Open Sesame: How Transition Fibers and the Transition Zone Control Ciliary Composition

Total Page:16

File Type:pdf, Size:1020Kb

Open Sesame: How Transition Fibers and the Transition Zone Control Ciliary Composition Downloaded from http://cshperspectives.cshlp.org/ on September 29, 2021 - Published by Cold Spring Harbor Laboratory Press Open Sesame: How Transition Fibers and the Transition Zone Control Ciliary Composition Francesc R. Garcia-Gonzalo1 and Jeremy F. Reiter2 1Departamento de Bioquı´mica, Facultad de Medicina, and Instituto de Investigaciones Biome´dicas Alberto Sols UAM-CSIC, Universidad Auto´noma de Madrid, 28029 Madrid, Spain 2Department of Biochemistry and Biophysics, and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California 94158 Correspondence: [email protected]; [email protected] Cilia are plasma membrane protrusions that act as cellular propellers or antennae. Toperform these functions, cilia must maintain a composition distinct from those of the contiguous cytosol and plasma membrane. The specialized composition of the cilium depends on the ciliary gate, the region at the ciliary base separating the cilium from the rest of the cell. The ciliary gate’s main structural features are electron dense struts connecting microtubules to the adjacent membrane. These structures include the transition fibers, which connect the distal basal body to the base of the ciliary membrane, and the Y-links,which connect the proximal axoneme and ciliary membrane within the transition zone. Both transition fibers and Y-links form early during ciliogenesis and play key roles in ciliary assembly and trafficking. Accordingly, many human ciliopathies are caused by mutations that perturb ciliary gate function. ilia are born from the docking of a mother to form. This proximal region of the cilium, Ccentriole to a membrane. The interaction known as the transition zone (TZ), begins at of centriole and membrane depends on the the distal end of the basal body and is de- centriolar distal appendages, whose tips anchor fined by the presence of Y-links, bifid fibers to the membrane. In the context of ciliogene- connecting each TZ microtubule doublet to sis, these membrane-anchored distal append- the adjacent membrane (Fig. 1). Perhaps be- ages are often referred to as transition fibers cause of their tethering to microtubules, ciliary (TFs) (Fig. 1). After this early ciliogenic step, gate membranes are particularly resistant to the nine concentric microtubule triplets in the detergent extraction and harbor specialized centriole, now referred to as the basal body, act proteinaceous structures like the ciliary neck- as templates onto which the nine axonemal lace (Fig. 1) (Gilula and Satir 1972; Horst et al. microtubule doublets are constructed. Because 1987). axoneme growth and disassembly occur only at The ciliary gate sits at the juncture between its distal tip, the basal-most axoneme is the first the basal body and axoneme, between the plas- Editors: Wallace Marshall and Renata Basto Additional Perspectives on Cilia available at www.cshperspectives.org Copyright # 2016 Cold Spring Harbor Laboratory Press; all rights reserved Advanced Online Article. Cite this article as Cold Spring Harb Perspect Biol doi: 10.1101/cshperspect.a028134 1 Downloaded from http://cshperspectives.cshlp.org/ on September 29, 2021 - Published by Cold Spring Harbor Laboratory Press F.R. Garcia-Gonzalo and J.F. Reiter A B Transition fibers Transition zone tf Ciliary membrane Ciliary lumen Transverse Axoneme Y-links Transition zone Ciliary Longitudinal * necklace C Ciliary gate Transition fibers Plasma membrane Basal body Figure 1. Ultrastructure of the ciliary gate. (A) Schematic showing the different parts of a cilium, with emphasis on the ciliary gate comprised by the transition fibers and the transition zone. (From Reiter et al. 2012; adapted, with permission, from the authors.) (B) Electron microscopic images of the transition fibers and transition