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Inoue R, Fukutani Y, Niwa T, Matsunami H, Yohda M. Identification and Characterization of Proteins That Are Involved in RTP1S-Dependent Transport of Olfactory Receptors. Int J Mol Sci 2023; 24:ijms24097829. [PMID: 37175532 PMCID: PMC10177996 DOI: 10.3390/ijms24097829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/17/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
Olfaction is mediated via olfactory receptors (ORs) that are expressed on the cilia membrane of olfactory sensory neurons in the olfactory epithelium. The functional expression of most ORs requires the assistance of receptor-transporting proteins (RTPs). We examined the interactome of RTP1S and OR via proximity biotinylation. Deubiquitinating protein VCIP135, the F-actin-capping protein sub-unit alpha-2, and insulin-like growth factor 2 mRNA-binding protein 2 were biotinylated via AirID fused with OR, RTP1S-AirID biotinylated heat shock protein A6 (HSPA6), and double-stranded RNA-binding protein Staufen homolog 2 (STAU2). Co-expression of HSPA6 partially enhanced the surface expression of Olfr544. The surface expression of Olfr544 increased by 50-80%. This effect was also observed when RTP1S was co-expressed. Almost identical results were obtained from the co-expression of STAU2. The interactions of HSPA6 and STAU2 with RTP1S were examined using a NanoBit assay. The results show that the RTP1S N-terminus interacted with the C-terminal domain of HSP6A and the N-terminal domain of STAU2. In contrast, OR did not significantly interact with STAU2 and HSPA6. Thus, HSP6A and STAU2 appear to be involved in the process of OR traffic through interaction with RTP1S.
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Affiliation(s)
- Ryosuke Inoue
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Yosuke Fukutani
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Tatsuya Niwa
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Masafumi Yohda
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
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2
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Paul S, Dansithong W, Gandelman M, Figueroa KP, Zu T, Ranum LPW, Scoles DR, Pulst SM. Staufen Impairs Autophagy in Neurodegeneration. Ann Neurol 2023; 93:398-416. [PMID: 36151701 PMCID: PMC9892312 DOI: 10.1002/ana.26515] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 09/20/2022] [Accepted: 09/22/2022] [Indexed: 02/04/2023]
Abstract
OBJECTIVE The mechanistic target of rapamycin (mTOR) kinase is one of the master coordinators of cellular stress responses, regulating metabolism, autophagy, and apoptosis. We recently reported that staufen1 (STAU1), a stress granule (SG) protein, was overabundant in fibroblast cell lines from patients with spinocerebellar ataxia type 2 (SCA2), amyotrophic lateral sclerosis, frontotemporal degeneration, Huntington's, Alzheimer's, and Parkinson's diseases as well as animal models, and patient tissues. STAU1 overabundance is associated with mTOR hyperactivation and links SG formation with autophagy. Our objective was to determine the mechanism of mTOR regulation by STAU1. METHODS We determined STAU1 abundance with disease- and chemical-induced cellular stressors in patient cells and animal models. We also used RNA-binding assays to contextualize STAU1 interaction with MTOR mRNA. RESULTS STAU1 and mTOR were overabundant in bacterial artificial chromosome (BAC)-C9ORF72, ATXN2Q127 , and Thy1-TDP-43 transgenic mouse models. Reducing STAU1 levels in these mice normalized mTOR levels and activity and autophagy-related marker proteins. We also saw increased STAU1 levels in HEK293 cells transfected to express C9ORF72-relevant dipeptide repeats (DPRs). Conversely, DPR accumulations were not observed in cells treated by STAU1 RNA interference (RNAi). Overexpression of STAU1 in HEK293 cells increased mTOR levels through direct MTOR mRNA interaction, activating downstream targets and impairing autophagic flux. Targeting mTOR by rapamycin or RNAi normalized STAU1 abundance in an SCA2 cellular model. INTERPRETATION STAU1 interaction with mTOR drives its hyperactivation and inhibits autophagic flux in multiple models of neurodegeneration. Staufen, therefore, constitutes a novel target to modulate mTOR activity and autophagy, and for the treatment of neurodegenerative diseases. ANN NEUROL 2023;93:398-416.
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Affiliation(s)
- Sharan Paul
- Department of Neurology, University of Utah, Salt Lake City, UT
| | | | - Mandi Gandelman
- Department of Neurology, University of Utah, Salt Lake City, UT
| | | | - Tao Zu
- Center for NeuroGenetics and Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL
| | - Laura P W Ranum
- Center for NeuroGenetics and Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL
| | - Daniel R Scoles
- Department of Neurology, University of Utah, Salt Lake City, UT
| | - Stefan M Pulst
- Department of Neurology, University of Utah, Salt Lake City, UT
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3
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Staszewski J, Lazarewicz N, Konczak J, Migdal I, Maciaszczyk-Dziubinska E. UPF1-From mRNA Degradation to Human Disorders. Cells 2023; 12:cells12030419. [PMID: 36766761 PMCID: PMC9914065 DOI: 10.3390/cells12030419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/07/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
Up-frameshift protein 1 (UPF1) plays the role of a vital controller for transcripts, ready to react in the event of an incorrect translation mechanism. It is well known as one of the key elements involved in mRNA decay pathways and participates in transcript and protein quality control in several different aspects. Firstly, UPF1 specifically degrades premature termination codon (PTC)-containing products in a nonsense-mediated mRNA decay (NMD)-coupled manner. Additionally, UPF1 can potentially act as an E3 ligase and degrade target proteins independently from mRNA decay pathways. Thus, UPF1 protects cells against the accumulation of misfolded polypeptides. However, this multitasking protein may still hide many of its functions and abilities. In this article, we summarize important discoveries in the context of UPF1, its involvement in various cellular pathways, as well as its structural importance and mutational changes related to the emergence of various pathologies and disease states. Even though the state of knowledge about this protein has significantly increased over the years, there are still many intriguing aspects that remain unresolved.
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Affiliation(s)
- Jacek Staszewski
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland
- Correspondence: (J.S.); (E.M.-D.)
| | - Natalia Lazarewicz
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland
- Institute of Genetics and Development of Rennes, CNRS UMR 6290, University of Rennes 1, 35000 Rennes, France
| | - Julia Konczak
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland
| | - Iwona Migdal
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland
| | - Ewa Maciaszczyk-Dziubinska
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, 50-328 Wroclaw, Poland
- Correspondence: (J.S.); (E.M.-D.)
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4
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Grzejda D, Mach J, Schweizer JA, Hummel B, Rezansoff AM, Eggenhofer F, Panhale A, Lalioti ME, Cabezas Wallscheid N, Backofen R, Felsenberg J, Hilgers V. The long noncoding RNA mimi scaffolds neuronal granules to maintain nervous system maturity. SCIENCE ADVANCES 2022; 8:eabo5578. [PMID: 36170367 PMCID: PMC9519039 DOI: 10.1126/sciadv.abo5578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 08/15/2022] [Indexed: 05/29/2023]
Abstract
RNA binding proteins and messenger RNAs (mRNAs) assemble into ribonucleoprotein granules that regulate mRNA trafficking, local translation, and turnover. The dysregulation of RNA-protein condensation disturbs synaptic plasticity and neuron survival and has been widely associated with human neurological disease. Neuronal granules are thought to condense around particular proteins that dictate the identity and composition of each granule type. Here, we show in Drosophila that a previously uncharacterized long noncoding RNA, mimi, is required to scaffold large neuronal granules in the adult nervous system. Neuronal ELAV-like proteins directly bind mimi and mediate granule assembly, while Staufen maintains condensate integrity. mimi granules contain mRNAs and proteins involved in synaptic processes; granule loss in mimi mutant flies impairs nervous system maturity and neuropeptide-mediated signaling and causes phenotypes of neurodegeneration. Our work reports an architectural RNA for a neuronal granule and provides a handle to interrogate functions of a condensate independently of those of its constituent proteins.
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Affiliation(s)
- Dominika Grzejda
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
- Faculty of Biology, Albert Ludwig University of Freiburg, Freiburg 79104, Germany
- International Max Planck Research School for Molecular and Cellular Biology (IMPRS- MCB), Freiburg 79108, Germany
| | - Jana Mach
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Johanna Aurelia Schweizer
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel 4058, Switzerland
- University of Basel, Basel 4001, Switzerland
| | - Barbara Hummel
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | | | - Florian Eggenhofer
- Department of Computer Science, Albert Ludwig University of Freiburg, Freiburg 79110, Germany
| | - Amol Panhale
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Maria-Eleni Lalioti
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | | | - Rolf Backofen
- Department of Computer Science, Albert Ludwig University of Freiburg, Freiburg 79110, Germany
- BIOSS and CIBSS Centres for Biological Signalling Studies, University of Freiburg, Freiburg 79104, Germany
| | - Johannes Felsenberg
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel 4058, Switzerland
| | - Valérie Hilgers
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg 79104, Germany
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5
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Ehses J, Schlegel M, Schröger L, Schieweck R, Derdak S, Bilban M, Bauer K, Harner M, Kiebler MA. The dsRBP Staufen2 governs RNP assembly of neuronal Argonaute proteins. Nucleic Acids Res 2022; 50:7034-7047. [PMID: 35687120 PMCID: PMC9262589 DOI: 10.1093/nar/gkac487] [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: 10/16/2021] [Revised: 05/10/2022] [Accepted: 05/26/2022] [Indexed: 12/24/2022] Open
Abstract
Mature microRNAs are bound by a member of the Argonaute (Ago1-4) protein family, forming the core of the RNA-induced silencing complex (RISC). Association of RISC with target mRNAs results in ribonucleoprotein (RNP) assembly involved in translational silencing or RNA degradation. Yet, the dynamics of RNP assembly and its underlying functional implications are unknown. Here, we have characterized the role of the RNA-binding protein Staufen2, a candidate Ago interactor, in RNP assembly. Staufen2 depletion resulted in the upregulation of Ago1/2 and the RISC effector proteins Ddx6 and Dcp1a. This upregulation was accompanied by the displacement of Ago1/2 from processing bodies, large RNPs implicated in RNA storage, and subsequent association of Ago2 with polysomes. In parallel, Staufen2 deficiency decreased global translation and increased dendritic branching. As the observed phenotypes can be rescued by Ago1/2 knockdown, we propose a working model in which both Staufen2 and Ago proteins depend on each other and contribute to neuronal homeostasis.
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Affiliation(s)
- Janina Ehses
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Melina Schlegel
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Luise Schröger
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Sophia Derdak
- Core Facilities, Medical University of Vienna, 1090 Vienna, Austria
| | - Martin Bilban
- Department of Laboratory Medicine and Core Facility Genomics, Medical University, of Vienna, 1090 Vienna, Austria
| | - Karl Bauer
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Max Harner
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Michael A Kiebler
- To whom correspondence should be addressed. Tel: +49 89 2180 75884; Fax: +49 89 2180 75885;
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6
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Bauer KE, Bargenda N, Schieweck R, Illig C, Segura I, Harner M, Kiebler MA. RNA supply drives physiological granule assembly in neurons. Nat Commun 2022; 13:2781. [PMID: 35589693 DOI: 10.1038/s41467-022-30067-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 04/11/2022] [Indexed: 11/09/2022] Open
Abstract
Membraneless cytoplasmic condensates of mRNAs and proteins, known as RNA granules, play pivotal roles in the regulation of mRNA fate. Their maintenance fine-tunes time and location of protein expression, affecting many cellular processes, which require complex protein distribution. Here, we report that RNA granules-monitored by DEAD-Box helicase 6 (DDX6)-disassemble during neuronal maturation both in cell culture and in vivo. This process requires neuronal function, as synaptic inhibition results in reversible granule assembly. Importantly, granule assembly is dependent on the RNA-binding protein Staufen2, known for its role in RNA localization. Altering the levels of free cytoplasmic mRNA reveals that RNA availability facilitates DDX6 granule formation. Specifically depleting RNA from DDX6 granules confirms RNA as an important driver of granule formation. Moreover, RNA is required for DDX6 granule assembly upon synaptic inhibition. Together, this data demonstrates how RNA supply favors RNA granule assembly, which not only impacts subcellular RNA localization but also translation-dependent synaptic plasticity, learning, and memory.
