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Mhaske A, Dileep K, Kumar M, Poojary M, Pandhare K, Zhang KY, Scaria V, Binukumar B. ATP7A Clinical Genetics Resource - A comprehensive clinically annotated database and resource for genetic variants in ATP7A gene. Comput Struct Biotechnol J 2020; 18:2347-2356. [PMID: 32994893 PMCID: PMC7501406 DOI: 10.1016/j.csbj.2020.08.021] [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: 06/26/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 12/21/2022] Open
Abstract
ATP7A is a critical copper transporter involved in Menkes Disease, Occipital horn Syndrome and X-linked distal spinal muscular atrophy type 3 which are X linked genetic disorders. These are rare diseases and their genetic epidemiology of the diseases is unknown. A number of genetic variants in the genes have been reported in published literature as well as databases, however, understanding the pathogenicity of variants and genetic epidemiology requires the data to be compiled in a unified format. To this end, we systematically compiled genetic variants from published literature and datasets. Each of the variants were systematically evaluated for evidences with respect to their pathogenicity and classified as per the American College of Medical Genetics and the Association of Molecular Pathologists (ACMG-AMP) guidelines into Pathogenic, Likely Pathogenic, Benign, Likely Benign and Variants of Uncertain Significance. Additional integrative analysis of population genomic datasets provides insights into the genetic epidemiology of the disease through estimation of carrier frequencies in global populations. To deliver a mechanistic explanation for the pathogenicity of selected variants, we also performed molecular modeling studies. Our modeling studies concluded that the small structural distortions observed in the local structures of the protein may lead to the destabilization of the global structure. To the best of our knowledge, ATP7A Clinical Genetics Resource is one of the most comprehensive compendium of variants in the gene providing clinically relevant annotations in gene.
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Affiliation(s)
- Aditi Mhaske
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
| | - K.V. Dileep
- Laboratory for Structural Bioinformatics, Center for Biosystems Dynamics Research, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Mukesh Kumar
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
- Academy of Scientific and Innovative Research, CSIR-IGIB South Campus, Mathura Road, Delhi, India
| | - Mukta Poojary
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
- Academy of Scientific and Innovative Research, CSIR-IGIB South Campus, Mathura Road, Delhi, India
| | - Kavita Pandhare
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
- Academy of Scientific and Innovative Research, CSIR-IGIB South Campus, Mathura Road, Delhi, India
| | - Kam Y.J. Zhang
- Laboratory for Structural Bioinformatics, Center for Biosystems Dynamics Research, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Vinod Scaria
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
- Academy of Scientific and Innovative Research, CSIR-IGIB South Campus, Mathura Road, Delhi, India
- Corresponding author at: CSIR-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, Sukhdev Vihar, New Delhi 110025, India.
| | - B.K. Binukumar
- CSIR Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110 025, India
- Academy of Scientific and Innovative Research, CSIR-IGIB South Campus, Mathura Road, Delhi, India
- Corresponding author at: CSIR-Institute of Genomics and Integrative Biology (IGIB), Mathura Road, Sukhdev Vihar, New Delhi 110025, India.
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de Gemmis P, Enzo MV, Lorenzetto E, Cattelan P, Segat D, Hladnik U. 13 novel putative mutations in ATP7A found in a cohort of 25 Italian families. Metab Brain Dis 2017; 32:1173-1183. [PMID: 28451781 DOI: 10.1007/s11011-017-0010-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 04/03/2017] [Indexed: 01/09/2023]
Abstract
ATP7A is a copper-transporting P-type adenosine triphosphatase whose loss of function leads to the Menkes disease, an X-linked copper metabolism multi-organ disorder (1 in 100.000 births). Here we document our experience with the ATP7A linked diseases in Italy. We analyzed the exonic structure of the ATP7A gene in 25 unrelated Italian families and studied the variants of unknown significance. We identified 22 different DNA alterations, 13 of which first reported in this study. The classical Menkes phenotype was present in 21 of the 25 families and was linked with highly damaging mutations (7 nonsense; 4 frame-shift; 2 small in-frame deletions, 2 splice site alterations, 2 gross deletions, and 1 gross duplication). Of the 4 cases with milder variants of the Menkes disease two had a missense mutation, one a leaky splice site alteration and one a nonsense mutation in exon 22. We determined in silico that all the mutations leading to the classical Menkes disease leave no residual activity of ATP7A including the apparently less severe in-frame deletions. Whereas milder forms of the disease are characterized by mutations that allow a limited residual activity of ATP7A, including the nonsense mutation observed.
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Affiliation(s)
- Paola de Gemmis
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy
| | - Maria Vittoria Enzo
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy
| | - Elisa Lorenzetto
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy
| | - Paola Cattelan
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy
| | - Daniela Segat
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy
| | - Uros Hladnik
- "Mauro Baschirotto" Institute for Rare Diseases - B.I.R.D. Foundation n.p.o., via B. Bizio, 1 36023, Costozza di Longare, Vicenza, Italy.
