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Kawai-Takaishi M, Miyagawa Y, Honda T, Inui M, Hosoyama T. Postnatal Pdzrn3 deficiency causes acute muscle atrophy without alterations in endplate morphology. Biochem Biophys Res Commun 2024; 696:149542. [PMID: 38244315 DOI: 10.1016/j.bbrc.2024.149542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/08/2024] [Accepted: 01/16/2024] [Indexed: 01/22/2024]
Abstract
PDZ domain-containing RING finger family protein 3 (PDZRN3) is expressed in various tissues, including the skeletal muscle. Although PDZRN3 plays a crucial role in the terminal differentiation of myoblasts and synaptic growth/maturation in myogenesis, the role of this molecule in postnatal muscles is completely unknown despite its lifelong expression in myofibers. In this study, we aimed to elucidate the function of PDZRN3 in mature myofibers using myofiber-specific conditional knockout mice. After tamoxifen injection, PDZRN3 deficiency was confirmed in both fast and slow myofibers of Myf6-CreERT2; Pdzrn3flox/flox (Pdzrn3mcKO) mice. Transcriptome analysis of the skeletal muscles of Pdzrn3mcKO mice identified differentially expressed genes, including muscle atrophy-related genes such as Smox, Amd1/2, and Mt1/2, suggesting that PDZRN3 is involved in the homeostatic maintenance of postnatal muscles. PDZRN3 deficiency caused muscle atrophy, predominantly in fast-twitch (type II) myofibers, and reduced muscle strength. While myofiber-specific PDZRN3 deficiency did not influence endplate morphology or expression of neuromuscular synaptic formation-related genes in postnatal muscles, indicating that the relationship between PDZRN3 and neuromuscular junctions might be limited during muscle development. Considering that the expression of Pdzrn3 in skeletal muscles was significantly lower in aged mice than in mature adult mice, we speculated that the PDZRN3-mediated muscle maintenance system might be associated with the pathophysiology of age-related muscle decline, such as sarcopenia.
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Affiliation(s)
- Minako Kawai-Takaishi
- Department of Musculoskeletal Disease, Geroscience Research Center, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
| | - Yoshihiro Miyagawa
- Department of Musculoskeletal Disease, Geroscience Research Center, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
| | - Takeshi Honda
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan; Department of Chemistry, Kurume University School of Medicine, Kurume, Fukuoka, Japan
| | - Makoto Inui
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Tohru Hosoyama
- Department of Musculoskeletal Disease, Geroscience Research Center, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan.
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Chen J, Xu Q, Wang X, Xu Z, Chen X. Cullin-3 intervenes in muscle atrophy in the elderly by mediating the degradation of nAchRs ubiquitination. Exp Gerontol 2023; 183:112318. [PMID: 37913946 DOI: 10.1016/j.exger.2023.112318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/20/2023] [Accepted: 10/22/2023] [Indexed: 11/03/2023]
Abstract
Sarcopenia involves in the loss of muscle mass associated with aging, which is the major cause of progressive muscle weakness and deterioration in older adults. Muscle atrophy is a direct presentation of sarcopenia, and it greatly contributes to the decline in quality of life among older adults. Neuromuscular junction (NMJ) stability is the key link to maintain muscle function. Besides, the degenerative change of NMJ promotes the process of muscle atrophy in the elderly. Based on previous transcriptome sequencing and bioinformatics analyses of aged muscle, this study used the 18-month-old aged mouse model and the 6-month-old young mouse model to deliberate the role and underlying mechanisms of Cullin-3 (Cul3) in age-related muscle atrophy. The results of reverse transcriptase polymerase chain reaction (RT-PCR) and immunoblotting analysis showed that the expression of CUL3 increased in aged muscle tissue, while the expression level of postsynaptic membrane nicotinic acetylcholine receptors (nAChRs) decreased significantly, which manfested a negative correlation. Meanwhile, immunofluorescence demonstrated that Cul3 was highly expressed in senile muscle NMJ. The results of ubiquitin indicated that the ubiquitin level of aged muscle nAChRs was evidently increased. Co-immunoprecipitation furtherly verified the correlation between Cul3 and nAChRs. Taken together, Cul3 may mediate the ubiquitination degradation of nAChRs protein at the NMJ site in aged mice, leading to NMJ degeneration and accelerated atrophy of fast-twitch muscle fibers in aged muscle. As a prominent element to maintain the stability of NMJ, Cul3 is supposed to be one of candidate intervention targets in sarcopenia.
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Affiliation(s)
- Jintao Chen
- The First Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China.
| | - Qun Xu
- Zhejiang University, School of Medicine, Hangzhou, China
| | - Xinyi Wang
- The First Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
| | - Zherong Xu
- Department of Geriatrics, The First Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China.
| | - Xujiao Chen
- Department of Geriatrics, Zhejiang Provincial Hospital of Chinese Medicine, Hangzhou, China; Zhejiang Hospital, Hangzhou, China.
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3
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A link between agrin signalling and Ca v3.2 at the neuromuscular junction in spinal muscular atrophy. Sci Rep 2022; 12:18960. [PMID: 36347955 PMCID: PMC9643518 DOI: 10.1038/s41598-022-23703-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 11/03/2022] [Indexed: 11/11/2022] Open
Abstract
SMN protein deficiency causes motoneuron disease spinal muscular atrophy (SMA). SMN-based therapies improve patient motor symptoms to variable degrees. An early hallmark of SMA is the perturbation of the neuromuscular junction (NMJ), a synapse between a motoneuron and muscle cell. NMJ formation depends on acetylcholine receptor (AChR) clustering triggered by agrin and its co-receptors lipoprotein receptor-related protein 4 (LRP4) and transmembrane muscle-specific kinase (MuSK) signalling pathway. We have previously shown that flunarizine improves NMJs in SMA model mice, but the mechanisms remain elusive. We show here that flunarizine promotes AChR clustering in cell-autonomous, dose- and agrin-dependent manners in C2C12 myotubes. This is associated with an increase in protein levels of LRP4, integrin-beta-1 and alpha-dystroglycan, three agrin co-receptors. Furthermore, flunarizine enhances MuSK interaction with integrin-beta-1 and phosphotyrosines. Moreover, the drug acts on the expression and splicing of Agrn and Cacna1h genes in a muscle-specific manner. We reveal that the Cacna1h encoded protein Cav3.2 closely associates in vitro with the agrin co-receptor LRP4. In vivo, it is enriched nearby NMJs during neonatal development and the drug increases this immunolabelling in SMA muscles. Thus, flunarizine modulates key players of the NMJ and identifies Cav3.2 as a new protein involved in the NMJ biology.
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Gemza A, Barresi C, Proemer J, Hatami J, Lazaridis M, Herbst R. Internalization of Muscle-Specific Kinase Is Increased by Agrin and Independent of Kinase-Activity, Lrp4 and Dynamin. Front Mol Neurosci 2022; 15:780659. [PMID: 35370548 PMCID: PMC8965242 DOI: 10.3389/fnmol.2022.780659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Muscle-specific kinase (MuSK) is a receptor tyrosine kinase absolutely required for neuromuscular junction formation. MuSK is activated by binding of motor neuron-derived Agrin to low-density lipoprotein receptor related protein 4 (Lrp4), which forms a complex with MuSK. MuSK activation and downstream signaling are critical events during the development of the neuromuscular junction. Receptor tyrosine kinases are commonly internalized upon ligand binding and crosstalk between endocytosis and signaling has been implicated. To extend our knowledge about endocytosis of synaptic proteins and its role during postsynaptic differentiation at the neuromuscular junction, we studied the stability and internalization of Lrp4, MuSK and acetylcholine receptors (AChRs) in response to Agrin. We provide evidence that MuSK but not Lrp4 internalization is increased by Agrin stimulation. MuSK kinase-activity is not sufficient to induce MuSK internalization and the absence of Lrp4 has no effect on MuSK endocytosis. Moreover, MuSK internalization and signaling are unaffected by the inhibition of Dynamin suggesting that MuSK endocytosis uses a non-conventional pathway and is not required for MuSK-dependent downstream signaling.
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Affiliation(s)
- Anna Gemza
- Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Cinzia Barresi
- Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Jakob Proemer
- Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Jasmin Hatami
- Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Margarita Lazaridis
- Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Ruth Herbst
- Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
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5
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Proteomic analysis identifies the E3 ubiquitin ligase Pdzrn3 as a regulatory target of Wnt5a-Ror signaling. Proc Natl Acad Sci U S A 2021; 118:2104944118. [PMID: 34135125 DOI: 10.1073/pnas.2104944118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Wnt5a-Ror signaling is a conserved pathway that regulates morphogenetic processes during vertebrate development [R. T. Moon et al, Development 119, 97-111 (1993); I. Oishi et al, Genes Cells 8, 645-654 (2003)], but its downstream signaling events remain poorly understood. Through a large-scale proteomic screen in mouse embryonic fibroblasts, we identified the E3 ubiquitin ligase Pdzrn3 as a regulatory target of the Wnt5a-Ror pathway. Upon pathway activation, Pdzrn3 is degraded in a β-catenin-independent, ubiquitin-proteasome system-dependent manner. We developed a flow cytometry-based reporter to monitor Pdzrn3 abundance and delineated a signaling cascade involving Frizzled, Dishevelled, Casein kinase 1, and Glycogen synthase kinase 3 that regulates Pdzrn3 stability. Epistatically, Pdzrn3 is regulated independently of Kif26b, another Wnt5a-Ror effector. Wnt5a-dependent degradation of Pdzrn3 requires phosphorylation of three conserved amino acids within its C-terminal LNX3H domain [M. Flynn, O. Saha, P. Young, BMC Evol. Biol. 11, 235 (2011)], which acts as a bona fide Wnt5a-responsive element. Importantly, this phospho-dependent degradation is essential for Wnt5a-Ror modulation of cell migration. Collectively, this work establishes a Wnt5a-Ror cell morphogenetic cascade involving Pdzrn3 phosphorylation and degradation.
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Hong J, Won M, Ro H. The Molecular and Pathophysiological Functions of Members of the LNX/PDZRN E3 Ubiquitin Ligase Family. Molecules 2020; 25:E5938. [PMID: 33333989 PMCID: PMC7765395 DOI: 10.3390/molecules25245938] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/10/2020] [Accepted: 12/10/2020] [Indexed: 12/27/2022] Open
Abstract
The ligand of Numb protein-X (LNX) family, also known as the PDZRN family, is composed of four discrete RING-type E3 ubiquitin ligases (LNX1, LNX2, LNX3, and LNX4), and LNX5 which may not act as an E3 ubiquitin ligase owing to the lack of the RING domain. As the name implies, LNX1 and LNX2 were initially studied for exerting E3 ubiquitin ligase activity on their substrate Numb protein, whose stability was negatively regulated by LNX1 and LNX2 via the ubiquitin-proteasome pathway. LNX proteins may have versatile molecular, cellular, and developmental functions, considering the fact that besides these proteins, none of the E3 ubiquitin ligases have multiple PDZ (PSD95, DLGA, ZO-1) domains, which are regarded as important protein-interacting modules. Thus far, various proteins have been isolated as LNX-interacting proteins. Evidence from studies performed over the last two decades have suggested that members of the LNX family play various pathophysiological roles primarily by modulating the function of substrate proteins involved in several different intracellular or intercellular signaling cascades. As the binding partners of RING-type E3s, a large number of substrates of LNX proteins undergo degradation through ubiquitin-proteasome system (UPS) dependent or lysosomal pathways, potentially altering key signaling pathways. In this review, we highlight recent and relevant findings on the molecular and cellular functions of the members of the LNX family and discuss the role of the erroneous regulation of these proteins in disease progression.