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Affiliation(s)
- Karl E Bauer
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Niklas Bargenda
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Rico Schieweck
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Christin Illig
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Inmaculada Segura
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany.,Max Planck Institute for Biological Intelligence (in foundation), Am Klopferspitz 18, 82152, Martinsried, Germany
| | - Max Harner
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Michael A Kiebler
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany.
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7
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Arzalluz-Luque A, Salguero P, Tarazona S, Conesa A. acorde unravels functionally interpretable networks of isoform co-usage from single cell data. Nat Commun 2022; 13:1828. [PMID: 35383181 PMCID: PMC8983708 DOI: 10.1038/s41467-022-29497-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 03/16/2022] [Indexed: 12/13/2022] Open
Abstract
Alternative splicing (AS) is a highly-regulated post-transcriptional mechanism known to modulate isoform expression within genes and contribute to cell-type identity. However, the extent to which alternative isoforms establish co-expression networks that may be relevant in cellular function has not been explored yet. Here, we present acorde, a pipeline that successfully leverages bulk long reads and single-cell data to confidently detect alternative isoform co-expression relationships. To achieve this, we develop and validate percentile correlations, an innovative approach that overcomes data sparsity and yields accurate co-expression estimates from single-cell data. Next, acorde uses correlations to cluster co-expressed isoforms into a network, unraveling cell type-specific alternative isoform usage patterns. By selecting same-gene isoforms between these clusters, we subsequently detect and characterize genes with co-differential isoform usage (coDIU) across cell types. Finally, we predict functional elements from long read-defined isoforms and provide insight into biological processes, motifs, and domains potentially controlled by the coordination of post-transcriptional regulation. The code for acorde is available at https://github.com/ConesaLab/acorde .
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Affiliation(s)
- Angeles Arzalluz-Luque
- Department of Applied Statistics, Operations Research and Quality, Universitat Politècnica de València, Valencia, Spain.,Institute for Integrative Systems Biology (CSIC-UV), Spanish National Research Council, Paterna, Valencia, Spain
| | - Pedro Salguero
- Department of Applied Statistics, Operations Research and Quality, Universitat Politècnica de València, Valencia, Spain
| | - Sonia Tarazona
- Department of Applied Statistics, Operations Research and Quality, Universitat Politècnica de València, Valencia, Spain.
| | - Ana Conesa
- Institute for Integrative Systems Biology (CSIC-UV), Spanish National Research Council, Paterna, Valencia, Spain. .,Microbiology and Cell Sciences Department, Institute for Food and Agricultural Research, University of Florida, Gainesville, FL, USA.
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8
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Li W, Jiang C, Zhang E. Advances in the phase separation-organized membraneless organelles in cells: a narrative review. Transl Cancer Res 2022; 10:4929-4946. [PMID: 35116344 PMCID: PMC8797891 DOI: 10.21037/tcr-21-1111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 10/29/2021] [Indexed: 11/26/2022]
Abstract
Membraneless organelles (MLOs) are micro-compartments that lack delimiting membranes, concentrating several macro-molecules with a high local concentration in eukaryotic cells. Recent studies have shown that MLOs have pivotal roles in multiple biological processes, including gene transcription, RNA metabolism, translation, protein modification, and signal transduction. These biological processes in cells have essential functions in many diseases, such as cancer, neurodegenerative diseases, and virus-related diseases. The liquid-liquid phase separation (LLPS) microenvironment within cells is thought to be the driving force for initiating the formation of micro-compartments with a liquid-like property, becoming an important organizing principle for MLOs to mediate organism responses. In this review, we comprehensively elucidated the formation of these MLOs and the relationship between biological functions and associated diseases. The mechanisms underlying the influence of protein concentration and valency on phase separation in cells are also discussed. MLOs undergoing the LLPS process have diverse functions, including stimulation of some adaptive and reversible responses to alter the transcriptional or translational processes, regulation of the concentrations of biomolecules in living cells, and maintenance of cell morphogenesis. Finally, we highlight that the development of this field could pave the way for developing novel therapeutic strategies for the treatment of LLPS-related diseases based on the understanding of phase separation in the coming years.
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Affiliation(s)
- Weihan Li
- Department of Immunology, School of Medicine, Nantong University, Nantong, China
| | - Chenwei Jiang
- Department of Immunology, School of Medicine, Nantong University, Nantong, China
| | - Erhao Zhang
- Department of Immunology, School of Medicine, Nantong University, Nantong, China.,Laboratory of Medical Science, School of Medicine, Nantong University, Nantong, China
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9
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RGS4 RNA Secondary Structure Mediates Staufen2 RNP Assembly in Neurons. Int J Mol Sci 2021; 22:ijms222313021. [PMID: 34884825 PMCID: PMC8657808 DOI: 10.3390/ijms222313021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/25/2021] [Accepted: 11/26/2021] [Indexed: 11/26/2022] Open
Abstract
RNA-binding proteins (RBPs) act as posttranscriptional regulators controlling the fate of target mRNAs. Unraveling how RNAs are recognized by RBPs and in turn are assembled into neuronal RNA granules is therefore key to understanding the underlying mechanism. While RNA sequence elements have been extensively characterized, the functional impact of RNA secondary structures is only recently being explored. Here, we show that Staufen2 binds complex, long-ranged RNA hairpins in the 3′-untranslated region (UTR) of its targets. These structures are involved in the assembly of Staufen2 into RNA granules. Furthermore, we provide direct evidence that a defined Rgs4 RNA duplex regulates Staufen2-dependent RNA localization to distal dendrites. Importantly, disrupting the RNA hairpin impairs the observed effects. Finally, we show that these secondary structures differently affect protein expression in neurons. In conclusion, our data reveal the importance of RNA secondary structure in regulating RNA granule assembly, localization and eventually translation. It is therefore tempting to speculate that secondary structures represent an important code for cells to control the intracellular fate of their mRNAs.
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10
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Kron NS, Fieber LA. Aplysia Neurons as a Model of Alzheimer's Disease: Shared Genes and Differential Expression. J Mol Neurosci 2021; 72:287-302. [PMID: 34664226 PMCID: PMC8840921 DOI: 10.1007/s12031-021-01918-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/18/2021] [Indexed: 11/19/2022]
Abstract
Although Alzheimer’s disease (AD) is the most common form of dementia in the United States, development of therapeutics has proven difficult. Invertebrate alternatives to current mammalian AD models have been successfully employed to study the etiology of the molecular hallmarks of AD. The marine snail Aplysia californica offers a unique and underutilized system in which to study the physiological, behavioral, and molecular impacts of AD. Mapping of the Aplysia proteome to humans and cross-referencing with two databases of genes of interest in AD research identified 898 potential orthologs of interest in Aplysia. Included among these orthologs were alpha, beta and gamma secretases, amyloid-beta, and tau. Comparison of age-associated differential expression in Aplysia sensory neurons with that of late-onset AD in the frontal lobe identified 59 ortholog with concordant differential expression across data sets. The 21 concordantly upregulated genes suggested increased cellular stress and protein dyshomeostasis. The 47 concordantly downregulated genes included important components of diverse neuronal processes, including energy metabolism, mitochondrial homeostasis, synaptic signaling, Ca++ regulation, and cellular cargo transport. Compromised functions in these processes are known hallmarks of both human aging and AD, the ramifications of which are suggested to underpin cognitive declines in aging and neurodegenerative disease.
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Affiliation(s)
- Nicholas S Kron
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA.
| | - Lynne A Fieber
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA
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11
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Gagné M, Deshaies JE, Sidibé H, Benchaar Y, Arbour D, Dubinski A, Litt G, Peyrard S, Robitaille R, Sephton CF, Vande Velde C. hnRNP A1B, a Splice Variant of HNRNPA1, Is Spatially and Temporally Regulated. Front Neurosci 2021; 15:724307. [PMID: 34630013 PMCID: PMC8498194 DOI: 10.3389/fnins.2021.724307] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 08/30/2021] [Indexed: 11/28/2022] Open
Abstract
RNA binding proteins (RBPs) play a key role in cellular growth, homoeostasis and survival and are tightly regulated. A deep understanding of their spatiotemporal regulation is needed to understand their contribution to physiology and pathology. Here, we have characterized the spatiotemporal expression pattern of hnRNP A1 and its splice variant hnRNP A1B in mice. We have found that hnRNP A1B expression is more restricted to the CNS compared to hnRNP A1, and that it can form an SDS-resistant dimer in the CNS. Also, hnRNP A1B expression becomes progressively restricted to motor neurons in the ventral horn of the spinal cord, compared to hnRNP A1 which is more broadly expressed. We also demonstrate that hnRNP A1B is present in neuronal processes, while hnRNP A1 is absent. This finding supports a hypothesis that hnRNP A1B may have a cytosolic function in neurons that is not shared with hnRNP A1. Our results demonstrate that both isoforms are differentially expressed across tissues and have distinct localization profiles, suggesting that the two isoforms may have specific subcellular functions that can uniquely contribute to disease progression.
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Affiliation(s)
- Myriam Gagné
- Department of Biochemistry, Université de Montréal, Montréal, QC, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Jade-Emmanuelle Deshaies
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Hadjara Sidibé
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada.,Department of Neurosciences, Université de Montréal, Montréal, QC, Canada
| | - Yousri Benchaar
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Laval University, Quebec City, QC, Canada
| | - Danielle Arbour
- Department of Neurosciences, Université de Montréal, Montréal, QC, Canada
| | - Alicia Dubinski
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada.,Department of Neurosciences, Université de Montréal, Montréal, QC, Canada
| | - Gurleen Litt
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Sarah Peyrard
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Richard Robitaille
- Department of Neurosciences, Université de Montréal, Montréal, QC, Canada
| | - Chantelle F Sephton
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Laval University, Quebec City, QC, Canada
| | - Christine Vande Velde
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada.,Department of Neurosciences, Université de Montréal, Montréal, QC, Canada
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12
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Kron NS, Fieber LA. Co-expression analysis identifies neuro-inflammation as a driver of sensory neuron aging in Aplysia californica. PLoS One 2021; 16:e0252647. [PMID: 34116561 PMCID: PMC8195618 DOI: 10.1371/journal.pone.0252647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 05/20/2021] [Indexed: 01/08/2023] Open
Abstract
Aging of the nervous system is typified by depressed metabolism, compromised proteostasis, and increased inflammation that results in cognitive impairment. Differential expression analysis is a popular technique for exploring the molecular underpinnings of neural aging, but technical drawbacks of the methodology often obscure larger expression patterns. Co-expression analysis offers a robust alternative that allows for identification of networks of genes and their putative central regulators. In an effort to expand upon previous work exploring neural aging in the marine model Aplysia californica, we used weighted gene correlation network analysis to identify co-expression networks in a targeted set of aging sensory neurons in these animals. We identified twelve modules, six of which were strongly positively or negatively associated with aging. Kyoto Encyclopedia of Genes analysis and investigation of central module transcripts identified signatures of metabolic impairment, increased reactive oxygen species, compromised proteostasis, disrupted signaling, and increased inflammation. Although modules with immune character were identified, there was no correlation between genes in Aplysia that increased in expression with aging and the orthologous genes in oyster displaying long-term increases in expression after a virus-like challenge. This suggests anti-viral response is not a driver of Aplysia sensory neuron aging.
