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Swiderski K, Naim T, Trieu J, Chee A, Herold MJ, Kueh AJ, Goodman CA, Gregorevic P, Lynch GS. Dystrophin S3059 phosphorylation partially attenuates denervation atrophy in mouse tibialis anterior muscles. Physiol Rep 2024; 12:e16145. [PMID: 39001580 PMCID: PMC11245571 DOI: 10.14814/phy2.16145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/02/2024] [Accepted: 07/02/2024] [Indexed: 07/16/2024] Open
Abstract
The dystrophin protein has well-characterized roles in force transmission and maintaining membrane integrity during muscle contraction. Studies have reported decreased expression of dystrophin in atrophying muscles during wasting conditions, and that restoration of dystrophin can attenuate atrophy, suggesting a role in maintaining muscle mass. Phosphorylation of S3059 within the cysteine-rich region of dystrophin enhances binding between dystrophin and β-dystroglycan, and mimicking phosphorylation at this site by site-directed mutagenesis attenuates myotube atrophy in vitro. To determine whether dystrophin phosphorylation can attenuate muscle wasting in vivo, CRISPR-Cas9 was used to generate mice with whole body mutations of S3059 to either alanine (DmdS3059A) or glutamate (DmdS3059E), to mimic a loss of, or constitutive phosphorylation of S3059, on all endogenous dystrophin isoforms, respectively. Sciatic nerve transection was performed on these mice to determine whether phosphorylation of dystrophin S3059 could attenuate denervation atrophy. At 14 days post denervation, atrophy of tibialis anterior (TA) but not gastrocnemius or soleus muscles, was partially attenuated in DmdS3059E mice relative to WT mice. Attenuation of atrophy was associated with increased expression of β-dystroglycan in TA muscles of DmdS3059E mice. Dystrophin S3059 phosphorylation can partially attenuate denervation-induced atrophy, but may have more significant impact in less severe modes of muscle wasting.
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Affiliation(s)
- Kristy Swiderski
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Timur Naim
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Jennifer Trieu
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Annabel Chee
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Marco J. Herold
- The Walter and Eliza Hall Institute of Medical ResearchParkvilleVictoriaAustralia
- Department of Medical BiologyThe University of MelbourneMelbourneVictoriaAustralia
- Olivia Newton‐John Cancer Research InstituteHeidelbergVictoriaAustralia
- School of Cancer MedicineLa Trobe UniversityHeidelbergVictoriaAustralia
| | - Andrew J. Kueh
- The Walter and Eliza Hall Institute of Medical ResearchParkvilleVictoriaAustralia
- Department of Medical BiologyThe University of MelbourneMelbourneVictoriaAustralia
- Olivia Newton‐John Cancer Research InstituteHeidelbergVictoriaAustralia
- School of Cancer MedicineLa Trobe UniversityHeidelbergVictoriaAustralia
| | - Craig A. Goodman
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Paul Gregorevic
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Gordon S. Lynch
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
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2
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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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3
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Nuclear transport and subcellular localization of the dystrophin Dp71 and Dp40 isoforms in the PC12 cell line. Biochem Biophys Res Commun 2022; 630:125-132. [PMID: 36155058 DOI: 10.1016/j.bbrc.2022.09.035] [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: 08/31/2022] [Accepted: 09/08/2022] [Indexed: 11/21/2022]
Abstract
The shortest dystrophins, Dp71 and Dp40, are transcribed from the DMD gene through an internal promoter located in intron 62. These proteins are the main product of the DMD gene in the nervous system and have been involved in various functions related to cellular differentiation and proliferation as well as other cellular processes. Dp71 mRNA undergoes alternative splicing that results in different Dp71 protein isoforms. The subcellular localization of some of these isoforms in the PC12 cell line has been previously reported, and a differential subcellular distribution was observed, which suggests a particular role for each isoform. With the aim of obtaining information on their function, this study identified factors involved in the nuclear transport of Dp71 and Dp40 isoforms in the PC12 cell line. Cell cultures were treated with specific nuclear import/export inhibitors to determine the Dp71 isoform transport routes. The results showed that all isoforms of Dp71 and Dp40 included in the analysis have the ability to enter the cell nucleus through α/β importin, and the main route of nuclear export for Dp71 isoforms is through the exportin CRM1, which is not the case for Dp40.
