1
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Tillery MML, Zheng C, Zheng Y, Megraw TL. Ninein domains required for its localization, association with partners dynein and ensconsin, and microtubule organization. Mol Biol Cell 2024; 35:ar116. [PMID: 39024292 DOI: 10.1091/mbc.e23-06-0245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024] Open
Abstract
Ninein (Nin) is a microtubule (MT) anchor at the subdistal appendages of mother centrioles and the pericentriolar material (PCM) of centrosomes that also functions to organize MTs at noncentrosomal MT-organizing centers (ncMTOCs). In humans, the NIN gene is mutated in Seckel syndrome, an inherited developmental disorder. Here, we dissect the protein domains involved in Nin's localization and interactions with dynein and ensconsin (ens/MAP7) and show that the association with ens cooperatively regulates MT assembly in Drosophila fat body cells. We define domains of Nin responsible for its localization to the ncMTOC on the fat body cell nuclear surface, localization within the nucleus, and association with Dynein light intermediate chain (Dlic) and ens, respectively. We show that Nin's association with ens synergistically regulates MT assembly. Together, these findings reveal novel features of Nin function and its regulation of a ncMTOC.
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Affiliation(s)
- Marisa M L Tillery
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, 32306-4300
| | - Chunfeng Zheng
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, 32306-4300
| | - Yiming Zheng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiang'an Hospital of Xiamen University, Xiamen University, Xiamen, China, 361102
- Shenzhen Research Institute of Xiamen University, Shenzhen, China, 518057
| | - Timothy L Megraw
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, 32306-4300
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2
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Linnert J, Knapp B, Güler BE, Boldt K, Ueffing M, Wolfrum U. Usher syndrome proteins ADGRV1 (USH2C) and CIB2 (USH1J) interact and share a common interactome containing TRiC/CCT-BBS chaperonins. Front Cell Dev Biol 2023; 11:1199069. [PMID: 37427378 PMCID: PMC10323441 DOI: 10.3389/fcell.2023.1199069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 06/06/2023] [Indexed: 07/11/2023] Open
Abstract
The human Usher syndrome (USH) is the most common form of a sensory hereditary ciliopathy characterized by progressive vision and hearing loss. Mutations in the genes ADGRV1 and CIB2 have been associated with two distinct sub-types of USH, namely, USH2C and USH1J. The proteins encoded by the two genes belong to very distinct protein families: the adhesion G protein-coupled receptor ADGRV1 also known as the very large G protein-coupled receptor 1 (VLGR1) and the Ca2+- and integrin-binding protein 2 (CIB2), respectively. In the absence of tangible knowledge of the molecular function of ADGRV1 and CIB2, pathomechanisms underlying USH2C and USH1J are still unknown. Here, we aimed to enlighten the cellular functions of CIB2 and ADGRV1 by the identification of interacting proteins, a knowledge that is commonly indicative of cellular functions. Applying affinity proteomics by tandem affinity purification in combination with mass spectrometry, we identified novel potential binding partners of the CIB2 protein and compared these with the data set we previously obtained for ADGRV1. Surprisingly, the interactomes of both USH proteins showed a high degree of overlap indicating their integration in common networks, cellular pathways and functional modules which we confirmed by GO term analysis. Validation of protein interactions revealed that ADGRV1 and CIB2 mutually interact. In addition, we showed that the USH proteins also interact with the TRiC/CCT chaperonin complex and the Bardet Biedl syndrome (BBS) chaperonin-like proteins. Immunohistochemistry on retinal sections demonstrated the co-localization of the interacting partners at the photoreceptor cilia, supporting the role of USH proteins ADGRV1 and CIB2 in primary cilia function. The interconnection of protein networks involved in the pathogenesis of both syndromic retinal dystrophies BBS and USH suggest shared pathomechanisms for both syndromes on the molecular level.
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Affiliation(s)
- Joshua Linnert
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Barbara Knapp
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Baran E. Güler
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Karsten Boldt
- Institute for Ophthalmic Research, Eberhard Karls University of Tuebingen, Tubingen, Germany
| | - Marius Ueffing
- Institute for Ophthalmic Research, Eberhard Karls University of Tuebingen, Tubingen, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
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3
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Gonzalez-Garcia P, Fiorillo Moreno O, Zarate Peñata E, Calderon-Villalba A, Pacheco Lugo L, Acosta Hoyos A, Villarreal Camacho JL, Navarro Quiroz R, Pacheco Londoño L, Aroca Martinez G, Moares N, Gabucio A, Fernandez-Ponce C, Garcia-Cozar F, Navarro Quiroz E. From Cell to Symptoms: The Role of SARS-CoV-2 Cytopathic Effects in the Pathogenesis of COVID-19 and Long COVID. Int J Mol Sci 2023; 24:ijms24098290. [PMID: 37175995 PMCID: PMC10179575 DOI: 10.3390/ijms24098290] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/23/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection triggers various events from molecular to tissue level, which in turn is given by the intrinsic characteristics of each patient. Given the molecular diversity characteristic of each cellular phenotype, the possible cytopathic, tissue and clinical effects are difficult to predict, which determines the heterogeneity of COVID-19 symptoms. The purpose of this article is to provide a comprehensive review of the cytopathic effects of SARS-CoV-2 on various cell types, focusing on the development of COVID-19, which in turn may lead, in some patients, to a persistence of symptoms after recovery from the disease, a condition known as long COVID. We describe the molecular mechanisms underlying virus-host interactions, including alterations in protein expression, intracellular signaling pathways, and immune responses. In particular, the article highlights the potential impact of these cytopathies on cellular function and clinical outcomes, such as immune dysregulation, neuropsychiatric disorders, and organ damage. The article concludes by discussing future directions for research and implications for the management and treatment of COVID-19 and long COVID.
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Affiliation(s)
| | - Ornella Fiorillo Moreno
- Clínica Iberoamerica, Barranquilla 080001, Colombia
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
| | - Eloina Zarate Peñata
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
| | | | - Lisandro Pacheco Lugo
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
| | - Antonio Acosta Hoyos
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
| | | | - Roberto Navarro Quiroz
- Department of Structural and Molecular Biology, Molecular Biology Institute of Barcelona, Spanish National Research Council, 08028 Barcelona, Spain
| | | | - Gustavo Aroca Martinez
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
- School of Medicine, Universidad del Norte, Barranquilla 080001, Colombia
| | - Noelia Moares
- Department of Biomedicine, Biotechnology and Public Health, Faculty of Medicine, University of Cadiz, 11003 Cádiz, Spain
| | - Antonio Gabucio
- Department of Biomedicine, Biotechnology and Public Health, Faculty of Medicine, University of Cadiz, 11003 Cádiz, Spain
| | - Cecilia Fernandez-Ponce
- Institute of Biomedical Research Cadiz (INIBICA), 11009 Cádiz, Spain
- Department of Biomedicine, Biotechnology and Public Health, Faculty of Medicine, University of Cadiz, 11003 Cádiz, Spain
| | - Francisco Garcia-Cozar
- Institute of Biomedical Research Cadiz (INIBICA), 11009 Cádiz, Spain
- Department of Biomedicine, Biotechnology and Public Health, Faculty of Medicine, University of Cadiz, 11003 Cádiz, Spain
| | - Elkin Navarro Quiroz
- Life Science Research Center, Universidad Simon Bolívar, Barranquilla 080001, Colombia
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4
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Stevens DA, Beierschmitt C, Mahesula S, Corley MR, Salogiannis J, Tsu BV, Cao B, Ryan AP, Hakozawki H, Reck-Peterson SL, Daugherty MD. Antiviral function and viral antagonism of the rapidly evolving dynein activating adaptor NINL. eLife 2022; 11:e81606. [PMID: 36222652 PMCID: PMC9651953 DOI: 10.7554/elife.81606] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
Viruses interact with the intracellular transport machinery to promote viral replication. Such host-virus interactions can drive host gene adaptation, leaving signatures of pathogen-driven evolution in host genomes. Here, we leverage these genetic signatures to identify the dynein activating adaptor, ninein-like (NINL), as a critical component in the antiviral innate immune response and as a target of viral antagonism. Unique among genes encoding components of active dynein complexes, NINL has evolved under recurrent positive (diversifying) selection, particularly in its carboxy-terminal cargo-binding region. Consistent with a role for NINL in host immunity, we demonstrate that NINL knockout cells exhibit an impaired response to interferon, resulting in increased permissiveness to viral replication. Moreover, we show that proteases encoded by diverse picornaviruses and coronaviruses cleave and disrupt NINL function in a host- and virus-specific manner. Our work reveals the importance of NINL in the antiviral response and the utility of using signatures of host-virus genetic conflicts to uncover new components of antiviral immunity and targets of viral antagonism.
