51
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Ott T, Kaufmann L, Granzow M, Hinderhofer K, Bartram CR, Theiß S, Seitz A, Paramasivam N, Schulz A, Moog U, Blum M, Evers CM. The Frog Xenopus as a Model to Study Joubert Syndrome: The Case of a Human Patient With Compound Heterozygous Variants in PIBF1. Front Physiol 2019; 10:134. [PMID: 30858804 PMCID: PMC6397843 DOI: 10.3389/fphys.2019.00134] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 02/04/2019] [Indexed: 12/16/2022] Open
Abstract
Joubert syndrome (JS) is a congenital autosomal-recessive or—in rare cases–X-linked inherited disease. The diagnostic hallmark of the so-called molar tooth sign describes the morphological manifestation of the mid- and hind-brain in axial brain scans. Affected individuals show delayed development, intellectual disability, ataxia, hyperpnea, sleep apnea, abnormal eye, and tongue movements as well as hypotonia. At the cellular level, JS is associated with the compromised biogenesis of sensory cilia, which identifies JS as a member of the large group of ciliopathies. Here we report on the identification of novel compound heterozygous variants (p.Y503C and p.Q485*) in the centrosomal gene PIBF1 in a patient with JS via trio whole exome sequencing. We have studied the underlying disease mechanism in the frog Xenopus, which offers fast assessment of cilia functions in a number of embryological contexts. Morpholino oligomer (MO) mediated knockdown of the orthologous Xenopus pibf1 gene resulted in defective mucociliary clearance in the larval epidermis, due to reduced cilia numbers and motility on multiciliated cells. To functionally assess patient alleles, mutations were analyzed in the larval skin: the p.Q485* nonsense mutation resulted in a disturbed localization of PIBF1 to the ciliary base. This mutant failed to rescue the ciliation phenotype following knockdown of endogenous pibf1. In contrast, the missense variant p.Y503C resulted in attenuated rescue capacity compared to the wild type allele. Based on these results, we conclude that in the case of this patient, JS is the result of a pathogenic combination of an amorphic and a hypomorphic PIBF1 allele. Our study underscores the versatility of the Xenopus model to study ciliopathies such as JS in a rapid and cost-effective manner, which should render this animal model attractive for future studies of human ciliopathies.
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Affiliation(s)
- Tim Ott
- Institute of Zoology, University of Hohenheim, Stuttgart, Germany
| | - Lilian Kaufmann
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Martin Granzow
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | | | - Claus R Bartram
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Susanne Theiß
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Angelika Seitz
- Department of Neuroradiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Nagarajan Paramasivam
- Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany.,Division of Theoretical Bioinformatics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Angela Schulz
- Genomics & Proteomics Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ute Moog
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Martin Blum
- Institute of Zoology, University of Hohenheim, Stuttgart, Germany
| | - Christina M Evers
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
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52
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Review of Ocular Manifestations of Joubert Syndrome. Genes (Basel) 2018; 9:genes9120605. [PMID: 30518138 PMCID: PMC6315342 DOI: 10.3390/genes9120605] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 11/13/2018] [Accepted: 11/27/2018] [Indexed: 12/13/2022] Open
Abstract
Joubert syndrome is a group of rare disorders that stem from defects in a sensory organelle, the primary cilia. Affected patients often present with disorders involving multiple organ systems, including the brain, eyes, and kidneys. Common symptoms include breathing abnormalities, mental developmental delays, loss of voluntary muscle coordination, and abnormal eye movements, with a diagnostic “molar tooth” sign observed by magnetic resonance imaging (MRI) of the midbrain. We reviewed the ocular phenotypes that can be found in patients with Joubert syndrome. Ocular motor apraxia is the most frequent (80% of patients), followed by strabismus (74%) and nystagmus (72%). A minority of patients also present with ptosis (43%), chorioretinal coloboma (30%), and optic nerve atrophy (22%). Although mutations in 34 genes have been found to be associated with Joubert syndrome, retinal degeneration has been reported in only 38% of patients. Mutations in AHI1 and CEP290, genes critical to primary cilia function, have been linked to retinal degeneration. In conclusion, Joubert syndrome is a rare pleiotropic group of disorders with variable ocular presentations.
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53
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Jensen VL, Lambacher NJ, Li C, Mohan S, Williams CL, Inglis PN, Yoder BK, Blacque OE, Leroux MR. Role for intraflagellar transport in building a functional transition zone. EMBO Rep 2018; 19:e45862. [PMID: 30429209 PMCID: PMC6280794 DOI: 10.15252/embr.201845862] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 10/22/2018] [Accepted: 10/26/2018] [Indexed: 12/21/2022] Open
Abstract
Genetic disorders caused by cilia dysfunction, termed ciliopathies, frequently involve the intraflagellar transport (IFT) system. Mutations in IFT subunits-including IFT-dynein motor DYNC2H1-impair ciliary structures and Hedgehog signalling, typically leading to "skeletal" ciliopathies such as Jeune asphyxiating thoracic dystrophy. Intriguingly, IFT gene mutations also cause eye, kidney and brain ciliopathies often linked to defects in the transition zone (TZ), a ciliary gate implicated in Hedgehog signalling. Here, we identify a C. elegans temperature-sensitive (ts) IFT-dynein mutant (che-3; human DYNC2H1) and use it to show a role for retrograde IFT in anterograde transport and ciliary maintenance. Unexpectedly, correct TZ assembly and gating function for periciliary proteins also require IFT-dynein. Using the reversibility of the novel ts-IFT-dynein, we show that restoring IFT in adults (post-developmentally) reverses defects in ciliary structure, TZ protein localisation and ciliary gating. Notably, this ability to reverse TZ defects declines as animals age. Together, our findings reveal a previously unknown role for IFT in TZ assembly in metazoans, providing new insights into the pathomechanism and potential phenotypic overlap between IFT- and TZ-associated ciliopathies.
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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
| | - Nils J Lambacher
- 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
| | - Swetha Mohan
- Department of Molecular Biology and Biochemistry, and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Corey L Williams
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, AL, USA
| | - Peter N Inglis
- Department of Biology, Kwantlen Polytechnic University, Surrey, BC, Canada
| | - Bradley K Yoder
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, AL, USA
| | - 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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54
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Lin H, Guo S, Dutcher SK. RPGRIP1L helps to establish the ciliary gate for entry of proteins. J Cell Sci 2018; 131:jcs220905. [PMID: 30237221 PMCID: PMC6215392 DOI: 10.1242/jcs.220905] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 09/10/2018] [Indexed: 12/12/2022] Open
Abstract
Mutations in transition zone genes change the composition of the ciliary proteome. We isolated new mutations in RPGRIP1L (denotated as RPG1 in algae) that affect the localization of the transition zone protein NPHP4 in the model organism Chlamydomonas reinhardtii NPHP4 localization is not affected in multiple new intraflagellar transport (IFT) mutants. We compared the proteome of cilia from wild-type and mutants that affect the transition zone (RPGRIP1L) or IFT (IFT172 and DHC1b) by mass spectrometry. The rpg1-1 mutant cilia show the most dramatic increase in cytoplasmic proteins. These nonciliary proteins function in translation, membrane remodeling, ATP production and as chaperonins. These proteins are excluded in isolated cilia from fla11-1 (IFT172) and fla24-1 (DHC1b). Our data support the idea that RPGRIP1L, but not IFT proteins, acts as part of the gate for cytoplasmic proteins. The rpg1-1 cilia lack only a few proteins, which suggests that RPGRIP1L only has a minor role of in the retention of ciliary proteins. The fla11-1 mutant shows the greatest loss/reduction of proteins, and one-third of these proteins have a transmembrane domain. Hence, IFT172 may play a role in the retention of proteins.
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Affiliation(s)
- Huawen Lin
- Department of Genetics, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Suyang Guo
- Department of Genetics, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Susan K Dutcher
- Department of Genetics, Washington University in St. Louis, St. Louis, MO 63110, USA
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55
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Scheidel N, Blacque OE. Intraflagellar Transport Complex A Genes Differentially Regulate Cilium Formation and Transition Zone Gating. Curr Biol 2018; 28:3279-3287.e2. [PMID: 30293716 DOI: 10.1016/j.cub.2018.08.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 06/08/2018] [Accepted: 08/07/2018] [Indexed: 02/03/2023]
Abstract
Cilia are found on most eukaryotic cell types, serving motility, environment sensing, and signaling (cell-cell) functions, and defects cause genetic diseases (ciliopathies), affecting the development of many tissues [1]. Cilia are built by intraflagellar transport (IFT), a bidirectional microtubule-based motility driven by kinesin-2 anterograde (toward ciliary tip) and IFT-dynein retrograde (toward ciliary base) motors together with IFT-A and IFT-B cargo adaptor complexes that control retrograde and anterograde IFT, respectively [2]. Ciliary composition is also facilitated by the transition zone (TZ) at the ciliary base and the associated Meckel-Gruber syndrome (MKS) and nephronophthisis (NPHP) modules that establish protein diffusion barriers and regulate cilium structure [3]. Although the molecular architecture of the IFT machine is emerging [2], how individual components contribute to cilium subtype formation and IFT remains relatively unexplored, especially in vivo. In addition, little is known about functional interactions between IFT and TZ modules. Here, in Caenorhabditis elegans (roundworms), we identify cell-type-specific mechanisms by which IFT-A sculpts the structures of discrete ciliary subtypes and regulates IFT. We also uncover differential roles for IFT-A subunits in controlling the TZ restriction of MKS module components and ciliary exclusion (gating) of periciliary membrane proteins, with IFT-140 controlling their ciliary entry and IFT-43/121/139 controlling their ciliary removal. Furthermore, we determine that IFT-A and MKS module components synergistically interact to determine cilium structure. Overall, this work provides insight into the functional architecture of a metazoan IFT-A complex in different cell types and uncovers new relationships between ciliopathy-associated IFT-A and TZ modules.
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Affiliation(s)
- Noémie Scheidel
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Oliver E Blacque
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
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56
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Weng RR, Yang TT, Huang CE, Chang CW, Wang WJ, Liao JC. Super-Resolution Imaging Reveals TCTN2 Depletion-Induced IFT88 Lumen Leakage and Ciliary Weakening. Biophys J 2018; 115:263-275. [PMID: 29866362 DOI: 10.1016/j.bpj.2018.04.051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 04/07/2018] [Accepted: 04/23/2018] [Indexed: 11/28/2022] Open
Abstract
The primary cilium is an essential organelle mediating key signaling activities, such as sonic hedgehog signaling. The molecular composition of the ciliary compartment is distinct from that of the cytosol, with the transition zone (TZ) gated the ciliary base. The TZ is a packed and organized protein complex containing multiple ciliopathy-associated protein species. Tectonic 2 (TCTN2) is one of the TZ proteins in the vicinity of the ciliary membrane, and its mutation is associated with Meckel syndrome. Despite its importance in ciliopathies, the role of TCTN2 in ciliary structure and molecules remains unclear. Here, we created a CRISPR/Cas9 TCTN2 knockout human retinal pigment epithelial cell line and conducted quantitative analysis of geometric localization using both wide-field and super-resolution microscopy techniques. We found that TCTN2 depletion resulted in partial TZ damage, loss of ciliary membrane proteins, leakage of intraflagellar transport protein IFT88 toward the basal body lumen, and cilium shortening and curving. The basal body lumen occupancy of IFT88 was also observed in si-RPGRIP1L cells and cytochalasin-D-treated wild-type cells, suggesting varying lumen accessibility for intraflagellar transport proteins under different perturbed conditions. Our findings support two possible models for the lumen leakage of IFT88, i.e., a tip leakage model and a misregulation model. Together, our quantitative image analysis augmented by super-resolution microscopy facilitates the observation of structural destruction and molecular redistribution in TCTN2-/- cilia, shedding light on mechanistic understanding of TZ-protein-associated ciliopathies.
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Affiliation(s)
- Rueyhung Roc Weng
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
| | - T Tony Yang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
| | - Chia-En Huang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
| | - Chih-Wei Chang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
| | - Won-Jing Wang
- Institute of Biochemistry and Molecular Biology, National Yang Ming University, Taipei, Taiwan
| | - Jung-Chi Liao
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan; Genome and Systems Biology Degree Program, National Taiwan University, Taipei, Taiwan.