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Affiliation(s)
- Jeongkwan Hong
- Department of Biological Sciences, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 305-764, Korea;
| | - Minho Won
- Biotechnology Process Engineering Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB), 30 Yeongudanji-ro, Cheongwon-gu, Cheongju 28116, Korea
| | - Hyunju Ro
- Department of Biological Sciences, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 305-764, Korea;
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7
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The Ubiquitin Proteasome System in Neuromuscular Disorders: Moving Beyond Movement. Int J Mol Sci 2020; 21:ijms21176429. [PMID: 32899400 PMCID: PMC7503226 DOI: 10.3390/ijms21176429] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/30/2020] [Accepted: 08/31/2020] [Indexed: 12/12/2022] Open
Abstract
Neuromuscular disorders (NMDs) affect 1 in 3000 people worldwide. There are more than 150 different types of NMDs, where the common feature is the loss of muscle strength. These disorders are classified according to their neuroanatomical location, as motor neuron diseases, peripheral nerve diseases, neuromuscular junction diseases, and muscle diseases. Over the years, numerous studies have pointed to protein homeostasis as a crucial factor in the development of these fatal diseases. The ubiquitin-proteasome system (UPS) plays a fundamental role in maintaining protein homeostasis, being involved in protein degradation, among other cellular functions. Through a cascade of enzymatic reactions, proteins are ubiquitinated, tagged, and translocated to the proteasome to be degraded. Within the ubiquitin system, we can find three main groups of enzymes: E1 (ubiquitin-activating enzymes), E2 (ubiquitin-conjugating enzymes), and E3 (ubiquitin-protein ligases). Only the ubiquitinated proteins with specific chain linkages (such as K48) will be degraded by the UPS. In this review, we describe the relevance of this system in NMDs, summarizing the UPS proteins that have been involved in pathological conditions and neuromuscular disorders, such as Spinal Muscular Atrophy (SMA), Charcot-Marie-Tooth disease (CMT), or Duchenne Muscular Dystrophy (DMD), among others. A better knowledge of the processes involved in the maintenance of proteostasis may pave the way for future progress in neuromuscular disorder studies and treatments.
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8
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Chen A, Bai L, Zhong K, Shu X, Wang A, Xiao Y, Zhang K, Shen C. APC2
CDH1
negatively regulates agrin signaling by promoting the ubiquitination and proteolytic degradation of DOK7. FASEB J 2020; 34:12009-12023. [PMID: 32687671 DOI: 10.1096/fj.202000485r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 01/28/2023]
Affiliation(s)
- Aizhong Chen
- The First Affiliated Hospital Institute of Translational Medicine School of Medicine Zhejiang University Zhejiang China
| | - Lei Bai
- The First Affiliated Hospital Institute of Translational Medicine School of Medicine Zhejiang University Zhejiang China
| | - Keke Zhong
- The First Affiliated Hospital Institute of Translational Medicine School of Medicine Zhejiang University Zhejiang China
| | - Xiaoqiu Shu
- The First Affiliated Hospital Institute of Translational Medicine School of Medicine Zhejiang University Zhejiang China
| | - Ailian Wang
- The First Affiliated Hospital Institute of Translational Medicine School of Medicine Zhejiang University Zhejiang China
| | - Yatao Xiao
- The First Affiliated Hospital Institute of Translational Medicine School of Medicine Zhejiang University Zhejiang China
| | - Kejing Zhang
- The First Affiliated Hospital Institute of Translational Medicine School of Medicine Zhejiang University Zhejiang China
| | - Chengyong Shen
- The First Affiliated Hospital Institute of Translational Medicine School of Medicine Zhejiang University Zhejiang China
- Department of Neurobiology Key Laboratory of Medical Neurobiology of Zhejiang Province School of Medicine Zhejiang University Zhejiang China
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9
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Limanaqi F, Busceti CL, Biagioni F, Cantini F, Lenzi P, Fornai F. Cell-Clearing Systems Bridging Repeat Expansion Proteotoxicity and Neuromuscular Junction Alterations in ALS and SBMA. Int J Mol Sci 2020; 21:ijms21114021. [PMID: 32512809 PMCID: PMC7312203 DOI: 10.3390/ijms21114021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/29/2020] [Accepted: 06/03/2020] [Indexed: 12/12/2022] Open
Abstract
The coordinated activities of autophagy and the ubiquitin proteasome system (UPS) are key to preventing the aggregation and toxicity of misfold-prone proteins which manifest in a number of neurodegenerative disorders. These include proteins which are encoded by genes containing nucleotide repeat expansions. In the present review we focus on the overlapping role of autophagy and the UPS in repeat expansion proteotoxicity associated with chromosome 9 open reading frame 72 (C9ORF72) and androgen receptor (AR) genes, which are implicated in two motor neuron disorders, amyotrophic lateral sclerosis (ALS) and spinal-bulbar muscular atrophy (SBMA), respectively. At baseline, both C9ORF72 and AR regulate autophagy, while their aberrantly-expanded isoforms may lead to a failure in both autophagy and the UPS, further promoting protein aggregation and toxicity within motor neurons and skeletal muscles. Besides proteotoxicity, autophagy and UPS alterations are also implicated in neuromuscular junction (NMJ) alterations, which occur early in both ALS and SBMA. In fact, autophagy and the UPS intermingle with endocytic/secretory pathways to regulate axonal homeostasis and neurotransmission by interacting with key proteins which operate at the NMJ, such as agrin, acetylcholine receptors (AChRs), and adrenergic beta2 receptors (B2-ARs). Thus, alterations of autophagy and the UPS configure as a common hallmark in both ALS and SBMA disease progression. The findings here discussed may contribute to disclosing overlapping molecular mechanisms which are associated with a failure in cell-clearing systems in ALS and SBMA.
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Affiliation(s)
- Fiona Limanaqi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy; (F.L.); (F.C.); (P.L.)
| | | | - Francesca Biagioni
- I.R.C.C.S. Neuromed, Via Atinense, 18, 86077 Pozzilli, Italy; (C.L.B.); (F.B.)
| | - Federica Cantini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy; (F.L.); (F.C.); (P.L.)
| | - Paola Lenzi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy; (F.L.); (F.C.); (P.L.)
| | - Francesco Fornai
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy; (F.L.); (F.C.); (P.L.)
- I.R.C.C.S. Neuromed, Via Atinense, 18, 86077 Pozzilli, Italy; (C.L.B.); (F.B.)
- Correspondence:
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10
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Rudell JC, Borges LS, Yarov-Yarovoy V, Ferns M. The MX-Helix of Muscle nAChR Subunits Regulates Receptor Assembly and Surface Trafficking. Front Mol Neurosci 2020; 13:48. [PMID: 32265653 PMCID: PMC7105636 DOI: 10.3389/fnmol.2020.00048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 03/06/2020] [Indexed: 12/22/2022] Open
Abstract
Nicotinic acetylcholine receptors (AChRs) are pentameric channels that mediate fast transmission at the neuromuscular junction (NMJ) and defects in receptor expression underlie neuromuscular disorders such as myasthenia gravis and congenital myasthenic syndrome (CMS). Nicotinic receptor expression at the NMJ is tightly regulated and we previously identified novel Golgi-retention signals in the β and δ subunit cytoplasmic loops that regulate trafficking of the receptor to the cell surface. Here, we show that the Golgi retention motifs are localized in the MX-helix, a juxta-membrane alpha-helix present in the proximal cytoplasmic loop of receptor subunits, which was defined in recent crystal structures of cys-loop receptor family members. First, mutational analysis of CD4-MX-helix chimeric proteins showed that the Golgi retention signal was dependent on both the amphipathic nature of the MX-helix and on specific lysine residues (βK353 and δK351). Moreover, retention was associated with ubiquitination of the lysines, and βK353R and δK351R mutations reduced ubiquitination and increased surface expression of CD4-β and δ MX-helix chimeric proteins. Second, mutation of these lysines in intact β and δ subunits perturbed Golgi-based glycosylation and surface trafficking of the AChR. Notably, combined βK353R and δK351R mutations increased the amount of surface AChR with immature forms of glycosylation, consistent with decreased Golgi retention and processing. Third, we found that previously identified CMS mutations in the ε subunit MX-helix decreased receptor assembly and surface levels, as did an analogous mutation introduced into the β subunit MX-helix. Together, these findings indicate that the subunit MX-helix contributes to receptor assembly and is required for normal expression of the AChR and function of the NMJ. In addition, specific determinants in the β and δ subunit MX-helix contribute to quality control of AChR expression by intracellular retention and ubiquitination of unassembled subunits, and by facilitating the appropriate glycosylation of assembled surface AChR.
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Affiliation(s)
- Jolene Chang Rudell
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Lucia Soares Borges
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Michael Ferns
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States.,Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA, United States
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11
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Kanduc D. The comparative biochemistry of viruses and humans: an evolutionary path towards autoimmunity. Biol Chem 2019; 400:629-638. [PMID: 30504522 DOI: 10.1515/hsz-2018-0271] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 11/07/2018] [Indexed: 11/15/2022]
Abstract
Analyses of the peptide sharing between five common human viruses (Borna disease virus, influenza A virus, measles virus, mumps virus and rubella virus) and the human proteome highlight a massive viral vs. human peptide overlap that is mathematically unexpected. Evolutionarily, the data underscore a strict relationship between viruses and the origin of eukaryotic cells. Indeed, according to the viral eukaryogenesis hypothesis and in light of the endosymbiotic theory, the first eukaryotic cell (our lineage) originated as a consortium consisting of an archaeal ancestor of the eukaryotic cytoplasm, a bacterial ancestor of the mitochondria and a viral ancestor of the nucleus. From a pathologic point of view, the peptide sequence similarity between viruses and humans may provide a molecular platform for autoimmune crossreactions during immune responses following viral infections/immunizations.
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Affiliation(s)
- Darja Kanduc
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona 4, I-70124 Bari, Italy
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12
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Christensen NR, Čalyševa J, Fernandes EFA, Lüchow S, Clemmensen LS, Haugaard‐Kedström LM, Strømgaard K. PDZ Domains as Drug Targets. ADVANCED THERAPEUTICS 2019; 2:1800143. [PMID: 32313833 PMCID: PMC7161847 DOI: 10.1002/adtp.201800143] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/25/2019] [Indexed: 12/14/2022]
Abstract
Protein-protein interactions within protein networks shape the human interactome, which often is promoted by specialized protein interaction modules, such as the postsynaptic density-95 (PSD-95), discs-large, zona occludens 1 (ZO-1) (PDZ) domains. PDZ domains play a role in several cellular functions, from cell-cell communication and polarization, to regulation of protein transport and protein metabolism. PDZ domain proteins are also crucial in the formation and stability of protein complexes, establishing an important bridge between extracellular stimuli detected by transmembrane receptors and intracellular responses. PDZ domains have been suggested as promising drug targets in several diseases, ranging from neurological and oncological disorders to viral infections. In this review, the authors describe structural and genetic aspects of PDZ-containing proteins and discuss the current status of the development of small-molecule and peptide modulators of PDZ domains. An overview of potential new therapeutic interventions in PDZ-mediated protein networks is also provided.
