1
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Zhao R, Huang S, Li J, Gu A, Fu M, Hua W, Mao Y, Lei QY, Lu B, Wen W. Excessive STAU1 condensate drives mTOR translation and autophagy dysfunction in neurodegeneration. J Cell Biol 2024; 223:e202311127. [PMID: 38913026 PMCID: PMC11194678 DOI: 10.1083/jcb.202311127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/20/2024] [Accepted: 05/03/2024] [Indexed: 06/25/2024] Open
Abstract
The double-stranded RNA-binding protein Staufen1 (STAU1) regulates a variety of physiological and pathological events via mediating RNA metabolism. STAU1 overabundance was observed in tissues from mouse models and fibroblasts from patients with neurodegenerative diseases, accompanied by enhanced mTOR signaling and impaired autophagic flux, while the underlying mechanism remains elusive. Here, we find that endogenous STAU1 forms dynamic cytoplasmic condensate in normal and tumor cell lines, as well as in mouse Huntington's disease knockin striatal cells. STAU1 condensate recruits target mRNA MTOR at its 5'UTR and promotes its translation both in vitro and in vivo, and thus enhanced formation of STAU1 condensate leads to mTOR hyperactivation and autophagy-lysosome dysfunction. Interference of STAU1 condensate normalizes mTOR levels, ameliorates autophagy-lysosome function, and reduces aggregation of pathological proteins in cellular models of neurodegenerative diseases. These findings highlight the importance of balanced phase separation in physiological processes, suggesting that modulating STAU1 condensate may be a strategy to mitigate the progression of neurodegenerative diseases with STAU1 overabundance.
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Affiliation(s)
- Ruiqian Zhao
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Shijing Huang
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Jingyu Li
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Aihong Gu
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Minjie Fu
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Wei Hua
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Ying Mao
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Qun-Ying Lei
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Boxun Lu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, New Cornerstone Science Laboratory, School of Life Sciences, Fudan University, Shanghai, China
| | - Wenyu Wen
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
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2
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Tarannum R, Mun G, Quddos F, Swanger SA, Steward O, Farris S. Dendritically localized RNAs are packaged as diversely composed Ribonucleoprotein particles with heterogeneous copy number states. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.13.603387. [PMID: 39071419 PMCID: PMC11275876 DOI: 10.1101/2024.07.13.603387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Localization of mRNAs to dendrites is a fundamental mechanism by which neurons achieve spatiotemporal control of gene expression. Translationally repressed neuronal mRNA transport granules, also referred to as ribonuclear proteins (RNPs), have been shown to be trafficked as single or low copy number RNPs and as larger complexes with multiple copies and/or species of mRNAs. However, there is little evidence of either population in intact neuronal circuits. Using single molecule fluorescence in situ hybridization studies in the dendrites of adult rat and mouse hippocampus, we provide evidence that supports the existence of multi-transcript RNPs with the constituents varying in amounts for each RNA species. By competing-off fluorescently labeled probe with serial increases of unlabeled probe, we detected stepwise decreases in Arc RNP number and fluorescence intensity, suggesting Arc RNAs localize to dendrites in both low- and multiple-copy number RNPs. When probing for multiple mRNAs, we find that localized RNPs are heterogeneous in size and colocalization patterns that vary per RNA. Further, localized RNAs that are targeted by the same trans-acting element (FMRP) display greater levels of colocalization compared to an RNA not targeted by FMRP. Simultaneous visualization and assessment of colocalization using highly multiplexed imaging of a dozen mRNA species targeted by FMRP demonstrates that dendritic RNAs are mostly trafficked as heteromeric cargoes of multiple types of RNAs (at least one or more RNAs). Moreover, the composition of these RNA cargoes correlates with the abundance of the transcripts even after accounting for expression. Collectively, these results suggest that dendritic RNPs are packaged as heterogeneous co-assemblies of different mRNAs and that RNP contents may be driven, at least partially, by highly abundant dendritic RNAs; a model that favors efficiency over fine-tuned control for sustaining long-distance trafficking of thousands of messenger molecules.
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Affiliation(s)
- Renesa Tarannum
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, Virginia
- Translational Biology, Medicine & Health Graduate Program, Virginia Tech, Blacksburg, Virginia
| | - Grace Mun
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, Virginia
| | - Fatima Quddos
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, Virginia
- Translational Biology, Medicine & Health Graduate Program, Virginia Tech, Blacksburg, Virginia
| | - Sharon A. Swanger
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, Virginia
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia
| | | | - Shannon Farris
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, Virginia
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia
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3
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Proske M, Janowski R, Bacher S, Kang HS, Monecke T, Koehler T, Hutten S, Tretter J, Crois A, Molitor L, Varela-Rial A, Fino R, Donati E, De Fabritiis G, Dormann D, Sattler M, Niessing D. PURA syndrome-causing mutations impair PUR-domain integrity and affect P-body association. eLife 2024; 13:RP93561. [PMID: 38655849 PMCID: PMC11042805 DOI: 10.7554/elife.93561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
Mutations in the human PURA gene cause the neurodevelopmental PURA syndrome. In contrast to several other monogenetic disorders, almost all reported mutations in this nucleic acid-binding protein result in the full disease penetrance. In this study, we observed that patient mutations across PURA impair its previously reported co-localization with processing bodies. These mutations either destroyed the folding integrity, RNA binding, or dimerization of PURA. We also solved the crystal structures of the N- and C-terminal PUR domains of human PURA and combined them with molecular dynamics simulations and nuclear magnetic resonance measurements. The observed unusually high dynamics and structural promiscuity of PURA indicated that this protein is particularly susceptible to mutations impairing its structural integrity. It offers an explanation why even conservative mutations across PURA result in the full penetrance of symptoms in patients with PURA syndrome.
