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Mei Z, Liu J, Bennett DA, Seyfried N, Wingo AP, Wingo TS. Unraveling sex differences in Alzheimer's disease and related endophenotypes with brain proteomes. Alzheimers Dement 2025; 21:e70206. [PMID: 40346727 PMCID: PMC12064417 DOI: 10.1002/alz.70206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2024] [Revised: 03/11/2025] [Accepted: 03/29/2025] [Indexed: 05/11/2025]
Abstract
INTRODUCTION Sex differences exist in Alzheimer's disease (AD), but the underlying mechanisms remain unclear. METHODS We examined brain proteomes profiled from the dorsolateral prefrontal cortex of 770 donors (66.2% female). RESULTS Proteome-wide differential expression analysis in males and females jointly identified many significant proteins for AD dementia (n = 1228), amyloid beta (n = 1183), tangles (n = 1309), and global cognitive trajectory (n = 2325) at a false discovery rate of <0.05. Sex-stratified analyses also identified many proteins associated with AD or its endophenotypes. Finally, we found 10 proteins with significant sex-by-trait interactions, including one in AD clinical diagnosis (MARCKS), seven in cognitive trajectories (TOGARAM1, PLCD3, SLC22A5, MTFR1L, DCUN1D5, S100A12, and TRIM46), and two in cerebral pathologies (PANK4 and SOS1). DISCUSSION The 10 proteins with sex interaction in AD cover a range of functions likely relevant for AD pathogenesis, including estrogen response, inflammation, and mitochondrial biology, and their specific roles in AD ought to be studied. Future work should test their potential as sex-specific AD biomarkers. HIGHLIGHTS At the phenotypic level, we found sex differences in baseline cognitive performance, cognitive trajectories, and AD hallmark pathologies. Proteome-wide differential expression analyses identified many brain proteins associated with AD and its endophenotypes in either sex alone or when considered together. We found 10 brain proteins with significant sex interactions in AD and its endophenotypes, which could be investigated as potential sex-specific biomarkers of AD.
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Affiliation(s)
- Zhen Mei
- Department of NeurologyUniversity of California, DavisSacramentoCaliforniaUSA
| | - Jiaqi Liu
- Department of PsychiatryUniversity of California, DavisSacramentoCaliforniaUSA
| | - David A Bennett
- Rush Alzheimer's Disease CenterRush University Medical CenterChicagoIllinoisUSA
| | - Nicholas Seyfried
- Department of BiochemistryEmory University School of MedicineAtlantaGeorgiaUSA
| | - Aliza P. Wingo
- Department of PsychiatryUniversity of California, DavisSacramentoCaliforniaUSA
- Division of Mental HealthAtlanta VA Medical CenterDecaturGeorgiaUSA
| | - Thomas S. Wingo
- Department of NeurologyUniversity of California, DavisSacramentoCaliforniaUSA
- Alzheimer's Disease Research CenterUniversity of California, DavisSacramentoCaliforniaUSA
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Jenkins PM, Bender KJ. Axon initial segment structure and function in health and disease. Physiol Rev 2025; 105:765-801. [PMID: 39480263 DOI: 10.1152/physrev.00030.2024] [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: 08/01/2024] [Revised: 10/18/2024] [Accepted: 10/23/2024] [Indexed: 11/06/2024] Open
Abstract
At the simplest level, neurons are structured to integrate synaptic input and perform computational transforms on that input, converting it into an action potential (AP) code. This process, converting synaptic input into AP output, typically occurs in a specialized region of the axon termed the axon initial segment (AIS). The AIS, as its name implies, is often contained to the first section of axon abutted to the soma and is home to a dizzying array of ion channels, attendant scaffolding proteins, intracellular organelles, extracellular proteins, and, in some cases, synapses. The AIS serves multiple roles as the final arbiter for determining if inputs are sufficient to evoke APs, as a gatekeeper that physically separates the somatodendritic domain from the axon proper, and as a regulator of overall neuronal excitability, dynamically tuning its size to best suit the needs of parent neurons. These complex roles have received considerable attention from experimentalists and theoreticians alike. Here, we review recent advances in our understanding of the AIS and its role in neuronal integration and polarity in health and disease.
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Affiliation(s)
- Paul M Jenkins
- Departments of Pharmacology and Psychiatry, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Kevin J Bender
- Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, California, United States
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3
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Fréal A, Hoogenraad CC. The dynamic axon initial segment: From neuronal polarity to network homeostasis. Neuron 2025; 113:649-669. [PMID: 39947181 DOI: 10.1016/j.neuron.2025.01.004] [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: 04/25/2024] [Revised: 09/15/2024] [Accepted: 01/07/2025] [Indexed: 03/08/2025]
Abstract
The axon initial segment (AIS) is a highly specialized compartment in neurons that resides in between axonal and somatodendritic domains. The localization of the AIS in the proximal part of the axon is essential for its two major functions: generating and modulating action potentials and maintaining neuron polarity. Recent findings revealed that the incredibly stable AIS is generated from highly dynamic components and can undergo extensive structural and functional changes in response to alterations in activity levels. These activity-dependent alterations of AIS structure and function have profound consequences for neuronal functioning, and AIS plasticity has emerged as a key regulator of network homeostasis. This review highlights the functions of the AIS, its architecture, and how its organization and remodeling are influenced by developmental plasticity and both acute and chronic adaptations. It also discusses the mechanisms underlying these processes and explores how dysregulated AIS plasticity may contribute to brain disorders.
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Affiliation(s)
- Amélie Fréal
- Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam, the Netherlands
| | - Casper C Hoogenraad
- Department of Neuroscience, Genentech, Inc, South San Francisco, CA 94080, USA.
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Cark O, Katkat E, Aydogdu I, Iscan E, Oktay Y, Ozhan G. tubg1 Somatic Mutants Show Tubulinopathy-Associated Neurodevelopmental Phenotypes in a Zebrafish Model. Mol Neurobiol 2025; 62:3024-3039. [PMID: 39215931 DOI: 10.1007/s12035-024-04448-2] [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: 05/11/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024]
Abstract
Development of the multilayered cerebral cortex relies on precise orchestration of neurogenesis, neuronal migration, and differentiation, processes tightly regulated by microtubule dynamics. Mutations in tubulin superfamily genes have been associated with tubulinopathies, encompassing a spectrum of cortical malformations including microcephaly and lissencephaly. Here, we focus on γ-tubulin, a pivotal regulator of microtubule nucleation encoded by TUBG1. We investigate its role in brain development using a zebrafish model with somatic tubg1 mutation, recapitulating features of TUBG1-associated tubulinopathies in patients and mouse disease models. We demonstrate that γ-tubulin deficiency disrupts neurogenesis and brain development, mirroring microcephaly phenotypes. Furthermore, we uncover a novel potential regulatory link between γ-tubulin and canonical Wnt/β-catenin signaling, with γ-tubulin deficiency impairing Wnt activity. Our findings provide insights into the pathogenesis of cortical defects and suggest that γ-tubulin could be a potential target for further research in neurodevelopmental disorders, although challenges such as mode of action, specificity, and potential side effects must be addressed.
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Affiliation(s)
- Ozge Cark
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health Campus, Inciralti-Balcova 35340, Izmir, Türkiye
- Izmir International Biomedicine and Genome Institute (IBG-Izmir), Dokuz Eylul University, Inciralti-Balcova 35340, Izmir, Türkiye
- Center for Regenerative Therapies at the TU Dresden, Technische Universität Dresden, 01307, Dresden, Germany
| | - Esra Katkat
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health Campus, Inciralti-Balcova 35340, Izmir, Türkiye
- Izmir International Biomedicine and Genome Institute (IBG-Izmir), Dokuz Eylul University, Inciralti-Balcova 35340, Izmir, Türkiye
| | - Ipek Aydogdu
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health Campus, Inciralti-Balcova 35340, Izmir, Türkiye
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, Urla, 35430, Izmir, Türkiye
| | - Evin Iscan
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health Campus, Inciralti-Balcova 35340, Izmir, Türkiye
- Izmir International Biomedicine and Genome Institute (IBG-Izmir), Dokuz Eylul University, Inciralti-Balcova 35340, Izmir, Türkiye
| | - Yavuz Oktay
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health Campus, Inciralti-Balcova 35340, Izmir, Türkiye
- Izmir International Biomedicine and Genome Institute (IBG-Izmir), Dokuz Eylul University, Inciralti-Balcova 35340, Izmir, Türkiye
- Department of Medical Biology, School of Medicine, Dokuz Eylul University, Izmir, 35340, Türkiye
| | - Gunes Ozhan
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health Campus, Inciralti-Balcova 35340, Izmir, Türkiye.
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, Urla, 35430, Izmir, Türkiye.
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Han Y, Hacker D, Donders BC, Parperis C, Thuenauer R, Leterrier C, Grünewald K, Mikhaylova M. Unveiling the cell biology of hippocampal neurons with dendritic axon origin. J Cell Biol 2025; 224:e202403141. [PMID: 39495320 PMCID: PMC11536041 DOI: 10.1083/jcb.202403141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 08/01/2024] [Accepted: 09/23/2024] [Indexed: 11/05/2024] Open
Abstract
In mammalian axon-carrying-dendrite (AcD) neurons, the axon emanates from a basal dendrite, instead of the soma, to create a privileged route for action potential generation at the axon initial segment (AIS). However, it is unclear how such unusual morphology is established and whether the structure and function of the AIS in AcD neurons are preserved. By using dissociated hippocampal cultures as a model, we show that the development of AcD morphology can occur prior to synaptogenesis and independently of the in vivo environment. A single precursor neurite first gives rise to the axon and then to the AcD. The AIS possesses a similar cytoskeletal architecture as the soma-derived AIS and similarly functions as a trafficking barrier to retain axon-specific molecular composition. However, it does not undergo homeostatic plasticity, contains lesser cisternal organelles, and receives fewer inhibitory inputs. Our findings reveal insights into AcD neuron biology and underscore AIS structural differences based on axon onset.
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Affiliation(s)
- Yuhao Han
- AG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin, Germany
- AG “Neuronal Protein Transport”, Centre for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
- Structural Cell Biology of Viruses, Leibniz Institute of Virology (LIV), Hamburg, Germany
| | - Daniela Hacker
- AG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin, Germany
| | | | | | - Roland Thuenauer
- Advanced Light and Fluorescence Microscopy (ALFM) Facility, Centre for Structural Systems Biology, Hamburg, Germany
- Technology Platform Light Microscopy, University of Hamburg, Hamburg, Germany
- Technology Platform Microscopy and Image Analysis (TP MIA), Leibniz Institute of Virology (LIV), Hamburg, Germany
| | | | - Kay Grünewald
- Centre for Structural Systems Biology, Hamburg, Germany
- Structural Cell Biology of Viruses, Leibniz Institute of Virology (LIV), Hamburg, Germany
- Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Marina Mikhaylova
- AG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin, Germany
- AG “Neuronal Protein Transport”, Centre for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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6
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Breuer H, Bell-Simons M, Zempel H. Axodendritic targeting of TAU and MAP2 and microtubule polarization in iPSC-derived versus SH-SY5Y-derived human neurons. Open Life Sci 2024; 19:20221010. [PMID: 39759106 PMCID: PMC11699562 DOI: 10.1515/biol-2022-1010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 10/21/2024] [Accepted: 11/07/2024] [Indexed: 01/07/2025] Open
Abstract
Cell polarity is crucial in neurons, characterized by distinct axonal and dendritic structures. Neurons generally have one long axon and multiple shorter dendrites, marked by specific microtubule (MT)-associated proteins, e.g., MAP2 for dendrites and TAU for axons, while the scaffolding proteins AnkG and TRIM46 mark the axon-initial-segment. In tauopathies, such as Alzheimer's disease (AD), TAU sorting, and neuronal polarity are disrupted, leading to MT loss. However, modeling and studying MTs in human neuronal cells relevant to the study of AD and TAU-related neurodegenerative diseases (NDD) is challenging. To study MT dynamics in human neurons, we compared two cell culture systems: SH-SY5Y-derived neurons (SHN) and induced pluripotent stem cell-derived neurons (iN). Using immunostaining and EB3-tdTomato time-lapse imaging, we found AnkG absent in SHN but present in iN, while TRIM46 was present in both. TAU and MAP2 showed axonal and dendritic enrichment, respectively, similar to mouse primary neurons. Both neuron types exhibited polarized MT structures, with unidirectional MTs in axons and bidirectional MTs in dendrites. Polymerization speeds were similar; however, iNs had more retrograde MT growth events, while SHN showed a higher overall number of growth events. Thus, SHN and iN are both suitable for studying neuronal cell polarity, with SHN being particularly suitable if the focus is not the AIS.