zone. Left panels show transition fibers in transverse. (Top, from O’Toole et al. 2003; adapted, with permission, from the American Society for Cell Biology # 2003; and longitudinal [bottom] views from Tateishi et al. 2013; reprinted under a Creative Commons License [Attribution–Noncommercial–Share Alike 3.0 Unported li- cense, as described at creativecommons.org/licenses/by-nc-sa/3.0].) Arrows point to transition fibers (tf ). Right panels show transverse and longitudinal views of transition zones from rat photoreceptor connecting cilia (From data in Horst et al. 1987; adapted, with permission, from the authors.) Arrows point to Y-links. Asterisk marks the distal end of the transition zone (TZ). (C) Freeze-fracture etching of the ciliary necklace of a rat tracheal cilium. (Image adapted from data in Gilula and Satir 1972.) Arrowheads point to beads in the ciliary necklace. ma membrane and ciliary membrane, and be- gate region. We conclude by identifying out- tween the cytosol and ciliary lumen (Fig. 1), and standing questions in the field. thus is in a position to regulate proteins enter- ing and exiting the cilium. A decade ago, little was known about this region other than its ul- TRANSITION FIBERS trastructure. The last 10 years, however, have Transition Fiber Architecture changed that: proteomes and interactomes of the ciliary gate and several of its components Basal bodies start their lives as mother centri- have been generated, superresolution microsco- oles, distinguished from daughter centrioles by py has helped localize several gate components, the distal appendages through which they dock loss of function genetic studies have elucidated to the vesicles that are eventually remodeled functional modules, and many ciliary gate genes into the ciliary membrane (Sorokin 1962; Lu have been linked to specific human ciliopathies. et al. 2015). When associated with the ciliary We are now at the point where an integrated membrane or its precursors, centriolar distal understanding of how the ciliary gate controls appendages are referred to as transition fibers ciliary composition can be anticipated. Below, (TFs) or alar sheets. Although the former term we review the architecture, composition, func- has gained general acceptance, the latter is evoc- tion, and disease involvement of each ciliary ative of their shape: wing-like trapezoidal sheets 2 Advanced Online Article. Cite this article as Cold Spring Harb Perspect Biol doi: 10.1101/cshperspect.a028134 Downloaded from http://cshperspectives.cshlp.org/ on September 29, 2021 - Published by Cold Spring Harbor Laboratory Press Controlling Ciliary Composition (Anderson 1972). There are nine TFs, each of ranged to give rise to these structures remains to which emerges from the distal portion of the C- be determined. tubule of the basal body and ends at an electron dense knob at the most proximal ciliary mem- Transition Fiber Functions brane (Fig. 1) (Gibbons and Grimstone 1960; Ringo 1967). Cross sections suggest that there is An early step in ciliogenesis is the recruitment of 60 nm between adjacent TFs, enough so that a small vesicles to the distal appendages of a ribosome, but not a vesicle, might pass between mother centriole, the distal appendage vesicles them (Nachury et al. 2010). Because the basal (DAVs). The DAVs fuse to form a larger ciliary body lumen is obstructed by centrin-2-con- vesicle that caps the distal centriole in a process taining electron dense structures (Fisch and that depends on EHD1 and EHD3 (Lu et al. Dupuis-Williams 2011), these spaces between 2015). Expansion of this ciliary vesicle gives TFs are likely to be the main passageways rise to the ciliary membrane, which is assem- for macromolecules entering and exiting the bled in parallel with the axoneme. Axoneme cilium. outgrowth is associated with removal from the The TF is comprised of at least five proteins distal mother centriole of CP110, a protein with (Graser et al. 2007; Sillibourne et al. 