1
|
The role of the dystrophin glycoprotein complex in muscle cell mechanotransduction. Commun Biol 2022; 5:1022. [PMID: 36168044 PMCID: PMC9515174 DOI: 10.1038/s42003-022-03980-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 09/12/2022] [Indexed: 11/09/2022] Open
Abstract
Dystrophin is the central protein of the dystrophin-glycoprotein complex (DGC) in skeletal and heart muscle cells. Dystrophin connects the actin cytoskeleton to the extracellular matrix (ECM). Severing the link between the ECM and the intracellular cytoskeleton has a devastating impact on the homeostasis of skeletal muscle cells, leading to a range of muscular dystrophies. In addition, the loss of a functional DGC leads to progressive dilated cardiomyopathy and premature death. Dystrophin functions as a molecular spring and the DGC plays a critical role in maintaining the integrity of the sarcolemma. Additionally, evidence is accumulating, linking the DGC to mechanosignalling, albeit this role is still less understood. This review article aims at providing an up-to-date perspective on the DGC and its role in mechanotransduction. We first discuss the intricate relationship between muscle cell mechanics and function, before examining the recent research for a role of the dystrophin glycoprotein complex in mechanotransduction and maintaining the biomechanical integrity of muscle cells. Finally, we review the current literature to map out how DGC signalling intersects with mechanical signalling pathways to highlight potential future points of intervention, especially with a focus on cardiomyopathies. A review of the function of the Dystrophic Glycoprotein Complex (DGC) in mechanosignaling provides an overview of the various components of DGC and potential mechanopathogenic mechanisms, particularly as they relate to muscular dystrophy.
Collapse
|
2
|
Sancho M, Fletcher J, Welsh DG. Inward Rectifier Potassium Channels: Membrane Lipid-Dependent Mechanosensitive Gates in Brain Vascular Cells. Front Cardiovasc Med 2022; 9:869481. [PMID: 35419431 PMCID: PMC8995785 DOI: 10.3389/fcvm.2022.869481] [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: 02/04/2022] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
Cerebral arteries contain two primary and interacting cell types, smooth muscle (SMCs) and endothelial cells (ECs), which are each capable of sensing particular hemodynamic forces to set basal tone and brain perfusion. These biomechanical stimuli help confer tone within arterial networks upon which local neurovascular stimuli function. Tone development is intimately tied to arterial membrane potential (VM) and changes in intracellular [Ca2+] driven by voltage-gated Ca2+ channels (VGCCs). Arterial VM is in turn set by the dynamic interplay among ion channel species, the strongly inward rectifying K+ (Kir) channel being of special interest. Kir2 channels possess a unique biophysical signature in that they strongly rectify, display negative slope conductance, respond to elevated extracellular K+ and are blocked by micromolar Ba2+. While functional Kir2 channels are expressed in both smooth muscle and endothelium, they lack classic regulatory control, thus are often viewed as a simple background conductance. Recent literature has provided new insight, with two membrane lipids, phosphatidylinositol 4,5-bisphosphate (PIP2) and cholesterol, noted to (1) stabilize Kir2 channels in a preferred open or closed state, respectively, and (2) confer, in association with the cytoskeleton, caveolin-1 (Cav1) and syntrophin, hemodynamic sensitivity. It is these aspects of vascular Kir2 channels that will be the primary focus of this review.
Collapse
Affiliation(s)
- Maria Sancho
- Department of Pharmacology, University of Vermont, Burlington, VT, United States
- Department of Physiology, Faculty of Medicine, Universidad Complutense de Madrid, Madrid, Spain
- *Correspondence: Maria Sancho,
| | - Jacob Fletcher
- Department of Physiology and Pharmacology, Robarts Research Institute, University of Western Ontario, London, ON, Canada
| | - Donald G. Welsh
- Department of Physiology and Pharmacology, Robarts Research Institute, University of Western Ontario, London, ON, Canada
- Donald G. Welsh,
| |
Collapse
|
3
|
Flavonoid Treatment of Breast Cancer Cells has Multifarious Consequences on Alpha-1-Syntrophin Expression and other Downstream Processes. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2020. [DOI: 10.1007/s13369-020-04508-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
4
|
Choi JH, Jeong SY, Oh MR, Allen PD, Lee EH. TRPCs: Influential Mediators in Skeletal Muscle. Cells 2020; 9:cells9040850. [PMID: 32244622 PMCID: PMC7226745 DOI: 10.3390/cells9040850] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/31/2020] [Accepted: 03/31/2020] [Indexed: 02/07/2023] Open
Abstract
Ca2+ itself or Ca2+-dependent signaling pathways play fundamental roles in various cellular processes from cell growth to death. The most representative example can be found in skeletal muscle cells where a well-timed and adequate supply of Ca2+ is required for coordinated Ca2+-dependent skeletal muscle functions, such as the interactions of contractile proteins during contraction. Intracellular Ca2+ movements between the cytosol and sarcoplasmic reticulum (SR) are strictly regulated to maintain the appropriate Ca2+ supply in skeletal muscle cells. Added to intracellular Ca2+ movements, the contribution of extracellular Ca2+ entry to skeletal muscle functions and its significance have been continuously studied since the early 1990s. Here, studies on the roles of channel proteins that mediate extracellular Ca2+ entry into skeletal muscle cells using skeletal myoblasts, myotubes, fibers, tissue, or skeletal muscle-originated cell lines are reviewed with special attention to the proposed functions of transient receptor potential canonical proteins (TRPCs) as store-operated Ca2+ entry (SOCE) channels under normal conditions and the potential abnormal properties of TRPCs in muscle diseases such as Duchenne muscular dystrophy (DMD).
Collapse
Affiliation(s)
- Jun Hee Choi
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul 06591, Korea
| | - Seung Yeon Jeong
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul 06591, Korea
| | - Mi Ri Oh
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul 06591, Korea
| | - Paul D. Allen
- Leeds Institute of Biomedical & Clinical Sciences, St. James’s University Hospital, University of Leeds, Leeds LS97TF, UK
| | - Eun Hui Lee
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul 06591, Korea
- Correspondence: ; Tel.: +82-2-2258-7279
| |
Collapse
|
5
|
Kim MJ, Whitehead NP, Bible KL, Adams ME, Froehner SC. Mice lacking α-, β1- and β2-syntrophins exhibit diminished function and reduced dystrophin expression in both cardiac and skeletal muscle. Hum Mol Genet 2019; 28:386-395. [PMID: 30256963 DOI: 10.1093/hmg/ddy341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 09/21/2018] [Indexed: 01/16/2023] Open
Abstract
Syntrophins are a family of modular adaptor proteins that are part of the dystrophin protein complex, where they recruit and anchor a variety of signaling proteins. Previously we generated mice lacking α- and/or β2-syntrophin but showed that in the absence of one isoform, other syntrophin isoforms can partially compensate. Therefore, in the current study, we generated mice that lacked α, β1 and β2-syntrophins [triple syntrophin knockout (tKO) mice] and assessed skeletal and cardiac muscle function. The tKO mice showed a profound reduction in voluntary wheel running activity at both 6 and 12 months of age. Function of the tibialis anterior was assessed in situ and we found that the specific force of tKO muscle was decreased by 20-25% compared with wild-type mice. This decrease was accompanied by a shift in fiber-type composition from fast 2B to more oxidative fast 2A fibers. Using echocardiography to measure cardiac function, it was revealed that tKO hearts had left ventricular cardiac dysfunction and were hypertrophic, with a thicker left ventricular posterior wall. Interestingly, we also found that membrane-localized dystrophin expression was lower in both skeletal and cardiac muscles of tKO mice. Since dystrophin mRNA levels were not different in tKO, this finding suggests that syntrophins may regulate dystrophin trafficking to, or stabilization at, the sarcolemma. These results show that the loss of all three major muscle syntrophins has a profound effect on exercise performance, and skeletal and cardiac muscle dysfunction contributes to this deficiency.
Collapse
Affiliation(s)
- Min Jeong Kim
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Nicholas P Whitehead
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Kenneth L Bible
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Marvin E Adams
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Stanley C Froehner
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| |
Collapse
|
6
|
Rao SB, Katoozi S, Skauli N, Froehner SC, Ottersen OP, Adams ME, Amiry-Moghaddam M. Targeted deletion of β1-syntrophin causes a loss of K ir 4.1 from Müller cell endfeet in mouse retina. Glia 2019; 67:1138-1149. [PMID: 30803043 DOI: 10.1002/glia.23600] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 02/02/2023]
Abstract
Proper function of the retina depends heavily on a specialized form of retinal glia called Müller cells. These cells carry out important homeostatic functions that are contingent on their polarized nature. Specifically, the Müller cell endfeet that contact retinal microvessels and the corpus vitreum show a tenfold higher concentration of the inwardly rectifying potassium channel Kir 4.1 than other Müller cell plasma membrane domains. This highly selective enrichment of Kir 4.1 allows K+ to be siphoned through endfoot membranes in a special form of spatial buffering. Here, we show that Kir 4.1 is enriched in endfoot membranes through an interaction with β1-syntrophin. Targeted disruption of this syntrophin caused a loss of Kir 4.1 from Müller cell endfeet without affecting the total level of Kir 4.1 expression in the retina. Targeted disruption of α1-syntrophin had no effect on Kir 4.1 localization. Our findings show that the Kir 4.1 aggregation that forms the basis for K+ siphoning depends on a specific syntrophin isoform that colocalizes with Kir 4.1 in Müller endfoot membranes.
