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Terada N, Saitoh Y, Saito M, Yamada T, Kamijo A, Yoshizawa T, Sakamoto T. Recent Progress on Genetically Modified Animal Models for Membrane Skeletal Proteins: The 4.1 and MPP Families. Genes (Basel) 2023; 14:1942. [PMID: 37895291 PMCID: PMC10606877 DOI: 10.3390/genes14101942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/29/2023] Open
Abstract
The protein 4.1 and membrane palmitoylated protein (MPP) families were originally found as components in the erythrocyte membrane skeletal protein complex, which helps maintain the stability of erythrocyte membranes by linking intramembranous proteins and meshwork structures composed of actin and spectrin under the membranes. Recently, it has been recognized that cells and tissues ubiquitously use this membrane skeletal system. Various intramembranous proteins, including adhesion molecules, ion channels, and receptors, have been shown to interact with the 4.1 and MPP families, regulating cellular and tissue dynamics by binding to intracellular signal transduction proteins. In this review, we focus on our previous studies regarding genetically modified animal models, especially on 4.1G, MPP6, and MPP2, to describe their functional roles in the peripheral nervous system, the central nervous system, the testis, and bone formation. As the membrane skeletal proteins are located at sites that receive signals from outside the cell and transduce signals inside the cell, it is necessary to elucidate their molecular interrelationships, which may broaden the understanding of cell and tissue functions.
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Affiliation(s)
- Nobuo Terada
- Health Science Division, Department of Medical Sciences, Shinshu University Graduate School of Medicine, Science and Technology, Matsumoto City, Nagano 390-8621, Japan
| | - Yurika Saitoh
- Health Science Division, Department of Medical Sciences, Shinshu University Graduate School of Medicine, Science and Technology, Matsumoto City, Nagano 390-8621, Japan
- Center for Medical Education, Teikyo University of Science, Adachi-ku, Tokyo 120-0045, Japan
| | - Masaki Saito
- School of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan;
| | - Tomoki Yamada
- Health Science Division, Department of Medical Sciences, Shinshu University Graduate School of Medicine, Science and Technology, Matsumoto City, Nagano 390-8621, Japan
| | - Akio Kamijo
- Health Science Division, Department of Medical Sciences, Shinshu University Graduate School of Medicine, Science and Technology, Matsumoto City, Nagano 390-8621, Japan
- Division of Basic & Clinical Medicine, Nagano College of Nursing, Komagane City, Nagano 399-4117, Japan
| | - Takahiro Yoshizawa
- Division of Animal Research, Research Center for Advanced Science and Technology, Shinshu University, Matsumoto City, Nagano 390-8621, Japan
| | - Takeharu Sakamoto
- Department of Cancer Biology, Institute of Biomedical Science, Kansai Medical University, Hirakata City, Osaka 573-1010, Japan
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2
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Burger CA, Jiang D, Mackin RD, Samuel MA. Development and maintenance of vision's first synapse. Dev Biol 2021; 476:218-239. [PMID: 33848537 DOI: 10.1016/j.ydbio.2021.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/02/2021] [Accepted: 04/03/2021] [Indexed: 12/21/2022]
Abstract
Synapses in the outer retina are the first information relay points in vision. Here, photoreceptors form synapses onto two types of interneurons, bipolar cells and horizontal cells. Because outer retina synapses are particularly large and highly ordered, they have been a useful system for the discovery of mechanisms underlying synapse specificity and maintenance. Understanding these processes is critical to efforts aimed at restoring visual function through repairing or replacing neurons and promoting their connectivity. We review outer retina neuron synapse architecture, neural migration modes, and the cellular and molecular pathways that play key roles in the development and maintenance of these connections. We further discuss how these mechanisms may impact connectivity in the retina.
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Affiliation(s)
- Courtney A Burger
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Danye Jiang
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Robert D Mackin
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Melanie A Samuel
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA.
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3
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Chytła A, Gajdzik-Nowak W, Olszewska P, Biernatowska A, Sikorski AF, Czogalla A. Not Just Another Scaffolding Protein Family: The Multifaceted MPPs. Molecules 2020; 25:molecules25214954. [PMID: 33114686 PMCID: PMC7662862 DOI: 10.3390/molecules25214954] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/16/2020] [Accepted: 10/20/2020] [Indexed: 01/03/2023] Open
Abstract
Membrane palmitoylated proteins (MPPs) are a subfamily of a larger group of multidomain proteins, namely, membrane-associated guanylate kinases (MAGUKs). The ubiquitous expression and multidomain structure of MPPs provide the ability to form diverse protein complexes at the cell membranes, which are involved in a wide range of cellular processes, including establishing the proper cell structure, polarity and cell adhesion. The formation of MPP-dependent complexes in various cell types seems to be based on similar principles, but involves members of different protein groups, such as 4.1-ezrin-radixin-moesin (FERM) domain-containing proteins, polarity proteins or other MAGUKs, showing their multifaceted nature. In this review, we discuss the function of the MPP family in the formation of multiple protein complexes. Notably, we depict their significant role for cell physiology, as the loss of interactions between proteins involved in the complex has a variety of negative consequences. Moreover, based on recent studies concerning the mechanism of membrane raft formation, we shed new light on a possible role played by MPPs in lateral membrane organization.
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Affiliation(s)
- Agnieszka Chytła
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.C.); (W.G.-N.); (P.O.); (A.B.)
| | - Weronika Gajdzik-Nowak
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.C.); (W.G.-N.); (P.O.); (A.B.)
| | - Paulina Olszewska
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.C.); (W.G.-N.); (P.O.); (A.B.)
| | - Agnieszka Biernatowska
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.C.); (W.G.-N.); (P.O.); (A.B.)
| | - Aleksander F. Sikorski
- Research and Development Center, Regional Specialist Hospital, Kamieńskiego 73a, 51-154 Wroclaw, Poland;
| | - Aleksander Czogalla
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland; (A.C.); (W.G.-N.); (P.O.); (A.B.)
- Correspondence: ; Tel.: +48-71375-6356
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4
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Kam JH, Weinrich TW, Shinhmar H, Powner MB, Roberts NW, Aboelnour A, Jeffery G. Fundamental differences in patterns of retinal ageing between primates and mice. Sci Rep 2019; 9:12574. [PMID: 31467395 PMCID: PMC6715671 DOI: 10.1038/s41598-019-49121-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 08/06/2019] [Indexed: 01/09/2023] Open
Abstract
Photoreceptors have high metabolic demands and age rapidly, undermining visual function. We base our understanding mainly on ageing mice where elevated inflammation, extracellular deposition, including that of amyloid beta, and rod and cone photoreceptor loss occur, but cones are not lost in ageing primate although their function declines, revealing that primate and mouse age differently. We examine ageing primate retinae and show elevated stress but low inflammation. However, aged primates have a >70% reduction in adenosine triphosphate (ATP) and a decrease in cytochrome c oxidase. There is a shift in cone mitochondrial positioning and glycolytic activity increases. Bruch’s membrane thickens but unlike in mice, amyloid beta is absent. Hence, reduced ATP may explain cone functional decline in ageing but their retained presence offers the possibility of functional restoration if they can be fuelled appropriately to restore cellular function. This is important because as humans we largely depend on cone function to see and are rarely fully dark adapted. Presence of limited aged inflammation and amyloid beta deposition question some of the therapeutic approaches taken to resolve problems of retinal ageing in humans and the possible lack of success in clinical trials in macular degeneration that have targeted inflammatory agents.
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Affiliation(s)
- Jaimie Hoh Kam
- University College London, Institute of Ophthalmology, EC1V9EL, London, UK
| | - Tobias W Weinrich
- University College London, Institute of Ophthalmology, EC1V9EL, London, UK
| | - Harpreet Shinhmar
- University College London, Institute of Ophthalmology, EC1V9EL, London, UK
| | - Michael B Powner
- City, University of London, Centre of Applied Vision Research, EC1V0HB, London, UK
| | - Nicholas W Roberts
- School of Biological Sciences, University of Bristol, BS8 1TQ, Bristol, UK
| | - Asmaa Aboelnour
- Histology and Cytology Department, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Glen Jeffery
- University College London, Institute of Ophthalmology, EC1V9EL, London, UK.
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5
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Dho SE, Silva-Gagliardi N, Morgese F, Coyaud E, Lamoureux E, Berry DM, Raught B, McGlade CJ. Proximity interactions of the ubiquitin ligase Mind bomb 1 reveal a role in regulation of epithelial polarity complex proteins. Sci Rep 2019; 9:12471. [PMID: 31462741 PMCID: PMC6713736 DOI: 10.1038/s41598-019-48902-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/14/2019] [Indexed: 02/07/2023] Open
Abstract
MIB1 belongs to the RING domain containing family of E3 ubiquitin ligases. In vertebrates, MIB1 plays an essential role in activation of Notch signaling during development, through the ubiquitination and endocytosis of Notch ligands. More recently, Notch independent functions for MIB1 have been described in centriole homeostasis, dendritic spine outgrowth and directional cell migration. Here we use proximity-dependent biotin identification (BioID) to define the MIB1 interactome that included 163 high confidence interactions with polypeptides linked to centrosomes and cilia, endosomal trafficking, RNA and DNA processing, the ubiquitin system, and cell adhesion. Biochemical analysis identified several proteins within these groups including CCDC14 and EPS15 that were ubiquitinated but not degraded when co-expressed with MIB1. The MIB1 interactome included the epithelial cell polarity protein, EPB41L5. MIB1 binds to and ubiquitinates EPB41L5 resulting in its degradation. Furthermore, MIB1 ubiquitinates the EPB41L5-associated polarity protein CRB1, an important determinant of the apical membrane. In polarized cells, MIB1 localized to the lateral membrane with EPB41L5 and to the tight junction with CRB1, CRB3 and ZO1. Furthermore, over expression of MIB1 resulted in altered epithelial cell morphology and apical membrane expansion. These results support a role for MIB1 in regulation of polarized epithelial cell morphology.
