251
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A Dynamic Protein Interaction Landscape of the Human Centrosome-Cilium Interface. Cell 2016; 163:1484-99. [PMID: 26638075 DOI: 10.1016/j.cell.2015.10.065] [Citation(s) in RCA: 375] [Impact Index Per Article: 46.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 09/24/2015] [Accepted: 10/27/2015] [Indexed: 10/24/2022]
Abstract
The centrosome is the primary microtubule organizing center of the cells and templates the formation of cilia, thereby operating at a nexus of critical cellular functions. Here, we use proximity-dependent biotinylation (BioID) to map the centrosome-cilium interface; with 58 bait proteins we generate a protein topology network comprising >7,000 interactions. Analysis of interaction profiles coupled with high resolution phenotypic profiling implicates a number of protein modules in centriole duplication, ciliogenesis, and centriolar satellite biogenesis and highlights extensive interplay between these processes. By monitoring dynamic changes in the centrosome-cilium protein interaction landscape during ciliogenesis, we also identify satellite proteins that support cilia formation. Systematic profiling of proximity interactions combined with functional analysis thus provides a rich resource for better understanding human centrosome and cilia biology. Similar strategies may be applied to other complex biological structures or pathways.
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252
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Yasunaga T, Hoff S, Schell C, Helmstädter M, Kretz O, Kuechlin S, Yakulov TA, Engel C, Müller B, Bensch R, Ronneberger O, Huber TB, Lienkamp SS, Walz G. The polarity protein Inturned links NPHP4 to Daam1 to control the subapical actin network in multiciliated cells. J Cell Biol 2016; 211:963-73. [PMID: 26644512 PMCID: PMC4674276 DOI: 10.1083/jcb.201502043] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Inturned-mediated complex formation of NPHP4 and DAAM1 is important for ciliogenesis and ciliary function in multiciliated cells, presumably because of its requirement for the local rearrangement of actin cytoskeleton. Motile cilia polarization requires intracellular anchorage to the cytoskeleton; however, the molecular machinery that supports this process remains elusive. We report that Inturned plays a central role in coordinating the interaction between cilia-associated proteins and actin-nucleation factors. We observed that knockdown of nphp4 in multiciliated cells of the Xenopus laevis epidermis compromised ciliogenesis and directional fluid flow. Depletion of nphp4 disrupted the subapical actin layer. Comparison to the structural defects caused by inturned depletion revealed striking similarities. Furthermore, coimmunoprecipitation assays demonstrated that the two proteins interact with each other and that Inturned mediates the formation of ternary protein complexes between NPHP4 and DAAM1. Knockdown of daam1, but not formin-2, resulted in similar disruption of the subapical actin web, whereas nphp4 depletion prevented the association of Inturned with the basal bodies. Thus, Inturned appears to function as an adaptor protein that couples cilia-associated molecules to actin-modifying proteins to rearrange the local actin cytoskeleton.
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Affiliation(s)
- Takayuki Yasunaga
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany
| | - Sylvia Hoff
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany
| | - Christoph Schell
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany
| | - Martin Helmstädter
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany
| | - Oliver Kretz
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany Neuroanatomy, University of Freiburg, 79104 Freiburg, Germany
| | - Sebastian Kuechlin
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany
| | - Toma A Yakulov
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany
| | - Christina Engel
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany
| | - Barbara Müller
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany
| | - Robert Bensch
- Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany Centre for Biological Signaling Studies, 79104 Freiburg, Germany
| | - Olaf Ronneberger
- Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany Centre for Biological Signaling Studies, 79104 Freiburg, Germany
| | - Tobias B Huber
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany Centre for Biological Signaling Studies, 79104 Freiburg, Germany
| | - Soeren S Lienkamp
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany Centre for Biological Signaling Studies, 79104 Freiburg, Germany
| | - Gerd Walz
- Renal Division, Department of Medicine, University of Freiburg Medical Center, 79106 Freiburg, Germany Centre for Biological Signaling Studies, 79104 Freiburg, Germany
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253
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Borrego-Pinto J, Somogyi K, Karreman MA, König J, Müller-Reichert T, Bettencourt-Dias M, Gönczy P, Schwab Y, Lénárt P. Distinct mechanisms eliminate mother and daughter centrioles in meiosis of starfish oocytes. J Cell Biol 2016; 212:815-27. [PMID: 27002173 PMCID: PMC4810307 DOI: 10.1083/jcb.201510083] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 02/22/2016] [Indexed: 11/22/2022] Open
Abstract
Centriole elimination is an essential process that occurs in female meiosis of metazoa to reset centriole number in the zygote at fertilization. How centrioles are eliminated remains poorly understood. Here we visualize the entire elimination process live in starfish oocytes. Using specific fluorescent markers, we demonstrate that the two older, mother centrioles are selectively removed from the oocyte by extrusion into polar bodies. We show that this requires specific positioning of the second meiotic spindle, achieved by dynein-driven transport, and anchorage of the mother centriole to the plasma membrane via mother-specific appendages. In contrast, the single daughter centriole remaining in the egg is eliminated before the first embryonic cleavage. We demonstrate that these distinct elimination mechanisms are necessary because if mother centrioles are artificially retained, they cannot be inactivated, resulting in multipolar zygotic spindles. Thus, our findings reveal a dual mechanism to eliminate centrioles: mothers are physically removed, whereas daughters are eliminated in the cytoplasm, preparing the egg for fertilization.
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Affiliation(s)
- Joana Borrego-Pinto
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Kálmán Somogyi
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Matthia A Karreman
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Julia König
- Experimental Center, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
| | - Thomas Müller-Reichert
- Experimental Center, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
| | | | - Pierre Gönczy
- Swiss Institute for Experimental Cancer Research, School of Life Sciences, Swiss Federal Institute of Technology, 1015 Lausanne, Switzerland
| | - Yannick Schwab
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Péter Lénárt
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
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254
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San Agustin JT, Klena N, Granath K, Panigrahy A, Stewart E, Devine W, Strittmatter L, Jonassen JA, Liu X, Lo CW, Pazour GJ. Genetic link between renal birth defects and congenital heart disease. Nat Commun 2016; 7:11103. [PMID: 27002738 PMCID: PMC4804176 DOI: 10.1038/ncomms11103] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/19/2016] [Indexed: 12/19/2022] Open
Abstract
Structural birth defects in the kidney and urinary tract are observed in 0.5% of live births and are a major cause of end-stage renal disease, but their genetic aetiology is not well understood. Here we analyse 135 lines of mice identified in large-scale mouse mutagenesis screen and show that 29% of mutations causing congenital heart disease (CHD) also cause renal anomalies. The renal anomalies included duplex and multiplex kidneys, renal agenesis, hydronephrosis and cystic kidney disease. To assess the clinical relevance of these findings, we examined patients with CHD and observed a 30% co-occurrence of renal anomalies of a similar spectrum. Together, these findings demonstrate a common shared genetic aetiology for CHD and renal anomalies, indicating that CHD patients are at increased risk for complications from renal anomalies. This collection of mutant mouse models provides a resource for further studies to elucidate the developmental link between renal anomalies and CHD.
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Affiliation(s)
- Jovenal T San Agustin
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Suite 213 373 Plantation Street Worcester, Massachusetts 01605, USA
| | - Nikolai Klena
- Department of Developmental Biology, University of Pittsburgh, 8111 Rangos Research Center, 530 45th Street, Pittsburgh, Pennsylvania 15201, USA
| | - Kristi Granath
- Department of Developmental Biology, University of Pittsburgh, 8111 Rangos Research Center, 530 45th Street, Pittsburgh, Pennsylvania 15201, USA
| | - Ashok Panigrahy
- Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Children's Hospital Drive 45th Street and Penn Avenue Pittsburgh, Pennsylvania 15201, USA
| | - Eileen Stewart
- Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Children's Hospital Drive 45th Street and Penn Avenue Pittsburgh, Pennsylvania 15201, USA
| | - William Devine
- Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Children's Hospital Drive 45th Street and Penn Avenue Pittsburgh, Pennsylvania 15201, USA
| | - Lara Strittmatter
- Electron Microscopy Core, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Julie A Jonassen
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Xiaoqin Liu
- Department of Developmental Biology, University of Pittsburgh, 8111 Rangos Research Center, 530 45th Street, Pittsburgh, Pennsylvania 15201, USA
| | - Cecilia W Lo
- Department of Developmental Biology, University of Pittsburgh, 8111 Rangos Research Center, 530 45th Street, Pittsburgh, Pennsylvania 15201, USA
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Suite 213 373 Plantation Street Worcester, Massachusetts 01605, USA
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255
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Pal K, Hwang SH, Somatilaka B, Badgandi H, Jackson PK, DeFea K, Mukhopadhyay S. Smoothened determines β-arrestin-mediated removal of the G protein-coupled receptor Gpr161 from the primary cilium. J Cell Biol 2016; 212:861-75. [PMID: 27002170 PMCID: PMC4810300 DOI: 10.1083/jcb.201506132] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 02/11/2016] [Indexed: 02/08/2023] Open
Abstract
Dynamic changes in membrane protein composition of the primary cilium are central to development and homeostasis, but we know little about mechanisms regulating membrane protein flux. Stimulation of the sonic hedgehog (Shh) pathway in vertebrates results in accumulation and activation of the effector Smoothened within cilia and concomitant disappearance of a negative regulator, the orphan G protein-coupled receptor (GPCR), Gpr161. Here, we describe a two-step process determining removal of Gpr161 from cilia. The first step involves β-arrestin recruitment by the signaling competent receptor, which is facilitated by the GPCR kinase Grk2. An essential factor here is the ciliary trafficking and activation of Smoothened, which by increasing Gpr161-β-arrestin binding promotes Gpr161 removal, both during resting conditions and upon Shh pathway activation. The second step involves clathrin-mediated endocytosis, which functions outside of the ciliary compartment in coordinating Gpr161 removal. Mechanisms determining dynamic compartmentalization of Gpr161 in cilia define a new paradigm for down-regulation of GPCRs during developmental signaling from a specialized subcellular compartment.
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Affiliation(s)
- Kasturi Pal
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Sun-Hee Hwang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Bandarigoda Somatilaka
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Hemant Badgandi
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Peter K Jackson
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305
| | - Kathryn DeFea
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521
| | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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256
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Verlhac MH. Mother centrioles are kicked out so that starfish zygote can grow. J Cell Biol 2016; 212:759-61. [PMID: 27002168 PMCID: PMC4810309 DOI: 10.1083/jcb.201602053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 02/17/2016] [Indexed: 11/22/2022] Open
Abstract
Most oocytes eliminate their centrioles during meiotic divisions through unclear mechanisms. In this issue, Borrego-Pinto et al. (2016. J Cell. Biol. http://dx.doi.org/10.1083/jcb.201510083) show that mother centrioles need to be eliminated from starfish oocytes by extrusion into the polar bodies for successful embryo development.