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57
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Wiegering A, Dildrop R, Kalfhues L, Spychala A, Kuschel S, Lier JM, Zobel T, Dahmen S, Leu T, Struchtrup A, Legendre F, Vesque C, Schneider-Maunoury S, Saunier S, Rüther U, Gerhardt C. Cell type-specific regulation of ciliary transition zone assembly in vertebrates. EMBO J 2018; 37:embj.201797791. [PMID: 29650680 PMCID: PMC5978567 DOI: 10.15252/embj.201797791] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 03/12/2018] [Accepted: 03/15/2018] [Indexed: 01/07/2023] Open
Abstract
Ciliopathies are life-threatening human diseases caused by defective cilia. They can often be traced back to mutations of genes encoding transition zone (TZ) proteins demonstrating that the understanding of TZ organisation is of paramount importance. The TZ consists of multimeric protein modules that are subject to a stringent assembly hierarchy. Previous reports place Rpgrip1l at the top of the TZ assembly hierarchy in Caenorhabditis elegans By performing quantitative immunofluorescence studies in RPGRIP1L-/- mouse embryos and human embryonic cells, we recognise a different situation in vertebrates in which Rpgrip1l deficiency affects TZ assembly in a cell type-specific manner. In cell types in which the loss of Rpgrip1l alone does not affect all modules, additional truncation or removal of vertebrate-specific Rpgrip1 results in an impairment of all modules. Consequently, Rpgrip1l and Rpgrip1 synergistically ensure the TZ composition in several vertebrate cell types, revealing a higher complexity of TZ assembly in vertebrates than in invertebrates.
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Affiliation(s)
- Antonia Wiegering
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Renate Dildrop
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Lisa Kalfhues
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - André Spychala
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Stefanie Kuschel
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Johanna Maria Lier
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Thomas Zobel
- Center for Advanced Imaging (CAi), Heinrich Heine University, Düsseldorf, Germany
| | - Stefanie Dahmen
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Tristan Leu
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Andreas Struchtrup
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Flora Legendre
- INSERM, U983, Hôpital Necker-Enfants Malades, Paris, France.,Sorbonne Paris Cité, Faculté de Médecine, Université Paris-Descartes, Paris, France
| | - Christine Vesque
- Paris-Seine (IBPS) - Developmental Biology Laboratory, Institut de Biologie, CNRS, UMR7622, INSERM U1156, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, Paris, France
| | - Sylvie Schneider-Maunoury
- Paris-Seine (IBPS) - Developmental Biology Laboratory, Institut de Biologie, CNRS, UMR7622, INSERM U1156, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, Paris, France
| | - Sophie Saunier
- INSERM, U983, Hôpital Necker-Enfants Malades, Paris, France.,Sorbonne Paris Cité, Faculté de Médecine, Université Paris-Descartes, Paris, France
| | - Ulrich Rüther
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Christoph Gerhardt
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
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58
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Shimada H, Lu Q, Insinna-Kettenhofen C, Nagashima K, English MA, Semler EM, Mahgerefteh J, Cideciyan AV, Li T, Brooks BP, Gunay-Aygun M, Jacobson SG, Cogliati T, Westlake CJ, Swaroop A. In Vitro Modeling Using Ciliopathy-Patient-Derived Cells Reveals Distinct Cilia Dysfunctions Caused by CEP290 Mutations. Cell Rep 2018; 20:384-396. [PMID: 28700940 DOI: 10.1016/j.celrep.2017.06.045] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 05/03/2017] [Accepted: 06/19/2017] [Indexed: 02/06/2023] Open
Abstract
Mutations in CEP290, a transition zone protein in primary cilia, cause diverse ciliopathies, including Leber congenital amaurosis (LCA) and Joubert-syndrome and related disorders (JSRD). We examined cilia biogenesis and function in cells derived from CEP290-LCA and CEP290-JSRD patients. CEP290 protein was reduced in LCA fibroblasts with no detectable impact on cilia; however, optic cups derived from induced pluripotent stem cells (iPSCs) of CEP290-LCA patients displayed less developed photoreceptor cilia. Lack of CEP290 in JSRD fibroblasts resulted in abnormal cilia and decreased ciliogenesis. We observed selectively reduced localization of ADCY3 and ARL13B. Notably, Hedgehog signaling was augmented in CEP290-JSRD because of enhanced ciliary transport of Smoothened and GPR161. These results demonstrate a direct correlation between the extent of ciliogenesis defects in fibroblasts and photoreceptors with phenotypic severity in JSRD and LCA, respectively, and strengthen the role of CEP290 as a selective ciliary gatekeeper for transport of signaling molecules in and out of the cilium.
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Affiliation(s)
- Hiroko Shimada
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Quanlong Lu
- Laboratory of Cell and Developmental Signaling, National Cancer Institute - Frederick, Frederick, MD 21702, USA
| | | | - Kunio Nagashima
- Electron Microscope Laboratory, Leidos Biomedical Research, Inc., National Cancer Institute - Frederick, Frederick, MD 21702, USA
| | - Milton A English
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Elizabeth M Semler
- Laboratory of Cell and Developmental Signaling, National Cancer Institute - Frederick, Frederick, MD 21702, USA
| | - Jacklyn Mahgerefteh
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Artur V Cideciyan
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tiansen Li
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Brian P Brooks
- Pediatric, Developmental, and Genetic Eye Disease Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Meral Gunay-Aygun
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA; Department of Pediatrics, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Samuel G Jacobson
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tiziana Cogliati
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Christopher J Westlake
- Laboratory of Cell and Developmental Signaling, National Cancer Institute - Frederick, Frederick, MD 21702, USA.
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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59
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Elliott KH, Brugmann SA. Sending mixed signals: Cilia-dependent signaling during development and disease. Dev Biol 2018; 447:28-41. [PMID: 29548942 DOI: 10.1016/j.ydbio.2018.03.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 03/03/2018] [Accepted: 03/06/2018] [Indexed: 01/09/2023]
Abstract
Molecular signals are the guiding force of development, imparting direction upon cells to divide, migrate, differentiate, etc. The mechanisms by which a cell can receive and transduce these signals into measurable actions remains a 'black box' in developmental biology. Primary cilia are ubiquitous, microtubule-based organelles that dynamically extend from a cell to receive and process molecular and mechanical signaling cues. In the last decade, this organelle has become increasingly intriguing to the research community due to its ability to act as a cellular antenna, receive and transduce molecular stimuli, and initiate a cellular response. In this review, we discuss the structure of primary cilia, emphasizing how the ciliary components contribute to the transduction of signaling pathways. Furthermore, we address how the cilium integrates these signals and conveys them into cellular processes such as proliferation, migration and tissue patterning. Gaining a deeper understanding of the mechanisms used by primary cilia to receive and integrate molecular signals is essential, as it opens the door for the identification of therapeutic targets within the cilium that could alleviate pathological conditions brought on by aberrant molecular signaling.
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Affiliation(s)
- Kelsey H Elliott
- Division of Plastic Surgery, Department of Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Samantha A Brugmann
- Division of Plastic Surgery, Department of Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
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60
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Canning P, Park K, Gonçalves J, Li C, Howard CJ, Sharpe TD, Holt LJ, Pelletier L, Bullock AN, Leroux MR. CDKL Family Kinases Have Evolved Distinct Structural Features and Ciliary Function. Cell Rep 2018; 22:885-894. [PMID: 29420175 PMCID: PMC5846859 DOI: 10.1016/j.celrep.2017.12.083] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 11/07/2017] [Accepted: 12/22/2017] [Indexed: 12/28/2022] Open
Abstract
Various kinases, including a cyclin-dependent kinase (CDK) family member, regulate the growth and functions of primary cilia, which perform essential roles in signaling and development. Neurological disorders linked to CDK-Like (CDKL) proteins suggest that these underexplored kinases may have similar functions. Here, we present the crystal structures of human CDKL1, CDKL2, CDKL3, and CDKL5, revealing their evolutionary divergence from CDK and mitogen-activated protein kinases (MAPKs), including an unusual ?J helix important for CDKL2 and CDKL3 activity. C. elegans CDKL-1, most closely related to CDKL1-4 and localized to neuronal cilia transition zones, modulates cilium length; this depends on its kinase activity and ?J helix-containing C terminus. Human CDKL5, linked to Rett syndrome, also localizes to cilia, and it impairs ciliogenesis when overexpressed. CDKL5 patient mutations modeled in CDKL-1 cause localization and/or cilium length defects. Together, our studies establish a disease model system suggesting cilium length defects as a pathomechanism for neurological disorders, including epilepsy.
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Affiliation(s)
- Peter Canning
- Structural Genomics Consortium, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Kwangjin Park
- Department of Molecular Biology and Biochemistry, and Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - João Gonçalves
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Chunmei Li
- Department of Molecular Biology and Biochemistry, and Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Conor J Howard
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Timothy D Sharpe
- Structural Genomics Consortium, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Liam J Holt
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Laurence Pelletier
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Alex N Bullock
- Structural Genomics Consortium, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford OX3 7DQ, UK.
| | - Michel R Leroux
- Department of Molecular Biology and Biochemistry, and Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada.
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61
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Seo S, Datta P. Photoreceptor outer segment as a sink for membrane proteins: hypothesis and implications in retinal ciliopathies. Hum Mol Genet 2017; 26:R75-R82. [PMID: 28453661 DOI: 10.1093/hmg/ddx163] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 04/24/2017] [Indexed: 12/28/2022] Open
Abstract
The photoreceptor outer segment (OS) is a unique modification of the primary cilium, specialized for light perception. Being homologous organelles, the primary cilium and the OS share common building blocks and molecular machinery to construct and maintain them. The OS, however, has several unique structural features that are not seen in primary cilia. Although these unique features of the OS have been well documented, their implications in protein localization have been under-appreciated. In this review, we compare the structural properties of the primary cilium and the OS, and propose a hypothesis that the OS can act as a sink for membrane proteins. We further discuss the implications of this hypothesis in polarized protein localization in photoreceptors and mechanisms of photoreceptor degeneration in retinal ciliopathies.
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Affiliation(s)
- Seongjin Seo
- Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Poppy Datta
- Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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62
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Lei H, Yan Z, Sun X, Zhang Y, Wang J, Ma C, Xu Q, Wang R, Jarvis ED, Sun Z. Axon guidance pathways served as common targets for human speech/language evolution and related disorders. BRAIN AND LANGUAGE 2017; 174:1-8. [PMID: 28692932 DOI: 10.1016/j.bandl.2017.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 05/17/2017] [Accepted: 06/29/2017] [Indexed: 06/07/2023]
Abstract
Human and several nonhuman species share the rare ability of modifying acoustic and/or syntactic features of sounds produced, i.e. vocal learning, which is the important neurobiological and behavioral substrate of human speech/language. This convergent trait was suggested to be associated with significant genomic convergence and best manifested at the ROBO-SLIT axon guidance pathway. Here we verified the significance of such genomic convergence and assessed its functional relevance to human speech/language using human genetic variation data. In normal human populations, we found the affected amino acid sites were well fixed and accompanied with significantly more associated protein-coding SNPs in the same genes than the rest genes. Diseased individuals with speech/language disorders have significant more low frequency protein coding SNPs but they preferentially occurred outside the affected genes. Such patients' SNPs were enriched in several functional categories including two axon guidance pathways (mediated by netrin and semaphorin) that interact with ROBO-SLITs. Four of the six patients have homozygous missense SNPs on PRAME gene family, one youngest gene family in human lineage, which possibly acts upon retinoic acid receptor signaling, similarly as FOXP2, to modulate axon guidance. Taken together, we suggest the axon guidance pathways (e.g. ROBO-SLIT, PRAME gene family) served as common targets for human speech/language evolution and related disorders.
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Affiliation(s)
- Huimeng Lei
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China.
| | - Zhangming Yan
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaohong Sun
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Yue Zhang
- Department of Children Healthcare, Capital Institute of Pediatrics, Beijing, 100020, China
| | - Jianhong Wang
- Department of Children Healthcare, Capital Institute of Pediatrics, Beijing, 100020, China
| | - Caihong Ma
- Reproductive Medicine Center of Peking University Third Hospital, Beijing, 100191, China
| | - Qunyuan Xu
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Rui Wang
- Hengkuan Telegenomics Co., Ltd., 36/F, 5 Meiyuan Rd., Tianjin 300384, China
| | - Erich D Jarvis
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Howard Hughes Medical Institute, Chevy Chase, MD, 20815-6789, USA
| | - Zhirong Sun
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China.
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Primary Cilium Formation and Ciliary Protein Trafficking Is Regulated by the Atypical MAP Kinase MAPK15 in Caenorhabditis elegans and Human Cells. Genetics 2017; 207:1423-1440. [PMID: 29021280 DOI: 10.1534/genetics.117.300383] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/05/2017] [Indexed: 11/18/2022] Open
Abstract
Motile and immotile (or primary) cilia are microtubule-based structures that mediate multiple cellular functions, including the transduction of environmental cues, developmental signaling, cellular motility, and modulation of fluid flow. Although their core architectures are similar, motile and primary cilia exhibit marked structural differences that underlie distinct functional properties. However, the extent to which ciliogenesis mechanisms are shared between these different cilia types is not fully described. Here, we report that the atypical MAP kinase MAPK15 (ERK7/8), implicated in the formation of vertebrate motile cilia, also regulates the formation of primary cilia in Caenorhabditis elegans sensory neurons and human cells. We find that MAPK15 localizes to a basal body subdomain with the ciliopathy protein BBS7 and to cell-cell junctions. MAPK15 also regulates the localization of ciliary proteins involved in cilium structure, transport, and signaling. Our results describe a primary cilia-related role for this poorly studied member of the MAPK family in vivo, and indicate a broad requirement for MAPK15 in the formation of multiple ciliary classes across species.