Collapse
Affiliation(s)
- Shreyas B Rao
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Shirin Katoozi
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Nadia Skauli
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Stanley C Froehner
- Department of Physiology and Biophysics, University of Washington, Seattle, Western Australia
| | - Ole Petter Ottersen
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Marvin E Adams
- Department of Physiology and Biophysics, University of Washington, Seattle, Western Australia
| | - Mahmood Amiry-Moghaddam
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| |
Collapse
|
7
|
Bhat SS, Ali R, Khanday FA. Syntrophins entangled in cytoskeletal meshwork: Helping to hold it all together. Cell Prolif 2018; 52:e12562. [PMID: 30515904 DOI: 10.1111/cpr.12562] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/23/2018] [Accepted: 11/08/2018] [Indexed: 01/10/2023] Open
Abstract
Syntrophins are a family of 59 kDa peripheral membrane-associated adapter proteins, containing multiple protein-protein and protein-lipid interaction domains. The syntrophin family consists of five isoforms that exhibit specific tissue distribution, distinct sub-cellular localization and unique expression patterns implying their diverse functional roles. These syntrophin isoforms form multiple functional protein complexes and ensure proper localization of signalling proteins and their binding partners to specific membrane domains and provide appropriate spatiotemporal regulation of signalling pathways. Syntrophins consist of two PH domains, a PDZ domain and a conserved SU domain. The PH1 domain is split by the PDZ domain. The PH2 and the SU domain are involved in the interaction between syntrophin and the dystrophin-glycoprotein complex (DGC). Syntrophins recruit various signalling proteins to DGC and link extracellular matrix to internal signalling apparatus via DGC. The different domains of the syntrophin isoforms are responsible for modulation of cytoskeleton. Syntrophins associate with cytoskeletal proteins and lead to various cellular responses by modulating the cytoskeleton. Syntrophins are involved in many physiological processes which involve cytoskeletal reorganization like insulin secretion, blood pressure regulation, myogenesis, cell migration, formation and retraction of focal adhesions. Syntrophins have been implicated in various pathologies like Alzheimer's disease, muscular dystrophy, cancer. Their role in cytoskeletal organization and modulation makes them perfect candidates for further studies in various cancers and other ailments that involve cytoskeletal modulation. The role of syntrophins in cytoskeletal organization and modulation has not yet been comprehensively reviewed till now. This review focuses on syntrophins and highlights their role in cytoskeletal organization, modulation and dynamics via its involvement in different cell signalling networks.
Collapse
Affiliation(s)
- Sahar S Bhat
- Division of Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar, India
| | - Roshia Ali
- Department of Biotechnology, University of Kashmir, Srinagar, India.,Department of Biochemistry, University of Kashmir, Srinagar, India
| | | |
Collapse
|
8
|
Leyva-Leyva M, Sandoval A, Felix R, González-Ramírez R. Biochemical and Functional Interplay Between Ion Channels and the Components of the Dystrophin-Associated Glycoprotein Complex. J Membr Biol 2018; 251:535-550. [PMID: 29779049 DOI: 10.1007/s00232-018-0036-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 05/09/2018] [Indexed: 12/19/2022]
Abstract
Dystrophin is a cytoskeleton-linked membrane protein that binds to a larger multiprotein assembly called the dystrophin-associated glycoprotein complex (DGC). The deficiency of dystrophin or the components of the DGC results in the loss of connection between the cytoskeleton and the extracellular matrix with significant pathophysiological implications in skeletal and cardiac muscle as well as in the nervous system. Although the DGC plays an important role in maintaining membrane stability, it can also be considered as a versatile and flexible molecular complex that contribute to the cellular organization and dynamics of a variety of proteins at specific locations in the plasma membrane. This review deals with the role of the DGC in transmembrane signaling by forming supramolecular assemblies for regulating ion channel localization and activity. These interactions are relevant for cell homeostasis, and its alterations may play a significant role in the etiology and pathogenesis of various disorders affecting muscle and nerve function.
Collapse
Affiliation(s)
- Margarita Leyva-Leyva
- Department of Molecular Biology and Histocompatibility, "Dr. Manuel Gea González" General Hospital, Mexico City, Mexico
| | - Alejandro Sandoval
- Faculty of Superior Studies Iztacala, National Autonomous University of Mexico (UNAM), Tlalnepantla, Mexico
| | - Ricardo Felix
- Department of Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav-IPN), Mexico City, Mexico.
| | - Ricardo González-Ramírez
- Department of Molecular Biology and Histocompatibility, "Dr. Manuel Gea González" General Hospital, Mexico City, Mexico.
| |
Collapse
|
9
|
Sifi M, Benabdesselam R, Souttou S, Annese T, Rendon A, Nico B, Dorbani-Mamine L. Dystrophin 71 and α1syntrophin in morpho-functional plasticity of rat supraoptic nuclei: Effect of saline surcharge and reversibly normal hydration. Acta Histochem 2018; 120:187-195. [PMID: 29395317 DOI: 10.1016/j.acthis.2018.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 12/25/2017] [Accepted: 01/09/2018] [Indexed: 02/02/2023]
Abstract
Dystrophin (Dp) is a multidomain protein that links the actin cytoskeleton to the extracellular matrix through the dystrophin associated proteins complex (DAPC). Dp of 71 kDa (Dp71), corresponding to the COOH-terminal domain of dystrophin, and α1-syntrophin (α1Syn) as the principal component of the DAPC, are strongly expressed in the brain. To clarify their involvement in the central control of osmotic homeostasis, we investigated the effect of 14 days of salt loading (with drinking water containing 2% NaCl) and then reversibly to 30 days of normal hydration (with drinking water without salt), first on the expression by western-blotting and the distribution by immunochemistry of Dp71 and α1Syn in the SON of the rat and, second, on the level of some physiological parameters, as the plasma osmolality, natremia and hematocrit. Dp71 is the most abundant form of dystrophin revealed in the supraoptic nucleu (SON) of control rat. Dp71 was localized in magnocellular neurons (MCNs) and astrocytes, when α1Syn was observed essentially in astrocytes end feet. After 14 days of salt-loading, Dp71 and α1Syn signals decreased and a dual signal for these two proteins was revealed in the astrocytes processes SON surrounding blood capillaries. In addition, salt loading leads to an increase in plasma osmolality, natremia and hematocrit. Reversibly, after 30 days of normal hydration, the intensity of the signal for the two proteins, Dp71 and α1Syn, increased and approached that of control. Furtheremore, the levels of the physiological parameters decreased and approximated those of control. This suggests that Dp71 and α1Syn may be involved in the functional activity of the SON. Their localization in astrocyte end feet emphasizes their importance in neuronal-vascular-astrocyte interactions for the central detection of osmolality. In the SON, Dp71 and α1Syn may be involved in osmosensitivity.
Collapse
Affiliation(s)
- Madina Sifi
- Equipe de Neurochimie, LBPO, Faculté des Sciences Biologiques, USTHB, Alger, Algeria
| | - Roza Benabdesselam
- Equipe de Neurochimie, LBPO, Faculté des Sciences Biologiques, USTHB, Alger, Algeria; Département de Biologie, Faculté des Sciences Biologiques et Agronomiques, UMMTO, Tizi Ouzou, Algeria.
| | - Sabrina Souttou
- Equipe de Neurochimie, LBPO, Faculté des Sciences Biologiques, USTHB, Alger, Algeria
| | - Tiziana Annese
- Department of Basic Medical Sciences, Neurosciences and Sensory Organes, University of Bari "Aldo Moro", Bari, Italy
| | - Alvaro Rendon
- Laboratoire de Physiopathologie Cellulaire et Moleculaire de la Retine, INSERM UMRS-592, Institut de la Vision, Paris, France
| | - Beatrice Nico
- Department of Basic Medical Sciences, Neurosciences and Sensory Organes, University of Bari "Aldo Moro", Bari, Italy
| | - Latifa Dorbani-Mamine
- Equipe de Neurochimie, LBPO, Faculté des Sciences Biologiques, USTHB, Alger, Algeria
| |
Collapse
|
10
|
Bhat HF, Mir SS, Dar KB, Bhat ZF, Shah RA, Ganai NA. ABC of multifaceted dystrophin glycoprotein complex (DGC). J Cell Physiol 2017; 233:5142-5159. [DOI: 10.1002/jcp.25982] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 05/01/2017] [Indexed: 01/16/2023]
Affiliation(s)
- Hina F. Bhat
- Division of BiotechnologySher‐e‐Kashmir University of Agricultural Sciences and Technology of Kashmir SKUAST‐KShuhama, SrinagarJammu and KashmirIndia
| | - Saima S. Mir
- Department of BiotechnologyUniversity of KashmirHazratbal, SrinagarJammu and KashmirIndia
| | - Khalid B. Dar
- Department of BiochemistryUniversity of KashmirHazratbal, SrinagarJammu and KashmirIndia
| | - Zuhaib F. Bhat
- Division of Livestock Products and TechnologySher‐e‐Kashmir University of Agricultural Sciences and Technology of Jammu (SKUAST‐J), R.S. PoraJammuJammu and KashmirIndia
| | - Riaz A. Shah
- Division of BiotechnologySher‐e‐Kashmir University of Agricultural Sciences and Technology of Kashmir SKUAST‐KShuhama, SrinagarJammu and KashmirIndia
| | - Nazir A. Ganai
- Division of BiotechnologySher‐e‐Kashmir University of Agricultural Sciences and Technology of Kashmir SKUAST‐KShuhama, SrinagarJammu and KashmirIndia
| |
Collapse
|
11
|
Moon JY, Choi SJ, Heo CH, Kim HM, Kim HS. α-Syntrophin stabilizes catalase to reduce endogenous reactive oxygen species levels during myoblast differentiation. FEBS J 2017; 284:2052-2065. [DOI: 10.1111/febs.14103] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 04/27/2017] [Accepted: 05/05/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Jae Yun Moon
- Department of Biological Science; College of Natural Sciences; Ajou University; Suwon Korea
| | - Su Jin Choi
- Department of Biological Science; College of Natural Sciences; Ajou University; Suwon Korea
| | - Cheol Ho Heo
- Departments of Chemistry and Energy Systems Research; Ajou University; Suwon Korea
| | - Hwan Myung Kim
- Departments of Chemistry and Energy Systems Research; Ajou University; Suwon Korea
| | - Hye Sun Kim
- Department of Biological Science; College of Natural Sciences; Ajou University; Suwon Korea
| |
Collapse
|
12
|
α-Syntrophin is involved in the survival signaling pathway in myoblasts under menadione-induced oxidative stress. Exp Cell Res 2016; 344:1-10. [DOI: 10.1016/j.yexcr.2016.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 03/31/2016] [Accepted: 04/02/2016] [Indexed: 01/24/2023]
|
13
|
Actin depolymerization mediated loss of SNTA1 phosphorylation and Rac1 activity has implications on ROS production, cell migration and apoptosis. Apoptosis 2016; 21:737-48. [DOI: 10.1007/s10495-016-1241-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
14
|
Allen DG, Whitehead NP, Froehner SC. Absence of Dystrophin Disrupts Skeletal Muscle Signaling: Roles of Ca2+, Reactive Oxygen Species, and Nitric Oxide in the Development of Muscular Dystrophy. Physiol Rev 2016; 96:253-305. [PMID: 26676145 DOI: 10.1152/physrev.00007.2015] [Citation(s) in RCA: 272] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Dystrophin is a long rod-shaped protein that connects the subsarcolemmal cytoskeleton to a complex of proteins in the surface membrane (dystrophin protein complex, DPC), with further connections via laminin to other extracellular matrix proteins. Initially considered a structural complex that protected the sarcolemma from mechanical damage, the DPC is now known to serve as a scaffold for numerous signaling proteins. Absence or reduced expression of dystrophin or many of the DPC components cause the muscular dystrophies, a group of inherited diseases in which repeated bouts of muscle damage lead to atrophy and fibrosis, and eventually muscle degeneration. The normal function of dystrophin is poorly defined. In its absence a complex series of changes occur with multiple muscle proteins showing reduced or increased expression or being modified in various ways. In this review, we will consider the various proteins whose expression and function is changed in muscular dystrophies, focusing on Ca(2+)-permeable channels, nitric oxide synthase, NADPH oxidase, and caveolins. Excessive Ca(2+) entry, increased membrane permeability, disordered caveolar function, and increased levels of reactive oxygen species are early changes in the disease, and the hypotheses for these phenomena will be critically considered. The aim of the review is to define the early damage pathways in muscular dystrophy which might be appropriate targets for therapy designed to minimize the muscle degeneration and slow the progression of the disease.
