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Aryal S, Anand D, Huang H, Reddy AP, Wilmarth PA, David LL, Lachke SA. Proteomic profiling of retina and retinal pigment epithelium combined embryonic tissue to facilitate ocular disease gene discovery. Hum Genet 2023; 142:927-947. [PMID: 37191732 PMCID: PMC10680127 DOI: 10.1007/s00439-023-02570-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/04/2023] [Indexed: 05/17/2023]
Abstract
To expedite gene discovery in eye development and its associated defects, we previously developed a bioinformatics resource-tool iSyTE (integrated Systems Tool for Eye gene discovery). However, iSyTE is presently limited to lens tissue and is predominantly based on transcriptomics datasets. Therefore, to extend iSyTE to other eye tissues on the proteome level, we performed high-throughput tandem mass spectrometry (MS/MS) on mouse embryonic day (E)14.5 retina and retinal pigment epithelium combined tissue and identified an average of 3300 proteins per sample (n = 5). High-throughput expression profiling-based gene discovery approaches-involving either transcriptomics or proteomics-pose a key challenge of prioritizing candidates from thousands of RNA/proteins expressed. To address this, we used MS/MS proteome data from mouse whole embryonic body (WB) as a reference dataset and performed comparative analysis-termed "in silico WB-subtraction"-with the retina proteome dataset. In silico WB-subtraction identified 90 high-priority proteins with retina-enriched expression at stringency criteria of ≥ 2.5 average spectral counts, ≥ 2.0 fold-enrichment, false discovery rate < 0.01. These top candidates represent a pool of retina-enriched proteins, several of which are associated with retinal biology and/or defects (e.g., Aldh1a1, Ank2, Ank3, Dcn, Dync2h1, Egfr, Ephb2, Fbln5, Fbn2, Hras, Igf2bp1, Msi1, Rbp1, Rlbp1, Tenm3, Yap1, etc.), indicating the effectiveness of this approach. Importantly, in silico WB-subtraction also identified several new high-priority candidates with potential regulatory function in retina development. Finally, proteins exhibiting expression or enriched-expression in the retina are made accessible in a user-friendly manner at iSyTE ( https://research.bioinformatics.udel.edu/iSyTE/ ), to allow effective visualization of this information and facilitate eye gene discovery.
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Affiliation(s)
- Sandeep Aryal
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Hongzhan Huang
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, 19713, USA
| | - Ashok P Reddy
- Proteomics Shared Resource, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Phillip A Wilmarth
- Proteomics Shared Resource, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Larry L David
- Proteomics Shared Resource, Oregon Health and Science University, Portland, OR, 97239, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA.
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, 19713, USA.
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2
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Zhou J, Welinder C, Ekström P. The Phosphoproteome of the Rd1 Mouse Retina, a Model of Inherited Photoreceptor Degeneration, Changes after Protein Kinase G Inhibition. Int J Mol Sci 2023; 24:9836. [PMID: 37372984 DOI: 10.3390/ijms24129836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 05/31/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
Retinitis pigmentosa (RP) is a frequent cause of blindness among the working population in industrial countries due to the inheritable death of photoreceptors. Though gene therapy was recently approved for mutations in the RPE65 gene, there is in general no effective treatment presently. Previously, abnormally high levels of cGMP and overactivation of its dependent protein kinase (PKG) have been suggested as causative for the fatal effects on photoreceptors, making it meaningful to explore the cGMP-PKG downstream signaling for more pathological insights and novel therapeutic target development purposes. Here, we manipulated the cGMP-PKG system in degenerating retinas from the rd1 mouse model pharmacologically via adding a PKG inhibitory cGMP-analogue to organotypic retinal explant cultures. A combination of phosphorylated peptide enrichment and mass spectrometry was then applied to study the cGMP-PKG-dependent phosphoproteome. We identified a host of novel potential cGMP-PKG downstream substrates and related kinases using this approach and selected the RAF1 protein, which may act as both a substrate and a kinase, for further validation. This showed that the RAS/RAF1/MAPK/ERK pathway may be involved in retinal degeneration in a yet unclarified mechanism, thus deserving further investigation in the future.
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Affiliation(s)
- Jiaming Zhou
- Ophthalmology, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 221 00 Lund, Sweden
| | - Charlotte Welinder
- Mass Spectrometry, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 221 00 Lund, Sweden
| | - Per Ekström
- Ophthalmology, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 221 00 Lund, Sweden
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3
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Stevens SR, Rasband MN. Pleiotropic Ankyrins: Scaffolds for Ion Channels and Transporters. Channels (Austin) 2022; 16:216-229. [PMID: 36082411 PMCID: PMC9467607 DOI: 10.1080/19336950.2022.2120467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The ankyrin proteins (Ankyrin-R, Ankyrin-B, and Ankyrin-G) are a family of scaffolding, or membrane adaptor proteins necessary for the regulation and targeting of several types of ion channels and membrane transporters throughout the body. These include voltage-gated sodium, potassium, and calcium channels in the nervous system, heart, lungs, and muscle. At these sites, ankyrins recruit ion channels, and other membrane proteins, to specific subcellular domains, which are then stabilized through ankyrin's interaction with the submembranous spectrin-based cytoskeleton. Several recent studies have expanded our understanding of both ankyrin expression and their ion channel binding partners. This review provides an updated overview of ankyrin proteins and their known channel and transporter interactions. We further discuss several potential avenues of future research that would expand our understanding of these important organizational proteins.