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64
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Bujakowska KM, Liu Q, Pierce EA. Photoreceptor Cilia and Retinal Ciliopathies. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a028274. [PMID: 28289063 DOI: 10.1101/cshperspect.a028274] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Photoreceptors are sensory neurons designed to convert light stimuli into neurological responses. This process, called phototransduction, takes place in the outer segments (OS) of rod and cone photoreceptors. OS are specialized sensory cilia, with analogous structures to those present in other nonmotile cilia. Deficient morphogenesis and/or dysfunction of photoreceptor sensory cilia (PSC) caused by mutations in a variety of photoreceptor-specific and common cilia genes can lead to inherited retinal degenerations (IRDs). IRDs can manifest as isolated retinal diseases or syndromic diseases. In this review, we describe the structure and composition of PSC and different forms of ciliopathies with retinal involvement. We review the genetics of the IRDs, which are monogenic disorders but genetically diverse with regard to causality.
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Affiliation(s)
- Kinga M Bujakowska
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114
| | - Qin Liu
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114
| | - Eric A Pierce
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114
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65
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Takao D, Wang L, Boss A, Verhey KJ. Protein Interaction Analysis Provides a Map of the Spatial and Temporal Organization of the Ciliary Gating Zone. Curr Biol 2017; 27:2296-2306.e3. [PMID: 28736169 DOI: 10.1016/j.cub.2017.06.044] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/09/2017] [Accepted: 06/16/2017] [Indexed: 11/19/2022]
Abstract
The motility and signaling functions of the primary cilium require a unique protein and lipid composition that is determined by gating mechanisms localized at the base of the cilium. Several protein complexes localize to the gating zone and may regulate ciliary protein composition; however, the mechanisms of ciliary gating and the dynamics of the gating components are largely unknown. Here, we used the BiFC (bimolecular fluorescence complementation) assay and report for the first time on the protein-protein interactions that occur between ciliary gating components and transiting cargoes during ciliary entry. We find that the nucleoporin Nup62 and the C termini of the nephronophthisis (NPHP) proteins NPHP4 and NPHP5 interact with the axoneme-associated kinesin-2 motor KIF17 and thus spatially map to the inner region of the ciliary gating zone. Nup62 and NPHP4 exhibit rapid turnover at the transition zone and thus define dynamic components of the gate. We find that B9D1, AHI1, and the N termini of NPHP4 and NPHP5 interact with the transmembrane protein SSTR3 and thus spatially map to the outer region of the ciliary gating zone. B9D1, AHI1, and NPHP5 exhibit little to no turnover at the transition zone and thus define components of a stable gating structure. These data provide the first comprehensive map of the molecular orientations of gating zone components along the inner-to-outer axis of the ciliary gating zone. These results advance our understanding of the functional roles of gating zone components in regulating ciliary protein composition.
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Affiliation(s)
- Daisuke Takao
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA
| | - Liang Wang
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA; The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Science, Jiangsu Normal University, 101 Shanghai Road, Tongshan District, Xuzhou 221116, China
| | - Allison Boss
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA
| | - Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA.
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Abstract
Motile and non-motile (primary) cilia are nearly ubiquitous cellular organelles. The dysfunction of cilia causes diseases known as ciliopathies. The number of reported ciliopathies (currently 35) is increasing, as is the number of established (187) and candidate (241) ciliopathy-associated genes. The characterization of ciliopathy-associated proteins and phenotypes has improved our knowledge of ciliary functions. In particular, investigating ciliopathies has helped us to understand the molecular mechanisms by which the cilium-associated basal body functions in early ciliogenesis, as well as how the transition zone functions in ciliary gating, and how intraflagellar transport enables cargo trafficking and signalling. Both basic biological and clinical studies are uncovering novel ciliopathies and the ciliary proteins involved. The assignment of these proteins to different ciliary structures, processes and ciliopathy subclasses (first order and second order) provides insights into how this versatile organelle is built, compartmentalized and functions in diverse ways that are essential for human health.
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67
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Van De Weghe JC, Rusterholz TD, Latour B, Grout ME, Aldinger KA, Shaheen R, Dempsey JC, Maddirevula S, Cheng YHH, Phelps IG, Gesemann M, Goel H, Birk OS, Alanzi T, Rawashdeh R, Khan AO, Bamshad MJ, Nickerson DA, Neuhauss SC, Dobyns WB, Alkuraya FS, Roepman R, Bachmann-Gagescu R, Doherty D, Doherty D. Mutations in ARMC9, which Encodes a Basal Body Protein, Cause Joubert Syndrome in Humans and Ciliopathy Phenotypes in Zebrafish. Am J Hum Genet 2017. [PMID: 28625504 DOI: 10.1016/j.ajhg.2017.05.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Joubert syndrome (JS) is a recessive neurodevelopmental disorder characterized by hypotonia, ataxia, abnormal eye movements, and variable cognitive impairment. It is defined by a distinctive brain malformation known as the "molar tooth sign" on axial MRI. Subsets of affected individuals have malformations such as coloboma, polydactyly, and encephalocele, as well as progressive retinal dystrophy, fibrocystic kidney disease, and liver fibrosis. More than 35 genes have been associated with JS, but in a subset of families the genetic cause remains unknown. All of the gene products localize in and around the primary cilium, making JS a canonical ciliopathy. Ciliopathies are unified by their overlapping clinical features and underlying mechanisms involving ciliary dysfunction. In this work, we identify biallelic rare, predicted-deleterious ARMC9 variants (stop-gain, missense, splice-site, and single-exon deletion) in 11 individuals with JS from 8 families, accounting for approximately 1% of the disorder. The associated phenotypes range from isolated neurological involvement to JS with retinal dystrophy, additional brain abnormalities (e.g., heterotopia, Dandy-Walker malformation), pituitary insufficiency, and/or synpolydactyly. We show that ARMC9 localizes to the basal body of the cilium and is upregulated during ciliogenesis. Typical ciliopathy phenotypes (curved body shape, retinal dystrophy, coloboma, and decreased cilia) in a CRISPR/Cas9-engineered zebrafish mutant model provide additional support for ARMC9 as a ciliopathy-associated gene. Identifying ARMC9 mutations as a cause of JS takes us one step closer to a full genetic understanding of this important disorder and enables future functional work to define the central biological mechanisms underlying JS and other ciliopathies.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Dan Doherty
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98101, USA.
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68
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Ganner A, Neumann-Haefelin E. Genetic kidney diseases: Caenorhabditis elegans as model system. Cell Tissue Res 2017; 369:105-118. [PMID: 28484847 DOI: 10.1007/s00441-017-2622-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 03/31/2017] [Indexed: 12/18/2022]
Abstract
Despite its apparent simplicity, the nematode Caenorhabditis elegans has a high rating as a model in molecular and developmental biology and biomedical research. C. elegans has no excretory system comparable with the mammalian kidney but many of the genes and molecular pathways involved in human kidney diseases are conserved in C. elegans. The plethora of genetic, molecular and imaging tools available in C. elegans has enabled major discoveries in renal research and advanced our understanding of the pathogenesis of genetic kidney diseases. In particular, studies in C. elegans have pioneered the fundamental role of cilia for cystic kidney diseases. In addition, proteins of the glomerular filtration barrier and podocytes are critical for cell recognition, assembly of functional neuronal circuits, mechanosensation and signal transduction in C. elegans. C. elegans has also proved tremendously valuable for aging research and the Von Hippel-Lindau tumor suppressor gene has been shown to modulate lifespan in the nematode. Further, studies of the excretory canal, membrane transport and ion channel function in C. elegans have provided insights into mechanisms of tubulogenesis and cellular homeostasis. This review recounts the way that C. elegans can be used to investigate various aspects of genetic and molecular nephrology. This model system opens up an exciting and new area of study of renal development and diseases.
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Affiliation(s)
- Athina Ganner
- Department of Nephrology, Medical Center, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany
| | - Elke Neumann-Haefelin
- Department of Nephrology, Medical Center, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
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69
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Serwas D, Su TY, Roessler M, Wang S, Dammermann A. Centrioles initiate cilia assembly but are dispensable for maturation and maintenance in C. elegans. J Cell Biol 2017; 216:1659-1671. [PMID: 28411189 PMCID: PMC5461022 DOI: 10.1083/jcb.201610070] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 03/10/2017] [Accepted: 04/10/2017] [Indexed: 01/17/2023] Open
Abstract
Cilia are cellular projections that assemble on centriole-derived basal bodies. While cilia assembly is absolutely dependent on centrioles, it is not known to what extent they contribute to downstream events. The nematode C. elegans provides a unique opportunity to address this question, as centrioles do not persist at the base of mature cilia. Using fluorescence microscopy and electron tomography, we find that centrioles degenerate early during ciliogenesis. The transition zone and axoneme are not completely formed at this time, indicating that cilia maturation does not depend on intact centrioles. The hydrolethalus syndrome protein HYLS-1 is the only centriolar protein known to remain at the base of mature cilia and is required for intraflagellar transport trafficking. Surprisingly, targeted degradation of HYLS-1 after initiation of ciliogenesis does not affect ciliary structures. Taken together, our results indicate that while centrioles are essential to initiate cilia formation, they are dispensable for cilia maturation and maintenance.
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Affiliation(s)
- Daniel Serwas
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), A-1030 Vienna, Austria
| | - Tiffany Y Su
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), A-1030 Vienna, Austria
| | - Max Roessler
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), A-1030 Vienna, Austria
| | - Shaohe Wang
- Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Alexander Dammermann
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), A-1030 Vienna, Austria
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70
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Mutations in TMEM260 Cause a Pediatric Neurodevelopmental, Cardiac, and Renal Syndrome. Am J Hum Genet 2017; 100:666-675. [PMID: 28318500 DOI: 10.1016/j.ajhg.2017.02.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 02/17/2017] [Indexed: 01/27/2023] Open
Abstract
Despite the accelerated discovery of genes associated with syndromic traits, the majority of families affected by such conditions remain undiagnosed. Here, we employed whole-exome sequencing in two unrelated consanguineous kindreds with central nervous system (CNS), cardiac, renal, and digit abnormalities. We identified homozygous truncating mutations in TMEM260, a locus predicted to encode numerous splice isoforms. Systematic expression analyses across tissues and developmental stages validated two such isoforms, which differ in the utilization of an internal exon. The mutations in both families map uniquely to the long isoform, raising the possibility of an isoform-specific disorder. Consistent with this notion, RT-PCR of lymphocyte cell lines from one of the kindreds showed reduced levels of only the long isoform, which could be ameliorated by emetine, suggesting that the mutation induces nonsense-mediated decay. Subsequent in vivo testing supported this hypothesis. First, either transient suppression or CRISPR/Cas9 genome editing of zebrafish tmem260 recapitulated key neurological phenotypes. Second, co-injection of morphants with the long human TMEM260 mRNA rescued CNS pathology, whereas the short isoform was significantly less efficient. Finally, immunocytochemical and biochemical studies showed preferential enrichment of the long TMEM260 isoform to the plasma membrane. Together, our data suggest that there is overall reduced, but not ablated, functionality of TMEM260 and that attenuation of the membrane-associated functions of this protein is a principal driver of pathology. These observations contribute to an appreciation of the roles of splice isoforms in genetic disorders and suggest that dissection of the functions of these transcripts will most likely inform pathomechanism.
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71
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Gonçalves J, Pelletier L. The Ciliary Transition Zone: Finding the Pieces and Assembling the Gate. Mol Cells 2017; 40:243-253. [PMID: 28401750 PMCID: PMC5424270 DOI: 10.14348/molcells.2017.0054] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 04/05/2017] [Indexed: 12/23/2022] Open
Abstract
Eukaryotic cilia are organelles that project from the surface of cells to fulfill motility and sensory functions. In vertebrates, the functions of both motile and immotile cilia are critical for embryonic development and adult tissue homeostasis. Importantly, a multitude of human diseases is caused by abnormal cilia biogenesis and functions which rely on the compartmentalization of the cilium and the maintenance of its protein composition. The transition zone (TZ) is a specialized ciliary domain present at the base of the cilium and is part of a gate that controls protein entry and exit from this organelle. The relevance of the TZ is highlighted by the fact that several of its components are coded by ciliopathy genes. Here we review recent developments in the study of TZ proteomes, the mapping of individual components to the TZ structure and the establishment of the TZ as a lipid gate.
