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Gale J, Aizenman E. The physiological and pathophysiological roles of copper in the nervous system. Eur J Neurosci 2024; 60:3505-3543. [PMID: 38747014 DOI: 10.1111/ejn.16370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 02/28/2024] [Accepted: 04/10/2024] [Indexed: 07/06/2024]
Abstract
Copper is a critical trace element in biological systems due the vast number of essential enzymes that require the metal as a cofactor, including cytochrome c oxidase, superoxide dismutase and dopamine-β-hydroxylase. Due its key role in oxidative metabolism, antioxidant defence and neurotransmitter synthesis, copper is particularly important for neuronal development and proper neuronal function. Moreover, increasing evidence suggests that copper also serves important functions in synaptic and network activity, the regulation of circadian rhythms, and arousal. However, it is important to note that because of copper's ability to redox cycle and generate reactive species, cellular levels of the metal must be tightly regulated to meet cellular needs while avoiding copper-induced oxidative stress. Therefore, it is essential that the intricate system of copper transporters, exporters, copper chaperones and copper trafficking proteins function properly and in coordinate fashion. Indeed, disorders of copper metabolism such as Menkes disease and Wilson disease, as well as diseases linked to dysfunction of copper-requiring enzymes, such as SOD1-linked amyotrophic lateral sclerosis, demonstrate the dramatic neurological consequences of altered copper homeostasis. In this review, we explore the physiological importance of copper in the nervous system as well as pathologies related to improper copper handling.
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Affiliation(s)
- Jenna Gale
- Department of Neurobiology and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Elias Aizenman
- Department of Neurobiology and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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2
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Pan Z, Huang L, Gan Y, Xia Y, Yu W. The Molecular Mechanisms of Cuproptosis and Small-Molecule Drug Design in Diabetes Mellitus. Molecules 2024; 29:2852. [PMID: 38930917 PMCID: PMC11206814 DOI: 10.3390/molecules29122852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 06/28/2024] Open
Abstract
In the field of human health research, the homeostasis of copper (Cu) is receiving increased attention due to its connection to pathological conditions, including diabetes mellitus (DM). Recent studies have demonstrated that proteins associated with Cu homeostasis, such as ATOX1, FDX1, ATP7A, ATPB, SLC31A1, p53, and UPS, also contribute to DM. Cuproptosis, characterized by Cu homeostasis dysregulation and Cu overload, has been found to cause the oligomerization of lipoylated proteins in mitochondria, loss of iron-sulfur protein, depletion of glutathione, production of reactive oxygen species, and cell death. Further research into how cuproptosis affects DM is essential to uncover its mechanism of action and identify effective interventions. In this article, we review the molecular mechanism of Cu homeostasis and the role of cuproptosis in the pathogenesis of DM. The study of small-molecule drugs that affect these proteins offers the possibility of moving from symptomatic treatment to treating the underlying causes of DM.
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Affiliation(s)
- Zhaowen Pan
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, China; (Z.P.); (Y.G.)
| | - Lan Huang
- School of Stomatology and Ophthalmology, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, China;
| | - Yuanyuan Gan
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, China; (Z.P.); (Y.G.)
| | - Yan Xia
- School of Biomedical Engineering and Medical Imaging, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, China;
| | - Wei Yu
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, China; (Z.P.); (Y.G.)
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3
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Dmitriev OY, Patry J. Structure and mechanism of the human copper transporting ATPases: Fitting the pieces into a moving puzzle. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184306. [PMID: 38408697 DOI: 10.1016/j.bbamem.2024.184306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 02/07/2024] [Accepted: 02/18/2024] [Indexed: 02/28/2024]
Abstract
Human copper transporters ATP7B and ATP7A deliver copper to biosynthetic pathways and maintain copper homeostasis in the cell. These enzymes combine several challenges for structural biology because they are large low abundance membrane proteins with many highly mobile domains and long disordered loops. No method has yet succeeded in solving the structure of the complete fully functional protein. Still, X-ray crystallography, Cryo-EM and NMR helped to piece together a structure based model of the enzyme activity and regulation by copper. We review the structures of ATP7B and ATP7A with an emphasis on the mechanistic insights into the unique aspects of the transport function and regulation of the human copper ATPases that have emerged from more than twenty years of research.
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Affiliation(s)
- Oleg Y Dmitriev
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada.
| | - Jaala Patry
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
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4
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Maiti BK, Moura I, Moura JJG. Molybdenum-Copper Antagonism In Metalloenzymes And Anti-Copper Therapy. Chembiochem 2024; 25:e202300679. [PMID: 38205937 DOI: 10.1002/cbic.202300679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/23/2023] [Accepted: 01/11/2024] [Indexed: 01/12/2024]
Abstract
The connection between 3d (Cu) and 4d (Mo) via the "Mo-S-Cu" unit is called Mo-Cu antagonism. Biology offers case studies of such interactions in metalloproteins such as Mo/Cu-CO Dehydrogenases (Mo/Cu-CODH), and Mo/Cu Orange Protein (Mo/Cu-ORP). The CODH significantly maintains the CO level in the atmosphere below the toxic level by converting it to non-toxic CO2 for respiring organisms. Several models were synthesized to understand the structure-function relationship of these native enzymes. However, this interaction was first observed in ruminants, and they convert molybdate (MoO4 2- ) into tetrathiomolybdate (MoS4 2- ; TTM), reacting with cellular Cu to yield biological unavailable Mo/S/Cu cluster, then developing Cu-deficiency diseases. These findings inspire the use of TTM as a Cu-sequester drug, especially for treating Cu-dependent human diseases such as Wilson diseases (WD) and cancer. It is well known that a balanced Cu homeostasis is essential for a wide range of biological processes, but negative consequence leads to cell toxicity. Therefore, this review aims to connect the Mo-Cu antagonism in metalloproteins and anti-copper therapy.
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Affiliation(s)
- Biplab K Maiti
- Department of Chemistry, School of sciences, Cluster University of Jammu, Canal Road, Jammu, 180001, India
| | - Isabel Moura
- LAQV, REQUIMTE, Department of Chemistry, NOVA School of Science and Technology (FCT NOVA), Universidade NOVA de Lisboa, Campus, de Caparica, Portugal
| | - José J G Moura
- LAQV, REQUIMTE, Department of Chemistry, NOVA School of Science and Technology (FCT NOVA), Universidade NOVA de Lisboa, Campus, de Caparica, Portugal
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5
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Tavares LA, Rodrigues RL, Santos da Costa C, Nascimento JA, Vargas de Carvalho J, Nogueira de Carvalho A, Mardones GA, daSilva LLP. AP-1γ2 is an adaptor protein 1 variant required for endosome-to-Golgi trafficking of the mannose-6-P receptor (CI-MPR) and ATP7B copper transporter. J Biol Chem 2024; 300:105700. [PMID: 38307383 PMCID: PMC10909764 DOI: 10.1016/j.jbc.2024.105700] [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: 07/22/2023] [Revised: 01/18/2024] [Accepted: 01/21/2024] [Indexed: 02/04/2024] Open
Abstract
Selective retrograde transport from endosomes back to the trans-Golgi network (TGN) is important for maintaining protein homeostasis, recycling receptors, and returning molecules that were transported to the wrong compartments. Two important transmembrane proteins directed to this pathway are the Cation-Independent Mannose-6-phosphate receptor (CI-MPR) and the ATP7B copper transporter. Among CI-MPR functions is the delivery of acid hydrolases to lysosomes, while ATP7B facilitates the transport of cytosolic copper ions into organelles or the extracellular space. Precise subcellular localization of CI-MPR and ATP7B is essential for the proper functioning of these proteins. This study shows that both CI-MPR and ATP7B interact with a variant of the clathrin adaptor 1 (AP-1) complex that contains a specific isoform of the γ-adaptin subunit called γ2. Through synchronized anterograde trafficking and cell-surface uptake assays, we demonstrated that AP-1γ2 is dispensable for ATP7B and CI-MPR exit from the TGN while being critically required for ATP7B and CI-MPR retrieval from endosomes to the TGN. Moreover, AP-1γ2 depletion leads to the retention of endocytosed CI-MPR in endosomes enriched in retromer complex subunits. These data underscore the importance of AP-1γ2 as a key component in the sorting and trafficking machinery of CI-MPR and ATP7B, highlighting its essential role in the transport of proteins from endosomes.
