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Calafate S, Özturan G, Thrupp N, Vanderlinden J, Santa-Marinha L, Morais-Ribeiro R, Ruggiero A, Bozic I, Rusterholz T, Lorente-Echeverría B, Dias M, Chen WT, Fiers M, Lu A, Vlaeminck I, Creemers E, Craessaerts K, Vandenbempt J, van Boekholdt L, Poovathingal S, Davie K, Thal DR, Wierda K, Oliveira TG, Slutsky I, Adamantidis A, De Strooper B, de Wit J. Early alterations in the MCH system link aberrant neuronal activity and sleep disturbances in a mouse model of Alzheimer's disease. Nat Neurosci 2023:10.1038/s41593-023-01325-4. [PMID: 37188873 DOI: 10.1038/s41593-023-01325-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 04/10/2023] [Indexed: 05/17/2023]
Abstract
Early Alzheimer's disease (AD) is associated with hippocampal hyperactivity and decreased sleep quality. Here we show that homeostatic mechanisms transiently counteract the increased excitatory drive to CA1 neurons in AppNL-G-F mice, but that this mechanism fails in older mice. Spatial transcriptomics analysis identifies Pmch as part of the adaptive response in AppNL-G-F mice. Pmch encodes melanin-concentrating hormone (MCH), which is produced in sleep-active lateral hypothalamic neurons that project to CA1 and modulate memory. We show that MCH downregulates synaptic transmission, modulates firing rate homeostasis in hippocampal neurons and reverses the increased excitatory drive to CA1 neurons in AppNL-G-F mice. AppNL-G-F mice spend less time in rapid eye movement (REM) sleep. AppNL-G-F mice and individuals with AD show progressive changes in morphology of CA1-projecting MCH axons. Our findings identify the MCH system as vulnerable in early AD and suggest that impaired MCH-system function contributes to aberrant excitatory drive and sleep defects, which can compromise hippocampus-dependent functions.
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Affiliation(s)
- Sara Calafate
- VIB Center for Brain & Disease Research, Leuven, Belgium.
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium.
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
| | - Gökhan Özturan
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Nicola Thrupp
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Jeroen Vanderlinden
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Luísa Santa-Marinha
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Rafaela Morais-Ribeiro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Antonella Ruggiero
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ivan Bozic
- Zentrum für Experimentelle Neurologie, Department of Neurology, Inselspital University Hospital Bern, University of Bern, Bern, Switzerland
| | - Thomas Rusterholz
- Zentrum für Experimentelle Neurologie, Department of Neurology, Inselspital University Hospital Bern, University of Bern, Bern, Switzerland
- Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Blanca Lorente-Echeverría
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Marcelo Dias
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Wei-Ting Chen
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Mark Fiers
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Ashley Lu
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Ine Vlaeminck
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Eline Creemers
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Katleen Craessaerts
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Joris Vandenbempt
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Luuk van Boekholdt
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
- KU Leuven, Department of Otorhinolaryngology, Leuven, Belgium
| | - Suresh Poovathingal
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Kristofer Davie
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Dietmar Rudolf Thal
- Department of Imaging and Pathology, Laboratory of Neuropathology, and Leuven Brain Institute, KU-Leuven, O&N IV, Leuven, Belgium
- Department of Pathology, UZ Leuven, Leuven, Belgium
| | - Keimpe Wierda
- VIB Center for Brain & Disease Research, Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Tiago Gil Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Inna Slutsky
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Antoine Adamantidis
- Zentrum für Experimentelle Neurologie, Department of Neurology, Inselspital University Hospital Bern, University of Bern, Bern, Switzerland
- Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Bart De Strooper
- VIB Center for Brain & Disease Research, Leuven, Belgium.
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium.
- UK Dementia Research Institute (UK DRI@UCL) at University College London, London, UK.
| | - Joris de Wit
- VIB Center for Brain & Disease Research, Leuven, Belgium.
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium.
