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Legal T, Joachimiak E, Parra M, Peng W, Tam A, Black C, Valente-Paterno M, Brouhard G, Gaertig J, Wloga D, Bui KH. Structure of the ciliary tip central pair reveals the unique role of the microtubule-seam binding protein SPEF1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.12.02.626492. [PMID: 39677611 PMCID: PMC11642885 DOI: 10.1101/2024.12.02.626492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2024]
Abstract
Motile cilia are unique organelles with the ability to autonomously move. Force generated by beating cilia propels cells and moves fluids. The ciliary skeleton is made of peripheral doublet microtubules and a central pair (CP) with a distinct structure at the tip. In this study, we present a high-resolution structure of the CP in the ciliary tip of the ciliate Tetrahymena thermophila and identify several tip proteins that bind and form unique patterns on both microtubules of the tip CP. Two of those proteins that contain tubulin polymerization-promoting protein (TPPP)-like domains, TLP1 and TLP2, bind to high curvature regions of the microtubule. TLP2, which contains two TPPP-like domains, is an unusually long protein that wraps laterally around half a microtubule and forms the bridge between the two microtubules. Moreover, we found that the conserved protein SPEF1 binds to both microtubule seams. In vitro, human SPEF1 not only binds to the microtubule seam but also crosslinks two parallel microtubules. Single-molecule microtubule dynamics assays indicate that SPEF1 stabilizes microtubules in vitro. Together, these data show that the proteins in the tip CP maintain stable microtubule structure and probably play important roles in maintaining the integrity of the axoneme.
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Affiliation(s)
- Thibault Legal
- Department of Anatomy and Cell Biology, McGill University, Montreal, Québec, Canada
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Str, 02-093 Warsaw, Poland
| | - Mireya Parra
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Wang Peng
- Department of Biology, McGill University, Montreal, Québec, Canada
| | - Amanda Tam
- Department of Anatomy and Cell Biology, McGill University, Montreal, Québec, Canada
| | - Corbin Black
- Department of Anatomy and Cell Biology, McGill University, Montreal, Québec, Canada
| | | | - Gary Brouhard
- Department of Biology, McGill University, Montreal, Québec, Canada
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Str, 02-093 Warsaw, Poland
| | - Khanh Huy Bui
- Department of Anatomy and Cell Biology, McGill University, Montreal, Québec, Canada
- Centre de Recherche en Biologie Structurale, McGill University, Montreal, Québec, Canada
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2
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Tapia R, Hecht GA. Spef1/CLAMP binds microtubules and actin-based structures and regulates cell migration and epithelia cell polarity. Ann N Y Acad Sci 2022; 1515:97-104. [PMID: 35710871 PMCID: PMC9796845 DOI: 10.1111/nyas.14845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
During migration, cells invade, repair, and create barriers leading to the formation of new cellular contacts in target tissues. Cell migration requires many proteins that collectively form the cytoskeleton. The main cytoskeletal elements are actin filaments, microtubules (MTs), and intermediate filaments. These structures work in concert with a large number of accessory proteins that contribute in a variety of ways to regulate filament assembly and turnover, to alter the configuration or arrangement of filaments by bundling or crosslinking, to link the cytoskeleton to other structures in the cell, such as membranes and junctions, and to transport cargo along the filaments. Sperm flagella protein-1 (Spef1), also designated calponin homology and microtubules-associated protein (CLAMP), is a multifunctional protein that interacts with cytoskeletal structures, including MTs, actin filaments, and focal adhesions in epithelia. In this review, we outline Spef1/CLAMP structure and expression in several cellular models. The function of Spef1/CLAMP in flagellar and ciliary motility, MT-binding and stability, regulation of planar cell polarity, and potential contribution to the maintenance of actin-based structures, such as lamellipodia and filopodia during cell migration, are also discussed.
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Affiliation(s)
- Rocio Tapia
- Division of Gastroenterology and Nutrition, Department of MedicineLoyola University Chicago, Loyola University Medical CenterMaywoodIllinoisUSA
| | - Gail A. Hecht
- Division of Gastroenterology and Nutrition, Department of MedicineLoyola University Chicago, Loyola University Medical CenterMaywoodIllinoisUSA
- Department of Microbiology and ImmunologyLoyola University Chicago, Loyola University Medical CenterMaywoodIllinoisUSA
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3
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Nommick A, Boutin C, Rosnet O, Schirmer C, Bazellières E, Thomé V, Loiseau E, Viallat A, Kodjabachian L. Lrrcc1 and Ccdc61 are conserved effectors of multiciliated cell function. J Cell Sci 2022; 135:274401. [DOI: 10.1242/jcs.258960] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 01/05/2022] [Indexed: 11/20/2022] Open
Abstract
Ciliated epithelia perform essential functions across animal evolution, ranging from locomotion of marine organisms to mucociliary clearance of airways in mammals. These epithelia are composed of multiciliated cells (MCCs) harbouring myriads of motile cilia, which rest on modified centrioles called basal bodies (BBs), and beat coordinately to generate directed fluid flows. Thus, BB biogenesis and organization is central to MCC function. In basal eukaryotes, the coiled-coil domain proteins Lrrcc1 and Ccdc61 were shown to be required for proper BB construction and function. Here, we used the Xenopus embryonic ciliated epidermis to characterize Lrrcc1 and Ccdc61 in vertebrate MCCs. We found that they both encode BB components, localized proximally at the junction with striated rootlets. Knocking down either gene caused defects in BB docking, spacing, and polarization. Moreover, their depletion impaired the apical cytoskeleton, and altered ciliary beating. Consequently, cilia-powered fluid flow was greatly reduced in morphant tadpoles, which displayed enhanced mortality when exposed to pathogenic bacteria. This work illustrates how integration across organizational scales make elementary BB components essential for the emergence of the physiological function of ciliated epithelia.
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Affiliation(s)
- Aude Nommick
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Camille Boutin
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Olivier Rosnet
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Claire Schirmer
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Elsa Bazellières
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Virginie Thomé
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Etienne Loiseau
- Aix Marseille Univ, CNRS, CINaM, Turing Center for Living Systems, Marseille, France
| | - Annie Viallat
- Aix Marseille Univ, CNRS, CINaM, Turing Center for Living Systems, Marseille, France
| | - Laurent Kodjabachian
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
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4
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Chen T, Rohacek AM, Caporizzo M, Nankali A, Smits JJ, Oostrik J, Lanting CP, Kücük E, Gilissen C, van de Kamp JM, Pennings RJE, Rakowiecki SM, Kaestner KH, Ohlemiller KK, Oghalai JS, Kremer H, Prosser BL, Epstein DJ. Cochlear supporting cells require GAS2 for cytoskeletal architecture and hearing. Dev Cell 2021; 56:1526-1540.e7. [PMID: 33964205 PMCID: PMC8137675 DOI: 10.1016/j.devcel.2021.04.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 02/01/2021] [Accepted: 04/16/2021] [Indexed: 11/16/2022]
Abstract
In mammals, sound is detected by mechanosensory hair cells that are activated in response to vibrations at frequency-dependent positions along the cochlear duct. We demonstrate that inner ear supporting cells provide a structural framework for transmitting sound energy through the cochlear partition. Humans and mice with mutations in GAS2, encoding a cytoskeletal regulatory protein, exhibit hearing loss due to disorganization and destabilization of microtubule bundles in pillar and Deiters' cells, two types of inner ear supporting cells with unique cytoskeletal specializations. Failure to maintain microtubule bundle integrity reduced supporting cell stiffness, which in turn altered cochlear micromechanics in Gas2 mutants. Vibratory responses to sound were measured in cochleae from live mice, revealing defects in the propagation and amplification of the traveling wave in Gas2 mutants. We propose that the microtubule bundling activity of GAS2 imparts supporting cells with mechanical properties for transmitting sound energy through the cochlea.