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Affiliation(s)
- Nikolaj R. Christensen
- Center for BiopharmaceuticalsDepartment of Drug Design and PharmacologyUniversity of CopenhagenUniversitetsparken 22100CopenhagenDenmark
| | - Jelena Čalyševa
- European Molecular Biology Laboratory (EMBL)Structural and Computational Biology UnitMeyerhofstraße 169117HeidelbergGermany
- EMBL International PhD ProgrammeFaculty of BiosciencesEMBL–Heidelberg UniversityGermany
| | - Eduardo F. A. Fernandes
- Center for BiopharmaceuticalsDepartment of Drug Design and PharmacologyUniversity of CopenhagenUniversitetsparken 22100CopenhagenDenmark
| | - Susanne Lüchow
- Department of Chemistry – BMCUppsala UniversityBox 576SE75123UppsalaSweden
| | - Louise S. Clemmensen
- Center for BiopharmaceuticalsDepartment of Drug Design and PharmacologyUniversity of CopenhagenUniversitetsparken 22100CopenhagenDenmark
| | - Linda M. Haugaard‐Kedström
- Center for BiopharmaceuticalsDepartment of Drug Design and PharmacologyUniversity of CopenhagenUniversitetsparken 22100CopenhagenDenmark
| | - Kristian Strømgaard
- Center for BiopharmaceuticalsDepartment of Drug Design and PharmacologyUniversity of CopenhagenUniversitetsparken 22100CopenhagenDenmark
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13
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Otsuka Y, Furihata T, Nakagawa K, Ohno Y, Reien Y, Ouchi M, Wakashin H, Tsuruoka S, Anzai N. Sodium-coupled monocarboxylate transporter 1 interacts with the RING finger- and PDZ domain-containing protein PDZRN3. J Physiol Sci 2019; 69:635-642. [PMID: 31098988 PMCID: PMC10717332 DOI: 10.1007/s12576-019-00681-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 04/27/2019] [Indexed: 10/26/2022]
Abstract
Sodium-coupled monocarboxylate transporter SMCT1 (SLC5A8) mediates monocarboxylate transport in the proximal tubule of the kidney. We have identified PDZK1 and PDZ domain-containing RING finger 3 (PDZRN3) as potent binding partners of SMCT1, which has a PDZ motif (Thr-Arg-Leu), by yeast two-hybrid screening and revealed that PDZK1 enhances the transport activity of SMCT1. In this study, we aimed to characterize the interaction between SMCT1 and PDZRN3 as well as to examine how PDZRN3 regulates SMCT1 function. An interaction between SMCT1 and PDZRN3 through the PDZ motif was observed in a co-immunoprecipitation assay and yeast two-hybrid assay. A transport assay showed that PDZRN3 abolished the enhancing effect of PDZK1 on nicotinate uptake via SMCT1. Our results suggest that SMCT1 interacts with PDZRN3 and that PDZRN3 may regulate SMCT1 function by interfering with the interaction between SMCT1 and PDZK1.
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Affiliation(s)
- Yusuke Otsuka
- Department of Pharmacology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan
- Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Tochigi, Japan
- Department of Nephrology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Tomomi Furihata
- Department of Pharmacology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan
| | - Kiyoshi Nakagawa
- Department of Pharmacology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan
| | - Yuta Ohno
- Department of Pharmacology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan
- Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Yoshie Reien
- Department of Pharmacology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan
| | - Motoshi Ouchi
- Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Hidefumi Wakashin
- Department of Pharmacology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan
| | - Shuichi Tsuruoka
- Department of Nephrology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Naohiko Anzai
- Department of Pharmacology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan.
- Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Tochigi, Japan.
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14
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Honda T, Inui M. PDZRN3 regulates differentiation of myoblasts into myotubes through transcriptional and posttranslational control of Id2. J Cell Physiol 2018; 234:2963-2972. [PMID: 30066954 DOI: 10.1002/jcp.27113] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/02/2018] [Indexed: 01/05/2023]
Abstract
PDZRN3 (also known as LNX3) is a member of the PDZ domain-containing RING finger protein family. We previously showed that PDZRN3 is essential for differentiation of myoblasts into myotubes and that depletion of PDZRN3 inhibits such differentiation downstream of the upregulation of myogenin, a basic helix-loop-helix (bHLH) transcription factor required for completion of the differentiation process. However, the mechanism by which PDZRN3 controls this process has remained unclear. Myogenin is rendered active during the late stage of myogenic differentiation by the downregulation of Id2, a negative regulator of bHLH transcription factors. We now show that depletion of PDZRN3 inhibits the differentiation of C2C12 cells by inducing the upregulation of Id2 and thereby delaying its downregulation. Knockdown of Id2 by RNA interference restores the differentiation of PDZRN3-depleted cells. Luciferase reporter assays revealed that a putative binding site for STAT5b in the Id2 gene promoter is required for the upregulation of Id2 expression by PDZRN3 depletion. In addition, the amount of phosphorylated Id2 was reduced and that of the nonphosphorylated protein concomitantly increased in PDZRN3-depleted cells, with the inhibitory effect of Id2 on bHLH transcription factors having previously been shown to be attenuated by phosphorylation of Id2 catalyzed by the complex of Cdk2 with cyclin A2 or E1. Indeed, the expression of cyclin A2, but not that of cyclin E1, was reduced in PDZRN3-depleted cells. Our results thus indicate that PDZRN3 plays a key role in the differentiation of myoblasts into myotubes by regulating Id2 at both transcriptional and posttranslational levels.
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Affiliation(s)
- Takeshi Honda
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Makoto Inui
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
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15
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Critchley WR, Pellet-Many C, Ringham-Terry B, Harrison MA, Zachary IC, Ponnambalam S. Receptor Tyrosine Kinase Ubiquitination and De-Ubiquitination in Signal Transduction and Receptor Trafficking. Cells 2018; 7:E22. [PMID: 29543760 PMCID: PMC5870354 DOI: 10.3390/cells7030022] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 03/09/2018] [Accepted: 03/13/2018] [Indexed: 12/13/2022] Open
Abstract
Receptor tyrosine kinases (RTKs) are membrane-based sensors that enable rapid communication between cells and their environment. Evidence is now emerging that interdependent regulatory mechanisms, such as membrane trafficking, ubiquitination, proteolysis and gene expression, have substantial effects on RTK signal transduction and cellular responses. Different RTKs exhibit both basal and ligand-stimulated ubiquitination, linked to trafficking through different intracellular compartments including the secretory pathway, plasma membrane, endosomes and lysosomes. The ubiquitin ligase superfamily comprising the E1, E2 and E3 enzymes are increasingly implicated in this post-translational modification by adding mono- and polyubiquitin tags to RTKs. Conversely, removal of these ubiquitin tags by proteases called de-ubiquitinases (DUBs) enables RTK recycling for another round of ligand sensing and signal transduction. The endocytosis of basal and activated RTKs from the plasma membrane is closely linked to controlled proteolysis after trafficking and delivery to late endosomes and lysosomes. Proteolytic RTK fragments can also have the capacity to move to compartments such as the nucleus and regulate gene expression. Such mechanistic diversity now provides new opportunities for modulating RTK-regulated cellular responses in health and disease states.
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Affiliation(s)
- William R Critchley
- Endothelial Cell Biology Unit, School of Molecular & Cellular Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Caroline Pellet-Many
- Centre for Cardiovascular Biology & Medicine, Rayne Building, University College London, London WC1E 6PT, UK.
| | - Benjamin Ringham-Terry
- Centre for Cardiovascular Biology & Medicine, Rayne Building, University College London, London WC1E 6PT, UK.
| | | | - Ian C Zachary
- Centre for Cardiovascular Biology & Medicine, Rayne Building, University College London, London WC1E 6PT, UK.
| | - Sreenivasan Ponnambalam
- Endothelial Cell Biology Unit, School of Molecular & Cellular Biology, University of Leeds, Leeds LS2 9JT, UK.
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16
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Fundamental Molecules and Mechanisms for Forming and Maintaining Neuromuscular Synapses. Int J Mol Sci 2018; 19:ijms19020490. [PMID: 29415504 PMCID: PMC5855712 DOI: 10.3390/ijms19020490] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 01/24/2018] [Accepted: 01/29/2018] [Indexed: 02/08/2023] Open
Abstract
The neuromuscular synapse is a relatively large synapse with hundreds of active zones in presynaptic motor nerve terminals and more than ten million acetylcholine receptors (AChRs) in the postsynaptic membrane. The enrichment of proteins in presynaptic and postsynaptic membranes ensures a rapid, robust, and reliable synaptic transmission. Over fifty years ago, classic studies of the neuromuscular synapse led to a comprehensive understanding of how a synapse looks and works, but these landmark studies did not reveal the molecular mechanisms responsible for building and maintaining a synapse. During the past two-dozen years, the critical molecular players, responsible for assembling the specialized postsynaptic membrane and regulating nerve terminal differentiation, have begun to be identified and their mechanism of action better understood. Here, we describe and discuss five of these key molecular players, paying heed to their discovery as well as describing their currently understood mechanisms of action. In addition, we discuss the important gaps that remain to better understand how these proteins act to control synaptic differentiation and maintenance.
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17
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Ghazanfari N, Trajanovska S, Morsch M, Liang SX, Reddel SW, Phillips WD. The mouse passive-transfer model of MuSK myasthenia gravis: disrupted MuSK signaling causes synapse failure. Ann N Y Acad Sci 2017; 1412:54-61. [DOI: 10.1111/nyas.13513] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/05/2017] [Accepted: 09/09/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Nazanin Ghazanfari
- Physiology and Bosch Institute; University of Sydney; Sydney New South Wales Australia
| | - Sofie Trajanovska
- Physiology and Bosch Institute; University of Sydney; Sydney New South Wales Australia
| | - Marco Morsch
- Physiology and Bosch Institute; University of Sydney; Sydney New South Wales Australia
- Department of Biomedical Sciences; Macquarie University; Sydney New South Wales Australia
| | - Simon X. Liang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences; Liaoning Medical University; Jinzhou China
| | - Stephen W. Reddel
- Department of Molecular Medicine; Concord Hospital; Sydney New South Wales Australia
| | - William D. Phillips
- Physiology and Bosch Institute; University of Sydney; Sydney New South Wales Australia
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18
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Modulation of hippocampal synapse maturation by activity-regulated E3 ligase via non-canonical pathway. Neuroscience 2017; 364:226-241. [DOI: 10.1016/j.neuroscience.2017.08.057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 08/14/2017] [Accepted: 08/30/2017] [Indexed: 12/25/2022]
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19
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Vriend J, Liu W, Reiter RJ. The pineal gland: A model for adrenergic modulation of ubiquitin ligases. PLoS One 2017; 12:e0172441. [PMID: 28212404 PMCID: PMC5315301 DOI: 10.1371/journal.pone.0172441] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/04/2017] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION A recent study of the pineal gland of the rat found that the expression of more than 3000 genes showed significant day/night variations (The Hartley dataset). The investigators of this report made available a supplemental table in which they tabulated the expression of many genes that they did not discuss, including those coding for components of the ubiquitin proteasome system. Herein we identify the genes of the ubiquitin proteasome system whose expression were significantly influenced by environmental lighting in the Hartley dataset, those that were stimulated by DBcAMP in pineal glands in culture, and those that were stimulated by norepinephrine. PURPOSE Using the Ubiquitin and Ubiquitin-like Conjugation Database (UUCA) we identified ubiquitin ligases and conjugases, and deubiquitinases in the Hartley dataset for the purpose of determining whether expression of genes of the ubiquitin proteasome pathway were significantly influenced by day/night variations and if these variations were regulated by autonomic innervation of the pineal gland from the superior cervical ganglia. METHODS In the Hartley experiments pineal glands groups of rats sacrificed during the day and groups sacrificed during the night were examined for gene expression. Additional groups of rats had their superior cervical ganglia removed surgically or surgically decentralized and the pineal glands likewise examined for gene expression. RESULTS The genes with at least a 2-fold day/night significant difference in expression included genes for 5 ubiquitin conjugating enzymes, genes for 58 ubiquitin E3 ligases and genes for 6 deubiquitinases. A 35-fold day/night difference was noted in the expression of the gene Sik1, which codes for a protein containing both an ubiquitin binding domain (UBD) and an ubiquitin-associated (UBA) domain. Most of the significant differences in these genes were prevented by surgical removal, or disconnection, of the superior cervical ganglia, and most were responsive, in vitro, to treatment with a cyclic AMP analog, and norepinephrine. All previously described 24-hour rhythms in the pineal require an intact sympathetic input from the superior cervical ganglia. CONCLUSIONS The Hartley dataset thus provides evidence that the pineal gland is a highly useful model for studying adrenergically dependent mechanisms regulating variations in ubiquitin ligases, ubiquitin conjugases, and deubiquitinases, mechanisms that may be physiologically relevant not only in the pineal gland, but in all adrenergically innervated tissue.
