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Ruehle MD, Li S, Agard DA, Pearson CG. Poc1 bridges basal body inner junctions to promote triplet microtubule integrity and connections. J Cell Biol 2024; 223:e202311104. [PMID: 38743010 PMCID: PMC11094743 DOI: 10.1083/jcb.202311104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/15/2024] [Accepted: 04/09/2024] [Indexed: 05/16/2024] Open
Abstract
Basal bodies (BBs) are conserved eukaryotic structures that organize cilia. They are comprised of nine, cylindrically arranged, triplet microtubules (TMTs) connected to each other by inter-TMT linkages which stabilize the structure. Poc1 is a conserved protein important for BB structural integrity in the face of ciliary forces transmitted to BBs. To understand how Poc1 confers BB stability, we identified the precise position of Poc1 in the Tetrahymena BB and the effect of Poc1 loss on BB structure. Poc1 binds at the TMT inner junctions, stabilizing TMTs directly. From this location, Poc1 also stabilizes inter-TMT linkages throughout the BB, including the cartwheel pinhead and the inner scaffold. The full localization of the inner scaffold protein Fam161A requires Poc1. As ciliary forces are increased, Fam161A is reduced, indicative of a force-dependent molecular remodeling of the inner scaffold. Thus, while not essential for BB assembly, Poc1 promotes BB interconnections that establish an architecture competent to resist ciliary forces.
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Affiliation(s)
- Marisa D. Ruehle
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Sam Li
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - David A. Agard
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Institute for Advanced Biological Imaging, Redwood Shores, CA, USA
| | - Chad G. Pearson
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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2
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Ruehle MD, Li S, Agard DA, Pearson CG. Poc1 is a basal body inner junction protein that promotes triplet microtubule integrity and interconnections. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.17.567593. [PMID: 38014135 PMCID: PMC10680851 DOI: 10.1101/2023.11.17.567593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Basal bodies (BBs) are conserved eukaryotic structures that organize motile and primary cilia. The BB is comprised of nine, cylindrically arranged, triplet microtubules (TMTs) that are connected to each other by inter-TMT linkages which maintain BB structure. During ciliary beating, forces transmitted to the BB must be resisted to prevent BB disassembly. Poc1 is a conserved BB protein important for BBs to resist ciliary forces. To understand how Poc1 confers BB stability, we identified the precise position of Poc1 binding in the Tetrahymena BB and the effect of Poc1 loss on BB structure. Poc1 binds at the TMT inner junctions, stabilizing TMTs directly. From this location, Poc1 also stabilizes inter-TMT linkages throughout the BB, including the cartwheel pinhead and the inner scaffold. Moreover, we identify a molecular response to ciliary forces via a molecular remodeling of the inner scaffold, as determined by differences in Fam161A localization. Thus, while not essential for BB assembly, Poc1 promotes BB interconnections that establish an architecture competent to resist ciliary forces.
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Affiliation(s)
- Marisa D. Ruehle
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Sam Li
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - David A. Agard
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Institute for Advanced Biological Imaging, 3400 Bridge Parkway, Redwood Shores, CA, USA
| | - Chad G. Pearson
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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3
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Niziolek M, Bicka M, Osinka A, Samsel Z, Sekretarska J, Poprzeczko M, Bazan R, Fabczak H, Joachimiak E, Wloga D. PCD Genes-From Patients to Model Organisms and Back to Humans. Int J Mol Sci 2022; 23:ijms23031749. [PMID: 35163666 PMCID: PMC8836003 DOI: 10.3390/ijms23031749] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/25/2022] [Accepted: 01/31/2022] [Indexed: 01/27/2023] Open
Abstract
Primary ciliary dyskinesia (PCD) is a hereditary genetic disorder caused by the lack of motile cilia or the assembxly of dysfunctional ones. This rare human disease affects 1 out of 10,000-20,000 individuals and is caused by mutations in at least 50 genes. The past twenty years brought significant progress in the identification of PCD-causative genes and in our understanding of the connections between causative mutations and ciliary defects observed in affected individuals. These scientific advances have been achieved, among others, due to the extensive motile cilia-related research conducted using several model organisms, ranging from protists to mammals. These are unicellular organisms such as the green alga Chlamydomonas, the parasitic protist Trypanosoma, and free-living ciliates, Tetrahymena and Paramecium, the invertebrate Schmidtea, and vertebrates such as zebrafish, Xenopus, and mouse. Establishing such evolutionarily distant experimental models with different levels of cell or body complexity was possible because both basic motile cilia ultrastructure and protein composition are highly conserved throughout evolution. Here, we characterize model organisms commonly used to study PCD-related genes, highlight their pros and cons, and summarize experimental data collected using these models.