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Affiliation(s)
- Marcel Proske
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz MunichNeuherbergGermany
- Institute of Pharmaceutical Biotechnology, Ulm UniversityUlmGermany
| | - Robert Janowski
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz MunichNeuherbergGermany
| | - Sabrina Bacher
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz MunichNeuherbergGermany
| | - Hyun-Seo Kang
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz MunichNeuherbergGermany
- Chemistry Department, Biomolecular NMR and Center for Integrated Protein Science Munich, Technical University of MunichMainzGermany
| | - Thomas Monecke
- Institute of Pharmaceutical Biotechnology, Ulm UniversityUlmGermany
| | - Tony Koehler
- Institute of Pharmaceutical Biotechnology, Ulm UniversityUlmGermany
| | - Saskia Hutten
- Biocenter, Institute of Molecular Physiology, Johannes Gutenberg-Universität (JGU)MainzGermany
| | - Jana Tretter
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz MunichNeuherbergGermany
| | - Anna Crois
- Institute of Pharmaceutical Biotechnology, Ulm UniversityUlmGermany
| | - Lena Molitor
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz MunichNeuherbergGermany
| | | | | | | | | | - Dorothee Dormann
- Biocenter, Institute of Molecular Physiology, Johannes Gutenberg-Universität (JGU)MainzGermany
- Institute of Molecular Biology (IMB)MainzGermany
| | - Michael Sattler
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz MunichNeuherbergGermany
- Chemistry Department, Biomolecular NMR and Center for Integrated Protein Science Munich, Technical University of MunichMainzGermany
| | - Dierk Niessing
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz MunichNeuherbergGermany
- Institute of Pharmaceutical Biotechnology, Ulm UniversityUlmGermany
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4
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Bauer KE, de Queiroz BR, Kiebler MA, Besse F. RNA granules in neuronal plasticity and disease. Trends Neurosci 2023:S0166-2236(23)00104-2. [PMID: 37202301 DOI: 10.1016/j.tins.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/11/2023] [Accepted: 04/16/2023] [Indexed: 05/20/2023]
Abstract
RNA granules are dynamic entities controlling the spatiotemporal distribution and translation of RNA molecules. In neurons, a variety of RNA granules exist both in the soma and in cellular processes. They contain transcripts encoding signaling and synaptic proteins as well as RNA-binding proteins causally linked to several neurological disorders. In this review, we highlight that neuronal RNA granules exhibit properties of biomolecular condensates that are regulated upon maturation and physiological aging and how they are reversibly remodeled in response to neuronal activity to control local protein synthesis and ultimately synaptic plasticity. Moreover, we propose a framework of how neuronal RNA granules mature over time in healthy conditions and how they transition into pathological inclusions in the context of late-onset neurodegenerative diseases.
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Affiliation(s)
- Karl E Bauer
- Biomedical Center (BMC), Department of Anatomy and Cell Biology, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Bruna R de Queiroz
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, Nice, France
| | - Michael A Kiebler
- Biomedical Center (BMC), Department of Anatomy and Cell Biology, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany.
| | - Florence Besse
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, Nice, France.
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5
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Wijegunawardana D, Vishal SS, Venkatesh N, Gopal PP. Ataxin-2 polyglutamine expansions aberrantly sequester TDP-43, drive ribonucleoprotein condensate transport dysfunction and suppress local translation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.30.526372. [PMID: 36778347 PMCID: PMC9915502 DOI: 10.1101/2023.01.30.526372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Altered RNA metabolism is a common pathogenic mechanism linked to familial and sporadic Amyotrophic lateral sclerosis (ALS). ALS is characterized by mislocalization and aggregation of TDP-43, an RNA-binding protein (RBP) with multiple roles in post-transcriptional RNA processing. Recent studies have identified genetic interactions between TDP-43 and Ataxin-2, a polyglutamine (polyQ) RBP in which intermediate length polyQ expansions confer increased ALS risk. Here, we used live-cell confocal imaging, photobleaching and translation reporter assays to study the localization, transport dynamics and mRNA regulatory functions of TDP-43/Ataxin-2 in rodent primary cortical neurons. We show that Ataxin-2 polyQ expansions aberrantly sequester TDP-43 within ribonucleoprotein (RNP) condensates, and disrupt both its motility along the axon and liquid-like properties. Our data suggest that Ataxin-2 governs motility and translation of neuronal RNP condensates and that Ataxin-2 polyQ expansions fundamentally perturb spatial localization of mRNA and suppress local translation. Overall, these results indicate Ataxin-2 polyQ expansions have detrimental effects on stability, localization, and translation of transcripts critical for axonal and cytoskeletal integrity, particularly important for motor neurons.