Collapse
Affiliation(s)
- David G Allen
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Nicholas P Whitehead
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Stanley C Froehner
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| |
Collapse
|
15
|
Constantin B. Role of Scaffolding Proteins in the Regulation of TRPC-Dependent Calcium Entry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 898:379-403. [PMID: 27161237 DOI: 10.1007/978-3-319-26974-0_16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
Plasma membrane ion channels, and in particular TRPC channels need a specific membrane environment and association with scaffolding, signaling, and cytoskeleton proteins in order to play their important functional role. The molecular composition of TRPC channels is an important factor in determining channel activation mechanisms. TRPC proteins are incorporated in macromolecular complexes including several key Ca(2 +) signaling proteins as well as proteins involved in vesicle trafficking, cytoskeletal interactions, and scaffolding. Evidence has been provided for association of TRPC with calmodulin (CaM), IP3R, PMCA, Gq/11, RhoA, and a variety of scaffolding proteins. The interaction between TRPC channels with adaptor proteins, determines their mode of regulation as well as their cellular localization and function. Adaptor proteins do not display any enzymatic activity but act as scaffold for the building of signaling complexes. The scaffolding proteins are involved in the assembling of these Ca(2+) signaling complexes, the correct sub-cellular localization of protein partners, and the regulation of the TRPC channelosome. In particular, these proteins, via their multiple protein-protein interaction motifs, can interact with various ion channels involved in the transmembrane potential, and membrane excitability. Scaffolding proteins are key components for the functional organization of TRPC channelosomes that serves as a platform regulating slow Ca(2+) entry, spatially and temporally controlled [Ca(2+)]i signals and Ca(2+) -dependent cellular functions.
Collapse
Affiliation(s)
- Bruno Constantin
- Laboratory STIM, ERL-7368 CNRS-Université de Poitiers, 1, rue Georges Bonnet, Bat. B36, Pôle Biologie-Santé, 86000, Poitiers, France.
| |
Collapse
|
16
|
Nichols B, Takeda S, Yokota T. Nonmechanical Roles of Dystrophin and Associated Proteins in Exercise, Neuromuscular Junctions, and Brains. Brain Sci 2015; 5:275-98. [PMID: 26230713 PMCID: PMC4588140 DOI: 10.3390/brainsci5030275] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/29/2015] [Accepted: 07/21/2015] [Indexed: 02/06/2023] Open
Abstract
Dystrophin-glycoprotein complex (DGC) is an important structural unit in skeletal muscle that connects the cytoskeleton (f-actin) of a muscle fiber to the extracellular matrix (ECM). Several muscular dystrophies, such as Duchenne muscular dystrophy, Becker muscular dystrophy, congenital muscular dystrophies (dystroglycanopathies), and limb-girdle muscular dystrophies (sarcoglycanopathies), are caused by mutations in the different DGC components. Although many early studies indicated DGC plays a crucial mechanical role in maintaining the structural integrity of skeletal muscle, recent studies identified novel roles of DGC. Beyond a mechanical role, these DGC members play important signaling roles and act as a scaffold for various signaling pathways. For example, neuronal nitric oxide synthase (nNOS), which is localized at the muscle membrane by DGC members (dystrophin and syntrophins), plays an important role in the regulation of the blood flow during exercise. DGC also plays important roles at the neuromuscular junction (NMJ) and in the brain. In this review, we will focus on recently identified roles of DGC particularly in exercise and the brain.
Collapse
Affiliation(s)
- Bailey Nichols
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry.
| | - Shin'ichi Takeda
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan.
| | - Toshifumi Yokota
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry.
- Muscular Dystrophy Canada Research Chair, 8812-112 St, Edmonton, AB T6G 2H7, Canada.
| |
Collapse
|
17
|
Walkup WG, Kennedy MB. Protein purification using PDZ affinity chromatography. CURRENT PROTOCOLS IN PROTEIN SCIENCE 2015; 80:9.10.1-9.10.37. [PMID: 25829303 PMCID: PMC4435810 DOI: 10.1002/0471140864.ps0910s80] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
PDZ domains function in nature as protein-binding domains within scaffold and membrane-associated proteins. They comprise approximately 90 residues and undergo specific, high-affinity interactions with complementary C-terminal peptide sequences, other PDZ domains, and/or phospholipids. We have previously shown that the specific, strong interactions of PDZ domains with their ligands make them well suited for use in affinity chromatography. This unit provides protocols for the PDZ affinity chromatography procedure that are applicable for the purification of proteins that contain PDZ domains or PDZ domain-binding ligands, either naturally or introduced by genetic engineering. We detail the preparation of affinity resins composed of PDZ domains or PDZ domain peptide ligands coupled to solid supports. These resins can be used to purify proteins containing endogenous or genetically introduced PDZ domains or ligands, eluting the proteins with free PDZ domain peptide ligands.
Collapse
Affiliation(s)
- Ward G. Walkup
- Department of Biology and Biological Engineering, California Institute of Technology, 1200 East California Blvd., Mail Code 216-76, Pasadena, California 91125
| | - Mary B. Kennedy
- Department of Biology and Biological Engineering, California Institute of Technology, 1200 East California Blvd., Mail Code 216-76, Pasadena, California 91125
| |
Collapse
|
18
|
Yokota T, Miyagoe-Suzuki Y, Ikemoto T, Matsuda R, Takeda S. α1-Syntrophin-deficient mice exhibit impaired muscle force recovery after osmotic shock. Muscle Nerve 2014; 49:728-35. [DOI: 10.1002/mus.23990] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Revised: 07/29/2013] [Accepted: 08/05/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Toshifumi Yokota
- Department of Medical Genetics, School of Human Development, Faculty of Medicine and Dentistry; University of Alberta; Edmonton Alberta Canada
- Department of Molecular Therapy; National Institute of Neuroscience; National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira Tokyo 187-8502 Japan
| | - Yuko Miyagoe-Suzuki
- Department of Molecular Therapy; National Institute of Neuroscience; National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira Tokyo 187-8502 Japan
| | - Takaaki Ikemoto
- Department of Molecular Therapy; National Institute of Neuroscience; National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira Tokyo 187-8502 Japan
| | - Ryoichi Matsuda
- Department of Life Sciences, Graduate School of Arts and Sciences; University of Tokyo; Tokyo Japan
| | - Shin'ichi Takeda
- Department of Molecular Therapy; National Institute of Neuroscience; National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira Tokyo 187-8502 Japan
| |
Collapse
|
19
|
Cerecedo D, Martínez-Vieyra I, Alonso-Rangel L, Benítez-Cardoza C, Ortega A. Epithelial sodium channel modulates platelet collagen activation. Eur J Cell Biol 2014; 93:127-36. [PMID: 24679405 DOI: 10.1016/j.ejcb.2014.02.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 01/30/2014] [Accepted: 02/24/2014] [Indexed: 12/14/2022] Open
Abstract
Activated platelets adhere to the exposed subendothelial extracellular matrix and undergo a rapid cytoskeletal rearrangement resulting in shape change and release of their intracellular dense and alpha granule contents to avoid hemorrhage. A central step in this process is the elevation of the intracellular Ca(2+) concentration through its release from intracellular stores and on throughout its influx from the extracellular space. The Epithelial sodium channel (ENaC) is a highly selective Na(+) channel involved in mechanosensation, nociception, fluid volume homeostasis, and control of arterial blood pressure. The present study describes the expression, distribution, and participation of ENaC in platelet migration and granule secretion using pharmacological inhibition with amiloride. Our biochemical and confocal analysis in suspended and adhered platelets suggests that ENaC is associated with Intermediate filaments (IF) and with Dystrophin-associated proteins (DAP) via α-syntrophin and β-dystroglycan. Migration assays, quantification of soluble P-selectin, and serotonin release suggest that ENaC is dispensable for migration and alpha and dense granule secretion, whereas Na(+) influx through this channel is fundamental for platelet collagen activation.