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Affiliation(s)
- Michal Niziolek
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Marta Bicka
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Faculty of Chemistry, University of Warsaw, 1 Pasteur Street, 02-093 Warsaw, Poland
| | - Anna Osinka
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Zuzanna Samsel
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Justyna Sekretarska
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Martyna Poprzeczko
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Laboratory of Immunology, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawinskiego Street, 02-106 Warsaw, Poland
| | - Rafal Bazan
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Hanna Fabczak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Correspondence: (E.J.); (D.W.); Tel.: +48-22-58-92-338 (E.J. & D.W.)
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Correspondence: (E.J.); (D.W.); Tel.: +48-22-58-92-338 (E.J. & D.W.)
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4
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Ruehle MD, Stemm-Wolf AJ, Pearson CG. Sas4 links basal bodies to cell division via Hippo signaling. J Cell Biol 2021; 219:151794. [PMID: 32435796 PMCID: PMC7401811 DOI: 10.1083/jcb.201906183] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 03/10/2020] [Accepted: 05/01/2020] [Indexed: 01/07/2023] Open
Abstract
Basal bodies (BBs) are macromolecular complexes required for the formation and cortical positioning of cilia. Both BB assembly and DNA replication are tightly coordinated with the cell cycle to ensure their accurate segregation and propagation to daughter cells, but the mechanisms ensuring coordination are unclear. The Tetrahymena Sas4/CPAP protein is enriched at assembling BBs, localizing to the core BB structure and to the base of BB-appendage microtubules and striated fiber. Sas4 is necessary for BB assembly and cortical microtubule organization, and Sas4 loss disrupts cell division furrow positioning and DNA segregation. The Hippo signaling pathway is known to regulate cell division furrow position, and Hippo molecules localize to BBs and BB-appendages. We find that Sas4 loss disrupts localization of the Hippo activator, Mob1, suggesting that Sas4 mediates Hippo activity by promoting scaffolds for Mob1 localization to the cell cortex. Thus, Sas4 links BBs with an ancient signaling pathway known to promote the accurate and symmetric segregation of the genome.
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Affiliation(s)
- Marisa D Ruehle
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Alexander J Stemm-Wolf
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Chad G Pearson
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO
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5
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Soh AWJ, van Dam TJP, Stemm-Wolf AJ, Pham AT, Morgan GP, O'Toole ET, Pearson CG. Ciliary force-responsive striated fibers promote basal body connections and cortical interactions. J Cell Biol 2020; 219:jcb.201904091. [PMID: 31740506 PMCID: PMC7039215 DOI: 10.1083/jcb.201904091] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/15/2019] [Accepted: 10/02/2019] [Indexed: 12/28/2022] Open
Abstract
Multi-ciliary arrays promote fluid flow and cellular motility using the polarized and coordinated beating of hundreds of motile cilia. Tetrahymena basal bodies (BBs) nucleate and position cilia, whereby BB-associated striated fibers (SFs) promote BB anchorage and orientation into ciliary rows. Mutants that shorten SFs cause disoriented BBs. In contrast to the cytotaxis model, we show that disoriented BBs with short SFs can regain normal orientation if SF length is restored. In addition, SFs adopt unique lengths by their shrinkage and growth to establish and maintain BB connections and cortical interactions in a ciliary force-dependent mechanism. Tetrahymena SFs comprise at least eight uniquely localizing proteins belonging to the SF-assemblin family. Loss of different proteins that localize to the SF base disrupts either SF steady-state length or ciliary force-induced SF elongation. Thus, the dynamic regulation of SFs promotes BB connections and cortical interactions to organize ciliary arrays.
