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Chen TS, Sheri N, Ehmann DS, Benson MD. Novel heterozygous PRPH2 variant identified in a patient with spinocerebellar ataxia type 14 and macular dystrophy. Ophthalmic Genet 2024; 45:409-412. [PMID: 38419591 DOI: 10.1080/13816810.2024.2321883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 02/03/2024] [Accepted: 02/18/2024] [Indexed: 03/02/2024]
Abstract
PURPOSE To report on a patient with spinocerebellar ataxia type 14 (SCA14) and macular dystrophy with identification of a novel PRPH2 variant. METHODS Case report. RESULTS A 63-year-old female with molecularly confirmed SCA14 presented with symmetric pigmentary disturbances in a perifoveal distribution resembling a pattern macular dystrophy. She had no history of using medications with recognized toxic macular effects. Subsequent genetic testing confirmed a novel heterozygous missense variant of unknown significance in PRPH2 (PRPH2: c.694 G>A, p.(Ala232Thr)). CONCLUSIONS To our knowledge, this is the first case of macular dystrophy identified in a patient with SCA14. While it is possible that the macular dystrophy observed in this patient might be an under-reported phenotype associated with SCA14, the pattern of macular changes is consistent with PRPH2-related disorders. The identified missense variant is predicted to be damaging by most in silico models, and the residue is highly conserved, adding support to a dual genetic diagnosis in this case.
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Affiliation(s)
- Tugche S Chen
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Canada
| | - Narin Sheri
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Canada
| | - David S Ehmann
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Canada
| | - Matthew D Benson
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Canada
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2
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Ihl T, Kadas EM, Oberwahrenbrock T, Endres M, Klockgether T, Schroeter J, Brandt AU, Paul F, Minnerop M, Doss S, Schmitz-Hübsch T, Zimmermann HG. Investigation of Visual System Involvement in Spinocerebellar Ataxia Type 14. CEREBELLUM (LONDON, ENGLAND) 2020; 19:469-482. [PMID: 32338350 PMCID: PMC7351844 DOI: 10.1007/s12311-020-01130-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Spinocerebellar ataxia type 14 (SCA-PRKCG, formerly SCA14) is a rare, slowly progressive disorder caused by conventional mutations in protein kinase Cγ (PKCγ). The disease usually manifests with ataxia, but previous reports suggested PRKCG variants in retinal pathology. To systematically investigate for the first time visual function and retinal morphology in patients with SCA-PRKCG. Seventeen patients with PRKCG variants and 17 healthy controls were prospectively recruited, of which 12 genetically confirmed SCA-PRKCG patients and 14 matched controls were analyzed. We enquired a structured history for visual symptoms. Vision-related quality of life was obtained with the National Eye Institute Visual Function Questionnaire (NEI-VFQ) including the Neuro-Ophthalmic Supplement (NOS). Participants underwent testing of visual acuity, contrast sensitivity, visual fields, and retinal morphology with optical coherence tomography (OCT). Measurements of the SCA-PRKCG group were analyzed for their association with clinical parameters (ataxia rating and disease duration). SCA-PRKCG patients rate their vision-related quality of life in NEI-VFQ significantly worse than controls. Furthermore, binocular visual acuity and contrast sensitivity were worse in SCA-PRKCG patients compared with controls. Despite this, none of the OCT measurements differed between groups. NEI-VFQ and NOS composite scores were related to ataxia severity. Additionally, we describe one patient with a genetic variant of uncertain significance in the catalytic domain of PKCγ who, unlike all confirmed SCA-PRKCG, presented with a clinically silent epitheliopathy. SCA-PRKCG patients had reduced binocular vision and vision-related quality of life. Since no structural retinal damage was found, the pathomechanism of these findings remains unclear.
