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Chaudhari K, Zhang K, Yam PT, Zang Y, Kramer DA, Gagnon S, Schlienger S, Calabretta S, Michaud JF, Collins M, Wang J, Srour M, Chen B, Charron F, Bashaw GJ. A human DCC variant causing mirror movement disorder reveals that the WAVE regulatory complex mediates axon guidance by netrin-1-DCC. Sci Signal 2024; 17:eadk2345. [PMID: 39353037 DOI: 10.1126/scisignal.adk2345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 05/06/2024] [Accepted: 09/06/2024] [Indexed: 10/04/2024]
Abstract
The axon guidance cue netrin-1 signals through its receptor DCC (deleted in colorectal cancer) to attract commissural axons to the midline. Variants in DCC are frequently associated with congenital mirror movements (CMMs). A CMM-associated variant in the cytoplasmic tail of DCC is located in a conserved motif predicted to bind to a regulator of actin dynamics called the WAVE (Wiskott-Aldrich syndrome protein-family verprolin homologous protein) regulatory complex (WRC). Here, we explored how this variant affects DCC function and may contribute to CMM. We found that a conserved WRC-interacting receptor sequence (WIRS) motif in the cytoplasmic tail of DCC mediated the interaction between DCC and the WRC. This interaction was required for netrin-1-mediated axon guidance in cultured rodent commissural neurons. Furthermore, the WIRS motif of Fra, the Drosophila DCC ortholog, was required for attractive signaling in vivo at the Drosophila midline. The CMM-associated R1343H variant of DCC, which altered the WIRS motif, prevented the DCC-WRC interaction and impaired axon guidance in cultured commissural neurons and in Drosophila. The findings reveal the WRC as a pivotal component of netrin-1-DCC signaling and uncover a molecular mechanism explaining how a human genetic variant in the cytoplasmic tail of DCC may lead to CMM.
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Affiliation(s)
- Karina Chaudhari
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kaiyue Zhang
- Montreal Clinical Research Institute (IRCM), Montreal, QC H2W 1R7, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B4, Canada
| | - Patricia T Yam
- Montreal Clinical Research Institute (IRCM), Montreal, QC H2W 1R7, Canada
| | - Yixin Zang
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Daniel A Kramer
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Sarah Gagnon
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sabrina Schlienger
- Montreal Clinical Research Institute (IRCM), Montreal, QC H2W 1R7, Canada
- Department of Anatomy and Cell Biology, Division of Experimental Medicine, McGill University, Montreal, QC H3A 0G4, Canada
| | - Sara Calabretta
- Montreal Clinical Research Institute (IRCM), Montreal, QC H2W 1R7, Canada
| | | | - Meagan Collins
- McGill University Health Center Research Institute, Montreal, QC H4A 3J1, Canada
| | - Junmei Wang
- Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Myriam Srour
- McGill University Health Center Research Institute, Montreal, QC H4A 3J1, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada
- Department of Pediatrics, Division of Pediatric Neurology, McGill University, Montreal, QC H4A 3J1, Canada
| | - Baoyu Chen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Frédéric Charron
- Montreal Clinical Research Institute (IRCM), Montreal, QC H2W 1R7, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B4, Canada
- Department of Anatomy and Cell Biology, Division of Experimental Medicine, McGill University, Montreal, QC H3A 0G4, Canada
- Department of Medicine, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Greg J Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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2
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Brugger M, Lauri A, Zhen Y, Gramegna LL, Zott B, Sekulić N, Fasano G, Kopajtich R, Cordeddu V, Radio FC, Mancini C, Pizzi S, Paradisi G, Zanni G, Vasco G, Carrozzo R, Palombo F, Tonon C, Lodi R, La Morgia C, Arelin M, Blechschmidt C, Finck T, Sørensen V, Kreiser K, Strobl-Wildemann G, Daum H, Michaelson-Cohen R, Ziccardi L, Zampino G, Prokisch H, Abou Jamra R, Fiorini C, Arzberger T, Winkelmann J, Caporali L, Carelli V, Stenmark H, Tartaglia M, Wagner M. Bi-allelic variants in SNF8 cause a disease spectrum ranging from severe developmental and epileptic encephalopathy to syndromic optic atrophy. Am J Hum Genet 2024; 111:594-613. [PMID: 38423010 PMCID: PMC10940020 DOI: 10.1016/j.ajhg.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 02/07/2024] [Accepted: 02/07/2024] [Indexed: 03/02/2024] Open
Abstract
The endosomal sorting complex required for transport (ESCRT) machinery is essential for membrane remodeling and autophagy and it comprises three multi-subunit complexes (ESCRT I-III). We report nine individuals from six families presenting with a spectrum of neurodevelopmental/neurodegenerative features caused by bi-allelic variants in SNF8 (GenBank: NM_007241.4), encoding the ESCRT-II subunit SNF8. The phenotypic spectrum included four individuals with severe developmental and epileptic encephalopathy, massive reduction of white matter, hypo-/aplasia of the corpus callosum, neurodevelopmental arrest, and early death. A second cohort shows a milder phenotype with intellectual disability, childhood-onset optic atrophy, or ataxia. All mildly affected individuals shared the same hypomorphic variant, c.304G>A (p.Val102Ile). In patient-derived fibroblasts, bi-allelic SNF8 variants cause loss of ESCRT-II subunits. Snf8 loss of function in zebrafish results in global developmental delay and altered embryo morphology, impaired optic nerve development, and reduced forebrain size. In vivo experiments corroborated the pathogenicity of the tested SNF8 variants and their variable impact on embryo development, validating the observed clinical heterogeneity. Taken together, we conclude that loss of ESCRT-II due to bi-allelic SNF8 variants is associated with a spectrum of neurodevelopmental/neurodegenerative phenotypes mediated likely via impairment of the autophagic flux.