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Affiliation(s)
- João Gonçalves
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5,
Canada
| | - Laurence Pelletier
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5,
Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8,
Canada
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72
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Broadgate S, Yu J, Downes SM, Halford S. Unravelling the genetics of inherited retinal dystrophies: Past, present and future. Prog Retin Eye Res 2017; 59:53-96. [PMID: 28363849 DOI: 10.1016/j.preteyeres.2017.03.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 02/07/2023]
Abstract
The identification of the genes underlying monogenic diseases has been of interest to clinicians and scientists for many years. Using inherited retinal dystrophies as an example of monogenic disease we describe the history of molecular genetic techniques that have been pivotal in the discovery of disease causing genes. The methods that were developed in the 1970's and 80's are still in use today but have been refined and improved. These techniques enabled the concept of the Human Genome Project to be envisaged and ultimately realised. When the successful conclusion of the project was announced in 2003 many new tools and, as importantly, many collaborations had been developed that facilitated a rapid identification of disease genes. In the post-human genome project era advances in computing power and the clever use of the properties of DNA replication has allowed the development of next-generation sequencing technologies. These methods have revolutionised the identification of disease genes because for the first time there is no need to define the position of the gene in the genome. The use of next generation sequencing in a diagnostic setting has allowed many more patients with an inherited retinal dystrophy to obtain a molecular diagnosis for their disease. The identification of novel genes that have a role in the development or maintenance of retinal function is opening up avenues of research which will lead to the development of new pharmacological and gene therapy approaches. Neither of which can be used unless the defective gene and protein is known. The continued development of sequencing technologies also holds great promise for the advent of truly personalised medicine.
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Affiliation(s)
- Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Jing Yu
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Susan M Downes
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, OX3 9DU, UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
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73
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Manojlovic Z, Earwood R, Kato A, Perez D, Cabrera OA, Didier R, Megraw TL, Stefanovic B, Kato Y. La-related protein 6 controls ciliated cell differentiation. Cilia 2017; 6:4. [PMID: 28344782 PMCID: PMC5364628 DOI: 10.1186/s13630-017-0047-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 02/16/2017] [Indexed: 01/07/2023] Open
Abstract
Background La-related protein 6 (LARP6) is an evolutionally conserved RNA-binding protein. Vertebrate LARP6 binds the 5′ stem-loop found in mRNAs encoding type I collagen to regulate their translation, but other target mRNAs and additional functions for LARP6 are unknown. The aim of this study was to elucidate an additional function of LARP6 and to evaluate the importance of its function during development. Methods To uncover the role of LARP6 in development, we utilized Morpholino Oligos to deplete LARP6 protein in Xenopus embryos. Then, embryonic phenotypes and ciliary structures of LAPR6 morphants were examined. To identify the molecular mechanism underlying ciliogenesis regulated by LARP6, we tested the expression level of cilia-related genes, which play important roles in ciliogenesis, by RT-PCR or whole mount in situ hybridization (WISH). Results We knocked down LARP6 in Xenopus embryos and found neural tube closure defects. LARP6 mutant, which compromises the collagen synthesis, could rescue these defects. Neural tube closure defects are coincident with lack of cilia, antenna-like cellular organelles with motility- or sensory-related functions, in the neural tube. The absence of cilia at the epidermis was also observed in LARP6 morphants, and this defect was due to the absence of basal bodies which are formed from centrioles and required for ciliary assembly. In the process of multi-ciliated cell (MCC) differentiation, mcidas, which activates the transcription of genes required for centriole formation during ciliogenesis, could partially restore MCCs in LARP6 morphants. In addition, LARP6 likely controls the expression of mcidas in a Notch-independent manner. Conclusions La-related protein 6 is involved in ciliated cell differentiation during development by controlling the expression of cilia-related genes including mcidas. This LARP6 function involves a mechanism that is distinct from its established role in binding to collagen mRNAs and regulating their translation. Electronic supplementary material The online version of this article (doi:10.1186/s13630-017-0047-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zarko Manojlovic
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA.,Department of Translational Genomics, Keck School of Medicine of University of Southern California, Los Angeles, CA 90089-9601 USA
| | - Ryan Earwood
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Akiko Kato
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Diana Perez
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Oscar A Cabrera
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Ruth Didier
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Timothy L Megraw
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Branko Stefanovic
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
| | - Yoichi Kato
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115W. Call Street, Tallahassee, FL 32306-4300 USA
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74
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Abstract
Nephronophthisis-related ciliopathies (NPHP-RC) are a group of inherited diseases that affect genes encoding proteins that localize to primary cilia or centrosomes. With few exceptions, ciliopathies are inherited in an autosomal recessive manner, and affected individuals manifest early during childhood or adolescence. NPHP-RC are genetically very heterogeneous, and, currently, mutations in more than 90 genes have been described as single-gene causes. The phenotypes of NPHP-RC are very diverse, and include cystic-fibrotic kidney disease, brain developmental defects, retinal degeneration, skeletal deformities, facial dimorphism, and, in some cases, laterality defects, and congenital heart disease. Mutations in the same gene can give rise to diverse phenotypes depending on the mutated allele. At the same time, there is broad phenotypic overlap between different monogenic genes. The identification of monogenic causes of ciliopathies has furthered the understanding of molecular mechanism and cellular pathways involved in the pathogenesis.
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Garcia-Gonzalo FR, Reiter JF. Open Sesame: How Transition Fibers and the Transition Zone Control Ciliary Composition. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a028134. [PMID: 27770015 DOI: 10.1101/cshperspect.a028134] [Citation(s) in RCA: 166] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cilia are plasma membrane protrusions that act as cellular propellers or antennae. To perform these functions, cilia must maintain a composition distinct from those of the contiguous cytosol and plasma membrane. The specialized composition of the cilium depends on the ciliary gate, the region at the ciliary base separating the cilium from the rest of the cell. The ciliary gate's main structural features are electron dense struts connecting microtubules to the adjacent membrane. These structures include the transition fibers, which connect the distal basal body to the base of the ciliary membrane, and the Y-links, which connect the proximal axoneme and ciliary membrane within the transition zone. Both transition fibers and Y-links form early during ciliogenesis and play key roles in ciliary assembly and trafficking. Accordingly, many human ciliopathies are caused by mutations that perturb ciliary gate function.
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Affiliation(s)
- Francesc R Garcia-Gonzalo
- Departamento de Bioquímica, Facultad de Medicina, and Instituto de Investigaciones Biomédicas Alberto Sols UAM-CSIC, Universidad Autónoma de Madrid, 28029 Madrid, Spain
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics, and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California 94158
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Molecular genetic findings and clinical correlations in 100 patients with Joubert syndrome and related disorders prospectively evaluated at a single center. Genet Med 2017; 19:875-882. [PMID: 28125082 DOI: 10.1038/gim.2016.204] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 11/08/2016] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Joubert syndrome (JS) is a genetically and clinically heterogeneous ciliopathy characterized by distinct cerebellar and brainstem malformations resulting in the diagnostic "molar tooth sign" on brain imaging. To date, more than 30 JS genes have been identified, but these do not account for all patients. METHODS In our cohort of 100 patients with JS from 86 families, we prospectively performed extensive clinical evaluation and provided molecular diagnosis using a targeted 27-gene Molecular Inversion Probes panel followed by whole-exome sequencing (WES). RESULTS We identified the causative gene in 94% of the families; 126 (27 novel) unique potentially pathogenic variants were found in 20 genes, including KIAA0753 and CELSR2, which had not previously been associated with JS. Genotype-phenotype correlation revealed the absence of retinal degeneration in patients with TMEM67, C5orf52, or KIAA0586 variants. Chorioretinal coloboma was associated with a decreased risk for retinal degeneration and increased risk for liver disease. TMEM67 was frequently associated with kidney disease. CONCLUSION In JS, WES significantly increases the yield for molecular diagnosis, which is essential for reproductive counseling and the option of preimplantation and prenatal diagnosis as well as medical management and prognostic counseling for the age-dependent and progressive organ-specific manifestations, including retinal, liver, and kidney disease.Genet Med advance online publication 26 January 2017.
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77
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Dyson JM, Conduit SE, Feeney SJ, Hakim S, DiTommaso T, Fulcher AJ, Sriratana A, Ramm G, Horan KA, Gurung R, Wicking C, Smyth I, Mitchell CA. INPP5E regulates phosphoinositide-dependent cilia transition zone function. J Cell Biol 2016; 216:247-263. [PMID: 27998989 PMCID: PMC5223597 DOI: 10.1083/jcb.201511055] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 09/19/2016] [Accepted: 12/02/2016] [Indexed: 02/07/2023] Open
Abstract
Dyson et al. demonstrate that the inositol polyphosphate 5-phosphatase INPP5E is essential for Hedgehog-dependent embryonic development. By regulating PI(4,5)P2 and PI(3,4,5)P3 signals at cilia, INPP5E contributes to cilia transition zone function and thereby Smoothened accumulation at cilia. Human ciliopathies, including Joubert syndrome (JBTS), arise from cilia dysfunction. The inositol polyphosphate 5-phosphatase INPP5E localizes to cilia and is mutated in JBTS. Murine Inpp5e ablation is embryonically lethal and recapitulates JBTS, including neural tube defects and polydactyly; however, the underlying defects in cilia signaling and the function of INPP5E at cilia are still emerging. We report Inpp5e−/− embryos exhibit aberrant Hedgehog-dependent patterning with reduced Hedgehog signaling. Using mouse genetics, we show increasing Hedgehog signaling via Smoothened M2 expression rescues some Inpp5e−/− ciliopathy phenotypes and “normalizes” Hedgehog signaling. INPP5E’s phosphoinositide substrates PI(4,5)P2 and PI(3,4,5)P3 accumulated at the transition zone (TZ) in Hedgehog-stimulated Inpp5e−/− cells, which was associated with reduced recruitment of TZ scaffolding proteins and reduced Smoothened levels at cilia. Expression of wild-type, but not 5-phosphatase-dead, INPP5E restored TZ molecular organization and Smoothened accumulation at cilia. Therefore, we identify INPP5E as an essential point of convergence between Hedgehog and phosphoinositide signaling at cilia that maintains TZ function and Hedgehog-dependent embryonic development.
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Affiliation(s)
- Jennifer M Dyson
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Sarah E Conduit
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Sandra J Feeney
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Sandra Hakim
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Tia DiTommaso
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Alex J Fulcher
- Monash Micro Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Absorn Sriratana
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Georg Ramm
- Monash Micro Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Kristy A Horan
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Rajendra Gurung
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Carol Wicking
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Ian Smyth
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.,Development and Stem Cells Program, Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Christina A Mitchell
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
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Thevenon J, Duplomb L, Phadke S, Eguether T, Saunier A, Avila M, Carmignac V, Bruel AL, St-Onge J, Duffourd Y, Pazour GJ, Franco B, Attie-Bitach T, Masurel-Paulet A, Rivière JB, Cormier-Daire V, Philippe C, Faivre L, Thauvin-Robinet C. Autosomal recessive IFT57 hypomorphic mutation cause ciliary transport defect in unclassified oral-facial-digital syndrome with short stature and brachymesophalangia. Clin Genet 2016; 90:509-517. [PMID: 27060890 PMCID: PMC5765760 DOI: 10.1111/cge.12785] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/31/2016] [Accepted: 04/01/2016] [Indexed: 11/30/2022]
Abstract
The 13 subtypes of oral-facial-digital syndrome (OFDS) belong to the heterogeneous group of ciliopathies. Disease-causing genes encode for centrosomal proteins, components of the transition zone or proteins implicated in ciliary signaling. A unique consanguineous family presenting with an unclassified OFDS with skeletal dysplasia and brachymesophalangia was explored. Homozygosity mapping and exome sequencing led to the identification of a homozygous mutation in IFT57, which encodes a protein implicated in ciliary transport. The mutation caused splicing anomalies with reduced expression of the wild-type transcript and protein. Both anterograde ciliary transport and sonic hedgehog signaling were significantly decreased in subjects' fibroblasts compared with controls. Sanger sequencing of IFT57 in 13 OFDS subjects and 12 subjects with Ellis-Van Creveld syndrome was negative. This report identifies the implication of IFT57 in human pathology and highlights the first description of a ciliary transport defect in OFDS, extending the genetic heterogeneity of this subgroup of ciliopathies.
