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Kubo T, Sasaki R, Oda T. Tubulin glycylation controls ciliary motility through modulation of outer-arm dyneins. Mol Biol Cell 2024; 35:ar90. [PMID: 38758663 PMCID: PMC11244163 DOI: 10.1091/mbc.e24-04-0154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2024] Open
Abstract
Tubulins undergo several kinds of posttranslational modifications (PTMs) including glutamylation and glycylation. The contribution of these PTMs to the motilities of cilia and flagella is still unclear. Here, we investigated the role of tubulin glycylation by examining a novel Chlamydomonas mutant lacking TTLL3, an enzyme responsible for initiating glycylation. Immunostaining of cells and flagella revealed that glycylation is only restricted to the axonemal tubulin composing the outer-doublet but not the central-pair microtubules. Furthermore, the flagellar localization of TTLL3 was found to be dependent on intraflagellar transport. The mutant, ttll3(ex5), completely lacks glycylation and consequently exhibits slower swimming velocity compared with the wild-type strain. By combining the ttll3(ex5) mutation with multiple axonemal dynein-deficient mutants, we found that the lack of glycylation does not affect the motility of the outer-arm dynein lacking mutations. Sliding disintegration assay using isolated axonemes revealed that the lack of glycylation decreases microtubule sliding velocity in the normal axoneme but not in the axoneme lacking the outerarm dyneins. Based on our recent study that glycylation occurs exclusively on β-tubulin in Chlamydomonas, these findings suggest that tubulin glycylation controls flagellar motility through modulating outer-arm dyneins, presumably by neutralizing the negative charges of glutamate residues at the C-terminus region of β-tubulin.
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Affiliation(s)
- Tomohiro Kubo
- Department of Anatomy and Structural Biology, Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan
| | - Rinka Sasaki
- Department of Anatomy and Structural Biology, Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan
| | - Toshiyuki Oda
- Department of Anatomy and Structural Biology, Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan
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2
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Gao J, Tong M, Lee C, Gaertig J, Legal T, Bui KH. DomainFit: Identification of protein domains in cryo-EM maps at intermediate resolution using AlphaFold2-predicted models. Structure 2024:S0969-2126(24)00143-6. [PMID: 38754431 DOI: 10.1016/j.str.2024.04.017] [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: 11/28/2023] [Revised: 03/18/2024] [Accepted: 04/19/2024] [Indexed: 05/18/2024]
Abstract
Cryoelectron microscopy (cryo-EM) has revolutionized the structural determination of macromolecular complexes. With the paradigm shift to structure determination of highly complex endogenous macromolecular complexes ex vivo and in situ structural biology, there are an increasing number of structures of native complexes. These complexes often contain unidentified proteins, related to different cellular states or processes. Identifying proteins at resolutions lower than 4 Å remains challenging because side chains cannot be visualized reliably. Here, we present DomainFit, a program for semi-automated domain-level protein identification from cryo-EM maps, particularly at resolutions lower than 4 Å. By fitting domains from AlphaFold2-predicted models into cryo-EM maps, the program performs statistical analyses and attempts to identify the domains and protein candidates forming the density. Using DomainFit, we identified two microtubule inner proteins, one of which contains a CCDC81 domain and is exclusively localized in the proximal region of the doublet microtubule in Tetrahymena thermophila.
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Affiliation(s)
- Jerry Gao
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Montréal, QC H3A 0C7, Canada; Centre de recherche en biologie structurale, McGill University, Montréal, QC H3G 0B1, Canada
| | - Maxwell Tong
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Montréal, QC H3A 0C7, Canada; Centre de recherche en biologie structurale, McGill University, Montréal, QC H3G 0B1, Canada
| | - Chinkyu Lee
- Department of Cellular Biology, University of Georgia, Athens 30602-2607, GA, USA
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens 30602-2607, GA, USA
| | - Thibault Legal
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Montréal, QC H3A 0C7, Canada; Centre de recherche en biologie structurale, McGill University, Montréal, QC H3G 0B1, Canada.
| | - Khanh Huy Bui
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Montréal, QC H3A 0C7, Canada; Centre de recherche en biologie structurale, McGill University, Montréal, QC H3G 0B1, Canada.
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3
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Wu S, Ran L, Zhang T, Li Y, Xu Y, Li Y, Liu H, Wang J. BdTTLL3B-mediated polyglycylation is involved in the spermatogenesis in Bactrocera dorsalis. Int J Biol Macromol 2024; 267:131508. [PMID: 38604421 DOI: 10.1016/j.ijbiomac.2024.131508] [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: 01/24/2024] [Revised: 02/29/2024] [Accepted: 04/08/2024] [Indexed: 04/13/2024]
Abstract
Polyglycylation is a post-translational modification that generates glycine side chains in the C-terminal domains of both α- and β-tubulins. To date, the patterns and significance of polyglycylation across insect species remain largely unknown. The TTLL3B was thought to be a polyglycylase and be essential for polyglycylation in dipteran insects. In this study, the TTLL3B of Bactrocera dorsalis (BdTTLL3B) was identified and characterized. The BdTTLL3B expressed remarkably higher in adult males, especially in testes. The spatio-temporal patterns of polyglycylation were consistent with that of BdTTLL3B. Along with spermatogenesis, the intensity of polyglycylation was enhanced steadily and concentrated in elongated flagella. The expression of recombinant BdTTLL3B in Hela cells, which are genetically deficient in polyglycylation, catalyzed intracellular polyglycylation, validating the identity of BdTTLL3B as a polyglycylase. Knockout of BdTTLL3B significantly suppressed polyglycylation in testes and impaired male fertility, probably due to abnormal morphology of mitochondrial derivatives and over-accumulation of paracrystalline. Taken together, these findings indicated that the BdTTLL3B-mediated polyglycylation is involved in the spermatogenesis and play an important role in fertility of adult B. dorsalis. Therefore, the BdTTLL3B can be considered as a candidate target gene for the management of B. dorsalis, such as developing gene silencing/knockout-based sterile insect technology (SIT).
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Affiliation(s)
- Shunjiao Wu
- College of Plant Protection, Southwest University, Chongqing 400715, China; Key Laboratory of Agriculture Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing 400715, China
| | - Lilin Ran
- College of Plant Protection, Southwest University, Chongqing 400715, China; Key Laboratory of Agriculture Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing 400715, China
| | - Tongfang Zhang
- College of Food Science, Southwest University, Chongqing 400715, China
| | - Ying Li
- College of Plant Protection, Southwest University, Chongqing 400715, China; Key Laboratory of Agriculture Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing 400715, China
| | - Yonghong Xu
- College of Plant Protection, Southwest University, Chongqing 400715, China; Key Laboratory of Agriculture Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing 400715, China
| | - Yaying Li
- College of Plant Protection, Southwest University, Chongqing 400715, China; Key Laboratory of Agriculture Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing 400715, China
| | - Huai Liu
- College of Plant Protection, Southwest University, Chongqing 400715, China; Key Laboratory of Agriculture Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing 400715, China.
| | - Jia Wang
- College of Plant Protection, Southwest University, Chongqing 400715, China; Key Laboratory of Agriculture Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing 400715, China.
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4
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Gao J, Tong M, Lee C, Gaertig J, Legal T, Bui KH. DomainFit: Identification of Protein Domains in cryo-EM maps at Intermediate Resolution using AlphaFold2-predicted Models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.28.569001. [PMID: 38077012 PMCID: PMC10705406 DOI: 10.1101/2023.11.28.569001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
Cryo-electron microscopy (cryo-EM) has revolutionized our understanding of macromolecular complexes, enabling high-resolution structure determination. With the paradigm shift to in situ structural biology recently driven by the ground-breaking development of cryo-focused ion beam milling and cryo-electron tomography, there are an increasing number of structures at sub-nanometer resolution of complexes solved directly within their cellular environment. These cellular complexes often contain unidentified proteins, related to different cellular states or processes. Identifying proteins at resolutions lower than 4 Å remains challenging because the side chains cannot be visualized reliably. Here, we present DomainFit, a program for automated domain-level protein identification from cryo-EM maps at resolutions lower than 4 Å. By fitting domains from artificial intelligence-predicted models such as AlphaFold2-predicted models into cryo-EM maps, the program performs statistical analyses and attempts to identify the proteins forming the density. Using DomainFit, we identified two microtubule inner proteins, one of them, a CCDC81 domain-containing protein, is exclusively localized in the proximal region of the doublet microtubule from the ciliate Tetrahymena thermophila. The flexibility and capability of DomainFit makes it a valuable tool for analyzing in situ structures.
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Affiliation(s)
- Jerry Gao
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Québec, Canada
- Centre de recherche en biologie structurale, McGill University, Montréal, Quebec, Canada
| | - Max Tong
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Québec, Canada
- Centre de recherche en biologie structurale, McGill University, Montréal, Quebec, Canada
| | - Chinkyu Lee
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Thibault Legal
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Québec, Canada
- Centre de recherche en biologie structurale, McGill University, Montréal, Quebec, Canada
| | - Khanh Huy Bui
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Québec, Canada
- Centre de recherche en biologie structurale, McGill University, Montréal, Quebec, Canada
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5
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Legal T, Parra M, Tong M, Black CS, Joachimiak E, Valente-Paterno M, Lechtreck K, Gaertig J, Bui KH. CEP104/FAP256 and associated cap complex maintain stability of the ciliary tip. J Cell Biol 2023; 222:e202301129. [PMID: 37756660 PMCID: PMC10522465 DOI: 10.1083/jcb.202301129] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 07/13/2023] [Accepted: 08/30/2023] [Indexed: 09/29/2023] Open
Abstract
Cilia are essential organelles that protrude from the cell body. Cilia are made of a microtubule-based structure called the axoneme. In most types of cilia, the ciliary tip is distinct from the rest of the cilium. Here, we used cryo-electron tomography and subtomogram averaging to obtain the structure of the ciliary tip of the ciliate Tetrahymena thermophila. We show that the microtubules at the tip are highly crosslinked with each other and stabilized by luminal proteins, plugs, and cap proteins at the plus ends. In the tip region, the central pair lacks typical projections and twists significantly. By analyzing cells lacking a ciliary tip-enriched protein CEP104/FAP256 by cryo-electron tomography and proteomics, we discovered candidates for the central pair cap complex and explained the potential functions of CEP104/FAP256. These data provide new insights into the function of the ciliary tip and the mechanisms of ciliary assembly and length regulation.