Collapse
Affiliation(s)
- Doris Cerecedo
- Laboratorio de Hematobiología, Escuela Nacional de Medicina y Homeopatía (ENMH), Instituto Politécnico Nacional (IPN), Mexico City, Mexico.
| | - Ivette Martínez-Vieyra
- Laboratorio de Hematobiología, Escuela Nacional de Medicina y Homeopatía (ENMH), Instituto Politécnico Nacional (IPN), Mexico City, Mexico
| | - Lea Alonso-Rangel
- Laboratorio de Hematobiología, Escuela Nacional de Medicina y Homeopatía (ENMH), Instituto Politécnico Nacional (IPN), Mexico City, Mexico
| | - Claudia Benítez-Cardoza
- Laboratorio de Bioquímica, Escuela Nacional de Medicina y Homeopatía (ENMH), Instituto Politécnico Nacional (IPN), Mexico City, Mexico
| | - Arturo Ortega
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (Cinvestav-IPN), Mexico City, Mexico
| |
Collapse
|
20
|
Walkup WG, Kennedy MB. PDZ affinity chromatography: a general method for affinity purification of proteins based on PDZ domains and their ligands. Protein Expr Purif 2014; 98:46-62. [PMID: 24607360 DOI: 10.1016/j.pep.2014.02.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 02/24/2014] [Accepted: 02/26/2014] [Indexed: 12/16/2022]
Abstract
PDZ (PSD-95, DiscsLarge, ZO1) domains function in nature as protein binding domains within scaffold and membrane-associated proteins. They comprise ∼90 residues and make specific, high affinity interactions with complementary C-terminal peptide sequences, with other PDZ domains, and with phospholipids. We hypothesized that the specific, strong interactions of PDZ domains with their ligands would make them well suited for use in affinity chromatography. Here we describe a novel affinity chromatography method applicable for the purification of proteins that contain PDZ domain-binding ligands, either naturally or introduced by genetic engineering. We created a series of affinity resins comprised of PDZ domains from the scaffold protein PSD-95, or from neuronal nitric oxide synthase (nNOS), coupled to solid supports. We used them to purify heterologously expressed neuronal proteins or protein domains containing endogenous PDZ domain ligands, eluting the proteins with free PDZ domain peptide ligands. We show that Proteins of Interest (POIs) lacking endogenous PDZ domain ligands can be engineered as fusion products containing C-terminal PDZ domain ligand peptides or internal, N- or C-terminal PDZ domains and then can be purified by the same method. Using this method, we recovered recombinant GFP fused to a PDZ domain ligand in active form as verified by fluorescence yield. Similarly, chloramphenicol acetyltransferase (CAT) and β-Galactosidase (LacZ) fused to a C-terminal PDZ domain ligand or an N-terminal PDZ domain were purified in active form as assessed by enzymatic assay. In general, PDZ domains and ligands derived from PSD-95 were superior to those from nNOS for this method. PDZ Domain Affinity Chromatography promises to be a versatile and effective method for purification of a wide variety of natural and recombinant proteins.
Collapse
Affiliation(s)
- Ward G Walkup
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Blvd, Mail Code 216-76, Pasadena, CA 91125, USA.
| | - Mary B Kennedy
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Blvd, Mail Code 216-76, Pasadena, CA 91125, USA
| |
Collapse
|
21
|
Dystrophin complex functions as a scaffold for signalling proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:635-42. [DOI: 10.1016/j.bbamem.2013.08.023] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 08/22/2013] [Accepted: 08/28/2013] [Indexed: 11/23/2022]
|
22
|
Barnabei MS, Martindale JM, Townsend D, Metzger JM. Exercise and muscular dystrophy: implications and analysis of effects on musculoskeletal and cardiovascular systems. Compr Physiol 2013; 1:1353-63. [PMID: 23733645 DOI: 10.1002/cphy.c100062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The muscular dystrophies are a heterogeneous collection of progressive, inherited diseases of muscle weakness and degeneration. Although these diseases can vary widely in their etiology and presentation, nearly all muscular dystrophies cause exercise intolerance to some degree. Here, we focus on Duchenne muscular dystrophy (DMD), the most common form of muscular dystrophy, as a paradigm for the effects of muscle disease on exercise capacity. First described in the mid-1800s, DMD is a rapidly progressive and lethal muscular dystrophy caused by mutations in the dystrophin gene. Dystrophin is a membrane-associated cytoskeletal protein, the loss of which causes numerous cellular defects including mechanical instability of the sarcolemma, increased influx of extracellular calcium, and cell signaling defects. Here, we discuss the physiological basis for exercise intolerance in DMD, focusing on the molecular and cellular defects caused by loss of dystrophin and how these manifest as organ-level dysfunction and reduced exercise capacity. The main focus of this article is the defects present in dystrophin-deficient striated muscle. However, discussion regarding the effects of dystrophin loss on other tissues, including vascular smooth muscle is also included. Collectively, the goal of this article is to summarize the current state of knowledge regarding the mechanistic basis for exercise intolerance in DMD, which may serve as an archetype for other muscular dystrophies and diseases of muscle wasting.
Collapse
Affiliation(s)
- Matthew S Barnabei
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | | | | | | |
Collapse
|
23
|
Ordered disorder of the astrocytic dystrophin-associated protein complex in the norm and pathology. PLoS One 2013; 8:e73476. [PMID: 24014171 PMCID: PMC3754965 DOI: 10.1371/journal.pone.0073476] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 07/19/2013] [Indexed: 12/13/2022] Open
Abstract
The abundance and potential functional roles of intrinsically disordered regions in aquaporin-4, Kir4.1, a dystrophin isoforms Dp71, α-1 syntrophin, and α-dystrobrevin; i.e., proteins constituting the functional core of the astrocytic dystrophin-associated protein complex (DAPC), are analyzed by a wealth of computational tools. The correlation between protein intrinsic disorder, single nucleotide polymorphisms (SNPs) and protein function is also studied together with the peculiarities of structural and functional conservation of these proteins. Our study revealed that the DAPC members are typical hybrid proteins that contain both ordered and intrinsically disordered regions. Both ordered and disordered regions are important for the stabilization of this complex. Many disordered binding regions of these five proteins are highly conserved among vertebrates. Conserved eukaryotic linear motifs and molecular recognition features found in the disordered regions of five protein constituting DAPC likely enhance protein-protein interactions that are required for the cellular functions of this complex. Curiously, the disorder-based binding regions are rarely affected by SNPs suggesting that these regions are crucial for the biological functions of their corresponding proteins.
Collapse
|
24
|
Bhat HF, Adams ME, Khanday FA. Syntrophin proteins as Santa Claus: role(s) in cell signal transduction. Cell Mol Life Sci 2013; 70:2533-54. [PMID: 23263165 PMCID: PMC11113789 DOI: 10.1007/s00018-012-1233-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 11/21/2012] [Accepted: 12/03/2012] [Indexed: 11/30/2022]
Abstract
Syntrophins are a family of cytoplasmic membrane-associated adaptor proteins, characterized by the presence of a unique domain organization comprised of a C-terminal syntrophin unique (SU) domain and an N-terminal pleckstrin homology (PH) domain that is split by insertion of a PDZ domain. Syntrophins have been recognized as an important component of many signaling events, and they seem to function more like the cell's own personal 'Santa Claus' that serves to 'gift' various signaling complexes with precise proteins that they 'wish for', and at the same time care enough for the spatial, temporal control of these signaling events, maintaining overall smooth functioning and general happiness of the cell. Syntrophins not only associate various ion channels and signaling proteins to the dystrophin-associated protein complex (DAPC), via a direct interaction with dystrophin protein but also serve as a link between the extracellular matrix and the intracellular downstream targets and cell cytoskeleton by interacting with F-actin. They play an important role in regulating the postsynaptic signal transduction, sarcolemmal localization of nNOS, EphA4 signaling at the neuromuscular junction, and G-protein mediated signaling. In our previous work, we reported a differential expression pattern of alpha-1-syntrophin (SNTA1) protein in esophageal and breast carcinomas. Implicated in several other pathologies, like cardiac dys-functioning, muscular dystrophies, diabetes, etc., these proteins provide a lot of scope for further studies. The present review focuses on the role of syntrophins in membrane targeting and regulation of cellular proteins, while highlighting their relevance in possible development and/or progression of pathologies including cancer which we have recently demonstrated.
Collapse
Affiliation(s)
- Hina F Bhat
- Department of Biotechnology, University of Kashmir, Srinagar, Jammu and Kashmir, India.
| | | | | |
Collapse
|
25
|
Mosqueira M, Zeiger U, Förderer M, Brinkmeier H, Fink RHA. Cardiac and respiratory dysfunction in Duchenne muscular dystrophy and the role of second messengers. Med Res Rev 2013; 33:1174-213. [PMID: 23633235 DOI: 10.1002/med.21279] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Duchenne muscular dystrophy (DMD) affects young boys and is characterized by the absence of dystrophin, a large cytoskeletal protein present in skeletal and cardiac muscle cells and neurons. The heart and diaphragm become necrotic in DMD patients and animal models of DMD, resulting in cardiorespiratory failure as the leading cause of death. The major consequences of the absence of dystrophin are high levels of intracellular Ca(2+) and the unbalanced production of NO that can finally trigger protein degradation and cell death. Cytoplasmic increase in Ca(2+) concentration directly and indirectly triggers different processes such as necrosis, fibrosis, and activation of macrophages. The absence of the neuronal isoform of nitric oxide synthase (nNOS) and the overproduction of NO by the inducible isoform (iNOS) further increase the intracellular Ca(2+) via a hypernitrosylation of the ryanodine receptor. NO overproduction, which further induces the expression of iNOS but decreases the expression of the endothelial isoform (eNOS), deregulates the muscle tissue blood flow creating an ischemic situation. The high levels of Ca(2+) in dystrophic muscles and the ischemic state of the muscle tissue would culminate in a positive feedback loop. While efforts continue toward optimizing cardiac and respiratory care of DMD patients, both Ca(2+) and NO in cardiac and respiratory muscle pathways have been shown to be important to the etiology of the disease. Understanding the mechanisms behind the fine regulation of Ca(2+) -NO may be important for a noninterventional and noninvasive supportive approach to treat DMD patients, improving the quality of life and natural history of DMD patients.
Collapse
Affiliation(s)
- Matias Mosqueira
- Medical Biophysics Unit, Institute of Physiology and Pathophysiology, INF326, Heidelberg University, 69120 Heidelberg, Germany.
| | | | | | | | | |
Collapse
|
26
|
Wawrzyniak AM, Kashyap R, Zimmermann P. Phosphoinositides and PDZ domain scaffolds. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 991:41-57. [PMID: 23775690 DOI: 10.1007/978-94-007-6331-9_4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The discovery that PSD-95/Discs large/ZO-1 (PDZ) domains can function as lipid-binding modules, in particular interacting with phosphoinositides (PIs), was made more than 10 years ago (Mol Cell 9(6): 1215-1225, 2002). Confirmatory studies and a series of functional follow-ups established PDZ domains as dual specificity modules displaying both peptide and lipid binding, and prompted a rethinking of the mode of action of PDZ domains in the control of cell signaling. In this chapter, after introducing PDZ domains, PIs and methods for studying protein-lipid interactions, we focus on (i) the prevalence and the specificity of PDZ-PIs interactions, (ii) the molecular determinants of PDZ-PIs interactions, (iii) the integration of lipid and peptide binding by PDZ domains, (iv) the common features of PIs interacting PDZ domains and (v) the regulation and functional significance of PDZ-PIs interactions.