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Affiliation(s)
- Helen Breuer
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Str. 34, 50931, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Robert-Koch-Str. 21, 50931, Cologne, Germany
| | - Michael Bell-Simons
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Str. 34, 50931, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Robert-Koch-Str. 21, 50931, Cologne, Germany
- Current address: Max-Planck-Institute for Aging, Joseph-Stelzmann-Straße 11, 50931, Cologne, Germany
| | - Hans Zempel
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Str. 34, 50931, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Robert-Koch-Str. 21, 50931, Cologne, Germany
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937, Cologne, Germany
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7
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Lyu J, MacDonald ML, Ruiz S, Chou S, Gilardi J, Buchwald SC, Grubisha MJ, Sweet RA. Deciphering the alteration of MAP2 interactome caused by a schizophrenia-associated phosphorylation. Neurobiol Dis 2024; 203:106731. [PMID: 39532265 DOI: 10.1016/j.nbd.2024.106731] [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: 03/11/2024] [Revised: 11/06/2024] [Accepted: 11/06/2024] [Indexed: 11/16/2024] Open
Abstract
Microtubule-associated protein 2 (MAP2) is a crucial regulator of dendritic structure and neuronal function, orchestrating diverse protein interactions within the microtubule network. We have shown MAP2 is hyperphosphorylated at serine 1782 (S1782) in schizophrenia and phosphomimetic mutation of S1782 in mice (MAP2S1782E) is sufficient to impair dendritic architecture. We sought to determine how this hyperphosphorylation affects the MAP2 interactome to provide insights into the disorder's mechanisms. We investigated the MAP2 interactome using co-immunoprecipitation and mass spectrometry in MAP2S1782E and MAP2WT mice. We found that S1782E MAP2 led to a substantial disruption of protein-protein interactions relative to WT MAP2. Reduced interactions with PDZ domain-containing proteins, calmodulin-binding proteins, ribosome proteins, and kinesin proteins may all contribute to dendritic impairments induced by S1782E, and may be linked to schizophrenia pathogenesis. Interestingly, novel gain-of-function interactions with PPM1L and KLHL8 nominated these as regulators of phosphoS1782 MAP2 abundance and potential therapeutic targets in schizophrenia.
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Affiliation(s)
- Jiali Lyu
- School of Medicine, Tsinghua University, China; Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, United States of America
| | - Matthew L MacDonald
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, United States of America; Health Sciences Mass Spectrometry Core, University of Pittsburgh, United States of America
| | - Shelby Ruiz
- Department of Neurobiology, University of Pittsburgh, United States of America
| | - Shinnyi Chou
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, United States of America
| | - Jordan Gilardi
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, United States of America
| | - Serena C Buchwald
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, United States of America
| | - Melanie J Grubisha
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, United States of America
| | - Robert A Sweet
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, United States of America; Department of Neurology, University of Pittsburgh, United States of America.
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Melton AJ, Palfini VL, Ogawa Y, Oses Prieto JA, Vainshtein A, Burlingame AL, Peles E, Rasband MN. TRIM46 Is Required for Microtubule Fasciculation In Vivo But Not Axon Specification or Axon Initial Segment Formation. J Neurosci 2024; 44:e0976242024. [PMID: 39251352 PMCID: PMC11484549 DOI: 10.1523/jneurosci.0976-24.2024] [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: 05/23/2024] [Revised: 08/23/2024] [Accepted: 08/29/2024] [Indexed: 09/11/2024] Open
Abstract
Vertebrate nervous systems use the axon initial segment (AIS) to initiate action potentials and maintain neuronal polarity. The microtubule-associated protein tripartite motif containing 46 (TRIM46) was reported to regulate axon specification, AIS assembly, and neuronal polarity through the bundling, or fasciculation, of microtubules in the proximal axon. However, these claims are based on TRIM46 knockdown in cultured neurons. To investigate TRIM46 function in vivo, we examined male and female TRIM46 knock-out mice. Contrary to previous reports, we find that TRIM46 is dispensable for axon specification and AIS formation. TRIM46 knock-out mice are viable, have normal behavior, and have normal brain structure. Thus, TRIM46 is not required for AIS formation, axon specification, or nervous system function. However, we confirm that TRIM46 is required for microtubule fasciculation. We also show TRIM46 enrichment in the first ∼100 μm of axon occurs independently of ankyrinG (AnkG) in vivo, although AnkG is required to restrict TRIM46 only to the AIS. Our results highlight the need for further investigation of the mechanisms by which the AIS and microtubules interact to shape neuronal structure and function.
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Affiliation(s)
- Allison J Melton
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Victoria L Palfini
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Yuki Ogawa
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Juan A Oses Prieto
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California 94158
| | - Anna Vainshtein
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alma L Burlingame
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California 94158
| | - Elior Peles
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
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Escobedo Jr. G, Wu Y, Ogawa Y, Ding X, Rasband MN. An evolutionarily conserved AnkyrinG-dependent motif clusters axonal K2P K+ channels. J Cell Biol 2024; 223:e202401140. [PMID: 39078369 PMCID: PMC11289519 DOI: 10.1083/jcb.202401140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 06/20/2024] [Accepted: 07/15/2024] [Indexed: 07/31/2024] Open
Abstract
The evolution of ion channel clustering at nodes of Ranvier enabled the development of complex vertebrate nervous systems. At mammalian nodes, the K+ leak channels TRAAK and TREK-1 underlie membrane repolarization. Despite the molecular similarities between nodes and the axon initial segment (AIS), TRAAK and TREK-1 are reportedly node-specific, suggesting a unique clustering mechanism. However, we show that TRAAK and TREK-1 are enriched at both nodes and AIS through a common mechanism. We identified a motif near the C-terminus of TRAAK that is necessary and sufficient for its clustering. The motif first evolved among cartilaginous fish. Using AnkyrinG (AnkG) conditional knockout mice, CRISPR/Cas9-mediated disruption of AnkG, co-immunoprecipitation, and surface recruitment assays, we show that TRAAK forms a complex with AnkG and that AnkG is necessary for TRAAK's AIS and nodal clustering. In contrast, TREK-1's clustering requires TRAAK. Our results expand the repertoire of AIS and nodal ion channel clustering mechanisms and emphasize AnkG's central role in assembling excitable domains.
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Affiliation(s)
| | - Yu Wu
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Yuki Ogawa
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Xiaoyun Ding
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Matthew N. Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
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Verma H, Kaur S, Kaur S, Gangwar P, Dhiman M, Mantha AK. Role of Cytoskeletal Elements in Regulation of Synaptic Functions: Implications Toward Alzheimer's Disease and Phytochemicals-Based Interventions. Mol Neurobiol 2024; 61:8320-8343. [PMID: 38491338 DOI: 10.1007/s12035-024-04053-3] [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: 07/03/2023] [Accepted: 02/13/2024] [Indexed: 03/18/2024]
Abstract
Alzheimer's disease (AD), a multifactorial disease, is characterized by the accumulation of neurofibrillary tangles (NFTs) and amyloid beta (Aβ) plaques. AD is triggered via several factors like alteration in cytoskeletal proteins, a mutation in presenilin 1 (PSEN1), presenilin 2 (PSEN2), amyloid precursor protein (APP), and post-translational modifications (PTMs) in the cytoskeletal elements. Owing to the major structural and functional role of cytoskeletal elements, like the organization of axon initial segmentation, dendritic spines, synaptic regulation, and delivery of cargo at the synapse; modulation of these elements plays an important role in AD pathogenesis; like Tau is a microtubule-associated protein that stabilizes the microtubules, and it also causes inhibition of nucleo-cytoplasmic transportation by disrupting the integrity of nuclear pore complex. One of the major cytoskeletal elements, actin and its dynamics, regulate the dendritic spine structure and functions; impairments have been documented towards learning and memory defects. The second major constituent of these cytoskeletal elements, microtubules, are necessary for the delivery of the cargo, like ion channels and receptors at the synaptic membranes, whereas actin-binding protein, i.e., Cofilin's activation form rod-like structures, is involved in the formation of paired helical filaments (PHFs) observed in AD. Also, the glial cells rely on their cytoskeleton to maintain synaptic functionality. Thus, making cytoskeletal elements and their regulation in synaptic structure and function as an important aspect to be focused for better management and targeting AD pathology. This review advocates exploring phytochemicals and Ayurvedic plant extracts against AD by elucidating their neuroprotective mechanisms involving cytoskeletal modulation and enhancing synaptic plasticity. However, challenges include their limited bioavailability due to the poor solubility and the limited potential to cross the blood-brain barrier (BBB), emphasizing the need for targeted strategies to improve therapeutic efficacy.
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Affiliation(s)
- Harkomal Verma
- Department of Zoology, School of Basic Sciences, Central University of Punjab, Village Ghudda, VPO - Ghudda, Bathinda, 151 401, Punjab, India
| | - Sharanjot Kaur
- Department of Microbiology, School of Basic Sciences, Central University of Punjab, Village Ghudda, Bathinda, Punjab, India
| | - Sukhchain Kaur
- Department of Microbiology, School of Basic Sciences, Central University of Punjab, Village Ghudda, Bathinda, Punjab, India
| | - Prabhakar Gangwar
- Department of Zoology, School of Basic Sciences, Central University of Punjab, Village Ghudda, VPO - Ghudda, Bathinda, 151 401, Punjab, India
| | - Monisha Dhiman
- Department of Microbiology, School of Basic Sciences, Central University of Punjab, Village Ghudda, Bathinda, Punjab, India
| | - Anil Kumar Mantha
- Department of Zoology, School of Basic Sciences, Central University of Punjab, Village Ghudda, VPO - Ghudda, Bathinda, 151 401, Punjab, India.
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Dey S, Kumar N, Balakrishnan S, Koushika SP, Ghosh-Roy A. KLP-7/Kinesin-13 orchestrates axon-dendrite checkpoints for polarized trafficking in neurons. Mol Biol Cell 2024; 35:ar115. [PMID: 38985513 PMCID: PMC7616348 DOI: 10.1091/mbc.e23-08-0335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 06/27/2024] [Accepted: 07/03/2024] [Indexed: 07/12/2024] Open
Abstract
The polarized nature of neurons depends on their microtubule dynamics and orientation determined by both microtubule-stabilizing and destabilizing factors. The role of destabilizing factors in developing and maintaining neuronal polarity is unclear. We investigated the function of KLP-7, a microtubule depolymerizing motor of the Kinesin-13 family, in axon-dendrite compartmentalization using PVD neurons in Caenorhabditis elegans. Loss of KLP-7 caused a mislocalization of axonal proteins, including RAB-3, SAD-1, and their motor UNC-104, to dendrites. This is rescued by cell-autonomous expression of the KLP-7 or colchicine treatment, indicating the involvement of KLP-7-dependent microtubule depolymerization. The high mobility of KLP-7 is correlated to increased microtubule dynamics in the dendrites, which restricts the enrichment of UNC-44, an integral component of Axon Initial Segment (AIS) in these processes. Due to the loss of KLP-7, ectopic enrichment of UNC-44 in the dendrite potentially redirects axonal traffic into dendrites that include plus-end out microtubules, axonal motors, and cargoes. These observations indicate that KLP-7-mediated depolymerization defines the microtubule dynamics conducive to the specific enrichment of AIS components in dendrites. This further compartmentalizes dendritic and axonal microtubules, motors, and cargoes, thereby influencing neuronal polarity.
