNA polymerase II (RNAPII) transcripts. It is associated with different complexes engaged in different aspects of plant RNA metabolism, including assemblies involved in transcription, splicing, polyadenylation, miRNA biogenesis, and RNA degradation. SE stability and interactome properties can be influenced by phosphorylation. SE exhibits an intriguing liquid-liquid phase separation property that may be important in the assembly of different RNA-processing bodies. Therefore, we propose that SE seems to participate in the coordination of different RNA-processing steps and can direct the fate of transcripts, targeting them for processing or degradation when they cannot be properly processed or are synthesized in excess.
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Affiliation(s)
- Monika Jozwiak
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland
| | - Dawid Bielewicz
- Center for Advanced Technology, Adam Mickiewicz University, Poznan, Poland
| | - Zofia Szweykowska-Kulinska
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland
| | - Artur Jarmolowski
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland.
| | - Mateusz Bajczyk
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland.
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14
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Fradera-Sola A, Nischwitz E, Bayer ME, Luck K, Butter F. RNA-dependent interactome allows network-based assignment of RNA-binding protein function. Nucleic Acids Res 2023; 51:5162-5176. [PMID: 37070168 PMCID: PMC10250244 DOI: 10.1093/nar/gkad245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 03/16/2023] [Accepted: 03/24/2023] [Indexed: 04/19/2023] Open
Abstract
RNA-binding proteins (RBPs) form highly diverse and dynamic ribonucleoprotein complexes, whose functions determine the molecular fate of the bound RNA. In the model organism Sacchromyces cerevisiae, the number of proteins identified as RBPs has greatly increased over the last decade. However, the cellular function of most of these novel RBPs remains largely unexplored. We used mass spectrometry-based quantitative proteomics to systematically identify protein-protein interactions (PPIs) and RNA-dependent interactions (RDIs) to create a novel dataset for 40 RBPs that are associated with the mRNA life cycle. Domain, functional and pathway enrichment analyses revealed an over-representation of RNA functionalities among the enriched interactors. Using our extensive PPI and RDI networks, we revealed putative new members of RNA-associated pathways, and highlighted potential new roles for several RBPs. Our RBP interactome resource is available through an online interactive platform as a community tool to guide further in-depth functional studies and RBP network analysis (https://www.butterlab.org/RINE).
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Affiliation(s)
- Albert Fradera-Sola
- Quantitative Proteomics, Institute of Molecular Biology, D-55128 Mainz, Germany
| | - Emily Nischwitz
- Quantitative Proteomics, Institute of Molecular Biology, D-55128 Mainz, Germany
| | | | - Katja Luck
- Integrative Systems Biology, Institute of Molecular Biology, D-55128 Mainz, Germany
| | - Falk Butter
- Quantitative Proteomics, Institute of Molecular Biology, D-55128 Mainz, Germany
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15
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Du J, Li Y, Su Y, Zhi W, Zhang J, Zhang C, Wang J, Deng W, Zhao S. LncRNA Pnky Positively Regulates Neural Stem Cell Migration by Modulating mRNA Splicing and Export of Target Genes. Cell Mol Neurobiol 2023; 43:1199-1218. [PMID: 35748966 DOI: 10.1007/s10571-022-01241-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 06/06/2022] [Indexed: 11/28/2022]
Abstract
Directed migration of neural stem cells (NSCs) is critical for embryonic neurogenesis and the healing of neurological injuries. The long noncoding RNA (lncRNA) Pnky has been reported to regulate neuronal differentiation of NSCs by interacting with PTBP1. However, its regulatory effect on NSC migration remains to be determined. Herein, we identified that Pnky is also a key regulator of NSC migration in mice, as underscored by the finding that Pnky silencing suppressed but Pnky overexpression promoted the in vitro migration of both C17.2 and NE4C murine NSCs. Additionally, in vivo cell tracking demonstrated that Pnky depletion attenuated but Pnky overexpression facilitated the migration of NE4C cells in the spinal canal after transplantation via injection into the spinal canal. Mechanistically, Pnky regulated the expression of a core set of critical regulators that direct NSC migration, including MMP2, MMP9, Connexin43, Paxillin, AKT, ERK, and P38MAPK. Using catRAPID, a web server for large-scale prediction of protein-RNA interactions, the splicing factors U2AF1 and U2AF1L4, as well as the mRNA export adaptors SARNP, Aly/Ref, and THOC7, were predicted to interact strongly with Pnky. Further investigations using colocalization and RNA immunoprecipitation (RIP) assays confirmed the direct binding of Pnky to U2AF1, SARNP, Aly/Ref, and THOC7. Transcriptomic profiling revealed that as many as 5319 differential splicing events of 3848 genes, which were highly enriched in focal adhesion, PI3K-Akt and MAPK signaling pathways, were affected by Pnky depletion. The predominant subtype of differential splicing by Pnky depletion is intron retention, followed by alternative 5' and 3' splice sites and mutually exclusive exons. Moreover, Pnky knockdown substantially blocked but Pnky overexpression facilitated the export of MMP2, Paxillin, AKT, p38MAPK, and other mRNAs to the cytosol. Collectively, our data showed that through interacting with U2AF1, SARNP, Aly/Ref, and THOC7, Pnky couples and modulates the splicing and export of target mRNAs, which consequently controlling NSC migration. These findings provide a possible theoretical basis of NSC migration regulation.
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Affiliation(s)
- Jiannan Du
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065, People's Republic of China
| | - Yuan Li
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065, People's Republic of China
| | - Yuting Su
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065, People's Republic of China
| | - Wenqian Zhi
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065, People's Republic of China
| | - Jiale Zhang
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065, People's Republic of China
| | - Cheng Zhang
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065, People's Republic of China
| | - Juan Wang
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065, People's Republic of China
| | - Wensheng Deng
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065, People's Republic of China.
| | - Shasha Zhao
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065, People's Republic of China.
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16
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Soriano-Sexto A, Gallego D, Leal F, Castejón-Fernández N, Navarrete R, Alcaide P, Couce ML, Martín-Hernández E, Quijada-Fraile P, Peña-Quintana L, Yahyaoui R, Correcher P, Ugarte M, Rodríguez-Pombo P, Pérez B. Identification of Clinical Variants beyond the Exome in Inborn Errors of Metabolism. Int J Mol Sci 2022; 23:ijms232112850. [PMID: 36361642 PMCID: PMC9654865 DOI: 10.3390/ijms232112850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/13/2022] [Accepted: 10/21/2022] [Indexed: 11/24/2022] Open
Abstract
Inborn errors of metabolism (IEM) constitute a huge group of rare diseases affecting 1 in every 1000 newborns. Next-generation sequencing has transformed the diagnosis of IEM, leading to its proposed use as a second-tier technology for confirming cases detected by clinical/biochemical studies or newborn screening. The diagnosis rate is, however, still not 100%. This paper reports the use of a personalized multi-omics (metabolomic, genomic and transcriptomic) pipeline plus functional genomics to aid in the genetic diagnosis of six unsolved cases, with a clinical and/or biochemical diagnosis of galactosemia, mucopolysaccharidosis type I (MPS I), maple syrup urine disease (MSUD), hyperphenylalaninemia (HPA), citrullinemia, or urea cycle deficiency. Eight novel variants in six genes were identified: six (four of them deep intronic) located in GALE, IDUA, PTS, ASS1 and OTC, all affecting the splicing process, and two located in the promoters of IDUA and PTS, thus affecting these genes’ expression. All the new variants were subjected to functional analysis to verify their pathogenic effects. This work underscores how the combination of different omics technologies and functional analysis can solve elusive cases in clinical practice.