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Affiliation(s)
- Donté Alexander Stevens
- Department of Cellular and Molecular Medicine, University of California, San DiegoLa JollaUnited States
| | | | - Swetha Mahesula
- Department of Cellular and Molecular Medicine, University of California, San DiegoLa JollaUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Miles R Corley
- Department of Molecular Biology, University of California, San DiegoLa JollaUnited States
| | - John Salogiannis
- Department of Cellular and Molecular Medicine, University of California, San DiegoLa JollaUnited States
| | - Brian V Tsu
- Department of Molecular Biology, University of California, San DiegoLa JollaUnited States
| | - Bryant Cao
- Department of Molecular Biology, University of California, San DiegoLa JollaUnited States
| | - Andrew P Ryan
- Department of Molecular Biology, University of California, San DiegoLa JollaUnited States
| | - Hiroyuki Hakozawki
- Nikon Imaging Center at UC San Diego, University of California, San DiegoSan DiegoUnited States
| | - Samara L Reck-Peterson
- Department of Cellular and Molecular Medicine, University of California, San DiegoLa JollaUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Department of Cell and Developmental Biology, University of California, San DiegoLa JollaUnited States
| | - Matthew D Daugherty
- Department of Molecular Biology, University of California, San DiegoLa JollaUnited States
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5
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Zhu Y, Cao B, Tolone A, Yan J, Christensen G, Arango-Gonzalez B, Ueffing M, Paquet-Durand F. In vitro Model Systems for Studies Into Retinal Neuroprotection. Front Neurosci 2022; 16:938089. [PMID: 35873807 PMCID: PMC9301112 DOI: 10.3389/fnins.2022.938089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
Therapy development for neurodegenerative diseases of the retina constitutes a major unmet medical need, and this may be particularly relevant for inherited diseases of the retina, which are largely untreatable to this day. Therapy development necessitates appropriate models to improve the understanding of the underlying degenerative mechanisms, as well as for the testing and evaluation of novel treatment approaches. This review provides an overview of various in vitro model systems used to study retinal neuroprotection. The in vitro methods and technologies discussed range from primary retinal cell cultures and cell lines, to retinal organoids and organotypic retinal explants, to the cultivation of whole eyeballs. The advantages and disadvantages of these methods are compared and evaluated, also in view of the 3R principles (i.e., the refinement, reduction, and replacement of live animal testing), to identify suitable in vitro alternatives for in vivo experimentation. The article further expands on the use of in vitro models to test and evaluate neuroprotective treatments and to aid the development of retinal drug delivery systems. Among the pharmacological agents tested and characterized in vitro are such that interfere with aberrant cyclic guanosine monophosphate (cGMP) -signaling or such that inhibit the activities of poly (ADP-ribose) polymerase (PARP), histone deacetylases (HDAC), calpain-type proteases, as well as unfolded protein response-related stress. We then introduce nanoparticle-based drug delivery systems and discuss how different in vitro systems may be used to assess their efficacy in the treatment of retinal diseases. The summary provides a brief comparison of available in vitro models and relates their advantages and limitations to the various experimental requirements, for instance, for studies into disease mechanisms, novel treatments, or retinal toxicity. In many cases, combinations of different in vitro models may be required to obtain a comprehensive view of the efficacy of a given retinal neuroprotection approach.
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Affiliation(s)
- Yu Zhu
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Bowen Cao
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
- Molecular Biology of Retinal Degenerations, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Arianna Tolone
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Jie Yan
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Gustav Christensen
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Blanca Arango-Gonzalez
- Molecular Biology of Retinal Degenerations, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Marius Ueffing
- Molecular Biology of Retinal Degenerations, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- *Correspondence: Marius Ueffing,
| | - François Paquet-Durand
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- François Paquet-Durand,
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6
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Zaw K, Carvalho LS, Aung-Htut MT, Fletcher S, Wilton SD, Chen FK, McLenachan S. Pathogenesis and Treatment of Usher Syndrome Type IIA. Asia Pac J Ophthalmol (Phila) 2022; 11:369-379. [PMID: 36041150 DOI: 10.1097/apo.0000000000000546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/27/2022] [Indexed: 12/16/2022] Open
Abstract
Usher syndrome (USH) is the most common form of deaf-blindness, with an estimated prevalence of 4.4 to 16.6 per 100,000 people worldwide. The most common form of USH is type IIA (USH2A), which is caused by homozygous or compound heterozygous mutations in the USH2A gene and accounts for around half of all USH cases. USH2A patients show moderate to severe hearing loss from birth, with diagnosis of retinitis pigmentosa in the second decade of life and variable vestibular involvement. Although hearing aids or cochlear implants can provide some mitigation of hearing deficits, there are currently no treatments aimed at preventing or restoring vision loss in USH2A patients. In this review, we first provide an overview of the molecular biology of the USH2A gene and its protein isoforms, which include a transmembrane protein (TM usherin) and an extracellular protein (EC usherin). The role of these proteins in the inner ear and retina and their impact on the pathogenesis of USH2A is discussed. We review animal cell-derived and patient cell-derived models currently used in USH2A research and conclude with an overview of potential treatment strategies currently in preclinical development and clinical trials.
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Affiliation(s)
- Khine Zaw
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Livia S Carvalho
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia
| | - May T Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, University of Western Australia, Nedlands, Western Australia, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, University of Western Australia, Nedlands, Western Australia, Australia
| | - Steve D Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, University of Western Australia, Nedlands, Western Australia, Australia
| | - Fred K Chen
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia
- Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Victoria, Australia
| | - Samuel McLenachan
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia
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7
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Yildirim A, Mozaffari-Jovin S, Wallisch AK, Schäfer J, Ludwig SEJ, Urlaub H, Lührmann R, Wolfrum U. SANS (USH1G) regulates pre-mRNA splicing by mediating the intra-nuclear transfer of tri-snRNP complexes. Nucleic Acids Res 2021; 49:5845-5866. [PMID: 34023904 PMCID: PMC8191790 DOI: 10.1093/nar/gkab386] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/22/2021] [Accepted: 04/28/2021] [Indexed: 02/06/2023] Open
Abstract
Splicing is catalyzed by the spliceosome, a compositionally dynamic complex assembled stepwise on pre-mRNA. We reveal links between splicing machinery components and the intrinsically disordered ciliopathy protein SANS. Pathogenic mutations in SANS/USH1G lead to Usher syndrome—the most common cause of deaf-blindness. Previously, SANS was shown to function only in the cytosol and primary cilia. Here, we have uncovered molecular links between SANS and pre-mRNA splicing catalyzed by the spliceosome in the nucleus. We show that SANS is found in Cajal bodies and nuclear speckles, where it interacts with components of spliceosomal sub-complexes such as SF3B1 and the large splicing cofactor SON but also with PRPFs and snRNAs related to the tri-snRNP complex. SANS is required for the transfer of tri-snRNPs between Cajal bodies and nuclear speckles for spliceosome assembly and may also participate in snRNP recycling back to Cajal bodies. SANS depletion alters the kinetics of spliceosome assembly, leading to accumulation of complex A. SANS deficiency and USH1G pathogenic mutations affects splicing of genes related to cell proliferation and human Usher syndrome. Thus, we provide the first evidence that splicing dysregulation may participate in the pathophysiology of Usher syndrome.
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Affiliation(s)
- Adem Yildirim
- Molecular Cell Biology, Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Germany
| | - Sina Mozaffari-Jovin
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Goettingen, Germany.,Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Bioanalytical Mass Spectrometry, Max-Planck-Institute for Biophysical Chemistry, Goettingen, Germany
| | - Ann-Kathrin Wallisch
- Molecular Cell Biology, Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Germany
| | - Jessica Schäfer
- Molecular Cell Biology, Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Germany
| | - Sebastian E J Ludwig
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Goettingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max-Planck-Institute for Biophysical Chemistry, Goettingen, Germany.,Bioanalytics, Department of Clinical Chemistry, University Medical Center Goettingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Goettingen, Germany
| | - Uwe Wolfrum
- Molecular Cell Biology, Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Germany
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8
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Sorusch N, Yildirim A, Knapp B, Janson J, Fleck W, Scharf C, Wolfrum U. SANS (USH1G) Molecularly Links the Human Usher Syndrome Protein Network to the Intraflagellar Transport Module by Direct Binding to IFT-B Proteins. Front Cell Dev Biol 2019; 7:216. [PMID: 31637240 PMCID: PMC6787559 DOI: 10.3389/fcell.2019.00216] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/18/2019] [Indexed: 01/19/2023] Open
Abstract
The human Usher syndrome (USH) is a retinal ciliopathy, characterized by profound congenital deafness, variable vestibular dysfunction and pre-pubertal onset of retinitis pigmentosa. In the effected sensory cells, USH protein networks are assumed to function in ciliary transport processes. The USH1G protein SANS is a scaffold of the ciliary/periciliary USH protein network of photoreceptor cells. Moreover, SANS is associated with microtubules, the transport routes for protein delivery toward the cilium. To enlighten the role of SANS in ciliary transport processes, we aimed to identify transport related proteins associated with SANS. The intraflagellar transport (IFT) system is a conserved mechanism for bi-directional transport toward and through primary cilia. Thus, we tested the direct binding of SANS to IFT molecules, namely IFT20, IFT57, and IFT74 in 1:1 yeast-two-hybrid assay. The identified SANS-IFT interactions were validated in vitro via independent complementary interaction assays and in cells by applying membrane targeting assays. Quantitative immunofluorescence microscopy revealed the co-localization of SANS with IFT20, IFT52, and IFT57 particularly at ciliary base of wild type mouse photoreceptor cells. Analysis of photoreceptor cells of SANS knock out mice revealed the decrease of IFTs in the ciliary compartment indicating a role of SANS in the proper positioning of IFT-B molecules in primary cilia. Our study demonstrated direct binding of IFT complex B proteins IFT52 and IFT57 to the N-terminal ankyrin repeats and the central domain of SANS. Our data also indicate that pathologic mutations in the N-terminus of SANS lead to the loos of SANS binding to IFT-B molecules. Our findings provide direct evidence for a molecular link between the ciliary USH protein network and the IFT transport module in primary cilia.
