1
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Oliveira MM, Mohamed M, Elder MK, Banegas-Morales K, Mamcarz M, Lu EH, Golhan EAN, Navrange N, Chatterjee S, Abel T, Klann E. The integrated stress response effector GADD34 is repurposed by neurons to promote stimulus-induced translation. Cell Rep 2024; 43:113670. [PMID: 38219147 PMCID: PMC10964249 DOI: 10.1016/j.celrep.2023.113670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 10/11/2023] [Accepted: 12/26/2023] [Indexed: 01/16/2024] Open
Abstract
Neuronal protein synthesis is required for long-lasting plasticity and long-term memory consolidation. Dephosphorylation of eukaryotic initiation factor 2α is one of the key translational control events that is required to increase de novo protein synthesis that underlies long-lasting plasticity and memory consolidation. Here, we interrogate the molecular pathways of translational control that are triggered by neuronal stimulation with brain-derived neurotrophic factor (BDNF), which results in eukaryotic initiation factor 2α (eIF2α) dephosphorylation and increases in de novo protein synthesis. Primary rodent neurons exposed to BDNF display elevated translation of GADD34, which facilitates eIF2α dephosphorylation and subsequent de novo protein synthesis. Furthermore, GADD34 requires G-actin generated by cofilin to dephosphorylate eIF2α and enhance protein synthesis. Finally, GADD34 is required for BDNF-induced translation of synaptic plasticity-related proteins. Overall, we provide evidence that neurons repurpose GADD34, an effector of the integrated stress response, as an orchestrator of rapid increases in eIF2-dependent translation in response to plasticity-inducing stimuli.
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Affiliation(s)
| | - Muhaned Mohamed
- Center for Neural Science, New York University, New York, NY, USA
| | - Megan K Elder
- Center for Neural Science, New York University, New York, NY, USA
| | | | - Maggie Mamcarz
- Center for Neural Science, New York University, New York, NY, USA
| | - Emily H Lu
- Center for Neural Science, New York University, New York, NY, USA
| | - Ela A N Golhan
- Center for Neural Science, New York University, New York, NY, USA
| | - Nishika Navrange
- Center for Neural Science, New York University, New York, NY, USA
| | - Snehajyoti Chatterjee
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Ted Abel
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY, USA; NYU Neuroscience Institute, New York University School of Medicine, New York, NY, USA.
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Davies DS, Arthur AT, Aitken HL, Crossett B, Goldsbury CS. Protein complexes from mouse and chick brain that interact with phospho-KXGS motif tau/microtubule associated protein antibody. Biol Open 2024; 13:bio060067. [PMID: 38299702 PMCID: PMC10924212 DOI: 10.1242/bio.060067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 01/29/2024] [Indexed: 02/02/2024] Open
Abstract
Mouse monoclonal 12E8 antibody, which recognises conserved serine phosphorylated KXGS motifs in the microtubule binding domains of tau/tau-like microtubule associated proteins (MAPs), shows elevated binding in brain during normal embryonic development (mammals and birds) and at the early stages of human Alzheimer's disease (AD). It also labels ADF/cofilin-actin rods that form in neurites during exposure to stressors. We aimed to identify direct and indirect 12E8 binding proteins in postnatal mouse brain and embryonic chick brain by immunoprecipitation (IP), mass spectrometry and immunofluorescence. Tau and/or MAP2 were major direct 12E8-binding proteins detected in all IPs, and actin and/or tubulin were co-immunoprecipitated in most samples. Additional proteins were different in mouse versus chick brain IP. In mouse brain IPs, FSD1l and intermediate filament proteins - vimentin, α-internexin, neurofilament polypeptides - were prominent. Immunofluorescence and immunoblot using recombinant intermediate filament subunits, suggests an indirect interaction of these proteins with the 12E8 antibody. In chick brain IPs, subunits of eukaryotic translation initiation factor 3 (EIF3) were found, but no direct interaction between 12E8 and recombinant Eif3e protein was detected. Fluorescence microscopy in primary cultured chick neurons showed evidence of co-localisation of Eif3e and tubulin labelling, consistent with previous data demonstrating cytoskeletal organisation of the translation apparatus. Neither total tau or MAP2 immunolabelling accumulated at ADF/cofilin-actin rods generated in primary cultured chick neurons, and we were unable to narrow down the major antigen recognised by 12E8 antibody on ADF/cofilin-actin rods.
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Affiliation(s)
- D. S. Davies
- Faculty of Medicine and Health, School of Medical Sciences, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - A. T. Arthur
- Faculty of Medicine and Health, School of Medical Sciences, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - H. L. Aitken
- Faculty of Medicine and Health, School of Medical Sciences, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - B. Crossett
- Sydney Mass Spectrometry, The University of Sydney, Sydney, NSW 2050, Australia
| | - C. S. Goldsbury
- Faculty of Medicine and Health, School of Medical Sciences, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
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Liu C, Hu X, Zhao Y, Huang A, Chen J, Lu T, Wu M, Lu H. High-Glucose-Induced Injury to Proximal Tubules of the Renal System Is Alleviated by Netrin-1 Suppression of Akt/mTOR. J Diabetes Res 2023; 2023:4193309. [PMID: 38033740 PMCID: PMC10684325 DOI: 10.1155/2023/4193309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 08/03/2023] [Accepted: 10/16/2023] [Indexed: 12/02/2023] Open
Abstract
The kidneys have a high level of Netrin-1 expression, which protects against some acute and chronic kidney disorders. However, it is yet unknown how Netrin-1 affects renal proximal tubule cells in diabetic nephropathy (DN) under pathological circumstances. Research has shown that autophagy protects the kidneys in animal models of renal disease. In this study, we looked at the probable autophagy regulation mechanism of Netrin-1 and its function in the pathogenesis of DN. We proved that in HK-2 cell, high blood sugar levels caused Netrin-1 to be downregulated, which then triggered the Akt/mTOR signaling pathway and enhanced cell death and actin cytoskeleton disruption. By adding Netrin-1 or an autophagy activator in vitro, these pathogenic alterations were reverted. Our results indicate that Netrin-1 stimulates autophagy by blocking the Akt/mTOR signaling pathway, which underlies high-glucose-induced malfunction of the renal proximal tubules. After HK-2 cells were incubated with Netrin-1 recombination protein and rapamycin under HG conditions for 24 h, the apoptosis was significantly reduced, as shown by the higher levels of Bcl-2, as well as lower levels of Bax and cleaved caspase-3 (P = 0.012, Cohen's d = 0.489, Glass's delta = 0.23, Hedges' g = 0.641). This study reveals that targeting Netrin-1-related signaling has therapeutic potential for DN and advances our knowledge of the processes operating in renal proximal tubules in DN.
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Affiliation(s)
- Chenxiao Liu
- Department of Endocrinology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, 242 Guangji Road, Jiangsu 215008, China
| | - Xingna Hu
- Department of Endocrinology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, 242 Guangji Road, Jiangsu 215008, China
| | - Yun Zhao
- Department of Endocrinology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, 242 Guangji Road, Jiangsu 215008, China
| | - Aijie Huang
- Department of Endocrinology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, 242 Guangji Road, Jiangsu 215008, China
| | - Jiaqi Chen
- Department of Endocrinology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, 242 Guangji Road, Jiangsu 215008, China
| | - Ting Lu
- Department of Endocrinology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, 242 Guangji Road, Jiangsu 215008, China
| | - Mian Wu
- Department of Endocrinology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, 242 Guangji Road, Jiangsu 215008, China
| | - Honghong Lu
- Department of Endocrinology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, 242 Guangji Road, Jiangsu 215008, China
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4
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Yan K, Bormuth I, Bormuth O, Tutukova S, Renner A, Bessa P, Schaub T, Rosário M, Tarabykin V. TrkB-dependent EphrinA reverse signaling regulates callosal axon fasciculate growth downstream of Neurod2/6. Cereb Cortex 2023; 33:1752-1767. [PMID: 35462405 DOI: 10.1093/cercor/bhac170] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 11/14/2022] Open
Abstract
Abnormal development of corpus callosum is relatively common and causes a broad spectrum of cognitive impairments in humans. We use acallosal Neurod2/6-deficient mice to study callosal axon guidance within the ipsilateral cerebral cortex. Initial callosal tracts form but fail to traverse the ipsilateral cingulum and are not attracted towards the midline in the absence of Neurod2/6. We show that the restoration of Ephrin-A4 (EfnA4) expression in the embryonic neocortex of Neurod2/6-deficient embryos is sufficient to partially rescue targeted callosal axon growth towards the midline. EfnA4 cannot directly mediate reverse signaling within outgrowing axons, but it forms co-receptor complexes with TrkB (Ntrk2). The ability of EfnA4 to rescue the guided growth of a subset of callosal axons in Neurod2/6-deficient mice is abolished by the co-expression of dominant negative TrkBK571N (kinase-dead) or TrkBY515F (SHC-binding deficient) variants, but not by TrkBY816F (PLCγ1-binding deficient). Additionally, EphA4 is repulsive to EfnA4-positive medially projecting axons in organotypic brain slice culture. Collectively, we suggest that EfnA4-mediated reverse signaling acts via TrkB-SHC and is required for ipsilateral callosal axon growth accuracy towards the midline downstream of Neurod family factors.