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Affiliation(s)
- Swagata Dey
- Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurugram, Haryana 122052, India
| | - Nitish Kumar
- Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurugram, Haryana 122052, India
| | - Supraja Balakrishnan
- Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurugram, Haryana 122052, India
| | - Sandhya P. Koushika
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Anindya Ghosh-Roy
- Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurugram, Haryana 122052, India
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Vadon C, Magiera MM, Cimarelli A. TRIM Proteins and Antiviral Microtubule Reorganization: A Novel Component in Innate Immune Responses? Viruses 2024; 16:1328. [PMID: 39205302 PMCID: PMC11359181 DOI: 10.3390/v16081328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2024] [Revised: 08/13/2024] [Accepted: 08/14/2024] [Indexed: 09/04/2024] Open
Abstract
TRIM proteins are a family of innate immune factors that play diverse roles in innate immunity and protect the cell against viral and bacterial aggression. As part of this special issue on TRIM proteins, we will take advantage of our findings on TRIM69, which acts by reorganizing the microtubules (MTs) in a manner that is fundamentally antiviral, to more generally discuss how host-pathogen interactions that take place for the control of the MT network represent a crucial facet of the struggle that opposes viruses to their cell environment. In this context, we will present several other TRIM proteins that are known to interact with microtubules in situations other than viral infection, and we will discuss evidence that may suggest a possible contribution to viral control. Overall, the present review will highlight the importance that the control of the microtubule network bears in host-pathogen interactions.
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Affiliation(s)
- Charlotte Vadon
- Centre International de Recherche en Infectiologie (CIRI), Univ Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69364 Lyon, France
| | - Maria Magda Magiera
- Institut Curie, CNRS, UMR3348, Centre Universitaire, Bat 110, F-91405 Orsay, France
| | - Andrea Cimarelli
- Centre International de Recherche en Infectiologie (CIRI), Univ Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69364 Lyon, France
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13
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Koppers M, Özkan N, Nguyen HH, Jurriens D, McCaughey J, Nguyen DTM, Li CH, Stucchi R, Altelaar M, MacGillavry HD, Kapitein LC, Hoogenraad CC, Farías GG. Axonal endoplasmic reticulum tubules control local translation via P180/RRBP1-mediated ribosome interactions. Dev Cell 2024; 59:2053-2068.e9. [PMID: 38815583 PMCID: PMC11338522 DOI: 10.1016/j.devcel.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/31/2024] [Accepted: 05/09/2024] [Indexed: 06/01/2024]
Abstract
Local mRNA translation in axons is critical for the spatiotemporal regulation of the axonal proteome. A wide variety of mRNAs are localized and translated in axons; however, how protein synthesis is regulated at specific subcellular sites in axons remains unclear. Here, we establish that the axonal endoplasmic reticulum (ER) supports axonal translation in developing rat hippocampal cultured neurons. Axonal ER tubule disruption impairs local translation and ribosome distribution. Using nanoscale resolution imaging, we find that ribosomes make frequent contacts with axonal ER tubules in a translation-dependent manner and are influenced by specific extrinsic cues. We identify P180/RRBP1 as an axonally distributed ribosome receptor that regulates local translation and binds to mRNAs enriched for axonal membrane proteins. Importantly, the impairment of axonal ER-ribosome interactions causes defects in axon morphology. Our results establish a role for the axonal ER in dynamically localizing mRNA translation, which is important for proper neuron development.
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Affiliation(s)
- Max Koppers
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands.
| | - Nazmiye Özkan
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Ha H Nguyen
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Daphne Jurriens
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Janine McCaughey
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Dan T M Nguyen
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Chun Hei Li
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Riccardo Stucchi
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands; Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Harold D MacGillavry
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Lukas C Kapitein
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Casper C Hoogenraad
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands; Department of Neuroscience, Genentech, Inc., South San Francisco, CA 94080, USA
| | - Ginny G Farías
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands.
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Guan F, Gao S, Sheng H, Ma Y, Chen W, Qi X, Zhang X, Gao X, Pang S, Zhang L, Zhang L. Trim46 knockout impaired neuronal architecture and caused hypoactive behavior in rats. Dev Dyn 2024; 253:659-676. [PMID: 38193537 DOI: 10.1002/dvdy.687] [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: 06/15/2023] [Revised: 10/16/2023] [Accepted: 12/10/2023] [Indexed: 01/10/2024] Open
Abstract
BACKGROUND Tripartite motif (TRIM46) is a relatively novel protein that belongs to tripartite motif family. TRIM46 organizes parallel microtubule arrays on the axons, which are important for neuronal polarity and axonal function. TRIM46 is highly expressed in the brain, but its biological function in adults has not yet been determined. RESULTS Trim46 knockout (KO) rat line was established using CRISPR/cas9. Trim46 KO rats had smaller hippocampus sizes, fewer neuronal dendritic arbors and dendritic spines, and shorter and more distant axon initial segment. Furthermore, the protein interaction between endogenous TRIM46 and FK506 binding protein 5 (FKBP5) in brain tissues was determined; Trim46 KO increased hippocampal FKBP5 protein levels and decreased hippocampal protein kinase B (Akt) phosphorylation, gamma-aminobutyric acid type A receptor subunit alpha1 (GABRA1) and glutamate ionotropic receptor NMDA type subunit 1 (NMDAR1) protein levels. Trim46 KO rats exhibited hypoactive behavioral changes such as reduced spontaneous activity, social interaction, sucrose preference, impaired prepulse inhibition (PPI), and short-term reference memory. CONCLUSIONS These results demonstrate the significant impact of Trim46 KO on brain structure and behavioral function. This study revealed a novel potential association of TRIM46 with dendritic development and neuropsychiatric behavior, providing new insights into the role of TRIM46 in the brain.
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Affiliation(s)
- Feifei Guan
- Beijing Engineering Research Center for Experimental Animal Models of Human Diseases, Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
| | - Shan Gao
- Key Laboratory of Human Disease Comparative Medicine, National Health Commission of China (NHC), Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
| | - Hanxuan Sheng
- Key Laboratory of Human Disease Comparative Medicine, National Health Commission of China (NHC), Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yuanwu Ma
- Beijing Engineering Research Center for Experimental Animal Models of Human Diseases, Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
| | - Wei Chen
- Key Laboratory of Human Disease Comparative Medicine, National Health Commission of China (NHC), Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaolong Qi
- Beijing Engineering Research Center for Experimental Animal Models of Human Diseases, Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
| | - Xu Zhang
- Beijing Engineering Research Center for Experimental Animal Models of Human Diseases, Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiang Gao
- Key Laboratory of Human Disease Comparative Medicine, National Health Commission of China (NHC), Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
| | - Shuo Pang
- Key Laboratory of Human Disease Comparative Medicine, National Health Commission of China (NHC), Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
| | - Lianfeng Zhang
- Key Laboratory of Human Disease Comparative Medicine, National Health Commission of China (NHC), Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
| | - Li Zhang
- Beijing Engineering Research Center for Experimental Animal Models of Human Diseases, Institute of Laboratory Animal Science, Peking Union Medicine College, Chinese Academy of Medical Sciences, Beijing, China
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15
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Melton AJ, Palfini VL, Ogawa Y, Rasband MN. TRIM46 is not required for axon specification or axon initial segment formation in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.23.595556. [PMID: 38826451 PMCID: PMC11142202 DOI: 10.1101/2024.05.23.595556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Vertebrate nervous systems use the axon initial segment (AIS) to initiate action potentials and maintain neuronal polarity. The microtubule-associated protein tripartite motif containing 46 (TRIM46) was reported to regulate axon specification, AIS assembly, and neuronal polarity through the bundling of microtubules in the proximal axon. However, these claims are based on TRIM46 knockdown in cultured neurons. To investigate TRIM46 function in vivo , we examined TRIM46 knockout mice. Contrary to previous reports, we find that TRIM46 is dispensable for AIS formation and maintenance, and axon specification. TRIM46 knockout mice are viable, have normal behavior, and have normal brain structure. Thus, TRIM46 is not required for AIS formation, axon specification, or nervous system function. We also show TRIM46 enrichment in the first ∼100 μm of axon occurs independently of ankyrinG (AnkG), although AnkG is required to restrict TRIM46 only to the AIS. Our results suggest an unidentified protein may compensate for loss of TRIM46 in vivo and highlight the need for further investigation of the mechanisms by which the AIS and microtubules interact to shape neuronal structure and function. SIGNIFICANCE STATEMENT A healthy nervous system requires the polarization of neurons into structurally and functionally distinct compartments, which depends on both the axon initial segment (AIS) and the microtubule cytoskeleton. In contrast to previous reports, we show that the microtubule-associated protein TRIM46 is not required for axon specification or AIS formation in mice. Our results emphasize the need for further investigation of the mechanisms by which the AIS and microtubules interact to shape neuronal structure and function.
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16
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Micinski D, Hotulainen P. Actin polymerization and longitudinal actin fibers in axon initial segment plasticity. Front Mol Neurosci 2024; 17:1376997. [PMID: 38799616 PMCID: PMC11120970 DOI: 10.3389/fnmol.2024.1376997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 04/26/2024] [Indexed: 05/29/2024] Open
Abstract
The location of the axon initial segment (AIS) at the junction between the soma and axon of neurons makes it instrumental in maintaining neural polarity and as the site for action potential generation. The AIS is also capable of large-scale relocation in an activity-dependent manner. This represents a form of homeostatic plasticity in which neurons regulate their own excitability by changing the size and/or position of the AIS. While AIS plasticity is important for proper functionality of AIS-containing neurons, the cellular and molecular mechanisms of AIS plasticity are poorly understood. Here, we analyzed changes in the AIS actin cytoskeleton during AIS plasticity using 3D structured illumination microscopy (3D-SIM). We showed that the number of longitudinal actin fibers increased transiently 3 h after plasticity induction. We further showed that actin polymerization, especially formin mediated actin polymerization, is required for AIS plasticity and formation of longitudinal actin fibers. From the formin family of proteins, Daam1 localized to the ends of longitudinal actin fibers. These results indicate that active re-organization of the actin cytoskeleton is required for proper AIS plasticity.
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Affiliation(s)
- David Micinski
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
- HiLIFE-Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Pirta Hotulainen
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
- Faculty of Medicine, University of Helsinki, Helsinki, Finland
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17
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Konietzny A, Han Y, Popp Y, van Bommel B, Sharma A, Delagrange P, Arbez N, Moutin MJ, Peris L, Mikhaylova M. Efficient axonal transport of endolysosomes relies on the balanced ratio of microtubule tyrosination and detyrosination. J Cell Sci 2024; 137:jcs261737. [PMID: 38525600 PMCID: PMC11112122 DOI: 10.1242/jcs.261737] [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: 10/18/2023] [Accepted: 03/14/2024] [Indexed: 03/26/2024] Open
Abstract
In neurons, the microtubule (MT) cytoskeleton forms the basis for long-distance protein transport from the cell body into and out of dendrites and axons. To maintain neuronal polarity, the axon initial segment (AIS) serves as a physical barrier, separating the axon from the somatodendritic compartment and acting as a filter for axonal cargo. Selective trafficking is further instructed by axonal enrichment of MT post-translational modifications, which affect MT dynamics and the activity of motor proteins. Here, we compared two knockout mouse lines lacking the respective enzymes for MT tyrosination and detyrosination, and found that both knockouts led to a shortening of the AIS. Neurons from both lines also showed an increased immobile fraction of endolysosomes present in the axon, whereas mobile organelles displayed shortened run distances in the retrograde direction. Overall, our results highlight the importance of maintaining the balance of tyrosinated and detyrosinated MTs for proper AIS length and axonal transport processes.