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Affiliation(s)
- Sharon R. Stevens
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Matthew N. Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA,CONTACT Matthew N. Rasband Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX77030, USA
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Schmid V, Wurzel A, Wetzel CH, Plössl K, Bruckmann A, Luckner P, Weber BHF, Friedrich U. Retinoschisin and novel Na/K-ATPase interaction partners Kv2.1 and Kv8.2 define a growing protein complex at the inner segments of mammalian photoreceptors. Cell Mol Life Sci 2022; 79:448. [PMID: 35876901 PMCID: PMC9314279 DOI: 10.1007/s00018-022-04409-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 05/05/2022] [Accepted: 05/30/2022] [Indexed: 11/28/2022]
Abstract
The RS1 gene on Xp 22.13 encodes retinoschisin which is known to directly interact with the retinal Na/K-ATPase at the photoreceptor inner segments. Pathologic mutations in RS1 cause X-linked juvenile retinoschisis (XLRS), a hereditary retinal dystrophy in young males. To further delineate the retinoschisin-Na/K-ATPase complex, co-immunoprecipitation was performed with porcine and murine retinal lysates targeting the ATP1A3 subunit. This identified the voltage-gated potassium (Kv) channel subunits Kv2.1 and Kv8.2 as direct interaction partners of the retinal Na/K-ATPase. Colocalization of the individual components of the complex was demonstrated at the membrane of photoreceptor inner segments. We further show that retinoschisin-deficiency, a frequent consequence of molecular pathology in XLRS, causes mislocalization of the macromolecular complex during postnatal retinal development with a simultaneous reduction of Kv2.1 and Kv8.2 protein expression, while the level of retinal Na/K-ATPase expression remains unaffected. Patch-clamp analysis revealed no effect of retinoschisin-deficiency on Kv channel mediated potassium ion currents in vitro. Together, our data suggest that Kv2.1 and Kv8.2 together with retinoschisin and the retinal Na/K-ATPase are integral parts of a macromolecular complex at the photoreceptor inner segments. Defective compartmentalization of this complex due to retinoschisin-deficiency may be a crucial step in initial XLRS pathogenesis.
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Affiliation(s)
- Verena Schmid
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - Alexander Wurzel
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - Christian H Wetzel
- Department of Psychiatry and Psychotherapy, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - Karolina Plössl
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - Astrid Bruckmann
- Institute of Biochemistry, Genetics and Microbiology, Protein Mass Spectrometry Group, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Patricia Luckner
- Institute of Biochemistry, Genetics and Microbiology, Protein Mass Spectrometry Group, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Bernhard H F Weber
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
- Institute of Clinical Human Genetics, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
| | - Ulrike Friedrich
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
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Functional compartmentalization of photoreceptor neurons. Pflugers Arch 2021; 473:1493-1516. [PMID: 33880652 DOI: 10.1007/s00424-021-02558-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/15/2021] [Accepted: 03/22/2021] [Indexed: 12/16/2022]
Abstract
Retinal photoreceptors are neurons that convert dynamically changing patterns of light into electrical signals that are processed by retinal interneurons and ultimately transmitted to vision centers in the brain. They represent the essential first step in seeing without which the remainder of the visual system is rendered moot. To support this role, the major functions of photoreceptors are segregated into three main specialized compartments-the outer segment, the inner segment, and the pre-synaptic terminal. This compartmentalization is crucial for photoreceptor function-disruption leads to devastating blinding diseases for which therapies remain elusive. In this review, we examine the current understanding of the molecular and physical mechanisms underlying photoreceptor functional compartmentalization and highlight areas where significant knowledge gaps remain.
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Shrivastava AN, Triller A, Melki R. Cell biology and dynamics of Neuronal Na +/K +-ATPase in health and diseases. Neuropharmacology 2018; 169:107461. [PMID: 30550795 DOI: 10.1016/j.neuropharm.2018.12.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 11/17/2018] [Accepted: 12/08/2018] [Indexed: 10/27/2022]
Abstract
Neuronal Na+/K+-ATPase is responsible for the maintenance of ionic gradient across plasma membrane. In doing so, in a healthy brain, Na+/K+-ATPase activity accounts for nearly half of total brain energy consumption. The α3-subunit containing Na+/K+-ATPase expression is restricted to neurons. Heterozygous mutations within α3-subunit leads to Rapid-onset Dystonia Parkinsonism, Alternating Hemiplegia of Childhood and other neurological and neuropsychiatric disorders. Additionally, proteins such as α-synuclein, amyloid-β, tau and SOD1 whose aggregation is associated to neurodegenerative diseases directly bind and impair α3-Na+/K+-ATPase activity. The review will provide a summary of neuronal α3-Na+/K+-ATPase functional properties, expression pattern, protein-protein interactions at the plasma membrane, biophysical properties (distribution and lateral diffusion). Lastly, the role of α3-Na+/K+-ATPase in neurological and neurodegenerative disorders will be discussed. This article is part of the special issue entitled 'Mobility and trafficking of neuronal membrane proteins'.
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Affiliation(s)
- Amulya Nidhi Shrivastava
- CEA, Institut François Jacob (MIRcen) and CNRS, Laboratory of Neurodegenerative Diseases (U9199), 18 Route du Panorama, 92265, Fontenay-aux-Roses, France.
| | - Antoine Triller
- Institut de Biologie de l'ENS (IBENS), École Normale Supérieure, INSERM, CNRS, PSL, Research University, 46 Rue d'Ulm, 75005 Paris, France
| | - Ronald Melki
- CEA, Institut François Jacob (MIRcen) and CNRS, Laboratory of Neurodegenerative Diseases (U9199), 18 Route du Panorama, 92265, Fontenay-aux-Roses, France
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7
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Plössl K, Royer M, Bernklau S, Tavraz NN, Friedrich T, Wild J, Weber BHF, Friedrich U. Retinoschisin is linked to retinal Na/K-ATPase signaling and localization. Mol Biol Cell 2017; 28:2178-2189. [PMID: 28615319 PMCID: PMC5531734 DOI: 10.1091/mbc.e17-01-0064] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/02/2017] [Accepted: 06/06/2017] [Indexed: 01/30/2023] Open
Abstract
Retinoschisin binds to the extracellular domain of Na/K-ATPase subunit β2. Retinoschisin inhibits Na/K-ATPase–associated signaling cascades and affects Na/K-ATPase localization. The retinoschisin-Na/K-ATPase complex overlaps with signaling mediators. Defective Na/K-ATPase signaling by retinoschisin deficiency may promote retinal dystrophy. Mutations in the RS1 gene cause X-linked juvenile retinoschisis (XLRS), a hereditary retinal dystrophy. We recently showed that retinoschisin, the protein encoded by RS1, regulates ERK signaling and apoptosis in retinal cells. In this study, we explored an influence of retinoschisin on the functionality of the Na/K-ATPase, its interaction partner at retinal plasma membranes. We show that retinoschisin binding requires the β2-subunit of the Na/K-ATPase, whereas the α-subunit is exchangeable. Our investigations revealed no effect of retinoschisin on Na/K-ATPase–mediated ATP hydrolysis and ion transport. However, we identified an influence of retinoschisin on Na/K-ATPase–regulated signaling cascades and Na/K-ATPase localization. In addition to the known ERK deactivation, retinoschisin treatment of retinoschisin-deficient (Rs1h-/Y) murine retinal explants decreased activation of Src, an initial transmitter in Na/K-ATPase signal transduction, and of Ca2+ signaling marker Camk2. Immunohistochemistry on murine retinae revealed an overlap of the retinoschisin–Na/K-ATPase complex with proteins involved in Na/K-ATPase signaling, such as caveolin, phospholipase C, Src, and the IP3 receptor. Finally, retinoschisin treatment altered Na/K-ATPase localization in photoreceptors of Rs1h-/Y retinae. Taken together, our results suggest a regulatory effect of retinoschisin on Na/K-ATPase signaling and localization, whereas Na/K-ATPase-dysregulation caused by retinoschisin deficiency could represent an initial step in XLRS pathogenesis.