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Affiliation(s)
- Adam W J Soh
- Anschutz Medical Campus, Department of Cell and Developmental Biology, University of Colorado, Aurora, CO
| | - Teunis J P van Dam
- Theoretical Biology and Bioinformatics, Department of Biology, Science Faculty, Utrecht University, Utrecht, Netherlands
| | - Alexander J Stemm-Wolf
- Anschutz Medical Campus, Department of Cell and Developmental Biology, University of Colorado, Aurora, CO
| | - Andrew T Pham
- Anschutz Medical Campus, Department of Cell and Developmental Biology, University of Colorado, Aurora, CO
| | - Garry P Morgan
- Molecular, Cellular and Developmental Biology, University of Colorado at Boulder, Boulder, CO
| | - Eileen T O'Toole
- Molecular, Cellular and Developmental Biology, University of Colorado at Boulder, Boulder, CO
| | - Chad G Pearson
- Anschutz Medical Campus, Department of Cell and Developmental Biology, University of Colorado, Aurora, CO
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6
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Heydeck W, Bayless BA, Stemm-Wolf AJ, O'Toole ET, Fabritius AS, Ozzello C, Nguyen M, Winey M. Tetrahymena Poc5 is a transient basal body component that is important for basal body maturation. J Cell Sci 2020; 133:jcs.240838. [PMID: 32350068 DOI: 10.1242/jcs.240838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Accepted: 04/06/2020] [Indexed: 01/26/2023] Open
Abstract
Basal bodies (BBs) are microtubule-based organelles that act as a template for and stabilize cilia at the cell surface. Centrins ubiquitously associate with BBs and function in BB assembly, maturation and stability. Human POC5 (hPOC5) is a highly conserved centrin-binding protein that binds centrins through Sfi1p-like repeats and is required for building full-length, mature centrioles. Here, we use the BB-rich cytoskeleton of Tetrahymena thermophila to characterize Poc5 BB functions. Tetrahymena Poc5 (TtPoc5) uniquely incorporates into assembling BBs and is then removed from mature BBs prior to ciliogenesis. Complete genomic knockout of TtPOC5 leads to a significantly increased production of BBs, yet a markedly reduced ciliary density, both of which are rescued by reintroduction of TtPoc5. A second Tetrahymena POC5-like gene, SFR1, is similarly implicated in modulating BB production. When TtPOC5 and SFR1 are co-deleted, cell viability is compromised and BB overproduction is exacerbated. Overproduced BBs display defective transition zone formation and a diminished capacity for ciliogenesis. This study uncovers a requirement for Poc5 in building mature BBs, providing a possible functional link between hPOC5 mutations and impaired cilia.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Westley Heydeck
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Brian A Bayless
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Alexander J Stemm-Wolf
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Eileen T O'Toole
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Amy S Fabritius
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Courtney Ozzello
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Marina Nguyen
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Mark Winey
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
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7
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Stoddard D, Zhao Y, Bayless BA, Gui L, Louka P, Dave D, Suryawanshi S, Tomasi RFX, Dupuis-Williams P, Baroud CN, Gaertig J, Winey M, Nicastro D. Tetrahymena RIB72A and RIB72B are microtubule inner proteins in the ciliary doublet microtubules. Mol Biol Cell 2018; 29:2566-2577. [PMID: 30133348 PMCID: PMC6254578 DOI: 10.1091/mbc.e18-06-0405] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Doublet and triplet microtubules are essential and highly stable core structures of centrioles, basal bodies, cilia, and flagella. In contrast to dynamic cytoplasmic microtubules, their luminal surface is coated with regularly arranged microtubule inner proteins (MIPs). However, the protein composition and biological function(s) of MIPs remain poorly understood. Using genetic, biochemical, and imaging techniques, we identified Tetrahymena RIB72A and RIB72B proteins as ciliary MIPs. Fluorescence imaging of tagged RIB72A and RIB72B showed that both proteins colocalize to Tetrahymena cilia and basal bodies but assemble independently. Cryoelectron tomography of RIB72A and/or RIB72B knockout strains revealed major structural defects in the ciliary A-tubule involving MIP1, MIP4, and MIP6 structures. The defects of individual mutants were complementary in the double mutant. All mutants had reduced swimming speed and ciliary beat frequencies, and high-speed video imaging revealed abnormal highly curved cilia during power stroke. Our results show that RIB72A and RIB72B are crucial for the structural assembly of ciliary A-tubule MIPs and are important for proper ciliary motility.