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Affiliation(s)
- Sascha E Dho
- Program in Cell Biology and The Arthur and Sonia Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
| | - Nancy Silva-Gagliardi
- Program in Cell Biology and The Arthur and Sonia Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
| | - Fabio Morgese
- Program in Cell Biology and The Arthur and Sonia Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
| | - Etienne Coyaud
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Emily Lamoureux
- Program in Cell Biology and The Arthur and Sonia Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
| | - Donna M Berry
- Program in Cell Biology and The Arthur and Sonia Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
| | - Brian Raught
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - C Jane McGlade
- Program in Cell Biology and The Arthur and Sonia Brain Tumour Research Centre, The Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada. .,Department of Medical Biophysics, University of Toronto, Toronto, Canada.
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6
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Quinn PM, Mulder AA, Henrique Alves C, Desrosiers M, de Vries SI, Klooster J, Dalkara D, Koster AJ, Jost CR, Wijnholds J. Loss of CRB2 in Müller glial cells modifies a CRB1-associated retinitis pigmentosa phenotype into a Leber congenital amaurosis phenotype. Hum Mol Genet 2019; 28:105-123. [PMID: 30239717 DOI: 10.1093/hmg/ddy337] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 09/17/2018] [Indexed: 11/14/2022] Open
Abstract
Variations in the human Crumbs homolog-1 (CRB1) gene lead to an array of retinal dystrophies including early onset of retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA) in children. To investigate the physiological roles of CRB1 and CRB2 in retinal Müller glial cells (MGCs), we analysed mouse retinas lacking both proteins in MGC. The peripheral retina showed a faster progression of dystrophy than the central retina. The central retina showed retinal folds, disruptions at the outer limiting membrane, protrusion of photoreceptor nuclei into the inner and outer segment layers and ingression of photoreceptor nuclei into the photoreceptor synaptic layer. The peripheral retina showed a complete loss of the photoreceptor synapse layer, intermingling of photoreceptor nuclei within the inner nuclear layer and ectopic photoreceptor cells in the ganglion cell layer. Electroretinography showed severe attenuation of the scotopic a-wave at 1 month of age with responses below detection levels at 3 months of age. The double knockout mouse retinas mimicked a phenotype equivalent to a clinical LCA phenotype due to loss of CRB1. Localization of CRB1 and CRB2 in non-human primate (NHP) retinas was analyzed at the ultrastructural level. We found that NHP CRB1 and CRB2 proteins localized to the subapical region adjacent to adherens junctions at the outer limiting membrane in MGC and photoreceptors. Our data suggest that loss of CRB2 in MGC aggravates the CRB1-associated RP-like phenotype towards an LCA-like phenotype.
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Affiliation(s)
- Peter M Quinn
- Department of Ophthalmology, Leiden University Medical Center, RC Leiden, The Netherlands
| | - Aat A Mulder
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), RC Leiden, The Netherlands
| | - C Henrique Alves
- Department of Ophthalmology, Leiden University Medical Center, RC Leiden, The Netherlands
| | - Mélissa Desrosiers
- Department of Therapeutics, Institut de la Vision, Sorbonne Universités, UPMC Univ Paris, UMR_S INSERM, CNRS, UMR, Paris, France
| | - Sharon I de Vries
- Department of Axonal Signaling, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), BA Amsterdam, The Netherlands
| | - Jan Klooster
- Department of Retina Signal Processing, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), BA Amsterdam, The Netherlands
| | - Deniz Dalkara
- Department of Therapeutics, Institut de la Vision, Sorbonne Universités, UPMC Univ Paris, UMR_S INSERM, CNRS, UMR, Paris, France
| | - Abraham J Koster
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), RC Leiden, The Netherlands
| | - Carolina R Jost
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), RC Leiden, The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center, RC Leiden, The Netherlands.,The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, BA Amsterdam, The Netherlands
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7
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Profiling of Alzheimer’s disease related genes in mild to moderate vitamin D hypovitaminosis. J Nutr Biochem 2019; 67:123-137. [DOI: 10.1016/j.jnutbio.2019.01.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 12/13/2018] [Accepted: 01/29/2019] [Indexed: 02/01/2023]
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8
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Quinn PM, Alves CH, Klooster J, Wijnholds J. CRB2 in immature photoreceptors determines the superior-inferior symmetry of the developing retina to maintain retinal structure and function. Hum Mol Genet 2019; 27:3137-3153. [PMID: 29893966 DOI: 10.1093/hmg/ddy194] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 05/11/2018] [Indexed: 11/13/2022] Open
Abstract
The mammalian apical-basal determinant Crumbs homolog-1 (CRB1) plays a crucial role in retinal structure and function by the maintenance of adherens junctions between photoreceptors and Müller glial cells. Patients with mutations in the CRB1 gene develop retinal dystrophies, including early-onset retinitis pigmentosa and Leber congenital amaurosis. Previously, we showed that Crb1 knockout mice developed a slow-progressing retinal phenotype at foci in the inferior retina, although specific ablation of Crb2 in immature photoreceptors leads to an early-onset phenotype throughout the retina. Here, we conditionally disrupted one or both alleles of Crb2 in immature photoreceptors, on a genetic background lacking Crb1, and studied the retinal dystrophies thereof. Our data showed that disruption of one allele of Crb2 in immature photoreceptors caused a substantial aggravation of the Crb1 phenotype in the entire inferior retina. The photoreceptor layer showed early-onset progressive thinning limited to the inferior retina, although the superior retina maintained intact. Surprisingly, disruption of both alleles of Crb2 in immature photoreceptors further aggravated the phenotype. Throughout the retina, photoreceptor synapses were disrupted and photoreceptor nuclei intermingled with nuclei of the inner nuclear layer. In the superior retina, the ganglion cell layer appeared thicker because of ectopic nuclei of photoreceptors. In conclusion, the data suggest that CRB2 is required to maintain retinal progenitor and photoreceptor cell adhesion and prevent photoreceptor ingression into the immature inner retina. We hypothesize, from these animal models, that decreased levels of CRB2 in immature photoreceptors adjust retinitis pigmentosa because of the loss of CRB1 into Leber congenital amaurosis phenotype.
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Affiliation(s)
- Peter M Quinn
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - C Henrique Alves
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jan Klooster
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands.,Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
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9
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The membrane palmitoylated protein, MPP6, is involved in myelin formation in the mouse peripheral nervous system. Histochem Cell Biol 2018; 151:385-394. [PMID: 30357511 DOI: 10.1007/s00418-018-1745-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2018] [Indexed: 01/01/2023]
Abstract
A membrane skeletal molecular complex, protein 4.1G-membrane palmitoylated protein 6 (MPP6)-Lin7-cell adhesion molecule 4 (CADM4), is incorporated in Schwann cells, especially in Schmidt-Lanterman incisures (SLIs), in the mouse peripheral nervous system (PNS). MPP6, Lin7, and CADM4 are transported to SLIs by 4.1G. In this study, we created MPP6-deficient mice and evaluated myelin structure and MPP6 protein complexes. In SLIs in MPP6-deficient nerves, Lin7 was rarely detected by immunohistochemistry and western blotting, but the localization and amount of CADM4 and 4.1G were not altered. Motor activity was not significantly impaired in a tail-suspension test, but the sciatic nerves of MPP6-deficient mice had thicker myelin in internodes by electron microscopy compared to that of wild-type mice. These results indicate that the MPP6-Lin7 complex regulates myelin formation.
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10
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Pang JJ, Yang Z, Jacoby RA, Wu SM. Cone synapses in mammalian retinal rod bipolar cells. J Comp Neurol 2018; 526:1896-1909. [PMID: 29667170 PMCID: PMC6031453 DOI: 10.1002/cne.24456] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 11/29/2017] [Accepted: 11/30/2017] [Indexed: 01/25/2023]
Abstract
Some mammalian rod bipolar cells (RBCs) can receive excitatory chemical synaptic inputs from both rods and cones (DBCR2 ), but anatomical evidence for mammalian cone-RBC contacts has been sparse. We examined anatomical cone-RBC contacts using neurobiotin (NB) to visualize individual mouse cones and standard immuno-markers to identify RBCs, cone pedicles and synapses in mouse and baboon retinas. Peanut agglutinin (PNA) stained the basal membrane of all cone pedicles, and mouse cones were positive for red/green (R/G)-opsin, whereas baboon cones were positive for calbindin D-28k. All synapses in the outer plexiform layer were labeled for synaptic vesicle protein 2 (SV2) and PSD (postsynaptic density)-95, and those that coincided with PNA resided closest to bipolar cell somas. Cone-RBC synaptic contacts were identified by: (a) RBC dendrites deeply invaginating into the center of cone pedicles (invaginating synapses), (b) RBC dendritic spines intruding into the surface of cone pedicles (superficial synapses), and (c) PKCα immunoreactivity coinciding with synaptic marker SV2, PSD-95, mGluR6, G protein beta 5 or PNA at cone pedicles. One RBC could form 0-1 invaginating and 1-3 superficial contacts with cones. 20.7% and 38.9% of mouse RBCs contacted cones in the peripheral and central retina (p < .05, n = 14 samples), respectively, while 34.4% (peripheral) and 48.5% (central) of cones contacted RBCs (p > .05). In baboon retinas (n = 4 samples), cone-RBC contacts involved 12.2% of RBCs (n = 416 cells) and 22.5% of cones (n = 225 cells). This suggests that rod and cone signals in the ON pathway are integrated in some RBCs before reaching AII amacrine cells.