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Affiliation(s)
- Marie-Hélène Verlhac
- Center for Interdisciplinary Research in Biology, Collège de France, Centre National de la Recherche Scientifique-UMR7241, and Institut National de la Santé et de la Recherche Médicale-U1050, Paris F-75005, France
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257
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Li C, Jensen VL, Park K, Kennedy J, Garcia-Gonzalo FR, Romani M, De Mori R, Bruel AL, Gaillard D, Doray B, Lopez E, Rivière JB, Faivre L, Thauvin-Robinet C, Reiter JF, Blacque OE, Valente EM, Leroux MR. MKS5 and CEP290 Dependent Assembly Pathway of the Ciliary Transition Zone. PLoS Biol 2016; 14:e1002416. [PMID: 26982032 PMCID: PMC4794247 DOI: 10.1371/journal.pbio.1002416] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 02/24/2016] [Indexed: 11/19/2022] Open
Abstract
Cilia have a unique diffusion barrier (“gate”) within their proximal region, termed transition zone (TZ), that compartmentalises signalling proteins within the organelle. The TZ is known to harbour two functional modules/complexes (Meckel syndrome [MKS] and Nephronophthisis [NPHP]) defined by genetic interaction, interdependent protein localisation (hierarchy), and proteomic studies. However, the composition and molecular organisation of these modules and their links to human ciliary disease are not completely understood. Here, we reveal Caenorhabditis elegans CEP-290 (mammalian Cep290/Mks4/Nphp6 orthologue) as a central assembly factor that is specific for established MKS module components and depends on the coiled coil region of MKS-5 (Rpgrip1L/Rpgrip1) for TZ localisation. Consistent with a critical role in ciliary gate function, CEP-290 prevents inappropriate entry of membrane-associated proteins into cilia and keeps ARL-13 (Arl13b) from leaking out of cilia via the TZ. We identify a novel MKS module component, TMEM-218 (Tmem218), that requires CEP-290 and other MKS module components for TZ localisation and functions together with the NPHP module to facilitate ciliogenesis. We show that TZ localisation of TMEM-138 (Tmem138) and CDKL-1 (Cdkl1/Cdkl2/Cdkl3/Cdlk4 related), not previously linked to a specific TZ module, similarly depends on CEP-290; surprisingly, neither TMEM-138 or CDKL-1 exhibit interdependent localisation or genetic interactions with core MKS or NPHP module components, suggesting they are part of a distinct, CEP-290-associated module. Lastly, we show that families presenting with Oral-Facial-Digital syndrome type 6 (OFD6) have likely pathogenic mutations in CEP-290-dependent TZ proteins, namely Tmem17, Tmem138, and Tmem231. Notably, patient fibroblasts harbouring mutated Tmem17, a protein not yet ciliopathy-associated, display ciliogenesis defects. Together, our findings expand the repertoire of MKS module-associated proteins—including the previously uncharacterised mammalian Tmem80—and suggest an MKS-5 and CEP-290-dependent assembly pathway for building a functional TZ. The transition zone is a barrier structure required to maintain the dynamic composition and functional integrity of the cilium. This study describes the pathway by which the transition zone is assembled during cilium formation. The primary cilium is a structure found in most animal cell types. Much like an antenna, it is responsible for sensing extracellular signals, including light and small molecules, and conveying this information to the receiving cell and respective tissue or organ. At the base of the cilium is the transition zone (TZ), which acts as a “gate” to regulate the entry and exit of ciliary proteins required for signal transduction. Here, we use the nematode Caenorhabditis elegans as a model system to dissect how different proteins within the TZ assemble to form a functional barrier. We find that the TZ protein MKS-5 (Rpgrip1/Rpgrip1L orthologue) forms the foundation for two different assembly pathways involving two distinct modules: Nephronophthisis (NPHP) and Meckel syndrome (MKS). We show that at the base of the MKS module is CEP-290, another TZ protein that assembles MKS module proteins, including a novel TZ protein we identify as TMEM-218. CEP-290 also helps assemble a potentially separate submodule containing TMEM-138 and CDKL-1. Notably, we provide evidence that the MKS module protein TMEM-17 facilitates cilium formation and is disrupted in the human disorder (ciliopathy) Oral-Facial-Digital Syndrome type 6 (OFD6). Together, our findings provide essential insights into the assembly pathway of the ciliary TZ and suggest further connections between the transition zone and human health.
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Affiliation(s)
- Chunmei Li
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Victor L. Jensen
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Kwangjin Park
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Julie Kennedy
- School of Biomolecular & Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Francesc R. Garcia-Gonzalo
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Marta Romani
- Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Roberta De Mori
- Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Ange-Line Bruel
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
| | | | - Bérénice Doray
- Service de Génétique clinique, CHRU Strasbourg, Strasbourg, France
| | - Estelle Lopez
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
| | - Jean-Baptiste Rivière
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
- Laboratoire de Génétique moléculaire, Plateau Technique de Biologie, CHU Dijon, Dijon, France
| | - Laurence Faivre
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
- Centre de Génétique, FHU-TRANSLAD, Hôpital d’Enfants, CHU Dijon, Dijon, France
| | - Christel Thauvin-Robinet
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
- Centre de Génétique, FHU-TRANSLAD, Hôpital d’Enfants, CHU Dijon, Dijon, France
| | - Jeremy F. Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Oliver E. Blacque
- School of Biomolecular & Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Enza Maria Valente
- Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
- Department of Medicine and Surgery, University of Salerno, Salerno, Italy
| | - Michel R. Leroux
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
- * E-mail:
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258
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Phosphatidylinositol phosphate kinase PIPKIγ and phosphatase INPP5E coordinate initiation of ciliogenesis. Nat Commun 2016; 7:10777. [PMID: 26916822 PMCID: PMC4773430 DOI: 10.1038/ncomms10777] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 01/19/2016] [Indexed: 02/08/2023] Open
Abstract
Defective primary cilia are causative to a wide spectrum of human genetic disorders, termed ciliopathies. Although the regulation of ciliogenesis is intensively studied, how it is initiated remains unclear. Here we show that type Iγ phosphatidylinositol 4-phosphate (PtdIns(4)P) 5-kinase (PIPKIγ) and inositol polyphosphate-5-phosphatase E (INPP5E), a Joubert syndrome protein, localize to the centrosome and coordinate the initiation of ciliogenesis. PIPKIγ counteracts INPP5E in regulating tau-tubulin kinase-2 (TTBK2) recruitment to the basal body, which promotes the removal of microtubule capping protein CP110 and the subsequent axoneme elongation. Interestingly, INPP5E and its product—PtdIns(4)P—accumulate at the centrosome/basal body in non-ciliated, but not ciliated, cells. PtdIns(4)P binding to TTBK2 and the distal appendage protein CEP164 compromises the TTBK2-CEP164 interaction and inhibits the recruitment of TTBK2. Our results reveal that PtdIns(4)P homoeostasis, coordinated by PIPKIγ and INPP5E at the centrosome/ciliary base, is vital for ciliogenesis by regulating the CEP164-dependent recruitment of TTBK2. The primary cilium is essential for embryonic development and tissue pattern formation. Here the authors show that PIPKIγ localizes to the basal body of the primary cilium and cooperates with the Joubert Syndrome associated protein INPP5E to regulate the initiation of ciliogenesis.
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259
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Casey JP, Brennan K, Scheidel N, McGettigan P, Lavin PT, Carter S, Ennis S, Dorkins H, Ghali N, Blacque OE, Mc Gee MM, Murphy H, Lynch SA. Recessive NEK9 mutation causes a lethal skeletal dysplasia with evidence of cell cycle and ciliary defects. Hum Mol Genet 2016; 25:1824-35. [PMID: 26908619 DOI: 10.1093/hmg/ddw054] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 02/15/2016] [Indexed: 01/05/2023] Open
Abstract
Skeletal dysplasias are a clinically and genetically heterogeneous group of bone and cartilage disorders. Whilst >450 skeletal dysplasias have been reported, 30% are genetically uncharacterized. We report two Irish Traveller families with a previously undescribed lethal skeletal dysplasia characterized by fetal akinesia, shortening of all long bones, multiple contractures, rib anomalies, thoracic dysplasia, pulmonary hypoplasia and protruding abdomen. Single nucleotide polymorphism homozygosity mapping and whole exome sequencing identified a novel homozygous stop-gain mutation in NEK9 (c.1489C>T; p.Arg497*) as the cause of this disorder. NEK9 encodes a never in mitosis gene A-related kinase involved in regulating spindle organization, chromosome alignment, cytokinesis and cell cycle progression. This is the first disorder to be associated with NEK9 in humans. Analysis of NEK9 protein expression and localization in patient fibroblasts showed complete loss of full-length NEK9 (107 kDa). Functional characterization of patient fibroblasts showed a significant reduction in cell proliferation and a delay in cell cycle progression. We also provide evidence to support possible ciliary associations for NEK9. Firstly, patient fibroblasts displayed a significant reduction in cilia number and length. Secondly, we show that the NEK9 orthologue in Caenorhabditis elegans, nekl-1, is almost exclusively expressed in a subset of ciliated cells, a strong indicator of cilia-related functions. In summary, we report the clinical and molecular characterization of a lethal skeletal dysplasia caused by NEK9 mutation and suggest that this disorder may represent a novel ciliopathy.
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Affiliation(s)
- Jillian P Casey
- Clinical Genetics, Children's University Hospital, Temple Street, Dublin 1, Ireland, UCD Academic Centre on Rare Diseases, School of Medicine and Medical Sciences,
| | - Kieran Brennan
- UCD School of Biomolecular & Biomedical Science, Conway Institute
| | - Noemie Scheidel
- UCD School of Biomolecular & Biomedical Science, Conway Institute
| | - Paul McGettigan
- UCD Academic Centre on Rare Diseases, School of Medicine and Medical Sciences, UCD School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Paul T Lavin
- UCD School of Biomolecular & Biomedical Science, Conway Institute
| | - Stephen Carter
- UCD School of Biomolecular & Biomedical Science, Conway Institute
| | - Sean Ennis
- UCD Academic Centre on Rare Diseases, School of Medicine and Medical Sciences
| | - Huw Dorkins
- North West Thames Regional Genetics Service, Northwick Park Hospital, London North West Healthcare NHS Trust, Watford Road, Harrow HA1 3UJ, UK, Leicestershire Genetics Service, Leicester Royal Infirmary, Leicester LE1 5WW, UK, St Peter's College, University of Oxford, Oxford OX1 2DL, UK and
| | - Neeti Ghali
- North West Thames Regional Genetics Service, Northwick Park Hospital, London North West Healthcare NHS Trust, Watford Road, Harrow HA1 3UJ, UK
| | - Oliver E Blacque
- UCD School of Biomolecular & Biomedical Science, Conway Institute
| | | | - Helen Murphy
- Manchester Academic Health Science Centre, Genetic Medicine-University of Manchester, St Mary's Hospital, Manchester, UK
| | - Sally Ann Lynch
- Clinical Genetics, Children's University Hospital, Temple Street, Dublin 1, Ireland, UCD Academic Centre on Rare Diseases, School of Medicine and Medical Sciences
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260
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Abstract
Xenopus has been one of the earliest and most important vertebrate model organisms for investigating the role and structure of basal bodies. Early transmission electron microscopy studies in Xenopus revealed the fine structures of Xenopus basal bodies and their accessory structures. Subsequent investigations using multiciliated cells in the Xenopus epidermis have further revealed many important features regarding the transcriptional regulation of basal body amplification as well as the regulation of basal body/cilia polarity. Future basal body research using Xenopus is expected to focus on the application of modern genome editing techniques (CRISPR/TALEN) to characterize the components of basal body proteins and their molecular functions.