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Affiliation(s)
- Daniel Stoddard
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02453.,Departments of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Ying Zhao
- Department of Molecular, Cellular & Developmental Biology University of Colorado Boulder, Boulder, CO 80309
| | - Brian A Bayless
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Long Gui
- Departments of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Panagiota Louka
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
| | - Drashti Dave
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
| | - Swati Suryawanshi
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
| | - Raphaël F-X Tomasi
- Department of Mechanics, LadHyX, CNRS and Ecole Polytechnique, 91128 Palaiseau Cedex, France.,Physical Microfluidics and Bioengineering, Department of Genomes and Genetics, Institut Pasteur, 75015 Paris, France
| | - Pascale Dupuis-Williams
- UMR-S 1174 Inserm, Universite Paris-Sud, 91405 Orsay Cedex, France.,Ecole Supérieure de Physique et de Chimie Industrielles ParisTech, 75005 Paris, France
| | - Charles N Baroud
- Department of Mechanics, LadHyX, CNRS and Ecole Polytechnique, 91128 Palaiseau Cedex, France.,Physical Microfluidics and Bioengineering, Department of Genomes and Genetics, Institut Pasteur, 75015 Paris, France
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
| | - Mark Winey
- Department of Molecular, Cellular & Developmental Biology University of Colorado Boulder, Boulder, CO 80309.,Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Daniela Nicastro
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02453.,Departments of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390
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8
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Abstract
Microtubules act as "railways" for motor-driven intracellular transport, interact with accessory proteins to assemble into larger structures such as the mitotic spindle, and provide an organizational framework to the rest of the cell. Key to these functions is the fact that microtubules are "dynamic." As with actin, the polymer dynamics are driven by nucleotide hydrolysis and influenced by a host of specialized regulatory proteins, including microtubule-associated proteins. However, microtubule turnover involves a surprising behavior-termed dynamic instability-in which individual polymers switch stochastically between growth and depolymerization. Dynamic instability allows microtubules to explore intracellular space and remodel in response to intracellular and extracellular cues. Here, we review how such instability is central to the assembly of many microtubule-based structures and to the robust functioning of the microtubule cytoskeleton.
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Affiliation(s)
- Holly V Goodson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Erin M Jonasson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
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9
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Tetrahymena as a Unicellular Model Eukaryote: Genetic and Genomic Tools. Genetics 2017; 203:649-65. [PMID: 27270699 DOI: 10.1534/genetics.114.169748] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 04/08/2016] [Indexed: 12/12/2022] Open
Abstract
Tetrahymena thermophila is a ciliate model organism whose study has led to important discoveries and insights into both conserved and divergent biological processes. In this review, we describe the tools for the use of Tetrahymena as a model eukaryote, including an overview of its life cycle, orientation to its evolutionary roots, and methodological approaches to forward and reverse genetics. Recent genomic tools have expanded Tetrahymena's utility as a genetic model system. With the unique advantages that Tetrahymena provide, we argue that it will continue to be a model organism of choice.