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Affiliation(s)
- Thibault Legal
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Québec, Canada
| | - Mireya Parra
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Maxwell Tong
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Québec, Canada
| | - Corbin S. Black
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Québec, Canada
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Melissa Valente-Paterno
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Québec, Canada
| | - Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Khanh Huy Bui
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Québec, Canada
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6
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McKenna ED, Sarbanes SL, Cummings SW, Roll-Mecak A. The Tubulin Code, from Molecules to Health and Disease. Annu Rev Cell Dev Biol 2023; 39:331-361. [PMID: 37843925 DOI: 10.1146/annurev-cellbio-030123-032748] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Microtubules are essential dynamic polymers composed of α/β-tubulin heterodimers. They support intracellular trafficking, cell division, cellular motility, and other essential cellular processes. In many species, both α-tubulin and β-tubulin are encoded by multiple genes with distinct expression profiles and functionality. Microtubules are further diversified through abundant posttranslational modifications, which are added and removed by a suite of enzymes to form complex, stereotyped cellular arrays. The genetic and chemical diversity of tubulin constitute a tubulin code that regulates intrinsic microtubule properties and is read by cellular effectors, such as molecular motors and microtubule-associated proteins, to provide spatial and temporal specificity to microtubules in cells. In this review, we synthesize the rapidly expanding tubulin code literature and highlight limitations and opportunities for the field. As complex microtubule arrays underlie essential physiological processes, a better understanding of how cells employ the tubulin code has important implications for human disease ranging from cancer to neurological disorders.
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Affiliation(s)
- Elizabeth D McKenna
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
| | - Stephanie L Sarbanes
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
| | - Steven W Cummings
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA
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7
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Kubo T, Tani Y, Yanagisawa HA, Kikkawa M, Oda T. α- and β-tubulin C-terminal tails with distinct modifications are crucial for ciliary motility and assembly. J Cell Sci 2023; 136:jcs261070. [PMID: 37519241 DOI: 10.1242/jcs.261070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 07/24/2023] [Indexed: 08/01/2023] Open
Abstract
α- and β-tubulin have an unstructured glutamate-rich region at their C-terminal tails (CTTs). The function of this region in cilia and flagella is still unclear, except that glutamates in CTTs act as the sites for post-translational modifications that affect ciliary motility. The unicellular alga Chlamydomonas possesses only two α-tubulin and two β-tubulin genes, each pair encoding an identical protein. This simple gene organization might enable a complete replacement of the wild-type tubulin with its mutated version. Here, using CRISPR/Cas9, we generated mutant strains expressing tubulins with modified CTTs. We found that the mutant strain in which four glutamate residues in the α-tubulin CTT had been replaced by alanine almost completely lacked polyglutamylated tubulin and displayed paralyzed cilia. In contrast, the mutant strain lacking the glutamate-rich region of the β-tubulin CTT assembled short cilia without the central apparatus. This phenotype is similar to mutant strains harboring a mutation in a subunit of katanin, the function of which has been shown to depend on the β-tubulin CTT. Therefore, our study reveals distinct and important roles of α- and β-tubulin CTTs in the formation and function of cilia.
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Affiliation(s)
- Tomohiro Kubo
- Department of Anatomy and Structural Biology, Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| | - Yuma Tani
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033, Japan
| | - Haru-Aki Yanagisawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masahide Kikkawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toshiyuki Oda
- Department of Anatomy and Structural Biology, Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
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8
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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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9
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RpS3 Is Required for Spermatogenesis of Drosophila melanogaster. Cells 2023; 12:cells12040573. [PMID: 36831240 PMCID: PMC9954509 DOI: 10.3390/cells12040573] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 02/03/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023] Open
Abstract
Ribosomal proteins (RPs) constitute the ribosome, thus participating in the protein biosynthesis process. Emerging studies have suggested that many RPs exhibit different expression levels across various tissues and function in a context-dependent manner for animal development. Drosophila melanogaster RpS3 encodes the ribosomal protein S3, one component of the 40S subunit of ribosomes. We found that RpS3 is highly expressed in the reproductive organs of adult flies and its depletion in male germline cells led to severe defects in sperm production and male fertility. Immunofluorescence staining showed that RpS3 knockdown had little effect on early germ cell differentiation, but strongly disrupted the spermatid elongation and individualization processes. Furthermore, we observed abnormal morphology and activity of mitochondrial derivatives in the elongating spermatids of RpS3-knockdown testes, which could cause the failure of axoneme elongation. We also found that RpS3 RNAi inhibited the formation of the individualization complex that takes charge of disassociating the spermatid bundle. In addition, excessive apoptotic cells were detected in the RpS3-knockdown testes, possibly to clean the defective spermatids. Together, our data demonstrated that RpS3 plays an important role in regulating spermatid elongation and individualization processes and, therefore, is required for normal Drosophila spermatogenesis.
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10
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Liu C, Chen Y, Xie Y, Xiang M. Tubulin Post-translational Modifications: Potential Therapeutic Approaches to Heart Failure. Front Cell Dev Biol 2022; 10:872058. [PMID: 35493101 PMCID: PMC9039000 DOI: 10.3389/fcell.2022.872058] [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] [Received: 02/09/2022] [Accepted: 03/09/2022] [Indexed: 11/13/2022] Open
Abstract
In recent decades, advancing insights into the mechanisms of cardiac dysfunction have focused on the involvement of microtubule network. A variety of tubulin post-translational modifications have been discovered to fine-tune the microtubules’ properties and functions. Given the limits of therapies based on conserved structures of the skeleton, targeting tubulin modifications appears to be a potentially promising therapeutic strategy. Here we review the current understanding of tubulin post-translational modifications in regulating microtubule functions in the cardiac system. We also discussed how altered modifications may lead to a range of cardiac dysfunctions, many of which are linked to heart failure.
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Affiliation(s)
- Chang Liu
- Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuwen Chen
- Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yao Xie
- Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Meixiang Xiang
- Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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11
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Gadadhar S, Hirschmugl T, Janke C. The tubulin code in mammalian sperm development and function. Semin Cell Dev Biol 2022; 137:26-37. [PMID: 35067438 DOI: 10.1016/j.semcdb.2021.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 01/11/2023]
Abstract
Microtubules are cytoskeletal elements that play key roles throughout the different steps of sperm development. As an integral part of the sperm flagellum, the molecular machine that generates sperm motility, microtubules are also essential for the progressive swimming of sperm to the oocyte, which is a prerequisite for fertilisation. Given the central role of microtubules in all steps of spermatogenesis, their functions need to be tightly controlled. Recent work has showcased tubulin posttranslational modifications as key players in sperm development and function, with aberrations often leading to male infertility with a broad spectrum of sperm defects. Posttranslational modifications are part of the tubulin code, a mechanism that can control microtubule functions by modulating the properties of their molecular building blocks, the tubulin proteins. Here we review the current knowledge on the implications of the tubulin code in sperm development and functions and its importance for male fertility.
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Affiliation(s)
- Sudarshan Gadadhar
- Institut Curie, Université PSL, CNRS UMR3348, F-91401 Orsay, France; Université Paris-Saclay, CNRS UMR3348, F-91401 Orsay, France.
| | | | - Carsten Janke
- Institut Curie, Université PSL, CNRS UMR3348, F-91401 Orsay, France; Université Paris-Saclay, CNRS UMR3348, F-91401 Orsay, France.
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12
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Joachimiak E, Wloga D. Tubulin post-translational modifications in protists - Tiny models for solving big questions. Semin Cell Dev Biol 2021; 137:3-15. [PMID: 34922809 DOI: 10.1016/j.semcdb.2021.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 11/09/2021] [Accepted: 12/01/2021] [Indexed: 11/15/2022]
Abstract
Protists are an exceptionally diverse group of mostly single-celled eukaryotes. The organization of the microtubular cytoskeleton in protists from various evolutionary lineages has different levels of sophistication, from a network of microtubules (MTs) supporting intracellular trafficking as in Dictyostelium, to complex structures such as basal bodies and cilia/flagella enabling cell motility, and lineage-specific adaptations such as the ventral disc in Giardia. MTs building these diverse structures have specific properties partly due to the presence of tubulin post-translational modifications (PTMs). Among them there are highly evolutionarily conserved PTMs: acetylation, detyrosination, (poly)glutamylation and (poly)glycylation. In some protists also less common tubulin PTMs were identified, including phosphorylation, methylation, Δ2-, Δ5- of α-tubulin, polyubiquitination, sumoylation, or S-palmitoylation. Not surprisingly, several single-celled organisms become models to study tubulin PTMs, including their effect on MT properties and discovery of the modifying enzymes. Here, we briefly summarize the current knowledge on tubulin PTMs in unicellular eukaryotes and highlight key findings in protists as model organisms.
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Affiliation(s)
- Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland.
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland.
