1
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Liang X, Agulto R, Eichel K, Taylor CA, Paat VA, Deng H, Ori-McKenney K, Shen K. CRMP/UNC-33 maintains neuronal microtubule arrays by promoting individual microtubule rescue. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.31.596870. [PMID: 38854103 PMCID: PMC11160792 DOI: 10.1101/2024.05.31.596870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Microtubules (MTs) are intrinsically dynamic polymers. In neurons, staggered individual microtubules form stable, polarized acentrosomal MT arrays spanning the axon and dendrite to support long-distance intracellular transport. How the stability and polarity of these arrays are maintained when individual MTs remain highly dynamic is still an open question. Here we visualize MT arrays in vivo in C. elegans neurons with single microtubule resolution. We find that the CRMP family homolog, UNC-33, is essential for the stability and polarity of MT arrays in neurites. In unc-33 mutants, MTs exhibit dramatically reduced rescue after catastrophe, develop gaps in coverage, and lose their polarity, leading to trafficking defects. UNC-33 is stably anchored on the cortical cytoskeleton and forms patch-like structures along the dendritic shaft. These discrete and stable UNC-33 patches concentrate free tubulins and correlate with MT rescue sites. In vitro , purified UNC-33 preferentially associates with MT tips and increases MT rescue frequency. Together, we propose that UNC-33 functions as a microtubule-associated protein (MAP) to promote individual MT rescue locally. Through this activity, UNC-33 prevents the loss of individual MTs, thereby maintaining the coverage and polarity of MT arrays throughout the lifetime of neurons.
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Park S, Noblett N, Pitts L, Colavita A, Wehman AM, Jin Y, Chisholm AD. Dopey-dependent regulation of extracellular vesicles maintains neuronal morphology. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.07.591898. [PMID: 38766017 PMCID: PMC11100700 DOI: 10.1101/2024.05.07.591898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Mature neurons maintain their distinctive morphology for extended periods in adult life. Compared to developmental neurite outgrowth, axon guidance, and target selection, relatively little is known of mechanisms that maintain mature neuron morphology. Loss of function in C. elegans DIP-2, a member of the conserved lipid metabolic regulator Dip2 family, results in progressive overgrowth of neurites in adults. We find that dip-2 mutants display specific genetic interactions with sax-2, the C. elegans ortholog of Drosophila Furry and mammalian FRY. Combined loss of DIP-2 and SAX-2 results in severe disruption of neuronal morphology maintenance accompanied by increased release of neuronal extracellular vesicles (EVs). By screening for suppressors of dip-2 sax-2 double mutant defects we identified gain-of-function (gf) mutations in the conserved Dopey family protein PAD-1 and its associated phospholipid flippase TAT-5/ATP9A. In dip-2 sax-2 double mutants carrying either pad-1(gf) or tat-5(gf) mutation, EV release is reduced and neuronal morphology across multiple neuron types is restored to largely normal. PAD-1(gf) acts cell autonomously in neurons. The domain containing pad-1(gf) is essential for PAD-1 function, and PAD-1(gf) protein displays increased association with the plasma membrane and inhibits EV release. Our findings uncover a novel functional network of DIP-2, SAX-2, PAD-1, and TAT-5 that maintains morphology of neurons and other types of cells, shedding light on the mechanistic basis of neurological disorders involving human orthologs of these genes.
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Affiliation(s)
- Seungmee Park
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Nathaniel Noblett
- Neuroscience Program, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Lauren Pitts
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA
| | - Antonio Colavita
- Neuroscience Program, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Ann M Wehman
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA
| | - Yishi Jin
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Andrew D Chisholm
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
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3
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DeVault L, Mateusiak C, Palucki J, Brent M, Milbrandt J, DiAntonio A. The response of Dual-leucine zipper kinase (DLK) to nocodazole: Evidence for a homeostatic cytoskeletal repair mechanism. PLoS One 2024; 19:e0300539. [PMID: 38574058 PMCID: PMC10994325 DOI: 10.1371/journal.pone.0300539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 02/28/2024] [Indexed: 04/06/2024] Open
Abstract
Genetic and pharmacological perturbation of the cytoskeleton enhances the regenerative potential of neurons. This response requires Dual-leucine Zipper Kinase (DLK), a neuronal stress sensor that is a central regulator of axon regeneration and degeneration. The damage and repair aspects of this response are reminiscent of other cellular homeostatic systems, suggesting that a cytoskeletal homeostatic response exists. In this study, we propose a framework for understanding DLK mediated neuronal cytoskeletal homeostasis. We demonstrate that low dose nocodazole treatment activates DLK signaling. Activation of DLK signaling results in a DLK-dependent transcriptional signature, which we identify through RNA-seq. This signature includes genes likely to attenuate DLK signaling while simultaneously inducing actin regulating genes. We identify alterations to the cytoskeleton including actin-based morphological changes to the axon. These results are consistent with the model that cytoskeletal disruption in the neuron induces a DLK-dependent homeostatic mechanism, which we term the Cytoskeletal Stress Response (CSR) pathway.
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Affiliation(s)
- Laura DeVault
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Chase Mateusiak
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Computer Science & Engineering, Washington University, St. Louis, MO, United States of America
| | - John Palucki
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Michael Brent
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Computer Science & Engineering, Washington University, St. Louis, MO, United States of America
| | - Jeffrey Milbrandt
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine, St. Louis, Missouri, United States of America
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4
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Gao Z, Huang E, Wang W, Xu L, Xu W, Zheng T, Rui M. Patronin regulates presynaptic microtubule organization and neuromuscular junction development in Drosophila. iScience 2024; 27:108944. [PMID: 38318379 PMCID: PMC10839449 DOI: 10.1016/j.isci.2024.108944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 11/20/2023] [Accepted: 01/15/2024] [Indexed: 02/07/2024] Open
Abstract
Synapses are fundamental components of the animal nervous system. Synaptic cytoskeleton is essential for maintaining proper neuronal development and wiring. Perturbations in neuronal microtubules (MTs) are correlated with numerous neuropsychiatric disorders. Despite discovering multiple synaptic MT regulators, the importance of MT stability, and particularly the polarity of MT in synaptic function, is still under investigation. Here, we identify Patronin, an MT minus-end-binding protein, for its essential role in presynaptic regulation of MT organization and neuromuscular junction (NMJ) development. Analyses indicate that Patronin regulates synaptic development independent of Klp10A. Subsequent research elucidates that it is short stop (Shot), a member of the Spectraplakin family of large cytoskeletal linker molecules, works synergistically with Patronin to govern NMJ development. We further raise the possibility that normal synaptic MT polarity contributes to proper NMJ morphology. Overall, this study demonstrates an unprecedented role of Patronin, and a potential involvement of MT polarity in synaptic development.
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Affiliation(s)
- Ziyang Gao
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Erqian Huang
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Wanting Wang
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Lizhong Xu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Wanyue Xu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Ting Zheng
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Menglong Rui
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
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5
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DeVault L, Mateusiak C, Palucki J, Brent M, Milbrandt J, DiAntonio A. The response of Dual-Leucine Zipper Kinase (DLK) to nocodazole: evidence for a homeostatic cytoskeletal repair mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.06.561227. [PMID: 37873434 PMCID: PMC10592635 DOI: 10.1101/2023.10.06.561227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Genetic and pharmacological perturbation of the cytoskeleton enhances the regenerative potential of neurons. This response requires Dual-leucine Zipper Kinase (DLK), a neuronal stress sensor that is a central regulator of axon regeneration and degeneration. The damage and repair aspects of this response are reminiscent of other cellular homeostatic systems, suggesting that a cytoskeletal homeostatic response exists. In this study, we propose a framework for understanding DLK mediated neuronal cytoskeletal homeostasis. We demonstrate that a) low dose nocodazole treatment activates DLK signaling and b) DLK signaling mitigates the microtubule damage caused by the cytoskeletal perturbation. We also perform RNA-seq to discover a DLK-dependent transcriptional signature. This signature includes genes likely to attenuate DLK signaling while simultaneously inducing actin regulating genes and promoting actin-based morphological changes to the axon. These results are consistent with the model that cytoskeletal disruption in the neuron induces a DLK-dependent homeostatic mechanism, which we term the Cytoskeletal Stress Response (CSR) pathway.
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6
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Gujar MR, Gao Y, Teng X, Ding WY, Lin J, Tan YS, Chew LY, Toyama Y, Wang H. Patronin/CAMSAP promotes reactivation and regeneration of Drosophila quiescent neural stem cells. EMBO Rep 2023; 24:e56624. [PMID: 37440685 PMCID: PMC10481672 DOI: 10.15252/embr.202256624] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 06/06/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
The ability of stem cells to switch between quiescent and proliferative states is crucial for maintaining tissue homeostasis and regeneration. Drosophila quiescent neural stem cells (qNSCs) extend a primary protrusion that is enriched in acentrosomal microtubules and can be regenerated upon injury. Arf1 promotes microtubule growth, reactivation (exit from quiescence), and regeneration of qNSC protrusions upon injury. However, how Arf1 is regulated in qNSCs remains elusive. Here, we show that the microtubule minus-end binding protein Patronin/CAMSAP promotes acentrosomal microtubule growth and quiescent NSC reactivation. Patronin is important for the localization of Arf1 at Golgi and physically associates with Arf1, preferentially with its GDP-bound form. Patronin is also required for the regeneration of qNSC protrusion, likely via the regulation of microtubule growth. Finally, Patronin functions upstream of Arf1 and its effector Msps/XMAP215 to target the cell adhesion molecule E-cadherin to NSC-neuropil contact sites during NSC reactivation. Our findings reveal a novel link between Patronin/CAMSAP and Arf1 in the regulation of microtubule growth and NSC reactivation. A similar mechanism might apply to various microtubule-dependent systems in mammals.