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Affiliation(s)
| | | | | | | | | | | | - Uwe Wolfrum
- Molecular Cell Biology, Institute of Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany
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9
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Qu Z, Yimer TA, Xie S, Wong F, Yu S, Liu X, Han S, Ma J, Lu Z, Hu X, Qin Y, Huang Y, Lv Y, Li J, Tang Z, Liu F, Liu M. Knocking out lca5 in zebrafish causes cone-rod dystrophy due to impaired outer segment protein trafficking. Biochim Biophys Acta Mol Basis Dis 2019; 1865:2694-2705. [PMID: 31348989 DOI: 10.1016/j.bbadis.2019.07.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/06/2019] [Accepted: 07/22/2019] [Indexed: 01/19/2023]
Abstract
Leber congenital amaurosis (LCA) is the most serious form of inherited retinal dystrophy that leads to blindness or severe visual impairment within a few months after birth. Approximately 1-2% of the reported cases are caused by mutations in the LCA5 gene. This gene encodes a ciliary protein called LCA5 that is localized to the connecting cilium of photoreceptors. The retinal phenotypes caused by LCA5 mutations and the underlying pathological mechanisms are still not well understood. In this study, we knocked out the lca5 gene in zebrafish using CRISPR/Cas9 technology. An early onset visual defect is detected by the ERG in 7 dpf lca5-/- zebrafish. Histological analysis by HE staining and immunofluorescence reveal progressive degeneration of rod and cone photoreceptors, with a pattern that cones are more severely affected than rods. In addition, ultrastructural analysis by transmission electron microscopy shows disordered and broken membrane discs in rods' and cones' outer segments, respectively. In our lca5-/- zebrafish, the red-cone opsin and cone α-transducin are selectively mislocalized to the inner segment and synaptic terminal. Moreover, we found that Ift88, a key component of the intraflagellar transport complex, is retained in the outer segments. These data suggest that the intraflagellar transport complex-mediated outer segment protein trafficking might be impaired due to lca5 deletion, which finally leads to a type of retinal degeneration mimicking the phenotype of cone-rod dystrophy in human. Our work provides a novel animal model to study the physiological function of LCA5 and develop potential treatments of LCA.
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Affiliation(s)
- Zhen Qu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Tinsae Assefa Yimer
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Shanglun Xie
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Fulton Wong
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Shanshan Yu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xiliang Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Shanshan Han
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Juanjuan Ma
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Zhaojing Lu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xuebin Hu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yayun Qin
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yuwen Huang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yuexia Lv
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Jingzhen Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Zhaohui Tang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Fei Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China.
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China.
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10
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Baehr W, Hanke-Gogokhia C, Sharif A, Reed M, Dahl T, Frederick JM, Ying G. Insights into photoreceptor ciliogenesis revealed by animal models. Prog Retin Eye Res 2018; 71:26-56. [PMID: 30590118 DOI: 10.1016/j.preteyeres.2018.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 12/10/2018] [Accepted: 12/18/2018] [Indexed: 12/11/2022]
Abstract
Photoreceptors are polarized neurons, with very specific subcellular compartmentalization and unique requirements for protein expression and trafficking. Each photoreceptor contains an outer segment, the site of photon capture that initiates vision, an inner segment that houses the biosynthetic machinery and a synaptic terminal for signal transmission to downstream neurons. Outer segments and inner segments are connected by a connecting cilium (CC), the equivalent of a transition zone (TZ) of primary cilia. The connecting cilium is part of the basal body/axoneme backbone that stabilizes the outer segment. This report will update the reader on late developments in photoreceptor ciliogenesis and transition zone formation, specifically in mouse photoreceptors, focusing on early events in photoreceptor ciliogenesis. The connecting cilium, an elongated and narrow structure through which all outer segment proteins and membrane components must traffic, functions as a gate that controls access to the outer segment. Here we will review genes and their protein products essential for basal body maturation and for CC/TZ genesis, sorted by phenotype. Emphasis is given to naturally occurring mouse mutants and gene knockouts that interfere with CC/TZ formation and ciliogenesis.
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Affiliation(s)
- Wolfgang Baehr
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA.
| | - Christin Hanke-Gogokhia
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Ali Sharif
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Michelle Reed
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Tiffanie Dahl
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Jeanne M Frederick
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Guoxin Ying
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
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11
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Kowanda M, Bergalet J, Wieczorek M, Brouhard G, Lécuyer É, Lasko P. Loss of function of the Drosophila Ninein-related centrosomal protein Bsg25D causes mitotic defects and impairs embryonic development. Biol Open 2016; 5:1040-51. [PMID: 27422905 PMCID: PMC5004617 DOI: 10.1242/bio.019638] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The centrosome-associated proteins Ninein (Nin) and Ninein-like protein (Nlp) play significant roles in microtubule stability, nucleation and anchoring at the centrosome in mammalian cells. Here, we investigate Blastoderm specific gene 25D (Bsg25D), which encodes the only Drosophila protein that is closely related to Nin and Nlp. In early embryos, we find that Bsg25D mRNA and Bsg25D protein are closely associated with centrosomes and astral microtubules. We show that sequences within the coding region and 3′UTR of Bsg25D mRNAs are important for proper localization of this transcript in oogenesis and embryogenesis. Ectopic expression of eGFP-Bsg25D from an unlocalized mRNA disrupts microtubule polarity in mid-oogenesis and compromises the distribution of the axis polarity determinant Gurken. Using total internal reflection fluorescence microscopy, we show that an N-terminal fragment of Bsg25D can bind microtubules in vitro and can move along them, predominantly toward minus-ends. While flies homozygous for a Bsg25D null mutation are viable and fertile, 70% of embryos lacking maternal and zygotic Bsg25D do not hatch and exhibit chromosome segregation defects, as well as detachment of centrosomes from mitotic spindles. We conclude that Bsg25D is a centrosomal protein that, while dispensable for viability, nevertheless helps ensure the integrity of mitotic divisions in Drosophila. Summary: In humans, mutations in Ninein or Ninein-like protein result in microcephaly and other severe diseases. We show that while flies lacking the Ninein orthologue can survive, many die as embryos with defects in mitosis.
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Affiliation(s)
- Michelle Kowanda
- Department of Biology, McGill University, Montréal, Québec H3G 0B1, Canada
| | - Julie Bergalet
- RNA Biology Unit, Institut de recherches cliniques de Montréal (IRCM), Montréal, Québec H2W 1R7, Canada
| | - Michal Wieczorek
- Department of Biology, McGill University, Montréal, Québec H3G 0B1, Canada
| | - Gary Brouhard
- Department of Biology, McGill University, Montréal, Québec H3G 0B1, Canada
| | - Éric Lécuyer
- RNA Biology Unit, Institut de recherches cliniques de Montréal (IRCM), Montréal, Québec H2W 1R7, Canada Département de Biochimie, Université de Montréal, Montréal, Québec H3T 1J4, Canada Division of Experimental Medicine, McGill University, Montréal, Québec H3A 1A3, Canada
| | - Paul Lasko
- Department of Biology, McGill University, Montréal, Québec H3G 0B1, Canada
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12
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Ribeiro JC, Oliveiros B, Pereira P, António N, Hummel T, Paiva A, Silva ED. Accelerated age-related olfactory decline among type 1 Usher patients. Sci Rep 2016; 6:28309. [PMID: 27329700 PMCID: PMC4916436 DOI: 10.1038/srep28309] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/02/2016] [Indexed: 12/22/2022] Open
Abstract
Usher Syndrome (USH) is a rare disease with hearing loss, retinitis pigmentosa and, sometimes, vestibular dysfunction. A phenotype heterogeneity is reported. Recent evidence indicates that USH is likely to belong to an emerging class of sensory ciliopathies. Olfaction has recently been implicated in ciliopathies, but the scarce literature about olfaction in USH show conflicting results. We aim to evaluate olfactory impairment as a possible clinical manifestation of USH. Prospective clinical study that included 65 patients with USH and 65 normal age-gender-smoking-habits pair matched subjects. A cross culturally validated version of the Sniffin’ Sticks olfaction test was used. Young patients with USH have significantly better olfactory scores than healthy controls. We observe that USH type 1 have a faster ageing olfactory decrease than what happens in healthy subjects, leading to significantly lower olfactory scores in older USH1 patients. Moreover, USH type 1 patients showed significantly higher olfactory scores than USH type 2, what can help distinguishing them. Olfaction represents an attractive tool for USH type classification and pre diagnostic screening due to the low cost and non-invasive nature of the testing. Olfactory dysfunction should be considered among the spectrum of clinical manifestations of Usher syndrome.