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Affiliation(s)
- Karolina Plössl
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
| | - Melanie Royer
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
| | - Sarah Bernklau
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
| | - Neslihan N Tavraz
- Institute of Chemistry, Technical University of Berlin, 10623 Berlin, Germany
| | - Thomas Friedrich
- Institute of Chemistry, Technical University of Berlin, 10623 Berlin, Germany
| | - Jens Wild
- Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg, University of Regensburg, 93053 Regensburg, Germany
| | - Bernhard H F Weber
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
| | - Ulrike Friedrich
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
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8
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Huq AJ, Pertile MD, Davis AM, Landon H, James PA, Kline CF, Vohra J, Mohler PJ, Delatycki MB. A Novel Mechanism for Human Cardiac Ankyrin-B Syndrome due to Reciprocal Chromosomal Translocation. Heart Lung Circ 2016; 26:612-618. [PMID: 27916589 DOI: 10.1016/j.hlc.2016.09.013] [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] [Received: 06/23/2016] [Revised: 09/23/2016] [Accepted: 09/27/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Cardiac rhythm abnormalities are a leading cause of morbidity and mortality in developed countries. Loss-of-function variants in the ANK2 gene can cause a variety of cardiac rhythm abnormalities including sinus node dysfunction, atrial fibrillation and ventricular arrhythmias (called the "ankyrin-B syndrome"). ANK2 encodes ankyrin-B, a molecule critical for the membrane targeting of key cardiac ion channels, transporters, and signalling proteins. METHODS AND RESULTS Here, we describe a family with a reciprocal chromosomal translocation between chromosomes 4q25 and 9q26 that transects the ANK2 gene on chromosome 4 resulting in loss-of-function of ankyrin-B. Select family members with ankyrin-B haploinsufficiency due to the translocation displayed clinical features of ankyrin-B syndrome. Furthermore, evaluation of primary lymphoblasts from a carrier of the translocation showed altered levels of ankyrin-B as well as a reduced expression of downstream ankyrin-binding partners. CONCLUSIONS Thus, our data conclude that, similar to previously described ANK2 loss-of-function "point mutations", large chromosomal translocations resulting in ANK2 haploinsufficiency are sufficient to cause the human cardiac ankyrin-B syndrome. The unexpected ascertainment of ANK2 dysfunction via the discovery of a chromosomal translocation in this family, the determination of the familial phenotype, as well as the complexities in formulating screening and treatment strategies are discussed.
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Affiliation(s)
- A J Huq
- Department of Clinical Genetics, Austin Hospital, Melbourne, Vic, Australia; Department of Genetic Medicine, Royal Melbourne Hospital, Melbourne, Vic, Australia.
| | - M D Pertile
- Victorian Clinical Genetics Services, Melbourne, Vic, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia
| | - A M Davis
- Department of Cardiology, Royal Children's Hospital, Melbourne, Vic, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia; Murdoch Childrens Research Institute, Melbourne, Vic, Australia
| | - H Landon
- Dorothy M. Davis Heart and Lung Research Institute; Departments of Physiology & Cell Biology and Internal Medicine; Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - P A James
- Department of Genetic Medicine, Royal Melbourne Hospital, Melbourne, Vic, Australia; Department of Pathology, University of Melbourne, Melbourne, Vic, Australia
| | - C F Kline
- Dorothy M. Davis Heart and Lung Research Institute; Departments of Physiology & Cell Biology and Internal Medicine; Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - J Vohra
- Department of Genetic Medicine, Royal Melbourne Hospital, Melbourne, Vic, Australia; Department of Cardiology, Royal Melbourne Hospital, Melbourne, Vic, Australia
| | - P J Mohler
- Dorothy M. Davis Heart and Lung Research Institute; Departments of Physiology & Cell Biology and Internal Medicine; Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - M B Delatycki
- Department of Clinical Genetics, Austin Hospital, Melbourne, Vic, Australia; Victorian Clinical Genetics Services, Melbourne, Vic, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia; Bruce Lefroy Centre, Murdoch Childrens Research Institute, Melbourne, Vic, Australia
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9
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An Adaptable Spectrin/Ankyrin-Based Mechanism for Long-Range Organization of Plasma Membranes in Vertebrate Tissues. CURRENT TOPICS IN MEMBRANES 2015; 77:143-84. [PMID: 26781832 DOI: 10.1016/bs.ctm.2015.10.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Ankyrins are membrane-associated proteins that together with their spectrin partners are responsible for micron-scale organization of vertebrate plasma membranes, including those of erythrocytes, excitable membranes of neurons and heart, lateral membrane domains of columnar epithelial cells, and striated muscle. Ankyrins coordinate functionally related membrane transporters and cell adhesion proteins (15 protein families identified so far) within plasma membrane compartments through independently evolved interactions of intrinsically disordered sequences with a highly conserved peptide-binding groove formed by the ANK repeat solenoid. Ankyrins are coupled to spectrins, which are elongated organelle-sized proteins that form mechanically resilient arrays through cross-linking by specialized actin filaments. In addition to protein interactions, cellular targeting and assembly of spectrin/ankyrin domains also critically depend on palmitoylation of ankyrin-G by aspartate-histidine-histidine-cysteine 5/8 palmitoyltransferases, as well as interaction of beta-2 spectrin with phosphoinositide lipids. These lipid-dependent spectrin/ankyrin domains are not static but are locally dynamic and determine membrane identity through opposing endocytosis of bulk lipids as well as specific proteins. A partnership between spectrin, ankyrin, and cell adhesion molecules first emerged in bilaterians over 500 million years ago. Ankyrin and spectrin may have been recruited to plasma membranes from more ancient roles in organelle transport. The basic bilaterian spectrin-ankyrin toolkit markedly expanded in vertebrates through gene duplications combined with variation in unstructured intramolecular regulatory sequences as well as independent evolution of ankyrin-binding activity by ion transporters involved in action potentials and calcium homeostasis. In addition, giant vertebrate ankyrins with specialized roles in axons acquired new coding sequences by exon shuffling. We speculate that early axon initial segments and epithelial lateral membranes initially were based on spectrin-ankyrin-cell adhesion molecule assemblies and subsequently served as "incubators," where ion transporters independently acquired ankyrin-binding activity through positive selection.
