1
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Soni V, LoTurco JJ. KATNAL2 mutations link ciliary dysfunction to hydrocephalus and autism. Proc Natl Acad Sci U S A 2024; 121:e2410761121. [PMID: 39008680 PMCID: PMC11287267 DOI: 10.1073/pnas.2410761121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/17/2024] Open
Affiliation(s)
- Videep Soni
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT06266
| | - Joseph J. LoTurco
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT06266
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2
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Gagnon J, Caron V, Tremblay A. SUMOylation of nuclear receptor Nor1/NR4A3 coordinates microtubule cytoskeletal dynamics and stability in neuronal cells. Cell Biosci 2024; 14:91. [PMID: 38997783 PMCID: PMC11245793 DOI: 10.1186/s13578-024-01273-x] [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: 10/25/2023] [Accepted: 07/05/2024] [Indexed: 07/14/2024] Open
Abstract
BACKGROUND Nor1/NR4A3 is a member of the NR4A subfamily of nuclear receptors that play essential roles in regulating gene expression related to development, cell homeostasis and neurological functions. However, Nor1 is still considered an orphan receptor, as its natural ligand remains unclear for mediating transcriptional activation. Yet other activation signals may modulate Nor1 activity, although their precise role in the development and maintenance of the nervous system remains elusive. METHODS We used transcriptional reporter assays, gene expression profiling, protein turnover measurement, and cell growth assays to assess the functional relevance of Nor1 and SUMO-defective variants in neuronal cells. SUMO1 and SUMO2 conjugation to Nor1 were assessed by immunoprecipitation. Tubulin stability was determined by acetylation and polymerization assays, and live-cell fluorescent microscopy. RESULTS Here, we demonstrate that Nor1 undergoes SUMO1 conjugation at Lys-89 within a canonical ψKxE SUMOylation motif, contributing to the complex pattern of Nor1 SUMOylation, which also includes Lys-137. Disruption of Lys-89, thereby preventing SUMO1 conjugation, led to reduced Nor1 transcriptional competence and protein stability, as well as the downregulation of genes involved in cell growth and metabolism, such as ENO3, EN1, and CFLAR, and in microtubule cytoskeleton dynamics, including MAP2 and MAPT, which resulted in reduced survival of neuronal cells. Interestingly, Lys-89 SUMOylation was potentiated in response to nocodazole, a microtubule depolymerizing drug, although this was insufficient to rescue cells from microtubule disruption despite enhanced Nor1 gene expression. Instead, Lys-89 deSUMOylation reduced the expression of microtubule-severing genes like KATNA1, SPAST, and FIGN, and enhanced α-tubulin cellular levels, acetylation, and microfilament organization, promoting microtubule stability and resistance to nocodazole. These effects contrasted with Lys-137 SUMOylation, suggesting distinct regulatory mechanisms based on specific Nor1 input SUMOylation signals. CONCLUSIONS Our study provides novel insights into Nor1 transcriptional signaling competence and identifies a hierarchical mechanism whereby selective Nor1 SUMOylation may govern neuronal cytoskeleton network dynamics and resistance against microtubule disturbances, a condition strongly associated with neurodegenerative diseases.
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Affiliation(s)
- Jonathan Gagnon
- Research Center, CHU Sainte-Justine, 3175 Côte Ste-Catherine, Montréal, Québec, H3T 1C5, Canada
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, University of Montreal, Montréal, Québec, H3T 1J4, Canada
| | - Véronique Caron
- Research Center, CHU Sainte-Justine, 3175 Côte Ste-Catherine, Montréal, Québec, H3T 1C5, Canada
| | - André Tremblay
- Research Center, CHU Sainte-Justine, 3175 Côte Ste-Catherine, Montréal, Québec, H3T 1C5, Canada.
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, University of Montreal, Montréal, Québec, H3T 1J4, Canada.
- Centre de Recherche en Reproduction et Fertilité, University of Montreal, Saint-Hyacinthe, Québec, J2S 7C6, Canada.
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Montreal, Montréal, Québec, H3T 1J4, Canada.
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3
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Saltini M, Deinum EE. Microtubule simulations in plant biology: A field coming to maturity. CURRENT OPINION IN PLANT BIOLOGY 2024; 81:102596. [PMID: 38981324 DOI: 10.1016/j.pbi.2024.102596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/24/2024] [Accepted: 06/10/2024] [Indexed: 07/11/2024]
Abstract
The plant cortical microtubule array is an important determinant of cell wall structure and, therefore, plant morphology and physiology. The array consists of dynamic microtubules interacting through frequent collisions. Since the discovery by Dixit and Cyr (2004) that the outcome of such collisions depends on the collision angle, computer simulations have been indispensable in studying array behaviour. Over the last decade, the available simulation tools have drastically improved: multiple high-quality simulation platforms exist with specific strengths and applications. Here, we review how these platforms differ on the critical aspects of microtubule nucleation, flexibility, and local orienting cues; and how such differences affect array behaviour. Building upon concepts and control parameters from theoretical models of collective microtubule behaviour, we conclude that all these factors matter in the debate about what is most important for orienting the array: local cues like mechanical stresses or global cues deriving from the cell geometry.
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Affiliation(s)
- Marco Saltini
- Mathematical & Statistical Methods (Biometris), Plant Science Group, Wageningen University, 6708 PB Wageningen, the Netherlands
| | - Eva E Deinum
- Mathematical & Statistical Methods (Biometris), Plant Science Group, Wageningen University, 6708 PB Wageningen, the Netherlands.
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4
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Beaumale E, Van Hove L, Pintard L, Joly N. Microtubule-binding domains in Katanin p80 subunit are essential for severing activity in C. elegans. J Cell Biol 2024; 223:e202308023. [PMID: 38329452 PMCID: PMC10853069 DOI: 10.1083/jcb.202308023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/22/2023] [Accepted: 01/09/2024] [Indexed: 02/09/2024] Open
Abstract
Microtubule-severing enzymes (MSEs), such as Katanin, Spastin, and Fidgetin play essential roles in cell division and neurogenesis. They damage the microtubule (MT) lattice, which can either destroy or amplify the MT cytoskeleton, depending on the cellular context. However, little is known about how they interact with their substrates. We have identified the microtubule-binding domains (MTBD) required for Katanin function in C. elegans. Katanin is a heterohexamer of dimers containing a catalytic subunit p60 and a regulatory subunit p80, both of which are essential for female meiotic spindle assembly. Here, we report that p80-like(MEI-2) dictates Katanin binding to MTs via two MTBDs composed of basic patches. Substituting these patches reduces Katanin binding to MTs, compromising its function in female meiotic-spindle assembly. Structural alignments of p80-like(MEI-2) with p80s from different species revealed that the MTBDs are evolutionarily conserved, even if the specific amino acids involved vary. Our findings highlight the critical importance of the regulatory subunit (p80) in providing MT binding to the Katanin complex.
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Affiliation(s)
- Eva Beaumale
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Lucie Van Hove
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Lionel Pintard
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Nicolas Joly
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
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5
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Chen F, Luo AF, Li MG, Zheng LX, Gu H, Zhou CF, Zeng W, Molenaar A, Ren HY, Bi YZ. 3-Methyl-4-nitrophenol Exposure Deteriorates Oocyte Maturation by Inducing Spindle Instability and Mitochondrial Dysfunction. Int J Mol Sci 2024; 25:3572. [PMID: 38612384 PMCID: PMC11011565 DOI: 10.3390/ijms25073572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 03/17/2024] [Accepted: 03/19/2024] [Indexed: 04/14/2024] Open
Abstract
3-methyl-4-nitrophenol (PNMC), a well-known constituent of diesel exhaust particles and degradation products of insecticide fenitrothion, is a widely distributed environmental contaminant. PNMC is toxic to the female reproductive system; however, how it affects meiosis progression in oocytes is unknown. In this study, in vitro maturation of mouse oocytes was applied to investigate the deleterious effects of PNMC. We found that exposure to PNMC significantly compromised oocyte maturation. PNMC disturbed the spindle stability; specifically, it decreased the spindle density and increased the spindle length. The weakened spindle pole location of microtubule-severing enzyme Fignl1 may result in a defective spindle apparatus in PNMC-exposed oocytes. PNMC exposure induced significant mitochondrial dysfunction, including mitochondria distribution, ATP production, mitochondrial membrane potential, and ROS accumulation. The mRNA levels of the mitochondria-related genes were also significantly impaired. Finally, the above-mentioned alterations triggered early apoptosis in the oocytes. In conclusion, PNMC exposure affected oocyte maturation and quality through the regulation of spindle stability and mitochondrial function.
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Affiliation(s)
- Fan Chen
- Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province, Institute of Animal Sciences and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430070, China; (F.C.); (A.-F.L.); (M.-G.L.); (L.-X.Z.); (H.G.); (C.-F.Z.); (A.M.)
| | - An-Feng Luo
- Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province, Institute of Animal Sciences and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430070, China; (F.C.); (A.-F.L.); (M.-G.L.); (L.-X.Z.); (H.G.); (C.-F.Z.); (A.M.)
| | - Ming-Guo Li
- Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province, Institute of Animal Sciences and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430070, China; (F.C.); (A.-F.L.); (M.-G.L.); (L.-X.Z.); (H.G.); (C.-F.Z.); (A.M.)
| | - Li-Xiang Zheng
- Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province, Institute of Animal Sciences and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430070, China; (F.C.); (A.-F.L.); (M.-G.L.); (L.-X.Z.); (H.G.); (C.-F.Z.); (A.M.)
| | - Hao Gu
- Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province, Institute of Animal Sciences and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430070, China; (F.C.); (A.-F.L.); (M.-G.L.); (L.-X.Z.); (H.G.); (C.-F.Z.); (A.M.)
| | - Chang-Fan Zhou
- Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province, Institute of Animal Sciences and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430070, China; (F.C.); (A.-F.L.); (M.-G.L.); (L.-X.Z.); (H.G.); (C.-F.Z.); (A.M.)
| | - Wei Zeng
- Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province, Institute of Animal Sciences and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430070, China; (F.C.); (A.-F.L.); (M.-G.L.); (L.-X.Z.); (H.G.); (C.-F.Z.); (A.M.)
| | - Adrian Molenaar
- Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province, Institute of Animal Sciences and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430070, China; (F.C.); (A.-F.L.); (M.-G.L.); (L.-X.Z.); (H.G.); (C.-F.Z.); (A.M.)