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Affiliation(s)
- Siwei Zhang
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 USA
| | - Brian J Mitchell
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 USA
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261
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The Dishevelled Protein Family: Still Rather a Mystery After Over 20 Years of Molecular Studies. Curr Top Dev Biol 2016; 117:75-91. [PMID: 26969973 DOI: 10.1016/bs.ctdb.2015.11.027] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Dishevelled (Dsh) is a key component of Wnt-signaling pathways and possibly also has other functional requirements. Dsh appears to be a key factor to interpret Wnt signals coming via the Wnt-receptor family, the Frizzled proteins, from the plasma membrane and route them into the correct intracellular pathways. However, how Dsh is regulated to relay signal flow to specific and distinct cellular responses upon interaction with the same Wnt-receptor family remains very poorly understood.
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262
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Takao D, Verhey KJ. Gated entry into the ciliary compartment. Cell Mol Life Sci 2016; 73:119-27. [PMID: 26472341 PMCID: PMC4959937 DOI: 10.1007/s00018-015-2058-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 09/28/2015] [Accepted: 09/29/2015] [Indexed: 11/26/2022]
Abstract
Cilia and flagella play important roles in cell motility and cell signaling. These functions require that the cilium establishes and maintains a unique lipid and protein composition. Recent work indicates that a specialized region at the base of the cilium, the transition zone, serves as both a barrier to entry and a gate for passage of select components. For at least some cytosolic proteins, the barrier and gate functions are provided by a ciliary pore complex (CPC) that shares molecular and mechanistic properties with nuclear gating. Specifically, nucleoporins of the CPC limit the diffusional entry of cytosolic proteins in a size-dependent manner and enable the active transport of large molecules and complexes via targeting signals, importins, and the small G protein Ran. For membrane proteins, the septin protein SEPT2 is part of the barrier to entry whereas the gating function is carried out and/or regulated by proteins associated with ciliary diseases (ciliopathies) such as nephronophthisis, Meckel–Gruber syndrome and Joubert syndrome. Here, we discuss the evidence behind these models of ciliary gating as well as the similarities to and differences from nuclear gating.
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Affiliation(s)
- Daisuke Takao
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl, Ann Arbor, MI 48109 USA
| | - Kristen J. Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl, Ann Arbor, MI 48109 USA
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263
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Hunter EL, Sale WS, Alford LM. Analysis of Axonemal Assembly During Ciliary Regeneration in Chlamydomonas. Methods Mol Biol 2016; 1454:237-43. [PMID: 27514926 DOI: 10.1007/978-1-4939-3789-9_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Chlamydomonas reinhardtii is an outstanding model genetic organism for study of assembly of cilia. Here, methods are described for synchronization of ciliary regeneration in Chlamydomonas to analyze the sequence in which ciliary proteins assemble. In addition, the methods described allow analysis of the mechanisms involved in regulation of ciliary length, the proteins required for ciliary assembly, and the temporal expression of genes encoding ciliary proteins. Ultimately, these methods can contribute to discovery of conserved genes that when defective lead to abnormal ciliary assembly and human disease.
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Affiliation(s)
- Emily L Hunter
- Department of Cell Biology, Emory University, 465 Whitehead Biomedical Research Building, 615 Michael Street, Atlanta, GA, 30322, USA
| | - Winfield S Sale
- Department of Cell Biology, Emory University, 465 Whitehead Biomedical Research Building, 615 Michael Street, Atlanta, GA, 30322, USA.
| | - Lea M Alford
- Department of Cell Biology, Emory University, 465 Whitehead Biomedical Research Building, 615 Michael Street, Atlanta, GA, 30322, USA
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264
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Tsuji T, Matsuo K, Nakahari T, Marunaka Y, Yokoyama T. Structural basis of the Inv compartment and ciliary abnormalities in Inv/nphp2 mutant mice. Cytoskeleton (Hoboken) 2015; 73:45-56. [PMID: 26615802 DOI: 10.1002/cm.21264] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 11/19/2015] [Accepted: 11/23/2015] [Indexed: 01/17/2023]
Abstract
The primary cilium is a hair like structure protruding from most mammalian cells. The basic design of the primary cilium consists of a nine microtubule doublet structure (the axoneme). The Inv compartment, a distinct proximal segment of the ciliary body, is defined as the region in which the Inv protein is localized. Inv gene is a responsible gene for human nephronophthisis type2 (NPHP2). Here, we show that renal cilia have a short proximal microtubule doublet region and a long distal microtubule singlet region. The length of the Inv compartment was similar to that of the microtubule doublet region, suggesting a possibility that the doublet region is the structural basis of the Inv compartment. Respiratory cilia of inv mouse mutants had ciliary rootlet malformation and showed reduced ciliary beating frequency and ciliary beating angle, which may explain recurrent bronchitis in NPHP2 patients. In multiciliated tracheal cells, most Inv proteins were retained in the basal body and did not accumulate in the Inv compartment. These results suggest that the machinery to transport and retain Inv in cilia is different between renal and tracheal cilia and that Inv may function in the basal body of tracheal cells.
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Affiliation(s)
- Takuma Tsuji
- Division of Anatomy and Developmental Biology, Department of Anatomy, Graduate School of Medicine, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Kazuhiko Matsuo
- Division of Anatomy and Developmental Biology, Department of Anatomy, Graduate School of Medicine, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Takashi Nakahari
- Division of Molecular Cell Physiology, Department of Physiology, Graduate School of Medicine, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Yoshinori Marunaka
- Division of Molecular Cell Physiology, Department of Physiology, Graduate School of Medicine, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Takahiko Yokoyama
- Division of Anatomy and Developmental Biology, Department of Anatomy, Graduate School of Medicine, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
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265
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DLK-1/p38 MAP Kinase Signaling Controls Cilium Length by Regulating RAB-5 Mediated Endocytosis in Caenorhabditis elegans. PLoS Genet 2015; 11:e1005733. [PMID: 26657059 PMCID: PMC4686109 DOI: 10.1371/journal.pgen.1005733] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 11/19/2015] [Indexed: 01/11/2023] Open
Abstract
Cilia are sensory organelles present on almost all vertebrate cells. Cilium length is constant, but varies between cell types, indicating that cilium length is regulated. How this is achieved is unclear, but protein transport in cilia (intraflagellar transport, IFT) plays an important role. Several studies indicate that cilium length and function can be modulated by environmental cues. As a model, we study a C. elegans mutant that carries a dominant active G protein α subunit (gpa-3QL), resulting in altered IFT and short cilia. In a screen for suppressors of the gpa-3QL short cilium phenotype, we identified uev-3, which encodes an E2 ubiquitin-conjugating enzyme variant that acts in a MAP kinase pathway. Mutation of two other components of this pathway, dual leucine zipper-bearing MAPKKK DLK-1 and p38 MAPK PMK-3, also suppress the gpa-3QL short cilium phenotype. However, this suppression seems not to be caused by changes in IFT. The DLK-1/p38 pathway regulates several processes, including microtubule stability and endocytosis. We found that reducing endocytosis by mutating rabx-5 or rme-6, RAB-5 GEFs, or the clathrin heavy chain, suppresses gpa-3QL. In addition, gpa-3QL animals showed reduced levels of two GFP-tagged proteins involved in endocytosis, RAB-5 and DPY-23, whereas pmk-3 mutant animals showed accumulation of GFP-tagged RAB-5. Together our results reveal a new role for the DLK-1/p38 MAPK pathway in control of cilium length by regulating RAB-5 mediated endocytosis. Cells detect cues in their environment using many different receptor and channel proteins, most of which localize to the plasma membrane of the cell. Some of these receptors and channels localize to a specialized sensory organelle, the primary cilium, that extends from the cell like a small antenna. Almost all cells of the human body have one or more cilia. Defects in cilium structure or function have been implicated in many diseases. Many studies have shown that the length of cilia is regulated and can be modulated by environmental signals. Several genes have been identified that function in cilium length regulation and it is clear that transport of proteins inside the cilium plays an important role. Here, we identify several genes of a MAP kinase cascade that modulate the length of cilia of the nematode Caenorhabditis elegans. Interestingly, this regulation seems not to be mediated by the transport system in the cilia, but by modulation of endocytosis. Our results suggest that regulated delivery and removal of proteins and/or lipids at the base of the cilium contributes to the regulation of cilium length.
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266
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Abstract
A powerful combination of two-colour imaging in vivo, Fourier-filtered kymography and simulations provides a high-resolution view of kinesin-2 transport dynamics in cilia. This study reveals heterotrimeric kinesin-II as an 'obstacle-course runner' and homodimeric OSM-3 (KIF17) as a 'long-distance runner', and elucidates the 'baton handoff' between these two kinesin-2 motors on the microtubule track.
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Affiliation(s)
- Robert O'Hagan
- Rutgers University, Human Genetics Institute and Department of Genetics, 145 Bevier Road, Piscataway, New Jersey 08854, USA
| | - Maureen M Barr
- Rutgers University, Human Genetics Institute and Department of Genetics, 145 Bevier Road, Piscataway, New Jersey 08854, USA
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267
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TMEM107 recruits ciliopathy proteins to subdomains of the ciliary transition zone and causes Joubert syndrome. Nat Cell Biol 2015; 18:122-31. [PMID: 26595381 DOI: 10.1038/ncb3273] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/20/2015] [Indexed: 01/10/2023]
Abstract
The transition zone (TZ) ciliary subcompartment is thought to control cilium composition and signalling by facilitating a protein diffusion barrier at the ciliary base. TZ defects cause ciliopathies such as Meckel-Gruber syndrome (MKS), nephronophthisis (NPHP) and Joubert syndrome (JBTS). However, the molecular composition and mechanisms underpinning TZ organization and barrier regulation are poorly understood. To uncover candidate TZ genes, we employed bioinformatics (coexpression and co-evolution) and identified TMEM107 as a TZ protein mutated in oral-facial-digital syndrome and JBTS patients. Mechanistic studies in Caenorhabditis elegans showed that TMEM-107 controls ciliary composition and functions redundantly with NPHP-4 to regulate cilium integrity, TZ docking and assembly of membrane to microtubule Y-link connectors. Furthermore, nematode TMEM-107 occupies an intermediate layer of the TZ-localized MKS module by organizing recruitment of the ciliopathy proteins MKS-1, TMEM-231 (JBTS20) and JBTS-14 (TMEM237). Finally, MKS module membrane proteins are immobile and super-resolution microscopy in worms and mammalian cells reveals periodic localizations within the TZ. This work expands the MKS module of ciliopathy-causing TZ proteins associated with diffusion barrier formation and provides insight into TZ subdomain architecture.
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268
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Shylo NA, Christopher KJ, Iglesias A, Daluiski A, Weatherbee SD. TMEM107 Is a Critical Regulator of Ciliary Protein Composition and Is Mutated in Orofaciodigital Syndrome. Hum Mutat 2015; 37:155-9. [PMID: 26518474 DOI: 10.1002/humu.22925] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/14/2015] [Indexed: 12/31/2022]
Abstract
The proximate causes of multiple human genetic syndromes (ciliopathies) are disruptions in the formation or function of the cilium, an organelle required for a multitude of developmental processes. We previously identified Tmem107 as a critical regulator of cilia formation and embryonic organ development in the mouse. Here, we describe a patient with a mutation in TMEM107 that developed atypical Orofaciodigital syndrome (OFD), and show that the OFD patient shares several morphological features with the Tmem107 mutant mouse including polydactyly and reduced numbers of ciliated cells. We show that TMEM107 appears to function within cilia to regulate protein content, as key ciliary proteins do not localize normally in cilia derived from the Tmem107 mouse mutant and the human patient. These data indicate that TMEM107 plays a key, conserved role in regulating ciliary protein composition, and is a novel candidate for ciliopathies of unknown etiology.