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10
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Laird JG, Pan Y, Modestou M, Yamaguchi DM, Song H, Sokolov M, Baker SA. Identification of a VxP Targeting Signal in the Flagellar Na+ /K+ -ATPase. Traffic 2015; 16:1239-53. [PMID: 26373354 DOI: 10.1111/tra.12332] [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] [Received: 01/26/2015] [Revised: 09/11/2015] [Accepted: 09/11/2015] [Indexed: 12/15/2022]
Abstract
Na(+) /K(+) -ATPase (NKA) participates in setting electrochemical gradients, cardiotonic steroid signaling and cellular adhesion. Distinct isoforms of NKA are found in different tissues and subcellular localization patterns. For example, NKA α1 is widely expressed, NKA α3 is enriched in neurons and NKA α4 is a testes-specific isoform found in sperm flagella. In some tissues, ankyrin, a key component of the membrane cytoskeleton, can regulate the trafficking of NKA. In the retina, NKA and ankyrin-B are expressed in multiple cell types and immunostaining for each is striking in the synaptic layers. Labeling for NKA is also prominent along the inner segment plasma membrane (ISPM) of photoreceptors. NKA co-immunoprecipitates with ankyrin-B, but on a subcellular level colocalization of these two proteins varies dependent on the cell type. We used transgenic Xenopus laevis tadpoles to evaluate the subcellular trafficking of NKA in photoreceptors. GFP-NKA α3 and α1 are localized to the ISPM, but α4 is localized to outer segments (OSs). We identified a VxP motif responsible for the OS targeting by using a series of chimeric and mutant NKA constructs. This motif is similar to previously identified ciliary targeting motifs. Given the structural similarities between OSs and flagella, our findings shed light on the subcellular targeting of this testes-specific NKA isoform.
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Affiliation(s)
- Joseph G Laird
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Yuan Pan
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.,Current address: Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Modestos Modestou
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - David M Yamaguchi
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Hongman Song
- Department of Ophthalmology, West Virginia University School of Medicine and West Virginia University Eye Institute, Morgantown, WV, 26506, USA.,Current address: Section for Translational Research in Retina & Macular Degeneration, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, 20892, USA
| | - Maxim Sokolov
- Department of Ophthalmology, West Virginia University School of Medicine and West Virginia University Eye Institute, Morgantown, WV, 26506, USA
| | - Sheila A Baker
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
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11
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Kobeissy FH, Liu MC, Yang Z, Zhang Z, Zheng W, Glushakova O, Mondello S, Anagli J, Hayes RL, Wang KK. Degradation of βII-Spectrin Protein by Calpain-2 and Caspase-3 Under Neurotoxic and Traumatic Brain Injury Conditions. Mol Neurobiol 2015; 52:696-709. [PMID: 25270371 PMCID: PMC4383741 DOI: 10.1007/s12035-014-8898-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 09/10/2014] [Indexed: 12/22/2022]
Abstract
A major consequence of traumatic brain injury (TBI) is the rapid proteolytic degradation of structural cytoskeletal proteins. This process is largely reflected by the interruption of axonal transport as a result of extensive axonal injury leading to neuronal cell injury. Previous work from our group has described the extensive degradation of the axonally enriched cytoskeletal αII-spectrin protein which results in molecular signature breakdown products (BDPs) indicative of injury mechanisms and to specific protease activation both in vitro and in vivo. In the current study, we investigated the integrity of βII-spectrin protein and its proteolytic profile both in primary rat cerebrocortical cell culture under apoptotic, necrotic, and excitotoxic challenge and extended to in vivo rat model of experimental TBI (controlled cortical impact model). Interestingly, our results revealed that the intact 260-kDa βII-spectrin is degraded into major fragments (βII-spectrin breakdown products (βsBDPs)) of 110, 108, 85, and 80 kDa in rat brain (hippocampus and cortex) 48 h post-injury. These βsBDP profiles were further characterized and compared to an in vitro βII-spectrin fragmentation pattern of naive rat cortex lysate digested by calpain-2 and caspase-3. Results revealed that βII-spectrin was degraded into major fragments of 110/85 kDa by calpain-2 activation and 108/80 kDa by caspase-3 activation. These data strongly support the hypothesis that in vivo activation of multiple protease system induces structural protein proteolysis involving βII-spectrin proteolysis via a specific calpain and/or caspase-mediated pathway resulting in a signature, protease-specific βsBDPs that are dependent upon the type of neural injury mechanism. This work extends on previous published work that discusses the interplay spectrin family (αII-spectrin and βII-spectrin) and their susceptibility to protease proteolysis and their implication to neuronal cell death mechanisms.
