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González-Iglesias A, Arcas A, Domingo-Muelas A, Mancini E, Galcerán J, Valcárcel J, Fariñas I, Nieto MA. Publisher Correction: Intron detention tightly regulates the stemness/differentiation switch in the adult neurogenic niche. Nat Commun 2024; 15:3458. [PMID: 38658565 PMCID: PMC11043426 DOI: 10.1038/s41467-024-47920-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Affiliation(s)
| | - Aida Arcas
- Instituto de Neurociencias (CSIC-UMH), Sant Joan d'Alacant, 03550, Spain
- Department of Gene Therapy and Regulation of Gene Expression, Center for Applied Medical Research, University of Navarra, Pamplona, 31008, Spain
| | - Ana Domingo-Muelas
- Departamento de Biología Celular, Biología Funcional y Antropología Física and Instituto de Biotecnología y Biomedicina, Universidad de Valencia, Burjassot, 46100, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28029, Madrid, Spain
- Carlos Simon Foundation, 46980, Paterna, Valencia, Spain
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Igenomix Foundation, 46980, Paterna, Valencia, Spain
| | - Estefania Mancini
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, 08003, Spain
| | - Joan Galcerán
- Instituto de Neurociencias (CSIC-UMH), Sant Joan d'Alacant, 03550, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER), 28029, Madrid, Spain
| | - Juan Valcárcel
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, 08003, Spain
- Universitat Pompeu Fabra (UPF), 08003, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010, Barcelona, Spain
| | - Isabel Fariñas
- Departamento de Biología Celular, Biología Funcional y Antropología Física and Instituto de Biotecnología y Biomedicina, Universidad de Valencia, Burjassot, 46100, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28029, Madrid, Spain
| | - M Angela Nieto
- Instituto de Neurociencias (CSIC-UMH), Sant Joan d'Alacant, 03550, Spain.
- Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER), 28029, Madrid, Spain.
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2
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González-Iglesias A, Arcas A, Domingo-Muelas A, Mancini E, Galcerán J, Valcárcel J, Fariñas I, Nieto MA. Intron detention tightly regulates the stemness/differentiation switch in the adult neurogenic niche. Nat Commun 2024; 15:2837. [PMID: 38565566 PMCID: PMC10987655 DOI: 10.1038/s41467-024-47092-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 03/13/2024] [Indexed: 04/04/2024] Open
Abstract
The adult mammalian brain retains some capacity to replenish neurons and glia, holding promise for brain regeneration. Thus, understanding the mechanisms controlling adult neural stem cell (NSC) differentiation is crucial. Paradoxically, adult NSCs in the subependymal zone transcribe genes associated with both multipotency maintenance and neural differentiation, but the mechanism that prevents conflicts in fate decisions due to these opposing transcriptional programmes is unknown. Here we describe intron detention as such control mechanism. In NSCs, while multiple mRNAs from stemness genes are spliced and exported to the cytoplasm, transcripts from differentiation genes remain unspliced and detained in the nucleus, and the opposite is true under neural differentiation conditions. We also show that m6A methylation is the mechanism that releases intron detention and triggers nuclear export, enabling rapid and synchronized responses. m6A RNA methylation operates as an on/off switch for transcripts with antagonistic functions, tightly controlling the timing of NSCs commitment to differentiation.
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Affiliation(s)
| | - Aida Arcas
- Instituto de Neurociencias (CSIC-UMH), Sant Joan d'Alacant, 03550, Spain
- Department of Gene Therapy and Regulation of Gene Expression, Center for Applied Medical Research, University of Navarra, Pamplona, 31008, Spain
| | - Ana Domingo-Muelas
- Departamento de Biología Celular, Biología Funcional y Antropología Física and Instituto de Biotecnología y Biomedicina, Universidad de Valencia, Burjassot, 46100, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28029, Madrid, Spain
- Carlos Simon Foundation, 46980, Paterna, Valencia, Spain
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Igenomix Foundation, 46980, Paterna, Valencia, Spain
| | - Estefania Mancini
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, 08003, Spain
| | - Joan Galcerán
- Instituto de Neurociencias (CSIC-UMH), Sant Joan d'Alacant, 03550, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER), 28029, Madrid, Spain
| | - Juan Valcárcel
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, 08003, Spain
- Universitat Pompeu Fabra (UPF), 08003, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010, Barcelona, Spain
| | - Isabel Fariñas
- Departamento de Biología Celular, Biología Funcional y Antropología Física and Instituto de Biotecnología y Biomedicina, Universidad de Valencia, Burjassot, 46100, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28029, Madrid, Spain
| | - M Angela Nieto
- Instituto de Neurociencias (CSIC-UMH), Sant Joan d'Alacant, 03550, Spain.
- Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER), 28029, Madrid, Spain.
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3
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Fujita KI, Ito M, Irie M, Harada K, Fujiwara N, Ikeda Y, Yoshioka H, Yamazaki T, Kojima M, Mikami B, Mayeda A, Masuda S. Structural differences between the closely related RNA helicases, UAP56 and URH49, fashion distinct functional apo-complexes. Nat Commun 2024; 15:455. [PMID: 38225262 PMCID: PMC10789772 DOI: 10.1038/s41467-023-44217-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 12/05/2023] [Indexed: 01/17/2024] Open
Abstract
mRNA export is an essential pathway for the regulation of gene expression. In humans, closely related RNA helicases, UAP56 and URH49, shape selective mRNA export pathways through the formation of distinct complexes, known as apo-TREX and apo-AREX complexes, and their subsequent remodeling into similar ATP-bound complexes. Therefore, defining the unidentified components of the apo-AREX complex and elucidating the molecular mechanisms underlying the formation of distinct apo-complexes is key to understanding their functional divergence. In this study, we identify additional apo-AREX components physically and functionally associated with URH49. Furthermore, by comparing the structures of UAP56 and URH49 and performing an integrated analysis of their chimeric mutants, we exhibit unique structural features that would contribute to the formation of their respective complexes. This study provides insights into the specific structural and functional diversification of these two helicases that diverged from the common ancestral gene Sub2.
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Affiliation(s)
- Ken-Ichi Fujita
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan.
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan.
- Division of Cancer Stem Cell, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.
| | - Misa Ito
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Midori Irie
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Kotaro Harada
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Naoko Fujiwara
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Yuya Ikeda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Hanae Yoshioka
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Tomohiro Yamazaki
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Masaki Kojima
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Bunzo Mikami
- Research Institute for Sustainable Humanosphere, Kyoto University, Kyoto, 611-0011, Japan
- Institute of Advanced Energy, Kyoto University, Kyoto, 611-0011, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Seiji Masuda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan.
- Department of Food Science and Nutrition, Faculty of Agriculture Kindai University, Nara, Nara, 631-8505, Japan.
- Agricultural Technology and Innovation Research Institute, Kindai University, Nara, Nara, 631-8505, Japan.
- Antiaging Center, Kindai University, Higashiosaka, Osaka, 577-8502, Japan.