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Affiliation(s)
- Tingfang Chen
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alex M Rohacek
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew Caporizzo
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Amir Nankali
- The Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angeles, CA, USA
| | - Jeroen J Smits
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jaap Oostrik
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Cornelis P Lanting
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Erdi Kücük
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jiddeke M van de Kamp
- Department of Clinical Genetics, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Ronald J E Pennings
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Staci M Rakowiecki
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Klaus H Kaestner
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kevin K Ohlemiller
- Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine, St. Louis, MO, USA
| | - John S Oghalai
- The Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angeles, CA, USA
| | - Hannie Kremer
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Benjamin L Prosser
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Douglas J Epstein
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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5
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Central Apparatus, the Molecular Kickstarter of Ciliary and Flagellar Nanomachines. Int J Mol Sci 2021; 22:ijms22063013. [PMID: 33809498 PMCID: PMC7999657 DOI: 10.3390/ijms22063013] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/10/2021] [Accepted: 03/12/2021] [Indexed: 02/07/2023] Open
Abstract
Motile cilia and homologous organelles, the flagella, are an early evolutionarily invention, enabling primitive eukaryotic cells to survive and reproduce. In animals, cilia have undergone functional and structural speciation giving raise to typical motile cilia, motile nodal cilia, and sensory immotile cilia. In contrast to other cilia types, typical motile cilia are able to beat in complex, two-phase movements. Moreover, they contain many additional structures, including central apparatus, composed of two single microtubules connected by a bridge-like structure and assembling numerous complexes called projections. A growing body of evidence supports the important role of the central apparatus in the generation and regulation of the motile cilia movement. Here we review data concerning the central apparatus structure, protein composition, and the significance of its components in ciliary beating regulation.
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6
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Collins C, Ventrella R, Mitchell BJ. Building a ciliated epithelium: Transcriptional regulation and radial intercalation of multiciliated cells. Curr Top Dev Biol 2020; 145:3-39. [PMID: 34074533 DOI: 10.1016/bs.ctdb.2020.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The epidermis of the Xenopus embryo has emerged as a powerful tool for studying the development of a ciliated epithelium. Interspersed throughout the epithelium are multiciliated cells (MCCs) with 100+ motile cilia that beat in a coordinated manner to generate fluid flow over the surface of the cell. MCCs are essential for various developmental processes and, furthermore, ciliary dysfunction is associated with numerous pathologies. Therefore, understanding the cellular mechanisms involved in establishing a ciliated epithelium are of particular interest. MCCs originate in the inner epithelial layer of Xenopus skin, where Notch signaling plays a critical role in determining which progenitors will adopt a ciliated cell fate. Then, activation of various transcriptional regulators, such as GemC1 and MCIDAS, initiate the MCC transcriptional program, resulting in centriole amplification and the formation of motile cilia. Following specification and differentiation, MCCs undergo the process of radial intercalation, where cells apically migrate from the inner layer to the outer epithelial layer. This process involves the cooperation of various cytoskeletal networks, activation of various signaling molecules, and changes in cell-ECM and cell-cell adhesion. Coordination of these cellular processes is required for complete incorporation into the outer epithelial layer and generation of a functional ciliated epithelium. Here, we highlight recent advances made in understanding the transcriptional cascades required for MCC specification and differentiation and the coordination of cellular processes that facilitate radial intercalation. Proper regulation of these signaling pathways and processes are the foundation for developing a ciliated epithelium.
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Affiliation(s)
- Caitlin Collins
- Department of Cell and Developmental Biology, Lurie Comprehensive Cancer Center, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
| | - Rosa Ventrella
- Department of Cell and Developmental Biology, Lurie Comprehensive Cancer Center, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
| | - Brian J Mitchell
- Department of Cell and Developmental Biology, Lurie Comprehensive Cancer Center, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States.
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Basal Body Protein TbSAF1 Is Required for Microtubule Quartet Anchorage to the Basal Bodies in Trypanosoma brucei. mBio 2020; 11:mBio.00668-20. [PMID: 32518185 PMCID: PMC7291619 DOI: 10.1128/mbio.00668-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Trypanosoma brucei contains a large array of single-copied organelles and structures. Through extensive interorganelle connections, these structures replicate and divide following a strict temporal and spatial order. A microtubule quartet (MtQ) originates from the basal bodies and extends toward the anterior end of the cell, stringing several cytoskeletal structures together along its path. In this study, we examined the interaction network of TbSpef1, the only protein specifically located to the MtQ. We identified an interaction between TbSpef1 and a basal body protein TbSAF1, which is required for MtQ anchorage to the basal bodies. This study thus provides the first molecular description of MtQ association with the basal bodies, since the discovery of this association ∼30 years ago. The results also reveal a general mechanism of the evolutionarily conserved Spef1/CLAMP, which achieves specific cellular functions via their conserved microtubule functions and their diverse molecular interaction networks. Sperm flagellar protein 1 (Spef1, also known as CLAMP) is a microtubule-associated protein involved in various microtubule-related functions from ciliary motility to polarized cell movement and planar cell polarity. In Trypanosoma brucei, the causative agent of trypanosomiasis, a single Spef1 ortholog (TbSpef1) is associated with a microtubule quartet (MtQ), which is in close association with several single-copied organelles and is required for their coordinated biogenesis during the cell cycle. Here, we investigated the interaction network of TbSpef1 using BioID, a proximity-dependent protein-protein interaction screening method. Characterization of selected candidates provided a molecular description of TbSpef1-MtQ interactions with nearby cytoskeletal structures. Of particular interest, we identified a new basal body protein TbSAF1, which is required for TbSpef1-MtQ anchorage to the basal bodies. The results demonstrate that MtQ-basal body anchorage is critical for the spatial organization of cytoskeletal organelles, as well as the morphology of the membrane-bound flagellar pocket where endocytosis takes place in this parasite.