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Affiliation(s)
- Firas H Kobeissy
- Center for Neuroproteomics & Biomarkers Research, Department
of Psychiatry, University of Florida, Gainesville, FL 32610, USA
| | - Ming Cheng Liu
- Center for Neuroproteomics & Biomarkers Research, Department
of Psychiatry, University of Florida, Gainesville, FL 32610, USA
| | - Zhihui Yang
- Center for Neuroproteomics & Biomarkers Research, Department
of Psychiatry, University of Florida, Gainesville, FL 32610, USA
| | - Zhiqun Zhang
- Center for Neuroproteomics & Biomarkers Research, Department
of Psychiatry, University of Florida, Gainesville, FL 32610, USA
| | - Wenrong Zheng
- Center for Neuroproteomics & Biomarkers Research, Department
of Psychiatry, University of Florida, Gainesville, FL 32610, USA
| | - Olena Glushakova
- Banyan Laboratory, Banyan Biomarkers, Inc., Alachua, FL 32615,
USA
| | - Stefania Mondello
- Department of Neurosciences, University of Messina, 98125
Messina, Italy
| | - John Anagli
- Banyan Laboratory, Banyan Biomarkers, Inc., Alachua, FL 32615,
USA
| | - Ronald L. Hayes
- Banyan Laboratory, Banyan Biomarkers, Inc., Alachua, FL 32615,
USA
| | - Kevin K.W. Wang
- Center for Neuroproteomics & Biomarkers Research, Department
of Psychiatry, University of Florida, Gainesville, FL 32610, USA
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12
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Ponceau A, Albigès-Rizo C, Colin-Aronovicz Y, Destaing O, Lecomte MC. αII-spectrin regulates invadosome stability and extracellular matrix degradation. PLoS One 2015; 10:e0120781. [PMID: 25830635 PMCID: PMC4382279 DOI: 10.1371/journal.pone.0120781] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 01/27/2015] [Indexed: 01/07/2023] Open
Abstract
Invadosomes are actin-rich adhesion structures involved in tissue invasion and extracellular matrix (ECM) remodelling. αII-Spectrin, an ubiquitous scaffolding component of the membrane skeleton and a partner of actin regulators (ABI1, VASP and WASL), accumulates highly and specifically in the invadosomes of multiple cell types, such as mouse embryonic fibroblasts (MEFs) expressing SrcY527F, the constitutively active form of Src or activated HMEC-1 endothelial cells. FRAP and live-imaging analysis revealed that αII-spectrin is a highly dynamic component of invadosomes as actin present in the structures core. Knockdown of αII-spectrin expression destabilizes invadosomes and reduces the ability of the remaining invadosomes to digest the ECM and to promote invasion. The ECM degradation defect observed in spectrin-depleted-cells is associated with highly dynamic and unstable invadosome rings. Moreover, FRAP measurement showed the specific involvement of αII-spectrin in the regulation of the mobile/immobile β3-integrin ratio in invadosomes. Our findings suggest that spectrin could regulate invadosome function and maturation by modulating integrin mobility in the membrane, allowing the normal processes of adhesion, invasion and matrix degradation. Altogether, these data highlight a new function for spectrins in the stability of invadosomes and the coupling between actin regulation and ECM degradation.
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Affiliation(s)
- Aurélie Ponceau
- Institut National de la Transfusion Sanguine, INSERM UMR-S 665, Paris, France, Université Paris 7/Denis Diderot, Paris, France
| | - Corinne Albigès-Rizo
- Institut Albert Bonniot, Université Joseph Fourier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale-Université Joseph Fourier U823 Site Santé, Grenoble, France
| | - Yves Colin-Aronovicz
- Institut National de la Transfusion Sanguine, INSERM UMR-S 665, Paris, France, Université Paris 7/Denis Diderot, Paris, France
| | - Olivier Destaing
- Institut Albert Bonniot, Université Joseph Fourier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale-Université Joseph Fourier U823 Site Santé, Grenoble, France
| | - Marie Christine Lecomte
- Institut National de la Transfusion Sanguine, INSERM UMR-S 665, Paris, France, Université Paris 7/Denis Diderot, Paris, France
- * E-mail:
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13
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Curran J, Mohler PJ. Alternative Paradigms for Ion Channelopathies: Disorders of Ion Channel Membrane Trafficking and Posttranslational Modification. Annu Rev Physiol 2015; 77:505-24. [DOI: 10.1146/annurev-physiol-021014-071838] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jerry Curran
- The Dorothy M. Davis Heart & Lung Research Institute,
- Department of Physiology and Cell Biology, and
| | - Peter J. Mohler
- The Dorothy M. Davis Heart & Lung Research Institute,
- Department of Physiology and Cell Biology, and
- Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio 43210;
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14
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Ding XQ, Matveev A, Singh A, Komori N, Matsumoto H. Exploration of cone cyclic nucleotide-gated channel-interacting proteins using affinity purification and mass spectrometry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 801:57-65. [PMID: 24664681 DOI: 10.1007/978-1-4614-3209-8_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Photopic (cone) vision essential for color sensation, central vision, and visual acuity is mediated by the activation of photoreceptor cyclic nucleotide-gated (CNG) channels. Naturally occurring mutations in the cone channel subunits CNGA3 and CNGB3 are associated with achromatopsia and cone dystrophies. This work investigated the functional modulation of cone CNG channel by exploring the channel-interacting proteins. Retinal protein extracts prepared from cone-dominant Nrl (- / -) mice were used in CNGA3 antibody affinity purification, followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) separation and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry analysis. The peptide mass fingerprinting of the tryptic digests and database search identified a number of proteins including spectrin alpha-2, ATPase (Na(+)/K(+) transporting) alpha-3, alpha and beta subunits of ATP synthase (H(+) transporting, mitochondrial F1 complex), and alpha-2 subunit of the guanine nucleotide-binding protein. In addition, the affinity-binding assays demonstrated an interaction between cone CNG channel and calmodulin but not cone Na(+)/Ca(2+)-K(+) exchanger in the mouse retina. Results of this study provide insight into our understanding of cone CNG channel-interacting proteins and the functional modulations.
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Affiliation(s)
- Xi-Qin Ding
- Departments of Cell Biology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 553, 73104, Oklahoma City, OK, USA,
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15
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Laßek M, Weingarten J, Volknandt W. The Proteome of the Murine Presynaptic Active Zone. Proteomes 2014; 2:243-257. [PMID: 28250380 PMCID: PMC5302740 DOI: 10.3390/proteomes2020243] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 04/09/2014] [Accepted: 04/21/2014] [Indexed: 01/09/2023] Open
Abstract
The proteome of the presynaptic active zone controls neurotransmitter release and the short- and long-term structural and functional dynamics of the nerve terminal. The proteinaceous inventory of the presynaptic active zone has recently been reported. This review will evaluate the subcellular fractionation protocols and the proteomic approaches employed. A breakthrough for the identification of the proteome of the presynaptic active zone was the successful employment of antibodies directed against a cytosolic epitope of membrane integral synaptic vesicle proteins for the immunopurification of synaptic vesicles docked to the presynaptic plasma membrane. Combining immunopurification and subsequent analytical mass spectrometry, hundreds of proteins, including synaptic vesicle proteins, components of the presynaptic fusion and retrieval machinery, proteins involved in intracellular and extracellular signaling and a large variety of adhesion molecules, were identified. Numerous proteins regulating the rearrangement of the cytoskeleton are indicative of the functional and structural dynamics of the presynapse. This review will critically discuss both the experimental approaches and prominent protein candidates identified. Many proteins have not previously been assigned to the presynaptic release sites and may be directly involved in the short- and long-term structural modulation of the presynaptic compartment. The identification of proteinaceous constituents of the presynaptic active zone provides the basis for further analyzing the interaction of presynaptic proteins with their targets and opens novel insights into the functional role of these proteins in neuronal communication.