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Affiliation(s)
- Alejandro Soriano-Sexto
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IdiPAZ, 28049 Madrid, Spain
| | - Diana Gallego
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IdiPAZ, 28049 Madrid, Spain
| | - Fátima Leal
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IdiPAZ, 28049 Madrid, Spain
| | - Natalia Castejón-Fernández
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IdiPAZ, 28049 Madrid, Spain
| | - Rosa Navarrete
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IdiPAZ, 28049 Madrid, Spain
| | - Patricia Alcaide
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IdiPAZ, 28049 Madrid, Spain
| | - María L. Couce
- Unit for the Diagnosis and Treatment of Congenital Metabolic Diseases, Clinical University Hospital of Santiago de Compostela, Health Research Institute of Santiago de Compostela, University of Santiago de Compostela, CIBERER, MetabERN, 15706 Santiago de Compostela, Spain
| | - Elena Martín-Hernández
- Unidad de Enfermedades Mitocondriales-Metabólicas Hereditarias, Servicio de Pediatría, Centro de Referencia Nacional (CSUR) y Europeo (MetabERN) para Enfermedades Metabólicas Hereditarias, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
| | - Pilar Quijada-Fraile
- Unidad de Enfermedades Mitocondriales-Metabólicas Hereditarias, Servicio de Pediatría, Centro de Referencia Nacional (CSUR) y Europeo (MetabERN) para Enfermedades Metabólicas Hereditarias, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
| | - Luis Peña-Quintana
- Pediatric Gastroenterology, Hepatology and Nutrition Unit, Complejo Hospitalario Universitario Insular Materno-Infantil (CHUIMI), Universidad de Las Palmas de Gran Canaria, Asociación Canaria para La Investigación Pediátrica, Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y la Nutrición (CIBEROBN) ISCIII, 35016 Gran Canaria, Spain
| | - Raquel Yahyaoui
- Laboratory of Metabolic Disorders and Newborn Screening, Institute of Biomedical Research in Málaga (IBIMA-Plafatorma BIONAND), IBIMA-RARE, Málaga Regional University Hospital, 29010 Málaga, Spain
| | - Patricia Correcher
- Nutrition and Metabolophaties Unit, Hospital Universitario La Fe, 46026 Valencia, Spain
| | - Magdalena Ugarte
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IdiPAZ, 28049 Madrid, Spain
| | - Pilar Rodríguez-Pombo
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IdiPAZ, 28049 Madrid, Spain
| | - Belén Pérez
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IdiPAZ, 28049 Madrid, Spain
- Correspondence:
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17
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Kuang Z, Ke J, Hong J, Zhu Z, Niu L. Structural assembly of the nucleic-acid-binding Thp3-Csn12-Sem1 complex functioning in mRNA splicing. Nucleic Acids Res 2022; 50:8882-8897. [PMID: 35904806 PMCID: PMC9410885 DOI: 10.1093/nar/gkac634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 06/26/2022] [Accepted: 07/21/2022] [Indexed: 12/02/2022] Open
Abstract
PCI domain proteins play important roles in post-transcriptional gene regulation. In the TREX-2 complex, PCI domain-containing Sac3 and Thp1 proteins and accessory Sem1 protein form a ternary complex required for mRNA nuclear export. In contrast, structurally related Thp3–Csn12–Sem1 complex mediates pre-mRNA splicing. In this study, we determined the structure of yeast Thp3186–470–Csn12–Sem1 ternary complex at 2.9 Å resolution. Both Thp3 and Csn12 structures have a typical PCI structural fold, characterized by a stack of α-helices capped by a C-terminal winged-helix (WH) domain. The overall structure of Thp3186–470–Csn12–Sem1 complex has an inverted V-shape with Thp3 and Csn12 forming the two sides. A fishhook-shaped Sem1 makes extensive contacts on Csn12 to stabilize its conformation. The overall structure of Thp3186–470–Csn12–Sem1 complex resembles the previously reported Sac3–Thp1–Sem1 complex, but also has significant structural differences. The C-terminal WH domains of Thp3 and Csn12 form a continuous surface to bind different forms of nucleic acids with micromolar affinity. Mutation of the basic residues in the WH domains of Thp3 and Csn12 affects nucleic acid binding in vitro and mRNA splicing in vivo. The Thp3–Csn12–Sem1 structure provides a foundation for further exploring the structural elements required for its specific recruitment to spliceosome for pre-mRNA splicing.
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Affiliation(s)
- Zhiling Kuang
- Hefei National Laboratory for Physical Sciences at the Microscale, Division of Molecular and Cellular Biophysics, University of Science and Technology of China, Hefei, Anhui 230026, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jiyuan Ke
- Institute of Health and Medicine, Hefei Comprehensive National Science Center, Northwest corner of Susong Rd & Guanhai Rd, Hefei, Anhui 230601, China
| | - Jiong Hong
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhongliang Zhu
- Hefei National Laboratory for Physical Sciences at the Microscale, Division of Molecular and Cellular Biophysics, University of Science and Technology of China, Hefei, Anhui 230026, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Liwen Niu
- Hefei National Laboratory for Physical Sciences at the Microscale, Division of Molecular and Cellular Biophysics, University of Science and Technology of China, Hefei, Anhui 230026, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
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18
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Thomas A, Rehfeld F, Zhang H, Chang TC, Goodarzi M, Gillet F, Mendell JT. RBM33 directs the nuclear export of transcripts containing GC-rich elements. Genes Dev 2022; 36:550-565. [PMID: 35589130 PMCID: PMC9186391 DOI: 10.1101/gad.349456.122] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 05/03/2022] [Indexed: 12/13/2022]
Abstract
Although splicing is a major driver of RNA nuclear export, many intronless RNAs are efficiently exported to the cytoplasm through poorly characterized mechanisms. For example, GC-rich sequences promote nuclear export in a splicing-independent manner, but how GC content is recognized and coupled to nuclear export is unknown. Here, we developed a genome-wide screening strategy to investigate the mechanism of export of NORAD, an intronless cytoplasmic long noncoding RNA (lncRNA). This screen revealed an RNA binding protein, RBM33, that directs the nuclear export of NORAD and numerous other transcripts. RBM33 directly binds substrate transcripts and recruits components of the TREX-NXF1/NXT1 RNA export pathway. Interestingly, high GC content emerged as the feature that specifies RBM33-dependent nuclear export. Accordingly, RBM33 directly binds GC-rich elements in target transcripts. These results provide a broadly applicable strategy for the genetic dissection of nuclear export mechanisms and reveal a long-sought nuclear export pathway for transcripts with GC-rich sequences.
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Affiliation(s)
- Anu Thomas
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Frederick Rehfeld
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - He Zhang
- Quantitative Biomedical Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Tsung-Cheng Chang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Mohammad Goodarzi
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Frank Gillet
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Joshua T Mendell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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19
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Aslam M, Fakher B, Qin Y. Big Role of Small RNAs in Female Gametophyte Development. Int J Mol Sci 2022; 23:ijms23041979. [PMID: 35216096 PMCID: PMC8878111 DOI: 10.3390/ijms23041979] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/02/2022] [Accepted: 02/09/2022] [Indexed: 02/04/2023] Open
Abstract
In living organisms, sexual reproduction relies on the successful development of the gametes. Flowering plants produce gametes in the specialized organs of the flower, the gametophytes. The female gametophyte (FG), a multicellular structure containing female gametes (egg cell and central cell), is often referred to as an embryo sac. Intriguingly, several protein complexes, molecular and genetic mechanisms participate and tightly regulate the female gametophyte development. Recent evidence indicates that small RNA (sRNA) mediated pathways play vital roles in female gametophyte development and specification. Here, we present an insight into our understanding and the recent updates on the molecular mechanism of different players of small RNA-directed regulatory pathways during ovule formation and growth.
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Affiliation(s)
- Mohammad Aslam
- Guangxi Key Lab of Sugarcane Biology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, Guangxi University, Nanning 530004, China;
- Center for Genomics and Biotechnology, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China;
| | - Beenish Fakher
- Center for Genomics and Biotechnology, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China;
| | - Yuan Qin
- Guangxi Key Lab of Sugarcane Biology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, Guangxi University, Nanning 530004, China;
- Center for Genomics and Biotechnology, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China;
- Correspondence:
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20
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Mars JC, Ghram M, Culjkovic-Kraljacic B, Borden KLB. The Cap-Binding Complex CBC and the Eukaryotic Translation Factor eIF4E: Co-Conspirators in Cap-Dependent RNA Maturation and Translation. Cancers (Basel) 2021; 13:6185. [PMID: 34944805 PMCID: PMC8699206 DOI: 10.3390/cancers13246185] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/30/2021] [Accepted: 12/02/2021] [Indexed: 12/26/2022] Open
Abstract
The translation of RNA into protein is a dynamic process which is heavily regulated during normal cell physiology and can be dysregulated in human malignancies. Its dysregulation can impact selected groups of RNAs, modifying protein levels independently of transcription. Integral to their suitability for translation, RNAs undergo a series of maturation steps including the addition of the m7G cap on the 5' end of RNAs, splicing, as well as cleavage and polyadenylation (CPA). Importantly, each of these steps can be coopted to modify the transcript signal. Factors that bind the m7G cap escort these RNAs through different steps of maturation and thus govern the physical nature of the final transcript product presented to the translation machinery. Here, we describe these steps and how the major m7G cap-binding factors in mammalian cells, the cap binding complex (CBC) and the eukaryotic translation initiation factor eIF4E, are positioned to chaperone transcripts through RNA maturation, nuclear export, and translation in a transcript-specific manner. To conceptualize a framework for the flow and integration of this genetic information, we discuss RNA maturation models and how these integrate with translation. Finally, we discuss how these processes can be coopted by cancer cells and means to target these in malignancy.