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Affiliation(s)
- Mahekta R Gujar
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
| | - Yang Gao
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
| | - Xiang Teng
- Mechanobiology InstituteSingaporeSingapore
| | - Wei Yung Ding
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
| | - Jiaen Lin
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
| | - Ye Sing Tan
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
| | - Liang Yuh Chew
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
- Present address:
Temasek LifeSciences LaboratorySingaporeSingapore
| | - Yusuke Toyama
- Mechanobiology InstituteSingaporeSingapore
- Department of Biological SciencesNational University of SingaporeSingaporeSingapore
| | - Hongyan Wang
- Neuroscience and Behavioral Disorders ProgrammeDuke‐NUS Medical SchoolSingaporeSingapore
- Department of Physiology, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
- Integrative Sciences and Engineering ProgrammeNational University of SingaporeSingaporeSingapore
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7
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Puri D, Sharma S, Samaddar S, Ravivarma S, Banerjee S, Ghosh-Roy A. Muscleblind-1 interacts with tubulin mRNAs to regulate the microtubule cytoskeleton in C. elegans mechanosensory neurons. PLoS Genet 2023; 19:e1010885. [PMID: 37603562 PMCID: PMC10470942 DOI: 10.1371/journal.pgen.1010885] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 08/31/2023] [Accepted: 07/26/2023] [Indexed: 08/23/2023] Open
Abstract
Regulation of the microtubule cytoskeleton is crucial for the development and maintenance of neuronal architecture, and recent studies have highlighted the significance of regulated RNA processing in the establishment and maintenance of neural circuits. In a genetic screen conducted using mechanosensory neurons of C. elegans, we identified a mutation in muscleblind-1/mbl-1 as a suppressor of loss of kinesin-13 family microtubule destabilizing factor klp-7. Muscleblind-1(MBL-1) is an RNA-binding protein that regulates the splicing, localization, and stability of RNA. Our findings demonstrate that mbl-1 is required cell-autonomously for axon growth and proper synapse positioning in the posterior lateral microtubule (PLM) neuron. Loss of mbl-1 leads to increased microtubule dynamics and mixed orientation of microtubules in the anterior neurite of PLM. These defects are also accompanied by abnormal axonal transport of the synaptic protein RAB-3 and reduction of gentle touch sensation in mbl-1 mutant. Our data also revealed that mbl-1 is genetically epistatic to mec-7 (β tubulin) and mec-12 (α tubulin) in regulating axon growth. Furthermore, mbl-1 is epistatic to sad-1, an ortholog of BRSK/Brain specific-serine/threonine kinase and a known regulator of synaptic machinery, for synapse formation at the correct location of the PLM neurite. Notably, the immunoprecipitation of MBL-1 resulted in the co-purification of mec-7, mec-12, and sad-1 mRNAs, suggesting a direct interaction between MBL-1 and these transcripts. Additionally, mbl-1 mutants exhibited reduced levels and stability of mec-7 and mec-12 transcripts. Our study establishes a previously unknown link between RNA-binding proteins and cytoskeletal machinery, highlighting their crucial roles in the development and maintenance of the nervous system.
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Affiliation(s)
- Dharmendra Puri
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sunanda Sharma
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sarbani Samaddar
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sruthy Ravivarma
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sourav Banerjee
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
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8
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Verdile V, Riccioni V, Guerra M, Ferrante G, Sette C, Valle C, Ferri A, Paronetto MP. An impaired splicing program underlies differentiation defects in hSOD1 G93A neural progenitor cells. Cell Mol Life Sci 2023; 80:236. [PMID: 37524863 PMCID: PMC11072603 DOI: 10.1007/s00018-023-04893-7] [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: 03/07/2023] [Revised: 07/17/2023] [Accepted: 07/19/2023] [Indexed: 08/02/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is an adult devastating neurodegenerative disease characterized by the loss of upper and lower motor neurons (MNs), resulting in progressive paralysis and death. Genetic animal models of ALS have highlighted dysregulation of synaptic structure and function as a pathogenic feature of ALS-onset and progression. Alternative pre-mRNA splicing (AS), which allows expansion of the coding power of genomes by generating multiple transcript isoforms from each gene, is widely associated with synapse formation and functional specification. Deciphering the link between aberrant splicing regulation and pathogenic features of ALS could pave the ground for novel therapeutic opportunities. Herein, we found that neural progenitor cells (NPCs) derived from the hSOD1G93A mouse model of ALS displayed increased proliferation and propensity to differentiate into neurons. In parallel, hSOD1G93A NPCs showed impaired splicing patterns in synaptic genes, which could contribute to the observed phenotype. Remarkably, master splicing regulators of the switch from stemness to neural differentiation are de-regulated in hSOD1G93A NPCs, thus impacting the differentiation program. Our data indicate that hSOD1G93A mutation impacts on neurogenesis by increasing the NPC pool in the developing mouse cortex and affecting their intrinsic properties, through the establishment of a specific splicing program.
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Affiliation(s)
- Veronica Verdile
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro de Bosis 6, 00135, Rome, Italy
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy
| | - Veronica Riccioni
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy
| | - Marika Guerra
- Section of Human Anatomy, Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
| | - Gabriele Ferrante
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy
| | - Claudio Sette
- Section of Human Anatomy, Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, 00168, Rome, Italy
| | - Cristiana Valle
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy
- Institute of Translational Pharmacology (IFT), Consiglio Nazionale delle Ricerche (CNR), 00133, Rome, Italy
| | - Alberto Ferri
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy
- Institute of Translational Pharmacology (IFT), Consiglio Nazionale delle Ricerche (CNR), 00133, Rome, Italy
| | - Maria Paola Paronetto
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro de Bosis 6, 00135, Rome, Italy.
- Laboratory of Molecular and Cellular Neurobiology and of Neurochemistry, Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143, Rome, Italy.
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9
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Zhao P, Mondal S, Martin C, DuPlissis A, Chizari S, Ma KY, Maiya R, Messing RO, Jiang N, Ben-Yakar A. Femtosecond laser microdissection for isolation of regenerating C. elegans neurons for single-cell RNA sequencing. Nat Methods 2023; 20:590-599. [PMID: 36928074 DOI: 10.1038/s41592-023-01804-3] [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: 12/30/2020] [Accepted: 01/26/2023] [Indexed: 03/18/2023]
Abstract
Our understanding of nerve regeneration can be enhanced by delineating its underlying molecular activities at single-neuron resolution in model organisms such as Caenorhabditis elegans. Existing cell isolation techniques cannot isolate neurons with specific regeneration phenotypes from C. elegans. We present femtosecond laser microdissection (fs-LM), a single-cell isolation method that dissects specific cells directly from living tissue by leveraging the micrometer-scale precision of fs-laser ablation. We show that fs-LM facilitates sensitive and specific gene expression profiling by single-cell RNA sequencing (scRNA-seq), while mitigating the stress-related transcriptional artifacts induced by tissue dissociation. scRNA-seq of fs-LM isolated regenerating neurons revealed transcriptional programs that are correlated with either successful or failed regeneration in wild-type and dlk-1 (0) animals, respectively. This method also allowed studying heterogeneity displayed by the same type of neuron and found gene modules with expression patterns correlated with axon regrowth rate. Our results establish fs-LM as a spatially resolved single-cell isolation method for phenotype-to-genotype mapping.
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Affiliation(s)
- Peisen Zhao
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Sudip Mondal
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Chris Martin
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Andrew DuPlissis
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Shahab Chizari
- Deparment of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Ke-Yue Ma
- Interdisciplinary Life Sciences Graduate Programs, The University of Texas at Austin, Austin, TX, USA
| | - Rajani Maiya
- Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
- Department of Neurology, Dell Medical School, The University of Texas at Austin, Austin, TX, USA
- Institute of Neuroscience, The University of Texas at Austin, Austin, TX, USA
- Department of Physiology, LSU Health Sciences Center, New Orleans, LA, USA
| | - Robert O Messing
- Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
- Department of Neurology, Dell Medical School, The University of Texas at Austin, Austin, TX, USA
- Institute of Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - Ning Jiang
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
- Deparment of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Interdisciplinary Life Sciences Graduate Programs, The University of Texas at Austin, Austin, TX, USA
| | - Adela Ben-Yakar
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, USA.
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA.
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA.
- Institute of Neuroscience, The University of Texas at Austin, Austin, TX, USA.
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10
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Gupta P, Keller SR, Patterson B. Recurrent episodes of vomiting and diarrhoea in a male child: a rare presentation of X-linked adrenoleukodystrophy. BMJ Case Rep 2022; 15:e249905. [PMID: 35948360 PMCID: PMC9379476 DOI: 10.1136/bcr-2022-249905] [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: 11/03/2022] Open
Abstract
Recurrent episodes of vomiting and diarrhoea in a child can present as a diagnostic dilemma and be easily misdiagnosed as recurrent viral gastroenteritis episodes. Primary adrenal insufficiency can present with recurrent episodes of vomiting and diarrhoea with the presence of metabolic acidosis and can be life-threatening if left undiagnosed and untreated. A high index of suspicion should be kept for diagnosing primary adrenal insufficiency in a child presenting with recurrent episodes of vomiting and diarrhoea with laboratory evidence of metabolic acidosis and hypoglycaemia. Primary adrenal insufficiency, in a male child specifically, should raise alarm for X-linked adrenoleukodystrophy (X-ALD). Very-long-chain fatty acids and confirmatory genetic testing for an ABCD1 gene mutation can help confirm the diagnosis. Addison's disease often presents prior to the onset of the cerebral form of X-ALD. Early diagnosis of X-ALD allows for MRI screening for the development of cerebral disease in its early stages when treatment with stem cell transplant can halt the disease and be lifesaving.
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Affiliation(s)
- Pranav Gupta
- Pediatric Endocrinology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Stephanie R Keller
- Pediatric Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Briana Patterson
- Pediatric Endocrinology, Emory University School of Medicine, Atlanta, Georgia, USA
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11
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Imasaki T, Kikkawa S, Niwa S, Saijo-Hamano Y, Shigematsu H, Aoyama K, Mitsuoka K, Shimizu T, Aoki M, Sakamoto A, Tomabechi Y, Sakai N, Shirouzu M, Taguchi S, Yamagishi Y, Setsu T, Sakihama Y, Nitta E, Takeichi M, Nitta R. CAMSAP2 organizes a γ-tubulin-independent microtubule nucleation centre through phase separation. eLife 2022; 11:77365. [PMID: 35762204 PMCID: PMC9239687 DOI: 10.7554/elife.77365] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 05/24/2022] [Indexed: 11/24/2022] Open
Abstract
Microtubules are dynamic polymers consisting of αβ-tubulin heterodimers. The initial polymerization process, called microtubule nucleation, occurs spontaneously via αβ-tubulin. Since a large energy barrier prevents microtubule nucleation in cells, the γ-tubulin ring complex is recruited to the centrosome to overcome the nucleation barrier. However, a considerable number of microtubules can polymerize independently of the centrosome in various cell types. Here, we present evidence that the minus-end-binding calmodulin-regulated spectrin-associated protein 2 (CAMSAP2) serves as a strong nucleator for microtubule formation by significantly reducing the nucleation barrier. CAMSAP2 co-condensates with αβ-tubulin via a phase separation process, producing plenty of nucleation intermediates. Microtubules then radiate from the co-condensates, resulting in aster-like structure formation. CAMSAP2 localizes at the co-condensates and decorates the radiating microtubule lattices to some extent. Taken together, these in vitro findings suggest that CAMSAP2 supports microtubule nucleation and growth by organizing a nucleation centre as well as by stabilizing microtubule intermediates and growing microtubules. Cells are able to hold their shape thanks to tube-like structures called microtubules that are made of hundreds of tubulin proteins. Microtubules are responsible for maintaining the uneven distribution of molecules throughout the cell, a phenomenon known as polarity that allows cells to differentiate into different types with various roles. A protein complex called the γ-tubulin ring complex (γ-TuRC) is necessary for microtubules to form. This protein helps bind the tubulin proteins together and stabilises microtubules. However, recent research has found that in highly polarized cells such as neurons, which have highly specialised regions, microtubules can form without γ-TuRC. Searching for the proteins that could be filling in for γ-TuRC in these cells some evidence has suggested that a group known as CAMSAPs may be involved, but it is not known how. To characterize the role of CAMSAPs, Imasaki, Kikkawa et al. studied how one of these proteins, CAMSAP2, interacts with tubulins. To do this, they reconstituted both CAMSAP2 and tubulins using recombinant biotechnology and mixed them in solution. These experiments showed that CAMSAP2 can help form microtubules by bringing together their constituent proteins so that they can bind to each other more easily. Once microtubules start to form, CAMSAP2 continues to bind to them, stabilizing them and enabling them to grow to full size. These results shed light on how polarity is established in cells such as neurons, muscle cells, and epithelial cells. Additionally, the ability to observe intermediate structures during microtubule formation can provide insights into the processes that these structures are involved in.