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4
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Mihaylov SR, Castelli LM, Lin YH, Gül A, Soni N, Hastings C, Flynn HR, Păun O, Dickman MJ, Snijders AP, Goldstone R, Bandmann O, Shelkovnikova TA, Mortiboys H, Ultanir SK, Hautbergue GM. The master energy homeostasis regulator PGC-1α exhibits an mRNA nuclear export function. Nat Commun 2023; 14:5496. [PMID: 37679383 PMCID: PMC10485026 DOI: 10.1038/s41467-023-41304-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 08/30/2023] [Indexed: 09/09/2023] Open
Abstract
PGC-1α plays a central role in maintaining mitochondrial and energy metabolism homeostasis, linking external stimuli to transcriptional co-activation of genes involved in adaptive and age-related pathways. The carboxyl-terminus encodes a serine/arginine-rich (RS) region and an RNA recognition motif, however the RNA-processing function(s) were poorly investigated over the past 20 years. Here, we show that the RS domain of human PGC-1α directly interacts with RNA and the nuclear RNA export receptor NXF1. Inducible depletion of PGC-1α and expression of RNAi-resistant RS-deleted PGC-1α further demonstrate that its RNA/NXF1-binding activity is required for the nuclear export of some canonical mitochondrial-related mRNAs and mitochondrial homeostasis. Genome-wide investigations reveal that the nuclear export function is not strictly linked to promoter-binding, identifying in turn novel regulatory targets of PGC-1α in non-homologous end-joining and nucleocytoplasmic transport. These findings provide new directions to further elucidate the roles of PGC-1α in gene expression, metabolic disorders, aging and neurodegeneration.
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Affiliation(s)
- Simeon R Mihaylov
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
- Kinases and Brain Development Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Lydia M Castelli
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
| | - Ya-Hui Lin
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
| | - Aytac Gül
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
| | - Nikita Soni
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
| | - Christopher Hastings
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
| | - Helen R Flynn
- Proteomics Science Technology Platform, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Oana Păun
- Neural Stem Cell Biology Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Mark J Dickman
- Department of Chemical and Biological Engineering, Sir Robert Hadfield Building, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Ambrosius P Snijders
- Proteomics Science Technology Platform, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Life Science Mass Spectrometry, Bruker Daltonics, Banner Lane, Coventry, CV4 9GH, UK
| | - Robert Goldstone
- Bioinformatics and Biostatistics Science and Technology Platform, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Oliver Bandmann
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Healthy Lifespan Institute (HELSI), University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Tatyana A Shelkovnikova
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Heather Mortiboys
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Healthy Lifespan Institute (HELSI), University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Sila K Ultanir
- Kinases and Brain Development Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Guillaume M Hautbergue
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ, UK.
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
- Healthy Lifespan Institute (HELSI), University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
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5
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Wippich F, Vaishali, Hennrich ML, Ephrussi A. Nutritional stress-induced regulation of microtubule organization and mRNP transport by HDAC1 controlled α-tubulin acetylation. Commun Biol 2023; 6:776. [PMID: 37491525 PMCID: PMC10368696 DOI: 10.1038/s42003-023-05138-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 07/12/2023] [Indexed: 07/27/2023] Open
Abstract
In response to nutritional stress, microtubules in cells of the Drosophila female germline are depleted from the cytoplasm and accumulate cortically. This triggers aggregation of mRNPs into large processing bodies (P-bodies) and oogenesis arrest. Here, we show that hyperacetylation of α-tubulin at lysine 40 (K40) alters microtubule dynamics and P-body formation. We found that depletion of histone deacetylase 1 (HDAC1) by RNAi phenocopies the nutritional stress response, causing α-tubulin hyperacetylation and accumulation of maternally deposited mRNPs in P-bodies. Through in vitro and in vivo studies, we identify HDAC1 as a direct regulator of α-tubulin K40 acetylation status. In well-fed flies, HDAC1 maintains low levels of α-tubulin acetylation, enabling the microtubule dynamics required for mRNP transport. Using quantitative phosphoproteomics we identify nutritional stress-induced changes in protein phosphorylation that act upstream of α-tubulin acetylation, including phosphorylation of HDAC1 at S391, which reduces its ability to deacetylate α-tubulin. These results reveal that Drosophila HDAC1 senses and relays the nutritional status, which regulates germline development through modulation of cytoskeleton dynamics.
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Affiliation(s)
- Frank Wippich
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg, 69117, Germany
- Cellzome GmbH, GlaxoSmithKline, Heidelberg, Germany
| | - Vaishali
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg, 69117, Germany
- Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Marco L Hennrich
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg, 69117, Germany
- Cellzome GmbH, GlaxoSmithKline, Heidelberg, Germany
| | - Anne Ephrussi
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg, 69117, Germany.
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6
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Hildebrandt RP, Moss KR, Janusz-Kaminska A, Knudson LA, Denes LT, Saxena T, Boggupalli DP, Li Z, Lin K, Bassell GJ, Wang ET. Muscleblind-like proteins use modular domains to localize RNAs by riding kinesins and docking to membranes. Nat Commun 2023; 14:3427. [PMID: 37296096 PMCID: PMC10256740 DOI: 10.1038/s41467-023-38923-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 05/22/2023] [Indexed: 06/12/2023] Open
Abstract
RNA binding proteins (RBPs) act as critical facilitators of spatially regulated gene expression. Muscleblind-like (MBNL) proteins, implicated in myotonic dystrophy and cancer, localize RNAs to myoblast membranes and neurites through unknown mechanisms. We find that MBNL forms motile and anchored granules in neurons and myoblasts, and selectively associates with kinesins Kif1bα and Kif1c through its zinc finger (ZnF) domains. Other RBPs with similar ZnFs associate with these kinesins, implicating a motor-RBP specificity code. MBNL and kinesin perturbation leads to widespread mRNA mis-localization, including depletion of Nucleolin transcripts from neurites. Live cell imaging and fractionation reveal that the unstructured carboxy-terminal tail of MBNL1 allows for anchoring at membranes. An approach, termed RBP Module Recruitment and Imaging (RBP-MRI), reconstitutes kinesin- and membrane-recruitment functions using MBNL-MS2 coat protein fusions. Our findings decouple kinesin association, RNA binding, and membrane anchoring functions of MBNL while establishing general strategies for studying multi-functional, modular domains of RBPs.
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Affiliation(s)
- Ryan P Hildebrandt
- Department of Molecular Genetics & Microbiology, Center for Neurogenetics, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Kathryn R Moss
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | | | - Luke A Knudson
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Lance T Denes
- Department of Molecular Genetics & Microbiology, Center for Neurogenetics, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Tanvi Saxena
- Department of Molecular Genetics & Microbiology, Center for Neurogenetics, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Devi Prasad Boggupalli
- Department of Molecular Genetics & Microbiology, Center for Neurogenetics, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Zhuangyue Li
- Department of Molecular Genetics & Microbiology, Center for Neurogenetics, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Kun Lin
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Gary J Bassell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA.
| | - Eric T Wang
- Department of Molecular Genetics & Microbiology, Center for Neurogenetics, Genetics Institute, University of Florida, Gainesville, FL, USA.
- Myology Institute, University of Florida, Gainesville, FL, USA.
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7
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Bhat P, Aksenova V, Gazzara M, Rex EA, Aslam S, Haddad C, Gao S, Esparza M, Cagatay T, Batten K, El Zahed SS, Arnaoutov A, Zhong H, Shay JW, Tolbert BS, Dasso M, Lynch KW, García-Sastre A, Fontoura BMA. Influenza virus mRNAs encode determinants for nuclear export via the cellular TREX-2 complex. Nat Commun 2023; 14:2304. [PMID: 37085480 PMCID: PMC10121598 DOI: 10.1038/s41467-023-37911-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 04/05/2023] [Indexed: 04/23/2023] Open
Abstract
Nuclear export of influenza A virus (IAV) mRNAs occurs through the nuclear pore complex (NPC). Using the Auxin-Induced Degron (AID) system to rapidly degrade proteins, we show that among the nucleoporins localized at the nucleoplasmic side of the NPC, TPR is the key nucleoporin required for nuclear export of influenza virus mRNAs. TPR recruits the TRanscription and EXport complex (TREX)-2 to the NPC for exporting a subset of cellular mRNAs. By degrading components of the TREX-2 complex (GANP, Germinal-center Associated Nuclear Protein; PCID2, PCI domain containing 2), we show that influenza mRNAs require the TREX-2 complex for nuclear export and replication. Furthermore, we found that cellular mRNAs whose export is dependent on GANP have a small number of exons, a high mean exon length, long 3' UTR, and low GC content. Some of these features are shared by influenza virus mRNAs. Additionally, we identified a 45 nucleotide RNA signal from influenza virus HA mRNA that is sufficient to mediate GANP-dependent mRNA export. Thus, we report a role for the TREX-2 complex in nuclear export of influenza mRNAs and identified RNA determinants associated with the TREX-2-dependent mRNA export.