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Affiliation(s)
- Anja Konietzny
- RG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin 10115, Germany
- Guest Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
- Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan
| | - Yuhao Han
- RG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin 10115, Germany
- Guest Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
- Centre for Structural Systems Biology, Hamburg 22607, Germany
- Structural Cell Biology of Viruses, Leibniz Institute of Virology (LIV), Hamburg 20251, Germany
| | - Yannes Popp
- RG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin 10115, Germany
- Guest Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
- Charité – Universitätsmedizin Berlin, Einstein Center for Neurosciences Berlin, 10117 Berlin, Germany
| | - Bas van Bommel
- Guest Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin 14195, Germany
| | - Aditi Sharma
- University Grenoble Alpes, Inserm U1216, CNRS, Grenoble Institut Neurosciences, 38000 Grenoble, France
| | | | - Nicolas Arbez
- Institut de Recherche Servier, Croissy 78290, France
| | - Marie-Jo Moutin
- University Grenoble Alpes, Inserm U1216, CNRS, Grenoble Institut Neurosciences, 38000 Grenoble, France
| | - Leticia Peris
- University Grenoble Alpes, Inserm U1216, CNRS, Grenoble Institut Neurosciences, 38000 Grenoble, France
| | - Marina Mikhaylova
- RG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin 10115, Germany
- Guest Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
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18
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Kohl PA, Song C, Fletcher BJ, Best RL, Tchounwou C, Garcia Arceo X, Chung PJ, Miller HP, Wilson L, Choi MC, Li Y, Feinstein SC, Safinya CR. Complexes of tubulin oligomers and tau form a viscoelastic intervening network cross-bridging microtubules into bundles. Nat Commun 2024; 15:2362. [PMID: 38491006 PMCID: PMC10943092 DOI: 10.1038/s41467-024-46438-x] [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: 02/09/2023] [Accepted: 02/28/2024] [Indexed: 03/18/2024] Open
Abstract
The axon-initial-segment (AIS) of mature neurons contains microtubule (MT) fascicles (linear bundles) implicated as retrograde diffusion barriers in the retention of MT-associated protein (MAP) tau inside axons. Tau dysfunction and leakage outside of the axon is associated with neurodegeneration. We report on the structure of steady-state MT bundles in varying concentrations of Mg2+ or Ca2+ divalent cations in mixtures containing αβ-tubulin, full-length tau, and GTP at 37 °C in a physiological buffer. A concentration-time kinetic phase diagram generated by synchrotron SAXS reveals a wide-spacing MT bundle phase (Bws), a transient intermediate MT bundle phase (Bint), and a tubulin ring phase. SAXS with TEM of plastic-embedded samples provides evidence of a viscoelastic intervening network (IN) of complexes of tubulin oligomers and tau stabilizing MT bundles. In this model, αβ-tubulin oligomers in the IN are crosslinked by tau's MT binding repeats, which also link αβ-tubulin oligomers to αβ-tubulin within the MT lattice. The model challenges whether the cross-bridging of MTs is attributed entirely to MAPs. Tubulin-tau complexes in the IN or bound to isolated MTs are potential sites for enzymatic modification of tau, promoting nucleation and growth of tau fibrils in tauopathies.
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Affiliation(s)
- Phillip A Kohl
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Chaeyeon Song
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Amorepacific R&I Center, Yongin, 17074, Republic of Korea
| | - Bretton J Fletcher
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Rebecca L Best
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Serimmune Inc., 150 Castilian Dr., Goleta, CA, 93117, USA
| | - Christine Tchounwou
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Ximena Garcia Arceo
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, CA, 93106, USA
| | - Peter J Chung
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, 90089, USA
| | - Herbert P Miller
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Leslie Wilson
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Myung Chul Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Daejeon, 34141, Korea
| | - Youli Li
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
| | - Stuart C Feinstein
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Cyrus R Safinya
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA.
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
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19
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McCormick LE, Barker NK, Herring LE, Gupton SL. Loss of the E3 ubiquitin ligase TRIM67 alters the post-synaptic density proteome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.05.574385. [PMID: 38260660 PMCID: PMC10802379 DOI: 10.1101/2024.01.05.574385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The E3 ubiquitin ligase TRIM67 is enriched in the central nervous system and is required for proper neuronal development. Previously we demonstrated TRIM67 coordinates with the closely related E3 ubiquitin ligase TRIM9 to regulate cytoskeletal dynamics downstream of the netrin-1 during axon guidance and axon branching in early neuronal morphogenesis. Interestingly, loss of Trim67 impacts cognitive flexibility in a spatial learning and memory task. Despite this behavioral phenotype, it was previously uninvestigated if TRIM67 was involved in synapse formation or function. Here we demonstrate TRIM67 localizes to the post-synaptic density (PSD) within dendritic spines. Furthermore, we show that loss of Trim67 significantly changes the PSD proteome, including changes in the regulation of the actin and microtubule cytoskeletons. Collectively, our data propose a synaptic role for TRIM67.
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Affiliation(s)
- Laura E McCormick
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Natalie K Barker
- Michael Hooker Proteomics Core, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Laura E Herring
- Michael Hooker Proteomics Core, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Stephanie L Gupton
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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20
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Kanaan NM. Tau here, tau there, tau almost everywhere: Clarifying the distribution of tau in the adult CNS. Cytoskeleton (Hoboken) 2024; 81:107-115. [PMID: 38102924 PMCID: PMC10851165 DOI: 10.1002/cm.21820] [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: 08/25/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/17/2023]
Abstract
The microtubule-associated protein tau has gained significant attention over the last several decades primarily due to its apparent role in the pathogenesis of several diseases, most notably Alzheimer's disease. While the field has focused largely on tau's potential contributions to disease mechanisms, comparably less work has focused on normal tau physiology. Moreover, as the field has grown, some misconceptions and dogmas regarding normal tau physiology have become engrained in the traditional narrative. Here, one of the most common misconceptions regarding tau, namely its normal cellular/subcellular distribution in the CNS, is discussed. The literature describing the presence of tau in neuronal somata, dendrites, axons and synapses, as well as in glial cells is described. The origins for the erroneous description of tau as an "axon-specific," "axon-enriched" and/or "neuron-specific" protein are discussed as well. The goal of this work is to help address these specific dogmatic misconceptions and provide a concise description of tau's normal cellular/subcellular localization in the adult CNS. This information can help refine our collective understanding of- and hypotheses about tau biology and pathobiology.
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Affiliation(s)
- Nicholas M. Kanaan
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Neuroscience Program, Michigan State University, East Lansing, Michigan, USA
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21
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Allroggen N, Breuer H, Bachmann S, Bell M, Zempel H. Studying Microtubule Dynamics in Human Neurons: Two-Dimensional Microtubule Tracing and Kymographs in iPSC- and SH-SY5Y-Derived Neurons for Tau Research. Methods Mol Biol 2024; 2754:561-580. [PMID: 38512690 DOI: 10.1007/978-1-0716-3629-9_33] [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] [Indexed: 03/23/2024]
Abstract
The study of microtubule (MT) dynamics is essential for the understanding of cellular transport, cell polarity, axon formation, and other neurodevelopmental mechanisms. All these processes rely on the constant transition between assembly and disassembly of tubulin polymers to/from MTs, known as dynamic instability. This process is well-regulated, among others, by phosphorylation of microtubule-associated proteins (MAP), including the Tau protein. Protein kinases, in particular the microtubule affinity regulating kinase (MARK), regulate the MT-Tau interaction, inducing Tau dissociation by phosphorylation. Phosphorylated Tau dissociates from microtubules forming insoluble aggregates known as neurofibrillary tangles. These accumulations of hyperphosphorylated Tau in the neurons disrupt the physiological MT-based transport machinery within the cell and can potentially lead to the development of neurodegenerative disorders, such as Alzheimer's disease (AD) and related tauopathies. Further investigations on the MT cytoskeleton dynamics are essential as they may elucidate pathomechanisms of neurodegenerative diseases - particularly tauopathies - as well as fundamental neurodevelopmental processes.The study of the dynamic assembly and disassembly of the MT network requires live-cell imaging rather than conventional immunocytochemistry based on fixed samples. To investigate MT dynamics, we perform live-cell imaging of neurons transfected with a fluorescently tagged version of the microtubule plus-end tracking protein (+TIP) EB3. This protein associates with the growing ends of MTs and thus visualizes MT growth in real time. Our imaging analysis protocol allows the determination of quantity, orientation, and velocity of MT growth in the soma and neurites of transfected neurons, using ImageJ-based tracking software and kymographs. Furthermore, functional effects of Tau and MARK kinases on the MT cytoskeleton can be assessed by overexpression or downregulation experiments of the respective protein prior to the live imaging assay. We use two different human neuronal cell models, naive and differentiated SH-SY5Y neuroblastoma cells, and neurons derived from induced pluripotent stem cells (iPSCs), both of which have shown success as models to study Tau-related pathologies.This protocol describes an optimized method for analysis of microtubule dynamics using fluorescent tagged EB3 protein as microtubule plus end marker. In this chapter, we outline the process of neuronal transfection, live-cell imaging, and necessary time-lapse image analysis based on ImageJ in two human-derived neuronal systems, which are suitable for the analysis of Tau trafficking and sorting studies.
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Affiliation(s)
- Nadine Allroggen
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Helen Breuer
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Sarah Bachmann
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Michael Bell
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Hans Zempel
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.
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22
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Buchholz S, Bell-Simons M, Cakmak C, Klimek J, Gan L, Zempel H. Cultivation, Differentiation, and Lentiviral Transduction of Human-Induced Pluripotent Stem Cell (hiPSC)-Derived Glutamatergic Neurons for Studying Human Tau. Methods Mol Biol 2024; 2754:533-549. [PMID: 38512688 DOI: 10.1007/978-1-0716-3629-9_31] [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] [Indexed: 03/23/2024]
Abstract
Tau pathology is a major hallmark of many neurodegenerative diseases summarized under the term tauopathies. In most of these disorders, such as Alzheimer's disease, the neuronal axonal microtubule-binding Tau protein becomes mislocalized to the somatodendritic compartment. In human disease, this missorting of Tau is accompanied by an abnormally high phosphorylation state of the Tau protein, and several downstream pathological consequences (e.g., loss of microtubules, degradation of postsynaptic spines, impaired synaptic transmission, neuronal death). While some mechanisms of Tau sorting, missorting, and associated pathologies have been addressed in rodent models, few studies have addressed human Tau in physiological disease-relevant human neurons. Thus, suitable human-derived in vitro models are necessary. This protocol provides a simple step-by-step protocol for generating homogeneous cultures of cortical glutamatergic neurons using an engineered Ngn2 transgene-carrying WTC11 iPSC line. We further demonstrate strategies to improve neuronal maturity, that is, synapse formation, Tau isoform expression, and neuronal activity by co-culturing hiPSC-derived glutamatergic neurons with mouse-derived astrocytes. Finally, we describe a simple protocol for high-efficiency lentiviral transduction of hiPSC-derived neurons at almost all stages of differentiation.