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Affiliation(s)
- Tsuyoshi Imasaki
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan.,JST, PRESTO, Saitama, Japan.,RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | - Satoshi Kikkawa
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Shinsuke Niwa
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Japan
| | - Yumiko Saijo-Hamano
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hideki Shigematsu
- RIKEN SPring-8 Center, Hyogo, Japan.,Japan Synchrotron Radiation Research Institute (JASRI), Hyogo, Japan
| | - Kazuhiro Aoyama
- Materials and Structural Analysis, Thermo Fisher Scientific, Tokyo, Japan.,Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Osaka, Japan
| | - Kaoru Mitsuoka
- Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Osaka, Japan
| | - Takahiro Shimizu
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Mari Aoki
- RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | - Ayako Sakamoto
- RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | - Yuri Tomabechi
- RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | - Naoki Sakai
- RIKEN SPring-8 Center, Hyogo, Japan.,Japan Synchrotron Radiation Research Institute (JASRI), Hyogo, Japan
| | - Mikako Shirouzu
- RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | - Shinya Taguchi
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yosuke Yamagishi
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomiyoshi Setsu
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yoshiaki Sakihama
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Eriko Nitta
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | | | - Ryo Nitta
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan.,RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
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12
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Vineethakumari C, Lüders J. Microtubule Anchoring: Attaching Dynamic Polymers to Cellular Structures. Front Cell Dev Biol 2022; 10:867870. [PMID: 35309944 PMCID: PMC8927778 DOI: 10.3389/fcell.2022.867870] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 02/11/2022] [Indexed: 01/01/2023] Open
Abstract
Microtubules are dynamic, filamentous polymers composed of α- and β-tubulin. Arrays of microtubules that have a specific polarity and distribution mediate essential processes such as intracellular transport and mitotic chromosome segregation. Microtubule arrays are generated with the help of microtubule organizing centers (MTOC). MTOCs typically combine two principal activities, the de novo formation of microtubules, termed nucleation, and the immobilization of one of the two ends of microtubules, termed anchoring. Nucleation is mediated by the γ-tubulin ring complex (γTuRC), which, in cooperation with its recruitment and activation factors, provides a template for α- and β-tubulin assembly, facilitating formation of microtubule polymer. In contrast, the molecules and mechanisms that anchor newly formed microtubules at MTOCs are less well characterized. Here we discuss the mechanistic challenges underlying microtubule anchoring, how this is linked with the molecular activities of known and proposed anchoring factors, and what consequences defective microtubule anchoring has at the cellular and organismal level.
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13
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Brar HK, Dey S, Bhardwaj S, Pande D, Singh P, Dey S, Ghosh-Roy A. Dendrite regeneration in C. elegans is controlled by the RAC GTPase CED-10 and the RhoGEF TIAM-1. PLoS Genet 2022; 18:e1010127. [PMID: 35344539 PMCID: PMC8989329 DOI: 10.1371/journal.pgen.1010127] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 04/07/2022] [Accepted: 02/28/2022] [Indexed: 01/30/2023] Open
Abstract
Neurons are vulnerable to physical insults, which compromise the integrity of both dendrites and axons. Although several molecular pathways of axon regeneration are identified, our knowledge of dendrite regeneration is limited. To understand the mechanisms of dendrite regeneration, we used the PVD neurons in C. elegans with stereotyped branched dendrites. Using femtosecond laser, we severed the primary dendrites and axon of this neuron. After severing the primary dendrites near the cell body, we observed sprouting of new branches from the proximal site within 6 hours, which regrew further with time in an unstereotyped manner. This was accompanied by reconnection between the proximal and distal dendrites, and fusion among the higher-order branches as reported before. We quantified the regeneration pattern into three aspects–territory length, number of branches, and fusion phenomena. Axonal injury causes a retraction of the severed end followed by a Dual leucine zipper kinase-1 (DLK-1) dependent regrowth from the severed end. We tested the roles of the major axon regeneration signalling hubs such as DLK-1-RPM-1, cAMP elevation, let-7 miRNA, AKT-1, Phosphatidylserine (PS) exposure/PS in dendrite regeneration. We found that neither dendrite regrowth nor fusion was affected by the axon injury pathway molecules. Surprisingly, we found that the RAC GTPase, CED-10 and its upstream GEF, TIAM-1 play a cell-autonomous role in dendrite regeneration. Additionally, the function of CED-10 in epidermal cell is critical for post-dendrotomy fusion phenomena. This work describes a novel regulatory mechanism of dendrite regeneration and provides a framework for understanding the cellular mechanism of dendrite regeneration using PVD neuron as a model system. The knowledge of the repair of injured neural circuits comes from the study of the regeneration of injured axons. The information receiving neurites, namely dendrites, are also vulnerable to physical insult during stroke and trauma. However, little knowledge is available on the mechanism of dendrite regeneration since the study of Cajal. In order to get insight into this process, we severed both axon and dendrites of PVD neuron in C. elegans using laser. By comparing the roles of axon regeneration pathways in both dendrite and axon regeneration in this neuron, we found that dendrite regeneration is independent of molecular mechanisms involving axon regrowth. We discovered that dendrite regeneration is dependent on the RAC GTPase CED-10 and GEF TIAM-1. Moreover, we found that CED-10 plays roles within both neuron and in the surrounding epithelia for mounting regeneration response to dendrite injury. This work provides mechanistic insight into the process of dendrite repair after physical injury.
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Affiliation(s)
- Harjot Kaur Brar
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Swagata Dey
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Smriti Bhardwaj
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Devashish Pande
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Pallavi Singh
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Shirshendu Dey
- Fluorescence Microscopy Division, Bruker India Scientific Pvt. Ltd., International Trade Tower, Nehru Place, New Delhi, India
| | - Anindya Ghosh-Roy
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
- * E-mail:
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14
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Yi Y, Qiu Z, Yao Z, Lin A, Qin Y, Sha R, Wei T, Wang Y, Cheng Q, Zhang J, Luo P, Shen W. CAMSAP1 Mutation Correlates With Improved Prognosis in Small Cell Lung Cancer Patients Treated With Platinum-Based Chemotherapy. Front Cell Dev Biol 2022; 9:770811. [PMID: 35087829 PMCID: PMC8787262 DOI: 10.3389/fcell.2021.770811] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 12/16/2021] [Indexed: 12/30/2022] Open
Abstract
Platinum-based chemotherapy is the first-line treatment for small cell lung cancer (SCLC). However, due to patients developing a resistance to the drug, most experience relapse and their cancer can become untreatable. A large number of recent studies have found that platinum drug sensitivity of various cancers is affected by specific gene mutations, and so with this study, we attempted to find an effective genetic biomarker in SCLC patients that indicates their sensitivity to platinum-based drugs. To do this, we first analyzed whole exome sequencing (WES) and clinical data from two cohorts to find gene mutations related to the prognosis and to the platinum drug sensitivity of SCLC patients. The cohorts used were the Zhujiang cohort (N = 138) and the cohort reported by George et al. (N = 101). We then carried out gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) to investigate possible molecular mechanisms through which these gene mutations affect patient prognosis and platinum drug sensitivity. We found that for SCLC patients, CAMSAP1 mutation can activate anti-tumor immunity, mediate tumor cell apoptosis, inhibit epithelial-mesenchymal transition (EMT), improve prognosis, and improve platinum drug sensitivity, suggesting that CAMSAP1 mutation may be a potential biomarker indicating platinum drug sensitivity and patient prognosis in SCLC.
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Affiliation(s)
- Yonglin Yi
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Zhengang Qiu
- Department of Oncology, First Affiliated Hospital of Gannan Medical University, Guangzhou, China
| | - Zifu Yao
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China.,The First Clinical Medical School, Southern Medical University, Guangzhou, China
| | - Anqi Lin
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yimin Qin
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Ruizhan Sha
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Ting Wei
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yanru Wang
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Quan Cheng
- Department of Neurosurgery, Xiangya Hospital, Center South University, Changsha, China
| | - Jian Zhang
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Peng Luo
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Weitao Shen
- Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
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15
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Dey S, Ghosh-Roy A. In vivo Assessment of Microtubule Dynamics and Orientation in Caenorhabditis elegans Neurons. J Vis Exp 2021:10.3791/62744. [PMID: 34866634 PMCID: PMC7614928 DOI: 10.3791/62744] [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] [Indexed: 10/31/2022] Open
Abstract
In neurons, microtubule orientation has been a key assessor to identify axons that have plus-end out microtubules and dendrites that generally have mixed orientation. Here we describe methods to label, image, and analyze the microtubule dynamics and growth during the development and regeneration of touch neurons in C. elegans. Using genetically encoded fluorescent reporters of microtubule tips, we imaged the axonal microtubules. The local changes in microtubule behavior that initiates axon regeneration following axotomy can be quantified using this protocol. This assay is adaptable to other neurons and genetic backgrounds to investigate the regulation of microtubule dynamics in various cellular processes.
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16
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Saito H, Matsukawa-Usami F, Fujimori T, Kimura T, Ide T, Yamamoto T, Shibata T, Onoue K, Okayama S, Yonemura S, Misaki K, Soba Y, Kakui Y, Sato M, Toya M, Takeichi M. Tracheal motile cilia in mice require CAMSAP3 for formation of central microtubule pair and coordinated beating. Mol Biol Cell 2021; 32:ar12. [PMID: 34319756 PMCID: PMC8684751 DOI: 10.1091/mbc.e21-06-0303] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Motile cilia of multiciliated epithelial cells undergo synchronized beating to produce fluid flow along the luminal surface of various organs. Each motile cilium consists of an axoneme and a basal body (BB), which are linked by a “transition zone” (TZ). The axoneme exhibits a characteristic 9+2 microtubule arrangement important for ciliary motion, but how this microtubule system is generated is not yet fully understood. Here we show that calmodulin-regulated spectrin-associated protein 3 (CAMSAP3), a protein that can stabilize the minus-end of a microtubule, concentrates at multiple sites of the cilium–BB complex, including the upper region of the TZ or the axonemal basal plate (BP) where the central pair of microtubules (CP) initiates. CAMSAP3 dysfunction resulted in loss of the CP and partial distortion of the BP, as well as the failure of multicilia to undergo synchronized beating. These findings suggest that CAMSAP3 plays pivotal roles in the formation or stabilization of the CP by localizing at the basal region of the axoneme and thereby supports the coordinated motion of multicilia in airway epithelial cells.