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Affiliation(s)
- N. S. Kron
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States of America
| | - L. A. Fieber
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States of America
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13
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Alluri RK, Li Z, McCrae KR. Stress Granule-Mediated Oxidized RNA Decay in P-Body: Hypothetical Role of ADAR1, Tudor-SN, and STAU1. Front Mol Biosci 2021; 8:672988. [PMID: 34150849 PMCID: PMC8211916 DOI: 10.3389/fmolb.2021.672988] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/11/2021] [Indexed: 12/26/2022] Open
Abstract
Reactive oxygen species (ROS) generated under oxidative stress (OS) cause oxidative damage to RNA. Recent studies have suggested a role for oxidized RNA in several human disorders. Under the conditions of oxidative stress, mRNAs released from polysome dissociation accumulate and initiate stress granule (SG) assembly. SGs are highly enriched in mRNAs, containing inverted repeat (IR) Alus in 3′ UTRs, AU-rich elements, and RNA-binding proteins. SGs and processing bodies (P-bodies) transiently interact through a docking mechanism to allow the exchange of RNA species. However, the types of RNA species exchanged, and the mechanisms and outcomes of exchange are still unknown. Specialized RNA-binding proteins, including adenosine deaminase acting on RNA (ADAR1-p150), with an affinity toward inverted repeat Alus, and Tudor staphylococcal nuclease (Tudor-SN) are specifically recruited to SGs under OS along with an RNA transport protein, Staufen1 (STAU1), but their precise biochemical roles in SGs and SG/P-body docking are uncertain. Here, we critically review relevant literature and propose a hypothetical mechanism for the processing and decay of oxidized-RNA in SGs/P-bodies, as well as the role of ADAR1-p150, Tudor-SN, and STAU1.
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Affiliation(s)
- Ravi Kumar Alluri
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Zhongwei Li
- Biomedical Science Department, College of Medicine, Florida Atlantic University, Boca Raton, FL, United States
| | - Keith R McCrae
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.,Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, United States
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14
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STAU2 protein level is controlled by caspases and the CHK1 pathway and regulates cell cycle progression in the non-transformed hTERT-RPE1 cells. BMC Mol Cell Biol 2021; 22:16. [PMID: 33663378 PMCID: PMC7934504 DOI: 10.1186/s12860-021-00352-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 02/22/2021] [Indexed: 11/10/2022] Open
Abstract
Background Staufen2 (STAU2) is an RNA binding protein involved in the posttranscriptional regulation of gene expression. In neurons, STAU2 is required to maintain the balance between differentiation and proliferation of neural stem cells through asymmetric cell division. However, the importance of controlling STAU2 expression for cell cycle progression is not clear in non-neuronal dividing cells. We recently showed that STAU2 transcription is inhibited in response to DNA-damage due to E2F1 displacement from the STAU2 gene promoter. We now study the regulation of STAU2 steady-state levels in unstressed cells and its consequence for cell proliferation. Results CRISPR/Cas9-mediated and RNAi-dependent STAU2 depletion in the non-transformed hTERT-RPE1 cells both facilitate cell proliferation suggesting that STAU2 expression influences pathway(s) linked to cell cycle controls. Such effects are not observed in the CRISPR STAU2-KO cancer HCT116 cells nor in the STAU2-RNAi-depleted HeLa cells. Interestingly, a physiological decrease in the steady-state level of STAU2 is controlled by caspases. This effect of peptidases is counterbalanced by the activity of the CHK1 pathway suggesting that STAU2 partial degradation/stabilization fines tune cell cycle progression in unstressed cells. A large-scale proteomic analysis using STAU2/biotinylase fusion protein identifies known STAU2 interactors involved in RNA translation, localization, splicing, or decay confirming the role of STAU2 in the posttranscriptional regulation of gene expression. In addition, several proteins found in the nucleolus, including proteins of the ribosome biogenesis pathway and of the DNA damage response, are found in close proximity to STAU2. Strikingly, many of these proteins are linked to the kinase CHK1 pathway, reinforcing the link between STAU2 functions and the CHK1 pathway. Indeed, inhibition of the CHK1 pathway for 4 h dissociates STAU2 from proteins involved in translation and RNA metabolism. Conclusions These results indicate that STAU2 is involved in pathway(s) that control(s) cell proliferation, likely via mechanisms of posttranscriptional regulation, ribonucleoprotein complex assembly, genome integrity and/or checkpoint controls. The mechanism by which STAU2 regulates cell growth likely involves caspases and the kinase CHK1 pathway. Supplementary Information The online version contains supplementary material available at 10.1186/s12860-021-00352-y.
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15
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Ford LK, Fioriti L. Coiled-Coil Motifs of RNA-Binding Proteins: Dynamicity in RNA Regulation. Front Cell Dev Biol 2020; 8:607947. [PMID: 33330512 PMCID: PMC7710910 DOI: 10.3389/fcell.2020.607947] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 10/30/2020] [Indexed: 01/29/2023] Open
Abstract
Neuronal granules are biomolecular condensates that concentrate high quantities of RNAs and RNA-related proteins within neurons. These dense packets of information are trafficked from the soma to distal sites rich in polysomes, where local protein synthesis can occur. Movement of neuronal granules to distal sites, and local protein synthesis, play a critical role in synaptic plasticity. The formation of neuronal granules is intriguing; these granules lack a membrane and instead phase separate due to protein and RNA interactions. Low complexity motifs and RNA binding domains are highly prevalent in these proteins. Here, we introduce the role that coiled-coil motifs play in neuronal granule proteins, and investigate the structure-function relationship of coiled-coil proteins in RNA regulation. Interestingly, low complexity domains and coiled-coil motifs are highly dynamic, allowing for increased functional response to environmental influences. Finally, biomolecular condensates have been suggested to drive the formation of toxic, neurodegenerative proteins such as TDP-43 and tau. Here, we review the conversion of coiled-coil motifs to amyloid structures, and speculate a role that neuronal granules play in coiled-coil to amyloid conversions of neurodegenerative proteins.
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Affiliation(s)
- Lenzie K Ford
- Department of Neuroscience, Zuckerman Institute, Columbia University, New York, NY, United States
| | - Luana Fioriti
- Laboratory of Molecular Mechanisms of Polyglutamine Disorders, Department of Neuroscience, Dulbecco Telethon Institute, Istituto di Ricerche Farmacologiche Mario Negri (IRCCS), Milan, Italy
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16
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Schieweck R, Ninkovic J, Kiebler MA. RNA-binding proteins balance brain function in health and disease. Physiol Rev 2020; 101:1309-1370. [PMID: 33000986 DOI: 10.1152/physrev.00047.2019] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Posttranscriptional gene expression including splicing, RNA transport, translation, and RNA decay provides an important regulatory layer in many if not all molecular pathways. Research in the last decades has positioned RNA-binding proteins (RBPs) right in the center of posttranscriptional gene regulation. Here, we propose interdependent networks of RBPs to regulate complex pathways within the central nervous system (CNS). These are involved in multiple aspects of neuronal development and functioning, including higher cognition. Therefore, it is not sufficient to unravel the individual contribution of a single RBP and its consequences but rather to study and understand the tight interplay between different RBPs. In this review, we summarize recent findings in the field of RBP biology and discuss the complex interplay between different RBPs. Second, we emphasize the underlying dynamics within an RBP network and how this might regulate key processes such as neurogenesis, synaptic transmission, and synaptic plasticity. Importantly, we envision that dysfunction of specific RBPs could lead to perturbation within the RBP network. This would have direct and indirect (compensatory) effects in mRNA binding and translational control leading to global changes in cellular expression programs in general and in synaptic plasticity in particular. Therefore, we focus on RBP dysfunction and how this might cause neuropsychiatric and neurodegenerative disorders. Based on recent findings, we propose that alterations in the entire regulatory RBP network might account for phenotypic dysfunctions observed in complex diseases including neurodegeneration, epilepsy, and autism spectrum disorders.
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Affiliation(s)
- Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Jovica Ninkovic
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Michael A Kiebler
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
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17
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Kulkarni A, Lopez DH, Extavour CG. Shared Cell Biological Functions May Underlie Pleiotropy of Molecular Interactions in the Germ Lines and Nervous Systems of Animals. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00215] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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18
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Roy R, Shiina N, Wang DO. More dynamic, more quantitative, unexpectedly intricate: Advanced understanding on synaptic RNA localization in learning and memory. Neurobiol Learn Mem 2019; 168:107149. [PMID: 31881355 DOI: 10.1016/j.nlm.2019.107149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 10/25/2019] [Accepted: 12/23/2019] [Indexed: 01/13/2023]
Abstract
Synaptic signaling exhibits great diversity, complexity, and plasticity which necessitates maintenance and rapid modification of a local proteome. One solution neurons actively exploit to meet such demands is the strategic deposition of mRNAs encoding proteins for both basal and experience-driven activities into ribonucleoprotein complexes at the synapse. Transcripts localized in this manner can be rapidly accessed for translation in response to a diverse range of stimuli in a temporal- and spatially-restricted manner. Here we review recent findings on localized RNAs and RNA binding proteins in the context of learning and memory, as revealed by cutting-edge in-vitro and in-vivo technologies capable of yielding quantitative and dynamic information. The new technologies include proteomic and transcriptomic analyses, high-resolution multiplexed RNA imaging, single-molecule RNA tracking in living neurons, animal models and human neuron cell models. Among many recent advances in the field, RNA chemical modification has emerged as one of the new regulatory layers of gene expression at synapse that is complex and yet largely unexplored. These exciting new discoveries have enhanced our understanding of the modulation mechanisms of synaptic gene expression and their roles in cognition.
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Affiliation(s)
- Rohini Roy
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan; Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Nobuyuki Shiina
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan; Department of Basic Biology, SOKENDAI, Okazaki, Japan; Exploratory Research Center on Life and Living Systems, Okazaki, Japan.
| | - Dan Ohtan Wang
- Wuya College of Innovation, Shenyang Pharmaceutical University, Liaoning, China; Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan; The Keihanshin Consortium for Fostering the Next Generation of Global Leaders in Research (K-CONNEX), Kyoto University, Kyoto, Japan.
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19
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Kim YK, Maquat LE. UPFront and center in RNA decay: UPF1 in nonsense-mediated mRNA decay and beyond. RNA (NEW YORK, N.Y.) 2019; 25:407-422. [PMID: 30655309 PMCID: PMC6426291 DOI: 10.1261/rna.070136.118] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Nonsense-mediated mRNA decay (NMD), which is arguably the best-characterized translation-dependent regulatory pathway in mammals, selectively degrades mRNAs as a means of post-transcriptional gene control. Control can be for the purpose of ensuring the quality of gene expression. Alternatively, control can facilitate the adaptation of cells to changes in their environment. The key to NMD, no matter what its purpose, is the ATP-dependent RNA helicase upstream frameshift 1 (UPF1), without which NMD fails to occur. However, UPF1 does much more than regulate NMD. As examples, UPF1 is engaged in functionally diverse mRNA decay pathways mediated by a variety of RNA-binding proteins that include staufen, stem-loop-binding protein, glucocorticoid receptor, and regnase 1. Moreover, UPF1 promotes tudor-staphylococcal/micrococcal-like nuclease-mediated microRNA decay. In this review, we first focus on how the NMD machinery recognizes an NMD target and triggers mRNA degradation. Next, we compare and contrast the mechanisms by which UPF1 functions in the decay of other mRNAs and also in microRNA decay. UPF1, as a protein polymath, engenders cells with the ability to shape their transcriptome in response to diverse biological and physiological needs.