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Affiliation(s)
- João Carlos Ribeiro
- Department of Otorhinolaryngology, Coimbra University Hospitals, Portugal.,Faculty of Medicine, University of Coimbra, Portugal.,Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, Portugal
| | - Bárbara Oliveiros
- Faculty of Medicine, University of Coimbra, Portugal.,Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, Portugal
| | - Paulo Pereira
- Faculty of Medicine, University of Coimbra, Portugal.,Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, Portugal
| | | | - Thomas Hummel
- Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - António Paiva
- Department of Otorhinolaryngology, Coimbra University Hospitals, Portugal.,Faculty of Medicine, University of Coimbra, Portugal
| | - Eduardo D Silva
- Faculty of Medicine, University of Coimbra, Portugal.,Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, Portugal
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13
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Dinculescu A, Stupay RM, Deng WT, Dyka FM, Min SH, Boye SL, Chiodo VA, Abrahan CE, Zhu P, Li Q, Strettoi E, Novelli E, Nagel-Wolfrum K, Wolfrum U, Smith WC, Hauswirth WW. AAV-Mediated Clarin-1 Expression in the Mouse Retina: Implications for USH3A Gene Therapy. PLoS One 2016; 11:e0148874. [PMID: 26881841 PMCID: PMC4755610 DOI: 10.1371/journal.pone.0148874] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 01/23/2016] [Indexed: 02/07/2023] Open
Abstract
Usher syndrome type III (USH3A) is an autosomal recessive disorder caused by mutations in clarin-1 (CLRN1) gene, leading to progressive retinal degeneration and sensorineural deafness. Efforts to develop therapies for preventing photoreceptor cell loss are hampered by the lack of a retinal phenotype in the existing USH3 mouse models and by conflicting reports regarding the endogenous retinal localization of clarin-1, a transmembrane protein of unknown function. In this study, we used an AAV-based approach to express CLRN1 in the mouse retina in order to determine the pattern of its subcellular localization in different cell types. We found that all major classes of retinal cells express AAV-delivered CLRN1 driven by the ubiquitous, constitutive small chicken β-actin promoter, which has important implications for the design of future USH3 gene therapy studies. Within photoreceptor cells, AAV-expressed CLRN1 is mainly localized at the inner segment region and outer plexiform layer, similar to the endogenous expression of other usher proteins. Subretinal delivery using a full strength viral titer led to significant loss of retinal function as evidenced by ERG analysis, suggesting that there is a critical limit for CLRN1 expression in photoreceptor cells. Taken together, these results suggest that CLRN1 expression is potentially supported by a variety of retinal cells, and the right combination of AAV vector dose, promoter, and delivery method needs to be selected to develop safe therapies for USH3 disorder.
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Affiliation(s)
- Astra Dinculescu
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
- * E-mail:
| | - Rachel M. Stupay
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Wen-Tao Deng
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Frank M. Dyka
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Seok-Hong Min
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Sanford L. Boye
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Vince A. Chiodo
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Carolina E. Abrahan
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Ping Zhu
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Qiuhong Li
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | | | | | - Kerstin Nagel-Wolfrum
- Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Uwe Wolfrum
- Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - W. Clay Smith
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
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14
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Mitotic regulator Nlp interacts with XPA/ERCC1 complexes and regulates nucleotide excision repair (NER) in response to UV radiation. Cancer Lett 2016; 373:214-21. [PMID: 26805762 DOI: 10.1016/j.canlet.2016.01.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/10/2016] [Accepted: 01/11/2016] [Indexed: 11/22/2022]
Abstract
Cellular response to DNA damage, including ionizing radiation (IR) and UV radiation, is critical for the maintenance of genomic fidelity. Defects of DNA repair often result in genomic instability and malignant cell transformation. Centrosomal protein Nlp (ninein-like protein) has been characterized as an important cell cycle regulator that is required for proper mitotic progression. In this study, we demonstrate that Nlp is able to improve nucleotide excision repair (NER) activity and protects cells against UV radiation. Upon exposure of cells to UVC, Nlp is translocated into the nucleus. The C-terminus (1030-1382) of Nlp is necessary and sufficient for its nuclear import. Upon UVC radiation, Nlp interacts with XPA and ERCC1, and enhances their association. Interestingly, down-regulated expression of Nlp is found to be associated with human skin cancers, indicating that dysregulated Nlp might be related to the development of human skin cancers. Taken together, this study identifies mitotic protein Nlp as a new and important member of NER pathway and thus provides novel insights into understanding of regulatory machinery involved in NER.
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15
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Dona M, Bachmann-Gagescu R, Texier Y, Toedt G, Hetterschijt L, Tonnaer EL, Peters TA, van Beersum SEC, Bergboer JGM, Horn N, de Vrieze E, Slijkerman RWN, van Reeuwijk J, Flik G, Keunen JE, Ueffing M, Gibson TJ, Roepman R, Boldt K, Kremer H, van Wijk E. NINL and DZANK1 Co-function in Vesicle Transport and Are Essential for Photoreceptor Development in Zebrafish. PLoS Genet 2015; 11:e1005574. [PMID: 26485514 PMCID: PMC4617706 DOI: 10.1371/journal.pgen.1005574] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 09/16/2015] [Indexed: 12/04/2022] Open
Abstract
Ciliopathies are Mendelian disorders caused by dysfunction of cilia, ubiquitous organelles involved in fluid propulsion (motile cilia) or signal transduction (primary cilia). Retinal dystrophy is a common phenotypic characteristic of ciliopathies since photoreceptor outer segments are specialized primary cilia. These ciliary structures heavily rely on intracellular minus-end directed transport of cargo, mediated at least in part by the cytoplasmic dynein 1 motor complex, for their formation, maintenance and function. Ninein-like protein (NINL) is known to associate with this motor complex and is an important interaction partner of the ciliopathy-associated proteins lebercilin, USH2A and CC2D2A. Here, we scrutinize the function of NINL with combined proteomic and zebrafish in vivo approaches. We identify Double Zinc Ribbon and Ankyrin Repeat domains 1 (DZANK1) as a novel interaction partner of NINL and show that loss of Ninl, Dzank1 or both synergistically leads to dysmorphic photoreceptor outer segments, accumulation of trans-Golgi-derived vesicles and mislocalization of Rhodopsin and Ush2a in zebrafish. In addition, retrograde melanosome transport is severely impaired in zebrafish lacking Ninl or Dzank1. We further demonstrate that NINL and DZANK1 are essential for intracellular dynein-based transport by associating with complementary subunits of the cytoplasmic dynein 1 motor complex, thus shedding light on the structure and stoichiometry of this important motor complex. Altogether, our results support a model in which the NINL-DZANK1 protein module is involved in the proper assembly and folding of the cytoplasmic dynein 1 motor complex in photoreceptor cells, a process essential for outer segment formation and function. The cytoplasmic dynein 1 motor complex is known to be essential for photoreceptor outer segment formation and function. NINL, an important interaction partner of three ciliopathy-associated proteins (lebercilin, USH2A and CC2D2A), was previously shown to associate with this motor complex. In this work, we scrutinize the role of NINL using a combination of affinity proteomics and zebrafish studies, in order to gain insight into the pathogenic mechanisms underlying these three associated hereditary disorders. We identify DZANK1 as an important interaction partner of NINL and show that loss of Ninl, Dzank1, or a combination of both synergistically results in impaired transport of trans Golgi-derived vesicles and, as a consequence, defective photoreceptor outer segment formation. Using affinity proteomics, we demonstrate that NINL and DZANK1 associate with complementary subunits of the cytoplasmic dynein 1 complex. Our results support a model in which the NINL-DZANK1 protein module is essential for the proper assembly and folding of the cytoplasmic dynein 1 motor complex, shedding light on the structure and stoichiometry of this important motor complex.