2011; Joo both positive and negative roles in early cilio- et al. 2013; Tanos et al. 2013). Hierarchical lo- genesis (Spektor et al. 2007; Tsang et al. 2008; calization analysis shows that Cep83 (also called Kobayashi et al. 2011; Yadav et al. 2016). Axo- Ccdc41) is required for the localization of neme formation also involves the construction Cep89 (also called Ccdc123 or Cep123) and of the TZ and recruitment of intraflagellar Sclt1, and the latter is required for localizing transport (IFT) particles, the microtubule mo- Fbf1 and Cep164 (Tanos et al. 2013). Many of tor-driven complexes that mediate ciliary trans- these core TF components are required for basal port and assembly (Lu et al. 2015). body docking to a membrane and ciliogenesis Disrupting distal appendage formation or (Schmidt et al. 2012; Tanos et al. 2013; Joo et al. function (e.g., interfering with Ofd1, C2cd3, 2013; Tateishi et al. 2013; Burke et al. 2014; Ye Odf2, Cep164, or Cep83) blocks ciliogenesis et al. 2014). Another protein, Chibby (Cby1), is and, in all cases where it has been examined, recruited to TFs by Cep164 and extends toward prevents DAV formation (Singla et al. 2010; the proximal TZ, but is dispensable for at least Schmidt et al. 2012; Joo et al. 2013; Tanos et al. some forms of ciliogenesis (Voronina et al. 2013; Tateishi et al. 2013; Burke et al. 2014; 2009; Burke et al. 2014; Lee et al. 2014). In Thauvin-Robinet et al. 2014; Ye et al. 2014). turn, TF localization of all the above proteins Moreover, TFs are essential to remove CP110 requires components of the distal centriole, in- from the distal centriole and recruit TZ and cluding Ofd1 and C2cd3, two proteins that, de- IFT proteins to the ciliary base (Deane et al. spite their shared role in building the distal ap- 2001; Schmidt et al. 2012; Joo et al. 2013; Tanos pendages, exert opposite effects on centriole et al. 2013; Cˇ aja´nek and Nigg 2014; Ye et al. length (Singla et al. 2010; Thauvin-Robinet 2014). et al. 2014; Ye et al. 2014), and Odf2 (Cenexin), Cep164 is a key TF component that pro- a Cby1 interactor required for the formation of motes ciliogenesis through several mechanisms. both distal and subdistal centriolar appendages First, facilitated by Cby1, Cep164 interacts with (Ishikawa et al.
Recommended publications
  • Educational Paper Ciliopathies
    Eur J Pediatr (2012) 171:1285–1300 DOI 10.1007/s00431-011-1553-z REVIEW Educational paper Ciliopathies Carsten Bergmann Received: 11 June 2011 /Accepted: 3 August 2011 /Published online: 7 September 2011 # The Author(s) 2011. This article is published with open access at Springerlink.com Abstract Cilia are antenna-like organelles found on the (NPHP) . Ivemark syndrome . Meckel syndrome (MKS) . surface of most cells. They transduce molecular signals Joubert syndrome (JBTS) . Bardet–Biedl syndrome (BBS) . and facilitate interactions between cells and their Alstrom syndrome . Short-rib polydactyly syndromes . environment. Ciliary dysfunction has been shown to Jeune syndrome (ATD) . Ellis-van Crefeld syndrome (EVC) . underlie a broad range of overlapping, clinically and Sensenbrenner syndrome . Primary ciliary dyskinesia genetically heterogeneous phenotypes, collectively (Kartagener syndrome) . von Hippel-Lindau (VHL) . termed ciliopathies. Literally, all organs can be affected. Tuberous sclerosis (TSC) . Oligogenic inheritance . Modifier. Frequent cilia-related manifestations are (poly)cystic Mutational load kidney disease, retinal degeneration, situs inversus, cardiac defects, polydactyly, other skeletal abnormalities, and defects of the central and peripheral nervous Introduction system, occurring either isolated or as part of syn- dromes. Characterization of ciliopathies and the decisive Defective cellular organelles such as mitochondria, perox- role of primary cilia in signal transduction and cell isomes, and lysosomes are well-known
    [Show full text]
  • Unraveling the Genetics of Joubert and Meckel-Gruber Syndromes