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Affiliation(s)
- Kuo Yan
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, D-10117, Berlin, Germany
| | - Ingo Bormuth
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, D-10117, Berlin, Germany
| | - Olga Bormuth
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, D-10117, Berlin, Germany.,Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, 603950, Nizhny Novgorod Oblast, Russia
| | - Svetlana Tutukova
- Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, 603950, Nizhny Novgorod Oblast, Russia.,Research Institute of Medical Genetics, Tomsk National Research Medical Center of the Russian Academy of Sciences, 634009, Tomsk, Russia
| | - Ana Renner
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, D-10117, Berlin, Germany
| | - Paraskevi Bessa
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, D-10117, Berlin, Germany
| | - Theres Schaub
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, D-10117, Berlin, Germany
| | - Marta Rosário
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, D-10117, Berlin, Germany
| | - Victor Tarabykin
- Institute of Cell Biology and Neurobiology, Charité - Universitätsmedizin Berlin, D-10117, Berlin, Germany.,Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, 603950, Nizhny Novgorod Oblast, Russia.,Research Institute of Medical Genetics, Tomsk National Research Medical Center of the Russian Academy of Sciences, 634009, Tomsk, Russia
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5
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Triantopoulou N, Vidaki M. Local mRNA translation and cytoskeletal reorganization: Mechanisms that tune neuronal responses. Front Mol Neurosci 2022; 15:949096. [PMID: 35979146 PMCID: PMC9376447 DOI: 10.3389/fnmol.2022.949096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/07/2022] [Indexed: 12/31/2022] Open
Abstract
Neurons are highly polarized cells with significantly long axonal and dendritic extensions that can reach distances up to hundreds of centimeters away from the cell bodies in higher vertebrates. Their successful formation, maintenance, and proper function highly depend on the coordination of intricate molecular networks that allow axons and dendrites to quickly process information, and respond to a continuous and diverse cascade of environmental stimuli, often without enough time for communication with the soma. Two seemingly unrelated processes, essential for these rapid responses, and thus neuronal homeostasis and plasticity, are local mRNA translation and cytoskeletal reorganization. The axonal cytoskeleton is characterized by high stability and great plasticity; two contradictory attributes that emerge from the powerful cytoskeletal rearrangement dynamics. Cytoskeletal reorganization is crucial during nervous system development and in adulthood, ensuring the establishment of proper neuronal shape and polarity, as well as regulating intracellular transport and synaptic functions. Local mRNA translation is another mechanism with a well-established role in the developing and adult nervous system. It is pivotal for axonal guidance and arborization, synaptic formation, and function and seems to be a key player in processes activated after neuronal damage. Perturbations in the regulatory pathways of local translation and cytoskeletal reorganization contribute to various pathologies with diverse clinical manifestations, ranging from intellectual disabilities (ID) to autism spectrum disorders (ASD) and schizophrenia (SCZ). Despite the fact that both processes are essential for the orchestration of pathways critical for proper axonal and dendritic function, the interplay between them remains elusive. Here we review our current knowledge on the molecular mechanisms and specific interaction networks that regulate and potentially coordinate these interconnected processes.
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Affiliation(s)
- Nikoletta Triantopoulou
- Division of Basic Sciences, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas (IMBB-FORTH), Heraklion, Greece
| | - Marina Vidaki
- Division of Basic Sciences, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas (IMBB-FORTH), Heraklion, Greece
- *Correspondence: Marina Vidaki,
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6
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Le P, Ahmed N, Yeo GW. Illuminating RNA biology through imaging. Nat Cell Biol 2022; 24:815-824. [PMID: 35697782 PMCID: PMC11132331 DOI: 10.1038/s41556-022-00933-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 05/06/2022] [Indexed: 12/14/2022]
Abstract
RNA processing plays a central role in accurately transmitting genetic information into functional RNA and protein regulators. To fully appreciate the RNA life-cycle, tools to observe RNA with high spatial and temporal resolution are critical. Here we review recent advances in RNA imaging and highlight how they will propel the field of RNA biology. We discuss current trends in RNA imaging and their potential to elucidate unanswered questions in RNA biology.
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Affiliation(s)
- Phuong Le
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
- Stem Cell Program, University of California San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, CA, USA
| | - Noorsher Ahmed
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
- Stem Cell Program, University of California San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, CA, USA
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA.
- Stem Cell Program, University of California San Diego, La Jolla, CA, USA.
- Institute for Genomic Medicine, University of California San Diego, La Jolla, CA, USA.
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA, USA.
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7
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Choi S, Kang D, Kang J, Hong DK, Kang BS, Kho AR, Choi BY, Huh SO, Suh SW. The Role of Zinc in Axon Formation via the mTORC1 Pathway. Mol Neurobiol 2022; 59:3206-3217. [PMID: 35293604 DOI: 10.1007/s12035-022-02785-8] [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: 09/23/2021] [Accepted: 02/15/2022] [Indexed: 10/18/2022]
Abstract
Zinc is an essential micronutrient required for proper function during neuronal development because it can modulate neuronal function and structure. A fully functional description of zinc in axonal processing in the central nervous system remains elusive. Here, we define the role of intracellular zinc in axon formation and elongation, involving the mammalian target of rapamycin complex 1 (mTORC1). To investigate the involvement of zinc in axon growth, we performed an ex vivo culture of mouse hippocampal neurons and administrated ZnCl2 as a media supplement. At 2 days in vitro, the administration of zinc induced the formation of multiple and elongated axons in the ex vivo culture system. A similar outcome was witnessed in callosal projection neurons in a developing mouse brain. Treatment with extracellular zinc activated the mTORC1 signaling pathway in mouse hippocampal neuronal cultures. The zinc-dependent enhancement of neuronal processing was inhibited either by the deactivation of mTORC1 with RAPTOR shRNA or by mTOR-insensitive 4EBP1 mutants. Additionally, zinc-dependent mTORC1 activation enhanced the axonal translation of TC10 and Par3 may be responsible for axonal growth. We identified a promising role of zinc in controlling axonogenesis in the developing brain, which, in turn, may indicate a novel structural role of zinc in the cytoskeleton and developing neurons.
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Affiliation(s)
- Seunghyuk Choi
- Department of Physiology, College of Medicine, Hallym University, Hallymdaehak-gil 1, Chuncheon, 24252, Republic of Korea
| | - Donghyeon Kang
- Department of Physiology, College of Medicine, Hallym University, Hallymdaehak-gil 1, Chuncheon, 24252, Republic of Korea
| | - Jieun Kang
- Department of Pharmacology, College of Medicine, Hallym University, Hallymdaehak-gil 1, Chuncheon, 24252, Republic of Korea
| | - Dae Ki Hong
- Department of Physiology, College of Medicine, Hallym University, Hallymdaehak-gil 1, Chuncheon, 24252, Republic of Korea
| | - Beom Seok Kang
- Department of Physiology, College of Medicine, Hallym University, Hallymdaehak-gil 1, Chuncheon, 24252, Republic of Korea
| | - A Ra Kho
- Department of Physiology, College of Medicine, Hallym University, Hallymdaehak-gil 1, Chuncheon, 24252, Republic of Korea
| | - Bo Young Choi
- Department of Physiology, College of Medicine, Hallym University, Hallymdaehak-gil 1, Chuncheon, 24252, Republic of Korea
| | - Sung-Oh Huh
- Department of Pharmacology, College of Medicine, Hallym University, Hallymdaehak-gil 1, Chuncheon, 24252, Republic of Korea
| | - Sang Won Suh
- Department of Physiology, College of Medicine, Hallym University, Hallymdaehak-gil 1, Chuncheon, 24252, Republic of Korea.