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Affiliation(s)
- Lucas Alves Tavares
- Center for Virology Research and Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Roger Luiz Rodrigues
- Center for Virology Research and Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Cristina Santos da Costa
- Center for Virology Research and Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Jonas Alburqueque Nascimento
- Center for Virology Research and Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Julianne Vargas de Carvalho
- Center for Virology Research and Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Andreia Nogueira de Carvalho
- Center for Virology Research and Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Gonzalo A Mardones
- Escuela de Medicina, Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia, Chile
| | - Luis L P daSilva
- Center for Virology Research and Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.
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Ruturaj, Mishra M, Saha S, Maji S, Rodriguez-Boulan E, Schreiner R, Gupta A. Regulation of the apico-basolateral trafficking polarity of the homologous copper-ATPases ATP7A and ATP7B. J Cell Sci 2024; 137:jcs261258. [PMID: 38032054 PMCID: PMC10729821 DOI: 10.1242/jcs.261258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 10/05/2023] [Indexed: 12/01/2023] Open
Abstract
The homologous P-type copper-ATPases (Cu-ATPases) ATP7A and ATP7B are the key regulators of copper homeostasis in mammalian cells. In polarized epithelia, upon copper treatment, ATP7A and ATP7B traffic from the trans-Golgi network (TGN) to basolateral and apical membranes, respectively. We characterized the sorting pathways of Cu-ATPases between TGN and the plasma membrane and identified the machinery involved. ATP7A and ATP7B reside on distinct domains of TGN in limiting copper conditions, and in high copper, ATP7A traffics to basolateral membrane, whereas ATP7B traverses common recycling, apical sorting and apical recycling endosomes en route to apical membrane. Mass spectrometry identified regulatory partners of ATP7A and ATP7B that include the adaptor protein-1 complex. Upon knocking out pan-AP-1, sorting of both Cu-ATPases is disrupted. ATP7A loses its trafficking polarity and localizes on both apical and basolateral surfaces in high copper. By contrast, ATP7B loses TGN retention but retained its trafficking polarity to the apical domain, which became copper independent. Using isoform-specific knockouts, we found that the AP-1A complex provides directionality and TGN retention for both Cu-ATPases, whereas the AP-1B complex governs copper-independent trafficking of ATP7B solely. Trafficking phenotypes of Wilson disease-causing ATP7B mutants that disrupts putative ATP7B-AP1 interaction further substantiates the role of AP-1 in apical sorting of ATP7B.
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Affiliation(s)
- Ruturaj
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Monalisa Mishra
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Soumyendu Saha
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Saptarshi Maji
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Enrique Rodriguez-Boulan
- Department of Ophthalmology, Margaret Dyson Vision Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Ryan Schreiner
- Division of Regenerative Medicine, Department of Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Arnab Gupta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
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Chakraborty K, Das S, Pal A, Maji S, Rai B, Gupta A, Bhattacharjee A. Wilson disease-causing mutations in the carboxyl terminus of ATP7B regulates its localization and Golgi exit selectively in the unpolarized cells. Metallomics 2023; 15:mfad051. [PMID: 37660282 PMCID: PMC10506129 DOI: 10.1093/mtomcs/mfad051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 08/06/2023] [Indexed: 09/04/2023]
Abstract
Mutational inactivation of the P-type Cu-ATPase ATP7B interferes with its cellular functions to varying extent leading to varied cellular phenotypes. Wilson's disease (WD) primarily affects organs composed of polarized/differentiated epithelial cells. Therefore, phenotypic variability might differ depending on the polarization/differentiation of the cells. The present study investigates the intracellular stability and localization of ATP7B harboring WD mutations in both unpolarized/undifferentiated and polarized/differentiated cell-based models. Green fluorescent protein (GFP)-ATP7B harboring the WD causing mutations, N41S, S653Y, R778Q, G1061E, H1069Q, S1423N, S1426I, and T1434M, are included for investigation. The C-terminal WD mutations (S1423N, S1426I, and T1434M), exhibit distinct localization and Cu(I) responsive anterograde and retrograde trafficking in undifferentiated/unpolarized vs. differentiated/polarized cells. While basal localization of the S1423N mutant gets corrected in the differentiated glia, its Cu(I) responsive anterograde and retrograde trafficking behavior is not identical to the wild-type. But localization and trafficking properties are completely rescued for the S1426I and T1434M mutants in the differentiated cells. Comprehensive meta-analysis on the effect of the reported C-terminal mutations on patient phenotype and cultured cells demonstrate discrete regions having distinct effects. While mutations in the proximal C-terminus affect ATP7B stability, the present study shows that the distal region dictates cell-specific Trans Golgi Network (TGN) localization and exit. The localization and export properties are corrected in the differentiated cells, which is a plausible mechanism for the milder phenotype exhibited by these mutations. It highlights the critical role of the C-terminus in cell-specific TGN retention and exit of ATP7B.
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Affiliation(s)
| | - Santanu Das
- Department of Biological Sciences, Indian Institute of Science Education and Research, Kolkata, India
| | - Anusree Pal
- Amity Institute of Biotechnology, Amity University, Kolkata, India
| | - Saptarshi Maji
- Department of Biological Sciences, Indian Institute of Science Education and Research, Kolkata, India
| | - Bhawana Rai
- Amity Institute of Biotechnology, Amity University, Kolkata, India
| | - Arnab Gupta
- Department of Biological Sciences, Indian Institute of Science Education and Research, Kolkata, India
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Das S, Mohammed A, Mandal T, Maji S, Verma J, Ruturaj, Gupta A. Polarized trafficking and copper transport activity of ATP7B: a mutational approach to establish genotype-phenotype correlation in Wilson disease. Hum Mutat 2022; 43:1408-1429. [PMID: 35762218 DOI: 10.1002/humu.24428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 11/07/2022]
Abstract
Mutation in ATP7B gene causes Wilson disease (WD) that is characterized by severe hepatic and neurological symptoms. ATP7B localizes at the trans-Golgi Network (TGN) transporting copper to copper-dependent enzymes and traffics in apically targeted vesicles upon intracellular copper elevation. To decode the cellular underpinnings of WD manifestation we investigated copper-responsive polarized trafficking and copper transport activity of fifteen WD causing point mutations in ATP7B. Amino-terminal mutations Gly85Val, Leu168Pro and Gly591Asp displayed TGN and sub-apical localization whereas, Leu492Ser mislocalized at the basolateral region. The actuator domain mutation Gly875Arg shows retention in the endoplasmic reticulum (ER), Ala874Val and Leu795Phe show partial targeting to TGN and post-Golgi vesicles. The Nucleotide-Binding Domain mutations His1069Gln and Leu1083Phe also display impaired targeting. The C-terminal mutations Leu1373Pro/Arg is arrested at ER but Ser1423Asn shows TGN localization. Transmembrane mutant Arg778Leu resides in ER and TGN while Arg969Gln is exclusively ER localized. Cellular Cu level does not alter the targeting of any of the studied mutations. Mutants that traffic to TGN exhibits biosynthetic function. Finally, we correlated cellular phenotypes with the clinical manifestation of the two most prevalent mutations; the early onset and more aggressive WD caused by Arg778Leu and the milder form of WD caused by mutation His1069Gln. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Santanu Das
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, 741246, India
| | - Ameena Mohammed
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, 741246, India
| | - Taniya Mandal
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, 741246, India
| | - Saptarshi Maji
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, 741246, India
| | - Jay Verma
- Maulana Azad Medical College, 2 Bahadur Shah Zafar Marg, New Delhi, Delhi, 110002, India
| | - Ruturaj
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, 741246, India
| | - Arnab Gupta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, 741246, India
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9
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Golgi Metal Ion Homeostasis in Human Health and Diseases. Cells 2022; 11:cells11020289. [PMID: 35053405 PMCID: PMC8773785 DOI: 10.3390/cells11020289] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/31/2021] [Accepted: 01/11/2022] [Indexed: 12/24/2022] Open
Abstract
The Golgi apparatus is a membrane organelle located in the center of the protein processing and trafficking pathway. It consists of sub-compartments with distinct biochemical compositions and functions. Main functions of the Golgi, including membrane trafficking, protein glycosylation, and sorting, require a well-maintained stable microenvironment in the sub-compartments of the Golgi, along with metal ion homeostasis. Metal ions, such as Ca2+, Mn2+, Zn2+, and Cu2+, are important cofactors of many Golgi resident glycosylation enzymes. The homeostasis of metal ions in the secretory pathway, which is required for proper function and stress response of the Golgi, is tightly regulated and maintained by transporters. Mutations in the transporters cause human diseases. Here we provide a review specifically focusing on the transporters that maintain Golgi metal ion homeostasis under physiological conditions and their alterations in diseases.