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Affiliation(s)
- Jerry Vriend
- Department of Human Anatomy and Cell Science, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Wenjun Liu
- Department of Pathology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, Texas, United States of America
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20
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Ben-Avraham D, Karasik D, Verghese J, Lunetta KL, Smith JA, Eicher JD, Vered R, Deelen J, Arnold AM, Buchman AS, Tanaka T, Faul JD, Nethander M, Fornage M, Adams HH, Matteini AM, Callisaya ML, Smith AV, Yu L, De Jager PL, Evans DA, Gudnason V, Hofman A, Pattie A, Corley J, Launer LJ, Knopman DS, Parimi N, Turner ST, Bandinelli S, Beekman M, Gutman D, Sharvit L, Mooijaart SP, Liewald DC, Houwing-Duistermaat JJ, Ohlsson C, Moed M, Verlinden VJ, Mellström D, van der Geest JN, Karlsson M, Hernandez D, McWhirter R, Liu Y, Thomson R, Tranah GJ, Uitterlinden AG, Weir DR, Zhao W, Starr JM, Johnson AD, Ikram MA, Bennett DA, Cummings SR, Deary IJ, Harris TB, Kardia SLR, Mosley TH, Srikanth VK, Windham BG, Newman AB, Walston JD, Davies G, Evans DS, Slagboom EP, Ferrucci L, Kiel DP, Murabito JM, Atzmon G. The complex genetics of gait speed: genome-wide meta-analysis approach. Aging (Albany NY) 2017; 9:209-246. [PMID: 28077804 PMCID: PMC5310665 DOI: 10.18632/aging.101151] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 12/26/2016] [Indexed: 01/08/2023]
Abstract
Emerging evidence suggests that the basis for variation in late-life mobility is attributable, in part, to genetic factors, which may become increasingly important with age. Our objective was to systematically assess the contribution of genetic variation to gait speed in older individuals. We conducted a meta-analysis of gait speed GWASs in 31,478 older adults from 17 cohorts of the CHARGE consortium, and validated our results in 2,588 older adults from 4 independent studies. We followed our initial discoveries with network and eQTL analysis of candidate signals in tissues. The meta-analysis resulted in a list of 536 suggestive genome wide significant SNPs in or near 69 genes. Further interrogation with Pathway Analysis placed gait speed as a polygenic complex trait in five major networks. Subsequent eQTL analysis revealed several SNPs significantly associated with the expression of PRSS16, WDSUB1 and PTPRT, which in addition to the meta-analysis and pathway suggested that genetic effects on gait speed may occur through synaptic function and neuronal development pathways. No genome-wide significant signals for gait speed were identified from this moderately large sample of older adults, suggesting that more refined physical function phenotypes will be needed to identify the genetic basis of gait speed in aging.
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Affiliation(s)
- Dan Ben-Avraham
- Department of Medicine and Genetics Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - David Karasik
- Institute for Aging Research, Hebrew SeniorLife, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02131, USA
- Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel
| | - Joe Verghese
- Integrated Divisions of Cognitive & Motor Aging (Neurology) and Geriatrics (Medicine), Montefiore-Einstein Center for the Aging Brain, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kathryn L. Lunetta
- The National Heart Lung and Blood Institute's Framingham Heart Study, Framingham, MA 01702, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, MA 02118, USA
| | - Jennifer A. Smith
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| | - John D. Eicher
- The National Heart Lung and Blood Institute's Framingham Heart Study, Framingham, MA 01702, USA
- Population Sciences Branch, National Heart Lung and Blood Institute, Framingham, MA 01702, USA
| | - Rotem Vered
- Psychology Department, University of Haifa, Haifa, Israel
| | - Joris Deelen
- Molecular Epidemiology, Leiden University Medical Center, Leiden, Netherlands
- Max Planck Institute for Biology of Ageing, Köln, Germany
| | - Alice M. Arnold
- Department of Biostatistics, University of Washington, Seattle, WA 98115, USA
| | - Aron S. Buchman
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60614, USA
| | - Toshiko Tanaka
- Translational Gerontology Branch, National Institute on Aging, Baltimore MD 21224, USA
| | - Jessica D. Faul
- Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI 48104, USA
| | - Maria Nethander
- Bioinformatics Core Facility, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Myriam Fornage
- The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Hieab H. Adams
- Department of Epidemiology, Erasmus MC, Rotterdam, Netherlands
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, Netherlands
| | - Amy M. Matteini
- Division of Geriatric Medicine, Johns Hopkins Medical Institutes, Baltimore, MD 21224, USA
| | - Michele L. Callisaya
- Medicine, Peninsula Health, Peninsula Clinical School, Central Clinical School, Frankston, Melbourne, Victoria, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Albert V. Smith
- Icelandic Heart Association, Faculty of Medicine, University of Iceland, 101 Reykjavik, Iceland
| | - Lei Yu
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60614, USA
| | - Philip L. De Jager
- Broad Institute of Harvard and MIT, Cambridge, Harvard Medical School, Department of Neurology, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Denis A. Evans
- Rush Institute for Healthy Aging and Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA
| | - Vilmundur Gudnason
- Icelandic Heart Association, Faculty of Medicine, University of Iceland, 101 Reykjavik, Iceland
| | - Albert Hofman
- Department of Epidemiology, Erasmus MC, Rotterdam, Netherlands
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Alison Pattie
- Department of Psychology, University of Edinburgh, Edinburgh, UK
| | - Janie Corley
- Department of Psychology, University of Edinburgh, Edinburgh, UK
| | - Lenore J. Launer
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Neeta Parimi
- California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA
| | - Stephen T. Turner
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Marian Beekman
- Molecular Epidemiology, Leiden University Medical Center, Leiden, Netherlands
| | - Danielle Gutman
- Department of Human Biology, Faculty of Natural Science, University of Haifa, Haifa, Israel
| | - Lital Sharvit
- Department of Human Biology, Faculty of Natural Science, University of Haifa, Haifa, Israel
| | - Simon P. Mooijaart
- Gerontology and Geriatrics, Leiden University Medical Center, Leiden, Netherland
| | - David C. Liewald
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Jeanine J. Houwing-Duistermaat
- Genetical Statistics, Leiden University Medical Center, Leiden, Netherland. Department of Statistics, University of Leeds, Leeds, UK
| | - Claes Ohlsson
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska, Academy, University of Gothenburg, Gothenburg, Sweden
| | - Matthijs Moed
- Molecular Epidemiology, Leiden University Medical Center, Leiden, Netherlands
| | | | - Dan Mellström
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska, Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Magnus Karlsson
- Clinical and Molecular Osteoporosis Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Dena Hernandez
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892, USA
| | - Rebekah McWhirter
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Yongmei Liu
- Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Russell Thomson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
- School of Computing, Engineering and Mathematics, University of Western Sydney, Sydney, Australia
| | - Gregory J. Tranah
- California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA
| | - Andre G. Uitterlinden
- Department of Internal Medicine, Erasmus MC, and Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam, The Netherlands
| | - David R. Weir
- Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI 48104, USA
| | - Wei Zhao
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| | - John M. Starr
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
- Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, UK
| | - Andrew D. Johnson
- The National Heart Lung and Blood Institute's Framingham Heart Study, Framingham, MA 01702, USA
- Population Sciences Branch, National Heart Lung and Blood Institute, Framingham, MA 01702, USA
| | - M. Arfan Ikram
- Department of Epidemiology, Erasmus MC, Rotterdam, Netherlands
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, Netherlands
| | - David A. Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60614, USA
| | - Steven R. Cummings
- California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA
| | - Ian J. Deary
- Department of Psychology, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Tamara B. Harris
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sharon L. R. Kardia
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| | - Thomas H. Mosley
- University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Velandai K. Srikanth
- Medicine, Peninsula Health, Peninsula Clinical School, Central Clinical School, Frankston, Melbourne, Victoria, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | | | - Ann B. Newman
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Jeremy D. Walston
- Division of Geriatric Medicine, Johns Hopkins Medical Institutes, Baltimore, MD 21224, USA
| | - Gail Davies
- Department of Psychology, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Daniel S. Evans
- California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA
| | - Eline P. Slagboom
- Molecular Epidemiology, Leiden University Medical Center, Leiden, Netherlands
| | - Luigi Ferrucci
- Translational Gerontology Branch, National Institute on Aging, Baltimore MD 21224, USA
| | - Douglas P. Kiel
- Institute for Aging Research, Hebrew SeniorLife, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02131, USA
- Broad Institute of Harvard and MIT, Boston, MA 02131, USA
| | - Joanne M. Murabito
- The National Heart Lung and Blood Institute's Framingham Heart Study, Framingham, MA 01702, USA
- Section of General Internal Medicine, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Gil Atzmon
- Department of Medicine and Genetics Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Human Biology, Faculty of Natural Science, University of Haifa, Haifa, Israel
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Hu T, Yang H, Han ZG. PDZRN4 acts as a suppressor of cell proliferation in human liver cancer cell lines. Cell Biochem Funct 2015; 33:443-9. [PMID: 26486104 DOI: 10.1002/cbf.3130] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/12/2015] [Accepted: 08/03/2015] [Indexed: 11/11/2022]
Abstract
Recently, some reports show that Ligand of Numb Protein-X 1 (LNX1) could be a suppressor gene in gliomas, while our current research has firstly shown that PDZ domain containing ring finger 4 (PDZRN4), another member of LNX family, could also be a potential suppressor in hepatocellular carcinoma (HCC). PDZRN4, also named LNX4 (Ligand of Numb Protein-X 4), is a member of the LNX family. We recently found that PDZRN4, but not LNX1, was down-regulated in HCC samples, and the role of PDZRN4 in the progression of HCC had not been studied before. To address this question, firstly, we evaluated the expression of PDZRN4 in HCC samples and adjacent non-cancerous tissues. Semi-quantitative polymerase chain reaction showed that PDZRN4 was down-regulated in 24/36 (66.7%) HCC samples separately. In addition, our research shows that PDZRN4 is silenced in all of the 12 HCC cell lines tested. Subsequently, cell-based functional assay exhibited that ectopic expression of PDZRN4 inhibits the proliferation, plate colony formation and anchorage-independent colony formation of HCC cells. Collectively, our results showed that PDZRN4 might be a potential tumour suppressor gene and had anti-proliferative effect on HCC cell proliferation, which would be of great significance to the researches on HCC.