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8
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Tapia R, Perez-Yepez EA, Carlino MJ, Karandikar UC, Kralicek SE, Estes MK, Hecht GA. Sperm Flagellar 1 Binds Actin in Intestinal Epithelial Cells and Contributes to Formation of Filopodia and Lamellipodia. Gastroenterology 2019; 157:1544-1555.e3. [PMID: 31473225 PMCID: PMC7016487 DOI: 10.1053/j.gastro.2019.08.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 08/21/2019] [Accepted: 08/23/2019] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS Sperm flagellar 1 (also called CLAMP) is a microtubule-associated protein that regulates microtubule dynamics and planar cell polarity in multi-ciliated cells. We investigated the localization and function of sperm flagellar 1, or CLAMP, in human intestinal epithelia cells (IECs). METHODS We performed studies with SKCO-15 and human intestinal enteroids established from biopsies from different intestinal segments (duodenal, jejunum, ileal, and colon) of a single donor. Enteroids were induced to differentiation after incubation with growth factors. The distribution of endogenous CLAMP in IECs was analyzed by immunofluorescence microscopy using total internal reflection fluorescence-ground state depletion and confocal microscopy. CLAMP localization was followed during the course of intestinal epithelial cell polarization as cells progressed from flat to compact, confluent monolayers. Protein interactions with endogenous CLAMP were determined in SKCO-15 cells using proximity ligation assays and co-immunoprecipitation. CLAMP was knocked down in SKCO-15 monolayers using small hairpin RNAs and cells were analyzed by immunoblot and immunofluorescence microscopy. The impact of CLAMP knock-down in migrating SKCO-15 cells was assessed using scratch-wound assays. RESULTS CLAMP bound to actin and apical junctional complex proteins but not microtubules in IECs. In silico analysis predicted the calponin-homology domain of CLAMP to contain conserved amino acids required for actin binding. During IEC polarization, CLAMP distribution changed from primarily basal stress fibers and cytoplasm in undifferentiated cells to apical membranes and microvilli in differentiated monolayers. CLAMP accumulated in lamellipodia and filopodia at the leading edge of migrating cells in association with actin. CLAMP knock-down reduced the number of filopodia, perturbed filopodia polarity, and altered the organization of actin filaments within lamellipodia. CONCLUSIONS CLAMP is an actin-binding protein, rather than a microtubule-binding protein, in IECs. CLAMP distribution changes during intestinal epithelial cell polarization, regulates the formation of filopodia, and appears to assist in the organization of actin bundles within lamellipodia of migrating IECs. Studies are needed to define the CLAMP domains that interact with actin and whether its loss from IECs affects intestinal function.
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Affiliation(s)
- Rocio Tapia
- Department of Medicine, Division of Gastroenterology and Nutrition
| | | | | | | | | | - Mary K. Estes
- Department of Molecular Virology and Microbiology,Department of Medicine - Gastroenterology and Hepatology and Infectious Diseases, Baylor College of Medicine, Houston, Texas
| | - Gail A. Hecht
- Department of Medicine, Division of Gastroenterology and Nutrition,Department of Microbiology and Immunology, Loyola University Chicago,Edward Hines Jr. VA Hospital, Hines, Illinois
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9
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Cilia Distal Domain: Diversity in Evolutionarily Conserved Structures. Cells 2019; 8:cells8020160. [PMID: 30769894 PMCID: PMC6406257 DOI: 10.3390/cells8020160] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 01/25/2019] [Accepted: 02/13/2019] [Indexed: 12/12/2022] Open
Abstract
Eukaryotic cilia are microtubule-based organelles that protrude from the cell surface to fulfill sensory and motility functions. Their basic structure consists of an axoneme templated by a centriole/basal body. Striking differences in ciliary ultra-structures can be found at the ciliary base, the axoneme and the tip, not only throughout the eukaryotic tree of life, but within a single organism. Defects in cilia biogenesis and function are at the origin of human ciliopathies. This structural/functional diversity and its relationship with the etiology of these diseases is poorly understood. Some of the important events in cilia function occur at their distal domain, including cilia assembly/disassembly, IFT (intraflagellar transport) complexes' remodeling, and signal detection/transduction. How axonemal microtubules end at this domain varies with distinct cilia types, originating different tip architectures. Additionally, they show a high degree of dynamic behavior and are able to respond to different stimuli. The existence of microtubule-capping structures (caps) in certain types of cilia contributes to this diversity. It has been proposed that caps play a role in axoneme length control and stabilization, but their roles are still poorly understood. Here, we review the current knowledge on cilia structure diversity with a focus on the cilia distal domain and caps and discuss how they affect cilia structure and function.
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10
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Zheng J, Liu H, Zhu L, Chen Y, Zhao H, Zhang W, Li F, Xie L, Yan X, Zhu X. Microtubule-bundling protein Spef1 enables mammalian ciliary central apparatus formation. J Mol Cell Biol 2019; 11:67-77. [PMID: 30535028 DOI: 10.1093/jmcb/mjy014] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 02/22/2018] [Indexed: 01/10/2023] Open
Abstract
Cilia are cellular protrusions containing nine microtubule (MT) doublets and function to propel cell movement or extracellular liquid flow through beating or sense environmental stimuli through signal transductions. Cilia require the central pair (CP) apparatus, consisting of two CP MTs covered with projections of CP proteins, for planar strokes. How the CP MTs of such '9 + 2' cilia are constructed, however, remains unknown. Here we identify Spef1, an evolutionarily conserved microtubule-bundling protein, as a core CP MT regulator in mammalian cilia. Spef1 was selectively expressed in mammalian cells with 9 + 2 cilia and specifically localized along the CP. Its depletion in multiciliated mouse ependymal cells by RNAi completely abolished the CP MTs and markedly attenuated ciliary localizations of CP proteins such as Hydin and Spag6, resulting in rotational beat of the ependymal cilia. Spef1, which binds to MTs through its N-terminal calponin-homologous domain, formed homodimers through its C-terminal coiled coil region to bundle and stabilize MTs. Disruption of either the MT-binding or the dimerization activity abolished the ability of exogenous Spef1 to restore the structure and functions of the CP apparatus. We propose that Spef1 bundles and stabilizes central MTs to enable the assembly and functions of the CP apparatus.