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Affiliation(s)
- Jean-Clement Mars
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC H3T 1J4, Canada
| | - Mehdi Ghram
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC H3T 1J4, Canada
| | - Biljana Culjkovic-Kraljacic
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC H3T 1J4, Canada
| | - Katherine L B Borden
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC H3T 1J4, Canada
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21
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Makeyeva YV, Shirayama M, Mello CC. Cues from mRNA splicing prevent default Argonaute silencing in C. elegans. Dev Cell 2021; 56:2636-2648.e4. [PMID: 34547227 DOI: 10.1016/j.devcel.2021.08.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/28/2021] [Accepted: 08/27/2021] [Indexed: 12/12/2022]
Abstract
In animals, Argonaute small-RNA pathways scan germline transcripts to silence self-replicating genetic elements. However, little is known about how endogenous gene expression is recognized and licensed. Here, we show that the presence of introns and, by inference, the process of mRNA splicing prevents default Argonaute-mediated silencing in the C. elegans germline. The silencing of intronless genes is initiated independently of the piRNA pathway but nevertheless engages multiple components of the downstream amplification and maintenance mechanisms that mediate transgenerational silencing, including both nuclear and cytoplasmic members of the worm-specific Argonaute gene family (WAGOs). Small RNAs amplified from intronless mRNAs can trans-silence cognate intron-containing genes. Interestingly, a second, small RNA-independent cis-acting mode of silencing also acts on intronless mRNAs. Our findings suggest that cues put in place during mRNA splicing license germline gene expression and provide evidence for a splicing-dependent and dsRNA- and piRNA-independent mechanism that can program Argonaute silencing.
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Affiliation(s)
- Yekaterina V Makeyeva
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Masaki Shirayama
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA; Howard Hughes Medical Institute, Worcester, MA 01605, USA
| | - Craig C Mello
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA; Howard Hughes Medical Institute, Worcester, MA 01605, USA.
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22
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Böwer F, Schnittger A. How to Switch from Mitosis to Meiosis: Regulation of Germline Entry in Plants. Annu Rev Genet 2021; 55:427-452. [PMID: 34530640 DOI: 10.1146/annurev-genet-112618-043553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
One of the major cell fate transitions in eukaryotes is entry into meiosis. While in single-celled yeast this decision is triggered by nutrient starvation, in multicellular eukaryotes, such as plants, it is under developmental control. In contrast to animals, plants have only a short germline and instruct cells to become meiocytes in reproductive organs late in development. This situation argues for a fundamentally different mechanism of how plants recruit meiocytes, and consistently, none of the regulators known to control meiotic entry in yeast and animals are present in plants. In recent years, several factors involved in meiotic entry have been identified, especially in the model plant Arabidopsis, and pieces of a regulatory network of germline control in plants are emerging. However, the corresponding studies also show that the mechanisms of meiotic entry control are diversified in flowering plants, calling for further analyses in different plant species. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Franziska Böwer
- Department of Developmental Biology, Institute for Plant Sciences and Microbiology, University of Hamburg, D-22609 Hamburg, Germany;
| | - Arp Schnittger
- Department of Developmental Biology, Institute for Plant Sciences and Microbiology, University of Hamburg, D-22609 Hamburg, Germany;
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23
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McCormack NM, Abera MB, Arnold ES, Gibbs RM, Martin SE, Buehler E, Chen YC, Chen L, Fischbeck KH, Burnett BG. A high-throughput genome-wide RNAi screen identifies modifiers of survival motor neuron protein. Cell Rep 2021; 35:109125. [PMID: 33979606 PMCID: PMC8679797 DOI: 10.1016/j.celrep.2021.109125] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 03/17/2021] [Accepted: 04/22/2021] [Indexed: 11/28/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a debilitating neurological disorder marked by degeneration of spinal motor neurons and muscle atrophy. SMA results from mutations in survival motor neuron 1 (SMN1), leading to deficiency of survival motor neuron (SMN) protein. Current therapies increase SMN protein and improve patient survival but have variable improvements in motor function, making it necessary to identify complementary strategies to further improve disease outcomes. Here, we perform a genome-wide RNAi screen using a luciferase-based activity reporter and identify genes involved in regulating SMN gene expression, RNA processing, and protein stability. We show that reduced expression of Transcription Export complex components increases SMN levels through the regulation of nuclear/cytoplasmic RNA transport. We also show that the E3 ligase, Neurl2, works cooperatively with Mib1 to ubiquitinate and promote SMN degradation. Together, our screen uncovers pathways through which SMN expression is regulated, potentially revealing additional strategies to treat SMA. Treatments for spinal muscular atrophy aim to increase survival motor neuron (SMN) protein. Using a genome-wide RNAi screen, McCormack et al. identify modifiers of SMN expression, including genes that are involved in transcription regulation, RNA processing, and protein stability.
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Affiliation(s)
- Nikki M McCormack
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MD 20814, USA
| | - Mahlet B Abera
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MD 20814, USA
| | - Eveline S Arnold
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Rebecca M Gibbs
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Scott E Martin
- Functional Genomics Lab, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20850, USA
| | - Eugen Buehler
- Functional Genomics Lab, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20850, USA
| | - Yu-Chi Chen
- Functional Genomics Lab, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20850, USA
| | - Lu Chen
- Functional Genomics Lab, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20850, USA
| | - Kenneth H Fischbeck
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Barrington G Burnett
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MD 20814, USA.
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24
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Role of promoters in regulating alternative splicing. Gene 2021; 782:145523. [PMID: 33667606 DOI: 10.1016/j.gene.2021.145523] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/31/2020] [Accepted: 02/09/2021] [Indexed: 01/19/2023]
Abstract
Alternative splicing (AS) plays a critical role in enhancing proteome complexity in higher eukaryotes. Almost all the multi intron-containing genes undergo AS in humans. Splicing mainly occurs co-transcriptionally, where RNA polymerase II (RNA pol II) plays a crucial role in coordinating transcription and pre-mRNA splicing. Aberrant AS leads to non-functional proteins causative in various pathophysiological conditions such as cancers, neurodegenerative diseases, and muscular dystrophies. Transcription and pre-mRNA splicing are deeply interconnected and can influence each other's functions. Several studies evinced that specific promoters employed by RNA pol II dictate the RNA processing decisions. Promoter-specific recruitment of certain transcriptional factors or transcriptional coactivators influences splicing, and the extent to which these factors affect splicing has not been discussed in detail. Here, in this review, various DNA-binding proteins and their influence on promoter-specific AS are extensively discussed. Besides, this review highlights how the promoter-specific epigenetic changes might regulate AS.
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25
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Abstract
The HIV-1 Rev protein is a nuclear export factor for unspliced and incompletely spliced HIV-1 RNAs. Without Rev, these intron-retaining RNAs are trapped in the nucleus. A genome-wide screen identified nine proteins of the spliceosome, which all enhanced expression from the HIV-1 unspliced RNA after CRISPR/Cas knockdown. Depletion of DHX38, WDR70, and four proteins of the Prp19-associated complex (ISY1, BUD31, XAB2, and CRNKL1) resulted in a more than 20-fold enhancement of unspliced HIV-1 RNA levels in the cytoplasm. Targeting of CRNKL1, DHX38, and BUD31 affected nuclear export efficiencies of the HIV-1 unspliced RNA to a much larger extent than splicing. Transcriptomic analyses further revealed that CRNKL1 also suppresses cytoplasmic levels of a subset of cellular mRNAs, including some with selectively retained introns. Thus, CRNKL1-dependent nuclear retention is a novel cellular mechanism for the regulation of cytoplasmic levels of intron-retaining HIV-1 mRNAs, which HIV-1 may have harnessed to direct its complex splicing pattern.IMPORTANCE To regulate its complex splicing pattern, HIV-1 uses the adaptor protein Rev to shuttle unspliced or partially spliced mRNA from the nucleus to the cytoplasm. In the absence of Rev, these RNAs are retained in the nucleus, but it is unclear why. Here we identify cellular proteins whose depletion enhances cytoplasmic levels of the HIV-1 unspliced RNA. Depletion of one of them, CRNKL1, also increases cytoplasmic levels of a subset of intron-retaining cellular mRNA, suggesting that CRNKL1-dependent nuclear retention may be a basic cellular mechanism exploited by HIV-1.
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26
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Lüdke D, Rohmann PFW, Wiermer M. Nucleocytoplasmic Communication in Healthy and Diseased Plant Tissues. FRONTIERS IN PLANT SCIENCE 2021; 12:719453. [PMID: 34394173 PMCID: PMC8357054 DOI: 10.3389/fpls.2021.719453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/09/2021] [Indexed: 05/16/2023]
Abstract
The double membrane of the nuclear envelope (NE) constitutes a selective compartment barrier that separates nuclear from cytoplasmic processes. Plant viability and responses to a changing environment depend on the spatial communication between both compartments. This communication is based on the bidirectional exchange of proteins and RNAs and is regulated by a sophisticated transport machinery. Macromolecular traffic across the NE depends on nuclear transport receptors (NTRs) that mediate nuclear import (i.e. importins) or export (i.e. exportins), as well as on nuclear pore complexes (NPCs) that are composed of nucleoporin proteins (NUPs) and span the NE. In this review, we provide an overview of plant NPC- and NTR-directed cargo transport and we consider transport independent functions of NPCs and NE-associated proteins in regulating plant developmental processes and responses to environmental stresses.