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Affiliation(s)
- Sarah Buchholz
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Michael Bell-Simons
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Cagla Cakmak
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Jennifer Klimek
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Li Gan
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Hans Zempel
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.
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23
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Zhang W, Fu Y, Peng L, Ogawa Y, Ding X, Rasband A, Zhou X, Shelly M, Rasband MN, Zou P. Immunoproximity biotinylation reveals the axon initial segment proteome. Nat Commun 2023; 14:8201. [PMID: 38081810 PMCID: PMC10713531 DOI: 10.1038/s41467-023-44015-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
The axon initial segment (AIS) is a specialized neuronal compartment required for action potential generation and neuronal polarity. However, understanding the mechanisms regulating AIS structure and function has been hindered by an incomplete knowledge of its molecular composition. Here, using immuno-proximity biotinylation we further define the AIS proteome and its dynamic changes during neuronal maturation. Among the many AIS proteins identified, we show that SCRIB is highly enriched in the AIS both in vitro and in vivo, and exhibits a periodic architecture like the axonal spectrin-based cytoskeleton. We find that ankyrinG interacts with and recruits SCRIB to the AIS. However, loss of SCRIB has no effect on ankyrinG. This powerful and flexible approach further defines the AIS proteome and provides a rich resource to elucidate the mechanisms regulating AIS structure and function.
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Affiliation(s)
- Wei Zhang
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing, 100871, China
- Academy for Advanced Interdisciplinary Studies, PKU-Tsinghua Center for Life Science, Peking University, Beijing, 100871, China
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Yu Fu
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing, 100871, China
| | - Luxin Peng
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing, 100871, China
| | - Yuki Ogawa
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Xiaoyun Ding
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Anne Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Xinyue Zhou
- Academy for Advanced Interdisciplinary Studies, PKU-Tsinghua Center for Life Science, Peking University, Beijing, 100871, China
| | - Maya Shelly
- Department of Neurobiology and Behavior, Stony Brook University, New York, NY, USA
| | - Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
| | - Peng Zou
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing, 100871, China.
- Academy for Advanced Interdisciplinary Studies, PKU-Tsinghua Center for Life Science, Peking University, Beijing, 100871, China.
- PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, China.
- Chinese Institute for Brain Research (CIBR), Beijing, 102206, China.
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24
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Dudley-Fraser J, Rittinger K. It's a TRIM-endous view from the top: the varied roles of TRIpartite Motif proteins in brain development and disease. Front Mol Neurosci 2023; 16:1287257. [PMID: 38115822 PMCID: PMC10728303 DOI: 10.3389/fnmol.2023.1287257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 11/13/2023] [Indexed: 12/21/2023] Open
Abstract
The tripartite motif (TRIM) protein family members have been implicated in a multitude of physiologies and pathologies in different tissues. With diverse functions in cellular processes including regulation of signaling pathways, protein degradation, and transcriptional control, the impact of TRIM dysregulation can be multifaceted and complex. Here, we focus on the cellular and molecular roles of TRIMs identified in the brain in the context of a selection of pathologies including cancer and neurodegeneration. By examining each disease in parallel with described roles in brain development, we aim to highlight fundamental common mechanisms employed by TRIM proteins and identify opportunities for therapeutic intervention.
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Affiliation(s)
- Jane Dudley-Fraser
- Molecular Structure of Cell Signalling Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Katrin Rittinger
- Molecular Structure of Cell Signalling Laboratory, The Francis Crick Institute, London, United Kingdom
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25
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Gilloteaux J, De Swert K, Suain V, Nicaise C. Thalamic Neuron Resilience during Osmotic Demyelination Syndrome (ODS) Is Revealed by Primary Cilium Outgrowth and ADP-ribosylation factor-like protein 13B Labeling in Axon Initial Segment. Int J Mol Sci 2023; 24:16448. [PMID: 38003639 PMCID: PMC10671465 DOI: 10.3390/ijms242216448] [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: 10/22/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
A murine osmotic demyelinating syndrome (ODS) model was developed through chronic hyponatremia, induced by desmopressin subcutaneous implants, followed by precipitous sodium restoration. The thalamic ventral posterolateral (VPL) and ventral posteromedial (VPM) relay nuclei were the most demyelinated regions where neuroglial damage could be evidenced without immune response. This report showed that following chronic hyponatremia, 12 h and 48 h time lapses after rebalancing osmolarity, amid the ODS-degraded outskirts, some resilient neuronal cell bodies built up primary cilium and axon hillock regions that extended into axon initial segments (AIS) where ADP-ribosylation factor-like protein 13B (ARL13B)-immunolabeled rod-like shape content was revealed. These AIS-labeled shaft lengths appeared proportional with the distance of neuronal cell bodies away from the ODS damaged epicenter and time lapses after correction of hyponatremia. Fine structure examination verified these neuron abundant transcriptions and translation regions marked by the ARL13B labeling associated with cell neurotubules and their complex cytoskeletal macromolecular architecture. This necessitated energetic transport to organize and restore those AIS away from the damaged ODS core demyelinated zone in the murine model. These labeled structures could substantiate how thalamic neuron resilience occurred as possible steps of a healing course out of ODS.
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Affiliation(s)
- Jacques Gilloteaux
- URPhyM, NARILIS, Université de Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; (J.G.); (K.D.S.)
- Department of Anatomical Sciences, St George’s University School of Medicine, Newcastle upon Tyne NE1 JG8, UK
| | - Kathleen De Swert
- URPhyM, NARILIS, Université de Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; (J.G.); (K.D.S.)
| | - Valérie Suain
- Laboratoire d’Histologie Générale, Université Libre de Bruxelles, Route de Lennik 808, B-1070 Bruxelles, Belgium;
| | - Charles Nicaise
- URPhyM, NARILIS, Université de Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; (J.G.); (K.D.S.)
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26
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Affiliation(s)
- Peng Lei
- Department of Neurology and State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China.
| | - Scott Ayton
- The Florey Neuroscience Institute, The University of Melbourne, Melbourne VIC 3052, Australia.
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27
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Wang Y, Risteski P, Yang Y, Chen H, Droby G, Walens A, Jayaprakash D, Troester M, Herring L, Chernoff J, Tolić I, Bowser J, Vaziri C. The TRIM69-MST2 signaling axis regulates centrosome dynamics and chromosome segregation. Nucleic Acids Res 2023; 51:10568-10589. [PMID: 37739411 PMCID: PMC10602929 DOI: 10.1093/nar/gkad766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/30/2023] [Accepted: 09/10/2023] [Indexed: 09/24/2023] Open
Abstract
Stringent control of centrosome duplication and separation is important for preventing chromosome instability. Structural and numerical alterations in centrosomes are hallmarks of neoplastic cells and contribute to tumorigenesis. We show that a Centrosome Amplification 20 (CA20) gene signature is associated with high expression of the Tripartite Motif (TRIM) family member E3 ubiquitin ligase, TRIM69. TRIM69-ablation in cancer cells leads to centrosome scattering and chromosome segregation defects. We identify Serine/threonine-protein kinase 3 (MST2) as a new direct binding partner of TRIM69. TRIM69 redistributes MST2 to the perinuclear cytoskeleton, promotes its association with Polo-like kinase 1 (PLK1) and stimulates MST2 phosphorylation at S15 (a known PLK1 phosphorylation site that is critical for centrosome disjunction). TRIM69 also promotes microtubule bundling and centrosome segregation that requires PRC1 and DYNEIN. Taken together, we identify TRIM69 as a new proximal regulator of distinct signaling pathways that regulate centrosome dynamics and promote bipolar mitosis.
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Affiliation(s)
- Yilin Wang
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Patrik Risteski
- Division of Molecular Biology, Ruđer Boskovic Institute, Bijenicka cesta 54, 10000 Zagreb, Croatia
| | - Yang Yang
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Huan Chen
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Gaith Droby
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Andrea Walens
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Deepika Jayaprakash
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- Oral and Craniofacial Biomedicine Program, Adam’s School of Dentistry, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Melissa Troester
- Department of Epidemiology, Gillings School of Global Public Health and UNC Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Laura Herring
- Department of Pharmacology, UNC Proteomics Core Facility, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | - Iva M Tolić
- Division of Molecular Biology, Ruđer Boskovic Institute, Bijenicka cesta 54, 10000 Zagreb, Croatia
| | - Jessica Bowser
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
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28
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Campbell LK, Peery RM, Magor KE. Evolution and expression of the duck TRIM gene repertoire. Front Immunol 2023; 14:1220081. [PMID: 37622121 PMCID: PMC10445537 DOI: 10.3389/fimmu.2023.1220081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 07/05/2023] [Indexed: 08/26/2023] Open
Abstract
Tripartite motif (TRIM) proteins are involved in development, innate immunity, and viral restriction. TRIM gene repertoires vary between species, likely due to diversification caused by selective pressures from pathogens; however, this has not been explored in birds. We mined a de novo assembled transcriptome for the TRIM gene repertoire of the domestic mallard duck (Anas platyrhynchos), a reservoir host of influenza A viruses. We found 57 TRIM genes in the duck, which represent all 12 subfamilies based on their C-terminal domains. Members of the C-IV subfamily with C-terminal PRY-SPRY domains are known to augment immune responses in mammals. We compared C-IV TRIM proteins between reptiles, birds, and mammals and show that many C-IV subfamily members have arisen independently in these lineages. A comparison of the MHC-linked C-IV TRIM genes reveals expansions in birds and reptiles. The TRIM25 locus with related innate receptor modifiers is adjacent to the MHC in reptile and marsupial genomes, suggesting the ancestral organization. Within the avian lineage, both the MHC and TRIM25 loci have undergone significant TRIM gene reorganizations and divergence, both hallmarks of pathogen-driven selection. To assess the expression of TRIM genes, we aligned RNA-seq reads from duck tissues. C-IV TRIMs had high relative expression in immune relevant sites such as the lung, spleen, kidney, and intestine, and low expression in immune privileged sites such as in the brain or gonads. Gene loss and gain in the evolution of the TRIM repertoire in birds suggests candidate immune genes and potential targets of viral subversion.
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Affiliation(s)
- Lee K. Campbell
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada
| | - Rhiannon M. Peery
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
- Department of Biology, Carleton University, Ottawa, ON, Canada
| | - Katharine E. Magor
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada
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29
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Best MN, Lim Y, Ferenc NN, Kim N, Min L, Wang DB, Sharifi K, Wasserman AE, McTavish SA, Siller KH, Jones MK, Jenkins PM, Mandell JW, Bloom GS. Extracellular Tau Oligomers Damage the Axon Initial Segment. J Alzheimers Dis 2023:JAD221284. [PMID: 37182881 DOI: 10.3233/jad-221284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
BACKGROUND In Alzheimer's disease (AD) brain, neuronal polarity and synaptic connectivity are compromised. A key structure for regulating polarity and functions of neurons is the axon initial segment (AIS), which segregates somatodendritic from axonal proteins and initiates action potentials. Toxic tau species, including extracellular oligomers (xcTauOs), spread tau pathology from neuron to neuron by a prion-like process, but few other cell biological effects of xcTauOs have been described. OBJECTIVE Test the hypothesis that AIS structure is sensitive to xcTauOs. METHODS Cultured wild type (WT) and tau knockout (KO) mouse cortical neurons were exposed to xcTauOs, and quantitative western blotting and immunofluorescence microscopy with anti-TRIM46 monitored effects on the AIS. The same methods were used to compare TRIM46 and two other resident AIS proteins in human hippocampal tissue obtained from AD and age-matched non-AD donors. RESULTS Without affecting total TRIM46 levels, xcTauOs reduce the concentration of TRIM46 within the AIS and cause AIS shortening in cultured WT, but not TKO neurons. Lentiviral-driven tau expression in tau KO neurons rescues AIS length sensitivity to xcTauOs. In human AD hippocampus, the overall protein levels of multiple resident AIS proteins are unchanged compared to non-AD brain, but TRIM46 concentration within the AIS and AIS length are reduced in neurons containing neurofibrillary tangles. CONCLUSION xcTauOs cause partial AIS damage in cultured neurons by a mechanism dependent on intracellular tau, thereby raising the possibility that the observed AIS reduction in AD neurons in vivo is caused by xcTauOs working in concert with endogenous neuronal tau.