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Affiliation(s)
- Yoon Ki Kim
- Creative Research Initiatives Center for Molecular Biology of Translation, Korea University, Seoul 02841, Republic of Korea
- Division of Life Sciences, Korea University, Seoul 02841, Republic of Korea
| | - Lynne E Maquat
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA
- Center for RNA Biology, University of Rochester, Rochester, New York 14642, USA
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20
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Oh JY, Lim CS, Yoo KS, Park H, Park YS, Kim EG, Lee YS, Kaang BK, Kim HK. Adenomatous polyposis coli-stimulated GEF 1 (Asef1) is a negative regulator of excitatory synaptic function. J Neurochem 2018; 147:595-608. [PMID: 30125942 DOI: 10.1111/jnc.14570] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 07/18/2018] [Accepted: 08/16/2018] [Indexed: 01/06/2023]
Abstract
Guanine nucleotide exchange factors (GEFs) play important roles in many cellular processes, including regulation of the structural plasticity of dendritic spines. A GEF protein, adenomatous polyposis coli-stimulated GEF 1 (Asef1, ARHGEF4) is highly expressed in the nervous system. However, the function of Asef1 has not been investigated in neurons. Here, we present evidence showing that Asef1 negatively regulates the synaptic localization of postsynaptic density protein 95 (PSD-95) in the excitatory synapse by inhibiting Staufen-mediated synaptic localization of PSD-95. Accordingly, Asef1 expression impairs synaptic transmission in hippocampal cultured neurons. In addition, neuronal activity facilitates the dissociation of Asef1 from Staufen in a phosphoinositide 3 kinase (PI3K)-dependent manner. Taken together, our data reveal Asef1 functions as a negative regulator of synaptic localization of PSD-95 and synaptic transmission.
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Affiliation(s)
- Jun-Young Oh
- Graduate Program in Neuroscience, Department of Medicine and Microbiology, College of Medicine, Chungbuk National University, Cheongju, Korea.,Korea Brain Research Institute, Daegu, Korea
| | - Chae-Seok Lim
- Department of Pharmacology, Wonkwang University School of Medicine, Iksan, Korea
| | - Ki-Seo Yoo
- Graduate Program in Neuroscience, Department of Medicine and Microbiology, College of Medicine, Chungbuk National University, Cheongju, Korea
| | | | - Young Seok Park
- Department of Neurosurgery, College of Medicine, Chungbuk National University, Cheongju, Korea
| | - Eung-Gook Kim
- Department of Medicine and Biochemistry, College of Medicine, Chungbuk National University, Cheongju, Korea
| | - Yong-Seok Lee
- Department of Physiology, Department of Biomedical Science, Seoul National University College of Medicine, Seoul, Korea
| | - Bong-Kiun Kaang
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Korea
| | - Hyong Kyu Kim
- Graduate Program in Neuroscience, Department of Medicine and Microbiology, College of Medicine, Chungbuk National University, Cheongju, Korea
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21
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Lazzaretti D, Bandholz-Cajamarca L, Emmerich C, Schaaf K, Basquin C, Irion U, Bono F. The crystal structure of Staufen1 in complex with a physiological RNA sheds light on substrate selectivity. Life Sci Alliance 2018; 1:e201800187. [PMID: 30456389 PMCID: PMC6238398 DOI: 10.26508/lsa.201800187] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 01/29/2023] Open
Abstract
Combination of in vitro and in vivo data show that RNA sequence influences Staufen target recognition and that protein–RNA base contacts are required for Staufen function in Drosophila. During mRNA localization, RNA-binding proteins interact with specific structured mRNA localization motifs. Although several such motifs have been identified, we have limited structural information on how these interact with RNA-binding proteins. Staufen proteins bind structured mRNA motifs through dsRNA-binding domains (dsRBD) and are involved in mRNA localization in Drosophila and mammals. We solved the structure of two dsRBDs of human Staufen1 in complex with a physiological dsRNA sequence. We identified interactions between the dsRBDs and the RNA sugar–phosphate backbone and direct contacts of conserved Staufen residues to RNA bases. Mutating residues mediating nonspecific backbone interactions only affected Staufen function in Drosophila when in vitro binding was severely reduced. Conversely, residues involved in base-directed interactions were required in vivo even when they minimally affected in vitro binding. Our work revealed that Staufen can read sequence features in the minor groove of dsRNA and suggests that these influence target selection in vivo.
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Affiliation(s)
| | | | | | - Kristina Schaaf
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Claire Basquin
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Uwe Irion
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Fulvia Bono
- Max Planck Institute for Developmental Biology, Tübingen, Germany.,Living Systems Institute, University of Exeter, Exeter, UK
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22
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Paul S, Dansithong W, Figueroa KP, Scoles DR, Pulst SM. Staufen1 links RNA stress granules and autophagy in a model of neurodegeneration. Nat Commun 2018; 9:3648. [PMID: 30194296 PMCID: PMC6128856 DOI: 10.1038/s41467-018-06041-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 07/17/2018] [Indexed: 11/26/2022] Open
Abstract
Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disease caused by expansion of polyglutamine tract in the ATXN2 protein. We identified Staufen1 (STAU1) as an interactor of ATXN2, and showed elevation in cells from SCA2 patients, amyotrophic lateral sclerosis (ALS) patients, and in SCA2 mouse models. We demonstrated recruitment of STAU1 to mutant ATXN2 aggregates in brain tissue from patients with SCA2 human brain and in an SCA2 mouse model, and association of STAU1 elevation with dysregulation of SCA2-related transcript abundances. Targeting STAU1 in vitro by RNAi restored PCP2 transcript levels and lowering mutant ATXN2 also normalized STAU1 levels. Reduction of Stau1 in vivo improved motor behavior in an SCA2 mouse model, normalized the levels of several SCA2-related proteins, and reduced aggregation of polyglutamine-expanded ATXN2. These findings suggest a function for STAU1 in aberrant RNA metabolism associated with ATXN2 mutation, suggesting STAU1 is a possible novel therapeutic target for SCA2.
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Affiliation(s)
- Sharan Paul
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, Utah 84132, USA
| | - Warunee Dansithong
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, Utah 84132, USA
| | - Karla P Figueroa
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, Utah 84132, USA
| | - Daniel R Scoles
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, Utah 84132, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, Utah 84132, USA.
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23
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Ravanidis S, Kattan FG, Doxakis E. Unraveling the Pathways to Neuronal Homeostasis and Disease: Mechanistic Insights into the Role of RNA-Binding Proteins and Associated Factors. Int J Mol Sci 2018; 19:ijms19082280. [PMID: 30081499 PMCID: PMC6121432 DOI: 10.3390/ijms19082280] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 07/26/2018] [Accepted: 07/31/2018] [Indexed: 12/13/2022] Open
Abstract
The timing, dosage and location of gene expression are fundamental determinants of brain architectural complexity. In neurons, this is, primarily, achieved by specific sets of trans-acting RNA-binding proteins (RBPs) and their associated factors that bind to specific cis elements throughout the RNA sequence to regulate splicing, polyadenylation, stability, transport and localized translation at both axons and dendrites. Not surprisingly, misregulation of RBP expression or disruption of its function due to mutations or sequestration into nuclear or cytoplasmic inclusions have been linked to the pathogenesis of several neuropsychiatric and neurodegenerative disorders such as fragile-X syndrome, autism spectrum disorders, spinal muscular atrophy, amyotrophic lateral sclerosis and frontotemporal dementia. This review discusses the roles of Pumilio, Staufen, IGF2BP, FMRP, Sam68, CPEB, NOVA, ELAVL, SMN, TDP43, FUS, TAF15, and TIA1/TIAR in RNA metabolism by analyzing their specific molecular and cellular function, the neurological symptoms associated with their perturbation, and their axodendritic transport/localization along with their target mRNAs as part of larger macromolecular complexes termed ribonucleoprotein (RNP) granules.
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Affiliation(s)
- Stylianos Ravanidis
- Basic Sciences Division I, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece.
| | - Fedon-Giasin Kattan
- Basic Sciences Division I, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece.
| | - Epaminondas Doxakis
- Basic Sciences Division I, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece.
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24
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Bakthavachalu B, Huelsmeier J, Sudhakaran IP, Hillebrand J, Singh A, Petrauskas A, Thiagarajan D, Sankaranarayanan M, Mizoue L, Anderson EN, Pandey UB, Ross E, VijayRaghavan K, Parker R, Ramaswami M. RNP-Granule Assembly via Ataxin-2 Disordered Domains Is Required for Long-Term Memory and Neurodegeneration. Neuron 2018; 98:754-766.e4. [PMID: 29772202 DOI: 10.1016/j.neuron.2018.04.032] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 03/07/2018] [Accepted: 04/23/2018] [Indexed: 02/07/2023]
Abstract
Human Ataxin-2 is implicated in the cause and progression of amyotrophic lateral sclerosis (ALS) and type 2 spinocerebellar ataxia (SCA-2). In Drosophila, a conserved atx2 gene is essential for animal survival as well as for normal RNP-granule assembly, translational control, and long-term habituation. Like its human homolog, Drosophila Ataxin-2 (Atx2) contains polyQ repeats and additional intrinsically disordered regions (IDRs). We demonstrate that Atx2 IDRs, which are capable of mediating liquid-liquid phase transitions in vitro, are essential for efficient formation of neuronal mRNP assemblies in vivo. Remarkably, ΔIDR mutants that lack neuronal RNP granules show normal animal development, survival, and fertility. However, they show defects in long-term memory formation/consolidation as well as in C9ORF72 dipeptide repeat or FUS-induced neurodegeneration. Together, our findings demonstrate (1) that higher-order mRNP assemblies contribute to long-term neuronal plasticity and memory, and (2) that a targeted reduction in RNP-granule formation efficiency can alleviate specific forms of neurodegeneration.
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Affiliation(s)
| | - Joern Huelsmeier
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin-2, Ireland
| | | | - Jens Hillebrand
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin-2, Ireland
| | - Amanjot Singh
- National Centre for Biological Sciences, TIFR, Bangalore 560065, India
| | - Arnas Petrauskas
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin-2, Ireland
| | | | | | - Laura Mizoue
- Department of Chemistry, University of Colorado, Boulder, CO 80309, USA; HHMI, University of Colorado, Boulder, CO 80309, USA
| | - Eric N Anderson
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Udai Bhan Pandey
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Eric Ross
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - K VijayRaghavan
- National Centre for Biological Sciences, TIFR, Bangalore 560065, India
| | - Roy Parker
- Department of Chemistry, University of Colorado, Boulder, CO 80309, USA; HHMI, University of Colorado, Boulder, CO 80309, USA
| | - Mani Ramaswami
- National Centre for Biological Sciences, TIFR, Bangalore 560065, India; Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin-2, Ireland.
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25
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Ortiz R, Georgieva MV, Gutiérrez S, Pedraza N, Fernández-Moya SM, Gallego C. Recruitment of Staufen2 Enhances Dendritic Localization of an Intron-Containing CaMKIIα mRNA. Cell Rep 2018; 20:13-20. [PMID: 28683307 DOI: 10.1016/j.celrep.2017.06.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 03/30/2017] [Accepted: 06/08/2017] [Indexed: 02/07/2023] Open
Abstract
Regulation of mRNA localization is a conserved cellular process observed in many types of cells and organisms. Asymmetrical mRNA distribution plays a particularly important role in the nervous system, where local translation of localized mRNA represents a key mechanism in synaptic plasticity. CaMKIIα is a very abundant mRNA detected in neurites, consistent with its crucial role at glutamatergic synapses. Here, we report the presence of CaMKIIα mRNA isoforms that contain intron i16 in dendrites, RNA granules, and synaptoneurosomes from primary neurons and brain. This subpopulation of unspliced mRNA preferentially localizes to distal dendrites in a synaptic-activity-dependent manner. Staufen2, a well-established marker of RNA transport in dendrites, interacts with intron i16 sequences and enhances its distal dendritic localization, pointing to the existence of intron-mediated mechanisms in the molecular pathways that modulate dendritic transport and localization of synaptic mRNAs.