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Affiliation(s)
- Hiroko Saito
- Laboratory for Cell Adhesion and Tissue Patterning, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Fumiko Matsukawa-Usami
- Division of Embryology, National Institute for Basic Biology, and Department of Basic Biology, School of Life Science, SOKENDAI, the Graduate University for Advanced Studies, Okazaki, 444-8787 Japan
| | - Toshihiko Fujimori
- Division of Embryology, National Institute for Basic Biology, and Department of Basic Biology, School of Life Science, SOKENDAI, the Graduate University for Advanced Studies, Okazaki, 444-8787 Japan
| | - Toshiya Kimura
- Laboratory for Cell Adhesion and Tissue Patterning, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Takahiro Ide
- Laboratory for Organismal Patterning, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Takaki Yamamoto
- Nonequilibrium Physics of Living Matter RIKEN Hakubi Research Team, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Tatsuo Shibata
- Laboratory for Physical Biology, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Kenta Onoue
- Laboratory for Ultrastructural Research, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Satoko Okayama
- Laboratory for Ultrastructural Research, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Shigenobu Yonemura
- Laboratory for Ultrastructural Research, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Kazuyo Misaki
- Ultrastructural Research Team, RIKEN Center for Life Science Technologies, Kobe 650-0047, Japan
| | - Yurina Soba
- Laboratory of Cytoskeletal Logistics, Center for Advanced Biomedical Sciences (TWIns), Waseda University, Tokyo 162-8480, Japan
| | - Yasutaka Kakui
- Laboratory of Cytoskeletal Logistics, Center for Advanced Biomedical Sciences (TWIns), Waseda University, Tokyo 162-8480, Japan.,Waseda Institute for Advanced Study, Waseda University, Tokyo 169-0051, Japan
| | - Masamitsu Sato
- Laboratory of Cytoskeletal Logistics, Center for Advanced Biomedical Sciences (TWIns), Waseda University, Tokyo 162-8480, Japan
| | - Mika Toya
- Laboratory for Cell Adhesion and Tissue Patterning, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan.,Laboratory of Cytoskeletal Logistics, Center for Advanced Biomedical Sciences (TWIns), Waseda University, Tokyo 162-8480, Japan.,Major in Bioscience, Global Center for Science and Engineering, Faculty of Science and Engineering, Waseda University, Tokyo 169-8555, Japan
| | - Masatoshi Takeichi
- Laboratory for Cell Adhesion and Tissue Patterning, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
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17
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Puri D, Ponniah K, Biswas K, Basu A, Dey S, Lundquist EA, Ghosh-Roy A. Wnt signaling establishes the microtubule polarity in neurons through regulation of Kinesin-13. J Cell Biol 2021; 220:212396. [PMID: 34137792 DOI: 10.1083/jcb.202005080] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Neuronal polarization is facilitated by the formation of axons with parallel arrays of plus-end-out and dendrites with the nonuniform orientation of microtubules. In C. elegans, the posterior lateral microtubule (PLM) neuron is bipolar with its two processes growing along the anterior-posterior axis under the guidance of Wnt signaling. Here we found that loss of the Kinesin-13 family microtubule-depolymerizing enzyme KLP-7 led to the ectopic extension of axon-like processes from the PLM cell body. Live imaging of the microtubules and axonal transport revealed mixed polarity of the microtubules in the short posterior process, which is dependent on both KLP-7 and the minus-end binding protein PTRN-1. KLP-7 is positively regulated in the posterior process by planar cell polarity components of Wnt involving rho-1/rock to induce mixed polarity of microtubules, whereas it is negatively regulated in the anterior process by the unc-73/ced-10 cascade to establish a uniform microtubule polarity. Our work elucidates how evolutionarily conserved Wnt signaling establishes the microtubule polarity in neurons through Kinesin-13.
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Affiliation(s)
- Dharmendra Puri
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Keerthana Ponniah
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Kasturi Biswas
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Atrayee Basu
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Swagata Dey
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Erik A Lundquist
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS
| | - Anindya Ghosh-Roy
- Department of Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
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18
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TAKEMOTO K. Optical manipulation of molecular function by chromophore-assisted light inactivation. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2021; 97:197-209. [PMID: 33840676 PMCID: PMC8062263 DOI: 10.2183/pjab.97.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 02/09/2021] [Indexed: 06/12/2023]
Abstract
In addition to simple on/off switches for molecular activity, spatiotemporal dynamics are also thought to be important for the regulation of cellular function. However, their physiological significance and in vivo importance remain largely unknown. Fluorescence imaging technology is a powerful technique that can reveal the spatiotemporal dynamics of molecular activity. In addition, because imaging detects the correlations between molecular activity and biological phenomena, the technique of molecular manipulation is also important to analyze causal relationships. Recent advances in optical manipulation techniques that artificially perturb molecules and cells via light can address this issue to elucidate the causality between manipulated target and its physiological function. The use of light enables the manipulation of molecular activity in microspaces, such as organelles and nerve spines. In this review, we describe the chromophore-assisted light inactivation method, which is an optical manipulation technique that has been attracting attention in recent years.
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Affiliation(s)
- Kiwamu TAKEMOTO
- Department of Biochemistry, Mie University, Graduate School of Medicine, Tsu-City, Mie, Japan
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19
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cnd-1/NeuroD1 Functions with the Homeobox Gene ceh-5/Vax2 and Hox Gene ceh-13/labial To Specify Aspects of RME and DD Neuron Fate in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2020; 10:3071-3085. [PMID: 32601060 PMCID: PMC7466980 DOI: 10.1534/g3.120.401515] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Identifying the mechanisms behind neuronal fate specification are key to understanding normal neural development in addition to neurodevelopmental disorders such as autism and schizophrenia. In vivo cell fate specification is difficult to study in vertebrates. However, the nematode Caenorhabditis elegans, with its invariant cell lineage and simple nervous system of 302 neurons, is an ideal organism to explore the earliest stages of neural development. We used a comparative transcriptome approach to examine the role of cnd-1/NeuroD1 in C. elegans nervous system development and function. This basic helix-loop-helix transcription factor is deeply conserved across phyla and plays a crucial role in cell fate specification in both the vertebrate nervous system and pancreas. We find that cnd-1 controls expression of ceh-5, a Vax2-like homeobox class transcription factor, in the RME head motorneurons and PVQ tail interneurons. We also show that cnd-1 functions redundantly with the Hox gene ceh-13/labial in defining the fate of DD1 and DD2 embryonic ventral nerve cord motorneurons. These data highlight the utility of comparative transcriptomes for identifying transcription factor targets and understanding gene regulatory networks.
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20
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CAMSAP1 breaks the homeostatic microtubule network to instruct neuronal polarity. Proc Natl Acad Sci U S A 2020; 117:22193-22203. [PMID: 32839317 DOI: 10.1073/pnas.1913177117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The establishment of axon/dendrite polarity is fundamental for neurons to integrate into functional circuits, and this process is critically dependent on microtubules (MTs). In the early stages of the establishment process, MTs in axons change dramatically with the morphological building of neurons; however, how the MT network changes are triggered is unclear. Here we show that CAMSAP1 plays a decisive role in the neuronal axon identification process by regulating the number of MTs. Neurons lacking CAMSAP1 form a multiple axon phenotype in vitro, while the multipolar-bipolar transition and radial migration are blocked in vivo. We demonstrate that the polarity regulator MARK2 kinase phosphorylates CAMSAP1 and affects its ability to bind to MTs, which in turn changes the protection of MT minus-ends and also triggers asymmetric distribution of MTs. Our results indicate that the polarized MT network in neurons is a decisive factor in establishing axon/dendritic polarity and is initially triggered by polarized signals.
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21
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Jin Y, Zheng B. Multitasking: Dual Leucine Zipper-Bearing Kinases in Neuronal Development and Stress Management. Annu Rev Cell Dev Biol 2020; 35:501-521. [PMID: 31590586 DOI: 10.1146/annurev-cellbio-100617-062644] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The dual leucine zipper-bearing kinase (DLK) and leucine zipper-bearing kinase (LZK) are evolutionarily conserved MAPKKKs of the mixed-lineage kinase family. Acting upstream of stress-responsive JNK and p38 MAP kinases, DLK and LZK have emerged as central players in neuronal responses to a variety of acute and traumatic injuries. Recent studies also implicate their function in astrocytes, microglia, and other nonneuronal cells, reflecting their expanding roles in the multicellular response to injury and in disease. Of particular note is the potential link of these kinases to neurodegenerative diseases and cancer. It is thus critical to understand the physiological contexts under which these kinases are activated, as well as the signal transduction mechanisms that mediate specific functional outcomes. In this review we first provide a historical overview of the biochemical and functional dissection of these kinases. We then discuss recent findings on regulating their activity to enhance cellular protection following injury and in disease, focusing on but not limited to the nervous system.
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Affiliation(s)
- Yishi Jin
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, USA; .,Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA;
| | - Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA; .,VA San Diego Healthcare System, San Diego, California 92161, USA
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22
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Lüders J. Nucleating microtubules in neurons: Challenges and solutions. Dev Neurobiol 2020; 81:273-283. [PMID: 32324945 DOI: 10.1002/dneu.22751] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 01/08/2020] [Accepted: 04/20/2020] [Indexed: 11/08/2022]
Abstract
The highly polarized morphology of neurons is crucial for their function and involves formation of two distinct types of cellular extensions, the axonal and dendritic compartments. An important effector required for the morphogenesis and maintenance and thus the identity of axons and dendrites is the microtubule cytoskeleton. Microtubules in axons and dendrites are arranged with distinct polarities, to allow motor-dependent, compartment-specific sorting of cargo. Despite the importance of the microtubule cytoskeleton in neurons, the molecular mechanisms that generate the intricate compartment-specific microtubule configurations remain largely obscure. Work in other cell types has identified microtubule nucleation, the de novo formation of microtubules, and its spatio-temporal regulation as essential for the proper organization of the microtubule cytoskeleton. Whereas regulation of microtubule nucleation usually involves microtubule organizing centers such as the centrosome, neurons seem to rely largely on decentralized nucleation mechanisms. In this review, I will discuss recent advances in deciphering nucleation mechanisms in neurons, how they contribute to the arrangement of microtubules with specific polarities, and how this affects neuron morphogenesis. While this work has shed some light on these important processes, we are far from a comprehensive understanding. Thus, to provide a coherent model, my discussion will include both well-established mechanisms and mechanisms with more limited supporting data. Finally, I will also highlight important outstanding questions for future investigation.