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Affiliation(s)
- Daniel Lüdke
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
| | - Philipp F. W. Rohmann
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
| | - Marcel Wiermer
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
- Molecular Biology of Plant-Microbe Interactions Research Group, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
- *Correspondence: Marcel Wiermer,
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27
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The Nuclear Pore Complex and mRNA Export in Cancer. Cancers (Basel) 2020; 13:cancers13010042. [PMID: 33375634 PMCID: PMC7796397 DOI: 10.3390/cancers13010042] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/11/2020] [Accepted: 12/22/2020] [Indexed: 02/07/2023] Open
Abstract
Export of mRNAs from the nucleus to the cytoplasm is a key regulatory step in the expression of proteins. mRNAs are transported through the nuclear pore complex (NPC). Export of mRNAs responds to a variety of cellular stimuli and stresses. Revelations of the specific effects elicited by NPC components and associated co-factors provides a molecular basis for the export of selected RNAs, independent of bulk mRNA export. Aberrant RNA export has been observed in primary human cancer specimens. These cargo RNAs encode factors involved in nearly all facets of malignancy. Indeed, the NPC components involved in RNA export as well as the RNA export machinery can be found to be dysregulated, mutated, or impacted by chromosomal translocations in cancer. The basic mechanisms associated with RNA export with relation to export machinery and relevant NPC components are described. Therapeutic strategies targeting this machinery in clinical trials is also discussed. These findings firmly position RNA export as a targetable feature of cancer along with transcription and translation.
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28
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Guha S, Bhaumik SR. Viral regulation of mRNA export with potentials for targeted therapy. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1864:194655. [PMID: 33246183 DOI: 10.1016/j.bbagrm.2020.194655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 10/15/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022]
Abstract
Eukaryotic gene expression begins with transcription in the nucleus to synthesize mRNA (messenger RNA), which is subsequently exported to the cytoplasm for translation to protein. Like transcription and translation, mRNA export is an important regulatory step of eukaryotic gene expression. Various factors are involved in regulating mRNA export, and thus gene expression. Intriguingly, some of these factors interact with viral proteins, and such interactions interfere with mRNA export of the host cell, favoring viral RNA export. Hence, viruses hijack host mRNA export machinery for export of their own RNAs from nucleus to cytoplasm for translation to proteins for viral life cycle, suppressing host mRNA export (and thus host gene expression and immune/antiviral response). Therefore, the molecules that can impair the interactions of these mRNA export factors with viral proteins could emerge as antiviral therapeutic agents to suppress viral RNA transport and enhance host mRNA export, thereby promoting host gene expression and immune response. Thus, there has been a number of studies to understand how virus hijacks mRNA export machinery in suppressing host gene expression and promoting its own RNA export to the cytoplasm for translation to proteins required for viral replication/assembly/life cycle towards developing targeted antiviral therapies, as concisely described here.
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Affiliation(s)
- Shalini Guha
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
| | - Sukesh R Bhaumik
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA.
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29
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Emerging molecular functions and novel roles for the DEAD-box protein Dbp5/DDX19 in gene expression. Cell Mol Life Sci 2020; 78:2019-2030. [PMID: 33205304 DOI: 10.1007/s00018-020-03680-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/21/2020] [Accepted: 10/06/2020] [Indexed: 12/23/2022]
Abstract
The DEAD-box protein (DBP) Dbp5, a member of the superfamily II (SFII) helicases, has multiple reported roles in gene expression. First identified as an essential regulator of mRNA export in Saccharomyces cerevisiae, the enzyme now has reported functions in non-coding RNA export, translation, transcription, and DNA metabolism. Localization of the protein to various cellular compartments (nucleoplasm, nuclear envelope, and cytoplasm) highlights the ability of Dbp5 to modulate different stages of the RNA lifecycle. While Dbp5 has been well studied for > 20 years, several critical questions remain regarding the mechanistic principles that govern Dbp5 localization, substrate selection, and functions in gene expression. This review aims to take a holistic view of the proposed functions of Dbp5 and evaluate models that accommodate current published data.
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30
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Guo J, Zhang Y, Gao H, Li S, Wang ZY, Huang CF. Mutation of HPR1 encoding a component of the THO/TREX complex reduces STOP1 accumulation and aluminium resistance in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2020; 228:179-193. [PMID: 32406528 DOI: 10.1111/nph.16658] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 04/30/2020] [Indexed: 05/28/2023]
Abstract
C2H2-type zinc finger transcription factor sensitive to proton rhizotoxicity 1 (STOP1) plays an essential role in aluminium (Al) resistance in Arabidopsis thaliana by controlling the expression of a set of Al-resistance genes, including the malate transporter-encoding gene A. thaliana aluminium activated malate transporter 1 (AtALMT1) that is critically required for Al resistance. STOP1 is suggested to be modulated by Al at post-transcriptional and/or post-translational levels. However, the underlying molecular mechanisms remain to be demonstrated. We carried out a forward genetic screen on an ethyl methanesulphonate mutagenized population, which contains the AtALMT1 promoter-driven luciferase reporter gene (pAtALMT1:LUC), and identified hyperrecombination protein 1 (HPR1), which encodes a subunit of the THO/TREX complex. We investigate the effect of hpr1 mutations on the expression of Al-resistance genes and Al resistance, and we also examined the regulatory role of HPR1 in nuclear messenger RNA (mRNA) and protein accumulation of STOP1 gene. Mutation of HPR1 reduces the expression of STOP1-regulated genes and the associated Al resistance. The hpr1 mutations increase STOP1 mRNA retention in the nucleus and consequently decrease STOP1 protein abundance. Mutation of regulation of AtALMT1 expression 1 (RAE1) that mediates STOP1 degradation in the hpr1 mutant background can partially rescue the deficient phenotypes of hpr1 mutants. Our results demonstrate that HPR1 modulates Al resistance partly through the regulation of nucleocytoplasmic STOP1 mRNA export.
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Affiliation(s)
- Jinliang Guo
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
- Shanghai Center for Plant Stress Biology and National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yang Zhang
- Shanghai Center for Plant Stress Biology and National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Huiling Gao
- Shanghai Center for Plant Stress Biology and National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Shengben Li
- College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhen-Yu Wang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan, 570228, China
| | - Chao-Feng Huang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
- Shanghai Center for Plant Stress Biology and National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
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31
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Global transcriptional downregulation of TREX and nuclear trafficking machinery as pan-senescence phenomena: evidence from human cells and tissues. Exp Mol Med 2020; 52:1351-1359. [PMID: 32859952 PMCID: PMC8080647 DOI: 10.1038/s12276-020-00490-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 06/19/2020] [Accepted: 06/24/2020] [Indexed: 01/09/2023] Open
Abstract
Nucleocytoplasmic trafficking (NCT) of macromolecules is a fundamental process in eukaryotes that requires tight controls to maintain proper cell functions. Downregulation of the classical NCT pathway in senescent cells has been reported. However, whether this is a hallmark that exists across all types of cellular senescence remains unknown, and whether the mRNA export machinery is altered during senescence has not been demonstrated. Here, we show that the global transcriptomic downregulation of both the TREX (transcription-export) machinery and classical NLS-dependent protein transport machinery is a hallmark of varying types of senescence. A gene set-based approach using 25 different studies showed that the TREX-NCT gene set displays distinct common downregulated patterns in senescent cells versus its expression in their nonsenescent counterparts regardless of the senescence type, such as replicative senescence (RS), tumor cell senescence (TCS), oncogene-induced senescence (OIS), stem cell senescence (SCS), progeria and endothelial cell senescence (ECS). Similar patterns of TREX-NCT gene downregulation were also shown in two large human tissue genomic databases, the Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) databases. We also found that early-stage cancer tissues show consistent age-related patterns of TREX-NCT enrichment, suggesting the potential significance of TREX-NCT genes in determining cell fate in the early stage of tumorigenesis. Moreover, human cancer tissues exhibit an opposite TREX-NCT enrichment pattern with aging, indicating that deviation from age-related changes in TREX-NCT genes may provide a novel but critical clue for the age-dependent pathogenesis of cancer and increase in cancer incidence with aging. Proteins that move genetic information out of the nucleus and into the rest of the cell may be important in aging, and serve as markers of early-stage cancer. DNA is stored in the cell’s nucleus, and the messages which it encodes must be exported from the nucleus for gene expression. Aging is thought to be linked to a decrease in this export, but the exact mechanism remains unclear. Sung Young Kim, Konkuk University School of Medicine, Seoul, South Korea, and co-workers investigated key nuclear export proteins in healthy, cancerous, and aging cells. They found that nuclear export is strongly decreased in aging cells and shows distinctive patterns in very-early-stage cancer cells. These results shed further light on the cellular basis of aging, and may provide novel biomarkers for early cancer detection.