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Affiliation(s)
- Melanie Laßek
- Institute for Cell Biology and Neuroscience, Department Molecular and Cellular Neurobiology, Max von Laue Str. 13, 60438 Frankfurt am Main, Germany.
| | - Jens Weingarten
- Institute for Cell Biology and Neuroscience, Department Molecular and Cellular Neurobiology, Max von Laue Str. 13, 60438 Frankfurt am Main, Germany.
| | - Walter Volknandt
- Institute for Cell Biology and Neuroscience, Department Molecular and Cellular Neurobiology, Max von Laue Str. 13, 60438 Frankfurt am Main, Germany.
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16
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Weingarten J, Lassek M, Mueller BF, Rohmer M, Lunger I, Baeumlisberger D, Dudek S, Gogesch P, Karas M, Volknandt W. The proteome of the presynaptic active zone from mouse brain. Mol Cell Neurosci 2014; 59:106-18. [PMID: 24534009 DOI: 10.1016/j.mcn.2014.02.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 02/05/2014] [Accepted: 02/07/2014] [Indexed: 01/07/2023] Open
Abstract
Neurotransmitter release as well as the structural and functional dynamics of the presynaptic active zone is controlled by proteinaceous components. Here we describe for the first time an experimental approach for the isolation of the presynaptic active zone from individual mouse brains, a prerequisite for understanding the functional inventory of the presynaptic protein network and for the later analysis of changes occurring in mutant mice. Using a monoclonal antibody against the ubiquitous synaptic vesicle protein SV2 we immunopurified synaptic vesicles docked to the presynaptic plasma membrane. Enrichment studies by means of Western blot analysis and mass spectrometry identified 485 proteins belonging to an impressive variety of functional categories. Our data suggest that presynaptic active zones represent focal hot spots that are not only involved in the regulation of neurotransmitter release but also in multiple structural and functional alterations the adult nerve terminal undergoes during neural activity in adult CNS. They furthermore open new avenues for characterizing alterations in the active zone proteome of mutant mice and their corresponding controls, including the various mouse models of neurological diseases.
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Affiliation(s)
- Jens Weingarten
- Institute for Cell Biology and Neuroscience, Biologicum, Goethe-University, Frankfurt am Main, Germany
| | - Melanie Lassek
- Institute for Cell Biology and Neuroscience, Biologicum, Goethe-University, Frankfurt am Main, Germany
| | - Benjamin F Mueller
- Institute of Pharmaceutical Chemistry, Cluster of Excellence "Macromolecular Complexes", Goethe-University, Frankfurt am Main, Germany
| | - Marion Rohmer
- Institute of Pharmaceutical Chemistry, Cluster of Excellence "Macromolecular Complexes", Goethe-University, Frankfurt am Main, Germany
| | - Ilaria Lunger
- Institute for Cell Biology and Neuroscience, Biologicum, Goethe-University, Frankfurt am Main, Germany
| | | | - Simone Dudek
- Institute for Cell Biology and Neuroscience, Biologicum, Goethe-University, Frankfurt am Main, Germany
| | - Patricia Gogesch
- Institute for Cell Biology and Neuroscience, Biologicum, Goethe-University, Frankfurt am Main, Germany
| | - Michael Karas
- Institute of Pharmaceutical Chemistry, Cluster of Excellence "Macromolecular Complexes", Goethe-University, Frankfurt am Main, Germany
| | - Walter Volknandt
- Institute for Cell Biology and Neuroscience, Biologicum, Goethe-University, Frankfurt am Main, Germany.
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17
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Papal S, Cortese M, Legendre K, Sorusch N, Dragavon J, Sahly I, Shorte S, Wolfrum U, Petit C, El-Amraoui A. The giant spectrin βV couples the molecular motors to phototransduction and Usher syndrome type I proteins along their trafficking route. Hum Mol Genet 2013; 22:3773-88. [PMID: 23704327 DOI: 10.1093/hmg/ddt228] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mutations in the myosin VIIa gene cause Usher syndrome type IB (USH1B), characterized by deaf-blindness. A delay of opsin trafficking has been observed in the retinal photoreceptor cells of myosin VIIa-deficient mice. We identified spectrin βV, the mammalian β-heavy spectrin, as a myosin VIIa- and rhodopsin-interacting partner in photoreceptor cells. Spectrin βV displays a polarized distribution from the Golgi apparatus to the base of the outer segment, which, unlike that of other β spectrins, matches the trafficking route of opsin and other phototransduction proteins. Formation of spectrin βV-rhodopsin complex could be detected in the differentiating photoreceptors as soon as their outer segment emerges. A failure of the spectrin βV-mediated coupling between myosin VIIa and opsin molecules thus probably accounts for the opsin transport delay in myosin VIIa-deficient mice. We showed that spectrin βV also associates with two USH1 proteins, sans (USH1G) and harmonin (USH1C). Spectrins are supposed to function as heteromers of α and β subunits, but fluorescence resonance energy transfer and in vitro binding experiments indicated that spectrin βV can also form homodimers, which likely supports its αII-independent βV functions. Finally, consistent with its distribution along the connecting cilia axonemes, spectrin βV binds to several subunits of the microtubule-based motor proteins, kinesin II and the dynein complex. We therefore suggest that spectrin βV homomers couple some USH1 proteins, opsin and other phototransduction proteins to both actin- and microtubule-based motors, thereby contributing to their transport towards the photoreceptor outer disks.
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Affiliation(s)
- Samantha Papal
- Institut Pasteur, Unité de génétique et physiologie de l'audition, Paris, France
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18
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He M, Tseng WC, Bennett V. A single divergent exon inhibits ankyrin-B association with the plasma membrane. J Biol Chem 2013; 288:14769-79. [PMID: 23569209 PMCID: PMC3663501 DOI: 10.1074/jbc.m113.465328] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Vertebrate ankyrin-B and ankyrin-G exhibit divergent subcellular localization and function despite their high sequence and structural similarity and common origin from a single ancestral gene at the onset of chordate evolution. Previous studies of ankyrin family diversity have focused on the C-terminal regulatory domain. Here, we identify an ankyrin-B-specific linker peptide connecting the ankyrin repeat domain to the ZU52-UPA module that inhibits binding of ankyrin-B to membrane protein partners E-cadherin and neurofascin 186 and prevents association of ankyrin-B with epithelial lateral membranes as well as neuronal plasma membranes. The residues of the ankyrin-B linker required for autoinhibition are encoded by a small exon that is highly divergent between ankyrin family members but conserved in the ankyrin-B lineage. We show that the ankyrin-B linker suppresses activity of the ANK repeat domain through an intramolecular interaction, likely with a groove on the surface of the ANK repeat solenoid, thereby regulating the affinities between ankyrin-B and its binding partners. These results provide a simple evolutionary explanation for how ankyrin-B and ankyrin-G have acquired striking differences in their plasma membrane association while maintaining overall high levels of sequence similarity.