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6
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Mroczek M, Iyadurai S. Neuromuscular and Neuromuscular Junction Manifestations of the PURA-NDD: A Systematic Review of the Reported Symptoms and Potential Treatment Options. Int J Mol Sci 2023; 24:ijms24032260. [PMID: 36768582 PMCID: PMC9917016 DOI: 10.3390/ijms24032260] [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: 11/30/2022] [Revised: 01/14/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023] Open
Abstract
PURA-related neurodevelopmental disorders (PURA-NDDs) are a rare genetic disease caused by pathogenic autosomal dominant variants in the PURA gene or a deletion encompassing the PURA gene. PURA-NDD is clinically characterized by neurodevelopmental delay, learning disability, neonatal hypotonia, feeding difficulties, abnormal movements, and epilepsy. It is generally considered to be central nervous system disorders, with generalized weakness, associated hypotonia, cognitive and development deficits in early development, and seizures in late stages. Although it is classified predominantly as a central nervous syndrome disorder, some phenotypic features, such as myopathic facies, respiratory insufficiency of muscle origin, and myopathic features on muscle biopsy and electrodiagnostic evaluation, point to a peripheral (neuromuscular) source of weakness. Patients with PURA-NDD have been increasingly identified in exome-sequenced cohorts of patients with neuromuscular- and congenital myasthenic syndrome-like phenotypes. Recently, fluctuating weakness noted in a PURA-NDD patient, accompanied by repetitive nerve stimulation abnormalities, suggested the disease to be a channelopathy and, more specifically, a neuromuscular junction disorder. Treatment with pyridostigmine or salbutamol led to clinical improvement of neuromuscular function in two reported cases. The goal of this systematic retrospective review is to highlight the motor symptoms of PURA-NDD, to further describe the neuromuscular phenotype, and to emphasize the role of potential treatment opportunities of the neuromuscular phenotype in the setting of the potential role of PURA protein in the neuromuscular junction and the muscles.
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Affiliation(s)
- Magdalena Mroczek
- Center for Cardiovascular Genetics & Gene Diagnostics, Foundation for People with Rare Diseases, 8952 Schlieren, Switzerland
- Correspondence: (M.M.); (S.I.)
| | - Stanley Iyadurai
- Division of Neurology, Johns Hopkins All Children’s Hospital, 501 6th Ave S, St. Petersburg, FL 33701, USA
- Correspondence: (M.M.); (S.I.)
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7
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Molitor L, Klostermann M, Bacher S, Merl-Pham J, Spranger N, Burczyk S, Ketteler C, Rusha E, Tews D, Pertek A, Proske M, Busch A, Reschke S, Feederle R, Hauck S, Blum H, Drukker M, Fischer-Posovszky P, König J, Zarnack K, Niessing D. Depletion of the RNA-binding protein PURA triggers changes in posttranscriptional gene regulation and loss of P-bodies. Nucleic Acids Res 2023; 51:1297-1316. [PMID: 36651277 PMCID: PMC9943675 DOI: 10.1093/nar/gkac1237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 01/19/2023] Open
Abstract
The RNA-binding protein PURA has been implicated in the rare, monogenetic, neurodevelopmental disorder PURA Syndrome. PURA binds both DNA and RNA and has been associated with various cellular functions. Only little is known about its main cellular roles and the molecular pathways affected upon PURA depletion. Here, we show that PURA is predominantly located in the cytoplasm, where it binds to thousands of mRNAs. Many of these transcripts change abundance in response to PURA depletion. The encoded proteins suggest a role for PURA in immune responses, mitochondrial function, autophagy and processing (P)-body activity. Intriguingly, reduced PURA levels decrease the expression of the integral P-body components LSM14A and DDX6 and strongly affect P-body formation in human cells. Furthermore, PURA knockdown results in stabilization of P-body-enriched transcripts, whereas other mRNAs are not affected. Hence, reduced PURA levels, as reported in patients with PURA Syndrome, influence the formation and composition of this phase-separated RNA processing machinery. Our study proposes PURA Syndrome as a new model to study the tight connection between P-body-associated RNA regulation and neurodevelopmental disorders.