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Maung MT, Carlson A, Olea-Flores M, Elkhadragy L, Schachtschneider KM, Navarro-Tito N, Padilla-Benavides T. The molecular and cellular basis of copper dysregulation and its relationship with human pathologies. FASEB J 2021; 35:e21810. [PMID: 34390520 DOI: 10.1096/fj.202100273rr] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 06/23/2021] [Accepted: 07/07/2021] [Indexed: 12/16/2022]
Abstract
Copper (Cu) is an essential micronutrient required for the activity of redox-active enzymes involved in critical metabolic reactions, signaling pathways, and biological functions. Transporters and chaperones control Cu ion levels and bioavailability to ensure proper subcellular and systemic Cu distribution. Intensive research has focused on understanding how mammalian cells maintain Cu homeostasis, and how molecular signals coordinate Cu acquisition and storage within organs. In humans, mutations of genes that regulate Cu homeostasis or facilitate interactions with Cu ions lead to numerous pathologic conditions. Malfunctions of the Cu+ -transporting ATPases ATP7A and ATP7B cause Menkes disease and Wilson disease, respectively. Additionally, defects in the mitochondrial and cellular distributions and homeostasis of Cu lead to severe neurodegenerative conditions, mitochondrial myopathies, and metabolic diseases. Cu has a dual nature in carcinogenesis as a promotor of tumor growth and an inducer of redox stress in cancer cells. Cu also plays role in cancer treatment as a component of drugs and a regulator of drug sensitivity and uptake. In this review, we provide an overview of the current knowledge of Cu metabolism and transport and its relation to various human pathologies.
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Affiliation(s)
- May T Maung
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT, USA
| | - Alyssa Carlson
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT, USA
| | - Monserrat Olea-Flores
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Guerrero, Mexico
| | - Lobna Elkhadragy
- Department of Radiology, University of Illinois at Chicago, Chicago, IL, USA
| | - Kyle M Schachtschneider
- Department of Radiology, University of Illinois at Chicago, Chicago, IL, USA.,Department of Biochemistry & Molecular Genetics, University of Illinois at Chicago, Chicago, IL, USA.,National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Napoleon Navarro-Tito
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Guerrero, Mexico
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Roy S, McCann CJ, Ralle M, Ray K, Ray J, Lutsenko S, Jayakanthan S. Analysis of Wilson disease mutations revealed that interactions between different ATP7B mutants modify their properties. Sci Rep 2020; 10:13487. [PMID: 32778786 PMCID: PMC7418023 DOI: 10.1038/s41598-020-70366-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 06/16/2020] [Indexed: 01/05/2023] Open
Abstract
Wilson disease (WD) is an autosomal-recessive disorder caused by mutations in the copper (Cu)-transporter ATP7B. Thus far, studies of WD mutations have been limited to analysis of ATP7B mutants in the homozygous states. However, the majority of WD patients are compound-heterozygous, and how different mutations on two alleles impact ATP7B properties is unclear. We characterized five mutations identified in Indian WD patients, first by expressing each alone and then by co-expressing two mutants with dissimilar properties. Mutations located in the regulatory domains of ATP7B-A595T, S1362A, and S1426I-do not affect ATP7B targeting to the trans-Golgi network (TGN) but reduce its Cu-transport activity. The S1362A mutation also inhibits Cu-dependent trafficking from the TGN. The G1061E and G1101R mutations, which are located within the ATP-binding domain, cause ATP7B retention in the endoplasmic reticulum, inhibit Cu-transport, and lower ATP7B protein abundance. Co-expression of the A595T and G1061E mutations, which mimics the compound-heterozygous state of some WD patients, revealed an interaction between these mutants that altered their intracellular localization and trafficking under both low and high Cu conditions. These findings highlight the need to study WD variants in both the homozygous and compound-heterozygous states to better understand the genotype-phenotype correlations and incomplete penetrance observed in WD.
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Affiliation(s)
- Shubhrajit Roy
- Department of Physiology, Johns Hopkins Medical Institute, Baltimore, MD, USA. .,S. N. Pradhan Centre for Neurosciences, University of Calcutta, Kolkata, India.
| | - Courtney J McCann
- Department of Physiology, Johns Hopkins Medical Institute, Baltimore, MD, USA
| | - Martina Ralle
- Oregon Health and Science University, Portland, OR, USA
| | - Kunal Ray
- ATGC Diagnostics Private Ltd, Kolkata, India
| | - Jharna Ray
- S. N. Pradhan Centre for Neurosciences, University of Calcutta, Kolkata, India
| | - Svetlana Lutsenko
- Department of Physiology, Johns Hopkins Medical Institute, Baltimore, MD, USA.
| | - Samuel Jayakanthan
- Department of Physiology, Johns Hopkins Medical Institute, Baltimore, MD, USA
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12
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Yi F, Poskanzer SA, Myers CT, Thies J, Collins CJ, Dayuha R, Duong P, Houwen R, Hahn SH. p.P1379S, a benign variant with reduced ATP7B protein level in Wilson Disease. JIMD Rep 2020; 54:32-36. [PMID: 32685348 PMCID: PMC7358663 DOI: 10.1002/jmd2.12127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/20/2020] [Accepted: 04/23/2020] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Wilson disease (WD) is an autosomal recessive disorder of copper transport caused by inherited defects in the ATP7B gene and results in toxic accumulation of copper in various organs. We previously reported a family with three consecutive generations affected by WD that carries the variant, p.P1379S, which was classified at the time as likely pathogenic. However, recent investigations of the p.P1379S variant indicate a possible conflict of interpretations regarding its pathogenicity. This led us to explore the quantification of ATP7B in dried blood spots (DBS) using a surrogate peptide to study the effects of the p.P1379S variant on ATP7B concentrations in two unrelated families with the common p.P1379S variant. METHODS AND RESULTS ATP7B was quantified using the peptide immunoaffinity enrichment coupled with selected reaction monitoring mass spectrometry (immuno-SRM) method which utilizes antibody-mediated peptide capture from DBS. Two patients affected with WD had undetectable ATP7B level while four compound heterozygous children with one known pathogenic variant and the p.P1379S had significantly reduced ATP7B levels. Of note, all four children remain asymptomatic without abnormal laboratory consequences despite being untreated for WD. CONCLUSION These two families demonstrated that p.P1379S, when compounded with two known pathogenic variants, resulted in significantly reduced protein levels but retained enough function to maintain normal copper homeostasis. This implies that p.P1379S is benign in nature. A better understanding of the nature and consequences of variants in WD will help in informing patient care and avoiding unnecessary treatments.