    Journal of Pediatric Genetics 3 (2014) 65–78 65 DOI 10.3233/PGE-14090 IOS Press Unraveling the genetics of Joubert and Meckel-Gruber syndromes Katarzyna Szymanska, Verity L. Hartill and Colin A. Johnson∗ Department of Ophthalmology and Neuroscience, University of Leeds, Leeds, UK Received 27 May 2014 Revised 11 July 2014 Accepted 14 July 2014 Abstract. Joubert syndrome (JBTS) and Meckel-Gruber syndrome (MKS) are recessive neurodevelopmental conditions caused by mutations in proteins that are structural or functional components of the primary cilium. In this review, we provide an overview of their clinical diagnosis, management and molecular genetics. Both have variable phenotypes, extreme genetic heterogeneity, and display allelism both with each other and other ciliopathies. Recent advances in genetic technology have significantly improved diagnosis and clinical management of ciliopathy patients, with the delineation of some general genotype-phenotype correlations. We highlight those that are most relevant for clinical practice, including the correlation between TMEM67 mutations and the JBTS variant phenotype of COACH syndrome. The subcellular localization of the known MKS and JBTS proteins is now well-described, and we discuss some of the contemporary ideas about ciliopathy disease pathogenesis. Most JBTS and MKS proteins localize to a discrete ciliary compartment called the transition zone, and act as structural components of the so-called “ciliary gate” to regulate the ciliary trafficking of cargo proteins or lipids. Cargo proteins include enzymes and transmembrane proteins that mediate intracellular signaling. The disruption of transition zone function may contribute to the ciliopathy phenotype by altering the composition of the ciliary membrane or axoneme, with impacts on essential developmental signaling including the Wnt and Shh pathways as well as the regulation of secondary messengers such as inositol-1,4,5-trisphosphate (InsP3) and cyclic adenosine monophosphate (cAMP).
    [Show full text]
  • GENETIC STUDY of RENAL DISEASES (Nephroref Global®) by MASSIVE SEQUENCING (NGS)
    Pablo Iglesias, 57 – Polígono Gran Via Sur 08908 L'Hospitalet de Llobregat (Barcelona) Tel. 932 593 700 – Fax. 932 845 000 GENETIC STUDY OF RENAL DISEASES (NephroRef Global®) BY MASSIVE SEQUENCING (NGS) Request No.: 000 Client: - Analysis code: 55580 Patient Name: xxx Date of Birth: N/A Patient Ref.: xxx Gender: Female Sample Type: Blood EDTA Sample Arrival Date: DD/MM/AAAA Date of Result: DD/MM/AAAA Clinical information: A 9-year-old patient with a nephrotic syndrome without response to corticosteroid therapy. She has nephrotic-range proteinuria with microhematuria, hypoalbuminemia with hypercholesterolemia and normal glomerular filtration. Paternal aunt with cortico-resistant nephrotic syndrome with evolution to end-stage renal failure that required renal transplantation at age 13. RESULT AND INTERPRETATION The presence of a heterozygous likely pathogenic variant has been identified. In addition, the presence of a heterozygous variant of uncertain clinical significance (VUS) has been identified.(See Interpretation and recommendations) The complete list of studied genes is available in Annex 1. (Methodology) The list of reported genes and coverage details is available in Table 1. (Methodology) Gene Variant* Zygosity Inheritance pattern Classification^ NPHS2 NM_014625.3: c.842A>C Heterozygosis Autosomal Recessive Likely Patogénica p.(Glu281Ala) INF2 NM_022489.3: c.67T>A Heterozygosis Autosomal Recessive VUS p.(Ser23Thr) * Nomenclature according to HGVS v15.11 ^ Based on the recommendations of the American College of Medical Genetics and Genomics (ACMG) Physician, technical specialist responsible for Clinical Analysis: Jaime Torrents Pont. The results relate to samples received and analysed. This report may not be reproduced in part without permission. This document is addressed to the addressee and contains confidential information.
