1
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Stathatos GG, Merriner DJ, O'Connor AE, Zenker J, Dunleavy JE, O'Bryan MK. Epsilon tubulin is an essential determinant of microtubule-based structures in male germ cells. EMBO Rep 2024; 25:2722-2742. [PMID: 38773322 PMCID: PMC11169422 DOI: 10.1038/s44319-024-00159-w] [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: 09/23/2023] [Revised: 04/08/2024] [Accepted: 04/30/2024] [Indexed: 05/23/2024] Open
Abstract
Alpha, beta, and gamma tubulins are essential building blocks for all eukaryotic cells. The functions of the non-canonical tubulins, delta, epsilon, and zeta, however, remain poorly understood and their requirement in mammalian development untested. Herein we have used a spermatogenesis model to define epsilon tubulin (TUBE1) function in mice. We show that TUBE1 is essential for the function of multiple complex microtubule arrays, including the meiotic spindle, axoneme and manchette and in its absence, there is a dramatic loss of germ cells and male sterility. Moreover, we provide evidence for the interplay between TUBE1 and katanin-mediated microtubule severing, and for the sub-specialization of individual katanin paralogs in the regulation of specific microtubule arrays.
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Affiliation(s)
- G Gemma Stathatos
- School of BioSciences and Bio21 Institute of Molecular Science and Biotechnology, Faculty of Science, The University of Melbourne, Parkville, VIC, 3010, Australia
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, 3800, Australia
| | - D Jo Merriner
- School of BioSciences and Bio21 Institute of Molecular Science and Biotechnology, Faculty of Science, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Anne E O'Connor
- School of BioSciences and Bio21 Institute of Molecular Science and Biotechnology, Faculty of Science, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jennifer Zenker
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Jessica Em Dunleavy
- School of BioSciences and Bio21 Institute of Molecular Science and Biotechnology, Faculty of Science, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Moira K O'Bryan
- School of BioSciences and Bio21 Institute of Molecular Science and Biotechnology, Faculty of Science, The University of Melbourne, Parkville, VIC, 3010, Australia.
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2
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Chato-Astrain I, Pronot M, Coppola T, Martin S. Molecular Organization and Regulation of the Mammalian Synapse by the Post-Translational Modification SUMOylation. Cells 2024; 13:420. [PMID: 38474384 DOI: 10.3390/cells13050420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
Neurotransmission occurs within highly specialized compartments forming the active synapse where the complex organization and dynamics of the interactions are tightly orchestrated both in time and space. Post-translational modifications (PTMs) are central to these spatiotemporal regulations to ensure an efficient synaptic transmission. SUMOylation is a dynamic PTM that modulates the interactions between proteins and consequently regulates the conformation, the distribution and the trafficking of the SUMO-target proteins. SUMOylation plays a crucial role in synapse formation and stabilization, as well as in the regulation of synaptic transmission and plasticity. In this review, we summarize the molecular consequences of this protein modification in the structural organization and function of the mammalian synapse. We also outline novel activity-dependent regulation and consequences of the SUMO process and explore how this protein modification can functionally participate in the compartmentalization of both pre- and post-synaptic sites.
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Affiliation(s)
- Isabel Chato-Astrain
- Université Côte d'Azur, CNRS, Inserm, IPMC, Sophia Antipolis, F-06560 Valbonne, France
| | - Marie Pronot
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Thierry Coppola
- Université Côte d'Azur, CNRS, Inserm, IPMC, Sophia Antipolis, F-06560 Valbonne, France
| | - Stéphane Martin
- Université Côte d'Azur, CNRS, Inserm, IPMC, Sophia Antipolis, F-06560 Valbonne, France
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3
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Ho KH, Candat A, Scarpetta V, Faucourt M, Weill S, Salio C, D'Este E, Meschkat M, Wurm CA, Kneussel M, Janke C, Magiera MM, Genovesio A, Meunier A, Sassoè-Pognetto M, Brill MS, Spassky N, Patrizi A. Choroid plexuses carry nodal-like cilia that undergo axoneme regression from early adult stage. Dev Cell 2023; 58:2641-2651.e6. [PMID: 37890489 DOI: 10.1016/j.devcel.2023.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/06/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023]
Abstract
Choroid plexuses (ChPs) produce cerebrospinal fluid and sense non-cell-autonomous stimuli to control the homeostasis of the central nervous system. They are mainly composed of epithelial multiciliated cells, whose development and function are still controversial. We have thus characterized the stepwise order of mammalian ChP epithelia cilia formation using a combination of super-resolution-microscopy approaches and mouse genetics. We show that ChP ciliated cells are built embryonically on a treadmill of spatiotemporally regulated events, starting with atypical centriole amplification and ending with the construction of nodal-like 9+0 cilia, characterized by both primary and motile features. ChP cilia undergo axoneme resorption at early postnatal stages through a microtubule destabilization process controlled by the microtubule-severing enzyme spastin and mitigated by polyglutamylation levels. Notably, this phenotype is preserved in humans, suggesting a conserved ciliary resorption mechanism in mammals.
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Affiliation(s)
- Kim Hoa Ho
- Schaller Research Group, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Faculty of Biosciences, Heidelberg University, Heidelberg 69120, Germany
| | - Adrien Candat
- Electron Microscopy Facility, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France
| | - Valentina Scarpetta
- Schaller Research Group, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Department of Neurosciences "Rita Levi Montalcini," University of Turin, Turin 10126, Italy
| | - Marion Faucourt
- Cilia biology and Neurogenesis Team, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France
| | - Solene Weill
- Computational Bioimaging and Bioinformatics Team, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France
| | - Chiara Salio
- Department of Veterinary Sciences, University of Turin, Grugliasco 10095, Italy
| | - Elisa D'Este
- Optical Microscopy Facility, Max Planck Institute for Medical Research, Heidelberg 69120, Germany
| | | | | | - Matthias Kneussel
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Carsten Janke
- Institut Curie, PSL Research University, CNRS UMR 3348, Orsay 91401, France; Université Paris-Saclay, CNRS UMR 3348, Orsay 91401, France
| | - Maria M Magiera
- Institut Curie, PSL Research University, CNRS UMR 3348, Orsay 91401, France; Université Paris-Saclay, CNRS UMR 3348, Orsay 91401, France
| | - Auguste Genovesio
- Computational Bioimaging and Bioinformatics Team, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France
| | - Alice Meunier
- Cilia biology and Neurogenesis Team, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France
| | - Marco Sassoè-Pognetto
- Department of Neurosciences "Rita Levi Montalcini," University of Turin, Turin 10126, Italy
| | - Monika S Brill
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich 80802, Germany; Munich Cluster of Systems Neurology (SyNergy), Munich 81377, Germany
| | - Nathalie Spassky
- Cilia biology and Neurogenesis Team, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France
| | - Annarita Patrizi
- Schaller Research Group, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Interdisciplinary Center for Neuroscience, Heidelberg University, Heidelberg 69120, Germany; Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg 69120, Germany.
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4
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Ma C, Wang J, Tu Q, Bo W, Hu Z, Zhuo R, Wu R, Dong Z, Qiang L, Liu Y, Liu M. Fidgetin interacting with microtubule end binding protein EB3 affects axonal regrowth in spinal cord injury. Neural Regen Res 2023; 18:2727-2732. [PMID: 37449637 DOI: 10.4103/1673-5374.373716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Abstract
Fidgetin, a microtubule-severing enzyme, regulates neurite outgrowth, axonal regeneration, and cell migration by trimming off the labile domain of microtubule polymers. Because maintenance of the microtubule labile domain is essential for axon initiation, elongation, and navigation, it is of interest to determine whether augmenting the microtubule labile domain via depletion of fidgetin serves as a therapeutic approach to promote axonal regrowth in spinal cord injury. In this study, we constructed rat models of spinal cord injury and sciatic nerve injury. Compared with spinal cord injury, we found that expression level of tyrosinated microtubules in the labile portion of microtubules continuously increased, whereas fidgetin decreased after peripheral nerve injury. Depletion of fidgetin enhanced axon regeneration after spinal cord injury, whereas expression level of end binding protein 3 (EB3) markedly increased. Next, we performed RNA interference to knockdown EB3 or fidgetin. We found that deletion of EB3 did not change fidgetin expression. Conversely, deletion of fidgetin markedly increased expression of tyrosinated microtubules and EB3. Deletion of fidgetin increased the amount of EB3 at the end of neurites and thereby increased the level of tyrosinated microtubules. Finally, we deleted EB3 and overexpressed fidgetin. We found that fidgetin trimmed tyrosinated tubulins by interacting with EB3. When fidgetin was deleted, the labile portion of microtubules was elongated, and as a result the length of axons and number of axon branches were increased. These findings suggest that fidgetin can be used as a novel therapeutic target to promote axonal regeneration after spinal cord injury. Furthermore, they reveal an innovative mechanism by which fidgetin preferentially severs labile microtubules.