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Henley JM, Nair JD, Seager R, Yucel BP, Woodhall G, Henley BS, Talandyte K, Needs HI, Wilkinson KA. Kainate and AMPA receptors in epilepsy: Cell biology, signalling pathways and possible crosstalk. Neuropharmacology 2021; 195:108569. [PMID: 33915142 DOI: 10.1016/j.neuropharm.2021.108569] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/13/2021] [Accepted: 04/09/2021] [Indexed: 02/06/2023]
Abstract
Epilepsy is caused when rhythmic neuronal network activity escapes normal control mechanisms, resulting in seizures. There is an extensive and growing body of evidence that the onset and maintenance of epilepsy involves alterations in the trafficking, synaptic surface expression and signalling of kainate and AMPA receptors (KARs and AMPARs). The KAR subunit GluK2 and AMPAR subunit GluA2 are key determinants of the properties of their respective assembled receptors. Both subunits are subject to extensive protein interactions, RNA editing and post-translational modifications. In this review we focus on the cell biology of GluK2-containing KARs and GluA2-containing AMPARs and outline how their regulation and dysregulation is implicated in, and affected by, seizure activity. Further, we discuss role of KARs in regulating AMPAR surface expression and plasticity, and the relevance of this to epilepsy. This article is part of the special issue on 'Glutamate Receptors - Kainate receptors'.
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Affiliation(s)
- Jeremy M Henley
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK; Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia.
| | - Jithin D Nair
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Richard Seager
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Busra P Yucel
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Gavin Woodhall
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK
| | - Benjamin S Henley
- Faculty of Medical Sciences, The Medical School, Newcastle University, Framlington Place, Newcastle Upon Tyne, NE2 4HH, UK
| | - Karolina Talandyte
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Hope I Needs
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Kevin A Wilkinson
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK.
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3
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Kelch-like proteins: Physiological functions and relationships with diseases. Pharmacol Res 2019; 148:104404. [DOI: 10.1016/j.phrs.2019.104404] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/15/2019] [Accepted: 08/19/2019] [Indexed: 02/07/2023]
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Schwieger-Briel A, Fuentes I, Castiglia D, Barbato A, Greutmann M, Leppert J, Duchatelet S, Hovnanian A, Burattini S, Yubero MJ, Ibañez-Arenas R, Rebolledo-Jaramillo B, Gräni C, Ott H, Theiler M, Weibel L, Paller AS, Zambruno G, Fischer J, Palisson F, Has C. Epidermolysis Bullosa Simplex with KLHL24 Mutations Is Associated with Dilated Cardiomyopathy. J Invest Dermatol 2018; 139:244-249. [PMID: 30120936 DOI: 10.1016/j.jid.2018.07.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/27/2018] [Accepted: 07/13/2018] [Indexed: 11/17/2022]
Affiliation(s)
- Agnes Schwieger-Briel
- Department of Pediatric Dermatology, University Children's Hospital Zurich, Zurich, Switzerland; Epidermolysis bullosa Centre, Department of Dermatology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Germany.
| | - Ignacia Fuentes
- Fundación DEBRA Chile, Santiago, Chile; Centro de Genética y Genómica, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | | | - Antonio Barbato
- Emergency Medicine and Hypertension Unit, Department of Clinical Medicine and Surgery, Federico II University Medical School, Naples, Italy
| | - Matthias Greutmann
- Department of Cardiology, University Hospital Zurich, Zurich, Switzerland
| | - Juna Leppert
- Epidermolysis bullosa Centre, Department of Dermatology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Sabine Duchatelet
- INSERM, Laboratory of Genetic Skin Diseases, Imagine Institute and Paris Descartes University, Paris, France
| | - Alain Hovnanian
- INSERM, Laboratory of Genetic Skin Diseases, Imagine Institute and Paris Descartes University, Paris, France
| | | | - M Joao Yubero
- Fundación DEBRA Chile, Santiago, Chile; Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Rodrigo Ibañez-Arenas
- Fundación DEBRA Chile, Santiago, Chile; Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile; Department of Cardiology, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Boris Rebolledo-Jaramillo
- Centro de Genética y Genómica, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Christoph Gräni
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Zurich, Switzerland
| | - Hagen Ott
- Division of Pediatric Dermatology and Allergology, Children's Hospital Auf der Bult, Hanover, Germany
| | - Martin Theiler
- Department of Pediatric Dermatology, University Children's Hospital Zurich, Zurich, Switzerland; Department of Dermatology, University Hospital Zurich, Zurich, Switzerland
| | - Lisa Weibel
- Department of Pediatric Dermatology, University Children's Hospital Zurich, Zurich, Switzerland; Department of Dermatology, University Hospital Zurich, Zurich, Switzerland
| | - Amy S Paller
- Departments of Dermatology and Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | | | - Judith Fischer
- Department of Human Genetics, Medical Center-University of Freiburg, Germany
| | - Francis Palisson
- Fundación DEBRA Chile, Santiago, Chile; Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile; Dermatology Department, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Cristina Has
- Epidermolysis bullosa Centre, Department of Dermatology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Germany.