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Affiliation(s)
- Natalia A Shylo
- Department of Genetics, Yale University, School of Medicine, P.O. Box 208005, SHM I-142D, 333 Cedar Street, New Haven, CT, 06520
| | - Kasey J Christopher
- Department of Genetics, Yale University, School of Medicine, P.O. Box 208005, SHM I-142D, 333 Cedar Street, New Haven, CT, 06520
| | - Alejandro Iglesias
- Division of Clinical Genetics, Department of Pediatrics, Columbia University Medical Center, New York, New York
| | - Aaron Daluiski
- Department of Hand and Upper Extremity Surgery, Hospital for Special Surgery, New York, New York
| | - Scott D Weatherbee
- Department of Genetics, Yale University, School of Medicine, P.O. Box 208005, SHM I-142D, 333 Cedar Street, New Haven, CT, 06520
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269
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Prevo B, Mangeol P, Oswald F, Scholey JM, Peterman EJG. Functional differentiation of cooperating kinesin-2 motors orchestrates cargo import and transport in C. elegans cilia. Nat Cell Biol 2015; 17:1536-45. [PMID: 26523365 DOI: 10.1038/ncb3263] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/30/2015] [Indexed: 12/19/2022]
Abstract
Intracellular transport depends on cooperation between distinct motor proteins. Two anterograde intraflagellar transport (IFT) motors, heterotrimeric kinesin-II and homodimeric OSM-3, cooperate to move cargo along Caenorhabditis elegans cilia. Here, using quantitative fluorescence microscopy, with single-molecule sensitivity, of IFT in living strains containing single-copy transgenes encoding fluorescent IFT proteins, we show that kinesin-II transports IFT trains through the ciliary base and transition zone to a 'handover zone' on the proximal axoneme. There, OSM-3 gradually replaces kinesin-II, yielding velocity profiles inconsistent with in vitro motility assays, and then drives transport to the ciliary tip. Dissociated kinesin-II motors undergo rapid turnaround and recycling to the ciliary base, whereas OSM-3 is recycled mainly to the handover zone. This reveals a functional differentiation in which the slower, less processive kinesin-II imports IFT trains into the cilium and OSM-3 drives their long-range transport, thereby optimizing cargo delivery.
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Affiliation(s)
- Bram Prevo
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081 1081 HV Amsterdam, The Netherlands
| | - Pierre Mangeol
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081 1081 HV Amsterdam, The Netherlands
| | - Felix Oswald
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081 1081 HV Amsterdam, The Netherlands
| | - Jonathan M Scholey
- Department of Molecular and Cellular Biology, University of California at Davis, Davis, California 95616, USA
| | - Erwin J G Peterman
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081 1081 HV Amsterdam, The Netherlands
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270
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Photoreceptor Sensory Cilium: Traversing the Ciliary Gate. Cells 2015; 4:674-86. [PMID: 26501325 PMCID: PMC4695852 DOI: 10.3390/cells4040674] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 10/07/2015] [Accepted: 10/09/2015] [Indexed: 01/13/2023] Open
Abstract
Cilia are antenna-like extensions of the plasma membrane found in nearly all cell types. In the retina of the eye, photoreceptors develop unique sensory cilia. Not much was known about the mechanisms underlying the formation and function of photoreceptor cilia, largely because of technical limitations and the specific structural and functional modifications that cannot be modeled in vitro. With recent advances in microscopy techniques and molecular and biochemical approaches, we are now beginning to understand the molecular basis of photoreceptor ciliary architecture, ciliary function and its involvement in human diseases. Here, I will discuss the studies that have revealed new knowledge of how photoreceptor cilia regulate their identity and function while coping with high metabolic and trafficking demands associated with processing light signal.
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271
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Abstract
Sperm motility is driven by motile cytoskeletal elements in the tail, called axonemes. The structure of axonemes consists of 9 + 2 microtubules, molecular motors (dyneins), and their regulatory structures. Axonemes are well conserved in motile cilia and flagella through eukaryotic evolution. Deficiency in the axonemal structure causes defects in sperm motility, and often leads to male infertility. It has been known since the 1970s that, in some cases, male infertility is linked with other symptoms or diseases such as Kartagener syndrome. Given that these links are mostly caused by deficiencies in the common components of cilia and flagella, they are called "immotile cilia syndrome" or "primary ciliary dyskinesia," or more recently, "ciliopathy," which includes deficiencies in primary and sensory cilia. Here, we review the structure of the sperm flagellum and epithelial cilia in the human body, and discuss how male fertility is linked to ciliopathy.
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272
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Jensen VL, Li C, Bowie RV, Clarke L, Mohan S, Blacque OE, Leroux MR. Formation of the transition zone by Mks5/Rpgrip1L establishes a ciliary zone of exclusion (CIZE) that compartmentalises ciliary signalling proteins and controls PIP2 ciliary abundance. EMBO J 2015; 34:2537-56. [PMID: 26392567 PMCID: PMC4609185 DOI: 10.15252/embj.201488044] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 08/22/2015] [Accepted: 08/26/2015] [Indexed: 01/09/2023] Open
Abstract
Cilia are thought to harbour a membrane diffusion barrier within their transition zone (TZ) that compartmentalises signalling proteins. How this "ciliary gate" assembles and functions remains largely unknown. Contrary to current models, we present evidence that Caenorhabditis elegans MKS-5 (orthologue of mammalian Mks5/Rpgrip1L/Nphp8 and Rpgrip1) may not be a simple structural scaffold for anchoring > 10 different proteins at the TZ, but instead, functions as an assembly factor. This activity is needed to form TZ ultrastructure, which comprises Y-shaped axoneme-to-membrane connectors. Coiled-coil and C2 domains within MKS-5 enable TZ localisation and functional interactions with two TZ modules, consisting of Meckel syndrome (MKS) and nephronophthisis (NPHP) proteins. Discrete roles for these modules at basal body-associated transition fibres and TZ explain their redundant functions in making essential membrane connections and thus sealing the ciliary compartment. Furthermore, MKS-5 establishes a ciliary zone of exclusion (CIZE) at the TZ that confines signalling proteins, including GPCRs and NPHP-2/inversin, to distal ciliary subdomains. The TZ/CIZE, potentially acting as a lipid gate, limits the abundance of the phosphoinositide PIP2 within cilia and is required for cell signalling. Together, our findings suggest a new model for Mks5/Rpgrip1L in TZ assembly and function that is essential for establishing the ciliary signalling compartment.
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Affiliation(s)
- Victor L Jensen
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Chunmei Li
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Rachel V Bowie
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Lara Clarke
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Swetha Mohan
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Michel R Leroux
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
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273
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Bachmann-Gagescu R, Dona M, Hetterschijt L, Tonnaer E, Peters T, de Vrieze E, Mans DA, van Beersum SEC, Phelps IG, Arts HH, Keunen JE, Ueffing M, Roepman R, Boldt K, Doherty D, Moens CB, Neuhauss SCF, Kremer H, van Wijk E. The Ciliopathy Protein CC2D2A Associates with NINL and Functions in RAB8-MICAL3-Regulated Vesicle Trafficking. PLoS Genet 2015; 11:e1005575. [PMID: 26485645 PMCID: PMC4617701 DOI: 10.1371/journal.pgen.1005575] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 09/16/2015] [Indexed: 12/16/2022] Open
Abstract
Ciliopathies are a group of human disorders caused by dysfunction of primary cilia, ubiquitous microtubule-based organelles involved in transduction of extra-cellular signals to the cell. This function requires the concentration of receptors and channels in the ciliary membrane, which is achieved by complex trafficking mechanisms, in part controlled by the small GTPase RAB8, and by sorting at the transition zone located at the entrance of the ciliary compartment. Mutations in the transition zone gene CC2D2A cause the related Joubert and Meckel syndromes, two typical ciliopathies characterized by central nervous system malformations, and result in loss of ciliary localization of multiple proteins in various models. The precise mechanisms by which CC2D2A and other transition zone proteins control protein entrance into the cilium and how they are linked to vesicular trafficking of incoming cargo remain largely unknown. In this work, we identify the centrosomal protein NINL as a physical interaction partner of CC2D2A. NINL partially co-localizes with CC2D2A at the base of cilia and ninl knockdown in zebrafish leads to photoreceptor outer segment loss, mislocalization of opsins and vesicle accumulation, similar to cc2d2a-/- phenotypes. Moreover, partial ninl knockdown in cc2d2a-/- embryos enhances the retinal phenotype of the mutants, indicating a genetic interaction in vivo, for which an illustration is found in patients from a Joubert Syndrome cohort. Similar to zebrafish cc2d2a mutants, ninl morphants display altered Rab8a localization. Further exploration of the NINL-associated interactome identifies MICAL3, a protein known to interact with Rab8 and to play an important role in vesicle docking and fusion. Together, these data support a model where CC2D2A associates with NINL to provide a docking point for cilia-directed cargo vesicles, suggesting a mechanism by which transition zone proteins can control the protein content of the ciliary compartment.
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Affiliation(s)
- Ruxandra Bachmann-Gagescu
- Institute for Molecular Life Sciences, University of Zurich, Zurich, Switzerland
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland
| | - Margo Dona
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
| | - Lisette Hetterschijt
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
| | - Edith Tonnaer
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Theo Peters
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
| | - Dorus A. Mans
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Sylvia E. C. van Beersum
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Ian G. Phelps
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
| | - Heleen H. Arts
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Jan E. Keunen
- Department of Ophthalmology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Marius Ueffing
- Division of Experimental Ophthalmology and Medical Proteome Center, Centre for Ophthalmology, Eberhard Karls University Tuebingen, Germany
| | - Ronald Roepman
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Karsten Boldt
- Division of Experimental Ophthalmology and Medical Proteome Center, Centre for Ophthalmology, Eberhard Karls University Tuebingen, Germany
| | - Dan Doherty
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
| | - Cecilia B. Moens
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | | | - Hannie Kremer
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
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274
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Ciliary subcompartments and cysto-proteins. Anat Sci Int 2015; 92:207-214. [DOI: 10.1007/s12565-015-0302-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 09/14/2015] [Indexed: 11/26/2022]
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275
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Balmer S, Dussert A, Collu GM, Benitez E, Iomini C, Mlodzik M. Components of Intraflagellar Transport Complex A Function Independently of the Cilium to Regulate Canonical Wnt Signaling in Drosophila. Dev Cell 2015; 34:705-18. [PMID: 26364750 PMCID: PMC4610147 DOI: 10.1016/j.devcel.2015.07.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 06/17/2015] [Accepted: 07/29/2015] [Indexed: 12/28/2022]
Abstract
The development of multicellular organisms requires the precisely coordinated regulation of an evolutionarily conserved group of signaling pathways. Temporal and spatial control of these signaling cascades is achieved through networks of regulatory proteins, segregation of pathway components in specific subcellular compartments, or both. In vertebrates, dysregulation of primary cilia function has been strongly linked to developmental signaling defects, yet it remains unclear whether cilia sequester pathway components to regulate their activation or cilia-associated proteins directly modulate developmental signaling events. To elucidate this question, we conducted an RNAi-based screen in Drosophila non-ciliated cells to test for cilium-independent loss-of-function phenotypes of ciliary proteins in developmental signaling pathways. Our results show no effect on Hedgehog signaling. In contrast, our screen identified several cilia-associated proteins as functioning in canonical Wnt signaling. Further characterization of specific components of Intraflagellar Transport complex A uncovered a cilia-independent function in potentiating Wnt signals by promoting β-catenin/Armadillo activity.