    [Show full text]
  • Ciliopathies Gene Panel
    Ciliopathies Gene Panel Contact details Introduction Regional Genetics Service The ciliopathies are a heterogeneous group of conditions with considerable phenotypic overlap. Levels 4-6, Barclay House These inherited diseases are caused by defects in cilia; hair-like projections present on most 37 Queen Square cells, with roles in key human developmental processes via their motility and signalling functions. Ciliopathies are often lethal and multiple organ systems are affected. Ciliopathies are London, WC1N 3BH united in being genetically heterogeneous conditions and the different subtypes can share T +44 (0) 20 7762 6888 many clinical features, predominantly cystic kidney disease, but also retinal, respiratory, F +44 (0) 20 7813 8578 skeletal, hepatic and neurological defects in addition to metabolic defects, laterality defects and polydactyly. Their clinical variability can make ciliopathies hard to recognise, reflecting the ubiquity of cilia. Gene panels currently offer the best solution to tackling analysis of genetically Samples required heterogeneous conditions such as the ciliopathies. Ciliopathies affect approximately 1:2,000 5ml venous blood in plastic EDTA births. bottles (>1ml from neonates) Ciliopathies are generally inherited in an autosomal recessive manner, with some autosomal Prenatal testing must be arranged dominant and X-linked exceptions. in advance, through a Clinical Genetics department if possible. Referrals Amniotic fluid or CV samples Patients presenting with a ciliopathy; due to the phenotypic variability this could be a diverse set should be sent to Cytogenetics for of features. For guidance contact the laboratory or Dr Hannah Mitchison dissecting and culturing, with ([email protected]) / Prof Phil Beales ([email protected]) instructions to forward the sample to the Regional Molecular Genetics Referrals will be accepted from clinical geneticists and consultants in nephrology, metabolic, laboratory for analysis respiratory and retinal diseases.
    [Show full text]
  • Evidence of Oligogenic Inheritance in Nephronophthisis
    JASN Express. Published on September 12, 2007 as doi: 10.1681/ASN.2007020243 CLINICAL RESEARCH www.jasn.org Evidence of Oligogenic Inheritance in Nephronophthisis Julia Hoefele,*† Matthias T.F. Wolf,* John F. O’Toole,* Edgar A. Otto,* Ulla Schultheiss,* Georges Deˆschenes,‡ Massimo Attanasio,* Boris Utsch,* Corinne Antignac,§ and ʈ Friedhelm Hildebrandt* ʈ Departments of *Pediatrics and Human Genetics, University of Michigan, Ann Arbor, Michigan; †Department of Pediatrics, University Children’s Hospital, University of Munich, Munich, Germany; and ‡Hoˆpital Robert Debre´, Pediatric Nephrology, AP-HP, and §INSERM, U574, Universite´ Paris Descartes, Faculte de Me´dicine Rene´ Descartes, and Hoˆpital Necker-Enfants Malades, AP-HP, Department of Genetics, Paris, France ABSTRACT Nephronophthisis is a recessive cystic renal disease that leads to end-stage renal failure in the first two decades of life. Twenty-five percent of nephronophthisis cases are caused by large homozygous deletions of NPHP1, but six genes responsible for nephronophthisis have been identified. Because oligogenic inheritance has been described for the related Bardet-Biedl syndrome, we evaluated whether mutations in more than one gene may also be detected in cases of nephronophthisis. Because the nephrocystins 1 to 4 are known to interact, we examined patients with nephronophthisis from 94 different families and sequenced all exons of the NPHP1, NPHP2, NPHP3, and NPHP4 genes. In our previous studies involving 44 families, we detected two mutations in one of the NPHP1–4 genes. Here, we detected in six families two mutations in either NPHP1, NPHP3, or NPHP4, and identified a third mutation in one of the other NPHP genes. Furthermore, we found possible digenic disease by detecting one individual who carried one mutation in NPHP2 and a second mutation in NPHP3.