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32
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The transcription and export complex THO/TREX contributes to transcription termination in plants. PLoS Genet 2020; 16:e1008732. [PMID: 32282821 PMCID: PMC7179932 DOI: 10.1371/journal.pgen.1008732] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 04/23/2020] [Accepted: 03/22/2020] [Indexed: 11/23/2022] Open
Abstract
Transcription termination has important regulatory functions, impacting mRNA stability, localization and translation potential. Failure to appropriately terminate transcription can also lead to read-through transcription and the synthesis of antisense RNAs which can have profound impact on gene expression. The Transcription-Export (THO/TREX) protein complex plays an important role in coupling transcription with splicing and export of mRNA. However, little is known about the role of the THO/TREX complex in the control of transcription termination. In this work, we show that two proteins of the THO/TREX complex, namely TREX COMPONENT 1 (TEX1 or THO3) and HYPER RECOMBINATION1 (HPR1 or THO1) contribute to the correct transcription termination at several loci in Arabidopsis thaliana. We first demonstrate this by showing defective termination in tex1 and hpr1 mutants at the nopaline synthase (NOS) terminator present in a T-DNA inserted between exon 1 and 3 of the PHO1 locus in the pho1-7 mutant. Read-through transcription beyond the NOS terminator and splicing-out of the T-DNA resulted in the generation of a near full-length PHO1 mRNA (minus exon 2) in the tex1 pho1-7 and hpr1 pho1-7 double mutants, with enhanced production of a truncated PHO1 protein that retained phosphate export activity. Consequently, the strong reduction of shoot growth associated with the severe phosphate deficiency of the pho1-7 mutant was alleviated in the tex1 pho1-7 and hpr1 pho1-7 double mutants. Additionally, we show that RNA termination defects in tex1 and hpr1 mutants leads to 3’UTR extensions in several endogenous genes. These results demonstrate that THO/TREX complex contributes to the regulation of transcription termination. Production of messenger RNAs (mRNAs) involves numerous steps including initiation of transcription, elongation, splicing, termination, as well as export out of the nucleus. All these steps are highly coordinated and failure in any steps has a profound impact on the level and identity of mRNAs produced. The THO/TREX protein complex is associated with nascent RNAs and contributes to several mRNA biogenesis steps, including splicing and export. However, the contribution of the THO/TREX complex to mRNA termination was poorly defined. We have identified a role for two components of the THO/TREX complex, namely the proteins TEX1 and HPR1, in the control of transcription termination in the plant Arabidopsis thaliana. We show that the tex1 and hpr1 mutants have defects in terminating mRNA at the nopaline synthase (NOS) terminator found in a T-DNA insertion mutant leading to the transcriptional read-through pass the NOS terminator. We also show that tex1 and hpr1 mutants have defects in mRNA termination at several endogenous genes, leading to the production of 3’UTR extensions. Together, these results highlight a role for the THO/TREX complex in mRNA termination.
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33
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Katahira J, Senokuchi K, Hieda M. Human THO maintains the stability of repetitive DNA. Genes Cells 2020; 25:334-342. [PMID: 32065701 DOI: 10.1111/gtc.12760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 01/31/2023]
Abstract
The evolutionarily conserved multiprotein complex THO/TREX is required for pre-mRNA processing, mRNA export and the maintenance of genome stability. In this study, we analyzed the genome-wide distribution of human THOC7, a component of human THO, by chromatin immunoprecipitation sequencing. The analysis revealed that human THOC7 occupies repetitive sequences, which include microsatellite repeats in genic and intergenic regions and telomeric repeats. The majority of the THOC7 ChIP peaks overlapped with those of the elongating form of RNA polymerase II and R-loops, indicating that THOC7 accumulates in transcriptionally active repeat regions. Knocking down THOC5, an RNA-binding component of human THO, by siRNA induced the accumulation of γH2AX in the repeat regions. We also observed an aberration in the telomeres in the THOC5-depleted condition. These results suggest that human THO restrains the transcription-associated instability of repeat regions in the human genome.
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Affiliation(s)
- Jun Katahira
- Laboratory of Cellular and Molecular Biology, Department of Veterinary Sciences, Osaka Prefecture University, Izumisano, Japan
| | - Kohei Senokuchi
- Laboratory of Cellular and Molecular Biology, Department of Veterinary Sciences, Osaka Prefecture University, Izumisano, Japan
| | - Miki Hieda
- Graduate School of Health Sciences, Ehime Prefectural University of Health Sciences, Iyo-gun, Japan
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34
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Into the basket and beyond: the journey of mRNA through the nuclear pore complex. Biochem J 2020; 477:23-44. [DOI: 10.1042/bcj20190132] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/28/2019] [Accepted: 12/10/2019] [Indexed: 02/06/2023]
Abstract
The genetic information encoded in nuclear mRNA destined to reach the cytoplasm requires the interaction of the mRNA molecule with the nuclear pore complex (NPC) for the process of mRNA export. Numerous proteins have important roles in the transport of mRNA out of the nucleus. The NPC embedded in the nuclear envelope is the port of exit for mRNA and is composed of ∼30 unique proteins, nucleoporins, forming the distinct structures of the nuclear basket, the pore channel and cytoplasmic filaments. Together, they serve as a rather stationary complex engaged in mRNA export, while a variety of soluble protein factors dynamically assemble on the mRNA and mediate the interactions of the mRNA with the NPC. mRNA export factors are recruited to and dissociate from the mRNA at the site of transcription on the gene, during the journey through the nucleoplasm and at the nuclear pore at the final stages of export. In this review, we present the current knowledge derived from biochemical, molecular, structural and imaging studies, to develop a high-resolution picture of the many events that culminate in the successful passage of the mRNA out of the nucleus.
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35
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Hock EM, Maniecka Z, Hruska-Plochan M, Reber S, Laferrière F, Sahadevan M K S, Ederle H, Gittings L, Pelkmans L, Dupuis L, Lashley T, Ruepp MD, Dormann D, Polymenidou M. Hypertonic Stress Causes Cytoplasmic Translocation of Neuronal, but Not Astrocytic, FUS due to Impaired Transportin Function. Cell Rep 2020; 24:987-1000.e7. [PMID: 30044993 DOI: 10.1016/j.celrep.2018.06.094] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 05/14/2018] [Accepted: 06/22/2018] [Indexed: 12/20/2022] Open
Abstract
The primarily nuclear RNA-binding protein FUS (fused in sarcoma) forms pathological cytoplasmic inclusions in a subset of early-onset amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) patients. In response to cellular stress, FUS is recruited to cytoplasmic stress granules, which are hypothesized to act as precursors of pathological inclusions. We monitored the stress-induced nucleocytoplasmic shuttling of endogenous FUS in an ex vivo mouse CNS model and human neural networks. We found that hyperosmolar, but not oxidative, stress induced robust cytoplasmic translocation of neuronal FUS, with transient nuclear clearance and loss of function. Surprisingly, this reaction is independent of stress granule formation and the molecular pathways activated by hyperosmolarity. Instead, it represents a mechanism mediated by cytoplasmic redistribution of Transportin 1/2 and is potentiated by transcriptional inhibition. Importantly, astrocytes, which remain unaffected in ALS/FTD-FUS, are spared from this stress reaction that may signify the initial event in the development of FUS pathology.
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Affiliation(s)
- Eva-Maria Hock
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Life Science Zurich Graduate School, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Zuzanna Maniecka
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Life Science Zurich Graduate School, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Marian Hruska-Plochan
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Stefan Reber
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Florent Laferrière
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Sonu Sahadevan M K
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Life Science Zurich Graduate School, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Helena Ederle
- BioMedical Center (BMC), Ludwig-Maximiians-University Munich, 82152 Planegg-Martinsried, Germany; Graduate School of Systemic Neurosciences (GSN), 82152 Planegg-Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Lauren Gittings
- Queen Square Brain Bank for Neurological Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1N 1PJ, UK
| | - Lucas Pelkmans
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Luc Dupuis
- Faculty of Medicine, INSERM UMR-S1118 and Fédération de Médecine Translationnelle, Université de Strasbourg, Strasbourg, France
| | - Tammaryn Lashley
- Queen Square Brain Bank for Neurological Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1N 1PJ, UK
| | - Marc-David Ruepp
- UK Dementia Research Institute Centre at King's College London, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Dorothee Dormann
- BioMedical Center (BMC), Ludwig-Maximiians-University Munich, 82152 Planegg-Martinsried, Germany; Graduate School of Systemic Neurosciences (GSN), 82152 Planegg-Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Magdalini Polymenidou
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Life Science Zurich Graduate School, University of Zurich and ETH Zurich, Zurich, Switzerland.