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Affiliation(s)
- Melanie Brugger
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
| | - Antonella Lauri
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
| | - Yan Zhen
- Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Laura L Gramegna
- IRCCS Istituto Delle Scienze Neurologiche di Bologna, Programma Neuroimmagini Funzionali e Molecolari, Bologna, Italy; Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Benedikt Zott
- Department of Diagnostic and Interventional Neuroradiology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany; Institute of Neuroscience, Technical University of Munich, Munich, Germany
| | - Nikolina Sekulić
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, Norway
| | - Giulia Fasano
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
| | - Robert Kopajtich
- Institute of Human Genetics, Technical University of Munich, Munich, Germany; Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Viviana Cordeddu
- Dipartimento di Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Rome, Italy
| | | | - Cecilia Mancini
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
| | - Simone Pizzi
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
| | - Graziamaria Paradisi
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy
| | - Ginevra Zanni
- Unit of Muscular and Neurodegenerative Disorders and Unit of Developmental Neurology Piazza S. Onofrio 4, 00165 Rome, Italy
| | - Gessica Vasco
- Department of Neurorehabilitation and Robotics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Rosalba Carrozzo
- Translational Pediatrics and Clinical Genetics Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Flavia Palombo
- IRCCS Istituto Delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Caterina Tonon
- IRCCS Istituto Delle Scienze Neurologiche di Bologna, Programma Neuroimmagini Funzionali e Molecolari, Bologna, Italy; Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Raffaele Lodi
- IRCCS Istituto Delle Scienze Neurologiche di Bologna, Programma Neuroimmagini Funzionali e Molecolari, Bologna, Italy; Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Chiara La Morgia
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy; IRCCS Istituto Delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Maria Arelin
- Department for Women and Child Health, Hospital for Children and Adolescents, University Hospitals, University of Leipzig, Leipzig, Germany
| | | | - Tom Finck
- Department of Diagnostic and Interventional Neuroradiology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Vigdis Sørensen
- Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Kornelia Kreiser
- Department of Radiology and Neuroradiology, Rehabilitation and University Hospital Ulm, Ulm, Germany
| | | | - Hagit Daum
- Department of Genetics, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rachel Michaelson-Cohen
- Department of Gynecology, Shaare Zedek Medical Center, Jerusalem, Israel; Medical Genetics Unit, Shaare Zedek Medical Center, Jerusalem, Israel
| | | | - Giuseppe Zampino
- Center for Rare Diseases and Birth Defects, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Università Cattolica Sacro Cuore, Rome, Italy
| | - Holger Prokisch
- Institute of Human Genetics, Technical University of Munich, Munich, Germany; Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Rami Abou Jamra
- Institute of Human Genetics, University Medical Center Leipzig, Leipzig, Germany
| | - Claudio Fiorini
- IRCCS Istituto Delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Thomas Arzberger
- Department of Psychiatry and Psychotherapy, University Hospital, Ludwig-Maximilians-University, Munich, Germany; Center for Neuropathology and Prion Research, University Hospital Munich, Ludwig-Maximilians-University, Munich, Germany
| | - Juliane Winkelmann
- Institute of Human Genetics, Technical University of Munich, Munich, Germany; Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Leonardo Caporali
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy; IRCCS Istituto Delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy; IRCCS Istituto Delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Harald Stenmark
- Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Marco Tartaglia
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy.
| | - Matias Wagner
- Institute of Human Genetics, Technical University of Munich, Munich, Germany; Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany; Division of Pediatric Neurology, LMU Center for Development and Children with Medical Complexity, Ludwig-Maximilians-University Munich, Munich, Germany.
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3
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Otis JP, Mowry KL. Hitting the mark: Localization of mRNA and biomolecular condensates in health and disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1807. [PMID: 37393916 PMCID: PMC10758526 DOI: 10.1002/wrna.1807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/29/2023] [Accepted: 06/06/2023] [Indexed: 07/04/2023]
Abstract
Subcellular mRNA localization is critical to a multitude of biological processes such as development of cellular polarity, embryogenesis, tissue differentiation, protein complex formation, cell migration, and rapid responses to environmental stimuli and synaptic depolarization. Our understanding of the mechanisms of mRNA localization must now be revised to include formation and trafficking of biomolecular condensates, as several biomolecular condensates that transport and localize mRNA have recently been discovered. Disruptions in mRNA localization can have catastrophic effects on developmental processes and biomolecular condensate biology and have been shown to contribute to diverse diseases. A fundamental understanding of mRNA localization is essential to understanding how aberrations in this biology contribute the etiology of numerous cancers though support of cancer cell migration and biomolecular condensate dysregulation, as well as many neurodegenerative diseases, through misregulation of mRNA localization and biomolecular condensate biology. This article is categorized under: RNA Export and Localization > RNA Localization RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Jessica P. Otis
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, United States, 02912
| | - Kimberly L. Mowry
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, United States, 02912
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4
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Dalla Costa I, Buchanan CN, Zdradzinski MD, Sahoo PK, Smith TP, Thames E, Kar AN, Twiss JL. The functional organization of axonal mRNA transport and translation. Nat Rev Neurosci 2021; 22:77-91. [PMID: 33288912 PMCID: PMC8161363 DOI: 10.1038/s41583-020-00407-7] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2020] [Indexed: 12/13/2022]
Abstract
Axons extend for tremendously long distances from the neuronal soma and make use of localized mRNA translation to rapidly respond to different extracellular stimuli and physiological states. The locally synthesized proteins support many different functions in both developing and mature axons, raising questions about the mechanisms by which local translation is organized to ensure the appropriate responses to specific stimuli. Publications over the past few years have uncovered new mechanisms for regulating the axonal transport and localized translation of mRNAs, with several of these pathways converging on the regulation of cohorts of functionally related mRNAs - known as RNA regulons - that drive axon growth, axon guidance, injury responses, axon survival and even axonal mitochondrial function. Recent advances point to these different regulatory pathways as organizing platforms that allow the axon's proteome to be modulated to meet its physiological needs.
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Affiliation(s)
- Irene Dalla Costa
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Courtney N Buchanan
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | | | - Pabitra K Sahoo
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Terika P Smith
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Elizabeth Thames
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Amar N Kar
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA.