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Affiliation(s)
- Meng He
- Department of Pharmacology and Cancer Biology, Duke University, Medical Center, Durham, North Carolina 27710, USA
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19
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Bennett V, Lorenzo DN. Spectrin- and Ankyrin-Based Membrane Domains and the Evolution of Vertebrates. CURRENT TOPICS IN MEMBRANES 2013; 72:1-37. [DOI: 10.1016/b978-0-12-417027-8.00001-5] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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20
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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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21
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Abstract
Many primary vestibular afferents form large cup-shaped postsynaptic terminals (calyces) that envelope the basolateral surfaces of type I hair cells. The calyceal terminals both respond to glutamate released from ribbon synapses in the type I cells and initiate spikes that propagate to the afferent's central terminals in the brainstem. The combination of synaptic and spike initiation functions in these unique sensory endings distinguishes them from the axonal nodes of central neurons and peripheral nerves, such as the sciatic nerve, which have provided most of our information about nodal specializations. We show that rat vestibular calyces express an unusual mix of voltage-gated Na and K channels and scaffolding, cell adhesion, and extracellular matrix proteins, which may hold the ion channels in place. Protein expression patterns form several microdomains within the calyx membrane: a synaptic domain facing the hair cell, the heminode abutting the first myelinated internode, and one or two intermediate domains. Differences in the expression and localization of proteins between afferent types and zones may contribute to known variations in afferent physiology.
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22
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Winslow RL, Greenstein JL. Cardiac myocytes and local signaling in nano-domains. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2011; 107:48-59. [PMID: 21718716 DOI: 10.1016/j.pbiomolbio.2011.06.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 06/14/2011] [Indexed: 10/18/2022]
Abstract
It is well known that calcium-induced calcium-release in cardiac myocytes takes place in spatially restricted regions known as dyads, where discrete patches of junctional sarcoplasmic reticulum tightly associate with the t-tubule membrane. The dimensions of a dyad are so small that it contains only a few Ca²⁺ ions at any given time. Ca²⁺ signaling in the dyad is therefore noisy, and dominated by the Brownian motion of Ca²⁺ ions in a potential field. Remarkably, from this complexity emerges the integrated behavior of the myocyte in which, under normal conditions, precise control of Ca²⁺ release and muscle contraction is maintained over the life of the cell. This is but one example of how signal processing within the cardiac myocyte and other cells often occurs in small "nano-domains" where proteins and protein complexes interact at spatial dimensions on the order of ∼1-10 nm and at time-scales on the order of nanoseconds to perform the functions of the cell. In this article, we will review several examples of local signaling in nano-domains, how it contributes to the integrative behavior of the cardiac myocyte, and present computational methods for modeling signal processing within these domains across differing spatio-temporal scales.
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Affiliation(s)
- Raimond L Winslow
- The Institute for Computational Medicine & Department of Biomedical Engineering, The Johns Hopkins University, School of Medicine & Whiting School of Engineering, Baltimore, MD 21218, USA.
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23
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Curran J, Mohler PJ. Coordinating electrical activity of the heart: ankyrin polypeptides in human cardiac disease. Expert Opin Ther Targets 2011; 15:789-801. [PMID: 21457127 DOI: 10.1517/14728222.2011.575363] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Over the past ten years, ankyrin polypeptides have emerged as players in cardiac excitation-contraction coupling. Once thought to solely play a structural role, loss-of-function variants of genes encoding ankyrin polypeptides have highlighted how this protein mediates subcellular localization of various electrical components of the excitation-contraction coupling machinery. Evidence has revealed how disruption of this localization is the primary cause of various cardiomyopathies, ranging from long-QT syndrome 4, to sinus node disease, to more common forms of arrhythmias. AREAS COVERED The roles of ankyrin polypeptides in excitation-contraction coupling in the heart and the development of ankyrin-specific cardiomyopathies. How ankyrin polypeptides may be involved in structural and electrical remodeling of the heart, post-myocardial infarct. How ankyrin interactions with membrane-bound ion channels may regulate these channels' response to stimuli. New data, which offers the potential for unique therapies, for not only combating heart disease, but also for wider applications to various disease states. EXPERT OPINION The ankyrin family of adapter proteins is emerging as an intimate player in cardiac excitation-contraction coupling. Until recently, these proteins have gone largely unappreciated for their importance in proper cardiac function. New insights into how these proteins function within the heart are offering potentially new avenues for therapies against cardiomyopathy.
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Affiliation(s)
- Jerry Curran
- The Ohio State University, The Dorothy M. Davis Heart and Lung Research Institute, Columbus, 43210, USA.
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24
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Tee JM, Peppelenbosch MP. Anchoring skeletal muscle development and disease: the role of ankyrin repeat domain containing proteins in muscle physiology. Crit Rev Biochem Mol Biol 2010; 45:318-30. [PMID: 20515317 PMCID: PMC2942773 DOI: 10.3109/10409238.2010.488217] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The ankyrin repeat is a protein module with high affinity for other ankyrin repeats based on strong Van der Waals forces. The resulting dimerization is unusually resistant to both mechanical forces and alkanization, making this module exceedingly useful for meeting the extraordinary demands of muscle physiology. Many aspects of muscle function are controlled by the superfamily ankyrin repeat domain containing proteins, including structural fixation of the contractile apparatus to the muscle membrane by ankyrins, the archetypical member of the family. Additionally, other ankyrin repeat domain containing proteins critically control the various differentiation steps during muscle development, with Notch and developmental stage-specific expression of the members of the Ankyrin repeat and SOCS box (ASB) containing family of proteins controlling compartment size and guiding the various steps of muscle specification. Also, adaptive responses in fully formed muscle require ankyrin repeat containing proteins, with Myotrophin/V-1 ankyrin repeat containing proteins controlling the induction of hypertrophic responses following excessive mechanical load, and muscle ankyrin repeat proteins (MARPs) acting as protective mechanisms of last resort following extreme demands on muscle tissue. Knowledge on mechanisms governing the ordered expression of the various members of superfamily of ankyrin repeat domain containing proteins may prove exceedingly useful for developing novel rational therapy for cardiac disease and muscle dystrophies.