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Affiliation(s)
- Fan Yi
- Seattle Children's Research InstituteSeattleWashingtonUSA
| | - Sheri A. Poskanzer
- Department of PediatricsUniversity of Washington, School of MedicineSeattleWashingtonUSA
| | - Candace T. Myers
- Department of LaboratoriesSeattle Children's HospitalSeattleWashingtonUSA
| | - Jenny Thies
- Biochemical GeneticsSeattle Children's HospitalSeattleWashingtonUSA
| | | | | | - Phi Duong
- Seattle Children's Research InstituteSeattleWashingtonUSA
| | - Roderick Houwen
- Wilhelmina Children's Hospital, Utrecht UniversityUtrechtNetherlands
| | - Si Houn Hahn
- Seattle Children's Research InstituteSeattleWashingtonUSA
- Department of PediatricsUniversity of Washington, School of MedicineSeattleWashingtonUSA
- Biochemical GeneticsSeattle Children's HospitalSeattleWashingtonUSA
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13
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Poskanzer SA, Thies J, Collins CJ, Myers CT, Dayuha R, Duong P, Yi F, Chang IJ, Ochs HD, Torgerson TR, Hahn SH. The co-occurrence of Wilson disease and X-linked agammaglobulinemia in one family highlights the promising diagnostic potential of proteolytic analysis. Mol Genet Genomic Med 2020; 8:e1172. [PMID: 32067425 PMCID: PMC7196455 DOI: 10.1002/mgg3.1172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND We report the first case of a family with co-occurrence of Wilson disease (WD), an autosomal recessive disorder of copper metabolism, and X-linked agammaglobulinemia (XLA), a primary immunodeficiency disorder (PIDD) that features marked reduction in circulating B lymphocytes and serum immunoglobulins. METHODS AND RESULTS Through utilization of a multiplexed biomarker peptide quantification method known as the immuno-SRM assay, we were able to simultaneously and independently identify which family members are affected with WD and which are affected with XLA using dried blood spots (DBS). CONCLUSION Being able to delineate multiple diagnoses using proteolytic analysis from a single DBS provides support for implementation of this methodology for clinical diagnostic use as well as large-scale population screening, such as newborn screening (NBS). This could allow for early identification and treatment of affected individuals with WD or XLA, which have been shown to reduce morbidity and decrease mortality in these two populations.
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Affiliation(s)
- Sheri A Poskanzer
- School of Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.,Biochemical Genetics, Seattle Children's Hospital, Seattle, WA, USA
| | - Jenny Thies
- Biochemical Genetics, Seattle Children's Hospital, Seattle, WA, USA
| | | | - Candace T Myers
- Department of Laboratories, Seattle Children's Hospital, Seattle, WA, USA
| | | | - Phi Duong
- Seattle Children's Research Institute, Seattle, WA, USA
| | - Fan Yi
- Seattle Children's Research Institute, Seattle, WA, USA
| | - Irene J Chang
- School of Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.,Biochemical Genetics, Seattle Children's Hospital, Seattle, WA, USA.,Seattle Children's Research Institute, Seattle, WA, USA
| | - Hans D Ochs
- School of Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.,Seattle Children's Research Institute, Seattle, WA, USA
| | - Troy R Torgerson
- School of Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.,Seattle Children's Research Institute, Seattle, WA, USA
| | - Si Houn Hahn
- School of Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.,Biochemical Genetics, Seattle Children's Hospital, Seattle, WA, USA.,Seattle Children's Research Institute, Seattle, WA, USA
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14
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Tone T, Nakayama K, Takatsu H, Shin HW. ATPase reaction cycle of P4-ATPases affects their transport from the endoplasmic reticulum. FEBS Lett 2019; 594:412-423. [PMID: 31571211 DOI: 10.1002/1873-3468.13629] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/09/2019] [Accepted: 09/11/2019] [Indexed: 12/18/2022]
Abstract
P4-ATPases belonging to the P-type ATPase superfamily mediate active transport of phospholipids across cellular membranes. Most P4-ATPases, except ATP9A and ATP9B proteins, form heteromeric complexes with CDC50 proteins, which are required for transport of P4-ATPases from the endoplasmic reticulum (ER) to their final destinations. P-type ATPases form autophosphorylated intermediates during the ATPase reaction cycle. However, the association of the catalytic cycle of P4-ATPases with their transport from the ER and their cellular localization has not been studied. Here, we show that transport of ATP9 and ATP11 proteins as well as that of ATP10A from the ER depends on the ATPase catalytic cycle, suggesting that conformational changes in P4-ATPases during the catalytic cycle are crucial for their transport from the ER.
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Affiliation(s)
- Takuya Tone
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan
| | - Hiroyuki Takatsu
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan
| | - Hye-Won Shin
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan
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15
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Polishchuk RS, Polishchuk EV. From and to the Golgi - defining the Wilson disease protein road map. FEBS Lett 2019; 593:2341-2350. [PMID: 31408533 DOI: 10.1002/1873-3468.13575] [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: 06/28/2019] [Revised: 08/01/2019] [Accepted: 08/08/2019] [Indexed: 11/05/2022]
Abstract
Recent studies highlight the continued growth in the identification of a variety of cellular functions that involve the Golgi apparatus. Apart from well-known membrane sorting/trafficking and glycosylation machineries, the Golgi harbors molecular platforms operating in intracellular signaling, cytoskeleton organization, and protein quality control mechanisms. One of new emerging Golgi functions consists in the regulation of copper homeostasis by coordinating the relocation and activity of copper transporters. Of these, the Cu-transporting ATPase ATP7B (known as Wilson disease protein) plays a key role in the maintenance of the Cu balance in the body via the supply of essential Cu to the systemic circulation and via elimination of excess Cu into the bile. These activities require tightly regulated shuttling of ATP7B between the Golgi and different post-Golgi compartments. Despite significant progress over recent years, a number of issues regarding ATP7B trafficking remain to be clarified. This review summarizes current views on ATP7B trafficking pathways from and to the Golgi and underscores the challenges that should be addressed to define the ATP7B trafficking routes and mechanisms in health and disease.
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Affiliation(s)
- Roman S Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy
| | - Elena V Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy.,ITMO University, St. Petersburg, Russia
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16
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Schmidt K, Ralle M, Schaffer T, Jayakanthan S, Bari B, Muchenditsi A, Lutsenko S. ATP7A and ATP7B copper transporters have distinct functions in the regulation of neuronal dopamine-β-hydroxylase. J Biol Chem 2018; 293:20085-20098. [PMID: 30341172 DOI: 10.1074/jbc.ra118.004889] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/17/2018] [Indexed: 01/06/2023] Open
Abstract
The copper (Cu) transporters ATPase copper-transporting alpha (ATP7A) and ATPase copper-transporting beta (ATP7B) are essential for the normal function of the mammalian central nervous system. Inactivation of ATP7A or ATP7B causes the severe neurological disorders, Menkes disease and Wilson disease, respectively. In both diseases, Cu imbalance is associated with abnormal levels of the catecholamine-type neurotransmitters dopamine and norepinephrine. Dopamine is converted to norepinephrine by dopamine-β-hydroxylase (DBH), which acquires its essential Cu cofactor from ATP7A. However, the role of ATP7B in catecholamine homeostasis is unclear. Here, using immunostaining of mouse brain sections and cultured cells, we show that DBH-containing neurons express both ATP7A and ATP7B. The two transporters are located in distinct cellular compartments and oppositely regulate the export of soluble DBH from cultured neuronal cells under resting conditions. Down-regulation of ATP7A, overexpression of ATP7B, and pharmacological Cu depletion increased DBH retention in cells. In contrast, ATP7B inactivation elevated extracellular DBH. Proteolytic processing and the specific activity of exported DBH were not affected by changes in ATP7B levels. These results establish distinct regulatory roles for ATP7A and ATP7B in neuronal cells and explain, in part, the lack of functional compensation between these two transporters in human disorders of Cu imbalance.