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36
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Scott DD, Aguilar LC, Kramar M, Oeffinger M. It's Not the Destination, It's the Journey: Heterogeneity in mRNA Export Mechanisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:33-81. [PMID: 31811630 DOI: 10.1007/978-3-030-31434-7_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The process of creating a translation-competent mRNA is highly complex and involves numerous steps including transcription, splicing, addition of modifications, and, finally, export to the cytoplasm. Historically, much of the research on regulation of gene expression at the level of the mRNA has been focused on either the regulation of mRNA synthesis (transcription and splicing) or metabolism (translation and degradation). However, in recent years, the advent of new experimental techniques has revealed the export of mRNA to be a major node in the regulation of gene expression, and numerous large-scale and specific mRNA export pathways have been defined. In this chapter, we will begin by outlining the mechanism by which most mRNAs are homeostatically exported ("bulk mRNA export"), involving the recruitment of the NXF1/TAP export receptor by the Aly/REF and THOC5 components of the TREX complex. We will then examine various mechanisms by which this pathway may be controlled, modified, or bypassed in order to promote the export of subset(s) of cellular mRNAs, which include the use of metazoan-specific orthologs of bulk mRNA export factors, specific cis RNA motifs which recruit mRNA export machinery via specific trans-acting-binding factors, posttranscriptional mRNA modifications that act as "inducible" export cis elements, the use of the atypical mRNA export receptor, CRM1, and the manipulation or bypass of the nuclear pore itself. Finally, we will discuss major outstanding questions in the field of mRNA export heterogeneity and outline how cutting-edge experimental techniques are providing new insights into and tools for investigating the intriguing field of mRNA export heterogeneity.
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Affiliation(s)
- Daniel D Scott
- Institut de recherches cliniques de Montréal, Montréal, QC, Canada.,Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC, Canada
| | | | - Mathew Kramar
- Institut de recherches cliniques de Montréal, Montréal, QC, Canada.,Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC, Canada
| | - Marlene Oeffinger
- Institut de recherches cliniques de Montréal, Montréal, QC, Canada. .,Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC, Canada. .,Faculté de Médecine, Département de Biochimie, Université de Montréal, Montréal, QC, Canada.
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37
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Soheilypour M, Mofrad MRK. Quality control of mRNAs at the entry of the nuclear pore: Cooperation in a complex molecular system. Nucleus 2019; 9:202-211. [PMID: 29431587 PMCID: PMC5973141 DOI: 10.1080/19491034.2018.1439304] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Despite extensive research on how mRNAs are quality controlled prior to export into the cytoplasm, the exact underlying mechanisms are still under debate. Specifically, it is unclear how quality control proteins at the entry of the nuclear pore complex (NPC) distinguish normal and aberrant mRNAs. While some of the involved components are suggested to act as switches and recruit different factors to normal versus aberrant mRNAs, some experimental and computational evidence suggests that the combined effect of the regulated stochastic interactions between the involved components could potentially achieve an efficient quality control of mRNAs. In this review, we present a state-of-the-art portrait of the mRNA quality control research and discuss the current hypotheses proposed for dynamics of the cooperation between the involved components and how it leads to their shared goal: mRNA quality control prior to export into the cytoplasm.
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Affiliation(s)
- Mohammad Soheilypour
- a Molecular Cell Biomechanics Laboratory , Departments of Bioengineering and Mechanical Engineering, University of California , Berkeley
| | - Mohammad R K Mofrad
- a Molecular Cell Biomechanics Laboratory , Departments of Bioengineering and Mechanical Engineering, University of California , Berkeley
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38
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Florini F, Naguleswaran A, Gharib WH, Bringaud F, Roditi I. Unexpected diversity in eukaryotic transcription revealed by the retrotransposon hotspot family of Trypanosoma brucei. Nucleic Acids Res 2019; 47:1725-1739. [PMID: 30544263 PMCID: PMC6393297 DOI: 10.1093/nar/gky1255] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/28/2018] [Accepted: 12/03/2018] [Indexed: 12/20/2022] Open
Abstract
The path from DNA to RNA to protein in eukaryotes is guided by a series of factors linking transcription, mRNA export and translation. Many of these are conserved from yeast to humans. Trypanosomatids, which diverged early in the eukaryotic lineage, exhibit unusual features such as polycistronic transcription and trans-splicing of all messenger RNAs. They possess basal transcription factors, but lack recognisable orthologues of many factors required for transcription elongation and mRNA export. We show that retrotransposon hotspot (RHS) proteins fulfil some of these functions and that their depletion globally impairs nascent RNA synthesis by RNA polymerase II. Three sub-families are part of a coordinated process in which RHS6 is most closely associated with chromatin, RHS4 is part of the Pol II complex and RHS2 connects transcription with the translation machinery. In summary, our results show that the components of eukaryotic transcription are far from being universal, and reveal unsuspected plasticity in the course of evolution.
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Affiliation(s)
- Francesca Florini
- Institute of Cell Biology, University of Bern, Bern, Switzerland.,Graduate School of Cellular and Biomedical Science, University of Bern, Bern, Switzerland
| | | | - Walid H Gharib
- Interfaculty Bioinformatics Unit, University of Bern, Switzerland
| | - Frédéric Bringaud
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234 CNRS, Université de Bordeaux, France
| | - Isabel Roditi
- Institute of Cell Biology, University of Bern, Bern, Switzerland
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39
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Ehrnsberger HF, Grasser M, Grasser KD. Nucleocytosolic mRNA transport in plants: export factors and their influence on growth and development. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3757-3763. [PMID: 30972423 DOI: 10.1093/jxb/erz173] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 04/01/2019] [Indexed: 05/28/2023]
Abstract
In eukaryotes, the regulated transport of mRNAs from the cell nucleus to the cytosol is a critical step in the expression of protein-coding genes, as it links nuclear mRNA synthesis with cytosolic translation. The pre-mRNAs that are synthesised by RNA polymerase II are processed by 5´-capping, splicing, and 3´-polyadenylation. The multi-subunit THO/TREX complex integrates mRNA biogenesis with their nucleocytosolic transport. Various export factors are recruited to the mRNAs during their maturation, which occurs essentially co-transcriptionally. These RNA-bound export factors ensure efficient transport of the export-competent mRNAs through nuclear pore complexes. In recent years, several factors involved in plant mRNA export have been functionally characterised. Analysis of mutant plants has demonstrated that impaired mRNA export causes defects in growth and development. Moreover, there is accumulating evidence that mRNA export can influence processes such as plant immunity, circadian regulation, and stress responses. Therefore, it is important to learn more details about the mechanism of nucleocytosolic mRNA transport in plants and its physiological significance.
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Affiliation(s)
- Hans F Ehrnsberger
- Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, Regensburg, Germany
| | - Marion Grasser
- Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, Regensburg, Germany
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40
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Kang GJ, Park MK, Byun HJ, Kim HJ, Kim EJ, Yu L, Kim B, Shim JG, Lee H, Lee CH. SARNP, a participant in mRNA splicing and export, negatively regulates E-cadherin expression via interaction with pinin. J Cell Physiol 2019; 235:1543-1555. [PMID: 31313837 DOI: 10.1002/jcp.29073] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 06/18/2019] [Indexed: 12/17/2022]
Abstract
Triple-negative breast cancer (TNBC) is associated with a high mortality rate, which is related to the insufficient number of appropriate biomarkers and targets. Therefore, there is an urgent need to discover appropriate biomarkers and targets for TNBC. SARNP (Hcc-1 and CIP29) is highly expressed in several cancers. It binds to UAP56, an RNA helicase component of the TREX complex in messenger RNA (mRNA) splicing and export. However, the role of SARNP in mRNA splicing and export and in the progression of breast cancer, especially of TNBC, remains unknown. Therefore, we examined the role of SARNP in mRNA splicing and export and progression of TNBC. We confirmed that SARNP binds to UAP56 and Aly and that SARNP overexpression enhances mRNA splicing, whereas its knockdown suppressed mRNA export. The SARNP overexpression induced the proliferation of MCF7 cells, whereas its knockdown induced E-cadherin expression and downregulated vimentin and N-cadherin expressions in SK-BR-3 and MDA-MB-231 cells. SARNP downregulates E-cadherin expression by interaction with pinin. Mice injected with MDA-MB-231shSARNP cells exhibited a significant reduction in tumor growth and lung metastasis compared with those injected with MDA-MB-231shCon cells in vivo. These findings suggested that SARNP is involved in mRNA splicing and export. SARNP maintains mesenchymal phenotype by escaping from inhibitory interaction with pinin leading to the downregulation of E-cadherin expression.