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Affiliation(s)
- Sophie Balmer
- Department of Developmental & Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Aurore Dussert
- Department of Developmental & Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Giovanna M Collu
- Department of Developmental & Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Elvira Benitez
- Department of Developmental & Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Carlo Iomini
- Department of Developmental & Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Marek Mlodzik
- Department of Developmental & Regenerative Biology and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA.
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276
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Luccardini C, Leclech C, Viou L, Rio JP, Métin C. Cortical interneurons migrating on a pure substrate of N-cadherin exhibit fast synchronous centrosomal and nuclear movements and reduced ciliogenesis. Front Cell Neurosci 2015; 9:286. [PMID: 26283922 PMCID: PMC4522564 DOI: 10.3389/fncel.2015.00286] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 07/13/2015] [Indexed: 01/14/2023] Open
Abstract
The embryonic development of the cortex involves a phase of long distance migration of interneurons born in the basal telencephalon. Interneurons first migrate tangentially and then reorient their trajectories radially to enter the developing cortex. We have shown that migrating interneurons can assemble a primary cilium, which maintains the centrosome to the plasma membrane and processes signals to control interneuron trajectory (Baudoin et al., 2012). In the developing cortex, N-cadherin is expressed by migrating interneurons and by cells in their migratory pathway. N-cadherin promotes the motility and maintains the polarity of tangentially migrating interneurons (Luccardini et al., 2013). Because N-cadherin is an important factor that regulates the migration of medial ganglionic eminence (MGE) cells in vivo, we further characterized the motility and polarity of MGE cells on a substrate that only comprises this protein. MGE cells migrating on a N-cadherin substrate were seven times faster than on a laminin substrate and two times faster than on a substrate of cortical cells. A primary cilium was much less frequently observed on MGE cells migrating on N-cadherin than on laminin. Nevertheless, the mature centriole (MC) frequently docked to the plasma membrane in MGE cells migrating on N-cadherin, suggesting that plasma membrane docking is a basic feature of the centrosome in migrating MGE cells. On the N-cadherin substrate, centrosomal and nuclear movements were remarkably synchronous and the centrosome remained near the nucleus. Interestingly, MGE cells with cadherin invalidation presented centrosomal movements no longer coordinated with nuclear movements. In summary, MGE cells migrating on a pure substrate of N-cadherin show fast, coordinated nuclear and centrosomal movements, and rarely present a primary cilium.
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Affiliation(s)
- Camilla Luccardini
- INSERM, UMR-S839 Paris, France ; Sorbonne Universités, UPMC University Paris 06, UMR-S839 Paris, France ; Institut du Fer à Moulin Paris, France
| | - Claire Leclech
- INSERM, UMR-S839 Paris, France ; Sorbonne Universités, UPMC University Paris 06, UMR-S839 Paris, France ; Institut du Fer à Moulin Paris, France
| | - Lucie Viou
- INSERM, UMR-S839 Paris, France ; Sorbonne Universités, UPMC University Paris 06, UMR-S839 Paris, France ; Institut du Fer à Moulin Paris, France
| | - Jean-Paul Rio
- INSERM, UMR-S839 Paris, France ; Sorbonne Universités, UPMC University Paris 06, UMR-S839 Paris, France ; Institut du Fer à Moulin Paris, France
| | - Christine Métin
- INSERM, UMR-S839 Paris, France ; Sorbonne Universités, UPMC University Paris 06, UMR-S839 Paris, France ; Institut du Fer à Moulin Paris, France
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277
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Non-Overlapping Distributions and Functions of the VDAC Family in Ciliogenesis. Cells 2015; 4:331-53. [PMID: 26264029 PMCID: PMC4588040 DOI: 10.3390/cells4030331] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 07/21/2015] [Accepted: 07/27/2015] [Indexed: 02/06/2023] Open
Abstract
Centrosomes are major microtubule-organizing centers of animal cells that consist of two centrioles. In mitotic cells, centrosomes are duplicated to serve as the poles of the mitotic spindle, while in quiescent cells, centrosomes move to the apical membrane where the oldest centriole is transformed into a basal body to assemble a primary cilium. We recently showed that mitochondrial outer membrane porin VDAC3 localizes to centrosomes where it negatively regulates ciliogenesis. We show here that the other two family members, VDAC1 and VDAC2, best known for their function in mitochondrial bioenergetics, are also found at centrosomes. Like VDAC3, centrosomal VDAC1 is predominantly localized to the mother centriole, while VDAC2 localizes to centriolar satellites in a microtubule-dependent manner. Down-regulation of VDAC1 leads to inappropriate ciliogenesis, while its overexpression suppresses cilia formation, suggesting that VDAC1 and VDAC3 both negatively regulate ciliogenesis. However, this negative effect on ciliogenesis is not shared by VDAC2, which instead appears to promote maturation of primary cilia. Moreover, because overexpression of VDAC3 cannot compensate for depletion of VDAC1, our data suggest that while the entire VDAC family localizes to centrosomes, they have non-redundant functions in cilogenesis.
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278
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Yano J, Valentine MS, Van Houten JL. Novel Insights into the Development and Function of Cilia Using the Advantages of the Paramecium Cell and Its Many Cilia. Cells 2015; 4:297-314. [PMID: 26230712 PMCID: PMC4588038 DOI: 10.3390/cells4030297] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/16/2015] [Accepted: 07/24/2015] [Indexed: 12/26/2022] Open
Abstract
Paramecium species, especially P. tetraurelia and caudatum, are model organisms for modern research into the form and function of cilia. In this review, we focus on the ciliary ion channels and other transmembrane proteins that control the beat frequency and wave form of the cilium by controlling the signaling within the cilium. We put these discussions in the context of the advantages that Paramecium brings to the understanding of ciliary motility: mutants for genetic dissections of swimming behavior, electrophysiology, structural analysis, abundant cilia for biochemistry and modern proteomics, genomics and molecular biology. We review the connection between behavior and physiology, which allows the cells to broadcast the function of their ciliary channels in real time. We build a case for the important insights and advantages that this model organism continues to bring to the study of cilia.
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Affiliation(s)
- Junji Yano
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | - Megan S Valentine
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
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279
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Novas R, Cardenas-Rodriguez M, Irigoín F, Badano JL. Bardet-Biedl syndrome: Is it only cilia dysfunction? FEBS Lett 2015; 589:3479-91. [PMID: 26231314 DOI: 10.1016/j.febslet.2015.07.031] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 07/14/2015] [Accepted: 07/15/2015] [Indexed: 01/12/2023]
Abstract
Bardet-Biedl syndrome (BBS) is a genetically heterogeneous, pleiotropic disorder, characterized by both congenital and late onset defects. From the analysis of the mutational burden in patients to the functional characterization of the BBS proteins, this syndrome has become a model for both understanding oligogenic patterns of inheritance and the biology of a particular cellular organelle: the primary cilium. Here we briefly review the genetics of BBS to then focus on the function of the BBS proteins, not only in the context of the cilium but also highlighting potential extra-ciliary roles that could be relevant to the etiology of the disorder. Finally, we provide an overview of how the study of this rare syndrome has contributed to the understanding of cilia biology and how this knowledge has informed on the cellular basis of different clinical manifestations that characterize BBS and the ciliopathies.
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Affiliation(s)
- Rossina Novas
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo CP11400, Uruguay
| | | | - Florencia Irigoín
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo CP11400, Uruguay; Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Gral. Flores 2125, Montevideo CP11800, Uruguay
| | - Jose L Badano
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo CP11400, Uruguay.
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280
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Chávez M, Ena S, Van Sande J, de Kerchove d'Exaerde A, Schurmans S, Schiffmann SN. Modulation of Ciliary Phosphoinositide Content Regulates Trafficking and Sonic Hedgehog Signaling Output. Dev Cell 2015; 34:338-50. [PMID: 26190144 DOI: 10.1016/j.devcel.2015.06.016] [Citation(s) in RCA: 196] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 03/31/2015] [Accepted: 06/18/2015] [Indexed: 01/23/2023]
Abstract
Ciliary transport is required for ciliogenesis, signal transduction, and trafficking of receptors to the primary cilium. Mutations in inositol polyphosphate 5-phosphatase E (INPP5E) have been associated with ciliary dysfunction; however, its role in regulating ciliary phosphoinositides is unknown. Here we report that in neural stem cells, phosphatidylinositol 4-phosphate (PI4P) is found in high levels in cilia whereas phosphatidylinositol (4,5)-bisphosphate (PI(4,5)P2) is not detectable. Upon INPP5E inactivation, PI(4,5)P2 accumulates at the ciliary tip whereas PI4P is depleted. This is accompanied by recruitment of the PI(4,5)P2-interacting protein TULP3 to the ciliary membrane, along with Gpr161. This results in an increased production of cAMP and a repression of the Shh transcription gene Gli1. Our results reveal the link between ciliary regulation of phosphoinositides by INPP5E and Shh regulation via ciliary trafficking of TULP3/Gpr161 and also provide mechanistic insight into ciliary alterations found in Joubert and MORM syndromes resulting from INPP5E mutations.
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Affiliation(s)
- Marcelo Chávez
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels 1070, Belgium.
| | - Sabrina Ena
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels 1070, Belgium
| | | | - Alban de Kerchove d'Exaerde
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels 1070, Belgium
| | - Stéphane Schurmans
- Laboratory of Functional Genetics, GIGA Research Centre, and WELBIO, Université de Liège, Liège 4000, Belgium
| | - Serge N Schiffmann
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels 1070, Belgium.
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281
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Kistler WS, Baas D, Lemeille S, Paschaki M, Seguin-Estevez Q, Barras E, Ma W, Duteyrat JL, Morlé L, Durand B, Reith W. RFX2 Is a Major Transcriptional Regulator of Spermiogenesis. PLoS Genet 2015; 11:e1005368. [PMID: 26162102 PMCID: PMC4498915 DOI: 10.1371/journal.pgen.1005368] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 06/17/2015] [Indexed: 11/21/2022] Open
Abstract
Spermatogenesis consists broadly of three phases: proliferation of diploid germ cells, meiosis, and finally extensive differentiation of the haploid cells into effective delivery vehicles for the paternal genome. Despite detailed characterization of many haploid developmental steps leading to sperm, only fragmentary information exists on the control of gene expression underlying these processes. Here we report that the RFX2 transcription factor is a master regulator of genes required for the haploid phase. A targeted mutation of Rfx2 was created in mice. Rfx2-/- mice are perfectly viable but show complete male sterility. Spermatogenesis appears to progress unperturbed through meiosis. However, haploid cells undergo a complete arrest in spermatid development just prior to spermatid elongation. Arrested cells show altered Golgi apparatus organization, leading to a deficit in the generation of a spreading acrosomal cap from proacrosomal vesicles. Arrested cells ultimately merge to form giant multinucleated cells released to the epididymis. Spermatids also completely fail to form the flagellar axoneme. RNA-Seq analysis and ChIP-Seq analysis identified 139 genes directly controlled by RFX2 during spermiogenesis. Gene ontology analysis revealed that genes required for cilium function are specifically enriched in down- and upregulated genes showing that RFX2 allows precise temporal expression of ciliary genes. Several genes required for cell adhesion and cytoskeleton remodeling are also downregulated. Comparison of RFX2-regulated genes with those controlled by other major transcriptional regulators of spermiogenesis showed that each controls independent gene sets. Altogether, these observations show that RFX2 plays a major and specific function in spermiogenesis. Failure of spermatogenesis, which is presumed to often result from genetic defects, is a common cause of male sterility. Although numerous genes associated with defects in male spermatogenesis have been identified, numerous cases of genetic male infertility remain unelucidated. We report here that the transcription factor RFX2 is a master regulator of gene expression programs required for progression through the haploid phase of spermatogenesis. Male RFX2-deficient mice are completely sterile. Spermatogenesis progresses through meiosis, but haploid cells undergo a complete block in development just prior to spermatid elongation. Gene expression profiling and ChIP-Seq analysis revealed that RFX2 controls key pathways implicated in cilium/flagellum formation, as well as genes implicated in microtubule and vesicle associated transport. The set of genes activated by RFX2 in spermatids exhibits virtually no overlap with those controlled by other known transcriptional regulators of spermiogenesis, establishing RFX2 as an essential new player in this developmental process. RFX2-deficient mice should therefore represent a valuable new model for deciphering the regulatory networks that direct sperm formation, and thereby contribute to the identification of causes of human male infertility.