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Affiliation(s)
- Taotao Hu
- Key Laboratory of Systems Biomedicine (Ministry of Education) of Rui-Jin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Shanghai-MOST Key Laboratory for Disease and Health Genomics, Chinese National Human Genome Center, Shanghai, Shanghai, China
| | - Hong Yang
- Key Laboratory of Systems Biomedicine (Ministry of Education) of Rui-Jin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Ze-Guang Han
- Key Laboratory of Systems Biomedicine (Ministry of Education) of Rui-Jin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Shanghai Center for Systems Biomedicine, Shanghai Jiaotong University, Shanghai, China.,Shanghai-MOST Key Laboratory for Disease and Health Genomics, Chinese National Human Genome Center, Shanghai, Shanghai, China
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22
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Bachiller S, Rybkina T, Porras-García E, Pérez-Villegas E, Tabares L, Armengol JA, Carrión AM, Ruiz R. The HERC1 E3 Ubiquitin Ligase is essential for normal development and for neurotransmission at the mouse neuromuscular junction. Cell Mol Life Sci 2015; 72:2961-71. [PMID: 25746226 PMCID: PMC11113414 DOI: 10.1007/s00018-015-1878-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 02/15/2015] [Accepted: 02/27/2015] [Indexed: 12/14/2022]
Abstract
The ubiquitin-proteasome system (UPS) plays a fundamental role in protein degradation in neurons, and there is strong evidence that it fulfills a key role in synaptic transmission. The aim of the present work was to study the implication of one component of the UPS, the HERC1 E3 Ubiquitin Ligase, in motor function and neuromuscular transmission. The tambaleante (tbl) mutant mouse carries a spontaneous mutation in HERC1 E3 Ubiquitin Ligase, provoking an ataxic phenotype that develops in the second month of life. Our results show that motor performance in mutant mice is altered at postnatal day 30, before the cerebellar neurodegeneration takes place. This defect is associated with by: (a) a reduction of the motor end-plate area, (b) less efficient neuromuscular activity in vivo, and (c) an impaired evoked neurotransmitter release. Together, these data suggest that the HERC1 E3 Ubiquitin Ligase is fundamental for normal muscle function and that it is essential for neurotransmitter release at the mouse neuromuscular junction.
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Affiliation(s)
- S. Bachiller
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Carretera de Utrera Km 1, 41013 Seville, Spain
| | - T. Rybkina
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Carretera de Utrera Km 1, 41013 Seville, Spain
| | - E. Porras-García
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Carretera de Utrera Km 1, 41013 Seville, Spain
| | - E. Pérez-Villegas
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Carretera de Utrera Km 1, 41013 Seville, Spain
| | - L. Tabares
- Department of Medical Physiology and Biophysics, University of Seville, Seville, Spain
| | - J. A. Armengol
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Carretera de Utrera Km 1, 41013 Seville, Spain
- School of Medicine, University of Cartagena de Indias, Cartagena, Colombia
| | - A. M. Carrión
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Carretera de Utrera Km 1, 41013 Seville, Spain
| | - R. Ruiz
- Department of Physiology, Anatomy and Cellular Biology, University of Pablo de Olavide, Carretera de Utrera Km 1, 41013 Seville, Spain
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PDZRN3/LNX3 is a novel target of human papillomavirus type 16 (HPV-16) and HPV-18 E6. J Virol 2014; 89:1439-44. [PMID: 25355882 DOI: 10.1128/jvi.01743-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
High-risk human papillomavirus (HPV) E6 proteins have a C-terminal PDZ binding motif through which they bind, and target for proteasome-mediated degradation, a number of PDZ-containing cellular targets. Recent studies have suggested that the RING-containing ubiquitin-protein ligase PDZRN3 might also be an HPV E6 target. In this analysis, we show that HPV-16 and HPV-18 E6 can target PDZRN3 in a PDZ- and proteasome-dependent manner and provide a connection between the HPV life cycle and differentiation-related STAT signaling.
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24
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Dürnberger G, Camurdanoglu BZ, Tomschik M, Schutzbier M, Roitinger E, Hudecz O, Mechtler K, Herbst R. Global analysis of muscle-specific kinase signaling by quantitative phosphoproteomics. Mol Cell Proteomics 2014; 13:1993-2003. [PMID: 24899341 DOI: 10.1074/mcp.m113.036087] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The development of the neuromuscular synapse depends on signaling processes that involve protein phosphorylation as a crucial regulatory event. Muscle-specific kinase (MuSK) is the key signaling molecule at the neuromuscular synapse whose activity is required for the formation of a mature and functional synapse. However, the signaling cascade downstream of MuSK and the regulation of the different components are still poorly understood. In this study we used a quantitative phosphoproteomics approach to study the phosphorylation events and their temporal regulation downstream of MuSK. We identified a total of 10,183 phosphopeptides, of which 203 were significantly up- or down-regulated. Regulated phosphopeptides were classified into four different clusters according to their temporal profiles. Within these clusters we found an overrepresentation of specific protein classes associated with different cellular functions. In particular, we found an enrichment of regulated phosphoproteins involved in posttranscriptional mechanisms and in cytoskeletal organization. These findings provide novel insights into the complex signaling network downstream of MuSK and form the basis for future mechanistic studies.
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Affiliation(s)
- Gerhard Dürnberger
- From the ‡Gregor Mendel Institute of Molecular Plant Biology, Dr. Bohr-Gasse 3, 1030 Vienna, Austria; §Institute for Molecular Pathology (IMP), Dr. Bohr-Gasse 7, 1030 Vienna, Austria; ¶Institute of Molecular Biotechnology (IMBA), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Bahar Z Camurdanoglu
- ‖Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Matthias Tomschik
- ‖Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Michael Schutzbier
- From the ‡Gregor Mendel Institute of Molecular Plant Biology, Dr. Bohr-Gasse 3, 1030 Vienna, Austria; §Institute for Molecular Pathology (IMP), Dr. Bohr-Gasse 7, 1030 Vienna, Austria
| | - Elisabeth Roitinger
- §Institute for Molecular Pathology (IMP), Dr. Bohr-Gasse 7, 1030 Vienna, Austria; ¶Institute of Molecular Biotechnology (IMBA), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Otto Hudecz
- §Institute for Molecular Pathology (IMP), Dr. Bohr-Gasse 7, 1030 Vienna, Austria; ¶Institute of Molecular Biotechnology (IMBA), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Karl Mechtler
- §Institute for Molecular Pathology (IMP), Dr. Bohr-Gasse 7, 1030 Vienna, Austria; ¶Institute of Molecular Biotechnology (IMBA), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Ruth Herbst
- ‖Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria; ‡‡Institute of Immunology, Medical University of Vienna, Lazarettgasse 19, 1090 Vienna, Austria
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25
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Ghazanfari N, Morsch M, Reddel SW, Liang SX, Phillips WD. Muscle-specific kinase (MuSK) autoantibodies suppress the MuSK pathway and ACh receptor retention at the mouse neuromuscular junction. J Physiol 2014; 592:2881-97. [PMID: 24860174 DOI: 10.1113/jphysiol.2013.270207] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Muscle-specific kinase (MuSK) autoantibodies from myasthenia gravis patients can block the activation of MuSK in vitro and/or reduce the postsynaptic localization of MuSK. Here we use a mouse model to examine the effects of MuSK autoantibodies upon some key components of the postsynaptic MuSK pathway and upon the regulation of junctional ACh receptor (AChR) numbers. Mice became weak after 14 daily injections of anti-MuSK-positive patient IgG. The intensity and area of AChR staining at the motor endplate was markedly reduced. Pulse-labelling of AChRs revealed an accelerated loss of pre-existing AChRs from postsynaptic AChR clusters without a compensatory increase in incorporation of (newly synthesized) replacement AChRs. Large, postsynaptic AChR clusters were replaced by a constellation of tiny AChR microaggregates. Puncta of AChR staining also appeared in the cytoplasm beneath the endplate. Endplate staining for MuSK, activated Src, rapsyn and AChR were all reduced in intensity. In the tibialis anterior muscle there was also evidence that phosphorylation of the AChR β-subunit-Y390 was reduced at endplates. In contrast, endplate staining for β-dystroglycan (through which rapsyn couples AChR to the synaptic basement membrane) remained intense. The results suggest that anti-MuSK IgG suppresses the endplate density of MuSK, thereby down-regulating MuSK signalling activity and the retention of junctional AChRs locally within the postsynaptic membrane scaffold.
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Affiliation(s)
- Nazanin Ghazanfari
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Marco Morsch
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Stephen W Reddel
- Department of Molecular Medicine, Concord Hospital, Concord, New South Wales, 2139, Australia
| | - Simon X Liang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Liaoning Medical University, China
| | - William D Phillips
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, 2006, Australia
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26
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Rudolf R, Bogomolovas J, Strack S, Choi KR, Khan MM, Wagner A, Brohm K, Hanashima A, Gasch A, Labeit D, Labeit S. Regulation of nicotinic acetylcholine receptor turnover by MuRF1 connects muscle activity to endo/lysosomal and atrophy pathways. AGE (DORDRECHT, NETHERLANDS) 2013; 35:1663-1674. [PMID: 22956146 PMCID: PMC3776120 DOI: 10.1007/s11357-012-9468-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 08/20/2012] [Indexed: 06/01/2023]
Abstract
Muscle atrophy is a process of muscle wasting induced under a series of catabolic stress conditions, such as denervation, disuse, cancer cachexia, heart and renal failure, AIDS, and aging. Neuromuscular junctions (NMJs), the synapses between motor neurons and muscle fibers undergo major changes in atrophying muscles, ranging from mild morphological alterations to complete disintegration. In this study, we hypothesized that remodeling of NMJs and muscle atrophy could be linked together. To test this, we examined if a major atrophy-promoting E3 ubiquitin ligase, MuRF1, is involved in the maintenance of NMJs. Immunofluorescence revealed that MuRF1 is highly enriched close to the NMJ. Affinity precipitation and in vivo imaging showed that MuRF1 interacts in endocytic structures with both, acetylcholine receptor, the primary postsynaptic protein of the NMJ, as well as with Bif-1, an autophagy- and endocytosis-regulating factor. In vivo imaging, radio labeling, and weighing approaches demonstrated that metabolic destabilization of acetylcholine receptors and muscle atrophy induced by denervation were significantly rescued in MuRF1-KO animals. Notably, interaction with Bif-1, and the rescue of AChR lifetime and muscle atrophy were specific to MuRF1 but not MuRF2. Our data demonstrate an involvement of MuRF1 in membrane protein-turnover, including the degradation of AChRs at the NMJ under atrophying conditions where MuRF1 also interacts and associates with Bif-1.