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Affiliation(s)
- Thomas Ihl
- Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- Department of Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Ella M Kadas
- Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Timm Oberwahrenbrock
- Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Matthias Endres
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- Department of Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE), partner site, Berlin, Germany
| | - Thomas Klockgether
- Department of Neurology, University Hospital of Bonn, Bonn, Germany
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Jan Schroeter
- University Tissue Bank, Cornea Bank Berlin, Institute of Transfusion Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Alexander U Brandt
- Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- Department of Neurology, University of California, Irvine, CA, USA
| | - Friedemann Paul
- Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- Department of Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Martina Minnerop
- Institute of Neuroscience and Medicine (INM-1), Research Centre Juelich, Juelich, Germany
- Department of Neurology, Center for Movement Disorders and Neuromodulation, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
- Department of Neurology and Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - Sarah Doss
- Department of Neurology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- Department of Neurological Sciences, Movement Disorders Section, University of Nebraska Medical Center, Omaha, NE, USA
| | - Tanja Schmitz-Hübsch
- Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Hanna G Zimmermann
- Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany.
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany.
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Valdés-Sánchez L, Calado SM, de la Cerda B, Aramburu A, García-Delgado AB, Massalini S, Montero-Sánchez A, Bhatia V, Rodríguez-Bocanegra E, Diez-Lloret A, Rodríguez-Martínez D, Chakarova C, Bhattacharya SS, Díaz-Corrales FJ. Retinal pigment epithelium degeneration caused by aggregation of PRPF31 and the role of HSP70 family of proteins. Mol Med 2019; 26:1. [PMID: 31892304 PMCID: PMC6938640 DOI: 10.1186/s10020-019-0124-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 12/05/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Mutations in pre-mRNA splicing factor PRPF31 can lead to retinitis pigmentosa (RP). Although the exact disease mechanism remains unknown, it has been hypothesized that haploinsufficiency might be involved in the pathophysiology of the disease. METHODS In this study, we have analyzed a mouse model containing the p.A216P mutation in Prpf31 gene. RESULTS We found that mutant Prpf31 protein produces cytoplasmic aggregates in the retinal pigment epithelium and decreasing the protein levels of this splicing factor in the nucleus. Additionally, normal protein was recruited in insoluble aggregates when the mutant protein was overexpressed in vitro. In response to protein aggregation, Hspa4l is overexpressed. This member of the HSP70 family of chaperones might contribute to the correct folding and solubilization of the mutant protein, allowing its translocation to the nucleus. CONCLUSIONS Our data suggests that a mechanism haploinsufficiency and dominant-negative is involved in retinal degeneration due to mutations in PRPF31. HSP70 over-expression might be a new therapeutic target for the treatment of retinal degeneration due to PRPF31 mutations.
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Affiliation(s)
- Lourdes Valdés-Sánchez
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
| | - Sofia M Calado
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
- Present Address: Center for Biomedical Research (CBMR), University of Algarve, 8800-139, Faro, Portugal
| | - Berta de la Cerda
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
| | - Ana Aramburu
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
- Present Address: Clinique de l'Oeil, Avenue Bois de la Chapelle 15, 1213, Onex, Switzerland
| | - Ana Belén García-Delgado
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
| | - Simone Massalini
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
- Present Address: Center for Molecular and Cellular Bioengineering (CMCB) DFG-Research Center for Regenerative Therapies Dresden (CRTD) Cluster of Excellence, Technische Universität Dresden, Fetscherstraße, 105 01307, Dresden, Germany
| | - Adoración Montero-Sánchez
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
| | - Vaibhav Bhatia
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
| | - Eduardo Rodríguez-Bocanegra
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
- Present Address: Universitätsklinikum Tübingen, Forschungsinstitut für Augenheilkunde, Elfriede-Aulhorn-Str. 7, 72076, Tübingen, Germany
| | - Andrea Diez-Lloret
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
| | - Daniel Rodríguez-Martínez
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain
| | - Christina Chakarova
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Shom S Bhattacharya
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK.
| | - Francisco J Díaz-Corrales
- Regeneration and Cell Therapy Department, Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER (Junta de Andalucía), CSIC, Universidad de Sevilla, Universidad Pablo de Olavide, Avda. Americo Vespucio 24, 41092, Seville, Spain.