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13
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Alzyoud E, Vedelek V, Réthi-Nagy Z, Lipinszki Z, Sinka R. Microtubule Organizing Centers Contain Testis-Specific γ-TuRC Proteins in Spermatids of Drosophila. Front Cell Dev Biol 2021; 9:727264. [PMID: 34660584 PMCID: PMC8511327 DOI: 10.3389/fcell.2021.727264] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/10/2021] [Indexed: 11/17/2022] Open
Abstract
Microtubule nucleation in eukaryotes is primarily promoted by γ-tubulin and the evolutionary conserved protein complex, γ-Tubulin Ring Complex (γ-TuRC). γ-TuRC is part of the centrosome and basal body, which are the best-known microtubule-organizing centers. Centrosomes undergo intensive and dynamic changes during spermatogenesis, as they turn into basal bodies, a prerequisite for axoneme formation during spermatogenesis. Here we describe the existence of a novel, tissue-specific γ-TuRC in Drosophila. We characterize three genes encoding testis-specific components of γ-TuRC (t-γ-TuRC) and find that presence of t-γ-TuRC is essential to male fertility. We show the diverse subcellular distribution of the t-γ-TuRC proteins during post-meiotic development, at first at the centriole adjunct and then also on the anterior tip of the nucleus, and finally, they appear in the tail region, close to the mitochondria. We also prove the physical interactions between the t-γ-TuRC members, γ-tubulin and Mozart1. Our results further indicate heterogeneity in γ-TuRC composition during spermatogenesis and suggest that the different post-meiotic microtubule organizing centers are orchestrated by testis-specific gene products, including t-γ-TuRC.
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Affiliation(s)
- Elham Alzyoud
- Department of Genetics, University of Szeged, Szeged, Hungary
- Faculty of Science and Informatics, Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Viktor Vedelek
- Department of Genetics, University of Szeged, Szeged, Hungary
| | - Zsuzsánna Réthi-Nagy
- Faculty of Science and Informatics, Doctoral School of Biology, University of Szeged, Szeged, Hungary
- Biological Research Centre, Institute of Biochemistry, MTA SZBK Lendület Laboratory of Cell Cycle Regulation, Eötvös Loránd Research Network (ELKH), Szeged, Hungary
| | - Zoltán Lipinszki
- Biological Research Centre, Institute of Biochemistry, MTA SZBK Lendület Laboratory of Cell Cycle Regulation, Eötvös Loránd Research Network (ELKH), Szeged, Hungary
| | - Rita Sinka
- Department of Genetics, University of Szeged, Szeged, Hungary
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14
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Yang WT, Hong SR, He K, Ling K, Shaiv K, Hu J, Lin YC. The Emerging Roles of Axonemal Glutamylation in Regulation of Cilia Architecture and Functions. Front Cell Dev Biol 2021; 9:622302. [PMID: 33748109 PMCID: PMC7970040 DOI: 10.3389/fcell.2021.622302] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 02/11/2021] [Indexed: 12/14/2022] Open
Abstract
Cilia, which either generate coordinated motion or sense environmental cues and transmit corresponding signals to the cell body, are highly conserved hair-like structures that protrude from the cell surface among diverse species. Disruption of ciliary functions leads to numerous human disorders, collectively referred to as ciliopathies. Cilia are mechanically supported by axonemes, which are composed of microtubule doublets. It has been recognized for several decades that tubulins in axonemes undergo glutamylation, a post-translational polymodification, that conjugates glutamic acid chains onto the C-terminal tail of tubulins. However, the physiological roles of axonemal glutamylation were not uncovered until recently. This review will focus on how cells modulate glutamylation on ciliary axonemes and how axonemal glutamylation regulates cilia architecture and functions, as well as its physiological importance in human health. We will also discuss the conventional and emerging new strategies used to manipulate glutamylation in cilia.
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Affiliation(s)
- Wen-Ting Yang
- Institute of Molecular Medicine, National Tsing Hua University, HsinChu City, Taiwan
| | - Shi-Rong Hong
- Institute of Molecular Medicine, National Tsing Hua University, HsinChu City, Taiwan
| | - Kai He
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, United States
| | - Kun Ling
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, United States
| | - Kritika Shaiv
- Institute of Molecular Medicine, National Tsing Hua University, HsinChu City, Taiwan
| | - JingHua Hu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, United States
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, United States
- Mayo Clinic Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, United States
| | - Yu-Chun Lin
- Institute of Molecular Medicine, National Tsing Hua University, HsinChu City, Taiwan
- Department of Medical Science, National Tsing Hua University, HsinChu City, Taiwan
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15
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Gadadhar S, Alvarez Viar G, Hansen JN, Gong A, Kostarev A, Ialy-Radio C, Leboucher S, Whitfield M, Ziyyat A, Touré A, Alvarez L, Pigino G, Janke C. Tubulin glycylation controls axonemal dynein activity, flagellar beat, and male fertility. Science 2021; 371:371/6525/eabd4914. [PMID: 33414192 DOI: 10.1126/science.abd4914] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/13/2020] [Accepted: 11/18/2020] [Indexed: 12/30/2022]
Abstract
Posttranslational modifications of the microtubule cytoskeleton have emerged as key regulators of cellular functions, and their perturbations have been linked to a growing number of human pathologies. Tubulin glycylation modifies microtubules specifically in cilia and flagella, but its functional and mechanistic roles remain unclear. In this study, we generated a mouse model entirely lacking tubulin glycylation. Male mice were subfertile owing to aberrant beat patterns of their sperm flagella, which impeded the straight swimming of sperm cells. Using cryo-electron tomography, we showed that lack of glycylation caused abnormal conformations of the dynein arms within sperm axonemes, providing the structural basis for the observed dysfunction. Our findings reveal the importance of microtubule glycylation for controlled flagellar beating, directional sperm swimming, and male fertility.
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Affiliation(s)
- Sudarshan Gadadhar
- Institut Curie, Université PSL, CNRS UMR3348, F-91400 Orsay, France. .,Université Paris-Saclay, CNRS UMR3348, F-91400 Orsay, France
| | - Gonzalo Alvarez Viar
- Max Planck Institute of Molecular Cell Biology and Genetics, D-01307 Dresden, Germany
| | - Jan Niklas Hansen
- Institute of Innate Immunity, Medical Faculty, University of Bonn, D-53127 Bonn, Germany
| | - An Gong
- Center of Advanced European Studies and Research, D-53175 Bonn, Germany
| | - Aleksandr Kostarev
- Max Planck Institute of Molecular Cell Biology and Genetics, D-01307 Dresden, Germany
| | - Côme Ialy-Radio
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France
| | - Sophie Leboucher
- Institut Curie, Université PSL, CNRS UMR3348, F-91400 Orsay, France.,Université Paris-Saclay, CNRS UMR3348, F-91400 Orsay, France
| | - Marjorie Whitfield
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France
| | - Ahmed Ziyyat
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France.,Service d'histologie, d'embryologie, Biologie de la reproduction, Assistance Publique-Hôpitaux de Paris, Hôpital Cochin, F-75014 Paris, France
| | - Aminata Touré
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France
| | - Luis Alvarez
- Center of Advanced European Studies and Research, D-53175 Bonn, Germany.
| | - Gaia Pigino
- Max Planck Institute of Molecular Cell Biology and Genetics, D-01307 Dresden, Germany. .,Human Technopole, I-20157 Milan, Italy
| | - Carsten Janke
- Institut Curie, Université PSL, CNRS UMR3348, F-91400 Orsay, France. .,Université Paris-Saclay, CNRS UMR3348, F-91400 Orsay, France
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16
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Wall KP, Hart H, Lee T, Page C, Hawkins TL, Hough LE. C-Terminal Tail Polyglycylation and Polyglutamylation Alter Microtubule Mechanical Properties. Biophys J 2020; 119:2219-2230. [PMID: 33137305 DOI: 10.1016/j.bpj.2020.09.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 09/20/2020] [Accepted: 09/25/2020] [Indexed: 11/13/2022] Open
Abstract
Microtubules are biopolymers that perform diverse cellular functions. Microtubule behavior regulation occurs in part through post-translational modification of both the α- and β-subunits of tubulin. One class of modifications is the heterogeneous addition of glycine and/or glutamate residues to the disordered C-terminal tails (CTTs) of tubulin. Because of their prevalence in stable, high-stress cellular structures such as cilia, we sought to determine if these modifications alter microtubules' intrinsic stiffness. Here, we describe the purification and characterization of differentially modified pools of tubulin from Tetrahymena thermophila. We found that post-translational modifications do affect microtubule stiffness but do not affect the number of protofilaments incorporated into microtubules. We measured the spin dynamics of nuclei in the CTT backbone by NMR spectroscopy to explore the mechanism of this change. Our results show that the α-tubulin CTT does not protrude out from the microtubule surface, as is commonly depicted in models, but instead interacts with the dimer's surface. This suggests that the interactions of the α-tubulin CTT with the tubulin body contributes to the stiffness of the assembled microtubule, thus providing insight into the mechanism by which polyglycylation and polyglutamylation can alter microtubule mechanical properties.
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Affiliation(s)
- Kathryn P Wall
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado; BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado
| | - Harold Hart
- Physics Department, University of Wisconsin La Crosse, La Crosse, Wisconsin
| | - Thomas Lee
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado
| | - Cynthia Page
- Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, Colorado
| | - Taviare L Hawkins
- Physics Department, University of Wisconsin La Crosse, La Crosse, Wisconsin
| | - Loren E Hough
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado; Department of Physics, University of Colorado Boulder, Boulder, Colorado.
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17
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Amargant F, Barragan M, Vassena R, Vernos I. Insights of the tubulin code in gametes and embryos: from basic research to potential clinical applications in humans†. Biol Reprod 2020; 100:575-589. [PMID: 30247519 DOI: 10.1093/biolre/ioy203] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 07/05/2018] [Accepted: 09/20/2018] [Indexed: 12/14/2022] Open
Abstract
Microtubules are intracellular filaments that define in space and in time a large number of essential cellular functions such as cell division, morphology and motility, intracellular transport and flagella and cilia assembly. They are therefore essential for spermatozoon and oocyte maturation and function, and for embryo development. The dynamic and functional properties of the microtubules are in large part defined by various classes of interacting proteins including MAPs (microtubule associated proteins), microtubule-dependent motors, and severing and modifying enzymes. Multiple mechanisms regulate these interactions. One of them is defined by the high diversity of the microtubules themselves generated by the combination of different tubulin isotypes and by several tubulin post-translational modifications (PTMs). This generates a so-called tubulin code that finely regulates the specific set of proteins that associates with a given microtubule thereby defining the properties and functions of the network. Here we provide an in depth review of the current knowledge on the tubulin isotypes and PTMs in spermatozoa, oocytes, and preimplantation embryos in various model systems and in the human species. We focus on functional implications of the tubulin code for cytoskeletal function, particularly in the field of human reproduction and development, with special emphasis on gamete quality and infertility. Finally, we discuss some of the knowledge gaps and propose future research directions.