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Affiliation(s)
- Raúl Ortiz
- Molecular Biology Institute of Barcelona (IBMB-CSIC), 08028 Barcelona, Catalonia, Spain
| | - Maya V Georgieva
- Molecular Biology Institute of Barcelona (IBMB-CSIC), 08028 Barcelona, Catalonia, Spain
| | - Sara Gutiérrez
- Molecular Biology Institute of Barcelona (IBMB-CSIC), 08028 Barcelona, Catalonia, Spain
| | - Neus Pedraza
- Institut de Recerca Biomèdica de Lleida (IRBLleida), Departament de Ciències Mèdiques Bàsiques, Universitat de Lleida, 25198 Lleida, Catalonia, Spain
| | - Sandra M Fernández-Moya
- Biomedical Center, Division of Anatomy and Cell Biology, Ludwig Maximilians University, 82152 Planegg-Martinsried, Germany
| | - Carme Gallego
- Molecular Biology Institute of Barcelona (IBMB-CSIC), 08028 Barcelona, Catalonia, Spain.
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26
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Kim JY, Deglincerti A, Jaffrey SR. A Staufen1-mediated decay pathway influences the local transcriptome in axons. ACTA ACUST UNITED AC 2017; 5:e1414016. [PMID: 29416957 DOI: 10.1080/21690731.2017.1414016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 11/28/2017] [Indexed: 12/23/2022]
Abstract
Local translation is critical for diverse aspects of neuronal function, including mediating responses of elongating axons to guidance cues and other signaling molecules. A major determinant of the protein synthetic capacity of axons and growth cones is the specific set of mRNAs that are trafficked to these sites. However, recently it has become clear that the axonal transcriptome can also be shaped by local RNA degradation mechanisms, such as nonsense-mediated decay. Here we show that Staufen1-mediated decay can also occur within axons and mediate degradation of specific axonal transcripts. We show that Staufen1 and Upf1, which function together in Staufen1-mediated decay, are localized in growth cones. Selective depletion of Staufen1 from neurons results in a complex pattern of transcriptional alterations, with a subset of transcripts showing increased expression and increased RNA half-life consistent with their regulation by Staufen1-mediated decay. Additionally, we show certain transcripts, such as Rac1, are regulated by Staufen1 within axons and growth cones. The functional significance of Staufen1 in growth cones is supported by morphological alterations in growth cones following Staufen1 knockdown. Together these data point to Staufen1-mediated decay as a novel mechanism to control mRNA expression levels in axons and growth cones through local RNA degradation.
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Affiliation(s)
- Ju Youn Kim
- Department of Pharmacology, Weill-Cornell Medical College, Cornell University, New York, NY, USA
| | - Alessia Deglincerti
- Department of Pharmacology, Weill-Cornell Medical College, Cornell University, New York, NY, USA
| | - Samie R Jaffrey
- Department of Pharmacology, Weill-Cornell Medical College, Cornell University, New York, NY, USA
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27
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Berger SM, Fernández-Lamo I, Schönig K, Fernández Moya SM, Ehses J, Schieweck R, Clementi S, Enkel T, Grothe S, von Bohlen Und Halbach O, Segura I, Delgado-García JM, Gruart A, Kiebler MA, Bartsch D. Forebrain-specific, conditional silencing of Staufen2 alters synaptic plasticity, learning, and memory in rats. Genome Biol 2017; 18:222. [PMID: 29149906 PMCID: PMC5693596 DOI: 10.1186/s13059-017-1350-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/26/2017] [Indexed: 12/16/2022] Open
Abstract
Background Dendritic messenger RNA (mRNA) localization and subsequent local translation in dendrites critically contributes to synaptic plasticity and learning and memory. Little is known, however, about the contribution of RNA-binding proteins (RBPs) to these processes in vivo. Results To delineate the role of the double-stranded RBP Staufen2 (Stau2), we generate a transgenic rat model, in which Stau2 expression is conditionally silenced by Cre-inducible expression of a microRNA (miRNA) targeting Stau2 mRNA in adult forebrain neurons. Known physiological mRNA targets for Stau2, such as RhoA, Complexin 1, and Rgs4 mRNAs, are found to be dysregulated in brains of Stau2-deficient rats. In vivo electrophysiological recordings reveal synaptic strengthening upon stimulation, showing a shift in the frequency-response function of hippocampal synaptic plasticity to favor long-term potentiation and impair long-term depression in Stau2-deficient rats. These observations are accompanied by deficits in hippocampal spatial working memory, spatial novelty detection, and in tasks investigating associative learning and memory. Conclusions Together, these experiments reveal a critical contribution of Stau2 to various forms of synaptic plasticity including spatial working memory and cognitive management of new environmental information. These findings might contribute to the development of treatments for conditions associated with learning and memory deficits. Electronic supplementary material The online version of this article (doi:10.1186/s13059-017-1350-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stefan M Berger
- Department of Molecular Biology, CIMH and Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany
| | - Iván Fernández-Lamo
- Division of Neurosciences, Pablo de Olavide University, 41013, Seville, Spain.,Present Address: Institute Cajal (CSIC), 28002, Madrid, Spain
| | - Kai Schönig
- Department of Molecular Biology, CIMH and Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany
| | - Sandra M Fernández Moya
- BioMedical Center, Medical Faculty, Ludwig Maximilians University, 82152, Planegg-Martinsried, Germany
| | - Janina Ehses
- BioMedical Center, Medical Faculty, Ludwig Maximilians University, 82152, Planegg-Martinsried, Germany
| | - Rico Schieweck
- BioMedical Center, Medical Faculty, Ludwig Maximilians University, 82152, Planegg-Martinsried, Germany
| | - Stefano Clementi
- Department of Molecular Biology, CIMH and Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany
| | - Thomas Enkel
- Department of Molecular Biology, CIMH and Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany
| | - Sascha Grothe
- Institute for Anatomy and Cell Biology, University Medicine Greifswald, 17487, Greifswald, Germany
| | | | - Inmaculada Segura
- BioMedical Center, Medical Faculty, Ludwig Maximilians University, 82152, Planegg-Martinsried, Germany.
| | | | - Agnès Gruart
- Division of Neurosciences, Pablo de Olavide University, 41013, Seville, Spain
| | - Michael A Kiebler
- BioMedical Center, Medical Faculty, Ludwig Maximilians University, 82152, Planegg-Martinsried, Germany.
| | - Dusan Bartsch
- Department of Molecular Biology, CIMH and Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany.
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28
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Rossi A, Moro A, Tebaldi T, Cornella N, Gasperini L, Lunelli L, Quattrone A, Viero G, Macchi P. Identification and dynamic changes of RNAs isolated from RALY-containing ribonucleoprotein complexes. Nucleic Acids Res 2017; 45:6775-6792. [PMID: 28379492 PMCID: PMC5499869 DOI: 10.1093/nar/gkx235] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 03/30/2017] [Indexed: 12/13/2022] Open
Abstract
RALY is a member of the heterogeneous nuclear ribonucleoprotein family (hnRNP), a large family of RNA-binding proteins involved in many aspects of RNA metabolism. Although RALY interactome has been recently characterized, a comprehensive global analysis of RALY-associated RNAs is lacking and the biological function of RALY remains elusive. Here, we performed RIP-seq analysis to identify RALY interacting RNAs and assessed the role of RALY in gene expression. We demonstrate that RALY binds specific coding and non-coding RNAs and associates with translating mRNAs of mammalian cells. Among the identified transcripts, we focused on ANXA1 and H1FX mRNAs, encoding for Annexin A1 and for the linker variant of the histone H1X, respectively. Both proteins are differentially expressed by proliferating cells and are considered as markers for tumorigenesis. We demonstrate that cells lacking RALY expression exhibit changes in the levels of H1FX and ANXA1 mRNAs and proteins in an opposite manner. We also provide evidence for a direct binding of RALY to the U-rich elements present within the 3΄UTR of both transcripts. Thus, our results identify RALY as a poly-U binding protein and as a regulator of H1FX and ANXA1 in mammalian cells.
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Affiliation(s)
- Annalisa Rossi
- Laboratory of Molecular and Cellular Neurobiology, Centre for Integrative Biology, University of Trento, via Sommarive 9, 38123 Trento (TN), Italy
| | - Albertomaria Moro
- Laboratory of Molecular and Cellular Neurobiology, Centre for Integrative Biology, University of Trento, via Sommarive 9, 38123 Trento (TN), Italy
| | - Toma Tebaldi
- Laboratory of Translational Genomics, CIBIO - Centre for Integrative Biology, University of Trento, Italy
| | - Nicola Cornella
- Laboratory of Molecular and Cellular Neurobiology, Centre for Integrative Biology, University of Trento, via Sommarive 9, 38123 Trento (TN), Italy
| | - Lisa Gasperini
- Laboratory of Molecular and Cellular Neurobiology, Centre for Integrative Biology, University of Trento, via Sommarive 9, 38123 Trento (TN), Italy
| | - Lorenzo Lunelli
- Laboratory of Biomolecular Sequence and Structure Analysis for Health, Fondazione Bruno Kessler, Via Sommarive 18, 38123 Povo (TN), Italy
| | - Alessandro Quattrone
- Laboratory of Translational Genomics, CIBIO - Centre for Integrative Biology, University of Trento, Italy
| | - Gabriella Viero
- Institute of Biophysics, CNR-Italian National Council for Research, via Sommarive 18, 38123 Trento (TN), Italy
| | - Paolo Macchi
- Laboratory of Molecular and Cellular Neurobiology, Centre for Integrative Biology, University of Trento, via Sommarive 9, 38123 Trento (TN), Italy
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29
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Crawford Parks TE, Ravel-Chapuis A, Bondy-Chorney E, Renaud JM, Côté J, Jasmin BJ. Muscle-specific expression of the RNA-binding protein Staufen1 induces progressive skeletal muscle atrophy via regulation of phosphatase tensin homolog. Hum Mol Genet 2017; 26:1821-1838. [PMID: 28369467 DOI: 10.1093/hmg/ddx085] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/02/2017] [Indexed: 12/14/2022] Open
Abstract
Converging lines of evidence have now highlighted the key role for post-transcriptional regulation in the neuromuscular system. In particular, several RNA-binding proteins are known to be misregulated in neuromuscular disorders including myotonic dystrophy type 1, spinal muscular atrophy and amyotrophic lateral sclerosis. In this study, we focused on the RNA-binding protein Staufen1, which assumes multiple functions in both skeletal muscle and neurons. Given our previous work that showed a marked increase in Staufen1 expression in various physiological and pathological conditions including denervated muscle, in embryonic and undifferentiated skeletal muscle, in rhabdomyosarcomas as well as in myotonic dystrophy type 1 muscle samples from both mouse models and humans, we investigated the impact of sustained Staufen1 expression in postnatal skeletal muscle. To this end, we generated a skeletal muscle-specific transgenic mouse model using the muscle creatine kinase promoter to drive tissue-specific expression of Staufen1. We report that sustained Staufen1 expression in postnatal skeletal muscle causes a myopathy characterized by significant morphological and functional deficits. These deficits are accompanied by a marked increase in the expression of several atrophy-associated genes and by the negative regulation of PI3K/AKT signaling. We also uncovered that Staufen1 mediates PTEN expression through indirect transcriptional and direct post-transcriptional events thereby providing the first evidence for Staufen1-regulated PTEN expression. Collectively, our data demonstrate that Staufen1 is a novel atrophy-associated gene, and highlight its potential as a biomarker and therapeutic target for neuromuscular disorders and conditions.