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Affiliation(s)
- Margo Dona
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Ruxandra Bachmann-Gagescu
- Institute of Molecular Life Sciences, University of Zurich, Zürich, Switzerland
- Institute of Medical Genetics, University of Zurich, Zürich, Switzerland
| | - Yves Texier
- Division of Experimental Ophthalmology, and Medical Proteome Center, Centre for Ophthalmology, Eberhard Karls University Tuebingen, Tübingen, Germany
| | - Grischa Toedt
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Lisette Hetterschijt
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Edith L. Tonnaer
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Theo A. Peters
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Sylvia E. C. van Beersum
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Judith G. M. Bergboer
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Nicola Horn
- Division of Experimental Ophthalmology, and Medical Proteome Center, Centre for Ophthalmology, Eberhard Karls University Tuebingen, Tübingen, Germany
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Ralph W. N. Slijkerman
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Jeroen van Reeuwijk
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Gert Flik
- Department of Organismal Animal Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Jan E. Keunen
- Department of Ophthalmology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Marius Ueffing
- Division of Experimental Ophthalmology, and Medical Proteome Center, Centre for Ophthalmology, Eberhard Karls University Tuebingen, Tübingen, Germany
| | - Toby J. Gibson
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Ronald Roepman
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Karsten Boldt
- Division of Experimental Ophthalmology, and Medical Proteome Center, Centre for Ophthalmology, Eberhard Karls University Tuebingen, Tübingen, Germany
| | - Hannie Kremer
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, the Netherlands
- * E-mail:
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16
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Bachmann-Gagescu R, Dona M, Hetterschijt L, Tonnaer E, Peters T, de Vrieze E, Mans DA, van Beersum SEC, Phelps IG, Arts HH, Keunen JE, Ueffing M, Roepman R, Boldt K, Doherty D, Moens CB, Neuhauss SCF, Kremer H, van Wijk E. The Ciliopathy Protein CC2D2A Associates with NINL and Functions in RAB8-MICAL3-Regulated Vesicle Trafficking. PLoS Genet 2015; 11:e1005575. [PMID: 26485645 PMCID: PMC4617701 DOI: 10.1371/journal.pgen.1005575] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 09/16/2015] [Indexed: 12/16/2022] Open
Abstract
Ciliopathies are a group of human disorders caused by dysfunction of primary cilia, ubiquitous microtubule-based organelles involved in transduction of extra-cellular signals to the cell. This function requires the concentration of receptors and channels in the ciliary membrane, which is achieved by complex trafficking mechanisms, in part controlled by the small GTPase RAB8, and by sorting at the transition zone located at the entrance of the ciliary compartment. Mutations in the transition zone gene CC2D2A cause the related Joubert and Meckel syndromes, two typical ciliopathies characterized by central nervous system malformations, and result in loss of ciliary localization of multiple proteins in various models. The precise mechanisms by which CC2D2A and other transition zone proteins control protein entrance into the cilium and how they are linked to vesicular trafficking of incoming cargo remain largely unknown. In this work, we identify the centrosomal protein NINL as a physical interaction partner of CC2D2A. NINL partially co-localizes with CC2D2A at the base of cilia and ninl knockdown in zebrafish leads to photoreceptor outer segment loss, mislocalization of opsins and vesicle accumulation, similar to cc2d2a-/- phenotypes. Moreover, partial ninl knockdown in cc2d2a-/- embryos enhances the retinal phenotype of the mutants, indicating a genetic interaction in vivo, for which an illustration is found in patients from a Joubert Syndrome cohort. Similar to zebrafish cc2d2a mutants, ninl morphants display altered Rab8a localization. Further exploration of the NINL-associated interactome identifies MICAL3, a protein known to interact with Rab8 and to play an important role in vesicle docking and fusion. Together, these data support a model where CC2D2A associates with NINL to provide a docking point for cilia-directed cargo vesicles, suggesting a mechanism by which transition zone proteins can control the protein content of the ciliary compartment.
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Affiliation(s)
- Ruxandra Bachmann-Gagescu
- Institute for Molecular Life Sciences, University of Zurich, Zurich, Switzerland
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland
| | - Margo Dona
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
| | - Lisette Hetterschijt
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
| | - Edith Tonnaer
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Theo Peters
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
| | - Dorus A. Mans
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Sylvia E. C. van Beersum
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Ian G. Phelps
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
| | - Heleen H. Arts
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Jan E. Keunen
- Department of Ophthalmology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Marius Ueffing
- Division of Experimental Ophthalmology and Medical Proteome Center, Centre for Ophthalmology, Eberhard Karls University Tuebingen, Germany
| | - Ronald Roepman
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Karsten Boldt
- Division of Experimental Ophthalmology and Medical Proteome Center, Centre for Ophthalmology, Eberhard Karls University Tuebingen, Germany
| | - Dan Doherty
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
| | - Cecilia B. Moens
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | | | - Hannie Kremer
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Radboud University Medical Centre, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, the Netherlands
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17
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Boloc D, Castillo-Lara S, Marfany G, Gonzàlez-Duarte R, Abril JF. Distilling a Visual Network of Retinitis Pigmentosa Gene-Protein Interactions to Uncover New Disease Candidates. PLoS One 2015; 10:e0135307. [PMID: 26267445 PMCID: PMC4534355 DOI: 10.1371/journal.pone.0135307] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 07/20/2015] [Indexed: 01/18/2023] Open
Abstract
Background Retinitis pigmentosa (RP) is a highly heterogeneous genetic visual disorder with more than 70 known causative genes, some of them shared with other non-syndromic retinal dystrophies (e.g. Leber congenital amaurosis, LCA). The identification of RP genes has increased steadily during the last decade, and the 30% of the cases that still remain unassigned will soon decrease after the advent of exome/genome sequencing. A considerable amount of genetic and functional data on single RD genes and mutations has been gathered, but a comprehensive view of the RP genes and their interacting partners is still very fragmentary. This is the main gap that needs to be filled in order to understand how mutations relate to progressive blinding disorders and devise effective therapies. Methodology We have built an RP-specific network (RPGeNet) by merging data from different sources: high-throughput data from BioGRID and STRING databases, manually curated data for interactions retrieved from iHOP, as well as interactions filtered out by syntactical parsing from up-to-date abstracts and full-text papers related to the RP research field. The paths emerging when known RP genes were used as baits over the whole interactome have been analysed, and the minimal number of connections among the RP genes and their close neighbors were distilled in order to simplify the search space. Conclusions In contrast to the analysis of single isolated genes, finding the networks linking disease genes renders powerful etiopathological insights. We here provide an interactive interface, RPGeNet, for the molecular biologist to explore the network centered on the non-syndromic and syndromic RP and LCA causative genes. By integrating tissue-specific expression levels and phenotypic data on top of that network, a more comprehensive biological view will highlight key molecular players of retinal degeneration and unveil new RP disease candidates.
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Affiliation(s)
- Daniel Boloc
- Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Sergio Castillo-Lara
- Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Gemma Marfany
- Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Catalonia, Spain
- CIBERER, Instituto de Salud Carlos III, Barcelona, Catalonia, Spain
| | - Roser Gonzàlez-Duarte
- Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Catalonia, Spain
- CIBERER, Instituto de Salud Carlos III, Barcelona, Catalonia, Spain
- * E-mail: (JFA); (RGD)
| | - Josep F. Abril
- Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Catalonia, Spain
- * E-mail: (JFA); (RGD)
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Usher syndrome protein network functions in the retina and their relation to other retinal ciliopathies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 801:527-33. [PMID: 24664740 DOI: 10.1007/978-1-4614-3209-8_67] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human Usher syndrome (USH) is the most frequent cause of combined hereditary deaf-blindness. USH is genetically and clinically heterogeneous: 15 chromosomal loci assigned to 3 clinical types, USH1-3. All USH1 and 2 proteins are organized into protein networks by the scaffold proteins harmonin (USH1C), whirlin (USH2D) and SANS (USH1G). This has contributed essentially to our current understanding of the USH protein function in the eye and the ear and explains why defects in proteins of different families cause very similar phenotypes. Ongoing in depth analyses of USH protein networks in the eye indicated cytoskeletal functions as well as roles in molecular transport processes and ciliary cargo delivery in photoreceptor cells. The analysis of USH protein networks revealed molecular links of USH to other ciliopathies, including non-syndromic inner ear defects and isolated retinal dystrophies but also to kidney diseases and syndromes like the Bardet-Biedl syndrome. These findings provide emerging evidence that USH is a ciliopathy molecularly related to other ciliopathies, which opens an avenue for common therapy strategies to treat these diseases.
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19
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Bauß K, Knapp B, Jores P, Roepman R, Kremer H, Wijk EV, Märker T, Wolfrum U. Phosphorylation of the Usher syndrome 1G protein SANS controls Magi2-mediated endocytosis. Hum Mol Genet 2014; 23:3923-42. [PMID: 24608321 DOI: 10.1093/hmg/ddu104] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The human Usher syndrome (USH) is a complex ciliopathy with at least 12 chromosomal loci assigned to three clinical subtypes, USH1-3. The heterogeneous USH proteins are organized into protein networks. Here, we identified Magi2 (membrane-associated guanylate kinase inverted-2) as a new component of the USH protein interactome, binding to the multifunctional scaffold protein SANS (USH1G). We showed that the SANS-Magi2 complex assembly is regulated by the phosphorylation of an internal PDZ-binding motif in the sterile alpha motif domain of SANS by the protein kinase CK2. We affirmed Magi2's role in receptor-mediated, clathrin-dependent endocytosis and showed that phosphorylated SANS tightly regulates Magi2-mediated endocytosis. Specific depletions by RNAi revealed that SANS and Magi2-mediated endocytosis regulates aspects of ciliogenesis. Furthermore, we demonstrated the localization of the SANS-Magi2 complex in the periciliary membrane complex facing the ciliary pocket of retinal photoreceptor cells in situ. Our data suggest that endocytotic processes may not only contribute to photoreceptor cell homeostasis but also counterbalance the periciliary membrane delivery accompanying the exocytosis processes for the cargo vesicle delivery. In USH1G patients, mutations in SANS eliminate Magi2 binding and thereby deregulate endocytosis, lead to defective ciliary transport modules and ultimately disrupt photoreceptor cell function inducing retinal degeneration.
