1
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Alnassar N, Hajto J, Rumney RMH, Verma S, Borczyk M, Saha C, Kanczler J, Butt AM, Occhipinti A, Pomeroy J, Angione C, Korostynski M, Górecki DC. Ablation of the dystrophin Dp71f alternative C-terminal variant increases sarcoma tumour cell aggressiveness. Hum Mol Genet 2024:ddae094. [PMID: 38850567 DOI: 10.1093/hmg/ddae094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 05/08/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024] Open
Abstract
Alterations in Dp71 expression, the most ubiquitous dystrophin isoform, have been associated with patient survival across tumours. Intriguingly, in certain malignancies, Dp71 acts as a tumour suppressor, while manifesting oncogenic properties in others. This diversity could be explained by the expression of two Dp71 splice variants encoding proteins with distinct C-termini, each with specific properties. Expression of these variants has impeded the exploration of their unique roles. Using CRISPR/Cas9, we ablated the Dp71f variant with the alternative C-terminus in a sarcoma cell line not expressing the canonical C-terminal variant, and conducted molecular (RNAseq) and functional characterisation of the knockout cells. Dp71f ablation induced major transcriptomic alterations, particularly affecting the expression of genes involved in calcium signalling and ECM-receptor interaction pathways. The genome-scale metabolic analysis identified significant downregulation of glucose transport via membrane vesicle reaction (GLCter) and downregulated glycolysis/gluconeogenesis pathway. Functionally, these molecular changes corresponded with, increased calcium responses, cell adhesion, proliferation, survival under serum starvation and chemotherapeutic resistance. Knockout cells showed reduced GLUT1 protein expression, survival without attachment and their migration and invasion in vitro and in vivo were unaltered, despite increased matrix metalloproteinases release. Our findings emphasise the importance of alternative splicing of dystrophin transcripts and underscore the role of the Dp71f variant, which appears to govern distinct cellular processes frequently dysregulated in tumour cells. The loss of this regulatory mechanism promotes sarcoma cell survival and treatment resistance. Thus, Dp71f is a target for future investigations exploring the intricate functions of specific DMD transcripts in physiology and across malignancies.
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Affiliation(s)
- Nancy Alnassar
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth PO1 2DT, United Kingdom
| | - Jacek Hajto
- Laboratory of Pharmacogenomics, Maj Institute of Pharmacology PAS, Smetna 12, Krakow 31155, Poland
| | - Robin M H Rumney
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth PO1 2DT, United Kingdom
| | - Suraj Verma
- School of Computing, Engineering and Digital Technologies, Teesside University, Middlesbrough, Tees Valley TS1 3BX, United Kingdom
| | - Malgorzata Borczyk
- Laboratory of Pharmacogenomics, Maj Institute of Pharmacology PAS, Smetna 12, Krakow 31155, Poland
| | - Chandrika Saha
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth PO1 2DT, United Kingdom
| | - Janos Kanczler
- Bone & Joint Research Group, Department of Human Development and Health, University of Southampton, Tremona Road, Southampton SO16 6YD, United Kingdom
| | - Arthur M Butt
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth PO1 2DT, United Kingdom
| | - Annalisa Occhipinti
- School of Computing, Engineering and Digital Technologies, Teesside University, Middlesbrough, Tees Valley TS1 3BX, United Kingdom
| | - Joanna Pomeroy
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth PO1 2DT, United Kingdom
| | - Claudio Angione
- School of Computing, Engineering and Digital Technologies, Teesside University, Middlesbrough, Tees Valley TS1 3BX, United Kingdom
| | - Michal Korostynski
- Laboratory of Pharmacogenomics, Maj Institute of Pharmacology PAS, Smetna 12, Krakow 31155, Poland
| | - Dariusz C Górecki
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth PO1 2DT, United Kingdom
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Donandt T, Todorow V, Hintze S, Graupner A, Schoser B, Walter MC, Meinke P. Nuclear Small Dystrophin Isoforms during Muscle Differentiation. Life (Basel) 2023; 13:1367. [PMID: 37374149 DOI: 10.3390/life13061367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/05/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
Mutations in the DMD gene can cause Duchenne or Becker muscular dystrophy (DMD/BMD) by affecting the giant isoform of dystrophin, a protein encoded by the DMD gene. The role of small dystrophin isoforms is not well investigated yet, and they may play a role in muscle development and molecular pathology. Here, we investigated the nuclear localization of short carboxy-terminal dystrophin isoforms during the in vitro differentiation of human, porcine, and murine myoblast cultures. We could not only confirm the presence of Dp71 in the nucleoplasm and at the nuclear envelope, but we could also identify the Dp40 isoform in muscle nuclei. The localization of both isoforms over the first six days of differentiation was similar between human and porcine myoblasts, but murine myoblasts behaved differently. This highlights the importance of the porcine model in investigating DMD. We could also detect a wave-like pattern of nuclear presence of both Dp71 and Dp40, indicating a direct or indirect involvement in gene expression control during muscle differentiation.