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Affiliation(s)
- Chao Ma
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University; Medical School of Nantong University, Nantong, Jiangsu Province, China
| | - Junpei Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu Province, China
| | - Qifeng Tu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu Province, China
| | - Weijuan Bo
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu Province, China
| | - Zunlu Hu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu Province, China
| | - Run Zhuo
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu Province, China
| | - Ronghua Wu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu Province, China
| | - Zhangji Dong
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu Province, China
| | - Liang Qiang
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Yan Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu Province, China
| | - Mei Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, Nantong, Jiangsu Province, China
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5
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Kubo T, Tani Y, Yanagisawa HA, Kikkawa M, Oda T. α- and β-tubulin C-terminal tails with distinct modifications are crucial for ciliary motility and assembly. J Cell Sci 2023; 136:jcs261070. [PMID: 37519241 DOI: 10.1242/jcs.261070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 07/24/2023] [Indexed: 08/01/2023] Open
Abstract
α- and β-tubulin have an unstructured glutamate-rich region at their C-terminal tails (CTTs). The function of this region in cilia and flagella is still unclear, except that glutamates in CTTs act as the sites for post-translational modifications that affect ciliary motility. The unicellular alga Chlamydomonas possesses only two α-tubulin and two β-tubulin genes, each pair encoding an identical protein. This simple gene organization might enable a complete replacement of the wild-type tubulin with its mutated version. Here, using CRISPR/Cas9, we generated mutant strains expressing tubulins with modified CTTs. We found that the mutant strain in which four glutamate residues in the α-tubulin CTT had been replaced by alanine almost completely lacked polyglutamylated tubulin and displayed paralyzed cilia. In contrast, the mutant strain lacking the glutamate-rich region of the β-tubulin CTT assembled short cilia without the central apparatus. This phenotype is similar to mutant strains harboring a mutation in a subunit of katanin, the function of which has been shown to depend on the β-tubulin CTT. Therefore, our study reveals distinct and important roles of α- and β-tubulin CTTs in the formation and function of cilia.
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Affiliation(s)
- Tomohiro Kubo
- Department of Anatomy and Structural Biology, Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| | - Yuma Tani
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033, Japan
| | - Haru-Aki Yanagisawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masahide Kikkawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toshiyuki Oda
- Department of Anatomy and Structural Biology, Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
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6
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Fan X, McKenney RJ. Control of motor landing and processivity by the CAP-Gly domain in the KIF13B tail. Nat Commun 2023; 14:4715. [PMID: 37543636 PMCID: PMC10404244 DOI: 10.1038/s41467-023-40425-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 07/27/2023] [Indexed: 08/07/2023] Open
Abstract
Microtubules are major components of the eukaryotic cytoskeleton. Posttranslational modifications (PTMs) of tubulin regulates interactions with microtubule-associated proteins (MAPs). One unique PTM is the cyclical removal and re-addition of the C-terminal tyrosine of α-tubulin and MAPs containing CAP-Gly domains specifically recognize tyrosinated microtubules. KIF13B, a long-distance transport kinesin, contains a conserved CAP-Gly domain, but the role of the CAP-Gly domain in KIF13B's motility along microtubules remains unknown. To address this, we investigate the interaction between KIF13B's CAP-Gly domain, and tyrosinated microtubules. We find that KIF13B's CAP-Gly domain influences the initial motor-microtubule interaction, as well as processive motility along microtubules. The effect of the CAP-Gly domain is enhanced when the motor domain is in the ADP state, suggesting an interplay between the N-terminal motor domain and C-terminal CAP-Gly domain. These results reveal that specialized kinesin tail domains play active roles in the initiation and continuation of motor movement.
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Affiliation(s)
- Xiangyu Fan
- Department of Molecular and Cellular Biology, University of California - Davis, 145 Briggs Hall, Davis, CA, 95616, USA
| | - Richard J McKenney
- Department of Molecular and Cellular Biology, University of California - Davis, 145 Briggs Hall, Davis, CA, 95616, USA.
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7
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Atkins M, Nicol X, Fassier C. Microtubule remodelling as a driving force of axon guidance and pruning. Semin Cell Dev Biol 2023; 140:35-53. [PMID: 35710759 DOI: 10.1016/j.semcdb.2022.05.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/26/2022] [Accepted: 05/31/2022] [Indexed: 01/28/2023]
Abstract
The establishment of neuronal connectivity relies on the microtubule (MT) cytoskeleton, which provides mechanical support, roads for axonal transport and mediates signalling events. Fine-tuned spatiotemporal regulation of MT functions by tubulin post-translational modifications and MT-associated proteins is critical for the coarse wiring and subsequent refinement of neuronal connectivity. The defective regulation of these processes causes a wide range of neurodevelopmental disorders associated with connectivity defects. This review focuses on recent studies unravelling how MT composition, post-translational modifications and associated proteins influence MT functions in axon guidance and/or pruning to build functional neuronal circuits. We here summarise experimental evidence supporting the key role of this network as a driving force for growth cone steering and branch-specific axon elimination. We further provide a global overview of the MT-interactors that tune developing axon behaviours, with a special emphasis on their emerging versatility in the regulation of MT dynamics/structure. Recent studies establishing the key and highly selective role of the tubulin code in the regulation of MT functions in axon pathfinding are also reported. Finally, our review highlights the emerging molecular links between these MT regulation processes and guidance signals that wire the nervous system.
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Affiliation(s)
- Melody Atkins
- INSERM, UMR-S 1270, Institut du Fer à Moulin, Sorbonne Université, F-75005 Paris, France
| | - Xavier Nicol
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, F-75012 Paris, France
| | - Coralie Fassier
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, F-75012 Paris, France.
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8
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Birnbaum R, Biswas J, Singer RH, Sharp DJ. mRNA Localization and Local Translation of the Microtubule Severing Enzyme, Fidgetin-Like 2, in Polarization, Migration and Outgrowth. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.17.537087. [PMID: 37131812 PMCID: PMC10153175 DOI: 10.1101/2023.04.17.537087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Cell motility requires strict spatiotemporal control of protein expression. During cell migration, mRNA localization and local translation in subcellular areas like the leading edge and protrusions are particularly advantageous for regulating the reorganization of the cytoskeleton. Fidgetin-Like 2 (FL2), a microtubule severing enzyme (MSE) that restricts migration and outgrowth, localizes to the leading edge of protrusions where it severs dynamic microtubules. FL2 is primarily expressed during development but in adulthood, is spatially upregulated at the leading edge minutes after injury. Here, we show mRNA localization and local translation in protrusions of polarized cells are responsible for FL2 leading edge expression after injury. The data suggests that the RNA binding protein IMP1 is involved in the translational regulation and stabilization of FL2 mRNA, in competition with the miRNA let-7. These data exemplify the role of local translation in microtubule network reorganization during migration and elucidate an unexplored MSE protein localization mechanism.
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Affiliation(s)
- Rayna Birnbaum
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jeetayu Biswas
- Present address: Department of Medicine, Weill Cornell Medicine, New York Presbyterian Hospital, New York, NY 10021, USA
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Robert H. Singer
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - David J. Sharp
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Microcures, Inc., Research and Development, Bronx, NY, 10461, USA
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9
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Akera T. Tubulin post-translational modifications in meiosis. Semin Cell Dev Biol 2023; 137:38-45. [PMID: 34836784 PMCID: PMC9124733 DOI: 10.1016/j.semcdb.2021.11.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 10/22/2021] [Accepted: 11/14/2021] [Indexed: 11/18/2022]
Abstract
Haploid gametes are produced from diploid parents through meiosis, a process inherent to all sexually reproducing eukaryotes. Faithful chromosome segregation in meiosis is essential for reproductive success, although it is less clear how the meiotic spindle achieves this compared to the mitotic spindle. It is becoming increasingly clear that tubulin post-translational modifications (PTMs) play critical roles in regulating microtubule functions in many biological processes, and meiosis is no exception. Here, I review recent advances in the understanding of tubulin PTMs in meiotic spindles, especially focusing on their roles in spindle integrity, oocyte aging, and non-Mendelian transmission.
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Affiliation(s)
- Takashi Akera
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda 20892, MD, USA.