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Affiliation(s)
- Rüdiger Rudolf
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
- Institute of Molecular and Cell Biology, University of Applied Sciences Mannheim, Windeckstrasse 110, 68163 Mannheim, Germany
- Institute of Medical Technology, University of Heidelberg and University of Applied Sciences Mannheim, Paul-Wittsack-Strasse 10, 68163 Mannheim, Germany
| | - Julius Bogomolovas
- Department for Integrative Pathophysiology, Universitätsmedizin Mannheim, Theodor-Kutzer-Ufer, 68167 Mannheim, Germany
| | - Siegfried Strack
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Kyeong-Rok Choi
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Muzamil Majid Khan
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Anika Wagner
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Kathrin Brohm
- Department for Integrative Pathophysiology, Universitätsmedizin Mannheim, Theodor-Kutzer-Ufer, 68167 Mannheim, Germany
| | - Akira Hanashima
- Department for Integrative Pathophysiology, Universitätsmedizin Mannheim, Theodor-Kutzer-Ufer, 68167 Mannheim, Germany
| | - Alexander Gasch
- Department for Integrative Pathophysiology, Universitätsmedizin Mannheim, Theodor-Kutzer-Ufer, 68167 Mannheim, Germany
| | - Dittmar Labeit
- Department for Integrative Pathophysiology, Universitätsmedizin Mannheim, Theodor-Kutzer-Ufer, 68167 Mannheim, Germany
| | - Siegfried Labeit
- Department for Integrative Pathophysiology, Universitätsmedizin Mannheim, Theodor-Kutzer-Ufer, 68167 Mannheim, Germany
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27
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Honda T, Ishii A, Inui M. Regulation of adipocyte differentiation of 3T3-L1 cells by PDZRN3. Am J Physiol Cell Physiol 2013; 304:C1091-7. [DOI: 10.1152/ajpcell.00343.2012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PDZRN3, a member of the PDZRN (or LNX) family of proteins, is essential for the differentiation of mesenchymal stem cells into myotubes, but it plays an inhibitory role in the differentiation of these cells into osteoblasts. Given that mesenchymal stem cells also differentiate into adipocytes, we examined the possible role of PDZRN3 in adipogenesis in mouse 3T3-L1 preadipocytes. The expression of PDZRN3 decreased at both the mRNA and protein levels during adipogenic differentiation. RNAi-mediated depletion of PDZRN3 enhanced the differentiation of 3T3-L1 cells into adipocytes as assessed on the basis of lipid accumulation. The upregulation of aP2 and CCAAT/enhancer-binding protein (C/EBP)-β during adipocyte differentiation was also enhanced in the PDZRN3-depleted cells, as was the induction of peroxisome proliferator-activated receptor-γ (PPARγ), an upstream regulator of aP2 and C/EBPα, at both the mRNA and protein levels. Among transcription factors that control the expression of PPARγ, we found that STAT5b, but not STAT5a, was upregulated in PDZRN3-depleted cells at both mRNA and protein levels. Tyrosine phosphorylation of STAT5b, but not that of STAT5a, was also enhanced at an early stage of differentiation by PDZRN3 depletion. In addition, the expression of C/EBPβ during the induction of differentiation was enhanced at the mRNA and protein levels in PDZRN3-depleted cells. Our results thus suggest that PDZRN3 negatively regulates adipogenesis in 3T3-L1 cells through downregulation of STAT5b and C/EBPβ and consequent suppression of PPARγ expression.
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Affiliation(s)
- Takeshi Honda
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Aiko Ishii
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Makoto Inui
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
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28
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Banduseela VC, Chen YW, Kultima HG, Norman HS, Aare S, Radell P, Eriksson LI, Hoffman EP, Larsson L. Impaired autophagy, chaperone expression, and protein synthesis in response to critical illness interventions in porcine skeletal muscle. Physiol Genomics 2013; 45:477-86. [PMID: 23572537 DOI: 10.1152/physiolgenomics.00141.2012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Critical illness myopathy (CIM) is characterized by a preferential loss of the motor protein myosin, muscle wasting, and impaired muscle function in critically ill intensive care unit (ICU) patients. CIM is associated with severe morbidity and mortality and has a significant negative socioeconomic effect. Neuromuscular blocking agents, corticosteroids, sepsis, mechanical ventilation, and immobilization have been implicated as important risk factors, but the causal relationship between CIM and the risk factors has not been established. A porcine ICU model has been used to determine the immediate molecular and cellular cascades that may contribute to the pathogenesis prior to myosin loss and extensive muscle wasting. Expression profiles have been compared between pigs exposed to the ICU interventions, i.e., mechanically ventilated, sedated, and immobilized for 5 days, with pigs exposed to critical illness interventions, i.e., neuromuscular blocking agents, corticosteroids, and induced sepsis in addition to the ICU interventions for 5 days. Impaired autophagy as well as impaired chaperone expression and protein synthesis were observed in the skeletal muscle in response to critical illness interventions. A novel finding in this study is impaired core autophagy machinery in response to critical illness interventions, which when in concert with downregulated chaperone expression and protein synthesis may collectively affect the proteostasis in skeletal muscle and may exacerbate the disease progression in CIM.
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Affiliation(s)
- Varuna C Banduseela
- Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala, Sweden.
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29
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Zhang Q, Li Y, Zhang L, Yang N, Meng J, Zuo P, Zhang Y, Chen J, Wang L, Gao X, Zhu D. E3 ubiquitin ligase RNF13 involves spatial learning and assembly of the SNARE complex. Cell Mol Life Sci 2013; 70:153-65. [PMID: 22890573 PMCID: PMC11113611 DOI: 10.1007/s00018-012-1103-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Revised: 07/01/2012] [Accepted: 07/19/2012] [Indexed: 11/26/2022]
Abstract
Changes in the structure and number of synapses modulate learning, memory and cognitive disorders. Ubiquitin-mediated protein modification is a key mechanism for regulating synaptic activity, though the precise control of this process remains poorly understood. RING finger protein 13 (RNF13) is a recently identified E3 ubiquitin ligase, and its in vivo function remains completely unknown. We show here that genetic deletion of RNF13 in mice leads to a significant deficit in spatial learning as determined by the Morris water maze test and Y-maze learning test. At the ultrastructral level, the synaptic vesicle density was decreased and the area of the active zone was increased at hippocampal synapses of RNF13-null mice compared with those of wild-type littermates. We found no change in the levels of SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptor) complex proteins in the hippocampus of RNF13-null mice, but impaired SNARE complex assembly. RNF13 directly interacted with snapin, a SNAP-25-interacting protein. Interestingly, snapin was ubiquitinated by RNF13 via the lysine-29 conjugated polyubiquitin chain, which in turn promoted the association of snapin with SNAP-25. Consistently, we found an attenuated interaction between snapin and SNAP-25 in the RNF13-null mice. Therefore, these results suggest that RNF13 is involved in the regulation of the SNARE complex, which thereby controls synaptic function.
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Affiliation(s)
- Qiang Zhang
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Yanfeng Li
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Lei Zhang
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Nan Yang
- Department of Pharmacology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Jiao Meng
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Pingping Zuo
- Department of Pharmacology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Yong Zhang
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Jie Chen
- Department of Pathology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tsinghua University, Beijing, 100730 China
| | - Li Wang
- Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
| | - Xiang Gao
- Model Animal Research Center and MOE Key Laboratory of Model Animal for Disease Research, Nanjing University, Nanjing, 210061 China
| | - Dahai Zhu
- Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Tsinghua University, Beijing, 100005 China
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30
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Singhal N, Martin PT. Role of extracellular matrix proteins and their receptors in the development of the vertebrate neuromuscular junction. Dev Neurobiol 2012; 71:982-1005. [PMID: 21766463 DOI: 10.1002/dneu.20953] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The vertebrate neuromuscular junction (NMJ) remains the best-studied model for understanding the mechanisms involved in synaptogenesis, due to its relatively large size, its simplicity of patterning, and its unparalleled experimental accessibility. During neuromuscular development, each skeletal myofiber secretes and deposits around its extracellular surface an assemblage of extracellular matrix (ECM) proteins that ultimately form a basal lamina. This is also the case at the NMJ, where the motor nerve contributes additional factors. Before most of the current molecular components were known, it was clear that the synaptic ECM of adult skeletal muscles was unique in composition and contained factors sufficient to induce the differentiation of both pre- and postsynaptic membranes. Biochemical, genetic, and microscopy studies have confirmed that agrin, laminin (221, 421, and 521), collagen IV (α3-α6), collagen XIII, perlecan, and the ColQ-bound form of acetylcholinesterase are all synaptic ECM proteins with important roles in neuromuscular development. The roles of their many potential receptors and/or binding proteins have been more difficult to assess at the genetic level due to the complexity of membrane interactions with these large proteins, but roles for MuSK-LRP4 in agrin signaling and for integrins, dystroglycan, and voltage-gated calcium channels in laminin-dependent phenotypes have been identified. Synaptic ECM proteins and their receptors are involved in almost all aspects of synaptic development, including synaptic initiation, topography, ultrastructure, maturation, stability, and transmission.
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Affiliation(s)
- Neha Singhal
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Department of Pediatrics, Ohio State University College of Medicine, Columbus, Ohio 43205, USA
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31
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Baptista MS, Duarte CB, Maciel P. Role of the ubiquitin-proteasome system in nervous system function and disease: using C. elegans as a dissecting tool. Cell Mol Life Sci 2012; 69:2691-715. [PMID: 22382927 PMCID: PMC11115168 DOI: 10.1007/s00018-012-0946-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 02/13/2012] [Accepted: 02/15/2012] [Indexed: 01/12/2023]
Abstract
In addition to its central roles in protein quality control, regulation of cell cycle, intracellular signaling, DNA damage response and transcription regulation, the ubiquitin-proteasome system (UPS) plays specific roles in the nervous system, where it contributes to precise connectivity through development, and later assures functionality by regulating a wide spectrum of neuron-specific cellular processes. Aberrations in this system have been implicated in the etiology of neurodevelopmental and neurodegenerative diseases. In this review, we provide an updated view on the UPS and highlight recent findings concerning its role in normal and diseased nervous systems. We discuss the advantages of the model organism Caenorhabditis elegans as a tool to unravel the major unsolved questions concerning this biochemical pathway and its involvement in nervous system function and dysfunction, and expose the new possibilities, using state-of-the-art techniques, to assess UPS function using this model system.
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Affiliation(s)
- Márcio S Baptista
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
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32
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A role for the calmodulin kinase II-related anchoring protein (αkap) in maintaining the stability of nicotinic acetylcholine receptors. J Neurosci 2012; 32:5177-85. [PMID: 22496563 DOI: 10.1523/jneurosci.6477-11.2012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
αkap, a muscle specific anchoring protein encoded within the Camk2a gene, is thought to play a role in targeting multiple calcium/calmodulin kinase II isoforms to specific subcellular locations. Here we demonstrate a novel function of αkap in stabilizing nicotinic acetylcholine receptors (AChRs). Knockdown of αkap expression with shRNA significantly enhanced the degradation of AChR α-subunits (AChRα), leading to fewer and smaller AChR clusters on the surface of differentiated C2C12 myotubes. Mutagenesis and biochemical studies in HEK293T cells revealed that αkap promoted AChRα stability by a ubiquitin-dependent mechanism. In the absence of αkap, AChRα was heavily ubiquitinated, and the number of AChRα was increased by proteasome inhibitors. However, in the presence of αkap, AChRα was less ubiquitinated and proteasome inhibitors had almost no effect on AChRα accumulation. The major sites of AChRα ubiquitination reside within the large intracellular loop and mutations of critical lysine residues in this loop to arginine increased AChRα stability in the absence of αkap. These results provide an unexpected mechanism by which αkap controls receptor trafficking onto the surface of muscle cells and thus the maintenance of postsynaptic receptor density and synaptic function.
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33
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Molecular mechanisms underlying maturation and maintenance of the vertebrate neuromuscular junction. Trends Neurosci 2012; 35:441-53. [PMID: 22633140 DOI: 10.1016/j.tins.2012.04.005] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 04/09/2012] [Accepted: 04/15/2012] [Indexed: 01/22/2023]
Abstract
The vertebrate neuromuscular junction (NMJ), a peripheral synapse formed between motoneuron and skeletal muscle, is characterized by a protracted postnatal period of maturation and life-long maintenance. In neuromuscular disorders such as congenital myasthenic syndromes (CMSs), disruptions of NMJ maturation and/or maintenance are frequently observed. In particular, defective neuromuscular transmission associated with structural and molecular abnormalities at the pre- and postsynaptic membranes, as well as at the synaptic cleft, has been reported in these patients. Here, we review recent advances in the understanding of molecular and cellular events that mediate NMJ maturation and maintenance. The underlying regulatory mechanisms, including key molecular regulators at the presynaptic nerve terminal, synaptic cleft, and postsynaptic muscle membrane, are discussed.