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5
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Pasterkamp RJ, Burk K. Axon guidance receptors: Endocytosis, trafficking and downstream signaling from endosomes. Prog Neurobiol 2020; 198:101916. [PMID: 32991957 DOI: 10.1016/j.pneurobio.2020.101916] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/06/2020] [Accepted: 09/21/2020] [Indexed: 02/06/2023]
Abstract
During the development of the nervous system, axons extend through complex environments. Growth cones at the axon tip allow axons to find and innervate their appropriate targets and form functional synapses. Axon pathfinding requires axons to respond to guidance signals and these cues need to be detected by specialized receptors followed by intracellular signal integration and translation. Several downstream signaling pathways have been identified for axon guidance receptors and it has become evident that these pathways are often initiated from intracellular vesicles called endosomes. Endosomes allow receptors to traffic intracellularly, re-locating receptors from one cellular region to another. The localization of axon guidance receptors to endosomal compartments is crucial for their function, signaling output and expression levels. For example, active receptors within endosomes can recruit downstream proteins to the endosomal membrane and facilitate signaling. Also, endosomal trafficking can re-locate receptors back to the plasma membrane to allow re-activation or mediate downregulation of receptor signaling via degradation. Accumulating evidence suggests that axon guidance receptors do not follow a pre-set default trafficking route but may change their localization within endosomes. This re-routing appears to be spatially and temporally regulated, either by expression of adaptor proteins or co-receptors. These findings shed light on how signaling in axon guidance is regulated and diversified - a mechanism which explains how a limited set of guidance cues can help to establish billions of neuronal connections. In this review, we summarize and discuss our current knowledge of axon guidance receptor trafficking and provide directions for future research.
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Affiliation(s)
- R J Pasterkamp
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, 3584 CG Utrecht, the Netherlands.
| | - K Burk
- Department of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany; Center for Biostructural Imaging of Neurodegeneration, 37075 Göttingen, Germany.
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Corradi E, Dalla Costa I, Gavoci A, Iyer A, Roccuzzo M, Otto TA, Oliani E, Bridi S, Strohbuecker S, Santos-Rodriguez G, Valdembri D, Serini G, Abreu-Goodger C, Baudet ML. Axonal precursor miRNAs hitchhike on endosomes and locally regulate the development of neural circuits. EMBO J 2020; 39:e102513. [PMID: 32073171 PMCID: PMC7073465 DOI: 10.15252/embj.2019102513] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 12/24/2019] [Accepted: 01/17/2020] [Indexed: 12/22/2022] Open
Abstract
Various species of non‐coding RNAs (ncRNAs) are enriched in specific subcellular compartments, but the mechanisms orchestrating their localization and their local functions remain largely unknown. We investigated both aspects using the elongating retinal ganglion cell axon and its tip, the growth cone, as models. We reveal that specific endogenous precursor microRNAs (pre‐miRNAs) are actively trafficked to distal axons by hitchhiking primarily on late endosomes/lysosomes. Upon exposure to the axon guidance cue semaphorin 3A (Sema3A), pre‐miRNAs are processed specifically within axons into newly generated miRNAs, one of which, in turn, silences the basal translation of tubulin beta 3 class III (TUBB3), but not amyloid beta precursor protein (APP). At the organismal level, these mature miRNAs are required for growth cone steering and a fully functional visual system. Overall, our results uncover a novel mode of ncRNA transport from one cytosolic compartment to another within polarized cells. They also reveal that newly generated miRNAs are critical components of a ncRNA‐based signaling pathway that transduces environmental signals into the structural remodeling of subcellular compartments.
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Affiliation(s)
- Eloina Corradi
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Irene Dalla Costa
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Antoneta Gavoci
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Archana Iyer
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Michela Roccuzzo
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Tegan A Otto
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Eleonora Oliani
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Simone Bridi
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Stephanie Strohbuecker
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | | | - Donatella Valdembri
- Candiolo Cancer Institute, FPO-IRCCS, Candiolo, Torino, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | - Guido Serini
- Candiolo Cancer Institute, FPO-IRCCS, Candiolo, Torino, Italy.,Department of Oncology, University of Torino School of Medicine, Candiolo, Italy
| | | | - Marie-Laure Baudet
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
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7
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Nawalpuri B, Ravindran S, Muddashetty RS. The Role of Dynamic miRISC During Neuronal Development. Front Mol Biosci 2020; 7:8. [PMID: 32118035 PMCID: PMC7025485 DOI: 10.3389/fmolb.2020.00008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 01/10/2020] [Indexed: 12/17/2022] Open
Abstract
Activity-dependent protein synthesis plays an important role during neuronal development by fine-tuning the formation and function of neuronal circuits. Recent studies have shown that miRNAs are integral to this regulation because of their ability to control protein synthesis in a rapid, specific and potentially reversible manner. miRNA mediated regulation is a multistep process that involves inhibition of translation before degradation of targeted mRNA, which provides the possibility to store and reverse the inhibition at multiple stages. This flexibility is primarily thought to be derived from the composition of miRNA induced silencing complex (miRISC). AGO2 is likely the only obligatory component of miRISC, while multiple RBPs are shown to be associated with this core miRISC to form diverse miRISC complexes. The formation of these heterogeneous miRISC complexes is intricately regulated by various extracellular signals and cell-specific contexts. In this review, we discuss the composition of miRISC and its functions during neuronal development. Neurodevelopment is guided by both internal programs and external cues. Neuronal activity and external signals play an important role in the formation and refining of the neuronal network. miRISC composition and diversity have a critical role at distinct stages of neurodevelopment. Even though there is a good amount of literature available on the role of miRNAs mediated regulation of neuronal development, surprisingly the role of miRISC composition and its functional dynamics in neuronal development is not much discussed. In this article, we review the available literature on the heterogeneity of the neuronal miRISC composition and how this may influence translation regulation in the context of neuronal development.