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10
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Song DH, Song CW, Chung J, Jang EH, Kim H, Hur Y, Hur EM, Kim D, Chang JB. In situ silver nanoparticle development for molecular-specific biological imaging via highly accessible microscopies. NANOSCALE ADVANCES 2023; 5:1636-1650. [PMID: 36926569 PMCID: PMC10012848 DOI: 10.1039/d2na00449f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 12/19/2022] [Indexed: 06/18/2023]
Abstract
In biological studies and diagnoses, brightfield (BF), fluorescence, and electron microscopy (EM) are used to image biomolecules inside cells. When compared, their relative advantages and disadvantages are obvious. BF microscopy is the most accessible of the three, but its resolution is limited to a few microns. EM provides a nanoscale resolution, but sample preparation is time-consuming. In this study, we present a new imaging technique, which we termed decoration microscopy (DecoM), and quantitative investigations to address the aforementioned issues in EM and BF microscopy. For molecular-specific EM imaging, DecoM labels proteins inside cells using antibodies bearing 1.4 nm gold nanoparticles (AuNPs) and grows silver layers on the AuNPs' surfaces. The cells are then dried without buffer exchange and imaged using scanning electron microscopy (SEM). Structures labeled with silver-grown AuNPs are clearly visible on SEM, even they are covered with lipid membranes. Using stochastic optical reconstruction microscopy, we show that the drying process causes negligible distortion of structures and that less structural deformation could be achieved through simple buffer exchange to hexamethyldisilazane. Using DecoM, we visualize the nanoscale alterations in microtubules by microtubule-severing proteins that cannot be observed with diffraction-limited fluorescence microscopy. We then combine DecoM with expansion microscopy to enable sub-micron resolution BF microscopy imaging. We first show that silver-grown AuNPs strongly absorb white light, and the structures labeled with them are clearly visible on BF microscopy. We then show that the application of AuNPs and silver development must follow expansion to visualize the labeled proteins clearly with sub-micron resolution.
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Affiliation(s)
- Dae-Hyeon Song
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology Daejeon Korea
| | - Chang Woo Song
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology Daejeon Korea
| | | | - Eun-Hae Jang
- Laboratory of Neuroscience, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University Seoul Korea
| | - Hyunwoo Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology Daejeon Korea
| | - Yongsuk Hur
- BioMedical Research Center, Korea Advanced Institute of Science and Technology Daejeon Korea
| | - Eun-Mi Hur
- Laboratory of Neuroscience, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University Seoul Korea
- BK21 Four Future Veterinary Medicine Leading Education & Research Center, Seoul National University Seoul Korea
| | - Doory Kim
- Department of Chemistry, Hanyang University Seoul Korea
| | - Jae-Byum Chang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology Daejeon Korea
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11
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Zocchi R, Compagnucci C, Bertini E, Sferra A. Deciphering the Tubulin Language: Molecular Determinants and Readout Mechanisms of the Tubulin Code in Neurons. Int J Mol Sci 2023; 24:ijms24032781. [PMID: 36769099 PMCID: PMC9917122 DOI: 10.3390/ijms24032781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/17/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Microtubules (MTs) are dynamic components of the cell cytoskeleton involved in several cellular functions, such as structural support, migration and intracellular trafficking. Despite their high similarity, MTs have functional heterogeneity that is generated by the incorporation into the MT lattice of different tubulin gene products and by their post-translational modifications (PTMs). Such regulations, besides modulating the tubulin composition of MTs, create on their surface a "biochemical code" that is translated, through the action of protein effectors, into specific MT-based functions. This code, known as "tubulin code", plays an important role in neuronal cells, whose highly specialized morphologies and activities depend on the correct functioning of the MT cytoskeleton and on its interplay with a myriad of MT-interacting proteins. In recent years, a growing number of mutations in genes encoding for tubulins, MT-interacting proteins and enzymes that post-translationally modify MTs, which are the main players of the tubulin code, have been linked to neurodegenerative processes or abnormalities in neural migration, differentiation and connectivity. Nevertheless, the exact molecular mechanisms through which the cell writes and, downstream, MT-interacting proteins decipher the tubulin code are still largely uncharted. The purpose of this review is to describe the molecular determinants and the readout mechanisms of the tubulin code, and briefly elucidate how they coordinate MT behavior during critical neuronal events, such as neuron migration, maturation and axonal transport.
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Affiliation(s)
- Riccardo Zocchi
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
| | - Claudia Compagnucci
- Molecular Genetics and Functional Genomics, Bambino Gesù Children’s Research Hospital, IRCCS, 00146 Rome, Italy
| | - Enrico Bertini
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
- Correspondence: (E.B.); or (A.S.); Tel.: +39-06-6859-2104 (E.B. & A.S.)
| | - Antonella Sferra
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
- Correspondence: (E.B.); or (A.S.); Tel.: +39-06-6859-2104 (E.B. & A.S.)
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12
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Pero ME, Chowdhury F, Bartolini F. Role of tubulin post-translational modifications in peripheral neuropathy. Exp Neurol 2023; 360:114274. [PMID: 36379274 DOI: 10.1016/j.expneurol.2022.114274] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/06/2022] [Accepted: 11/08/2022] [Indexed: 11/14/2022]
Abstract
Peripheral neuropathy is a common disorder that results from nerve damage in the periphery. The degeneration of sensory axon terminals leads to changes or loss of sensory functions, often manifesting as debilitating pain, weakness, numbness, tingling, and disability. The pathogenesis of most peripheral neuropathies remains to be fully elucidated. Cumulative evidence from both early and recent studies indicates that tubulin damage may provide a common underlying mechanism of axonal injury in various peripheral neuropathies. In particular, tubulin post-translational modifications have been recently implicated in both toxic and inherited forms of peripheral neuropathy through regulation of axonal transport and mitochondria dynamics. This knowledge forms a new area of investigation with the potential for developing therapeutic strategies to prevent or delay peripheral neuropathy by restoring tubulin homeostasis.
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Affiliation(s)
- Maria Elena Pero
- Department of Pathology and Cell Biology, Columbia University, New York, USA; Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Italy
| | - Farihah Chowdhury
- Department of Pathology and Cell Biology, Columbia University, New York, USA
| | - Francesca Bartolini
- Department of Pathology and Cell Biology, Columbia University, New York, USA.
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13
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Macke AC, Kelly MS, Varikoti RA, Mullen S, Groves D, Forbes C, Dima RI. Microtubule Severing Enzymes Oligomerization and Allostery: A Tale of Two Domains. J Phys Chem B 2022; 126:10569-10586. [PMID: 36475672 DOI: 10.1021/acs.jpcb.2c05288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Severing proteins are nanomachines from the AAA+ (ATPases associated with various cellular activities) superfamily whose function is to remodel the largest cellular filaments, microtubules. The standard AAA+ machines adopt hexameric ring structures for functional reasons, while being primarily monomeric in the absence of the nucleotide. Both major severing proteins, katanin and spastin, are believed to follow this trend. However, studies proposed that they populate lower-order oligomers in the presence of cofactors, which are functionally relevant. Our simulations show that the preferred oligomeric assembly is dependent on the binding partners and on the type of severing protein. Essential dynamics analysis predicts that the stability of an oligomer is dependent on the strength of the interface between the helical bundle domain (HBD) of a monomer and the convex face of the nucleotide binding domain (NBD) of a neighboring monomer. Hot spots analysis found that the region consisting of the HBD tip and the C-terminal (CT) helix is the only common element between the allosteric networks responding to nucleotide, substrate, and intermonomer binding. Clustering analysis indicates the existence of multiple pathways for the transition between the secondary structure of the HBD tip in monomers and the structure(s) it adopts in oligomers.
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Affiliation(s)
- Amanda C Macke
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Maria S Kelly
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Rohith Anand Varikoti
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Sarah Mullen
- Department of Chemistry, The College of Wooster, Wooster, Ohio 44691, United States
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Daniel Groves
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Clare Forbes
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Ruxandra I Dima
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
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14
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Szczesna E, Zehr EA, Cummings SW, Szyk A, Mahalingan KK, Li Y, Roll-Mecak A. Combinatorial and antagonistic effects of tubulin glutamylation and glycylation on katanin microtubule severing. Dev Cell 2022; 57:2497-2513.e6. [PMID: 36347241 PMCID: PMC9665884 DOI: 10.1016/j.devcel.2022.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 08/17/2022] [Accepted: 10/11/2022] [Indexed: 11/09/2022]
Abstract
Microtubules have spatiotemporally complex posttranslational modification patterns. How cells interpret this tubulin modification code is largely unknown. We show that C. elegans katanin, a microtubule severing AAA ATPase mutated in microcephaly and critical for cell division, axonal elongation, and cilia biogenesis, responds precisely, differentially, and combinatorially to three chemically distinct tubulin modifications-glycylation, glutamylation, and tyrosination-but is insensitive to acetylation. Glutamylation and glycylation are antagonistic rheostats with glycylation protecting microtubules from severing. Katanin exhibits graded and divergent responses to glutamylation on the α- and β-tubulin tails, and these act combinatorially. The katanin hexamer central pore constrains the polyglutamate chain patterns on β-tails recognized productively. Elements distal to the katanin AAA core sense α-tubulin tyrosination, and detyrosination downregulates severing. The multivalent microtubule recognition that enables katanin to read multiple tubulin modification inputs explains in vivo observations and illustrates how effectors can integrate tubulin code signals to produce diverse functional outcomes.