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Affiliation(s)
- Tina Donandt
- Friedrich-Baur-Institute at the Department of Neurology, LMU University Hospital, Ludwig Maximilians University, 81377 Munich, Germany
| | - Vanessa Todorow
- Friedrich-Baur-Institute at the Department of Neurology, LMU University Hospital, Ludwig Maximilians University, 81377 Munich, Germany
| | - Stefan Hintze
- Friedrich-Baur-Institute at the Department of Neurology, LMU University Hospital, Ludwig Maximilians University, 81377 Munich, Germany
| | - Alexandra Graupner
- Friedrich-Baur-Institute at the Department of Neurology, LMU University Hospital, Ludwig Maximilians University, 81377 Munich, Germany
| | - Benedikt Schoser
- Friedrich-Baur-Institute at the Department of Neurology, LMU University Hospital, Ludwig Maximilians University, 81377 Munich, Germany
| | - Maggie C Walter
- Friedrich-Baur-Institute at the Department of Neurology, LMU University Hospital, Ludwig Maximilians University, 81377 Munich, Germany
| | - Peter Meinke
- Friedrich-Baur-Institute at the Department of Neurology, LMU University Hospital, Ludwig Maximilians University, 81377 Munich, Germany
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Rugerio-Martínez CI, Ramos D, Segura-Olvera A, Murillo-Melo NM, Tapia-Guerrero YS, Argüello-García R, Leyva-García N, Hernández-Hernández O, Cisneros B, Suárez-Sánchez R. Dp71 Point Mutations Induce Protein Aggregation, Loss of Nuclear Lamina Integrity and Impaired Braf35 and Ibraf Function in Neuronal Cells. Int J Mol Sci 2022; 23:ijms231911876. [PMID: 36233175 PMCID: PMC9570083 DOI: 10.3390/ijms231911876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/04/2022] [Accepted: 10/04/2022] [Indexed: 11/16/2022] Open
Abstract
Dystrophin Dp71 is the most abundant product of the Duchenne muscular dystrophy gene in the nervous system, and mutations impairing its function have been associated with the neurodevelopmental symptoms present in a third of DMD patients. Dp71 is required for the clustering of neurotransmitter receptors and the neuronal differentiation of cultured cells; nonetheless, its precise role in neuronal cells remains to be poorly understood. In this study, we analyzed the effect of two pathogenic DMD gene point mutations on the Dp71 function in neurons. We engineered C272Y and E299del mutations to express GFP-tagged Dp71 protein variants in N1E-115 and SH-SY5Y neuronal cells. Unexpectedly, the ectopic expression of Dp71 mutants resulted in protein aggregation, which may be mechanistically caused by the effect of the mutations on Dp71 structure, as predicted by protein modeling and molecular dynamics simulations. Interestingly, Dp71 mutant variants acquired a dominant negative function that, in turn, dramatically impaired the distribution of different Dp71 protein partners, including β-dystroglycan, nuclear lamins A/C and B1, the high-mobility group (HMG)-containing protein (BRAF35) and the BRAF35-family-member inhibitor of BRAF35 (iBRAF). Further analysis of Dp71 mutants provided evidence showing a role for Dp71 in modulating both heterochromatin marker H3K9me2 organization and the neuronal genes’ expression, via its interaction with iBRAF and BRAF5.
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Affiliation(s)
- Claudia Ivette Rugerio-Martínez
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de Mexico 07360, Mexico
| | - Daniel Ramos
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Abel Segura-Olvera
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Nadia Mireya Murillo-Melo
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Yessica Sarai Tapia-Guerrero
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Raúl Argüello-García
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de Mexico 07360, Mexico
| | - Norberto Leyva-García
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Oscar Hernández-Hernández
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
| | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de Mexico 07360, Mexico
| | - Rocío Suárez-Sánchez
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de Mexico 14389, Mexico
- Correspondence: or ; Tel.: +52-55-5999-1000 (ext. 14710)
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Farea M, Maeta K, Nishio H, Matsuo M. Human Dystrophin Dp71ab Enhances the Proliferation of Myoblasts Across Species But Not Human Nonmyoblast Cells. Front Cell Dev Biol 2022; 10:877612. [PMID: 35547811 PMCID: PMC9081641 DOI: 10.3389/fcell.2022.877612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
Dystrophin Dp71 is an isoform produced from the Dp71 promoter in intron 62 of the DMD gene, mutations in which cause Duchenne muscular dystrophy. Dp71 is involved in various cellular processes and comprises more than 10 isoforms produced by alternative splicing. Dp71ab, in which both exons 71 and 78 are deleted, has a hydrophobic C-terminus that is hydrophilic in Dp71. Therefore, Dp71ab is believed to have different roles from Dp71. Previously, we reported that Dp71ab enhanced the proliferation of human myoblasts. Here, we further characterized Dp71ab, focusing on the activation of cell proliferation. Dp71ab increased the proliferation of immortalized human myoblasts in a dose-dependent manner. In contrast, Dp71 suppressed proliferation in a dose-dependent manner. Consistent with these opposite effects, eGFP-tagged Dp71ab and mCherry-tagged Dp71 showed different cellular distributions, with Dp71ab mostly in the nucleus. Notably, human Dp71ab enhanced the proliferation of rat and mouse myoblasts. Despite these findings, human Dp71ab did not enhance the proliferation of human nonmyoblast cells, including rhabdomyosarcoma cells. We concluded that Dp71ab is a myoblast-specific proliferation enhancer. In further studies, Dp71ab will be employed for the expansion of myoblasts in clinical settings.
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Affiliation(s)
- Manal Farea
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe, Japan
| | - Kazuhiro Maeta
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe, Japan
- KNC Department of Nucleic Acid Drug Discovery, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan
| | - Hisahide Nishio
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe, Japan
- Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan
| | - Masafumi Matsuo
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe, Japan
- KNC Department of Nucleic Acid Drug Discovery, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan
- *Correspondence: Masafumi Matsuo,
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Naidoo M, Anthony K. Dystrophin Dp71 and the Neuropathophysiology of Duchenne Muscular Dystrophy. Mol Neurobiol 2020; 57:1748-1767. [PMID: 31836945 PMCID: PMC7060961 DOI: 10.1007/s12035-019-01845-w] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 11/22/2019] [Indexed: 12/13/2022]
Abstract
Duchenne muscular dystrophy (DMD) is caused by frameshift mutations in the DMD gene that prevent the body-wide translation of its protein product, dystrophin. Besides a severe muscle phenotype, cognitive impairment and neuropsychiatric symptoms are prevalent. Dystrophin protein 71 (Dp71) is the major DMD gene product expressed in the brain and mutations affecting its expression are associated with the DMD neuropsychiatric syndrome. As with dystrophin in muscle, Dp71 localises to dystrophin-associated protein complexes in the brain. However, unlike in skeletal muscle; in the brain, Dp71 is alternatively spliced to produce many isoforms with differential subcellular localisations and diverse cellular functions. These include neuronal differentiation, adhesion, cell division and excitatory synapse organisation as well as nuclear functions such as nuclear scaffolding and DNA repair. In this review, we first describe brain involvement in DMD and the abnormalities observed in the DMD brain. We then review the gene expression, RNA processing and functions of Dp71. We review genotype-phenotype correlations and discuss emerging cellular/tissue evidence for the involvement of Dp71 in the neuropathophysiology of DMD. The literature suggests changes observed in the DMD brain are neurodevelopmental in origin and that their risk and severity is associated with a cumulative loss of distal DMD gene products such as Dp71. The high risk of neuropsychiatric syndromes in Duchenne patients warrants early intervention to achieve the best possible quality of life. Unravelling the function and pathophysiological significance of dystrophin in the brain has become a high research priority to inform the development of brain-targeting treatments for Duchenne.