    [Show full text]
  • Joubert Syndrome Genereview
    Title: Joubert Syndrome GeneReview — Molecular Genetics: Less Common Genetic Causes Authors: Parisi M, Glass I Updated: June 2017 Note: The following information is provided by the authors listed above and has not been reviewed by GeneReviews staff. Joubert Syndrome: Less Common Genetic Causes ARL13B B9D1 B9D2 CEP41 IFT172 KIF7 OFD1 (CXORF5) PDE6D POC1B TCTN1 TCTN3 TMEM138 TMEM231 TMEM237 (ALS2CR4) TTC21B ARL13B Gene structure. ARL13B is a ten-exon gene that encodes a 428-amino acid protein. Pathogenic variants. Two families with a phenotype typical of classic Joubert syndrome had missense and/or nonsense variants in this gene; one of these individuals also had evidence of a retinopathy [Cantagrel et al 2008]. Normal gene product. ARL13B encodes ADP-ribosylation factor-like protein 13B, a member of the ADP-ribosylation factor-like family. Multiple transcript variants result from alternate splicing; two protein isoforms are known. The AR13B protein is a small GTPase in the Ras superfamily that contains both N-terminal and C-terminal guanine nucleotide-binding motifs. It is localized to the cilia and plays a role in cilia formation and maintenance as well as sonic hedgehog signaling. Abnormal gene product. In C elegans, pathogenic variants in the homolog arl13 exhibit defective cilium morphology, localization, and anterograde intraflagellar transport [Cevik et al 2010]. Mice with defects in the murine ortholog have neural tube defects and polydactyly, as well as an embryonic-lethal phenotype [Cantagrel et al 2008, Doherty 2009]. B9D1. See Tables A and B. B9D2. See Tables A and B. CEP41 Gene structure. The gene consists of 11 exons and spans approximately 50 kb.
    [Show full text]
  • Renal Cystic Disorders Infosheet 6-14-19
    Next Generation Sequencing Panel for Renal Cystic Disorders Clinical Features: Renal cystic diseases are a genetically heterogeneous group of conditions characterized By isolated renal disease or renal cysts in conjunction with extrarenal features (1). Age of onset of renal cystic disease ranges from neonatal to adult onset. Common features of renal cystic diseases include renal insufficiency and progression to end stage renal disease (ESRD). Identification of the genetic etiology of renal cystic disease can aid in appropriate clinical management of the affected patient. Our Renal Cystic Disorders Panel includes sequence and deletion/duplicaton analysis of all 79 genes listed below. Renal Cystic Disorders Sequencing Panel AHI1 BMPER HNF1B NEK8 TCTN3 WDPCP ANKS6 C5orf42 IFT27 NOTCH2 TFAP2A WDR19 ARL13B CC2D2A IFT140 NPHP1 TMEM107 XPNPEP3 ARL6 CDC73 IFT172 NPHP3 TMEM138 ZNF423 B9D1 CEP104 INPP5E NPHP4 TMEM216 B9D2 CEP120 INVS OFD1 TMEM231 BBIP1 CEP164 IQCB1 PDE6D TMEM237 BBS1 CEP290 JAG1 PKD2 TMEM67 BBS10 CEP41 KIAA0556 PKHD1 TRIM32 BBS12 CEP83 KIAA0586 REN TSC1 BBS2 CRB2 KIF14 RPGRIP1L TSC2 BBS4 CSPP1 KIF7 SALL1 TTC21B BBS5 DCDC2 LZTFL1 SDCCAG8 TTC8 BBS7 GLIS2 MKKS TCTN1 UMOD BBS9 GLIS3 MKS1 TCTN2 VHL Disorder Genes Inheritance Clinical features/molecular genetics Bardet Biedl ARL6 AR Bardet-Biedl syndrome (BBS) is an autosomal syndrome BBS1 recessive multi-systemic ciliopathy characterized By BBS10 retinal dystrophy, oBesity, postaxial polydactyly, BBS12 leaning difficulties, renal involvement and BBS2 genitourinary abnormalities (2). Visual prognosis is BBS4 poor, and the mean age of legal Blindness is 15.5 BBS5 years. Birth weight is typically normal But significant BBS7 weight gain Begins within the first year. Renal BBS9 disease is a major cause of morBidity and mortality.