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Affiliation(s)
- W. Stephen Kistler
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, United States of America
- * E-mail: (WSK); (BD)
| | - Dominique Baas
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, Villeurbanne, Lyon, France
| | - Sylvain Lemeille
- Department of Pathology and Immunology, University of Geneva Medical School, CMU, Geneva, Switzerland
| | - Marie Paschaki
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, Villeurbanne, Lyon, France
| | - Queralt Seguin-Estevez
- Department of Pathology and Immunology, University of Geneva Medical School, CMU, Geneva, Switzerland
| | - Emmanuèle Barras
- Department of Pathology and Immunology, University of Geneva Medical School, CMU, Geneva, Switzerland
| | - Wenli Ma
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, United States of America
| | - Jean-Luc Duteyrat
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, Villeurbanne, Lyon, France
| | - Laurette Morlé
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, Villeurbanne, Lyon, France
| | - Bénédicte Durand
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, Villeurbanne, Lyon, France
- * E-mail: (WSK); (BD)
| | - Walter Reith
- Department of Pathology and Immunology, University of Geneva Medical School, CMU, Geneva, Switzerland
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282
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Leslie M. Cilia drop anchor. J Biophys Biochem Cytol 2015. [PMCID: PMC4494005 DOI: 10.1083/jcb.2101if] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Neurons use cilium’s transition zone to get a grip on surfaces.
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283
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Kessler K, Wunderlich I, Uebe S, Falk NS, Gießl A, Brandstätter JH, Popp B, Klinger P, Ekici AB, Sticht H, Dörr HG, Reis A, Roepman R, Seemanová E, Thiel CT. DYNC2LI1 mutations broaden the clinical spectrum of dynein-2 defects. Sci Rep 2015; 5:11649. [PMID: 26130459 PMCID: PMC4486972 DOI: 10.1038/srep11649] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 05/27/2015] [Indexed: 12/30/2022] Open
Abstract
Skeletal ciliopathies are a heterogeneous group of autosomal recessive osteochondrodysplasias caused by defects in formation, maintenance and function of the primary cilium. Mutations in the underlying genes affect the molecular motors, intraflagellar transport complexes (IFT), or the basal body. The more severe phenotypes are caused by defects of genes of the dynein-2 complex, where mutations in DYNC2H1, WDR34 and WDR60 have been identified. In a patient with a Jeune-like phenotype we performed exome sequencing and identified compound heterozygous missense and nonsense mutations in DYNC2LI1 segregating with the phenotype. DYNC2LI1 is ubiquitously expressed and interacts with DYNC2H1 to form the dynein-2 complex important for retrograde IFT. Using DYNC2LI1 siRNA knockdown in fibroblasts we identified a significantly reduced cilia length proposed to affect cilia function. In addition, depletion of DYNC2LI1 induced altered cilia morphology with broadened ciliary tips and accumulation of IFT-B complex proteins in accordance with retrograde IFT defects. Our results expand the clinical spectrum of ciliopathies caused by defects of the dynein-2 complex.
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Affiliation(s)
- Kristin Kessler
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Ina Wunderlich
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Steffen Uebe
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Nathalie S Falk
- Animal Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Andreas Gießl
- Animal Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | | | - Bernt Popp
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Patricia Klinger
- Department of Orthopaedic Rheumatology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Arif B Ekici
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Heinrich Sticht
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Helmuth-Günther Dörr
- Department of Pediatrics and Adolescent Medicine, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Ronald Roepman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Eva Seemanová
- Department of Clinical Genetics, Institute of Biology and Medical Genetics, 2nd Medical School, Charles University, Prague, Czech Republic
| | - Christian T Thiel
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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284
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Schouteden C, Serwas D, Palfy M, Dammermann A. The ciliary transition zone functions in cell adhesion but is dispensable for axoneme assembly in C. elegans. J Cell Biol 2015; 210:35-44. [PMID: 26124290 PMCID: PMC4493997 DOI: 10.1083/jcb.201501013] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 06/01/2015] [Indexed: 12/24/2022] Open
Abstract
C. elegans transition zone structures are dispensable for axoneme assembly but are required for cell–matrix interactions during neurite extension, revealing an unexpected role for the transition zone in cell adhesion. Cilia are cellular projections that perform sensory and motile functions. A key ciliary subdomain is the transition zone, which lies between basal body and axoneme. Previous work in Caenorhabditis elegans identified two ciliopathy-associated protein complexes or modules that direct assembly of transition zone Y-links. Here, we identify C. elegans CEP290 as a component of a third module required to form an inner scaffolding structure called the central cylinder. Co-inhibition of all three modules completely disrupted transition zone structure. Surprisingly, axoneme assembly was only mildly perturbed. However, dendrite extension by retrograde migration was strongly impaired, revealing an unexpected role for the transition zone in cell adhesion.
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Affiliation(s)
- Clementine Schouteden
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), A-1030 Vienna, Austria
| | - Daniel Serwas
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), A-1030 Vienna, Austria
| | - Mate Palfy
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), A-1030 Vienna, Austria
| | - Alexander Dammermann
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), A-1030 Vienna, Austria
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285
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Roberson EC, Dowdle WE, Ozanturk A, Garcia-Gonzalo FR, Li C, Halbritter J, Elkhartoufi N, Porath JD, Cope H, Ashley-Koch A, Gregory S, Thomas S, Sayer JA, Saunier S, Otto EA, Katsanis N, Davis EE, Attié-Bitach T, Hildebrandt F, Leroux MR, Reiter JF. TMEM231, mutated in orofaciodigital and Meckel syndromes, organizes the ciliary transition zone. ACTA ACUST UNITED AC 2015; 209:129-42. [PMID: 25869670 PMCID: PMC4395494 DOI: 10.1083/jcb.201411087] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
TMEM231, a functional component of the MKS complex at the ciliary transition zone, is mutated in orofaciodigital syndrome type 3 and Meckel syndrome. The Meckel syndrome (MKS) complex functions at the transition zone, located between the basal body and axoneme, to regulate the localization of ciliary membrane proteins. We investigated the role of Tmem231, a two-pass transmembrane protein, in MKS complex formation and function. Consistent with a role in transition zone function, mutation of mouse Tmem231 disrupts the localization of proteins including Arl13b and Inpp5e to cilia, resulting in phenotypes characteristic of MKS such as polydactyly and kidney cysts. Tmem231 and B9d1 are essential for each other and other complex components such as Mks1 to localize to the transition zone. As in mouse, the Caenorhabditis elegans orthologue of Tmem231 localizes to and controls transition zone formation and function, suggesting an evolutionarily conserved role for Tmem231. We identified TMEM231 mutations in orofaciodigital syndrome type 3 (OFD3) and MKS patients that compromise transition zone function. Thus, Tmem231 is critical for organizing the MKS complex and controlling ciliary composition, defects in which cause OFD3 and MKS.
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Affiliation(s)
- Elle C Roberson
- Department of Biochemistry and Biophysics and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158
| | - William E Dowdle
- Department of Biochemistry and Biophysics and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158
| | - Aysegul Ozanturk
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Francesc R Garcia-Gonzalo
- Department of Biochemistry and Biophysics and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158
| | - Chunmei Li
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 Canada
| | - Jan Halbritter
- Division of Nephrology, Department of Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115
| | - Nadia Elkhartoufi
- Département de Génétique, Hôpital Necker-Enfants Malades, Assistance Publique/Hôpitaux de Paris, 75015 Paris, France
| | - Jonathan D Porath
- Division of Nephrology, Department of Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115
| | - Heidi Cope
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Allison Ashley-Koch
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710 Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Simon Gregory
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Sophie Thomas
- Institut National de la Santé et de la Recherche Médicale UMR1163, 75015 Paris, France Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France
| | - John A Sayer
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, England, UK Newcastle Hospitals National Health Service Foundation Trust, Newcastle upon Tyne NE7 7DN, England, UK
| | - Sophie Saunier
- Institut National de la Santé et de la Recherche Médicale UMR1163, 75015 Paris, France Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France
| | - Edgar A Otto
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Erica E Davis
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Tania Attié-Bitach
- Institut National de la Santé et de la Recherche Médicale UMR1163, 75015 Paris, France Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France Département de Génétique, Hôpital Necker-Enfants Malades, Assistance Publique/Hôpitaux de Paris, 75015 Paris, France
| | - Friedhelm Hildebrandt
- Division of Nephrology, Department of Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115 Howard Hughes Medical Institute, Chevy Chase, MD 20815
| | - Michel R Leroux
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 Canada
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158
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286
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Megaw RD, Soares DC, Wright AF. RPGR: Its role in photoreceptor physiology, human disease, and future therapies. Exp Eye Res 2015; 138:32-41. [PMID: 26093275 PMCID: PMC4553903 DOI: 10.1016/j.exer.2015.06.007] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 06/03/2015] [Accepted: 06/04/2015] [Indexed: 12/21/2022]
Abstract
Mammalian photoreceptors contain specialised connecting cilia that connect the inner (IS) to the outer segments (OS). Dysfunction of the connecting cilia due to mutations in ciliary proteins are a common cause of the inherited retinal dystrophy retinitis pigmentosa (RP). Mutations affecting the Retinitis Pigmentosa GTPase Regulator (RPGR) protein is one such cause, affecting 10-20% of all people with RP and the majority of those with X-linked RP. RPGR is located in photoreceptor connecting cilia. It interacts with a wide variety of ciliary proteins, but its exact function is unknown. Recently, there have been important advances both in our understanding of RPGR function and towards the development of a therapy. This review summarises the existing literature on human RPGR function and dysfunction, and suggests that RPGR plays a role in the function of the ciliary gate, which controls access of both membrane and soluble proteins to the photoreceptor outer segment. We discuss key models used to investigate and treat RPGR disease and suggest that gene augmentation therapy offers a realistic therapeutic approach, although important questions still remain to be answered, while cell replacement therapy based on retinal progenitor cells represents a more distant prospect.
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Affiliation(s)
- Roly D Megaw
- Scottish Centre for Regenerative Medicine, University of Edinburgh, 5 Little France Drive, Edinburgh EH16 4UU, United Kingdom.
| | - Dinesh C Soares
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom.
| | - Alan F Wright
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom.