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Affiliation(s)
- Bharti Nawalpuri
- Centre for Brain Development and Repair, Institute for Stem Cell Science and Regenerative Medicine (Instem), Bangalore, India.,School of Chemical and Biotechnology, Shanmugha Arts, Science, and Technology and Research Academy (SASTRA) University, Thanjavur, India
| | - Sreenath Ravindran
- Centre for Brain Development and Repair, Institute for Stem Cell Science and Regenerative Medicine (Instem), Bangalore, India.,Manipal Academy of Higher Education, Manipal, India
| | - Ravi S Muddashetty
- Centre for Brain Development and Repair, Institute for Stem Cell Science and Regenerative Medicine (Instem), Bangalore, India
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8
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Pushpalatha KV, Besse F. Local Translation in Axons: When Membraneless RNP Granules Meet Membrane-Bound Organelles. Front Mol Biosci 2019; 6:129. [PMID: 31824961 PMCID: PMC6882739 DOI: 10.3389/fmolb.2019.00129] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 11/06/2019] [Indexed: 12/14/2022] Open
Abstract
Eukaryotic cell compartmentalization relies on long-known membrane-delimited organelles, as well as on more recently discovered membraneless macromolecular condensates. How these two types of organelles interact to regulate cellular functions is still largely unclear. In this review, we highlight how membraneless ribonucleoprotein (RNP) organelles, enriched in RNAs and associated regulatory proteins, cooperate with membrane-bound organelles for tight spatio-temporal control of gene expression in the axons of neuronal cells. Specifically, we present recent evidence that motile membrane-bound organelles are used as vehicles by RNP cargoes, promoting the long-range transport of mRNA molecules to distal axons. As demonstrated by recent work, membrane-bound organelles also promote local protein synthesis, by serving as platforms for the local translation of mRNAs recruited to their outer surface. Furthermore, dynamic and specific association between RNP cargoes and membrane-bound organelles is mediated by bi-partite adapter molecules that interact with both types of organelles selectively, in a regulated-manner. Maintaining such a dynamic interplay is critical, as alterations in this process are linked to neurodegenerative diseases. Together, emerging studies thus point to the coordination of membrane-bound and membraneless organelles as an organizing principle underlying local cellular responses.
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Affiliation(s)
| | - Florence Besse
- Université Côte d'Azur, CNRS, Inserm, Institut de Biology Valrose, Nice, France
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9
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Koppers M, Cagnetta R, Shigeoka T, Wunderlich LCS, Vallejo-Ramirez P, Qiaojin Lin J, Zhao S, Jakobs MAH, Dwivedy A, Minett MS, Bellon A, Kaminski CF, Harris WA, Flanagan JG, Holt CE. Receptor-specific interactome as a hub for rapid cue-induced selective translation in axons. eLife 2019; 8:e48718. [PMID: 31746735 PMCID: PMC6894925 DOI: 10.7554/elife.48718] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 11/19/2019] [Indexed: 12/17/2022] Open
Abstract
Extrinsic cues trigger the local translation of specific mRNAs in growing axons via cell surface receptors. The coupling of ribosomes to receptors has been proposed as a mechanism linking signals to local translation but it is not known how broadly this mechanism operates, nor whether it can selectively regulate mRNA translation. We report that receptor-ribosome coupling is employed by multiple guidance cue receptors and this interaction is mRNA-dependent. We find that different receptors associate with distinct sets of mRNAs and RNA-binding proteins. Cue stimulation of growing Xenopus retinal ganglion cell axons induces rapid dissociation of ribosomes from receptors and the selective translation of receptor-specific mRNAs. Further, we show that receptor-ribosome dissociation and cue-induced selective translation are inhibited by co-exposure to translation-repressive cues, suggesting a novel mode of signal integration. Our findings reveal receptor-specific interactomes and suggest a generalizable model for cue-selective control of the local proteome.
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Affiliation(s)
- Max Koppers
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Roberta Cagnetta
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Toshiaki Shigeoka
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Lucia CS Wunderlich
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeUnited Kingdom
| | - Pedro Vallejo-Ramirez
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeUnited Kingdom
| | - Julie Qiaojin Lin
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Sixian Zhao
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Maximilian AH Jakobs
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Asha Dwivedy
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeUnited Kingdom
| | - Michael S Minett
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Anaïs Bellon
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Clemens F Kaminski
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeUnited Kingdom
| | - William A Harris
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - John G Flanagan
- Department of Cell BiologyHarvard Medical SchoolBostonUnited States
| | - Christine E Holt
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
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10
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Jankowski S, Pohlmann T, Baumann S, Müntjes K, Devan SK, Zander S, Feldbrügge M. The multi PAM2 protein Upa2 functions as novel core component of endosomal mRNA transport. EMBO Rep 2019; 20:e47381. [PMID: 31338952 PMCID: PMC6726905 DOI: 10.15252/embr.201847381] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 06/14/2019] [Accepted: 06/21/2019] [Indexed: 12/28/2022] Open
Abstract
mRNA transport determines spatiotemporal protein expression. Transport units are higher-order ribonucleoprotein complexes containing cargo mRNAs, RNA-binding proteins and accessory proteins. Endosomal mRNA transport in fungal hyphae belongs to the best-studied translocation mechanisms. Although several factors are known, additional core components are missing. Here, we describe the 232 kDa protein Upa2 containing multiple PAM2 motifs (poly[A]-binding protein [Pab1]-associated motif 2) as a novel core component. Loss of Upa2 disturbs transport of cargo mRNAs and associated Pab1. Upa2 is present on almost all transport endosomes in an mRNA-dependent manner. Surprisingly, all four PAM2 motifs are dispensable for function during unipolar hyphal growth. Instead, Upa2 harbours a novel N-terminal effector domain as important functional determinant as well as a C-terminal GWW motif for specific endosomal localisation. In essence, Upa2 meets all the criteria of a novel core component of endosomal mRNA transport and appears to carry out crucial scaffolding functions.