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Affiliation(s)
- Katharina Bauß
- Cell and Matrix Biology, Institute of Zoology, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Barbara Knapp
- Cell and Matrix Biology, Institute of Zoology, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Pia Jores
- Cell and Matrix Biology, Institute of Zoology, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Ronald Roepman
- Department of Human Genetics, Institute for Genetic and Metabolic Disease, Nijmegen Centre for Molecular Life Sciences and
| | - Hannie Kremer
- Department of Human Genetics, Department of Otorhinolaryngology, Head and Neck Surgery, Nijmegen Centre for Molecular Life Sciences and Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, 6500 HB, Nijmegen, Netherlands
| | - Erwin V Wijk
- Department of Human Genetics, Department of Otorhinolaryngology, Head and Neck Surgery, Nijmegen Centre for Molecular Life Sciences and Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, 6500 HB, Nijmegen, Netherlands
| | - Tina Märker
- Cell and Matrix Biology, Institute of Zoology, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Uwe Wolfrum
- Cell and Matrix Biology, Institute of Zoology, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
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Wheway G, Parry DA, Johnson CA. The role of primary cilia in the development and disease of the retina. Organogenesis 2014; 10:69-85. [PMID: 24162842 PMCID: PMC4049897 DOI: 10.4161/org.26710] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 10/01/2013] [Accepted: 10/04/2013] [Indexed: 02/07/2023] Open
Abstract
The normal development and function of photoreceptors is essential for eye health and visual acuity in vertebrates. Mutations in genes encoding proteins involved in photoreceptor development and function are associated with a suite of inherited retinal dystrophies, often as part of complex multi-organ syndromic conditions. In this review, we focus on the role of the photoreceptor outer segment, a highly modified and specialized primary cilium, in retinal health and disease. We discuss the many defects in the structure and function of the photoreceptor primary cilium that can cause a class of inherited conditions known as ciliopathies, often characterized by retinal dystrophy and degeneration, and highlight the recent insights into disease mechanisms.
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Affiliation(s)
- Gabrielle Wheway
- Section of Ophthalmology and Neurosciences; Leeds Institute of Molecular Medicine; The University of Leeds; Leeds, United Kingdom
| | - David A Parry
- Section of Genetics; Leeds Institute of Molecular Medicine; The University of Leeds; Leeds, United Kingdom
| | - Colin A Johnson
- Section of Ophthalmology and Neurosciences; Leeds Institute of Molecular Medicine; The University of Leeds; Leeds, United Kingdom
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21
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Abstract
The 10 different genes associated with the deaf/blind disorder, Usher syndrome, encode a number of structurally and functionally distinct proteins, most expressed as multiple isoforms/protein variants. Functional characterization of these proteins suggests a role in stereocilia development in cochlear hair cells, likely owing to adhesive interactions in hair bundles. In mature hair cells, homodimers of the Usher cadherins, cadherin 23 and protocadherin 15, interact to form a structural fiber, the tip link, and the linkages that anchor the taller stereocilia's actin cytoskeleton core to the shorter adjacent stereocilia and the elusive mechanotransduction channels, explaining the deafness phenotype when these molecular interactions are perturbed. The conundrum is that photoreceptors lack a synonymous mechanotransduction apparatus, and so a common theory for Usher protein function in the two neurosensory cell types affected in Usher syndrome is lacking. Recent evidence linking photoreceptor cell dysfunction in the shaker 1 mouse model for Usher syndrome to light-induced protein translocation defects, combined with localization of an Usher protein interactome at the periciliary region of the photoreceptors suggests Usher proteins might regulate protein trafficking between the inner and outer segments of photoreceptors. A distinct Usher protein complex is trafficked to the ribbon synapses of hair cells, and synaptic defects have been reported in Usher mutants in both hair cells and photoreceptors. This review aims to clarify what is known about Usher protein function at the synaptic and apical poles of hair cells and photoreceptors and the prospects for identifying a unifying pathobiological mechanism to explain deaf/blindness in Usher syndrome.
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Méndez-Vidal C, González-del Pozo M, Vela-Boza A, Santoyo-López J, López-Domingo FJ, Vázquez-Marouschek C, Dopazo J, Borrego S, Antiñolo G. Whole-exome sequencing identifies novel compound heterozygous mutations in USH2A in Spanish patients with autosomal recessive retinitis pigmentosa. Mol Vis 2013; 19:2187-95. [PMID: 24227914 PMCID: PMC3820429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 11/05/2013] [Indexed: 10/25/2022] Open
Abstract
PURPOSE Retinitis pigmentosa (RP) is an inherited retinal dystrophy characterized by extreme genetic and clinical heterogeneity. Thus, the diagnosis is not always easily performed due to phenotypic and genetic overlap. Current clinical practices have focused on the systematic evaluation of a set of known genes for each phenotype, but this approach may fail in patients with inaccurate diagnosis or infrequent genetic cause. In the present study, we investigated the genetic cause of autosomal recessive RP (arRP) in a Spanish family in which the causal mutation has not yet been identified with primer extension technology and resequencing. METHODS We designed a whole-exome sequencing (WES)-based approach using NimbleGen SeqCap EZ Exome V3 sample preparation kit and the SOLiD 5500×l next-generation sequencing platform. We sequenced the exomes of both unaffected parents and two affected siblings. Exome analysis resulted in the identification of 43,204 variants in the index patient. All variants passing filter criteria were validated with Sanger sequencing to confirm familial segregation and absence in the control population. In silico prediction tools were used to determine mutational impact on protein function and the structure of the identified variants. RESULTS Novel Usher syndrome type 2A (USH2A) compound heterozygous mutations, c.4325T>C (p.F1442S) and c.15188T>G (p.L5063R), located in exons 20 and 70, respectively, were identified as probable causative mutations for RP in this family. Family segregation of the variants showed the presence of both mutations in all affected members and in two siblings who were apparently asymptomatic at the time of family ascertainment. Clinical reassessment confirmed the diagnosis of RP in these patients. CONCLUSIONS Using WES, we identified two heterozygous novel mutations in USH2A as the most likely disease-causing variants in a Spanish family diagnosed with arRP in which the cause of the disease had not yet been identified with commonly used techniques. Our data reinforce the clinical role of WES in the molecular diagnosis of highly heterogeneous genetic diseases where conventional genetic approaches have previously failed in achieving a proper diagnosis.
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Affiliation(s)
- Cristina Méndez-Vidal
- Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Seville, Spain
| | - María González-del Pozo
- Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Seville, Spain
| | - Alicia Vela-Boza
- Medical Genome Project, Genomics and Bioinformatics Platform of Andalusia (GBPA), Seville, Spain
| | - Javier Santoyo-López
- Medical Genome Project, Genomics and Bioinformatics Platform of Andalusia (GBPA), Seville, Spain
| | | | | | - Joaquin Dopazo
- Medical Genome Project, Genomics and Bioinformatics Platform of Andalusia (GBPA), Seville, Spain,Department of Bioinformatics, Centro de Investigación Príncipe Felipe, Valencia, Spain,Functional Genomics Node (INB), Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Salud Borrego
- Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Seville, Spain
| | - Guillermo Antiñolo
- Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Seville, Spain,Medical Genome Project, Genomics and Bioinformatics Platform of Andalusia (GBPA), Seville, Spain
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23
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Corton M, Avila-Fernandez A, Vallespín E, López-Molina MI, Almoguera B, Martín-Garrido E, Tatu SD, Khan MI, Blanco-Kelly F, Riveiro-Alvarez R, Brión M, García-Sandoval B, Cremers FPM, Carracedo A, Ayuso C. Involvement of LCA5 in Leber congenital amaurosis and retinitis pigmentosa in the Spanish population. Ophthalmology 2013; 121:399-407. [PMID: 24144451 DOI: 10.1016/j.ophtha.2013.08.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 07/29/2013] [Accepted: 08/21/2013] [Indexed: 10/26/2022] Open
Abstract
OBJECTIVE We aimed to identify novel genetic defects in the LCA5 gene underlying Leber congenital amaurosis (LCA) in the Spanish population and to describe the associated phenotype. DESIGN Case series. PARTICIPANTS A cohort of 217 unrelated Spanish families affected by autosomal recessive or isolated retinal dystrophy, that is, 79 families with LCA and 138 families with early-onset retinitis pigmentosa (EORP). A total of 100 healthy, unrelated Spanish individuals were screened as controls. METHODS High-resolution homozygosity mapping was performed in 44 patients with LCA using genome-wide single nucleotide polymorphism (SNP) microarrays. Direct sequencing of the LCA5 gene was performed in 5 patients who showed homozygous regions at chromosome 6 and in 173 unrelated individuals with LCA or EORP. The ophthalmic history of 8 patients carrying LCA5 mutations was reviewed and additional examinations were performed, including electroretinography (ERG), optical coherence tomography (OCT), and fundus photography. MAIN OUTCOME MEASURES Single nucleotide polymorphism genotyping, identity-by-descent (IBD) regions, LCA5 mutations, best-corrected visual acuity, visual field assessments, fundus appearance, ERG, and OCT findings. RESULTS Four novel and 2 previously reported LCA5 mutations have been identified in 6 unrelated families with LCA by homozygosity mapping or Sanger sequencing. Thus, LCA5 mutations have a frequency of 7.6% in the Spanish population. However, no LCA5 mutations were found in 138 patients with EORP. Although most of the identified LCA5 mutations led to a truncated protein, a likely pathogenic missense variant was identified for the first time as a cause of LCA, segregating in 2 families. We also have characterized a novel splicing site mutation at the RNA level, demonstrating that the mutant LCA5 transcript was absent in a patient. All patients carrying LCA5 mutations presented nystagmus, night blindness, and progressive loss of visual acuity and visual field leading to blindness toward the third decade of life. Fundoscopy showed fundus features of pigmentary retinopathy with atrophic macular lesions. CONCLUSIONS This work reveals a higher frequency of LCA5 mutations in a Spanish LCA cohort than in other populations. This study established gene-specific frequencies and the underlying phenotype of LCA5 mutations in the Spanish population.