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Affiliation(s)
| | | | - Sabrina Bacher
- Institute of Structural Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Juliane Merl-Pham
- Metabolomics and Proteomics Core, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Nadine Spranger
- Institute of Structural Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Sandra Burczyk
- Institute of Pharmaceutical Biotechnology, Ulm University, 89081 Ulm, Germany
| | - Carolin Ketteler
- Institute of Structural Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Ejona Rusha
- Induced Pluripotent Stem Cell Core Facility, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Daniel Tews
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89070 Ulm, Germany
| | - Anna Pertek
- Induced Pluripotent Stem Cell Core Facility, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Marcel Proske
- Institute of Structural Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany,Institute of Pharmaceutical Biotechnology, Ulm University, 89081 Ulm, Germany
| | - Anke Busch
- Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Sarah Reschke
- Laboratory for Functional Genome Analysis, Gene Center, Ludwig-Maximilians University Munich, 81377 Munich, Germany
| | - Regina Feederle
- Monoclonal Antibody Core Facility, Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Stefanie M Hauck
- Metabolomics and Proteomics Core, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Helmut Blum
- Laboratory for Functional Genome Analysis, Gene Center, Ludwig-Maximilians University Munich, 81377 Munich, Germany
| | - Micha Drukker
- Institute of Stem Cell Research, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany,Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research (LACDR), Leiden University, 2333 CC Leiden, The Netherlands
| | - Pamela Fischer-Posovszky
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89070 Ulm, Germany
| | - Julian König
- Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Kathi Zarnack
- Correspondence may also be addressed to Kathi Zarnack. Tel: +49 69 798 42506; Fax: +49 69 798 763 42506;
| | - Dierk Niessing
- To whom correspondence should be addressed. Tel: +49 731 50 23160; Fax: +49 731 50 23169;
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8
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Forming cytoplasmic stress granules PURα suppresses mRNA translation initiation of IGFBP3 to promote esophageal squamous cell carcinoma progression. Oncogene 2022; 41:4336-4348. [PMID: 35945453 PMCID: PMC9481463 DOI: 10.1038/s41388-022-02426-3] [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: 04/02/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 01/29/2023]
Abstract
Esophageal squamous cell carcinoma (ESCC) is one of the most fatal malignancies worldwide. Recently, our group identified purine-rich element binding protein alpha (PURα), a single-stranded DNA/RNA-binding protein, to be significantly associated with the progression of ESCC. Additional immunofluorescence staining demonstrated that PURα forms cytoplasmic stress granules to suppress mRNA translation initiation. The expression level of cytoplasmic PURα in ESCC tumor tissues was significantly higher than that in adjacent epithelia and correlated with a worse patient survival rate by immunohistochemistry. Functionally, PURα strongly preferred to bind to UG-/U-rich motifs and mRNA 3´UTR by CLIP-seq analysis. Moreover, PURα knockout significantly increased the protein level of insulin-like growth factor binding protein 3 (IGFBP3). In addition, it was further demonstrated that PURα-interacting proteins are remarkably associated with translation initiation factors and ribosome-related proteins and that PURα regulates protein expression by interacting with translation initiation factors, such as PABPC1, eIF3B and eIF3F, in an RNA-independent manner, while the interaction with ribosome-related proteins is significantly dependent on RNA. Specifically, PURα was shown to interact with the mRNA 3´UTR of IGFBP3 and inhibit its expression by suppressing mRNA translation initiation. Together, this study identifies cytoplasmic PURα as a modulator of IGFBP3, which could be a promising therapeutic target for ESCC treatment.
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9
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Rajgor D, Welle TM, Smith KR. The Coordination of Local Translation, Membranous Organelle Trafficking, and Synaptic Plasticity in Neurons. Front Cell Dev Biol 2021; 9:711446. [PMID: 34336865 PMCID: PMC8317219 DOI: 10.3389/fcell.2021.711446] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 06/14/2021] [Indexed: 12/16/2022] Open
Abstract
Neurons are highly complex polarized cells, displaying an extraordinary degree of spatial compartmentalization. At presynaptic and postsynaptic sites, far from the cell body, local protein synthesis is utilized to continually modify the synaptic proteome, enabling rapid changes in protein production to support synaptic function. Synapses undergo diverse forms of plasticity, resulting in long-term, persistent changes in synapse strength, which are paramount for learning, memory, and cognition. It is now well-established that local translation of numerous synaptic proteins is essential for many forms of synaptic plasticity, and much work has gone into deciphering the strategies that neurons use to regulate activity-dependent protein synthesis. Recent studies have pointed to a coordination of the local mRNA translation required for synaptic plasticity and the trafficking of membranous organelles in neurons. This includes the co-trafficking of RNAs to their site of action using endosome/lysosome “transports,” the regulation of activity-dependent translation at synapses, and the role of mitochondria in fueling synaptic translation. Here, we review our current understanding of these mechanisms that impact local translation during synaptic plasticity, providing an overview of these novel and nuanced regulatory processes involving membranous organelles in neurons.