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Affiliation(s)
- Prasanna Bhat
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Vasilisa Aksenova
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Matthew Gazzara
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Emily A Rex
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Sadaf Aslam
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Christina Haddad
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Shengyan Gao
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Matthew Esparza
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Tolga Cagatay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Kimberly Batten
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Sara S El Zahed
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Alexei Arnaoutov
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Hualin Zhong
- Department of Biological Sciences, Hunter College, New York, NY, 10065, USA
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Blanton S Tolbert
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Mary Dasso
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Kristen W Lynch
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Adolfo García-Sastre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Pathology, Molecular and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Beatriz M A Fontoura
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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8
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Mendonsa S, von Kügelgen N, Dantsuji S, Ron M, Breimann L, Baranovskii A, Lödige I, Kirchner M, Fischer M, Zerna N, Bujanic L, Mertins P, Ulitsky I, Chekulaeva M. Massively parallel identification of mRNA localization elements in primary cortical neurons. Nat Neurosci 2023; 26:394-405. [PMID: 36646877 DOI: 10.1038/s41593-022-01243-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 12/01/2022] [Indexed: 01/18/2023]
Abstract
Cells adopt highly polarized shapes and form distinct subcellular compartments in many cases due to the localization of many mRNAs to specific areas, where they are translated into proteins with local functions. This mRNA localization is mediated by specific cis-regulatory elements in mRNAs, commonly called 'zipcodes'. Although there are hundreds of localized mRNAs, only a few zipcodes have been characterized. Here we describe a novel neuronal zipcode identification protocol (N-zip) that can identify zipcodes across hundreds of 3' untranslated regions. This approach combines a method of separating the principal subcellular compartments of neurons-cell bodies and neurites-with a massively parallel reporter assay. N-zip identifies the let-7 binding site and (AU)n motif as de novo zipcodes in mouse primary cortical neurons. Our analysis also provides, to our knowledge, the first demonstration of an miRNA affecting mRNA localization and suggests a strategy for detecting many more zipcodes.
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9
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Acuña ML, García-Morin A, Orozco-Sepúlveda R, Ontiveros C, Flores A, Diaz AV, Gutiérrez-Zubiate I, Patil AR, Alvarado LA, Roy S, Russell WK, Rosas-Acosta G. Alternative splicing of the SUMO1/2/3 transcripts affects cellular SUMOylation and produces functionally distinct SUMO protein isoforms. Sci Rep 2023; 13:2309. [PMID: 36759644 PMCID: PMC9911741 DOI: 10.1038/s41598-023-29357-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 02/02/2023] [Indexed: 02/11/2023] Open
Abstract
Substantial increases in the conjugation of the main human SUMO paralogs, SUMO1, SUMO2, and SUMO3, are observed upon exposure to different cellular stressors, and such increases are considered important to facilitate cell survival to stress. Despite their critical cellular role, little is known about how the levels of the SUMO modifiers are regulated in the cell, particularly as it relates to the changes observed upon stress. Here we characterize the contribution of alternative splicing towards regulating the expression of the main human SUMO paralogs under normalcy and three different stress conditions, heat-shock, cold-shock, and Influenza A Virus infection. Our data reveal that the normally spliced transcript variants are the predominant mature mRNAs produced from the SUMO genes and that the transcript coding for SUMO2 is by far the most abundant of all. We also provide evidence that alternatively spliced transcripts coding for protein isoforms of the prototypical SUMO proteins, which we refer to as the SUMO alphas, are also produced, and that their abundance and nuclear export are affected by stress in a stress- and cell-specific manner. Additionally, we provide evidence that the SUMO alphas are actively synthesized in the cell as their coding mRNAs are found associated with translating ribosomes. Finally, we provide evidence that the SUMO alphas are functionally different from their prototypical counterparts, with SUMO1α and SUMO2α being non-conjugatable to protein targets, SUMO3α being conjugatable but targeting a seemingly different subset of protein from those targeted by SUMO3, and all three SUMO alphas displaying different cellular distributions from those of the prototypical SUMOs. Thus, alternative splicing appears to be an important contributor to the regulation of the expression of the SUMO proteins and the cellular functions of the SUMOylation system.
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Affiliation(s)
- Myriah L Acuña
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, 79968, USA
| | - Andrea García-Morin
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, 79968, USA
| | - Rebeca Orozco-Sepúlveda
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, 79968, USA
| | - Carlos Ontiveros
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, 79968, USA
- Graduate School of Biomedical Sciences, University of Texas Health, San Antonio, TX, 78229, USA
| | - Alejandra Flores
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, 79968, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Arely V Diaz
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, 79968, USA
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | | | - Abhijeet R Patil
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Luis A Alvarado
- Biostatistics and Epidemiology Consulting Lab, Texas Tech University Health Sciences Center, El Paso, TX, 79905, USA
| | - Sourav Roy
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, 79968, USA
- Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX, 79968, USA
| | - William K Russell
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Germán Rosas-Acosta
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, 79968, USA.
- Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX, 79968, USA.
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10
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Lefaudeux D, Sen S, Jiang K, Hoffmann A. Kinetics of mRNA nuclear export regulate innate immune response gene expression. Nat Commun 2022; 13:7197. [PMID: 36424375 PMCID: PMC9691726 DOI: 10.1038/s41467-022-34635-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 11/01/2022] [Indexed: 11/25/2022] Open
Abstract
The abundance and stimulus-responsiveness of mature mRNA is thought to be determined by nuclear synthesis, processing, and cytoplasmic decay. However, the rate and efficiency of moving mRNA to the cytoplasm almost certainly contributes, but has rarely been measured. Here, we investigated mRNA export rates for innate immune genes. We generated high spatio-temporal resolution RNA-seq data from endotoxin-stimulated macrophages and parameterized a mathematical model to infer kinetic parameters with confidence intervals. We find that the effective chromatin-to-cytoplasm export rate is gene-specific, varying 100-fold: for some genes, less than 5% of synthesized transcripts arrive in the cytoplasm as mature mRNAs, while others show high export efficiency. Interestingly, effective export rates do not determine temporal gene responsiveness, but complement the wide range of mRNA decay rates; this ensures similar abundances of short- and long-lived mRNAs, which form successive innate immune response expression waves.
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Affiliation(s)
- Diane Lefaudeux
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, CA, 90095, USA
| | - Supriya Sen
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
- Molecular Biology Institute, University of California, Los Angeles, CA, 90095, USA
| | - Kevin Jiang
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, CA, 90095, USA
| | - Alexander Hoffmann
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA.
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, CA, 90095, USA.
- Molecular Biology Institute, University of California, Los Angeles, CA, 90095, USA.