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8
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Tariq K, Luikart BW. Striking a balance: PIP 2 and PIP 3 signaling in neuronal health and disease. EXPLORATION OF NEUROPROTECTIVE THERAPY 2022; 1:86-100. [PMID: 35098253 PMCID: PMC8797975 DOI: 10.37349/ent.2021.00008] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Phosphoinositides are membrane phospholipids involved in a variety of cellular processes like growth, development, metabolism, and transport. This review focuses on the maintenance of cellular homeostasis of phosphatidylinositol 4,5-bisphosphate (PIP2), and phosphatidylinositol 3,4,5-trisphosphate (PIP3). The critical balance of these PIPs is crucial for regulation of neuronal form and function. The activity of PIP2 and PIP3 can be regulated through kinases, phosphatases, phospholipases and cholesterol microdomains. PIP2 and PIP3 carry out their functions either indirectly through their effectors activating integral signaling pathways, or through direct regulation of membrane channels, transporters, and cytoskeletal proteins. Any perturbations to the balance between PIP2 and PIP3 signaling result in neurodevelopmental and neurodegenerative disorders. This review will discuss the upstream modulators and downstream effectors of the PIP2 and PIP3 signaling, in the context of neuronal health and disease.
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Affiliation(s)
- Kamran Tariq
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Bryan W Luikart
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
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9
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Buscaglia G, Northington KR, Aiken J, Hoff KJ, Bates EA. Bridging the Gap: The Importance of TUBA1A α-Tubulin in Forming Midline Commissures. Front Cell Dev Biol 2022; 9:789438. [PMID: 35127710 PMCID: PMC8807549 DOI: 10.3389/fcell.2021.789438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/20/2021] [Indexed: 11/13/2022] Open
Abstract
Developing neurons undergo dramatic morphological changes to appropriately migrate and extend axons to make synaptic connections. The microtubule cytoskeleton, made of α/β-tubulin dimers, drives neurite outgrowth, promotes neuronal growth cone responses, and facilitates intracellular transport of critical cargoes during neurodevelopment. TUBA1A constitutes the majority of α-tubulin in the developing brain and mutations to TUBA1A in humans cause severe brain malformations accompanied by varying neurological defects, collectively termed tubulinopathies. Studies of TUBA1A function in mammalian cells have been limited by the presence of multiple genes encoding highly similar tubulin proteins, which leads to α-tubulin antibody promiscuity and makes genetic manipulation challenging. Here, we test mutant tubulin levels and assembly activity and analyze the impact of TUBA1A reduction on growth cone composition, neurite extension, and commissural axon architecture during brain development. We present a novel tagging method for studying and manipulating TUBA1A in cells without impairing tubulin function. Using this tool, we show that a TUBA1A loss-of-function mutation TUBA1A N102D (TUBA1A ND ), reduces TUBA1A protein levels and prevents incorporation of TUBA1A into microtubule polymers. Reduced Tuba1a α-tubulin in heterozygous Tuba1a ND/+ mice leads to grossly normal brain formation except a significant impact on axon extension and impaired formation of forebrain commissures. Neurons with reduced Tuba1a as a result of the Tuba1a ND mutation exhibit slower neuron outgrowth compared to controls. Neurons deficient in Tuba1a failed to localize microtubule associated protein-1b (Map1b) to the developing growth cone, likely impacting stabilization of microtubules. Overall, we show that reduced Tuba1a is sufficient to support neuronal migration and cortex development but not commissure formation, and provide mechanistic insight as to how TUBA1A tunes microtubule function to support neurodevelopment.
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Affiliation(s)
- Georgia Buscaglia
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Kyle R. Northington
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Jayne Aiken
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Katelyn J. Hoff
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Emily A. Bates
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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10
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Gasparski AN, Mason DE, Moissoglu K, Mili S. Regulation and outcomes of localized RNA translation. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1721. [PMID: 35166036 PMCID: PMC9787767 DOI: 10.1002/wrna.1721] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/18/2022] [Accepted: 01/22/2022] [Indexed: 12/31/2022]
Abstract
Spatial segregation of mRNAs in the cytoplasm of cells is a well-known biological phenomenon that is widely observed in diverse species spanning different kingdoms of life. In mammalian cells, localization of mRNAs has been documented and studied quite extensively in highly polarized cells, most notably in neurons, where localized mRNAs function to direct protein production at sites that are quite distant from the soma. Recent studies have strikingly revealed that a large proportion of the cellular transcriptome exhibits polarized distributions even in cells that lack an obvious need for long-range transport, such as fibroblasts or epithelial cells. This review focuses on emerging concepts regarding the functional outcomes of mRNA targeting in the cytoplasm of such cells. We also discuss regulatory mechanisms controlling these events, with an emphasis on the role of cell mechanics and the organization of the cytoskeleton. This article is categorized under: Translation > Regulation RNA Export and Localization > RNA Localization.
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Affiliation(s)
- Alexander N. Gasparski
- Laboratory of Cellular and Molecular Biology, Center for Cancer ResearchNational Cancer Institute, NIHBethesdaMarylandUSA
| | - Devon E. Mason
- Laboratory of Cellular and Molecular Biology, Center for Cancer ResearchNational Cancer Institute, NIHBethesdaMarylandUSA
| | - Konstadinos Moissoglu
- Laboratory of Cellular and Molecular Biology, Center for Cancer ResearchNational Cancer Institute, NIHBethesdaMarylandUSA
| | - Stavroula Mili
- Laboratory of Cellular and Molecular Biology, Center for Cancer ResearchNational Cancer Institute, NIHBethesdaMarylandUSA
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11
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Li L, Yu J, Ji SJ. Axonal mRNA localization and translation: local events with broad roles. Cell Mol Life Sci 2021; 78:7379-7395. [PMID: 34698881 PMCID: PMC11072051 DOI: 10.1007/s00018-021-03995-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 09/17/2021] [Accepted: 10/14/2021] [Indexed: 12/19/2022]
Abstract
Messenger RNA (mRNA) can be transported and targeted to different subcellular compartments and locally translated. Local translation is an evolutionally conserved mechanism that in mammals, provides an important tool to exquisitely regulate the subcellular proteome in different cell types, including neurons. Local translation in axons is involved in processes such as neuronal development, function, plasticity, and diseases. Here, we summarize the current progress on axonal mRNA transport and translation. We focus on the regulatory mechanisms governing how mRNAs are transported to axons and how they are locally translated in axons. We discuss the roles of axonally synthesized proteins, which either function locally in axons, or are retrogradely trafficked back to soma to achieve neuron-wide gene regulation. We also examine local translation in neurological diseases. Finally, we give a critical perspective on the remaining questions that could be answered to uncover the fundamental rules governing local translation, and discuss how this could lead to new therapeutic targets for neurological diseases.
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Affiliation(s)
- Lichao Li
- School of Life Sciences, Department of Biology, Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Jun Yu
- School of Life Sciences, Department of Biology, Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Sheng-Jian Ji
- School of Life Sciences, Department of Biology, Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China.