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Affiliation(s)
- Marta Corton
- Department of Genetics, IIS - Fundación Jiménez Díaz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - Almudena Avila-Fernandez
- Department of Genetics, IIS - Fundación Jiménez Díaz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - Elena Vallespín
- Instituto de Genética Médica y Molecular, IdiPaz, Hospital Universitario La Paz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - María Isabel López-Molina
- Department of Ophthalmology, Fundación Jiménez Díaz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - Berta Almoguera
- Department of Genetics, IIS - Fundación Jiménez Díaz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - Esther Martín-Garrido
- Department of Genetics, IIS - Fundación Jiménez Díaz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - Sorina D Tatu
- Department of Genetics, IIS - Fundación Jiménez Díaz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - M Imran Khan
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Fiona Blanco-Kelly
- Department of Genetics, IIS - Fundación Jiménez Díaz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - Rosa Riveiro-Alvarez
- Department of Genetics, IIS - Fundación Jiménez Díaz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - María Brión
- Genetics of Cardiovascular and Ophthalmologic Diseases, Instituto de Investigación Sanitaria de Santiago de Compostela, RIC, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - Blanca García-Sandoval
- Department of Ophthalmology, Fundación Jiménez Díaz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Angel Carracedo
- Genomic Medicine Group-USC, Fundación Publica Galega de Medicina Xenómica, Santiago de Compostela, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain
| | - Carmen Ayuso
- Department of Genetics, IIS - Fundación Jiménez Díaz, Madrid, Spain; Centre for Biomedical Network Research on Rare Diseases, ISCIII, Valencia, Spain.
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24
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Eisenberger T, Slim R, Mansour A, Nauck M, Nürnberg G, Nürnberg P, Decker C, Dafinger C, Ebermann I, Bergmann C, Bolz HJ. Targeted next-generation sequencing identifies a homozygous nonsense mutation in ABHD12, the gene underlying PHARC, in a family clinically diagnosed with Usher syndrome type 3. Orphanet J Rare Dis 2012; 7:59. [PMID: 22938382 PMCID: PMC3518140 DOI: 10.1186/1750-1172-7-59] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 08/29/2012] [Indexed: 12/21/2022] Open
Abstract
Background Usher syndrome (USH) is an autosomal recessive genetically heterogeneous disorder with congenital sensorineural hearing impairment and retinitis pigmentosa (RP). We have identified a consanguineous Lebanese family with two affected members displaying progressive hearing loss, RP and cataracts, therefore clinically diagnosed as USH type 3 (USH3). Our study was aimed at the identification of the causative mutation in this USH3-like family. Methods Candidate loci were identified using genomewide SNP-array-based homozygosity mapping followed by targeted enrichment and next-generation sequencing. Results Using a capture array targeting the three identified homozygosity-by-descent regions on chromosomes 1q43-q44, 20p13-p12.2 and 20p11.23-q12, we identified a homozygous nonsense mutation, p.Arg65X, in ABHD12 segregating with the phenotype. Conclusion Mutations of ABHD12, an enzyme hydrolyzing an endocannabinoid lipid transmitter, cause PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa, and early-onset cataract). After the identification of the ABHD12 mutation in this family, one patient underwent neurological examination which revealed ataxia, but no polyneuropathy. ABHD12 is not known to be related to the USH protein interactome. The phenotype of our patient represents a variant of PHARC, an entity that should be taken into account as differential diagnosis for USH3. Our study demonstrates the potential of comprehensive genetic analysis for improving the clinical diagnosis.
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Affiliation(s)
- Tobias Eisenberger
- Bioscientia Center for Human Genetics, Konrad Adenauer-Str, 17, Ingelheim 55218, Germany
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Nek2 localises to the distal portion of the mother centriole/basal body and is required for timely cilium disassembly at the G2/M transition. Eur J Cell Biol 2012; 91:675-86. [PMID: 22613497 DOI: 10.1016/j.ejcb.2012.03.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 03/21/2012] [Accepted: 03/29/2012] [Indexed: 01/12/2023] Open
Abstract
The NIMA-related kinase Nek2 promotes centrosome separation at the G2/M transition and, consistent with this role, is known to be concentrated at the proximal ends of centrioles. Here, we show by immunofluorescence microscopy that Nek2 also localises to the distal portion of the mother centriole. Its accumulation at this site is cell cycle-dependent and appears to peak in late G2. These findings are consistent with previous data implicating Nek2 in promoting reorganisation of centrosome-anchored microtubules at the G2/M transition, given that microtubules are anchored at the subdistal appendages of the mother centriole in interphase. In addition, we report that siRNA-mediated depletion of Nek2 compromises the ability of cells to resorb primary cilia before the onset of mitosis, while overexpression of catalytically active Nek2A reduces ciliation and cilium length in serum-starved cells. Based on these findings, we propose that Nek2 has a role in promoting cilium disassembly at the onset of mitosis. We also present evidence that recruitment of Nek2 to the proximal ends of centrioles is dependent on one of its substrates, the centrosome cohesion protein C-Nap1.
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26
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Kersten FF, van Wijk E, Hetterschijt L, Bauβ K, Peters TA, Aslanyan MG, van der Zwaag B, Wolfrum U, Keunen JE, Roepman R, Kremer H. The mitotic spindle protein SPAG5/Astrin connects to the Usher protein network postmitotically. Cilia 2012; 1:2. [PMID: 23351521 PMCID: PMC3541543 DOI: 10.1186/2046-2530-1-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 04/25/2012] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED BACKGROUND Mutations in the gene for Usher syndrome 2A (USH2A) are causative for non-syndromic retinitis pigmentosa and Usher syndrome, a condition that is the most common cause of combined deaf-blindness. To gain insight into the molecular pathology underlying USH2A-associated retinal degeneration, we aimed to identify interacting proteins of USH2A isoform B (USH2AisoB) in the retina. RESULTS We identified the centrosomal and microtubule-associated protein sperm-associated antigen (SPAG)5 in the retina. SPAG5 was also found to interact with another previously described USH2AisoB interaction partner: the centrosomal ninein-like protein NINLisoB. Using In situ hybridization, we found that Spag5 was widely expressed during murine embryonic development, with prominent signals in the eye, cochlea, brain, kidney and liver. SPAG5 expression in adult human tissues was detected by quantitative PCR, which identified expression in the retina, brain, intestine, kidney and testis. In the retina, Spag5, Ush2aisoB and NinlisoB were present at several subcellular structures of photoreceptor cells, and colocalized at the basal bodies. CONCLUSIONS Based on these results and on the suggested roles for USH proteins in vesicle transport and providing structural support to both the inner ear and the retina, we hypothesize that SPAG5, USH2AisoB and NINLisoB may function together in microtubule-based cytoplasmic trafficking of proteins that are essential for cilium formation, maintenance and/or function.
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Affiliation(s)
- Ferry Fj Kersten
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, The Netherlands.
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Miyadera K, Acland GM, Aguirre GD. Genetic and phenotypic variations of inherited retinal diseases in dogs: the power of within- and across-breed studies. Mamm Genome 2012; 23:40-61. [PMID: 22065099 PMCID: PMC3942498 DOI: 10.1007/s00335-011-9361-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 09/26/2011] [Indexed: 12/31/2022]
Abstract
Considerable clinical and molecular variations have been known in retinal blinding diseases in man and also in dogs. Different forms of retinal diseases occur in specific breed(s) caused by mutations segregating within each isolated breeding population. While molecular studies to find genes and mutations underlying retinal diseases in dogs have benefited largely from the phenotypic and genetic uniformity within a breed, within- and across-breed variations have often played a key role in elucidating the molecular basis. The increasing knowledge of phenotypic, allelic, and genetic heterogeneities in canine retinal degeneration has shown that the overall picture is rather more complicated than initially thought. Over the past 20 years, various approaches have been developed and tested to search for genes and mutations underlying genetic traits in dogs, depending on the availability of genetic tools and sample resources. Candidate gene, linkage analysis, and genome-wide association studies have so far identified 24 mutations in 18 genes underlying retinal diseases in at least 58 dog breeds. Many of these genes have been associated with retinal diseases in humans, thus providing opportunities to study the role in pathogenesis and in normal vision. Application in therapeutic interventions such as gene therapy has proven successful initially in a naturally occurring dog model followed by trials in human patients. Other genes whose human homologs have not been associated with retinal diseases are potential candidates to explain equivalent human diseases and contribute to the understanding of their function in vision.