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Affiliation(s)
- Farners Amargant
- Clínica EUGIN, Barcelona, Spain.,Cell and Developmental Biology Programme, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Barcelona, Spain
| | | | | | - Isabelle Vernos
- Cell and Developmental Biology Programme, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain.,Institució Catalana de Recerca I Estudis Avançats (ICREA), Barcelona, Spain
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18
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Structure and beating behavior of the sperm motility apparatus in aquatic animals. Theriogenology 2019; 135:152-163. [DOI: 10.1016/j.theriogenology.2019.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 05/28/2019] [Accepted: 06/04/2019] [Indexed: 01/03/2023]
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19
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Huang KJ, Huang ZY, Lin CY, Wang LH, Chou PH, Chen CS, Li HH. Generation of clade- and symbiont-specific antibodies to characterize marker molecules during Cnidaria-Symbiodinium endosymbiosis. Sci Rep 2017; 7:5488. [PMID: 28710419 PMCID: PMC5511166 DOI: 10.1038/s41598-017-05945-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 06/06/2017] [Indexed: 01/24/2023] Open
Abstract
The endosymbiosis between cnidarians and dinoflagellates is responsible for the formation of coral reefs. Changes in molecules have been identified during the process of cnidaria-Symbiodinium endosymbiosis. However, the complexity of the molecular interaction has prevented the establishment of a mechanistic explanation of cellular regulation in this mutualistic symbiosis. To date, no marker molecules have been identified to specifically represent the symbiotic status. Because the endosymbiotic association occurs in the symbiotic gastrodermal cells (SGCs), whole cells of isolated SGCs were used as an antigen to generate monoclonal antibodies (mAb) to screen possible molecular candidates of symbiotic markers. The results showed that one of the generated monoclonal antibodies, 2–6F, specifically recognized clade C symbiotic Symbiodinium but not its free-living counterpart or other Symbiodinium clades. The expression levels of 2–6F mAb-recognized proteins are highly correlated with the symbiotic status, and these proteins were characterized as N-linked glycoproteins via treatment with peptide N-glycosidase F. Furthermore, their glycan moieties were markedly different from those of free-living Symbiodinium, potentially suggesting host regulation of post-translational modification. Consequently, the 2–6F mAb can be used to detect the symbiotic state of corals and investigate the complex molecular interactions in cnidaria-Symbiodinium endosymbiosis.
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Affiliation(s)
- Kao-Jean Huang
- Institute of Biologics, Development Center for Biotechnology, New Taipei City, 22180, Taiwan
| | - Zi-Yu Huang
- Graduate Institute of Marine Biology, National Dong-Hwa University, Pingtung, 94450, Taiwan
| | - Ching-Yen Lin
- Department of Life Science, National Dong Hwa University, Hualien, 97401, Taiwan
| | - Li-Hsueh Wang
- Graduate Institute of Marine Biology, National Dong-Hwa University, Pingtung, 94450, Taiwan.,Taiwan Coral Research Center, National Museum of Marine Biology and Aquarium, Pingtung, 94450, Taiwan
| | - Pin-Hsiang Chou
- Taiwan Coral Research Center, National Museum of Marine Biology and Aquarium, Pingtung, 94450, Taiwan
| | - Chii-Shiarng Chen
- Graduate Institute of Marine Biology, National Dong-Hwa University, Pingtung, 94450, Taiwan. .,Taiwan Coral Research Center, National Museum of Marine Biology and Aquarium, Pingtung, 94450, Taiwan. .,Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan.
| | - Hsing-Hui Li
- Graduate Institute of Marine Biology, National Dong-Hwa University, Pingtung, 94450, Taiwan. .,Taiwan Coral Research Center, National Museum of Marine Biology and Aquarium, Pingtung, 94450, Taiwan.
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20
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Gadadhar S, Dadi H, Bodakuntla S, Schnitzler A, Bièche I, Rusconi F, Janke C. Tubulin glycylation controls primary cilia length. J Cell Biol 2017; 216:2701-2713. [PMID: 28687664 PMCID: PMC5584158 DOI: 10.1083/jcb.201612050] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 04/28/2017] [Accepted: 05/24/2017] [Indexed: 02/05/2023] Open
Abstract
In motile cilia and flagella, tubulin glycylation is involved in axoneme stabilization. Using a newly developed antibody, Gadadhar et al. now show that glycylation also accumulates in primary cilia, where it controls ciliary length. This suggests an important role for this PTM in primary cilia homeostasis. As essential components of the eukaryotic cytoskeleton, microtubules fulfill a variety of functions that can be temporally and spatially controlled by tubulin posttranslational modifications. Tubulin glycylation has so far been mostly found on motile cilia and flagella, where it is involved in the stabilization of the axoneme. In contrast, barely anything is known about the role of glycylation in primary cilia because of limitations in detecting this modification in these organelles. We thus developed novel glycylation-specific antibodies with which we detected glycylation in many primary cilia. Glycylation accumulates in primary cilia in a length-dependent manner, and depletion or overexpression of glycylating enzymes modulates the length of primary cilia in cultured cells. This strongly suggests that glycylation is essential for the homeostasis of primary cilia, which has important implications for human disorders related to primary cilia dysfunctions, such as ciliopathies and certain types of cancer.
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Affiliation(s)
- Sudarshan Gadadhar
- Institut Curie, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique UMR3348, Orsay, France.,Université Paris Sud, Université Paris-Saclay, Centre National de la Recherche Scientifique UMR3348, Orsay, France
| | - Hala Dadi
- Université Paris Sud, Université Paris-Saclay, Centre National de la Recherche Scientifique UMR8000, Orsay, France
| | - Satish Bodakuntla
- Institut Curie, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique UMR3348, Orsay, France.,Université Paris Sud, Université Paris-Saclay, Centre National de la Recherche Scientifique UMR3348, Orsay, France
| | - Anne Schnitzler
- Department of Genetics, Institut Curie, Paris Sciences et Lettres Research University, Paris, France
| | - Ivan Bièche
- Department of Genetics, Institut Curie, Paris Sciences et Lettres Research University, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Filippo Rusconi
- Université Paris Sud, Université Paris-Saclay, Centre National de la Recherche Scientifique UMR8000, Orsay, France
| | - Carsten Janke
- Institut Curie, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique UMR3348, Orsay, France .,Université Paris Sud, Université Paris-Saclay, Centre National de la Recherche Scientifique UMR3348, Orsay, France
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21
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Crystal structure of tubulin tyrosine ligase-like 3 reveals essential architectural elements unique to tubulin monoglycylases. Proc Natl Acad Sci U S A 2017; 114:6545-6550. [PMID: 28576883 DOI: 10.1073/pnas.1617286114] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glycylation and glutamylation, the posttranslational addition of glycines and glutamates to genetically encoded glutamates in the intrinsically disordered tubulin C-terminal tails, are crucial for the biogenesis and stability of cilia and flagella and play important roles in metazoan development. Members of the diverse family of tubulin tyrosine ligase-like (TTLL) enzymes catalyze these modifications, which are part of an evolutionarily conserved and complex tubulin code that regulates microtubule interactions with cellular effectors. The site specificity of TTLL enzymes and their biochemical interplay remain largely unknown. Here, we report an in vitro characterization of a tubulin glycylase. We show that TTLL3 glycylates the β-tubulin tail at four sites in a hierarchical order and that TTLL3 and the glutamylase TTLL7 compete for overlapping sites on the tubulin tail, providing a molecular basis for the anticorrelation between glutamylation and glycylation observed in axonemes. This anticorrelation demonstrates how a combinatorial tubulin code written in two different posttranslational modifications can arise through the activities of related but distinct TTLL enzymes. To elucidate what structural elements differentiate TTLL glycylases from glutamylases, with which they share the common TTL scaffold, we determined the TTLL3 X-ray structure at 2.3-Å resolution. This structure reveals two architectural elements unique to glycyl initiases and critical for their activity. Thus, our work sheds light on the structural and functional diversification of TTLL enzymes, and constitutes an initial important step toward understanding how the tubulin code is written through the intersection of activities of multiple TTLL enzymes.
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22
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Wloga D, Joachimiak E, Louka P, Gaertig J. Posttranslational Modifications of Tubulin and Cilia. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a028159. [PMID: 28003186 DOI: 10.1101/cshperspect.a028159] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Tubulin undergoes several highly conserved posttranslational modifications (PTMs) including acetylation, detyrosination, glutamylation, and glycylation. These PTMs accumulate on a subset of microtubules that are long-lived, including those in the basal bodies and axonemes. Tubulin PTMs are distributed nonuniformly. In the outer doublet microtubules of the axoneme, the B-tubules are highly enriched in the detyrosinated, polyglutamylated, and polyglycylated tubulin, whereas the A-tubules contain mostly unmodified tubulin. The nonuniform patterns of tubulin PTMs may functionalize microtubules in a position-dependent manner. Recent studies indicate that tubulin PTMs contribute to the assembly, disassembly, maintenance, and motility of cilia. In particular, tubulin glutamylation has emerged as a key PTM that affects ciliary motility through regulation of axonemal dynein arms and controls the stability and length of the axoneme.