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Affiliation(s)
- Michael Naidoo
- Centre for Physical Activity and Life Sciences, Faculty of Arts, Science and Technology, University of Northampton, University Drive, Northampton, Northamptonshire, NN1 5PH, UK
| | - Karen Anthony
- Centre for Physical Activity and Life Sciences, Faculty of Arts, Science and Technology, University of Northampton, University Drive, Northampton, Northamptonshire, NN1 5PH, UK.
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Ruggieri S, De Giorgis M, Annese T, Tamma R, Notarangelo A, Marzullo A, Senetta R, Cassoni P, Notarangelo M, Ribatti D, Nico B. Dp71 Expression in Human Glioblastoma. Int J Mol Sci 2019; 20:E5429. [PMID: 31683640 PMCID: PMC6862465 DOI: 10.3390/ijms20215429] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 10/14/2019] [Accepted: 10/30/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Dp71 is the most abundant dystrophin (DMD) gene product in the nervous system. Mutation in the Dp71 coding region is associated with cognitive disturbances in Duchenne muscular dystrophy (DMD) patients, but the function of dystrophin Dp71 in tumor progression remains to be established. This study investigated Dp71 expression in glioblastoma, the most common and aggressive primary tumor of the central nervous system (CNS). METHODS Dp71 expression was analyzed by immunofluorescence, immunohistochemistry, RT-PCR, and immunoblotting in glioblastoma cell lines and cells isolated from human glioblastoma multiforme (GBM) bioptic specimens. RESULTS Dp71 isoform was expressed in normal human astrocytes (NHA) cell lines and decreased in glioblastoma cell lines and cells isolated from human glioblastoma multiforme bioptic specimens. Moreover, Dp71 was localized in the nucleus in normal cells, while it was localized into the cytoplasm of glioblastoma cells organized in clusters. We have shown, by double labeling, that Dp71 colocalizes with lamin B in normal astrocytes cells, confirming the roles of Dp71 and lamin B in maintaining nuclear architecture. Finally, we demonstrated that decreased Dp71 protein in cells isolated from human bioptic specimens was inversely correlated with the Ki-67 tumor proliferative index. CONCLUSION A decreased Dp71 expression is associated with cancer proliferation and poor prognosis in glioblastoma.
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Affiliation(s)
- Simona Ruggieri
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Michelina De Giorgis
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Tiziana Annese
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Roberto Tamma
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Angelo Notarangelo
- Medical Genetic Unit, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, 71013 Foggia, Italy.
| | - Andrea Marzullo
- Department of Emergency and Transplantation, Pathology Unit, University of Bari Medical School, 70124 Bari, Italy.
| | - Rebecca Senetta
- Pathology Unit, Department of Medical Sciences, University of Turin, University of Turin Medical School, 10124 Turin, Italy.
| | - Paola Cassoni
- Pathology Unit, Department of Medical Sciences, University of Turin, University of Turin Medical School, 10124 Turin, Italy.
| | - Michela Notarangelo
- Centre for Integrative Biology, CIBIO, University of Trento, 38123 Trento, Italy.
| | - Domenico Ribatti
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
| | - Beatrice Nico
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy.
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Aranmolate A, Tse N, Colognato H. Myelination is delayed during postnatal brain development in the mdx mouse model of Duchenne muscular dystrophy. BMC Neurosci 2017; 18:63. [PMID: 28806929 PMCID: PMC5556620 DOI: 10.1186/s12868-017-0381-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 08/07/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In Duchenne muscular dystrophy (DMD), the loss of the dystrophin component of the dystrophin-glycoprotein complex (DGC) compromises plasma membrane integrity in skeletal muscle, resulting in extensive muscle degeneration. In addition, many DMD patients exhibit brain deficits in which the cellular etiology remains poorly understood. We recently found that dystroglycan, a receptor component of the DGC that binds intracellularly to dystrophin, regulates the development of oligodendrocytes, the myelinating glial cells of the brain. RESULTS We investigated whether dystrophin contributes to oligodendroglial function and brain myelination. We found that oligodendrocytes express up to three dystrophin isoforms, in conjunction with classic DGC components, which are developmentally regulated during differentiation and in response to extracellular matrix engagement. We found that mdx mice, a model of DMD lacking expression of the largest dystrophin isoform, have delayed myelination and inappropriate oligodendrocyte progenitor proliferation in the cerebral cortex. When we prevented the expression of all oligodendroglial dystrophin isoforms in cultured oligodendrocytes using RNA interference, we found that later stages of oligodendrocyte maturation were significantly delayed, similar to mdx phenotypes in the developing brain. CONCLUSIONS We find that dystrophin is expressed in oligodendrocytes and influences developmental myelination, which provides new insight into potential cellular contributors to brain dysfunction associated with DMD.
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Affiliation(s)
- Azeez Aranmolate
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11794-8651, USA
| | - Nathaniel Tse
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11794-8651, USA
| | - Holly Colognato
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11794-8651, USA.