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Affiliation(s)
- Ewa Szczesna
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Elena A Zehr
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Steven W Cummings
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Agnieszka Szyk
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Kishore K Mahalingan
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Yan Li
- Proteomic Core Facility, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA; Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, Bethesda, MD 20892, USA.
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15
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Kocaman S, Lo YH, Krahn JM, Sobhany M, Dandey VP, Petrovich ML, Etigunta SK, Williams JG, Deterding LJ, Borgnia MJ, Stanley RE. Communication network within the essential AAA-ATPase Rix7 drives ribosome assembly. PNAS NEXUS 2022; 1:pgac118. [PMID: 36090660 PMCID: PMC9437592 DOI: 10.1093/pnasnexus/pgac118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/08/2022] [Indexed: 02/06/2023]
Abstract
Rix7 is an essential AAA+ ATPase that functions during the early stages of ribosome biogenesis. Rix7 is composed of three domains including an N-terminal domain (NTD) and two AAA+ domains (D1 and D2) that assemble into an asymmetric stacked hexamer. It was recently established that Rix7 is a presumed protein translocase that removes substrates from preribosomes by translocating them through its central pore. However, how the different domains of Rix7 coordinate their activities within the overall hexameric structure was unknown. We captured cryo-electron microscopy (EM) structures of single and double Walker B variants of full length Rix7. The disordered NTD was not visible in the cryo-EM reconstructions, but cross-linking mass spectrometry revealed that the NTD can associate with the central channel in vitro. Deletion of the disordered NTD enabled us to obtain a structure of the Rix7 hexamer to 2.9 Å resolution, providing high resolution details of critical motifs involved in substrate translocation and interdomain communication. This structure coupled with cell-based assays established that the linker connecting the D1 and D2 domains as well as the pore loops lining the central channel are essential for formation of the large ribosomal subunit. Together, our work shows that Rix7 utilizes a complex communication network to drive ribosome biogenesis.
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Affiliation(s)
- Seda Kocaman
- Department of Health and Human Services, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Yu-Hua Lo
- Department of Health and Human Services, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Juno M Krahn
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Mack Sobhany
- Department of Health and Human Services, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Venkata P Dandey
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Matthew L Petrovich
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Suhas K Etigunta
- Department of Health and Human Services, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Jason G Williams
- Department of Health and Human Services, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Leesa J Deterding
- Department of Health and Human Services, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Mario J Borgnia
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Robin E Stanley
- Department of Health and Human Services, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
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16
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Li S, Liang Y, Zou J, Cai Z, Yang H, Yang J, Zhang Y, Lin H, Zhang G, Tan M. SUMOylation of microtubule-cleaving enzyme KATNA1 promotes microtubule severing and neurite outgrowth. J Biol Chem 2022; 298:102292. [PMID: 35868557 PMCID: PMC9403493 DOI: 10.1016/j.jbc.2022.102292] [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: 06/15/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 12/01/2022] Open
Abstract
Katanin p60 ATPase-containing subunit A1 (KATNA1) is a microtubule-cleaving enzyme that regulates the development of neural protrusions through cytoskeletal rearrangements. However, the mechanism underlying the linkage of the small ubiquitin-like modifier (SUMO) protein to KATNA1 and how this modification regulates the development of neural protrusions is unclear. Here we discovered, using mass spectrometry analysis, that SUMO-conjugating enzyme UBC9, an enzyme necessary for the SUMOylation process, was present in the KATNA1 interactome. Moreover, GST-pull down and co-immunoprecipitation assays confirmed that KATNA1 and SUMO interact. We further demonstrated using immunofluorescence experiments that KATNA1 and the SUMO2 isoform colocalized in hippocampal neurites. We also performed a bioinformatics analysis of KATNA1 protein sequences to identify three potentially conserved SUMOylation sites (K77, K157, and K330) among vertebrates. Mutation of K330, but not K77 or K157, abolished KATNA1-induced microtubule severing and decreased the level of binding observed for KATNA1 and SUMO2. Cotransfection of SUMO2 and wildtype KATNA1 in COS7 cells increased microtubule severing, whereas no effect was observed after cotransfection with the K330R KATNA1 mutant. Furthermore, in cultured hippocampal neurons, overexpression of wildtype KATNA1 significantly promoted neurite outgrowth, whereas the K330R mutant eliminated this effect. Taken together, our results demonstrate that the K330 site in KATNA1 is modified by SUMOylation and SUMOylation of KATNA1 promotes microtubule dynamics and hippocampal neurite outgrowth.
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Affiliation(s)
- Shaojin Li
- Department of Orthopaedics, the First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Yaozhong Liang
- Department of Orthopaedics, the First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Jianyu Zou
- Department of Orthopaedics, the First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Zhenbin Cai
- Department of Orthopaedics, the First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Hua Yang
- Department of Orthopaedics, the First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Jie Yang
- Department of Orthopaedics, the First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Yunlong Zhang
- Department of Orthopaedics, the First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Hongsheng Lin
- Department of Orthopaedics, the First Affiliated Hospital of Jinan University, Guangzhou 510630, China.
| | - Guowei Zhang
- Department of Orthopaedics, the First Affiliated Hospital of Jinan University, Guangzhou 510630, China.
| | - Minghui Tan
- Department of Orthopaedics, the First Affiliated Hospital of Jinan University, Guangzhou 510630, China.
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17
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Costa AC, Sousa MM. The Role of Spastin in Axon Biology. Front Cell Dev Biol 2022; 10:934522. [PMID: 35865632 PMCID: PMC9294387 DOI: 10.3389/fcell.2022.934522] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/07/2022] [Indexed: 12/05/2022] Open
Abstract
Neurons are highly polarized cells with elaborate shapes that allow them to perform their function. In neurons, microtubule organization—length, density, and dynamics—are essential for the establishment of polarity, growth, and transport. A mounting body of evidence shows that modulation of the microtubule cytoskeleton by microtubule-associated proteins fine tunes key aspects of neuronal cell biology. In this respect, microtubule severing enzymes—spastin, katanin and fidgetin—a group of microtubule-associated proteins that bind to and generate internal breaks in the microtubule lattice, are emerging as key modulators of the microtubule cytoskeleton in different model systems. In this review, we provide an integrative view on the latest research demonstrating the key role of spastin in neurons, specifically in the context of axonal cell biology. We focus on the function of spastin in the regulation of microtubule organization, and axonal transport, that underlie its importance in the intricate control of axon growth, branching and regeneration.
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Affiliation(s)
- Ana Catarina Costa
- Nerve Regeneration Group, Instituto de Biologia Molecular e Celular (IBMC), Instituto de Investigação e Inovação Em Saúde (i3S), University of Porto, Porto, Portugal
- Graduate Program in Molecular and Cell Biology, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- *Correspondence: Ana Catarina Costa, ; Monica Mendes Sousa,
| | - Monica Mendes Sousa
- Nerve Regeneration Group, Instituto de Biologia Molecular e Celular (IBMC), Instituto de Investigação e Inovação Em Saúde (i3S), University of Porto, Porto, Portugal
- *Correspondence: Ana Catarina Costa, ; Monica Mendes Sousa,
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18
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Wang L, Toutkoushian H, Belyy V, Kokontis CY, Walter P. Conserved structural elements specialize ATAD1 as a membrane protein extraction machine. eLife 2022; 11:e73941. [PMID: 35550246 PMCID: PMC9273213 DOI: 10.7554/elife.73941] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 05/12/2022] [Indexed: 11/13/2022] Open
Abstract
The mitochondrial AAA (ATPase Associated with diverse cellular Activities) protein ATAD1 (in humans; Msp1 in yeast) removes mislocalized membrane proteins, as well as stuck import substrates from the mitochondrial outer membrane, facilitating their re-insertion into their cognate organelles and maintaining mitochondria's protein import capacity. In doing so, it helps to maintain proteostasis in mitochondria. How ATAD1 tackles the energetic challenge to extract hydrophobic membrane proteins from the lipid bilayer and what structural features adapt ATAD1 for its particular function has remained a mystery. Previously, we determined the structure of Msp1 in complex with a peptide substrate (Wang et al., 2020). The structure showed that Msp1's mechanism follows the general principle established for AAA proteins while adopting several structural features that specialize it for its function. Among these features in Msp1 was the utilization of multiple aromatic amino acids to firmly grip the substrate in the central pore. However, it was not clear whether the aromatic nature of these amino acids were required, or if they could be functionally replaced by aliphatic amino acids. In this work, we determined the cryo-EM structures of the human ATAD1 in complex with a peptide substrate at near atomic resolution. The structures show that phylogenetically conserved structural elements adapt ATAD1 for its function while generally adopting a conserved mechanism shared by many AAA proteins. We developed a microscopy-based assay reporting on protein mislocalization, with which we directly assessed ATAD1's activity in live cells and showed that both aromatic amino acids in pore-loop 1 are required for ATAD1's function and cannot be substituted by aliphatic amino acids. A short α-helix at the C-terminus strongly facilitates ATAD1's oligomerization, a structural feature that distinguishes ATAD1 from its closely related proteins.