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34
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Kidins220/ARMS interacts with Pdzrn3, a protein containing multiple binding domains. Biochimie 2012; 94:2054-7. [PMID: 22609016 DOI: 10.1016/j.biochi.2012.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 05/04/2012] [Indexed: 11/22/2022]
Abstract
We report the identification of a novel partner of Kidins220/ARMS (Kinase D-interacting substrate of 220 kDa/Ankyrin Repeat-rich Membrane Spanning) an adaptor of neurotrophin receptors playing crucial roles during neurogenesis. Screening a phage display library of brain cDNA products we found that D. rerio Pdzrn3, a protein containing RING-finger and PDZ-domains, interacts with Kidins220/ARMS through its first PDZ-domain. Both zebrafish proteins share high homology with the corresponding mammalian proteins and both genes are developmentally expressed in neural districts where early neurogenesis occurs. The interaction was also confirmed by biochemical assays and by co-localization at the tips of growing neurites of PC12 cells induced with nerve growth factor.
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35
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Barik A, Xiong WC, Mei L. MuSK: A Kinase Critical for the Formation and Maintenance of the Neuromuscular Junction. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/978-1-61779-824-5_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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36
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Mori S, Yamada S, Kubo S, Chen J, Matsuda S, Shudou M, Maruyama N, Shigemoto K. Divalent and monovalent autoantibodies cause dysfunction of MuSK by distinct mechanisms in a rabbit model of myasthenia gravis. J Neuroimmunol 2012; 244:1-7. [DOI: 10.1016/j.jneuroim.2011.12.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 11/07/2011] [Accepted: 12/05/2011] [Indexed: 12/21/2022]
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37
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Flynn M, Saha O, Young P. Molecular evolution of the LNX gene family. BMC Evol Biol 2011; 11:235. [PMID: 21827680 PMCID: PMC3162930 DOI: 10.1186/1471-2148-11-235] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 08/09/2011] [Indexed: 02/07/2023] Open
Abstract
Background LNX (Ligand of Numb Protein-X) proteins typically contain an amino-terminal RING domain adjacent to either two or four PDZ domains - a domain architecture that is unique to the LNX family. LNX proteins function as E3 ubiquitin ligases and their domain organisation suggests that their ubiquitin ligase activity may be targeted to specific substrates or subcellular locations by PDZ domain-mediated interactions. Indeed, numerous interaction partners for LNX proteins have been identified, but the in vivo functions of most family members remain largely unclear. Results To gain insights into their function we examined the phylogenetic origins and evolution of the LNX gene family. We find that a LNX1/LNX2-like gene arose in an early metazoan lineage by gene duplication and fusion events that combined a RING domain with four PDZ domains. These PDZ domains are closely related to the four carboxy-terminal domains from multiple PDZ domain containing protein-1 (MUPP1). Duplication of the LNX1/LNX2-like gene and subsequent loss of PDZ domains appears to have generated a gene encoding a LNX3/LNX4-like protein, with just two PDZ domains. This protein has novel carboxy-terminal sequences that include a potential modular LNX3 homology domain. The two ancestral LNX genes are present in some, but not all, invertebrate lineages. They were, however, maintained in the vertebrate lineage, with further duplication events giving rise to five LNX family members in most mammals. In addition, we identify novel interactions of LNX1 and LNX2 with three known MUPP1 ligands using yeast two-hybrid asssays. This demonstrates conservation of binding specificity between LNX and MUPP1 PDZ domains. Conclusions The LNX gene family has an early metazoan origin with a LNX1/LNX2-like protein likely giving rise to a LNX3/LNX4-like protein through the loss of PDZ domains. The absence of LNX orthologs in some lineages indicates that LNX proteins are not essential in invertebrates. In contrast, the maintenance of both ancestral LNX genes in the vertebrate lineage suggests the acquisition of essential vertebrate specific functions. The revelation that the LNX PDZ domains are phylogenetically related to domains in MUPP1, and have common binding specificities, suggests that LNX and MUPP1 may have similarities in their cellular functions.
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Affiliation(s)
- Michael Flynn
- Department of Biochemistry, University College Cork, Cork, Ireland
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Woller B, Luiskandl S, Popovic M, Prieler BEM, Ikonge G, Mutzl M, Rehmann H, Herbst R. Rin-like, a novel regulator of endocytosis, acts as guanine nucleotide exchange factor for Rab5a and Rab22. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1198-210. [PMID: 21419809 PMCID: PMC3096779 DOI: 10.1016/j.bbamcr.2011.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 03/08/2011] [Accepted: 03/10/2011] [Indexed: 11/23/2022]
Abstract
RIN proteins serve as guanine nucleotide exchange factors for Rab5a. They are characterized by the presence of a RIN homology domain and a C-terminal Vps9 domain. Currently three family members have been described and analyzed. Here we report the identification of a novel RIN family member, Rin-like (Rinl), that represents a new interaction partner of the receptor tyrosine kinase MuSK, which is an essential key regulator of neuromuscular synapse development. Rinl is localized to neuromuscular synapses but shows the highest expression in thymus and spleen. Rinl preferentially binds to nucleotide-free Rab5a and catalyzes the exchange of GDP for GTP. Moreover, Rinl also binds GDP-bound Rab22 and increases the GDP/GTP exchange implicating Rinl in endocytotic processes regulated by Rab5a and Rab22. Interestingly, Rinl shows a higher catalytic rate for Rab22 compared to Rab5a. Rinl is closely associated with the cytoskeleton and thus contributes to the spatial control of Rab5a and Rab22 signaling at actin-positive compartments. Most importantly, overexpression of Rinl affects fluid-phase as well as EGFR endocytosis.
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Affiliation(s)
- Barbara Woller
- Center for Brain Research, Medical University of Vienna, Spitalgasse 4, A-1090 Vienna, Austria
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Dente L, Gestri G, Tsang M, Kudoh T, Wilson SW, Dawid IB, Andreazzoli M. Cloning and developmental expression of zebrafish pdzrn3. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2011; 55:989-93. [PMID: 22252497 PMCID: PMC3418813 DOI: 10.1387/ijdb.113437ld] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Pdzrn3, a member of the PDZRN/SEMCAP/LNX protein family containing a RING finger and two PDZ domains, has been implicated in myoblast and osteoblast differentiation. However, its spatio-temporal expression pattern during embryonic development has not been defined. Here, we describe the cloning and expression pattern of pdzrn3 during zebrafish development. We found that in addition to being expressed in several mesodermal structures, this gene displays specific expression in the central nervous system including rhombomere 1, ventral retina, thalamus and motor neurons, indicating a novel function during neural development. In particular, the absence of expression of pdzrn3 in the ventral retina of noi mutant fish suggests a possible role for this gene in regulating fasciculation and/or navigation of retinal ganglion cell axons.
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Affiliation(s)
| | - Gaia Gestri
- Department of Anatomy and Developmental Biology, University College London, UK
| | - Michael Tsang
- Laboratory of Molecular Genetics, NICHD, NIH, Bethesda, MD, USA
| | - Tetsuhiro Kudoh
- Laboratory of Molecular Genetics, NICHD, NIH, Bethesda, MD, USA
| | - Stephen W. Wilson
- Department of Anatomy and Developmental Biology, University College London, UK
| | - Igor B. Dawid
- Laboratory of Molecular Genetics, NICHD, NIH, Bethesda, MD, USA
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40
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Abstract
Neurons are highly specialized cells whose connectivity at synapses subserves rapid information transfer in the brain. Proper information processing, learning, and memory storage in the brain requires continuous remodeling of synaptic networks. Such remodeling includes synapse formation, elimination, synaptic protein turnover, and changes in synaptic transmission. An emergent mechanism for regulating synapse function is posttranslational modification through the ubiquitin pathway at the postsynaptic membrane. Here, we discuss recent findings implicating ubiquitination and protein degradation in postsynaptic function and plasticity. We describe postsynaptic ubiquitination pathways and their role in brain development, neuronal physiology, and brain disorders.
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Affiliation(s)
- Angela M Mabb
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710, USA
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Ghazanfari N, Fernandez KJ, Murata Y, Morsch M, Ngo ST, Reddel SW, Noakes PG, Phillips WD. Muscle specific kinase: organiser of synaptic membrane domains. Int J Biochem Cell Biol 2010; 43:295-8. [PMID: 20974278 DOI: 10.1016/j.biocel.2010.10.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 10/15/2010] [Accepted: 10/15/2010] [Indexed: 11/19/2022]
Abstract
Muscle Specific Kinase (MuSK) is a transmembrane tyrosine kinase vital for forming and maintaining the mammalian neuromuscular junction (NMJ: the synapse between motor nerve and skeletal muscle). MuSK expression switches on during skeletal muscle differentiation. MuSK then becomes restricted to the postsynaptic membrane of the NMJ, where it functions to cluster acetylcholine receptors (AChRs). The expression, activation and turnover of MuSK are each regulated by signals from the motor nerve terminal. MuSK forms the core of an emerging signalling complex that can be acutely activated by neural agrin (N-agrin), a heparin sulfate proteoglycan secreted from the nerve terminal. MuSK activation initiates complex intracellular signalling events that coordinate the local synthesis and assembly of synaptic proteins. The importance of MuSK as a synapse organiser is highlighted by cases of autoimmune myasthenia gravis in which MuSK autoantibodies can deplete MuSK from the postsynaptic membrane, leading to complete disassembly of the adult NMJ.
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Affiliation(s)
- Nazanin Ghazanfari
- Physiology and Bosch Institute, Anderson Stuart Bldg (F13), The University of Sydney, Sydney, NSW 2006, Australia.
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42
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Cole RN, Ghazanfari N, Ngo ST, Gervásio OL, Reddel SW, Phillips WD. Patient autoantibodies deplete postsynaptic muscle-specific kinase leading to disassembly of the ACh receptor scaffold and myasthenia gravis in mice. J Physiol 2010; 588:3217-29. [PMID: 20603331 PMCID: PMC2976017 DOI: 10.1113/jphysiol.2010.190298] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2010] [Accepted: 07/02/2010] [Indexed: 01/14/2023] Open
Abstract
The postsynaptic muscle-specific kinase (MuSK) coordinates formation of the neuromuscular junction (NMJ) during embryonic development. Here we have studied the effects of MuSK autoantibodies upon the NMJ in adult mice. Daily injections of IgG from four MuSK autoantibody-positive myasthenia gravis patients (MuSK IgG; 45 mg day(1)i.p. for 14 days) caused reductions in postsynaptic ACh receptor (AChR) packing as assessed by fluorescence resonance energy transfer (FRET). IgG from the patients with the highest titres of MuSK autoantibodies caused large (51-73%) reductions in postsynaptic MuSK staining (cf. control mice; P < 0.01) and muscle weakness. Among mice injected for 14 days with control and MuSK patient IgGs, the residual level of MuSK correlated with the degree of impairment of postsynaptic AChR packing. However, the loss of postsynaptic MuSK preceded this impairment of postsynaptic AChR. When added to cultured C2 muscle cells the MuSK autoantibodies caused tyrosine phosphorylation of MuSK and the AChR beta-subunit, and internalization of MuSK from the plasma membrane. The results suggest a pathogenic mechanism in which MuSK autoantibodies rapidly deplete MuSK from the postsynaptic membrane leading to progressive dispersal of postsynaptic AChRs. Moreover, maintenance of postsynaptic AChR packing at the adult NMJ would appear to depend upon physical engagement of MuSK with the AChR scaffold, notwithstanding activation of the MuSK-rapsyn system of AChR clustering.