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Affiliation(s)
- Merci N Best
- Department of Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Yunu Lim
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Nina N Ferenc
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Nayoung Kim
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Lia Min
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Dora Bigler Wang
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Kamyar Sharifi
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Anna E Wasserman
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Sloane A McTavish
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Karsten H Siller
- Research Computing, University of Virginia, Charlottesville, VA, USA
| | - Marieke K Jones
- Claude Moore Health Sciences Library, University of Virginia, Charlottesville, VA, USA
| | - Paul M Jenkins
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Psychiatry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - James W Mandell
- Department of Pathology, University of Virginia, Charlottesville, VA, USA
| | - George S Bloom
- Department of Biology, University of Virginia, Charlottesville, VA, USA
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
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30
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Adler J. The Axon Initial Segment Plays a Dynamic Role in Peripheral Motor Neuron Synapse Regeneration following Injury. J Neurosci 2023; 43:3199-3201. [PMID: 37137706 PMCID: PMC10162451 DOI: 10.1523/jneurosci.2326-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 03/16/2023] [Accepted: 03/21/2023] [Indexed: 05/05/2023] Open
Affiliation(s)
- Joy Adler
- Anschutz Medical Neuroscience Graduate Training Program, University of Colorado, Aurora, Colorado 80045
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31
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Iwanski MK, Kapitein LC. Cellular cartography: Towards an atlas of the neuronal microtubule cytoskeleton. Front Cell Dev Biol 2023; 11:1052245. [PMID: 37035244 PMCID: PMC10073685 DOI: 10.3389/fcell.2023.1052245] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 02/28/2023] [Indexed: 04/11/2023] Open
Abstract
Microtubules, one of the major components of the cytoskeleton, play a crucial role during many aspects of neuronal development and function, such as neuronal polarization and axon outgrowth. Consequently, the microtubule cytoskeleton has been implicated in many neurodevelopmental and neurodegenerative disorders. The polar nature of microtubules is quintessential for their function, allowing them to serve as tracks for long-distance, directed intracellular transport by kinesin and dynein motors. Most of these motors move exclusively towards either the plus- or minus-end of a microtubule and some have been shown to have a preference for either dynamic or stable microtubules, those bearing a particular post-translational modification or those decorated by a specific microtubule-associated protein. Thus, it becomes important to consider the interplay of these features and their combinatorial effects on transport, as well as how different types of microtubules are organized in the cell. Here, we discuss microtubule subsets in terms of tubulin isotypes, tubulin post-translational modifications, microtubule-associated proteins, microtubule stability or dynamicity, and microtubule orientation. We highlight techniques used to study these features of the microtubule cytoskeleton and, using the information from these studies, try to define the composition, role, and organization of some of these subsets in neurons.
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Affiliation(s)
| | - Lukas C. Kapitein
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
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32
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Ruiz-Reig N, García-Sánchez D, Schakman O, Gailly P, Tissir F. Inhibitory synapse dysfunction and epileptic susceptibility associated with KIF2A deletion in cortical interneurons. Front Mol Neurosci 2023; 15:1110986. [PMID: 36733270 PMCID: PMC9887042 DOI: 10.3389/fnmol.2022.1110986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 12/30/2022] [Indexed: 01/18/2023] Open
Abstract
Malformation of cortical development (MCD) is a family of neurodevelopmental disorders, which usually manifest with intellectual disability and early-life epileptic seizures. Mutations in genes encoding microtubules (MT) and MT-associated proteins are one of the most frequent causes of MCD in humans. KIF2A is an atypical kinesin that depolymerizes MT in ATP-dependent manner and regulates MT dynamics. In humans, single de novo mutations in KIF2A are associated with MCD with epileptic seizures, posterior pachygyria, microcephaly, and partial agenesis of corpus callosum. In this study, we conditionally ablated KIF2A in forebrain inhibitory neurons and assessed its role in development and function of inhibitory cortical circuits. We report that adult mice with specific deletion of KIF2A in GABAergic interneurons display abnormal behavior and increased susceptibility to epilepsy. KIF2A is essential for tangential migration of cortical interneurons, their positioning in the cerebral cortex, and for formation of inhibitory synapses in vivo. Our results shed light on how KIF2A deregulation triggers functional alterations in neuronal circuitries and contributes to epilepsy.
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Affiliation(s)
- Nuria Ruiz-Reig
- Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium,*Correspondence: Nuria Ruiz-Reig, Fadel Tissir, ;
| | | | - Olivier Schakman
- Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Philippe Gailly
- Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Fadel Tissir
- Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium,College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar,*Correspondence: Nuria Ruiz-Reig, Fadel Tissir, ;
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33
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Eckel BD, Cruz R, Craig EM, Baas PW. Microtubule polarity flaws as a treatable driver of neurodegeneration. Brain Res Bull 2023; 192:208-215. [PMID: 36442694 DOI: 10.1016/j.brainresbull.2022.11.013] [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: 07/08/2022] [Revised: 11/07/2022] [Accepted: 11/17/2022] [Indexed: 11/26/2022]
Abstract
Microtubule disruption is a common downstream mechanism leading to axonal degeneration in a number of neurological diseases. To date, most studies on this topic have focused on the loss of microtubule mass from the axon, as well as changes in the stability properties of the microtubules and/or their tubulin composition. Here we posit corruption of the normal pattern of microtubule polarity orientation as an underappreciated and yet treatable contributor to axonal degeneration. We include computational modeling to fortify the rigor of our considerations. Our simulations demonstrate that even a small deviation from the usual polarity pattern of axonal microtubules is detrimental to motor-based trafficking of organelles and other intracellular cargo. Additional modeling predicts that axons with such deviations will exhibit significantly reduced speed and reliability of organelle transport, and that localized clusters of wrongly oriented microtubules will result in traffic jams of accumulated organelles.
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Affiliation(s)
- Bridie D Eckel
- Dept Neurobiol/Anat, Drexel University, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Roy Cruz
- Dept Physics, Central Washington University, Ellensburg, WA 98926, USA
| | - Erin M Craig
- Dept Physics, Central Washington University, Ellensburg, WA 98926, USA
| | - Peter W Baas
- Dept Neurobiol/Anat, Drexel University, 2900 Queen Lane, Philadelphia, PA 19129, USA.
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34
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Tulin EKC, Yoshimura T, Nakazawa C, Saito S, Kanai K, Kozono T, Nakakita SI, Tonozuka T, Ikenaka K, Nishikawa A. Recombinant lectin Gg for brain imaging of glycan structure and formation in the CNS node of Ranvier. J Neurochem 2022; 163:461-477. [PMID: 36156798 DOI: 10.1111/jnc.15695] [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: 04/26/2022] [Revised: 08/12/2022] [Accepted: 09/13/2022] [Indexed: 01/19/2023]
Abstract
The nodes of Ranvier are unmyelinated gaps in the axon, important for the efficient transmission of action potentials. Despite the identification of several glycoproteins involved in node formation and maintenance, glycans' structure and formation in the node remain unclear. Previously, we developed a recombinant lectin from the Clostridium botulinum neurotoxin complex, specific to the galactose and N-acetylgalactosamine terminal epitopes (Gg). Gg stained Neuro2a cells. Here, we show Gg punctuate staining in mouse brain cryosections. Thus, we hypothesized that Gg could help study glycans in the node of Ranvier. Lectin histochemistry on mouse brain cryosections confirmed that Gg binds specifically to the node of Ranvier in the central nervous system (CNS). Using a combination of lectin blotting, glycosidase treatment on tissue sections, and lectin histochemistry, Gg ligands were identified as α-galactose terminal glycoproteins in the perinodal extracellular matrix. Furthermore, we detected the spatiotemporal distribution of galactosylated glycans in the CNS node of Ranvier in mouse brain tissues at different postnatal times. Finally, we observed impaired clustering of galactosylated glycans in the nodes during demyelination and remyelination in cuprizone-induced demyelination and remyelination mouse model. In conclusion, Gg can serve as a novel brain imaging tool in glycobiology and report glycoprotein formation and alterations in the CNS node of Ranvier. Our findings might serve as a first step to establish the role of glycans in the node of Ranvier.
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Affiliation(s)
- Ea Kristine Clarisse Tulin
- Department of Applied Life Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Takeshi Yoshimura
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Chiaki Nakazawa
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Shion Saito
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Kyoko Kanai
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Takuma Kozono
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | | | - Takashi Tonozuka
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi, Japan
| | - Atsushi Nishikawa
- Department of Applied Life Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.,Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
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35
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Burute M, Jansen KI, Mihajlovic M, Vermonden T, Kapitein LC. Local changes in microtubule network mobility instruct neuronal polarization and axon specification. SCIENCE ADVANCES 2022; 8:eabo2343. [PMID: 36332030 PMCID: PMC9635826 DOI: 10.1126/sciadv.abo2343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
The polarization of neurons into axons and dendrites depends on extracellular cues, intracellular signaling, cytoskeletal rearrangements, and polarized transport, but the interplay between these processes during polarization remains unresolved. Here, we show that axon specification is determined by differences in microtubule network mobility between neurites, regulated by Rho guanosine triphosphatases (GTPases) and extracellular cues. In developing neurons, retrograde microtubule flow prevents the entry of the axon-selective motor protein Kinesin-1 into most neurites. Using inducible assays to control microtubule network flow, we demonstrate that local inhibition of microtubule mobility is sufficient to guide Kinesin-1 into a specific neurite, whereas long-term global inhibition induces the formation of multiple axons. We furthermore show that extracellular mechanical cues and intracellular Rho GTPase signaling control the local differences in microtubule network flow. These results reveal a novel cytoskeletal mechanism for neuronal polarization.
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Affiliation(s)
- Mithila Burute
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
| | - Klara I. Jansen
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
| | - Marko Mihajlovic
- Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical Sciences (UIPS), Science for Life, Utrecht University, Universiteitsweg 99, 3508 TB Utrecht, Netherlands
| | - Tina Vermonden
- Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical Sciences (UIPS), Science for Life, Utrecht University, Universiteitsweg 99, 3508 TB Utrecht, Netherlands
| | - Lukas C. Kapitein
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
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36
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Schelski M, Bradke F. Microtubule retrograde flow retains neuronal polarization in a fluctuating state. SCIENCE ADVANCES 2022; 8:eabo2336. [PMID: 36332023 PMCID: PMC9635824 DOI: 10.1126/sciadv.abo2336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
In developing vertebrate neurons, a neurite is formed by more than a hundred microtubules. While individual microtubules are dynamic, the microtubule array has been regarded as stationary. Using live-cell imaging of neurons in culture or in brain slices, combined with photoconversion techniques and pharmacological manipulations, we uncovered that the microtubule array flows retrogradely within neurites to the soma. This flow drives cycles of microtubule density, a hallmark of the fluctuating state before axon formation, thereby inhibiting neurite growth. The motor protein dynein fuels this process. Shortly after axon formation, microtubule retrograde flow slows down in the axon, reducing microtubule density cycles and enabling axon extension. Thus, keeping neurites short is an active process. Microtubule retrograde flow is a previously unknown type of cytoskeletal dynamics, which changes the hitherto axon-centric view of neuronal polarization.