Collapse
|
27
|
Fuhrmann-Stroissnigg H, Noiges R, Descovich L, Fischer I, Albrecht DE, Nothias F, Froehner SC, Propst F. The light chains of microtubule-associated proteins MAP1A and MAP1B interact with α1-syntrophin in the central and peripheral nervous system. PLoS One 2012; 7:e49722. [PMID: 23152929 PMCID: PMC3496707 DOI: 10.1371/journal.pone.0049722] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 10/17/2012] [Indexed: 12/24/2022] Open
Abstract
Microtubule-associated proteins of the MAP1 family (MAP1A, MAP1B, and MAP1S) share, among other features, a highly conserved COOH-terminal domain approximately 125 amino acids in length. We conducted a yeast 2-hybrid screen to search for proteins interacting with this domain and identified α1-syntrophin, a member of a multigene family of adapter proteins involved in signal transduction. We further demonstrate that the interaction between the conserved COOH-terminal 125-amino acid domain (which is located in the light chains of MAP1A, MAP1B, and MAP1S) and α1-syntrophin is direct and occurs through the pleckstrin homology domain 2 (PH2) and the postsynaptic density protein 95/disk large/zonula occludens-1 protein homology domain (PDZ) of α1-syntrophin. We confirmed the interaction of MAP1B and α1-syntrophin by co-localization of the two proteins in transfected cells and by co-immunoprecipitation experiments from mouse brain. In addition, we show that MAP1B and α1-syntrophin partially co-localize in Schwann cells of the murine sciatic nerve during postnatal development and in the adult. However, intracellular localization of α1-syntrophin and other Schwann cell proteins such as ezrin and dystrophin-related protein 2 (DRP2) and the localization of the axonal node of Ranvier-associated protein Caspr1/paranodin were not affected in MAP1B null mice. Our findings add to a growing body of evidence that classical MAPs are likely to be involved in signal transduction not only by directly modulating microtubule function, but also through their interaction with signal transduction proteins.
Collapse
Affiliation(s)
- Heike Fuhrmann-Stroissnigg
- Max F. Perutz Laboratories, University of Vienna, Department of Biochemistry and Cell Biology, Vienna, Austria
| | - Rainer Noiges
- Max F. Perutz Laboratories, University of Vienna, Department of Biochemistry and Cell Biology, Vienna, Austria
| | - Luise Descovich
- Max F. Perutz Laboratories, University of Vienna, Department of Biochemistry and Cell Biology, Vienna, Austria
| | - Irmgard Fischer
- Max F. Perutz Laboratories, University of Vienna, Department of Biochemistry and Cell Biology, Vienna, Austria
| | - Douglas E. Albrecht
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington, United States of America
| | - Fatiha Nothias
- INSERM U952, CNRS UMR 7224, Université Pierre et Marie Curie (UPMC) - Paris-06, Paris, France
| | - Stanley C. Froehner
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington, United States of America
| | - Friedrich Propst
- Max F. Perutz Laboratories, University of Vienna, Department of Biochemistry and Cell Biology, Vienna, Austria
- * E-mail:
| |
Collapse
|
28
|
Yokota T, Duddy W, Echigoya Y, Kolski H. Exon skipping for nonsense mutations in Duchenne muscular dystrophy: too many mutations, too few patients? Expert Opin Biol Ther 2012; 12:1141-52. [PMID: 22650324 DOI: 10.1517/14712598.2012.693469] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Duchenne muscular dystrophy (DMD), one of the most common and lethal genetic disorders, is caused by mutations of the dystrophin gene. Removal of an exon or of multiple exons using antisense molecules has been demonstrated to allow synthesis of truncated 'Becker muscular dystrophy-like' dystrophin. AREAS COVERED Approximately 15% of DMD cases are caused by a nonsense mutation. Although patient databases have previously been surveyed for applicability to each deletion mutation pattern, this is not so for nonsense mutations. Here, we examine the world-wide database containing notations for more than 1200 patients with nonsense mutations. Approximately 47% of nonsense mutations can be potentially treated with single exon skipping, rising to 90% with double exon skipping, but to reach this proportion requires the development of exon skipping molecules targeting some 68 of dystrophin's 79 exons, with patient numbers spread thinly across those exons. In this review, we discuss progress and remaining hurdles in exon skipping and an alternative strategy, stop-codon readthrough. EXPERT OPINION Antisense-mediated exon skipping therapy is targeted highly at the individual patient and is a clear example of personalized medicine. An efficient regulatory path for drug approval will be a key to success.
Collapse
Affiliation(s)
- Toshifumi Yokota
- University of Alberta, Department of Medical Genetics, School of Human Development, Faculty of Medicine and Dentistry, 829 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada.
| | | | | | | |
Collapse
|
29
|
Cheng J, Norstrand DWV, Medeiros-Domingo A, Tester DJ, Valdivia CR, Tan BH, Vatta M, Makielski JC, Ackerman MJ. LQTS-associated mutation A257G in α1-syntrophin interacts with the intragenic variant P74L to modify its biophysical phenotype. CARDIOGENETICS 2011; 1. [PMID: 24319568 DOI: 10.4081/cardiogenetics.2011.e13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The SNTA1-encoded α1-syntrophin (SNTA1) missense mutation, p.A257G, causes long QT syndrome (LQTS) by pathogenic accentuation of Nav1.5's sodium current (INa). Subsequently, we found p.A257G in combination with the SNTA1 polymorphism, p.P74L in 4 victims of sudden infant death syndrome (SIDS) as well as in 3 adult controls. We hypothesized that p.P74L-SNTA1 could functionally modify the pathogenic phenotype of p.A257G-SNTA1, thus explaining its occurrence in non-LQTS populations. The SNTA1 variants p.P74L, p.A257G, and the combination variant p.P74L/p.A257G were engineered using PCR-based overlap-extension and were co-expressed heterologously with SCN5A in HEK293 cells. INa was recorded using the whole-cell method. Compared to wild-type (WT), the significant increase in peak INa and window current found with p.A257G was reversed by the intragenic variant p.P74L (p.P74L/p.A257G). These results report for the first time the intragenic rescue of an LQT-associated SNTA1 mutation when found in combination with the SNTA1 polymorphism p.P74L, suggesting an ever-increasing picture of complexity in terms of genetic risk stratification for arrhythmia.
Collapse
Affiliation(s)
- Jianding Cheng
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI, USA ; Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Tham DKL, Moukhles H. Regulation of Kir4.1 and AQP4 expression and stability at the basolateral domain of epithelial MDCK cells by the extracellular matrix. Am J Physiol Renal Physiol 2011; 301:F396-409. [PMID: 21543416 DOI: 10.1152/ajprenal.00315.2010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The proper targeting of ion channels to specialized domains is crucial for cell function. Kir4.1, the inwardly rectifying potassium channel, and aquaporin-4 (AQP4), the type 4 water-permeable channel, are localized at the basolateral domain of polarized epithelial cells; however, the mechanisms involved in their localization have yet to be determined. In this study, we investigated the role of the extracellular matrix in the localization of these channels in polarized Madin-Darby canine kidney (MDCK) cells. MDCK cells expressing green fluorescent protein-Kir4.1 or -AQP4 were cultured on laminin-1 or fibronectin and examined by confocal microscopy and cell surface biotinylation to assess plasma membrane expression of Kir4.1 and AQP4. Our data show that laminin-1 and fibronectin induce a significant increase in cell surface expression of both channels at the basolateral domain. Using fluorescence recovery after photobleaching, we demonstrate that laminin-1 and fibronectin reduce the diffusion rates of these channels. Finally, we show that the laminin receptor dystroglycan is important for cell surface expression of Kir4.1 but not AQP4. However, laminin-1 increases cell surface expression of both channels in cells deficient for dystroglycan, indicating that other receptors are involved. Indeed, RGD-containing peptides, which inhibit fibronectin binding to certain integrins, prevent the fibronectin-induced increase in Kir4.1 and AQP4 cell surface expression and reverse the laminin- and fibronectin-induced reduction in both channels' diffusion rates. Similarly, the αvβ3-integrin function-blocking antibody alters the reduction of AQP4 diffusion rates induced by both laminin and fibronectin, suggesting that αvβ3-integrin plays a role in the stabilization of APQ4 at the basolateral domain of epithelial cells.
Collapse
Affiliation(s)
- Daniel Kai Long Tham
- Dept of Cellular and Physiological Sciences, Univ. of British Columbia, Vancouver, Canada
| | | |
Collapse
|
31
|
Current status of pharmaceutical and genetic therapeutic approaches to treat DMD. Mol Ther 2011; 19:830-40. [PMID: 21468001 DOI: 10.1038/mt.2011.59] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a genetic disease affecting about one in every 3,500 boys. This X-linked pathology is due to the absence of dystrophin in muscle fibers. This lack of dystrophin leads to the progressive muscle degeneration that is often responsible for the death of the DMD patients during the third decade of their life. There are currently no curative treatments for this disease but different therapeutic approaches are being studied. Gene therapy consists of introducing a transgene coding for full-length or a truncated version of dystrophin complementary DNA (cDNA) in muscles, whereas pharmaceutical therapy includes the use of chemical/biochemical substances to restore dystrophin expression or alleviate the DMD phenotype. Over the past years, many potential drugs were explored. This led to several clinical trials for gentamicin and ataluren (PTC124) allowing stop codon read-through. An alternative approach is to induce the expression of an internally deleted, partially functional dystrophin protein through exon skipping. The vectors and the methods used in gene therapy have been continually improving in order to obtain greater encapsidation capacity and better transduction efficiency. The most promising experimental approaches using pharmaceutical and gene therapies are reviewed in this article.