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Affiliation(s)
- Katharina Schmidt
- From the Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Martina Ralle
- the Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97239
| | - Thomas Schaffer
- the Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland 21205, and
| | - Samuel Jayakanthan
- From the Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Bilal Bari
- the Department of Neuroscience, Brain Science Institute, Johns Hopkins University, Baltimore, Maryland 21205
| | - Abigael Muchenditsi
- From the Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Svetlana Lutsenko
- From the Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205,.
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17
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Berzina A, Martinsone I, Svirskis S, Murovska M, Kalis M. Curcumin Effect on Copper Transport in HepG2 Cells. MEDICINA (KAUNAS, LITHUANIA) 2018; 54:E14. [PMID: 30344245 PMCID: PMC6037243 DOI: 10.3390/medicina54020014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 04/10/2018] [Accepted: 04/10/2018] [Indexed: 12/12/2022]
Abstract
Background and Objective: In Wilson's disease, copper metabolism is impaired due to defective copper transporting protein ATP7B, resulting in copper accumulation in liver and brain and causing damage to liver and brain tissues. Published data suggest that one of the possible treatments for Wilson's disease is curcumin-a compound found in the root of Curcuma longa. In this study, we tested whether curcumin affects copper transport and excretion in HepG2 hepatocytes carrying wildtype ATP7B. Materials and Methods: We examined the impact of 5 µM and 25 µM curcumin on the transport of copper in HepG2 cells incubated with 20 µM and 100 µM CuCl₂, as well as copper excretion from cells. First, immunofluorescent staining and co-localization analysis were carried out in HepG2 cells using confocal laser scanning microscope and Nikon NIS Elements software. Second, a concentration of copper extracted into cell culture medium was determined using atomic absorption spectrometry. Results: The analysis of the co-localization between Golgi complex and ATP7B revealed that both 5 µM and 25 µM doses of curcumin improve the ability of liver cells to transport copper to plasma membrane at 20 µM CuCl₂, but not at 100 µM CuCl₂ concentration. However, atomic absorption spectrometry showed that curcumin rather promotes copper absorption into liver cell line HepG2 than excretion of it. Conclusions: Curcumin accelerates the transport of copper within liver cells, but does not promote copper excretion from HepG2 cells.
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Affiliation(s)
- Anita Berzina
- August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Dzirciema 16, Riga LV-1007, Latvia.
| | - Inese Martinsone
- Institute of Occupational Safety and Environmental Health, Riga Stradins University, Dzirciema 16, Riga LV-1007, Latvia.
| | - Simons Svirskis
- August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Dzirciema 16, Riga LV-1007, Latvia.
| | - Modra Murovska
- August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Dzirciema 16, Riga LV-1007, Latvia.
| | - Martins Kalis
- August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Dzirciema 16, Riga LV-1007, Latvia.
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18
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Modulation of hepatic copper-ATPase activity by insulin and glucagon involves protein kinase A (PKA) signaling pathway. Biochim Biophys Acta Mol Basis Dis 2016; 1862:2086-2097. [DOI: 10.1016/j.bbadis.2016.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/25/2016] [Accepted: 08/09/2016] [Indexed: 11/23/2022]
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19
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Fieten H, Gill Y, Martin AJ, Concilli M, Dirksen K, van Steenbeek FG, Spee B, van den Ingh TSGAM, Martens ECCP, Festa P, Chesi G, van de Sluis B, Houwen RHJH, Watson AL, Aulchenko YS, Hodgkinson VL, Zhu S, Petris MJ, Polishchuk RS, Leegwater PAJ, Rothuizen J. The Menkes and Wilson disease genes counteract in copper toxicosis in Labrador retrievers: a new canine model for copper-metabolism disorders. Dis Model Mech 2016; 9:25-38. [PMID: 26747866 PMCID: PMC4728329 DOI: 10.1242/dmm.020263] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The deleterious effects of a disrupted copper metabolism are illustrated by hereditary diseases caused by mutations in the genes coding for the copper transporters ATP7A and ATP7B. Menkes disease, involving ATP7A, is a fatal neurodegenerative disorder of copper deficiency. Mutations in ATP7B lead to Wilson disease, which is characterized by a predominantly hepatic copper accumulation. The low incidence and the phenotypic variability of human copper toxicosis hamper identification of causal genes or modifier genes involved in the disease pathogenesis. The Labrador retriever was recently characterized as a new canine model for copper toxicosis. Purebred dogs have reduced genetic variability, which facilitates identification of genes involved in complex heritable traits that might influence phenotype in both humans and dogs. We performed a genome-wide association study in 235 Labrador retrievers and identified two chromosome regions containing ATP7A and ATP7B that were associated with variation in hepatic copper levels. DNA sequence analysis identified missense mutations in each gene. The amino acid substitution ATP7B:p.Arg1453Gln was associated with copper accumulation, whereas the amino acid substitution ATP7A:p.Thr327Ile partly protected against copper accumulation. Confocal microscopy indicated that aberrant copper metabolism upon expression of the ATP7B variant occurred because of mis-localization of the protein in the endoplasmic reticulum. Dermal fibroblasts derived from ATP7A:p.Thr327Ile dogs showed copper accumulation and delayed excretion. We identified the Labrador retriever as the first natural, non-rodent model for ATP7B-associated copper toxicosis. Attenuation of copper accumulation by the ATP7A mutation sheds an interesting light on the interplay of copper transporters in body copper homeostasis and warrants a thorough investigation of ATP7A as a modifier gene in copper-metabolism disorders. The identification of two new functional variants in ATP7A and ATP7B contributes to the biological understanding of protein function, with relevance for future development of therapy. Summary: Labrador retrievers with hereditary copper toxicosis are a useful new model for copper-metabolism disorders.
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Affiliation(s)
- Hille Fieten
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands
| | - Yadvinder Gill
- The WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Melton Mowbray, Leicestershire, LE14 4RT, UK
| | - Alan J Martin
- The WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Melton Mowbray, Leicestershire, LE14 4RT, UK
| | - Mafalda Concilli
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli (NA), Italy
| | - Karen Dirksen
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands
| | - Frank G van Steenbeek
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands
| | - Bart Spee
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands
| | | | - Ellen C C P Martens
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands
| | - Paola Festa
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli (NA), Italy
| | - Giancarlo Chesi
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli (NA), Italy
| | - Bart van de Sluis
- Department of Pediatrics, Molecular Genetics Section, University of Groningen, University Medical Center, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Roderick H J H Houwen
- Department of Pediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Center, Lundlaan 6, 3584 EA Utrecht, The Netherlands
| | - Adrian L Watson
- The WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Melton Mowbray, Leicestershire, LE14 4RT, UK
| | - Yurii S Aulchenko
- Novosibirsk State University, 630090 Novosibirsk, Russia Institute of Cytology and Genetics, 630090 Novosibirsk, Russia
| | - Victoria L Hodgkinson
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA The Christopher S. Bond Life Science Center, University of Missouri, Columbia, MO 65211, USA
| | - Sha Zhu
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA The Christopher S. Bond Life Science Center, University of Missouri, Columbia, MO 65211, USA
| | - Michael J Petris
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA The Christopher S. Bond Life Science Center, University of Missouri, Columbia, MO 65211, USA Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211, USA
| | - Roman S Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli (NA), Italy
| | - Peter A J Leegwater
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands
| | - Jan Rothuizen
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands
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20
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Lalioti V, Peiró R, Pérez-Berlanga M, Tsuchiya Y, Muñoz A, Villalba T, Sanchez C, Sandoval IV. Basolateral sorting and transcytosis define the Cu+-regulated translocation of ATP7B to the bile canaliculus. J Cell Sci 2016; 129:2190-201. [DOI: 10.1242/jcs.184663] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/28/2016] [Indexed: 01/22/2023] Open
Abstract
The Cu+ pump ATP7B plays an irreplaceable role in the elimination of excess Cu+ by the hepatocyte into the bile. The traffic and site of ATP7B action is a subject of controversy. One current proposal is that an increase in intracellular Cu+ results in the translocation of ATP7B to the lysosomes and excretion of excess Cu+ by lysosomal mediated exocytosis at the bile canaliculus. Here we show that ATP7B is transported from the trans-Golgi network to the bile canaliculus by basolateral sorting and endocytosis, and microtubule mediated transcytosis through the subapical compartment. Trafficking ATP7B is not incorporated into lysosomes and addition of Cu+ does not cause relocalization of lysosomes and the appearance of lysosome markers in the bile canaliculus. Our data describes the pathway of the Cu+-mediated transport of ATP7B from the TGN to the bile canaliculus and indicates that the bile canaliculus is the prime site of ATP7B action in the elimination of excess Cu+.