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Affiliation(s)
- Lan Wang
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
- Howard Hughes Medical Institute, University of California at San FranciscoSan FranciscoUnited States
| | - Hannah Toutkoushian
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
- Howard Hughes Medical Institute, University of California at San FranciscoSan FranciscoUnited States
| | - Vladislav Belyy
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
- Howard Hughes Medical Institute, University of California at San FranciscoSan FranciscoUnited States
| | - Claire Y Kokontis
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
| | - Peter Walter
- Department of Biochemistry and Biophysics, University of California at San FranciscoSan FranciscoUnited States
- Howard Hughes Medical Institute, University of California at San FranciscoSan FranciscoUnited States
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19
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Saunders HAJ, Johnson-Schlitz DM, Jenkins BV, Volkert PJ, Yang SZ, Wildonger J. Acetylated α-tubulin K394 regulates microtubule stability to shape the growth of axon terminals. Curr Biol 2022; 32:614-630.e5. [PMID: 35081332 PMCID: PMC8843987 DOI: 10.1016/j.cub.2021.12.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 10/19/2021] [Accepted: 12/07/2021] [Indexed: 02/09/2023]
Abstract
Microtubules are essential to neuron shape and function. Acetylation of tubulin has the potential to directly tune the behavior and function of microtubules in cells. Although proteomic studies have identified several acetylation sites in α-tubulin, the effects of acetylation at these sites remains largely unknown. This includes the highly conserved residue lysine 394 (K394), which is located at the αβ-tubulin dimer interface. Using a fly model, we show that α-tubulin K394 is acetylated in the nervous system and is an essential residue. We found that an acetylation-blocking mutation in endogenous α-tubulin, K394R, perturbs the synaptic morphogenesis of motoneurons and reduces microtubule stability. Intriguingly, the K394R mutation has opposite effects on the growth of two functionally and morphologically distinct motoneurons, revealing neuron-type-specific responses when microtubule stability is altered. Eliminating the deacetylase HDAC6 increases K394 acetylation, and the over-expression of HDAC6 reduces microtubule stability similar to the K394R mutant. Thus, our findings implicate α-tubulin K394 and its acetylation in the regulation of microtubule stability and suggest that HDAC6 regulates K394 acetylation during synaptic morphogenesis.
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Affiliation(s)
- Harriet A. J. Saunders
- Integrated Program in Biochemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI, 53706, USA,Department of Biochemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI, 53706, USA
| | - Dena M. Johnson-Schlitz
- Department of Biochemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI, 53706, USA
| | - Brian V. Jenkins
- Department of Biochemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI, 53706, USA
| | - Peter J. Volkert
- Department of Biochemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI, 53706, USA,Biochemistry Scholars Program, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI, 53706, USA
| | - Sihui Z. Yang
- Department of Biochemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI, 53706, USA,Cellular & Molecular Biology Graduate Program, University of Wisconsin-Madison, 1525 Linden Drive, Madison, WI, 53706, USA
| | - Jill Wildonger
- Department of Biochemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI, 53706, USA,Current address: Pediatrics Department and Biological Sciences Division, Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA,Lead and author for correspondence:
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20
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Wdr47, Camsaps, and Katanin cooperate to generate ciliary central microtubules. Nat Commun 2021; 12:5796. [PMID: 34608154 PMCID: PMC8490363 DOI: 10.1038/s41467-021-26058-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/10/2021] [Indexed: 02/08/2023] Open
Abstract
The axonemal central pair (CP) are non-centrosomal microtubules critical for planar ciliary beat. How they form, however, is poorly understood. Here, we show that mammalian CP formation requires Wdr47, Camsaps, and microtubule-severing activity of Katanin. Katanin severs peripheral microtubules to produce central microtubule seeds in nascent cilia. Camsaps stabilize minus ends of the seeds to facilitate microtubule outgrowth, whereas Wdr47 concentrates Camsaps into the axonemal central lumen to properly position central microtubules. Wdr47 deficiency in mouse multicilia results in complete loss of CP, rotatory beat, and primary ciliary dyskinesia. Overexpression of Camsaps or their microtubule-binding regions induces central microtubules in Wdr47-/- ependymal cells but at the expense of low efficiency, abnormal numbers, and wrong location. Katanin levels and activity also impact the central microtubule number. We propose that Wdr47, Camsaps, and Katanin function together for the generation of non-centrosomal microtubule arrays in polarized subcellular compartments.
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21
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Jang EH, Bae YH, Yang EM, Gim Y, Suh HJ, Kim S, Park SM, Park JB, Hur EM. Comparing axon regeneration in male and female mice after peripheral nerve injury. J Neurosci Res 2021; 99:2874-2887. [PMID: 34510521 DOI: 10.1002/jnr.24955] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/07/2021] [Accepted: 08/17/2021] [Indexed: 02/06/2023]
Abstract
Axons in the adult mammalian central nervous system fail to regenerate after injury. By contrast, spontaneous axon regeneration occurs in the peripheral nervous system (PNS) due to a supportive PNS environment and an increase in the intrinsic growth potential induced by injury via cooperative activation of multifaceted biological pathways. This study compared axon regeneration and injury responses in C57BL/6 male and female mice after sciatic nerve crush (SNC) injury. The extent of axon regeneration in vivo was indistinguishable in male and female mice when observed at 3 days after SNC injury, and primary dorsal root ganglion (DRG) neurons from injured, male and female mice extended axons to a similar length. Moreover, the induction of selected regeneration-associated genes (RAGs), such as Atf3, Sprr1a, Gap43, Sox11, Jun, Gadd45a, and Smad1 were comparable in male and female DRGs when assessed by quantitative real-time reverse transcription polymerase chain reaction. Furthermore, the RNA-seq analysis of male and female DRGs revealed that differentially expressed genes (DEGs) in SNC groups compared to sham-operated groups included many common genes associated with neurite outgrowth. However, we also found that a large number of genes in the DEGs were sex dependent, implicating the involvement of distinct gene regulatory network in the two sexes following peripheral nerve injury. In conclusion, we found that male and female mice mounted a comparable axon regeneration response and many RAGs were commonly induced in response to SNC. However, given that many DEGs were sex-dependently expressed, future studies are needed to investigate whether they contribute to peripheral axon regeneration, and if so, to what extent.
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Affiliation(s)
- Eun-Hae Jang
- Laboratory of Neuroscience, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Yun-Hee Bae
- Laboratory of Neuroscience, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Eun Mo Yang
- Laboratory of Neuroscience, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, South Korea.,BK21 Four Future Veterinary Medicine Leading Education & Research Center, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Yunho Gim
- Laboratory of Neuroscience, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Hyun-Jun Suh
- Laboratory of Neuroscience, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Subin Kim
- Laboratory of Neuroscience, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Seong-Min Park
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Republic of Korea
| | - Jong Bae Park
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Republic of Korea.,Rare Cancer Branch, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea
| | - Eun-Mi Hur
- Laboratory of Neuroscience, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, South Korea.,BK21 Four Future Veterinary Medicine Leading Education & Research Center, College of Veterinary Medicine, Seoul National University, Seoul, South Korea.,Interdisciplinary Program in Neuroscience, College of Natural Sciences, Seoul National University, Seoul, South Korea
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22
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Post-translational modifications and stabilization of microtubules regulate transport of viral factors during infections. Biochem Soc Trans 2021; 49:1735-1748. [PMID: 34436545 DOI: 10.1042/bst20210017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/05/2021] [Accepted: 08/10/2021] [Indexed: 11/17/2022]
Abstract
Tubulin post-translational modifications (PTMs) constitute a source of diversity for microtubule (MT) functions, in addition to the different isotypes of α and β-tubulin acting as building blocks of MTs. Also, MT-associated proteins (MAPs) confer different characteristics to MTs. The combination of all these factors regulates the stability of these structures that act as rails to transport organelles within the cell, facilitating the association of motor complexes. All these functions are involved in crucial cellular processes in most cell types, ranging from spindle formation in mitosis to the defense against incoming cellular threats during phagocytosis mediated by immune cells. The regulation of MT dynamics through tubulin PTMs has evolved to depend on many different factors that act in a complex orchestrated manner. These tightly regulated processes are particularly relevant during the induction of effective immune responses against pathogens. Viruses have proved not only to hijack MTs and MAPs in order to favor an efficient infection, but also to induce certain PTMs that improve their cellular spread and lead to secondary consequences of viral processes. In this review, we offer a perspective on relevant MT-related elements exploited by viruses.