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Affiliation(s)
- Tara E Crawford Parks
- Department of Cellular and Molecular Medicine, Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Emma Bondy-Chorney
- Department of Cellular and Molecular Medicine, Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jean-Marc Renaud
- Department of Cellular and Molecular Medicine, Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jocelyn Côté
- Department of Cellular and Molecular Medicine, Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
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30
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Sharangdhar T, Sugimoto Y, Heraud-Farlow J, Fernández-Moya SM, Ehses J, Ruiz de Los Mozos I, Ule J, Kiebler MA. A retained intron in the 3'-UTR of Calm3 mRNA mediates its Staufen2- and activity-dependent localization to neuronal dendrites. EMBO Rep 2017; 18:1762-1774. [PMID: 28765142 DOI: 10.15252/embr.201744334] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/30/2017] [Accepted: 07/05/2017] [Indexed: 11/09/2022] Open
Abstract
Dendritic localization and hence local mRNA translation contributes to synaptic plasticity in neurons. Staufen2 (Stau2) is a well-known neuronal double-stranded RNA-binding protein (dsRBP) that has been implicated in dendritic mRNA localization. The specificity of Stau2 binding to its target mRNAs remains elusive. Using individual-nucleotide resolution CLIP (iCLIP), we identified significantly enriched Stau2 binding to the 3'-UTRs of 356 transcripts. In 28 (7.9%) of those, binding occurred to a retained intron in their 3'-UTR The strongest bound 3'-UTR intron was present in the longest isoform of Calmodulin 3 (Calm3L ) mRNA Calm3L 3'-UTR contains six Stau2 crosslink clusters, four of which are in this retained 3'-UTR intron. The Calm3L mRNA localized to neuronal dendrites, while lack of the 3'-UTR intron impaired its dendritic localization. Importantly, Stau2 mediates this dendritic localization via the 3'-UTR intron, without affecting its stability. Also, NMDA-mediated synaptic activity specifically promoted the dendritic mRNA localization of the Calm3L isoform, while inhibition of synaptic activity reduced it substantially. Together, our results identify the retained intron as a critical element in recruiting Stau2, which then allows for the localization of Calm3L mRNA to distal dendrites.
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Affiliation(s)
| | - Yoichiro Sugimoto
- Department of Molecular Neuroscience, University College London Institute of Neurology, London, UK.,The Francis Crick Institute, London, UK
| | | | | | - Janina Ehses
- Division of Cell Biology, Biomedical Center, LMU Munich, Martinsried, Germany
| | - Igor Ruiz de Los Mozos
- Department of Molecular Neuroscience, University College London Institute of Neurology, London, UK.,The Francis Crick Institute, London, UK
| | - Jernej Ule
- Department of Molecular Neuroscience, University College London Institute of Neurology, London, UK.,The Francis Crick Institute, London, UK
| | - Michael A Kiebler
- Division of Cell Biology, Biomedical Center, LMU Munich, Martinsried, Germany
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31
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Beaujois R, Ottoni E, Zhang X, Gagnon C, Hassine S, Mollet S, Viranaicken W, DesGroseillers L. The M-phase specific hyperphosphorylation of Staufen2 involved the cyclin-dependent kinase CDK1. BMC Cell Biol 2017; 18:25. [PMID: 28705199 PMCID: PMC5513041 DOI: 10.1186/s12860-017-0142-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/10/2017] [Indexed: 01/21/2023] Open
Abstract
Background Staufen2 (STAU2) is an RNA-binding protein involved in the post-transcriptional regulation of gene expression. This protein was shown to be required for organ formation and cell differentiation. Although STAU2 functions have been reported in neuronal cells, its role in dividing cells remains deeply uncharacterized. Especially, its regulation during the cell cycle is completely unknown. Results In this study, we showed that STAU2 isoforms display a mitosis-specific slow migration pattern on SDS-gels in all tested transformed and untransformed cell lines. Deeper analyses in hTert-RPE1 and HeLa cells further indicated that the slow migration pattern of STAU2 isoforms is due to phosphorylation. Time course studies showed that STAU2 phosphorylation occurs before prometaphase and terminates as cells exit mitosis. Interestingly, STAU2 isoforms were phosphorylated on several amino acid residues in the C-terminal half via the cyclin-dependent kinase 1 (Cdk1), an enzyme known to play crucial roles during mitosis. Introduction of phospho-mimetic or phospho-null mutations in STAU2 did not impair its RNA-binding capacity, its stability, its interaction with protein co-factors or its sub-cellular localization, suggesting that STAU2 phosphorylation in mitosis does not regulate these functions. Similarly, STAU2 phosphorylation is not likely to be crucial for cell cycle progression since expression of phosphorylation mutants in hTert-RPE1 cells did not impair cell proliferation. Conclusions Altogether, these results indicate that STAU2 isoforms are phosphorylated during mitosis and that the phosphorylation process involves Cdk1. The meaning of this post-translational modification is still elusive. Electronic supplementary material The online version of this article (doi:10.1186/s12860-017-0142-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rémy Beaujois
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Elizabeth Ottoni
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Xin Zhang
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Christina Gagnon
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Sami Hassine
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Stéphanie Mollet
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Wildriss Viranaicken
- Present address: UMR PIMIT, Processus Infectieux en Milieu Insulaire Tropical, Université de la Réunion, 97490 Sainte Clotilde, La Réunion, France
| | - Luc DesGroseillers
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit, Montréal, QC, H3T 1J4, Canada.
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32
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Mitsumori K, Takei Y, Hirokawa N. Components of RNA granules affect their localization and dynamics in neuronal dendrites. Mol Biol Cell 2017; 28:1412-1417. [PMID: 28404748 PMCID: PMC5449141 DOI: 10.1091/mbc.e16-07-0497] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 03/31/2017] [Accepted: 04/05/2017] [Indexed: 11/24/2022] Open
Abstract
In neurons, mRNAs are transported along dendrites as large RNA granules. Localization of these granules was found to be developmentally regulated, and Staufen1, a major component of RNA transport granules, was critical for activity-dependent synaptic localization. In neurons, RNA transport is important for local protein synthesis. mRNAs are transported along dendrites as large RNA granules. The localization and dynamics of Puralpha and Staufen1 (Stau1), major components of RNA transport granules, were investigated in cultured hippocampal neurons. Puralpha-positive granules were localized in both the shafts and spines of dendrites. In contrast, Stau1-positive granules tended to be localized mainly in dendritic shafts. More than 90% of Puralpha-positive granules were positive for Stau1 in immature dendrites, while only half were positive in mature dendrites. Stau1-negative Puralpha granules tended to be stationary with fewer anterograde and retrograde movements than Stau1-positive Puralpha granules. After metabotropic glutamate receptor 5 activation, Stau1-positive granules remained in the dendritic shafts, while Puralpha granules translocated from the shaft to the spine. The translocation of Puralpha granules was dependent on myosin Va, an actin-based molecular motor protein. Collectively our findings suggest the possibility that the loss of Stau1 in Puralpha-positive RNA granules might promote their activity-dependent translocation into dendritic spines, which could underlie the regulation of protein synthesis in synapses.
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Affiliation(s)
- Kazuhiko Mitsumori
- Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yosuke Takei
- Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan .,Department of Anatomy and Neuroscience, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Nobutaka Hirokawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan .,Center of Excellence in Genome Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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33
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Novel Roles for Staufen1 in Embryonal and Alveolar Rhabdomyosarcoma via c-myc-dependent and -independent events. Sci Rep 2017; 7:42342. [PMID: 28211476 PMCID: PMC5314364 DOI: 10.1038/srep42342] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 01/09/2017] [Indexed: 01/19/2023] Open
Abstract
Rhabdomyosarcoma is the most common soft tissue sarcoma in children and young adults. Rhabdomyosarcomas are skeletal muscle-like tumours that typically arise in muscle beds, and express key myogenic regulatory factors. However, their developmental program remains blocked in the proliferative phase with cells unable to exit the cell cycle to fuse into myotubes. Recently, we uncovered a key role for the RNA-binding protein Staufen1 during myogenic differentiation through the regulation of c-myc translation. Given the known implication of c-myc in rhabdomyosarcoma, we hypothesized in the current work that Staufen1 controls rhabdomyosarcoma tumorigenesis. Here, we report for the first time the novel role of Staufen1 in cancer, specifically in rhabdomyosarcoma. We demonstrate that Staufen1 is markedly upregulated in human rhabdomyosarcoma tumours and cell lines as compared to normal skeletal muscle. Moreover, we show that Staufen1 promotes the tumorigenesis of embryonal and alveolar rhabdomyosarcoma subtypes both in cell culture and in animal models. Finally, our data demonstrate that Staufen1 has differential roles in embryonal versus alveolar rhabdomyosarcoma through the control of proliferative and apoptotic pathways, respectively. Together, these results provide the first evidence for Staufen1’s direct implication in cancer biology. Accordingly, Staufen1 thus represents a novel target for the development of future therapeutic strategies for rhabdomyosarcoma.
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34
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Zhang N, Ashizawa T. RNA toxicity and foci formation in microsatellite expansion diseases. Curr Opin Genet Dev 2017; 44:17-29. [PMID: 28208060 DOI: 10.1016/j.gde.2017.01.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 01/04/2017] [Accepted: 01/18/2017] [Indexed: 12/11/2022]
Abstract
More than 30 incurable neurological and neuromuscular diseases are caused by simple microsatellite expansions consisted of 3-6 nucleotides. These repeats can occur in non-coding regions and often result in a dominantly inherited disease phenotype that is characteristic of a toxic RNA gain-of-function. The expanded RNA adopts unusual secondary structures, sequesters various RNA binding proteins to form insoluble nuclear foci, and causes cellular defects at a multisystem level. Nuclear foci are dynamic in size, shape and colocalization of RNA binding proteins in different expansion diseases and tissue types. This review sets to provide new insights into the disease mechanisms of RNA toxicity and foci modulation, in light of recent advancement on bi-directional transcription, antisense RNA, repeat-associated non-ATG translation and beyond.
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Affiliation(s)
- Nan Zhang
- Neurosciences Research Program, Houston Methodist Research Institute, Houston, TX 77030, United States; Division of Cell and Molecular Biology, South Kensington Campus, Imperial College London, London SW7 2AZ, UK
| | - Tetsuo Ashizawa
- Neurosciences Research Program, Houston Methodist Research Institute, Houston, TX 77030, United States.
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35
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Koh HR, Kidwell MA, Doudna J, Myong S. RNA Scanning of a Molecular Machine with a Built-in Ruler. J Am Chem Soc 2016; 139:262-268. [DOI: 10.1021/jacs.6b10387] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Hye Ran Koh
- Department
of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | | | | | - Sua Myong
- Department
of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Physics
Frontier Center (Center for Physics of Living Cells), University of Illinois, Urbana, Illinois 61801, United States
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36
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Akbalik G, Langebeck-Jensen K, Tushev G, Sambandan S, Rinne J, Epstein I, Cajigas I, Vlatkovic I, Schuman EM. Visualization of newly synthesized neuronal RNA in vitro and in vivo using click-chemistry. RNA Biol 2016; 14:20-28. [PMID: 27801616 PMCID: PMC5270548 DOI: 10.1080/15476286.2016.1251541] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The neuronal transcriptome changes dynamically to adapt to stimuli from the extracellular and intracellular environment. In this study, we adapted for the first time a click chemistry technique to label the newly synthesized RNA in cultured hippocampal neurons and intact larval zebrafish brain. Ethynyl uridine (EU) was incorporated into neuronal RNA in a time- and concentration-dependent manner. Newly synthesized RNA granules observed throughout the dendrites were colocalized with mRNA and rRNA markers. In zebrafish larvae, the application of EU to the swim water resulted in uptake and labeling throughout the brain. Using a GABA receptor antagonist, PTZ (pentylenetetrazol), to elevate neuronal activity, we demonstrate that newly transcribed RNA signal increased in specific regions involved in neurogenesis.