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Chelban V, Wiethoff S, Fabian-Jessing BK, Haridy NA, Khan A, Efthymiou S, Becker EBE, O'Connor E, Hersheson J, Newland K, Hojland AT, Gregersen PA, Lindquist SG, Petersen MB, Nielsen JE, Nielsen M, Wood NW, Giunti P, Houlden H. Genotype-phenotype correlations, dystonia and disease progression in spinocerebellar ataxia type 14. Mov Disord 2018; 33:1119-1129. [PMID: 29603387 PMCID: PMC6175136 DOI: 10.1002/mds.27334] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/16/2018] [Accepted: 01/21/2018] [Indexed: 12/11/2022] Open
Abstract
Background: Spinocerebellar ataxia type 14 is a rare form of autosomal dominant cerebellar ataxia caused by mutations in protein kinase Cγ gene. Clinically, it presents with a slowly progressive, mainly pure cerebellar ataxia. Methods: Using next generation sequencing, we screened 194 families with autosomal dominant cerebellar ataxia and normal polyglutamine repeats. In‐depth phenotyping was performed using validated clinical rating scales neuroimaging and electrophysiological investigations. Results: We identified 25 individuals from 13 families carrying pathogenic mutations in protein kinase Cγ gene. A total of 10 unique protein kinase Cγ gene mutations have been confirmed of which 5 are novel and 5 were previously described. Our data suggest that the age at onset is highly variable; disease course is slowly progressive and rarely associated with severe disability. However, one third of patients presented with a complex ataxia comprising severe focal and/or task‐induced dystonia, peripheral neuropathy, parkinsonism, myoclonus, and pyramidal syndrome. The most complex phenotype is related to a missense mutation in the catalytic domain in exon 11. Conclusion: We present one of the largest genetically confirmed spinocerebellar ataxia type 14 cohorts contributing novel variants and clinical characterisation. We show that although protein kinase Cγ gene mutations present mainly as slowly progressive pure ataxia, more than a third of cases had a complex phenotype. Overall, our case series extends the phenotype and suggests that protein kinase Cγ gene mutations should be considered in patients with slowly progressive autosomal dominant cerebellar ataxia, particularly when myoclonus, dystonia, or mild cognitive impairment are present in the absence of polyglutamine expansion. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Viorica Chelban
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK.,National Hospital for Neurology and Neurosurgery, London, UK.,Department of Neurology and Neurosurgery, Institute of Emergency Medicine, Chisinau, Republic of Moldova
| | - Sarah Wiethoff
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK.,Center for Neurology and Hertie Institute for Clinical Brain Research, Eberhard-Karls-University, Tübingen, Germany
| | | | - Nourelhoda A Haridy
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK.,Department of Neurology and Psychiatry, Assiut University Hospital, Faculty of Medicine, Assiut, Egypt
| | - Alaa Khan
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK
| | - Stephanie Efthymiou
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK
| | - Esther B E Becker
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Emer O'Connor
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK
| | - Joshua Hersheson
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK
| | - Katrina Newland
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK
| | | | | | - Suzanne G Lindquist
- Danish Dementia Research Centre, Neurogenetics Clinic, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Genetics, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Michael B Petersen
- Department of Clinical Genetics, Aalborg University Hospital, Aalborg, Denmark
| | - Jørgen E Nielsen
- Danish Dementia Research Centre, Neurogenetics Clinic, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Michael Nielsen
- Department of Neurology, Aalborg University Hospital, Aalborg, Denmark
| | - Nicholas W Wood
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK.,National Hospital for Neurology and Neurosurgery, London, UK
| | - Paola Giunti