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Affiliation(s)
- Ji-Jie Pang
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030
| | - Zhuo Yang
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030
| | - Roy A Jacoby
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030
| | - Samuel M Wu
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030
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11
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The common variants implicated in microstructural abnormality of first episode and drug-naïve patients with schizophrenia. Sci Rep 2017; 7:11750. [PMID: 28924203 PMCID: PMC5603592 DOI: 10.1038/s41598-017-10507-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/09/2017] [Indexed: 02/05/2023] Open
Abstract
Both post-mortem and neuroimaging studies have identified abnormal white matter (WM) microstructure in patients with schizophrenia. However, its genetic underpinnings and relevant biological pathways remain unclear. In order to unravel the genes and the pathways associated with abnormal WM microstructure in schizophrenia, we recruited 100 first-episode, drug-naïve patients with schizophrenia and 140 matched healthy controls to conduct genome-wide association analysis of fractional anisotropy (FA) value measured using diffusing tensor imaging (DTI), followed by multivariate association study and pathway enrichment analysis. The results showed that one intergenic SNP (rs11901793), which is 20 kb upstream of CXCR7 gene on chromosome 2, was associated with the total mean FA values with genome-wide significance (p = 4.37 × 10−8), and multivariate association analysis identified a strong association between one region-specific SNP (rs10509852), 400 kb upstream of SORCS1 gene on chromosome 10, and the global trait of abnormal WM microstructure (p = 1.89 × 10−7). Furthermore, one pathway that is involved in cell cycle regulation, REACTOME_CHROMOSOME _MAINTENANCE, was significantly enriched by the genes that were identified in our study (p = 1.54 × 10−17). In summary, our study provides suggestive evidence that abnormal WM microstructure in schizophrenia is associated with genes that are likely involved in diverse biological signals and cell-cycle regulation although further replication in a larger independent sample is needed.
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12
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LONG-TERM FOLLOW-UP OF PATIENTS WITH RETINITIS PIGMENTOSA TYPE 12 CAUSED BY CRB1 MUTATIONS. Retina 2017; 37:161-172. [PMID: 27380427 DOI: 10.1097/iae.0000000000001127] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Hoh Kam J, Morgan JE, Jeffery G. Aged complement factor H knockout mice kept in a clean barriered environment have reduced retinal pathology. Exp Eye Res 2016; 149:116-125. [PMID: 27397653 DOI: 10.1016/j.exer.2016.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 06/14/2016] [Accepted: 07/06/2016] [Indexed: 01/02/2023]
Abstract
Age-related macular degeneration (AMD) is the largest cause of visual loss in those over 60 years in the West and is a condition increasing in prevalence. Many diseases result from genetic/environmental interactions and 50% of AMD cases have an association with polymorphisms of the complement system including complement factor H. Here we explore interactions between genetic predisposition and environmental conditions in triggering retinal pathology in two groups of aged complement factor H knock out (Cfh(-/-)) mice. Mice were maintained over 9 months in either a conventional open environment or a barriered pathogen free environment. Open environment Cfh(-/-) mice had significant increases in subretinal macrophage numbers, inflammatory and stress responses and reduced photoreceptor numbers over mice kept in a pathogen free environment. Hence, environmental factors can drive retinal disease in these mice when linked to complement deficits impairing immune function. Both groups of mice had similar levels of retinal amyloid beta accumulation. Consequently there is no direct link between this and inflammation in Cfh(-/-) mice.
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Affiliation(s)
- Jaimie Hoh Kam
- Institute of Ophthalmology, University College London, UK
| | - James E Morgan
- School of Optometry and Visual Science, Cardiff University, UK
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, UK.
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14
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Vishal M, Sharma A, Kaurani L, Alfano G, Mookherjee S, Narta K, Agrawal J, Bhattacharya I, Roychoudhury S, Ray J, Waseem NH, Bhattacharya SS, Basu A, Sen A, Ray K, Mukhopadhyay A. Genetic association and stress mediated down-regulation in trabecular meshwork implicates MPP7 as a novel candidate gene in primary open angle glaucoma. BMC Med Genomics 2016; 9:15. [PMID: 27001270 PMCID: PMC4802647 DOI: 10.1186/s12920-016-0177-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 03/11/2016] [Indexed: 12/04/2022] Open
Abstract
Background Glaucoma is the largest cause of irreversible blindness affecting more than 60 million people globally. The disease is defined as a gradual loss of peripheral vision due to death of Retinal Ganglion Cells (RGC). The RGC death is largely influenced by the rate of aqueous humor production by ciliary processes and its passage through the trabecular meshwork (TM) in the anterior part of the eye. Primary open angle glaucoma (POAG), the most common subtype, is a genetically complex disease. Multiple genes and many loci have been reported to be involved in POAG but taken together they explain less than 10 % of the patients from a genetic perspective warranting more studies in different world populations. The purpose of this study was to perform genome-wide search for common variants associated with POAG in an east-Indian population. Methods The study recruited 746 POAG cases and 697 controls distributed into discovery and validation cohorts. In the discovery phase, genome-wide genotype data was generated on Illumina Infinium 660 W-Quad platform and the significant SNPs were genotyped using Illumina GGGT assay in the second phase. Logistic regression was used to test association in the discovery phase to adjust for population sub-structure and chi-square test was used for association analysis in validation phase. Publicly available expression dataset for trabecular meshwork was used to check for expression of the candidate gene under cyclic mechanical stress. Western blot and immunofluorescence experiments were performed in human TM cells and murine eye, respectively to check for expression of the candidate gene. Results Meta-analysis of discovery and validation phase data revealed the association of rs7916852 in MPP7 gene (p = 5.7x10−7) with POAG. We have shown abundant expression of MPP7 in the HTM cells. Expression analysis shows that upon cyclic mechanical stress MPP7 was significantly down-regulated in HTM (Fold change: 2.6; p = 0.018). MPP7 protein expression was also found to be enriched in the ciliary processes of the murine eye. Conclusion Using a genome-wide approach we have identified MPP7 as a novel candidate gene for POAG with evidence of its expression in relevant ocular tissues and dysregulation under mechanical stress possibly mimicking the disease scenario. Electronic supplementary material The online version of this article (doi:10.1186/s12920-016-0177-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mansi Vishal
- Molecular and Human Genetics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India.,Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India
| | - Anchal Sharma
- Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India
| | - Lalit Kaurani
- Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India
| | | | - Suddhasil Mookherjee
- Molecular and Human Genetics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India
| | - Kiran Narta
- Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India
| | - Jyoti Agrawal
- Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India
| | | | - Susanta Roychoudhury
- Cancer Biology and Inflammatory disorder division, CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India
| | - Jharna Ray
- S. N. Pradhan Centre for Neurosciences, University of Calcutta, Kolkata, 700019, India
| | | | | | - Analabha Basu
- National Institute of Biomedical Genomics, Kalyani, 741251, India
| | | | - Kunal Ray
- Molecular and Human Genetics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India. .,Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India.
| | - Arijit Mukhopadhyay
- Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India. .,Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India. .,UCL Institute of Ophthalmology, London, EC1V 9EL, UK.
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15
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Immunohistochemical study of the membrane skeletal protein, membrane protein palmitoylated 6 (MPP6), in the mouse small intestine. Histochem Cell Biol 2015; 145:81-92. [PMID: 26496923 DOI: 10.1007/s00418-015-1374-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2015] [Indexed: 12/14/2022]
Abstract
The membrane protein palmitoylated (MPP) family belongs to the membrane-associated guanylate kinase (MAGUK) family. MPP1 interacts with the protein 4.1 family member, 4.1R, as a membrane skeletal protein complex in erythrocytes. We previously described the interaction of another MPP family, MPP6, with 4.1G in the mouse peripheral nervous system. In the present study, the immunolocalization of MPP6 in the mouse small intestine was examined and compared with that of E-cadherin, zonula occludens (ZO)-1, and 4.1B, which we previously investigated in intestinal epithelial cells. The immunolocalization of MPP6 was also assessed in the small intestines of 4.1B-deficient (-/-) mice. In the small intestine, Western blotting revealed that the molecular weight of MPP6 was approximately 55-kDa, and MPP6 was immunostained under the cell membranes in the basolateral portions of almost all epithelial cells from the crypts to the villi. The immunostaining pattern of MPP6 in epithelial cells was similar to that of E-cadherin, but differed from that of ZO-1. In intestinal epithelial cells, the immunostained area of MPP6 was slightly different from that of 4.1B, which was restricted to the intestinal villi. The immunolocalization of MPP6 in small intestinal epithelial cells was similar between 4.1B(-/-) mice and 4.1B(+/+) mice. In the immunoprecipitation study, another MAGUK family protein, calcium/calmodulin-dependent serine protein kinase (CASK), was shown to molecularly interact with MPP6. Thus, we herein showed the immunolocalization and interaction proteins of MPP6 in the mouse small intestine, and also that 4.1B in epithelial cells was not essential for the sorting of MPP6.
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16
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Pellissier LP, Lundvig DMS, Tanimoto N, Klooster J, Vos RM, Richard F, Sothilingam V, Garcia Garrido M, Le Bivic A, Seeliger MW, Wijnholds J. CRB2 acts as a modifying factor of CRB1-related retinal dystrophies in mice. Hum Mol Genet 2014; 23:3759-71. [PMID: 24565864 DOI: 10.1093/hmg/ddu089] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mutations in the CRB1 gene lead to retinal dystrophies ranging from Leber congenital amaurosis (LCA) to early-onset retinitis pigmentosa (RP), due to developmental defects or loss of adhesion between photoreceptors and Müller glia cells, respectively. Whereas over 150 mutations have been found, no clear genotype-phenotype correlation has been established. Mouse Crb1 knockout retinas show a mild phenotype limited to the inferior quadrant, whereas Crb2 knockout retinas display a severe degeneration throughout the retina mimicking the phenotype observed in RP patients associated with CRB1 mutations. Crb1Crb2 double mutant retinas have severe developmental defects similar to the phenotype observed in LCA patients associated with CRB1 mutations. Therefore, CRB2 is a candidate modifying gene of human CRB1-related retinal dystrophy. In this study, we studied the cellular localization of CRB1 and CRB2 in human retina and tested the influence of the Crb2 gene allele on Crb1-retinal dystrophies in mice. We found that in contrast to mice, in the human retina CRB1 protein was expressed at the subapical region in photoreceptors and Müller glia cells, and CRB2 only in Müller glia cells. Genetic ablation of one allele of Crb2 in heterozygote Crb1(+/-) retinas induced a mild retinal phenotype, but in homozygote Crb1 knockout mice lead to an early and severe phenotype limited to the entire inferior retina. Our data provide mechanistic insight for CRB1-related LCA and RP.