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5
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Abstract
Skin fragility refers to a large group of conditions in which the ability of the skin to provide protection against trivial mechanical trauma is diminished, resulting in the formation of blisters, erosions, wounds, or scars. Acquired and physiological skin fragility is common; genetic disorders are rare but give insight into the molecular mechanisms ensuring skin stability. The paradigm is represented by inherited epidermolysis bullosa. This review is focused on recent advances in understanding the molecular basis of genetic skin fragility, including emerging concepts, controversies, unanswered questions, and opinions of the author. In spite of the advanced knowledge on the genetic causes of skin fragility, the molecular pathology is still expanding. Open questions in understanding the molecular basis of genetic skin fragility are the following: what are the causes of phenotypes which remain genetically unsolved, and what are the molecular modifiers which might explain phenotypic differences among individuals with similar mutations? New mutational mechanisms and new genes have recently been discovered and are briefly described here. Comprehensive next-generation sequencing-based genetic testing improved mutation detection and facilitated the identification of the genetic basis of unclear and new phenotypes. Characterization of the biochemical and cell biological consequences of the genetic variants is challenging and laborious but may represent the basis for personalized therapeutic approaches. Molecular modifiers of skin fragility have been uncovered in particular animal and genetic models but not in larger cohorts of patients. This scientific progress is the basis for revisions of the epidermolysis bullosa classification and for innovative therapeutic approaches designed for this intractable condition.
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Affiliation(s)
- Cristina Has
- Department of Dermatology and Venerology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstrasse 7, DE-79104, Freiburg, Germany
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6
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The "Kelch" Surprise: KLHL24, a New Player in the Pathogenesis of Skin Fragility. J Invest Dermatol 2017; 137:1211-1212. [PMID: 28532758 DOI: 10.1016/j.jid.2017.02.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 02/13/2017] [Indexed: 02/06/2023]
Abstract
A new protein, kelch-like 24, has recently been associated with a distinct subtype of epidermolysis bullosa simplex, a heterogeneous group of disorders associated with mechanical fragility of epidermal keratinocytes. All mutations involve the translation initiation codon and lead to a degradation-resistant N-terminally truncated kelch-like 24. Kelch-like 24 appears to be involved in the turnover of intermediated filaments, in particular of keratin 14, in keratinocytes.
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7
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He Y, Maier K, Leppert J, Hausser I, Schwieger-Briel A, Weibel L, Theiler M, Kiritsi D, Busch H, Boerries M, Hannula-Jouppi K, Heikkilä H, Tasanen K, Castiglia D, Zambruno G, Has C. Monoallelic Mutations in the Translation Initiation Codon of KLHL24 Cause Skin Fragility. Am J Hum Genet 2016; 99:1395-1404. [PMID: 27889062 DOI: 10.1016/j.ajhg.2016.11.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 11/07/2016] [Indexed: 11/28/2022] Open
Abstract
The genetic basis of epidermolysis bullosa, a group of genetic disorders characterized by the mechanically induced formation of skin blisters, is largely known, but a number of cases still remain genetically unsolved. Here, we used whole-exome and targeted sequencing to identify monoallelic mutations, c.1A>G and c.2T>C, in the translation initiation codon of the gene encoding kelch-like protein 24 (KLHL24) in 14 individuals with a distinct skin-fragility phenotype and skin cleavage within basal keratinocytes. Remarkably, mutation c.1A>G occurred de novo and was recurrent in families originating from different countries. The striking similarities of the clinical features of the affected individuals point to a unique and very specific pathomechanism. We showed that mutations in the translation initiation codon of KLHL24 lead to the usage of a downstream translation initiation site with the same reading frame and formation of a truncated polypeptide. The pathobiology was examined in keratinocytes and fibroblasts of the affected individuals and via expression of mutant KLHL24, and we found mutant KLHL24 to be associated with abnormalities of intermediate filaments in keratinocytes and fibroblasts. In particular, KLHL24 mutations were associated with irregular and fragmented keratin 14. Recombinant overexpression of normal KLHL24 promoted keratin 14 degradation, whereas mutant KLHL24 showed less activity than the normal molecule. These findings identify KLHL24 mutations as a cause of skin fragility and identify a role for KLHL24 in maintaining the balance between intermediate filament stability and degradation required for skin integrity.