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Affiliation(s)
- Max Schelski
- Axon Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
- International Max Planck Research School for Brain and Behavior, University of Bonn, Bonn, Germany
| | - Frank Bradke
- Axon Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
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37
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He L, van Beem L, Snel B, Hoogenraad CC, Harterink M. PTRN-1 (CAMSAP) and NOCA-2 (NINEIN) are required for microtubule polarity in Caenorhabditis elegans dendrites. PLoS Biol 2022; 20:e3001855. [PMID: 36395330 PMCID: PMC9714909 DOI: 10.1371/journal.pbio.3001855] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 12/01/2022] [Accepted: 09/27/2022] [Indexed: 11/18/2022] Open
Abstract
The neuronal microtubule cytoskeleton is key to establish axon-dendrite polarity. Dendrites are characterized by the presence of minus-end out microtubules. However, the mechanisms that organize these microtubules with the correct orientation are still poorly understood. Using Caenorhabditis elegans as a model system for microtubule organization, we characterized the role of 2 microtubule minus-end related proteins in this process, the microtubule minus-end stabilizing protein calmodulin-regulated spectrin-associated protein (CAMSAP/PTRN-1), and the NINEIN homologue, NOCA-2 (noncentrosomal microtubule array). We found that CAMSAP and NINEIN function in parallel to mediate microtubule organization in dendrites. During dendrite outgrowth, RAB-11-positive vesicles localized to the dendrite tip to nucleate microtubules and function as a microtubule organizing center (MTOC). In the absence of either CAMSAP or NINEIN, we observed a low penetrance MTOC vesicles mislocalization to the cell body, and a nearly fully penetrant phenotype in double mutant animals. This suggests that both proteins are important for localizing the MTOC vesicles to the growing dendrite tip to organize microtubules minus-end out. Whereas NINEIN localizes to the MTOC vesicles where it is important for the recruitment of the microtubule nucleator γ-tubulin, CAMSAP localizes around the MTOC vesicles and is cotranslocated forward with the MTOC vesicles upon dendritic growth. Together, these results indicate that microtubule nucleation from the MTOC vesicles and microtubule stabilization are both important to localize the MTOC vesicles distally to organize dendritic microtubules minus-end out.
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Affiliation(s)
- Liu He
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Lotte van Beem
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Berend Snel
- Theoretical Biology and Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Casper C. Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
- Department of Neuroscience, Genentech, Inc., South San Francisco, California, United States of America
| | - Martin Harterink
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
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38
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Teliska LH, Dalla Costa I, Sert O, Twiss JL, Rasband MN. Axon Initial Segments Are Required for Efficient Motor Neuron Axon Regeneration and Functional Recovery of Synapses. J Neurosci 2022; 42:8054-8065. [PMID: 36096668 PMCID: PMC9636994 DOI: 10.1523/jneurosci.1261-22.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 08/02/2022] [Indexed: 11/21/2022] Open
Abstract
The axon initial segment (AIS) generates action potentials and maintains neuronal polarity by regulating the differential trafficking and distribution of proteins, transport vesicles, and organelles. Injury and disease can disrupt the AIS, and the subsequent loss of clustered ion channels and polarity mechanisms may alter neuronal excitability and function. However, the impact of AIS disruption on axon regeneration after injury is unknown. We generated male and female mice with AIS-deficient multipolar motor neurons by deleting AnkyrinG, the master scaffolding protein required for AIS assembly and maintenance. We found that after nerve crush, neuromuscular junction reinnervation was significantly delayed in AIS-deficient motor neurons compared with control mice. In contrast, loss of AnkyrinG from pseudo-unipolar sensory neurons did not impair axon regeneration into the intraepidermal nerve fiber layer. Even after AIS-deficient motor neurons reinnervated the neuromuscular junction, they failed to functionally recover because of reduced synaptic vesicle protein 2 at presynaptic terminals. In addition, mRNA trafficking was disrupted in AIS-deficient axons. Our results show that, after nerve injury, an intact AIS is essential for efficient regeneration and functional recovery of axons in multipolar motor neurons. Our results also suggest that loss of polarity in AIS-deficient motor neurons impairs the delivery of axonal proteins, mRNAs, and other cargoes necessary for regeneration. Thus, therapeutic strategies for axon regeneration must consider preservation or reassembly of the AIS.SIGNIFICANCE STATEMENT Disruption of the axon initial segment is a common event after nervous system injury. For multipolar motor neurons, we show that axon initial segments are essential for axon regeneration and functional recovery after injury. Our results may help explain injuries where axon regeneration fails, and suggest strategies to promote more efficient axon regeneration.
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Affiliation(s)
- Lindsay H Teliska
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Irene Dalla Costa
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208
| | - Ozlem Sert
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208
| | - Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
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39
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Lin CH, Chen YC, Chan SP, Ou CY. TIAM-1 differentially regulates dendritic and axonal microtubule organization in patterning neuronal development through its multiple domains. PLoS Genet 2022; 18:e1010454. [PMID: 36223408 PMCID: PMC9612824 DOI: 10.1371/journal.pgen.1010454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 10/27/2022] [Accepted: 09/29/2022] [Indexed: 12/02/2022] Open
Abstract
Axon and dendrite development require the cooperation of actin and microtubule cytoskeletons. Microtubules form a well-organized network to direct polarized trafficking and support neuronal processes formation with distinct actin structures. However, it is largely unknown how cytoskeleton regulators differentially regulate microtubule organization in axon and dendrite development. Here, we characterize the role of actin regulators in axon and dendrite development and show that the RacGEF TIAM-1 regulates dendritic patterns through its N-terminal domains and suppresses axon growth through its C-terminal domains. TIAM-1 maintains plus-end-out microtubule orientation in posterior dendrites and prevents the accumulation of microtubules in the axon. In somatodendritic regions, TIAM-1 interacts with UNC-119 and stabilizes the organization between actin filaments and microtubules. UNC-119 is required for TIAM-1 to control axon growth, and its expression levels determine axon length. Taken together, TIAM-1 regulates neuronal microtubule organization and patterns axon and dendrite development respectively through its different domains.
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Affiliation(s)
- Chih-Hsien Lin
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ying-Chun Chen
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shih-Peng Chan
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chan-Yen Ou
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
- * E-mail:
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40
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Jakobs MAH, Zemel A, Franze K. Unrestrained growth of correctly oriented microtubules instructs axonal microtubule orientation. eLife 2022; 11:e77608. [PMID: 36214669 PMCID: PMC9550224 DOI: 10.7554/elife.77608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 08/19/2022] [Indexed: 11/23/2022] Open
Abstract
In many eukaryotic cells, directed molecular transport occurs along microtubules. Within neuronal axons, transport over vast distances particularly relies on uniformly oriented microtubules, whose plus-ends point towards the distal axon tip (anterogradely polymerizing, or plus-end-out). However, axonal microtubules initially have mixed orientations, and how they orient during development is not yet fully understood. Using live imaging of primary Drosophila melanogaster neurons, we found that, in the distal part of the axon, catastrophe rates of plus-end-out microtubules were significantly reduced compared to those of minus-end-out microtubules. Physical modelling revealed that plus-end-out microtubules should therefore exhibit persistent long-term growth, while growth of minus-end-out microtubules should be limited, leading to a bias in overall axonal microtubule orientation. Using chemical and physical perturbations of microtubule growth and genetic perturbations of the anti -catastrophe factor p150, which was enriched in the distal axon tip, we confirmed that the enhanced growth of plus-end-out microtubules is critical for achieving uniform microtubule orientation. Computer simulations of axon development integrating the enhanced plus-end-out microtubule growth identified here with previously suggested mechanisms, that is, dynein-based microtubule sliding and augmin-mediated templating, correctly predicted the long-term evolution of axonal microtubule orientation as found in our experiments. Our study thus leads to a holistic explanation of how axonal microtubules orient uniformly, a prerequisite for efficient long-range transport essential for neuronal functioning.
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Affiliation(s)
- Maximilian AH Jakobs
- Department of Physiology, Development and Neuroscience, University of CambridgeCambridgeUnited Kingdom
- DeepMirrorCambridgeUnited Kingdom
| | - Assaf Zemel
- Institute of Biomedical and Oral Research, and the Fritz Haber Center for Molecular Dynamics, Hebrew University of JerusalemJerusalemIsrael
| | - Kristian Franze
- Department of Physiology, Development and Neuroscience, University of CambridgeCambridgeUnited Kingdom
- Institute for Medical Physics, Friedrich-Alexander-Universität Erlangen-NürnbergErlangenGermany
- Max-Planck-Zentrum für Physik und MedizinErlangenGermany
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41
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Moore RE, Pop S, Alleyne C, Clarke JDW. Microtubules are not required to generate a nascent axon in embryonic spinal neurons
in vivo. EMBO Rep 2022; 23:e52493. [DOI: 10.15252/embr.202152493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 09/05/2022] [Accepted: 09/08/2022] [Indexed: 11/06/2022] Open
Affiliation(s)
- Rachel E Moore
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience King's College London London UK
| | - Sînziana Pop
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience King's College London London UK
- The Francis Crick Institute London UK
| | - Caché Alleyne
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience King's College London London UK
| | - Jonathan D W Clarke
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience King's College London London UK
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42
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Dorrego-Rivas A, Ezan J, Moreau MM, Poirault-Chassac S, Aubailly N, De Neve J, Blanchard C, Castets F, Fréal A, Battefeld A, Sans N, Montcouquiol M. The core PCP protein Prickle2 regulates axon number and AIS maturation by binding to AnkG and modulating microtubule bundling. SCIENCE ADVANCES 2022; 8:eabo6333. [PMID: 36083912 PMCID: PMC9462691 DOI: 10.1126/sciadv.abo6333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Core planar cell polarity (PCP) genes, which are involved in various neurodevelopmental disorders such as neural tube closure, epilepsy, and autism spectrum disorder, have poorly defined molecular signatures in neurons, mostly synapse-centric. Here, we show that the core PCP protein Prickle-like protein 2 (Prickle2) controls neuronal polarity and is a previously unidentified member of the axonal initial segment (AIS) proteome. We found that Prickle2 is present and colocalizes with AnkG480, the AIS master organizer, in the earliest stages of axonal specification and AIS formation. Furthermore, by binding to and regulating AnkG480, Prickle2 modulates its ability to bundle microtubules, a crucial mechanism for establishing neuronal polarity and AIS formation. Prickle2 depletion alters cytoskeleton organization, and Prickle2 levels determine both axon number and AIS maturation. Last, early Prickle2 depletion produces impaired action potential firing.
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Affiliation(s)
- Ana Dorrego-Rivas
- Univ. Bordeaux, INSERM, Magendie, U1215, F-33077 Bordeaux, France
- Corresponding author.
| | - Jerome Ezan
- Univ. Bordeaux, INSERM, Magendie, U1215, F-33077 Bordeaux, France
| | - Maïté M Moreau
- Univ. Bordeaux, INSERM, Magendie, U1215, F-33077 Bordeaux, France
| | | | | | - Julie De Neve
- Univ. Bordeaux, INSERM, Magendie, U1215, F-33077 Bordeaux, France
| | | | - Francis Castets
- Aix-Marseille Université, CNRS, Institut de Biologie du Développement de Marseille, UMR 7288, Case 907, 13288 Marseille Cedex 09, France
| | - Amélie Fréal
- Department of Functional Genomics, Vrije Universiteit (VU), Amsterdam, Netherlands
| | - Arne Battefeld
- Univ. Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
| | - Nathalie Sans
- Univ. Bordeaux, INSERM, Magendie, U1215, F-33077 Bordeaux, France
- Corresponding author.