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Affiliation(s)
| | | | - Naoyuki Tanimoto
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen D-72076, Germany and
| | - Jan Klooster
- Department of Retinal Signal Processing, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105 BA, The Netherlands
| | | | - Fabrice Richard
- Aix-Marseille Université, CNRS, UMR 7288, Developmental Biology Institute of Marseille (IBDM), Case 907, Marseille, Cedex 09 13288, France
| | - Vithiyanjali Sothilingam
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen D-72076, Germany and
| | - Marina Garcia Garrido
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen D-72076, Germany and
| | - André Le Bivic
- Aix-Marseille Université, CNRS, UMR 7288, Developmental Biology Institute of Marseille (IBDM), Case 907, Marseille, Cedex 09 13288, France
| | - Mathias W Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen D-72076, Germany and
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17
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Schmitz F. Presynaptic [Ca(2+)] and GCAPs: aspects on the structure and function of photoreceptor ribbon synapses. Front Mol Neurosci 2014; 7:3. [PMID: 24567702 PMCID: PMC3915146 DOI: 10.3389/fnmol.2014.00003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 01/15/2014] [Indexed: 12/21/2022] Open
Abstract
Changes in intracellular calcium ions [Ca2+] play important roles in photoreceptor signaling. Consequently, intracellular [Ca2+] levels need to be tightly controlled. In the light-sensitive outer segments (OS) of photoreceptors, Ca2+ regulates the activity of retinal guanylate cyclases thus playing a central role in phototransduction and light-adaptation by restoring light-induced decreases in cGMP. In the synaptic terminals, changes of intracellular Ca2+ trigger various aspects of neurotransmission. Photoreceptors employ tonically active ribbon synapses that encode light-induced, graded changes of membrane potential into modulation of continuous synaptic vesicle exocytosis. The active zones of ribbon synapses contain large electron-dense structures, synaptic ribbons, that are associated with large numbers of synaptic vesicles. Synaptic coding at ribbon synapses differs from synaptic coding at conventional (phasic) synapses. Recent studies revealed new insights how synaptic ribbons are involved in this process. This review focuses on the regulation of [Ca2+] in presynaptic photoreceptor terminals and on the function of a particular Ca2+-regulated protein, the neuronal calcium sensor protein GCAP2 (guanylate cyclase-activating protein-2) in the photoreceptor ribbon synapse. GCAP2, an EF-hand-containing protein plays multiple roles in the OS and in the photoreceptor synapse. In the OS, GCAP2 works as a Ca2+-sensor within a Ca2+-regulated feedback loop that adjusts cGMP levels. In the photoreceptor synapse, GCAP2 binds to RIBEYE, a component of synaptic ribbons, and mediates Ca2+-dependent plasticity at that site. Possible mechanisms are discussed.
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Affiliation(s)
- Frank Schmitz
- Department of Neuroanatomy, Institute for Anatomy and Cell Biology, Medical School Homburg/Saar, Saarland University Saarland, Germany
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18
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Alves CH, Pellissier LP, Wijnholds J. The CRB1 and adherens junction complex proteins in retinal development and maintenance. Prog Retin Eye Res 2014; 40:35-52. [PMID: 24508727 DOI: 10.1016/j.preteyeres.2014.01.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/21/2014] [Accepted: 01/27/2014] [Indexed: 12/30/2022]
Abstract
The early developing retinal neuroepithelium is composed of multipotent retinal progenitor cells that differentiate in a time specific manner, giving rise to six major types of neuronal and one type of glial cells. These cells migrate and organize in three distinct nuclear layers divided by two plexiform layers. Apical and adherens junction complexes have a crucial role in this process by the establishment of polarity and adhesion. Changes in these complexes disturb the spatiotemporal aspects of retinogenesis, leading to retinal degeneration resulting in mild or severe impairment of retinal function and vision. In this review, we summarize the mouse models for the different members of the apical and adherens junction protein complexes and describe the main features of their retinal phenotypes. The knowledge acquired from the different mutant animals for these proteins corroborate their importance in retina development and maintenance of normal retinal structure and function. More recently, several studies have tried to unravel the connection between the apical proteins, important cellular signaling pathways and their relation in retina development. Still, the mechanisms by which these proteins function remain largely unknown. Here, we hypothesize how the mammalian apical CRB1 complex might control retinogenesis and prevents onset of Leber congenital amaurosis or retinitis pigmentosa.
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Affiliation(s)
- Celso Henrique Alves
- Department of Neuromedical Genetics, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
| | - Lucie P Pellissier
- Department of Neuromedical Genetics, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
| | - Jan Wijnholds
- Department of Neuromedical Genetics, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Meibergdreef 47, 1105 BA Amsterdam, The Netherlands.
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19
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Alves CH, Pellissier LP, Vos RM, Garcia Garrido M, Sothilingam V, Seide C, Beck SC, Klooster J, Furukawa T, Flannery JG, Verhaagen J, Seeliger MW, Wijnholds J. Targeted ablation of Crb2 in photoreceptor cells induces retinitis pigmentosa. Hum Mol Genet 2014; 23:3384-401. [PMID: 24493795 DOI: 10.1093/hmg/ddu048] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In humans, the Crumbs homolog-1 (CRB1) gene is mutated in autosomal recessive Leber congenital amaurosis and early-onset retinitis pigmentosa. In mammals, the Crumbs family is composed of: CRB1, CRB2, CRB3A and CRB3B. Recently, we showed that removal of mouse Crb2 from retinal progenitor cells, and consequent removal from Müller glial and photoreceptor cells, results in severe and progressive retinal degeneration with concomitant loss of retinal function that mimics retinitis pigmentosa due to mutations in the CRB1 gene. Here, we studied the effects of cell-type-specific loss of CRB2 from the developing mouse retina using targeted conditional deletion of Crb2 in photoreceptors or Müller cells. We analyzed the consequences of targeted loss of CRB2 in the adult mouse retina using adeno-associated viral vectors encoding Cre recombinase and short hairpin RNA against Crb2. In vivo retinal imaging by means of optical coherence tomography on retinas lacking CRB2 in photoreceptors showed progressive thinning of the photoreceptor layer and cellular mislocalization. Electroretinogram recordings under scotopic conditions showed severe attenuation of the a-wave, confirming the degeneration of photoreceptors. Retinas lacking CRB2 in developing photoreceptors showed early onset of abnormal lamination, whereas retinas lacking CRB2 in developing Müller cells showed late onset retinal disorganization. Our data suggest that in the developing retina, CRB2 has redundant functions in Müller glial cells, while CRB2 has essential functions in photoreceptors. Our data suggest that short-term loss of CRB2 in adult mouse photoreceptors, but not in Müller glial cells, causes sporadic loss of adhesion between photoreceptors and Müller cells.
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Affiliation(s)
| | | | | | - Marina Garcia Garrido
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen D-72076, Germany
| | - Vithiyanjali Sothilingam
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen D-72076, Germany
| | - Christina Seide
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen D-72076, Germany
| | - Susanne C Beck
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen D-72076, Germany
| | | | - Takahisa Furukawa
- Institute for Protein Research & CREST-JST, Osaka University, Osaka, Japan Department of Developmental Biology, Osaka Bioscience Institute, Suita, Osaka, Japan and
| | - John G Flannery
- Department of Molecular and Cellular Biology and The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - Joost Verhaagen
- Department of Neuroregeneration, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
| | - Mathias W Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, Eberhard Karls University of Tübingen, Tübingen D-72076, Germany
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20
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Luz M, Knust E. Fluorescently tagged Lin7c is a dynamic marker for polarity maturation in the zebrafish retinal epithelium. Biol Open 2013; 2:867-71. [PMID: 24143272 PMCID: PMC3773332 DOI: 10.1242/bio.20135371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 05/28/2013] [Indexed: 12/12/2022] Open
Abstract
Development of epithelial cell polarity is a highly dynamic process, and often established by the sequential recruitment of conserved protein complexes, such as the Par or the Crumbs (Crb) complex. However, detailed insights into the refinement of polarity and the formation of the complexes are still lacking. Here, we established fluorescently tagged Lin7c, a core member of the Crb complex, as an ideal tool to follow development of polarity in zebrafish epithelia. We find that in gastrula stages, RFP-Lin7c is found in the cytosol of the enveloping layer, while Pard3-GFP is already polarized at this stage. During development of the retinal epithelium, RFP-Lin7c localization is refined from being cytosolic at 14 hours post fertilization (hpf) to almost entirely apical in cells of the eye cup at 28 hpf. This apical Lin7c localization depends on the Crb complex members Oko meduzy and Nagie oko. Thus, fluorescently tagged Lin7c can be used in a broad range of epithelia to follow polarity maturation in vivo and specifically to elucidate the sequence of events determining Crb complex-mediated polarity.