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Affiliation(s)
- Dipen Rajgor
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Theresa M Welle
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Katharine R Smith
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
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10
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Das S, Vera M, Gandin V, Singer RH, Tutucci E. Intracellular mRNA transport and localized translation. Nat Rev Mol Cell Biol 2021; 22:483-504. [PMID: 33837370 PMCID: PMC9346928 DOI: 10.1038/s41580-021-00356-8] [Citation(s) in RCA: 141] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2021] [Indexed: 02/08/2023]
Abstract
Fine-tuning cellular physiology in response to intracellular and environmental cues requires precise temporal and spatial control of gene expression. High-resolution imaging technologies to detect mRNAs and their translation state have revealed that all living organisms localize mRNAs in subcellular compartments and create translation hotspots, enabling cells to tune gene expression locally. Therefore, mRNA localization is a conserved and integral part of gene expression regulation from prokaryotic to eukaryotic cells. In this Review, we discuss the mechanisms of mRNA transport and local mRNA translation across the kingdoms of life and at organellar, subcellular and multicellular resolution. We also discuss the properties of messenger ribonucleoprotein and higher order RNA granules and how they may influence mRNA transport and local protein synthesis. Finally, we summarize the technological developments that allow us to study mRNA localization and local translation through the simultaneous detection of mRNAs and proteins in single cells, mRNA and nascent protein single-molecule imaging, and bulk RNA and protein detection methods.
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Affiliation(s)
- Sulagna Das
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, New York, NY, USA.,Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, New York, NY, USA
| | - Maria Vera
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | | | - Robert H. Singer
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, New York, NY, USA.,Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, New York, NY, USA.,Janelia Research Campus of the HHMI, Ashburn, VA, USA.,;
| | - Evelina Tutucci
- Systems Biology Lab, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,;
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11
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Molitor L, Bacher S, Burczyk S, Niessing D. The Molecular Function of PURA and Its Implications in Neurological Diseases. Front Genet 2021; 12:638217. [PMID: 33777106 PMCID: PMC7990775 DOI: 10.3389/fgene.2021.638217] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/09/2021] [Indexed: 12/19/2022] Open
Abstract
In recent years, genome-wide analyses of patients have resulted in the identification of a number of neurodevelopmental disorders. Several of them are caused by mutations in genes that encode for RNA-binding proteins. One of these genes is PURA, for which in 2014 mutations have been shown to cause the neurodevelopmental disorder PURA syndrome. Besides intellectual disability (ID), patients develop a variety of symptoms, including hypotonia, metabolic abnormalities as well as epileptic seizures. This review aims to provide a comprehensive assessment of research of the last 30 years on PURA and its recently discovered involvement in neuropathological abnormalities. Being a DNA- and RNA-binding protein, PURA has been implicated in transcriptional control as well as in cytoplasmic RNA localization. Molecular interactions are described and rated according to their validation state as physiological targets. This information will be put into perspective with available structural and biophysical insights on PURA’s molecular functions. Two different knock-out mouse models have been reported with partially contradicting observations. They are compared and put into context with cell biological observations and patient-derived information. In addition to PURA syndrome, the PURA protein has been found in pathological, RNA-containing foci of patients with the RNA-repeat expansion diseases such as fragile X-associated tremor ataxia syndrome (FXTAS) and amyotrophic lateral sclerosis (ALS)/fronto-temporal dementia (FTD) spectrum disorder. We discuss the potential role of PURA in these neurodegenerative disorders and existing evidence that PURA might act as a neuroprotective factor. In summary, this review aims at informing researchers as well as clinicians on our current knowledge of PURA’s molecular and cellular functions as well as its implications in very different neuronal disorders.
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Affiliation(s)
- Lena Molitor
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Sabrina Bacher
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Sandra Burczyk
- Institute of Pharmaceutical Biotechnology, Ulm University, Ulm, Germany
| | - Dierk Niessing
- Institute of Structural Biology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany.,Institute of Pharmaceutical Biotechnology, Ulm University, Ulm, Germany
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12
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Jeon P, Lee JA. Dr. Jekyll and Mr. Hyde? Physiology and Pathology of Neuronal Stress Granules. Front Cell Dev Biol 2021; 9:609698. [PMID: 33718353 PMCID: PMC7947226 DOI: 10.3389/fcell.2021.609698] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 01/25/2021] [Indexed: 11/30/2022] Open
Abstract
Stress granules (SGs) are membraneless cytosolic granules containing dense aggregations of RNA-binding proteins and RNAs. They appear in the cytosol under stress conditions and inhibit the initiation of mRNA translation. SGs are dynamically assembled under stressful conditions and rapidly disassembled after stress removal. They are heterogeneous in their RNA and protein content and are cell type- and stress-specific. In post-mitotic neurons, which do not divide, the dynamics of neuronal SGs are tightly regulated, implying that their dysregulation leads to neurodegeneration. Mutations in RNA-binding proteins are associated with SGs. SG components accumulate in cytosolic inclusions in many neurodegenerative diseases, such as frontotemporal dementia and amyotrophic lateral sclerosis. Although SGs primarily mediate a pro-survival adaptive response to cellular stress, abnormal persistent SGs might develop into aggregates and link to the pathogenesis of diseases. In this review, we present recent advances in the study of neuronal SGs in physiology and pathology, and discuss potential therapeutic approaches to remove abnormal, persistent SGs associated with neurodegeneration.