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10
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Sfr1, a Tetrahymena thermophila Sfi1 Repeat Protein, Modulates the Production of Cortical Row Basal Bodies. mSphere 2016; 1:mSphere00257-16. [PMID: 27904881 PMCID: PMC5112337 DOI: 10.1128/msphere.00257-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 10/14/2016] [Indexed: 01/08/2023] Open
Abstract
Basal bodies and centrioles are structurally similar and, when rendered dysfunctional as a result of improper assembly or maintenance, are associated with human diseases. Centrins are conserved and abundant components of both structures whose basal body and centriolar functions remain incompletely understood. Despite the extensive study of centrins in Tetrahymena thermophila, little is known about how centrin-binding proteins contribute to centrin’s roles in basal body assembly, stability, and orientation. The sole previous study of the large centrin-binding protein family in Tetrahymena revealed a role for Sfr13 in the stabilization and separation of basal bodies. In this study, we found that Sfr1 localizes to all Tetrahymena basal bodies and complete genetic deletion of SFR1 leads to overproduction of basal bodies. The uncovered inhibitory role of Sfr1 in basal body production suggests that centrin-binding proteins, as well as centrins, may influence basal body number both positively and negatively. Basal bodies are essential microtubule-based structures that template, anchor, and orient cilia at the cell surface. Cilia act primarily in the generation of directional fluid flow and sensory reception, both of which are utilized for a broad spectrum of cellular processes. Although basal bodies contribute to vital cell functions, the molecular contributors of their assembly and maintenance are poorly understood. Previous studies of the ciliate Tetrahymena thermophila revealed important roles for two centrin family members in basal body assembly, separation of new basal bodies, and stability. Here, we characterize the basal body function of a centrin-binding protein, Sfr1, in Tetrahymena. Sfr1 is part of a large family of 13 proteins in Tetrahymena that contain Sfi1 repeats (SFRs), a motif originally identified in Saccharomyces cerevisiae Sfi1 that binds centrin. Sfr1 is the only SFR protein in Tetrahymena that localizes to all cortical row and oral apparatus basal bodies. In addition, Sfr1 resides predominantly at the microtubule scaffold from the proximal cartwheel to the distal transition zone. Complete genomic knockout of SFR1 (sfr1Δ) causes a significant increase in both cortical row basal body density and the number of cortical rows, contributing to an overall overproduction of basal bodies. Reintroduction of Sfr1 into sfr1Δ mutant cells leads to a marked reduction of cortical row basal body density and the total number of cortical row basal bodies. Therefore, Sfr1 directly modulates cortical row basal body production. This study reveals an inhibitory role for Sfr1, and potentially centrins, in Tetrahymena basal body production. IMPORTANCE Basal bodies and centrioles are structurally similar and, when rendered dysfunctional as a result of improper assembly or maintenance, are associated with human diseases. Centrins are conserved and abundant components of both structures whose basal body and centriolar functions remain incompletely understood. Despite the extensive study of centrins in Tetrahymena thermophila, little is known about how centrin-binding proteins contribute to centrin’s roles in basal body assembly, stability, and orientation. The sole previous study of the large centrin-binding protein family in Tetrahymena revealed a role for Sfr13 in the stabilization and separation of basal bodies. In this study, we found that Sfr1 localizes to all Tetrahymena basal bodies and complete genetic deletion of SFR1 leads to overproduction of basal bodies. The uncovered inhibitory role of Sfr1 in basal body production suggests that centrin-binding proteins, as well as centrins, may influence basal body number both positively and negatively.
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11
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Bayless BA, Galati DF, Junker AD, Backer CB, Gaertig J, Pearson CG. Asymmetrically localized proteins stabilize basal bodies against ciliary beating forces. J Cell Biol 2016; 215:457-466. [PMID: 27807131 PMCID: PMC5119938 DOI: 10.1083/jcb.201604135] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 08/24/2016] [Accepted: 10/04/2016] [Indexed: 11/26/2022] Open
Abstract
Basal bodies (BBs) organize and anchor motile cilia. This study uncovers components that asymmetrically localize to the rotationally symmetric BBs, where they fortify specific BB domains. Asymmetrically localized BB components are necessary to resist asymmetric ciliary forces. Basal bodies are radially symmetric, microtubule-rich structures that nucleate and anchor motile cilia. Ciliary beating produces asymmetric mechanical forces that are resisted by basal bodies. To resist these forces, distinct regions within the basal body ultrastructure and the microtubules themselves must be stable. However, the molecular components that stabilize basal bodies remain poorly defined. Here, we determine that Fop1 functionally interacts with the established basal body stability components Bld10 and Poc1. We find that Fop1 and microtubule glutamylation incorporate into basal bodies at distinct stages of assembly, culminating in their asymmetric enrichment at specific triplet microtubule regions that are predicted to experience the greatest mechanical force from ciliary beating. Both Fop1 and microtubule glutamylation are required to stabilize basal bodies against ciliary beating forces. Our studies reveal that microtubule glutamylation and Bld10, Poc1, and Fop1 stabilize basal bodies against the forces produced by ciliary beating via distinct yet interdependent mechanisms.