- Rumen Microbiology and Animal Nutrition and Physiology AgResearch, Grasslands Campus, Fitzherbert Research Centre, Palmerston North 4410, New Zealand
| | - Hong-Yan Ren
- Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province, Institute of Animal Sciences and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430070, China; (F.C.); (A.-F.L.); (M.-G.L.); (L.-X.Z.); (H.G.); (C.-F.Z.); (A.M.)
| | - Yan-Zhen Bi
- Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province, Institute of Animal Sciences and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430070, China; (F.C.); (A.-F.L.); (M.-G.L.); (L.-X.Z.); (H.G.); (C.-F.Z.); (A.M.)
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6
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Qi L, Chen S, Liao Z, Fan M, Zhang J, Gao Y, Shen J, Sun Y, Wang Q. Comprehensive characterization of Fidgetin on tumor immune microenvironment evaluation and immunotherapy in human hepatocellular carcinoma. Aging (Albany NY) 2024; 16:4445-4468. [PMID: 38421251 PMCID: PMC10968695 DOI: 10.18632/aging.205598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 01/29/2024] [Indexed: 03/02/2024]
Abstract
Most cancers have a downregulation of Fidgetin (FIGN), which has been linked to tumor growth. However, there aren't many papers that mention FIGN's connection to hepatocellular carcinoma (HCC). Here, FIGN expression in HCC tissues was markedly reduced as compared to nearby normal liver tissues. According to univariate and multivariate Cox regression, it served as an independent predictor of survival outcomes. Patients with high levels of FIGN expression had a worse outcome. FIGN was shown to be engaged in immune-related pathways and to have a positive correlation with immunological score and immune cells according to KEGG pathway analysis. In HCC patients, FIGN was substantially linked with immunological checkpoints and the hot tumor state. Additionally, immunotherapy and chemotherapy showed a significant therapeutic response in HCC patients with low FIGN expression. This research revealed that FIGN expression was tightly related to hepatoma immunity and might be employed as a biomarker to predict patient prognosis and guide medication.
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Affiliation(s)
- Longju Qi
- Laboratory Animal Center, Medical School, Nantong University, Nantong, China
- Affiliated Nantong Hospital 3 of Nantong University, Nantong University, Nantong, China
| | - Shiyuan Chen
- Laboratory Animal Center, Medical School, Nantong University, Nantong, China
| | - Zehua Liao
- Laboratory Animal Center, Medical School, Nantong University, Nantong, China
| | - Mengjie Fan
- Laboratory Animal Center, Medical School, Nantong University, Nantong, China
| | - Jiayi Zhang
- Laboratory Animal Center, Medical School, Nantong University, Nantong, China
| | - Yuan Gao
- Laboratory Animal Center, Medical School, Nantong University, Nantong, China
| | - Jiabao Shen
- Laboratory Animal Center, Medical School, Nantong University, Nantong, China
| | - Yuyu Sun
- Affiliated Nantong Hospital 3 of Nantong University, Nantong University, Nantong, China
| | - Qinghua Wang
- Laboratory Animal Center, Medical School, Nantong University, Nantong, China
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7
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Shiff CE, Kondev J, Mohapatra L. Ultrasensitivity of microtubule severing due to damage repair. iScience 2024; 27:108874. [PMID: 38327774 PMCID: PMC10847648 DOI: 10.1016/j.isci.2024.108874] [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: 06/16/2023] [Revised: 01/01/2024] [Accepted: 01/08/2024] [Indexed: 02/09/2024] Open
Abstract
Microtubule-based cytoskeletal structures aid in cell motility, cell polarization, and intracellular transport. These functions require a coordinated effort of regulatory proteins which interact with microtubule cytoskeleton distinctively. In-vitro experiments have shown that free tubulin can repair nanoscale damages of microtubules created by severing proteins. Based on this observation, we theoretically analyze microtubule severing as a competition between the processes of damage spreading and tubulin-induced repair. We demonstrate that this model is in quantitative agreement with in-vitro experiments and predict the existence of a critical tubulin concentration above which severing becomes rare, fast, and sensitive to concentration of free tubulin. We show that this sensitivity leads to a dramatic increase in the dynamic range of steady-state microtubule lengths when the free tubulin concentration is varied, and microtubule lengths are controlled by severing. Our work demonstrates how synergy between tubulin and microtubule-associated proteins can bring about specific dynamical properties of microtubules.
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Affiliation(s)
- Chloe E. Shiff
- Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Jane Kondev
- Department of Physics, Brandeis University, Waltham, MA 02454, USA
| | - Lishibanya Mohapatra
- School of Physics and Astronomy, College of Science, Rochester Institute of Technology, Rochester, NY 14623, USA
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8
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Smart K, Sharp DJ. The fidgetin family: Shaking things up among the microtubule-severing enzymes. Cytoskeleton (Hoboken) 2024; 81:151-166. [PMID: 37823563 DOI: 10.1002/cm.21799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
The microtubule cytoskeleton is required for several crucial cellular processes, including chromosome segregation, cell polarity and orientation, and intracellular transport. These functions rely on microtubule stability and dynamics, which are regulated by microtubule-binding proteins (MTBPs). One such type of regulator is the microtubule-severing enzymes (MSEs), which are ATPases Associated with Diverse Cellular Activities (AAA+ ATPases). The most recently identified family are the fidgetins, which contain three members: fidgetin, fidgetin-like 1 (FL1), and fidgetin-like 2 (FL2). Of the three known MSE families, the fidgetins have the most diverse range of functions in the cell, spanning mitosis/meiosis, development, cell migration, DNA repair, and neuronal function. Furthermore, they offer intriguing novel therapeutic targets for cancer, cardiovascular disease, and wound healing. In the two decades since their first report, there has been great progress in our understanding of the fidgetins; however, there is still much left unknown about this unusual family. This review aims to consolidate the present body of knowledge of the fidgetin family of MSEs and to inspire deeper exploration into the fidgetins and the MSEs as a whole.
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Affiliation(s)
- Karishma Smart
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - David J Sharp
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA
- Microcures, Inc., Bronx, New York, USA
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9
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Ito M, Fujita Y, Shinohara A. Positive and negative regulators of RAD51/DMC1 in homologous recombination and DNA replication. DNA Repair (Amst) 2024; 134:103613. [PMID: 38142595 DOI: 10.1016/j.dnarep.2023.103613] [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: 08/02/2023] [Revised: 12/10/2023] [Accepted: 12/10/2023] [Indexed: 12/26/2023]
Abstract
RAD51 recombinase plays a central role in homologous recombination (HR) by forming a nucleoprotein filament on single-stranded DNA (ssDNA) to catalyze homology search and strand exchange between the ssDNA and a homologous double-stranded DNA (dsDNA). The catalytic activity of RAD51 assembled on ssDNA is critical for the DNA-homology-mediated repair of DNA double-strand breaks in somatic and meiotic cells and restarting stalled replication forks during DNA replication. The RAD51-ssDNA complex also plays a structural role in protecting the regressed/reversed replication fork. Two types of regulators control RAD51 filament formation, stability, and dynamics, namely positive regulators, including mediators, and negative regulators, so-called remodelers. The appropriate balance of action by the two regulators assures genome stability. This review describes the roles of positive and negative RAD51 regulators in HR and DNA replication and its meiosis-specific homolog DMC1 in meiotic recombination. We also provide future study directions for a comprehensive understanding of RAD51/DMC1-mediated regulation in maintaining and inheriting genome integrity.
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Affiliation(s)
- Masaru Ito
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
| | - Yurika Fujita
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
| | - Akira Shinohara
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
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10
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Fábián A, Péntek BK, Soós V, Sági L. Heat stress during male meiosis impairs cytoskeletal organization, spindle assembly and tapetum degeneration in wheat. FRONTIERS IN PLANT SCIENCE 2024; 14:1314021. [PMID: 38259921 PMCID: PMC10800805 DOI: 10.3389/fpls.2023.1314021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 12/13/2023] [Indexed: 01/24/2024]
Abstract
The significance of heat stress in agriculture is ever-increasing with the progress of global climate changes. Due to a negative effect on the yield of staple crops, including wheat, the impairment of plant reproductive development triggered by high ambient temperature became a restraint in food production. Although the heat sensitivity of male meiosis and the following gamete development in wheat has long been recognized, a detailed structural characterization combined with a comprehensive gene expression analysis has not been done about this phenomenon. We demonstrate here that heat stress severely alters the cytoskeletal configuration, triggers the failure of meiotic division in wheat. Moreover, it changes the expression of genes related to gamete development in male meiocytes and the tapetum layer in a genotype-dependent manner. 'Ellvis', a heat-tolerant winter wheat cultivar, showed high spikelet fertility rate and only scarce structural aberrations upon exposure to high temperature. In addition, heat shock genes and genes involved in scavenging reactive oxygen species were significantly upregulated in 'Ellvis', and the expression of meiosis-specific and major developmental genes showed high stability in this cultivar. In the heat-sensitive 'Mv 17-09', however, genes participating in cytoskeletal fiber nucleation, the spindle assembly checkpoint genes, and tapetum-specific developmental regulators were downregulated. These alterations may be related to the decreased cytoskeleton content, frequent micronuclei formation, and the erroneous persistence of the tapetum layer observed in the sensitive genotype. Our results suggest that understanding the heat-sensitive regulation of these gene functions would be an essential contribution to the development of new, heat-tolerant cultivars.