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Affiliation(s)
- Vasiliki Lalioti
- Department of Cell Biology and Immunology, Centro de Biología Molecular Severo Ochoa, Cantoblanco, 28049 Madrid, Spain
| | - Ramón Peiró
- Genomics and Massive Sequencing, Centro de Biología Molecular Severo Ochoa, Cantoblanco, 28049 Madrid, Spain
| | - Manuela Pérez-Berlanga
- Department of Cell Biology and Immunology, Centro de Biología Molecular Severo Ochoa, Cantoblanco, 28049 Madrid, Spain
| | - Yo Tsuchiya
- Department of Cell Biology and Immunology, Centro de Biología Molecular Severo Ochoa, Cantoblanco, 28049 Madrid, Spain
| | - Angeles Muñoz
- Optical and Confocal Microscopy, Centro de Biología Molecular Severo Ochoa, Cantoblanco, 28049 Madrid, Spain
| | - Teresa Villalba
- Optical and Confocal Microscopy, Centro de Biología Molecular Severo Ochoa, Cantoblanco, 28049 Madrid, Spain
| | - Carlos Sanchez
- Optical and Confocal Microscopy, Centro de Biología Molecular Severo Ochoa, Cantoblanco, 28049 Madrid, Spain
| | - Ignacio V. Sandoval
- Department of Cell Biology and Immunology, Centro de Biología Molecular Severo Ochoa, Cantoblanco, 28049 Madrid, Spain
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21
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Braiterman LT, Gupta A, Chaerkady R, Cole RN, Hubbard AL. Communication between the N and C termini is required for copper-stimulated Ser/Thr phosphorylation of Cu(I)-ATPase (ATP7B). J Biol Chem 2015; 290:8803-19. [PMID: 25666620 DOI: 10.1074/jbc.m114.627414] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Indexed: 11/06/2022] Open
Abstract
The Wilson disease protein ATP7B exhibits copper-dependent trafficking. In high copper, ATP7B exits the trans-Golgi network and moves to the apical domain of hepatocytes where it facilitates elimination of excess copper through the bile. Copper levels also affect ATP7B phosphorylation. ATP7B is basally phosphorylated in low copper and becomes more phosphorylated ("hyperphosphorylated") in elevated copper. The functional significance of hyperphosphorylation remains unclear. We showed that hyperphosphorylation occurs even when ATP7B is restricted to the trans-Golgi network. We performed comprehensive phosphoproteomics of ATP7B in low versus high copper, which revealed that 24 Ser/Thr residues in ATP7B could be phosphorylated, and only four of these were copper-responsive. Most of the phosphorylated sites were found in the N- and C-terminal cytoplasmic domains. Using truncation and mutagenesis, we showed that inactivation or elimination of all six N-terminal metal binding domains did not block copper-dependent, reversible, apical trafficking but did block hyperphosphorylation in hepatic cells. We showed that nine of 15 Ser/Thr residues in the C-terminal domain were phosphorylated. Inactivation of 13 C-terminal phosphorylation sites reduced basal phosphorylation and eliminated hyperphosphorylation, suggesting that copper binding at the N terminus propagates to the ATP7B C-terminal region. C-terminal mutants with either inactivating or phosphomimetic substitutions showed little effect upon copper-stimulated trafficking, indicating that trafficking does not depend on phosphorylation at these sites. Thus, our studies revealed that copper-dependent conformational changes in the N-terminal region lead to hyperphosphorylation at C-terminal sites, which seem not to affect trafficking and may instead fine-tune copper sequestration.
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Affiliation(s)
| | | | - Raghothama Chaerkady
- the Mass Spectrometry and Proteomics Facility, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Robert N Cole
- the Mass Spectrometry and Proteomics Facility, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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22
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Jain S, Farías GG, Bonifacino JS. Polarized sorting of the copper transporter ATP7B in neurons mediated by recognition of a dileucine signal by AP-1. Mol Biol Cell 2014; 26:218-28. [PMID: 25378584 PMCID: PMC4294670 DOI: 10.1091/mbc.e14-07-1177] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Recognition of dileucine signals by AP-1 mediates somatodendritic sorting of the copper transporter ATP7B and the SNARE VAMP4 in hippocampal neurons, establishing AP-1 as a global regulator of polarized sorting and contributing to the understanding of neuronal copper metabolism under physiological and pathological conditions. Neurons are highly polarized cells having distinct somatodendritic and axonal domains. Here we report that polarized sorting of the Cu2+ transporter ATP7B and the vesicle-SNARE VAMP4 to the somatodendritic domain of rat hippocampal neurons is mediated by recognition of dileucine-based signals in the cytosolic domains of the proteins by the σ1 subunit of the clathrin adaptor AP-1. Under basal Cu2+ conditions, ATP7B was localized to the trans-Golgi network (TGN) and the plasma membrane of the soma and dendrites but not the axon. Mutation of a dileucine-based signal in ATP7B or overexpression of a dominant-negative σ1 mutant resulted in nonpolarized distribution of ATP7B between the somatodendritic and axonal domains. Furthermore, addition of high Cu2+ concentrations, previously shown to reduce ATP7B incorporation into AP-1–containing clathrin-coated vesicles, caused loss of TGN localization and somatodendritic polarity of ATP7B. These findings support the notion of AP-1 as an effector of polarized sorting in neurons and suggest that altered polarity of ATP7B in polarized cell types might contribute to abnormal copper metabolism in the MEDNIK syndrome, a neurocutaneous disorder caused by mutations in the σ1A subunit isoform of AP-1.
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Affiliation(s)
- Shweta Jain
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Ginny G Farías
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Juan S Bonifacino
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
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23
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Nyasae LK, Schell MJ, Hubbard AL. Copper directs ATP7B to the apical domain of hepatic cells via basolateral endosomes. Traffic 2014; 15:1344-65. [PMID: 25243755 DOI: 10.1111/tra.12229] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 09/16/2014] [Indexed: 01/01/2023]
Abstract
Physiologic Cu levels regulate the intracellular location of the Cu ATPase ATP7B. Here, we determined the routes of Cu-directed trafficking of endogenous ATP7B in the polarized hepatic cell line WIF-B and in the liver in vivo. Copper (10 µm) caused ATP7B to exit the trans-Golgi network (TGN) in vesicles, which trafficked via large basolateral endosomes to the apical domain within 1 h. Although perturbants of luminal acidification had little effect on the TGN localization of ATP7B in low Cu, they blocked delivery to the apical membrane in elevated Cu. If the vesicular proton-pump inhibitor bafilomycin-A1 (Baf) was present with Cu, ATP7B still exited the TGN, but accumulated in large endosomes located near the coverslip, in the basolateral region. Baf washout restored ATP7B trafficking to the apical domain. If ATP7B was staged apically in high Cu, Baf addition promoted the accumulation of ATP7B in subapical endosomes, indicating a blockade of apical recycling, with concomitant loss of ATP7B at the apical membrane. The retrograde pathway to the TGN, induced by Cu removal, was far less affected by Baf than the anterograde (Cu-stimulated) case. Overall, loss of acidification-impaired Cu-regulated trafficking of ATP7B at two main sites: (i) sorting and exit from large basolateral endosomes and (ii) recycling via endosomes near the apical membrane.