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Dystrophin Dp71 Isoforms Are Differentially Expressed in the Mouse Brain and Retina: Report of New Alternative Splicing and a Novel Nomenclature for Dp71 Isoforms. Mol Neurobiol 2017; 55:1376-1386. [PMID: 28127699 DOI: 10.1007/s12035-017-0405-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 01/12/2017] [Indexed: 12/27/2022]
Abstract
Multiple dystrophin Dp71 isoforms have been identified in rats, mice, and humans and in several cell line models. These Dp71 isoforms are produced by the alternative splicing of exons 71 to 74 and 78 and intron 77. Three main groups of Dp71 proteins are defined based on their C-terminal specificities: Dp71d, Dp71f, and Dp71e. Dp71 is highly expressed in the brain and retina; however, the specific isoforms present in these tissues have not been determined to date. In this work, we explored the expression of Dp71 isoforms in the mouse brain and retina using RT-PCR assays followed by the cloning of PCR products into the pGEM-T Easy vector, which was used to transform DH5α cells. Dp71-positive colonies were later analyzed by PCR multiplex and DNA sequencing to determine the alternative splicing. We thus demonstrated the expression of Dp71 transcripts corresponding to Dp71, Dp71a, Dp71c, Dp71b, Dp71ab, Dp71 Δ110, and novel Dp71 isoforms spliced in exon 74; 71 and 74; 71, 73 and 74; and 74 and 78, which we named Dp71d Δ74 , Dp71d Δ71,74 , Dp71d Δ71,73-74 , and Dp71f Δ74 , respectively. Additionally, we demonstrated that the Dp71d group of isoforms is highly expressed in the brain, while the Dp71f group predominates in the retina, at both the cDNA and protein levels. These findings suggest that distinct Dp71 isoforms may play different roles in the brain and retina.
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Quaranta MT, Spinello I, Paolillo R, Macchia G, Boe A, Ceccarini M, Labbaye C, Macioce P. Identification of β-Dystrobrevin as a Direct Target of miR-143: Involvement in Early Stages of Neural Differentiation. PLoS One 2016; 11:e0156325. [PMID: 27223470 PMCID: PMC4880309 DOI: 10.1371/journal.pone.0156325] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 05/12/2016] [Indexed: 11/25/2022] Open
Abstract
Duchenne Muscular Dystrophy, a genetic disorder that results in a gradual breakdown of muscle, is associated to mild to severe cognitive impairment in about one-third of dystrophic patients. The brain dysfunction is independent of the muscular pathology, occurs early, and is most likely due to defects in the assembly of the Dystrophin-associated Protein Complex (DPC) during embryogenesis. We have recently described the interaction of the DPC component β-dystrobrevin with members of complexes that regulate chromatin dynamics, and suggested that β-dystrobrevin may play a role in the initiation of neuronal differentiation. Since oxygen concentrations and miRNAs appear as well to be involved in the cellular processes related to neuronal development, we have studied how these factors act on β-dystrobrevin and investigated the possibility of their functional interplay using the NTera-2 cell line, a well-established model for studying neurogenesis. We followed the pattern of expression and regulation of β-dystrobrevin during the early stages of neuronal differentiation induced by exposure to retinoic acid (RA) under hypoxia as compared with normoxia, and found that β-dystrobrevin expression is regulated during RA-induced differentiation of NTera-2 cells. We also found that β-dystrobrevin pattern is delayed under hypoxic conditions, together with a delay in the differentiation and an increase in the proliferation rate of cells. We identified miRNA-143 as a direct regulator of β-dystrobrevin expression, demonstrated that β-dystrobrevin is expressed in the nucleus and showed that, in line with our previous in vitro results, β-dystrobrevin is a repressor of synapsin I in live cells. Altogether the newly identified regulatory pathway miR-143/β-dystrobrevin/synapsin I provides novel insights into the functions of β-dystrobrevin and opens up new perspectives for elucidating the molecular mechanisms underlying the neuronal involvement in muscular dystrophy.
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Affiliation(s)
- Maria Teresa Quaranta
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Isabella Spinello
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Rosa Paolillo
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Gianfranco Macchia
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
| | - Alessandra Boe
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Marina Ceccarini
- National Centre for Rare Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Catherine Labbaye
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Pompeo Macioce
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
- * E-mail:
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Nishida A, Yasuno S, Takeuchi A, Awano H, Lee T, Niba ETE, Fujimoto T, Itoh K, Takeshima Y, Nishio H, Matsuo M. HEK293 cells express dystrophin Dp71 with nucleus-specific localization of Dp71ab. Histochem Cell Biol 2016; 146:301-9. [PMID: 27109495 DOI: 10.1007/s00418-016-1439-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2016] [Indexed: 11/30/2022]
Abstract
The dystrophin gene consists of 79 exons and encodes tissue-specific isoforms. Mutations in the dystrophin gene cause Duchenne muscular dystrophy, of which a substantial proportion of cases are complicated by non-progressive mental retardation. Abnormalities of Dp71, an isoform transcribed from a promoter in intron 62, are a suspected cause of mental retardation. However, the roles of Dp71 in human brain have not been fully elucidated. Here, we characterized dystrophin in human HEK293 cells with the neuronal lineage. Reverse transcription-PCR amplification of the full-length dystrophin transcript revealed the absence of fragments covering the 5' part of the dystrophin cDNA. In contrast, fragments covering exons 64-79 were present. The Dp71 promoter-specific exon G1 was shown spliced to exon 63. We demonstrated that the Dp71 transcript comprised two subisoforms: one lacking exon 78 (Dp71b) and the other lacking both exons 71 and 78 (Dp71ab). Western blotting of cell lysates using an antibody against the dystrophin C-terminal region revealed two bands, corresponding to Dp71b and Dp71ab. Immunohistochemical examination with the dystrophin antibody revealed scattered punctate signals in the cytoplasm and the nucleus. Western blotting revealed one band corresponding to Dp71b in the cytoplasm and two bands corresponding to Dp71b and Dp71ab in the nucleus, with Dp71b being predominant. These results indicated that Dp71ab is a nucleus-specific subisoform. We concluded that Dp71, comprising Dp71b and Dp71ab, was expressed exclusively in HEK293 cells and that Dp71ab was specifically localized to the nucleus. Our findings suggest that Dp71ab in the nucleus contributes to the diverse functions of HEK293 cells.