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Affiliation(s)
- Attila Fábián
- Centre for Agricultural Research, Hungarian Research Network, Martonvásár, Hungary
- Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Budapest, Hungary
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | | | - Vilmos Soós
- Centre for Agricultural Research, Hungarian Research Network, Martonvásár, Hungary
| | - László Sági
- Centre for Agricultural Research, Hungarian Research Network, Martonvásár, Hungary
- Agribiotechnology and Precision Breeding for Food Security National Laboratory, Plant Biotechnology Section, Centre for Agricultural Research, Hungarian Research Network, Martonvásár, Hungary
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11
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Ori-McKenney KM, McKenney RJ. Tau oligomerization on microtubules in health and disease. Cytoskeleton (Hoboken) 2024; 81:35-40. [PMID: 37747123 PMCID: PMC10841430 DOI: 10.1002/cm.21785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/26/2023]
Affiliation(s)
- Kassandra M Ori-McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, California, USA
| | - Richard J McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, California, USA
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12
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Lawrence EJ, Chatterjee S, Zanic M. More is different: Reconstituting complexity in microtubule regulation. J Biol Chem 2023; 299:105398. [PMID: 37898404 PMCID: PMC10694663 DOI: 10.1016/j.jbc.2023.105398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 10/13/2023] [Accepted: 10/18/2023] [Indexed: 10/30/2023] Open
Abstract
Microtubules are dynamic cytoskeletal filaments that undergo stochastic switching between phases of polymerization and depolymerization-a behavior known as dynamic instability. Many important cellular processes, including cell motility, chromosome segregation, and intracellular transport, require complex spatiotemporal regulation of microtubule dynamics. This coordinated regulation is achieved through the interactions of numerous microtubule-associated proteins (MAPs) with microtubule ends and lattices. Here, we review the recent advances in our understanding of microtubule regulation, focusing on results arising from biochemical in vitro reconstitution approaches using purified multiprotein ensembles. We discuss how the combinatory effects of MAPs affect both the dynamics of individual microtubule ends, as well as the stability and turnover of the microtubule lattice. In addition, we highlight new results demonstrating the roles of protein condensates in microtubule regulation. Our overall intent is to showcase how lessons learned from reconstitution approaches help unravel the regulatory mechanisms at play in complex cellular environments.
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Affiliation(s)
- Elizabeth J Lawrence
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Saptarshi Chatterjee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Marija Zanic
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA.
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13
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Deretic J, Odabasi E, Firat-Karalar EN. The multifaceted roles of microtubule-associated proteins in the primary cilium and ciliopathies. J Cell Sci 2023; 136:jcs261148. [PMID: 38095645 DOI: 10.1242/jcs.261148] [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] [Indexed: 12/18/2023] Open
Abstract
The primary cilium is a conserved microtubule-based organelle that is critical for transducing developmental, sensory and homeostatic signaling pathways. It comprises an axoneme with nine parallel doublet microtubules extending from the basal body, surrounded by the ciliary membrane. The axoneme exhibits remarkable stability, serving as the skeleton of the cilium in order to maintain its shape and provide tracks to ciliary trafficking complexes. Although ciliary trafficking and signaling have been exhaustively characterized over the years, less is known about the unique structural and functional complexities of the axoneme. Recent work has yielded new insights into the mechanisms by which the axoneme is built with its proper length and architecture, particularly regarding the activity of microtubule-associated proteins (MAPs). In this Review, we first summarize current knowledge about the architecture, composition and specialized compartments of the primary cilium. Next, we discuss the mechanistic underpinnings of how a functional cilium is assembled, maintained and disassembled through the regulation of its axonemal microtubules. We conclude by examining the diverse localizations and functions of ciliary MAPs for the pathobiology of ciliary diseases.
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Affiliation(s)
- Jovana Deretic
- Department of Molecular Biology and Genetics, Koç University, Istanbul 34450, Turkey
| | - Ezgi Odabasi
- Department of Molecular Biology and Genetics, Koç University, Istanbul 34450, Turkey
| | - Elif Nur Firat-Karalar
- Department of Molecular Biology and Genetics, Koç University, Istanbul 34450, Turkey
- School of Medicine, Koç University, Istanbul 34450, Turkey
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14
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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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15
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Naren P, Samim KS, Tryphena KP, Vora LK, Srivastava S, Singh SB, Khatri DK. Microtubule acetylation dyshomeostasis in Parkinson's disease. Transl Neurodegener 2023; 12:20. [PMID: 37150812 PMCID: PMC10165769 DOI: 10.1186/s40035-023-00354-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 04/06/2023] [Indexed: 05/09/2023] Open
Abstract
The inter-neuronal communication occurring in extensively branched neuronal cells is achieved primarily through the microtubule (MT)-mediated axonal transport system. This mechanistically regulated system delivers cargos (proteins, mRNAs and organelles such as mitochondria) back and forth from the soma to the synapse. Motor proteins like kinesins and dynein mechanistically regulate polarized anterograde (from the soma to the synapse) and retrograde (from the synapse to the soma) commute of the cargos, respectively. Proficient axonal transport of such cargos is achieved by altering the microtubule stability via post-translational modifications (PTMs) of α- and β-tubulin heterodimers, core components constructing the MTs. Occurring within the lumen of MTs, K40 acetylation of α-tubulin via α-tubulin acetyl transferase and its subsequent deacetylation by HDAC6 and SIRT2 are widely scrutinized PTMs that make the MTs highly flexible, which in turn promotes their lifespan. The movement of various motor proteins, including kinesin-1 (responsible for axonal mitochondrial commute), is enhanced by this PTM, and dyshomeostasis of neuronal MT acetylation has been observed in a variety of neurodegenerative conditions, including Alzheimer's disease and Parkinson's disease (PD). PD is the second most common neurodegenerative condition and is closely associated with impaired MT dynamics and deregulated tubulin acetylation levels. Although the relationship between status of MT acetylation and progression of PD pathogenesis has become a chicken-and-egg question, our review aims to provide insights into the MT-mediated axonal commute of mitochondria and dyshomeostasis of MT acetylation in PD. The enzymatic regulators of MT acetylation along with their synthetic modulators have also been briefly explored. Moving towards a tubulin-based therapy that enhances MT acetylation could serve as a disease-modifying treatment in neurological conditions that lack it.
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Affiliation(s)
- Padmashri Naren
- Molecular and Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India
| | - Khan Sabiya Samim
- Molecular and Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India
| | - Kamatham Pushpa Tryphena
- Molecular and Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India
| | - Lalitkumar K Vora
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK.
| | - Saurabh Srivastava
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India.
| | - Shashi Bala Singh
- Molecular and Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India
| | - Dharmendra Kumar Khatri
- Molecular and Cellular Neuroscience Lab, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, 500037, India.
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16
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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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17
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Carmona B, Marinho HS, Matos CL, Nolasco S, Soares H. Tubulin Post-Translational Modifications: The Elusive Roles of Acetylation. BIOLOGY 2023; 12:biology12040561. [PMID: 37106761 PMCID: PMC10136095 DOI: 10.3390/biology12040561] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/27/2023] [Accepted: 04/03/2023] [Indexed: 04/29/2023]
Abstract
Microtubules (MTs), dynamic polymers of α/β-tubulin heterodimers found in all eukaryotes, are involved in cytoplasm spatial organization, intracellular transport, cell polarity, migration and division, and in cilia biology. MTs functional diversity depends on the differential expression of distinct tubulin isotypes and is amplified by a vast number of different post-translational modifications (PTMs). The addition/removal of PTMs to α- or β-tubulins is catalyzed by specific enzymes and allows combinatory patterns largely enriching the distinct biochemical and biophysical properties of MTs, creating a code read by distinct proteins, including microtubule-associated proteins (MAPs), which allow cellular responses. This review is focused on tubulin-acetylation, whose cellular roles continue to generate debate. We travel through the experimental data pointing to α-tubulin Lys40 acetylation role as being a MT stabilizer and a typical PTM of long lived MTs, to the most recent data, suggesting that Lys40 acetylation enhances MT flexibility and alters the mechanical properties of MTs, preventing MTs from mechanical aging characterized by structural damage. Additionally, we discuss the regulation of tubulin acetyltransferases/desacetylases and their impacts on cell physiology. Finally, we analyze how changes in MT acetylation levels have been found to be a general response to stress and how they are associated with several human pathologies.
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Affiliation(s)
- Bruno Carmona
- Centro de Química Estrutural, Institute of Molecular Sciences, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
- Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Av. D. João II, Lote 4.69.01, 1990-096 Lisboa, Portugal
| | - H Susana Marinho
- Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Catarina Lopes Matos
- Centro de Química Estrutural, Institute of Molecular Sciences, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Sofia Nolasco
- Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Av. D. João II, Lote 4.69.01, 1990-096 Lisboa, Portugal
- CIISA-Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Helena Soares
- Centro de Química Estrutural, Institute of Molecular Sciences, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
- Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Av. D. João II, Lote 4.69.01, 1990-096 Lisboa, Portugal
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18
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Al-Hiyasat A, Tuna Y, Kuo YW, Howard J. Herding of proteins by the ends of shrinking polymers. Phys Rev E 2023; 107:L042601. [PMID: 37198784 DOI: 10.1103/physreve.107.l042601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 02/17/2023] [Indexed: 05/19/2023]
Abstract
The control of biopolymer length is mediated by proteins that localize to polymer ends and regulate polymerization dynamics. Several mechanisms have been proposed to achieve end localization. Here, we propose a novel mechanism by which a protein that binds to a shrinking polymer and slows its shrinkage will be spontaneously enriched at the shrinking end through a "herding" effect. We formalize this process using both lattice-gas and continuum descriptions, and we present experimental evidence that the microtubule regulator spastin employs this mechanism. Our findings extend to more general problems involving diffusion within shrinking domains.