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Affiliation(s)
- Jin-Ming Tee
- Hubrecht Institute for Developmental Biology and Stem Cell Research-University Medical Center Utrecht, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
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25
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Getty AL, Pearce DA. Interactions of the proteins of neuronal ceroid lipofuscinosis: clues to function. Cell Mol Life Sci 2010; 68:453-74. [PMID: 20680390 DOI: 10.1007/s00018-010-0468-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 07/07/2010] [Accepted: 07/13/2010] [Indexed: 12/21/2022]
Abstract
Neuronal ceroid lipofuscinoses (NCL) are caused by mutations in eight different genes, are characterized by lysosomal accumulation of autofluorescent storage material, and result in a disease that causes degeneration of the central nervous system (CNS). Although functions are defined for some of the soluble proteins that are defective in NCL (cathepsin D, PPT1, and TPP1), the primary function of the other proteins defective in NCLs (CLN3, CLN5, CLN6, CLN7, and CLN8) remain poorly defined. Understanding the localization and network of interactions for these proteins can offer clues as to the function of the NCL proteins and also the pathways that will be disrupted in their absence. Here, we present a review of the current understanding of the localization, interactions, and function of the proteins associated with NCL.
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Affiliation(s)
- Amanda L Getty
- Sanford Children's Health Research Center, Sanford Research USD, Sanford School of Medicine of the University of South Dakota, 2301 East 60th Street North, Sioux Falls, SD 57104-0589, USA
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26
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Ankyrin-based patterning of membrane microdomains: new insights into a novel class of cardiovascular diseases. J Cardiovasc Pharmacol 2009; 54:106-15. [PMID: 19636256 DOI: 10.1097/fjc.0b013e3181b2b6ed] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The organization of membrane-spanning proteins within discrete microdomains is critical for their physiologic function. This is especially important in the heart, where ion transporter and force-transducing microdomains are responsible for excitation-contraction coupling, anisotropic depolarization, and mechanotransduction. The following review will discuss recent advances in our understanding of the patterning of ion channel and force-transmitting membrane microdomains in cardiomyocytes, focusing on the T-tubule and intercalated disc.
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27
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Abstract
In eukaryotic cells, ankyrins serve as adaptor proteins that link membrane proteins to the underlying cytoskeleton. These adaptor proteins form protein complexes consisting of integral membrane proteins, signalling molecules and cytoskeletal components. With their modular architecture and ability to interact with many proteins, ankyrins organize and stabilize these protein networks, thereby establishing the infrastructure of membrane domains with specialized functions. To this end, ankyrin collaborates with a number of proteins including cytoskeletal proteins, cell adhesion molecules and large structural proteins. This review addresses the targeting and stabilization of protein networks related to ankyrin interactions with the cytoskeletal protein β-spectrin, L1-cell adhesion molecules and the large myofibrillar protein obscurin. The significance of these interactions for differential targeting of cardiac proteins and neuronal membrane formation is also presented. Finally, this review concludes with a discussion about ankyrin dysfunction in human diseases such as haemolytic anaemia, cardiac arrhythmia and neurological disorders.
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Affiliation(s)
- Shane R Cunha
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA.
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28
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Hashemi SM, Hund TJ, Mohler PJ. Cardiac ankyrins in health and disease. J Mol Cell Cardiol 2009; 47:203-9. [PMID: 19394342 DOI: 10.1016/j.yjmcc.2009.04.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 04/10/2009] [Accepted: 04/17/2009] [Indexed: 10/20/2022]
Abstract
Ankyrins are critical components of ion channel and transporter signaling complexes in the cardiovascular system. Over the past 5 years, ankyrin dysfunction has been linked with abnormal ion channel and transporter membrane organization and fatal human arrhythmias. Loss-of-function variants in the ankyrin-B gene (ANK2) cause "ankyrin-B syndrome" (previously called type 4 long QT syndrome), manifested by a complex cardiac phenotype including ventricular arrhythmias and sudden cardiac death. More recently, dysfunction in the ankyrin-B-based targeting pathway has been linked with a highly penetrant and severe form of human sinus node disease. Ankyrin-G (a second ankyrin gene product) is required for normal expression, membrane localization, and biophysical function of the primary cardiac voltage-gated sodium channel, Na(v)1.5. Loss of the ankyrin-G/Na(v)1.5 interaction is associated with human cardiac arrhythmia (Brugada syndrome). Finally, in the past year ankyrin dysfunction has been associated with more common arrhythmia and cardiovascular disease phenotypes. Specifically, large animal studies reveal striking remodeling of ankyrin-B and associated proteins following myocardial infarction. Additionally, the ANK2 locus has been linked with QT(c) interval variability in the general human population. Together, these findings identify a host of unanticipated and exciting roles for ankyrin polypeptides in cardiac function. More broadly, these findings illustrate the importance of local membrane organization for normal cardiac physiology.
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Affiliation(s)
- Seyed M Hashemi
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA
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29
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Kizhatil K, Baker SA, Arshavsky VY, Bennett V. Ankyrin-G promotes cyclic nucleotide-gated channel transport to rod photoreceptor sensory cilia. Science 2009; 323:1614-7. [PMID: 19299621 PMCID: PMC2792576 DOI: 10.1126/science.1169789] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Cyclic nucleotide-gated (CNG) channels localize exclusively to the plasma membrane of photosensitive outer segments of rod photoreceptors where they generate the electrical response to light. Here, we report the finding that targeting of CNG channels to the rod outer segment required their interaction with ankyrin-G. Ankyrin-G localized exclusively to rod outer segments, coimmunoprecipitated with the CNG channel, and bound to the C-terminal domain of the channel beta1 subunit. Ankyrin-G depletion in neonatal mouse retinas markedly reduced CNG channel expression. Transgenic expression of CNG channel beta-subunit mutants in Xenopus rods showed that ankyrin-G binding was necessary and sufficient for targeting of the beta1 subunit to outer segments. Thus, ankyrin-G is required for transport of CNG channels to the plasma membrane of rod outer segments.
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