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Affiliation(s)
- Silke Jankowski
- Institute for MicrobiologyCluster of Excellence on Plant SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany
| | - Thomas Pohlmann
- Institute for MicrobiologyCluster of Excellence on Plant SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany
| | - Sebastian Baumann
- Institute for MicrobiologyCluster of Excellence on Plant SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany
- Present address:
Cell and Developmental BiologyCentre for Genomic Regulation (CRG)BarcelonaSpain
| | - Kira Müntjes
- Institute for MicrobiologyCluster of Excellence on Plant SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany
| | - Senthil Kumar Devan
- Institute for MicrobiologyCluster of Excellence on Plant SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany
| | - Sabrina Zander
- Institute for MicrobiologyCluster of Excellence on Plant SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany
| | - Michael Feldbrügge
- Institute for MicrobiologyCluster of Excellence on Plant SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany
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11
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The endosomal sorting adaptor HD-PTP is required for ephrin-B:EphB signalling in cellular collapse and spinal motor axon guidance. Sci Rep 2019; 9:11945. [PMID: 31420572 PMCID: PMC6697728 DOI: 10.1038/s41598-019-48421-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 08/02/2019] [Indexed: 12/25/2022] Open
Abstract
The signalling output of many transmembrane receptors that mediate cell-cell communication is restricted by the endosomal sorting complex required for transport (ESCRT), but the impact of this machinery on Eph tyrosine kinase receptor function is unknown. We identified the ESCRT-associated adaptor protein HD-PTP as part of an EphB2 proximity-dependent biotin identification (BioID) interactome, and confirmed this association using co-immunoprecipitation. HD-PTP loss attenuates the ephrin-B2:EphB2 signalling-induced collapse of cultured cells and axonal growth cones, and results in aberrant guidance of chick spinal motor neuron axons in vivo. HD-PTP depletion abrogates ephrin-B2-induced EphB2 clustering, and EphB2 and Src family kinase activation. HD-PTP loss also accelerates ligand-induced EphB2 degradation, contrasting the effects of HD-PTP loss on the relay of signals from other cell surface receptors. Our results link Eph function to the ESCRT machinery and demonstrate a role for HD-PTP in the earliest steps of ephrin-B:EphB signalling, as well as in obstructing premature receptor depletion.
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12
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Core components of endosomal mRNA transport are evolutionarily conserved in fungi. Fungal Genet Biol 2019; 126:12-16. [PMID: 30738139 DOI: 10.1016/j.fgb.2019.01.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 01/31/2019] [Accepted: 01/31/2019] [Indexed: 12/21/2022]
Abstract
Active movement of mRNAs by sophisticated transport machineries determines precise spatiotemporal expression of encoded proteins. A prominent example discovered in fungi is microtubule-dependent transport via endosomes. This mode of transport was thought to be only operational in the basidiomycete Ustilago maydis. Here, we report that distinct core components are evolutionarily conserved in fungal species of distantly related phyla like Mucoromycota. Interestingly, orthologues of the key RNA-binding protein Rrm4 from the higher basidiomycete Coprinopsis cinerea and the mucoromycete Rhizophagus irregularis shuttle on endosomes in hyphae of U. maydis. Thus, endosomal mRNA transport appears to be more wide-spread than initially anticipated.
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13
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Cioni JM, Lin JQ, Holtermann AV, Koppers M, Jakobs MAH, Azizi A, Turner-Bridger B, Shigeoka T, Franze K, Harris WA, Holt CE. Late Endosomes Act as mRNA Translation Platforms and Sustain Mitochondria in Axons. Cell 2019; 176:56-72.e15. [PMID: 30612743 PMCID: PMC6333918 DOI: 10.1016/j.cell.2018.11.030] [Citation(s) in RCA: 257] [Impact Index Per Article: 51.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 09/10/2018] [Accepted: 11/18/2018] [Indexed: 12/14/2022]
Abstract
Local translation regulates the axonal proteome, playing an important role in neuronal wiring and axon maintenance. How axonal mRNAs are localized to specific subcellular sites for translation, however, is not understood. Here we report that RNA granules associate with endosomes along the axons of retinal ganglion cells. RNA-bearing Rab7a late endosomes also associate with ribosomes, and real-time translation imaging reveals that they are sites of local protein synthesis. We show that RNA-bearing late endosomes often pause on mitochondria and that mRNAs encoding proteins for mitochondrial function are translated on Rab7a endosomes. Disruption of Rab7a function with Rab7a mutants, including those associated with Charcot-Marie-Tooth type 2B neuropathy, markedly decreases axonal protein synthesis, impairs mitochondrial function, and compromises axonal viability. Our findings thus reveal that late endosomes interact with RNA granules, translation machinery, and mitochondria and suggest that they serve as sites for regulating the supply of nascent pro-survival proteins in axons. Ribonucleoprotein particles are associated with endosomes in axons Rab7a endosomes provide sites for axonal local translation Rab7a endosomes support axonal synthesis of survival factors CMT2B-Rab7a mutations affect axonal translation and mitochondrial integrity
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Affiliation(s)
- Jean-Michel Cioni
- 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
| | - Anne V Holtermann
- 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
| | - Maximilian A H Jakobs
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Afnan Azizi
- 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
| | - Toshiaki Shigeoka
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Kristian Franze
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - William A Harris
- 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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14
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Haag C, Klein T, Feldbrügge M. ESCRT Mutant Analysis and Imaging of ESCRT Components in the Model Fungus Ustilago maydis. Methods Mol Biol 2019; 1998:251-271. [PMID: 31250308 DOI: 10.1007/978-1-4939-9492-2_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The ESCRT machinery (endosomal sorting complex required for transport) is an evolutionarily highly conserved multiprotein complex involved in numerous cellular processes like endocytosis, membrane repair, or endosomal long-distance transport. In fungal hyphae, endocytosis and long-distance mRNA transport are tightly linked, as endocytotic vesicles are also the key carrier vehicles for mRNAs. Studying the regulatory component Did2 (CHMP1) in the plant pathogen Ustilago maydis revealed that loss of Did2 resulted in disturbed endosomal maturation, thereby causing defects in microtubule-dependent transport of early endosomes. Here, we describe methods and protocols that allow studying the role of ESCRT components during endosomal transport. We present experimental strategies to analyze U. maydis ESCRT mutant phenotypes and test complementation with heterologous components, such as ESCRT regulators from Drosophila melanogaster.