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Affiliation(s)
- Atsushi Nishida
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan
| | - Sato Yasuno
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan.,Kobe Pharmaceutical University, Higashinada, Kobe, 658-8558, Japan
| | - Atsuko Takeuchi
- Kobe Pharmaceutical University, Higashinada, Kobe, 658-8558, Japan
| | - Hiroyuki Awano
- Department of Pediatrics, Graduate School of Medicine, Kobe University, Chuo, Kobe, 650-0017, Japan
| | - Tomoko Lee
- Department of Pediatrics, Hyogo College of Medicine, Mukogawacho, Nishinomiya, 663-8501, Japan
| | - Emma Tabe Eko Niba
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan
| | - Takahiro Fujimoto
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Kyoko Itoh
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Yasuhiro Takeshima
- Department of Pediatrics, Hyogo College of Medicine, Mukogawacho, Nishinomiya, 663-8501, Japan
| | - Hisahide Nishio
- Department of Community Medicine and Social Healthcare Science, Graduate School of Medicine, Kobe University, Chuo, Kobe, 650-0017, Japan
| | - Masafumi Matsuo
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan.
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Aragón J, Martínez-Herrera A, Romo-Yáñez J, Ceja V, Azotla-Vilchis C, Siqueiros-Márquez L, Soid-Raggi G, Herrera-Salazar A, Montañez C. Identification of Dp71 Isoforms Expressed in PC12 Cells: Subcellular Localization and Colocalization with β-Dystroglycan and α1-Syntrophin. J Mol Neurosci 2015; 58:201-9. [DOI: 10.1007/s12031-015-0657-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 09/14/2015] [Indexed: 11/24/2022]
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12
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Rodríguez-Muñoz R, Cárdenas-Aguayo MDC, Alemán V, Osorio B, Chávez-González O, Rendon A, Martínez-Rojas D, Meraz-Ríos MA. Novel Nuclear Protein Complexes of Dystrophin 71 Isoforms in Rat Cultured Hippocampal GABAergic and Glutamatergic Neurons. PLoS One 2015; 10:e0137328. [PMID: 26378780 PMCID: PMC4574971 DOI: 10.1371/journal.pone.0137328] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 07/22/2015] [Indexed: 01/19/2023] Open
Abstract
The precise functional role of the dystrophin 71 in neurons is still elusive. Previously, we reported that dystrophin 71d and dystrophin 71f are present in nuclei from cultured neurons. In the present work, we performed a detailed analysis of the intranuclear distribution of dystrophin 71 isoforms (Dp71d and Dp71f), during the temporal course of 7-day postnatal rats hippocampal neurons culture for 1h, 2, 4, 10, 15 and 21 days in vitro (DIV). By immunofluorescence assays, we detected the highest level of nuclear expression of both dystrophin Dp71 isoforms at 10 DIV, during the temporal course of primary culture. Dp71d and Dp71f were detected mainly in bipolar GABAergic (≥60%) and multipolar Glutamatergic (≤40%) neurons, respectively. We also characterized the existence of two nuclear dystrophin-associated protein complexes (DAPC): dystrophin 71d or dystrophin 71f bound to β-dystroglycan, α1-, β-, α2-dystrobrevins, α-syntrophin, and syntrophin-associated protein nNOS (Dp71d-DAPC or Dp71f-DAPC, respectively), in the hippocampal neurons. Furthermore, both complexes were localized in interchromatin granule cluster structures (nuclear speckles) of neuronal nucleoskeleton preparations. The present study evinces that each Dp71's complexes differ slightly in dystrobrevins composition. The results demonstrated that Dp71d-DAPC was mainly localized in bipolar GABAergic and Dp71f-DAPC in multipolar Glutamatergic hippocampal neurons. Taken together, our results show that dystrophin 71d, dystrophin 71f and DAP integrate protein complexes, and both complexes were associated to nuclear speckles structures.
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Affiliation(s)
- Rafael Rodríguez-Muñoz
- Departments of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), México D.F., México
| | - María del Carmen Cárdenas-Aguayo
- Molecular Biomedicine, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), México D.F., México
| | - Víctor Alemán
- Departments of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), México D.F., México
| | - Beatriz Osorio
- Departments of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), México D.F., México
| | - Oscar Chávez-González
- Departments of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), México D.F., México
| | - Alvaro Rendon
- Institut de la Vision, UMR Inserm, Laboratoire de Physiopathologie Cellulaire et Moléculaire de la Rétine, Université Pierre et Marie Curie, Paris, France
| | - Dalila Martínez-Rojas
- Departments of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), México D.F., México
- * E-mail: (MAMMR); (DMR)
| | - Marco Antonio Meraz-Ríos
- Molecular Biomedicine, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), México D.F., México
- * E-mail: (MAMMR); (DMR)
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Fujimoto T, Itoh K, Yaoi T, Fushiki S. Somatodendritic and excitatory postsynaptic distribution of neuron-type dystrophin isoform, Dp40, in hippocampal neurons. Biochem Biophys Res Commun 2014; 452:79-84. [PMID: 25152393 DOI: 10.1016/j.bbrc.2014.08.064] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 08/12/2014] [Indexed: 11/18/2022]
Abstract
The Duchenne muscular dystrophy (DMD) gene produces multiple dystrophin (Dp) products due to the presence of several promoters. We previously reported the existence of a novel short isoform of Dp, Dp40, in adult mouse brain. However, the exact biochemical expression profile and cytological distribution of the Dp40 protein remain unknown. In this study, we generated a polyclonal antibody against the NH2-terminal region of the Dp40 and identified the expression profile of Dp40 in the mouse brain. Through an analysis using embryonic and postnatal mouse cerebrums, we found that Dp40 emerged from the early neonatal stages until adulthood, whereas Dp71, an another Dp short isoform, was highly detected in both prenatal and postnatal cerebrums. Intriguingly, relative expressions of Dp40 and Dp71 were prominent in cultured dissociated neurons and non-neuronal cells derived from mouse hippocampus, respectively. Furthermore, the immunocytological distribution of Dp40 was analyzed in dissociated cultured neurons, revealing that Dp40 is detected in the soma and its dendrites, but not in the axon. It is worthy to note that Dp40 is localized along the subplasmalemmal region of the dendritic shafts, as well as at excitatory postsynaptic sites. Thus, Dp40 was identified as a neuron-type Dp possibly involving dendritic and synaptic functions.