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Affiliation(s)
- Güney Akbalik
- a Max Planck Institute for Brain Research , Frankfurt , Germany
| | | | - Georgi Tushev
- a Max Planck Institute for Brain Research , Frankfurt , Germany
| | | | - Jennifer Rinne
- b Institute for Organic Chemistry and Chemical Biology, Goethe University , Frankfurt , Germany
| | - Irina Epstein
- a Max Planck Institute for Brain Research , Frankfurt , Germany
| | - Iván Cajigas
- a Max Planck Institute for Brain Research , Frankfurt , Germany
| | - Irena Vlatkovic
- a Max Planck Institute for Brain Research , Frankfurt , Germany
| | - Erin M Schuman
- a Max Planck Institute for Brain Research , Frankfurt , Germany
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Hypoxia and ER stress promote Staufen1 expression through an alternative translation mechanism. Biochem Biophys Res Commun 2016; 479:365-371. [PMID: 27644878 DOI: 10.1016/j.bbrc.2016.09.082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 09/16/2016] [Indexed: 11/22/2022]
Abstract
Under physiological stress conditions the cell protects itself through a global blockade on cap-dependent translation of mRNA. This allows cap-independent mechanisms such as internal ribosome entry site (IRES)-mediated translation to take over and initiate the translation of a specific pool of mRNAs that encode proteins involved in protecting the cell from stress. Staufen 1 (Stau1) is an RNA-binding protein that has been previously implicated in the regulation of stress granule formation and therefore could play a key role in protecting the cell against stress stimuli such as oxidative and endoplasmic reticulum (ER) stress. We hypothesized that Stau1 mRNA could, like many stress response genes, contain an IRES in its 5'UTR. Here we describe that a bona fide IRES element is present in the 5'UTR of Stau1 mRNA, which is activated under hypoxic and ER stress conditions. Further, we show that the activity of PERK kinase, a major effector of the ER stress response, is required for Stau1 IRES-mediated translation during ER stress. These results suggest that Stau1 is a stress response gene that remains efficiently translated during hypoxia and ER stress despite the substantial global inhibition of cap-dependent protein translation, promoting cell recovery following stress.
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Baj G, Pinhero V, Vaghi V, Tongiorgi E. Signaling pathways controlling activity-dependent local translation of BDNF and their localization in dendritic arbors. J Cell Sci 2016; 129:2852-64. [PMID: 27270670 DOI: 10.1242/jcs.177626] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 05/31/2016] [Indexed: 12/26/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is encoded by multiple mRNA variants whose differential subcellular distribution constitutes a 'spatial code' for local translation of BDNF and selective morphological remodeling of dendrites. Here, we investigated where BDNF translation takes place and what are the signaling pathways involved. Cultured hippocampal neurons treated with KCl showed increased BDNF in the soma, proximal and distal dendrites, even in quaternary branches. This activity-dependent increase of BDNF was abolished by cycloheximide, suggesting local translation, and required activation of glutamate and Trk receptors. Our data showed that BDNF translation was regulated by multiple signaling cascades including RAS-Erk and mTOR pathways, and CaMKII-CPEB1, Aurora-A-CPEB1 and Src-ZBP1 pathways. Aurora-A, CPEB1, ZBP1 (also known as IGF2BP1), eiF4E, S6 (also known as rpS6) were present throughout the dendritic arbor. Neuronal activity increased the levels of Aurora-A, CPEB1 and ZBP1 in distal dendrites whereas those of eiF4E and S6 were unaffected. BDNF-6, the main dendritic BDNF transcript, was translated in the same subcellular domains and in response to the same pathways as total BDNF. In conclusion, we identified the signaling cascades controlling BDNF translation and we describe how the translational machinery localization is modulated in response to electrical activity.
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Affiliation(s)
- Gabriele Baj
- Department of Life Sciences, B.R.A.I.N. Centre for Neuroscience, University of Trieste, Trieste 34127, Italy
| | - Vera Pinhero
- Department of Life Sciences, B.R.A.I.N. Centre for Neuroscience, University of Trieste, Trieste 34127, Italy
| | - Valentina Vaghi
- Department of Life Sciences, B.R.A.I.N. Centre for Neuroscience, University of Trieste, Trieste 34127, Italy
| | - Enrico Tongiorgi
- Department of Life Sciences, B.R.A.I.N. Centre for Neuroscience, University of Trieste, Trieste 34127, Italy
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Raab-Graham KF, Workman ER, Namjoshi S, Niere F. Pushing the threshold: How NMDAR antagonists induce homeostasis through protein synthesis to remedy depression. Brain Res 2016; 1647:94-104. [PMID: 27125595 DOI: 10.1016/j.brainres.2016.04.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 04/04/2016] [Accepted: 04/07/2016] [Indexed: 12/17/2022]
Abstract
Healthy neurons have an optimal operating range, coded globally by the frequency of action potentials or locally by calcium. The maintenance of this range is governed by homeostatic plasticity. Here, we discuss how new approaches to treat depression alter synaptic activity. These approaches induce the neuron to recruit homeostatic mechanisms to relieve depression. Homeostasis generally implies that the direction of activity necessary to restore the neuron's critical operating range is opposite in direction to its current activity pattern. Unconventional antidepressant therapies-deep brain stimulation and NMDAR antagonists-alter the neuron's "depressed" state by pushing the neuron's current activity in the same direction but to the extreme edge. These therapies rally the intrinsic drive of neurons in the opposite direction, thereby allowing the cell to return to baseline activity, form new synapses, and restore proper communication. In this review, we discuss seminal studies on protein synthesis dependent homeostatic plasticity and their contribution to our understanding of molecular mechanisms underlying the effectiveness of NMDAR antagonists as rapid antidepressants. Rapid antidepressant efficacy is likely to require a cascade of mRNA translational regulation. Emerging evidence suggests that changes in synaptic strength or intrinsic excitability converge on the same protein synthesis pathways, relieving depressive symptoms. Thus, we address the question: Are there multiple homeostatic mechanisms that induce the neuron and neuronal circuits to self-correct to regulate mood in vivo? Targeting alternative ways to induce homeostatic protein synthesis may provide, faster, safer, and longer lasting antidepressants. This article is part of a Special Issue entitled SI:RNA Metabolism in Disease.
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Affiliation(s)
- Kimberly F Raab-Graham
- Center for Learning and Memory, Department of Neuroscience, Institute of Neuroscience, University of Texas at Austin, Austin, TX 78712, United States; Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX 78712, United States; Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX 78712, United States.
| | - Emily R Workman
- Center for Learning and Memory, Department of Neuroscience, Institute of Neuroscience, University of Texas at Austin, Austin, TX 78712, United States; Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX 78712, United States
| | - Sanjeev Namjoshi
- Center for Learning and Memory, Department of Neuroscience, Institute of Neuroscience, University of Texas at Austin, Austin, TX 78712, United States; Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX 78712, United States
| | - Farr Niere
- Center for Learning and Memory, Department of Neuroscience, Institute of Neuroscience, University of Texas at Austin, Austin, TX 78712, United States; Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX 78712, United States
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Zhang X, Trépanier V, Beaujois R, Viranaicken W, Drobetsky E, DesGroseillers L. The downregulation of the RNA-binding protein Staufen2 in response to DNA damage promotes apoptosis. Nucleic Acids Res 2016; 44:3695-712. [PMID: 26843428 PMCID: PMC4856980 DOI: 10.1093/nar/gkw057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/21/2016] [Indexed: 12/14/2022] Open
Abstract
Staufen2 (Stau2) is an RNA-binding protein involved in cell fate decision by controlling several facets of mRNA processing including localization, splicing, translation and stability. Herein we report that exposure to DNA-damaging agents that generate replicative stress such as camptothecin (CPT), 5-fluoro-uracil (5FU) and ultraviolet radiation (UVC) causes downregulation of Stau2 in HCT116 colorectal cancer cells. In contrast, other agents such as doxorubicin and ionizing radiation had no effect on Stau2 expression. Consistently, Stau2 expression is regulated by the ataxia telangiectasia and Rad3-related (ATR) signaling pathway but not by the DNA-PK or ataxia telangiectasia mutated/checkpoint kinase 2 pathways. Stau2 downregulation is initiated at the level of transcription, independently of apoptosis induction. Promoter analysis identified a short 198 bp region which is necessary and sufficient for both basal and CPT-regulated Stau2 expression. The E2F1 transcription factor regulates Stau2 in untreated cells, an effect that is abolished by CPT treatment due to E2F1 displacement from the promoter. Strikingly, Stau2 downregulation enhances levels of DNA damage and promotes apoptosis in CPT-treated cells. Taken together our results suggest that Stau2 is an anti-apoptotic protein that could be involved in DNA replication and/or maintenance of genome integrity and that its expression is regulated by E2F1 via the ATR signaling pathway.
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Affiliation(s)
- Xin Zhang
- Département de Biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit Montréal, QC H3T 1J4, Canada
| | - Véronique Trépanier
- Département de Biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit Montréal, QC H3T 1J4, Canada
| | - Remy Beaujois
- Département de Biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit Montréal, QC H3T 1J4, Canada
| | - Wildriss Viranaicken
- Département de Biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit Montréal, QC H3T 1J4, Canada
| | - Elliot Drobetsky
- Département de Médecine, Université de Montréal and Centre de Recherche, Hôpital Maisonneuve Rosemont, Montréal, Québec, H1T 2M4, Canada
| | - Luc DesGroseillers
- Département de Biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Edouard Montpetit Montréal, QC H3T 1J4, Canada
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41
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Abstract
The localization of mRNAs to specific subcellular sites is widespread, allowing cells to spatially restrict and regulate protein production, and playing important roles in development and cellular physiology. This process has been studied in mechanistic detail for several RNAs. However, the generality or specificity of RNA localization systems and mechanisms that impact the many thousands of localized mRNAs has been difficult to assess. In this review, we discuss the current state of the field in determining which RNAs localize, which RNA sequences mediate localization, the protein factors involved, and the biological implications of localization. For each question, we examine prominent systems and techniques that are used to study individual messages, highlight recent genome-wide studies of RNA localization, and discuss the potential for adapting other high-throughput approaches to the study of localization.
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Affiliation(s)
- J Matthew Taliaferro
- a Department of Biology; Massachusetts Institute of Technology ; Cambridge , MA USA
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42
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Maglogiannis I, Georgakopoulos S, Tasoulis S, Plagianakos V. A software tool for the automatic detection and quantification of fibrotic tissues in microscopy images. Inf Sci (N Y) 2015. [DOI: 10.1016/j.ins.2014.10.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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43
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Abstract
RNAs adopt diverse folded structures that are essential for function and thus play critical roles in cellular biology. A striking example of this is the ribosome, a complex, three-dimensionally folded macromolecular machine that orchestrates protein synthesis. Advances in RNA biochemistry, structural and molecular biology, and bioinformatics have revealed other non-coding RNAs whose functions are dictated by their structure. It is not surprising that aberrantly folded RNA structures contribute to disease. In this Review, we provide a brief introduction into RNA structural biology and then describe how RNA structures function in cells and cause or contribute to neurological disease. Finally, we highlight successful applications of rational design principles to provide chemical probes and lead compounds targeting structured RNAs. Based on several examples of well-characterized RNA-driven neurological disorders, we demonstrate how designed small molecules can facilitate the study of RNA dysfunction, elucidating previously unknown roles for RNA in disease, and provide lead therapeutics.
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Affiliation(s)
- Viachaslau Bernat
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Matthew D Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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44
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Antonacci S, Forand D, Wolf M, Tyus C, Barney J, Kellogg L, Simon MA, Kerr G, Wells KL, Younes S, Mortimer NT, Olesnicky EC, Killian DJ. Conserved RNA-binding proteins required for dendrite morphogenesis in Caenorhabditis elegans sensory neurons. G3 (BETHESDA, MD.) 2015; 5:639-53. [PMID: 25673135 PMCID: PMC4390579 DOI: 10.1534/g3.115.017327] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/09/2015] [Indexed: 01/22/2023]
Abstract
The regulation of dendritic branching is critical for sensory reception, cell-cell communication within the nervous system, learning, memory, and behavior. Defects in dendrite morphology are associated with several neurologic disorders; thus, an understanding of the molecular mechanisms that govern dendrite morphogenesis is important. Recent investigations of dendrite morphogenesis have highlighted the importance of gene regulation at the posttranscriptional level. Because RNA-binding proteins mediate many posttranscriptional mechanisms, we decided to investigate the extent to which conserved RNA-binding proteins contribute to dendrite morphogenesis across phyla. Here we identify a core set of RNA-binding proteins that are important for dendrite morphogenesis in the PVD multidendritic sensory neuron in Caenorhabditis elegans. Homologs of each of these genes were previously identified as important in the Drosophila melanogaster dendritic arborization sensory neurons. Our results suggest that RNA processing, mRNA localization, mRNA stability, and translational control are all important mechanisms that contribute to dendrite morphogenesis, and we present a conserved set of RNA-binding proteins that regulate these processes in diverse animal species. Furthermore, homologs of these genes are expressed in the human brain, suggesting that these RNA-binding proteins are candidate regulators of dendrite development in humans.