- Deparmtent of Molecular Neuroscience, Ataxia Centre UCL, Institute of Neurology, London, UK
| | - Henry Houlden
- Department of Molecular Neuroscience, University College London, Institute of Neurology, London, UK.,National Hospital for Neurology and Neurosurgery, London, UK
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5
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Barnett ME, Madgwick DK, Takemoto DJ. Protein kinase C as a stress sensor. Cell Signal 2007; 19:1820-9. [PMID: 17629453 PMCID: PMC1986756 DOI: 10.1016/j.cellsig.2007.05.014] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Revised: 05/24/2007] [Accepted: 05/25/2007] [Indexed: 11/22/2022]
Abstract
While there are many reviews which examine the group of proteins known as protein kinase C (PKC), the focus of this article is to examine the cellular roles of two PKCs that are important for stress responses in neurological tissues (PKC gamma and epsilon) and in cardiac tissues (PKC epsilon). These two kinases, in particular, seem to have overlapping functions and interact with an identical target, connexin 43 (Cx43), a gap junction protein which is central to proper control of signals in both tissues. While PKC gamma and PKC epsilon both help protect neural tissue from ischemia, PKC epsilon is the primary PKC isoform responsible for responding to decreased oxygen, or ischemia, in the heart. Both do this through Cx43. It is clear that both PKC gamma and PKC epsilon are necessary for protection from ischemia. However, the importance of these kinases has been inferred from preconditioning experiments which demonstrate that brief periods of hypoxia protect neurological and cardiac tissues from future insults, and that this depends on the activation, translocation, or ability for PKC gamma and/or PKC epsilon to interact with distinct cellular targets, especially Cx43. This review summarizes the recent findings which define the roles of PKC gamma and PKC epsilon in cardiac and neurological functions and their relationships to ischemia/reperfusion injury. In addition, a biochemical comparison of PKC gamma and PKC epsilon and a proposed argument for why both forms are present in neurological tissue while only PKC epsilon is present in heart, are discussed. Finally, the biochemistry of PKCs and future directions for the field are discussed, in light of this new information.
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Affiliation(s)
- Micheal E Barnett
- Department of Biochemistry, Kansas State University, Manhattan, Kansas 66506-3902, USA.
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6
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Mochizuki H, Seki T, Adachi N, Saito N, Mishima HK, Sakai N. R659S mutation of gammaPKC is susceptible to cell death: implication of this mutation/polymorphism in the pathogenesis of retinitis pigmentosa. Neurochem Int 2006; 49:669-75. [PMID: 16828200 DOI: 10.1016/j.neuint.2006.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Revised: 04/27/2006] [Accepted: 05/18/2006] [Indexed: 12/01/2022]
Abstract
It has been reported that mutations of gammaPKC cause hereditary spinocerebellar atrophy type 14 (SCA14). Our recent study has revealed that the SCA14 mutant gammaPKC is susceptible to aggregation and causes cell death. Among mutations/polymorphisms of gammaPKC, the R659S mutation was firstly segregated from families with hereditary retinitis pigmentosa type 11 (RP11). Although more reliable etiological mutations of RP11 were subsequently discovered in a human homologue of yeast pre-mRNA splicing gene (PRP31), the role of this R659S missense change in the pathogenicity of RP11 is still controversial. In this study, we overexpressed R659S gammaPKC in CHO cells and characterized the properties of this mutant protein. We found that R659S gammaPKC more prominently induced cell death than did wild-type. This mutant gammaPKC had higher basal activity than wild-type, however, no difference was found in the extent of aggregation and insolubility to detergent between R659S mutant and wild-type. These results suggest that the R659S mutation is susceptible to neuronal death and is involved in the pathogenesis of neurodegenerative diseases, including RP11.