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Affiliation(s)
- R N Cole
- Physiology, Anderson Stuart Bldg (F13), University of Sydney, NSW 2006 Australia
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Honda T, Yamamoto H, Ishii A, Inui M. PDZRN3 negatively regulates BMP-2-induced osteoblast differentiation through inhibition of Wnt signaling. Mol Biol Cell 2010; 21:3269-77. [PMID: 20668165 PMCID: PMC2938391 DOI: 10.1091/mbc.e10-02-0117] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
PDZRN3, a member of the PDZ domain–containing RING finger family of proteins plays an important role in negative feedback control of BMP-2–induced osteoblast differentiation in C2C12 mouse mesenchymal progenitor cells through inhibition of Wnt–β-catenin signaling. PDZRN3 is a member of the PDZ domain–containing RING finger family of proteins. We previously showed that PDZRN3 is essential for the differentiation of C2C12 mouse mesenchymal progenitor cells into myotubes. Mesenchymal progenitor cells differentiate into osteoblasts, chondrocytes, and adipocytes in addition to myotubes, and we have now examined the potential role of PDZRN3 in the differentiation of C2C12 cells into osteoblasts. The abundance of PDZRN3 in C2C12 cells was increased after the induction of osteoblast differentiation by exposure to bone morphogenetic protein (BMP)-2 in low-serum medium. Depletion of PDZRN3 in C2C12 cells by RNA interference resulted in marked enhancement of the BMP-2–induced up-regulation of alkaline phosphatase (ALP) activity. Dkk1, an inhibitor of Wnt signaling, markedly attenuated the enhancement of the BMP-2–induced increase in ALP activity by PDZRN3 depletion. The up-regulation of ALP activity by Wnta3a was also promoted by depletion of PDZRN3. Furthermore, the expression and Wnt3a-induced phosphorylation of LRP6 as well as the increase in the cytosolic abundance of β-catenin induced by Wnt3a were potentiated in PDZRN3-depleted cells. These results indicate that PDZRN3 plays an important role in negative feedback control of BMP-2–induced osteoblast differentiation in C2C12 cells through inhibition of Wnt–β-catenin signaling.
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Affiliation(s)
- Takeshi Honda
- Department of Pharmacology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan
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Del Rincón SV, Rogers J, Widschwendter M, Sun D, Sieburg HB, Spruck C. Development and validation of a method for profiling post-translational modification activities using protein microarrays. PLoS One 2010; 5:e11332. [PMID: 20596523 PMCID: PMC2893156 DOI: 10.1371/journal.pone.0011332] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Accepted: 06/03/2010] [Indexed: 12/20/2022] Open
Abstract
Background Post-translational modifications (PTMs) impact on the stability, cellular location, and function of a protein thereby achieving a greater functional diversity of the proteome. To fully appreciate how PTMs modulate signaling networks, proteome-wide studies are necessary. However, the evaluation of PTMs on a proteome-wide scale has proven to be technically difficult. To facilitate these analyses we have developed a protein microarray-based assay that is capable of profiling PTM activities in complex biological mixtures such as whole-cell extracts and pathological specimens. Methodology/Principal Findings In our assay, protein microarrays serve as a substrate platform for in vitro enzymatic reactions in which a recombinant ligase, or extracts prepared from whole cells or a pathological specimen is overlaid. The reactions include labeled modifiers (e.g., ubiquitin, SUMO1, or NEDD8), ATP regenerating system, and other required components (depending on the assay) that support the conjugation of the modifier. In this report, we apply this methodology to profile three molecularly complex PTMs (ubiquitylation, SUMOylation, and NEDDylation) using purified ligase enzymes and extracts prepared from cultured cell lines and pathological specimens. We further validate this approach by confirming the in vivo modification of several novel PTM substrates identified by our assay. Conclusions/Significance This methodology offers several advantages over currently used PTM detection methods including ease of use, rapidity, scale, and sample source diversity. Furthermore, by allowing for the intrinsic enzymatic activities of cell populations or pathological states to be directly compared, this methodology could have widespread applications for the study of PTMs in human diseases and has the potential to be directly applied to most, if not all, basic PTM research.
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Affiliation(s)
- Sonia V Del Rincón
- Signal Transduction Program, Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
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Wu H, Xiong WC, Mei L. To build a synapse: signaling pathways in neuromuscular junction assembly. Development 2010; 137:1017-33. [PMID: 20215342 DOI: 10.1242/dev.038711] [Citation(s) in RCA: 379] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Synapses, as fundamental units of the neural circuitry, enable complex behaviors. The neuromuscular junction (NMJ) is a synapse type that forms between motoneurons and skeletal muscle fibers and that exhibits a high degree of subcellular specialization. Aided by genetic techniques and suitable animal models, studies in the past decade have brought significant progress in identifying NMJ components and assembly mechanisms. This review highlights recent advances in the study of NMJ development, focusing on signaling pathways that are activated by diffusible cues, which shed light on synaptogenesis in the brain and contribute to a better understanding of muscular dystrophy.
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Affiliation(s)
- Haitao Wu
- Program of Developmental Neurobiology, Institute of Molecular Medicine and Genetics, Department of Neurology, Medical College of Georgia, Augusta, GA 30912, USA
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46
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The ubiquitin-proteasome system regulates the stability of neuronal nicotinic acetylcholine receptors. J Mol Neurosci 2009; 40:177-84. [PMID: 19693707 DOI: 10.1007/s12031-009-9272-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Accepted: 07/20/2009] [Indexed: 12/16/2022]
Abstract
Ubiquitination is a key event for protein degradation by the proteasome system, membrane protein internalization, and protein trafficking among cellular compartments. Few data are available on the role of the ubiquitin-proteasome system (UPS) in the trafficking of neuronal nicotinic acetylcholine receptors (nAChRs). Experiments conducted in neuron-like differentiated rat pheochromocytoma cells (PC12 cells) show that the alpha3, beta2, and beta4 nAChR subunits are ubiquitinated and that their ubiquitination is necessary for degradation. A 24-h treatment with the proteasome inhibitor PS-341 increased the total levels of alpha3 and the two beta subunits in both whole cell lysates and fractions enriched for the ER/Golgi compartment. nAChR subunit upregulation was also detected in plasma membrane-enriched fractions. Inhibition of the lysosomal degradation machinery by E-64 had a significantly smaller effect on nAChR turnover. The present data, together with previous results showing that the alpha7 nAChR subunit is a target of the UPS, point to a prominent role of the proteasome in nAChR trafficking.
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Liu Y, Oppenheim RW, Sugiura Y, Lin W. Abnormal development of the neuromuscular junction in Nedd4-deficient mice. Dev Biol 2009; 330:153-66. [PMID: 19345204 DOI: 10.1016/j.ydbio.2009.03.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 03/23/2009] [Accepted: 03/25/2009] [Indexed: 11/28/2022]
Abstract
Nedd4 (neural precursor cell expressed developmentally down-regulated gene 4) is an E3 ubiquitin ligase highly conserved from yeast to humans. The expression of Nedd4 is developmentally down-regulated in the mammalian nervous system, but the role of Nedd4 in mammalian neural development remains poorly understood. Here we show that a null mutation of Nedd4 in mice leads to perinatal lethality: mutant mice were stillborn and many of them died in utero before birth (between E15.5-E18.5). In Nedd4 mutant embryos, skeletal muscle fiber sizes and motoneuron numbers are significantly reduced. Surviving motoneurons project axons to their target muscles on schedule, but motor nerves defasciculate upon reaching the muscle surface, suggesting that Nedd4 plays a critical role in fine-tuning the interaction between the nerve and the muscle. Electrophysiological analyses of the neuromuscular junction (NMJ) demonstrate an increased spontaneous miniature endplate potential (mEPP) frequency in Nedd4 mutants. However, the mutant neuromuscular synapses are less responsive to membrane depolarization, compared to the wildtypes. Ultrastructural analyses further reveal that the pre-synaptic nerve terminal branches at the NMJs of Nedd4 mutants are increased in number, but decreased in diameter compared to the wildtypes. These ultrastructural changes are consistent with functional alternation of the NMJs in Nedd4 mutants. Unexpectedly, Nedd4 is not expressed in motoneurons, but is highly expressed in skeletal muscles and Schwann cells. Together, these results demonstrate that Nedd4 is involved in regulating the formation and function of the NMJs through non-cell autonomous mechanisms.
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Affiliation(s)
- Yun Liu
- Department of Neuroscience, UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9111, USA
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Abstract
The heparan sulfate proteoglycan agrin is best known for its essential role during formation, maintenance and regeneration of the neuromuscular junction. Mutations in agrin-interacting proteins are the genetic basis for a number of neuromuscular disorders. However, agrin is widely expressed in many tissues including neurons and glial cells of the brain, where its precise function is much less understood. Fewer synapses develop in brains that lack agrin, consistent with a function of agrin during CNS synaptogenesis. Recently, a specific transmembrane form of agrin (TM-agrin) was identified that is concentrated at that interneuronal synapses in the brain. Clustering or overexpression of TM-agrin leads to the formation of filopodia-like processes, which might be precursors for CNS synapses. Agrin is subject to defined and activity-dependent proteolytic cleavage by neurotrypsin at synapses and dysregulation of agrin processing might contribute to the development of mental retardation. This review summarizes what is known about the role of agrin during synapse formation at the neuromuscular junction and in the developing CNS and will discuss additional functions of agrin in the adult CNS, in particular during BBB formation, during recovery after traumatic brain injury and in the etiology of diseases, including Alzheimer’s disease and mental retardation.
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Affiliation(s)
- Stephan Kröger
- Department of Physiological Genomics, Ludwig-Maximilians University, Schillerstrasse 46, D-80336 Munich, Germany
| | - Heike Pfister
- Department of Physiological Genomics, Ludwig-Maximilians University, Schillerstrasse 46, D-80336 Munich, Germany
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Ding M, Shen K. The role of the ubiquitin proteasome system in synapse remodeling and neurodegenerative diseases. Bioessays 2008; 30:1075-83. [PMID: 18937340 DOI: 10.1002/bies.20843] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The ubiquitin proteasome system is a potent regulatory mechanism used to control protein stability in numerous cellular processes, including neural development. Many neurodegenerative diseases are featured by the accumulation of UPS-associated proteins, suggesting the UPS dysfunction may be crucial for pathogenesis. Recent experiments have highlighted the UPS as a key player during synaptic development. Here we summarize recent discoveries centered on the role of the UPS in synapse remodeling and draw attention to the potential link between the synaptic UPS dysfunction and the pathology of neurodegenerative diseases.
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Affiliation(s)
- Mei Ding
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
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A mechanism distinct from highwire for the Drosophila ubiquitin conjugase bendless in synaptic growth and maturation. J Neurosci 2008; 28:8615-23. [PMID: 18716220 DOI: 10.1523/jneurosci.2990-08.2008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The signaling mechanisms that allow the conversion of a growth cone into a mature and stable synapse are yet to be completely understood. Ubiquitination plays key regulatory roles in synaptic development and may be involved in this process. Previous studies identified the Drosophila ubiquitin conjugase bendless (ben) to be important for central synapse formation, but the precise role it plays has not been elucidated. Our studies indicate that Ben plays a pivotal role in synaptic growth and maturation. We have determined that an incipient synapse is present with a high penetrance in ben mutants, suggesting that Ben is required for a developmental step after target recognition. We used cell-autonomous rescue experiments to show that Ben has a presynaptic role in synapse growth. We then harnessed the TARGET system to transiently express UAS (upstream activating sequence)-ben in a ben mutant background and identified a well defined critical period for Ben function in establishing a full-grown, mature synaptic terminal. We demonstrate that the protein must be present at a time point before but not during the actual growth process. We also provide phenotypic evidence demonstrating that Ben is not a part of the signal transduction pathway involving the well characterized ubiquitin ligase highwire. We conclude that Bendless functions as a novel developmental switch that permits the transition from axonal growth and incipient synapse formation to synaptic growth and maturation in the CNS.
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