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Affiliation(s)
- Lydia K Nyasae
- Department of Cell Biology, The Johns Hopkins School of Medicine, 725 N. Wolfe Street, Baltimore, MD, 20184, USA
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24
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Lalioti V, Hernandez-Tiedra S, Sandoval IV. DKWSLLL, a versatile DXXXLL-type signal with distinct roles in the Cu(+)-regulated trafficking of ATP7B. Traffic 2014; 15:839-60. [PMID: 24831241 DOI: 10.1111/tra.12176] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 05/09/2014] [Accepted: 05/09/2014] [Indexed: 11/27/2022]
Abstract
In the liver, the P-type ATPase and membrane pump ATP7B plays a crucial role in Cu(+) donation to cuproenzymes and in the elimination of excess Cu(+). ATP7B is endowed with a COOH-cytoplasmic (DE)XXXLL-type traffic signal. We find that accessory (Lys -3, Trp -2, Ser -1 and Leu +2) and canonical (D -4, Leu 0 and Leu +1) residues confer the DKWSLLL signal with the versatility required for the Cu(+)-regulated cycling of ATP7B between the trans-Golgi network (TGN) and the plasma membrane (PM). The separate mutation of these residues caused a disruption of the signal, resulting in different ATP7B distribution phenotypes. These phenotypes indicate the key roles of specific residues at separate steps of ATP7B trafficking, including sorting at the TGN, transport from the TGN to the PM and its endocytosis, and recycling to the TGN and PM. The distinct roles of ATP7B in the TGN and PM and the variety of phenotypes caused by the mutation of the canonical and accessory residues of the DKWSLLL signal can explain the separate or joined presentation of Wilson's cuprotoxicosis and the dysfunction of the cuproenzymes that accept Cu(+) at the TGN.
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Affiliation(s)
- Vasiliki Lalioti
- Centro Biología Molecular Severo Ochoa, Cantoblanco, 28049, Madrid, Spain
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Distinct phenotype of a Wilson disease mutation reveals a novel trafficking determinant in the copper transporter ATP7B. Proc Natl Acad Sci U S A 2014; 111:E1364-73. [PMID: 24706876 DOI: 10.1073/pnas.1314161111] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Wilson disease (WD) is a monogenic autosomal-recessive disorder of copper accumulation that leads to liver failure and/or neurological deficits. WD is caused by mutations in ATP7B, a transporter that loads Cu(I) onto newly synthesized cupro-enzymes in the trans-Golgi network (TGN) and exports excess copper out of cells by trafficking from the TGN to the plasma membrane. To date, most WD mutations have been shown to disrupt ATP7B activity and/or stability. Using a multidisciplinary approach, including clinical analysis of patients, cell-based assays, and computational studies, we characterized a patient mutation, ATP7B(S653Y), which is stable, does not disrupt Cu(I) transport, yet renders the protein unable to exit the TGN. Bulky or charged substitutions at position 653 mimic the phenotype of the patient mutation. Molecular modeling and dynamic simulation suggest that the S653Y mutation induces local distortions within the transmembrane (TM) domain 1 and alter TM1 interaction with TM2. S653Y abolishes the trafficking-stimulating effects of a secondary mutation in the N-terminal apical targeting domain. This result indicates a role for TM1/TM2 in regulating conformations of cytosolic domains involved in ATP7B trafficking. Taken together, our experiments revealed an unexpected role for TM1/TM2 in copper-regulated trafficking of ATP7B and defined a unique class of WD mutants that are transport-competent but trafficking-defective. Understanding the precise consequences of WD-causing mutations will facilitate the development of advanced mutation-specific therapies.
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Abstract
Hepatocytes, like other epithelia, are situated at the interface between the organism's exterior and the underlying internal milieu and organize the vectorial exchange of macromolecules between these two spaces. To mediate this function, epithelial cells, including hepatocytes, are polarized with distinct luminal domains that are separated by tight junctions from lateral domains engaged in cell-cell adhesion and from basal domains that interact with the underlying extracellular matrix. Despite these universal principles, hepatocytes distinguish themselves from other nonstriated epithelia by their multipolar organization. Each hepatocyte participates in multiple, narrow lumina, the bile canaliculi, and has multiple basal surfaces that face the endothelial lining. Hepatocytes also differ in the mechanism of luminal protein trafficking from other epithelia studied. They lack polarized protein secretion to the luminal domain and target single-spanning and glycosylphosphatidylinositol-anchored bile canalicular membrane proteins via transcytosis from the basolateral domain. We compare this unique hepatic polarity phenotype with that of the more common columnar epithelial organization and review our current knowledge of the signaling mechanisms and the organization of polarized protein trafficking that govern the establishment and maintenance of hepatic polarity. The serine/threonine kinase LKB1, which is activated by the bile acid taurocholate and, in turn, activates adenosine monophosphate kinase-related kinases including AMPK1/2 and Par1 paralogues has emerged as a key determinant of hepatic polarity. We propose that the absence of a hepatocyte basal lamina and differences in cell-cell adhesion signaling that determine the positioning of tight junctions are two crucial determinants for the distinct hepatic and columnar polarity phenotypes.
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Affiliation(s)
- Aleksandr Treyer
- Albert Einstein College of Medicine, Department of Developmental and Molecular Biology, Bronx, New York, USA
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Telianidis J, Hung YH, Materia S, Fontaine SL. Role of the P-Type ATPases, ATP7A and ATP7B in brain copper homeostasis. Front Aging Neurosci 2013; 5:44. [PMID: 23986700 PMCID: PMC3750203 DOI: 10.3389/fnagi.2013.00044] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 08/05/2013] [Indexed: 12/21/2022] Open
Abstract
Over the past two decades there have been significant advances in our understanding of copper homeostasis and the pathological consequences of copper dysregulation. Cumulative evidence is revealing a complex regulatory network of proteins and pathways that maintain copper homeostasis. The recognition of copper dysregulation as a key pathological feature in prominent neurodegenerative disorders such as Alzheimer's, Parkinson's, and prion diseases has led to increased research focus on the mechanisms controlling copper homeostasis in the brain. The copper-transporting P-type ATPases (copper-ATPases), ATP7A and ATP7B, are critical components of the copper regulatory network. Our understanding of the biochemistry and cell biology of these complex proteins has grown significantly since their discovery in 1993. They are large polytopic transmembrane proteins with six copper-binding motifs within the cytoplasmic N-terminal domain, eight transmembrane domains, and highly conserved catalytic domains. These proteins catalyze ATP-dependent copper transport across cell membranes for the metallation of many essential cuproenzymes, as well as for the removal of excess cellular copper to prevent copper toxicity. A key functional aspect of these copper transporters is their copper-responsive trafficking between the trans-Golgi network and the cell periphery. ATP7A- and ATP7B-deficiency, due to genetic mutation, underlie the inherited copper transport disorders, Menkes and Wilson diseases, respectively. Their importance in maintaining brain copper homeostasis is underscored by the severe neuropathological deficits in these disorders. Herein we will review and update our current knowledge of these copper transporters in the brain and the central nervous system, their distribution and regulation, their role in normal brain copper homeostasis, and how their absence or dysfunction contributes to disturbances in copper homeostasis and neurodegeneration.