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Affiliation(s)
- Hideki Mochizuki
- Department of Ophthalmology and Visual Sciences, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551, Japan
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7
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Chen DH, Brkanac Z, Verlinde CLMJ, Tan XJ, Bylenok L, Nochlin D, Matsushita M, Lipe H, Wolff J, Fernandez M, Cimino PJ, Bird TD, Raskind WH. Missense mutations in the regulatory domain of PKC gamma: a new mechanism for dominant nonepisodic cerebellar ataxia. Am J Hum Genet 2003; 72:839-49. [PMID: 12644968 PMCID: PMC1180348 DOI: 10.1086/373883] [Citation(s) in RCA: 193] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2002] [Accepted: 12/30/2002] [Indexed: 11/03/2022] Open
Abstract
We report a nonepisodic autosomal dominant (AD) spinocerebellar ataxia (SCA) not caused by a nucleotide repeat expansion that is, to our knowledge, the first such SCA. The AD SCAs currently comprise a group of > or =16 genetically distinct neurodegenerative conditions, all characterized by progressive incoordination of gait and limbs and by speech and eye-movement disturbances. Six of the nine SCAs for which the genes are known result from CAG expansions that encode polyglutamine tracts. Noncoding CAG, CTG, and ATTCT expansions are responsible for three other SCAs. Approximately 30% of families with SCA do not have linkage to the known loci. We recently mapped the locus for an AD SCA in a family (AT08) to chromosome 19q13.4-qter. A particularly compelling candidate gene, PRKCG, encodes protein kinase C gamma (PKC gamma), a member of a family of serine/threonine kinases. The entire coding region of PRKCG was sequenced in an affected member of family AT08 and in a group of 39 unrelated patients with ataxia not attributable to trinucleotide expansions. Three different nonconservative missense mutations in highly conserved residues in C1, the cysteine-rich region of the protein, were found in family AT08, another familial case, and a sporadic case. The mutations cosegregated with disease in both families. Structural modeling predicts that two of these amino acid substitutions would severely abrogate the zinc-binding or phorbol ester-binding capabilities of the protein. Immunohistochemical studies on cerebellar tissue from an affected member of family AT08 demonstrated reduced staining for both PKC gamma and ataxin 1 in Purkinje cells, whereas staining for calbindin was preserved. These results strongly support a new mechanism for neuronal cell dysfunction and death in hereditary ataxias and suggest that there may be a common pathway for PKC gamma-related and polyglutamine-related neurodegeneration.
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Affiliation(s)
- Dong-Hui Chen
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - Zoran Brkanac
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - Christophe L. M. J. Verlinde
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - Xiao-Jian Tan
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - Laura Bylenok
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - David Nochlin
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - Mark Matsushita
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - Hillary Lipe
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - John Wolff
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - Magali Fernandez
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - P. J. Cimino
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - Thomas D. Bird
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
| | - Wendy H. Raskind
- Departments of Psychiatry and Behavioral Sciences, Biochemistry, Biological Structure, Medicine, Pathology, and Neurology, University of Washington School of Medicine, and Geriatric Research, Education and Clinical Center and VISN 20 Mental Illness Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle; and Department of Medicine, Ohio State University, Columbus
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8
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Buchet-Poyau K, Mehenni H, Radhakrishna U, Antonarakis SE. Search for the second Peutz-Jeghers syndrome locus: exclusion of the STK13, PRKCG, KLK10, and PSCD2 genes on chromosome 19 and the STK11IP gene on chromosome 2. Cytogenet Genome Res 2003; 97:171-8. [PMID: 12438709 DOI: 10.1159/000066620] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Pathogenic mutations in the serine/threonine kinase STK11 (alias LKB1) cause Peutz-Jeghers syndrome (PJS) in most affected individuals. However, in a considerable number of PJS-patients mutations cannot be detected in STK11 suggesting genetic heterogeneity. One PJS family without STK11 mutations (PJS07) has previously been described with significant evidence for linkage to a second potential PJS locus on 19q13.3-->q13.4. In this study we investigated candidate genes within markers D19S180 and D19S254, since multipoint linkage analysis yielded significant LOD scores for this region in this family. Four genes in the region (cytohesin 2: PSCD2, kallikrein 10: KLK10, protein kinase C gamma: PRKCG, and serine/threonine kinase 13: STK13) potentially involved in growth inhibitory pathways or in the pathophysiology of can- cer, were considered as candidates. We first determined the genomic structure of the PSCD2 and PRKCG genes, and performed mutation analysis of all exons and exon-intron junctions of the four genes, in the PJS07 family. No pathogenic mutation was identified in these four genes in affected individuals. A very rare polymorphism resulting in a conserved amino acid change Lys to Arg was found in PSCD2. These data provide considerable evidence for exclusion of these four genes as candidates for the second locus on 19q13.3-->q13.4 in PJS. Finally, we also excluded the recently identified STK11-interacting protein gene (STK11IP, alias LIP1) mapped in 2q36 as candidate for PJS in the PJS07 family, although this could be a good candidate in other non-STK11/LKB1 families.
