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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Li J, Wu F, Cheng L, Zhang J, Cha C, Chen L, Feng T, Zhang J, Guo G. A nuclear localization signal is required for the nuclear translocation of Fign and its microtubule‑severing function. Mol Med Rep 2020; 21:2367-2374. [PMID: 32236575 PMCID: PMC7185285 DOI: 10.3892/mmr.2020.11040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 03/04/2020] [Indexed: 01/21/2023] Open
Abstract
It is commonly known that the specific function of a given ATPase associated with diverse cellular activities protein (i.e., a member of the AAA superfamily of proteins) depends primarily on its subcellular location. The microtubule-severing protein fidgetin (Fign) possesses a nuclear localization signal (NLS) that facilitates its translocation to the nucleus, where its assembly is finalized; here, Fign contributes to the regulation of microtubule configuration by cutting and trimming microtubule polymers. In the present study, Fign was found to be a nuclear protein, whose N-terminal sequence (SSLKRKAFYM; residues 314–323) acts as an NLS. Following substitution (KR to NN; 317–318) or deletion (NT; 314–323) mutations within the NLS, Fign, which is predominantly expressed in the nucleus, was found to reside in the cytoplasm of transfected cells. Furthermore, Fign was found to have an essential role in microtubule severing by preferentially targeting highly-tyrosinated microtubules (tyr-MTs). Mutation of the Fign NLS did not affect its microtubule-severing function or the cleavage of tyr-MTs, but did affect the cellular distribution of the Fign protein itself. Taken altogether, an NLS for Fign was identified, and it was demonstrated that the basic amino acids K317 and R318 are necessary for regulating its entry into the nucleus, whereas an increase in Fign in the cytosol due to mutations of the NLS did not affect its cleavage function.
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Affiliation(s)
- Jiong Li
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Fengming Wu
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Longfei Cheng
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Jiaqi Zhang
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Caihui Cha
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Li Chen
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Taoshan Feng
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Jifeng Zhang
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Guoqing Guo
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, Guangdong 510632, P.R. China
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Belonogov L, Bailey ME, Tyler MA, Kazemi A, Ross JL. Katanin catalyzes microtubule depolymerization independently of tubulin C-terminal tails. Cytoskeleton (Hoboken) 2019; 76:254-268. [PMID: 30980604 PMCID: PMC6618852 DOI: 10.1002/cm.21522] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 04/10/2019] [Indexed: 02/03/2023]
Abstract
Microtubule network remodeling is an essential process for cell development, maintenance, cell division, and motility. Microtubule‐severing enzymes are key players in the remodeling of the microtubule network; however, there are still open questions about their fundamental biochemical and biophysical mechanisms. Here, we explored the ability of the microtubule‐severing enzyme katanin to depolymerize stabilized microtubules. Interestingly, we found that the tubulin C‐terminal tail (CTT), which is required for severing, is not required for katanin‐catalyzed depolymerization. We also found that the depolymerization of microtubules lacking the CTT does not require ATP or katanin's ATPase activity, although the ATP turnover enhanced depolymerization. We also observed that the depolymerization rate depended on the katanin concentration and was best described by a hyperbolic function. Finally, we demonstrate that katanin can bind to filaments that lack the CTT, contrary to previous reports. The results of our work indicate that microtubule depolymerization likely involves a mechanism in which binding, but not enzymatic activity, is required for tubulin dimer removal from the filament ends.