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Affiliation(s)
- Jens Lüders
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
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23
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Microtubule Minus-End Binding Protein CAMSAP2 and Kinesin-14 Motor KIFC3 Control Dendritic Microtubule Organization. Curr Biol 2020; 30:899-908.e6. [PMID: 32084403 PMCID: PMC7063570 DOI: 10.1016/j.cub.2019.12.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 10/28/2019] [Accepted: 12/18/2019] [Indexed: 12/21/2022]
Abstract
Neuronal dendrites are characterized by an anti-parallel microtubule organization. The mixed oriented microtubules promote dendrite development and facilitate polarized cargo trafficking; however, the mechanism that regulates dendritic microtubule organization is still unclear. Here, we found that the kinesin-14 motor KIFC3 is important for organizing dendritic microtubules and to control dendrite development. The kinesin-14 motor proteins (Drosophila melanogaster Ncd, Saccharomyces cerevisiae Kar3, Saccharomyces pombe Pkl1, and Xenopus laevis XCTK2) are characterized by a C-terminal motor domain and are well described to organize the spindle microtubule during mitosis using an additional microtubule binding site in the N terminus [1-4]. In mammals, there are three kinesin-14 members, KIFC1, KIFC2, and KIFC3. It was recently shown that KIFC1 is important for organizing axonal microtubules in neurons, a process that depends on the two microtubule-interacting domains [5]. Unlike KIFC1, KIFC2 and KIFC3 lack the N-terminal microtubule binding domain and only have one microtubule-interacting domain, the motor domain [6, 7]. Thus, in order to regulate microtubule-microtubule crosslinking or sliding, KIFC2 and KIFC3 need to interact with additional microtubule binding proteins to connect two microtubules. We found that KIFC3 has a dendrite-specific distribution and interacts with microtubule minus-end binding protein CAMSAP2. Depletion of KIFC3 or CAMSAP2 results in increased microtubule dynamics during dendritic development. We propose a model in which CAMSAP2 anchors KIFC3 at microtubule minus ends and immobilizes microtubule arrays in dendrites.
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24
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Atherton J, Luo Y, Xiang S, Yang C, Rai A, Jiang K, Stangier M, Vemu A, Cook AD, Wang S, Roll-Mecak A, Steinmetz MO, Akhmanova A, Baldus M, Moores CA. Structural determinants of microtubule minus end preference in CAMSAP CKK domains. Nat Commun 2019; 10:5236. [PMID: 31748546 PMCID: PMC6868217 DOI: 10.1038/s41467-019-13247-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 10/23/2019] [Indexed: 12/20/2022] Open
Abstract
CAMSAP/Patronins regulate microtubule minus-end dynamics. Their end specificity is mediated by their CKK domains, which we proposed recognise specific tubulin conformations found at minus ends. To critically test this idea, we compared the human CAMSAP1 CKK domain (HsCKK) with a CKK domain from Naegleria gruberi (NgCKK), which lacks minus-end specificity. Here we report near-atomic cryo-electron microscopy structures of HsCKK- and NgCKK-microtubule complexes, which show that these CKK domains share the same protein fold, bind at the intradimer interprotofilament tubulin junction, but exhibit different footprints on microtubules. NMR experiments show that both HsCKK and NgCKK are remarkably rigid. However, whereas NgCKK binding does not alter the microtubule architecture, HsCKK remodels its microtubule interaction site and changes the underlying polymer structure because the tubulin lattice conformation is not optimal for its binding. Thus, in contrast to many MAPs, the HsCKK domain can differentiate subtly specific tubulin conformations to enable microtubule minus-end recognition.
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Affiliation(s)
- Joseph Atherton
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, UK.
| | - Yanzhang Luo
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Shengqi Xiang
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
- MOE Key Lab for biomolecular Condensates & Cellular Dynamics, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, Anhui, China
| | - Chao Yang
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Ankit Rai
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Kai Jiang
- Medical Research Institute, School of Medicine, Wuhan University, 430071, Wuhan, China
| | - Marcel Stangier
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, PSI, Switzerland
| | - Annapurna Vemu
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD, 20892, USA
| | - Alexander D Cook
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, UK
| | - Su Wang
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, UK
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD, 20892, USA
- Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, MD, 20892, USA
| | - Michel O Steinmetz
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, PSI, Switzerland
- University of Basel, Biozentrum, CH-4056, Basel, Switzerland
| | - Anna Akhmanova
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Marc Baldus
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
| | - Carolyn A Moores
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, UK.
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25
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Nance J, Frøkjær-Jensen C. The Caenorhabditis elegans Transgenic Toolbox. Genetics 2019; 212:959-990. [PMID: 31405997 PMCID: PMC6707460 DOI: 10.1534/genetics.119.301506] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/01/2019] [Indexed: 12/30/2022] Open
Abstract
The power of any genetic model organism is derived, in part, from the ease with which gene expression can be manipulated. The short generation time and invariant developmental lineage have made Caenorhabditis elegans very useful for understanding, e.g., developmental programs, basic cell biology, neurobiology, and aging. Over the last decade, the C. elegans transgenic toolbox has expanded considerably, with the addition of a variety of methods to control expression and modify genes with unprecedented resolution. Here, we provide a comprehensive overview of transgenic methods in C. elegans, with an emphasis on recent advances in transposon-mediated transgenesis, CRISPR/Cas9 gene editing, conditional gene and protein inactivation, and bipartite systems for temporal and spatial control of expression.
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Affiliation(s)
- Jeremy Nance
- Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, Department of Cell Biology, New York University School of Medicine, New York 10016
| | - Christian Frøkjær-Jensen
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division (BESE), KAUST Environmental Epigenetics Program (KEEP), Thuwal 23955-6900, Saudi Arabia
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26
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Broihier HT. Expecto Patronin for slow and persistent minus end microtubule growth in dendrites. J Cell Biol 2019; 218:2084-2085. [PMID: 31189609 PMCID: PMC6605785 DOI: 10.1083/jcb.201906038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Microtubule plus ends are highly dynamic in neurons, while minus ends are often capped and stable. In this issue, Feng et al. (2019. J. Cell Biol. https://doi.org/10.1083/jcb.201810155) demonstrate that in dendrites, free minus ends undergo slow and processive growth mediated by the minus end-binding protein Patronin.
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Affiliation(s)
- Heather T Broihier
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH
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27
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Abstract
Microtubules are cytoskeletal filaments essential for numerous aspects of cell physiology. They are polarized polymeric tubes with a fast growing plus end and a slow growing minus end. In this Cell Science at a Glance article and the accompanying poster, we review the current knowledge on the dynamics and organization of microtubule minus ends. Several factors, including the γ-tubulin ring complex, CAMSAP/Patronin, ASPM/Asp, SPIRAL2 (in plants) and the KANSL complex recognize microtubule minus ends and regulate their nucleation, stability and interactions with partners, such as microtubule severing enzymes, microtubule depolymerases and protein scaffolds. Together with minus-end-directed motors, these microtubule minus-end targeting proteins (-TIPs) also control the formation of microtubule-organizing centers, such as centrosomes and spindle poles, and mediate microtubule attachment to cellular membrane structures, including the cell cortex, Golgi complex and the cell nucleus. Structural and functional studies are starting to reveal the molecular mechanisms by which dynamic -TIP networks control microtubule minus ends.
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Affiliation(s)
- Anna Akhmanova
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Michel O Steinmetz
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland .,University of Basel, Biozentrum, CH-4056 Basel, Switzerland
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28
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Feng C, Thyagarajan P, Shorey M, Seebold DY, Weiner AT, Albertson RM, Rao KS, Sagasti A, Goetschius DJ, Rolls MM. Patronin-mediated minus end growth is required for dendritic microtubule polarity. J Cell Biol 2019; 218:2309-2328. [PMID: 31076454 PMCID: PMC6605808 DOI: 10.1083/jcb.201810155] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 03/13/2019] [Accepted: 04/23/2019] [Indexed: 02/06/2023] Open
Abstract
Feng et al. describe persistent neuronal microtubule minus end growth that depends on the CAMSAP protein Patronin and is needed for dendritic minus-end-out polarity. Microtubule minus ends are thought to be stable in cells. Surprisingly, in Drosophila and zebrafish neurons, we observed persistent minus end growth, with runs lasting over 10 min. In Drosophila, extended minus end growth depended on Patronin, and Patronin reduction disrupted dendritic minus-end-out polarity. In fly dendrites, microtubule nucleation sites localize at dendrite branch points. Therefore, we hypothesized minus end growth might be particularly important beyond branch points. Distal dendrites have mixed polarity, and reduction of Patronin lowered the number of minus-end-out microtubules. More strikingly, extra Patronin made terminal dendrites almost completely minus-end-out, indicating low Patronin normally limits minus-end-out microtubules. To determine whether minus end growth populated new dendrites with microtubules, we analyzed dendrite development and regeneration. Minus ends extended into growing dendrites in the presence of Patronin. In sum, our data suggest that Patronin facilitates sustained microtubule minus end growth, which is critical for populating dendrites with minus-end-out microtubules.
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Affiliation(s)
- Chengye Feng
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA
| | - Pankajam Thyagarajan
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA
| | - Matthew Shorey
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA
| | - Dylan Y Seebold
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA
| | - Alexis T Weiner
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA
| | - Richard M Albertson
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA
| | - Kavitha S Rao
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA
| | - Alvaro Sagasti
- Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA
| | - Daniel J Goetschius
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA
| | - Melissa M Rolls
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA
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29
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Wang Y, Rui M, Tang Q, Bu S, Yu F. Patronin governs minus-end-out orientation of dendritic microtubules to promote dendrite pruning in Drosophila. eLife 2019; 8:39964. [PMID: 30920370 PMCID: PMC6438692 DOI: 10.7554/elife.39964] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 03/08/2019] [Indexed: 01/09/2023] Open
Abstract
Class IV ddaC neurons specifically prune larval dendrites without affecting axons during Drosophila metamorphosis. ddaCs distribute the minus ends of microtubules (MTs) to dendrites but the plus ends to axons. However, a requirement of MT minus-end-binding proteins in dendrite-specific pruning remains completely unknown. Here, we identified Patronin, a minus-end-binding protein, for its crucial and dose-sensitive role in ddaC dendrite pruning. The CKK domain is important for Patronin’s function in dendrite pruning. Moreover, we show that both patronin knockdown and overexpression resulted in a drastic decrease of MT minus ends and a concomitant increase of plus-end-out MTs in ddaC dendrites, suggesting that Patronin stabilizes dendritic minus-end-out MTs. Consistently, attenuation of Klp10A MT depolymerase in patronin mutant neurons significantly restored minus-end-out MTs in dendrites and thereby rescued dendrite-pruning defects. Thus, our study demonstrates that Patronin orients minus-end-out MT arrays in dendrites to promote dendrite-specific pruning mainly through antagonizing Klp10A activity. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that minor issues remain unresolved (see decision letter).