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Affiliation(s)
- Keiko Miyadera
- Section of Ophthalmology, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 3900 Delancey St., Philadelphia, PA 19104, USA
| | - Gregory M. Acland
- James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Hungerford Hill Rd., Ithaca, NY 14853, USA
| | - Gustavo D. Aguirre
- Section of Ophthalmology, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 3900 Delancey St., Philadelphia, PA 19104, USA
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Yang J, Wang L, Song H, Sokolov M. Current understanding of usher syndrome type II. Front Biosci (Landmark Ed) 2012; 17:1165-83. [PMID: 22201796 DOI: 10.2741/3979] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Usher syndrome is the most common deafness-blindness caused by genetic mutations. To date, three genes have been identified underlying the most prevalent form of Usher syndrome, the type II form (USH2). The proteins encoded by these genes are demonstrated to form a complex in vivo. This complex is localized mainly at the periciliary membrane complex in photoreceptors and the ankle-link of the stereocilia in hair cells. Many proteins have been found to interact with USH2 proteins in vitro, suggesting that they are potential additional components of this USH2 complex and that the genes encoding these proteins may be the candidate USH2 genes. However, further investigations are critical to establish their existence in the USH2 complex in vivo. Based on the predicted functional domains in USH2 proteins, their cellular localizations in photoreceptors and hair cells, the observed phenotypes in USH2 mutant mice, and the known knowledge about diseases similar to USH2, putative biological functions of the USH2 complex have been proposed. Finally, therapeutic approaches for this group of diseases are now being actively explored.
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Affiliation(s)
- Jun Yang
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, Utah 84132
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29
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Direct interaction of the Usher syndrome 1G protein SANS and myomegalin in the retina. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1883-92. [PMID: 21767579 DOI: 10.1016/j.bbamcr.2011.05.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 05/18/2011] [Accepted: 05/19/2011] [Indexed: 01/21/2023]
Abstract
The human Usher syndrome (USH) is the most frequent cause of combined hereditary deaf-blindness. USH is genetically heterogeneous with at least 11 chromosomal loci assigned to 3 clinical types, USH1-3. We have previously demonstrated that all USH1 and 2 proteins in the eye and the inner ear are organized into protein networks by scaffold proteins. This has contributed essentially to our current understanding of the function of USH proteins and explains why defects in proteins of different families cause very similar phenotypes. We have previously shown that the USH1G protein SANS (scaffold protein containing ankyrin repeats and SAM domain) contributes to the periciliary protein network in retinal photoreceptor cells. This study aimed to further elucidate the role of SANS by identifying novel interaction partners. In yeast two-hybrid screens of retinal cDNA libraries we identified 30 novel putative interacting proteins binding to the central domain of SANS (CENT). We confirmed the direct binding of the phosphodiesterase 4D interacting protein (PDE4DIP), a Golgi associated protein synonymously named myomegalin, to the CENT domain of SANS by independent assays. Correlative immunohistochemical and electron microscopic analyses showed a co-localization of SANS and myomegalin in mammalian photoreceptor cells in close association with microtubules. Based on the present results we propose a role of the SANS-myomegalin complex in microtubule-dependent inner segment cargo transport towards the ciliary base of photoreceptor cells.
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Boldt K, Mans DA, Won J, van Reeuwijk J, Vogt A, Kinkl N, Letteboer SJF, Hicks WL, Hurd RE, Naggert JK, Texier Y, den Hollander AI, Koenekoop RK, Bennett J, Cremers FPM, Gloeckner CJ, Nishina PM, Roepman R, Ueffing M. Disruption of intraflagellar protein transport in photoreceptor cilia causes Leber congenital amaurosis in humans and mice. J Clin Invest 2011; 121:2169-80. [PMID: 21606596 DOI: 10.1172/jci45627] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Accepted: 04/12/2011] [Indexed: 01/19/2023] Open
Abstract
The mutations that cause Leber congenital amaurosis (LCA) lead to photoreceptor cell death at an early age, causing childhood blindness. To unravel the molecular basis of LCA, we analyzed how mutations in LCA5 affect the connectivity of the encoded protein lebercilin at the interactome level. In photoreceptors, lebercilin is uniquely localized at the cilium that bridges the inner and outer segments. Using a generally applicable affinity proteomics approach, we showed that lebercilin specifically interacted with the intraflagellar transport (IFT) machinery in HEK293T cells. This interaction disappeared when 2 human LCA-associated lebercilin mutations were introduced, implicating a specific disruption of IFT-dependent protein transport, an evolutionarily conserved basic mechanism found in all cilia. Lca5 inactivation in mice led to partial displacement of opsins and light-induced translocation of arrestin from photoreceptor outer segments. This was consistent with a defect in IFT at the connecting cilium, leading to failure of proper outer segment formation and subsequent photoreceptor degeneration. These data suggest that lebercilin functions as an integral element of selective protein transport through photoreceptor cilia and provide a molecular demonstration that disrupted IFT can lead to LCA.
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Affiliation(s)
- Karsten Boldt
- Division of Experimental Ophthalmology and Medical Proteome Center, Center of Ophthalmology, University of Tübingen, Tübingen, Germany
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Li J, Zhan Q. The role of centrosomal Nlp in the control of mitotic progression and tumourigenesis. Br J Cancer 2011; 104:1523-8. [PMID: 21505454 PMCID: PMC3101908 DOI: 10.1038/bjc.2011.130] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The human centrosomal ninein-like protein (Nlp) is a new member of the γ-tubulin complexes binding proteins (GTBPs) that is essential for proper execution of various mitotic events. The primary function of Nlp is to promote microtubule nucleation that contributes to centrosome maturation, spindle formation and chromosome segregation. Its subcellular localisation and protein stability are regulated by several crucial mitotic kinases, such as Plk1, Nek2, Cdc2 and Aurora B. Several lines of evidence have linked Nlp to human cancer. Deregulation of Nlp in cell models results in aberrant spindle, chromosomal missegregation and multinulei, and induces chromosomal instability and renders cells tumourigenic. Overexpression of Nlp induces anchorage-independent growth and immortalised primary cell transformation. In addition, we first demonstrate that the expression of Nlp is elevated primarily due to NLP gene amplification in human breast cancer and lung carcinoma. Consistently, transgenic mice overexpressing Nlp display spontaneous tumours in breast, ovary and testicle, and show rapid onset of radiation-induced lymphoma, indicating that Nlp is involved in tumourigenesis. This review summarises our current knowledge of physiological roles of Nlp, with an emphasis on its potentials in tumourigenesis.
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Affiliation(s)
- J Li
- State Key Laboratory of Molecular Oncology, Cancer Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
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Wright AF, Chakarova CF, Abd El-Aziz MM, Bhattacharya SS. Photoreceptor degeneration: genetic and mechanistic dissection of a complex trait. Nat Rev Genet 2010; 11:273-84. [PMID: 20212494 DOI: 10.1038/nrg2717] [Citation(s) in RCA: 445] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Jacobson SG, Aleman TS, Cideciyan AV, Sumaroka A, Schwartz SB, Windsor EA, Swider M, Herrera W, Stone EM. Leber congenital amaurosis caused by Lebercilin (LCA5) mutation: retained photoreceptors adjacent to retinal disorganization. Mol Vis 2009; 15:1098-106. [PMID: 19503738 PMCID: PMC2690955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Accepted: 05/22/2009] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To determine the retinal disease expression in the rare form of Leber congenital amaurosis (LCA) caused by Lebercilin (LCA5) mutation. METHODS Two young unrelated LCA patients, ages six years (P1) and 25 years (P2) at last visit, both with the same homozygous mutation in the LCA5 gene, were evaluated clinically and with noninvasive studies. En face imaging was performed with near-infrared (NIR) reflectance and autofluorescence (AF); cross-sectional retinal images were obtained with optical coherence tomography (OCT). Dark-adapted thresholds were measured in the older patient; and the transient pupillary light reflex was recorded and quantified in both patients. RESULTS Both LCA5 patients had light perception vision only, hyperopia, and nystagmus. P1 showed a prominent central island of retinal pigment epithelium (RPE) surrounded by alternating elliptical-appearing areas of decreased and increased pigmentation. Retinal laminar architecture at and near the fovea was abnormal in both patients. Foveal outer nuclear layer (ONL) was present in P1 and P2 but to different degrees. With increasing eccentricity, there was retinal laminar disorganization. Regions of pericentral and midperipheral retina in P1, but not P2, could retain measurable ONL and less laminopathy. P2 had a small central island of perception with >5 log units of sensitivity loss. Pupillary responsiveness was present in both LCA5 patients; the thresholds were abnormally elevated by >or=5.5 log units. CONCLUSIONS LCA5 patients had evidence of retained photoreceptors mainly in the central retina. Retinal remodeling was present in pericentral regions in both patients. The NIR reflectance and NIR-AF imaging in the younger patient suggested preserved RPE in retinal regions with retained photoreceptors. Detailed phenotype studies in other LCA5 patients with longitudinal follow-up will help determine the feasibility of future intervention in this rare disease.
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Affiliation(s)
- Samuel G. Jacobson
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA
| | - Tomas S. Aleman
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA
| | - Artur V. Cideciyan
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA
| | - Alexander Sumaroka
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA
| | - Sharon B. Schwartz
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA
| | - Elizabeth A.M. Windsor
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA
| | - Malgorzata Swider
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA
| | - Waldo Herrera
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA
| | - Edwin M. Stone
- Howard Hughes Medical Institute and Department of Ophthalmology, University of Iowa Hospitals and Clinics, Iowa City, IA
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