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Affiliation(s)
- Amer Al-Hiyasat
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Yazgan Tuna
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
| | - Yin-Wei Kuo
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
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19
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Genova M, Grycova L, Puttrich V, Magiera MM, Lansky Z, Janke C, Braun M. Tubulin polyglutamylation differentially regulates microtubule-interacting proteins. EMBO J 2023; 42:e112101. [PMID: 36636822 PMCID: PMC9975938 DOI: 10.15252/embj.2022112101] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 12/16/2022] [Accepted: 12/22/2022] [Indexed: 01/14/2023] Open
Abstract
Tubulin posttranslational modifications have been predicted to control cytoskeletal functions by coordinating the molecular interactions between microtubules and their associating proteins. A prominent tubulin modification in neurons is polyglutamylation, the deregulation of which causes neurodegeneration. Yet, the underlying molecular mechanisms have remained elusive. Here, using in-vitro reconstitution, we determine how polyglutamylation generated by the two predominant neuronal polyglutamylases, TTLL1 and TTLL7, specifically modulates the activities of three major microtubule interactors: the microtubule-associated protein Tau, the microtubule-severing enzyme katanin and the molecular motor kinesin-1. We demonstrate that the unique modification patterns generated by TTLL1 and TTLL7 differentially impact those three effector proteins, thus allowing for their selective regulation. Given that our experiments were performed with brain tubulin from mouse models in which physiological levels and patterns of polyglutamylation were altered by the genetic knockout of the main modifying enzymes, our quantitative measurements provide direct mechanistic insight into how polyglutamylation could selectively control microtubule interactions in neurons.
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Affiliation(s)
- Mariya Genova
- Institut Curie, Université PSL, CNRS UMR3348OrsayFrance
- Université Paris‐Saclay, CNRS UMR3348OrsayFrance
| | - Lenka Grycova
- Institute of BiotechnologyCzech Academy of Sciences, BIOCEVPrague WestCzech Republic
| | - Verena Puttrich
- Institute of BiotechnologyCzech Academy of Sciences, BIOCEVPrague WestCzech Republic
| | - Maria M Magiera
- Institut Curie, Université PSL, CNRS UMR3348OrsayFrance
- Université Paris‐Saclay, CNRS UMR3348OrsayFrance
| | - Zdenek Lansky
- Institute of BiotechnologyCzech Academy of Sciences, BIOCEVPrague WestCzech Republic
| | - Carsten Janke
- Institut Curie, Université PSL, CNRS UMR3348OrsayFrance
- Université Paris‐Saclay, CNRS UMR3348OrsayFrance
| | - Marcus Braun
- Institute of BiotechnologyCzech Academy of Sciences, BIOCEVPrague WestCzech Republic
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20
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Sardina F, Valente D, Fattorini G, Cioffi E, Zanna GD, Tessa A, Trisciuoglio D, Soddu S, Santorelli FM, Casali C, Rinaldo C. New cellular imaging-based method to distinguish the SPG4 subtype of hereditary spastic paraplegia. Eur J Neurol 2023; 30:1734-1744. [PMID: 36815539 DOI: 10.1111/ene.15756] [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: 12/23/2022] [Revised: 02/07/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023]
Abstract
BACKGROUND AND PURPOSE Microtubule defects are a common feature in several neurodegenerative disorders, including hereditary spastic paraplegia. The most frequent form of hereditary spastic paraplegia is caused by mutations in the SPG4/SPAST gene, encoding the microtubule severing enzyme spastin. To date, there is no effective therapy available but spastin-enhancing therapeutic approaches are emerging; thus prognostic and predictive biomarkers are urgently required. METHODS An automated, simple, fast and non-invasive cell imaging-based method was developed to quantify microtubule cytoskeleton organization changes in lymphoblastoid cells and peripheral blood mononuclear cells. RESULTS It was observed that lymphoblastoid cells and peripheral blood mononuclear cells from individuals affected by SPG4-hereditary spastic paraplegia show a polarized microtubule cytoskeleton organization. In a pilot study on freshly isolated peripheral blood mononuclear cells, our method discriminates SPG4-hereditary spastic paraplegia from healthy donors and other hereditary spastic paraplegia subtypes. In addition, it is shown that our method can detect the effects of spastin protein level changes. CONCLUSIONS These findings open the possibility of a rapid, non-invasive, inexpensive test useful to recognize SPG4-hereditary spastic paraplegia subtype and evaluate the effects of spastin-enhancing drug in non-neuronal cells.
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Affiliation(s)
- Francesca Sardina
- Institute of Molecular Biology and Pathology (IBPM), Consiglio Nazionale delle Ricerche (CNR), c/o Sapienza University of Rome, Rome, Italy
| | - Davide Valente
- Institute of Molecular Biology and Pathology (IBPM), Consiglio Nazionale delle Ricerche (CNR), c/o Sapienza University of Rome, Rome, Italy
- Unit of Cellular Networks and Molecular Therapeutic Targets, IRCCS-Regina Elena National Cancer Institute, Rome, Italy
| | - Gaia Fattorini
- Institute of Molecular Biology and Pathology (IBPM), Consiglio Nazionale delle Ricerche (CNR), c/o Sapienza University of Rome, Rome, Italy
- Department of Biology and Biotechnology, "Charles Darwin" Sapienza University of Rome, Rome, Italy
| | - Ettore Cioffi
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | - Gianmarco Dalla Zanna
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | | | - Daniela Trisciuoglio
- Institute of Molecular Biology and Pathology (IBPM), Consiglio Nazionale delle Ricerche (CNR), c/o Sapienza University of Rome, Rome, Italy
| | - Silvia Soddu
- Unit of Cellular Networks and Molecular Therapeutic Targets, IRCCS-Regina Elena National Cancer Institute, Rome, Italy
| | | | - Carlo Casali
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | - Cinzia Rinaldo
- Institute of Molecular Biology and Pathology (IBPM), Consiglio Nazionale delle Ricerche (CNR), c/o Sapienza University of Rome, Rome, Italy
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21
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Luchniak A, Kuo YW, McGuinness C, Sutradhar S, Orbach R, Mahamdeh M, Howard J. Dynamic microtubules slow down during their shrinkage phase. Biophys J 2023; 122:616-623. [PMID: 36659852 PMCID: PMC9989939 DOI: 10.1016/j.bpj.2023.01.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 11/25/2022] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Microtubules are dynamic polymers that undergo stochastic transitions between growing and shrinking phases. The structural and chemical properties of these phases remain poorly understood. The transition from growth to shrinkage, termed catastrophe, is not a first-order reaction but rather a multistep process whose frequency increases with the growth time: the microtubule ages as the older microtubule tip becomes more unstable. Aging shows that the growing phase is not a single state but comprises several substates of increasing instability. To investigate whether the shrinking phase is also multistate, we characterized the kinetics of microtubule shrinkage following catastrophe using an in vitro reconstitution assay with purified tubulins. We found that the shrinkage speed is highly variable across microtubules and that the shrinkage speed of individual microtubules slows down over time by as much as several fold. The shrinkage slowdown was observed in both fluorescently labeled and unlabeled microtubules as well as in microtubules polymerized from tubulin purified from different species, suggesting that the shrinkage slowdown is a general property of microtubules. These results indicate that microtubule shrinkage, like catastrophe, is time dependent and that the shrinking microtubule tip passes through a succession of states of increasing stability. We hypothesize that the shrinkage slowdown is due to destabilizing events that took place during growth, which led to multistep catastrophe. This suggests that the aging associated with growth is also manifested during shrinkage, with the older, more unstable growing tip being associated with a faster depolymerizing shrinking tip.
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Affiliation(s)
- Anna Luchniak
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut
| | - Yin-Wei Kuo
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut
| | - Catherine McGuinness
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut
| | - Sabyasachi Sutradhar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut
| | - Ron Orbach
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut
| | - Mohammed Mahamdeh
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut.
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22
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Zhang L, Lin X, Yang Z, Jiang L, Hou Q, Xie Z, Li Y, Pei H. The role of microtubules in microalgae: promotion of lipid accumulation and extraction. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:7. [PMID: 36635732 PMCID: PMC9837904 DOI: 10.1186/s13068-023-02257-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 01/01/2023] [Indexed: 01/14/2023]
Abstract
BACKGROUND Microtubules in cells are closely related to the growth and metabolism of microalgae. To date, the study of microalgal microtubules has mainly concentrated on revealing the relationship between microtubule depolymerization and synthesis of precursors for flagellar regeneration. While information on the link between microtubule depolymerization and biosynthesis of precursors for complex organic matter (such as lipid, carbohydrate and protein), is still lacking, a better understanding of this could help to achieve a breakthrough in lipid regulation. With the aim of testing the assumption that microtubule disruption could regulate carbon precursors and redirect carbon flow to promote lipid accumulation, Chlorella sorokiniana SDEC-18 was pretreated with different concentrations of oryzalin. RESULTS Strikingly, microalgae that were pretreated with 1.5 mM oryzalin accumulated lipid contents of 41.06%, which was attributed to carbon redistribution induced by microtubule destruction. To promote the growth of microalgae, two-stage cultivation involving microtubule destruction was employed, which resulted in the lipid productivity being 1.44 times higher than that for microalgae with routine single-stage cultivation, as well as yielding a desirable biodiesel quality following from increases in monounsaturated fatty acid (MUFA) content. Furthermore, full extraction of lipid was achieved after only a single extraction step, because microtubule destruction caused removal of cellulose synthase and thereby blocked cellulose biosynthesis. CONCLUSIONS This study provides an important advance towards observation of microtubules in microalgae through immunocolloidal gold techniques combined with TEM. Moreover, the observation of efficient lipid accumulation and increased cell fragility engendered by microtubule destruction has expanded our knowledge of metabolic regulation by microtubules. Finally, two-stage cultivation involving microtubule destruction has established ideal growth, coupling enhanced lipid accumulation and efficient oil extraction; thus gaining advances in both applied and fundamental research in algal biodiesel production.