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Affiliation(s)
- Yinghong He
- Department of Dermatology, University Medical Center Freiburg, Freiburg 79104, Germany
| | - Kristin Maier
- Department of Dermatology, University Medical Center Freiburg, Freiburg 79104, Germany
| | - Juna Leppert
- Department of Dermatology, University Medical Center Freiburg, Freiburg 79104, Germany
| | - Ingrid Hausser
- Department of Pathology, University of Heidelberg, Heidelberg 69120, Germany
| | - Agnes Schwieger-Briel
- Department of Paediatric Dermatology, University Children's Hospital Zurich, Zurich 8091, Switzerland; Department of Dermatology, University Hospital Zurich, Zurich 8091, Switzerland
| | - Lisa Weibel
- Department of Paediatric Dermatology, University Children's Hospital Zurich, Zurich 8091, Switzerland; Department of Dermatology, University Hospital Zurich, Zurich 8091, Switzerland
| | - Martin Theiler
- Department of Paediatric Dermatology, University Children's Hospital Zurich, Zurich 8091, Switzerland; Department of Dermatology, University Hospital Zurich, Zurich 8091, Switzerland
| | - Dimitra Kiritsi
- Department of Dermatology, University Medical Center Freiburg, Freiburg 79104, Germany
| | - Hauke Busch
- Systems Biology of the Cellular Microenvironment Group, Institute of Molecular Medicine and Cell Research, Albert-Ludwigs-University Freiburg, Freiburg 79104, Germany; German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Comprehensive Cancer Center Freiburg, Freiburg 79106, Germany
| | - Melanie Boerries
- Systems Biology of the Cellular Microenvironment Group, Institute of Molecular Medicine and Cell Research, Albert-Ludwigs-University Freiburg, Freiburg 79104, Germany; German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Comprehensive Cancer Center Freiburg, Freiburg 79106, Germany
| | - Katariina Hannula-Jouppi
- Department of Dermatology and Allergology, University of Helsinki and Helsinki University Hospital, Helsinki 00014, Finland; Folkhälsan Institute of Genetics, University of Helsinki, Helsinki 00014, Finland
| | - Hannele Heikkilä
- Department of Dermatology and Allergology, University of Helsinki and Helsinki University Hospital, Helsinki 00014, Finland
| | - Kaisa Tasanen
- Department of Dermatology, PEDEGO Research Unit, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu 90014, Finland
| | - Daniele Castiglia
- Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata, Istituto di Ricovero e Cura a Carattere Scientifico, Rome 00167, Italy
| | - Giovanna Zambruno
- Genetic and Rare Diseases Research Area, Bambino Gesù Children's Hospital, Istituto di Ricovero e Cura a Carattere Scientifico, Rome 00165, Italy
| | - Cristina Has
- Department of Dermatology, University Medical Center Freiburg, Freiburg 79104, Germany.