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Affiliation(s)
- Jianqun Zheng
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai0, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - Hao Liu
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai0, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - Lei Zhu
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai0, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - Yawen Chen
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai0, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - Huijie Zhao
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai0, China
| | - Wei Zhang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai0, China
| | - Fan Li
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai0, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - Lele Xie
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai0, China
| | - Xiumin Yan
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai0, China
| | - Xueliang Zhu
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai0, China
- University of Chinese Academy of Sciences, Shanghai, China
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11
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Srivastava S, Panda D. A centrosomal protein STARD9 promotes microtubule stability and regulates spindle microtubule dynamics. Cell Cycle 2018; 17:2052-2068. [PMID: 30160609 DOI: 10.1080/15384101.2018.1513764] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Centrosomal proteins play important roles in the spindle assembly and the segregation of chromosomes in the eukaryotic cells. STARD9, a recently identified centrosomal protein, was reported to influence the spindle pole assembly. However, the role of STARD9 in maintaining the stability and organization of microtubules are not known. Here, we show that STARD9 regulates the assembly and dynamics of both interphase and mitotic microtubules. The knockdown of STARD9 in HeLa or HCT116 cells with siRNA or shRNA induced a strong depolymerization of the interphase microtubules. The over-expression of the motor domain of STARD9 stabilizes microtubules against cold and nocodazole suggesting that STARD9 stabilizes microtubules in HeLa cells. Using fluorescent recovery after photobleaching, we showed that the knockdown of STARD9 strongly reduced microtubule dynamics in the live spindles of HeLa cells. The reassembly of microtubules in the STARD9-depleted cells was strongly reduced as compared to the microtubules in the control cells implying the role of STARD9 in the nucleation of microtubules. Further, the depletion of STARD9 inhibited chromosome separation and the STARD9-depleted HeLa cells were blocked at mitosis. Interestingly, the frequency of multipolar spindle formation increased significantly in the STARD9-depleted HeLa cells in the presence of vinblastine and the STARD9-depleted cells showed much higher sensitivity towards vinblastine than the control cells indicating a new approach for cancer chemotherapy. The evidence suggests that STARD9 regulates the assembly and stability of both interphase and spindle microtubules and thereby, play important roles in the cell cycle progression.
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Affiliation(s)
- Shalini Srivastava
- a Department of Biosciences & Bioengineering , Indian Institute of Technology Bombay , Mumbai , India
| | - Dulal Panda
- a Department of Biosciences & Bioengineering , Indian Institute of Technology Bombay , Mumbai , India
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12
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Kim SK, Zhang S, Werner ME, Brotslaw EJ, Mitchell JW, Altabbaa MM, Mitchell BJ. CLAMP/Spef1 regulates planar cell polarity signaling and asymmetric microtubule accumulation in the Xenopus ciliated epithelia. J Cell Biol 2018. [PMID: 29514918 PMCID: PMC5940297 DOI: 10.1083/jcb.201706058] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Kim et al. show that CLAMP regulates planar cell polarity (PCP) signaling. Its depletion causes a loss of the atypical cadherin Celsr2, a loss of PCP protein asymmetry, and a defect in cilia polarity and oriented cell division. CLAMP also, via its role in PCP, regulates the accumulation of an asymmetric pool of microtubules. Most epithelial cells polarize along the axis of the tissue, a feature known as planar cell polarity (PCP). The initiation of PCP requires cell–cell signaling via the noncanonical Wnt/PCP pathway. Additionally, changes in the cytoskeleton both facilitate and reflect this polarity. We have identified CLAMP/Spef1 as a novel regulator of PCP signaling. In addition to decorating microtubules (MTs) and the ciliary rootlet, a pool of CLAMP localizes at the apical cell cortex. Depletion of CLAMP leads to the loss of PCP protein asymmetry, defects in cilia polarity, and defects in the angle of cell division. Additionally, depletion of CLAMP leads to a loss of the atypical cadherin-like molecule Celrs2, suggesting that CLAMP facilitates the stabilization of junctional interactions responsible for proper PCP protein localization. Depletion of CLAMP also affects the polarized organization of MTs. We hypothesize that CLAMP facilitates the establishment of cell polarity and promotes the asymmetric accumulation of MTs downstream of the establishment of proper PCP.
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Affiliation(s)
- Sun K Kim
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Siwei Zhang
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Michael E Werner
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Eva J Brotslaw
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Jennifer W Mitchell
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Mohamed M Altabbaa
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Brian J Mitchell
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
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13
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Zhang HG, Wang RX, Pan Y, Zhang H, Li LL, Zhu HB, Liu RZ. A report of nine cases and review of the literature of infertile men carrying balanced translocations involving chromosome 5. Mol Cytogenet 2018; 11:10. [PMID: 29416565 PMCID: PMC5785882 DOI: 10.1186/s13039-018-0360-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/16/2018] [Indexed: 12/21/2022] Open
Abstract
Background Balanced translocations may cause the loss of genetic material at the breakpoints and may result in failure of spermatogenesis. However, carriers of reciprocal translocation may naturally conceive. Genetic counseling of male carriers of translocations remains challenging. This study explores the clinical features of carriers of chromosome 5 translocations, enabling informed genetic counseling of these patients. Results Of 82 translocation carriers, 9 (11%) were carriers of a chromosome 5 translocation. One case had azoospermia, while three cases had experienced recurrent spontaneous abortions, two cases had each experienced stillbirth, and three cases produced a phenotypically normal child confirmed by amniocentesis. A literature review identified 106 patients who carried chromosome 5 translocations. The most common chromosome 5 translocation was t(4,5), observed in 13 patients. Breakpoint at 5p15 was observed in 11 patients. All breakpoints at chromosome 5 were associated with gestational infertility. Conclusion In genetic counseling, physicians should consider chromosome 5 and its breakpoints. Carriers of chromosome 5 translocations may continue with natural conception or use assisted reproductive technologies, such as preimplantation genetic diagnosis.
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Affiliation(s)
- Hong-Guo Zhang
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital, Jilin University, 71 Xinmin Street, Chaoyang District, Changchun, Jilin Province 130021 China
| | - Rui-Xue Wang
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital, Jilin University, 71 Xinmin Street, Chaoyang District, Changchun, Jilin Province 130021 China
| | - Yuan Pan
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital, Jilin University, 71 Xinmin Street, Chaoyang District, Changchun, Jilin Province 130021 China
| | - Han Zhang
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital, Jilin University, 71 Xinmin Street, Chaoyang District, Changchun, Jilin Province 130021 China
| | - Lei-Lei Li
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital, Jilin University, 71 Xinmin Street, Chaoyang District, Changchun, Jilin Province 130021 China
| | - Hai-Bo Zhu
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital, Jilin University, 71 Xinmin Street, Chaoyang District, Changchun, Jilin Province 130021 China
| | - Rui-Zhi Liu
- Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital, Jilin University, 71 Xinmin Street, Chaoyang District, Changchun, Jilin Province 130021 China
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14
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Mustyatsa VV, Boyakhchyan AV, Ataullakhanov FI, Gudimchuk NB. EB-family proteins: Functions and microtubule interaction mechanisms. BIOCHEMISTRY (MOSCOW) 2017; 82:791-802. [DOI: 10.1134/s0006297917070045] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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Olender T, Keydar I, Pinto JM, Tatarskyy P, Alkelai A, Chien MS, Fishilevich S, Restrepo D, Matsunami H, Gilad Y, Lancet D. The human olfactory transcriptome. BMC Genomics 2016; 17:619. [PMID: 27515280 PMCID: PMC4982115 DOI: 10.1186/s12864-016-2960-3] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 07/21/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Olfaction is a versatile sensory mechanism for detecting thousands of volatile odorants. Although molecular basis of odorant signaling is relatively well understood considerable gaps remain in the complete charting of all relevant gene products. To address this challenge, we applied RNAseq to four well-characterized human olfactory epithelial samples and compared the results to novel and published mouse olfactory epithelium as well as 16 human control tissues. RESULTS We identified 194 non-olfactory receptor (OR) genes that are overexpressed in human olfactory tissues vs. CONTROLS The highest overexpression is seen for lipocalins and bactericidal/permeability-increasing (BPI)-fold proteins, which in other species include secreted odorant carriers. Mouse-human discordance in orthologous lipocalin expression suggests different mammalian evolutionary paths in this family. Of the overexpressed genes 36 have documented olfactory function while for 158 there is little or no previous such functional evidence. The latter group includes GPCRs, neuropeptides, solute carriers, transcription factors and biotransformation enzymes. Many of them may be indirectly implicated in sensory function, and ~70 % are over expressed also in mouse olfactory epithelium, corroborating their olfactory role. Nearly 90 % of the intact OR repertoire, and ~60 % of the OR pseudogenes are expressed in the olfactory epithelium, with the latter showing a 3-fold lower expression. ORs transcription levels show a 1000-fold inter-paralog variation, as well as significant inter-individual differences. We assembled 160 transcripts representing 100 intact OR genes. These include 1-4 short 5' non-coding exons with considerable alternative splicing and long last exons that contain the coding region and 3' untranslated region of highly variable length. Notably, we identified 10 ORs with an intact open reading frame but with seemingly non-functional transcripts, suggesting a yet unreported OR pseudogenization mechanism. Analysis of the OR upstream regions indicated an enrichment of the homeobox family transcription factor binding sites and a consensus localization of a specific transcription factor binding site subfamily (Olf/EBF). CONCLUSIONS We provide an overview of expression levels of ORs and auxiliary genes in human olfactory epithelium. This forms a transcriptomic view of the entire OR repertoire, and reveals a large number of over-expressed uncharacterized human non-receptor genes, providing a platform for future discovery.