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11
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Cassella L, Ephrussi A. Subcellular spatial transcriptomics identifies three mechanistically different classes of localizing RNAs. Nat Commun 2022; 13:6355. [PMID: 36289223 DOI: 10.1038/s41467-022-34004-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 10/03/2022] [Indexed: 12/25/2022] Open
Abstract
Intracellular RNA localization is a widespread and dynamic phenomenon that compartmentalizes gene expression and contributes to the functional polarization of cells. Thus far, mechanisms of RNA localization identified in Drosophila have been based on a few RNAs in different tissues, and a comprehensive mechanistic analysis of RNA localization in a single tissue is lacking. Here, by subcellular spatial transcriptomics we identify RNAs localized in the apical and basal domains of the columnar follicular epithelium (FE) and we analyze the mechanisms mediating their localization. Whereas the dynein/BicD/Egl machinery controls apical RNA localization, basally-targeted RNAs require kinesin-1 to overcome a default dynein-mediated transport. Moreover, a non-canonical, translation- and dynein-dependent mechanism mediates apical localization of a subgroup of dynein-activating adaptor-encoding RNAs (BicD, Bsg25D, hook). Altogether, our study identifies at least three mechanisms underlying RNA localization in the FE, and suggests a possible link between RNA localization and dynein/dynactin/adaptor complex formation in vivo.
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12
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Matabishi-Bibi L, Challal D, Barucco M, Libri D, Babour A. Termination of the unfolded protein response is guided by ER stress-induced HAC1 mRNA nuclear retention. Nat Commun 2022; 13:6331. [PMID: 36284099 PMCID: PMC9596429 DOI: 10.1038/s41467-022-34133-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 10/14/2022] [Indexed: 12/25/2022] Open
Abstract
Cellular homeostasis is maintained by surveillance mechanisms that intervene at virtually every step of gene expression. In the nucleus, the yeast chromatin remodeler Isw1 holds back maturing mRNA ribonucleoparticles to prevent their untimely export, but whether this activity operates beyond quality control of mRNA biogenesis to regulate gene expression is unknown. Here, we identify the mRNA encoding the central effector of the unfolded protein response (UPR) HAC1, as an Isw1 RNA target. The direct binding of Isw1 to the 3' untranslated region of HAC1 mRNA restricts its nuclear export and is required for accurate UPR abatement. Accordingly, ISW1 inactivation sensitizes cells to endoplasmic reticulum (ER) stress while its overexpression reduces UPR induction. Our results reveal an unsuspected mechanism, in which binding of ER-stress induced Isw1 to HAC1 mRNA limits its nuclear export, providing a feedback loop that fine-tunes UPR attenuation to guarantee homeostatic adaptation to ER stress.
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Affiliation(s)
- Laura Matabishi-Bibi
- grid.508487.60000 0004 7885 7602Univ Paris Diderot, Sorbonne Paris Cité, INSERM U944, CNRS UMR7212, Hôpital St. Louis 1, Avenue Claude Vellefaux, 75475 Paris Cedex 10, France
| | - Drice Challal
- grid.457334.20000 0001 0667 2738Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Mara Barucco
- grid.461913.80000 0001 0676 2143Institut Jacques Monod, Univ Paris Diderot, Sorbonne Paris Cité, CNRS, Bâtiment Buffon, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
| | - Domenico Libri
- grid.429192.50000 0004 0599 0285Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Anna Babour
- grid.508487.60000 0004 7885 7602Univ Paris Diderot, Sorbonne Paris Cité, INSERM U944, CNRS UMR7212, Hôpital St. Louis 1, Avenue Claude Vellefaux, 75475 Paris Cedex 10, France
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13
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Ruland JA, Krüger AM, Dörner K, Bhatia R, Wirths S, Poetes D, Kutay U, Siebrasse JP, Kubitscheck U. Nuclear export of the pre-60S ribosomal subunit through single nuclear pores observed in real time. Nat Commun 2021; 12:6211. [PMID: 34707094 DOI: 10.1038/s41467-021-26323-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 09/02/2021] [Indexed: 11/08/2022] Open
Abstract
Ribosomal biogenesis has been studied by biochemical, genetic and electron microscopic approaches, but live cell data on the in vivo kinetics are still missing. Here we analyse the export kinetics of the large ribosomal subunit (pre-60S particle) through single NPCs in human cells. We established a stable cell line co-expressing Halo-tagged eIF6 and GFP-fused NTF2 to simultaneously label pre-60S particles and NPCs, respectively. By combining single molecule tracking and super resolution confocal microscopy we visualize the dynamics of single pre-60S particles during export through single NPCs. For export events, maximum particle accumulation is found in the centre of the pore, while unsuccessful export terminates within the nuclear basket. The export has a single rate limiting step and a duration of ∼24 milliseconds. Only about 1/3 of attempted export events are successful. Our results show that the mass flux through a single NPC can reach up to ~125 MDa·s-1 in vivo.
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14
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Denes LT, Kelley CP, Wang ET. Microtubule-based transport is essential to distribute RNA and nascent protein in skeletal muscle. Nat Commun 2021; 12:6079. [PMID: 34707124 DOI: 10.1038/s41467-021-26383-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 10/04/2021] [Indexed: 12/18/2022] Open
Abstract
While the importance of RNA localization in highly differentiated cells is well appreciated, basic principles of RNA localization in skeletal muscle remain poorly characterized. Here, we develop a method to detect and quantify single molecule RNA localization patterns in skeletal myofibers, and uncover a critical role for directed transport of RNPs in muscle. We find that RNAs localize and are translated along sarcomere Z-disks, dispersing tens of microns from progenitor nuclei, regardless of encoded protein function. We find that directed transport along the lattice-like microtubule network of myofibers becomes essential to achieve this localization pattern as muscle development progresses; disruption of this network leads to extreme accumulation of RNPs and nascent protein around myonuclei. Our observations suggest that global active RNP transport may be required to distribute RNAs in highly differentiated cells and reveal fundamental mechanisms of gene regulation, with consequences for myopathies caused by perturbations to RNPs or microtubules.
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15
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Laliotis GI, Kenney AD, Chavdoula E, Orlacchio A, Kaba A, La Ferlita A, Anastas V, Tsatsanis C, Beane JD, Sehgal L, Coppola V, Yount JS, Tsichlis PN. Phosphor-IWS1-dependent U2AF2 splicing regulates trafficking of CAR-E-positive intronless gene mRNAs and sensitivity to viral infection. Commun Biol 2021; 4:1179. [PMID: 34635782 DOI: 10.1038/s42003-021-02668-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 08/24/2021] [Indexed: 12/28/2022] Open
Abstract
AKT-phosphorylated IWS1 promotes Histone H3K36 trimethylation and alternative RNA splicing of target genes, including the U2AF65 splicing factor-encoding U2AF2. The predominant U2AF2 transcript, upon IWS1 phosphorylation block, lacks the RS-domain-encoding exon 2, and encodes a protein which fails to bind Prp19. Here we show that although both U2AF65 isoforms bind intronless mRNAs containing cytoplasmic accumulation region elements (CAR-E), only the RS domain-containing U2AF65 recruits Prp19 and promotes their nuclear export. The loading of U2AF65 to CAR-Elements was RS domain-independent, but RNA PolII-dependent. Virus- or poly(I:C)-induced type I IFNs are encoded by genes targeted by the pathway. IWS1 phosphorylation-deficient cells therefore, express reduced levels of IFNα1/IFNβ1 proteins, and exhibit enhanced sensitivity to infection by multiple cytolytic viruses. Enhanced sensitivity of IWS1-deficient cells to Vesicular Stomatitis Virus and Reovirus resulted in enhanced apoptotic cell death via caspase activation. Inhibition of this pathway may therefore sensitize cancer cells to oncolytic viruses.