    [Show full text]
  • Intrafamilial Variability and Clinical Heterogeneity in Two Siblings With
    r Biomar ula ke c rs le o & M D f i a o g l Journal of Molecular Biomarkers n a o n Nabhan, et al., J Mol Biomark Diagn 2015, 6:2 r s i u s o J DOI: 10.4172/2155-9929.1000217 ISSN: 2155-9929 & Diagnosis Case Report Open Access Intrafamilial Variability and Clinical Heterogeneity in Two Siblings with NPHP4 loss of Function Mutations Marwa M Nabhan1,2, Susann Brenzinger3, Sahar N Saleem4, Edgar A Otto3, Friedhelm Hildebrandt3,5 and Neveen A Soliman1,2* 1Center of Pediatric Nephrology and Transplantation, Department of Pediatrics, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt 2Egyptian Group for Orphan Renal Diseases (EGORD), Cairo, Egypt 3Department of Pediatrics, University of Michigan, Ann Arbor, Michigan 4Radiology Department, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt 5Howard Hughes Medical Institute, Chevy Chase, USA *Corresponding author: Neveen A Soliman, Center of Pediatric Nephrology & Transplantation, Department of Pediatrics, Kasr Al Aini School of Medicine, Cairo University, Cairo, Egypt, Tel: 0201062132300; Fax: 020223630039; E-mail: [email protected] Rec date: Nov 27, 2014; Acc date: Jan 26, 2015; Pub date: Jan 28, 2015 Copyright: © 2015 Nabhan MM, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Joubert syndrome–related disorders (JSRDs) are a group of clinically and genetically pleiotropic conditions that share a midbrain-hindbrain malformation, the pathognomonic molar tooth sign (MTS) visible on brain imaging, with variable involvement of other organs and systems mainly the eyes and the kidneys.
    [Show full text]
  • Senior-Loken Syndrome: a Novel NPHP5 Gene Mutation in a Family from Kuwait
    The Egyptian Journal of Medical Human Genetics (2014) 15, 203–207 Ain Shams University The Egyptian Journal of Medical Human Genetics www.ejmhg.eg.net www.sciencedirect.com CASE REPORT Senior-Loken syndrome: A novel NPHP5 gene mutation in a family from Kuwait Makia J Marafie a,*, Fahd Al-Mulla b a Kuwait Medical Genetics Centre, Maternity Hospital, Sabah Medical Area, P.O. Box 5833, Safat 13059, Kuwait b Department of Pathology, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait Received 30 November 2013; accepted 15 December 2013 Available online 8 January 2014 KEYWORDS Abstract Background: Rare autosomal recessive disorders of variable severity are segregating in Arab; many highly consanguineous families from the Arab population. One of these deleterious diseases Ciliopathy; is Senior-Loken syndrome, a hereditary heterogeneous multiorgan disorder, which combines neph- Consanguinity; ronophthisis with retinal dystrophy, leading to blindness and eventually end stage renal failure. This Nephronophthisis; disorder has been reported in many cases worldwide, including two unrelated families from Arabian Senior-Loken syndrome; Gulf countries, which share the gene pool with Kuwait. Premarital counselling Case report: Here, we are reporting two children from an Arab family with a novel frameshift mutation found in IQCB1/NPHP5 gene; c.1241-1242delTC, predicted to cause protein termination p.Leu414HisfsStop4, and describing the associated clinical features. Conclusion: Identification of this pathogenic mutation helped in confirmation of the clinical diagnosis and in providing a proper pre-marital genetic counselling and testing for a couple embarking on marriage from this highly consanguineous high-risk family. Ó 2013 Production and hosting by Elsevier B.V.