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Affiliation(s)
- Pureum Jeon
- Department of Biotechnology and Biological Sciences, Hannam University, Daejeon, South Korea
| | - Jin A Lee
- Department of Biotechnology and Biological Sciences, Hannam University, Daejeon, South Korea
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13
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Mukherjee N, Mukherjee C. Germ cell ribonucleoprotein granules in different clades of life: From insects to mammals. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 12:e1642. [PMID: 33555143 DOI: 10.1002/wrna.1642] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 12/12/2022]
Abstract
Ribonucleoprotein (RNP) granules are no newcomers in biology. Found in all life forms, ranging across taxa, these membrane-less "organelles" have been classified into different categories based on their composition, structure, behavior, function, and localization. Broadly, they can be listed as stress granules (SGs), processing bodies (PBs), neuronal granules (NGs), and germ cell granules (GCGs). Keeping in line with the topic of this review, RNP granules present in the germ cells have been implicated in a wide range of cellular functions including cellular specification, differentiation, proliferation, and so forth. The mechanisms used by them can be diverse and many of them remain partly obscure and active areas of research. GCGs can be of different types in different organisms and at different stages of development, with multiple types coexisting in the same cell. In this review, the different known subcategories of GCGs have been studied with respect to five distinct model organisms, namely, Drosophila, Caenorhabditis elegans, Xenopus, Zebrafish, and mammals. Of them, the cytoplasmic polar granules in Drosophila, P granules in C. elegans, balbiani body in Xenopus and Zebrafish, and chromatoid bodies in mammals have been specifically emphasized upon. A descriptive account of the same has been provided along with insights into our current understanding of their functional significance with respect to cellular events relating to different developmental and reproductive processes. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Export and Localization > RNA Localization RNA in Disease and Development > RNA in Disease.
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14
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Broix L, Turchetto S, Nguyen L. Coordination between Transport and Local Translation in Neurons. Trends Cell Biol 2021; 31:372-386. [PMID: 33526339 DOI: 10.1016/j.tcb.2021.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/31/2020] [Accepted: 01/04/2021] [Indexed: 11/15/2022]
Abstract
The axonal microtubules (MTs) support long-distance transport of cargoes that are dispatched to distinct cellular subcompartments. Among them, mRNAs are directly transported in membraneless ribonucleoprotein (RNP) granules that, together with ribosomes, can also hitchhike on fast-moving membrane-bound organelles for accurate transport along MTs. These organelles serve as platforms for mRNA translation, thus generating axonal foci of newly synthesized proteins. Local translation along axons not only supports MT network integrity but also modulates the processivity and function of molecular motors to allow proper trafficking of cargoes along MTs. Thus, identifying the mechanisms that coordinate axonal transport with local protein synthesis will shed new light on the processes underlying axon development and maintenance, whose deregulation often contribute to neurological disorders.
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Affiliation(s)
- Loïc Broix
- GIGA Stem Cells, GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Silvia Turchetto
- GIGA Stem Cells, GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium
| | - Laurent Nguyen
- GIGA Stem Cells, GIGA-Neurosciences, University of Liège, C.H.U. Sart Tilman, Liège 4000, Belgium.
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15
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Engel KL, Arora A, Goering R, Lo HYG, Taliaferro JM. Mechanisms and consequences of subcellular RNA localization across diverse cell types. Traffic 2020; 21:404-418. [PMID: 32291836 PMCID: PMC7304542 DOI: 10.1111/tra.12730] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 02/07/2023]
Abstract
Essentially all cells contain a variety of spatially restricted regions that are important for carrying out specialized functions. Often, these regions contain specialized transcriptomes that facilitate these functions by providing transcripts for localized translation. These transcripts play a functional role in maintaining cell physiology by enabling a quick response to changes in the cellular environment. Here, we review how RNA molecules are trafficked within cells, with a focus on the subcellular locations to which they are trafficked, mechanisms that regulate their transport and clinical disorders associated with misregulation of the process.