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Affiliation(s)
- Takahiro Fujimoto
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Kyoko Itoh
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
| | - Takeshi Yaoi
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Shinji Fushiki
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
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Suárez-Sánchez R, Aguilar A, Wagstaff KM, Velez G, Azuara-Medina PM, Gomez P, Vásquez-Limeta A, Hernández-Hernández O, Lieu KG, Jans DA, Cisneros B. Nucleocytoplasmic shuttling of the Duchenne muscular dystrophy gene product dystrophin Dp71d is dependent on the importin α/β and CRM1 nuclear transporters and microtubule motor dynein. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1843:985-1001. [PMID: 24486332 DOI: 10.1016/j.bbamcr.2014.01.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 12/17/2013] [Accepted: 01/24/2014] [Indexed: 01/08/2023]
Abstract
Even though the Duchenne muscular dystrophy (DMD) gene product Dystrophin Dp71d is involved in various key cellular processes through its role as a scaffold for structural and signalling proteins at the plasma membrane as well as the nuclear envelope, its subcellular trafficking is poorly understood. Here we map the nuclear import and export signals of Dp71d by truncation and point mutant analysis, showing for the first time that Dp71d shuttles between the nucleus and cytoplasm mediated by the conventional nuclear transporters, importin (IMP) α/β and the exportin CRM1. Binding was confirmed in cells using pull-downs, while in vitro binding assays showed direct, high affinity (apparent dissociation coefficient of c. 0.25nM) binding of Dp71d to IMPα/β. Interestingly, treatment of cells with the microtubule depolymerizing reagent nocodazole or the dynein inhibitor EHNA both decreased Dp71d nuclear localization, implying that Dp71d nuclear import may be facilitated by microtubules and the motor protein dynein. The role of Dp71d in the nucleus appears to relate in part to interaction with the nuclear envelope protein emerin, and maintenance of the integrity of the nuclear architecture. The clear implication is that Dp71d's previously unrecognised nuclear transport properties likely contribute to various, important physiological roles.
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Affiliation(s)
- R Suárez-Sánchez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico; Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México D.F, Mexico
| | - A Aguilar
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - K M Wagstaff
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - G Velez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - P M Azuara-Medina
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - P Gomez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - A Vásquez-Limeta
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - O Hernández-Hernández
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México D.F, Mexico
| | - K G Lieu
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - D A Jans
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia.
| | - B Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico.
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15
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Vásquez-Limeta A, Wagstaff KM, Ortega A, Crouch DH, Jans DA, Cisneros B. Nuclear import of β-dystroglycan is facilitated by ezrin-mediated cytoskeleton reorganization. PLoS One 2014; 9:e90629. [PMID: 24599031 PMCID: PMC3944073 DOI: 10.1371/journal.pone.0090629] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 02/04/2014] [Indexed: 12/12/2022] Open
Abstract
The β-dystroglycan (β-DG) protein has the ability to target to multiple sites in eukaryotic cells, being a member of diverse protein assemblies including the transmembranal dystrophin-associated complex, and a nuclear envelope-localised complex that contains emerin and lamins A/C and B1. We noted that the importin α2/β1-recognised nuclear localization signal (NLS) of β-DG is also a binding site for the cytoskeletal-interacting protein ezrin, and set out to determine whether ezrin binding might modulate β-DG nuclear translocation for the first time. Unexpectedly, we found that ezrin enhances rather than inhibits β-DG nuclear translocation in C2C12 myoblasts. Both overexpression of a phosphomimetic activated ezrin variant (Ez-T567D) and activation of endogenous ezrin through stimulation of the Rho pathway resulted in both formation of actin-rich surface protrusions and significantly increased nuclear translocation of β-DG as shown by quantitative microscopy and subcellular fractionation/Western analysis. In contrast, overexpression of a nonphosphorylatable inactive ezrin variant (Ez-T567A) or inhibition of Rho signaling, decreased nuclear translocation of β-DG concomitant with a lack of cell surface protrusions. Further, a role for the actin cytoskeleton in ezrin enhancement of β-DG nuclear translocation was implicated by the observation that an ezrin variant lacking its actin-binding domain failed to enhance nuclear translocation of β-DG, while disruption of the actin cytoskeleton led to a reduction in β-DG nuclear localization. Finally, we show that ezrin-mediated cytoskeletal reorganization enhances nuclear translocation of the cytoplasmic but not the transmembranal fraction of β-DG. This is the first study showing that cytoskeleton reorganization can modulate nuclear translocation of β-DG, with the implication that β-DG can respond to cytoskeleton-driven changes in cell morphology by translocating from the cytoplasm to the nucleus to orchestrate nuclear processes in response to the functional requirements of the cell.