Collapse
|
32
|
Nakamori M, Takahashi MP. The role of α-dystrobrevin in striated muscle. Int J Mol Sci 2011; 12:1660-71. [PMID: 21673914 PMCID: PMC3111625 DOI: 10.3390/ijms12031660] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 01/29/2011] [Accepted: 02/23/2011] [Indexed: 12/29/2022] Open
Abstract
Muscular dystrophies are a group of diseases that primarily affect striated muscle and are characterized by the progressive loss of muscle strength and integrity. Major forms of muscular dystrophies are caused by the abnormalities of the dystrophin glycoprotein complex (DGC) that plays crucial roles as a structural unit and scaffolds for signaling molecules at the sarcolemma. α-Dystrobrevin is a component of the DGC and directly associates with dystrophin. α-Dystrobrevin also binds to intermediate filaments as well as syntrophin, a modular adaptor protein thought to be involved in signaling. Although no muscular dystrophy has been associated within mutations of the α-dystrobrevin gene, emerging findings suggest potential significance of α-dystrobrevin in striated muscle. This review addresses the functional role of α-dystrobrevin in muscle as well as its possible implication for muscular dystrophy.
Collapse
Affiliation(s)
- Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2, D-4, Yamadaoka, Suita, Osaka 565-0871, Japan; E-Mail:
- Department of Neurology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 645 URMC, Rochester, NY 14642, USA
| | - Masanori P. Takahashi
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2, D-4, Yamadaoka, Suita, Osaka 565-0871, Japan; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-6-6879-3571; Fax: +81-6-6879-3579
| |
Collapse
|
33
|
Α-syntrophin modulates myogenin expression in differentiating myoblasts. PLoS One 2010; 5:e15355. [PMID: 21179410 PMCID: PMC3003685 DOI: 10.1371/journal.pone.0015355] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 11/11/2010] [Indexed: 11/26/2022] Open
Abstract
Background α-Syntrophin is a scaffolding protein linking signaling proteins to the sarcolemmal dystrophin complex in mature muscle. However, α-syntrophin is also expressed in differentiating myoblasts during the early stages of muscle differentiation. In this study, we examined the relationship between the expression of α-syntrophin and myogenin, a key muscle regulatory factor. Methods and Findings The absence of α-syntrophin leads to reduced and delayed myogenin expression. This conclusion is based on experiments using muscle cells isolated from α-syntrophin null mice, muscle regeneration studies in α-syntrophin null mice, experiments in Sol8 cells (a cell line that expresses only low levels of α-syntrophin) and siRNA studies in differentiating C2 cells. In primary cultured myocytes isolated from α-syntrophin null mice, the level of myogenin was less than 50% that from wild type myocytes (p<0.005) 40 h after differentiation induction. In regenerating muscle, the expression of myogenin in the α-syntrophin null muscle was reduced to approximately 25% that of wild type muscle (p<0.005). Conversely, myogenin expression is enhanced in primary cultures of myoblasts isolated from a transgenic mouse over-expressing α-syntrophin and in Sol8 cells transfected with a vector to over-express α-syntrophin. Moreover, we find that myogenin mRNA is reduced in the absence of α-syntrophin and increased by α-syntrophin over-expression. Immunofluorescence microscopy shows that α-syntrophin is localized to the nuclei of differentiating myoblasts. Finally, immunoprecipitation experiments demonstrate that α-syntrophin associates with Mixed-Lineage Leukemia 5, a regulator of myogenin expression. Conclusions We conclude that α-syntrophin plays an important role in regulating myogenesis by modulating myogenin expression.
Collapse
|
34
|
Bhat HF, Baba RA, Bashir M, Saeed S, Kirmani D, Wani MM, Wani NA, Wani KA, Khanday FA. Alpha-1-syntrophin protein is differentially expressed in human cancers. Biomarkers 2010; 16:31-6. [DOI: 10.3109/1354750x.2010.522731] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
35
|
Aquaporin expression in normal and pathological skeletal muscles: a brief review with focus on AQP4. J Biomed Biotechnol 2010; 2010:731569. [PMID: 20339523 PMCID: PMC2842974 DOI: 10.1155/2010/731569] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 01/12/2010] [Accepted: 01/17/2010] [Indexed: 11/30/2022] Open
Abstract
Freeze-fracture electron microscopy enabled us to observe the molecular architecture of the biological membranes. We were studying the myofiber plasma membranes of health and disease by using this technique and were interested in the special assembly called orthogonal arrays (OAs). OAs were present in normal myofiber plasma membranes and were especially numerous in fast twitch type 2 myofibers; while OAs were lost from sarcolemmal plasma membranes of severely affected muscles with dystrophinopathy and dysferlinopathy but not with caveolinopathy. In the mid nineties of the last century, the OAs turned out to be a water channel named aquaporin 4 (AQP4). Since this discovery, several groups of investigators have been studying AQP4 expression in diseased muscles. This review summarizes the papers which describe the expression of OAs, AQP4, and other AQPs at the sarcolemma of healthy and diseased muscle and discusses the possible role of AQPs, especially that of AQP4, in normal and pathological skeletal muscles.
Collapse
|
36
|
Regulation by scaffolding proteins of canonical transient receptor potential channels in striated muscle. J Muscle Res Cell Motil 2010; 30:289-97. [PMID: 20195709 DOI: 10.1007/s10974-010-9206-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Accepted: 02/09/2010] [Indexed: 01/10/2023]
Abstract
Recent studies proposed a pivotal role of TRPC channels, in particular TRPC1, in the striated muscle tissue and in the development of calcium mishandling observed in dystrophin-deficient skeletal and cardiac muscle cells (Vandebrouck et al. in J Cell Biol 158:1089-1096, 2002; Williams and Allen in Am J Physiol Heart Circ Physiol 292:H846-H855, 2007; Stiber et al. in Mol Cell Biol 28:2637-2647, 2008). In skeletal muscle, TRPCs are proposed to function in a costameric macromolecular complex (Vandebrouck et al. in FASEB J 21:608-617, 2007; Gervasio et al. in J Cell Sci 121:2246-2255, 2008) in which scaffolding proteins and dystrophin are central components maintaining normal calcium entry (Stiber et al. in Mol Cell Biol 28:2637-2647, 2008; Sabourin et al. in J Biol Chem 284:36248-61, 2009). In this review, we shall summarize the roles played by scaffolding proteins in regulating the calcium entry through TRPC channels of skeletal muscle cells and the implications in muscle physiopathology. Interactions of TRPC1 with caveolin-3, Homer-1 and alpha-syntrophin will be addressed and these complexes will be compared with signalplex in other systems. The mechanosensitive function of scaffolding proteins will be discussed as well as interactions with TRPV2 channels regarding to calcium mishandling in Duchenne dystrophy.
Collapse
|
37
|
Wu G, Ai T, Kim JJ, Mohapatra B, Xi Y, Li Z, Abbasi S, Purevjav E, Samani K, Ackerman MJ, Qi M, Moss AJ, Shimizu W, Towbin JA, Cheng J, Vatta M. alpha-1-syntrophin mutation and the long-QT syndrome: a disease of sodium channel disruption. Circ Arrhythm Electrophysiol 2009; 1:193-201. [PMID: 19684871 DOI: 10.1161/circep.108.769224] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Long-QT syndrome (LQTS) is an inherited disorder associated with sudden cardiac death. The cytoskeletal protein syntrophin-alpha(1) (SNTA1) is known to interact with the cardiac sodium channel (hNa(v)1.5), and we hypothesized that SNTA1 mutations might cause phenotypic LQTS in patients with genotypically normal hNa(v)1.5 by secondarily disturbing sodium channel function. METHODS AND RESULTS Mutational analysis of SNTA1 was performed on 39 LQTS patients (QTc> or =480 ms) with previously negative genetic screening for the known LQTS-causing genes. We identified a novel A257G-SNTA1 missense mutation, which affects a highly conserved residue, in 3 unrelated LQTS probands but not in 400 ethnic-matched control alleles. Only 1 of these probands had a preexisting family history of LQTS and sudden death with an additional intronic variant in KCNQ1. Electrophysiological analysis was performed using HEK-293 cells stably expressing hNa(v)1.5 and transiently transfected with either wild-type or mutant SNTA1 and, in neonatal rat cardiomyocytes, transiently transfected with either wild-type or mutant SNTA1. In both HEK-293 cells and neonatal rat cardiomyocytes, increased peak sodium currents were noted along with a 10-mV negative shift of the onset and peak of currents of the current-voltage relationships. In addition, A257G-SNTA1 shifted the steady-state activation (V(h)) leftward by 9.4 mV, whereas the voltage-dependent inactivation kinetics and the late sodium currents were similar to wild-type SNTA1. CONCLUSION SNTA1 is a new susceptibility gene for LQTS. A257G-SNTA1 can cause gain-of-function of Na(v)1.5 similar to the LQT3.
Collapse
Affiliation(s)
- Geru Wu
- Electrophysiology Research Laboratory, Texas Heart Institute/St. Luke's Episcopal Hospital, Houston, Texas, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Sabourin J, Lamiche C, Vandebrouck A, Magaud C, Rivet J, Cognard C, Bourmeyster N, Constantin B. Regulation of TRPC1 and TRPC4 cation channels requires an alpha1-syntrophin-dependent complex in skeletal mouse myotubes. J Biol Chem 2009; 284:36248-36261. [PMID: 19812031 DOI: 10.1074/jbc.m109.012872] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The dystrophin-associated protein complex (DAPC) is essential for skeletal muscle, and the lack of dystrophin in Duchenne muscular dystrophy results in a reduction of DAPC components such as syntrophins and in fiber necrosis. By anchoring various molecules, the syntrophins may confer a role in cell signaling to the DAPC. Calcium disorders and abnormally elevated cation influx in dystrophic muscle cells have suggested that the DAPC regulates some sarcolemmal cationic channels. We demonstrated previously that mini-dystrophin and alpha1-syntrophin restore normal cation entry in dystrophin-deficient myotubes and that sarcolemmal TRPC1 channels associate with dystrophin and the bound PDZ domain of alpha1-syntrophin. This study shows that small interfering RNA (siRNA) silencing of alpha1-syntrophin dysregulated cation influx in myotubes. Moreover, deletion of the PDZ-containing domain prevented restoration of normal cation entry by alpha1-syntrophin transfection in dystrophin-deficient myotubes. TRPC1 and TRPC4 channels are expressed at the sarcolemma of muscle cells; forced expression or siRNA silencing showed that cation influx regulated by alpha1-syntrophin is supported by TRPC1 and TRPC4. A molecular association was found between TRPC1 and TRPC4 channels and the alpha1-syntrophin-dystrophin complex. TRPC1 and TRPC4 channels may form sarcolemmal channels anchored to the DAPC, and alpha1-syntrophin is necessary to maintain the normal regulation of TRPC-supported cation entry in skeletal muscle. Cation channels with DAPC form a signaling complex that modulates cation entry and may be crucial for normal calcium homeostasis in skeletal muscles.