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Lin Z, Li S, Feng C, Yang S, Wang H, Ma D, Zhang J, Gou M, Bu D, Zhang T, Kong X, Wang X, Sarig O, Ren Y, Dai L, Liu H, Zhang J, Li F, Hu Y, Padalon-Brauch G, Vodo D, Zhou F, Chen T, Deng H, Sprecher E, Yang Y, Tan X. Stabilizing mutations of KLHL24 ubiquitin ligase cause loss of keratin 14 and human skin fragility. Nat Genet 2016; 48:1508-1516. [DOI: 10.1038/ng.3701] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/26/2016] [Indexed: 12/30/2022]
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Li B, Rex E, Wang H, Qian Y, Ogden AM, Bleakman D, Johnson KW. Pharmacological Modulation of GluK1 and GluK2 by NETO1, NETO2, and PSD95. Assay Drug Dev Technol 2016; 14:131-43. [PMID: 26991362 DOI: 10.1089/adt.2015.689] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The association between the kainate receptors (KARs) GluK1 and GluK2 and the modifying proteins neuropilin- and tolloid-like 1 (NETO1), neuropilin- and tolloid-like 2 (NETO2), and postsynaptic density protein 95 (PSD95) is likely to produce distinct GluK1 and GluK2 pharmacology in postsynaptic neurons. However, little is known about their corresponding modulatory effects on GluK1 and GluK2 activity in high-throughput assays for cell-based drug discovery. Using heterologous cells that potentially mimic the response in native cells in a fluorescence imaging plate reader (FLIPR) assay, we have investigated assays that incorporate (1) coexpression of GluK1 or GluK2 with their modulatory proteins (NETO1, NETO2, PSD95) and/or (2) enablement of assays with physiological concentration of native GluK1 and GluK2 agonist (glutamate) in the absence of an artificial potentiator (e.g., concanavalin A [Con A]). We found that in the absence of Con A, both NETO1 and NETO2 accessory proteins are able to potentiate kainate- and glutamate-evoked GluK1-mediated Ca(2+) influx. We also noted the striking ability of PSD95 to enhance glutamate-stimulated potentiation effects of NETO2 on GluK1 without the need for Con A and with a robust signal that could be utilized for high-throughput FLIPR assays. These experiments demonstrate the utility of heterologous cells coexpressing PSD95/NETO2 with GluK1 or GluK2 in native cell-mimicking heterologous cell systems for high-throughput assays and represent new avenues into the discovery of KAR modulating therapies.
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Affiliation(s)
- Baolin Li
- 1 Neuroscience Discovery, Lilly Corporate Center , Eli Lilly and Company, Indianapolis, Indiana
| | - Elizabeth Rex
- 1 Neuroscience Discovery, Lilly Corporate Center , Eli Lilly and Company, Indianapolis, Indiana
| | - He Wang
- 2 TTx-Reagents-Proteins, Lilly Corporate Center , Eli Lilly and Company, Indianapolis, Indiana
| | - Yuewei Qian
- 2 TTx-Reagents-Proteins, Lilly Corporate Center , Eli Lilly and Company, Indianapolis, Indiana
| | - Ann Marie Ogden
- 1 Neuroscience Discovery, Lilly Corporate Center , Eli Lilly and Company, Indianapolis, Indiana
| | - David Bleakman
- 1 Neuroscience Discovery, Lilly Corporate Center , Eli Lilly and Company, Indianapolis, Indiana
| | - Kirk W Johnson
- 1 Neuroscience Discovery, Lilly Corporate Center , Eli Lilly and Company, Indianapolis, Indiana
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10
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Sturgeon M, Davis D, Albers A, Beatty D, Austin R, Ferguson M, Tounsel B, Liebl FLW. The Notch ligand E3 ligase, Mind Bomb1, regulates glutamate receptor localization in Drosophila. Mol Cell Neurosci 2015; 70:11-21. [PMID: 26596173 DOI: 10.1016/j.mcn.2015.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 11/09/2015] [Accepted: 11/16/2015] [Indexed: 12/29/2022] Open
Abstract
The postsynaptic density (PSD) is a protein-rich network important for the localization of postsynaptic glutamate receptors (GluRs) and for signaling downstream of these receptors. Although hundreds of PSD proteins have been identified, many are functionally uncharacterized. We conducted a reverse genetic screen for mutations that affected GluR localization using Drosophila genes that encode homologs of mammalian PSD proteins. 42.8% of the mutants analyzed exhibited a significant change in GluR localization at the third instar larval neuromuscular junction (NMJ), a model synapse that expresses homologs of AMPA receptors. We identified the E3 ubiquitin ligase, Mib1, which promotes Notch signaling, as a regulator of synaptic GluR localization. Mib1 positively regulates the localization of the GluR subunits GluRIIA, GluRIIB, and GluRIIC. Mutations in mib1 and ubiquitous expression of Mib1 that lacks its ubiquitin ligase activity result in the loss of synaptic GluRIIA-containing receptors. In contrast, overexpression of Mib1 in all tissues increases postsynaptic levels of GluRIIA. Cellular levels of Mib1 are also important for the structure of the presynaptic motor neuron. While deficient Mib1 signaling leads to overgrowth of the NMJ, ubiquitous overexpression of Mib1 results in a reduction in the number of presynaptic motor neuron boutons and branches. These synaptic changes may be secondary to attenuated glutamate release from the presynaptic motor neuron in mib1 mutants as mib1 mutants exhibit significant reductions in the vesicle-associated protein cysteine string protein and in the frequency of spontaneous neurotransmission.