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287
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Wei Q, Ling K, Hu J. The essential roles of transition fibers in the context of cilia. Curr Opin Cell Biol 2015; 35:98-105. [PMID: 25988548 DOI: 10.1016/j.ceb.2015.04.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 04/18/2015] [Accepted: 04/23/2015] [Indexed: 12/18/2022]
Abstract
Once thought of as a vestigial organelle, the primary cilium is now recognized as a signaling hub for key cellular pathways in vertebrate development. The recent renaissance in cilia studies significantly improved our understanding of how cilia form and function, but little is known about how ciliogenesis is initiated and how ciliary proteins enter cilia. These important ciliary events require transition fibers (TFs) that are positioned at the ciliary base as symmetric nine-bladed propeller fibrous structures. Up until recently, TFs have been the most underappreciated ciliary structures due to limited knowledge about their molecular composition and function. Here, we highlight recent advances in our understanding of TF composition and the indispensable roles of TFs in regulating the initiation of ciliogenesis and the selective import of ciliary proteins.
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Affiliation(s)
- Qing Wei
- Department of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA; Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Kun Ling
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Jinghua Hu
- Department of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA; Mayo Translational PKD Center, Rochester, MN, USA; Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA.
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288
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Rachel RA, Yamamoto EA, Dewanjee MK, May-Simera HL, Sergeev YV, Hackett AN, Pohida K, Munasinghe J, Gotoh N, Wickstead B, Fariss RN, Dong L, Li T, Swaroop A. CEP290 alleles in mice disrupt tissue-specific cilia biogenesis and recapitulate features of syndromic ciliopathies. Hum Mol Genet 2015; 24:3775-91. [PMID: 25859007 DOI: 10.1093/hmg/ddv123] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 04/07/2015] [Indexed: 12/22/2022] Open
Abstract
Distinct mutations in the centrosomal-cilia protein CEP290 lead to diverse clinical findings in syndromic ciliopathies. We show that CEP290 localizes to the transition zone in ciliated cells, precisely to the region of Y-linkers between central microtubules and plasma membrane. To create models of CEP290-associated ciliopathy syndromes, we generated Cep290(ko/ko) and Cep290(gt/gt) mice that produce no or a truncated CEP290 protein, respectively. Cep290(ko/ko) mice exhibit early vision loss and die from hydrocephalus. Retinal photoreceptors in Cep290(ko/ko) mice lack connecting cilia, and ciliated ventricular ependyma fails to mature. The minority of Cep290(ko/ko) mice that escape hydrocephalus demonstrate progressive kidney pathology. Cep290(gt/gt) mice die at mid-gestation, and the occasional Cep290(gt/gt) mouse that survives shows hydrocephalus and severely cystic kidneys. Partial loss of CEP290-interacting ciliopathy protein MKKS mitigates lethality and renal pathology in Cep290(gt/gt) mice. Our studies demonstrate domain-specific functions of CEP290 and provide novel therapeutic paradigms for ciliopathies.
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Affiliation(s)
| | | | | | | | | | | | | | - Jeeva Munasinghe
- National Institute of Neurological Disease and Stroke, National Institutes of Health, Bethesda, MD 20892, USA and
| | | | - Bill Wickstead
- School of Life Sciences, University of Nottingham, Nottingham, UK
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289
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Abdelhamed ZA, Natarajan S, Wheway G, Inglehearn CF, Toomes C, Johnson CA, Jagger DJ. The Meckel-Gruber syndrome protein TMEM67 controls basal body positioning and epithelial branching morphogenesis in mice via the non-canonical Wnt pathway. Dis Model Mech 2015; 8:527-41. [PMID: 26035863 PMCID: PMC4457033 DOI: 10.1242/dmm.019083] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 04/01/2015] [Indexed: 01/16/2023] Open
Abstract
Ciliopathies are a group of developmental disorders that manifest with multi-organ anomalies. Mutations in TMEM67 (MKS3) cause a range of human ciliopathies, including Meckel-Gruber and Joubert syndromes. In this study we describe multi-organ developmental abnormalities in the Tmem67tm1Dgen/H1 knockout mouse that closely resemble those seen in Wnt5a and Ror2 knockout mice. These include pulmonary hypoplasia, ventricular septal defects, shortening of the body longitudinal axis, limb abnormalities, and cochlear hair cell stereociliary bundle orientation and basal body/kinocilium positioning defects. The basal body/kinocilium complex was often uncoupled from the hair bundle, suggesting aberrant basal body migration, although planar cell polarity and apical planar asymmetry in the organ of Corti were normal. TMEM67 (meckelin) is essential for phosphorylation of the non-canonical Wnt receptor ROR2 (receptor-tyrosine-kinase-like orphan receptor 2) upon stimulation with Wnt5a-conditioned medium. ROR2 also colocalises and interacts with TMEM67 at the ciliary transition zone. Additionally, the extracellular N-terminal domain of TMEM67 preferentially binds to Wnt5a in an in vitro binding assay. Cultured lungs of Tmem67 mutant mice failed to respond to stimulation of epithelial branching morphogenesis by Wnt5a. Wnt5a also inhibited both the Shh and canonical Wnt/β-catenin signalling pathways in wild-type embryonic lung. Pulmonary hypoplasia phenotypes, including loss of correct epithelial branching morphogenesis and cell polarity, were rescued by stimulating the non-canonical Wnt pathway downstream of the Wnt5a-TMEM67-ROR2 axis by activating RhoA. We propose that TMEM67 is a receptor that has a main role in non-canonical Wnt signalling, mediated by Wnt5a and ROR2, and normally represses Shh signalling. Downstream therapeutic targeting of the Wnt5a-TMEM67-ROR2 axis might, therefore, reduce or prevent pulmonary hypoplasia in ciliopathies and other congenital conditions. Highlighted Article: TMEM67 is a receptor of non-canonical Wnt signalling, implicating the Wnt5a-TMEM67-ROR2 axis during developmental signalling and disruption in ciliopathy disease state.
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Affiliation(s)
- Zakia A Abdelhamed
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK Department of Anatomy and Embryology, Faculty of Medicine, Al-Azhar University, Cairo 11844, Egypt
| | - Subaashini Natarajan
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
| | - Gabrielle Wheway
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
| | - Christopher F Inglehearn
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
| | - Carmel Toomes
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
| | - Colin A Johnson
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
| | - Daniel J Jagger
- UCL Ear Institute, University College London, 332 Gray's Inn Road, London WC1X 8EE, UK
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290
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Stinchcombe JC, Griffiths GM. Communication, the centrosome and the immunological synapse. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0463. [PMID: 25047617 PMCID: PMC4113107 DOI: 10.1098/rstb.2013.0463] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Recent findings on the behaviour of the centrosome at the immunological synapse suggest a critical role for centrosome polarization in controlling the communication between immune cells required to generate an effective immune response. The features observed at the immunological synapse show parallels to centrosome (basal body) polarization seen in cilia and flagella, and the cellular communication that is now known to occur at all of these sites.
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Affiliation(s)
- Jane C Stinchcombe
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 OXY, UK
| | - Gillian M Griffiths
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 OXY, UK
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291
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Sanders AAWM, Kennedy J, Blacque OE. Image analysis of Caenorhabditis elegans ciliary transition zone structure, ultrastructure, molecular composition, and function. Methods Cell Biol 2015; 127:323-47. [PMID: 25837399 DOI: 10.1016/bs.mcb.2015.01.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The transition zone (TZ) at the ciliary base has emerged as an important regulator of the composition and functions of cilia, which are microtubule-based structures extending from the surfaces of most eukaryotic cells, serving motility, chemo-/mechano-/photosensation and developmental signaling roles. Possessing distinct ultrastructural features such as microtubule-membrane spanning Y-links, the ∼0.2-1.0-μm long TZ is thought to act as a gated cytosolic (size dependent) and membrane diffusion barrier that drives ciliary compartmentalization by preventing unregulated protein exchange between the cilium and the rest of the cell. Multiple proteins associated with ciliary diseases (ciliopathies) such as Meckel-Gruber syndrome (MKS) and nephronophthisis are specifically found in the TZ, and work from a number of model systems, including Chlamydomonas reinharditii, Caenorhabditis elegans and the mouse indicates TZ-gating and associated ciliogenic functions for a number of these proteins. Here we present a suite of assays for probing the structure, function, and molecular composition of the C. elegans TZ, with emphasis on TZ ultrastructure, diffusion barrier kinetics, MKS module assembly hierarchy, and TZ-dependent behaviors.
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Affiliation(s)
- Anna A W M Sanders
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
| | - Julie Kennedy
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
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292
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Burke MC, Li FQ, Cyge B, Arashiro T, Brechbuhl HM, Chen X, Siller SS, Weiss MA, O'Connell CB, Love D, Westlake CJ, Reynolds SD, Kuriyama R, Takemaru KI. Chibby promotes ciliary vesicle formation and basal body docking during airway cell differentiation. ACTA ACUST UNITED AC 2015; 207:123-37. [PMID: 25313408 PMCID: PMC4195830 DOI: 10.1083/jcb.201406140] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Airway multiciliated epithelial cells play crucial roles in the mucosal defense system, but their differentiation process remains poorly understood. Mice lacking the basal body component Chibby (Cby) exhibit impaired mucociliary transport caused by defective ciliogenesis, resulting in chronic airway infection. In this paper, using primary cultures of mouse tracheal epithelial cells, we show that Cby facilitates basal body docking to the apical cell membrane through proper formation of ciliary vesicles at the distal appendage during the early stages of ciliogenesis. Cby is recruited to the distal appendages of centrioles via physical interaction with the distal appendage protein CEP164. Cby then associates with the membrane trafficking machinery component Rabin8, a guanine nucleotide exchange factor for the small guanosine triphosphatase Rab8, to promote recruitment of Rab8 and efficient assembly of ciliary vesicles. Thus, our study identifies Cby as a key regulator of ciliary vesicle formation and basal body docking during the differentiation of airway ciliated cells.
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Affiliation(s)
- Michael C Burke
- Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794 Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Feng-Qian Li
- Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794 Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Benjamin Cyge
- Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Takeshi Arashiro
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455
| | - Heather M Brechbuhl
- Division of Cell Biology, Department of Pediatrics, National Jewish Heath, Denver, CO 80206
| | - Xingwang Chen
- Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Saul S Siller
- Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794 Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Matthew A Weiss
- Laboratory of Cell and Developmental Signaling, National Cancer Institute, Frederick, MD 21072
| | | | - Damon Love
- Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Christopher J Westlake
- Laboratory of Cell and Developmental Signaling, National Cancer Institute, Frederick, MD 21072
| | - Susan D Reynolds
- Division of Cell Biology, Department of Pediatrics, National Jewish Heath, Denver, CO 80206
| | - Ryoko Kuriyama
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455
| | - Ken-Ichi Takemaru
- Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794 Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794 Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794 Graduate Program in Genetics, Medical Scientist Training Program, Graduate Program in Molecular and Cellular Pharmacology, and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794
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293
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Lin H, Dutcher SK. Genetic and genomic approaches to identify genes involved in flagellar assembly in Chlamydomonas reinhardtii. Methods Cell Biol 2015; 127:349-86. [PMID: 25837400 DOI: 10.1016/bs.mcb.2014.12.001] [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: 01/22/2023]
Abstract
Flagellar assembly requires intraflagellar transport of components from the cell body to the flagellar tip for assembly. The understanding of flagellar assembly has been aided by the ease of biochemistry and the availability of mutants in the unicellular green alga, Chlamydomonas reinhardtii. In this chapter, we discuss means to identify genes involved in these processes using forward and reverse genetics. In particular, the ease and low cost of whole genome sequencing (WGS) will help to make gene identification easier and promote the understanding of this important process.