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Affiliation(s)
- Lijie Zhang
- grid.27255.370000 0004 1761 1174School of Environmental Science and Engineering, Shandong University, Qingdao, 266237 China
| | - Xiao Lin
- grid.5335.00000000121885934Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS UK
| | - Zhigang Yang
- grid.27255.370000 0004 1761 1174School of Environmental Science and Engineering, Shandong University, Qingdao, 266237 China
| | - Liqun Jiang
- grid.27255.370000 0004 1761 1174School of Environmental Science and Engineering, Shandong University, Qingdao, 266237 China
| | - Qingjie Hou
- grid.27255.370000 0004 1761 1174School of Environmental Science and Engineering, Shandong University, Qingdao, 266237 China
| | - Zhen Xie
- grid.27255.370000 0004 1761 1174School of Environmental Science and Engineering, Shandong University, Qingdao, 266237 China
| | - Yizhen Li
- grid.27255.370000 0004 1761 1174School of Environmental Science and Engineering, Shandong University, Qingdao, 266237 China
| | - Haiyan Pei
- grid.27255.370000 0004 1761 1174School of Environmental Science and Engineering, Shandong University, Qingdao, 266237 China ,grid.8547.e0000 0001 0125 2443Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 China ,Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, 250061 China
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23
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Zhang Y, He X, Zou J, Yang J, Ma A, Tan M. Phosphorylation mutation impairs the promoting effect of spastin on neurite outgrowth without affecting its microtubule severing ability. Eur J Histochem 2023; 67. [PMID: 36632786 DOI: 10.4081/ejh.2023.3594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 12/27/2022] [Indexed: 01/13/2023] Open
Abstract
Spastin, a microtubule-severing enzyme, is known to be important for neurite outgrowth. However, the role of spastin post-translational modification, particularly its phosphorylation regulation in neuronal outgrowth, remains unclear. This study aimed to investigate the effects of eliminating spastin phosphorylation on the neurite outgrowth of rat hippocampal neurons. To accomplish this, we constructed a spastin mutant with eleven potential phosphorylation sites mutated to alanine. The phosphorylation levels of the wildtype spastin (WT) and the mutant (11A) were then detected using Phos-tag SDS-PAGE. The spastin constructs were transfected into COS7 cells for the observation of microtubule severing, and into rat hippocampal neurons for the detection of neuronal outgrowth. The results showed that compared to the spastin WT, the phosphorylation levels were significantly reduced in the spastin 11A mutant. The spastin mutant 11A impaired its ability to promote neurite length, branching, and complexity in hippocampal neurons, but did not affect its ability to sever microtubules in COS7 cells. In conclusion, the data suggest that mutations at multiple phosphorylation sites of spastin do not impair its microtubule cleavage ability in COS7 cells, but reduce its ability to promote neurite outgrowth in rat hippocampal neurons.
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Affiliation(s)
- Yunlong Zhang
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou.
| | - Xin He
- Clinical Laboratory Center, The First Affiliated Hospital of Jinan University, Guangzhou.
| | - Jianyu Zou
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou.
| | - Jie Yang
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou.
| | | | - Minghui Tan
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou.
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24
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Iwanski MK, Kapitein LC. Cellular cartography: Towards an atlas of the neuronal microtubule cytoskeleton. Front Cell Dev Biol 2023; 11:1052245. [PMID: 37035244 PMCID: PMC10073685 DOI: 10.3389/fcell.2023.1052245] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 02/28/2023] [Indexed: 04/11/2023] Open
Abstract
Microtubules, one of the major components of the cytoskeleton, play a crucial role during many aspects of neuronal development and function, such as neuronal polarization and axon outgrowth. Consequently, the microtubule cytoskeleton has been implicated in many neurodevelopmental and neurodegenerative disorders. The polar nature of microtubules is quintessential for their function, allowing them to serve as tracks for long-distance, directed intracellular transport by kinesin and dynein motors. Most of these motors move exclusively towards either the plus- or minus-end of a microtubule and some have been shown to have a preference for either dynamic or stable microtubules, those bearing a particular post-translational modification or those decorated by a specific microtubule-associated protein. Thus, it becomes important to consider the interplay of these features and their combinatorial effects on transport, as well as how different types of microtubules are organized in the cell. Here, we discuss microtubule subsets in terms of tubulin isotypes, tubulin post-translational modifications, microtubule-associated proteins, microtubule stability or dynamicity, and microtubule orientation. We highlight techniques used to study these features of the microtubule cytoskeleton and, using the information from these studies, try to define the composition, role, and organization of some of these subsets in neurons.
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25
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Tsitkov S, Rodriguez JB, Bassir Kazeruni NM, Sweet M, Nitta T, Hess H. The rate of microtubule breaking increases exponentially with curvature. Sci Rep 2022; 12:20899. [PMID: 36463258 PMCID: PMC9719553 DOI: 10.1038/s41598-022-24912-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 11/22/2022] [Indexed: 12/04/2022] Open
Abstract
Microtubules, cylindrical assemblies of tubulin proteins with a 25 nm diameter and micrometer lengths, are a central part of the cytoskeleton and also serve as building blocks for nanobiodevices. Microtubule breaking can result from the activity of severing enzymes and mechanical stress. Breaking can lead to a loss of structural integrity, or an increase in the numbers of microtubules. We observed breaking of taxol-stabilized microtubules in a gliding motility assay where microtubules are propelled by surface-adhered kinesin-1 motor proteins. We find that over 95% of all breaking events are associated with the strong bending following pinning events (where the leading tip of the microtubule becomes stuck). Furthermore, the breaking rate increased exponentially with increasing curvature. These observations are explained by a model accounting for the complex mechanochemistry of a microtubule. The presence of severing enzymes is not required to observe breaking at rates comparable to those measured previously in cells.
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Affiliation(s)
- Stanislav Tsitkov
- grid.21729.3f0000000419368729Columbia University, 351L Engineering Terrace, MC 8904, 1210 Amsterdam Avenue, New York, NY 10027 USA
| | - Juan B. Rodriguez
- grid.21729.3f0000000419368729Columbia University, 351L Engineering Terrace, MC 8904, 1210 Amsterdam Avenue, New York, NY 10027 USA
| | - Neda M. Bassir Kazeruni
- grid.21729.3f0000000419368729Columbia University, 351L Engineering Terrace, MC 8904, 1210 Amsterdam Avenue, New York, NY 10027 USA
| | - May Sweet
- grid.256342.40000 0004 0370 4927Applied Physics Course, Faculty of Engineering, Gifu University, Gifu, 501-1193 Japan
| | - Takahiro Nitta
- grid.256342.40000 0004 0370 4927Applied Physics Course, Faculty of Engineering, Gifu University, Gifu, 501-1193 Japan
| | - Henry Hess
- grid.21729.3f0000000419368729Columbia University, 351L Engineering Terrace, MC 8904, 1210 Amsterdam Avenue, New York, NY 10027 USA
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26
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Miryala CSJ, Holland ED, Dent EW. Contributions of microtubule dynamics and transport to presynaptic and postsynaptic functions. Mol Cell Neurosci 2022; 123:103787. [PMID: 36252720 PMCID: PMC9838116 DOI: 10.1016/j.mcn.2022.103787] [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: 08/29/2022] [Revised: 10/07/2022] [Accepted: 10/11/2022] [Indexed: 11/27/2022] Open
Abstract
Microtubules (MT) are elongated, tubular, cytoskeletal structures formed from polymerization of tubulin dimers. They undergo continuous cycles of polymerization and depolymerization, primarily at their plus ends, termed dynamic instability. Although this is an intrinsic property of MTs, there are a myriad of MT-associated proteins that function in regulating MT dynamic instability and other dynamic processes that shape the MT array. Additionally, MTs assemble into long, semi-rigid structures which act as substrates for long-range, motor-driven transport of many different types of cargoes throughout the cell. Both MT dynamics and motor-based transport play important roles in the function of every known type of cell. Within the last fifteen years many groups have shown that MT dynamics and transport play ever-increasing roles in the neuronal function of mature neurons. Not only are neurons highly polarized cells, but they also connect with one another through synapses to form complex networks. Here we will focus on exciting studies that have illuminated how MTs function both pre-synaptically in axonal boutons and post-synaptically in dendritic spines. It is becoming clear that MT dynamics and transport both serve important functions in synaptic plasticity. Thus, it is not surprising that disruption of MTs, either through hyperstabilization or destabilization, has profound consequences for learning and memory. Together, the studies described here suggest that MT dynamics and transport play key roles in synaptic function and when disrupted result in compromised learning and memory.