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Affiliation(s)
- Julien Thevenon
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Equipe EA4271 GAD, Université de Bourgogne, Dijon, France
- Centre de Référence maladies rares « Anomalies du Développement et syndrome malformatifs » de l’Est et Centre de Génétique, Hôpital d’Enfants, CHU, Dijon, France
| | - Laurence Duplomb
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Equipe EA4271 GAD, Université de Bourgogne, Dijon, France
| | - Shubha Phadke
- Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Thibaut Eguether
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Aline Saunier
- Laboratoire de Génétique Médicale, CHU - Hopitaux de Brabois, 54511 Vandoeuvre les Nancy cedex, France
| | - Magali Avila
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Equipe EA4271 GAD, Université de Bourgogne, Dijon, France
| | - Virginie Carmignac
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Equipe EA4271 GAD, Université de Bourgogne, Dijon, France
| | - Ange-Line Bruel
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Equipe EA4271 GAD, Université de Bourgogne, Dijon, France
| | - Judith St-Onge
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Equipe EA4271 GAD, Université de Bourgogne, Dijon, France
- Laboratoire de Génétique Moléculaire, PTB, CHU Dijon, Dijon, France
| | - Yannis Duffourd
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Equipe EA4271 GAD, Université de Bourgogne, Dijon, France
| | - Gregory J. Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine-TIGEM, Naples, Italy
- Department of Medical Translational Sciences, Division of Pediatrics, Federico II University of Naples, Italy
| | - Tania Attie-Bitach
- Service de Génétique, Hôpital Necker-Enfants Malades, APHP, Institut Imagine, INSERM UMR1163, University Sorbonne-Paris-Cité, Paris, France
| | - Alice Masurel-Paulet
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Centre de Référence maladies rares « Anomalies du Développement et syndrome malformatifs » de l’Est et Centre de Génétique, Hôpital d’Enfants, CHU, Dijon, France
| | - Jean-Baptiste Rivière
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Equipe EA4271 GAD, Université de Bourgogne, Dijon, France
- Laboratoire de Génétique Moléculaire, PTB, CHU Dijon, Dijon, France
| | - Valérie Cormier-Daire
- Service de Génétique, Hôpital Necker-Enfants Malades, APHP, Institut Imagine, INSERM UMR1163, University Sorbonne-Paris-Cité, Paris, France
| | - Christophe Philippe
- Laboratoire de Génétique Médicale, CHU - Hopitaux de Brabois, 54511 Vandoeuvre les Nancy cedex, France
| | - Laurence Faivre
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Equipe EA4271 GAD, Université de Bourgogne, Dijon, France
- Centre de Référence maladies rares « Anomalies du Développement et syndrome malformatifs » de l’Est et Centre de Génétique, Hôpital d’Enfants, CHU, Dijon, France
| | - Christel Thauvin-Robinet
- FHU-TRANSLAD, Université de Bourgogne/CHU Dijon; France
- Equipe EA4271 GAD, Université de Bourgogne, Dijon, France
- Centre de Référence maladies rares « Anomalies du Développement et syndrome malformatifs » de l’Est et Centre de Génétique, Hôpital d’Enfants, CHU, Dijon, France
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Yu M, Liu Y, Li J, Natale BN, Cao S, Wang D, Amack JD, Hu H. Eyes shut homolog is required for maintaining the ciliary pocket and survival of photoreceptors in zebrafish. Biol Open 2016; 5:1662-1673. [PMID: 27737822 PMCID: PMC5155541 DOI: 10.1242/bio.021584] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mutations in the extracellular matrix protein eyes shut homolog (EYS) cause photoreceptor degeneration in patients with retinitis pigmentosa 25 (RP25). Functions of EYS remain poorly understood, due in part to the lack of an EYS gene in mouse. We investigated the localization of vertebrate EYS proteins and engineered loss-of-function alleles in zebrafish. Immunostaining indicated that EYS localized near the connecting cilium/transition zone in photoreceptors. EYS also strongly localized to the cone outer segments and weakly to the rod outer segments and cone terminals in primate retinas. Analysis of mutant EYS zebrafish revealed disruption of the ciliary pocket in cone photoreceptors, indicating that EYS is required for maintaining the integrity of the ciliary pocket lumen. Mutant zebrafish exhibited progressive loss of cone and rod photoreceptors. Our results indicate that EYS protein localization is species-dependent and that EYS is required for maintaining ciliary pocket morphology and survival of photoreceptors in zebrafish. Summary: The extracellular matrix protein Eyes shut homolog is required for maintaining the integrity of the ciliary pocket and survival of photoreceptors in zebrafish.
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Affiliation(s)
- Miao Yu
- Center for Vision Research, Departments of Ophthalmology and Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Yu Liu
- Center for Vision Research, Departments of Ophthalmology and Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Jing Li
- Center for Vision Research, Departments of Ophthalmology and Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Brianna N Natale
- Center for Vision Research, Departments of Ophthalmology and Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Shuqin Cao
- Center for Vision Research, Departments of Ophthalmology and Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Dongliang Wang
- Department of Public Health and Preventive Medicine, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Jeffrey D Amack
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Huaiyu Hu
- Center for Vision Research, Departments of Ophthalmology and Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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80
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Oud MM, Lamers IJC, Arts HH. Ciliopathies: Genetics in Pediatric Medicine. J Pediatr Genet 2016; 6:18-29. [PMID: 28180024 DOI: 10.1055/s-0036-1593841] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 02/08/2016] [Indexed: 12/15/2022]
Abstract
Ciliary disorders, which are also referred to as ciliopathies, are a group of hereditary disorders that result from dysfunctional cilia. The latter are cellular organelles that stick up from the apical plasma membrane. Cilia have important roles in signal transduction and facilitate communications between cells and their surroundings. Ciliary disruption can result in a wide variety of clinically and genetically heterogeneous disorders with overlapping phenotypes. Because cilia occur widespread in our bodies many organs and sensory systems can be affected when they are dysfunctional. Ciliary disorders may be isolated or syndromic, and common features are cystic liver and/or kidney disease, blindness, neural tube defects, brain anomalies and intellectual disability, skeletal abnormalities ranging from polydactyly to abnormally short ribs and limbs, ectodermal defects, obesity, situs inversus, infertility, and recurrent respiratory tract infections. In this review, we summarize the features, frequency, morbidity, and mortality of each of the different ciliopathies that occur in pediatrics. The importance of genetics and the occurrence of genotype-phenotype correlations are indicated, and advances in gene identification are discussed. The use of next-generation sequencing by which a gene panel or all genes can be screened in a single experiment is highlighted as this technology significantly lowered costs and time of the mutation detection process in the past. We discuss the challenges of this new technology and briefly touch upon the use of whole-exome sequencing as a diagnostic test for ciliary disorders. Finally, a perspective on the future of genetics in the context of ciliary disorders is provided.
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Affiliation(s)
- Machteld M Oud
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ideke J C Lamers
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Heleen H Arts
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
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81
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Suzuki T, Miyake N, Tsurusaki Y, Okamoto N, Alkindy A, Inaba A, Sato M, Ito S, Muramatsu K, Kimura S, Ieda D, Saitoh S, Hiyane M, Suzumura H, Yagyu K, Shiraishi H, Nakajima M, Fueki N, Habata Y, Ueda Y, Komatsu Y, Yan K, Shimoda K, Shitara Y, Mizuno S, Ichinomiya K, Sameshima K, Tsuyusaki Y, Kurosawa K, Sakai Y, Haginoya K, Kobayashi Y, Yoshizawa C, Hisano M, Nakashima M, Saitsu H, Takeda S, Matsumoto N. Molecular genetic analysis of 30 families with Joubert syndrome. Clin Genet 2016; 90:526-535. [PMID: 27434533 DOI: 10.1111/cge.12836] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 06/27/2016] [Accepted: 07/14/2016] [Indexed: 02/02/2023]
Abstract
Joubert syndrome (JS) is rare recessive disorders characterized by the combination of hypoplasia/aplasia of the cerebellar vermis, thickened and elongated superior cerebellar peduncles, and a deep interpeduncular fossa which is defined by neuroimaging and is termed the 'molar tooth sign'. JS is genetically highly heterogeneous, with at least 29 disease genes being involved. To further understand the genetic causes of JS, we performed whole-exome sequencing in 24 newly recruited JS families. Together with six previously reported families, we identified causative mutations in 25 out of 30 (24 + 6) families (83.3%). We identified eight mutated genes in 27 (21 + 6) Japanese families, TMEM67 (7/27, 25.9%) and CEP290 (6/27, 22.2%) were the most commonly mutated. Interestingly, 9 of 12 CEP290 disease alleles were c.6012-12T>A (75.0%), an allele that has not been reported in non-Japanese populations. Therefore c.6012-12T>A is a common allele in the Japanese population. Importantly, one Japanese and one Omani families carried compound biallelic mutations in two distinct genes (TMEM67/RPGRIP1L and TMEM138/BBS1, respectively). BBS1 is the causative gene in Bardet-Biedl syndrome. These concomitant mutations led to severe and/or complex clinical features in the patients, suggesting combined effects of different mutant genes.
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Affiliation(s)
- T Suzuki
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan.,Department of Obstetrics and Gynecology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - N Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Y Tsurusaki
- Clinical Research Institute, Kanagawa Children's Medical Center, Yokohama, Japan
| | - N Okamoto
- Department of Medical Genetics, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan
| | - A Alkindy
- Department of Genetics, Sultan Qaboos University Hospital, Muscat, Oman
| | - A Inaba
- Yokohama City University Medical Center, Children's Medical Center, Yokohama, Japan
| | - M Sato
- Division of Nephrology and Rheumatology, National Center for Child Health and Development, Tokyo, Japan
| | - S Ito
- Department of Pediatrics, Graduate school of Medicine, Yokohama City University, Yokohama, Japan
| | - K Muramatsu
- Department of Pediatrics, Gunma University Graduate School of Medicine, Gunma, Japan
| | - S Kimura
- Kumamoto City Child Development Support Center, Kumamoto, Japan
| | - D Ieda
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - S Saitoh
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - M Hiyane
- Division of Child Neurology, Okinawa Prefectural Southern Medical Center & Children's Medical Center, Okinawa, Japan
| | - H Suzumura
- Department of Pediatrics, Dokkyo Medical University, Tochigi, Japan
| | - K Yagyu
- Department of Child and Adolescent Psychiatry, Graduate School of Medicine, Hokkaido University, Hokkaido, Japan
| | - H Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Hokkaido, Japan
| | - M Nakajima
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Hokkaido, Japan
| | - N Fueki
- Division of Rehabilitation, Nagano Children's Hospital, Nagano, Japan
| | - Y Habata
- Department of Pediatric Rehabilitation, Hokkaido Medical Center for Child Health and Rehabilitation, Hokkaido, Japan
| | - Y Ueda
- Nire-no-kai Children's Clinic, Hokkaido, Japan
| | - Y Komatsu
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - K Yan
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - K Shimoda
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Y Shitara
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - S Mizuno
- Department of Pediatrics, Central Hospital, Aichi Human Service Center, Aichi, Japan
| | - K Ichinomiya
- Department of Neonatology, Gunma Children's Medical Center, Gunma, Japan
| | - K Sameshima
- Division of Medical Genetics, Gunma Children's Medical Center, Gunma, Japan
| | - Y Tsuyusaki
- Division of Neurology, Clinical Research Institute, Kanagawa Children's Medical Center, Yokohama, Japan
| | - K Kurosawa
- Division of Medical Genetics, Clinical Research Institute, Kanagawa Children's Medical Center, Yokohama, Japan
| | - Y Sakai
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - K Haginoya
- Department of Pediatric Neurology, Miyagi Children's Hospital, Sendai, Japan
| | - Y Kobayashi
- Department of Pediatrics, Gunma University Graduate School of Medicine, Gunma, Japan.,Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, UK
| | - C Yoshizawa
- Department of Pediatrics, Gunma University Graduate School of Medicine, Gunma, Japan
| | - M Hisano
- Department of Nephrology, Chiba Children's Hospital, Chiba, Japan
| | - M Nakashima
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - H Saitsu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan.,Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - S Takeda
- Department of Obstetrics and Gynecology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - N Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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82
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Wei Q, Zhang Y, Schouteden C, Zhang Y, Zhang Q, Dong J, Wonesch V, Ling K, Dammermann A, Hu J. The hydrolethalus syndrome protein HYLS-1 regulates formation of the ciliary gate. Nat Commun 2016; 7:12437. [PMID: 27534274 PMCID: PMC4992140 DOI: 10.1038/ncomms12437] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 06/30/2016] [Indexed: 12/18/2022] Open
Abstract
Transition fibres (TFs), together with the transition zone (TZ), are basal ciliary structures thought to be crucial for cilium biogenesis and function by acting as a ciliary gate to regulate selective protein entry and exit. Here we demonstrate that the centriolar and basal body protein HYLS-1, the C. elegans orthologue of hydrolethalus syndrome protein 1, is required for TF formation, TZ organization and ciliary gating. Loss of HYLS-1 compromises the docking and entry of intraflagellar transport (IFT) particles, ciliary gating for both membrane and soluble proteins, and axoneme assembly. Additional depletion of the TF component DYF-19 in hyls-1 mutants further exacerbates TZ anomalies and completely abrogates ciliogenesis. Our data support an important role for HYLS-1 and TFs in establishment of the ciliary gate and underline the importance of selective protein entry for cilia assembly.