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Affiliation(s)
- Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Department of Cell Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Panagiota Louka
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
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23
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Abstract
Microtubules are key cytoskeletal elements of all eukaryotic cells and are assembled of evolutionarily conserved α-tubulin-β-tubulin heterodimers. Despite their uniform structure, microtubules fulfill a large diversity of functions. A regulatory mechanism to control the specialization of the microtubule cytoskeleton is the 'tubulin code', which is generated by (i) expression of different α- and β-tubulin isotypes, and by (ii) post-translational modifications of tubulin. In this Cell Science at a Glance article and the accompanying poster, we provide a comprehensive overview of the molecular components of the tubulin code, and discuss the mechanisms by which these components contribute to the generation of functionally specialized microtubules.
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Affiliation(s)
- Sudarshan Gadadhar
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Satish Bodakuntla
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Kathiresan Natarajan
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Carsten Janke
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France .,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
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24
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Bosch Grau M, Masson C, Gadadhar S, Rocha C, Tort O, Marques Sousa P, Vacher S, Bieche I, Janke C. Alterations in the balance of tubulin glycylation and glutamylation in photoreceptors leads to retinal degeneration. J Cell Sci 2017; 130:938-949. [PMID: 28104815 DOI: 10.1242/jcs.199091] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/10/2017] [Indexed: 01/09/2023] Open
Abstract
Tubulin is subject to a wide variety of posttranslational modifications, which, as part of the tubulin code, are involved in the regulation of microtubule functions. Glycylation has so far predominantly been found in motile cilia and flagella, and absence of this modification leads to ciliary disassembly. Here, we demonstrate that the correct functioning of connecting cilia of photoreceptors, which are non-motile sensory cilia, is also dependent on glycylation. In contrast to many other tissues, only one glycylase, TTLL3, is expressed in retina. Ttll3-/- mice lack glycylation in photoreceptors, which results in shortening of connecting cilia and slow retinal degeneration. Moreover, absence of glycylation results in increased levels of tubulin glutamylation in photoreceptors, and inversely, the hyperglutamylation observed in the Purkinje cell degeneration (pcd) mouse abolishes glycylation. This suggests that both posttranslational modifications compete for modification sites, and that unbalancing the glutamylation-glycylation equilibrium on axonemes of connecting cilia, regardless of the enzymatic mechanism, invariably leads to retinal degeneration.
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Affiliation(s)
- Montserrat Bosch Grau
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Christel Masson
- CERTO Centre d'Etudes et de Recherches Thérapeutiques en Ophtalmologie, Université Paris Sud, Université Paris-Saclay, CNRS UMR9197, Orsay F-91405, France
| | - Sudarshan Gadadhar
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Cecilia Rocha
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Olivia Tort
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Patricia Marques Sousa
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Sophie Vacher
- Institut Curie, PSL Research University, Department of Genetics, Paris F-75005, France
| | - Ivan Bieche
- Institut Curie, PSL Research University, Department of Genetics, Paris F-75005, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris F-75005, France
| | - Carsten Janke
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France .,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
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25
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Vedelek V, Laurinyecz B, Kovács AL, Juhász G, Sinka R. Testis-Specific Bb8 Is Essential in the Development of Spermatid Mitochondria. PLoS One 2016; 11:e0161289. [PMID: 27529784 PMCID: PMC4986964 DOI: 10.1371/journal.pone.0161289] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/02/2016] [Indexed: 11/18/2022] Open
Abstract
Mitochondria are essential organelles of developing spermatids in Drosophila, which undergo dramatic changes in size and shape after meiotic division, where mitochondria localized in the cytoplasm, migrate near the nucleus, aggregate, fuse and create the Nebenkern. During spermatid elongation the two similar mitochondrial derivatives of the Nebenkern start to elongate parallel to the axoneme. One of the elongated mitochondrial derivatives starts to lose volume and becomes the minor mitochondrial derivative, while the other one accumulates paracrystalline and becomes the major mitochondrial derivative. Proteins and intracellular environment that are responsible for cyst elongation and paracrystalline formation in the major mitochondrial derivative need to be identified. In this work we investigate the function of the testis specific big bubble 8 (bb8) gene during spermatogenesis. We show that a Minos element insertion in bb8 gene, a predicted glutamate dehydrogenase, causes recessive male sterility. We demonstrate bb8 mRNA enrichment in spermatids and the mitochondrial localisation of Bb8 protein during spermatogenesis. We report that megamitochondria develop in the homozygous mutant testes, in elongating spermatids. Ultrastructural analysis of the cross section of elongated spermatids shows enlarged mitochondria and the production of paracrystalline in both major and minor mitochondrial derivatives. Our results suggest that the Bb8 protein and presumably glutamate metabolism has a crucial role in the normal development and establishment of the identity of the mitochondrial derivatives during spermatid elongation.
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Affiliation(s)
- Viktor Vedelek
- Department of Genetics, University of Szeged, Szeged, Hungary
| | | | - Attila L Kovács
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Rita Sinka
- Department of Genetics, University of Szeged, Szeged, Hungary
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26
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The de-ubiquitylating enzyme DUBA is essential for spermatogenesis in Drosophila. Cell Death Differ 2016; 23:2019-2030. [PMID: 27518434 DOI: 10.1038/cdd.2016.79] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 06/21/2016] [Accepted: 07/05/2016] [Indexed: 01/21/2023] Open
Abstract
De-ubiquitylating enzymes (DUBs) reverse protein ubiquitylation and thereby control essential cellular functions. Screening for a DUB that counteracts caspase ubiquitylation to regulate cell survival, we identified the Drosophila ovarian tumour-type DUB DUBA (CG6091). DUBA physically interacts with the initiator caspase death regulator Nedd2-like caspase (Dronc) and de-ubiquitylates it, thereby contributing to efficient inhibitor of apoptosis-antagonist-induced apoptosis in the fly eye. Searching also for non-apoptotic functions of DUBA, we found that Duba-null mutants are male sterile and display defects in spermatid individualisation, a process that depends on non-apoptotic caspase activity. Spermatids of DUBA-deficient flies showed reduced caspase activity and lack critical structures of the individualisation process. Biochemical characterisation revealed an obligate activation step of DUBA by phosphorylation. With genetic rescue experiments we demonstrate that DUBA phosphorylation and catalytic activity are crucial in vivo for DUBA function in spermatogenesis. Our results demonstrate for the first time the importance of de-ubiquitylation for fly spermatogenesis.
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Groebner JL, Tuma PL. The Altered Hepatic Tubulin Code in Alcoholic Liver Disease. Biomolecules 2015; 5:2140-59. [PMID: 26393662 PMCID: PMC4598792 DOI: 10.3390/biom5032140] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 08/21/2015] [Accepted: 08/24/2015] [Indexed: 01/01/2023] Open
Abstract
The molecular mechanisms that lead to the progression of alcoholic liver disease have been actively examined for decades. Because the hepatic microtubule cytoskeleton supports innumerable cellular processes, it has been the focus of many such mechanistic studies. It has long been appreciated that α-tubulin is a major target for modification by highly reactive ethanol metabolites and reactive oxygen species. It is also now apparent that alcohol exposure induces post-translational modifications that are part of the natural repertoire, mainly acetylation. In this review, the modifications of the "tubulin code" are described as well as those adducts by ethanol metabolites. The potential cellular consequences of microtubule modification are described with a focus on alcohol-induced defects in protein trafficking and enhanced steatosis. Possible mechanisms that can explain hepatic dysfunction are described and how this relates to the onset of liver injury is discussed. Finally, we propose that agents that alter the cellular acetylation state may represent a novel therapeutic strategy for treating liver disease.
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Affiliation(s)
- Jennifer L Groebner
- Department of Biology, The Catholic University of America, Washington, DC 20064, USA.
| | - Pamela L Tuma
- Department of Biology, The Catholic University of America, Washington, DC 20064, USA.
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28
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Abstract
Microtubules give rise to intracellular structures with diverse morphologies and dynamics that are crucial for cell division, motility, and differentiation. They are decorated with abundant and chemically diverse posttranslational modifications that modulate their stability and interactions with cellular regulators. These modifications are important for the biogenesis and maintenance of complex microtubule arrays such as those found in spindles, cilia, neuronal processes, and platelets. Here we discuss the nature and subcellular distribution of these posttranslational marks whose patterns have been proposed to constitute a tubulin code that is interpreted by cellular effectors. We review the enzymes responsible for writing the tubulin code, explore their functional consequences, and identify outstanding challenges in deciphering the tubulin code.
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Affiliation(s)
- Ian Yu
- From the Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, NINDS, and
| | - Christopher P Garnham
- From the Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, NINDS, and
| | - Antonina Roll-Mecak
- From the Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, NINDS, and NHLBI, National Institutes of Health, Bethesda, Maryland 20892
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29
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Delgehyr N, Meunier A, Faucourt M, Bosch Grau M, Strehl L, Janke C, Spassky N. Ependymal cell differentiation, from monociliated to multiciliated cells. Methods Cell Biol 2015; 127:19-35. [PMID: 25837384 DOI: 10.1016/bs.mcb.2015.01.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Primary and motile cilia differ in their structure, composition, and function. In the brain, primary cilia are immotile signalling organelles present on neural stem cells and neurons. Multiple motile cilia are found on the surface of ependymal cells in all brain ventricles, where they contribute to the flow of cerebrospinal fluid. During development, monociliated ependymal progenitor cells differentiate into multiciliated ependymal cells, thus providing a simple system for studying the transition between these two stages. In this chapter, we provide protocols for immunofluorescence staining of developing ependymal cells in vivo, on whole mounts of lateral ventricle walls, and in vitro, on cultured ependymal cells. We also provide a list of markers we currently use to stain both types of cilia, including proteins at the ciliary membrane and tubulin posttranslational modifications of the axoneme.