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Affiliation(s)
- Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
| | - Ifat Keydar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Jayant M Pinto
- Section of Otolaryngology-Head and Neck Surgery, University of Chicago, Chicago, IL, USA
| | - Pavlo Tatarskyy
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Anna Alkelai
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Ming-Shan Chien
- Department of Molecular Genetics and Microbiology, Department of Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC, USA
| | - Simon Fishilevich
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Diego Restrepo
- Department of Cell and Developmental Biology, Neuroscience Program, and Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, Aurora, CO, USA
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Department of Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC, USA
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Doron Lancet
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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16
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Werner ME, Mitchell JW, Putzbach W, Bacon E, Kim SK, Mitchell BJ. Radial intercalation is regulated by the Par complex and the microtubule-stabilizing protein CLAMP/Spef1. J Cell Biol 2014; 206:367-76. [PMID: 25070955 PMCID: PMC4121976 DOI: 10.1083/jcb.201312045] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 06/25/2014] [Indexed: 01/28/2023] Open
Abstract
The directed movement of cells is critical for numerous developmental and disease processes. A developmentally reiterated form of migration is radial intercalation; the process by which cells move in a direction orthogonal to the plane of the tissue from an inner layer to an outer layer. We use the radial intercalation of cells into the skin of Xenopus laevis embryos as a model to study directed cell migration within an epithelial tissue. We identify a novel function for both the microtubule-binding protein CLAMP and members of the microtubule-regulating Par complex during intercalation. Specifically, we show that Par3 and aPKC promote the apical positioning of centrioles, whereas CLAMP stabilizes microtubules along the axis of migration. We propose a model in which the Par complex defines the orientation of apical migration during intercalation and in which subcellular localization of CLAMP promotes the establishment of an axis of microtubule stability required for the active migration of cells into the outer epithelium.
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Affiliation(s)
- Michael E Werner
- Department of Cell and Molecular Biology and Driskill Graduate Program in Life Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - Jennifer W Mitchell
- Department of Cell and Molecular Biology and Driskill Graduate Program in Life Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - William Putzbach
- Department of Cell and Molecular Biology and Driskill Graduate Program in Life Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - Elizabeth Bacon
- Department of Cell and Molecular Biology and Driskill Graduate Program in Life Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - Sun K Kim
- Department of Cell and Molecular Biology and Driskill Graduate Program in Life Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
| | - Brian J Mitchell
- Department of Cell and Molecular Biology and Driskill Graduate Program in Life Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611
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17
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Abstract
In the nervous system, cilia dysfunction perturbs the circulation of the cerebrospinal fluid, thus affecting neurogenesis and brain homeostasis. A role for planar cell polarity (PCP) signaling in the orientation of cilia (rotational polarity) and ciliogenesis is established. However, whether and how PCP regulates cilia positioning in the apical domain (translational polarity) in radial progenitors and ependymal cells remain unclear. By analysis of a large panel of mutant mice, we show that two PCP signals are operating in ciliated cells. The first signal, controlled by cadherin, EGF-like, laminin G-like, seven-pass, G-type receptor (Celsr) 2, Celsr3, Frizzled3 (Fzd3) and Van Gogh like2 (Vangl2) organizes multicilia in individual cells (single-cell polarity), whereas the second signal, governed by Celsr1, Fzd3, and Vangl2, coordinates polarity between cells in both radial progenitors and ependymal cells (tissue polarity). Loss of either of these signals is associated with specific defects in the cytoskeleton. Our data reveal unreported functions of PCP and provide an integrated view of planar polarization of the brain ciliated cells.
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18
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Abstract
The propagation of all organisms depends on the accurate and orderly segregation of chromosomes in mitosis and meiosis. Budding yeast has long served as an outstanding model organism to identify the components and underlying mechanisms that regulate chromosome segregation. This review focuses on the kinetochore, the macromolecular protein complex that assembles on centromeric chromatin and maintains persistent load-bearing attachments to the dynamic tips of spindle microtubules. The kinetochore also serves as a regulatory hub for the spindle checkpoint, ensuring that cell cycle progression is coupled to the achievement of proper microtubule-kinetochore attachments. Progress in understanding the composition and overall architecture of the kinetochore, as well as its properties in making and regulating microtubule attachments and the spindle checkpoint, is discussed.
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19
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Gheiratmand L, Brasseur A, Zhou Q, He CY. Biochemical characterization of the bi-lobe reveals a continuous structural network linking the bi-lobe to other single-copied organelles in Trypanosoma brucei. J Biol Chem 2012; 288:3489-99. [PMID: 23235159 DOI: 10.1074/jbc.m112.417428] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trypanosoma brucei, a unicellular parasite, contains several single-copied organelles that duplicate and segregate in a highly coordinated fashion during the cell cycle. In the procyclic stage, a bi-lobed structure is found adjacent to the single ER exit site and Golgi apparatus, forming both stable and dynamic association with other cytoskeletal components including the basal bodies that seed the flagellum and the flagellar pocket collar that is critical for flagellar pocket biogenesis. To further understand the bi-lobe and its association with adjacent organelles, we performed proteomic analyses on the immunoisolated bi-lobe complex. Candidate proteins were localized to the flagellar pocket, the basal bodies, a tripartite attachment complex linking the basal bodies to the kinetoplast, and a segment of microtubule quartet linking the flagellar pocket collar and bi-lobe to the basal bodies. These results supported an extensive connection among the single-copied organelles in T. brucei, a strategy employed by the parasite for orderly organelle assembly and inheritance during the cell cycle.