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Affiliation(s)
- Chandra S. J. Miryala
- Department of Neuroscience, University of Wisconsin, School of Medicine and Public Health, Madison, WI 53705
| | - Elizabeth D. Holland
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53705
| | - Erik W. Dent
- Department of Neuroscience, University of Wisconsin, School of Medicine and Public Health, Madison, WI 53705,Corresponding Author: Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705,
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27
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Ma C, Wu D, Chen Q, Gao N. Structural dynamics of AAA + ATPase Drg1 and mechanism of benzo-diazaborine inhibition. Nat Commun 2022; 13:6765. [PMID: 36351914 PMCID: PMC9646744 DOI: 10.1038/s41467-022-34511-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 10/27/2022] [Indexed: 11/11/2022] Open
Abstract
The type II AAA + ATPase Drg1 is a ribosome assembly factor, functioning to release Rlp24 from the pre-60S particle just exported from nucleus, and its activity in can be inhibited by a drug molecule diazaborine. However, molecular mechanisms of Drg1-mediated Rlp24 removal and diazaborine-mediated inhibition are not fully understood. Here, we report Drg1 structures in different nucleotide-binding and benzo-diazaborine treated states. Drg1 hexamers transits between two extreme conformations (planar or helical arrangement of protomers). By forming covalent adducts with ATP molecules in both ATPase domain, benzo-diazaborine locks Drg1 hexamers in a symmetric and non-productive conformation to inhibits both inter-protomer and inter-ring communication of Drg1 hexamers. We also obtained a substrate-engaged mutant Drg1 structure, in which conserved pore-loops form a spiral staircase to interact with the polypeptide through a sequence-independent manner. Structure-based mutagenesis data highlight the functional importance of the pore-loop, the D1-D2 linker and the inter-subunit signaling motif of Drg1, which share similar regulatory mechanisms with p97. Our results suggest that Drg1 may function as an unfoldase that threads a substrate protein within the pre-60S particle.
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Affiliation(s)
- Chengying Ma
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, 100871 Beijing, China ,Changping Laboratory, 102206 Beijing, China
| | - Damu Wu
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, 100871 Beijing, China
| | - Qian Chen
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, 100871 Beijing, China
| | - Ning Gao
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, 100871 Beijing, China ,Changping Laboratory, 102206 Beijing, China ,grid.11135.370000 0001 2256 9319National Biomedical Imaging Center, Peking University, 100871 Beijing, China
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28
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He L, van Beem L, Snel B, Hoogenraad CC, Harterink M. PTRN-1 (CAMSAP) and NOCA-2 (NINEIN) are required for microtubule polarity in Caenorhabditis elegans dendrites. PLoS Biol 2022; 20:e3001855. [PMID: 36395330 PMCID: PMC9714909 DOI: 10.1371/journal.pbio.3001855] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 12/01/2022] [Accepted: 09/27/2022] [Indexed: 11/18/2022] Open
Abstract
The neuronal microtubule cytoskeleton is key to establish axon-dendrite polarity. Dendrites are characterized by the presence of minus-end out microtubules. However, the mechanisms that organize these microtubules with the correct orientation are still poorly understood. Using Caenorhabditis elegans as a model system for microtubule organization, we characterized the role of 2 microtubule minus-end related proteins in this process, the microtubule minus-end stabilizing protein calmodulin-regulated spectrin-associated protein (CAMSAP/PTRN-1), and the NINEIN homologue, NOCA-2 (noncentrosomal microtubule array). We found that CAMSAP and NINEIN function in parallel to mediate microtubule organization in dendrites. During dendrite outgrowth, RAB-11-positive vesicles localized to the dendrite tip to nucleate microtubules and function as a microtubule organizing center (MTOC). In the absence of either CAMSAP or NINEIN, we observed a low penetrance MTOC vesicles mislocalization to the cell body, and a nearly fully penetrant phenotype in double mutant animals. This suggests that both proteins are important for localizing the MTOC vesicles to the growing dendrite tip to organize microtubules minus-end out. Whereas NINEIN localizes to the MTOC vesicles where it is important for the recruitment of the microtubule nucleator γ-tubulin, CAMSAP localizes around the MTOC vesicles and is cotranslocated forward with the MTOC vesicles upon dendritic growth. Together, these results indicate that microtubule nucleation from the MTOC vesicles and microtubule stabilization are both important to localize the MTOC vesicles distally to organize dendritic microtubules minus-end out.
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Affiliation(s)
- Liu He
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Lotte van Beem
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Berend Snel
- Theoretical Biology and Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Casper C. Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
- Department of Neuroscience, Genentech, Inc., South San Francisco, California, United States of America
| | - Martin Harterink
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands
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29
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Walker SD, Olivares AO. The activated ClpP peptidase forcefully grips a protein substrate. Biophys J 2022; 121:3907-3916. [PMID: 36045571 PMCID: PMC9674977 DOI: 10.1016/j.bpj.2022.08.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 08/12/2022] [Accepted: 08/26/2022] [Indexed: 11/26/2022] Open
Abstract
ATPases associated with diverse cellular activities (AAA+) proteases power the maintenance of protein homeostasis by coupling ATP hydrolysis to mechanical protein unfolding, translocation, and ultimately degradation. Although ATPase activity drives a large portion of the mechanical work these molecular machines perform, how the peptidase contributes to the forceful denaturation and processive threading of substrates remains unknown. Here, using single-molecule optical trapping, we examine the mechanical activity of the caseinolytic peptidase P (ClpP) from Escherichia coli in the absence of a partner ATPase and in the presence of an activating small-molecule acyldepsipeptide. We demonstrate that ClpP grips protein substrate under mechanical loads exceeding 40 pN, which are greater than those observed for the AAA+ unfoldase ClpX and the AAA+ protease complexes ClpXP and ClpAP. We further characterize substrate-ClpP bond lifetimes and rupture forces under varying loads. We find that the resulting slip bond behavior does not depend on ClpP peptidase activity. In addition, we find that unloaded bond lifetimes between ClpP and protein substrate are on a timescale relevant to unfolding times (up to ∼160 s) for difficult to unfold model substrate proteins. These direct measurements of the substrate-peptidase bond under load define key properties required by AAA+ proteases to mechanically unfold and degrade protein substrates.
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Affiliation(s)
- Steven D Walker
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee; Chemical and Physical Biology Graduate Program, Vanderbilt University, Nashville, Tennessee
| | - Adrian O Olivares
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee.
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30
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Wenzel DM, Mackay DR, Skalicky JJ, Paine EL, Miller MS, Ullman KS, Sundquist WI. Comprehensive analysis of the human ESCRT-III-MIT domain interactome reveals new cofactors for cytokinetic abscission. eLife 2022; 11:e77779. [PMID: 36107470 PMCID: PMC9477494 DOI: 10.7554/elife.77779] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Abstract
The 12 related human ESCRT-III proteins form filaments that constrict membranes and mediate fission, including during cytokinetic abscission. The C-terminal tails of polymerized ESCRT-III subunits also bind proteins that contain Microtubule-Interacting and Trafficking (MIT) domains. MIT domains can interact with ESCRT-III tails in many different ways to create a complex binding code that is used to recruit essential cofactors to sites of ESCRT activity. Here, we have comprehensively and quantitatively mapped the interactions between all known ESCRT-III tails and 19 recombinant human MIT domains. We measured 228 pairwise interactions, quantified 60 positive interactions, and discovered 18 previously unreported interactions. We also report the crystal structure of the SPASTIN MIT domain in complex with the IST1 C-terminal tail. Three MIT enzymes were studied in detail and shown to: (1) localize to cytokinetic midbody membrane bridges through interactions with their specific ESCRT-III binding partners (SPASTIN-IST1, KATNA1-CHMP3, and CAPN7-IST1), (2) function in abscission (SPASTIN, KATNA1, and CAPN7), and (3) function in the 'NoCut' abscission checkpoint (SPASTIN and CAPN7). Our studies define the human MIT-ESCRT-III interactome, identify new factors and activities required for cytokinetic abscission and its regulation, and provide a platform for analyzing ESCRT-III and MIT cofactor interactions in all ESCRT-mediated processes.
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Affiliation(s)
- Dawn M Wenzel
- Department of Biochemistry, University of Utah School of MedicineSalt Lake CityUnited States
| | - Douglas R Mackay
- Department of Oncological Sciences, Huntsman Cancer Institute, University of UtahSalt Lake CityUnited States
| | - Jack J Skalicky
- Department of Biochemistry, University of Utah School of MedicineSalt Lake CityUnited States
| | - Elliott L Paine
- Department of Biochemistry, University of Utah School of MedicineSalt Lake CityUnited States
| | - Matthew S Miller
- Department of Biochemistry, University of Utah School of MedicineSalt Lake CityUnited States
| | - Katharine S Ullman
- Department of Oncological Sciences, Huntsman Cancer Institute, University of UtahSalt Lake CityUnited States
| | - Wesley I Sundquist
- Department of Biochemistry, University of Utah School of MedicineSalt Lake CityUnited States
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31
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Kontou A, Herman EK, Field MC, Dacks JB, Koumandou VL. Evolution of factors shaping the endoplasmic reticulum. Traffic 2022; 23:462-473. [PMID: 36040076 PMCID: PMC9804665 DOI: 10.1111/tra.12863] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 06/30/2022] [Accepted: 07/24/2022] [Indexed: 01/09/2023]
Abstract
Endomembrane system compartments are significant elements in virtually all eukaryotic cells, supporting functions including protein synthesis, post-translational modifications and protein/lipid targeting. In terms of membrane area the endoplasmic reticulum (ER) is the largest intracellular organelle, but the origins of proteins defining the organelle and the nature of lineage-specific modifications remain poorly studied. To understand the evolution of factors mediating ER morphology and function we report a comparative genomics analysis of experimentally characterized ER-associated proteins involved in maintaining ER structure. We find that reticulons, REEPs, atlastins, Ufe1p, Use1p, Dsl1p, TBC1D20, Yip3p and VAPs are highly conserved, suggesting an origin at least as early as the last eukaryotic common ancestor (LECA), although many of these proteins possess additional non-ER functions in modern eukaryotes. Secondary losses are common in individual species and in certain lineages, for example lunapark is missing from the Stramenopiles and the Alveolata. Lineage-specific innovations include protrudin, Caspr1, Arl6IP1, p180, NogoR, kinectin and CLIMP-63, which are restricted to the Opisthokonta. Hence, much of the machinery required to build and maintain the ER predates the LECA, but alternative strategies for the maintenance and elaboration of ER shape and function are present in modern eukaryotes. Moreover, experimental investigations for ER maintenance factors in diverse eukaryotes are expected to uncover novel mechanisms.