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12
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Moon HH, Kreis NN, Friemel A, Roth S, Schulte D, Solbach C, Louwen F, Yuan J, Ritter A. Mitotic Centromere-Associated Kinesin (MCAK/KIF2C) Regulates Cell Migration and Invasion by Modulating Microtubule Dynamics and Focal Adhesion Turnover. Cancers (Basel) 2021; 13:5673. [PMID: 34830827 PMCID: PMC8616312 DOI: 10.3390/cancers13225673] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 01/16/2023] Open
Abstract
The microtubule (MT) cytoskeleton is crucial for cell motility and migration by regulating multiple cellular activities such as transport and endocytosis of key components of focal adhesions (FA). The kinesin-13 family is important in the regulation of MT dynamics and the best characterized member of this family is the mitotic centromere-associated kinesin (MCAK/KIF2C). Interestingly, its overexpression has been reported to be related to increased metastasis in various tumor entities. Moreover, MCAK is involved in the migration and invasion behavior of various cell types. However, the precise molecular mechanisms were not completely clarified. To address these issues, we generated CRISPR/dCas9 HeLa and retinal pigment epithelium (RPE) cell lines overexpressing or downregulating MCAK. Both up- or downregulation of MCAK led to reduced cell motility and poor migration in malignant as well as benign cells. Specifically, it's up- or downregulation impaired FA protein composition and phosphorylation status, interfered with a proper spindle and chromosome segregation, disturbed the assembly and disassembly rate of FA, delayed cell adhesion, and compromised the plus-tip dynamics of MTs. In conclusion, our data suggest MCAK act as an important regulator for cell motility and migration by affecting the actin-MT cytoskeleton dynamics and the FA turnover, providing molecular mechanisms by which deregulated MCAK could promote malignant progression and metastasis of tumor cells.
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Affiliation(s)
- Ha Hyung Moon
- Obstetrics and Prenatal Medicine, Department of Gynecology and Obstetrics, University Hospital Frankfurt, J. W. Goethe-University Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany; (H.H.M.); (N.-N.K.); (A.F.); (S.R.); (C.S.); (F.L.); (J.Y.)
| | - Nina-Naomi Kreis
- Obstetrics and Prenatal Medicine, Department of Gynecology and Obstetrics, University Hospital Frankfurt, J. W. Goethe-University Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany; (H.H.M.); (N.-N.K.); (A.F.); (S.R.); (C.S.); (F.L.); (J.Y.)
| | - Alexandra Friemel
- Obstetrics and Prenatal Medicine, Department of Gynecology and Obstetrics, University Hospital Frankfurt, J. W. Goethe-University Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany; (H.H.M.); (N.-N.K.); (A.F.); (S.R.); (C.S.); (F.L.); (J.Y.)
| | - Susanne Roth
- Obstetrics and Prenatal Medicine, Department of Gynecology and Obstetrics, University Hospital Frankfurt, J. W. Goethe-University Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany; (H.H.M.); (N.-N.K.); (A.F.); (S.R.); (C.S.); (F.L.); (J.Y.)
| | - Dorothea Schulte
- Institute of Neurology (Edinger Institute), University Hospital Frankfurt, J. W. Goethe University, D-60528 Frankfurt, Germany;
| | - Christine Solbach
- Obstetrics and Prenatal Medicine, Department of Gynecology and Obstetrics, University Hospital Frankfurt, J. W. Goethe-University Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany; (H.H.M.); (N.-N.K.); (A.F.); (S.R.); (C.S.); (F.L.); (J.Y.)
| | - Frank Louwen
- Obstetrics and Prenatal Medicine, Department of Gynecology and Obstetrics, University Hospital Frankfurt, J. W. Goethe-University Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany; (H.H.M.); (N.-N.K.); (A.F.); (S.R.); (C.S.); (F.L.); (J.Y.)
| | - Juping Yuan
- Obstetrics and Prenatal Medicine, Department of Gynecology and Obstetrics, University Hospital Frankfurt, J. W. Goethe-University Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany; (H.H.M.); (N.-N.K.); (A.F.); (S.R.); (C.S.); (F.L.); (J.Y.)
| | - Andreas Ritter
- Obstetrics and Prenatal Medicine, Department of Gynecology and Obstetrics, University Hospital Frankfurt, J. W. Goethe-University Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany; (H.H.M.); (N.-N.K.); (A.F.); (S.R.); (C.S.); (F.L.); (J.Y.)
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13
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Müntjes K, Devan SK, Reichert AS, Feldbrügge M. Linking transport and translation of mRNAs with endosomes and mitochondria. EMBO Rep 2021; 22:e52445. [PMID: 34402186 PMCID: PMC8490996 DOI: 10.15252/embr.202152445] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 07/06/2021] [Accepted: 07/27/2021] [Indexed: 01/01/2023] Open
Abstract
In eukaryotic cells, proteins are targeted to their final subcellular locations with precise timing. A key underlying mechanism is the active transport of cognate mRNAs, which in many systems can be linked intimately to membrane trafficking. A prominent example is the long-distance endosomal transport of mRNAs and their local translation. Here, we describe current highlights of fundamental mechanisms of the underlying transport process as well as of biological functions ranging from endosperm development in plants to fungal pathogenicity and neuronal processes. Translation of endosome-associated mRNAs often occurs at the cytoplasmic surface of endosomes, a process that is needed for membrane-assisted formation of heteromeric protein complexes and for accurate subcellular targeting of proteins. Importantly, endosome-coupled translation of mRNAs encoding mitochondrial proteins, for example, seems to be particularly important for efficient organelle import and for regulating subcellular mitochondrial activity. In essence, these findings reveal a new mechanism of loading newly synthesised proteins onto endocytic membranes enabling intimate crosstalk between organelles. The novel link between endosomes and mitochondria adds an inspiring new level of complexity to trafficking and organelle biology.
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Affiliation(s)
- Kira Müntjes
- Institute of MicrobiologyCluster of Excellence on Plant SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany
| | - Senthil Kumar Devan
- Institute of MicrobiologyCluster of Excellence on Plant SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany
| | - Andreas S Reichert
- Institute of Biochemistry and Molecular Biology IMedical Faculty and University Hospital DüsseldorfHeinrich Heine University DüsseldorfDüsseldorfGermany
| | - Michael Feldbrügge
- Institute of MicrobiologyCluster of Excellence on Plant SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany
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14
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Agrawal M, Welshhans K. Local Translation Across Neural Development: A Focus on Radial Glial Cells, Axons, and Synaptogenesis. Front Mol Neurosci 2021; 14:717170. [PMID: 34434089 PMCID: PMC8380849 DOI: 10.3389/fnmol.2021.717170] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 07/20/2021] [Indexed: 11/13/2022] Open
Abstract
In the past two decades, significant progress has been made in our understanding of mRNA localization and translation at distal sites in axons and dendrites. The existing literature shows that local translation is regulated in a temporally and spatially restricted manner and is critical throughout embryonic and post-embryonic life. Here, recent key findings about mRNA localization and local translation across the various stages of neural development, including neurogenesis, axon development, and synaptogenesis, are reviewed. In the early stages of development, mRNAs are localized and locally translated in the endfeet of radial glial cells, but much is still unexplored about their functional significance. Recent in vitro and in vivo studies have provided new information about the specific mechanisms regulating local translation during axon development, including growth cone guidance and axon branching. Later in development, localization and translation of mRNAs help mediate the major structural and functional changes that occur in the axon during synaptogenesis. Clinically, changes in local translation across all stages of neural development have important implications for understanding the etiology of several neurological disorders. Herein, local translation and mechanisms regulating this process across developmental stages are compared and discussed in the context of function and dysfunction.
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Affiliation(s)
- Manasi Agrawal
- School of Biomedical Sciences, Kent State University, Kent, OH, United States
| | - Kristy Welshhans
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States
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15
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Mendoza MB, Gutierrez S, Ortiz R, Moreno DF, Dermit M, Dodel M, Rebollo E, Bosch M, Mardakheh FK, Gallego C. The elongation factor eEF1A2 controls translation and actin dynamics in dendritic spines. Sci Signal 2021; 14:14/691/eabf5594. [PMID: 34257105 DOI: 10.1126/scisignal.abf5594] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Synaptic plasticity involves structural modifications in dendritic spines that are modulated by local protein synthesis and actin remodeling. Here, we investigated the molecular mechanisms that connect synaptic stimulation to these processes. We found that the phosphorylation of isoform-specific sites in eEF1A2-an essential translation elongation factor in neurons-is a key modulator of structural plasticity in dendritic spines. Expression of a nonphosphorylatable eEF1A2 mutant stimulated mRNA translation but reduced actin dynamics and spine density. By contrast, a phosphomimetic eEF1A2 mutant exhibited decreased association with F-actin and was inactive as a translation elongation factor. Activation of metabotropic glutamate receptor signaling triggered transient dissociation of eEF1A2 from its regulatory guanine exchange factor (GEF) protein in dendritic spines in a phosphorylation-dependent manner. We propose that eEF1A2 establishes a cross-talk mechanism that coordinates translation and actin dynamics during spine remodeling.