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Affiliation(s)
- Morgan Sturgeon
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Dustin Davis
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Amanda Albers
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Derek Beatty
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Rik Austin
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Matt Ferguson
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Brittany Tounsel
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Faith L W Liebl
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States.
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Cheng D, Qian W, Wang Y, Meng M, Wei L, Li Z, Kang L, Peng J, Xia Q. Nuclear import of transcription factor BR-C is mediated by its interaction with RACK1. PLoS One 2014; 9:e109111. [PMID: 25280016 PMCID: PMC4184850 DOI: 10.1371/journal.pone.0109111] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 08/29/2014] [Indexed: 11/18/2022] Open
Abstract
The transcription factor Broad Complex (BR-C) is an early ecdysone response gene in insects and contains two types of domains: two zinc finger domains for the activation of gene transcription and a Bric-a-brac/Tramtrack/Broad complex (BTB) domain for protein-protein interaction. Although the mechanism of zinc finger-mediated gene transcription is well studied, the partners interacting with the BTB domain of BR-C has not been elucidated until now. Here, we performed a yeast two-hybrid screen using the BTB domain of silkworm BR-C as bait and identified the receptor for activated C-kinase 1 (RACK1), a scaffolding/anchoring protein, as the novel partner capable of interacting with BR-C. The interaction between BR-C and RACK1 was further confirmed by far-western blotting and pull-down assays. Importantly, the disruption of this interaction, via RNAi against the endogenous RACK1 gene or deletion of the BTB domain, abolished the nuclear import of BR-C in BmN4 cells. In addition, RNAi against the endogenous PKC gene as well as phosphorylation-deficient mutation of the predicted PKC phosphorylation sites at either Ser373 or Thr406 in BR-C phenocopied RACK1 RNAi and altered the nuclear localization of BR-C. However, when BTB domain was deleted, phosphorylation mimics of either Ser373 or Thr406 had no effect on the nuclear import of BR-C. Moreover, mutating the PKC phosphorylation sites at Ser373 and Thr406 or deleting the BTB domain significantly decreased the transcriptional activation of a BR-C target gene. Given that RACK1 is necessary for recruiting PKC to close and phosphorylate target proteins, we suggest that the PKC-mediated phosphorylation and nuclear import of BR-C is determined by its interaction with RACK1. This novel finding will be helpful for further deciphering the mechanism underlying the role of BR-C proteins during insect development.
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Affiliation(s)
- Daojun Cheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Wenliang Qian
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Yonghu Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Meng Meng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ling Wei
- School of Life Science, Southwest University, Chongqing, China
| | - Zhiqing Li
- Laboratory of Silkworm Science, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan
| | - Lixia Kang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Jian Peng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- * E-mail:
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12
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Pahl S, Tapken D, Haering SC, Hollmann M. Trafficking of kainate receptors. MEMBRANES 2014; 4:565-95. [PMID: 25141211 PMCID: PMC4194049 DOI: 10.3390/membranes4030565] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Revised: 08/04/2014] [Accepted: 08/12/2014] [Indexed: 11/17/2022]
Abstract
Ionotropic glutamate receptors (iGluRs) mediate the vast majority of excitatory neurotransmission in the central nervous system of vertebrates. In the protein family of iGluRs, kainate receptors (KARs) comprise the probably least well understood receptor class. Although KARs act as key players in the regulation of synaptic network activity, many properties and functions of these proteins remain elusive until now. Especially the precise pre-, extra-, and postsynaptic localization of KARs plays a critical role for neuronal function, as an unbalanced localization of KARs would ultimately lead to dysregulated neuronal excitability. Recently, important advances in the understanding of the regulation of surface expression, function, and agonist-dependent endocytosis of KARs have been achieved. Post-translational modifications like PKC-mediated phosphorylation and SUMOylation have been reported to critically influence surface expression and endocytosis, while newly discovered auxiliary proteins were shown to shape the functional properties of KARs.