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Affiliation(s)
- Carl Haag
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Microbiology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Thomas Klein
- Institute of Genetics, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Michael Feldbrügge
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Microbiology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany.
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15
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Béthune J, Jansen RP, Feldbrügge M, Zarnack K. Membrane-Associated RNA-Binding Proteins Orchestrate Organelle-Coupled Translation. Trends Cell Biol 2018; 29:178-188. [PMID: 30455121 DOI: 10.1016/j.tcb.2018.10.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/28/2018] [Accepted: 10/29/2018] [Indexed: 02/02/2023]
Abstract
Proteins are positioned and act at defined subcellular locations. This is particularly important in eukaryotic cells that deliver proteins to membrane-bound organelles such as the endoplasmic reticulum (ER), mitochondria, or endosomes. It is axiomatic that organelle targeting depends mainly on polypeptide signals. However, recent results demonstrate that targeting elements within the encoding transcripts are essential for efficient protein localisation. Key readers of these elements are membrane-associated RNA-binding proteins (memRBPs) that orchestrate organelle-coupled translation. The translation products then either cross the membrane for organelle entry or hitchhike on organelle surfaces for complex assembly and co-transport. Understanding the interaction of protein- and RNA-based targeting signals is essential to decipher the molecular basis for mutant phenotypes in disease.
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Affiliation(s)
- Julien Béthune
- Heidelberg University, Biochemistry Center, Cluster of Excellence CellNetworks, 69120 Heidelberg, Germany
| | - Ralf-Peter Jansen
- Eberhard-Karls-University Tübingen, Interfaculty Institute of Biochemistry, Hoppe-Seyler-Straße 4, 72076 Tübingen, Germany
| | - Michael Feldbrügge
- Heinrich-Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences, 40204 Düsseldorf, Germany.
| | - Kathi Zarnack
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany.
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16
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Firkowska M, Macias M, Jaworski J. ESCRT Proteins Control the Dendritic Morphology of Developing and Mature Hippocampal Neurons. Mol Neurobiol 2018; 56:4866-4879. [PMID: 30406428 PMCID: PMC6647414 DOI: 10.1007/s12035-018-1418-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/29/2018] [Indexed: 11/30/2022]
Abstract
The proper shape of dendritic arbors of different types of neurons determines their proper communication within neuronal networks. The shape of dendritic arbors is acquired during a complex and multistep process called dendritogenesis. In most cases, once proper morphology is achieved, it remains stable throughout the lifespan, with the exception of rare events during which dendrites are abruptly pruned. The endosomal sorting complex required for transport (ESCRT) is multisubunit machinery that is involved in various cellular processes when membrane scission is needed. ESCRT subcomplexes regulate dendrite pruning in Drosophila neurons. However, the contribution of ESCRT components to the dendritogenesis of mammalian neurons and control of dendrite stability remains poorly defined. In the present study, we found that ESCRT-0, ESCRT-I, ESCRT-II, and ESCRT-III and Vps4 are required for proper dendrite morphology under basal culture conditions and for accelerated dendritogenesis in response to phosphoinositide 3-kinase (PI3K) activation. The knockdown of Vps28 (ESCRT-I) and Vps25 (ESCRT-II) resulted in downregulation of the activity of mechanistic/mammalian target of rapamycin complex 1. We also demonstrated that Vps28, Vps24, and Vps25 are required for dendrite stabilization in mature neurons.
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Affiliation(s)
- Marcelina Firkowska
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Ks. Trojdena St. 4, 02-109, Warsaw, Poland
| | - Matylda Macias
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Ks. Trojdena St. 4, 02-109, Warsaw, Poland.,Core Facility, International Institute of Molecular and Cell Biology, 02-109, Warsaw, Poland
| | - Jacek Jaworski
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Ks. Trojdena St. 4, 02-109, Warsaw, Poland.
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17
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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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18
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Emerman AB, Blower MD. The RNA-binding complex ESCRT-II in Xenopus laevis eggs recognizes purine-rich sequences through its subunit, Vps25. J Biol Chem 2018; 293:12593-12605. [PMID: 29903915 DOI: 10.1074/jbc.ra118.003718] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/12/2018] [Indexed: 12/29/2022] Open
Abstract
RNA-binding proteins (RBP) are critical regulators of gene expression. Recent studies have uncovered hundreds of mRNA-binding proteins that do not contain annotated RNA-binding domains and have well-established roles in other cellular processes. Investigation of these nonconventional RBPs is critical for revealing novel RNA-binding domains and may disclose connections between RNA regulation and other aspects of cell biology. The endosomal sorting complex required for transport II (ESCRT-II) is a nonconventional RNA-binding complex that has a canonical role in multivesicular body formation. ESCRT-II was identified previously as an RNA-binding complex in Drosophila oocytes, but whether its RNA-binding properties extend beyond Drosophila is unknown. In this study, we found that the RNA-binding properties of ESCRT-II are conserved in Xenopus eggs, where ESCRT-II interacted with hundreds of mRNAs. Using a UV cross-linking approach, we demonstrated that ESCRT-II binds directly to RNA through its subunit, Vps25. UV cross-linking and immunoprecipitation (CLIP)-Seq revealed that Vps25 specifically recognizes a polypurine (i.e. GA-rich) motif in RNA. Using purified components, we could reconstitute the selective Vps25-mediated binding of the polypurine motif in vitro Our results provide insight into the mechanism by which ESCRT-II selectively binds to mRNA and also suggest an unexpected link between endosome biology and RNA regulation.