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4
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Swiderski K, Brock CJ, Trieu J, Chee A, Thakur SS, Baum DM, Gregorevic P, Murphy KT, Lynch GS. Phosphorylation of ERK and dystrophin S3059 protects against inflammation-associated C2C12 myotube atrophy. Am J Physiol Cell Physiol 2021; 320:C956-C965. [PMID: 33729835 DOI: 10.1152/ajpcell.00513.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The dystrophin-glycoprotein complex (DGC) is a multiprotein structure required to maintain muscle fiber membrane integrity, transmit force by linking the actin cytoskeleton with the extracellular matrix, and maintain muscle homeostasis. Membrane localization of dystrophin is perturbed in muscles wasting as a consequence of cancer cachexia, tenotomy, and advanced aging, which are all associated with low level, chronic inflammation. Strategies to preserve dystrophin expression at the sarcolemma might therefore combat muscle wasting. Phosphorylation of dystrophin serine 3059 (S3059) enhances the interaction between dystrophin and β-dystroglycan. To test the contribution of amino acid phosphorylation to muscle fiber size changes, dystrophin constructs with phospho-null and phosphomimetic mutations were transfected into C2C12 muscle cells or AAV-293 cells in the presence or absence of kinase inhibitors/activators to assess effects on myotube diameter and protein function. Overexpression of a dystrophin construct with a phospho-null mutation at S3059 in vitro reduced myotube size in healthy C2C12 cells. Conversely overexpression of a phosphomimetic mutation at S3059 attenuated inflammation-induced myotube atrophy. Increased ERK activation by addition of phorbol myristate acetate (PMA) also reduced inflammation-associated myotube atrophy and increased the interaction between dystrophin and β-dystroglycan. These findings demonstrate a link between increased ERK activation, dystrophin S3059 phosphorylation, stabilization of the DGC, and the regulation of muscle fiber size. Interventions that increase dystrophin S3059 phosphorylation to promote stronger binding of dystrophin to β-dystroglycan may have therapeutic potential for attenuation of inflammation-associated muscle wasting.
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Affiliation(s)
- Kristy Swiderski
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Christopher J Brock
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jennifer Trieu
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Annabel Chee
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Savant S Thakur
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Dale M Baum
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Paul Gregorevic
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Kate T Murphy
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Gordon S Lynch
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
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5
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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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Annese T, Ruggieri S, De Giorgis M, Ribatti D, Tamma R, Nico B. α-Methyl-prednisolone normalizes the PKC mediated brain angiogenesis in dystrophic mdx mice. Brain Res Bull 2019; 147:69-77. [PMID: 30711624 DOI: 10.1016/j.brainresbull.2019.01.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 01/24/2019] [Indexed: 10/27/2022]
Abstract
A fraction of patients affected by Duchenne Muscular Dystrophy (DMD) shows mental disability as a consequence of neuronal and metabolic alteration. In this study, we evaluated the effect of α-methyl-prednisolone (PDN) on the expression of the angiogenic marker HIF1α, VEGFA and VEGFR-2 (FLK1) in correlation with PKC expression in the brain of mdx mouse, an experimental model of DMD. We demonstrated that HIF1α, VEGFA and FLK1 are overexpressed in the brain of dystrophic mdx mice in parallel with an increase of PKC expression and reduction of the tight junctions Occludin leading to altered angiogenesis. Moreover, we demonstrated that PDN treatment induces a significant reduction in the HIF1α, VEGF, FLK1, and PKC mRNA and proteins levels and restores Occludin expression reducing its phosphorylation pattern. Our results suggest a new mechanism of action of PDN that through PKC suppression normalizes the angiogenesis in dystrophic mdx brains.
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Affiliation(s)
- Tiziana Annese
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Section of Human Anatomy and Histology, University of Bari Medical School Bari, University of Bari, Italy.
| | - Simona Ruggieri
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Section of Human Anatomy and Histology, University of Bari Medical School Bari, University of Bari, Italy.
| | - Michela De Giorgis
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Section of Human Anatomy and Histology, University of Bari Medical School Bari, University of Bari, Italy.
| | - Domenico Ribatti
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Section of Human Anatomy and Histology, University of Bari Medical School Bari, University of Bari, Italy.
| | - Roberto Tamma
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Section of Human Anatomy and Histology, University of Bari Medical School Bari, University of Bari, Italy.
| | - Beatrice Nico
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Section of Human Anatomy and Histology, University of Bari Medical School Bari, University of Bari, Italy.