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Affiliation(s)
- Qing Wei
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, USA.,Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yingyi Zhang
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Clementine Schouteden
- Max F. Perutz Laboratories, Vienna Biocenter (VBC), University of Vienna, A-1030 Vienna, Austria
| | - Yuxia Zhang
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Qing Zhang
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Jinhong Dong
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Veronika Wonesch
- Max F. Perutz Laboratories, Vienna Biocenter (VBC), University of Vienna, A-1030 Vienna, Austria
| | - Kun Ling
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Alexander Dammermann
- Max F. Perutz Laboratories, Vienna Biocenter (VBC), University of Vienna, A-1030 Vienna, Austria
| | - Jinghua Hu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, USA.,Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota 55905, USA.,Mayo Translational PKD Center, Mayo Clinic, Rochester, Minnesota 55905, USA
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83
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Cilium transition zone proteome reveals compartmentalization and differential dynamics of ciliopathy complexes. Proc Natl Acad Sci U S A 2016; 113:E5135-43. [PMID: 27519801 DOI: 10.1073/pnas.1604258113] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The transition zone (TZ) of eukaryotic cilia and flagella is a structural intermediate between the basal body and the axoneme that regulates ciliary traffic. Mutations in genes encoding TZ proteins (TZPs) cause human inherited diseases (ciliopathies). Here, we use the trypanosome to identify TZ components and localize them to TZ subdomains, showing that the Bardet-Biedl syndrome complex (BBSome) is more distal in the TZ than the Meckel syndrome (MKS) complex. Several of the TZPs identified here have human orthologs. Functional analysis shows essential roles for TZPs in motility, in building the axoneme central pair apparatus and in flagellum biogenesis. Analysis using RNAi and HaloTag fusion protein approaches reveals that most TZPs (including the MKS ciliopathy complex) show long-term stable association with the TZ, whereas the BBSome is dynamic. We propose that some Bardet-Biedl syndrome and MKS pleiotropy may be caused by mutations that impact TZP complex dynamics.
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84
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The nephronophthisis-related gene ift-139 is required for ciliogenesis in Caenorhabditis elegans. Sci Rep 2016; 6:31544. [PMID: 27515926 PMCID: PMC4981862 DOI: 10.1038/srep31544] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 07/22/2016] [Indexed: 12/21/2022] Open
Abstract
Defects in cilia cause a spectrum of diseases known as ciliopathies. Nephronophthisis, a ciliopathy, is the most common genetic cause of renal disease. Here, I cloned and analysed a nephronophthisis-related gene ift-139 in Caenorhabditis elegans. ift-139 was exclusively expressed in ciliated neurons in C. elegans. Genetic and cellular analyses suggest that ift-139 plays a role in retrograde intraflagellar transport and is required for cilia formation. A homologous point mutation that causes ciliopathy disrupted the function of ift-139 in C. elegans. ift-139 is an orthologue of human TTC21B, mutations in which are known to cause nephronophthisis 12 and short-rib thoracic dysplasia 4. These results suggest that ift-139 is evolutionarily conserved and fundamental to the formation of cilia.
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85
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Abstract
Primary cilia are organelles that are present on many different cell types, either transiently or permanently. They play a crucial role in receiving signals from the environment and passing these signals to other parts of the cell. In that way, they are involved in diverse processes such as adipocyte differentiation and olfactory sensation. Mutations in genes coding for ciliary proteins often have pleiotropic effects and lead to clinical conditions, ciliopathies, with multiple symptoms. In this study, we reviewed observations from ciliopathies with obesity as one of the symptoms. It shows that variation in cilia-related genes is itself not a major cause of obesity in the population but may be a part of the multifactorial aetiology of this complex condition. Both common polymorphisms and rare deleterious variants may contribute to the obesity risk. Genotype-phenotype relationships have been noticed. Among the ciliary genes, obesity differs with regard to severity and age of onset, which may relate to the influence of each gene on the balance between pro- and anti-adipogenic processes. Analysis of the function and location of the proteins encoded by these ciliary genes suggests that obesity is more linked to activities at the basal area of the cilium, including initiation of the intraflagellar transport, but less to the intraflagellar transport itself. Regarding the role of cilia, three possible mechanistic processes underlying obesity are described: adipogenesis, neuronal food intake regulation and food odour perception.
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86
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Triggs-Raine B, Dyck T, Boycott KM, Innes AM, Ober C, Parboosingh JS, Botkin A, Greenberg CR, Spriggs EL. Development of a diagnostic DNA chip to screen for 30 autosomal recessive disorders in the Hutterite population. Mol Genet Genomic Med 2016; 4:312-21. [PMID: 27247959 PMCID: PMC4867565 DOI: 10.1002/mgg3.206] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 12/16/2015] [Accepted: 12/18/2015] [Indexed: 12/03/2022] Open
Abstract
Background The Hutterites are a religious isolate living in colonies across the North American prairies. This population originated from approximately 90 founders, resulting in a number of genetic diseases that are overrepresented, underrepresented, or unique. The founder effect in this population increases the likelihood that Hutterite couples carry the same recessive mutations. We have designed a diagnostic chip on a fee‐for‐service basis with Asper Biotech to provide Hutterites with the option of comprehensive carrier screening. Methods A total of 32 disease‐causing mutations in 30 genes were selected and primers were designed for array primer extension‐based testing. Selected mutations were limited to those leading to autosomal recessive disorders, maintaining its primary use as a test for determining carrier status. Results The DNA chip was developed and validated using 59 DNA controls for all but one of the mutations, for which a synthetic control was used. All mutations were readily detected except for a duplication causing restrictive dermopathy where heterozygotes and homozygotes could only be distinguished by sequencing. Blinded testing of 12 additional samples from healthy Hutterites was performed by Asper Biotech using chip testing. All known mutations from previous molecular testing were detected on the chip. As well, additional mutations identified by the chip in these 12 samples were subsequently verified by a second method. Conclusions Our analysis indicates that the chip is a sensitive and specific means of carrier testing in the Hutterite population and can serve as a model for other founder populations.
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Affiliation(s)
- Barbara Triggs-Raine
- Departments of Biochemistry & Medical GeneticsUniversity of ManitobaWinnipegCanada; Pediatrics & Child HealthUniversity of Manitoba745 Bannatyne Ave.WinnipegMB R3E 0J9Canada; The Manitoba Institute of Child Health513-715 McDermot Ave.WinnipegMB R3E 3P4Canada
| | - Tamara Dyck
- Clinical Biochemistry and Genetics Diagnostic Services Manitoba at Health Sciences Centre Winnipeg MB R3A 1R9 Canada
| | - Kym M Boycott
- Children's Hospital of Eastern Ontario Research Institute University of Ottawa Ottawa ON K1H 8L1 Canada
| | - A Micheil Innes
- Department of Medical Genetics Alberta Children's Hospital and Alberta Children's Hospital Research Institute for Child and Maternal Health Cumming School of Medicine University of Calgary Calgary Alberta Canada
| | - Carole Ober
- Departments of Human Genetics and Obstetrics and Gynecology The University of Chicago Chicago Illinois
| | - Jillian S Parboosingh
- Department of Medical Genetics Alberta Children's Hospital and Alberta Children's Hospital Research Institute for Child and Maternal Health Cumming School of Medicine University of Calgary Calgary Alberta Canada
| | - Alexis Botkin
- Pediatrics & Child Health University of Manitoba 745 Bannatyne Ave. Winnipeg MB R3E 0J9 Canada
| | - Cheryl R Greenberg
- Departments of Biochemistry & Medical GeneticsUniversity of ManitobaWinnipegCanada; Pediatrics & Child HealthUniversity of Manitoba745 Bannatyne Ave.WinnipegMB R3E 0J9Canada; The Manitoba Institute of Child Health513-715 McDermot Ave.WinnipegMB R3E 3P4Canada
| | - Elizabeth L Spriggs
- Departments of Biochemistry & Medical GeneticsUniversity of ManitobaWinnipegCanada; Pediatrics & Child HealthUniversity of Manitoba745 Bannatyne Ave.WinnipegMB R3E 0J9Canada; Clinical Biochemistry and GeneticsDiagnostic Services Manitoba at Health Sciences CentreWinnipegMB R3A 1R9Canada
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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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Gabriel E, Wason A, Ramani A, Gooi LM, Keller P, Pozniakovsky A, Poser I, Noack F, Telugu NS, Calegari F, Šarić T, Hescheler J, Hyman AA, Gottardo M, Callaini G, Alkuraya FS, Gopalakrishnan J. CPAP promotes timely cilium disassembly to maintain neural progenitor pool. EMBO J 2016; 35:803-19. [PMID: 26929011 PMCID: PMC4972140 DOI: 10.15252/embj.201593679] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/05/2016] [Indexed: 12/28/2022] Open
Abstract
A mutation in the centrosomal‐P4.1‐associated protein (CPAP) causes Seckel syndrome with microcephaly, which is suggested to arise from a decline in neural progenitor cells (NPCs) during development. However, mechanisms of NPCs maintenance remain unclear. Here, we report an unexpected role for the cilium in NPCs maintenance and identify CPAP as a negative regulator of ciliary length independent of its role in centrosome biogenesis. At the onset of cilium disassembly, CPAP provides a scaffold for the cilium disassembly complex (CDC), which includes Nde1, Aurora A, and OFD1, recruited to the ciliary base for timely cilium disassembly. In contrast, mutated CPAP fails to localize at the ciliary base associated with inefficient CDC recruitment, long cilia, retarded cilium disassembly, and delayed cell cycle re‐entry leading to premature differentiation of patient iPS‐derived NPCs. Aberrant CDC function also promotes premature differentiation of NPCs in Seckel iPS‐derived organoids. Thus, our results suggest a role for cilia in microcephaly and its involvement during neurogenesis and brain size control.
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Affiliation(s)
- Elke Gabriel
- Center for Molecular Medicine and Institute for Biochemistry I of the University of Cologne, Cologne, Germany
| | - Arpit Wason
- Center for Molecular Medicine and Institute for Biochemistry I of the University of Cologne, Cologne, Germany
| | - Anand Ramani
- Center for Molecular Medicine and Institute for Biochemistry I of the University of Cologne, Cologne, Germany
| | - Li Ming Gooi
- Center for Molecular Medicine and Institute for Biochemistry I of the University of Cologne, Cologne, Germany
| | - Patrick Keller
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Andrei Pozniakovsky
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Ina Poser
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Florian Noack
- DFG-Research Center and Cluster of Excellence for Regenerative Therapies, TU-Dresden, Dresden, Germany
| | - Narasimha Swamy Telugu
- Center for Physiology and Pathophysiology, Institute for Neurophysiology Medical Faculty University of Cologne, Cologne, Germany
| | - Federico Calegari
- DFG-Research Center and Cluster of Excellence for Regenerative Therapies, TU-Dresden, Dresden, Germany
| | - Tomo Šarić
- Center for Physiology and Pathophysiology, Institute for Neurophysiology Medical Faculty University of Cologne, Cologne, Germany
| | - Jürgen Hescheler
- Center for Physiology and Pathophysiology, Institute for Neurophysiology Medical Faculty University of Cologne, Cologne, Germany
| | - Anthony A Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Marco Gottardo
- Department of Life Sciences, University of Siena, Siena, Italy
| | | | - Fowzan Sami Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center Alfasial University, Riyadh, Saudi Arabia Department of Anatomy and Cell Biology, College of Medicine Alfasial University, Riyadh, Saudi Arabia
| | - Jay Gopalakrishnan
- Center for Molecular Medicine and Institute for Biochemistry I of the University of Cologne, Cologne, Germany
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89
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Masyukova SV, Landis DE, Henke SJ, Williams CL, Pieczynski JN, Roszczynialski KN, Covington JE, Malarkey EB, Yoder BK. A Screen for Modifiers of Cilia Phenotypes Reveals Novel MKS Alleles and Uncovers a Specific Genetic Interaction between osm-3 and nphp-4. PLoS Genet 2016; 12:e1005841. [PMID: 26863025 PMCID: PMC4749664 DOI: 10.1371/journal.pgen.1005841] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 01/12/2016] [Indexed: 12/04/2022] Open
Abstract
Nephronophthisis (NPHP) is a ciliopathy in which genetic modifiers may underlie the variable penetrance of clinical features. To identify modifiers, a screen was conducted on C. elegans nphp-4(tm925) mutants. Mutations in ten loci exacerbating nphp-4(tm925) ciliary defects were obtained. Four loci have been identified, three of which are established ciliopathy genes mks-1, mks-2, and mks-5. The fourth allele (yhw66) is a missense mutation (S316F) in OSM-3, a kinesin required for cilia distal segment assembly. While osm-3(yhw66) mutants alone have no overt cilia phenotype, nphp-4(tm925);osm-3(yhw66) double mutants lack distal segments and are dye-filling (Dyf) and osmotic avoidance (Osm) defective, similar to osm-3(mn357) null mutants. In osm-3(yhw66) mutants anterograde intraflagellar transport (IFT) velocity is reduced. Furthermore, expression of OSM-3(S316F)::GFP reduced IFT velocities in nphp-4(tm925) mutants, but not in wild type animals. In silico analysis indicates the S316F mutation may affect a phosphorylation site. Putative phospho-null OSM-3(S316F) and phospho-mimetic OSM-3(S316D) proteins accumulate at the cilia base and tip respectively. FRAP analysis indicates that the cilia entry rate of OSM-3(S316F) is slower than OSM-3 and that in the presence of OSM-3(S316F), OSM-3 and OSM-3(S316D) rates decrease. In the presence OSM-3::GFP or OSM-3(S316D)::GFP, OSM-3(S316F)::tdTomato redistributes along the cilium and accumulates in the cilia tip. OSM-3(S316F) and OSM-3(S316D) are functional as they restore cilia distal segment formation in osm-3(mn357) null mutants; however, only OSM-3(S316F) rescues the osm-3(mn357) null Dyf phenotype. Despite rescue of cilia length in osm-3(mn357) null mutants, neither OSM-3(S316F) nor OSM-3(S316D) restores ciliary defects in nphp-4(tm925);osm-3(yhw66) double mutants. Thus, these OSM-3 mutations cause NPHP-4 dependent and independent phenotypes. These data indicate that in addition to regulating cilia protein entry or exit, NPHP-4 influences localization and function of a distal ciliary kinesin. Moreover, data suggest human OSM-3 homolog (Kif17) could act as a modifying locus affecting disease penetrance or expressivity in NPHP patients. Nephronophthisis (NPHP) is a genetically heterogeneous ciliopathy that has minimal genotype-phenotype correlation. The cause of this variation is not known, but could result from additional mutations in the patients’ backgrounds capable of modifying the phenotype. To identify candidate NPHP modifying loci, we conducted an enhancer mutagenesis screen using C. elegans nphp-4(tm925) mutants. Mutations in ten loci were obtained that severely exacerbated the cilia defects in the nphp-4(tm925) mutants, but importantly, had minimal defects in the absence of the nphp-4 mutation. Here we identified four of these loci, each encoding a cilia protein. Three mutations are in known ciliopathy genes, mks-1, mks-2 and mks-5. The fourth allele is a missense (S316F) mutation in OSM-3, a kinesin required for distal cilia assembly and is the sole kinesin responsible for intraflagellar transport along the cilia distal segment in C. elegans. The osm-3(yhw66) mutation affects a putative phosphorylation site that is important for OSM-3 localization, movement, and function, largely in an nphp-4 dependent manner. These data establish a genetic interaction between osm-3 and nphp-4 that regulates kinesin activity and localization and raises the possibility that mutations in Kif17, the mammalian homolog of osm-3, may influence the phenotypes in human NPHP patients.