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Affiliation(s)
- Brian A Bayless
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Domenico F Galati
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Anthony D Junker
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Chelsea B Backer
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA 30602
| | - Chad G Pearson
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045
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12
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Galati DF, Bonney S, Kronenberg Z, Clarissa C, Yandell M, Elde NC, Jerka-Dziadosz M, Giddings TH, Frankel J, Pearson CG. DisAp-dependent striated fiber elongation is required to organize ciliary arrays. ACTA ACUST UNITED AC 2015; 207:705-15. [PMID: 25533842 PMCID: PMC4274257 DOI: 10.1083/jcb.201409123] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
DisAp is a novel kinetodesmal fiber component that is essential for force-dependent fiber elongation and the alignment of basal body orientation in multiciliary arrays. Cilia-organizing basal bodies (BBs) are microtubule scaffolds that are visibly asymmetrical because they have attached auxiliary structures, such as striated fibers. In multiciliated cells, BB orientation aligns to ensure coherent ciliary beating, but the mechanisms that maintain BB orientation are unclear. For the first time in Tetrahymena thermophila, we use comparative whole-genome sequencing to identify the mutation in the BB disorientation mutant disA-1. disA-1 abolishes the localization of the novel protein DisAp to T.thermophila striated fibers (kinetodesmal fibers; KFs), which is consistent with DisAp’s similarity to the striated fiber protein SF-assemblin. We demonstrate that DisAp is required for KFs to elongate and to resist BB disorientation in response to ciliary forces. Newly formed BBs move along KFs as they approach their cortical attachment sites. However, because they contain short KFs that are rotated, BBs in disA-1 cells display aberrant spacing and disorientation. Therefore, DisAp is a novel KF component that is essential for force-dependent KF elongation and BB orientation in multiciliary arrays.
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Affiliation(s)
- Domenico F Galati
- Anschutz Medical Campus, Department of Cell and Developmental Biology, University of Colorado, Aurora, CO 80045
| | - Stephanie Bonney
- Anschutz Medical Campus, Department of Cell and Developmental Biology, University of Colorado, Aurora, CO 80045
| | - Zev Kronenberg
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Christina Clarissa
- Molecular, Cellular and Developmental Biology, University of Colorado at Boulder, Boulder, CO 80309
| | - Mark Yandell
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Nels C Elde
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Maria Jerka-Dziadosz
- Department of Cell Biology, M. Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
| | - Thomas H Giddings
- Molecular, Cellular and Developmental Biology, University of Colorado at Boulder, Boulder, CO 80309
| | - Joseph Frankel
- Department of Biological Sciences, University of Iowa, Iowa City, IA 52242
| | - Chad G Pearson
- Anschutz Medical Campus, Department of Cell and Developmental Biology, University of Colorado, Aurora, CO 80045
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13
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Jiang YY, Lechtreck K, Gaertig J. Total internal reflection fluorescence microscopy of intraflagellar transport in Tetrahymena thermophila. Methods Cell Biol 2015; 127:445-56. [PMID: 25837403 DOI: 10.1016/bs.mcb.2015.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Live imaging has become a powerful tool in studies of ciliary proteins. Tetrahymena thermophila is an established ciliated model with well-developed genetic and biochemical approaches, but its large size, complex shape, and the large number of short and overlapping cilia, have made live imaging of ciliary proteins challenging. Here we describe a method that combines paralysis of cilia by nickel ions and total internal reflection microscopy for live imaging of fluorescent proteins inside cilia of Tetrahymena. Using this method, we quantitatively documented the intraflagellar transport in Tetrahymena.