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Affiliation(s)
- Nathalie Delgehyr
- Institut de Biologie de l'Ecole Normal Supérieure (IBENS), Paris, France; INSERM, U1024, Paris, France; CNRS, UMR 8197, Paris, France
| | - Alice Meunier
- Institut de Biologie de l'Ecole Normal Supérieure (IBENS), Paris, France; INSERM, U1024, Paris, France; CNRS, UMR 8197, Paris, France
| | - Marion Faucourt
- Institut de Biologie de l'Ecole Normal Supérieure (IBENS), Paris, France; INSERM, U1024, Paris, France; CNRS, UMR 8197, Paris, France
| | - Montserrat Bosch Grau
- Curie Institute, Orsay, France; CNRS, UMR3306, Orsay, France; INSERM, U1005, Orsay, France; INSERM, UMRS 1120; Unité de Génétique et Physiologie de l'Audition, Pasteur Institute, Paris, France
| | - Laetitia Strehl
- Institut de Biologie de l'Ecole Normal Supérieure (IBENS), Paris, France; INSERM, U1024, Paris, France; CNRS, UMR 8197, Paris, France; INSERM, UMRS 975, Brain and Spinal Cord Institute, Hôpital de la Salpêtrière, Paris, France
| | - Carsten Janke
- Curie Institute, Orsay, France; CNRS, UMR3306, Orsay, France; INSERM, U1005, Orsay, France
| | - Nathalie Spassky
- Institut de Biologie de l'Ecole Normal Supérieure (IBENS), Paris, France; INSERM, U1024, Paris, France; CNRS, UMR 8197, Paris, France
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Aubusson-Fleury A, Cohen J, Lemullois M. Ciliary heterogeneity within a single cell: the Paramecium model. Methods Cell Biol 2015; 127:457-85. [PMID: 25837404 DOI: 10.1016/bs.mcb.2014.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Paramecium is a single cell able to divide in its morphologically differentiated stage that has many cilia anchored at its cell surface. Many thousands of cilia are thus assembled in a short period of time during division to duplicate the cell pattern while the cell continues swimming. Most, but not all, of these sensory cilia are motile and involved in two main functions: prey capture and cell locomotion. These cilia display heterogeneity, both in their length and their biochemical properties. Thanks to these properties, as well as to the availability of many postgenomic tools and the possibility to follow the regrowth of cilia after deciliation, Paramecium offers a nice opportunity to study the assembly of the cilia, as well as the genesis of their diversity within a single cell. In this paper, after a brief survey of Paramecium morphology and cilia properties, we describe the tools and the protocols currently used for immunofluorescence, transmission electron microscopy, and ultrastructural immunocytochemistry to analyze cilia, with special recommendations to overcome the problem raised by cilium diversity.
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Affiliation(s)
- Anne Aubusson-Fleury
- Centre de Génétique Moléculaire, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Bat 26 Allée de la terrasse, 91 198 Gif sur Yvette Cedex, France
| | - Jean Cohen
- Centre de Génétique Moléculaire, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Bat 26 Allée de la terrasse, 91 198 Gif sur Yvette Cedex, France
| | - Michel Lemullois
- Centre de Génétique Moléculaire, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Bat 26 Allée de la terrasse, 91 198 Gif sur Yvette Cedex, France
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31
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Abstract
Microtubules are cytoskeletal filaments that are dynamically assembled from α/β-tubulin heterodimers. The primary sequence and structure of the tubulin proteins and, consequently, the properties and architecture of microtubules are highly conserved in eukaryotes. Despite this conservation, tubulin is subject to heterogeneity that is generated in two ways: by the expression of different tubulin isotypes and by posttranslational modifications (PTMs). Identifying the mechanisms that generate and control tubulin heterogeneity and how this heterogeneity affects microtubule function are long-standing goals in the field. Recent work on tubulin PTMs has shed light on how these modifications could contribute to a “tubulin code” that coordinates the complex functions of microtubules in cells.
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Affiliation(s)
- Carsten Janke
- Institut Curie, 91405 Orsay, France Centre National de la Recherche Scientifique Unité Mixte de Recherche 3306, 91405 Orsay, France Institut National de la Santé et de la Recherche Médicale U1005, 91405 Orsay, France Paris Sciences et Lettres Research University, 75005 Paris, France
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32
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Rocha C, Papon L, Cacheux W, Marques Sousa P, Lascano V, Tort O, Giordano T, Vacher S, Lemmers B, Mariani P, Meseure D, Medema JP, Bièche I, Hahne M, Janke C. Tubulin glycylases are required for primary cilia, control of cell proliferation and tumor development in colon. EMBO J 2014; 33:2247-60. [PMID: 25180231 DOI: 10.15252/embj.201488466] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
TTLL3 and TTLL8 are tubulin glycine ligases catalyzing posttranslational glycylation of microtubules. We show here for the first time that these enzymes are required for robust formation of primary cilia. We further discover the existence of primary cilia in colon and demonstrate that TTLL3 is the only glycylase in this organ. As a consequence, colon epithelium shows a reduced number of primary cilia accompanied by an increased rate of cell division in TTLL3-knockout mice. Strikingly, higher proliferation is compensated by faster tissue turnover in normal colon. In a mouse model for tumorigenesis, lack of TTLL3 strongly promotes tumor development. We further demonstrate that decreased levels of TTLL3 expression are linked to the development of human colorectal carcinomas. Thus, we have uncovered a novel role for tubulin glycylation in primary cilia maintenance, which controls cell proliferation of colon epithelial cells and plays an essential role in colon cancer development.
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Affiliation(s)
- Cecilia Rocha
- Institut Curie, Orsay, France PSL Research University, Paris, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France IGMM CNRS UMR5535, Montpellier, France Université Montpellier Sud de France, Montpellier, France
| | - Laura Papon
- IGMM CNRS UMR5535, Montpellier, France Université Montpellier Sud de France, Montpellier, France
| | | | - Patricia Marques Sousa
- Institut Curie, Orsay, France PSL Research University, Paris, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France
| | | | - Olivia Tort
- Institut Curie, Orsay, France PSL Research University, Paris, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France Institut de Biotecnologia i de Biomedicina, Department of Biochemistry and Molecular Biology, Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain
| | - Tiziana Giordano
- Institut Curie, Orsay, France PSL Research University, Paris, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France
| | | | - Benedicte Lemmers
- IGMM CNRS UMR5535, Montpellier, France Université Montpellier Sud de France, Montpellier, France
| | | | | | | | | | - Michael Hahne
- IGMM CNRS UMR5535, Montpellier, France Université Montpellier Sud de France, Montpellier, France Academic Medical Center, Amsterdam, The Netherlands
| | - Carsten Janke
- Institut Curie, Orsay, France PSL Research University, Paris, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France
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33
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Soulavie F, Piepenbrock D, Thomas J, Vieillard J, Duteyrat JL, Cortier E, Laurençon A, Göpfert MC, Durand B. hemingway is required for sperm flagella assembly and ciliary motility in Drosophila. Mol Biol Cell 2014; 25:1276-86. [PMID: 24554765 PMCID: PMC3982993 DOI: 10.1091/mbc.e13-10-0616] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Motile cilia play important functions in many organisms. In Drosophila, hemingway (hmw) encodes a novel protein conserved in species with motile cilia. hmw-mutant flies are hearing impaired and male sterile. HMW is required for acquisition of motile properties of cilia in the fly sound receiver and stability of the sperm axoneme. Cilia play major functions in physiology and development, and ciliary dysfunctions are responsible for several diseases in humans called ciliopathies. Cilia motility is required for cell and fluid propulsion in organisms. In humans, cilia motility deficiencies lead to primary ciliary dyskinesia, with upper-airways recurrent infections, left–right asymmetry perturbations, and fertility defects. In Drosophila, we identified hemingway (hmw) as a novel component required for motile cilia function. hmw encodes a 604–amino acid protein characterized by a highly conserved coiled-coil domain also found in the human orthologue, KIAA1430. We show that HMW is conserved in species with motile cilia and that, in Drosophila, hmw is expressed in ciliated sensory neurons and spermatozoa. We created hmw-knockout flies and found that they are hearing impaired and male sterile. hmw is implicated in the motility of ciliated auditory sensory neurons and, in the testis, is required for elongation and maintenance of sperm flagella. Because HMW is absent from mature flagella, we propose that HMW is not a structural component of the motile axoneme but is required for proper acquisition of motile properties. This identifies HMW as a novel, evolutionarily conserved component necessary for motile cilium function and flagella assembly.
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Affiliation(s)
- Fabien Soulavie
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, UMR 5534, Centre National de la Recherche Scientifique, Université de Lyon 1, 69622 Lyon, France Department of Cellular Neurobiology, University of Göttingen, 37077 Göttingen, Germany
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34
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Lalle M, Leptourgidou F, Camerini S, Pozio E, Skoulakis EMC. Interkingdom complementation reveals structural conservation and functional divergence of 14-3-3 proteins. PLoS One 2013; 8:e78090. [PMID: 24147113 PMCID: PMC3795638 DOI: 10.1371/journal.pone.0078090] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 09/06/2013] [Indexed: 12/28/2022] Open
Abstract
The 14-3-3s are small acidic cytosolic proteins that interact with multiple clients and participate in essential cellular functions in all eukaryotes. Available structural and functional information about 14-3-3s is largely derived from higher eukaryotes, which contain multiple members of this protein family suggesting functional specialization. The exceptional sequence conservation among 14-3-3 family members from diverse species suggests a common ancestor for 14-3-3s, proposed to have been similar to modern 14-3-3ε isoforms. Structural features of the sole family member from the protozoan Giardia duodenalis (g14-3-3), are consistent with this hypothesis, but whether g14-3-3 is functionally homologous to the epsilon isoforms is unknown. We use inter-kingdom reciprocal functional complementation and biochemical methods to determine whether g14-3-3 is structurally and functionally homologous with members of the two 14-3-3 conservation groups of the metazoan Drosophila melanogaster. Our results indicate that although g14-3-3 is structurally homologous to D14-3-3ε, functionally it diverges presenting characteristics of other 14-3-3s. Given the basal position of Giardia in eukaryotic evolution, this finding is consistent with the hypothesis that 14-3-3ε isoforms are ancestral to other family members.