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Affiliation(s)
- Jonathon Telianidis
- Strategic Research Centre for Molecular and Medical Research, School of Life and Environmental Sciences, Deakin UniversityBurwood, VIC, Australia
- Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin UniversityBurwood, VIC, Australia
| | - Ya Hui Hung
- Oxidation Biology Unit, Florey Institute of Neuroscience and Mental HealthParkville, VIC, Australia
- Centre for Neuroscience Research, The University of MelbourneParkville, VIC, Australia
| | - Stephanie Materia
- Strategic Research Centre for Molecular and Medical Research, School of Life and Environmental Sciences, Deakin UniversityBurwood, VIC, Australia
- Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin UniversityBurwood, VIC, Australia
| | - Sharon La Fontaine
- Strategic Research Centre for Molecular and Medical Research, School of Life and Environmental Sciences, Deakin UniversityBurwood, VIC, Australia
- Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin UniversityBurwood, VIC, Australia
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Polishchuk R, Lutsenko S. Golgi in copper homeostasis: a view from the membrane trafficking field. Histochem Cell Biol 2013; 140:285-95. [PMID: 23846821 DOI: 10.1007/s00418-013-1123-8] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2013] [Indexed: 01/06/2023]
Abstract
Copper is essential for a variety of important biological processes as a cofactor and regulator of many enzymes. Incorporation of copper into the secreted and plasma membrane-targeted cuproenzymes takes place in Golgi, a compartment central for normal copper homeostasis. The Golgi complex harbors copper-transporting ATPases, ATP7A and ATP7B that transfer copper from the cytosol into Golgi lumen for incorporation into copper-dependent enzymes. The Golgi complex also sends these ATPases to appropriate post-Golgi destinations to ensure correct Cu fluxes in the body and to avoid potentially toxic copper accumulation. Mutations in ATP7A or ATP7B or in the proteins that regulate their trafficking affect their exit from Golgi or subsequent retrieval to this organelle. This, in turn, disrupts the homeostatic Cu balance, resulting in copper deficiency (Menkes disease) or copper overload (Wilson disease). Research over the last decade has yielded significant insights into the enzymatic properties and cell biology of the copper ATPases. However, the mechanisms through which the Golgi regulates trafficking of ATP7A/7B and, therefore, maintains Cu homeostasis remain unclear. This review summarizes current data on the role of the Golgi in Cu metabolism and outlines questions and challenges that should be addressed to understand ATP7A and ATP7B trafficking mechanisms in health and disease.
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Affiliation(s)
- Roman Polishchuk
- Telethon Institute of Genetics and Medicine TIGEM, Via Pietro Castellino, 111, 80131 Naples, Italy.
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29
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Timal S, Hoischen A, Lehle L, Adamowicz M, Huijben K, Sykut-Cegielska J, Paprocka J, Jamroz E, van Spronsen FJ, Körner C, Gilissen C, Rodenburg RJ, Eidhof I, Van den Heuvel L, Thiel C, Wevers RA, Morava E, Veltman J, Lefeber DJ. Gene identification in the congenital disorders of glycosylation type I by whole-exome sequencing. Hum Mol Genet 2012; 21:4151-61. [PMID: 22492991 DOI: 10.1093/hmg/dds123] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Congenital disorders of glycosylation type I (CDG-I) form a growing group of recessive neurometabolic diseases. Identification of disease genes is compromised by the enormous heterogeneity in clinical symptoms and the large number of potential genes involved. Until now, gene identification included the sequential application of biochemical methods in blood samples and fibroblasts. In genetically unsolved cases, homozygosity mapping has been applied in consanguineous families. Altogether, this time-consuming diagnostic strategy led to the identification of defects in 17 different CDG-I genes. Here, we applied whole-exome sequencing (WES) in combination with the knowledge of the protein N-glycosylation pathway for gene identification in our remaining group of six unsolved CDG-I patients from unrelated non-consanguineous families. Exome variants were prioritized based on a list of 76 potential CDG-I candidate genes, leading to the rapid identification of one known and two novel CDG-I gene defects. These included the first X-linked CDG-I due to a de novo mutation in ALG13, and compound heterozygous mutations in DPAGT1, together the first two steps in dolichol-PP-glycan assembly, and mutations in PGM1 in two cases, involved in nucleotide sugar biosynthesis. The pathogenicity of the mutations was confirmed by showing the deficient activity of the corresponding enzymes in patient fibroblasts. Combined with these results, the gene defect has been identified in 98% of our CDG-I patients. Our results implicate the potential of WES to unravel disease genes in the CDG-I in newly diagnosed singleton families.
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Affiliation(s)
- Sharita Timal
- Department of Neurology, Institute for Genetic and Metabolic Disease, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
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Hasan NM, Lutsenko S. Regulation of copper transporters in human cells. CURRENT TOPICS IN MEMBRANES 2012; 69:137-61. [PMID: 23046650 DOI: 10.1016/b978-0-12-394390-3.00006-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Copper is essential for normal growth and development of human organisms. The role of copper as a cofactor of important metabolic enzymes, such as cytochrome c oxidase, superoxide dismutase, lysyl oxidase, dopamine-β-hydroxylase, and many others, has been well established. In recent years, new regulatory roles of copper have emerged. Accumulating evidence points to the involvement of copper in lipid metabolism, antimicrobial defense, neuronal activity, resistance of tumor cells to platinum-based chemotherapeutic drugs, kinase-mediated signal transduction, and other essential cellular processes. For many of these processes, the precise mechanism of copper action remains to be established. Nevertheless, it is increasingly clear that many regulatory and signaling events are associated with changes in the intracellular localization and abundance of copper transporters, as well as distinct compartmentalization of copper itself. In this review, we discuss current data on regulation of the localization and abundance of copper transporters in response to metabolic and signaling events in human cells. Regulation by kinase-mediated phosphorylation will be addressed along with the emerging area of the redox-driven control of copper transport. We highlight mechanistic questions that await further testing.
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Affiliation(s)
- Nesrin M Hasan
- Department of Physiology, Johns Hopkins University, Baltimore, MD, USA
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31
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Inesi G. Calcium and copper transport ATPases: analogies and diversities in transduction and signaling mechanisms. J Cell Commun Signal 2011; 5:227-37. [PMID: 21656155 PMCID: PMC3145875 DOI: 10.1007/s12079-011-0136-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 04/28/2011] [Indexed: 12/17/2022] Open
Abstract
The calcium transport ATPase and the copper transport ATPase are members of the P-ATPase family and retain an analogous catalytic mechanism for ATP utilization, including intermediate phosphoryl transfer to a conserved aspartyl residue, vectorial displacement of bound cation, and final hydrolytic cleavage of Pi. Both ATPases undergo protein conformational changes concomitant with catalytic events. Yet, the two ATPases are prototypes of different features with regard to transduction and signaling mechanisms. The calcium ATPase resides stably on membranes delimiting cellular compartments, acquires free Ca2+ with high affinity on one side of the membrane, and releases the bound Ca2+ on the other side of the membrane to yield a high free Ca2+ gradient. These features are a basic requirement for cellular Ca2+ signaling mechanisms. On the other hand, the copper ATPase acquires copper through exchange with donor proteins, and undergoes intracellular trafficking to deliver copper to acceptor proteins. In addition to the cation transport site and the conserved aspartate undergoing catalytic phosphorylation, the copper ATPase has copper binding regulatory sites on a unique N-terminal protein extension, and has also serine residues undergoing kinase assisted phosphorylation. These additional features are involved in the mechanism of copper ATPase intracellular trafficking which is required to deliver copper to plasma membranes for extrusion, and to the trans-Golgi network for incorporation into metalloproteins. Isoform specific glyocosylation contributes to stabilization of ATP7A copper ATPase in plasma membranes.
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Affiliation(s)
- Giuseppe Inesi
- California Pacific Medical Center Research Institute, 475 Brannan Street, San Francisco, CA, 94107, USA,
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