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Affiliation(s)
- Mònica B Mendoza
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain
| | - Sara Gutierrez
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain
| | - Raúl Ortiz
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain
| | - David F Moreno
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain
| | - Maria Dermit
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse square, London EC1M 6BQ, UK
| | - Martin Dodel
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse square, London EC1M 6BQ, UK
| | - Elena Rebollo
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain
| | - Miquel Bosch
- Department of Basic Sciences, Universitat Internacional de Catalunya (UIC-Barcelona), Sant Cugat del Vallès 08195, Spain.,Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona 08028, Spain
| | - Faraz K Mardakheh
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse square, London EC1M 6BQ, UK
| | - Carme Gallego
- Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain.
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16
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Ucha M, Roura-Martínez D, Ambrosio E, Higuera-Matas A. The role of the mTOR pathway in models of drug-induced reward and the behavioural constituents of addiction. J Psychopharmacol 2020; 34:1176-1199. [PMID: 32854585 DOI: 10.1177/0269881120944159] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Exposure to drugs of abuse induces neuroadaptations in critical nodes of the so-called reward systems that are thought to mediate the transition from controlled drug use to the compulsive drug-seeking that characterizes addictive disorders. These neural adaptations are likely to require protein synthesis, which is regulated, among others, by the mechanistic target of the rapamycin kinase (mTOR) signalling cascade. METHODS We have performed a narrative review of the literature available in PubMed about the involvement of the mTOR pathway in drug-reward and addiction-related phenomena. AIMS The aim of this study was to review the underlying architecture of this complex intracellular network and to discuss the alterations of its components that are evident after exposure to drugs of abuse. The aim was also to delineate the effects that manipulations of the mTOR network have on models of drug reward and on paradigms that recapitulate some of the psychological components of addiction. RESULTS There is evidence for the involvement of the mTOR pathway in the acute and rewarding effects of drugs of abuse, especially psychostimulants. However, the data regarding opiates are scarce. There is a need to use sophisticated animal models of addiction to ascertain the real role of the mTOR pathway in this pathology and not just in drug-mediated reward. The involvement of this pathway in behavioural addictions and impulsivity should also be studied in detail in the future. CONCLUSIONS Although there is a plethora of data about the modulation of mTOR by drugs of abuse, the involvement of this signalling pathway in addictive disorders requires further research.
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Affiliation(s)
- Marcos Ucha
- Department of Psychobiology, National University for Distance Learning (UNED), Madrid, Spain
| | - David Roura-Martínez
- Department of Psychobiology, National University for Distance Learning (UNED), Madrid, Spain
| | - Emilio Ambrosio
- Department of Psychobiology, National University for Distance Learning (UNED), Madrid, Spain
| | - Alejandro Higuera-Matas
- Department of Psychobiology, National University for Distance Learning (UNED), Madrid, Spain
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17
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Moon GJ, Shin M, Kim SR. Upregulation of Neuronal Rheb(S16H) for Hippocampal Protection in the Adult Brain. Int J Mol Sci 2020; 21:E2023. [PMID: 32188096 PMCID: PMC7139780 DOI: 10.3390/ijms21062023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/14/2020] [Accepted: 03/16/2020] [Indexed: 12/20/2022] Open
Abstract
Ras homolog protein enriched in brain (Rheb) is a key activator of mammalian target of rapamycin complex 1 (mTORC1). The activation of mTORC1 by Rheb is associated with various processes such as protein synthesis, neuronal growth, differentiation, axonal regeneration, energy homeostasis, autophagy, and amino acid uptake. In addition, Rheb-mTORC1 signaling plays a crucial role in preventing the neurodegeneration of hippocampal neurons in the adult brain. Increasing evidence suggests that the constitutive activation of Rheb has beneficial effects against neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Our recent studies revealed that adeno-associated virus serotype 1 (AAV1) transduction with Rheb(S16H), a constitutively active form of Rheb, exhibits neuroprotective properties through the induction of various neurotrophic factors, promoting neurotrophic interactions between neurons and astrocytes in the hippocampus of the adult brain. This review provides compelling evidence for the therapeutic potential of AAV1-Rheb(S16H) transduction in the hippocampus of the adult brain by exploring its neuroprotective effects and mechanisms.
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Affiliation(s)
- Gyeong Joon Moon
- BK21 plus KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea;
| | - Minsang Shin
- Brain Science and Engineering Institute, Kyungpook National University, Daegu 41566, Korea;
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu 41944, Korea
| | - Sang Ryong Kim
- BK21 plus KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea;
- Brain Science and Engineering Institute, Kyungpook National University, Daegu 41566, Korea;
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18
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Cioni JM, Wong HHW, Bressan D, Kodama L, Harris WA, Holt CE. Axon-Axon Interactions Regulate Topographic Optic Tract Sorting via CYFIP2-Dependent WAVE Complex Function. Neuron 2019. [PMID: 29518358 PMCID: PMC5855093 DOI: 10.1016/j.neuron.2018.01.027] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The axons of retinal ganglion cells (RGCs) are topographically sorted before they arrive at the optic tectum. This pre-target sorting, typical of axon tracts throughout the brain, is poorly understood. Here, we show that cytoplasmic FMR1-interacting proteins (CYFIPs) fulfill non-redundant functions in RGCs, with CYFIP1 mediating axon growth and CYFIP2 specifically involved in axon sorting. We find that CYFIP2 mediates homotypic and heterotypic contact-triggered fasciculation and repulsion responses between dorsal and ventral axons. CYFIP2 associates with transporting ribonucleoprotein particles in axons and regulates translation. Axon-axon contact stimulates CYFIP2 to move into growth cones where it joins the actin nucleating WAVE regulatory complex (WRC) in the periphery and regulates actin remodeling and filopodial dynamics. CYFIP2’s function in axon sorting is mediated by its binding to the WRC but not its translational regulation. Together, these findings uncover CYFIP2 as a key regulatory link between axon-axon interactions, filopodial dynamics, and optic tract sorting. CYFIP1 and CYFIP2 serve non-redundant functions in retinal axon growth and guidance CYFIP2 regulates growth cone filopodial dynamics and axon-axon responses CYFIP2 interacts with RNPs and the WRC in distinct cellular compartments Axon sorting is mediated by CYFIP2’s interaction with the WRC
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Affiliation(s)
- Jean-Michel Cioni
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK
| | - Hovy Ho-Wai Wong
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK
| | - Dario Bressan
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE, UK
| | - Lay Kodama
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK
| | - William A Harris
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK
| | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK.
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19
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Refueling the Ischemic CNS: Guidance Molecules for Vascular Repair. Trends Neurosci 2019; 42:644-656. [PMID: 31285047 DOI: 10.1016/j.tins.2019.05.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/09/2019] [Accepted: 05/20/2019] [Indexed: 12/30/2022]
Abstract
Stroke patients have only limited therapeutic options and often remain with considerable disabilities. To promote neurological recovery, angiogenesis in the ischemic peri-infarct region has been recognized as an encouraging therapeutic target. Despite advances in mechanistic understanding of vascular growth and repair, effective and safe angiogenic treatments are currently missing. Besides the most intensively studied angiogenic growth factors, recent research has indicated that the process of vascular sprouting and migration also requires the participation of guidance molecules, many of which were initially identified as regulators of axonal growth. Here, we review the inhibitory and growth-promoting effects of guidance molecules on the vascular system and discuss their potential as novel angiogenic targets for neurovascular diseases.