Collapse
Affiliation(s)
- Jessica Sabourin
- Institut de Physiologie et Biologie Cellulaires, UMR CNRS 6187, Université de Poitiers, 86022 Poitiers, France
| | - Coralie Lamiche
- Institut de Physiologie et Biologie Cellulaires, UMR CNRS 6187, Université de Poitiers, 86022 Poitiers, France
| | - Aurelie Vandebrouck
- Institut de Physiologie et Biologie Cellulaires, UMR CNRS 6187, Université de Poitiers, 86022 Poitiers, France
| | - Christophe Magaud
- Institut de Physiologie et Biologie Cellulaires, UMR CNRS 6187, Université de Poitiers, 86022 Poitiers, France
| | - Jerome Rivet
- Institut de Physiologie et Biologie Cellulaires, UMR CNRS 6187, Université de Poitiers, 86022 Poitiers, France
| | - Christian Cognard
- Institut de Physiologie et Biologie Cellulaires, UMR CNRS 6187, Université de Poitiers, 86022 Poitiers, France
| | - Nicolas Bourmeyster
- Institut de Physiologie et Biologie Cellulaires, UMR CNRS 6187, Université de Poitiers, 86022 Poitiers, France
| | - Bruno Constantin
- Institut de Physiologie et Biologie Cellulaires, UMR CNRS 6187, Université de Poitiers, 86022 Poitiers, France.
| |
Collapse
|
39
|
Waite A, Tinsley CL, Locke M, Blake DJ. The neurobiology of the dystrophin-associated glycoprotein complex. Ann Med 2009; 41:344-59. [PMID: 19172427 DOI: 10.1080/07853890802668522] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
While the function of dystrophin in muscle disease has been thoroughly investigated, dystrophin and associated proteins also have important roles in the central nervous system. Many patients with Duchenne and Becker muscular dystrophies (D/BMD) have cognitive impairment, learning disability, and an increased incidence of some neuropsychiatric disorders. Accordingly, dystrophin and members of the dystrophin-associated glycoprotein complex (DGC) are found in the brain where they participate in macromolecular assemblies that anchor receptors to specialized sites within the membrane. In neurons, dystrophin and the DGC participate in the postsynaptic clustering and stabilization of some inhibitory GABAergic synapses. During development, alpha-dystroglycan functions as an extracellular matrix receptor controlling, amongst other things, neuronal migration in the developing cortex and cerebellum. Several types of congenital muscular dystrophy caused by impaired alpha-dystroglycan glycosylation cause neuronal migration abnormalities and mental retardation. In glial cells, the DGC is involved in the organization of protein complexes that target water-channels to the plasma membrane. Finally, mutations in the gene encoding epsilon-sarcoglycan cause the neurogenic movement disorder, myoclonus-dystonia syndrome implicating epsilon-sarcoglycan in dopaminergic neurotransmission. In this review we describe the recent progress in defining the role of the DGC and associated proteins in the brain.
Collapse
Affiliation(s)
- Adrian Waite
- Department of Psychological Medicine, Cardiff University, Heath Park, Cardiff, UK
| | | | | | | |
Collapse
|
40
|
Lyssand JS, DeFino MC, Tang XB, Hertz AL, Feller DB, Wacker JL, Adams ME, Hague C. Blood pressure is regulated by an alpha1D-adrenergic receptor/dystrophin signalosome. J Biol Chem 2008; 283:18792-800. [PMID: 18468998 DOI: 10.1074/jbc.m801860200] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hypertension is a cardiovascular disease associated with increased plasma catecholamines, overactivation of the sympathetic nervous system, and increased vascular tone and total peripheral resistance. A key regulator of sympathetic nervous system function is the alpha(1D)-adrenergic receptor (AR), which belongs to the adrenergic family of G-protein-coupled receptors (GPCRs). Endogenous catecholamines norepinephrine and epinephrine activate alpha(1D)-ARs on vascular smooth muscle to stimulate vasoconstriction, which increases total peripheral resistance and mean arterial pressure. Indeed, alpha(1D)-AR KO mice display a hypotensive phenotype and are resistant to salt-induced hypertension. Unfortunately, little information exists about how this important GPCR functions because of an inability to obtain functional expression in vitro. Here, we identified the dystrophin proteins, syntrophin, dystrobrevin, and utrophin as essential GPCR-interacting proteins for alpha(1D)-ARs. We found that dystrophins complex with alpha(1D)-AR both in vitro and in vivo to ensure proper functional expression. More importantly, we demonstrate that knock-out of multiple syntrophin isoforms results in the complete loss of alpha(1D)-AR function in mouse aortic smooth muscle cells and abrogation of alpha(1D)-AR-mediated increases in blood pressure. Our findings demonstrate that syntrophin and utrophin associate with alpha(1D)-ARs to create a functional signalosome, which is essential for alpha(1D)-AR regulation of vascular tone and blood pressure.
Collapse
Affiliation(s)
- John S Lyssand
- Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Albrecht DE, Sherman DL, Brophy PJ, Froehner SC. The ABCA1 cholesterol transporter associates with one of two distinct dystrophin-based scaffolds in Schwann cells. Glia 2008; 56:611-8. [PMID: 18286648 PMCID: PMC4335170 DOI: 10.1002/glia.20636] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cytoskeletal scaffolding complexes help organize specialized membrane domains with unique functions on the surface of cells. In this study, we define the scaffolding potential of the Schwann cell dystrophin glycoprotein complex (DGC) by establishing the presence of four syntrophin isoforms, (alpha1, beta1, beta2, and gamma2), and one dystrobrevin isoform, (alpha-dystrobrevin-1), in the abaxonal membrane. Furthermore, we demonstrate the existence of two separate DGCs in Schwann cells that divide the abaxonal membrane into spatially distinct domains, the DRP2/periaxin rich plaques and the Cajal bands that contain Dp116, utrophin, alpha-dystrobrevin-1 and four syntrophin isoforms. Finally, we show that the two different DGCs can scaffold unique accessory molecules in distinct areas of the Schwann cell membrane. Specifically, the cholesterol transporter ABCA1, associates with the Dp116/syntrophin complex in Cajal bands and is excluded from the DRP2/periaxin rich plaques.
Collapse
Affiliation(s)
- Douglas E Albrecht
- Department of Physiology and Biophysics, University of Washington, 1959 NE Pacific St, Box 357290, Seattle WA 98195-7290, USA
| | | | | | | |
Collapse
|
42
|
Dp71, utrophin and beta-dystroglycan expression and distribution in PC12/L6 cell cocultures. Neuroreport 2008; 18:1657-61. [PMID: 17921863 DOI: 10.1097/wnr.0b013e3282f0e42d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Function of dystrophin Dp71 isoforms is unknown but seems related to neurite outgrowth and synapse formation. To evaluate Dp71 role in myoneural synapses, we established a coculture model using PC12 cells and L6 myotubes and analyzed expression and localization of Dp71 and related proteins, utrophin and beta-dystroglycan, in PC12 cells. Confocal microscopy showed Dp71d isoform in PC12 nuclei, golgi-complex-like and endoplasmic reticulum-like structures, whereas Dp71ab concentrates at neurite tips and cytoplasm, colocalizing with beta-dystroglycan, utrophin, synaptophysin and acetylcholine receptors. Evidences suggest that Dp71ab isoform, unlike Dp71d, may take part in neurite-related processes. This is the first work on Dp and members of Dp-associated protein complex roles in a cell-line based coculturing system, which may be useful in determining Dp71 isoforms associations.
Collapse
|
43
|
Okumura A, Nagai K, Okumura N. Interaction of α1-syntrophin with multiple isoforms of heterotrimeric G protein α subunits. FEBS J 2007; 275:22-33. [DOI: 10.1111/j.1742-4658.2007.06174.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
44
|
Hibino H, Kurachi Y. Distinct detergent-resistant membrane microdomains (lipid rafts) respectively harvest K(+) and water transport systems in brain astroglia. Eur J Neurosci 2007; 26:2539-55. [PMID: 17970725 DOI: 10.1111/j.1460-9568.2007.05876.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The detergent-resistant microdomains (DRM) of cell membranes scaffold different molecules and regulate cell functions by orchestrating various signaling pathways including G-proteins and tyrosine kinase. Here we report a novel role for DRM in astroglial cells. K(+)-buffering inwardly rectifying Kir4.1 channels and the water channel AQP4 are expressed in astrocytes and they may be functionally coupled to maintain ionic and osmotic homeostasis in the brain. Kir4.1 and AQP4 channel proteins were abundant in noncaveloar DRM in the brain and also in HEK293T cells when exogenously expressed. In HEK293T cells, depletion of membrane cholesterol by methyl-beta-cyclodextrin (MbetaCD) resulted in loss of Kir4.1 association with DRM and its channel activity but did not affect either the distribution or the function of AQP4. Immunolabeling showed that Kir4.1 and AQP4 were occasionally distributed in close proximity but in distinct compartments of the astroglial cell membrane. Astroglial noncaveolar DRM may therefore be made up of at least two distinct compartments, MbetaCD-sensitive and MbetaCD-resistant microdomains, which control localization and function of, respectively, Kir and AQP4 channels on the cell membrane.