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43
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Kiryu-Seo S, Matsushita R, Tashiro Y, Yoshimura T, Iguchi Y, Katsuno M, Takahashi R, Kiyama H. Impaired disassembly of the axon initial segment restricts mitochondrial entry into damaged axons. EMBO J 2022; 41:e110486. [PMID: 36004759 PMCID: PMC9574747 DOI: 10.15252/embj.2021110486] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 07/15/2022] [Accepted: 07/20/2022] [Indexed: 11/09/2022] Open
Abstract
The proteasome is essential for cellular responses to various physiological stressors. However, how proteasome function impacts the stress resilience of regenerative damaged motor neurons remains unclear. Here, we develop a unique mouse model using a regulatory element of the activating transcription factor (Atf3) gene to label mitochondria in a damage‐induced manner while simultaneously genetically disrupting the proteasome. Using this model, we observed that in injury‐induced proteasome‐deficient mouse motor neurons, the increase of mitochondrial influx from soma into axons is inhibited because neurons fail to disassemble ankyrin G, an organizer of the axon initial segment (AIS), in a proteasome‐dependent manner. Further, these motor neurons exhibit amyotrophic lateral sclerosis (ALS)‐like degeneration despite having regenerative potential. Selectively vulnerable motor neurons in SOD1G93A ALS mice, which induce ATF3 in response to pathological damage, also fail to disrupt the AIS, limiting the number of axonal mitochondria at a pre‐symptomatic stage. Thus, damage‐induced proteasome‐sensitive AIS disassembly could be a critical post‐translational response for damaged motor neurons to temporarily transit to an immature state and meet energy demands for axon regeneration or preservation.
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Affiliation(s)
- Sumiko Kiryu-Seo
- Department of Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Reika Matsushita
- Department of Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshitaka Tashiro
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takeshi Yoshimura
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Osaka, Japan.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Yohei Iguchi
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Ryosuke Takahashi
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hiroshi Kiyama
- Department of Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, Nagoya, Japan
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44
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Kumari D, Ray K. Phosphoregulation of Kinesins Involved in Long-Range Intracellular Transport. Front Cell Dev Biol 2022; 10:873164. [PMID: 35721476 PMCID: PMC9203973 DOI: 10.3389/fcell.2022.873164] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/29/2022] [Indexed: 12/28/2022] Open
Abstract
Kinesins, the microtubule-dependent mechanochemical enzymes, power a variety of intracellular movements. Regulation of Kinesin activity and Kinesin-Cargo interactions determine the direction, timing and flux of various intracellular transports. This review examines how phosphorylation of Kinesin subunits and adaptors influence the traffic driven by Kinesin-1, -2, and -3 family motors. Each family of Kinesins are phosphorylated by a partially overlapping set of serine/threonine kinases, and each event produces a unique outcome. For example, phosphorylation of the motor domain inhibits motility, and that of the stalk and tail domains induces cargo loading and unloading effects according to the residue and context. Also, the association of accessory subunits with cargo and adaptor proteins with the motor, respectively, is disrupted by phosphorylation. In some instances, phosphorylation by the same kinase on different Kinesins elicited opposite outcomes. We discuss how this diverse range of effects could manage the logistics of Kinesin-dependent, long-range intracellular transport.
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45
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Thyagarajan P, Feng C, Lee D, Shorey M, Rolls MM. Microtubule polarity is instructive for many aspects of neuronal polarity. Dev Biol 2022; 486:56-70. [PMID: 35341730 PMCID: PMC9058238 DOI: 10.1016/j.ydbio.2022.03.009] [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: 11/29/2021] [Revised: 03/04/2022] [Accepted: 03/22/2022] [Indexed: 11/25/2022]
Abstract
Many neurons in bilaterian animals are polarized with functionally distinct axons and dendrites. Microtubule polarity, microtubule stability, and the axon initial segment (AIS) have all been shown to influence polarized transport in neurons. Each of these cytoskeletal cues could act independently to control axon and dendrite identity, or there could be a hierarchy in which one acts upstream of the others. Here we test the hypothesis that microtubule polarity acts as a master regulator of neuronal polarity by using a Drosophila genetic background in which some dendrites have normal minus-end-out microtubule polarity and others have the axonal plus-end-out polarity. In these mosaic dendrite arbors, we found that ribosomes, which are more abundant in dendrites than axons, were reduced in plus-end-out dendrites, while an axonal cargo was increased. In addition, we determined that microtubule stability was different in plus-end-out and minus-end-out dendrites, with plus-end-out ones having more stable microtubules like axons. Similarly, we found that ectopic diffusion barriers, like those at the AIS, formed at the base of dendrites with plus-end-out regions. Thus, changes in microtubule polarity were sufficient to rearrange other cytoskeletal features associated with neuronal polarization. However, overall neuron shape was maintained with only subtle changes in branching in mosaic arbors. We conclude that microtubule polarity can act upstream of many aspects of intracellular neuronal polarization, but shape is relatively resilient to changes in microtubule polarity in vivo.
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Affiliation(s)
- Pankajam Thyagarajan
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Chengye Feng
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - David Lee
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Matthew Shorey
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Melissa M Rolls
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
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46
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Eichel K, Shen K. The function of the axon initial segment in neuronal polarity. Dev Biol 2022; 489:47-54. [DOI: 10.1016/j.ydbio.2022.05.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 05/09/2022] [Accepted: 05/23/2022] [Indexed: 11/25/2022]
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47
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Vuong JK, Ergin V, Chen L, Zheng S. Multilayered regulations of alternative splicing, NMD, and protein stability control temporal induction and tissue-specific expression of TRIM46 during axon formation. Nat Commun 2022; 13:2081. [PMID: 35440129 PMCID: PMC9019110 DOI: 10.1038/s41467-022-29786-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 03/16/2022] [Indexed: 12/15/2022] Open
Abstract
The gene regulation underlying axon formation and its exclusiveness to neurons remains elusive. TRIM46 is postulated to determine axonal fate. We show Trim46 mRNA is expressed before axonogenesis, but TRIM46 protein level is inhibited by alternative splicing of two cassette exons coupled separately to stability controls of Trim46 mRNA and proteins, effectively inducing functional knockout of TRIM46 proteins. Exon 8 inclusion causes nonsense-mediated mRNA decay of Trim46 transcripts. PTBP2-mediated exon 10 skipping produces transcripts encoding unstable TRIM46 proteins. During axonogenesis, transcriptional activation, decreased exon 8 inclusion, and enhanced exon 10 inclusion converge to increase TRIM46 proteins, leading to its neural-specific expression. Genetic deletion of these exons alters TRIM46 protein levels and shows TRIM46 is instructive though not always required for AnkG localization nor a determinant of AnkG density. Therefore, two concurrently but independently regulated alternative exons orchestrate the temporal induction and tissue-specific expression of TRIM46 proteins to mediate axon formation.
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Affiliation(s)
- John K Vuong
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, 92521, USA
| | - Volkan Ergin
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, 92521, USA
| | - Liang Chen
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Sika Zheng
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, 92521, USA.
- Center for RNA Biology and Medicine, University of California Riverside, Riverside, CA, 91521, USA.
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48
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Akhmanova A, Kapitein LC. Mechanisms of microtubule organization in differentiated animal cells. Nat Rev Mol Cell Biol 2022; 23:541-558. [PMID: 35383336 DOI: 10.1038/s41580-022-00473-y] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2022] [Indexed: 02/08/2023]
Abstract
Microtubules are polarized cytoskeletal filaments that serve as tracks for intracellular transport and form a scaffold that positions organelles and other cellular components and modulates cell shape and mechanics. In animal cells, the geometry, density and directionality of microtubule networks are major determinants of cellular architecture, polarity and proliferation. In dividing cells, microtubules form bipolar spindles that pull chromosomes apart, whereas in interphase cells, microtubules are organized in a cell type-specific fashion, which strongly correlates with cell physiology. In motile cells, such as fibroblasts and immune cells, microtubules are organized as radial asters, whereas in immotile epithelial and neuronal cells and in muscles, microtubules form parallel or antiparallel arrays and cortical meshworks. Here, we review recent work addressing how the formation of such microtubule networks is driven by the plethora of microtubule regulatory proteins. These include proteins that nucleate or anchor microtubule ends at different cellular structures and those that sever or move microtubules, as well as regulators of microtubule elongation, stability, bundling or modifications. The emerging picture, although still very incomplete, shows a remarkable diversity of cell-specific mechanisms that employ conserved building blocks to adjust microtubule organization in order to facilitate different cellular functions.
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Affiliation(s)
- Anna Akhmanova
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands.
| | - Lukas C Kapitein
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands.
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49
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TRIM46 activates AKT/HK2 signaling by modifying PHLPP2 ubiquitylation to promote glycolysis and chemoresistance of lung cancer cells. Cell Death Dis 2022; 13:285. [PMID: 35354796 PMCID: PMC8967906 DOI: 10.1038/s41419-022-04727-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 02/23/2022] [Accepted: 03/11/2022] [Indexed: 12/13/2022]
Abstract
The incidence of lung cancer is increasing worldwide. Although great progress in lung cancer treatment has been made, the clinical outcome is still unsatisfactory. Tripartite motif (TRIM)-containing proteins has been shown to be closely related to tumor progression. However, the function of TRIM46 in lung cancer is largely unknown. Here, TRIM46 amplification was found in lung adenocarcinoma (LUAD) tissues and TRIM46 amplification was significantly associated with a poor survival rate. Overexpression of wild type TRIM46 increased the proliferation of LUAD cells and glycolysis, promoted xenografts growth, and enhanced cisplatin (DDP) resistance of LUAD cells via increased ubiquitination of pleckstrin homology domain leucine-rich repeat protein phosphatase 2 (PHLPP2) and upregulation of p-AKT. In contrast, overexpression of RING-mutant TRIM46 did not show any effects, suggesting the function of TRIM46 was dependent on the E3 ligase activity. Furthermore, we found that TRIM46 promoted LUAD cell proliferation and DDP resistance by enhancing glycolysis. PHLPP2 overexpression reversed the effects of TRIM46 overexpression. Amplification of TRIM46 also promoted LUAD growth and enhanced its DDP resistance in a patient-derived xenograft (PDX) model. In conclusion, our data highlight the importance of TRIM46/PHLPP2/AKT signaling in lung cancer and provide new insights into therapeutic strategies for lung cancer.
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50
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Rolls MM. Principles of microtubule polarity in linear cells. Dev Biol 2022; 483:112-117. [PMID: 35016908 PMCID: PMC10071391 DOI: 10.1016/j.ydbio.2022.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 01/06/2022] [Indexed: 01/30/2023]
Abstract
The microtubule cytoskeleton is critical for maintenance of long and long-lived neurons. The overlapping array of microtubules extends from the major site of synthesis in the cell body to the far reaches of axons and dendrites. New materials are transported from the cell body along these neuronal roads by motor proteins, and building blocks and information about the state of affairs in other parts of the cell are returned by motors moving in the opposite direction. As motor proteins walk only in one direction along microtubules, the combination of correct motor and correctly oriented microtubules is essential for moving cargoes in the right direction. In this review, we focus on how microtubule polarity is established and maintained in neurons. At first thought, it seems that figuring out how microtubules are organized in neurons should be simple. After all, microtubules are essentially sticks with a slow-growing minus end and faster-growing plus end, and arranging sticks within the constrained narrow tubes of axons and dendrites should be straightforward. It is therefore quite surprising how many mechanisms contribute to making sure they are arranged in the correct polarity. Some of these mechanisms operate to generate plus-end-out polarity of axons, and others control mixed or minus-end-out dendrites.
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Affiliation(s)
- Melissa M Rolls
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
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