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Affiliation(s)
- Yu-Yang Jiang
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
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14
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Stemm-Wolf AJ, Meehl JB, Winey M. Sfr13, a member of a large family of asymmetrically localized Sfi1-repeat proteins, is important for basal body separation and stability in Tetrahymena thermophila. J Cell Sci 2013; 126:1659-71. [PMID: 23426847 DOI: 10.1242/jcs.120238] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Directed fluid flow, which is achieved by the coordinated beating of motile cilia, is required for processes as diverse as cellular swimming, developmental patterning and mucus clearance. Cilia are nucleated, anchored and aligned at the plasma membrane by basal bodies, which are cylindrical microtubule-based structures with ninefold radial symmetry. In the unicellular ciliate Tetrahymena thermophila, two centrin family members associated with the basal body are important for both basal body organization and stabilization. We have identified a family of 13 proteins in Tetrahymena that contain centrin-binding repeats related to those identified in the Saccharomyces cerevisiae Sfi1 protein. We have named these proteins Sfr1-Sfr13 (for Sfi1-repeat). Nine of the Sfr proteins localize in unique polarized patterns surrounding the basal body, suggesting non-identical roles in basal body organization and association with basal body accessory structures. Furthermore, the Sfr proteins are found in distinct basal body populations in Tetrahymena cells, indicating that they are responsive to particular developmental programs. A complete genetic deletion of one of the family members, Sfr13, causes unstable basal bodies and defects in daughter basal body separation from the mother, phenotypes also observed with centrin disruption. It is likely that the other Sfr family members are involved in distinct centrin functions, providing specificity to the tasks that centrins perform at basal bodies.
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Affiliation(s)
- Alexander J Stemm-Wolf
- Department of Molecular, Cellular and Developmental Biology, University of Colorado - Boulder, Boulder, CO 80309, USA
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15
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Gaertig J, Wloga D, Vasudevan KK, Guha M, Dentler W. Discovery and functional evaluation of ciliary proteins in Tetrahymena thermophila. Methods Enzymol 2013; 525:265-84. [PMID: 23522474 PMCID: PMC4392907 DOI: 10.1016/b978-0-12-397944-5.00013-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
The ciliate Tetrahymena thermophila is an excellent model system for the discovery and functional studies of ciliary proteins. The power of the model is based on the ease with which cilia can be purified in large quantities for fractionation and proteomic identification, and the ability to knock out any gene by homologous DNA recombination. Here, we include methods used by our laboratories for isolation and fractionation of cilia, in vivo tagging and localization of ciliary proteins, and the evaluation of ciliary mutants.
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Affiliation(s)
- Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA 30605, USA
| | - Dorota Wloga
- Nencki Institute of Experimental Biology, Polish Academy of Science, 02-093 Warsaw, Poland
| | | | - Mayukh Guha
- Department of Cellular Biology, University of Georgia, Athens, GA 30605, USA
| | - William Dentler
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA
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16
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Bayless BA, Giddings TH, Winey M, Pearson CG. Bld10/Cep135 stabilizes basal bodies to resist cilia-generated forces. Mol Biol Cell 2012; 23:4820-32. [PMID: 23115304 PMCID: PMC3521689 DOI: 10.1091/mbc.e12-08-0577] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 10/18/2012] [Accepted: 10/23/2012] [Indexed: 12/03/2022] Open
Abstract
Basal bodies nucleate, anchor, and organize cilia. As the anchor for motile cilia, basal bodies must be resistant to the forces directed toward the cell as a consequence of ciliary beating. The molecules and generalized mechanisms that contribute to the maintenance of basal bodies remain to be discovered. Bld10/Cep135 is a basal body outer cartwheel domain protein that has established roles in the assembly of nascent basal bodies. We find that Bld10 protein first incorporates stably at basal bodies early during new assembly. Bld10 protein continues to accumulate at basal bodies after assembly, and we hypothesize that the full complement of Bld10 is required to stabilize basal bodies. We identify a novel mechanism for Bld10/Cep135 in basal body maintenance so that basal bodies can withstand the forces produced by motile cilia. Bld10 stabilizes basal bodies by promoting the stability of the A- and C-tubules of the basal body triplet microtubules and by properly positioning the triplet microtubule blades. The forces generated by ciliary beating promote basal body disassembly in bld10Δ cells. Thus Bld10/Cep135 acts to maintain the structural integrity of basal bodies against the forces of ciliary beating in addition to its separable role in basal body assembly.
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Affiliation(s)
- Brian A. Bayless
- Department of Cell and Developmental Biology, University of Colorado Denver–Anshutz Medical Campus, Aurora, CO 80045-2537
| | - Thomas H. Giddings
- Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, CO 80309-0347
| | - Mark Winey
- Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, CO 80309-0347
| | - Chad G. Pearson
- Department of Cell and Developmental Biology, University of Colorado Denver–Anshutz Medical Campus, Aurora, CO 80045-2537
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