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Affiliation(s)
- K Buchet-Poyau
- Division of Medical Genetics, Geneva University Medical School, and University Hospitals, Geneva, Switzerland
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9
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Farrar G, Kenna PF, Humphries P. On the genetics of retinitis pigmentosa and on mutation-independent approaches to therapeutic intervention. EMBO J 2002; 21:857-64. [PMID: 11867514 PMCID: PMC125887 DOI: 10.1093/emboj/21.5.857] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Retinitis pigmentosa (RP), the group of hereditary conditions involving death of retinal photoreceptors, represents the most prevalent cause of visual handicap among working populations in developed countries. Here we provide an overview of the molecular pathologies associated with such disorders, from which it becomes clearly apparent that RP is one of the most genetically heterogeneous of hereditary conditions for which molecular pathologies have so far been elucidated. While heterogeneity of such magnitude would appear to represent a major impediment to the development of therapeutics, mutation-independent approaches to therapy are being developed to effectively by-pass such diversity in genetic aetiology. The implications of such technologies in terms of therapeutic intervention in RP, and indeed other genetically heterogeneous conditions, will be addressed.
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MESH Headings
- 3' Untranslated Regions
- 5' Untranslated Regions
- Animals
- Apoptosis/drug effects
- Disease Progression
- Eye Proteins/genetics
- Eye Proteins/physiology
- Genes, Dominant
- Genes, Recessive
- Genetic Heterogeneity
- Genetic Linkage
- Genetic Therapy
- Humans
- Mammals/anatomy & histology
- Mice
- Mice, Knockout
- Models, Animal
- Nerve Growth Factors/therapeutic use
- Optic Atrophy, Hereditary, Leber/genetics
- Optic Atrophy, Hereditary, Leber/pathology
- RNA, Catalytic/therapeutic use
- RNA, Messenger/antagonists & inhibitors
- RNA, Messenger/genetics
- Retina/ultrastructure
- Retinal Rod Photoreceptor Cells/physiology
- Retinal Rod Photoreceptor Cells/radiation effects
- Retinitis Pigmentosa/genetics
- Retinitis Pigmentosa/pathology
- Retinitis Pigmentosa/therapy
- Rhodopsin/deficiency
- Rhodopsin/genetics
- Syndrome
- Transcription Factors/deficiency
- Transcription Factors/genetics
- X Chromosome/genetics
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Affiliation(s)
| | | | - Peter Humphries
- The Ocular Genetics Unit, Department of Genetics, Trinity College Dublin, Dublin 2, Ireland
Corresponding author e-mail:
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10
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Kofler K, Erdel M, Utermann G, Baier G. Molecular genetics and structural genomics of the human protein kinase C gene module. Genome Biol 2002; 3:RESEARCH0014. [PMID: 11897026 PMCID: PMC88812 DOI: 10.1186/gb-2002-3-3-research0014] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2002] [Revised: 02/05/2002] [Accepted: 02/06/2002] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Protein kinase C (PKC) has become a major focus among cell biologists interested in second-messenger signal transduction and much has been learned about differences in the cellular localization and function of its different isotypes. In this study we systematically address the genomic locations and gene structures of the human PKC gene module. RESULTS We first carried out fine chromosomal mapping of all nine PKC genes by fluorescence in situ hybridization (FISH), using cosmid and BAC probes. The PKC genes are found to be dispersed throughout the genome, and in some positions distinct from those previously reported: PKCalpha is at 17q24, PKCbeta at 16p12, PKCgamma at 19q13.4, PKCdelta at 3p21.2, PKCepsilon at 2p21, PKCzeta at 1p36.3, PKCeta at 14q22-23, PKCtheta; at 10p15 and PKCiota at 3q26. For PKCiota, an additional FISH signal mapped on Xq21.3 revealed a pseudogene (derived by retrotransposition). PKCgamma, zeta, and theta; are found to map to the most distal positions on the chromosomes, potentially implicating telomere position effects in their expression. Using the complete human genome draft sequence and bioinformatics tools, we then carried out a systematic analysis of PKC gene structure, including determination of the occurrence of single-nucleotide polymorphisms corresponding to the PKC loci. CONCLUSION This resource of genomic information now facilitates investigation of the PKC gene module in structural chromosomal abnormalities and human disease locus mapping studies.