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23
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Lynn NA, Martinez E, Nguyen H, Torres JZ. The Mammalian Family of Katanin Microtubule-Severing Enzymes. Front Cell Dev Biol 2021; 9:692040. [PMID: 34414183 PMCID: PMC8369831 DOI: 10.3389/fcell.2021.692040] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/04/2021] [Indexed: 12/12/2022] Open
Abstract
The katanin family of microtubule-severing enzymes is critical for cytoskeletal rearrangements that affect key cellular processes like division, migration, signaling, and homeostasis. In humans, aberrant expression, or dysfunction of the katanins, is linked to developmental, proliferative, and neurodegenerative disorders. Here, we review current knowledge on the mammalian family of katanins, including an overview of evolutionary conservation, functional domain organization, and the mechanisms that regulate katanin activity. We assess the function of katanins in dividing and non-dividing cells and how their dysregulation promotes impaired ciliary signaling and defects in developmental programs (corticogenesis, gametogenesis, and neurodevelopment) and contributes to neurodegeneration and cancer. We conclude with perspectives on future katanin research that will advance our understanding of this exciting and dynamic class of disease-associated enzymes.
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Affiliation(s)
- Nicole A. Lynn
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, United States
| | - Emily Martinez
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, United States
| | - Hieu Nguyen
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, United States
| | - Jorge Z. Torres
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, United States
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA, United States
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24
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Wang H, Sun J, Yang F, Weng Y, Chen P, Du S, Wei A, Li Y. CsKTN1 for a katanin p60 subunit is associated with the regulation of fruit elongation in cucumber (Cucumis sativus L.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2021; 134:2429-2441. [PMID: 34043036 DOI: 10.1007/s00122-021-03833-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/03/2021] [Indexed: 06/12/2023]
Abstract
We identified a short fruit3 (sf3) mutant in cucumber. Map-based cloning revealed that CsKTN1 gene encodes a katanin p60 subunit, which is associated with the regulation of fruit elongation. Fruit length is an important horticultural trait for both fruit yield and quality of cucumber (Cucumis sativus L.). Knowledge on the molecular regulation of fruit elongation in cucumber is very limited. In this study, we identified and characterized a cucumber short fruit3 (sf3) mutant. Histological examination indicated that the shorter fruit in the mutant was due to reduced cell numbers. Genetic analysis revealed that the phenotype of the sf3 mutant was controlled by a single gene with semi-dominant inheritance. By map-based cloning and Arabidopsis genetic transformation, we showed that Sf3 was a homolog of KTN1 (CsKTN1) encoding a katanin p60 subunit. A non-synonymous mutation in the fifth exon of CsKTN1 resulted in an amino acid substitution from Serine in the wild type to Phenylalanine in the sf3 mutant. CsKTN1 expressed in all tissues of both the wild type and the sf3 mutant. However, there was no significant difference in CsKTN1 expression levels between the wild type and the sf3 mutant. The hormone quantitation and RNA-seq analysis suggested that auxin and gibberellin contents are decreased in sf3 by changing the expression levels of genes related with auxin and gibberellin metabolism and signaling. This work helps understand the function of the katanin and the molecular mechanisms of fruit growth regulation in cucumber.
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Affiliation(s)
- Hui Wang
- College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jing Sun
- College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Fan Yang
- College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yiqun Weng
- Horticulture Department, USDA-ARS Vegetable Crops Research Unit, University of Wisconsin, Madison, WI, 53706, USA
| | - Peng Chen
- College of Life Science, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Shengli Du
- Tianjin Vegetable Research Center, Tianjin, 300192, China
- National Key Laboratory of Vegetable Germplasm Innovation, Tianjin, 300192, China
| | - Aimin Wei
- Tianjin Vegetable Research Center, Tianjin, 300192, China.
- National Key Laboratory of Vegetable Germplasm Innovation, Tianjin, 300192, China.
| | - Yuhong Li
- College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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25
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MacTaggart B, Kashina A. Posttranslational modifications of the cytoskeleton. Cytoskeleton (Hoboken) 2021; 78:142-173. [PMID: 34152688 DOI: 10.1002/cm.21679] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 06/13/2021] [Accepted: 06/16/2021] [Indexed: 12/12/2022]
Abstract
The cytoskeleton plays important roles in many essential processes at the cellular and organismal levels, including cell migration and motility, cell division, and the establishment and maintenance of cell and tissue architecture. In order to facilitate these varied functions, the main cytoskeletal components-microtubules, actin filaments, and intermediate filaments-must form highly diverse intracellular arrays in different subcellular areas and cell types. The question of how this diversity is conferred has been the focus of research for decades. One key mechanism is the addition of posttranslational modifications (PTMs) to the major cytoskeletal proteins. This posttranslational addition of various chemical groups dramatically increases the complexity of the cytoskeletal proteome and helps facilitate major global and local cytoskeletal functions. Cytoskeletal proteins undergo many PTMs, most of which are not well understood. Recent technological advances in proteomics and cell biology have allowed for the in-depth study of individual PTMs and their functions in the cytoskeleton. Here, we provide an overview of the major PTMs that occur on the main structural components of the three cytoskeletal systems-tubulin, actin, and intermediate filament proteins-and highlight the cellular function of these modifications.
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Affiliation(s)
- Brittany MacTaggart
- School of Veterinary Medicine, Department of Biomedical Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anna Kashina
- School of Veterinary Medicine, Department of Biomedical Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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26
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Huang J, Liang Z, Guan C, Hua S, Jiang K. WDR62 regulates spindle dynamics as an adaptor protein between TPX2/Aurora A and katanin. J Cell Biol 2021; 220:212395. [PMID: 34137789 PMCID: PMC8240853 DOI: 10.1083/jcb.202007167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 04/12/2021] [Accepted: 05/18/2021] [Indexed: 12/21/2022] Open
Abstract
WDR62 is a microcephaly-related, microtubule (MT)-associated protein (MAP) that localizes to the spindle pole and regulates spindle organization, but the underlying mechanisms remain elusive. Here, we show that WDR62 regulates spindle dynamics by recruiting katanin to the spindle pole and further reveal a TPX2–Aurora A–WDR62–katanin axis in cells. By combining cellular and in vitro experiments, we demonstrate that WDR62 shows preference for curved segments of dynamic GDP-MTs, as well as GMPCPP- and paclitaxel-stabilized MTs, suggesting that it recognizes extended MT lattice. Consistent with this property, WDR62 alone is inefficient in recruiting katanin to GDP-MTs, while WDR62 complexed with TPX2/Aurora A can potently promote katanin-mediated severing of GDP-MTs in vitro. In addition, the MT-binding affinity of WDR62 is autoinhibited through JNK phosphorylation-induced intramolecular interaction. We propose that WDR62 is an atypical MAP and functions as an adaptor protein between its recruiting factor TPX2/Aurora A and the effector katanin to orchestrate the regulation of spindle dynamics.
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Affiliation(s)
- Junjie Huang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Zhuobi Liang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Cuirong Guan
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Shasha Hua
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Kai Jiang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
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27
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Bigman LS, Levy Y. Modulating Microtubules: A Molecular Perspective on the Effects of Tail Modifications. J Mol Biol 2021; 433:166988. [PMID: 33865866 DOI: 10.1016/j.jmb.2021.166988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 10/21/2022]
Abstract
Microtubules (MTs), an essential component of the eukaryotic cytoskeleton, are a lattice of polymerized tubulin dimers and are crucial for various cellular processes. The genetic and chemical diversity of tubulin and their disordered tails gives rise to a "tubulin code". The functional role of tubulin post-translational modifications (PTMs), which contribute to the chemical diversity of the tubulin code, is gradually being unraveled. However, variation in the length and spatial organization of tubulin poly-modifications leads to an enormous combinatorial PTM space, which is difficult to study experimentally. Hence, the impact of the combinatorial tubulin PTM space on the biophysical properties of tubulin tails and their interactions with other proteins remains elusive. Here, we combine all-atom and coarse-grained molecular dynamics simulations to elucidate the biophysical implications of the large combinatorial tubulin PTM space in the context of an MT lattice. We find that tail-body interactions are more dominant in the tubulin dimer than in an MT lattice, and are more significant for the tails of α compared with β tubulin. In addition, polyglutamylation, but not polyglycylation, expands the dimensions of the tubulin tails. Polyglutamylation also leads to a decrease in the diffusion rate of MT-associated protein EB1 on MTs, while polyglycylation often increases diffusion rate. These observations are generally not sensitive to the organization of the polymodifications. The effect of PTMs on MT charge density and tail dynamics are also discussed. Overall, this study presents a molecular quantification of the biophysical properties of tubulin tails and their polymodifications, and provides predictions on the functional importance of tubulin PTMs.