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Affiliation(s)
- Amy B Emerman
- From the Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114 and the Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115
| | - Michael D Blower
- From the Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114 and the Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115
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19
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Abstract
During nervous system development, neurons extend axons to reach their targets and form functional circuits. The faulty assembly or disintegration of such circuits results in disorders of the nervous system. Thus, understanding the molecular mechanisms that guide axons and lead to neural circuit formation is of interest not only to developmental neuroscientists but also for a better comprehension of neural disorders. Recent studies have demonstrated how crosstalk between different families of guidance receptors can regulate axonal navigation at choice points, and how changes in growth cone behaviour at intermediate targets require changes in the surface expression of receptors. These changes can be achieved by a variety of mechanisms, including transcription, translation, protein-protein interactions, and the specific trafficking of proteins and mRNAs. Here, I review these axon guidance mechanisms, highlighting the most recent advances in the field that challenge the textbook model of axon guidance.
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Affiliation(s)
- Esther T Stoeckli
- University of Zurich, Institute of Molecular Life Sciences, Neuroscience Center Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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20
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Kaul Z, Chakrabarti O. Endosomal sorting complexes required for ESCRTing cells toward death during neurogenesis, neurodevelopment and neurodegeneration. Traffic 2018; 19:485-495. [DOI: 10.1111/tra.12569] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 03/21/2018] [Accepted: 03/21/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Zenia Kaul
- Biophysics & Structural Genomics Division; Saha Institute of Nuclear Physics; Kolkata India
| | - Oishee Chakrabarti
- Biophysics & Structural Genomics Division; Saha Institute of Nuclear Physics; Kolkata India
- Homi Bhabha National Institute; Mumbai India
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21
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Abstract
Electroporation allows targeting of genetic materials (e.g., DNA, RNA, antisense morpholinos) to the tissue of interest with high spatial and temporal specificity. Here, we describe a highly efficient and reproducible electroporation strategy for targeting the central nervous system in Xenopus. This versatile approach can be combined with live imaging or other existing experimental procedures to aid the investigation of different research questions.
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Affiliation(s)
- Hovy Ho-Wai Wong
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
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22
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Niessing D, Jansen RP, Pohlmann T, Feldbrügge M. mRNA transport in fungal top models. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 9. [PMID: 28994236 DOI: 10.1002/wrna.1453] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 08/28/2017] [Accepted: 09/05/2017] [Indexed: 01/13/2023]
Abstract
Eukaryotic cells rely on the precise determination of when and where proteins are synthesized. Spatiotemporal expression is supported by localization of mRNAs to specific subcellular sites and their subsequent local translation. This holds true for somatic cells as well as for oocytes and embryos. Most commonly, mRNA localization is achieved by active transport of the molecules along the actin or microtubule cytoskeleton. Key factors are molecular motors, adaptors, and RNA-binding proteins that recognize defined sequences or structures in cargo mRNAs. A deep understanding of this process has been gained from research on fungal model systems such as Saccharomyces cerevisiae and Ustilago maydis. Recent highlights of these studies are the following: (1) synergistic binding of two RNA-binding proteins is needed for high affinity recognition; (2) RNA sequences undergo profound structural rearrangements upon recognition; (3) mRNA transport is tightly linked to membrane trafficking; (4) mRNAs and ribosomes are transported on the cytoplasmic surface of endosomes; and (5) heteromeric protein complexes are, most likely, assembled co-translationally during endosomal transport. Thus, the study of simple fungal model organisms provides valuable insights into fundamental mechanisms of mRNA transport boosting the understanding of similar events in higher eukaryotes. WIREs RNA 2018, 9:e1453. doi: 10.1002/wrna.1453 This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Export and Localization > RNA Localization.
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Affiliation(s)
- Dierk Niessing
- Department of Cell Biology, Biomedical Center, Ludwig-Maximilians-University München, Planegg-Martinsried, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Ralf-Peter Jansen
- Interfaculty Institute of Biochemistry, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Thomas Pohlmann
- Centre of Excellence on Plant Sciences, Institute for Microbiology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Michael Feldbrügge
- Centre of Excellence on Plant Sciences, Institute for Microbiology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
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23
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Lu P, Li H, Li N, Singh RN, Bishop CE, Chen X, Lu B. MEX3C interacts with adaptor-related protein complex 2 and involves in miR-451a exosomal sorting. PLoS One 2017; 12:e0185992. [PMID: 28982131 PMCID: PMC5628917 DOI: 10.1371/journal.pone.0185992] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 09/23/2017] [Indexed: 12/16/2022] Open
Abstract
Some RNA species, especially microRNAs, are non-randomly sorted into exosomes, but how selectivity of RNA exosomal sorting is achieved is unknown. We found that all three variants of RNA-binding ubiquitin E3 ligase (MEX3C)-MEX3C-1, MEX3C-2, and MEX3C-3 -interact with adaptor-related protein complex 2 (AP-2), a cargo adaptor in clathrin-mediated endocytosis. MEX3C's C-terminal RING finger domain and the hnRNP K homology (KH) domain shared by the three MEX3C variants are both necessary for MEX3C/AP-2 interaction. MEX3C associates with the endolysosomal compartment through an endocytosis-like process. siRNA-mediated inhibition of the MEX3C or AP-2 complex substantially decreased exosomal but not cellular microRNA miR-451a expression. Exosomal sorting is ceramide-dependent but not ESCRT-dependent in microRNA miR-451a. That RNA-binding protein associates with membrane trafficking machinery, and that its involvement in exosomal microRNA expression, suggest the existence of a mechanism for specific recruiting of RNA molecules to endosomes for subsequent exosomal sorting.