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Affiliation(s)
- Liudmila Belonogov
- Department of Physics, University of Massachusetts, Amherst, Massachusetts
| | - Megan E Bailey
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts
| | - Madison A Tyler
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts
| | - Arianna Kazemi
- Department of Physics, University of Massachusetts, Amherst, Massachusetts
| | - Jennifer L Ross
- Department of Physics, University of Massachusetts, Amherst, Massachusetts.,Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts
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Matamoros AJ, Tom VJ, Wu D, Rao Y, Sharp DJ, Baas PW. Knockdown of Fidgetin Improves Regeneration of Injured Axons by a Microtubule-Based Mechanism. J Neurosci 2019; 39:2011-24. [PMID: 30647150 DOI: 10.1523/JNEUROSCI.1888-18.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/21/2018] [Accepted: 12/24/2018] [Indexed: 12/16/2022] Open
Abstract
Fidgetin is a microtubule-severing protein that pares back the labile domains of microtubules in the axon. Experimental depletion of fidgetin results in elongation of the labile domains of microtubules and faster axonal growth. To test whether fidgetin knockdown assists axonal regeneration, we plated dissociated adult rat DRGs transduced using AAV5-shRNA-fidgetin on a laminin substrate with spots of aggrecan, a growth-inhibitory chondroitin sulfate proteoglycan. This cell culture assay mimics the glial scar formed after CNS injury. Aggrecan is more concentrated at the edge of the spot, such that axons growing from within the spot toward the edge encounter a concentration gradient that causes growth cones to become dystrophic and axons to retract or curve back on themselves. Fidgetin knockdown resulted in faster-growing axons on both laminin and aggrecan and enhanced crossing of axons from laminin onto aggrecan. Strikingly, axons from within the spot grew more avidly against the inhibitory aggrecan concentration gradient to cross onto laminin, without retracting or curving back. We also tested whether depleting fidgetin improves axonal regeneration in vivo after a dorsal root crush in adult female rats. Whereas control DRG neurons failed to extend axons across the dorsal root entry zone after injury, DRG neurons in which fidgetin was knocked down displayed enhanced regeneration of axons across the dorsal root entry zone into the spinal cord. Collectively, these results establish fidgetin as a novel therapeutic target to augment nerve regeneration and provide a workflow template by which microtubule-related targets can be compared in the future.SIGNIFICANCE STATEMENT Here we establish a workflow template from cell culture to animals in which microtubule-based treatments can be tested and compared with one another for their effectiveness in augmenting regeneration of injured axons relevant to spinal cord injury. The present work uses a viral transduction approach to knock down fidgetin from rat neurons, which coaxes nerve regeneration by elevating microtubule mass in their axons. Unlike previous strategies using microtubule-stabilizing drugs, fidgetin knockdown adds microtubule mass that is labile (rather than stable), thereby better recapitulating the growth status of a developing axon.
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Advani S, Maresca TJ, Ross JL. Creation and testing of a new, local microtubule-disruption tool based on the microtubule-severing enzyme, katanin p60. Cytoskeleton (Hoboken) 2018; 75:531-544. [PMID: 30176123 DOI: 10.1002/cm.21482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/25/2018] [Accepted: 07/13/2018] [Indexed: 12/18/2022]
Abstract
Current methods to disrupt the microtubule cytoskeleton do not easily provide rapid, local control with standard cell manipulation reagents. Here, we develop a new microtubule-disruption tool based on katanin p60 severing activity and demonstrate proof-of-principle by targeting it to kinetochores in Drosophila melanogaster S2 cells. Specifically, we show that human katanin p60 can remove microtubule polymer mass in S2 cells and an increase in misaligned chromosomes when globally overexpressed. When katanin p60 was targeted to the kinetochores via Mis12, we were able to recapitulate the misalignment only when using a phosphorylation-resistant mutant katanin p60. Our results demonstrate that targeting an active version of katanin p60 to the kinetochore can reduce the fidelity of achieving full chromosome alignment in metaphase and could serve as a microtubule disruption tool for the future.