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Affiliation(s)
- Aspasia Kontou
- Genetics Laboratory, Department of BiotechnologyAgricultural University of AthensAthensGreece
| | - Emily K. Herman
- Division of Infectious Diseases, Department of MedicineUniversity of AlbertaEdmontonAlbertaCanada,Present address:
Department of Agricultural, Food and Nutritional Science, Faculty of Agricultural, Life and Environmental SciencesUniversity of AlbertaEdmontonAlbertaCanada
| | - Mark C. Field
- School of Life SciencesUniversity of DundeeDundeeUK,Biology CentreCzech Academy of SciencesČeské BudějoviceCzech Republic
| | - Joel B. Dacks
- Division of Infectious Diseases, Department of MedicineUniversity of AlbertaEdmontonAlbertaCanada,Biology CentreCzech Academy of SciencesČeské BudějoviceCzech Republic,Centre for Life's Origin and Evolution, Department of Genetics, Evolution and EnvironmentUniversity College of LondonLondonUK
| | - V. Lila Koumandou
- Genetics Laboratory, Department of BiotechnologyAgricultural University of AthensAthensGreece
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32
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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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33
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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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34
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Kuo YW, Mahamdeh M, Tuna Y, Howard J. The force required to remove tubulin from the microtubule lattice by pulling on its α-tubulin C-terminal tail. Nat Commun 2022; 13:3651. [PMID: 35752623 PMCID: PMC9233703 DOI: 10.1038/s41467-022-31069-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/01/2022] [Indexed: 11/18/2022] Open
Abstract
Severing enzymes and molecular motors extract tubulin from the walls of microtubules by exerting mechanical force on subunits buried in the lattice. However, how much force is needed to remove tubulin from microtubules is not known, nor is the pathway by which subunits are removed. Using a site-specific functionalization method, we applied forces to the C-terminus of α-tubulin with an optical tweezer and found that a force of ~30 pN is required to extract tubulin from the microtubule wall. Additionally, we discovered that partial unfolding is an intermediate step in tubulin removal. The unfolding and extraction forces are similar to those generated by AAA-unfoldases. Lastly, we show that three kinesin-1 motor proteins can also extract tubulin from the microtubule lattice. Our results provide the first experimental investigation of how tubulin responds to mechanical forces exerted on its α-tubulin C-terminal tail and have implications for the mechanisms of severing enzymes and microtubule stability. Tubulin, the building blocks of microtubules, can be removed from the microtubule wall by mechanical forces. Using single-molecule methods, the authors show that tubulin partially unfolds prior to its removal and determined the tubulin-extraction force.
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Affiliation(s)
- Yin-Wei Kuo
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Mohammed Mahamdeh
- Harvard Medical School, Boston, MA, USA.,Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Yazgan Tuna
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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35
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Akhmanova A, Kapitein LC. Mechanisms of microtubule organization in differentiated animal cells. Nat Rev Mol Cell Biol 2022; 23:541-558. [PMID: 35383336 DOI: 10.1038/s41580-022-00473-y] [Citation(s) in RCA: 57] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2022] [Indexed: 02/08/2023]
Abstract
Microtubules are polarized cytoskeletal filaments that serve as tracks for intracellular transport and form a scaffold that positions organelles and other cellular components and modulates cell shape and mechanics. In animal cells, the geometry, density and directionality of microtubule networks are major determinants of cellular architecture, polarity and proliferation. In dividing cells, microtubules form bipolar spindles that pull chromosomes apart, whereas in interphase cells, microtubules are organized in a cell type-specific fashion, which strongly correlates with cell physiology. In motile cells, such as fibroblasts and immune cells, microtubules are organized as radial asters, whereas in immotile epithelial and neuronal cells and in muscles, microtubules form parallel or antiparallel arrays and cortical meshworks. Here, we review recent work addressing how the formation of such microtubule networks is driven by the plethora of microtubule regulatory proteins. These include proteins that nucleate or anchor microtubule ends at different cellular structures and those that sever or move microtubules, as well as regulators of microtubule elongation, stability, bundling or modifications. The emerging picture, although still very incomplete, shows a remarkable diversity of cell-specific mechanisms that employ conserved building blocks to adjust microtubule organization in order to facilitate different cellular functions.
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Affiliation(s)
- Anna Akhmanova
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands.
| | - Lukas C Kapitein
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands.
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36
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Kuo YW, Howard J. In Vitro Reconstitution of Microtubule Dynamics and Severing Imaged by Label-Free Interference-Reflection Microscopy. Methods Mol Biol 2022; 2430:73-91. [PMID: 35476326 PMCID: PMC9131738 DOI: 10.1007/978-1-0716-1983-4_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dynamic architecture of the microtubule cytoskeleton is crucial for cell division, motility and morphogenesis. The dynamic properties of microtubules-growth, shrinkage, nucleation, and severing-are regulated by an arsenal of microtubule-associated proteins (MAPs). The activities of many of these MAPs have been reconstituted in vitro using microscope assays. As an alternative to fluorescence microscopy, interference-reflection microscopy (IRM) has been introduced as an easy-to-use, wide-field imaging technique that allows label-free visualization of microtubules with high contrast and speed. IRM circumvents several problems associated with fluorescence microscopy including the high concentrations of tubulin required for fluorescent labeling, the potential perturbation of function caused by the fluorophores, and the risks of photodamage. IRM can be implemented on a standard epifluorescence microscope at low cost and can be combined with fluorescence techniques like total-internal-reflection-fluorescence (TIRF) microscopy. Here we describe the experimental procedure to image microtubule dynamics and severing using IRM , providing practical tips and guidelines to resolve possible experimental hurdles.
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Affiliation(s)
- Yin-Wei Kuo
- Department of Chemistry, Yale University, New Haven, CT, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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Li CR, Wang RL, Xie SY, Li YR, Gao LL, Yang ZX, Zhang D. Fidgetin knockdown and knockout influences female reproduction distinctly in mice. J Biomed Res 2022; 36:269-279. [PMID: 35965436 PMCID: PMC9376731 DOI: 10.7555/jbr.36.20220086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Microtubule-severing proteins (MTSPs), are a family of proteins which use adenosine triphosphate to sever microtubules. MTSPs have been shown to play an important role in multiple microtubule-involved cellular processes. One member of this family, fidgetin (FIGN), is also involved in male fertility; however, no studies have explored its roles in female fertility. In this study, we found mouse fidgetin is rich within oocyte zona pellucida (ZP) and is the only MTSP member to do so. Fidgetin also appears to interact with all three ZP proteins. These findings prompted us to propose that fidgetin might prevent polyspermy. Results from in vitro maturation oocytes analysis showed that fidgetin knockdown did cause polyspermy. We then deleted all three fidgetin isoforms with CRISPR/Cas9 technologies; however, female mice remained healthy and with normal fertility. Of all mouse MTSPs, only the mRNA level of fidgetin-like 1 (FIGNL1) significantly increased. Therefore, we assert that fidgetin-like 1 compensates fidgetin's roles in fidgetin knockout female mice.
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Affiliation(s)
- Cong-Rong Li
- State Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Ruo-Lei Wang
- State Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Shi-Ya Xie
- State Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yan-Ru Li
- State Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Lei-Lei Gao
- State Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Zhi-Xia Yang
- State Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Dong Zhang and Zhi-Xia Yang, State Key Lab of Reproductive Medicine, Nanjing Medical University, 101 Longmian Ave, Nanjing, Jiangsu 211166, China. Tel/Fax: +86-25-86869504, E-mails:
and
| | - Dong Zhang
- State Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Animal Core Facility, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Dong Zhang and Zhi-Xia Yang, State Key Lab of Reproductive Medicine, Nanjing Medical University, 101 Longmian Ave, Nanjing, Jiangsu 211166, China. Tel/Fax: +86-25-86869504, E-mails:
and
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Lawrence EJ, Arpag G, Arnaiz C, Zanic M. SSNA1 stabilizes dynamic microtubules and detects microtubule damage. eLife 2021; 10:67282. [PMID: 34970964 PMCID: PMC8798045 DOI: 10.7554/elife.67282] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 12/30/2021] [Indexed: 11/13/2022] Open
Abstract
Sjögren’s syndrome nuclear autoantigen-1 (SSNA1/NA14) is a microtubule-associated protein with important functions in cilia, dividing cells, and developing neurons. However, the direct effects of SSNA1 on microtubules are not known. We employed in vitro reconstitution with purified proteins and TIRF microscopy to investigate the activity of human SSNA1 on dynamic microtubule ends and lattices. Our results show that SSNA1 modulates all parameters of microtubule dynamic instability—slowing down the rates of growth, shrinkage, and catastrophe, and promoting rescue. We find that SSNA1 forms stretches along growing microtubule ends and binds cooperatively to the microtubule lattice. Furthermore, SSNA1 is enriched on microtubule damage sites, occurring both naturally, as well as induced by the microtubule severing enzyme spastin. Finally, SSNA1 binding protects microtubules against spastin’s severing activity. Taken together, our results demonstrate that SSNA1 is both a potent microtubule-stabilizing protein and a novel sensor of microtubule damage; activities that likely underlie SSNA1’s functions on microtubule structures in cells.