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Affiliation(s)
- Krysta L Engel
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Ankita Arora
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Raeann Goering
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Hei-Yong G Lo
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - J Matthew Taliaferro
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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16
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Zhao J, Fok AHK, Fan R, Kwan PY, Chan HL, Lo LHY, Chan YS, Yung WH, Huang J, Lai CSW, Lai KO. Specific depletion of the motor protein KIF5B leads to deficits in dendritic transport, synaptic plasticity and memory. eLife 2020; 9:53456. [PMID: 31961321 PMCID: PMC7028368 DOI: 10.7554/elife.53456] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/20/2020] [Indexed: 12/16/2022] Open
Abstract
The kinesin I family of motor proteins are crucial for axonal transport, but their roles in dendritic transport and postsynaptic function are not well-defined. Gene duplication and subsequent diversification give rise to three homologous kinesin I proteins (KIF5A, KIF5B and KIF5C) in vertebrates, but it is not clear whether and how they exhibit functional specificity. Here we show that knockdown of KIF5A or KIF5B differentially affects excitatory synapses and dendritic transport in hippocampal neurons. The functional specificities of the two kinesins are determined by their diverse carboxyl-termini, where arginine methylation occurs in KIF5B and regulates its function. KIF5B conditional knockout mice exhibit deficits in dendritic spine morphogenesis, synaptic plasticity and memory formation. Our findings provide insights into how expansion of the kinesin I family during evolution leads to diversification and specialization of motor proteins in regulating postsynaptic function. Transporting molecules within a cell becomes a daunting task when the cell is a neuron, with fibers called axons and dendrites that can stretch as long as a meter. Neurons use many different molecules to send messages across the body and store memories in the brain. If the right molecules cannot be delivered along the length of nerve cells, connections to neighboring neurons may decay, which may impair learning and memory. Motor proteins are responsible for transporting molecules within cells. Kinesins are a type of motor protein that typically transports materials from the body of a neuron to the cell’s periphery, including the dendrites, which is where a neuron receives messages from other nerve cells. Each cell has up to 45 different kinesin motors, but it is not known whether each one performs a distinct task or if they have overlapping roles. Now, Zhao, Fok et al. have studied two similar kinesins, called KIF5A and KIF5B, in rodent neurons to determine their roles. First, it was shown that both proteins were found at dendritic spines, which are small outgrowths on dendrites where contact with other cells occurs. Next, KIF5A and KIF5B were depleted, one at a time, from neurons extracted from a brain region called the hippocampus. Removing KIF5B interfered with the formation of dendritic spines, but removing KIF5A did not have an effect. Dendritic spines are essential for learning and memory, so several behavioral tests were conducted on mice that had been genetically modified to express less KIF5B in the forebrain. These tests revealed that the mice performed poorly in tasks that tested their memory recall. This work opens a new area of research studying the specific roles of different kinesin motor proteins in nerve cells. This could have important implications because certain kinesin motor proteins such as KIF5A are known to be defective in some inherited neurodegenerative diseases.
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Affiliation(s)
- Junjun Zhao
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Albert Hiu Ka Fok
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Ruolin Fan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Pui-Yi Kwan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Hei-Lok Chan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Louisa Hoi-Ying Lo
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Ying-Shing Chan
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Wing-Ho Yung
- School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Jiandong Huang
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China.,State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China.,Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Cora Sau Wan Lai
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China.,State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Kwok-On Lai
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China.,State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
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17
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Rieckher M, Markaki M, Princz A, Schumacher B, Tavernarakis N. Maintenance of Proteostasis by P Body-Mediated Regulation of eIF4E Availability during Aging in Caenorhabditis elegans. Cell Rep 2020; 25:199-211.e6. [PMID: 30282029 PMCID: PMC6180348 DOI: 10.1016/j.celrep.2018.09.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 08/01/2018] [Accepted: 09/05/2018] [Indexed: 11/16/2022] Open
Abstract
Aging is accompanied by a pervasive collapse of proteostasis, while reducing general protein synthesis promotes longevity across taxa. Here, we show that the eIF4E isoform IFE-2 is increasingly sequestered in mRNA processing (P) bodies during aging and upon stress in Caenorhabditis elegans. Loss of the enhancer of mRNA decapping EDC-3 causes further entrapment of IFE-2 in P bodies and lowers protein synthesis rates in somatic tissues. Animals lacking EDC-3 are long lived and stress resistant, congruent with IFE-2-deficient mutants. Notably, neuron-specific expression of EDC-3 is sufficient to reverse lifespan extension, while sequestration of IFE-2 in neuronal P bodies counteracts age-related neuronal decline. The effects of mRNA decapping deficiency on stress resistance and longevity are orchestrated by a multimodal stress response involving the transcription factor SKN-1, which mediates lifespan extension upon reduced protein synthesis. Our findings elucidate a mechanism of proteostasis control during aging through P body-mediated regulation of protein synthesis in the soma.
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Affiliation(s)
- Matthias Rieckher
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Heraklion 71110, Greece; Institute for Genome Stability in Ageing and Disease, Cologne Cluster of Excellence in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University Hospital Cologne, 50931 Cologne, Germany
| | - Maria Markaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Heraklion 71110, Greece
| | - Andrea Princz
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Heraklion 71110, Greece
| | - Björn Schumacher
- Institute for Genome Stability in Ageing and Disease, Cologne Cluster of Excellence in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University Hospital Cologne, 50931 Cologne, Germany
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Heraklion 71110, Greece; Department of Basic Sciences, School of Medicine, University of Crete, Heraklion 71110, Greece.
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18
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Das S, Singer RH, Yoon YJ. The travels of mRNAs in neurons: do they know where they are going? Curr Opin Neurobiol 2019; 57:110-116. [PMID: 30784978 PMCID: PMC6650148 DOI: 10.1016/j.conb.2019.01.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 01/14/2019] [Indexed: 11/19/2022]
Abstract
Neurons are highly polarized cells that can extend processes far from the cell body. As such, transport of messenger RNAs serves as a set of blueprints for the synthesis of specific proteins at distal sites. RNA localization to dendrites and axons confers the ability to regulate translation with extraordinary precision in space and time. Although the rationale for RNA localization is quite compelling, it is unclear how a neuron orchestrates such a complex task of distributing over a thousand different mRNAs to their respective subcellular compartments. Recent single-molecule imaging studies have led to insights into the kinetics of individual mRNAs. We can now peer into the transport dynamics of mRNAs in both dendrites and axons.