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Affiliation(s)
| | - Mi Kyung Park
- Division of Cancer Biology, National Cancer Center, Goyang, Korea
| | | | - Hyun Ji Kim
- College of Pharmacy, Dongguk University, Seoul, Korea
| | - Eun Ji Kim
- College of Pharmacy, Dongguk University, Seoul, Korea
| | - Lu Yu
- College of Pharmacy, Dongguk University, Seoul, Korea
| | - Boram Kim
- College of Pharmacy, Dongguk University, Seoul, Korea
| | - Jae Gal Shim
- Division of Cancer Biology, National Cancer Center, Goyang, Korea
| | - Ho Lee
- Division of Cancer Biology, National Cancer Center, Goyang, Korea
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41
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Berson A, Goodman LD, Sartoris AN, Otte CG, Aykit JA, Lee VMY, Trojanowski JQ, Bonini NM. Drosophila Ref1/ALYREF regulates transcription and toxicity associated with ALS/FTD disease etiologies. Acta Neuropathol Commun 2019; 7:65. [PMID: 31036086 PMCID: PMC6487524 DOI: 10.1186/s40478-019-0710-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/25/2019] [Indexed: 12/11/2022] Open
Abstract
RNA-binding proteins (RBPs) are associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), but the underlying disease mechanisms remain unclear. In an unbiased screen in Drosophila for RBPs that genetically interact with TDP-43, we found that downregulation of the mRNA export factor Ref1 (fly orthologue to human ALYREF) mitigated TDP-43 induced toxicity. Further, Ref1 depletion also reduced toxicity caused by expression of the C9orf72 GGGGCC repeat expansion. Ref1 knockdown lowered the mRNA levels for these related disease genes and reduced the encoded proteins with no effect on a wild-type Tau disease transgene or a control transgene. Interestingly, expression of TDP-43 or the GGGGCC repeat expansion increased endogenous Ref1 mRNA levels in the fly brain. Further, the human orthologue ALYREF was upregulated by immunohistochemistry in ALS motor neurons, with the strongest upregulation occurring in ALS cases harboring the GGGGCC expansion in C9orf72. These data support ALYREF as a contributor to ALS/FTD and highlight its downregulation as a potential therapeutic target that may affect co-existing disease etiologies.
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Affiliation(s)
- Amit Berson
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Lindsey D Goodman
- Neuroscience Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ashley N Sartoris
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Charlton G Otte
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - James A Aykit
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Virginia M-Y Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Nancy M Bonini
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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42
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Oqani RK, Lin T, Lee JE, Kang JW, Shin HY, Il Jin D. Iws1 and Spt6 Regulate Trimethylation of Histone H3 on Lysine 36 through Akt Signaling and are Essential for Mouse Embryonic Genome Activation. Sci Rep 2019; 9:3831. [PMID: 30846735 PMCID: PMC6405902 DOI: 10.1038/s41598-019-40358-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 02/15/2019] [Indexed: 11/08/2022] Open
Abstract
The mRNA processing and export factor, Iws1, interacts with the histone H3/H4 chaperone, Spt6 (Supt6 in mouse gene ontology) and recruits the lysine methyltransferase, Setd2, to chromatin to regulate H3K36me3. This recruitment is known to be crucial for pre-mRNA splicing and Iws1 has been shown to interact with REF1/Aly to mediate mRNA export. However, the role of this complex has not yet been examined in embryonic development. Here, we show that knockdown of either Iws1 or Supt6 blocked embryo development, primarily at the 8/16-cell stage, indicating that Iws1 and Supt6 are crucial for mouse preimplantation development. In the knockdown embryos, we observed decreases in pre-mRNA splicing, mRNA export and the expression of the lineage-specific transcription factor, Nanog. We found that either Iws1 or Supt6 are required for H3K36 trimethylation and that concurrent knockdown of both Iws1 and Supt6 blocks embryonic development at the 2-cell stage. We show that H3K36me3 is modulated by the Pi3k/Akt pathway, as inhibition of this pathway reduced the global level of H3K36me3 while activation of the pathway increased the level of this modification in 2-cell embryos. We observed that Iws1 interacts with nuclear Akt in early embryos, and herein propose that Akt modulates H3K36me3 through interaction with Iws1. Together, our results indicate that the Iws1 and Supt6 play crucial roles in embryonic genome activation, lineage specification, and histone modification during mouse early development.
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Affiliation(s)
- Reza K Oqani
- Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Tao Lin
- Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jae Eun Lee
- Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jeong Won Kang
- Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Hyun Young Shin
- Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Dong Il Jin
- Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea.
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43
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Zhang H, Fu Y, Guo H, Zhang L, Wang C, Song W, Yan Z, Wang Y, Ji W. Transcriptome and Proteome-Based Network Analysis Reveals a Model of Gene Activation in Wheat Resistance to Stripe Rust. Int J Mol Sci 2019; 20:ijms20051106. [PMID: 30836695 PMCID: PMC6429138 DOI: 10.3390/ijms20051106] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/24/2019] [Accepted: 02/27/2019] [Indexed: 12/20/2022] Open
Abstract
Stripe rust, caused by the pathogen Puccinia striiformis f. sp. tritici (Pst), is an important fungal foliar disease of wheat (Triticum aestivum). To study the mechanism underlying the defense of wheat to Pst, we used the next-generation sequencing and isobaric tags for relative and absolute quantification (iTRAQ) technologies to generate transcriptomic and proteomic profiles of seedling leaves at different stages under conditions of pathogen stress. By conducting comparative proteomic analysis using iTRAQ, we identified 2050, 2190, and 2258 differentially accumulated protein species at 24, 48, and 72 h post-inoculation (hpi). Using pairwise comparisons and weighted gene co-expression network analysis (WGCNA) of the transcriptome, we identified a stress stage-specific module enriching in transcription regulator genes. The homologs of several regulators, including splicing and transcription factors, were similarly identified as hub genes operating in the Pst-induced response network. Moreover, the Hsp70 protein were predicted as a key point in protein–protein interaction (PPI) networks from STRING database. Taking the genetics resistance gene locus into consideration, we identified 32 induced proteins in chromosome 1BS as potential candidates involved in Pst resistance. This study indicated that the transcriptional regulation model plays an important role in activating resistance-related genes in wheat responding to Pst stress.
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Affiliation(s)
- Hong Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Shaanxi 712100, China.
| | - Ying Fu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Shaanxi 712100, China.
| | - Huan Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Shaanxi 712100, China.
| | - Lu Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Shaanxi 712100, China.
| | - Changyou Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Shaanxi 712100, China.
| | - Weining Song
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Shaanxi 712100, China.
| | - Zhaogui Yan
- College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China.
| | - Yajuan Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Shaanxi 712100, China.
- Shaanxi Research Station of Crop Gene Resource & Germplasm Enhancement, Ministry of Agriculture, Shaanxi 712100, China.
| | - Wanquan Ji
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Shaanxi 712100, China.
- Shaanxi Research Station of Crop Gene Resource & Germplasm Enhancement, Ministry of Agriculture, Shaanxi 712100, China.
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Katahira J, Ishikawa H, Tsujimura K, Kurono S, Hieda M. Human THO coordinates transcription termination and subsequent transcript release from the
HSP70
locus. Genes Cells 2019; 24:272-283. [DOI: 10.1111/gtc.12672] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/16/2019] [Accepted: 01/31/2019] [Indexed: 02/05/2023]
Affiliation(s)
- Jun Katahira
- Laboratory of Cellular and Molecular Biology, Department of Veterinary Sciences Osaka Prefecture University Izumisano Osaka Japan
| | - Hiroki Ishikawa
- Laboratory of Cellular and Molecular Biology, Department of Veterinary Sciences Osaka Prefecture University Izumisano Osaka Japan
| | - Kakeru Tsujimura
- Laboratory of Cellular and Molecular Biology, Department of Veterinary Sciences Osaka Prefecture University Izumisano Osaka Japan
| | - Sadamu Kurono
- Graduate School of Medicine and Health Sciences Osaka University Suita Osaka Japan
- Laboratory Chemicals Division Wako Pure Chemical Industries Ltd Osaka Japan
| | - Miki Hieda
- Graduate School of Health Sciences Ehime Prefectural University of Health Sciences Iyo‐gun Ehime Japan
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45
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Palazzo AF, Lee ES. Sequence Determinants for Nuclear Retention and Cytoplasmic Export of mRNAs and lncRNAs. Front Genet 2018; 9:440. [PMID: 30386371 PMCID: PMC6199362 DOI: 10.3389/fgene.2018.00440] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 09/14/2018] [Indexed: 11/26/2022] Open
Abstract
Eukaryotes are divided into two major compartments: the nucleus where RNA is synthesized and processed, and the cytoplasm, where mRNA is translated into proteins. Although many different RNAs are made, only a subset is allowed access to the cytoplasm, primarily RNAs involved in protein synthesis (mRNA, tRNA, and rRNA). In contrast, nuclear retained transcripts are mostly long non-coding RNAs (lncRNAs) whose role in cell physiology has been a source of much investigation in the past few years. In addition, it is likely that many non-functional RNAs, which arise by spurious transcription and misprocessing of functional RNAs, are also retained in the nucleus and degraded. In this review, the main sequence features that dictate whether any particular mRNA or lncRNA is a substrate for retention in the nucleus, or export to the cytoplasm, are discussed. Although nuclear export is promoted by RNA-splicing due to the fact that the spliceosome can help recruit export factors to the mature RNA, nuclear export does not require splicing. Indeed, most stable unspliced transcripts are well exported and associate with these same export factors in a splicing-independent manner. In contrast, nuclear retention is promoted by specialized cis-elements found in certain RNAs. This new understanding of the determinants of nuclear retention and cytoplasmic export provides a deeper understanding of how information flow is regulated in eukaryotic cells. Ultimately these processes promote the evolution of complexity in eukaryotes by shaping the genomic content through constructive neutral evolution.