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16
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Aksenova V, Smith A, Lee H, Bhat P, Esnault C, Chen S, Iben J, Kaufhold R, Yau KC, Echeverria C, Fontoura B, Arnaoutov A, Dasso M. Nucleoporin TPR is an integral component of the TREX-2 mRNA export pathway. Nat Commun 2020; 11:4577. [PMID: 32917881 PMCID: PMC7486939 DOI: 10.1038/s41467-020-18266-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 08/14/2020] [Indexed: 11/24/2022] Open
Abstract
Nuclear pore complexes (NPCs) are important for cellular functions beyond nucleocytoplasmic trafficking, including genome organization and gene expression. This multi-faceted nature and the slow turnover of NPC components complicates investigations of how individual nucleoporins act in these diverse processes. To address this question, we apply an Auxin-Induced Degron (AID) system to distinguish roles of basket nucleoporins NUP153, NUP50 and TPR. Acute depletion of TPR causes rapid and pronounced changes in transcriptomic profiles. These changes are dissimilar to shifts observed after loss of NUP153 or NUP50, but closely related to changes caused by depletion of mRNA export receptor NXF1 or the GANP subunit of the TRanscription-EXport-2 (TREX-2) mRNA export complex. Moreover, TPR depletion disrupts association of TREX-2 subunits (GANP, PCID2, ENY2) to NPCs and results in abnormal RNA transcription and export. Our findings demonstrate a unique and pivotal role of TPR in gene expression through TREX-2- and/or NXF1-dependent mRNA turnover.
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Affiliation(s)
- Vasilisa Aksenova
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Alexandra Smith
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Hangnoh Lee
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Prasanna Bhat
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Caroline Esnault
- Bioinformatics and Scientific Programming Core, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20879, USA
| | - Shane Chen
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - James Iben
- Molecular Genomics Core, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20879, USA
| | - Ross Kaufhold
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ka Chun Yau
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Carlos Echeverria
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Beatriz Fontoura
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Alexei Arnaoutov
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Mary Dasso
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA.
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17
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Abstract
RNA molecules play vital roles in many cellular processes. Visualising their dynamics in live cells at single-molecule resolution is essential to elucidate their role in RNA metabolism. RNA aptamers, such as Spinach and Mango, have recently emerged as a powerful background-free technology for live-cell RNA imaging due to their fluorogenic properties upon ligand binding. Here, we report a novel array of Mango II aptamers for RNA imaging in live and fixed cells with high contrast and single-molecule sensitivity. Direct comparison of Mango II and MS2-tdMCP-mCherry dual-labelled mRNAs show marked improvements in signal to noise ratio using the fluorogenic Mango aptamers. Using both coding (β-actin mRNA) and long non-coding (NEAT1) RNAs, we show that the Mango array does not affect cellular localisation. Additionally, we can track single mRNAs for extended time periods, likely due to bleached fluorophore replacement. This property makes the arrays readily compatible with structured illumination super-resolution microscopy.
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Affiliation(s)
- Adam D Cawte
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, Du Cane Rd, London, UK
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, Du Cane Rd, London, UK
| | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada.
| | - David S Rueda
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, Du Cane Rd, London, UK.
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, Du Cane Rd, London, UK.
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18
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Jackson PEH, Huang J, Sharma M, Rasmussen SK, Hammarskjold ML, Rekosh D. A novel retroviral vector system to analyze expression from mRNA with retained introns using fluorescent proteins and flow cytometry. Sci Rep 2019; 9:6467. [PMID: 31015546 PMCID: PMC6478720 DOI: 10.1038/s41598-019-42914-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/11/2019] [Indexed: 12/16/2022] Open
Abstract
The ability to overcome cellular restrictions that exist for the export and translation of mRNAs with retained introns is a requirement for the replication of retroviruses and also for the expression of many mRNA isoforms transcribed from cellular genes. In some cases, RNA structures have been identified in the mRNA that directly interact with cellular factors to promote the export and expression of isoforms with retained introns. In other cases, a viral protein is also required to act as an adapter. In this report we describe a novel vector system that allows measurement of the ability of cis- and trans-acting factors to promote the export and translation of mRNAs with retained introns. One reporter vector used in this system is derived from an HIV proviral clone engineered to express two different fluorescent proteins from spliced and unspliced transcripts. The ratio of fluorescent signals is a measurement of the efficiency of export and translation. A second vector utilizes a third fluorescent protein to measure the expression of viral export proteins that interact with some of the export elements. Both vectors can be packaged into viral particles and be used to transduce cells, allowing expression at physiological levels from the integrated vector.
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Affiliation(s)
- Patrick E H Jackson
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
| | - Jing Huang
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Monika Sharma
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Sara K Rasmussen
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Marie-Louise Hammarskjold
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - David Rekosh
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA.
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA.
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19
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Yang Y, Chou HL, Crofts AJ, Zhang L, Tian L, Washida H, Fukuda M, Kumamaru T, Oviedo OJ, Starkenburg SR, Okita TW. Selective sets of mRNAs localize to extracellular paramural bodies in a rice glup6 mutant. J Exp Bot 2018; 69:5045-5058. [PMID: 30102323 PMCID: PMC6189835 DOI: 10.1093/jxb/ery297] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/07/2018] [Indexed: 05/18/2023]
Abstract
The transport of rice glutelin storage proteins to the storage vacuoles requires the Rab5 GTPase and its related guanine nucleotide exchange factor (Rab5-GEF). Loss of function of these membrane vesicular trafficking factors results in the initial secretion of storage proteins and later their partial engulfment by the plasma membrane to form an extracellular paramural body (PMB), an aborted endosome complex. Here, we show that in the rice Rab5-GEF mutant glup6, glutelin RNAs are specifically mislocalized from their normal location on the cisternal endoplasmic reticulum (ER) to the protein body-ER, and are also apparently translocated to the PMBs. We substantiated the association of mRNAs with this aborted endosome complex by RNA-seq of PMBs purified by flow cytometry. Two PMB-associated groups of RNA were readily resolved: those that were specifically enriched in this aborted complex and those that were highly expressed in the cytoplasm. Examination of the PMB-enriched RNAs indicated that they were not a random sampling of the glup6 transcriptome but, instead, encompassed only a few functional mRNA classes. Although specific autophagy is also an alternative mechanism, our results support the view that RNA localization may co-opt membrane vesicular trafficking, and that many RNAs that share function or intracellular location are co-transported in developing rice seeds.
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Affiliation(s)
- Yongil Yang
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
- Present address: Institute of Agriculture, The University of Tennessee, Knoxville, TN 37996, USA
| | - Hong-Li Chou
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
- Present address: The Huck Institutes of the Life Sciences, Pennsylvania State University, PA 16802, USA
| | - Andrew J Crofts
- International Liberal Arts Program, Akita International University, Akita, Japan
| | - Laining Zhang
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Haruhiko Washida
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
- Present Address: Organic Nico Co., Ltd, North #205, Kyodai Katsura Venture Plaza, 1–36, Goryo-Ohara, Nishikyo-ku, Kyoto 615–8245, Japan
| | - Masako Fukuda
- Faculty of Agriculture, Kyushu University, Motooka Nishi-ku, Fukuoka, Japan
| | - Toshihiro Kumamaru
- Faculty of Agriculture, Kyushu University, Motooka Nishi-ku, Fukuoka, Japan
| | | | | | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
- Correspondence:
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20
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Terns MP, Terns RM. Small nucleolar RNAs: versatile trans-acting molecules of ancient evolutionary origin. Gene Expr 2018; 10:17-39. [PMID: 11868985 PMCID: PMC5977530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The small nucleolar RNAs (snoRNAs) are an abundant class of trans-acting RNAs that function in ribosome biogenesis in the eukaryotic nucleolus. Elegant work has revealed that most known snoRNAs guide modification of pre-ribosomal RNA (pre-rRNA) by base pairing near target sites. Other snoRNAs are involved in cleavage of pre-rRNA by mechanisms that have not yet been detailed. Moreover, our appreciation of the cellular roles of the snoRNAs is expanding with new evidence that snoRNAs also target modification of small nuclear RNAs and messenger RNAs. Many snoRNAs are produced by unorthodox modes of biogenesis including salvage from introns of pre-mRNAs. The recent discovery that homologs of snoRNAs as well as associated proteins exist in the domain Archaea indicates that the RNA-guided RNA modification system is of ancient evolutionary origin. In addition, it has become clear that the RNA component of vertebrate telomerase (an enzyme implicated in cancer and cellular senescence) is related to snoRNAs. During its evolution, vertebrate telomerase RNA appears to have co-opted a snoRNA domain that is essential for the function of telomerase RNA in vivo. The unique properties of snoRNAs are now being harnessed for basic research and therapeutic applications.