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Affiliation(s)
- Marta Luz
- Max-Planck-Institute of Molecular Cell Biology and Genetics , Pfotenhauerstrasse 108, D-01307 Dresden , Germany
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21
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Dudok JJ, Sanz AS, Lundvig DMS, Sothilingam V, Garrido MG, Klooster J, Seeliger MW, Wijnholds J. MPP3 regulates levels of PALS1 and adhesion between photoreceptors and Müller cells. Glia 2013; 61:1629-44. [DOI: 10.1002/glia.22545] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 12/30/2022]
Affiliation(s)
- Jacobus J. Dudok
- Department of Neuromedical Genetics; Netherlands Institute for Neuroscience; Royal Netherlands Academy of Arts and Sciences; 1105; BA Amsterdam; The Netherlands
| | - Alicia Sanz Sanz
- Department of Neuromedical Genetics; Netherlands Institute for Neuroscience; Royal Netherlands Academy of Arts and Sciences; 1105; BA Amsterdam; The Netherlands
| | - Ditte M. S. Lundvig
- Department of Neuromedical Genetics; Netherlands Institute for Neuroscience; Royal Netherlands Academy of Arts and Sciences; 1105; BA Amsterdam; The Netherlands
| | - Vithiyanjali Sothilingam
- Division of Ocular Neurodegeneration; Institute for Ophthalmic Research, Eberhard Karls University of Tübingen; 72076; Tübingen; Germany
| | - Marina Garcia Garrido
- Division of Ocular Neurodegeneration; Institute for Ophthalmic Research, Eberhard Karls University of Tübingen; 72076; Tübingen; Germany
| | - Jan Klooster
- Department of Retinal Signal Processing; Netherlands Institute for Neuroscience; Royal Netherlands Academy of Arts and Sciences; 1105; BA Amsterdam; The Netherlands
| | - Mathias W. Seeliger
- Division of Ocular Neurodegeneration; Institute for Ophthalmic Research, Eberhard Karls University of Tübingen; 72076; Tübingen; Germany
| | - Jan Wijnholds
- Department of Neuromedical Genetics; Netherlands Institute for Neuroscience; Royal Netherlands Academy of Arts and Sciences; 1105; BA Amsterdam; The Netherlands
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22
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Zabouri N, Haverkamp S. Calcium channel-dependent molecular maturation of photoreceptor synapses. PLoS One 2013; 8:e63853. [PMID: 23675510 PMCID: PMC3652833 DOI: 10.1371/journal.pone.0063853] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 04/08/2013] [Indexed: 01/08/2023] Open
Abstract
Several studies have shown the importance of calcium channels in the development and/or maturation of synapses. The CaV1.4(α1F) knockout mouse is a unique model to study the role of calcium channels in photoreceptor synapse formation. It features abnormal ribbon synapses and aberrant cone morphology. We investigated the expression and targeting of several key elements of ribbon synapses and analyzed the cone morphology in the CaV1.4(α1F) knockout retina. Our data demonstrate that most abnormalities occur after eye opening. Indeed, scaffolding proteins such as Bassoon and RIM2 are properly targeted at first, but their expression and localization are not maintained in adulthood. This indicates that either calcium or the CaV1.4 channel, or both are necessary for the maintenance of their normal expression and distribution in photoreceptors. Other proteins, such as Veli3 and PSD-95, also display abnormal expression in rods prior to eye opening. Conversely, vesicle related proteins appear normal. Our data demonstrate that the CaV1.4 channel is important for maintaining scaffolding proteins in the ribbon synapse but less vital for proteins related to vesicular release. This study also confirms that in adult retinae, cones show developmental features such as sprouting and synaptogenesis. Overall we present evidence that in the absence of the CaV1.4 channel, photoreceptor synapses remain immature and are unable to stabilize.
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Affiliation(s)
- Nawal Zabouri
- Neuroanatomy, Max-Planck-Institute for Brain Research, Frankfurt am Main, Germany.
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23
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Abstract
Photoreceptors are exquisitely adapted to transform light stimuli into electrical signals that modulate neurotransmitter release. These cells are organized into several compartments including the unique outer segment (OS). Its whole function is to absorb light and transduce this signal into a change of membrane potential. Another compartment is the inner segment where much of metabolism and regulation of membrane potential takes place and that connects the OS and synapse. The synapse is the compartment where changes in membrane potentials are relayed to other neurons in the retina via release of neurotransmitter. The composition of the plasma membrane surrounding these compartments varies to accommodate their specific functions. In this chapter, we discuss the organization of the plasma membrane emphasizing the protein composition of each region as it relates to visual signaling. We also point out examples where mutations in these proteins cause visual impairment.
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Affiliation(s)
- Sheila A Baker
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
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Herranz-Martín S, Jimeno D, Paniagua AE, Velasco A, Lara JM, Aijón J, Lillo C. Immunocytochemical evidence of the localization of the Crumbs homologue 3 protein (CRB3) in the developing and mature mouse retina. PLoS One 2012; 7:e50511. [PMID: 23226298 PMCID: PMC3511585 DOI: 10.1371/journal.pone.0050511] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 10/22/2012] [Indexed: 12/28/2022] Open
Abstract
CRB3 (Crumbs homologue 3), a member of the CRB protein family (homologous to the Drosophila Crumbs), is expressed in different epithelium-derived cell types in mammals, where it seems to be involved in regulating the establishment and stability of tight junctions and in ciliogenesis. This protein has been also detected in the retina, but little is known about its localization and function in this tissue. Our goal here was to perform an in-depth study of the presence of CRB3 protein in the mouse retina and to analyze its expression during photoreceptor ciliogenesis and the establishment of the plexiform retinal layers. Double immunofluorescence experiments for CRB3 and well-known markers for the different retinal cell types were performed to study the localization of the CRB3 protein. According to our results, CRB3 is present from postnatal day 0 (P0) until adulthood in the mouse retina. It is localized in the inner segments (IS) of photoreceptor cells, especially concentrated in the area where the connecting cilium is located, in their synaptic terminals in the outer plexiform layer (OPL), and in sub-populations of amacrine and bipolar cells in the inner plexiform layer (IPL).
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Affiliation(s)
- Saúl Herranz-Martín
- Institute of Neurosciences of Castilla y León (INCyL), Institute of Biomedical Research of Salamanca (IBSAL), Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
| | - David Jimeno
- Centro de Investigación del Cáncer-IBMCC (CSIC-USAL), University of Salamanca, Campus Unamuno, Salamanca, Spain
| | - Antonio E. Paniagua
- Institute of Neurosciences of Castilla y León (INCyL), Institute of Biomedical Research of Salamanca (IBSAL), Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
| | - Almudena Velasco
- Institute of Neurosciences of Castilla y León (INCyL), Institute of Biomedical Research of Salamanca (IBSAL), Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
| | - Juan M. Lara
- Institute of Neurosciences of Castilla y León (INCyL), Institute of Biomedical Research of Salamanca (IBSAL), Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
| | - José Aijón
- Institute of Neurosciences of Castilla y León (INCyL), Institute of Biomedical Research of Salamanca (IBSAL), Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
| | - Concepción Lillo
- Institute of Neurosciences of Castilla y León (INCyL), Institute of Biomedical Research of Salamanca (IBSAL), Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
- * E-mail:
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25
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The dynamic architecture of photoreceptor ribbon synapses: cytoskeletal, extracellular matrix, and intramembrane proteins. Vis Neurosci 2012; 28:453-71. [PMID: 22192503 DOI: 10.1017/s0952523811000356] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Rod and cone photoreceptors possess ribbon synapses that assist in the transmission of graded light responses to second-order bipolar and horizontal cells of the vertebrate retina. Proper functioning of the synapse requires the juxtaposition of presynaptic release sites immediately adjacent to postsynaptic receptors. In this review, we focus on the synaptic, cytoskeletal, and extracellular matrix proteins that help to organize photoreceptor ribbon synapses in the outer plexiform layer. We examine the proteins that foster the clustering of release proteins, calcium channels, and synaptic vesicles in the presynaptic terminals of photoreceptors adjacent to their postsynaptic contacts. Although many proteins interact with one another in the presynaptic terminal and synaptic cleft, these protein-protein interactions do not create a static and immutable structure. Instead, photoreceptor ribbon synapses are remarkably dynamic, exhibiting structural changes on both rapid and slow time scales.
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Runkle EA, Antonetti DA. The blood-retinal barrier: structure and functional significance. Methods Mol Biol 2011; 686:133-48. [PMID: 21082369 DOI: 10.1007/978-1-60761-938-3_5] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Formation and maintenance of the blood-retinal barrier is required for proper vision and loss of this barrier contributes to the pathology of a wide number of retinal diseases. The retina is responsible for converting visible light into the electrochemical signal interpreted by the brain as vision. Multiple cell types are required for this function, which are organized into eight distinct cell layers. These neural and glial cells gain metabolic support from a unique vascular structure that provides the necessary nutrients while minimizing interference with light sensing. In addition to the vascular contribution, the retina also possesses an epithelial barrier, the retinal pigment epithelium, which is located at the posterior of the eye and controls exchange of nutrients with the choroidal vessels. Together the vascular and epithelial components of the blood-retinal barrier maintain the specialized environment of the neural retina. Both the vascular endothelium and pigment epithelium possess a well-developed junctional complex that includes both adherens and tight junctions conferring a high degree of control of solute and fluid permeability. Understanding induction and regulation of the blood-retinal barrier will allow the development of therapies aimed at restoring the barrier when compromised in disease or allowing the specific transport of therapies across this barrier when needed. This chapter will highlight the anatomical structure of the blood-retinal barrier and explore the molecular structure of the tight junctions that provide the unique barrier properties of the blood--retinal barrier.