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Affiliation(s)
- Yan Wang
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, National University of Singapore, Singapore, Singapore
| | - Menglong Rui
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Quan Tang
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Shufeng Bu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,Neuroscience and Behavioral Disorder Program, Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore
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30
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Zhang M, Ergin V, Lin L, Stork C, Chen L, Zheng S. Axonogenesis Is Coordinated by Neuron-Specific Alternative Splicing Programming and Splicing Regulator PTBP2. Neuron 2019; 101:690-706.e10. [PMID: 30733148 DOI: 10.1016/j.neuron.2019.01.022] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 11/08/2018] [Accepted: 01/14/2019] [Indexed: 12/20/2022]
Abstract
How a neuron acquires an axon is a fundamental question. Piecemeal identification of many axonogenesis-related genes has been done, but coordinated regulation is unknown. Through unbiased transcriptome profiling of immature primary cortical neurons during early axon formation, we discovered an association between axonogenesis and neuron-specific alternative splicing. Known axonogenesis genes exhibit little expression alternation but widespread splicing changes. Axonogenesis-associated splicing is governed by RNA binding protein PTBP2, which is enriched in neurons and peaks around axonogenesis in the brain. Cortical depletion of PTBP2 prematurely induces axonogenesis-associated splicing, causes imbalanced expression of axonogenesis-associated isoforms, and specifically affects axon formation in vitro and in vivo. PTBP2-controlled axonogenesis-associated Shtn1 splicing determines SHTN1's capacity to regulate actin interaction, polymerization, and axon growth. Precocious Shtn1 isoform switch contributes to disorganized axon formation of Ptbp2-/- neurons. We conclude that PTBP2-orchestrated alternative splicing programming is required for robust generation of a single axon in mammals.
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Affiliation(s)
- Min Zhang
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Volkan Ergin
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Lin Lin
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521, USA
| | - Cheryl Stork
- Graduate Program in Cell, Molecular and Developmental Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Liang Chen
- Department of Biological Sciences, Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA.
| | - Sika Zheng
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521, USA; Graduate Program in Cell, Molecular and Developmental Biology, University of California, Riverside, Riverside, CA 92521, USA.
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31
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Massive cytoplasmic transport and microtubule organization in fertilized chordate eggs. Dev Biol 2018; 448:154-160. [PMID: 30521810 DOI: 10.1016/j.ydbio.2018.11.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 11/24/2018] [Accepted: 11/30/2018] [Indexed: 01/13/2023]
Abstract
Eggs have developed their own strategies for early development. Amphibian, teleost fish, and ascidian eggs show cortical rotation and an accompanying structure, a cortical parallel microtubule (MT) array, during the one-cell embryonic stage. Cortical rotation is thought to relocate maternal deposits to a certain compartment of the egg and to polarize the embryo. The common features and differences among chordate eggs as well as localized maternal proteins and mRNAs that are related to the organization of MT structures are described in this review. Furthermore, recent studies report progress in elucidating the molecular nature and functions of the noncentrosomal MT organizing center (ncMTOC). The parallel array of MT bundles is presumably organized by ncMTOCs; therefore, the mechanism of ncMTOC control is likely inevitable for these species. Thus, the molecules related to the ncMTOC provide clues for understanding the mechanisms of early developmental systems, which ultimately determine the embryonic axis.
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32
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Ding C, Hammarlund M. Aberrant information transfer interferes with functional axon regeneration. eLife 2018; 7:38829. [PMID: 30371349 PMCID: PMC6231761 DOI: 10.7554/elife.38829] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 10/26/2018] [Indexed: 12/16/2022] Open
Abstract
Functional axon regeneration requires regenerating neurons to restore appropriate synaptic connectivity and circuit function. To model this process, we developed an assay in Caenorhabditis elegans that links axon and synapse regeneration of a single neuron to recovery of behavior. After axon injury and regeneration of the DA9 neuron, synapses reform at their pre-injury location. However, these regenerated synapses often lack key molecular components. Further, synaptic vesicles accumulate in the dendrite in response to axon injury. Dendritic vesicle release results in information misrouting that suppresses behavioral recovery. Dendritic synapse formation depends on dynein and jnk-1. But even when information transfer is corrected, axonal synapses fail to adequately transmit information. Our study reveals unexpected plasticity during functional regeneration. Regeneration of the axon is not sufficient for the reformation of correct neuronal circuits after injury. Rather, synapse reformation and function are also key variables, and manipulation of circuit reformation improves behavioral recovery.
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Affiliation(s)
- Chen Ding
- Department of Neuroscience, Yale University, New Haven, United States
| | - Marc Hammarlund
- Department of Neuroscience, Yale University, New Haven, United States.,Department of Genetics, Yale University, New Haven, United States
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33
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Abstract
Each neuron forms a single axon and multiple dendrites, and this configuration is important for wiring the brain. How only a single axon extends from a neuron, however, remains unknown. This study demonstrates that CAMSAP3, a protein that binds the minus-end of microtubules, preferentially localizes along axons in hippocampal neurons. Remarkably, mutations of CAMSAP3 lead to production of multiple axons in these neurons. In attempts to uncover mechanisms underlying this abnormal axon extension, the authors found that CAMSAP3-anchored microtubules escape from acetylation, a process mediated by α-tubulin acetyltransferase-1, and depletion of this enzyme abolishes abnormal axon formation in CAMSAP3 mutants. These findings reveal that CAMSAP3 controls microtubule dynamics, preventing tubulin acetylation; this mechanism is required for single-axon formation. The molecular mechanisms that guide each neuron to become polarized, forming a single axon and multiple dendrites, remain unknown. Here we show that CAMSAP3 (calmodulin-regulated spectrin-associated protein 3), a protein that regulates the minus-end dynamics of microtubules, plays a key role in maintaining neuronal polarity. In mouse hippocampal neurons, CAMSAP3 was enriched in axons. Although axonal microtubules were generally acetylated, CAMSAP3 was preferentially localized along a less-acetylated fraction of the microtubules. CAMSAP3-mutated neurons often exhibited supernumerary axons, along with an increased number of neurites having nocodazole-resistant/acetylated microtubules compared with wild-type neurons. Analysis using cell lines showed that CAMSAP3 depletion promoted tubulin acetylation, and conversely, mild overexpression of CAMSAP3 inhibited it, suggesting that CAMSAP3 works to retain nonacetylated microtubules. In contrast, CAMSAP2, a protein related to CAMSAP3, was detected along all neurites, and its loss did not affect neuronal polarity, nor did it cause increased tubulin acetylation. Depletion of α-tubulin acetyltransferase-1 (αTAT1), the key enzyme for tubulin acetylation, abolished CAMSAP3 loss-dependent multiple-axon formation. These observations suggest that CAMSAP3 sustains a nonacetylated pool of microtubules in axons, interfering with the action of αTAT1, and this process is important to maintain neuronal polarity.
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34
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Atherton J, Stouffer M, Francis F, Moores CA. Microtubule architecture in vitro and in cells revealed by cryo-electron tomography. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2018; 74:572-584. [PMID: 29872007 PMCID: PMC6096491 DOI: 10.1107/s2059798318001948] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 02/01/2018] [Indexed: 01/03/2023]
Abstract
Electron microscopy is a key methodology for studying microtubule structure and organization. Here, the results of cryo-electron tomography experiments on in vitro-polymerized microtubules and comparisons with microtubule ultrastructure in cells are described. The microtubule cytoskeleton is involved in many vital cellular processes. Microtubules act as tracks for molecular motors, and their polymerization and depolymerization can be harnessed to generate force. The structures of microtubules provide key information about the mechanisms by which their cellular roles are accomplished and the physiological context in which these roles are performed. Cryo-electron microscopy allows the visualization of in vitro-polymerized microtubules and has provided important insights into their overall morphology and the influence of a range of factors on their structure and dynamics. Cryo-electron tomography can be used to determine the unique three-dimensional structure of individual microtubules and their ends. Here, a previous cryo-electron tomography study of in vitro-polymerized GMPCPP-stabilized microtubules is revisited, the findings are compared with new tomograms of dynamic in vitro and cellular microtubules, and the information that can be extracted from such data is highlighted. The analysis shows the surprising structural heterogeneity of in vitro-polymerized microtubules. Lattice defects can be observed both in vitro and in cells. The shared ultrastructural properties in these different populations emphasize the relevance of three-dimensional structures of in vitro microtubules for understanding microtubule cellular functions.
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Affiliation(s)
- Joseph Atherton
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, England
| | | | - Fiona Francis
- INSERM UMR-S 839, 17 Rue du Fer à Moulin, 75005 Paris, France
| | - Carolyn A Moores
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, England
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35
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Gong T, Yan Y, Zhang J, Liu S, Liu H, Gao J, Zhou X, Chen J, Shi A. PTRN-1/CAMSAP promotes CYK-1/formin-dependent actin polymerization during endocytic recycling. EMBO J 2018; 37:embj.201798556. [PMID: 29567645 DOI: 10.15252/embj.201798556] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 02/18/2018] [Accepted: 02/27/2018] [Indexed: 01/01/2023] Open
Abstract
Cargo sorting and membrane carrier initiation in recycling endosomes require appropriately coordinated actin dynamics. However, the mechanism underlying the regulation of actin organization during recycling transport remains elusive. Here we report that the loss of PTRN-1/CAMSAP stalled actin exchange and diminished the cytosolic actin structures. Furthermore, we found that PTRN-1 is required for the recycling of clathrin-independent cargo hTAC-GFP The N-terminal calponin homology (CH) domain and central coiled-coils (CC) region of PTRN-1 can synergistically sustain the flow of hTAC-GFP We identified CYK-1/formin as a binding partner of PTRN-1. The N-terminal GTPase-binding domain (GBD) of CYK-1 serves as the binding interface for the PTRN-1 CH domain. The presence of the PTRN-1 CH domain promoted CYK-1-mediated actin polymerization, which suggests that the PTRN-1-CH:CYK-1-GBD interaction efficiently relieves autoinhibitory interactions within CYK-1. As expected, the overexpression of the CYK-1 formin homology domain 2 (FH2) substantially restored actin structures and partially suppressed the hTAC-GFP overaccumulation phenotype in ptrn-1 mutants. We conclude that the PTRN-1 CH domain is required to stimulate CYK-1 to facilitate actin dynamics during endocytic recycling.
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Affiliation(s)
- Ting Gong
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yanling Yan
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jing Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shuai Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Hang Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jinghu Gao
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xin Zhou
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Juan Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Anbing Shi
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China .,Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, Hubei, China.,Key Laboratory of Neurological Disease of National Education Ministry, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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36
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Chen L. Microtubules and axon regeneration in C. elegans. Mol Cell Neurosci 2018; 91:160-166. [PMID: 29551667 DOI: 10.1016/j.mcn.2018.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/14/2018] [Accepted: 03/15/2018] [Indexed: 11/28/2022] Open
Abstract
Axon regeneration is a fundamental and conserved process that allows the nervous system to repair circuits after trauma. Due to its conserved genome, transparent body, and relatively simple neuroanatomy, C. elegans has become a powerful model organism for studying the cellular and molecular mechanisms underlying axon regeneration. Various studies from different model organisms have found microtubule dynamics to be pivotal to axon regrowth. In this review, we will discuss the latest findings on how microtubule dynamics are regulated during axon regeneration in C. elegans. Understanding the mechanisms of axon regeneration will aid in the development of more effective therapeutic strategies for treatments of diseases involving disconnection of axons, such as spinal cord injury and stroke.