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Affiliation(s)
- Sulagna Das
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Robert H Singer
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA; Janelia Research Campus, Ashburn, VA, USA.
| | - Young J Yoon
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA; Janelia Research Campus, Ashburn, VA, USA.
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19
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Formicola N, Vijayakumar J, Besse F. Neuronal ribonucleoprotein granules: Dynamic sensors of localized signals. Traffic 2019; 20:639-649. [PMID: 31206920 DOI: 10.1111/tra.12672] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/03/2019] [Accepted: 06/11/2019] [Indexed: 12/14/2022]
Abstract
Membrane-less organelles, because of their capacity to dynamically, selectively and reversibly concentrate molecules, are very well adapted for local information processing and rapid response to environmental fluctuations. These features are particularly important in the context of neuronal cells, where synapse-specific activation, or localized extracellular cues, induce signaling events restricted to specialized axonal or dendritic subcompartments. Neuronal ribonucleoprotein (RNP) particles, or granules, are nonmembrane bound macromolecular condensates that concentrate specific sets of mRNAs and regulatory proteins, promoting their long-distance transport to axons or dendrites. Neuronal RNP granules also have a dual function in regulating the translation of associated mRNAs: while preventing mRNA translation at rest, they fuel local protein synthesis upon activation. As revealed by recent work, rapid and reversible switches between these two functional modes are triggered by modifications of the networks of interactions underlying RNP granule assembly. Such flexible properties also come with a cost, as neuronal RNP granules are prone to transition into pathological aggregates in response to mutations, aging, or cellular stresses, further emphasizing the need to better understand the mechanistic principles governing their dynamic assembly and regulation in living systems.
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20
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Olesnicky EC, Wright EG. Drosophila as a Model for Assessing the Function of RNA-Binding Proteins during Neurogenesis and Neurological Disease. J Dev Biol 2018; 6:E21. [PMID: 30126171 PMCID: PMC6162566 DOI: 10.3390/jdb6030021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/15/2018] [Accepted: 08/15/2018] [Indexed: 12/16/2022] Open
Abstract
An outstanding question in developmental neurobiology is how RNA processing events contribute to the regulation of neurogenesis. RNA processing events are increasingly recognized as playing fundamental roles in regulating multiple developmental events during neurogenesis, from the asymmetric divisions of neural stem cells, to the generation of complex and diverse neurite morphologies. Indeed, both asymmetric cell division and neurite morphogenesis are often achieved by mechanisms that generate asymmetric protein distributions, including post-transcriptional gene regulatory mechanisms such as the transport of translationally silent messenger RNAs (mRNAs) and local translation of mRNAs within neurites. Additionally, defects in RNA splicing have emerged as a common theme in many neurodegenerative disorders, highlighting the importance of RNA processing in maintaining neuronal circuitry. RNA-binding proteins (RBPs) play an integral role in splicing and post-transcriptional gene regulation, and mutations in RBPs have been linked with multiple neurological disorders including autism, dementia, amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), Fragile X syndrome (FXS), and X-linked intellectual disability disorder. Despite their widespread nature and roles in neurological disease, the molecular mechanisms and networks of regulated target RNAs have been defined for only a small number of specific RBPs. This review aims to highlight recent studies in Drosophila that have advanced our knowledge of how RBP dysfunction contributes to neurological disease.
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Affiliation(s)
- Eugenia C Olesnicky
- Department of Biology, University of Colorado Colorado Springs, 1420 Austin Bluffs Parkway, Colorado Springs, CO 80918, USA.
| | - Ethan G Wright
- Department of Biology, University of Colorado Colorado Springs, 1420 Austin Bluffs Parkway, Colorado Springs, CO 80918, USA.
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21
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Neuronal RNP granules: from physiological to pathological assemblies. Biol Chem 2018; 399:623-635. [DOI: 10.1515/hsz-2018-0141] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/30/2018] [Indexed: 12/11/2022]
Abstract
Abstract
Neuronal cells rely on macro- and micro-cellular compartmentalization to rapidly process information, and respond locally to external stimuli. Such a cellular organization is achieved via the assembly of neuronal ribonucleoprotein (RNP) granules, dynamic membrane-less organelles enriched in RNAs and associated regulatory proteins. In this review, we discuss how these high-order structures transport mRNAs to dendrites and axons, and how they contribute to the spatio-temporal regulation of localized mRNA translation. We also highlight how recent biophysical studies have shed light on the mechanisms underlying neuronal RNP granule dynamic assembly, remodeling and maturation, in both physiological and pathological contexts.
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22
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Van Driesche SJ, Martin KC. New frontiers in RNA transport and local translation in neurons. Dev Neurobiol 2018; 78:331-339. [DOI: 10.1002/dneu.22574] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 12/27/2017] [Accepted: 12/27/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Sarah J. Van Driesche
- Department of Biological Chemistry; University of California; Los Angeles California
| | - Kelsey C. Martin
- Department of Biological Chemistry; University of California; Los Angeles California
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