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Affiliation(s)
- Marco Lalle
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | | | - Serena Camerini
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
| | - Edoardo Pozio
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Rome, Italy
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35
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Bosch Grau M, Gonzalez Curto G, Rocha C, Magiera MM, Marques Sousa P, Giordano T, Spassky N, Janke C. Tubulin glycylases and glutamylases have distinct functions in stabilization and motility of ependymal cilia. ACTA ACUST UNITED AC 2013; 202:441-51. [PMID: 23897886 PMCID: PMC3734080 DOI: 10.1083/jcb.201305041] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tubulin glutamylating enzymes are important for beating behavior of ependymal cilia in the brain, whereas glycylating enzymes are critical for stability and maintenance of these cilia. Microtubules are subject to a variety of posttranslational modifications that potentially regulate cytoskeletal functions. Two modifications, glutamylation and glycylation, are highly enriched in the axonemes of most eukaryotes, and might therefore play particularly important roles in cilia and flagella. Here we systematically analyze the dynamics of glutamylation and glycylation in developing mouse ependymal cilia and the expression of the corresponding enzymes in the brain. By systematically screening enzymes of the TTLL family for specific functions in ependymal cilia, we demonstrate that the glycylating enzymes TTLL3 and TTLL8 were required for stability and maintenance of ependymal cilia, whereas the polyglutamylase TTLL6 was necessary for coordinated beating behavior. Our work provides evidence for a functional separation of glutamylating and glycylating enzymes in mammalian ependymal cilia. It further advances the elucidation of the functions of tubulin posttranslational modifications in motile cilia of the mammalian brain and their potential importance in brain development and disease.
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36
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Ludueña RF. A Hypothesis on the Origin and Evolution of Tubulin. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 302:41-185. [DOI: 10.1016/b978-0-12-407699-0.00002-9] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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37
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Magiera MM, Janke C. Investigating tubulin posttranslational modifications with specific antibodies. Methods Cell Biol 2013; 115:247-67. [PMID: 23973077 DOI: 10.1016/b978-0-12-407757-7.00016-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Microtubules play highly diverse and essential roles in every eukaryotic cell. While built from conserved dimers of α- and β-tubulin, microtubules can be diversified by posttranslational modifications in order to fulfill specific functions in cells. The tubulin posttranslational modifications: acetylation, detyrosination, polyglutamylation, and polyglycylation play important roles in microtubule functions; however, only little functional and mechanistic insight has been gained so far. The modification state of microtubules can be visualized with specific antibodies. A drawback is that detailed information about the specificities and limitations of these antibodies are not easily accessible in the literature. We provide here a comprehensive description of the currently available set of antibodies specific to tubulin modifications. Focusing on glutamylation antibodies, we discuss specific protocols that allow using these antibodies to gain semi-quantitative information on the levels and distribution of tubulin modifications in immunocytochemistry and immunoblot.
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38
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Garnham CP, Roll-Mecak A. The chemical complexity of cellular microtubules: tubulin post-translational modification enzymes and their roles in tuning microtubule functions. Cytoskeleton (Hoboken) 2012; 69:442-63. [PMID: 22422711 PMCID: PMC3459347 DOI: 10.1002/cm.21027] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 02/28/2012] [Accepted: 03/07/2012] [Indexed: 01/20/2023]
Abstract
Cellular microtubules are marked by abundant and evolutionarily conserved post-translational modifications that have the potential to tune their functions. This review focuses on the astonishing chemical complexity introduced in the tubulin heterodimer at the post-translational level and summarizes the recent advances in identifying the enzymes responsible for these modifications and deciphering the consequences of tubulin's chemical diversity on the function of molecular motors and microtubule associated proteins.
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Affiliation(s)
- Christopher P. Garnham
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, U.S.A
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, U.S.A
- National Heart, Lung and Blood Institute, Bethesda, MD 20892, U.S.A
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39
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Abstract
Drosophila melanogaster spermatids undergo dramatic morphological changes as they differentiate from small round cells approximately 12 μm in diameter into highly polarized, 1.8 mm long, motile sperm capable of participating in fertilization. During spermiogenesis, syncytial cysts of 64 haploid spermatids undergo synchronous differentiation. Numerous changes occur at a subcellular level, including remodeling of existing organelles (mitochondria, nuclei), formation of new organelles (flagellar axonemes, acrosomes), polarization of elongating cysts and plasma membrane addition. At the end of spermatid morphogenesis, organelles, mitochondrial DNA and cytoplasmic components not needed in mature sperm are stripped away in a caspase-dependent process called individualization that results in formation of individual sperm. Here, we review the stages of Drosophila spermiogenesis and examine our current understanding of the cellular and molecular mechanisms involved in shaping male germ cell-specific organelles and forming mature, fertile sperm.
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Affiliation(s)
- Lacramioara Fabian
- Cell Biology Program; The Hospital for Sick Children (SickKids); Toronto, ON Canada
| | - Julie A. Brill
- Cell Biology Program; The Hospital for Sick Children (SickKids); Toronto, ON Canada
- Department of Molecular Genetics; University of Toronto; Toronto, ON Canada
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40
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Konno A, Setou M, Ikegami K. Ciliary and flagellar structure and function--their regulations by posttranslational modifications of axonemal tubulin. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 294:133-70. [PMID: 22364873 DOI: 10.1016/b978-0-12-394305-7.00003-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Eukaryotic cilia and flagella are evolutionarily conserved microtubule-based organelles protruding from the cell surface. They perform dynein-driven beating which contributes to cell locomotion or flow generation. They also play important roles in sensing as cellular antennae, which allows cells to respond to various external stimuli. The main components of cilia and flagella, α- and β-tubulins, are known to undergo various posttranslational modifications (PTMs), including phosphorylation, palmitoylation, tyrosination/detyrosination, Δ2 modification, acetylation, glutamylation, and glycylation. Recent identification of tubulin-modifying enzymes, especially tubulin tyrosine ligase-like proteins which perform tubulin glutamylation and glycylation, has demonstrated the importance of tubulin modifications for the assembly and functions of cilia and flagella. In this chapter, we review recent work on PTMs of ciliary and flagellar tubulins in conjunction with discussing the basic knowledge.
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Affiliation(s)
- Alu Konno
- Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Japan
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41
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Janke C, Bulinski JC. Post-translational regulation of the microtubule cytoskeleton: mechanisms and functions. Nat Rev Mol Cell Biol 2011; 12:773-86. [PMID: 22086369 DOI: 10.1038/nrm3227] [Citation(s) in RCA: 622] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Half a century of biochemical and biophysical experiments has provided attractive models that may explain the diverse functions of microtubules within cells and organisms. However, the notion of functionally distinct microtubule types has not been explored with similar intensity, mostly because mechanisms for generating divergent microtubule species were not yet known. Cells generate distinct microtubule subtypes through expression of different tubulin isotypes and through post-translational modifications, such as detyrosination and further cleavage to Δ2-tubulin, acetylation, polyglutamylation and polyglycylation. The recent discovery of enzymes responsible for many tubulin post-translational modifications has enabled functional studies demonstrating that these post-translational modifications may regulate microtubule functions through an amazing range of mechanisms.
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Affiliation(s)
- Carsten Janke
- Department of Signalling, Neurobiology and Cancer, Institut Curie, Bât. 110, Centre Universitaire, 91405 Orsay Cedex, France.
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Rotkopf S, Hamberg Y, Aigaki T, Snapper SB, Shilo BZ, Schejter ED. The WASp-based actin polymerization machinery is required in somatic support cells for spermatid maturation and release. Development 2011; 138:2729-39. [PMID: 21652648 DOI: 10.1242/dev.059865] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
WASp family proteins serve as conserved regulators of branched microfilament array formation via the Arp2/3 actin polymerization machinery. We have identified a specific role during spermatogenesis for the Drosophila WASp homolog (Wsp) and associated elements. Spermatogenesis within the fly testis is carried out in cysts, where a pair of somatic cyst cells encloses differentiating sperm. The final phase of the process involves the attachment of matured cysts to a specialized epithelium at the base of the testis, followed by release of individual motile spermatids into the adjoining seminal vesicle. Wsp mutant cysts contain fully mature sperm, but spermatid release does not occur, resulting in male sterility. Our data suggest that the Wsp-Arp2/3-based machinery acts in the cyst cells to influence proper microfilament organization and to enable cyst attachment to the base of the testis. Wsp activity in this context is mediated by the small GTPase Cdc42. Involvement of the cell surface protein Sticks and stones and the Wsp adapter protein D-WIP (Vrp1) is also crucial. In parallel, we demonstrate that N-WASp (Wasl), the major mammalian WASp family protein, is required in the somatic Sertoli cells of the mouse testis for sperm maturation. A requirement for WASp-based activity in somatic support cells therefore appears to be a universal feature of spermatogenesis.
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Affiliation(s)
- Shay Rotkopf
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 76100, Israel
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43
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Inaba K. Sperm flagella: comparative and phylogenetic perspectives of protein components. Mol Hum Reprod 2011; 17:524-38. [PMID: 21586547 DOI: 10.1093/molehr/gar034] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Sperm motility is necessary for the transport of male DNA to eggs in species with both external and internal fertilization. Flagella comprise several proteins for generating and regulating motility. Central cytoskeletal structures called axonemes have been well conserved through evolution. In mammalian sperm flagella, two accessory structures (outer dense fiber and the fibrous sheath) surround the axoneme. The axonemal bend movement is based on the active sliding of axonemal doublet microtubules by the molecular motor dynein, which is divided into outer and inner arm dyneins according to positioning on the doublet microtubule. Outer and inner arm dyneins play different roles in the production and regulation of flagellar motility. Several regulatory mechanisms are known for both dyneins, which are important in motility activation and chemotaxis at fertilization. Although dynein itself has certain properties that contribute to the formation and propagation of flagellar bending, other axonemal structures-specifically, the radial spoke/central pair apparatus-have essential roles in the regulation of flagellar bending. Recent genetic and proteomic studies have explored several new components of axonemes and shed light on the generation and regulation of sperm motility during fertilization.