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Affiliation(s)
- Svetlana V. Masyukova
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Dawn E. Landis
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Scott J. Henke
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Corey L. Williams
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Jay N. Pieczynski
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Kelly N. Roszczynialski
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Jannese E. Covington
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Erik B. Malarkey
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Bradley K. Yoder
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
- * E-mail:
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Schueler M, Halbritter J, Phelps IG, Braun DA, Otto EA, Porath JD, Gee HY, Shendure J, O'Roak BJ, Lawson JA, Nabhan MM, Soliman NA, Doherty D, Hildebrandt F. Large-scale targeted sequencing comparison highlights extreme genetic heterogeneity in nephronophthisis-related ciliopathies. J Med Genet 2015; 53:208-14. [PMID: 26673778 DOI: 10.1136/jmedgenet-2015-103304] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 11/13/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND The term nephronophthisis-related ciliopathies (NPHP-RC) describes a group of rare autosomal-recessive cystic kidney diseases, characterised by broad genetic and clinical heterogeneity. NPHP-RC is frequently associated with extrarenal manifestations and accounts for the majority of genetically caused chronic kidney disease (CKD) during childhood and adolescence. Generation of a molecular diagnosis has been impaired by this broad genetic heterogeneity. However, recently developed high-throughput exon sequencing techniques represent powerful and efficient tools to screen large cohorts for dozens of causative genes. METHODS Therefore, we performed massively multiplexed targeted sequencing using the modified molecular inversion probe strategy (MIPs) in an international cohort of 384 patients diagnosed with NPHP-RC. RESULTS As a result, we established the molecular diagnoses in 81/384 unrelated individuals (21.1%). We detected 127 likely disease-causing mutations in 18 of 34 evaluated NPHP-RC genes, 22 of which were novel. We further compared a subgroup of current findings to the results of a previous study in which we used an array-based microfluidic PCR technology in the same cohort. While 78 likely disease-causing mutations were previously detected by the array-based microfluidic PCR, the MIPs approach identified 94 likely pathogenic mutations. Compared with the previous approach, MIPs redetected 66 out of 78 variants and 28 previously unidentified variants, for a total of 94 variants. CONCLUSIONS In summary, we demonstrate that the modified MIPs technology is a useful approach to screen large cohorts for a multitude of established NPHP genes in order to identify the underlying molecular cause. Combined application of two independent library preparation and sequencing techniques, however, may still be indicated for Mendelian diseases with extensive genetic heterogeneity in order to further increase diagnostic sensitivity.
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Affiliation(s)
- Markus Schueler
- Divison of Nephology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Jan Halbritter
- Divison of Nephology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA Divison of Nephrology, Department of Internal Medicine, University Clinic Leipzig, Leipzig, Germany
| | - Ian G Phelps
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA
| | - Daniela A Braun
- Divison of Nephology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Edgar A Otto
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Jonathan D Porath
- Divison of Nephology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Heon Yung Gee
- Divison of Nephology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Jay Shendure
- University of Washington, Genome Sciences, Seattle, Washington, USA
| | - Brian J O'Roak
- Oregon Health and Science University, Molecular and Medical Genetics, Portland, Oregon, USA
| | - Jennifer A Lawson
- Divison of Nephology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Marwa M Nabhan
- Department of Pediatrics, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt Egyptian Group for Orphan Renal Diseases (EGORD), Cairo, Egypt
| | - Neveen A Soliman
- Department of Pediatrics, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt Egyptian Group for Orphan Renal Diseases (EGORD), Cairo, Egypt
| | - Dan Doherty
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA
| | - Friedhelm Hildebrandt
- Divison of Nephology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
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91
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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: 99] [Impact Index Per Article: 11.0] [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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92
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Chafai-Elalaoui S, Chalon M, Elkhartoufi N, Kriouele Y, Mansouri M, Attié-Bitach T, Sefiani A, Baala L. A homozygous AHI1 gene mutation (p.Thr304AsnfsX6) in a consanguineous Moroccan family with Joubert syndrome: a case report. J Med Case Rep 2015; 9:254. [PMID: 26541515 PMCID: PMC4635607 DOI: 10.1186/s13256-015-0732-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 10/08/2015] [Indexed: 12/31/2022] Open
Abstract
Introduction Joubert syndrome is a rare congenital disorder characterized by brain malformation, developmental delay with hypotonia, ocular motor apraxia, and breathing abnormalities. Joubert syndrome is a genetically highly heterogeneous ciliopathy disorder with 23 identified causative genes. The diagnosis is based on brain imaging showing the “molar tooth sign” with cerebellar vermis agenesis. We describe a consanguineous Moroccan family with three affected siblings (18-year-old boy, 13-year-old girl, and 10-year-old boy) showing typical signs of Joubert syndrome, and attempt to identify the underlying genetic defect in this family. Methods We performed genome-wide homozygosity mapping using a high-resolution array followed by targeted Sanger sequencing to identify the causative gene. Results This approach found three homozygous regions, one including the AHI1 gene. Direct sequencing of the 26 coding exons of AHI1 revealed a homozygous mutation (p.Thr304AsnfsX6) located in exon 7 present in the three Joubert syndrome-affected Moroccan siblings. Of more interest, this truncating mutation was previously reported in patients with compound heterozygous Joubert syndrome originating from Spain (one patient) and from the Netherlands (two patients), suggesting a possible founder effect or mutational hotspot. Conclusions Combined homozygosity mapping and targeted sequencing allowed the rapid detection of the disease-causing mutation in the AHI1 gene in this family affected with a highly genetically heterogeneous disorder. Carriers of the same truncating mutation (p.Thr304AsnfsX6), originating from Spain and the Netherlands, presented variable clinical characteristics, thereby corroborating the extreme heterogeneity of Joubert syndrome.
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Affiliation(s)
- Siham Chafai-Elalaoui
- Département de Génétique Médicale, Institut National d'Hygiène, Rabat, Maroc.,Centre de Génomique Humaine, Faculté de Médecine et de Pharmacie, Université Mohammed V Souissi, Rabat, Maroc
| | - Matthias Chalon
- Université d'Orléans & CNRS, INEM-UMR7355, Immunologie Expérimentale et Moléculaire & Neurogénétique, Orléans, France
| | - Nadia Elkhartoufi
- Service d'Histologie-Embryologie-Cytogénétique, Hôpital Necker-Enfants Malades, AP-HP, Paris, France
| | - Yamna Kriouele
- Service de Pédiatrie IIA, Hôpital d'Enfants, Rabat, Maroc
| | - Maria Mansouri
- Département de Génétique Médicale, Institut National d'Hygiène, Rabat, Maroc.,Centre de Génomique Humaine, Faculté de Médecine et de Pharmacie, Université Mohammed V Souissi, Rabat, Maroc
| | - Tania Attié-Bitach
- Service d'Histologie-Embryologie-Cytogénétique, Hôpital Necker-Enfants Malades, AP-HP, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, France, Institut IMAGINE, Paris, France.,INSERM UMR1163, Paris Descartes - Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Abdelaziz Sefiani
- Département de Génétique Médicale, Institut National d'Hygiène, Rabat, Maroc.,Centre de Génomique Humaine, Faculté de Médecine et de Pharmacie, Université Mohammed V Souissi, Rabat, Maroc
| | - Lekbir Baala
- Université d'Orléans & CNRS, INEM-UMR7355, Immunologie Expérimentale et Moléculaire & Neurogénétique, Orléans, France. .,Centre Hospitalier Régional d'Orléans (CHRO), Pôle de Biopathologie, Orléans, France.
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93
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Yee LE, Garcia-Gonzalo FR, Bowie RV, Li C, Kennedy JK, Ashrafi K, Blacque OE, Leroux MR, Reiter JF. Conserved Genetic Interactions between Ciliopathy Complexes Cooperatively Support Ciliogenesis and Ciliary Signaling. PLoS Genet 2015; 11:e1005627. [PMID: 26540106 PMCID: PMC4635004 DOI: 10.1371/journal.pgen.1005627] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/05/2015] [Indexed: 11/18/2022] Open
Abstract
Mutations in genes encoding cilia proteins cause human ciliopathies, diverse disorders affecting many tissues. Individual genes can be linked to ciliopathies with dramatically different phenotypes, suggesting that genetic modifiers may participate in their pathogenesis. The ciliary transition zone contains two protein complexes affected in the ciliopathies Meckel syndrome (MKS) and nephronophthisis (NPHP). The BBSome is a third protein complex, affected in the ciliopathy Bardet-Biedl syndrome (BBS). We tested whether mutations in MKS, NPHP and BBS complex genes modify the phenotypic consequences of one another in both C. elegans and mice. To this end, we identified TCTN-1, the C. elegans ortholog of vertebrate MKS complex components called Tectonics, as an evolutionarily conserved transition zone protein. Neither disruption of TCTN-1 alone or together with MKS complex components abrogated ciliary structure in C. elegans. In contrast, disruption of TCTN-1 together with either of two NPHP complex components, NPHP-1 or NPHP-4, compromised ciliary structure. Similarly, disruption of an NPHP complex component and the BBS complex component BBS-5 individually did not compromise ciliary structure, but together did. As in nematodes, disrupting two components of the mouse MKS complex did not cause additive phenotypes compared to single mutants. However, disrupting both Tctn1 and either Nphp1 or Nphp4 exacerbated defects in ciliogenesis and cilia-associated developmental signaling, as did disrupting both Tctn1 and the BBSome component Bbs1. Thus, we demonstrate that ciliary complexes act in parallel to support ciliary function and suggest that human ciliopathy phenotypes are altered by genetic interactions between different ciliary biochemical complexes. Ciliopathies, diseases arising from defects in the functions of primary cilia, have many different manifestations and vary dramatically in severity. How genetics influence ciliopathy phenotypes is poorly understood. Building off of our increasing knowledge of how different biochemical complexes contribute to ciliary function, we investigated how ciliopathy-associated genes interact to support ciliogenesis. Using a combination of nematode and mouse genetics, we found that genes encoding components of different biochemical complexes interact, whereas genes encoding different components within a single complex do not. These results revealed overlapping ciliary functions of biochemically distinct proteins complexes such as the BBSome, the transition zone MKS complex and the transition zone NPHP complex. This work indicates the genetic interactions that may alter the phenotypic consequences of human ciliopathy mutations.