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Affiliation(s)
- Alejandra Vásquez-Limeta
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F., Mexico
| | - Kylie M. Wagstaff
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Arturo Ortega
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F., Mexico
| | - Dorothy H. Crouch
- School of Dentistry, University of Dundee, Dundee, Scotland, United Kingdom
| | - David A. Jans
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
- * E-mail: (BC); david.jans@ monash.edu (DAJ)
| | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F., Mexico
- * E-mail: (BC); david.jans@ monash.edu (DAJ)
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Alpha-Dystrobrevin and its associated proteins in human promyelocytic leukemia cells induced to apoptosis. J Proteomics 2012; 75:3291-303. [PMID: 22507200 DOI: 10.1016/j.jprot.2012.03.041] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 03/19/2012] [Accepted: 03/25/2012] [Indexed: 12/13/2022]
Abstract
Dystrobrevin is a dystrophin-related component of the dystrophin-associated protein complex (DAPC). Using alpha-dystrobrevin as indicator, we aimed to elucidate the interaction network of the DAPC with other proteins during apoptosis of promyelocytic HL-60 cells. The precise role(s) of DBs are not known, but we and others have shown that they play a role in intracellular signal transduction and cellular organization. Apoptosis was induced with etoposide in the absence or presence of Z-VAD to block caspase activity, and we then followed the cellular distribution of α-DB and its association with other proteins, using confocal imaging and cell fractions analyses after immune-precipitation with anti-α-DB and mass spectrometry. Confocal imaging revealed distinct spatial relocalizations of α-DB between the cell membrane, cytosol and nucleus after induction of apoptosis. The expression levels of the identified proteins were evaluated with computer-assisted image analysis of the gels. We thus identified associations with structural and transport proteins (tropomyosin, myosin), membrane (ADAM21, syntrophin), ER-Golgi (TGN51, eIF38) and nuclear (Lamins, ribonucleoprotein C1/C2) proteins. These results suggest that apoptosis-induction in HL-60 cells involves not only classical markers of apoptosis but also a network α-DB-associated proteins at the cell membrane, the cytoplasm and nucleus, affecting key cellular transport processes and cellular structure.
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Tozawa T, Itoh K, Yaoi T, Tando S, Umekage M, Dai H, Hosoi H, Fushiki S. The shortest isoform of dystrophin (Dp40) interacts with a group of presynaptic proteins to form a presumptive novel complex in the mouse brain. Mol Neurobiol 2012; 45:287-97. [PMID: 22258561 PMCID: PMC3311850 DOI: 10.1007/s12035-012-8233-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 01/02/2012] [Indexed: 02/08/2023]
Abstract
Duchenne muscular dystrophy (DMD) causes cognitive impairment in one third of the patients, although the underlying mechanisms remain to be elucidated. Recent studies showed that mutations in the distal part of the dystrophin gene correlate well with the cognitive impairment in DMD patients, which is attributed to Dp71. The study on the expression of the shortest isoform, Dp40, has not been possible due to the lack of an isoform specific antibody. Dp40 has the same promoter as that found in Dp71 and lacks the normal C-terminal end of Dp427. In the present study, we have raised polyclonal antibody against the N-terminal sequence common to short isoforms of dystrophin, including Dp40, and investigated the expression pattern of Dp40 in the mouse brain. Affinity chromatography with this antibody and the consecutive LC-MS/MS analysis on the interacting proteins revealed that Dp40 was abundantly expressed in synaptic vesicles and interacted with a group of presynaptic proteins, including syntaxin1A and SNAP25, which are involved in exocytosis of synaptic vesicles in neurons. We thus suggest that Dp40 may form a novel protein complex and play a crucial role in presynaptic function. Further studies on these aspects of Dp40 function might provide more insight into the molecular mechanisms of cognitive impairment found in patients with DMD.
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Affiliation(s)
- Takenori Tozawa
- Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
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Dystrophin Dp71: The Smallest but Multifunctional Product of the Duchenne Muscular Dystrophy Gene. Mol Neurobiol 2011; 45:43-60. [DOI: 10.1007/s12035-011-8218-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/02/2011] [Indexed: 01/06/2023]
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Aragón J, Romo-Yáñez J, Martínez-Herrera A, Ceja V, Rendon A, Montañez C. Characterization of Dp71Δ(78-79), a novel dystrophin mutant that stimulates PC12 cell differentiation. J Neurochem 2011; 119:697-707. [PMID: 21668890 DOI: 10.1111/j.1471-4159.2011.07347.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dp71 has an important role in the central nervous system. To better understand the function of Dp71 domains in neuronal differentiation, PC12 cells were stably transfected with a dystrophin mutant, Dp71Δ(78-79) , which lacks exons 78 and 79. Based on the percentage of cells bearing neurites and neurite length analyses, we found that cells stably expressing Dp71Δ(78-79) (PC12-C11) differentiate more efficiently than non-transfected cells. While wild-type cells reach their maximum differentiation 9-12 days after initiating the differentiation process, the PC12-C11 cells reach differentiation in 4-6 days. Protein expression analysis showed a down-regulation of Dp71a and an up-regulation of Dp71ab and/or Up71, β-dystroglycan and neuron-specific enolase in undifferentiated and in neural growth factor differentiated PC12-C11 cells. No change was observed in the expression of Grb2 and Up400. The subcellular localization of Dp71Δ(78-79) was in the cell periphery, and there was no change in localization during the differentiation process, which was also observed throughout the neurite extensions.