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Affiliation(s)
- Pin Lu
- Anhui Normal University, Wuhu, China
- Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston Salem, North Carolina, United States of America
| | - Huanhuan Li
- Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston Salem, North Carolina, United States of America
| | - Ning Li
- Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston Salem, North Carolina, United States of America
| | - Ravi N. Singh
- Department of Cancer Biology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, United States of America
| | - Colin E. Bishop
- Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston Salem, North Carolina, United States of America
| | - Xiangxian Chen
- Anhui Normal University, Wuhu, China
- Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston Salem, North Carolina, United States of America
| | - Baisong Lu
- Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston Salem, North Carolina, United States of America
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24
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Horner DS, Pasini ME, Beltrame M, Mastrodonato V, Morelli E, Vaccari T. ESCRT genes and regulation of developmental signaling. Semin Cell Dev Biol 2017; 74:29-39. [PMID: 28847745 DOI: 10.1016/j.semcdb.2017.08.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/06/2017] [Accepted: 08/18/2017] [Indexed: 11/30/2022]
Abstract
ESCRT (Endosomal Sorting Complex Required for Transport) proteins have been shown to control an increasing number of membrane-associated processes. Some of these, and prominently regulation of receptor trafficking, profoundly shape signal transduction. Evidence in fungi, plants and multiple animal models support the emerging concept that ESCRTs are main actors in coordination of signaling with the changes in cells and tissues occurring during development and homeostasis. Consistent with their pleiotropic function, ESCRTs are regulated in multiple ways to tailor signaling to developmental and homeostatic needs. ESCRT activity is crucial to correct execution of developmental programs, especially at key transitions, allowing eukaryotes to thrive and preventing appearance of congenital defects.
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Affiliation(s)
- David S Horner
- Dipartimento di Bioscienze, Universita' degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Maria E Pasini
- Dipartimento di Bioscienze, Universita' degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Monica Beltrame
- Dipartimento di Bioscienze, Universita' degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Valeria Mastrodonato
- IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milano, Italy
| | - Elena Morelli
- IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milano, Italy
| | - Thomas Vaccari
- Dipartimento di Bioscienze, Universita' degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy; IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milano, Italy.
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25
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Sadoul R, Laporte MH, Chassefeyre R, Chi KI, Goldberg Y, Chatellard C, Hemming FJ, Fraboulet S. The role of ESCRT during development and functioning of the nervous system. Semin Cell Dev Biol 2017; 74:40-49. [PMID: 28811263 DOI: 10.1016/j.semcdb.2017.08.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/21/2017] [Accepted: 08/04/2017] [Indexed: 12/12/2022]
Abstract
The endosomal sorting complex required for transport (ESCRT) is made of subcomplexes (ESCRT 0-III), crucial to membrane remodelling at endosomes, nuclear envelope and cell surface. ESCRT-III shapes membranes and in most cases cooperates with the ATPase VPS4 to mediate fission of membrane necks from the inside. The first ESCRT complexes mainly serve to catalyse the formation of ESCRT-III but can be bypassed by accessory proteins like the Alg-2 interacting protein-X (ALIX). In the nervous system, ALIX/ESCRT controls the survival of embryonic neural progenitors and later on the outgrowth and pruning of axons and dendrites, all necessary steps to establish a functional brain. In the adult brain, ESCRTs allow the endosomal turn over of synaptic vesicle proteins while stable ESCRT complexes might serve as scaffolds for the postsynaptic parts. The necessity of ESCRT for the harmonious function of the brain has its pathological counterpart, the mutations in CHMP2B of ESCRT-III giving rise to several neurodegenerative diseases.
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Affiliation(s)
- Rémy Sadoul
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1216, F-38042 Grenoble, France; Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France.
| | - Marine H Laporte
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1216, F-38042 Grenoble, France; Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Romain Chassefeyre
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1216, F-38042 Grenoble, France; Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Kwang Il Chi
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1216, F-38042 Grenoble, France; Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Yves Goldberg
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1216, F-38042 Grenoble, France; Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Christine Chatellard
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1216, F-38042 Grenoble, France; Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Fiona J Hemming
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1216, F-38042 Grenoble, France; Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Sandrine Fraboulet
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1216, F-38042 Grenoble, France; Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
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26
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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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27
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Haag C, Pohlmann T, Feldbrügge M. The ESCRT regulator Did2 maintains the balance between long-distance endosomal transport and endocytic trafficking. PLoS Genet 2017; 13:e1006734. [PMID: 28422978 PMCID: PMC5415202 DOI: 10.1371/journal.pgen.1006734] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 05/03/2017] [Accepted: 04/04/2017] [Indexed: 01/01/2023] Open
Abstract
In highly polarised cells, like fungal hyphae, early endosomes function in both endocytosis as well as long-distance transport of various cargo including mRNA and protein complexes. However, knowledge on the crosstalk between these seemingly different trafficking processes is scarce. Here, we demonstrate that the ESCRT regulator Did2 coordinates endosomal transport in fungal hyphae of Ustilago maydis. Loss of Did2 results in defective vacuolar targeting, less processive long-distance transport and abnormal shuttling of early endosomes. Importantly, the late endosomal protein Rab7 and vacuolar protease Prc1 exhibit increased shuttling on these aberrant endosomes suggesting defects in endosomal maturation and identity. Consistently, molecular motors fail to attach efficiently explaining the disturbed processive movement. Furthermore, the endosomal mRNP linker protein Upa1 is hardly present on endosomes resulting in defects in long-distance mRNA transport. In conclusion, the ESCRT regulator Did2 coordinates precise maturation of endosomes and thus provides the correct membrane identity for efficient endosomal long-distance transport.
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Affiliation(s)
- Carl Haag
- Heinrich Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Thomas Pohlmann
- Heinrich Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Michael Feldbrügge
- Heinrich Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
- * E-mail:
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28
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Abstract
During neural circuit formation, axons need to navigate to their target cells in a complex, constantly changing environment. Although we most likely have identified most axon guidance cues and their receptors, we still cannot explain the molecular background of pathfinding for any subpopulation of axons. We lack mechanistic insight into the regulation of interactions between guidance receptors and their ligands. Recent developments in the field of axon guidance suggest that the regulation of surface expression of guidance receptors comprises transcriptional, translational, and post-translational mechanisms, such as trafficking of vesicles with specific cargos, protein-protein interactions, and specific proteolysis of guidance receptors. Not only axon guidance molecules but also the regulatory mechanisms that control their spatial and temporal expression are involved in synaptogenesis and synaptic plasticity. Therefore, it is not surprising that genes associated with axon guidance are frequently found in genetic and genomic studies of neurodevelopmental disorders.
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Affiliation(s)
- Esther Stoeckli
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
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