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Affiliation(s)
- Laura E. Yee
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California, United States of America
| | - Francesc R. Garcia-Gonzalo
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California, United States of America
| | - Rachel V. Bowie
- School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Chunmei Li
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Julie K. Kennedy
- School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Kaveh Ashrafi
- Department of Physiology, University of California, San Francisco, San Francisco, California, United States of America
| | - Oliver E. Blacque
- School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Michel R. Leroux
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Jeremy F. Reiter
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail:
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94
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Srour M, Hamdan F, McKnight D, Davis E, Mandel H, Schwartzentruber J, Martin B, Patry L, Nassif C, Dionne-Laporte A, Ospina L, Lemyre E, Massicotte C, Laframboise R, Maranda B, Labuda D, Décarie JC, Rypens F, Goldsher D, Fallet-Bianco C, Soucy JF, Laberge AM, Maftei C, Boycott K, Brais B, Boucher RM, Rouleau G, Katsanis N, Majewski J, Elpeleg O, Kukolich M, Shalev S, Michaud J, Michaud JL. Joubert Syndrome in French Canadians and Identification of Mutations in CEP104. Am J Hum Genet 2015; 97:744-53. [PMID: 26477546 DOI: 10.1016/j.ajhg.2015.09.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/22/2015] [Indexed: 10/22/2022] Open
Abstract
Joubert syndrome (JBTS) is a primarily autosomal-recessive disorder characterized by a distinctive mid-hindbrain and cerebellar malformation, oculomotor apraxia, irregular breathing, developmental delay, and ataxia. JBTS is a genetically heterogeneous ciliopathy. We sought to characterize the genetic landscape associated with JBTS in the French Canadian (FC) population. We studied 43 FC JBTS subjects from 35 families by combining targeted and exome sequencing. We identified pathogenic (n = 32 families) or possibly pathogenic (n = 2 families) variants in genes previously associated with JBTS in all of these subjects, except for one. In the latter case, we found a homozygous splice-site mutation (c.735+2T>C) in CEP104. Interestingly, we identified two additional non-FC JBTS subjects with mutations in CEP104; one of these subjects harbors a maternally inherited nonsense mutation (c.496C>T [p.Arg166*]) and a de novo splice-site mutation (c.2572-2A>G), whereas the other bears a homozygous frameshift mutation (c.1328_1329insT [p.Tyr444fs*3]) in CEP104. Previous studies have shown that CEP104 moves from the mother centriole to the tip of the primary cilium during ciliogenesis. Knockdown of CEP104 in retinal pigment epithelial (RPE1) cells resulted in severe defects in ciliogenesis. These observations suggest that CEP104 acts early during cilia formation by regulating the conversion of the mother centriole into the cilia basal body. We conclude that disruption of CEP104 causes JBTS. Our study also reveals that the cause of JBTS has been elucidated in the great majority of our FC subjects (33/35 [94%] families), even though JBTS shows substantial locus and allelic heterogeneity in this population.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Jacques L Michaud
- Research Center, Centre Hospitalier Universitaire Sainte-Justine, Montreal, QC H3T 1C5, Canada; Department of Pediatrics, Université de Montréal, Montreal, QC H3T 1J4, Canada; Department of Neurosciences, Université de Montréal, Montreal, QC H3T 1J4, Canada.
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95
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Deming JD, Pak JS, Brown BM, Kim MK, Aung MH, Eom YS, Shin JA, Lee EJ, Pardue MT, Craft CM. Visual Cone Arrestin 4 Contributes to Visual Function and Cone Health. Invest Ophthalmol Vis Sci 2015; 56:5407-16. [PMID: 26284544 DOI: 10.1167/iovs.15-16647] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
PURPOSE Visual arrestins (ARR) play a critical role in shutoff of rod and cone phototransduction. When electrophysiological responses are measured for a single mouse cone photoreceptor, ARR1 expression can substitute for ARR4 in cone pigment desensitization; however, each arrestin may also contribute its own, unique role to modulate other cellular functions. METHODS A combination of ERG, optokinetic tracking, immunohistochemistry, and immunoblot analysis was used to investigate the retinal phenotypes of Arr4 null mice (Arr4-/-) compared with age-matched control, wild-type mice. RESULTS When 2-month-old Arr4-/- mice were compared with wild-type mice, they had diminished visual acuity and contrast sensitivity, yet enhanced ERG flicker response and higher photopic ERG b-wave amplitudes. In contrast, in older Arr4-/- mice, all ERG amplitudes were significantly reduced in magnitude compared with age-matched controls. Furthermore, in older Arr4-/- mice, the total cone numbers decreased and cone opsin protein immunoreactive expression levels were significantly reduced, while overall photoreceptor outer nuclear layer thickness was unchanged. CONCLUSIONS Our study demonstrates that Arr4-/- mice display distinct phenotypic differences when compared to controls, suggesting that ARR4 modulates essential functions in high acuity vision and downstream cellular signaling pathways that are not fulfilled or substituted by the coexpression of ARR1, despite its high expression levels in all mouse cones. Without normal ARR4 expression levels, cones slowly degenerate with increasing age, making this a new model to study age-related cone dystrophy.
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Affiliation(s)
- Janise D Deming
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States
| | - Joseph S Pak
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States
| | - Bruce M Brown
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States
| | - Moon K Kim
- Rehabilitation Research & Development Center of Excellence, Atlanta VA Medical Center, Decatur, Georgia, United States
| | - Moe H Aung
- Neuroscience/Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Yun Sung Eom
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States 4Dornsife College of Letters, Arts and Sciences, Univers
| | - Jung-A Shin
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States 5Department of Anatomy, School of Medicine, Ewha Womans
| | - Eun-Jin Lee
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States 6Department of Biomedical Engineering, University of Sou
| | - Machelle T Pardue
- Rehabilitation Research & Development Center of Excellence, Atlanta VA Medical Center, Decatur, Georgia, United States 3Neuroscience/Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Cheryl Mae Craft
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States 7Department of Cell & Neurobiology, Keck School of Medic
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96
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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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97
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Knopp C, Rudnik-Schöneborn S, Eggermann T, Bergmann C, Begemann M, Schoner K, Zerres K, Ortiz Brüchle N. Syndromic ciliopathies: From single gene to multi gene analysis by SNP arrays and next generation sequencing. Mol Cell Probes 2015; 29:299-307. [DOI: 10.1016/j.mcp.2015.05.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 05/13/2015] [Accepted: 05/19/2015] [Indexed: 01/23/2023]
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98
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Superresolution Pattern Recognition Reveals the Architectural Map of the Ciliary Transition Zone. Sci Rep 2015; 5:14096. [PMID: 26365165 PMCID: PMC4568515 DOI: 10.1038/srep14096] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 08/18/2015] [Indexed: 12/31/2022] Open
Abstract
The transition zone (TZ) of primary cilia serves as a diffusion barrier to regulate ciliogenesis and receptor localization for key signaling events such as sonic hedgehog signaling. Its gating mechanism is poorly understood due to the tiny volume accommodating a large number of ciliopathy-associated molecules. Here we performed stimulated emission depletion (STED) imaging of collective samples and recreated superresolved relative localizations of eight representative species of ciliary proteins using position averages and overlapped with representative electron microscopy (EM) images, defining an architectural foundation at the ciliary base. Upon this framework, transmembrane proteins TMEM67 and TCTN2 were accumulated at the same axial level as MKS1 and RPGRIP1L, suggesting that their regulation roles for tissue-specific ciliogenesis occur at a specific level of the TZ. CEP290 is surprisingly localized at a different axial level bridging the basal body (BB) and other TZ proteins. Upon this molecular architecture, two reservoirs of intraflagellar transport (IFT) particles, correlating with phases of ciliary growth, are present: one colocalized with the transition fibers (TFs) while the other situated beyond the distal edge of the TZ. Together, our results reveal an unprecedented structural framework of the TZ, facilitating our understanding in molecular screening and assembly at the ciliary base.
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99
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Bachmann-Gagescu R, Dempsey JC, Phelps IG, O'Roak BJ, Knutzen DM, Rue TC, Ishak GE, Isabella CR, Gorden N, Adkins J, Boyle EA, de Lacy N, O'Day D, Alswaid A, Ramadevi A R, Lingappa L, Lourenço C, Martorell L, Garcia-Cazorla À, Ozyürek H, Haliloğlu G, Tuysuz B, Topçu M, Chance P, Parisi MA, Glass IA, Shendure J, Doherty D. Joubert syndrome: a model for untangling recessive disorders with extreme genetic heterogeneity. J Med Genet 2015; 52:514-22. [PMID: 26092869 PMCID: PMC5082428 DOI: 10.1136/jmedgenet-2015-103087] [Citation(s) in RCA: 191] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 06/01/2015] [Indexed: 12/23/2022]
Abstract
BACKGROUND Joubert syndrome (JS) is a recessive neurodevelopmental disorder characterised by hypotonia, ataxia, cognitive impairment, abnormal eye movements, respiratory control disturbances and a distinctive mid-hindbrain malformation. JS demonstrates substantial phenotypic variability and genetic heterogeneity. This study provides a comprehensive view of the current genetic basis, phenotypic range and gene-phenotype associations in JS. METHODS We sequenced 27 JS-associated genes in 440 affected individuals (375 families) from a cohort of 532 individuals (440 families) with JS, using molecular inversion probe-based targeted capture and next-generation sequencing. Variant pathogenicity was defined using the Combined Annotation Dependent Depletion algorithm with an optimised score cut-off. RESULTS We identified presumed causal variants in 62% of pedigrees, including the first B9D2 mutations associated with JS. 253 different mutations in 23 genes highlight the extreme genetic heterogeneity of JS. Phenotypic analysis revealed that only 34% of individuals have a 'pure JS' phenotype. Retinal disease is present in 30% of individuals, renal disease in 25%, coloboma in 17%, polydactyly in 15%, liver fibrosis in 14% and encephalocele in 8%. Loss of CEP290 function is associated with retinal dystrophy, while loss of TMEM67 function is associated with liver fibrosis and coloboma, but we observe no clear-cut distinction between JS subtypes. CONCLUSIONS This work illustrates how combining advanced sequencing techniques with phenotypic data addresses extreme genetic heterogeneity to provide diagnostic and carrier testing, guide medical monitoring for progressive complications, facilitate interpretation of genome-wide sequencing results in individuals with a variety of phenotypes and enable gene-specific treatments in the future.
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Affiliation(s)
- R Bachmann-Gagescu
- Institute for Molecular Life Sciences and Institute of Medical Genetics, University of Zurich, Zurich, Switzerland
| | - J C Dempsey
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - I G Phelps
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - B J O'Roak
- Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon, USA
| | - D M Knutzen
- Department of Oncology, Franciscan Health System, Tacoma, Washington, USA
| | - T C Rue
- Department of Biostatistics, University of Washington, Seattle, Washington, USA
| | - G E Ishak
- Department of Radiology, University of Washington, Seattle Children's Hospital, Seattle, Washington, USA
| | - C R Isabella
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - N Gorden
- Department of Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - J Adkins
- Division of Integrated Cancer Genomics, Translational Genomics Research Institute, Phoenix, Arizona, USA
| | - E A Boyle
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - N de Lacy
- Department of Psychiatry, University of Washington, Seattle, Washington, USA
| | - D O'Day
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - A Alswaid
- Department of Pediatrics, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | | | - L Lingappa
- Department of Child Neurology, Rainbow Children Hospital, Hyderabad, India
| | - C Lourenço
- Department of Neurosciences and Behavior Neurosciences, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - L Martorell
- Department of Genetica Molecular, Hospital Sant Joan de Deu, Barcelona, Spain
| | - À Garcia-Cazorla
- Department of Neurology, Neurometabolic Unit, Hospital Sant Joan de Déu and CIBERER, ISCIII, Barcelona, Spain
| | - H Ozyürek
- Department of Pediatric Neurology, Faculty of Medicine, Ondokuz Mayis University, Samsun, Turkey
| | - G Haliloğlu
- Department of Pediatric Neurology, Hacettepe University Children's Hospital, Ankara, Turkey
| | - B Tuysuz
- Department of Pediatric Genetics, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey
| | - M Topçu
- Department of Pediatric Neurology, Hacettepe University Children's Hospital, Ankara, Turkey
| | - P Chance
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - M A Parisi
- National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - I A Glass
- Department of Pediatrics, University of Washington, Seattle, Washington, USA Seattle Children's Research Institute, Seattle, Washington, USA
| | - J Shendure
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - D Doherty
- Department of Pediatrics, University of Washington, Seattle, Washington, USA Seattle Children's Research Institute, Seattle, Washington, USA
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100
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An siRNA-based functional genomics screen for the identification of regulators of ciliogenesis and ciliopathy genes. Nat Cell Biol 2015; 17:1074-1087. [PMID: 26167768 PMCID: PMC4536769 DOI: 10.1038/ncb3201] [Citation(s) in RCA: 176] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 06/05/2015] [Indexed: 12/13/2022]
Abstract
Defects in primary cilium biogenesis underlie the ciliopathies, a growing group of genetic disorders. We describe a whole genome siRNA-based reverse genetics screen for defects in biogenesis and/or maintenance of the primary cilium, obtaining a global resource. We identify 112 candidate ciliogenesis and ciliopathy genes, including 44 components of the ubiquitin-proteasome system, 12 G-protein-coupled receptors, and three pre-mRNA processing factors (PRPF6, PRPF8 and PRPF31) mutated in autosomal dominant retinitis pigmentosa. The PRPFs localise to the connecting cilium, and PRPF8- and PRPF31-mutated cells have ciliary defects. Combining the screen with exome sequencing data identified recessive mutations in PIBF1/CEP90 and C21orf2/LRRC76 as causes of the ciliopathies Joubert and Jeune syndromes. Biochemical approaches place C21orf2 within key ciliopathy-associated protein modules, offering an explanation for the skeletal and retinal involvement observed in individuals with C21orf2-variants. Our global, unbiased approaches provide insights into ciliogenesis complexity and identify roles for unanticipated pathways in human genetic disease.
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