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Affiliation(s)
- Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan.
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Chatterjee N, Rollins J, Mahowald AP, Bazinet C. Neurotransmitter Transporter-Like: a male germline-specific SLC6 transporter required for Drosophila spermiogenesis. PLoS One 2011; 6:e16275. [PMID: 21298005 PMCID: PMC3029318 DOI: 10.1371/journal.pone.0016275] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 12/13/2010] [Indexed: 02/03/2023] Open
Abstract
The SLC6 class of membrane transporters, known primarily as neurotransmitter transporters, is increasingly appreciated for its roles in nutritional uptake of amino acids and other developmentally specific functions. A Drosophila SLC6 gene, Neurotransmitter transporter-like (Ntl), is expressed only in the male germline. Mobilization of a transposon inserted near the 3' end of the Ntl coding region yields male-sterile mutants defining a single complementation group. Germline transformation with Ntl cDNAs under control of male germline-specific control elements restores Ntl/Ntl homozygotes to normal fertility, indicating that Ntl is required only in the germ cells. In mutant males, sperm morphogenesis appears normal, with elongated, individualized and coiled spermiogenic cysts accumulating at the base of the testes. However, no sperm are transferred to the seminal vesicle. The level of polyglycylation of Ntl mutant sperm tubulin appears to be significantly lower than that of wild type controls. Glycine transporters are the most closely related SLC6 transporters to Ntl, suggesting that Ntl functions as a glycine transporter in developing sperm, where augmentation of the cytosolic pool of glycine may be required for the polyglycylation of the massive amounts of tubulin in the fly's giant sperm. The male-sterile phenotype of Ntl mutants may provide a powerful genetic system for studying the function of an SLC6 transporter family in a model organism.
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Affiliation(s)
- Nabanita Chatterjee
- Department of Biological Sciences, St. John's University, Jamaica, New York, United States of America
| | - Janet Rollins
- Department of Biological Sciences, St. John's University, Jamaica, New York, United States of America
| | - Anthony P. Mahowald
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois, United States of America
| | - Christopher Bazinet
- Department of Biological Sciences, St. John's University, Jamaica, New York, United States of America
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Wloga D, Gaertig J. Post-translational modifications of microtubules. J Cell Sci 2011; 123:3447-55. [PMID: 20930140 DOI: 10.1242/jcs.063727] [Citation(s) in RCA: 195] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Microtubules--polymers of tubulin--perform essential functions, including regulation of cell shape, intracellular transport and cell motility. How microtubules are adapted to perform multiple diverse functions is not well understood. Post-translational modifications of tubulin subunits diversify the outer and luminal surfaces of microtubules and provide a potential mechanism for their functional specialization. Recent identification of a number of tubulin-modifying and -demodifying enzymes has revealed key roles of tubulin modifications in the regulation of motors and factors that affect the organization and dynamics of microtubules.
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Affiliation(s)
- Dorota Wloga
- Department of Cell Biology, Nencki Institute of Experimental Biology, Polish Academy of Science, 02-093 Warsaw, Poland
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Pathak N, Austin CA, Drummond IA. Tubulin tyrosine ligase-like genes ttll3 and ttll6 maintain zebrafish cilia structure and motility. J Biol Chem 2011; 286:11685-95. [PMID: 21262966 DOI: 10.1074/jbc.m110.209817] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Tubulin post-translational modifications generate microtubule heterogeneity and modulate microtubule function, and are catalyzed by tubulin tyrosine ligase-like (TTLL) proteins. Using antibodies specific to monoglycylated, polyglycylated, and glutamylated tubulin in whole mount immunostaining of zebrafish embryos, we observed distinct, tissue-specific patterns of tubulin modifications. Tubulin modification patterns in cilia correlated with the expression of ttll3 and ttll6 in ciliated cells. Expression screening of all zebrafish tubulin tyrosine ligase-like genes revealed additional tissue-specific expression of ttll1 in brain neurons, ttll4 in muscle, and ttll7 in otic placodes. Knockdown of ttll3 eliminated cilia tubulin glycylation but had surprisingly mild effects on cilia structure and motility. Similarly, knockdown of ttll6 strongly reduced cilia tubulin glutamylation but only partially affected cilia structure and motility. Combined loss of function of ttll3 and ttll6 caused near complete loss of cilia motility and induced a variety of axonemal ultrastructural defects similar to defects previously observed in zebrafish fleer mutants, which were shown to lack tubulin glutamylation. Consistently, we find that fleer mutants also lack tubulin glycylation. These results indicate that tubulin glycylation and glutamylation have overlapping functions in maintaining cilia structure and motility and that the fleer/dyf-1 TPR protein is required for both types of tubulin post-translational modification.
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Affiliation(s)
- Narendra Pathak
- Nephrology Division, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
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Lalle M, Camerini S, Cecchetti S, Blasetti Fantauzzi C, Crescenzi M, Pozio E. Giardia duodenalis 14-3-3 protein is polyglycylated by a tubulin tyrosine ligase-like member and deglycylated by two metallocarboxypeptidases. J Biol Chem 2010; 286:4471-84. [PMID: 21135098 DOI: 10.1074/jbc.m110.181511] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The flagellated protozoan Giardia duodenalis is a parasite of the upper part of the small intestine of mammals, including humans, and an interesting biological model. Giardia harbors a single 14-3-3 isoform, a multifunctional protein family, that is modified at the C terminus by polyglycylation, an unusual post-translational modification consisting of the covalent addition of one or multiple glycines on the γ-carboxyl groups of specific glutamic acids. Polyglycylation affects the intracellular localization of g14-3-3, as the shortening of the polyglycine chain is correlated with a partial relocalization of 14-3-3 inside the nuclei during encystation. In this work we demonstrate that the gTTLL3, a member of the tubulin tyrosine ligase-like family, is the enzyme responsible for the 14-3-3 polyglycylation. We also identify two metallopeptidases of the M20 family, here termed gDIP1 (giardial dipeptidase 1) and gDIP2, as enzymes able to shorten the g14-3-3 polyglycine tail both in vivo and in vitro. Finally, we show that the ectopic expression of gDIP2 alters the g14-3-3 localization and strongly hampers the cyst formation. In conclusion, we have identified a polyglycylase and two deglycylases that act in concert to modulate the stage-dependent glycylation status of the multifunctional regulatory g14-3-3 protein in G. duodenalis.
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Affiliation(s)
- Marco Lalle
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, 00161 Rome, Italy
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Beisson J, Bétermier M, Bré MH, Cohen J, Duharcourt S, Duret L, Kung C, Malinsky S, Meyer E, Preer JR, Sperling L. Paramecium tetraurelia: the renaissance of an early unicellular model. Cold Spring Harb Protoc 2010; 2010:pdb.emo140. [PMID: 20150105 DOI: 10.1101/pdb.emo140] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Janine Beisson
- Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, FRE3144, F-91198 Gif-sur-Yvette, France
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Bader M, Arama E, Steller H. A novel F-box protein is required for caspase activation during cellular remodeling in Drosophila. Development 2010; 137:1679-88. [PMID: 20392747 DOI: 10.1242/dev.050088] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Terminal differentiation of male germ cells in Drosophila and mammals requires extensive cytoarchitectural remodeling, the elimination of many organelles, and a large reduction in cell volume. The associated process, termed spermatid individualization, is facilitated by the apoptotic machinery, including caspases, but does not result in cell death. From a screen for genes defective in caspase activation in this system, we isolated a novel F-box protein, which we termed Nutcracker, that is strictly required for caspase activation and sperm differentiation. Nutcracker interacts through its F-box domain with members of a Cullin-1-based ubiquitin ligase complex (SCF): Cullin-1 and SkpA. This ubiquitin ligase does not regulate the stability of the caspase inhibitors DIAP1 and DIAP2, but physically binds Bruce, a BIR-containing giant protein involved in apoptosis regulation. Furthermore, nutcracker mutants disrupt proteasome activity without affecting their distribution. These findings define a new SCF complex required for caspase activation during sperm differentiation and highlight the role of regulated proteolysis during this process.
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Affiliation(s)
- Maya Bader
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10021, USA
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50
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Hearing in Drosophila requires TilB, a conserved protein associated with ciliary motility. Genetics 2010; 185:177-88. [PMID: 20215474 DOI: 10.1534/genetics.110.114009] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Cilia were present in the earliest eukaryotic ancestor and underlie many biological processes ranging from cell motility and propulsion of extracellular fluids to sensory physiology. We investigated the contribution of the touch insensitive larva B (tilB) gene to cilia function in Drosophila melanogaster. Mutants of tilB exhibit dysfunction in sperm flagella and ciliated dendrites of chordotonal organs that mediate hearing and larval touch sensitivity. Mutant sperm axonemes as well as sensory neuron dendrites of Johnston's organ, the fly's auditory organ, lack dynein arms. Through deficiency mapping and sequencing candidate genes, we identified tilB mutations in the annotated gene CG14620. A genomic CG14620 transgene rescued deafness and male sterility of tilB mutants. TilB is a 395-amino-acid protein with a conserved N-terminal leucine-rich repeat region at residues 16-164 and a coiled-coil domain at residues 171-191. A tilB-Gal4 transgene driving fluorescently tagged TilB proteins elicits cytoplasmic expression in embryonic chordotonal organs, in Johnston's organ, and in sperm flagella. TilB does not appear to affect tubulin polyglutamylation or polyglycylation. The phenotypes and expression of tilB indicate function in cilia construction or maintenance, but not in intraflagellar transport. This is also consistent with phylogenetic association of tilB homologs with presence of genes encoding axonemal dynein arm components. Further elucidation of tilB functional mechanisms will provide greater understanding of cilia function and will facilitate understanding ciliary diseases.
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