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Affiliation(s)
- Ladan Gheiratmand
- Department of Biological Sciences, Centre for BioImaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
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20
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Buey RM, Mohan R, Leslie K, Walzthoeni T, Missimer JH, Menzel A, Bjelić S, Bargsten K, Grigoriev I, Smal I, Meijering E, Aebersold R, Akhmanova A, Steinmetz MO. Insights into EB1 structure and the role of its C-terminal domain for discriminating microtubule tips from the lattice. Mol Biol Cell 2011; 22:2912-23. [PMID: 21737692 PMCID: PMC3154886 DOI: 10.1091/mbc.e11-01-0017] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 05/12/2011] [Accepted: 06/16/2011] [Indexed: 12/31/2022] Open
Abstract
End-binding proteins (EBs) comprise a conserved family of microtubule plus end-tracking proteins. The concerted action of calponin homology (CH), linker, and C-terminal domains of EBs is important for their autonomous microtubule tip tracking, regulation of microtubule dynamics, and recruitment of numerous partners to microtubule ends. Here we report the detailed structural and biochemical analysis of mammalian EBs. Small-angle X-ray scattering, electron microscopy, and chemical cross-linking in combination with mass spectrometry indicate that EBs are elongated molecules with two interacting CH domains, an arrangement reminiscent of that seen in other microtubule- and actin-binding proteins. Removal of the negatively charged C-terminal tail did not affect the overall conformation of EBs; however, it increased the dwell times of EBs on the microtubule lattice in microtubule tip-tracking reconstitution experiments. An even more stable association with the microtubule lattice was observed when the entire negatively charged C-terminal domain of EBs was replaced by a neutral coiled-coil motif. In contrast, the interaction of EBs with growing microtubule tips was not significantly affected by these C-terminal domain mutations. Our data indicate that long-range electrostatic repulsive interactions between the C-terminus and the microtubule lattice drive the specificity of EBs for growing microtubule ends.
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Affiliation(s)
- Rubén M. Buey
- Biomolecular Research, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Renu Mohan
- Department of Cell Biology, Erasmus Medical Center, Rotterdam 3000 CA, Netherlands
| | - Kris Leslie
- Department of Cell Biology, Erasmus Medical Center, Rotterdam 3000 CA, Netherlands
| | - Thomas Walzthoeni
- Institute of Molecular Systems Biology, ETH Zürich, 8093 Zürich, Switzerland
- Ph.D. Program in Molecular Life Sciences, University of Zürich/ETH Zürich, 8093 Zürich, Switzerland
| | - John H. Missimer
- Biomolecular Research, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Andreas Menzel
- Synchrotron Radiation and Nanotechnology, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Saša Bjelić
- Biomolecular Research, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Katja Bargsten
- Biomolecular Research, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Ilya Grigoriev
- Department of Cell Biology, Erasmus Medical Center, Rotterdam 3000 CA, Netherlands
| | - Ihor Smal
- Biomedical Imaging Group Rotterdam, Department of Medical Informatics and Radiology, Erasmus Medical Center, Rotterdam 3000 CA, Netherlands
| | - Erik Meijering
- Biomedical Imaging Group Rotterdam, Department of Medical Informatics and Radiology, Erasmus Medical Center, Rotterdam 3000 CA, Netherlands
| | - Ruedi Aebersold
- Institute of Molecular Systems Biology, ETH Zürich, 8093 Zürich, Switzerland
- Faculty of Science, University of Zürich, 8093 Zürich, Switzerland
- Competence Center for Systems Physiology and Metabolic Diseases, 8093 Zürich, Switzerland
| | - Anna Akhmanova
- Ph.D. Program in Molecular Life Sciences, University of Zürich/ETH Zürich, 8093 Zürich, Switzerland
| | - Michel O. Steinmetz
- Biomolecular Research, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
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21
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Duarte DT, Hul S, Sacher M. A yeast two hybrid screen identifies SPATA4 as a TRAPP interactor. FEBS Lett 2011; 585:2676-81. [PMID: 21827752 DOI: 10.1016/j.febslet.2011.07.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 07/25/2011] [Accepted: 07/26/2011] [Indexed: 11/17/2022]
Abstract
The TRAPP vesicle-tethering complex consists of more than 10 distinct polypeptides and is involved in protein transport. Using the C2 subunit as bait we identified SPATA4, a spermatocyte-specific protein of unknown function, as an interacting partner in a yeast two hybrid screen. Further studies indicate SPATA4 interacts with the C2 portion of the TRAPP complex. SPATA4 fractionates with both cytosolic and nuclear fractions suggesting it may have several distinct functions. SPATA4 is one of only three human proteins that contain a DUF1042 domain and we show that C2 does not interact with another one of the DUF1042 domain-containing proteins. Our results suggest a role for SPATA4 in membrane traffic and a specialized function for TRAPP in spermatocytes.
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22
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Sundin LJR, Guimaraes GJ, Deluca JG. The NDC80 complex proteins Nuf2 and Hec1 make distinct contributions to kinetochore-microtubule attachment in mitosis. Mol Biol Cell 2011; 22:759-68. [PMID: 21270439 PMCID: PMC3057701 DOI: 10.1091/mbc.e10-08-0671] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The NDC80 complex is known to function in kinetochore-microtubule attachment during mitosis. We analyzed the mitotic roles of three separate structural motifs within the complex and found that the Nuf2 CH domain, the Hec1 CH domain, and the Hec1 tail domain each make distinct contributions at the kinetochore-microtubule interface. Successful mitosis requires that kinetochores stably attach to the plus ends of spindle microtubules. Central to generating these attachments is the NDC80 complex, made of the four proteins Spc24, Spc25, Nuf2, and Hec1/Ndc80. Structural studies have revealed that portions of both Hec1 and Nuf2 N termini fold into calponin homology (CH) domains, which are known to mediate microtubule binding in certain proteins. Hec1 also contains a basic, positively charged stretch of amino acids that precedes its CH domain, referred to as the “tail.” Here, using a gene silence and rescue approach in HeLa cells, we show that the CH domain of Hec1, the CH domain of Nuf2, and the Hec1 tail each contributes to kinetochore–microtubule attachment in distinct ways. The most severe defects in kinetochore–microtubule attachment were observed in cells rescued with a Hec1 CH domain mutant, followed by those rescued with a Hec1 tail domain mutant. Cells rescued with Nuf2 CH domain mutants, however, generated stable kinetochore–microtubule attachments but failed to generate wild-type interkinetochore tension and failed to enter anaphase in a timely manner. These data suggest that the CH and tail domains of Hec1 generate essential contacts between kinetochores and microtubules in cells, whereas the Nuf2 CH domain does not.