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Affiliation(s)
- Huawen Lin
- Department of Genetics, Washington University, St. Louis, MO, USA
| | - Susan K Dutcher
- Department of Genetics, Washington University, St. Louis, MO, USA.
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294
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Aubusson-Fleury A, Cohen J, Lemullois M. Ciliary heterogeneity within a single cell: the Paramecium model. Methods Cell Biol 2015; 127:457-85. [PMID: 25837404 DOI: 10.1016/bs.mcb.2014.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Paramecium is a single cell able to divide in its morphologically differentiated stage that has many cilia anchored at its cell surface. Many thousands of cilia are thus assembled in a short period of time during division to duplicate the cell pattern while the cell continues swimming. Most, but not all, of these sensory cilia are motile and involved in two main functions: prey capture and cell locomotion. These cilia display heterogeneity, both in their length and their biochemical properties. Thanks to these properties, as well as to the availability of many postgenomic tools and the possibility to follow the regrowth of cilia after deciliation, Paramecium offers a nice opportunity to study the assembly of the cilia, as well as the genesis of their diversity within a single cell. In this paper, after a brief survey of Paramecium morphology and cilia properties, we describe the tools and the protocols currently used for immunofluorescence, transmission electron microscopy, and ultrastructural immunocytochemistry to analyze cilia, with special recommendations to overcome the problem raised by cilium diversity.
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Affiliation(s)
- Anne Aubusson-Fleury
- Centre de Génétique Moléculaire, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Bat 26 Allée de la terrasse, 91 198 Gif sur Yvette Cedex, France
| | - Jean Cohen
- Centre de Génétique Moléculaire, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Bat 26 Allée de la terrasse, 91 198 Gif sur Yvette Cedex, France
| | - Michel Lemullois
- Centre de Génétique Moléculaire, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Bat 26 Allée de la terrasse, 91 198 Gif sur Yvette Cedex, France
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295
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Breslow DK, Nachury MV. Analysis of soluble protein entry into primary cilia using semipermeabilized cells. Methods Cell Biol 2015; 127:203-21. [PMID: 25837393 DOI: 10.1016/bs.mcb.2014.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The primary cilium is a protrusion from the cell surface that serves as a specialized compartment for signal transduction. Many signaling factors are known to be dynamically concentrated within cilia and to require cilia for their function. Yet protein entry into primary cilia remains poorly understood. To enable a mechanistic analysis of soluble protein entry into cilia, we developed a method for semipermeabilization of mammalian cells in which the plasma membrane is permeabilized while the ciliary membrane remains intact. Using semipermeabilized cells as the basis for an in vitro diffusion-to-capture assay, we uncovered a size-dependent diffusion barrier that restricts soluble protein exchange between the cytosol and the cilium. The manipulability of this in vitro system enabled an extensive characterization of the ciliary diffusion barrier and led us to show that the barrier is mechanistically distinct from those at the axon initial segment and the nuclear pore complex. Because semipermeabilized cells enable a range of experimental perturbations that would not be easily feasible in intact cells, we believe this methodology will provide a unique resource for investigating primary cilium function in development and disease.
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Affiliation(s)
- David K Breslow
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Maxence V Nachury
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
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296
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Chuang JZ, Hsu YC, Sung CH. Ultrastructural visualization of trans-ciliary rhodopsin cargoes in mammalian rods. Cilia 2015; 4:4. [PMID: 25664179 PMCID: PMC4320831 DOI: 10.1186/s13630-015-0013-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/15/2015] [Indexed: 11/28/2022] Open
Abstract
Background Cilia are vital to various cellular and sensory functions. The pathway by which ciliary membrane proteins translocate through the transition zone is not well understood. Direct morphological characterization of ciliary cargoes in transit remains lacking. In the vertebrate photoreceptor, rhodopsin is synthesized and transported from the inner segment to the disc membranes of the outer segment (OS), which is a modified cilium. To date, the membrane topology of the basal OS and the mechanisms by which rhodopsin is transported through the transition zone (i.e., connecting cilium) and by which nascent disc membranes are formed remain controversial. Results Using an antibody recognizing its cytoplasmic C-terminus, we localize rhodopsin on both the plasma membrane and lumen of the connecting cilium by immuno-electron microscopy (EM). We also use transmission EM to visualize the electron-dense enzymatic products derived from the rhodopsin-horseradish peroxidase (HRP) fusion in transfected rodent rods. In the connecting cilium, rhodopsin is not only expressed in the plasma membrane but also in the lumen on two types of membranous carriers, long smooth tubules and small, coated, filament-bound vesicles. Additionally, membrane-bound rhodopsin carriers are also found in close proximity to the nascent discs at the basal OS axoneme and in the distal inner segment. This topology-indicative HRP-rhodopsin reporter shows that the nascent basalmost discs and the mature discs have the same membrane topology, with no indication of evagination or invagination from the basal OS plasma membranes. Serial block face and focus ion beam scanning EM analyses both indicate that the transport carriers enter the connecting cilium lumen from either the basal body lumen or cytoplasmic space between the axonemal microtubules and the ciliary plasma membrane. Conclusions Our results suggest the existence of multiple ciliary gate entry pathways in rod photoreceptors. Rhodopsin is likely transported across the connecting cilium on the plasma membrane and through the lumens on two types of tubulovesicular carriers produced in the inner segment. Our findings agree with a previous model that rhodopsin carriers derived from the cell body may fuse directly onto nascent discs as they grow and mature. Electronic supplementary material The online version of this article (doi:10.1186/s13630-015-0013-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jen-Zen Chuang
- Department of Ophthalmology, Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, NY 10065 USA
| | - Ya-Chu Hsu
- Department of Ophthalmology, Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, NY 10065 USA
| | - Ching-Hwa Sung
- Department of Ophthalmology, Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, NY 10065 USA ; Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, NY 10067 USA ; The Margaret M. Dyson Vision Research Institute, Weill Medical College of Cornell University, 1300 York Avenue, LC313, New York, NY 10065 USA
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297
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Ciliary ectosomes: transmissions from the cell's antenna. Trends Cell Biol 2015; 25:276-85. [PMID: 25618328 DOI: 10.1016/j.tcb.2014.12.008] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 12/20/2014] [Accepted: 12/22/2014] [Indexed: 12/21/2022]
Abstract
The cilium is the site of function for a variety of membrane receptors, enzymes and signal transduction modules crucial for a spectrum of cellular processes. Through targeted transport and selective gating mechanisms, the cell localizes specific proteins to the cilium that equip it for the role of sensory antenna. This capacity of the cilium to serve as a specialized compartment where specific proteins can be readily concentrated for sensory reception also makes it an ideal organelle to employ for the regulated emission of specific biological material and information. In this review we present and discuss an emerging body of evidence centered on ciliary ectosomes - bioactive vesicles released from the surface of the cilium.
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298
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Bangs FK, Schrode N, Hadjantonakis AK, Anderson KV. Lineage specificity of primary cilia in the mouse embryo. Nat Cell Biol 2015; 17:113-22. [PMID: 25599390 PMCID: PMC4406239 DOI: 10.1038/ncb3091] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 12/11/2014] [Indexed: 12/11/2022]
Abstract
Primary cilia are required for vertebrate cells to respond to specific intercellular signals. Here we define when and where primary cilia appear in the mouse embryo using a transgenic line that expresses ARL13B-mCherry in cilia and Centrin 2-GFP in centrosomes. Primary cilia first appear on cells of the epiblast at E6.0 and are subsequently present on all derivatives of the epiblast. In contrast, extraembryonic cells of the visceral endoderm and trophectoderm lineages have centrosomes but no cilia. Stem cell lines derived from embryonic lineages recapitulate the in vivo pattern: epiblast stem cells are ciliated, whereas trophoblast stem cells and extraembryonic endoderm (XEN) stem cells lack cilia. Basal bodies in XEN cells are mature and can form cilia when the AURKA-HDAC6 cilium disassembly pathway is inhibited. The lineage-dependent distribution of cilia is stable throughout much of gestation, defining which cells in the placenta and yolk sac are able to respond to Hedgehog ligands.
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Affiliation(s)
- Fiona K Bangs
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue New York, New York 10065, USA
| | - Nadine Schrode
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue New York, New York 10065, USA
| | - Anna-Katerina Hadjantonakis
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue New York, New York 10065, USA
| | - Kathryn V Anderson
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue New York, New York 10065, USA
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299
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Diener DR, Lupetti P, Rosenbaum JL. Proteomic analysis of isolated ciliary transition zones reveals the presence of ESCRT proteins. Curr Biol 2015; 25:379-384. [PMID: 25578910 DOI: 10.1016/j.cub.2014.11.066] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/13/2014] [Accepted: 11/20/2014] [Indexed: 10/24/2022]
Abstract
The transition zone (TZ) is a specialized region of the cilium characterized by Y-shaped connectors between the microtubules of the ciliary axoneme and the ciliary membrane [1]. Located near the base of the cilium, the TZ is in the prime location to act as a gate for proteins into and out of the ciliary compartment, a role supported by experimental evidence [2-6]. The importance of the TZ has been underscored by studies showing that mutations affecting proteins located in the TZ result in cilia-related diseases, or ciliopathies, presenting symptoms including renal cysts, retinal degeneration, and situs inversus [7-9]. Some TZ proteins have been identified and shown to interact with each other through coprecipitation studies in vertebrate cells [4, 10, 11] and genetics studies in C. elegans [3]. As a distinct approach to identify TZ proteins, we have taken advantage of the biology of Chlamydomonas to isolate TZs. Proteomic analysis identified 115 proteins, ten of which were known TZ proteins related to ciliopathies, indicating that the preparation was highly enriched for TZs. Interestingly, six proteins of the endosomal sorting complexes required for transport (ESCRT) were also associated with the TZs. Identification of these and other proteins in the TZ will provide new insights into functions of the TZ, as well as candidate ciliopathy genes.
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Affiliation(s)
- Dennis R Diener
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511, USA.
| | - Pietro Lupetti
- Department of Life Sciences, University of Siena, Siena 53100, Italy
| | - Joel L Rosenbaum
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511, USA.
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Abstract
A rare disease is defined as a condition that affects less than 1 in 2000 individuals. Currently more than 7000 rare diseases have been documented, and most are thought to be of genetic origin. Rare diseases primarily affect children, and congenital craniofacial syndromes and disorders constitute a significant proportion of rare diseases, with over 700 having been described to date. Modeling craniofacial disorders in animal models has been instrumental in uncovering the etiology and pathogenesis of numerous conditions and in some cases has even led to potential therapeutic avenues for their prevention. In this chapter, we focus primarily on two general classes of rare disorders, ribosomopathies and ciliopathies, and the surprising finding that the disruption of fundamental, global processes can result in tissue-specific craniofacial defects. In addition, we discuss recent advances in understanding the pathogenesis of an extremely rare and specific craniofacial condition known as syngnathia, based on the first mouse models for this condition. Approximately 1% of all babies are born with a minor or major developmental anomaly, and individuals suffering from rare diseases deserve the same quality of treatment and care and attention to their disease as other patients.
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Affiliation(s)
- Annita Achilleos
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | - Paul A Trainor
- Stowers Institute for Medical Research, Kansas City, Missouri, USA; Department of Anatomy & Cell Biology, University of Kansas Medical Center, Kansas City, Kansas, USA.
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