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Affiliation(s)
- E Aaron Runkle
- Department of Ophthalmology, Penn State College of Medicine, Hershey, PA, USA
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27
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Aartsen WM, van Cleef KWR, Pellissier LP, Hoek RM, Vos RM, Blits B, Ehlert EME, Balaggan KS, Ali RR, Verhaagen J, Wijnholds J. GFAP-driven GFP expression in activated mouse Müller glial cells aligning retinal blood vessels following intravitreal injection of AAV2/6 vectors. PLoS One 2010; 5:e12387. [PMID: 20808778 PMCID: PMC2927518 DOI: 10.1371/journal.pone.0012387] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 07/27/2010] [Indexed: 12/25/2022] Open
Abstract
Background Müller cell gliosis occurs in various retinal pathologies regardless of the underlying cellular defect. Because activated Müller glial cells span the entire retina and align areas of injury, they are ideal targets for therapeutic strategies, including gene therapy. Methodology/Principal Findings We used adeno-associated viral AAV2/6 vectors to transduce mouse retinas. The transduction pattern of AAV2/6 was investigated by studying expression of the green fluorescent protein (GFP) transgene using scanning-laser ophthalmoscopy and immuno-histochemistry. AAV2/6 vectors transduced mouse Müller glial cells aligning the retinal blood vessels. However, the transduction capacity was hindered by the inner limiting membrane (ILM) and besides Müller glial cells, several other inner retinal cell types were transduced. To obtain Müller glial cell-specific transgene expression, the cytomegalovirus (CMV) promoter was replaced by the glial fibrillary acidic protein (GFAP) promoter. Specificity and activation of the GFAP promoter was tested in a mouse model for retinal gliosis. Mice deficient for Crumbs homologue 1 (CRB1) develop gliosis after light exposure. Light exposure of Crb1−/− retinas transduced with AAV2/6-GFAP-GFP induced GFP expression restricted to activated Müller glial cells aligning retinal blood vessels. Conclusions/Significance Our experiments indicate that AAV2 vectors carrying the GFAP promoter are a promising tool for specific expression of transgenes in activated glial cells.
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Affiliation(s)
- Wendy M. Aartsen
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Koen W. R. van Cleef
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Lucie P. Pellissier
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Robert M. Hoek
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Rogier M. Vos
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Bas Blits
- Department of Neuroregeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
- Amsterdam Molecular Therapeutics, Amsterdam, The Netherlands
| | - Erich M. E. Ehlert
- Department of Neuroregeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Kamaljit S. Balaggan
- Division of Molecular Therapy, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Robin R. Ali
- Division of Molecular Therapy, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Joost Verhaagen
- Department of Neuroregeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Jan Wijnholds
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
- * E-mail:
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Thomas U, Kobler O, Gundelfinger ED. TheDrosophilaLarval Neuromuscular Junction as a Model for Scaffold Complexes at Glutamatergic Synapses: Benefits and Limitations. J Neurogenet 2010; 24:109-19. [DOI: 10.3109/01677063.2010.493589] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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29
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Ritchey ER, Bongini RE, Code KA, Zelinka C, Petersen-Jones S, Fischer AJ. The pattern of expression of guanine nucleotide-binding protein beta3 in the retina is conserved across vertebrate species. Neuroscience 2010; 169:1376-91. [PMID: 20538044 DOI: 10.1016/j.neuroscience.2010.05.081] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 05/28/2010] [Accepted: 05/29/2010] [Indexed: 01/25/2023]
Abstract
Guanine nucleotide-binding protein beta3 (GNB3) is an isoform of the beta subunit of the heterotrimeric G protein second messenger complex that is commonly associated with transmembrane receptors. The presence of GNB3 in photoreceptors, and possibly bipolar cells, has been confirmed in murine, bovine and primate retinas [Lee RH, Lieberman BS, Yamane HK, Bok D, Fung BK (1992) J Biol Chem 267:24776-24781; Peng YW, Robishaw JD, Levine MA, Yau KW (1992) Proc Natl Acad Sci U S A 89:10882-10886; Huang L, Max M, Margolskee RF, Su H, Masland RH, Euler T (2003) J Comp Neurol 455:1-10]. Studies have indicated that a mutation in the GNB3 gene causes progressive retinopathy and globe enlargement (RGE) in chickens. The goals of this study were to (1) examine the expression pattern of GNB3 in wild-type and RGE mutant chickens, (2) characterize the types of bipolar cells that express GNB3 and (3) examine whether the expression of GNB3 in the retina is conserved across vertebrate species. We find that chickens homozygous for the RGE allele completely lack GNB3 protein. We find that the pattern of expression of GNB3 in the retina is highly conserved across vertebrate species, including teleost fish (Carassius auratus), frogs (Xenopus laevis), chickens (Gallus domesticus), mice (Mus musculata), guinea-pigs (Cavia porcellus), dogs (Canis familiaris) and non-human primates (Macaca fasicularis). Regardless of the species, we find that GNB3 is expressed by Islet1-positive cone ON-bipolar cells and by cone photoreceptors. In some vertebrates, GNB3-immunoreactivity was observed in both rod and cone photoreceptors. A protein-protein alignment of GNB3 across different vertebrates, from fish to humans, indicates a high degree (>92%) of sequence conservation. Given that analogous types of retinal neurons express GNB3 in different species, we propose that the functions and the mechanisms that regulate the expression of GNB3 are highly conserved.
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Affiliation(s)
- E R Ritchey
- College of Optometry, The Ohio State University, 338 West 10th Avenue, Columbus, OH 43210, USA
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30
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A perisynaptic ménage à trois between Dlg, DLin-7, and Metro controls proper organization of Drosophila synaptic junctions. J Neurosci 2010; 30:5811-24. [PMID: 20427642 DOI: 10.1523/jneurosci.0778-10.2010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Structural plasticity of synaptic junctions is a prerequisite to achieve and modulate connectivity within nervous systems, e.g., during learning and memory formation. It demands adequate backup systems that allow remodeling while retaining sufficient stability to prevent unwanted synaptic disintegration. The strength of submembranous scaffold complexes, which are fundamental to the architecture of synaptic junctions, likely constitutes a crucial determinant of synaptic stability. Postsynaptic density protein-95 (PSD-95)/ Discs-large (Dlg)-like membrane-associated guanylate kinases (DLG-MAGUKs) are principal scaffold proteins at both vertebrate and invertebrate synapses. At Drosophila larval glutamatergic neuromuscular junctions (NMJs) DlgA and DlgS97 exert pleiotropic functions, probably reflecting a few known and a number of yet-unknown binding partners. In this study we have identified Metro, a novel p55/MPP-like Drosophila MAGUK as a major binding partner of perisynaptic DlgS97 at larval NMJs. Based on homotypic LIN-2,-7 (L27) domain interactions, Metro stabilizes junctional DlgS97 in a complex with the highly conserved adaptor protein DLin-7. In a remarkably interdependent manner, Metro and DLin-7 act downstream of DlgS97 to control NMJ expansion and proper establishment of synaptic boutons. Using quantitative 3D-imaging we further demonstrate that the complex controls the size of postsynaptic glutamate receptor fields. Our findings accentuate the importance of perisynaptic scaffold complexes for synaptic stabilization and organization.
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31
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Bulgakova NA, Knust E. The Crumbs complex: from epithelial-cell polarity to retinal degeneration. J Cell Sci 2009; 122:2587-96. [DOI: 10.1242/jcs.023648] [Citation(s) in RCA: 190] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The evolutionarily conserved Crumbs protein complex is a key regulator of cell polarity and cell shape in both invertebrates and vertebrates. The important role of this complex in normal cell function is illustrated by the finding that mutations in one of its components, Crumbs, are associated with retinal degeneration in humans, mice and flies. Recent results suggest that the Crumbs complex plays a role in the development of other disease processes that are based on epithelial dysfunction, such as tumorigenesis or the formation of cystic kidneys. Localisation of the complex is restricted to a distinct region of the apical plasma membrane that abuts the zonula adherens in epithelia and photoreceptor cells of invertebrates and vertebrates, including humans. In addition to the core components, a variety of other proteins can be recruited to the complex, depending on the cell type and/or developmental stage. Together with diverse post-transcriptional and post-translational mechanisms that regulate the individual components, this provides an enormous functional diversity and flexibility of the complex. In this Commentary, we summarise findings concerning the organisation and modification of the Crumbs complex, and the conservation of its constituents from flies to mammals. In addition, we discuss recent results that suggest its participation in various human diseases, including blindness and tumour formation.
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Affiliation(s)
- Natalia A. Bulgakova
- Max-Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, Dresden, Germany
| | - Elisabeth Knust
- Max-Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, Dresden, Germany
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TMEM16B, a novel protein with calcium-dependent chloride channel activity, associates with a presynaptic protein complex in photoreceptor terminals. J Neurosci 2009; 29:6809-18. [PMID: 19474308 DOI: 10.1523/jneurosci.5546-08.2009] [Citation(s) in RCA: 174] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Photoreceptor ribbon synapses release glutamate in response to graded changes in membrane potential evoked by vast, logarithmically scalable light intensities. Neurotransmitter release is modulated by intracellular calcium levels. Large Ca(2+)-dependent chloride currents are important regulators of synaptic transmission from photoreceptors to second-order neurons; the molecular basis underlying these currents is unclear. We cloned human and mouse TMEM16B, a member of the TMEM16 family of transmembrane proteins, and show that it is abundantly present in the photoreceptor synaptic terminals in mouse retina. TMEM16B colocalizes with adaptor proteins PSD95, VELI3, and MPP4 at the ribbon synapses and contains a consensus PDZ class I binding motif capable of interacting with PDZ domains of PSD95. Furthermore, TMEM16B is lost from photoreceptor membranes of MPP4-deficient mice. This suggests that TMEM16B is a novel component of a presynaptic protein complex recruited to specialized plasma membrane domains of photoreceptors. TMEM16B confers Ca(2+)-dependent chloride currents when overexpressed in mammalian cells as measured by halide sensitive fluorescent protein assays and whole-cell patch-clamp recordings. The compartmentalized localization and the electrophysiological properties suggest TMEM16B to be a strong candidate for the long sought-after Ca(2+)-dependent chloride channel in the photoreceptor synapse.