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7
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Dp71 is regulated by phosphorylation and ubiquitin-proteasome system in neuronal cells. Biochem Biophys Res Commun 2017; 492:349-355. [PMID: 28851655 DOI: 10.1016/j.bbrc.2017.08.108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 08/26/2017] [Indexed: 01/29/2023]
Abstract
The Dystrophin (Dp) gene is responsible for Duchenne muscular dystrophy (DMD), which is characterized by progressive muscular degeneration and variable degrees of cognitive impairment. Although Dp71 is the most abundant among the Dp isoforms in the brain, the regulatory mechanisms of the related expression levels have not been elucidated. In this study, we found that the constitutive expression levels of Dp71 in PC12 cells were sensitive to proteasomal inhibition. The ectopic expression of FLAG-tagged ubiquitin revealed that Dp71 was ubiquitinated intracellularly. Interestingly, proteasomal inhibition was accompanied by a posttranslational accumulation of modified Dp71, which was restored by protein phosphatase treatment in vitro, indicating that phosphorylation is responsible for the modification and affects the proteasome-dependent degradation of Dp71. Proteasomal activity-sensitive phosphorylated Dp71 is closely associated with syntrophin, a well-known binding partner of Dp71, and syntrophin is also regulated by proteasomal activity in a similar way to Dp71, suggesting that the posttranslational regulatory machinery for Dp71 level is coupled with Dp71-syntrophin molecular complex. Taken together, our results indicated that the expression levels of Dp71 are posttranslationally regulated by the phosphorylation-ubiquitin-proteasomal pathway, which may indicate the presence of regulatory mechanisms underlying the proteostasis of both Dp and its molecular complex, which may lead to better therapeutic approaches for the treatment of Dp-related diseases.
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8
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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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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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Aragón J, Martínez-Herrera A, Bermúdez-Cruz RM, Bazán ML, Soid-Raggi G, Ceja V, Coy-Arechavaleta AS, Alemán V, Depardón F, Montañez C. EF-hand domains are involved in the differential cellular distribution of dystrophin Dp40. Neurosci Lett 2015; 600:115-20. [PMID: 26004254 DOI: 10.1016/j.neulet.2015.05.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 05/11/2015] [Accepted: 05/19/2015] [Indexed: 10/23/2022]
Abstract
Dp40 is the shortest DMD gene product that has been reported to date. It is encoded by exons 63-70, a region required for a β-dystroglycan interaction. Its expression has been identified in rat, mouse, and human; however, its function remains unknown. To explore the expression of Dp40 transcript and subcellular localization of epitope-tagged Dp40 proteins, RT-PCR and immunofluorescence assays were performed in PC12 cells. The expression of Dp40 mRNA was found in undifferentiated and nerve growth factor-differentiated PC12 cells. According to immunofluorescence analyses, the recombinant protein Dp40 was mainly localized in the cell periphery/cytoplasm of undifferentiated and differentiated PC12 cells, a small amount of this protein is localized to the nucleus of differentiated cells. With the aim to identify the amino acids involved in the nuclear localization of Dp40, an in silico analysis was performed and it predicted that prolines 93 and 170, located within EF1 and EF2-hand domains, are involved in the nuclear localization of this protein. This prediction was confirmed by site-directed mutagenesis, the Dp40-L93P mutant was localized to the nucleus and cell periphery, while Dp40-L170P and Dp40-L93/170P showed mainly a nuclear localization. Dp40 co-localizes with β-dystroglycan and the co-localization score was statistically reduced in Dp40-L93P, Dp40-L170P and Dp40-L93/170P mutants.
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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 D. F., Mexico
| | - Alejandro Martínez-Herrera
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México D. F., Mexico
| | - Rosa Ma Bermúdez-Cruz
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México D. F., Mexico
| | - Ma Luisa Bazán
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México D. F., Mexico
| | - Gabriela Soid-Raggi
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México D. F., Mexico
| | - Víctor Ceja
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México D. F., Mexico
| | - Andrea Santos Coy-Arechavaleta
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México D. F., Mexico
| | - Víctor Alemán
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México D. F., Mexico
| | - Francisco Depardón
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México D. F., Mexico
| | - Cecilia Montañez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México D. F., Mexico.
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11
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Swiderski K, Shaffer SA, Gallis B, Odom GL, Arnett AL, Scott Edgar J, Baum DM, Chee A, Naim T, Gregorevic P, Murphy KT, Moody J, Goodlett DR, Lynch GS, Chamberlain JS. Phosphorylation within the cysteine-rich region of dystrophin enhances its association with β-dystroglycan and identifies a potential novel therapeutic target for skeletal muscle wasting. Hum Mol Genet 2014; 23:6697-711. [PMID: 25082828 DOI: 10.1093/hmg/ddu388] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in dystrophin lead to Duchenne muscular dystrophy, which is among the most common human genetic disorders. Dystrophin nucleates assembly of the dystrophin-glycoprotein complex (DGC), and a defective DGC disrupts an essential link between the intracellular cytoskeleton and the basal lamina, leading to progressive muscle wasting. In vitro studies have suggested that dystrophin phosphorylation may affect interactions with actin or syntrophin, yet whether this occurs in vivo or affects protein function remains unknown. Utilizing nanoflow liquid chromatography mass spectrometry, we identified 18 phosphorylated residues within endogenous dystrophin. Mutagenesis revealed that phosphorylation at S3059 enhances the dystrophin-dystroglycan interaction and 3D modeling utilizing the Rosetta software program provided a structural model for how phosphorylation enhances this interaction. These findings demonstrate that phosphorylation is a key mechanism regulating the interaction between dystrophin and the DGC and reveal that posttranslational modification of a single amino acid directly modulates the function of dystrophin.