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20
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Wang D, Enck J, Howell BW, Olson EC. Ethanol Exposure Transiently Elevates but Persistently Inhibits Tyrosine Kinase Activity and Impairs the Growth of the Nascent Apical Dendrite. Mol Neurobiol 2019; 56:5749-5762. [PMID: 30674037 DOI: 10.1007/s12035-019-1473-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 01/10/2019] [Indexed: 12/11/2022]
Abstract
Dendritogenesis can be impaired by exposure to alcohol, and aspects of this impairment share phenotypic similarities to dendritic defects observed after blockade of the Reelin-Dab1 tyrosine kinase signaling pathway. In this study, we find that 10 min of alcohol exposure (400 mg/dL ethanol) by itself causes an unexpected increase in tyrosine phosphorylation of many proteins including Src and Dab1 that are essential downstream effectors of Reelin signaling. This increase in phosphotyrosine is dose-dependent and blockable by selective inhibitors of Src Family Kinases (SFKs). However, the response is transient, and phosphotyrosine levels return to baseline after 30 min of continuous ethanol exposure, both in vitro and in vivo. During this latter period, Src is inactivated and Reelin application cannot stimulate Dab1 phosphorylation. This suggests that ethanol initially activates but then silences the Reelin-Dab1 signaling pathway by brief activation and then sustained inactivation of SFKs. Time-lapse analyses of dendritic growth dynamics show an overall decrease in growth and branching compared to controls after ethanol-exposure that is similar to that observed with Reelin-deficiency. However, unlike Reelin-signaling disruptions, the dendritic filopodial speeds are decreased after ethanol exposure, and this decrease is associated with sustained dephosphorylation and activation of cofilin, an F-actin severing protein. These findings suggest that persistent Src inactivation coupled to cofilin activation may contribute to the dendritic disruptions observed with fetal alcohol exposure.
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Affiliation(s)
- Dandan Wang
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, 505 Irving Ave, Syracuse, NY, 13210, USA.,Developmental Exposure to Alcohol Research Center (DEARC), Binghamton University, Binghamton, NY, 13902, USA
| | - Joshua Enck
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, 505 Irving Ave, Syracuse, NY, 13210, USA.,Developmental Exposure to Alcohol Research Center (DEARC), Binghamton University, Binghamton, NY, 13902, USA
| | - Brian W Howell
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, 505 Irving Ave, Syracuse, NY, 13210, USA
| | - Eric C Olson
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, 505 Irving Ave, Syracuse, NY, 13210, USA. .,Developmental Exposure to Alcohol Research Center (DEARC), Binghamton University, Binghamton, NY, 13902, USA.
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21
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Leung KM, Lu B, Wong HHW, Lin JQ, Turner-Bridger B, Holt CE. Cue-Polarized Transport of β-actin mRNA Depends on 3'UTR and Microtubules in Live Growth Cones. Front Cell Neurosci 2018; 12:300. [PMID: 30250426 PMCID: PMC6139529 DOI: 10.3389/fncel.2018.00300] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/17/2018] [Indexed: 11/13/2022] Open
Abstract
Guidance cues trigger fast responses in axonal growth cones such as directional turning and collapse that require local protein synthesis. An attractive cue-gradient, such as Netrin-1, triggers de novo synthesis of β-actin localized to the near-side compartment of the growth cone that promotes F-actin assembly and attractive steering. How this precise spatial asymmetry in mRNA translation arises across the small expanse of the growth cone is poorly understood. Pre-localized mRNAs in the vicinity of activated receptors could be selectively translated and/or new mRNAs could be trafficked into the area. Here we have performed live imaging of fluorescent-tagged β-actin mRNA to investigate mRNA trafficking dynamics in Xenopus retinal ganglion cell (RGC) axons and growth cones in response to Netrin-1. A Netrin-1 gradient was found to elicit the transport of β-actin mRNA granules to the near-side of growth cones within a 4-7 min window. This polarized mRNA trafficking depended on the 3' untranslated region (UTR) since mRNA-Δ3'UTR mutant failed to exhibit cue-induced localization. Global application of Netrin-1 significantly increased the anterograde movement of β-actin mRNA along axons and also promoted microtubule-dependent mRNA excursions from the central domain of the growth cone into the periphery (filopodia and lamellipodia). Dual channel imaging revealed β-actin mRNA riding behind the microtubule plus-end tracking protein, EB1, in movements along dynamic microtubules into filopodia. The mRNA-EB1 movements were unchanged by a Netrin-1 gradient indicating the dynamic microtubules themselves do not underlie the cue-induced polarity of RNA movement. Finally, fast-moving elongated "worm-like" trains of Cy3-RNA, distinct from mitochondria, were seen transporting RNA along axons in vitro and in vivo suggesting the existence of a novel transport organelle. Overall, the results provide evidence that the axonal trafficking of β-actin mRNA can be regulated by the guidance cue Netrin-1 to transduce the polarity of an extracellular stimulus and that the 3'UTR is essential for this cue-induced regulation.
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Affiliation(s)
| | | | | | | | | | - Christine E. Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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22
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Khalil B, Morderer D, Price PL, Liu F, Rossoll W. mRNP assembly, axonal transport, and local translation in neurodegenerative diseases. Brain Res 2018; 1693:75-91. [PMID: 29462608 PMCID: PMC5997521 DOI: 10.1016/j.brainres.2018.02.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 01/31/2018] [Accepted: 02/13/2018] [Indexed: 12/12/2022]
Abstract
The development, maturation, and maintenance of the mammalian nervous system rely on complex spatiotemporal patterns of gene expression. In neurons, this is achieved by the expression of differentially localized isoforms and specific sets of mRNA-binding proteins (mRBPs) that regulate RNA processing, mRNA trafficking, and local protein synthesis at remote sites within dendrites and axons. There is growing evidence that axons contain a specialized transcriptome and are endowed with the machinery that allows them to rapidly alter their local proteome via local translation and protein degradation. This enables axons to quickly respond to changes in their environment during development, and to facilitate axon regeneration and maintenance in adult organisms. Aside from providing autonomy to neuronal processes, local translation allows axons to send retrograde injury signals to the cell soma. In this review, we discuss evidence that disturbances in mRNP transport, granule assembly, axonal localization, and local translation contribute to pathology in various neurodegenerative diseases, including spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and Alzheimer's disease (AD).
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Affiliation(s)
- Bilal Khalil
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Dmytro Morderer
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Phillip L Price
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA; Department of Cell Biology, Emory University, Atlanta, GA 30322 USA
| | - Feilin Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA; Eye Center, The Second Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Wilfried Rossoll
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA.
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23
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Hoshi O, Sugizaki A, Cho Y, Takei N. BDNF Reduces eEF2 Phosphorylation and Enhances Novel Protein Synthesis in the Growth Cones of Dorsal Root Ganglia Neurons. Neurochem Res 2018; 43:1242-1249. [PMID: 29736615 DOI: 10.1007/s11064-018-2541-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/19/2018] [Accepted: 04/27/2018] [Indexed: 11/26/2022]
Abstract
The local translation, which is regulated by extracellular stimuli such as guidance molecules, in growth cones of neurons provides a molecular mechanism for axonal development. In this study, we performed immunocytochemistry together with atomic force microscopy to investigate the localization of ribosomal proteins in the growth cones of rat dorsal root ganglion (DRG) neurons. The immunoreactivity of ribosomal protein P0/1/2 and S6, and novel protein synthesis were observed in the central, sterically bulky region of growth cones. Brain derived neurotrophic factor (BDNF) reduced the eEF2 phosphorylation, indicating its activation, and enhanced protein synthesis within 30 min. The effects of BDNF were completely inhibited by rapamycin, an inhibitor of mammalian target of rapamycin (mTOR). These results indicated that BDNF rapidly activates translation and enhances novel protein synthesis in growth cones of DRG though the mTOR signaling.
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Affiliation(s)
- Osamu Hoshi
- Department of Anatomy and Physiological Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
| | - Ayana Sugizaki
- Department of Anatomy and Physiological Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Yuichiro Cho
- Department of Anatomy and Physiological Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Nobuyuki Takei
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan.
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24
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Chudinova EM, Nadezhdina ES. Interactions between the Translation Machinery and Microtubules. BIOCHEMISTRY (MOSCOW) 2018; 83:S176-S189. [PMID: 29544439 DOI: 10.1134/s0006297918140146] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Microtubules are components of eukaryotic cytoskeleton that are involved in the transport of various components from the nucleus to the cell periphery and back. They also act as a platform for assembly of complex molecular ensembles. Ribonucleoprotein (RNP) complexes, such as ribosomes and mRNPs, are transported over significant distances (e.g. to neuronal processes) along microtubules. The association of RNPs with microtubules and their transport along these structures are essential for compartmentalization of protein biosynthesis in cells. Microtubules greatly facilitate assembly of stress RNP granules formed by accumulation of translation machinery components during cell stress response. Microtubules are necessary for the cytoplasm-to-nucleus transport of proteins, including ribosomal proteins. At the same time, ribosomal proteins and RNA-binding proteins can influence cell mobility and cytoplasm organization by regulating microtubule dynamics. The molecular mechanisms underlying the association between the translation machinery components and microtubules have not been studied systematically; the results of such studies are mostly fragmentary. In this review, we attempt to fill this gap by summarizing and discussing the data on protein and RNA components of the translation machinery that directly interact with microtubules or microtubule motor proteins.