Collapse
Affiliation(s)
- Hiroshi Hibino
- Division of Molecular and Cellular Pharmacology, Department of Pharmacology, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan
| | | |
Collapse
|
45
|
Hnia K, Hugon G, Rivier F, Masmoudi A, Mercier J, Mornet D. Modulation of p38 mitogen-activated protein kinase cascade and metalloproteinase activity in diaphragm muscle in response to free radical scavenger administration in dystrophin-deficient Mdx mice. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 170:633-43. [PMID: 17255331 PMCID: PMC1851881 DOI: 10.2353/ajpath.2007.060344] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Duchenne muscular dystrophy muscles undergo increased oxidative stress and altered calcium homeostasis, which contribute to myofiber loss by trigging both necrosis and apoptosis. Here, we asked whether treatment with free radical scavengers could improve the dystrophic pattern of mdx muscles. Five-week-old mdx mice were treated for 2 weeks with alpha-lipoic acid/l-carnitine. This treatment decreased the plasmatic creatine kinase level, the antioxidant enzyme activity, and lipid peroxidation products in mdx diaphragm. Free radical scavengers also modulated the phosphorylation/activity of some component of the mitogen-activated protein kinase (MAPK) cascades: p38 MAPK, the extracellular signal-related kinase, and the Jun kinase. beta-Dystroglycan (beta-DG), a multifunctional adaptor or scaffold capable of interacting with components of the extracellular signal-related kinase-MAP kinase cascade, was also affected after treatment. In the mdx muscles, beta-DG (43 kd) was cleaved by matrix metalloproteinases into a 30-kd form (beta-DG30). We show that the proinflammatory protein nuclear factor-kappaB activator decreased after the treatment, leading to a significant reduction of matrix metalloproteinase activity in the mdx diaphragm. Our data highlight the implication of oxidative stress and cell signaling defects in dystrophin-deficient muscle via the MAP kinase cascade-beta-DG interaction and nuclear factor-kappaB-mediated inflammation process.
Collapse
Affiliation(s)
- Karim Hnia
- Institut National de la Santé, et de la Recherche Médicale, Equipe ERI 25, Muscle et Pathologies, Université de Montpellier1, Unité de Formation et de Recherche de Médecine, EA701, 4 Boulevard Henri IV, 34060 Montpellier, France
| | | | | | | | | | | |
Collapse
|
46
|
Peter AK, Miller G, Crosbie RH. Disrupted mechanical stability of the dystrophin-glycoprotein complex causes severe muscular dystrophy in sarcospan transgenic mice. J Cell Sci 2007; 120:996-1008. [PMID: 17311848 DOI: 10.1242/jcs.03360] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The dystrophin-glycoprotein complex spans the muscle plasma membrane and provides a mechanical linkage between laminin in the extracellular matrix and actin in the intracellular cytoskeleton. Within the dystrophin-glycoprotein complex, the sarcoglycans and sarcospan constitute a subcomplex of transmembrane proteins that stabilize α-dystroglycan, a receptor for laminin and other components of the extracellular matrix. In order to elucidate the function of sarcospan, we generated transgenic mice that overexpress sarcospan in skeletal muscle. Sarcospan transgenic mice with moderate (tenfold) levels of sarcospan overexpression exhibit a severe phenotype that is similar to mouse models of laminin-deficient congenital muscular dystrophy (MD). Sarcospan transgenic mice display severe kyphosis and die prematurely between 6 and 10 weeks of age. Histological analysis reveals that sarcospan expression causes muscle pathology marked by increased muscle fiber degeneration and/or regeneration. Sarcospan transgenic muscle does not display sarcolemma damage, which is distinct from dystrophin- and sarcoglycan-deficient muscular dystrophies. We show that sarcospan clusters the sarcoglycans into insoluble protein aggregates and causes destabilization of α-dystroglycan. Evidence is provided to demonstrate abnormal extracellular matrix assembly, which represents a probable pathological mechanism for the severe and lethal dystrophic phenotype. Taken together, these data suggest that sarcospan plays an important mechanical role in stabilizing the dystrophin-glycoprotein complex.
Collapse
Affiliation(s)
- Angela K Peter
- Department of Physiological Science, University of California, Los Angeles, CA 90095, USA
| | | | | |
Collapse
|
47
|
Rees MLJ, Lien CF, Górecki DC. Dystrobrevins in muscle and non-muscle tissues. Neuromuscul Disord 2007; 17:123-34. [PMID: 17251025 DOI: 10.1016/j.nmd.2006.11.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 10/26/2006] [Accepted: 11/20/2006] [Indexed: 01/23/2023]
Abstract
The alpha- and beta-dystrobrevins belong to the family of dystrophin-related and dystrophin-associated proteins. As constituents of the dystrophin-associated protein complex, alpha-dystrobrevin was believed to have a role predominantly in muscles and beta-dystrobrevin in non-muscle tissues. Recent reports described novel localisations and molecular characteristics of alpha-dystrobrevin isoforms in non-muscle tissues (developing and adult). While single and double knockout studies have revealed distinct functions of dystrobrevin in some tissues, these also suggested a strong compensatory mechanism, where dystrobrevins displaying overlapping tissue expression pattern and structure/function similarity can substitute each other. No human disease has been unequivocally associated within mutations of dystrobrevin genes. However, some significant exceptions to these overlapping expression patterns, mainly in the brain, suggest that dystrobrevin mutations might underlie some specific motor, behavioural or cognitive defects. Dystrobrevin binding partner DTNBP1 (dysbindin) is a probable susceptibility gene for schizophrenia and bipolar affective disorder in some populations. As dysbindin abnormality is linked to Hermansky-Pudlak syndrome, dystrobrevins and/or their binding partners may also be required for proper function of other non-muscle tissues.
Collapse
Affiliation(s)
- Melissa L J Rees
- Department of Molecular Medicine, Institute of Biomedical and Biomolecular Sciences, School of Pharmacy and Biomedical Sciences, University of Portsmouth, UK
| | | | | |
Collapse
|
48
|
|
49
|
Rafii MS, Hagiwara H, Mercado ML, Seo NS, Xu T, Dugan T, Owens RT, Hook M, McQuillan DJ, Young MF, Fallon JR. Biglycan binds to alpha- and gamma-sarcoglycan and regulates their expression during development. J Cell Physiol 2006; 209:439-47. [PMID: 16883602 PMCID: PMC2929672 DOI: 10.1002/jcp.20740] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The dystrophin-associated protein complex (DAPC), which links the cytoskeleton to the extracellular matrix, is essential for muscle cell survival, and is defective in a wide range of muscular dystrophies. The DAPC contains two transmembrane subcomplexes-the dystroglycans and the sarcoglycans. Although several extracellular binding partners have been identified for the dystroglycans, none have been described for the sarcoglycan subcomplex. Here we show that the small leucine-rich repeat (LRR) proteoglycan biglycan binds to alpha- and gamma-sarcoglycan as judged by ligand blot overlay and co-immunoprecipitation assays. Our studies with biglycan-decorin chimeras show that alpha- and gamma-sarcoglycan bind to distinct sites on the polypeptide core of biglycan. Both biglycan proteoglycan as well as biglycan polypeptide lacking glycosaminoglycan (GAG) side chains are components of the dystrophin glycoprotein complex isolated from adult skeletal muscle membranes. Finally, our immunohistochemical and biochemical studies with biglycan null mice show that the expression of alpha- and gamma-sarcoglycan is selectively reduced in muscle from young (P14-P21) animals, while levels in adult muscle (> or = P35) are unchanged. We conclude that biglycan is a ligand for two members of the sarcoglycan complex and regulates their expression at discrete developmental ages.
Collapse
Affiliation(s)
- Michael S. Rafii
- Department of Neuroscience, Brown University, Providence RI, 02912
| | - Hiroki Hagiwara
- Department of Neuroscience, Brown University, Providence RI, 02912
| | | | | | - Tianshun Xu
- Craniofacial and Skeletal Diseases Branch, National Institutes of Dental Research, National Institutes of Health, Bethesda MD, 20892
| | - Tracey Dugan
- Texas A&M University System Health Science Center Institute of Biosciences and Technology
| | | | - Magnus Hook
- Texas A&M University System Health Science Center Institute of Biosciences and Technology
| | | | - Marian F. Young
- Craniofacial and Skeletal Diseases Branch, National Institutes of Dental Research, National Institutes of Health, Bethesda MD, 20892
| | - Justin R. Fallon
- Department of Neuroscience, Brown University, Providence RI, 02912
| |
Collapse
|
50
|
Fuentes-Mera L, Rodríguez-Muñoz R, González-Ramírez R, García-Sierra F, González E, Mornet D, Cisneros B. Characterization of a novel Dp71 dystrophin-associated protein complex (DAPC) present in the nucleus of HeLa cells: members of the nuclear DAPC associate with the nuclear matrix. Exp Cell Res 2006; 312:3023-35. [PMID: 16824516 DOI: 10.1016/j.yexcr.2006.06.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 05/06/2006] [Accepted: 06/02/2006] [Indexed: 11/26/2022]
Abstract
Dystrophin is an essential component in the assembly and maintenance of the dystrophin-associated protein complex (DAPC), which includes members of the dystroglycan, syntrophin, sarcoglycan and dystrobrevin protein families. Distinctive complexes have been described in the cell membrane of different tissues and cultured cells. In this work, we report the identification and characterization of a novel DAPC present in the nuclei of HeLa cells, which contains dystrophin Dp71 as a key component. Using confocal microscopy and cell fractionation analyses, we found the presence of Dp71, beta-sarcoglycan, beta-dystroglycan, alpha- and beta-syntrophin, alpha1- and beta-dystrobrevin and nNOS in the nuclei of HeLa cells. Furthermore, we demonstrated by co-immunoprecipitation experiments that most of these proteins form a complex in the nuclear compartment. Next, we analyze the possible association of the nuclear DAPC with the nuclear matrix. We found the presence of Dp71, beta-dystroglycan, nNOS, beta-sarcoglycan, alpha/beta syntrophin, alpha1-dystrobrevin and beta-dystrobrevin in the nuclear matrix protein fractions and in situ nuclear matrix preparations from HeLa cells. Moreover, we found that Dp71, beta-dystroglycan and beta-dystrobrevin co-immunoprecipitated with the nuclear matrix proteins lamin B1 and actin. The association of members of the nuclear DAPC with the nuclear matrix indicates that they may work as scaffolding proteins involved in nuclear architecture.
Collapse
Affiliation(s)
- Lizeth Fuentes-Mera
- Department of Genetics and Molecular Biology, Centro de Investigación y de Estudios Avanzados del IPN, Avenida Instituto Politécnico Nacional 2508, Apartado Postal 14-740, C.P. 07000, México D.F., México
| | | | | | | | | | | | | |
Collapse
|