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Affiliation(s)
- Lizhen Chen
- Barshop Institute for Longevity and Aging Studies, Department of Cell Systems and Anatomy, Department of Molecular Medicine, University of Texas Health Science Center San Antonio, San Antonio, TX, USA.
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37
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Abstract
The contribution of microtubule tip dynamics to the assembly and function of plant microtubule arrays remains poorly understood. Here, we report that the Arabidopsis SPIRAL2 (SPR2) protein modulates the dynamics of the acentrosomal cortical microtubule plus and minus ends in an opposing manner. Live imaging of a functional SPR2-mRuby fusion protein revealed that SPR2 shows both microtubule plus- and minus-end tracking activity in addition to localization at microtubule intersections and along the lattice. Analysis of microtubule dynamics showed that cortical microtubule plus ends rarely undergo catastrophe in the spr2-2 knockout mutant compared to wild-type. In contrast, cortical microtubule minus ends in spr2-2 depolymerized at a much faster rate than in wild-type. Destabilization of the minus ends in spr2-2 caused a significant decrease in the lifetime of microtubule crossovers, which dramatically reduced the microtubule-severing frequency and inhibited light-induced microtubule array reorientation. Using in vitro reconstitution experiments combined with single-molecule imaging, we found that recombinant SPR2-GFP intrinsically localizes to microtubule minus ends, where it binds stably and inhibits their dynamics. Together, our data establish SPR2 as a new type of microtubule tip regulator that governs the length and lifetime of microtubules.
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Affiliation(s)
- Yuanwei Fan
- Department of Biology and Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Graham M Burkart
- Department of Biology and Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ram Dixit
- Department of Biology and Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO 63130, USA.
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Vibert L, Daulny A, Jarriault S. Wound healing, cellular regeneration and plasticity: the elegans way. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2018; 62:491-505. [PMID: 29938761 PMCID: PMC6161810 DOI: 10.1387/ijdb.180123sj] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Regeneration and wound healing are complex processes that allow organs and tissues to regain their integrity and functionality after injury. Wound healing, a key property of epithelia, involves tissue closure that in some cases leads to scar formation. Regeneration, a process rather limited in mammals, is the capacity to regrow (parts of) an organ or a tissue, after damage or amputation. What are the properties of organs and the features of tissue permitting functional regrowth and repair? What are the cellular and molecular mechanisms underlying these processes? These questions are crucial both in fundamental and applied contexts, with important medical implications. The mechanisms and cells underlying tissue repair have thus been the focus of intense investigation. The last decades have seen rapid progress in the domain and new models emerging. Here, we review the fundamental advances and the perspectives that the use of C. elegans as a model have brought to the mechanisms of wound healing and cellular plasticity, axon regeneration and transdifferentiation in vivo.
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Affiliation(s)
- Laura Vibert
- Department of Development and Stem Cells, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), CNRS UMR 7104/INSERM U1258, Université de Strasbourg, Strasbourg, France
| | - Anne Daulny
- Department of Development and Stem Cells, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), CNRS UMR 7104/INSERM U1258, Université de Strasbourg, Strasbourg, France
| | - Sophie Jarriault
- Department of Development and Stem Cells, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), CNRS UMR 7104/INSERM U1258, Université de Strasbourg, Strasbourg, France
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39
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Atherton J, Jiang K, Stangier MM, Luo Y, Hua S, Houben K, van Hooff JJ, Joseph AP, Scarabelli G, Grant BJ, Roberts AJ, Topf M, Steinmetz MO, Baldus M, Moores CA, Akhmanova A. A structural model for microtubule minus-end recognition and protection by CAMSAP proteins. Nat Struct Mol Biol 2017; 24:931-943. [PMID: 28991265 PMCID: PMC6134180 DOI: 10.1038/nsmb.3483] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Accepted: 09/12/2017] [Indexed: 12/12/2022]
Abstract
CAMSAP and Patronin family members regulate microtubule minus-end stability and localization and thus organize noncentrosomal microtubule networks, which are essential for cell division, polarization and differentiation. Here, we found that the CAMSAP C-terminal CKK domain is widely present among eukaryotes and autonomously recognizes microtubule minus ends. Through a combination of structural approaches, we uncovered how mammalian CKK binds between two tubulin dimers at the interprotofilament interface on the outer microtubule surface. In vitro reconstitution assays combined with high-resolution fluorescence microscopy and cryo-electron tomography suggested that CKK preferentially associates with the transition zone between curved protofilaments and the regular microtubule lattice. We propose that minus-end-specific features of the interprotofilament interface at this site serve as the basis for CKK's minus-end preference. The steric clash between microtubule-bound CKK and kinesin motors explains how CKK protects microtubule minus ends against kinesin-13-induced depolymerization and thus controls the stability of free microtubule minus ends.
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Affiliation(s)
- Joseph Atherton
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom
| | - Kai Jiang
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Marcel M. Stangier
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen PSI, Switzerland
| | - Yanzhang Luo
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, the Netherlands
| | - Shasha Hua
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Klaartje Houben
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, the Netherlands
| | - Jolien J.E. van Hooff
- Hubrecht Institute, Utrecht, the Netherlands
- Theoretical Biology and Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
- Molecular Cancer Research, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Agnel-Praveen Joseph
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom
| | - Guido Scarabelli
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Barry J. Grant
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Anthony J. Roberts
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom
| | - Maya Topf
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom
| | - Michel O. Steinmetz
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen PSI, Switzerland
- University of Basel, Biozentrum, Basel, Switzerland
| | - Marc Baldus
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, the Netherlands
| | - Carolyn A. Moores
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom
| | - Anna Akhmanova
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
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40
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Muroyama A, Lechler T. Microtubule organization, dynamics and functions in differentiated cells. Development 2017; 144:3012-3021. [PMID: 28851722 DOI: 10.1242/dev.153171] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Over the past several decades, numerous studies have greatly expanded our knowledge about how microtubule organization and dynamics are controlled in cultured cells in vitro However, our understanding of microtubule dynamics and functions in vivo, in differentiated cells and tissues, remains under-explored. Recent advances in generating genetic tools and imaging technologies to probe microtubules in situ, coupled with an increased interest in the functions of this cytoskeletal network in differentiated cells, are resulting in a renaissance. Here, we discuss the lessons learned from such approaches, which have revealed that, although some differentiated cells utilize conserved strategies to remodel microtubules, there is considerable diversity in the underlying molecular mechanisms of microtubule reorganization. This highlights a continued need to explore how differentiated cells regulate microtubule geometry in vivo.
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Affiliation(s)
- Andrew Muroyama
- Departments of Dermatology and Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Terry Lechler
- Departments of Dermatology and Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
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41
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Wei J, Xu H, Meng W. Noncentrosomal microtubules regulate autophagosome transport through CAMSAP2-EB1 cross-talk. FEBS Lett 2017; 591:2379-2393. [PMID: 28726242 DOI: 10.1002/1873-3468.12758] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/02/2017] [Accepted: 07/13/2017] [Indexed: 12/24/2022]
Abstract
Microtubules (MTs) play essential roles in many steps of autophagy, an important degradation pathway in the maintenance of cellular homoeostasis. In many cells, MT networks are comprised of centrosomal MTs and noncentrosomal MTs. However, it is unknown whether noncentrosomal MTs and its binding proteins are involved in autophagy. Here, we show in HeLa cells that calmodulin-regulated spectrin-associated protein 2 (CAMSAP2), a noncentrosomal MT minus-end stabilizing protein, regulates retrograde transport of autophagosomes through MT dynamics. CAMSAP2 cooperates with EB1 to regulate end-binding protein 1 (EB1) behaviour at MT plus ends, MT growth directions and autophagosome transport. An association between CAMSAP2 and EB1 in the cytosol may modulate EB1 binding to MT plus ends. Collectively, our data indicate that noncentrosomal MTs regulate autophagy through a cross-talk between CAMSAP2 and EB1.
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Affiliation(s)
- Jieli Wei
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Honglin Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Wenxiang Meng
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
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42
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Microtubule Organization Determines Axonal Transport Dynamics. Neuron 2017; 92:449-460. [PMID: 27764672 DOI: 10.1016/j.neuron.2016.09.036] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 08/02/2016] [Accepted: 09/15/2016] [Indexed: 12/31/2022]
Abstract
Axonal microtubule (MT) arrays are the major cytoskeleton substrate for cargo transport. How MT organization, i.e., polymer length, number, and minus-end spacing, is regulated and how it impinges on axonal transport are unclear. We describe a method for analyzing neuronal MT organization using light microscopy. This method circumvents the need for electron microscopy reconstructions and is compatible with live imaging of cargo transport and MT dynamics. Examination of a C. elegans motor neuron revealed how age, MT-associated proteins, and signaling pathways control MT length, minus-end spacing, and coverage. In turn, MT organization determines axonal transport progression: cargoes pause at polymer termini, suggesting that switching MT tracks is rate limiting for efficient transport. Cargo run length is set by MT length, and higher MT coverage correlates with shorter pauses. These results uncover the principles and mechanisms of neuronal MT organization and its regulation of axonal cargo transport.
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43
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Nashchekin D, Fernandes AR, St Johnston D. Patronin/Shot Cortical Foci Assemble the Noncentrosomal Microtubule Array that Specifies the Drosophila Anterior-Posterior Axis. Dev Cell 2017; 38:61-72. [PMID: 27404359 PMCID: PMC4943857 DOI: 10.1016/j.devcel.2016.06.010] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 05/03/2016] [Accepted: 06/08/2016] [Indexed: 02/06/2023]
Abstract
Noncentrosomal microtubules play an important role in polarizing differentiated cells, but little is known about how these microtubules are organized. Here we identify the spectraplakin, Short stop (Shot), as the cortical anchor for noncentrosomal microtubule organizing centers (ncMTOCs) in the Drosophila oocyte. Shot interacts with the cortex through its actin-binding domain and recruits the microtubule minus-end-binding protein, Patronin, to form cortical ncMTOCs. Shot/Patronin foci do not co-localize with γ-tubulin, suggesting that they do not nucleate new microtubules. Instead, they capture and stabilize existing microtubule minus ends, which then template new microtubule growth. Shot/Patronin foci are excluded from the oocyte posterior by the Par-1 polarity kinase to generate the polarized microtubule network that localizes axis determinants. Both proteins also accumulate apically in epithelial cells, where they are required for the formation of apical-basal microtubule arrays. Thus, Shot/Patronin ncMTOCs may provide a general mechanism for organizing noncentrosomal microtubules in differentiated cells. The Drosophila spectraplakin, Shot, recruits Patronin to form noncentrosomal MTOCs The actin-binding domain of Shot anchors the ncMTOCs to the oocyte cortex Par-1 excludes Shot from the posterior cortex to define the anterior-posterior axis Shot/Patronin ncMTOCs lack γ-tubulin and grow MTs from stabilized minus-end stumps
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Affiliation(s)
- Dmitry Nashchekin
- The Gurdon Institute and the Department of Genetics, the University of Cambridge, Cambridge CB2 1QN, UK
| | - Artur Ribeiro Fernandes
- The Gurdon Institute and the Department of Genetics, the University of Cambridge, Cambridge CB2 1QN, UK
| | - Daniel St Johnston
- The Gurdon Institute and the Department of Genetics, the University of Cambridge, Cambridge CB2 1QN, UK.