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Affiliation(s)
- Steffen Pahl
- Department of Biochemistry I, Ruhr University Bochum, Universitätsstr. 150, 44780 Bochum, Germany.
| | - Daniel Tapken
- Department of Biochemistry I, Ruhr University Bochum, Universitätsstr. 150, 44780 Bochum, Germany.
| | - Simon C Haering
- Department of Biochemistry I, Ruhr University Bochum, Universitätsstr. 150, 44780 Bochum, Germany.
| | - Michael Hollmann
- Department of Biochemistry I, Ruhr University Bochum, Universitätsstr. 150, 44780 Bochum, Germany.
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13
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Abstract
Our understanding of the molecular properties of kainate receptors and their involvement in synaptic physiology has progressed significantly over the last 30 years. A plethora of studies indicate that kainate receptors are important mediators of the pre- and postsynaptic actions of glutamate, although the mechanisms underlying such effects are still often a topic for discussion. Three clear fields related to their behavior have emerged: there are a number of interacting proteins that pace the properties of kainate receptors; their activity is unconventional since they can also signal through G proteins, behaving like metabotropic receptors; they seem to be linked to some devastating brain diseases. Despite the significant progress in their importance in brain function, kainate receptors remain somewhat puzzling. Here we examine discoveries linking these receptors to physiology and their probable implications in disease, in particular mood disorders, and propose some ideas to obtain a deeper understanding of these intriguing proteins.
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14
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Oberg EA, Nifoussi SK, Gingras AC, Strack S. Selective proteasomal degradation of the B'β subunit of protein phosphatase 2A by the E3 ubiquitin ligase adaptor Kelch-like 15. J Biol Chem 2012; 287:43378-89. [PMID: 23135275 DOI: 10.1074/jbc.m112.420281] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Protein phosphatase 2A (PP2A), a ubiquitous and pleiotropic regulator of intracellular signaling, is composed of a core dimer (AC) bound to a variable (B) regulatory subunit. PP2A is an enzyme family of dozens of heterotrimers with different subcellular locations and cellular substrates dictated by the B subunit. B'β is a brain-specific PP2A regulatory subunit that mediates dephosphorylation of Ca(2+)/calmodulin-dependent protein kinase II and tyrosine hydroxylase. Unbiased proteomic screens for B'β interactors identified Cullin3 (Cul3), a scaffolding component of E3 ubiquitin ligase complexes, and the previously uncharacterized Kelch-like 15 (KLHL15). KLHL15 is one of ∼40 Kelch-like proteins, many of which have been identified as adaptors for the recruitment of substrates to Cul3-based E3 ubiquitin ligases. Here, we report that KLHL15-Cul3 specifically targets B'β to promote turnover of the PP2A subunit by ubiquitylation and proteasomal degradation. Comparison of KLHL15 and B'β tissue expression profiles suggests that the E3 ligase adaptor contributes to selective expression of the PP2A/B'β holoenzyme in the brain. We mapped KLHL15 residues critical for homodimerization as well as interaction with Cul3 and B'β. Explaining PP2A subunit selectivity, the divergent N terminus of B'β was found necessary and sufficient for KLHL15-mediated degradation, with Tyr-52 having an obligatory role. Although KLHL15 can interact with the PP2A/B'β heterotrimer, it only degrades B'β, thus promoting exchange with other regulatory subunits. E3 ligase adaptor-mediated control of PP2A holoenzyme composition thereby adds another layer of regulation to cellular dephosphorylation events.
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Affiliation(s)
- Elizabeth A Oberg
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
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15
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González-González IM, Konopacki FA, Rocca DL, Doherty AJ, Jaafari N, Wilkinson KA, Henley JM. Kainate receptor trafficking. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/wmts.23] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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16
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Abstract
Pore-forming subunits of ion channels show channel activity in heterologous cells. However, recombinant and native channels often differ in their channel properties. These discrepancies are resolved by the identification of channel auxiliary subunits. In this review article, an auxiliary subunit of ligand-gated ion channels is defined using four criteria: (1) as a Non-pore-forming subunit, (2) direct and stable interaction with a pore-forming subunit, (3) modulation of channel properties and/or trafficking in heterologous cells, (4) necessity in vivo. We focus particularly on three classes of ionotropic glutamate receptors and their transmembrane interactors. Precise identification of auxiliary subunits and reconstruction of native glutamate receptors will open new directions to understanding the brain and its functions.