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Affiliation(s)
- Siddheshwari Advani
- Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, Massachusetts
| | - Thomas J Maresca
- Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, Massachusetts.,Department of Biology, University of Massachusetts Amherst, Amherst, Massachusetts
| | - Jennifer L Ross
- Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, Massachusetts.,Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts
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Baas PW, Rao AN, Matamoros AJ, Leo L. Stability properties of neuronal microtubules. Cytoskeleton (Hoboken) 2016; 73:442-60. [PMID: 26887570 PMCID: PMC5541393 DOI: 10.1002/cm.21286] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 02/02/2016] [Accepted: 02/12/2016] [Indexed: 01/12/2023]
Abstract
Neurons are terminally differentiated cells that use their microtubule arrays not for cell division but rather as architectural elements required for the elaboration of elongated axons and dendrites. In addition to acting as compression-bearing struts that provide for the shape of the neuron, microtubules also act as directional railways for organelle transport. The stability properties of neuronal microtubules are commonly discussed in the biomedical literature as crucial to the development and maintenance of the nervous system, and have recently gained attention as central to the etiology of neurodegenerative diseases. Drugs that affect microtubule stability are currently under investigation as potential therapies for disease and injury of the nervous system. There is often a lack of consistency, however, in how the issue of microtubule stability is discussed in the literature, and this can affect the design and interpretation of experiments as well as potential therapeutic regimens. Neuronal microtubules are considered to be more stable than microtubules in dividing cells. On average, this is true, but in addition to an abundant stable microtubule fraction in neurons, there is also an abundant labile microtubule fraction. Both are functionally important. Individual microtubules consist of domains that differ in their stability properties, and these domains can also differ markedly in their composition as well as how they interact with various microtubule-related proteins in the neuron. Myriad proteins and pathways have been discussed as potential contributors to microtubule stability in neurons. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Peter W Baas
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
| | - Anand N Rao
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Andrew J Matamoros
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Lanfranco Leo
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
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Wacławek E, Włoga D. [Microtubule severing proteins - structure and activity regulation]. Postepy Biochem 2016; 62:46-51. [PMID: 28132444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 01/21/2016] [Indexed: 06/06/2023]
Abstract
Microtubule severing proteins, katanin, spastin and fidgetin cause local destabilization of the microtubules structure. This ATP-dependent activity leads to the shortening or disassembly of the existing microtubules. The generated short microtubule fragments may serve as templates to polymerize new microtubules and in consequence, the activity of the microtubule severing proteins leads to the reorganization of the microtubular cytoskeleton. This review summarizes current knowledge concerning structural organization of the microtubule severing proteins, the molecular mechanism of their action, factors that regulate the level of the katanin and spastin within the cells and their microtubule severing activity.
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Affiliation(s)
- Ewa Wacławek
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw; 3 Pasteur St., 02-093 Warsaw, Poland
| | - Dorota Włoga
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw; 3 Pasteur St., 02-093 Warsaw, Poland
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Wacławek E, Włoga D. [Role of microtubule severing proteins in cytoskeleton reorganization]. Postepy Biochem 2016; 62:52-59. [PMID: 28132445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 01/21/2016] [Indexed: 06/06/2023]
Abstract
ATP-dependent severing activity of microtubule severing proteins leads to the local destabilization of the microtubule structure and causes shortening or disassembly of the existing microtubules or formation of the numerous short microtubule fragments that serve as templates during new microtubule polymerization. Microtubule severing protein-dependent rearrangement of the microtubular cytoskeleton plays an important role in the numerous cellular processes including chromosome segregation during meiosis and mitosis, cells migration, dendrites and axon formation, cilia assembly and arrangement of the cortical microtubules in plant cells.
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Affiliation(s)
- Ewa Wacławek
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Dorota Włoga
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
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Abstract
Microtubule-severing enzymes are a novel class of microtubule regulators. They are enzymes from the ATPases associated with various cellular activities family (AAA+) that utilize ATP to cut microtubules into smaller filaments. Discovered over 20 years ago, there are still many open questions about severing enzymes. Both cellular and biochemical studies need to be pursued to fully understand how these enzymes function mechanistically in the cell. Here, we present methods to express, purify, and test the biophysical nature of these proteins in vitro to begin to address the biochemical and biophysical mechanisms of this important and novel group of microtubule destabilizers.
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