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Affiliation(s)
- Lavi S Bigman
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yaakov Levy
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel.
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28
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Bodakuntla S, Janke C, Magiera MM. Tubulin polyglutamylation, a regulator of microtubule functions, can cause neurodegeneration. Neurosci Lett 2021; 746:135656. [PMID: 33482309 DOI: 10.1016/j.neulet.2021.135656] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 02/07/2023]
Abstract
Neurodegenerative diseases lead to a progressive demise of neuronal functions that ultimately results in neuronal death. Besides a large variety of molecular pathways that have been linked to the degeneration of neurons, dysfunctions of the microtubule cytoskeleton are common features of many human neurodegenerative disorders. Yet, it is unclear whether microtubule dysfunctions are causative, or mere bystanders in the disease progression. A so-far little explored regulatory mechanism of the microtubule cytoskeleton, the posttranslational modifications of tubulin, emerge as candidate mechanisms involved in neuronal dysfunction, and thus, degeneration. Here we review the role of tubulin polyglutamylation, a prominent modification of neuronal microtubules. We discuss the current understanding of how polyglutamylation controls microtubule functions in healthy neurons, and how deregulation of this modification leads to neurodegeneration in mice and humans.
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Affiliation(s)
- Satish Bodakuntla
- Institut Curie, PSL Research University, CNRS UMR3348, F-91401 Orsay, France; Université Paris-Saclay, CNRS UMR3348, F-91401 Orsay, France
| | - Carsten Janke
- Institut Curie, PSL Research University, CNRS UMR3348, F-91401 Orsay, France; Université Paris-Saclay, CNRS UMR3348, F-91401 Orsay, France.
| | - Maria M Magiera
- Institut Curie, PSL Research University, CNRS UMR3348, F-91401 Orsay, France; Université Paris-Saclay, CNRS UMR3348, F-91401 Orsay, France.
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29
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Wall KP, Hart H, Lee T, Page C, Hawkins TL, Hough LE. C-Terminal Tail Polyglycylation and Polyglutamylation Alter Microtubule Mechanical Properties. Biophys J 2020; 119:2219-2230. [PMID: 33137305 DOI: 10.1016/j.bpj.2020.09.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 09/20/2020] [Accepted: 09/25/2020] [Indexed: 11/13/2022] Open
Abstract
Microtubules are biopolymers that perform diverse cellular functions. Microtubule behavior regulation occurs in part through post-translational modification of both the α- and β-subunits of tubulin. One class of modifications is the heterogeneous addition of glycine and/or glutamate residues to the disordered C-terminal tails (CTTs) of tubulin. Because of their prevalence in stable, high-stress cellular structures such as cilia, we sought to determine if these modifications alter microtubules' intrinsic stiffness. Here, we describe the purification and characterization of differentially modified pools of tubulin from Tetrahymena thermophila. We found that post-translational modifications do affect microtubule stiffness but do not affect the number of protofilaments incorporated into microtubules. We measured the spin dynamics of nuclei in the CTT backbone by NMR spectroscopy to explore the mechanism of this change. Our results show that the α-tubulin CTT does not protrude out from the microtubule surface, as is commonly depicted in models, but instead interacts with the dimer's surface. This suggests that the interactions of the α-tubulin CTT with the tubulin body contributes to the stiffness of the assembled microtubule, thus providing insight into the mechanism by which polyglycylation and polyglutamylation can alter microtubule mechanical properties.
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Affiliation(s)
- Kathryn P Wall
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado; BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado
| | - Harold Hart
- Physics Department, University of Wisconsin La Crosse, La Crosse, Wisconsin
| | - Thomas Lee
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado
| | - Cynthia Page
- Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, Colorado
| | - Taviare L Hawkins
- Physics Department, University of Wisconsin La Crosse, La Crosse, Wisconsin
| | - Loren E Hough
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado; Department of Physics, University of Colorado Boulder, Boulder, Colorado.
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30
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Lopes D, Maiato H. The Tubulin Code in Mitosis and Cancer. Cells 2020; 9:cells9112356. [PMID: 33114575 PMCID: PMC7692294 DOI: 10.3390/cells9112356] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/20/2020] [Accepted: 10/24/2020] [Indexed: 12/23/2022] Open
Abstract
The “tubulin code” combines different α/β-tubulin isotypes with several post-translational modifications (PTMs) to generate microtubule diversity in cells. During cell division, specific microtubule populations in the mitotic spindle are differentially modified, but only recently, the functional significance of the tubulin code, with particular emphasis on the role specified by tubulin PTMs, started to be elucidated. This is the case of α-tubulin detyrosination, which was shown to guide chromosomes during congression to the metaphase plate and allow the discrimination of mitotic errors, whose correction is required to prevent chromosomal instability—a hallmark of human cancers implicated in tumor evolution and metastasis. Although alterations in the expression of certain tubulin isotypes and associated PTMs have been reported in human cancers, it remains unclear whether and how the tubulin code has any functional implications for cancer cell properties. Here, we review the role of the tubulin code in chromosome segregation during mitosis and how it impacts cancer cell properties. In this context, we discuss the existence of an emerging “cancer tubulin code” and the respective implications for diagnostic, prognostic and therapeutic purposes.
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Affiliation(s)
- Danilo Lopes
- Chromosome Instability & Dynamics Group, i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal;
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Helder Maiato
- Chromosome Instability & Dynamics Group, i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal;
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
- Cell Division Group, Experimental Biology Unit, Department of Biomedicine, Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
- Correspondence: ; Tel.: +351-22-040-8800
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31
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Microtubule Organization in Striated Muscle Cells. Cells 2020; 9:cells9061395. [PMID: 32503326 PMCID: PMC7349303 DOI: 10.3390/cells9061395] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/25/2020] [Accepted: 05/28/2020] [Indexed: 12/13/2022] Open
Abstract
Distinctly organized microtubule networks contribute to the function of differentiated cell types such as neurons, epithelial cells, skeletal myotubes, and cardiomyocytes. In striated (i.e., skeletal and cardiac) muscle cells, the nuclear envelope acts as the dominant microtubule-organizing center (MTOC) and the function of the centrosome—the canonical MTOC of mammalian cells—is attenuated, a common feature of differentiated cell types. We summarize the mechanisms known to underlie MTOC formation at the nuclear envelope, discuss the significance of the nuclear envelope MTOC for muscle function and cell cycle progression, and outline potential mechanisms of centrosome attenuation.
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32
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The tubulin code and its role in controlling microtubule properties and functions. Nat Rev Mol Cell Biol 2020; 21:307-326. [PMID: 32107477 DOI: 10.1038/s41580-020-0214-3] [Citation(s) in RCA: 384] [Impact Index Per Article: 96.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2020] [Indexed: 02/07/2023]
Abstract
Microtubules are core components of the eukaryotic cytoskeleton with essential roles in cell division, shaping, motility and intracellular transport. Despite their functional heterogeneity, microtubules have a highly conserved structure made from almost identical molecular building blocks: the tubulin proteins. Alternative tubulin isotypes and a variety of post-translational modifications control the properties and functions of the microtubule cytoskeleton, a concept known as the 'tubulin code'. Here we review the current understanding of the molecular components of the tubulin code and how they impact microtubule properties and functions. We discuss how tubulin isotypes and post-translational modifications control microtubule behaviour at the molecular level and how this translates into physiological functions at the cellular and organism levels. We then go on to show how fine-tuning of microtubule function by some tubulin modifications can affect homeostasis and how perturbation of this fine-tuning can lead to a range of dysfunctions, many of which are linked to human disease.
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33
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Wang L, Myasnikov A, Pan X, Walter P. Structure of the AAA protein Msp1 reveals mechanism of mislocalized membrane protein extraction. eLife 2020; 9:e54031. [PMID: 31999255 PMCID: PMC7018516 DOI: 10.7554/elife.54031] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 01/29/2020] [Indexed: 01/03/2023] Open
Abstract
The AAA protein Msp1 extracts mislocalized tail-anchored membrane proteins and targets them for degradation, thus maintaining proper cell organization. How Msp1 selects its substrates and firmly engages them during the energetically unfavorable extraction process remains a mystery. To address this question, we solved cryo-EM structures of Msp1-substrate complexes at near-atomic resolution. Akin to other AAA proteins, Msp1 forms hexameric spirals that translocate substrates through a central pore. A singular hydrophobic substrate recruitment site is exposed at the spiral's seam, which we propose positions the substrate for entry into the pore. There, a tight web of aromatic amino acids grips the substrate in a sequence-promiscuous, hydrophobic milieu. Elements at the intersubunit interfaces coordinate ATP hydrolysis with the subunits' positions in the spiral. We present a comprehensive model of Msp1's mechanism, which follows general architectural principles established for other AAA proteins yet specializes Msp1 for its unique role in membrane protein extraction.