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Affiliation(s)
- Dan Yan
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
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Mott DD, Rojas A, Fisher JL, Dingledine RJ, Benveniste M. Subunit-specific desensitization of heteromeric kainate receptors. J Physiol 2009; 588:683-700. [PMID: 20026616 DOI: 10.1113/jphysiol.2009.185207] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Kainate receptor subunits can form functional channels as homomers of GluK1, GluK2 or GluK3, or as heteromeric combinations with each other or incorporating GluK4 or GluK5 subunits. However, GluK4 and GluK5 cannot form functional channels by themselves. Incorporation of GluK4 or GluK5 into a heteromeric complex increases glutamate apparent affinity and also enables receptor activation by the agonist AMPA. Utilizing two-electrode voltage clamp of Xenopus oocytes injected with cRNA encoding kainate receptor subunits, we have observed that heteromeric channels composed of GluK2/GluK4 and GluK2/GluK5 have steady state concentration-response curves that were bell-shaped in response to either glutamate or AMPA. By contrast, homomeric GluK2 channels exhibited a monophasic steady state concentration-response curve that simply plateaued at high glutamate concentrations. By fitting several specific Markov models to GluK2/GluK4 heteromeric and GluK2 homomeric concentration-response data, we have determined that: (a) two strikingly different agonist binding affinities exist; (b) the high-affinity binding site leads to channel opening; and (c) the low-affinity agonist binding site leads to strong desensitization after agonist binding. Model parameters also approximate the onset and recovery kinetics of desensitization observed for macroscopic currents measured from HEK-293 cells expressing GluK2 and GluK4 subunits. The GluK2(E738D) mutation lowers the steady state apparent affinity for glutamate by 9000-fold in comparison to GluK2 homomeric wildtype receptors. When this mutant subunit was expressed with GluK4, the rising phase of the glutamate steady state concentration-response curve overlapped with the wildtype curve, whereas the declining phase was right-shifted toward lower affinity. Taken together, these data are consistent with a scheme whereby high-affinity agonist binding to a non-desensitizing GluK4 subunit opens the heteromeric channel, whereas low-affinity agonist binding to GluK2 desensitizes the whole channel complex.
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Affiliation(s)
- David D Mott
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina, School of Medicine, Columbia, SC 29208, USA
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Ectodermal-neural cortex 1 down-regulates Nrf2 at the translational level. PLoS One 2009; 4:e5492. [PMID: 19424503 PMCID: PMC2675063 DOI: 10.1371/journal.pone.0005492] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Accepted: 04/16/2009] [Indexed: 12/30/2022] Open
Abstract
The transcription factor Nrf2 is the master regulator of a cellular defense mechanism against environmental insults. The Nrf2-mediated antioxidant response is accomplished by the transcription of a battery of genes that encode phase II detoxifying enzymes, xenobiotic transporters, and antioxidants. Coordinated expression of these genes is critical in protecting cells from toxic and carcinogenic insults and in maintaining cellular redox homeostasis. Activation of the Nrf2 pathway is primarily controlled by Kelch-like ECH-associated protein 1 (Keap1), which is a molecular switch that turns on or off the Nrf2 signaling pathway according to intracellular redox conditions. Here we report our finding of a novel Nrf2 suppressor ectodermal-neural cortex 1 (ENC1), which is a BTB-Kelch protein and belongs to the same family as Keap1. Transient expression of ENC1 reduced steady-state levels of Nrf2 and its downstream gene expression. Although ENC1 interacted with Keap1 indirectly, the ENC1-mediated down-regulation of Nrf2 was independent of Keap1. The negative effect of ENC1 on Nrf2 was not due to a change in the stability of Nrf2 because neither proteasomal nor lysosomal inhibitors had any effects. Overexpression of ENC1 did not result in a change in the level of Nrf2 mRNA, rather, it caused a decrease in the rate of Nrf2 protein synthesis. These results demonstrate that ENC1 functions as a negative regulator of Nrf2 through suppressing Nrf2 protein translation, which adds another level of complexity in controlling the Nrf2 signaling pathway.
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