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Epstein-Barr Virus-Induced Nodules on Viral Replication Compartments Contain RNA Processing Proteins and a Viral Long Noncoding RNA. J Virol 2018; 92:JVI.01254-18. [PMID: 30068640 DOI: 10.1128/jvi.01254-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 07/23/2018] [Indexed: 11/20/2022] Open
Abstract
Profound alterations in host cell nuclear architecture accompany the lytic phase of Epstein-Barr virus (EBV) infection. Viral replication compartments assemble, host chromatin marginalizes to the nuclear periphery, cytoplasmic poly(A)-binding protein translocates to the nucleus, and polyadenylated mRNAs are sequestered within the nucleus. Virus-induced changes to nuclear architecture that contribute to viral host shutoff (VHS) must accommodate selective processing and export of viral mRNAs. Here we describe additional previously unrecognized nuclear alterations during EBV lytic infection in which viral and cellular factors that function in pre-mRNA processing and mRNA export are redistributed. Early during lytic infection, before formation of viral replication compartments, two cellular pre-mRNA splicing factors, SC35 and SON, were dispersed from interchromatin granule clusters, and three mRNA export factors, Y14, ALY, and NXF1, were depleted from the nucleus. During late lytic infection, virus-induced nodular structures (VINORCs) formed at the periphery of viral replication compartments. VINORCs were composed of viral (BMLF1 and BGLF5) and cellular (SC35, SON, SRp20, and NXF1) proteins that mediate pre-mRNA processing and mRNA export. BHLF1 long noncoding RNA was invariably found in VINORCs. VINORCs did not contain other nodular nuclear cellular proteins (PML or coilin), nor did they contain viral proteins (BRLF1 or BMRF1) found exclusively within replication compartments. VINORCs are novel EBV-induced nuclear structures. We propose that EBV-induced dispersal and depletion of pre-mRNA processing and mRNA export factors during early lytic infection contribute to VHS; subsequent relocalization of these pre-mRNA processing and mRNA export proteins to VINORCs and viral replication compartments facilitates selective processing and export of viral mRNAs.IMPORTANCE In order to make protein, mRNA transcribed from DNA in the nucleus must enter the cytoplasm. Nuclear export of mRNA requires correct processing of mRNAs by enzymes that function in splicing and nuclear export. During the Epstein-Barr virus (EBV) lytic cycle, nuclear export of cellular mRNAs is blocked, yet export of viral mRNAs is facilitated. Here we report the dispersal and dramatic reorganization of cellular (SC35, SON, SRp20, Y14, ALY, and NXF1) and viral (BMLF1 and BGLF5) proteins that play key roles in pre-mRNA processing and export of mRNA. These virus-induced nuclear changes culminate in formation of VINORCs, novel nodular structures composed of viral and cellular RNA splicing and export factors. VINORCs localize to the periphery of viral replication compartments, where viral mRNAs reside. These EBV-induced changes in nuclear organization may contribute to blockade of nuclear export of host mRNA, while enabling selective processing and export of viral mRNA.
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47
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The splicing factor SRSF3 is functionally connected to the nuclear RNA exosome for intronless mRNA decay. Sci Rep 2018; 8:12901. [PMID: 30150655 PMCID: PMC6110769 DOI: 10.1038/s41598-018-31078-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 07/24/2018] [Indexed: 12/22/2022] Open
Abstract
The RNA exosome fulfills important functions in the processing and degradation of numerous RNAs species. However, the mechanisms of recruitment to its various nuclear substrates are poorly understood. Using Epstein-Barr virus mRNAs as a model, we have discovered a novel function for the splicing factor SRSF3 in the quality control of nuclear mRNAs. We have found that viral mRNAs generated from intronless genes are particularly unstable due to their degradation by the nuclear RNA exosome. This effect is counteracted by the viral RNA-binding protein EB2 which stabilizes these mRNAs in the nucleus and stimulates both their export to the cytoplasm and their translation. In the absence of EB2, SRSF3 participates in the destabilization of these viral RNAs by interacting with both the RNA exosome and its adaptor complex NEXT. Taken together, our results provide direct evidence for a connection between the splicing machinery and mRNA decay mediated by the RNA exosome. Our results suggest that SRSF3 aids the nuclear RNA exosome and the NEXT complex in the recognition and degradation of certain mRNAs.
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Zhen Y, Zhang Y, Yu Y. A Cell-Line-Specific Atlas of PARP-Mediated Protein Asp/Glu-ADP-Ribosylation in Breast Cancer. Cell Rep 2018; 21:2326-2337. [PMID: 29166620 DOI: 10.1016/j.celrep.2017.10.106] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 10/18/2017] [Accepted: 10/26/2017] [Indexed: 12/21/2022] Open
Abstract
PARP1 plays a critical role in regulating many biological processes linked to cellular stress responses. Although DNA strand breaks are potent stimuli of PARP1 enzymatic activity, the context-dependent mechanism regulating PARP1 activation and signaling is poorly understood. We performed global characterization of the PARP1-dependent, Asp/Glu-ADP-ribosylated proteome in a panel of cell lines originating from benign breast epithelial cells, as well as common subtypes of breast cancer. From these analyses, we identified 503 specific ADP-ribosylation sites on 322 proteins. Despite similar expression levels, PARP1 is differentially activated in these cell lines under genotoxic conditions, which generates signaling outputs with substantial heterogeneity. By comparing protein abundances and ADP-ribosylation levels, we could dissect cell-specific PARP1 targets that are driven by unique expression patterns versus cell-specific regulatory mechanisms of PARylation. Intriguingly, PARP1 modifies many proteins in a cell-specific manner, including those involved in transcriptional regulation, mRNA metabolism, and protein translation.
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Affiliation(s)
- Yuanli Zhen
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yajie Zhang
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yonghao Yu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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RNA processing in the male germline: Mechanisms and implications for fertility. Semin Cell Dev Biol 2018; 79:80-91. [DOI: 10.1016/j.semcdb.2017.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/04/2017] [Accepted: 10/09/2017] [Indexed: 12/22/2022]
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Ederle H, Funk C, Abou-Ajram C, Hutten S, Funk EBE, Kehlenbach RH, Bailer SM, Dormann D. Nuclear egress of TDP-43 and FUS occurs independently of Exportin-1/CRM1. Sci Rep 2018; 8:7084. [PMID: 29728564 PMCID: PMC5935713 DOI: 10.1038/s41598-018-25007-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 04/13/2018] [Indexed: 12/11/2022] Open
Abstract
TDP-43 and FUS are nuclear proteins with multiple functions in mRNA processing. They play key roles in ALS (amyotrophic lateral sclerosis) and FTD (frontotemporal dementia), where they are partially lost from the nucleus and aggregate in the cytoplasm of neurons and glial cells. Defects in nucleocytoplasmic transport contribute to this pathology, hence nuclear import of both proteins has been studied in detail. However, their nuclear export routes remain poorly characterized and it is unclear whether aberrant nuclear export contributes to TDP-43 or FUS pathology. Here we show that predicted nuclear export signals in TDP-43 and FUS are non-functional and that both proteins are exported independently of the export receptor CRM1/Exportin-1. Silencing of Exportin-5 or the mRNA export factor Aly/REF, as well as mutations that abrogate RNA-binding do not impair export of TDP-43 and FUS. However, artificially enlarging TDP-43 or FUS impairs their nuclear egress, suggesting that they could leave the nucleus by passive diffusion. Finally, we found that inhibition of transcription causes accelerated nuclear egress of TDP-43, suggesting that newly synthesized RNA retains TDP-43 in the nucleus, limiting its egress into the cytoplasm. Our findings implicate reduced nuclear retention as a possible factor contributing to mislocalization of TDP-43 in ALS/FTD.
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Affiliation(s)
- Helena Ederle
- BioMedical Center (BMC), Cell Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
- Graduate School of Systemic Neurosciences (GSN), 82152, Planegg-Martinsried, Germany
| | - Christina Funk
- Institute for Interfacial Engineering and Plasma Technology IGVP, University of Stuttgart, 70569, Stuttgart, Germany
- Frauenhofer Institute for Interfacial Engineering and Biotechnology, 70569, Stuttgart, Germany
| | - Claudia Abou-Ajram
- BioMedical Center (BMC), Cell Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
| | - Saskia Hutten
- BioMedical Center (BMC), Cell Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
| | - Eva B E Funk
- BioMedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, 81377, Munich, Germany
| | - Ralph H Kehlenbach
- Department of Molecular Biology, Faculty of Medicine, GZMB, Georg-August-University Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Susanne M Bailer
- Institute for Interfacial Engineering and Plasma Technology IGVP, University of Stuttgart, 70569, Stuttgart, Germany
- Frauenhofer Institute for Interfacial Engineering and Biotechnology, 70569, Stuttgart, Germany
| | - Dorothee Dormann
- BioMedical Center (BMC), Cell Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany.
- Graduate School of Systemic Neurosciences (GSN), 82152, Planegg-Martinsried, Germany.
- Munich Cluster for Systems Neurology (SyNergy), 81377, Munich, Germany.
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