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Affiliation(s)
- Lynsie J R Sundin
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
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23
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Interaction of microtubules and actin with the N-terminus of βPix-b(L) directs cellular pinocytosis. Mol Cell Biochem 2011; 351:207-15. [PMID: 21249427 DOI: 10.1007/s11010-011-0728-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 01/10/2011] [Indexed: 12/30/2022]
Abstract
βPix is a Rac/Cdc42 guanine nucleotide exchange factor (GEF) that is known to be a regulator of actin cytoskeleton remodeling. Recently, a novel splicing isoform, βPix-b(L), was identified as an alternative translational product of the βPix-b mRNA with an extended N-terminus comprising a partial calponin homology (CH) domain and a serine-rich (SR) domain. However, the cellular function of βPix-b(L) is largely unknown. In the current study, we analyzed the genomic DNA structure and cellular functions of βPix-b(L). The results of this study demonstrate that βPix is composed of 24 exons and 21 introns spanning around 100 kb. RT-PCR experiments revealed that there are two forms of βPix mRNA with distinct 5' UTRs that are the result of alternative splicing of exon 1 and 2 from βPix genomic DNA. In addition, affinity chromatography analysis and a pull-down assay with the N-terminal region of βPix-b(L) revealed that βPix-b(L) interacts with tubulin and actin via its N-terminal CH and SR domains, respectively. Interaction with tubulin enabled βPix-b(L) to bundle the microtubule and form membrane protrusions. Furthermore, the N-terminus of βPix-b(L) was also critical for its localization to cellular vesicles. Functionally, βPix-b(L) induced pinocytosis through cooperative action of the CH and Dbl homology (DH) domains, demonstrating the role of βPix-b(L) in the regulation of membrane dynamics.
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24
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Friedberg F. Singlet CH domain containing human multidomain proteins: an inventory. Mol Biol Rep 2010; 37:1531-9. [PMID: 19459066 DOI: 10.1007/s11033-009-9554-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 04/30/2009] [Indexed: 01/09/2023]
Abstract
The actin cytoskeleton presents the basic force in processes such as cytokinesis, endocytosis, vesicular trafficking and cell migration. Here, we list 30 human singlet CH (calpononin homology/actin binding) containing multidomain molecules, each encoded by one gene. We show the domain distributions as given by the SMART program. These mosaic proteins organize geographically the placement of selected proteins in proximity within the cell. In most instances, their precise location, their actin binding capacity by way of the singlet CH (or by other domains?) and their physiological functions need further elucidation. A dendrogram based solely on the relationship for the human singlet CH domains (in terms of AA sequences) for the various molecules that possess the domain, implies that the singlet descended from a common ancestor which in turn sprouted three main branches of protein products. Each branch bifurcated multiple times thus accounting for a cornucopia of products. Wherever, additional (unassigned), highly homologous regions exist in related proteins (e.g., in LIM and LMO7 or in Tangerin and EH/BP1), these unrecognized domain regions await assignment as specific functional domains. Frequently genes coding multidomain proteins duplicated. The varying modular nature within multidomain proteins should have accelerated evolutionary changes to a degree not feasible to achieve by means of mere post-duplication mutational changes.
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25
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Structural and mechanistic insights into microtubule end-binding proteins. Curr Opin Cell Biol 2010; 22:88-95. [DOI: 10.1016/j.ceb.2009.10.009] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 10/23/2009] [Accepted: 10/31/2009] [Indexed: 12/17/2022]
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26
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Gray RS, Abitua PB, Wlodarczyk BJ, Szabo-Rogers HL, Blanchard O, Lee I, Weiss GS, Liu KJ, Marcotte EM, Wallingford JB, Finnell RH. The planar cell polarity effector Fuz is essential for targeted membrane trafficking, ciliogenesis and mouse embryonic development. Nat Cell Biol 2009; 11:1225-32. [PMID: 19767740 PMCID: PMC2755648 DOI: 10.1038/ncb1966] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Accepted: 06/22/2009] [Indexed: 11/08/2022]
Abstract
The planar cell polarity (PCP) signalling pathway is essential for embryonic development because it governs diverse cellular behaviours, and 'core PCP' proteins, such as Dishevelled and Frizzled, have been extensively characterized. By contrast, the 'PCP effector' proteins, such as Intu and Fuz, remain largely unstudied. These proteins are essential for PCP signalling, but they have never been investigated in mammals and their cell biological activities remain entirely unknown. We report here that Fuz mutant mice show neural tube defects, skeletal dysmorphologies and Hedgehog signalling defects stemming from disrupted ciliogenesis. Using bioinformatics and imaging of an in vivo mucociliary epithelium, we established a central role for Fuz in membrane trafficking, showing that Fuz is essential for trafficking of cargo to basal bodies and to the apical tips of cilia. Fuz is also essential for exocytosis in secretory cells. Finally, we identified a Rab-related small GTPase as a Fuz interaction partner that is also essential for ciliogenesis and secretion. These results are significant because they provide new insights into the mechanisms by which developmental regulatory systems such as PCP signalling interface with fundamental cellular systems such as the vesicle trafficking machinery.
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Affiliation(s)
- Ryan S. Gray
- Dept. of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712
| | - Philip B. Abitua
- Dept. of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712
| | - Bogdan J. Wlodarczyk
- Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030
| | | | - Otis Blanchard
- Dept. of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712
| | - Insuk Lee
- Dept. Chemistry and Biochemistry and Center for Systems and Synthetic Biology, University of Texas, Austin, Texas 78712
| | - Greg S. Weiss
- Dept. of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712
- Dept. Chemistry and Biochemistry and Center for Systems and Synthetic Biology, University of Texas, Austin, Texas 78712
| | - Karen J. Liu
- Dept. of Craniofacial Development, King’s College London, London, UK SE1 9RT
| | - Edward M. Marcotte
- Dept. Chemistry and Biochemistry and Center for Systems and Synthetic Biology, University of Texas, Austin, Texas 78712
| | - John B. Wallingford
- Dept. of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712
| | - Richard H. Finnell
- Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030
- The Texas A&M Institute for Genomic Medicine, Houston, Texas 77030
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27
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Wilson-Kubalek EM, Cheeseman IM, Yoshioka C, Desai A, Milligan RA. Orientation and structure of the Ndc80 complex on the microtubule lattice. ACTA ACUST UNITED AC 2008; 182:1055-61. [PMID: 18794333 PMCID: PMC2542468 DOI: 10.1083/jcb.200804170] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The four-subunit Ndc80 complex, comprised of Ndc80/Nuf2 and Spc24/Spc25 dimers, directly connects kinetochores to spindle microtubules. The complex is anchored to the kinetochore at the Spc24/25 end, and the Ndc80/Nuf2 dimer projects outward to bind to microtubules. Here, we use cryoelectron microscopy and helical image analysis to visualize the interaction of the Ndc80/Nuf2 dimer with microtubules. Our results, when combined with crystallography data, suggest that the globular domain of the Ndc80 subunit binds strongly at the interface between tubulin dimers and weakly at the adjacent intradimer interface along the protofilament axis. Such a binding mode, in which the Ndc80 complex interacts with sequential alpha/beta-tubulin heterodimers, may be important for stabilizing kinetochore-bound microtubules. Additionally, we define the binding of the Ndc80 complex relative to microtubule polarity, which reveals that the microtubule interaction surface is at a considerable distance from the opposite kinetochore-anchored end; this binding geometry may facilitate polymerization and depolymerization at kinetochore-attached microtubule ends.