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Affiliation(s)
- Lan Wang
- Howard Hughes Medical InstituteChevy Chase, MarylandUnited States
- Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
| | - Alexander Myasnikov
- Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
- Centre for Integrative Biology, Department of Integrated Structural Biology, IGBMC, CNRS, Inserm, Université de StrasbourgIllkirchFrance
| | - Xingjie Pan
- UCSF/UCB Graduate Program in Bioengineering, University of California, San FranciscoSan FranciscoUnited States
| | - Peter Walter
- Howard Hughes Medical InstituteChevy Chase, MarylandUnited States
- Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
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34
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Zehr EA, Szyk A, Szczesna E, Roll-Mecak A. Katanin Grips the β-Tubulin Tail through an Electropositive Double Spiral to Sever Microtubules. Dev Cell 2020; 52:118-131.e6. [PMID: 31735665 PMCID: PMC7060837 DOI: 10.1016/j.devcel.2019.10.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 09/11/2019] [Accepted: 10/14/2019] [Indexed: 11/16/2022]
Abstract
The AAA ATPase katanin severs microtubules. It is critical in cell division, centriole biogenesis, and neuronal morphogenesis. Its mutation causes microcephaly. The microtubule templates katanin hexamerization and activates its ATPase. The structural basis for these activities and how they lead to severing is unknown. Here, we show that β-tubulin tails are necessary and sufficient for severing. Cryoelectron microscopy (cryo-EM) structures reveal the essential tubulin tail glutamates gripped by a double spiral of electropositive loops lining the katanin central pore. Each spiral couples allosterically to the ATPase and binds alternating, successive substrate residues, with consecutive residues coordinated by adjacent protomers. This tightly couples tail binding, hexamerization, and ATPase activation. Hexamer structures in different states suggest an ATPase-driven, ratchet-like translocation of the tubulin tail through the pore. A disordered region outside the AAA core anchors katanin to the microtubule while the AAA motor exerts the forces that extract tubulin dimers and sever the microtubule.
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Affiliation(s)
- Elena A Zehr
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20982, USA
| | - Agnieszka Szyk
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20982, USA
| | - Ewa Szczesna
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20982, USA
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20982, USA; Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, Bethesda, MD 20892, USA.
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35
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Hahn I, Voelzmann A, Liew YT, Costa-Gomes B, Prokop A. The model of local axon homeostasis - explaining the role and regulation of microtubule bundles in axon maintenance and pathology. Neural Dev 2019; 14:11. [PMID: 31706327 PMCID: PMC6842214 DOI: 10.1186/s13064-019-0134-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 10/02/2019] [Indexed: 12/20/2022] Open
Abstract
Axons are the slender, cable-like, up to meter-long projections of neurons that electrically wire our brains and bodies. In spite of their challenging morphology, they usually need to be maintained for an organism's lifetime. This makes them key lesion sites in pathological processes of ageing, injury and neurodegeneration. The morphology and physiology of axons crucially depends on the parallel bundles of microtubules (MTs), running all along to serve as their structural backbones and highways for life-sustaining cargo transport and organelle dynamics. Understanding how these bundles are formed and then maintained will provide important explanations for axon biology and pathology. Currently, much is known about MTs and the proteins that bind and regulate them, but very little about how these factors functionally integrate to regulate axon biology. As an attempt to bridge between molecular mechanisms and their cellular relevance, we explain here the model of local axon homeostasis, based on our own experiments in Drosophila and published data primarily from vertebrates/mammals as well as C. elegans. The model proposes that (1) the physical forces imposed by motor protein-driven transport and dynamics in the confined axonal space, are a life-sustaining necessity, but pose a strong bias for MT bundles to become disorganised. (2) To counterbalance this risk, MT-binding and -regulating proteins of different classes work together to maintain and protect MT bundles as necessary transport highways. Loss of balance between these two fundamental processes can explain the development of axonopathies, in particular those linking to MT-regulating proteins, motors and transport defects. With this perspective in mind, we hope that more researchers incorporate MTs into their work, thus enhancing our chances of deciphering the complex regulatory networks that underpin axon biology and pathology.
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Affiliation(s)
- Ines Hahn
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, The University of Manchester, School of Biology, Manchester, UK
| | - André Voelzmann
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, The University of Manchester, School of Biology, Manchester, UK
| | - Yu-Ting Liew
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, The University of Manchester, School of Biology, Manchester, UK
| | - Beatriz Costa-Gomes
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, The University of Manchester, School of Biology, Manchester, UK
| | - Andreas Prokop
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, The University of Manchester, School of Biology, Manchester, UK.
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Faltova L, Jiang K, Frey D, Wu Y, Capitani G, Prota AE, Akhmanova A, Steinmetz MO, Kammerer RA. Crystal Structure of a Heterotetrameric Katanin p60:p80 Complex. Structure 2019; 27:1375-1383.e3. [PMID: 31353241 DOI: 10.1016/j.str.2019.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 05/27/2019] [Accepted: 07/05/2019] [Indexed: 10/26/2022]
Abstract
Katanin is a microtubule-severing enzyme that is crucial for many cellular processes. Katanin consists of two subunits, p60 and p80, that form a stable complex. The interaction between subunits is mediated by the p60 N-terminal microtubule-interacting and -trafficking domain (p60-MIT) and the p80 C-terminal domain (p80-CTD). Here, we performed a biophysical characterization of the mouse p60-MIT:p80-CTD heterodimer and show that this complex can assemble into heterotetramers. We identified two mutations that enhance heterotetramer formation and determined the X-ray crystal structure of this mutant complex. The structure revealed a domain-swapped heterotetramer consisting of two p60-MIT:p80-CTD heterodimers. Structure-based sequence alignments suggest that heterotetramerization of katanin might be a common feature of various species. Furthermore, we show that enhanced heterotetramerization of katanin impairs its microtubule end-binding properties and increases the enzyme's microtubule lattice binding and severing activities. Therefore, our findings suggest the existence of different katanin oligomers that possess distinct functional properties.
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Affiliation(s)
- Lenka Faltova
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Kai Jiang
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands; The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan 430071, China; Medical Research Institute, Wuhan University, Wuhan 430071, China
| | - Daniel Frey
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Yufan Wu
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Guido Capitani
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Andrea E Prota
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - 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, 5232 Villigen PSI, Switzerland; Biozentrum, University of Basel, 4056 Basel, Switzerland.
| | - Richard A Kammerer
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.
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Leung JC, Cassimeris L. Reorganization of paclitaxel-stabilized microtubule arrays at mitotic entry: roles of depolymerizing kinesins and severing proteins. Cancer Biol Ther 2019; 20:1337-1347. [PMID: 31345098 PMCID: PMC6783116 DOI: 10.1080/15384047.2019.1638678] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Paclitaxel is a widely used anti-cancer treatment that disrupts cell cycle progression by blocking cells in mitosis. The block at mitosis, with spindles assembled from short microtubules, is surprising given paclitaxel’s microtubule stabilizing activity and the need to depolymerize long interphase microtubules prior to spindle formation. Cells must antagonize paclitaxel’s microtubule stabilizing activity during a brief window of time at the transition from interphase to mitosis, allowing microtubule reorganization into a mitotic spindle, although the mechanism underlying microtubule depolymerization in the presence of paclitaxel has not been examined. Here we test the hypothesis that microtubule severing and/or depolymerizing proteins active at mitotic entry are necessary to clear the interphase array in paclitaxel-treated cells and allow subsequent formation of mitotic spindles formed of short microtubules. A549 and LLC-PK1 cells treated with 30nM paclitaxel approximately 4 h prior to mitotic entry successfully progress through the G2/M transition by clearing the interphase microtubule array from the cell interior outward to the cell periphery, a spatial pattern of reorganization that differs from that of cells possessing dynamic microtubules. Depletion of kinesin-8s, KIF18A and/or KIF18B obstructed interphase microtubule clearing at mitotic entry in paclitaxel-treated cells, with KIF18B making the larger contribution. Of the severing proteins, depletion of spastin, but not katanin, reduced microtubule loss as cells entered mitosis in the presence of paclitaxel. These results support a model in which KIF18A, KIF18B, and spastin promote interphase microtubule array disassembly at mitotic entry and can overcome paclitaxel-induced microtubule stability specifically at the G2/M transition.
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Affiliation(s)
- Jessica C Leung
- Department of Biological Sciences, 111 Research Dr. Lehigh University , Bethlehem , PA , USA
| | - Lynne Cassimeris
- Department of Biological Sciences, 111 Research Dr. Lehigh University , Bethlehem , PA , USA
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