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Aartsen WM, Arsanto JP, Chauvin JP, Vos RM, Versteeg I, Cardozo BN, Bivic AL, Wijnholds J. PSD95β regulates plasma membrane Ca(2+) pump localization at the photoreceptor synapse. Mol Cell Neurosci 2009; 41:156-65. [DOI: 10.1016/j.mcn.2009.02.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 01/27/2009] [Accepted: 02/10/2009] [Indexed: 01/05/2023] Open
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Förster JR, Lochnit G, Stöhr H. Proteomic analysis of the membrane palmitoylated protein-4 (MPP4)-associated protein complex in the retina. Exp Eye Res 2008; 88:39-48. [PMID: 18955048 DOI: 10.1016/j.exer.2008.09.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 09/17/2008] [Accepted: 09/19/2008] [Indexed: 12/26/2022]
Abstract
Membrane palmitoylated protein-4 (MPP4) is a retina-specific scaffolding protein of the membrane-associated guanylate kinase family that has been implicated in organizing presynaptic protein complexes in the photoreceptor ribbon synapse. To isolate the components of this complex we applied a proteomic approach based on immunoaffinity chromatography with a monoclonal anti-MPP4 antibody followed by two-dimensional electrophoresis and mass spectrometry. Among the identified molecules were previously reported proteins of the MPP4 scaffolding complex including adaptor proteins Veli3 and Psd95. Here we demonstrate a selective association between MPP4 and the Psd95-beta isoform that is mediated by interaction of their N-terminal L27 domains. In addition, we have identified recoverin and Hsc70 as novel associated proteins of the MPP4 multiprotein complex in the retina. This study demonstrates the utility of anti-MPP4 antibody precipitation for the elucidation of the MPP4-associated protein complex, which is essential in understanding its precise role in signal transmission at the photoreceptor synapse.
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Affiliation(s)
- Johanna R Förster
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
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35
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Haverkamp S, Specht D, Majumdar S, Zaidi NF, Brandstätter JH, Wasco W, Wässle H, Tom Dieck S. Type 4 OFF cone bipolar cells of the mouse retina express calsenilin and contact cones as well as rods. J Comp Neurol 2008; 507:1087-101. [PMID: 18095322 DOI: 10.1002/cne.21612] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Immunocytochemical discrimination of distinct bipolar cell types in the mouse retina is a prerequisite for analyzing retinal circuitry in wild-type and transgenic mice. Here we demonstrate that among the more than 10 anatomically defined mouse bipolar cell types, type 4 bipolar cells are specifically recognized by anti-calsenilin antibodies. Axon terminals in the inner plexiform layer are not readily identifiable because calsenilin is also expressed in a subset of amacrine and ganglion cells. In contrast, in the outer plexiform layer calsenilin immunoreactivity allows the analysis of photoreceptor to type 4 bipolar cell contacts. A dense plexus of calsenilin-positive dendrites makes several basal contacts at cone pedicles. An individual calsenilin-positive bipolar cell contacts five to seven cones. In addition, some calsenilin-positive dendrites contact rod photoreceptors. On average we counted 10 rod spherule contacts per type 4 bipolar cell, and approximately 10% of rods contacted type 4 bipolar cells. We suggest that type 4 bipolar cells, together with the recently described type 3a and b cells, provide an alternative and direct route from rods to OFF cone bipolar cells. In the Bassoon DeltaEx4/5 mouse, a mouse mutant that shows extensive remodeling of the rod system including sprouting of horizontal and rod bipolar cells into the outer nuclear layer due to impaired synaptic transmission, we found that in addition mixed-input (type 3 and 4) OFF bipolar cells sprout to ectopic sites. In contrast, true cone-selective type 1 and 2 OFF cone bipolar cells did not show sprouting in the Bassoon mouse mutant.
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Affiliation(s)
- Silke Haverkamp
- Department of Neuroanatomy, Max Planck Institute for Brain Research, 60528 Frankfurt/Main, Germany
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36
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Gosens I, den Hollander AI, Cremers FPM, Roepman R. Composition and function of the Crumbs protein complex in the mammalian retina. Exp Eye Res 2008; 86:713-26. [PMID: 18407265 DOI: 10.1016/j.exer.2008.02.005] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2007] [Revised: 01/09/2008] [Accepted: 02/18/2008] [Indexed: 11/27/2022]
Abstract
The Crumbs proteins (CRBs) are transmembrane proteins, homologous to Drosophila Crumbs, with a key role in defining the apical membrane domain in photoreceptors as well as in embryonic epithelia. Crumbs proteins are conserved between species and their intracellular domains are involved in organizing a conserved macromolecular protein scaffold with important roles in cell polarity as well as morphogenesis and maintenance of the retina. Mutations in the gene encoding human CRB1, the first one identified out of the three human orthologs, have been associated with a number of retinal dystrophies including Leber amaurosis and retinitis pigmentosa type 12. Although no other mammalian Crumbs complex members as of yet have been associated with retinal degeneration, disruption of different zebrafish and fruitfly orthologs can lead to various retinal defects. The core Crumbs complex localizes apical to the outer limiting membrane, where photoreceptors and Müller glia contact each other. Correct functioning of Crumbs ensures adhesion between these cells by an unknown mechanism. This review summarizes the current view on the composition and function of the Crumbs prsotein complex in the mammalian retina. Recently, a number of new members of the Crumbs protein complex have been identified. These include most members of the membrane palmitoylated protein family (MPP), involved in assembly of macromolecular protein complexes. Some components of the complex are found to exert a function in the photoreceptor synapses and/or at the region of the connecting cilium. Studies using polarized cell cultures or model organisms, like Drosophila and zebrafish, suggest important links of the Crumbs protein complex to several biological processes in the mammalian eye, including retinal patterning, ciliogenesis and vesicular transport.
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Affiliation(s)
- Ilse Gosens
- Department of Human Genetics and Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Geert Grooteplein Zuid 10, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
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Bachmann A, Grawe F, Johnson K, Knust E. Drosophila Lin-7 is a component of the Crumbs complex in epithelia and photoreceptor cells and prevents light-induced retinal degeneration. Eur J Cell Biol 2008; 87:123-36. [PMID: 18177979 DOI: 10.1016/j.ejcb.2007.11.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 11/11/2007] [Accepted: 11/13/2007] [Indexed: 11/27/2022] Open
Abstract
The Drosophila Crumbs protein complex is required to maintain epithelial cell polarity in the embryo, to ensure proper morphogenesis of photoreceptor cells and to prevent light-dependent retinal degeneration. In Drosophila, the core components of the complex are the transmembrane protein Crumbs, the membrane-associated guanylate kinase (MAGUK) Stardust and the scaffolding protein DPATJ. The composition of the complex and some of its functions are conserved in mammalian epithelial and photoreceptor cells. Here, we report that Drosophila Lin-7, a scaffolding protein with one Lin-2/Lin-7 (L27) domain and one PSD-95/Dlg/ZO-1 (PDZ) domain, is associated with the Crumbs complex in the subapical region of embryonic and follicle epithelia and at the stalk membrane of adult photoreceptor cells. DLin-7 loss-of-function mutants are viable and fertile. While DLin-7 localization depends on Crumbs, neither Crumbs, Stardust nor DPATJ require DLin-7 for proper accumulation in the subapical region. Unlike other components of the Crumbs complex, DLin-7 is also enriched in the first optic ganglion, the lamina, where it co-localizes with Discs large, another member of the MAGUK family. In contrast to crumbs mutant photoreceptor cells, those mutant for DLin-7 do not display any morphogenetic abnormalities. Similar to crumbs mutant eyes, however, DLin-7 mutant photoreceptors undergo progressive, light-dependent degeneration. These results support the previous conclusions that the function of the Crumbs complex in cell survival is independent from its function in photoreceptor morphogenesis.
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Affiliation(s)
- André Bachmann
- Institut für Genetik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
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38
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van de Pavert SA, Sanz AS, Aartsen WM, Vos RM, Versteeg I, Beck SC, Klooster J, Seeliger MW, Wijnholds J. Crb1 is a determinant of retinal apical Müller glia cell features. Glia 2007; 55:1486-97. [PMID: 17705196 DOI: 10.1002/glia.20561] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Mutations in the human Crumbs homologue-1 (CRB1) gene cause retinal blinding diseases, such as Leber congenital amaurosis and retinitis pigmentosa. In the previous studies we have shown that Crb1 resides in retinal Müller glia cells and that loss of Crb1 results in retinal degeneration (particularly in the inferior temporal quadrant of the mouse eye). Degeneration is increased by exposure to white light. Here, we studied the role of light and aging to gain a better understanding of the factors involved in the progress of retinal disease. Our data reveal that light is neither sufficient nor required to induce retinal disorganization and degeneration in young Crb1(-/-) mutant mice, suggesting that it rather modulates the retinal phenotype. Gene expression profiling showed that expression of five genes is altered in light-exposed Crb1(-/-) mutant retinas. Three of the five genes are involved in chromosome stabilization (Pituitary tumor transforming gene 1 or Pttg1, Establishment of cohesion 1 homolog 1 or Esco1, and a gene similar to histone H2B). In aged retinas, degeneration of photoreceptors, inner retinal neurons, and retinal pigment epithelium was practically limited to the inferior temporal quadrant. Loss of Crb1 in Müller glia cells resulted in an irregular number and size of their apical villi. We propose that Crb1 is required to regulate number and size of these Müller glia cell villi. The subsequent loss of retinal integrity resulted in neovascularization, in which blood vessels of the choroid protruded into the neural retina.