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Affiliation(s)
- Kristy Swiderski
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA
| | - Scott A Shaffer
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Byron Gallis
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Guy L Odom
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA
| | - Andrea L Arnett
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA
| | - J Scott Edgar
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Dale M Baum
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Annabel Chee
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Timur Naim
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Paul Gregorevic
- Muscle Biology and Therapeutics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
| | - Kate T Murphy
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - James Moody
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195-7350, USA and Program in Molecular and Cellular Biology, University of Washington School of Medicine, Seattle, WA 98195-7275, USA
| | - David R Goodlett
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Gordon S Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Jeffrey S Chamberlain
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195-7350, USA and Program in Molecular and Cellular Biology, University of Washington School of Medicine, Seattle, WA 98195-7275, USA
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12
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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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13
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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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14
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Saint Martín A, Aragón J, Depardon-Benítez F, Sánchez-Trujillo A, Mendoza-Hernández G, Ceja V, Montañez C. Identification of Dp71e, a new dystrophin with a novel carboxy-terminal end. FEBS J 2011; 279:66-77. [DOI: 10.1111/j.1742-4658.2011.08399.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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15
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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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16
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Lara-Chacón B, de León MB, Leocadio D, Gómez P, Fuentes-Mera L, Martínez-Vieyra I, Ortega A, Jans DA, Cisneros B. Characterization of an Importin α/β-recognized nuclear localization signal in β-dystroglycan. J Cell Biochem 2010; 110:706-17. [DOI: 10.1002/jcb.22581] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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17
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Pilgram GSK, Potikanond S, Baines RA, Fradkin LG, Noordermeer JN. The roles of the dystrophin-associated glycoprotein complex at the synapse. Mol Neurobiol 2009; 41:1-21. [PMID: 19899002 PMCID: PMC2840664 DOI: 10.1007/s12035-009-8089-5] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 10/15/2009] [Indexed: 12/30/2022]
Abstract
Duchenne muscular dystrophy is caused by mutations in the dystrophin gene and is characterized by progressive muscle wasting. A number of Duchenne patients also present with mental retardation. The dystrophin protein is part of the highly conserved dystrophin-associated glycoprotein complex (DGC) which accumulates at the neuromuscular junction (NMJ) and at a variety of synapses in the peripheral and central nervous systems. Many years of research into the roles of the DGC in muscle have revealed its structural function in stabilizing the sarcolemma. In addition, the DGC also acts as a scaffold for various signaling pathways. Here, we discuss recent advances in understanding DGC roles in the nervous system, gained from studies in both vertebrate and invertebrate model systems. From these studies, it has become clear that the DGC is important for the maturation of neurotransmitter receptor complexes and for the regulation of neurotransmitter release at the NMJ and central synapses. Furthermore, roles for the DGC have been established in consolidation of long-term spatial and recognition memory. The challenges ahead include the integration of the behavioral and mechanistic studies and the use of this information to identify therapeutic targets.
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Affiliation(s)
- Gonneke S K Pilgram
- Department of Molecular and Cell Biology, Leiden University Medical Center, The Netherlands
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Hashimoto R, Yamaguchi M. Dynamic changes in the subcellular localization of Drosophila beta-sarcoglycan during the cell cycle. Cell Struct Funct 2006; 31:173-80. [PMID: 17159290 DOI: 10.1247/csf.06025] [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] [Indexed: 11/11/2022] Open
Abstract
One of the proposed roles of sarcoglycan is to stabilize dystrophin glycoprotein complexes in muscle sarcolemma. Involvement in signal transduction has also been proposed and abnormalities in some sarcoglycan genes are known to be responsible for muscular dystrophy. While characterization of sarcoglycans in muscle has been performed, little is known about its functions in the non-muscle tissues in which mammalian sarcoglycans are expressed. Here, we investigated temporal and spatial expression patterns of Drosophila beta-sarcoglycan (dScgbeta) during development by immunohistochemistry. In addition to almost ubiquitous expression in various tissues and organs, as seen for its mammalian counterpart, anti-dScgbeta staining data of embryos, eye imaginal discs, and salivary glands demonstrated cytoplasmic localization during S phase in addition to plasma membrane staining. Furthermore we found that subcellular localization of dScgbeta dramatically changes during mitosis through possible association with tubulin. These observations point to a complex role of sarcoglycans in non-muscle tissues.
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Affiliation(s)
- Reina Hashimoto
- Department of Applied Biology and Insect Biomedical Research Center, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan
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