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44
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Chisholm AD, Hutter H, Jin Y, Wadsworth WG. The Genetics of Axon Guidance and Axon Regeneration in Caenorhabditis elegans. Genetics 2016; 204:849-882. [PMID: 28114100 PMCID: PMC5105865 DOI: 10.1534/genetics.115.186262] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 09/06/2016] [Indexed: 11/18/2022] Open
Abstract
The correct wiring of neuronal circuits depends on outgrowth and guidance of neuronal processes during development. In the past two decades, great progress has been made in understanding the molecular basis of axon outgrowth and guidance. Genetic analysis in Caenorhabditis elegans has played a key role in elucidating conserved pathways regulating axon guidance, including Netrin signaling, the slit Slit/Robo pathway, Wnt signaling, and others. Axon guidance factors were first identified by screens for mutations affecting animal behavior, and by direct visual screens for axon guidance defects. Genetic analysis of these pathways has revealed the complex and combinatorial nature of guidance cues, and has delineated how cues guide growth cones via receptor activity and cytoskeletal rearrangement. Several axon guidance pathways also affect directed migrations of non-neuronal cells in C. elegans, with implications for normal and pathological cell migrations in situations such as tumor metastasis. The small number of neurons and highly stereotyped axonal architecture of the C. elegans nervous system allow analysis of axon guidance at the level of single identified axons, and permit in vivo tests of prevailing models of axon guidance. C. elegans axons also have a robust capacity to undergo regenerative regrowth after precise laser injury (axotomy). Although such axon regrowth shares some similarities with developmental axon outgrowth, screens for regrowth mutants have revealed regeneration-specific pathways and factors that were not identified in developmental screens. Several areas remain poorly understood, including how major axon tracts are formed in the embryo, and the function of axon regeneration in the natural environment.
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Affiliation(s)
| | - Harald Hutter
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, and
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093
- Department of Pathology and Laboratory Medicine, Howard Hughes Medical Institute, Chevy Chase, Maryland, and
| | - William G Wadsworth
- Department of Pathology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
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45
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Chuang M, Hsiao TI, Tong A, Xu S, Chisholm AD. DAPK interacts with Patronin and the microtubule cytoskeleton in epidermal development and wound repair. eLife 2016; 5. [PMID: 27661253 PMCID: PMC5053806 DOI: 10.7554/elife.15833] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 09/22/2016] [Indexed: 12/11/2022] Open
Abstract
Epidermal barrier epithelia form a first line of defense against the environment, protecting animals against infection and repairing physical damage. In C. elegans, death-associated protein kinase (DAPK-1) regulates epidermal morphogenesis, innate immunity and wound repair. Combining genetic suppressor screens and pharmacological tests, we find that DAPK-1 maintains epidermal tissue integrity through regulation of the microtubule (MT) cytoskeleton. dapk-1 epidermal phenotypes are suppressed by treatment with microtubule-destabilizing drugs and mimicked or enhanced by microtubule-stabilizing drugs. Loss of function in ptrn-1, the C. elegans member of the Patronin/Nezha/CAMSAP family of MT minus-end binding proteins, suppresses dapk-1 epidermal and innate immunity phenotypes. Over-expression of the MT-binding CKK domain of PTRN-1 triggers epidermal and immunity defects resembling those of dapk-1 mutants, and PTRN-1 localization is regulated by DAPK-1. DAPK-1 and PTRN-1 physically interact in co-immunoprecipitation experiments, and DAPK-1 itself undergoes MT-dependent transport. Our results uncover an unexpected interdependence of DAPK-1 and the microtubule cytoskeleton in maintenance of epidermal integrity.
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Affiliation(s)
- Marian Chuang
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, San Diego, United States
| | - Tiffany I Hsiao
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, San Diego, United States
| | - Amy Tong
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, San Diego, United States
| | - Suhong Xu
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, San Diego, United States
| | - Andrew D Chisholm
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, San Diego, United States
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46
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Byrne AB, Hammarlund M. Axon regeneration in C. elegans: Worming our way to mechanisms of axon regeneration. Exp Neurol 2016; 287:300-309. [PMID: 27569538 DOI: 10.1016/j.expneurol.2016.08.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/19/2016] [Accepted: 08/24/2016] [Indexed: 12/12/2022]
Abstract
How axons repair themselves after injury is a fundamental question in neurobiology. With its conserved genome, relatively simple nervous system, and transparent body, C. elegans has recently emerged as a productive model to uncover the cellular mechanisms that regulate and execute axon regeneration. In this review, we discuss the strengths and weaknesses of the C. elegans model of regeneration. We explore the technical advances that enable the use of C. elegans for in vivo regeneration studies, review findings in C. elegans that have contributed to our understanding of the regeneration response across species, discuss the potential of C. elegans research to provide insight into mechanisms that function in the injured mammalian nervous system, and present potential future directions of axon regeneration research using C. elegans.
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Affiliation(s)
- Alexandra B Byrne
- Department of Genetics, Yale University School of Medicine, New Haven, CT, United States; Department of Neuroscience, Yale University School of Medicine, New Haven, CT, United States
| | - Marc Hammarlund
- Department of Genetics, Yale University School of Medicine, New Haven, CT, United States; Department of Neuroscience, Yale University School of Medicine, New Haven, CT, United States.
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47
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Non-centrosomal nucleation mediated by augmin organizes microtubules in post-mitotic neurons and controls axonal microtubule polarity. Nat Commun 2016; 7:12187. [PMID: 27405868 PMCID: PMC4947180 DOI: 10.1038/ncomms12187] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 06/09/2016] [Indexed: 12/19/2022] Open
Abstract
Neurons display a highly polarized microtubule network that mediates trafficking throughout the extensive cytoplasm and is crucial for neuronal differentiation and function. In newborn migrating neurons, the microtubule network is organized by the centrosome. During neuron maturation, however, the centrosome gradually loses this activity, and how microtubules are organized in more mature neurons remains poorly understood. Here, we demonstrate that microtubule organization in post-mitotic neurons strongly depends on non-centrosomal nucleation mediated by augmin and by the nucleator γTuRC. Disruption of either complex not only reduces microtubule density but also microtubule bundling. These microtubule defects impair neurite formation, interfere with axon specification and growth, and disrupt axonal trafficking. In axons augmin does not merely mediate nucleation of microtubules but ensures their uniform plus end-out orientation. Thus, the augmin-γTuRC module, initially identified in mitotic cells, may be commonly used to generate and maintain microtubule configurations with specific polarity. In mature neurons the centrosome no longer functions as the main microtubule organizer and it is unclear how ordered microtubule arrays are assembled. Here, the authors show that in post-mitotic neurons this process depends on non-centrosomal nucleation mediated by the protein complex augmin and the nucleator gamma-TuRC.
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48
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Takahashi S, Mui VJ, Rosenberg SK, Homma K, Cheatham MA, Zheng J. Cadherin 23-C Regulates Microtubule Networks by Modifying CAMSAP3's Function. Sci Rep 2016; 6:28706. [PMID: 27349180 PMCID: PMC4923861 DOI: 10.1038/srep28706] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 06/08/2016] [Indexed: 02/05/2023] Open
Abstract
Cadherin-related 23 (CDH23) is an adhesive protein important for hearing and vision, while CAMSAP3/Marshalin is a microtubule (MT) minus-end binding protein that regulates MT networks. Although both CDH23 and CAMSAP3/Marshalin are expressed in the organ of Corti, and carry several protein-protein interaction domains, no functional connection between these two proteins has been proposed. In this report, we demonstrate that the C isoform of CDH23 (CDH23-C) directly binds to CAMSAP3/Marshalin and modifies its function by inhibiting CAMSAP3/Marshalin-induced bundle formation, a process that requires a tubulin-binding domain called CKK. We further identified a conserved N-terminal region of CDH23-C that binds to the CKK domain. This CKK binding motif (CBM) is adjacent to the domain that interacts with harmonin, a binding partner of CDH23 implicated in deafness. Because the human Usher Syndrome 1D-associated mutation, CDH23 R3175H, maps to the CBM, we created a matched mutation in mouse CDH23-C at R55H. Both in vivo and in vitro assays decreased the ability of CDH23-C to interact with CAMSAP3/Marshalin, indicating that the interaction between CDH23 and CAMSAP3/Marshalin plays a vital role in hearing and vision. Together, our data suggest that CDH23-C is a CAMSAP3/Marshalin-binding protein that can modify MT networks indirectly through its interaction with CAMSAP3/Marshalin.
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Affiliation(s)
- Satoe Takahashi
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago IL 60611, USA
| | - Vincent J Mui
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago IL 60611, USA
| | - Samuel K Rosenberg
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago IL 60611, USA
| | - Kazuaki Homma
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago IL 60611, USA.,Knowles Hearing Center, Northwestern University, Evanston, IL 60208, USA
| | - Mary Ann Cheatham
- Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL 60208, USA.,Knowles Hearing Center, Northwestern University, Evanston, IL 60208, USA
| | - Jing Zheng
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago IL 60611, USA.,Knowles Hearing Center, Northwestern University, Evanston, IL 60208, USA
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49
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He Z, Jin Y. Intrinsic Control of Axon Regeneration. Neuron 2016; 90:437-51. [DOI: 10.1016/j.neuron.2016.04.022] [Citation(s) in RCA: 337] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/10/2016] [Accepted: 04/13/2016] [Indexed: 01/12/2023]
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50
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Abstract
The capacity of an axon to regenerate is regulated by its external environment and by cell-intrinsic factors. Studies in a variety of organisms suggest that alterations in axonal microtubule (MT) dynamics have potent effects on axon regeneration. We review recent findings on the regulation of MT dynamics during axon regeneration, focusing on the nematode Caenorhabditis elegans. In C. elegans the dual leucine zipper kinase (DLK) promotes axon regeneration, whereas the exchange factor for Arf6 (EFA-6) inhibits axon regeneration. Both DLK and EFA-6 respond to injury and control axon regeneration in part via MT dynamics. How the DLK and EFA-6 pathways are related is a topic of active investigation, as is the mechanism by which EFA-6 responds to axonal injury. We evaluate potential candidates, such as the MT affinity-regulating kinase PAR-1/MARK, in regulation of EFA-6 and axonal MT dynamics in regeneration.
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Affiliation(s)
- Ngang Heok Tang
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Andrew D Chisholm
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
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