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MESH Headings
- Aging/genetics
- Aging/metabolism
- Aging/pathology
- Animals
- Gene Expression Profiling
- Gene Expression Regulation/genetics
- Genetic Predisposition to Disease/genetics
- Light/adverse effects
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Electron, Transmission
- Microvilli/metabolism
- Microvilli/pathology
- Neovascularization, Pathologic/genetics
- Neovascularization, Pathologic/metabolism
- Neovascularization, Pathologic/physiopathology
- Nerve Tissue Proteins/genetics
- Neuroglia/metabolism
- Neuroglia/pathology
- Optic Atrophy, Hereditary, Leber/genetics
- Optic Atrophy, Hereditary, Leber/metabolism
- Optic Atrophy, Hereditary, Leber/physiopathology
- Photic Stimulation/adverse effects
- Photoreceptor Cells/metabolism
- Photoreceptor Cells/pathology
- Photoreceptor Cells/physiopathology
- Retina/metabolism
- Retina/pathology
- Retina/physiopathology
- Retinal Degeneration/genetics
- Retinal Degeneration/metabolism
- Retinal Degeneration/physiopathology
- Retinitis Pigmentosa/genetics
- Retinitis Pigmentosa/metabolism
- Retinitis Pigmentosa/physiopathology
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Affiliation(s)
- Serge A van de Pavert
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences , Amsterdam, The Netherlands
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Berger S, Bulgakova NA, Grawe F, Johnson K, Knust E. Unraveling the genetic complexity of Drosophila stardust during photoreceptor morphogenesis and prevention of light-induced degeneration. Genetics 2007; 176:2189-200. [PMID: 17603117 PMCID: PMC1950624 DOI: 10.1534/genetics.107.071449] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Drosophila Stardust, a membrane-associated guanylate kinase (MAGUK), recruits the transmembrane protein Crumbs and the cytoplasmic proteins DPATJ and DLin-7 into an apically localized protein scaffold. This evolutionarily conserved complex is required for epithelial cell polarity in Drosophila embryos and mammalian cells in culture. In addition, mutations in Drosophila crumbs and DPATJ impair morphogenesis of photoreceptor cells (PRCs) and result in light-dependent retinal degeneration. Here we show that stardust is a genetically complex locus. While all alleles tested perturb epithelial cell polarity in the embryo, only a subset of them affects morphogenesis of PRCs or induces light-dependent retinal degeneration. Alleles retaining particular postembryonic functions still express some Stardust protein in pupal and/or adult eyes. The phenotypic complexity is reflected by the expression of distinct splice variants at different developmental stages. All proteins expressed in the retina contain the PSD95, Discs Large, ZO-1 (PDZ), Src homology 3 (SH3), and guanylate kinase (GUK) domain, but lack a large region in the N terminus encoded by one exon. These results suggest that Stardust-based protein scaffolds are dynamic, which is not only mediated by multiple interaction partners, but in addition by various forms of the Stardust protein itself.
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Affiliation(s)
- Sandra Berger
- Max-Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-10307 Dresden, Germany
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40
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Yang J, Pawlyk B, Wen XH, Adamian M, Soloviev M, Michaud N, Zhao Y, Sandberg MA, Makino CL, Li T. Mpp4 is required for proper localization of plasma membrane calcium ATPases and maintenance of calcium homeostasis at the rod photoreceptor synaptic terminals. Hum Mol Genet 2007; 16:1017-29. [PMID: 17341488 DOI: 10.1093/hmg/ddm047] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Membrane palmitoylated protein 4 (Mpp4) is a member of the membrane-associated guanylate kinase family. We show that Mpp4 localizes specifically to the plasma membrane of photoreceptor synaptic terminals. Plasma membrane Ca(2+) ATPases (PMCAs), the Ca(2+) extrusion pumps, interact with an Mpp4-dependent presynaptic membrane protein complex that includes Veli3 and PSD95. In mice lacking Mpp4, PMCAs were lost from rod photoreceptor presynaptic membranes. Synaptic ribbons were enlarged, a phenomenon known to correlate with higher Ca(2+). SERCA2 (sarcoplasmic-endoplasmic reticulum Ca(2+) ATPase, type 2), which pumps cytosolic Ca(2+) into intracellular Ca(2+) stores and localizes next to the ribbons, was increased. The distribution of IP(3)RII (InsP(3) receptor, type 2), which releases Ca(2+) from the stores, was shifted away from the synaptic terminals. Synaptic transmission to second-order neurons was maintained but was reduced in amplitude. These data suggest that loss of Mpp4 disrupts a Ca(2+) extrusion mechanism at the presynaptic membranes, with ensuing adaptive responses by the photoreceptor to restore Ca(2+) homeostasis. We propose that Mpp4 organizes a presynaptic protein complex that includes PMCAs and has a role in modulating Ca(2+) homeostasis and synaptic transmission in rod photoreceptors.
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Affiliation(s)
- Jun Yang
- The Berman-Gund Laboratory for Study of Retinal Degenerations, Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
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van de Pavert SA, Meuleman J, Malysheva A, Aartsen WM, Versteeg I, Tonagel F, Kamphuis W, McCabe CJ, Seeliger MW, Wijnholds J. A single amino acid substitution (Cys249Trp) in Crb1 causes retinal degeneration and deregulates expression of pituitary tumor transforming gene Pttg1. J Neurosci 2007; 27:564-73. [PMID: 17234588 PMCID: PMC6672796 DOI: 10.1523/jneurosci.3496-06.2007] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Different mutations in the human Crumbs homolog-1 (CRB1) gene cause a variety of retinal dystrophies, such as Leber congenital amaurosis, early onset retinitis pigmentosa (e.g., RP12), RP with Coats-like exudative vasculopathy, and pigmented paravenous retinochoroidal atrophy. Loss of Crb1 leads to displaced photoreceptors and focal degeneration of all neural layers attributable to loss of adhesion between photoreceptors and Müller glia cells. To gain insight into genotype-phenotype relationship, we generated Crb1(C249W) mice that harbor an amino acid substitution (Cys249Trp) in the extracellular sixth calcium-binding epidermal growth factor domain of Crb1. Our analysis showed that Crb1(C249W) as wild-type protein trafficked to the subapical region adjacent to adherens junctions at the outer limiting membrane (OLM). Hence, these data suggest correct trafficking of the corresponding mutant CRB1 in RP12 patients. Crb1(C249W) mice showed loss of photoreceptors in the retina, relatively late compared with mice lacking Crb1. Scanning laser ophthalmoscopy revealed autofluorescent dots that presumably represent layer abnormalities after OLM disturbance. Gene expression analyses revealed lower levels of pituitary tumor transforming gene 1 (Pttg1) transcripts in Crb1(C249W/-) knock-in and Crb1(-/-) knock-out compared with control retinas. Exposure to white light decreased levels of Pttg1 in Crb1 mutant retinas. We hypothesize deregulation of Pttg1 expression attributable to a C249W substitution in the extracellular domain of Crb1.
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Affiliation(s)
- Serge A van de Pavert
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, 1105 BA Amsterdam, The Netherlands
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Richard M, Roepman R, Aartsen WM, van Rossum AGSH, den Hollander AI, Knust E, Wijnholds J, Cremers FPM. Towards understanding CRUMBS function in retinal dystrophies. Hum Mol Genet 2006; 15 Spec No 2:R235-43. [PMID: 16987889 DOI: 10.1093/hmg/ddl195] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mutations in the Crumbs homologue 1 (CRB1) gene cause autosomal recessive retinitis pigmentosa (arRP) and autosomal Leber congenital amaurosis (arLCA). The crumbs (crb) gene was originally identified in Drosophila and encodes a large transmembrane protein required for maintenance of apico-basal cell polarity and adherens junction in embryonic epithelia. Human CRB1 and its two paralogues, CRB2 and CRB3, are highly conserved throughout the animal kingdom. Both in Drosophila and in vertebrates, the short intracellular domain of Crb/CRB organizes an evolutionary conserved protein scaffold. Several lines of evidence, obtained both in Drosophila and in mouse, show that loss-of-function of crb/CRB1 or some of its intracellular interactors lead to morphological defects and light-induced degeneration of photoreceptor cells, features comparable to those observed in patients lacking CRB1 function. In this review, we describe how understanding Crb complex function in fly and vertebrate retina enhances our knowledge of basic cell biological processes and might lead to new therapeutic approaches for patients affected with retinal dystrophies caused by mutations in the CRB1 gene.
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Affiliation(s)
- Mélisande Richard
- Institut für Genetik, Heinrich Heine Universität Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
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van Rossum AGSH, Aartsen WM, Meuleman J, Klooster J, Malysheva A, Versteeg I, Arsanto JP, Le Bivic A, Wijnholds J. Pals1/Mpp5 is required for correct localization of Crb1 at the subapical region in polarized Muller glia cells. Hum Mol Genet 2006; 15:2659-72. [PMID: 16885194 DOI: 10.1093/hmg/ddl194] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mutations in the human Crumbs homologue-1 (CRB1) gene cause retinal diseases including Leber's congenital amaurosis (LCA) and retinitis pigmentosa type 12. The CRB1 transmembrane protein localizes at a subapical region (SAR) above intercellular adherens junctions between photoreceptor and Müller glia (MG) cells. We demonstrate that the Crb1-/- phenotype, as shown in Crb1-/- mice, is accelerated and intensified in primary retina cultures. Immuno-electron microscopy showed strong Crb1 immunoreactivity at the SAR in MG cells but barely in photoreceptor cells, whereas Crb2, Crb3, Patj, Pals1 and Mupp1 were present in both cell types. Human CRB1, introduced in MG cells in Crb1-/- primary retinas, was targeted to the SAR. RNA interference-induced silencing of the Crb1-interacting-protein Pals1 (protein associated with Lin7; Mpp5) in MG cells resulted in loss of Crb1, Crb2, Mupp1 and Veli3 protein localization and partial loss of Crb3. We conclude that Pals1 is required for correct localization of Crb family members and its interactors at the SAR of polarized MG cells.
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Affiliation(s)
- Agnes G S H van Rossum
- Department of Neuromedical Genetics, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
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