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Affiliation(s)
- E M Chudinova
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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25
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Cioni JM, Koppers M, Holt CE. Molecular control of local translation in axon development and maintenance. Curr Opin Neurobiol 2018; 51:86-94. [PMID: 29549711 DOI: 10.1016/j.conb.2018.02.025] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 02/24/2018] [Accepted: 02/26/2018] [Indexed: 11/27/2022]
Abstract
The tips of axons are often far away from the cell soma where most proteins are synthesized. Recent work has revealed that axonal mRNA transport and localised translation are key regulatory mechanisms that allow these distant outposts of the cell to respond rapidly to extrinsic factors and maintain axonal homeostasis. Here, we review recent evidence pointing to an increasingly broad role for local protein synthesis in controlling axon shape, synaptogenesis and axon survival by regulating diverse cellular processes such as vesicle trafficking, cytoskeletal remodelling and mitochondrial integrity. We further highlight current research on the regulatory mechanisms that coordinate the localization and translation of functionally linked mRNAs in axons.
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Affiliation(s)
- Jean-Michel Cioni
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Max Koppers
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK.
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26
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A heterogeneous tRNA granule structure exhibiting rapid, bi-directional neuritic transport. Eur J Cell Biol 2018; 97:168-179. [PMID: 29482850 DOI: 10.1016/j.ejcb.2018.02.002] [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: 12/15/2017] [Revised: 02/09/2018] [Accepted: 02/12/2018] [Indexed: 11/23/2022] Open
Abstract
mRNA translation is regulated by diverse mechanisms that converge at the initiation and elongation steps to determine the rate, profile, and localization of proteins synthesized. A consistently relevant feature of these mechanisms is the spatial re-distribution of translation machinery, a process of particular importance in neural cells. This process has, however, been largely overlooked with respect to its potential role in regulating the local concentration of cytoplasmic tRNAs, even as a multitude of data suggest that spatial regulation of the tRNA pool may help explain the remarkably high rates of peptide elongation. Here, we report that Cy3/Cy5-labeled bulk tRNAs transfected into neural cells distribute into granule-like structures - "tRNA granules" - that exhibit dynamic mixing of tRNAs between granules and rapid, bi-directional vectorial movement within neurites. Imaging of endogenous tRNAgly and tRNAlys by fluorescent in situ hybridization revealed a similar granular distribution of tRNAs in somata and neurites; this distribution was highly overlapping with granules imaged by introduction of exogenous Cy5-tRNAthr and Cy3-tRNAval. A subset of tRNA granules located in the cell body, neurite branch points and growth cones displayed fluorescence resonance energy transfer (FRET) between Cy3 and Cy5-labeled tRNAs indicative of translation, and co-localization with elongation machinery. A population of smaller, rapidly trafficked granules in neurites lacked FRET and showed poor colocalization with translation initiation and elongation factors, suggesting that they are a translationally inactive tRNA transport particle. Our data suggest that tRNAs are packaged into granules that are rapidly transported to loci where translation is needed, where they may greatly increase the local concentration of tRNAs in support of efficient elongation. The potential implications of this newly described structure for channeling of elongation, local translation, and diseases associated with altered tRNA levels or function are discussed.
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27
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Wong HHW, Lin JQ, Ströhl F, Roque CG, Cioni JM, Cagnetta R, Turner-Bridger B, Laine RF, Harris WA, Kaminski CF, Holt CE. RNA Docking and Local Translation Regulate Site-Specific Axon Remodeling In Vivo. Neuron 2017; 95:852-868.e8. [PMID: 28781168 PMCID: PMC5563073 DOI: 10.1016/j.neuron.2017.07.016] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 06/09/2017] [Accepted: 07/14/2017] [Indexed: 12/03/2022]
Abstract
Nascent proteins can be positioned rapidly at precise subcellular locations by local protein synthesis (LPS) to facilitate localized growth responses. Axon arbor architecture, a major determinant of synaptic connectivity, is shaped by localized growth responses, but it is unknown whether LPS influences these responses in vivo. Using high-resolution live imaging, we examined the spatiotemporal dynamics of RNA and LPS in retinal axons during arborization in vivo. Endogenous RNA tracking reveals that RNA granules dock at sites of branch emergence and invade stabilized branches. Live translation reporter analysis reveals that de novo β-actin hotspots colocalize with docked RNA granules at the bases and tips of new branches. Inhibition of axonal β-actin mRNA translation disrupts arbor dynamics primarily by reducing new branch emergence and leads to impoverished terminal arbors. The results demonstrate a requirement for LPS in building arbor complexity and suggest a key role for pre-synaptic LPS in assembling neural circuits. Tracking endogenous RNA shows that RNA docking predicts axon branch emergence in vivo Axon arbor complexity in vivo depends on local protein synthesis Axonal β-actin synthesis regulates branching by increased branch initiation Live imaging reveals de novo synthesis of β-actin hotspots during branch formation
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Affiliation(s)
- Hovy Ho-Wai Wong
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Julie Qiaojin Lin
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Florian Ströhl
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Cláudio Gouveia Roque
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Jean-Michel Cioni
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Roberta Cagnetta
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Benita Turner-Bridger
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Romain F Laine
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - William A Harris
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK.
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28
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Swiatkowski P, Nikolaeva I, Kumar G, Zucco A, Akum BF, Patel MV, D'Arcangelo G, Firestein BL. Role of Akt-independent mTORC1 and GSK3β signaling in sublethal NMDA-induced injury and the recovery of neuronal electrophysiology and survival. Sci Rep 2017; 7:1539. [PMID: 28484273 PMCID: PMC5431483 DOI: 10.1038/s41598-017-01826-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 04/03/2017] [Indexed: 01/02/2023] Open
Abstract
Glutamate-induced excitotoxicity, mediated by overstimulation of N-methyl-D-aspartate (NMDA) receptors, is a mechanism that causes secondary damage to neurons. The early phase of injury causes loss of dendritic spines and changes to synaptic activity. The phosphatidylinositol-4,5-bisphosphate 3-kinase/Akt/ mammalian target of rapamycin (PI3K/Akt/mTOR) pathway has been implicated in the modulation and regulation of synaptic strength, activity, maturation, and axonal regeneration. The present study focuses on the physiology and survival of neurons following manipulation of Akt and several downstream targets, such as GSK3β, FOXO1, and mTORC1, prior to NMDA-induced injury. Our analysis reveals that exposure to sublethal levels of NMDA does not alter phosphorylation of Akt, S6, and GSK3β at two and twenty four hours following injury. Electrophysiological recordings show that NMDA-induced injury causes a significant decrease in spontaneous excitatory postsynaptic currents at both two and twenty four hours, and this phenotype can be prevented by inhibiting mTORC1 or GSK3β, but not Akt. Additionally, inhibition of mTORC1 or GSK3β promotes neuronal survival following NMDA-induced injury. Thus, NMDA-induced excitotoxicity involves a mechanism that requires the permissive activity of mTORC1 and GSK3β, demonstrating the importance of these kinases in the neuronal response to injury.
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Affiliation(s)
- Przemyslaw Swiatkowski
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Molecular Biosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Ina Nikolaeva
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Molecular Biosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Gaurav Kumar
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Avery Zucco
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Neurosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Barbara F Akum
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Mihir V Patel
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Neurosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Gabriella D'Arcangelo
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.