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Affiliation(s)
- Jorge Aragón
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, DF, México
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Villarreal-Silva M, Centeno-Cruz F, Suárez-Sánchez R, Garrido E, Cisneros B. Knockdown of dystrophin Dp71 impairs PC12 cells cycle: localization in the spindle and cytokinesis structures implies a role for Dp71 in cell division. PLoS One 2011; 6:e23504. [PMID: 21886794 PMCID: PMC3158767 DOI: 10.1371/journal.pone.0023504] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Accepted: 07/18/2011] [Indexed: 12/22/2022] Open
Abstract
The function of dystrophin Dp71 in neuronal cells remains to be established. Previously, we revealed the involvement of this protein in both nerve growth factor (NGF)-induced neuronal differentiation and cell adhesion by isolation and characterization of PC12 neuronal cells with depleted levels of Dp71. In this work, a novel phenotype of Dp71-knockdown cells was characterized, which is their delayed growth rate. Cell cycle analyses revealed an altered behavior of Dp71-depleted cells, which consists of a delay in G0/G1 transition and an increase in apoptosis during nocodazole-induced mitotic arrest. Dp71 associates with lamin B1 and β-dystroglycan, proteins involved in aspects of the cell division cycle; therefore, we compared the distribution of Dp71 with that of lamin B1 and β-dystroglycan in PC12 cells at mitosis and cytokinesis by means of immunofluorescence and confocal microscopy analysis. All of these three proteins exhibited a similar immunostaining pattern, localized at mitotic spindle, cleavage furrow, and midbody. It is noteworthy that a drastic decreased staining in mitotic spindle, cleavage furrow, and midbody was observed for both lamin B1 and β-dystroglycan in Dp71-depleted cells. Furthermore, we demonstrated the interaction of Dp71 with lamin B1 in PC12 cells by immunoprecipitation and pull-down assays, and importantly, we revealed that knockdown of Dp71 expression caused a marked reduction in lamin B1 levels and altered localization of the nuclear envelope protein emerin. Our data indicate that Dp71 is a component of the mitotic spindle and cytokinesis multi-protein apparatuses that might modulate the cell division cycle by affecting lamin B1 and β-dystroglycan levels.
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Affiliation(s)
- Marcela Villarreal-Silva
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México Distrito Federal, México
| | - Federico Centeno-Cruz
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México Distrito Federal, México
- Laboratorio de Enfermedades Complejas, Instituto Nacional de Medicina Genómica, México Distrito Federal, México
| | - Rocío Suárez-Sánchez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México Distrito Federal, México
- Departamento de Genética, Instituto Nacional de Rehabilitación, México Distrito Federal, México
| | - Efraín Garrido
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México Distrito Federal, México
| | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México Distrito Federal, México
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Expression of Dystrophins and the Dystrophin-Associated-Protein Complex by Pituicytes in Culture. Neurochem Res 2011; 36:1407-16. [DOI: 10.1007/s11064-011-0466-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2011] [Indexed: 11/30/2022]
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Dystrophins and DAPs are expressed in adipose tissue and are regulated by adipogenesis and extracellular matrix. Biochem Biophys Res Commun 2010; 404:717-22. [PMID: 21147070 DOI: 10.1016/j.bbrc.2010.12.049] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2010] [Accepted: 12/08/2010] [Indexed: 11/20/2022]
Abstract
The dystrophin-associated protein complex (DAPC), consisting of dystrophin, dystroglycans, sarcoglycans, dystrobrevins and syntrophins, provides a linkage between the cytoskeleton and the extracellular matrix. The disruption of DAPC leads to Duchenne/Becker muscular dystrophy and other neuromuscular diseases. Although adipose-derived stem cells had been used for the experimental treatment of Duchenne/Becker disease with promising results, little is known on the expression and function of DAPC in adipose tissue. Here we show that visceral and subcutaneous rat adipose depots express mRNAs for all known dystrophin isoforms, utrophin, α- and β-dystrobrevins, and α-, βI-, βII-, and γII-syntrophins. Visceral and subcutaneous rat preadipocytes express Dp116 and Dp71 mRNAs and proteins, and this expression is differentially regulated during adipogenesis. Rat preadipocytes also express β-dystrobrevin, α-, βI-, βII- and γII-syntrophins, β-dystroglycan and β-, δ-, and ε-sarcoglycans with no changes during adipogenesis. We also show that α-dystrobrevin increases their expression during adipose differentiation and extracellular matrix differentially regulates the expression of dystrophin isoforms mRNAs during adipogenesis. Our results show that DAPC components are expressed in adipose tissues and suggest that this complex has a role on the adipose biology.
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Moore CJ, Winder SJ. Dystroglycan versatility in cell adhesion: a tale of multiple motifs. Cell Commun Signal 2010; 8:3. [PMID: 20163697 PMCID: PMC2834674 DOI: 10.1186/1478-811x-8-3] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Accepted: 02/17/2010] [Indexed: 12/02/2022] Open
Abstract
Dystroglycan is a ubiquitously expressed heterodimeric adhesion receptor. The extracellular α-subunit makes connections with a number of laminin G domain ligands including laminins, agrin and perlecan in the extracellular matrix and the transmembrane β-subunit makes connections to the actin filament network via cytoskeletal linkers including dystrophin, utrophin, ezrin and plectin, depending on context. Originally discovered as part of the dystrophin glycoprotein complex of skeletal muscle, dystroglycan is an important adhesion molecule and signalling scaffold in a multitude of cell types and tissues and is involved in several diseases. Dystroglycan has emerged as a multifunctional adhesion platform with many interacting partners associating with its short unstructured cytoplasmic domain. Two particular hotspots are the cytoplasmic juxtamembrane region and at the very carboxy terminus of dystroglycan. Regions which between them have several overlapping functions: in the juxtamembrane region; a nuclear localisation signal, ezrin/radixin/moesin protein, rapsyn and ERK MAP Kinase binding function, and at the C terminus a regulatory tyrosine governing WW, SH2 and SH3 domain interactions. We will discuss the binding partners for these motifs and how their interactions and regulation can modulate the involvement of dystroglycan in a range of different adhesion structures and functions depending on context. Thus dystroglycan presents as a multifunctional scaffold involved in adhesion and adhesion-mediated signalling with its functions under exquisite spatio-temporal regulation.
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Affiliation(s)
- Chris J Moore
- Department of Biomedical Science, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, UK.
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