    [Show full text]
  • THE CELL BIOLOGICAL BASIS of CILIARY DISEASE • MARSHALL 19 and Channels Are Located in This Specialized Membrane, Which References Are Crucial for Ciliary Function
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE JCB: MINI-REVIEWprovided by PubMed Central The cell biological basis of ciliary disease Wallace F. Marshall Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143 Defects in cilia cause a broad spectrum of human diseases For instance, Bardet-Biedl patients suffer from obesity, retinal known collectively as the ciliopathies. Although all ciliop- degeneration, and cystic kidneys, whereas Oral-Facial-Digital athies arise from defective cilia, the range of symptoms syndrome patients suffer from polydactyly and cystic kidneys. However, both types of diseases result from defects in genes can vary significantly, and only a small subset of the whose protein products localize to the ciliary basal body. Why possible ciliary disease symptoms may be present in any don ’ t all ciliary defects produce the same set of symptoms? The key given syndrome. This complexity is puzzling until one re- to this question is to realize that despite the growing wealth of alizes that the cilia are themselves exceedingly complex genomic and proteomic data on cilia composition ( Inglis et al., machines that perform multiple functions simultaneously, 2006 ), cilia are not just lists of genes but complex organelles such that breaking one piece of the machine can leave with variable ultrastructures that must assemble and function in different tissue contexts. some functions intact while destroying others. The clinical Why might defects in two cilia-related genes lead to dis- complexity of the ciliopathies can therefore only be under- tinct diseases? There are several ways this can happen: (1) some stood in light of the basic cell biology of the cilia them- ciliary genes may have additional cilia-unrelated gene func- selves, which I will discuss from the viewpoint of cell tions; (2) some mutations may affect the ciliogenesis of only a biological studies in model organisms.
    [Show full text]
  • Research Article Mouse Model Resources for Vision Research
    Hindawi Publishing Corporation Journal of Ophthalmology Volume 2011, Article ID 391384, 12 pages doi:10.1155/2011/391384 Research Article Mouse Model Resources for Vision Research Jungyeon Won, Lan Ying Shi, Wanda Hicks, Jieping Wang, Ronald Hurd, Jurgen¨ K. Naggert, Bo Chang, and Patsy M. Nishina The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA Correspondence should be addressed to Patsy M. Nishina, [email protected] Received 1 July 2010; Accepted 21 September 2010 Academic Editor: Radha Ayyagari Copyright © 2011 Jungyeon Won et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The need for mouse models, with their well-developed genetics and similarity to human physiology and anatomy, is clear and their central role in furthering our understanding of human disease is readily apparent in the literature. Mice carrying mutations that alter developmental pathways or cellular function provide model systems for analyzing defects in comparable human disorders and for testing therapeutic strategies. Mutant mice also provide reproducible, experimental systems for elucidating pathways of normal development and function. Two programs, the Eye Mutant Resource and the Translational Vision Research Models, focused on providing such models to the vision research community are described herein. Over 100 mutant lines from the Eye Mutant Resource and 60 mutant lines from the Translational Vision Research Models have been developed. The ocular diseases of the mutant lines include a wide range of phenotypes, including cataracts, retinal dysplasia and degeneration, and abnormal blood vessel formation.
    [Show full text]
  • Human Induced Pluripotent Stem Cell–Derived Podocytes Mature Into Vascularized Glomeruli Upon Experimental Transplantation
    BASIC RESEARCH www.jasn.org Human Induced Pluripotent Stem Cell–Derived Podocytes Mature into Vascularized Glomeruli upon Experimental Transplantation † Sazia Sharmin,* Atsuhiro Taguchi,* Yusuke Kaku,* Yasuhiro Yoshimura,* Tomoko Ohmori,* ‡ † ‡ Tetsushi Sakuma, Masashi Mukoyama, Takashi Yamamoto, Hidetake Kurihara,§ and | Ryuichi Nishinakamura* *Department of Kidney Development, Institute of Molecular Embryology and Genetics, and †Department of Nephrology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan; ‡Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Hiroshima, Japan; §Division of Anatomy, Juntendo University School of Medicine, Tokyo, Japan; and |Japan Science and Technology Agency, CREST, Kumamoto, Japan ABSTRACT Glomerular podocytes express proteins, such as nephrin, that constitute the slit diaphragm, thereby contributing to the filtration process in the kidney. Glomerular development has been analyzed mainly in mice, whereas analysis of human kidney development has been minimal because of limited access to embryonic kidneys. We previously reported the induction of three-dimensional primordial glomeruli from human induced pluripotent stem (iPS) cells. Here, using transcription activator–like effector nuclease-mediated homologous recombination, we generated human iPS cell lines that express green fluorescent protein (GFP) in the NPHS1 locus, which encodes nephrin, and we show that GFP expression facilitated accurate visualization of nephrin-positive podocyte formation in
    [Show full text]