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Affiliation(s)
- Elizabeth J Lawrence
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Goker Arpag
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States
| | - Cayetana Arnaiz
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Marija Zanic
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States
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Bu S, Yong WL, Lim BJW, Kondo S, Yu F. A systematic analysis of microtubule-destabilizing factors during dendrite pruning in Drosophila. EMBO Rep 2021; 22:e52679. [PMID: 34338441 DOI: 10.15252/embr.202152679] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 07/10/2021] [Accepted: 07/12/2021] [Indexed: 11/09/2022] Open
Abstract
It has long been thought that microtubule disassembly, one of the earliest cellular events, contributes to neuronal pruning and neurodegeneration in development and disease. However, how microtubule disassembly drives neuronal pruning remains poorly understood. Here, we conduct a systematic investigation of various microtubule-destabilizing factors and identify exchange factor for Arf6 (Efa6) and Stathmin (Stai) as new regulators of dendrite pruning in ddaC sensory neurons during Drosophila metamorphosis. We show that Efa6 is both necessary and sufficient to regulate dendrite pruning. Interestingly, Efa6 and Stai facilitate microtubule turnover and disassembly prior to dendrite pruning without compromising the minus-end-out microtubule orientation in dendrites. Moreover, our pharmacological and genetic manipulations strongly support a key role of microtubule disassembly in promoting dendrite pruning. Thus, this systematic study highlights the importance of two selective microtubule destabilizers in dendrite pruning and substantiates a causal link between microtubule disassembly and neuronal pruning.
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Affiliation(s)
- Shufeng Bu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Wei Lin Yong
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Bryan Jian Wei Lim
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Shu Kondo
- Invertebrate Genetics Laboratory, National Institute of Genetics, Shizuoka, Japan
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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Barisic M, Rajendraprasad G, Steblyanko Y. The metaphase spindle at steady state - Mechanism and functions of microtubule poleward flux. Semin Cell Dev Biol 2021; 117:99-117. [PMID: 34053864 DOI: 10.1016/j.semcdb.2021.05.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/13/2021] [Accepted: 05/13/2021] [Indexed: 11/24/2022]
Abstract
The mitotic spindle is a bipolar cellular structure, built from tubulin polymers, called microtubules, and interacting proteins. This macromolecular machine orchestrates chromosome segregation, thereby ensuring accurate distribution of genetic material into the two daughter cells during cell division. Powered by GTP hydrolysis upon tubulin polymerization, the microtubule ends exhibit a metastable behavior known as the dynamic instability, during which they stochastically switch between the growth and shrinkage phases. In the context of the mitotic spindle, dynamic instability is furthermore regulated by microtubule-associated proteins and motor proteins, which enables the spindle to undergo profound changes during mitosis. This highly dynamic behavior is essential for chromosome capture and congression in prometaphase, as well as for chromosome alignment to the spindle equator in metaphase and their segregation in anaphase. In this review we focus on the mechanisms underlying microtubule dynamics and sliding and their importance for the maintenance of shape, structure and dynamics of the metaphase spindle. We discuss how these spindle properties are related to the phenomenon of microtubule poleward flux, highlighting its highly cooperative molecular basis and role in keeping the metaphase spindle at a steady state.
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Affiliation(s)
- Marin Barisic
- Cell Division and Cytoskeleton, Danish Cancer Society Research Center (DCRC), Strandboulevarden 49, 2100 Copenhagen, Denmark; Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
| | - Girish Rajendraprasad
- Cell Division and Cytoskeleton, Danish Cancer Society Research Center (DCRC), Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Yulia Steblyanko
- Cell Division and Cytoskeleton, Danish Cancer Society Research Center (DCRC), Strandboulevarden 49, 2100 Copenhagen, Denmark
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41
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To nucleate or not, that is the question in neurons. Neurosci Lett 2021; 751:135806. [PMID: 33705928 DOI: 10.1016/j.neulet.2021.135806] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/23/2021] [Accepted: 02/26/2021] [Indexed: 01/19/2023]
Abstract
Microtubules are the structural center of neurons, stretching in overlapping arrays from the cell body to the far reaches of axons and dendrites. They also act as the tracks for long-range transport mediated by dynein and kinesin motors. Transcription and most translation take place in the cell body, and newly made cargoes must be shipped from this site of synthesis to sites of function in axons and dendrites. This constant demand for transport means that the microtubule array must be present without gaps throughout the cell over the lifetime of the animal. This task is made slightly easier in many animals by the relatively long, stable microtubules present in neurons. However, even stable neuronal microtubules have ends that are dynamic, and individual microtubules typically last on the order of hours, while the neurons around them last a lifetime. "Birth" of new microtubules is therefore required to maintain the neuronal microtubule array. In this review we discuss the nucleation of new microtubules in axons and dendrites, including how and where they are nucleated. In addition, it is becoming clear that neuronal microtubule nucleation is highly regulated, with unexpected machinery impinging on the decision of whether nucleation sites are active or inactive through space and time.
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Bogan JS. Granular detail of β cell structures for insulin secretion. J Cell Biol 2021; 220:e202012082. [PMID: 33427875 PMCID: PMC7802365 DOI: 10.1083/jcb.202012082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pancreatic β cells secrete insulin in response to increased glucose concentrations. Müller et al. (2021. J. Cell Biol. https://doi.org/10.1083/jcb.202010039) use 3D FIB-SEM to study the architecture of these cells and to elucidate how glucose stimulation remodels microtubules to control insulin secretory granule exocytosis.
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Affiliation(s)
- Jonathan S. Bogan
- Section of Endocrinology and Metabolism, Department of Internal Medicine; and Department of Cell Biology, Yale School of Medicine, New Haven, CT
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Heinze K, Rengsberger M, Gajda M, Jansen L, Osmers L, Oliveira-Ferrer L, Schmalfeldt B, Dürst M, Häfner N, Runnebaum IB. CAMK2N1/RUNX3 methylation is an independent prognostic biomarker for progression-free and overall survival of platinum-sensitive epithelial ovarian cancer patients. Clin Epigenetics 2021; 13:15. [PMID: 33482905 PMCID: PMC7824928 DOI: 10.1186/s13148-021-01006-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 01/05/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND To date, no predictive or prognostic molecular biomarkers except BRCA mutations are clinically established for epithelial ovarian cancer (EOC) despite being the deadliest gynecological malignancy. Aim of this biomarker study was the analysis of DNA methylation biomarkers for their prognostic value independent from clinical variables in a heterogeneous cohort of 203 EOC patients from two university medical centers. RESULTS The marker combination CAMK2N1/RUNX3 exhibited a significant prognostic value for progression-free (PFS) and overall survival (OS) of sporadic platinum-sensitive EOC (n = 188) both in univariate Kaplan-Meier (LogRank p < 0.05) and multivariate Cox regression analysis (p < 0.05; hazard ratio HR = 1.587). KRT86 methylation showed a prognostic value only in univariate analysis because of an association with FIGO staging (Fisher's exact test p < 0.01). Thus, it may represent a marker for EOC staging. Dichotomous prognostic values were observed for KATNAL2 methylation depending on BRCA aberrations. KATNAL2 methylation exhibited a negative prognostic value for PFS in sporadic EOC patients without BRCA1 methylation (HR 1.591, p = 0.012) but positive prognostic value in sporadic EOC with BRCA1 methylation (HR 0.332, p = 0.04) or BRCA-mutated EOC (HR 0.620, n.s.). CONCLUSION The retrospective analysis of 188 sporadic platinum-sensitive EOC proved an independent prognostic value of the methylation marker combination CAMK2N1/RUNX3 for PFS and OS. If validated prospectively this combination may identify EOC patients with worse prognosis after standard therapy potentially benefiting from intensive follow-up, maintenance therapies or inclusion in therapeutic studies. The dichotomous prognostic value of KATNAL2 should be validated in larger sample sets of EOC.
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Affiliation(s)
- Karolin Heinze
- Department of Gynecology and Reproduction Medicine, Jena University Hospital-Friedrich Schiller University Jena, 07747, Jena, Germany
| | - Matthias Rengsberger
- Department of Gynecology and Reproduction Medicine, Jena University Hospital-Friedrich Schiller University Jena, 07747, Jena, Germany
| | - Mieczyslaw Gajda
- Department of Forensic Medicine, Section of Pathology, Jena University Hospital - Friedrich Schiller University Jena, 07747, Jena, Germany
| | - Lars Jansen
- Department of Gynecology and Reproduction Medicine, Jena University Hospital-Friedrich Schiller University Jena, 07747, Jena, Germany
| | - Linea Osmers
- Department of Gynecology and Reproduction Medicine, Jena University Hospital-Friedrich Schiller University Jena, 07747, Jena, Germany
| | - Leticia Oliveira-Ferrer
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Barbara Schmalfeldt
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Matthias Dürst
- Department of Gynecology and Reproduction Medicine, Jena University Hospital-Friedrich Schiller University Jena, 07747, Jena, Germany
| | - Norman Häfner
- Department of Gynecology and Reproduction Medicine, Jena University Hospital-Friedrich Schiller University Jena, 07747, Jena, Germany.
| | - Ingo B Runnebaum
- Department of Gynecology and Reproduction Medicine, Jena University Hospital-Friedrich Schiller University Jena, 07747, Jena, Germany.
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