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29
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Switon K, Kotulska K, Janusz-Kaminska A, Zmorzynska J, Jaworski J. Molecular neurobiology of mTOR. Neuroscience 2017; 341:112-153. [PMID: 27889578 DOI: 10.1016/j.neuroscience.2016.11.017] [Citation(s) in RCA: 263] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/09/2016] [Accepted: 11/13/2016] [Indexed: 01/17/2023]
Abstract
Mammalian/mechanistic target of rapamycin (mTOR) is a serine-threonine kinase that controls several important aspects of mammalian cell function. mTOR activity is modulated by various intra- and extracellular factors; in turn, mTOR changes rates of translation, transcription, protein degradation, cell signaling, metabolism, and cytoskeleton dynamics. mTOR has been repeatedly shown to participate in neuronal development and the proper functioning of mature neurons. Changes in mTOR activity are often observed in nervous system diseases, including genetic diseases (e.g., tuberous sclerosis complex, Pten-related syndromes, neurofibromatosis, and Fragile X syndrome), epilepsy, brain tumors, and neurodegenerative disorders (Alzheimer's disease, Parkinson's disease, and Huntington's disease). Neuroscientists only recently began deciphering the molecular processes that are downstream of mTOR that participate in proper function of the nervous system. As a result, we are gaining knowledge about the ways in which aberrant changes in mTOR activity lead to various nervous system diseases. In this review, we provide a comprehensive view of mTOR in the nervous system, with a special focus on the neuronal functions of mTOR (e.g., control of translation, transcription, and autophagy) that likely underlie the contribution of mTOR to nervous system diseases.
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Affiliation(s)
- Katarzyna Switon
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Aleja Dzieci Polskich 20, Warsaw 04-730, Poland
| | | | - Justyna Zmorzynska
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland
| | - Jacek Jaworski
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland.
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30
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Ylivinkka I, Keski-Oja J, Hyytiäinen M. Netrin-1: A regulator of cancer cell motility? Eur J Cell Biol 2016; 95:513-520. [PMID: 27793362 DOI: 10.1016/j.ejcb.2016.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 09/20/2016] [Accepted: 10/04/2016] [Indexed: 02/01/2023] Open
Abstract
Netrins form a family of secreted and membrane-associated proteins, netrin-1 being the prototype and most investigated member of the family. The major physiological functions of netrin-1 lie in the regulation of axonal development as well as morphogenesis of different branched organs, by promoting the polarity of migratory/invasive front of the cell. On the other hand, netrin-1 acts as a factor preventing cell apoptosis. These events are mediated via a range of different receptors, including UNC5 and DCC-families. Cancer cells often employ developmental pathways to gain survival and motility advantage. Within recent years, there has been increasing number of observations of upregulation of netrin-1 expression in different forms of cancer, and the increased expression of netrin-1 has been linked to its functions as a survival and invasion promoting factor. We review here recent advances in the netrin-1 related developmental processes that may be of special interest in tumor biology, in addition to the known functions of netrin-1 in tumor biology with special focus on cancer cell migration.
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Affiliation(s)
- Irene Ylivinkka
- Translational Cancer Biology Research Program, Faculty of Medicine, University of Helsinki, Finland; The Hospital District of Helsinki and Uusimaa, Finland
| | - Jorma Keski-Oja
- Translational Cancer Biology Research Program, Faculty of Medicine, University of Helsinki, Finland; The Hospital District of Helsinki and Uusimaa, Finland
| | - Marko Hyytiäinen
- Translational Cancer Biology Research Program, Faculty of Medicine, University of Helsinki, Finland.
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31
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Korsak LIT, Mitchell ME, Shepard KA, Akins MR. Regulation of neuronal gene expression by local axonal translation. CURRENT GENETIC MEDICINE REPORTS 2016; 4:16-25. [PMID: 27722035 DOI: 10.1007/s40142-016-0085-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
RNA localization is a key mechanism in the regulation of protein expression. In neurons, this includes the axonal transport of select mRNAs based on the recognition of axonal localization motifs in these RNAs by RNA binding proteins. Bioinformatic analyses of axonal RNAs suggest that selective inclusion of such localization motifs in mature mRNAs is one mechanism controlling the composition of the axonal transcriptome. The subsequent translation of axonal transcripts in response to specific stimuli provides precise spatiotemporal control of the axonal proteome. This axonal translation supports local phenomena including axon pathfinding, mitochondrial function, and synapse-specific plasticity. Axonal protein synthesis also provides transport machinery and signals for retrograde trafficking to the cell body to effect somatic changes including altering the transcriptional program. Here we review the remarkable progress made in recent years to identify and characterize these phenomena.
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Affiliation(s)
- Lulu I T Korsak
- Drexel University, PISB 312; 3245 Chestnut St, Philadelphia, PA 19104,
| | - Molly E Mitchell
- Drexel University, PISB 312; 3245 Chestnut St, Philadelphia, PA 19104,
| | | | - Michael R Akins
- Assistant Professor, Department of Biology, Department of Neurobiology & Anatomy, Drexel University, PISB 319; 3245 Chestnut St, Philadelphia, PA 19104,
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32
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Yang Y, Zhao B, Ji Z, Zhang G, Zhang J, Li S, Guo G, Lin H. CRMPs colocalize and interact with cytoskeleton in hippocampal neurons. Int J Clin Exp Med 2015; 8:22337-22344. [PMID: 26885211 PMCID: PMC4729997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/05/2015] [Indexed: 06/05/2023]
Abstract
CRMP family proteins (CRMPs) are widely expressed in the developing neurons, mediating a variety of fundamental functions such as growth cone guidance, neuronal polarity and axon elongation. However, whether all the CRMP proteins interact with cytoskeleton remains unknown. In this study, we found that in cultured hippocampal neurons, CRMPs mainly colocalized with tubulin and actin network in neurites. In growth cones, CRMPs colocalized with tubulinmainly in the central (C-) domain and transition zone (T-zone), less in the peripheral (P-) domain and colocalized with actin in all the C-domain, T-zone and P-domain. The correlation efficiency of CRMPs between actin was significantly higher than that between tubulin, especially in growth cones. We successfully constructed GST-CRMPs plasmids, expressed and purified the GST-CRMP proteins. By GST-pulldown assay, all the CRMP family proteins were found to beinteracted with cytoskeleton proteins. Taken together, we revealed that CRMPs were colocalized with cytoskeleton in hippocampal neurons, especially in growth cones. CRMPs can interact with both tubulin and actin, thus mediating neuronal development.
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Affiliation(s)
- Yuhao Yang
- Department of Orthopedics, The First Affiliated Hospital of Jinan UniversityGuangzhou 510630, China
- Department of Anatomy, Medical College of Jinan UniversityGuangzhou 510630, China
| | - Bo Zhao
- Department of Anatomy, Medical College of Jinan UniversityGuangzhou 510630, China
| | - Zhisheng Ji
- Department of Orthopedics, The First Affiliated Hospital of Jinan UniversityGuangzhou 510630, China
- Department of Anatomy, Medical College of Jinan UniversityGuangzhou 510630, China
| | - Guowei Zhang
- Department of Orthopedics, The First Affiliated Hospital of Jinan UniversityGuangzhou 510630, China
| | - Jifeng Zhang
- Department of Anatomy, Medical College of Jinan UniversityGuangzhou 510630, China
| | - Sumei Li
- Department of Anatomy, Medical College of Jinan UniversityGuangzhou 510630, China
| | - Guoqing Guo
- Department of Anatomy, Medical College of Jinan UniversityGuangzhou 510630, China
| | - Hongsheng Lin
- Department of Orthopedics, The First Affiliated Hospital of Jinan UniversityGuangzhou 510630, China
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33
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Piper M, Lee AC, van Horck FPG, McNeilly H, Lu TB, Harris WA, Holt CE. Erratum to: Differential requirement of F-actin and microtubule cytoskeleton in cue-induced local protein synthesis in axonal growth cones. Neural Dev 2015; 10:16. [PMID: 26088085 PMCID: PMC4474465 DOI: 10.1186/s13064-015-0043-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Michael Piper
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing street, Cambridge, CB2 3DY, UK.,Current address: The School of Biomedical Sciences and the Queensland Brain Institute, The University of Queensland, St Lucia, 4072, QLD, Australia
| | - Aih Cheun Lee
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing street, Cambridge, CB2 3DY, UK.,Current address: Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Francisca P G van Horck
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing street, Cambridge, CB2 3DY, UK
| | - Heather McNeilly
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing street, Cambridge, CB2 3DY, UK
| | - Trina Bo Lu
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing street, Cambridge, CB2 3DY, UK
| | - William A Harris
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing street, Cambridge, CB2 3DY, UK
| | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing street, Cambridge, CB2 3DY, UK.
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