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MESH Headings
- Animals
- Base Pairing
- Biological Transport
- Cell Nucleolus/metabolism
- Cell Nucleus/metabolism
- Eukaryotic Cells/metabolism
- Evolution, Molecular
- Methylation
- Prokaryotic Cells/metabolism
- Pseudouridine/metabolism
- RNA/metabolism
- RNA Precursors/metabolism
- RNA Processing, Post-Transcriptional/genetics
- RNA, Archaeal/genetics
- RNA, Archaeal/physiology
- RNA, Catalytic/metabolism
- RNA, Messenger/metabolism
- RNA, Ribosomal/biosynthesis
- RNA, Small Nucleolar/chemistry
- RNA, Small Nucleolar/classification
- RNA, Small Nucleolar/genetics
- RNA, Small Nucleolar/metabolism
- RNA, Small Nucleolar/physiology
- Ribonucleoproteins, Small Nucleolar/metabolism
- Ribosomes/metabolism
- Species Specificity
- Structure-Activity Relationship
- Telomerase/metabolism
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Affiliation(s)
- Michael P Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens 30602, USA.
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21
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MacKellar AL, Greenleaf AL. Cotranscriptional association of mRNA export factor Yra1 with C-terminal domain of RNA polymerase II. J Biol Chem 2011; 286:36385-95. [PMID: 21856751 PMCID: PMC3196081 DOI: 10.1074/jbc.m111.268144] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 07/28/2011] [Indexed: 11/06/2022] Open
Abstract
The unique C-terminal domain (CTD) of RNA polymerase II, composed of tandem heptad repeats of the consensus sequence YSPTSPS, is subject to differential phosphorylation throughout the transcription cycle. Several RNA processing factors have been shown to bind the phosphorylated CTD and use it to localize to nascent pre-mRNA during transcription. In Saccharomyces cerevisiae, the mRNA export protein Yra1 (ALY/RNA export factor in metazoa) cotranscriptionally associates with mRNA and delivers it to the nuclear pore complex for export to the cytoplasm. Here we report that Yra1 directly binds in vitro the hyperphosphorylated form of the CTD characteristic of elongating RNA polymerase II and contains a phospho-CTD-interacting domain within amino acids 18-184, which also include an "RNA recognition motif" (RRM) (residues 77-184). Using UV cross-linking, we showed that the RRM alone binds RNA, although a larger segment extending to the C terminus (amino acids 77-226) displayed stronger RNA binding activity. Although the RRM is implicated in both RNA and CTD binding, RRM point mutations separated these two functions. Both functions are important in vivo as RNA binding-defective or CTD binding-defective versions of Yra1 engendered growth and mRNA export defects. We also report the construction and characterization of a useful new temperature-sensitive YRA1 allele (R107A/F126A). Using ChIP, we demonstrated that removing the N-terminal 76 amino acids of Yra1 (all of the phospho-CTD-interacting domain up to the RRM) results in a 10-fold decrease in Yra1 recruitment to genes during elongation. These results indicate that the phospho-CTD is likely involved directly in the cotranscriptional recruitment of Yra1.
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Affiliation(s)
- April L. MacKellar
- From the Department of Biochemistry and Center for RNA Biology, Duke University Medical Center, Durham, North Carolina 27710
| | - Arno L. Greenleaf
- From the Department of Biochemistry and Center for RNA Biology, Duke University Medical Center, Durham, North Carolina 27710
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22
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Li P, Ham BK, Lucas WJ. CmRBP50 protein phosphorylation is essential for assembly of a stable phloem-mobile high-affinity ribonucleoprotein complex. J Biol Chem 2011; 286:23142-9. [PMID: 21572046 PMCID: PMC3123081 DOI: 10.1074/jbc.m111.244129] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 04/29/2011] [Indexed: 01/30/2023] Open
Abstract
RNA-binding proteins (RBPs) form ribonucleoprotein (RNP) complexes that play crucial roles in RNA processing for gene regulation. The angiosperm sieve tube system contains a unique population of transcripts, some of which function as long-distance signaling agents involved in regulating organ development. These phloem-mobile mRNAs are translocated as RNP complexes. One such complex is based on a phloem RBP named Cucurbita maxima RNA-binding protein 50 (CmRBP50), a member of the polypyrimidine track binding protein family. The core of this RNP complex contains six additional phloem proteins. Here, requirements for assembly of this CmRBP50 RNP complex are reported. Phosphorylation sites on CmRBP50 were mapped, and then coimmunoprecipitation and protein overlay studies established that the phosphoserine residues, located at the C terminus of CmRBP50, are critical for RNP complex assembly. In vitro pull-down experiments revealed that three phloem proteins, C. maxima phloem protein 16, C. maxima GTP-binding protein, and C. maxima phosphoinositide-specific phospholipase-like protein, bind directly with CmRBP50. This interaction required CmRBP50 phosphorylation. Gel mobility-shift assays demonstrated that assembly of the CmRBP50-based protein complex results in a system having enhanced binding affinity for phloem-mobile mRNAs carrying polypyrimidine track binding motifs. This property would be essential for effective long-distance translocation of bound mRNA to the target tissues.
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Affiliation(s)
- Pingfang Li
- From the Department of Plant Biology, College of Biological Sciences, University of California, Davis, California, 95616 and
- the Department of Horticulture, Huajiachi Campus, Zhejiang University, Kaixuan Road 268, Hangzhou, 310029, China
| | - Byung-Kook Ham
- From the Department of Plant Biology, College of Biological Sciences, University of California, Davis, California, 95616 and
| | - William J. Lucas
- From the Department of Plant Biology, College of Biological Sciences, University of California, Davis, California, 95616 and
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23
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Abstract
Visualization of in vivo mRNA localization provides a tool for understanding steps in the mechanism of transport. Here we detail a method of fluorescently labeling mRNA transcripts and microinjecting them into Xenopus laevis oocytes followed with imaging by confocal microscopy. This technique overcomes a significant hurdle of imaging RNA in the frog oocyte while providing a rapid method of visualizing mRNA localization in high resolution.