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Affiliation(s)
- Simona Antonacci
- Department of Molecular Biology, Colorado College, Colorado Springs, Colorado 80903
| | - Daniel Forand
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado 80918
| | - Margaret Wolf
- Department of Molecular Biology, Colorado College, Colorado Springs, Colorado 80903
| | - Courtney Tyus
- Department of Molecular Biology, Colorado College, Colorado Springs, Colorado 80903
| | - Julia Barney
- Department of Molecular Biology, Colorado College, Colorado Springs, Colorado 80903
| | - Leah Kellogg
- Department of Molecular Biology, Colorado College, Colorado Springs, Colorado 80903
| | - Margo A Simon
- Department of Molecular Biology, Colorado College, Colorado Springs, Colorado 80903
| | - Genevieve Kerr
- Department of Molecular Biology, Colorado College, Colorado Springs, Colorado 80903
| | - Kristen L Wells
- Department of Molecular Biology, Colorado College, Colorado Springs, Colorado 80903
| | - Serena Younes
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado 80918
| | - Nathan T Mortimer
- Department of Biological Sciences, University of Denver, Denver, Colorado 80208
| | - Eugenia C Olesnicky
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado 80918
| | - Darrell J Killian
- Department of Molecular Biology, Colorado College, Colorado Springs, Colorado 80903
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45
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Kim S, Martin KC. Neuron-wide RNA transport combines with netrin-mediated local translation to spatially regulate the synaptic proteome. eLife 2015; 4. [PMID: 25569157 PMCID: PMC4337609 DOI: 10.7554/elife.04158] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 01/08/2015] [Indexed: 11/13/2022] Open
Abstract
The persistence of experience-dependent changes in brain connectivity requires RNA localization and protein synthesis. Previous studies have demonstrated a role for local translation in altering the structure and function of synapses during synapse formation and experience-dependent synaptic plasticity. In this study, we ask whether in addition to promoting local translation, local stimulation also triggers directed trafficking of RNAs from nucleus to stimulated synapses. Imaging of RNA localization and translation in cultured Aplysia sensory-motor neurons revealed that RNAs were delivered throughout the arbor of the sensory neuron, but that translation was enriched only at sites of synaptic contact and/or synaptic stimulation. Investigation of the mechanisms that trigger local translation revealed a role for calcium-dependent retrograde netrin-1/DCC receptor signaling. Spatially restricting gene expression by regulating local translation rather than by directing the delivery of mRNAs from nucleus to stimulated synapses maximizes the readiness of the entire neuronal arbor to respond to local cues.
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Affiliation(s)
- Sangmok Kim
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, United States
| | - Kelsey C Martin
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, United States
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46
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Leal G, Afonso PM, Duarte CB. Neuronal activity induces synaptic delivery of hnRNP A2/B1 by a BDNF-dependent mechanism in cultured hippocampal neurons. PLoS One 2014; 9:e108175. [PMID: 25286195 PMCID: PMC4186808 DOI: 10.1371/journal.pone.0108175] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 08/26/2014] [Indexed: 12/18/2022] Open
Abstract
Dendritic protein synthesis plays a critical role in several forms of synaptic plasticity, including BDNF (brain-derived neurotrophic factor)-mediated long-term synaptic potentiation (LTP). Dendritic transcripts are typically transported in a repressed state as components of large ribonucleoprotein complexes, and then translated upon stimulation at, or in the vicinity, of activated synapses. Heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1) is a trans-acting factor involved in dendritic mRNA trafficking, but how the distribution of the protein in dendrites is regulated has not been characterized. Here we found that a fraction of hnRNP A2/B1 is present at the synapse under resting conditions in cultured hippocampal neurons. Accordingly, this ribonucleoprotein was detected in free mRNP, monosomal, and polyribosomal fractions obtained from synaptoneurosomes. Neuronal activity and BDNF treatment increased hnRNP A2/B1 protein levels in the cell body and dendritic compartments, and induced the delivery of this protein to synaptic sites. The activity-dependent accumulation of hnRNP A2/B1 at the synapse required, at least in part, the activation of TrkB receptors, presumably by BDNF. This neurotrophin also upregulated the hnRNP A2/B1 mRNA in the soma but was without effect on the abundance of neuritic hnRNP A2/B1 transcripts. These results show that the distribution of hnRNP A2/B1 is regulated by BDNF and by neuronal activity, an effect that may have a role in BDNF-induced synaptic plasticity events.
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Affiliation(s)
- Graciano Leal
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Pedro M. Afonso
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Carlos B. Duarte
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Department of Life Sciences, University of Coimbra, Coimbra, Portugal
- * E-mail:
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47
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Gardiol A, St Johnston D. Staufen targets coracle mRNA to Drosophila neuromuscular junctions and regulates GluRIIA synaptic accumulation and bouton number. Dev Biol 2014; 392:153-67. [PMID: 24951879 PMCID: PMC4111903 DOI: 10.1016/j.ydbio.2014.06.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 06/08/2014] [Accepted: 06/09/2014] [Indexed: 11/28/2022]
Abstract
The post-synaptic translation of localised mRNAs has been postulated to underlie several forms of plasticity at vertebrate synapses, but the mechanisms that target mRNAs to these postsynaptic sites are not well understood. Here we show that the evolutionary conserved dsRNA binding protein, Staufen, localises to the postsynaptic side of the Drosophila neuromuscular junction (NMJ), where it is required for the localisation of coracle mRNA and protein. Staufen plays a well-characterised role in the localisation of oskar mRNA to the oocyte posterior, where Staufen dsRNA-binding domain 5 is specifically required for its translation. Removal of Staufen dsRNA-binding domain 5, disrupts the postsynaptic accumulation of Coracle protein without affecting the localisation of cora mRNA, suggesting that Staufen similarly regulates Coracle translation. Tropomyosin II, which functions with Staufen in oskar mRNA localisation, is also required for coracle mRNA localisation, suggesting that similar mechanisms target mRNAs to the NMJ and the oocyte posterior. Coracle, the orthologue of vertebrate band 4.1, functions in the anchoring of the glutamate receptor IIA subunit (GluRIIA) at the synapse. Consistent with this, staufen mutant larvae show reduced accumulation of GluRIIA at synapses. The NMJs of staufen mutant larvae have also a reduced number of synaptic boutons. Altogether, this suggests that this novel Staufen-dependent mRNA localisation and local translation pathway may play a role in the developmentally regulated growth of the NMJ.
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Affiliation(s)
- Alejandra Gardiol
- The WellcomeCRUK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
| | - Daniel St Johnston
- The WellcomeCRUK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom.
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48
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Heraud-Farlow JE, Kiebler MA. The multifunctional Staufen proteins: conserved roles from neurogenesis to synaptic plasticity. Trends Neurosci 2014; 37:470-9. [PMID: 25012293 PMCID: PMC4156307 DOI: 10.1016/j.tins.2014.05.009] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 05/22/2014] [Accepted: 05/27/2014] [Indexed: 12/11/2022]
Abstract
Staufen (Stau) proteins have evolutionarily conserved functions in the brain. Stau proteins asymmetrically segregate mRNAs during mouse and fly neurogenesis. Stau proteins regulate synaptic plasticity and memory formation in flies and mammals. Stau proteins have roles in translation, localisation, and ribonucleoprotein formation. New data indicate that mammalian Stau1 and Stau2 can both stabilise and destabilise target mRNAs.
Staufen (Stau) proteins belong to a family of RNA-binding proteins (RBPs) that are important for RNA localisation in many organisms. In this review we discuss recent findings on the conserved role played by Stau during both the early differentiation of neurons and in the synaptic plasticity of mature neurons. Recent molecular data suggest mechanisms for how Stau2 regulates mRNA localisation, mRNA stability, translation, and ribonucleoprotein (RNP) assembly. We offer a perspective on how this multifunctional RBP has been adopted to regulate mRNA localisation under several different cellular and developmental conditions.
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Affiliation(s)
- Jacki E Heraud-Farlow
- Department of Chromosome Biology, Max F. Perutz Laboratories, University of Vienna, 1030 Vienna, Austria
| | - Michael A Kiebler
- Department of Anatomy and Cell Biology, Ludwig-Maximilians-University, 80336 Munich, Germany.
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49
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Shelkovnikova TA, Robinson HK, Southcombe JA, Ninkina N, Buchman VL. Multistep process of FUS aggregation in the cell cytoplasm involves RNA-dependent and RNA-independent mechanisms. Hum Mol Genet 2014; 23:5211-26. [PMID: 24842888 PMCID: PMC4159159 DOI: 10.1093/hmg/ddu243] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Fused in sarcoma (FUS) is an RNA-binding protein involved in pathogenesis of several neurodegenerative diseases. Aggregation of mislocalized FUS into non-amyloid inclusions is believed to be pivotal in the development of cell dysfunction, but the mechanism of their formation is unclear. Using transient expression of a panel of deletion and chimeric FUS variants in various cultured cells, we demonstrated that FUS accumulating in the cytoplasm nucleates a novel type of RNA granules, FUS granules (FGs), that are structurally similar but not identical to physiological RNA transport granules. Formation of FGs requires FUS N-terminal prion-like domain and the ability to bind specific RNAs. Clustering of FGs coupled with further recruitment of RNA and proteins produce larger structures, FUS aggregates (FAs), that resemble but are clearly distinct from stress granules. In conditions of attenuated transcription, FAs lose RNA and dissociate into RNA-free FUS complexes that become precursors of large aggresome-like structures. We propose a model of multistep FUS aggregation involving RNA-dependent and RNA-independent stages. This model can be extrapolated to formation of pathological inclusions in human FUSopathies.
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Affiliation(s)
- Tatyana A Shelkovnikova
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, UK, Institute of Physiologically Active Compounds Russian Academy of Sciences, 1 Severniy proezd, Chernogolovka 142432, Moscow Region, Russian Federation and
| | - Hannah K Robinson
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, UK
| | - Joshua A Southcombe
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, UK
| | - Natalia Ninkina
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, UK, Institute of General Pathology and Pathophysiology of Russian Academy of Medical Science, 8 Baltijskaya str, Moscow 125315, Russian Federation
| | - Vladimir L Buchman
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, UK,
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50
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Lenzken SC, Achsel T, Carrì MT, Barabino SML. Neuronal RNA-binding proteins in health and disease. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:565-76. [PMID: 24687864 DOI: 10.1002/wrna.1231] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/25/2014] [Accepted: 02/26/2014] [Indexed: 12/12/2022]
Abstract
In mammalian cells in general and in neurons in particular, mRNA maturation, translation, and degradation are highly complex and dynamic processes. RNA-binding proteins (RBPs) play crucial roles in all these events. First, they participate in the choice of pre-mRNA splice sites and in the selection of the polyadenylation sites, determining which of the possible isoforms is produced from a given precursor mRNA. Then, once in the cytoplasm, the protein composition of the RNP particles determines whether the mature mRNA is transported along the dendrites or the axon of a neuron to the synapses, how efficiently it is translated, and how stable it is. In agreement with their importance for neuronal function, mutations in genes that code for RBPs are associated with various neurological diseases. In this review, we illustrate how individual RBPs determine the fate of an mRNA, and we discuss how mutations in RBPs or perturbations of the mRNA metabolism can cause neurodegenerative disorders.
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