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Affiliation(s)
- Kurt Kofler
- Institute for Medical Biology and Human Genetics, University of Innsbruck, Schoepfstrasse 41, A-6020 Innsbruck, Austria.
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11
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Wang Q, Chen Q, Zhao K, Wang L, Wang L, Traboulsi EI. Update on the molecular genetics of retinitis pigmentosa. Ophthalmic Genet 2001; 22:133-54. [PMID: 11559856 DOI: 10.1076/opge.22.3.133.2224] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Retinitis pigmentosa (RP) is a heterogeneous group of retinal dystrophies characterized by photoreceptor cell degeneration. RP causes night blindness, a gradual loss of peripheral visual fields, and eventual loss of central vision. Advances in molecular genetics have provided new insights into the genes responsible and the pathogenic mechanisms of RP. The genetics of RP is complex, and the disease can be inherited in autosomal dominant, recessive, X-linked, or digenic modes. Twenty-six causative genes have been identified or cloned for RP, and an additional fourteen genes have been mapped, but not yet identified. Eight autosomal dominant forms are due to mutations in RHO on chromosome 3q21-24, RDS on 6p21.1-cen, RP1 on 8p11-21, RGR on 10q23, ROM1 on 11q13, NRL on 14q11.1-11.2, CRX on 19q13.3, and PRKCG on 19q13.4. Autosomal recessive genes include RPE65 on chromosome 1p31, ABCA4 on 1p21-13, CRB1 on 1q31-32.1, USH2A on 1q41, MERTK on 2q14.1, SAG on 2q37.1, RHO on 3q21-24, PDE6B on 4p16.3, CNGA1 on 4p14-q13, PDE6A on 5q31.2-34, TULP1 on 6p21.3, RGR on 10q, NR2E3 on 15q23, and RLBP1 on 15q26. For X-linked RP, two genes, RP2 and RP3 (RPGR), have been cloned. Moreover, heterozygous mutations in ROM1 on 11q13, in combination with heterozygous mutations in RDS on 6p21.1-cen, cause digenic RP (the two-locus mechanism). These exciting molecular discoveries have defined the genetic pathways underlying the pathogenesis of retinitis pigmentosa, and have raised the hope of genetic testing for RP and the development of new avenues for therapy.
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Affiliation(s)
- Q Wang
- Center for Molecular Genetics, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44195, USA.
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12
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Vithana EN, Abu-Safieh L, Allen MJ, Carey A, Papaioannou M, Chakarova C, Al-Maghtheh M, Ebenezer ND, Willis C, Moore AT, Bird AC, Hunt DM, Bhattacharya SS. A human homolog of yeast pre-mRNA splicing gene, PRP31, underlies autosomal dominant retinitis pigmentosa on chromosome 19q13.4 (RP11). Mol Cell 2001; 8:375-81. [PMID: 11545739 DOI: 10.1016/s1097-2765(01)00305-7] [Citation(s) in RCA: 235] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We report mutations in a gene (PRPF31) homologous to Saccharomyces cerevisiae pre-mRNA splicing gene PRP31 in families with autosomal dominant retinitis pigmentosa linked to chromosome 19q13.4 (RP11; MIM 600138). A positional cloning approach supported by bioinformatics identified PRPF31 comprising 14 exons and encoding a protein of 499 amino acids. The level of sequence identity to the yeast PRP31 gene indicates that PRPF31 is also likely to be involved in pre-mRNA splicing. Mutations that include missense substitutions, deletions, and insertions have been identified in four RP11-linked families and three sporadic RP cases. The identification of mutations in a pre-mRNA splicing gene implicates defects in the splicing process as a novel mechanism of photoreceptor degeneration.
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Affiliation(s)
- E N Vithana
- Department of Molecular Genetics, Institute of Ophthalmology, University College London, ECIV 9EL, London, United Kingdom
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13
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Dryja TP, McEvoy J, McGee TL, Berson EL. No mutations in the coding region of the PRKCG gene in three families with retinitis pigmentosa linked to the RP11 locus on chromosome 19q. Am J Hum Genet 1999; 65:926-8. [PMID: 10441600 PMCID: PMC1378000 DOI: 10.1086/302554] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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