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24
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Tholanikunnel BG, Joseph K, Kandasamy K, Baldys A, Raymond JR, Luttrell LM, McDermott PJ, Fernandes DJ. Novel mechanisms in the regulation of G protein-coupled receptor trafficking to the plasma membrane. J Biol Chem 2010; 285:33816-25. [PMID: 20739277 PMCID: PMC2962481 DOI: 10.1074/jbc.m110.168229] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Indexed: 11/06/2022] Open
Abstract
β(2)-adrenergic receptors (β(2)-AR) are low abundance, integral membrane proteins that mediate the effects of catecholamines at the cell surface. Whereas the processes governing desensitization of activated β(2)-ARs and their subsequent removal from the cell surface have been characterized in considerable detail, little is known about the mechanisms controlling trafficking of neo-synthesized receptors to the cell surface. Since the discovery of the signal peptide, the targeting of the integral membrane proteins to plasma membrane has been thought to be determined by structural features of the amino acid sequence alone. Here we report that localization of translationally silenced β(2)-AR mRNA to the peripheral cytoplasmic regions is critical for receptor localization to the plasma membrane. β(2)-AR mRNA is recognized by the nucleocytoplasmic shuttling RNA-binding protein HuR, which silences translational initiation while chaperoning the mRNA-protein complex to the cell periphery. When HuR expression is down-regulated, β(2)-AR mRNA translation is initiated prematurely in perinuclear polyribosomes, leading to overproduction of receptors but defective trafficking to the plasma membrane. Our results underscore the importance of the spatiotemporal relationship between β(2)-AR mRNA localization, translation, and trafficking to the plasma membrane, and establish a novel mechanism whereby G protein-coupled receptor (GPCR) responsiveness is regulated by RNA-based signals.
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Affiliation(s)
- Baby G Tholanikunnel
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
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25
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Zheng C, Fasken MB, Marshall NJ, Brockmann C, Rubinson ME, Wente SR, Corbett AH, Stewart M. Structural basis for the function of the Saccharomyces cerevisiae Gfd1 protein in mRNA nuclear export. J Biol Chem 2010; 285:20704-15. [PMID: 20463024 PMCID: PMC2898303 DOI: 10.1074/jbc.m110.107276] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 04/30/2010] [Indexed: 01/08/2023] Open
Abstract
Following transcription, mRNA is processed, packaged into messenger ribonucleoprotein (mRNP) particles, and transported through nuclear pores (NPCs) to the cytoplasm. At the NPC cytoplasmic face, Dbp5 mediates mRNP remodeling and mRNA export factor dissociation, releasing transcripts for translation. In Saccharomyces cerevisiae, the conserved poly(A) RNA-binding protein, Nab2, facilitates NPC targeting of transcripts and also modulates poly(A) tail length. Dbp5 removes Nab2 from mRNPs at the cytoplasmic face of the pore and, importantly, a Nab2 RNA-binding mutant suppresses the thermosensitive rat8-2 (dbp5) mutant. GFD1 is a multicopy suppressor of rat8-2 (dbp5), and Gfd1 interacts physically with both Dbp5 and the Nab2 N-terminal domain (Nab2-N). Here, we present a structural and functional analysis of the Gfd1/Nab2-N interaction. Crystallography, supported by solution NMR, shows that Gfd1 residues 126-150 form an alpha-helix when bound to Nab2-N. Engineered Nab2-N and Gfd1 mutants that inhibit this interaction in vitro were used to probe its function in vivo using the genetic interaction between GFD1 and NAB2. Although GFD1 is not essential for viability, its deletion severely impairs growth of rat8-2 (dbp5) cells. Moreover, although Gfd1 overexpression suppresses rat8-2 (dbp5), Gfd1 mutants that do not bind Nab2 only partially suppress rat8-2 (dbp5). Furthermore, rat8-2 (dbp5) cells that express nab2-Y34A, in which binding to Gfd1 is impaired, show a synthetic growth phenotype and nuclear accumulation of poly(A) RNA. These data support the importance of the Gfd1/Nab2 interaction for Dbp5 activity and provide further molecular details of the interactions that facilitate Dbp5-mediated mRNP remodeling in the terminal step of mRNA export.
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Affiliation(s)
- Chao Zheng
- From the MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, United Kingdom
| | - Milo B. Fasken
- the Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Neil J. Marshall
- From the MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, United Kingdom
| | - Christoph Brockmann
- From the MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, United Kingdom
| | - Max E. Rubinson
- the Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Susan R. Wente
- the Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Anita H. Corbett
- the Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Murray Stewart
- From the MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, United Kingdom
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26
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Abstract
Small untranslated BC1 and BC200 RNAs are translational regulators that are selectively targeted to somatodendritic domains of neurons. They are thought to operate as modulators of local protein synthesis in postsynaptic dendritic microdomains, in a capacity in which they would contribute to the maintenance of long-term synaptic plasticity. Because plasticity failure has been proposed to be a starting point for the neurodegenerative changes that are seen in Alzheimer's disease (AD), we asked whether somatodendritic levels of human BC200 RNA are deregulated in AD brains. We found that in normal aging, BC200 levels in cortical areas were reduced by >60% between the ages of 49 and 86. In contrast, BC200 RNA was significantly up-regulated in AD brains, in comparison with age-matched normal brains. This up-regulation in AD was specific to brain areas that are involved in the disease. Relative BC200 levels in those areas increased in parallel with the progression of AD, as reflected by Clinical Dementia Rating scores. In more advanced stages of the disease, BC200 RNA often assumed a clustered perikaryal localization, indicating that dendritic loss is accompanied by somatic overexpression. Mislocalization and overexpression of BC200 RNA may be reactive-compensatory to, or causative of, synaptodendritic deterioration in AD neurons.
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Affiliation(s)
- El Mus
- *The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and
| | - Patrick R. Hof
- Department of Neuroscience, Mount Sinai School of Medicine, New York, NY 10029
| | - Henri Tiedge
- *The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology and Pharmacology, and
- Department of Neurology, State University of New York Health Science Center, Brooklyn, NY 11203; and
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27
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Rackham O, Brown CM. Visualization of RNA-protein interactions in living cells: FMRP and IMP1 interact on mRNAs. EMBO J 2004; 23:3346-55. [PMID: 15282548 PMCID: PMC514514 DOI: 10.1038/sj.emboj.7600341] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2003] [Accepted: 07/01/2004] [Indexed: 11/09/2022] Open
Abstract
Protein expression depends significantly on the stability, translation efficiency and localization of mRNA. These qualities are largely dictated by the RNA-binding proteins associated with an mRNA. Here, we report a method to visualize and localize RNA-protein interactions in living mammalian cells. Using this method, we found that the fragile X mental retardation protein (FMRP) isoform 18 and the human zipcode-binding protein 1 ortholog IMP1, an RNA transport factor, were present on common mRNAs. These interactions occurred predominantly in the cytoplasm, in granular structures. In addition, FMRP and IMP1 interacted independently of RNA. Tethering of FMRP to an mRNA caused IMP1 to be recruited to the same mRNA and resulted in granule formation. The intimate association of FMRP and IMP1 suggests a link between mRNA transport and translational repression in mammalian cells.