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28
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Ciferri C, Pasqualato S, Screpanti E, Varetti G, Santaguida S, Reis GD, Maiolica A, Polka J, De Luca JG, De Wulf P, Salek M, Rappsilber J, Moores CA, Salmon ED, Musacchio A. Implications for kinetochore-microtubule attachment from the structure of an engineered Ndc80 complex. Cell 2008; 133:427-39. [PMID: 18455984 PMCID: PMC4754795 DOI: 10.1016/j.cell.2008.03.020] [Citation(s) in RCA: 417] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 02/06/2008] [Accepted: 03/20/2008] [Indexed: 01/07/2023]
Abstract
Kinetochores are proteinaceous assemblies that mediate the interaction of chromosomes with the mitotic spindle. The 180 kDa Ndc80 complex is a direct point of contact between kinetochores and microtubules. Its four subunits contain coiled coils and form an elongated rod structure with functional globular domains at either end. We crystallized an engineered "bonsai" Ndc80 complex containing a shortened rod domain but retaining the globular domains required for kinetochore localization and microtubule binding. The structure reveals a microtubule-binding interface containing a pair of tightly interacting calponin-homology (CH) domains with a previously unknown arrangement. The interaction with microtubules is cooperative and predominantly electrostatic. It involves positive charges in the CH domains and in the N-terminal tail of the Ndc80 subunit and negative charges in tubulin C-terminal tails and is regulated by the Aurora B kinase. We discuss our results with reference to current models of kinetochore-microtubule attachment and centromere organization.
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Affiliation(s)
- Claudio Ciferri
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, I 20139 Milan, Italy
| | - Sebastiano Pasqualato
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, I 20139 Milan, Italy
| | - Emanuela Screpanti
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, I 20139 Milan, Italy
| | - Gianluca Varetti
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, I 20139 Milan, Italy
| | - Stefano Santaguida
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, I 20139 Milan, Italy
| | - Gabriel Dos Reis
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, I 20139 Milan, Italy
| | - Alessio Maiolica
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, I 20139 Milan, Italy
| | - Jessica Polka
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280, USA
| | - Jennifer G. De Luca
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1870, USA
| | - Peter De Wulf
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, I 20139 Milan, Italy
| | | | - Juri Rappsilber
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, UK
| | - Carolyn A. Moores
- School of Crystallography, Birkbeck College, University of London, London WC1E 7HX, UK
| | - Edward D. Salmon
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280, USA
| | - Andrea Musacchio
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, I 20139 Milan, Italy,Research Unit of the Italian Institute of Technology (IIT) Foundation at the IFOM-IEO Campus, Via Adamello 16, I-20139 Milan, Italy,Correspondence:
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29
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Akhmanova A, Steinmetz MO. Tracking the ends: a dynamic protein network controls the fate of microtubule tips. Nat Rev Mol Cell Biol 2008; 9:309-22. [PMID: 18322465 DOI: 10.1038/nrm2369] [Citation(s) in RCA: 779] [Impact Index Per Article: 48.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Microtubule plus-end tracking proteins (+TIPs) are a diverse group of evolutionarily conserved cellular factors that accumulate at the ends of growing microtubules. They form dynamic networks through the interaction of a limited set of protein modules, repeat sequences and linear motifs that bind to each other with moderate affinities. +TIPs regulate different aspects of cell architecture by controlling microtubule dynamics, microtubule interactions with cellular structures and signalling factors, and the forces that are exerted on microtubule networks.
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Affiliation(s)
- Anna Akhmanova
- Department of Cell Biology, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, the Netherlands.
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30
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Slep KC, Vale RD. Structural basis of microtubule plus end tracking by XMAP215, CLIP-170, and EB1. Mol Cell 2007; 27:976-91. [PMID: 17889670 PMCID: PMC2052927 DOI: 10.1016/j.molcel.2007.07.023] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Revised: 06/27/2007] [Accepted: 07/17/2007] [Indexed: 02/01/2023]
Abstract
Microtubule plus end binding proteins (+TIPs) localize to the dynamic plus ends of microtubules, where they stimulate microtubule growth and recruit signaling molecules. Three main +TIP classes have been identified (XMAP215, EB1, and CLIP-170), but whether they act upon microtubule plus ends through a similar mechanism has not been resolved. Here, we report crystal structures of the tubulin binding domains of XMAP215 (yeast Stu2p and Drosophila Msps), EB1 (yeast Bim1p and human EB1), and CLIP-170 (human), which reveal diverse tubulin binding interfaces. Functional studies, however, reveal a common property that native or artificial dimerization of tubulin binding domains (including chemically induced heterodimers of EB1 and CLIP-170) induces tubulin nucleation/assembly in vitro and, in most cases, plus end tracking in living cells. We propose that +TIPs, although diverse in structure, share a common property of multimerizing tubulin, thus acting as polymerization chaperones that aid in subunit addition to the microtubule plus end.
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Affiliation(s)
- Kevin C Slep
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
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31
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Galkin VE, Orlova A, Fattoum A, Walsh MP, Egelman EH. The CH-domain of calponin does not determine the modes of calponin binding to F-actin. J Mol Biol 2006; 359:478-85. [PMID: 16626733 DOI: 10.1016/j.jmb.2006.03.044] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2006] [Revised: 03/15/2006] [Accepted: 03/20/2006] [Indexed: 11/30/2022]
Abstract
Many actin-binding proteins have been observed to have a modular architecture. One of the most abundant modules is the calponin-homology (CH) domain, found as tandem repeats in proteins that cross-link actin filaments (such as fimbrin, spectrin and alpha-actinin) or link the actin cytoskeleton to intermediate filaments (such as plectin). In proteins such as the eponymous calponin, IQGAP1, and Scp1, a single CH-domain exists, but there has been some controversy over whether this domain binds to actin filaments. A previous three-dimensional reconstruction of the calponin-F-actin complex has led to the conclusion that the visualized portion of calponin bound to actin belongs to its amino-terminal homology (CH) domain. We show, using a calponin fragment lacking the CH-domain, that this domain is not bound to F-actin, and cannot be positioning calponin on F-actin as hypothesized. Further, using classification methods, we show a multiplicity in cooperative modes of binding of calponin to F-actin, similar to what has been observed for other actin-binding proteins such as tropomyosin and cofilin. Our results suggest that the form and function of the structurally conserved CH-domain found in many other actin-binding proteins have diverged. This has broad implications for inferring function from the presence of structurally conserved domains.
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Affiliation(s)
- Vitold E Galkin
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908-0733, USA
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