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Affiliation(s)
- Oliver Rackham
- Biochemistry Department, University of Otago, Dunedin, New Zealand
| | - Chris M Brown
- Biochemistry Department, University of Otago, Dunedin, New Zealand
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28
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Macchi P, Kroening S, Palacios IM, Baldassa S, Grunewald B, Ambrosino C, Goetze B, Lupas A, St Johnston D, Kiebler M. Barentsz, a new component of the Staufen-containing ribonucleoprotein particles in mammalian cells, interacts with Staufen in an RNA-dependent manner. J Neurosci 2003; 23:5778-88. [PMID: 12843282 PMCID: PMC6741274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023] Open
Abstract
Staufen1, the mammalian homolog of Drosophila Staufen, assembles into ribonucleoprotein particles (RNPs), which are thought to transport and localize RNA into dendrites of mature hippocampal neurons. We therefore investigated whether additional components of the RNA localization complex besides Staufen are conserved. One candidate is the mammalian homolog of Drosophila Barentsz (Btz), which is essential for the localization of oskar mRNA to the posterior pole of the Drosophila oocyte and is a component of the oskar RNA localization complex along with Staufen. In this study, we report the characterization of mammalian Btz, which behaves like a nucleocytoplasmic shuttling protein. When expressed in the Drosophila egg chamber, mammalian Btz is still able to interact with Drosophila Staufen and reach the posterior pole in the wild-type oocyte, but does not rescue the btz mutant phenotype. Most interestingly, we show by immunoprecipitation assays that Btz interacts with mammalian Staufen in an RNA-dependent manner through a conserved domain, which encompasses the region of homology to the Drosophila Btz protein and contains a novel conserved motif. One candidate for an RNA that mediates this interaction is the dendritically localized brain cytoplasmic 1 transcript. In addition, Btz and Staufen1 colocalize within particles in the cell body and, to a more variable extent, in dendrites of mature hippocampal neurons. Together, our data suggest that the mRNA transport machinery is conserved during evolution, and that mammalian Btz is an additional component of the dendritic RNPs in hippocampal neurons.
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Affiliation(s)
- Paolo Macchi
- Max-Planck-Institute for Developmental Biology, D-72076 Tübingen, Germany
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29
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Abstract
The matrix (M) protein of vesicular stomatitis virus inhibits both nuclear import and export. Here, we demonstrate that this inhibitory property is conserved between the M proteins from two other vesiculoviruses, chandipura virus and spring viremia carp virus. All three M proteins completely block nuclear transport of spliced mRNA, small nuclear RNAs, and small nuclear ribonucleoproteins and slow the nuclear transport of many other cargoes. In all cases where transport was merely slowed by the M proteins, the chandipura virus M protein had the strongest inhibitory activity. When expressed in transfected HeLa cells, active M proteins displayed prominent association with the nuclear rim. Moreover, mutation of a conserved methionine abolished both the inhibitory activity and efficient targeting of the M proteins to the nuclear rim. We propose that all of the vesiculoviral M proteins associate with the same nuclear target, which is likely to be a component of the nuclear pore complex.
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Affiliation(s)
- J M Petersen
- Department of Biomolecular Chemistry, University of Wisconsin, Madison, WI 53706-1532, USA
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30
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Abstract
Proteins are responsible for most cellular and extra-cellular functions. If altered, proteins can loose their normal activity and/or gain new properties. Either way the consequences may be deleterious for the cell and lead to disease at the organism level. Not surprisingly, eukaryotes have evolved mechanisms to recognize abnormal messenger RNAs and prevent them from producing faulty proteins. Protein-encoding genes are transcribed in the nucleus by RNA polymerase II as precursor RNAs that undergo extensive processing before being translocated to the cytoplasm for translation by the ribosomes. This spatial and temporal separation between RNA and protein synthesis offers an immense opportunity for control and regulation. Here we review recent studies that are beginning to unravel how the coupling between transcription, processing and transport of mRNAs contributes to control the quality of gene expression in the nucleus.
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Affiliation(s)
- N Custódio
- Institute of Histology and Embryology, Faculty of Medicine, University of Lisbon, Lisbon, Portugal
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31
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Johnson C, Primorac D, McKinstry M, McNeil J, Rowe D, Lawrence JB. Tracking COL1A1 RNA in osteogenesis imperfecta. splice-defective transcripts initiate transport from the gene but are retained within the SC35 domain. J Cell Biol 2000; 150:417-32. [PMID: 10931857 PMCID: PMC2175183 DOI: 10.1083/jcb.150.3.417] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/1999] [Accepted: 06/28/2000] [Indexed: 11/22/2022] Open
Abstract
This study illuminates the intra-nuclear fate of COL1A1 RNA in osteogenesis imperfecta (OI) Type I. Patient fibroblasts were shown to carry a heterozygous defect in splicing of intron 26, blocking mRNA export. Both the normal and mutant allele associated with a nuclear RNA track, a localized accumulation of posttranscriptional RNA emanating to one side of the gene. Both tracks had slightly elongated or globular morphology, but mutant tracks were cytologically distinct in that they lacked the normal polar distribution of intron 26. Normal COL1A1 RNA tracks distribute throughout an SC-35 domain, from the gene at the periphery. Normally, almost all 50 COL1A1 introns are spliced at or adjacent to the gene, before mRNA transits thru the domain. Normal COL1A1 transcripts may undergo maturation needed for export within the domain such as removal of a slow-splicing intron (shown for intron 24), after which they may disperse. Splice-defective transcripts still distribute thru the SC-35 domain, moving approximately 1-3 micrometer from the gene. However, microfluorimetric analyses demonstrate mutant transcripts accumulate to abnormal levels within the track and domain. Hence, mutant transcripts initiate transport from the gene, but are impeded in exit from the SC-35 domain. This identifies a previously undefined step in mRNA export, involving movement through an SC-35 domain. A model is presented in which maturation and release for export of COL1A1 mRNA is linked to rapid cycling of metabolic complexes within the splicing factor domain, adjacent to the gene. This paradigm may apply to SC-35 domains more generally, which we suggest may be nucleated at sites of high demand and comprise factors being actively used to facilitate expression of associated loci.
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Affiliation(s)
- Carol Johnson
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655
| | - Dragan Primorac
- Department of Pediatrics, University of Connecticut Health Center, Farmington, Connecticut 06030
| | - Monique McKinstry
- Department of Pediatrics, University of Connecticut Health Center, Farmington, Connecticut 06030
| | - John McNeil
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655
| | - David Rowe
- Department of Pediatrics, University of Connecticut Health Center, Farmington, Connecticut 06030
| | - Jeanne Bentley Lawrence
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655
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32
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Muslimov IA, Santi E, Homel P, Perini S, Higgins D, Tiedge H. RNA transport in dendrites: a cis-acting targeting element is contained within neuronal BC1 RNA. J Neurosci 1997; 17:4722-33. [PMID: 9169532 PMCID: PMC1850620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/1997] [Revised: 03/28/1997] [Accepted: 03/31/1997] [Indexed: 02/04/2023] Open
Abstract
In nerve cells, a select group of RNAs has been localized to dendritic domains. Here we have examined dendritic RNA transport in sympathetic neurons in primary culture, using a microinjection protocol with neuronal BC1 RNA and with BC1-derived sequence segments. After cytoplasmic microinjection, full-length BC1 RNA was selectively transported to dendrites; in contrast, control RNAs such as nuclear RNAs and random-sequence irrelevant RNAs remained restricted to cytoplasmic areas proximal to the injection sites. Chimeric RNAs were constructed that contained the full-length BC1 sequence inserted upstream or downstream of the coding regions of nondendritic mRNAs. After microinjection, such chimeric RNAs were specifically targeted to dendrites; microinjected corresponding nonchimeric mRNAs were not. Dendritic transport of BC1 RNA was rapid: the average dendritic delivery rate within the first hour after microinjection was 242 +/- 25 microm/hr. Whereas a 5'-BC1 segment of 62 nucleotides was transported to dendrites to extents and at levels similar to full-length BC1 RNA, a 3'-BC1 segment of 60 nucleotides did not exit injected somata to any significant degree. A cis-acting dendritic targeting element is thus contained in the 5' part of neuronal BC1 RNA. These results demonstrate that mechanisms exist in neurons for fast and specific transport of selected RNAs to dendrites.
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Affiliation(s)
- I A Muslimov
- Department of Pharmacology, State University of New York, Health Science Center at Brooklyn, Brooklyn, New York 11203, USA
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