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Moizard MP, Ronce N, Blesson S, Bieth E, Burglen L, Mignot C, Mortemousque I, Marmin N, Dessay B, Danesino C, Feillet F, Castelnau P, Toutain A, Moraine C, Raynaud M. Twenty-five novel mutations including duplications in the ATP7A gene. Clin Genet 2015; 79:243-53. [PMID: 21208200 DOI: 10.1111/j.1399-0004.2010.01461.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Twenty-five novel mutations including duplications in the ATP7A gene. Menkes disease (MD) and occipital horn syndrome (OHS) are allelic X-linked recessive copper deficiency disorders resulting from ATP7A gene mutations. MD is a severe condition leading to progressive neurological degeneration and death in early childhood, whereas OHS has a milder phenotype with mainly connective tissue abnormalities. Until now, molecular analyses have revealed only deletions and point mutations in both diseases. This study reports new molecular data in a series of 40 patients referred for either MD or OHS. We describe 23 point mutations (9 missense mutations, 7 splice site variants, 4 nonsense mutations, and 3 small insertions or deletions) and 7 intragenic deletions. Of these, 18 point mutations and 3 deletions are novel. Furthermore, our finding of four whole exon duplications enlarges the mutation spectrum in the ATP7A gene. ATP7A alterations were found in 85% of cases. Of these alterations, two thirds were point mutations and the remaining one third consisted of large rearrangements. We found that 66.6% of point mutations resulted in impaired ATP7A transcript splicing, a phenomenon more frequent than expected. This finding enabled us to confirm the pathogenic role of ATP7A mutations, particularly in missense and splice site variants.
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Affiliation(s)
- M-P Moizard
- CHRU de Tours, Service de Génétique, Tours, F-37044, France INSERM U930, Tours, F-37044, France CHU Hôpital Purpan, Service de Génétique médicale, Toulouse, F-31059, France CHU Hôpital d'Enfants Armand-Trousseau, AP-HP, Service de Génétique et Embryologie médicales, Paris, F-75571, France CHU Hôpital d'Enfants Armand-Trousseau, AP-HP, Service de Neuropédiatrie, Paris, F-75012, France Genetica Medica, Università di Pavia, Fondazione IRCCS S. Matteo, Pavia, I-27100, Italie Centre de Référence des Maladies Héréditaires du Métabolisme, INSERM U954. Hôpital d'Enfants, Vandoeuvre les Nancy, F-54511, France CHRU de Tours, Service de Neuropédiatrie, Tours, F-37044 France; Université François Rabelais Tours, F-37044, France
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Tümer Z. An overview and update of ATP7A mutations leading to Menkes disease and occipital horn syndrome. Hum Mutat 2013; 34:417-29. [PMID: 23281160 DOI: 10.1002/humu.22266] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/11/2012] [Indexed: 01/28/2023]
Abstract
Menkes disease (MD) is a lethal multisystemic disorder of copper metabolism. Progressive neurodegeneration and connective tissue disturbances, together with the peculiar "kinky" hair, are the main manifestations. MD is inherited as an X-linked recessive trait, and as expected the vast majority of patients are males. MD occurs because of mutations in the ATP7A gene and the vast majority of ATP7A mutations are intragenic mutations or partial gene deletions. ATP7A is an energy-dependent transmembrane protein, which is involved in the delivery of copper to the secreted copper enzymes and in the export of surplus copper from cells. Severely affected MD patients die usually before the third year of life. A cure for the disease does not exist, but very early copper-histidine treatment may correct some of the neurological symptoms. This study reviews 274 published and 18 novel disease causing mutations identified in 370 unrelated MD patients, nonpathogenic variants of ATP7A, functional studies of the ATP7A mutations, and animal models of MD.
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Affiliation(s)
- Zeynep Tümer
- Applied Human Molecular Genetics, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Glostrup, Denmark.
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Prasad AN, Levin S, Rupar CA, Prasad C. Menkes disease and infantile epilepsy. Brain Dev 2011; 33:866-76. [PMID: 21924848 DOI: 10.1016/j.braindev.2011.08.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 07/26/2011] [Accepted: 08/03/2011] [Indexed: 12/16/2022]
Abstract
OBJECTIVES Menkes disease, an X linked recessive neurodegenerative disorder, results from a mutation in the gene coding for the copper transporting ATPase (ATP7A). Epilepsy is a major clinical feature of this disorder. We describe the clinical presentation, evolution of epilepsy and explore the biological underpinnings of epileptogenesis in Menkes disease. METHODS Longitudinal case study illustrating the natural history of epilepsy and results of subcutaneous cupric chloride supplementation in a patient with Menkes disease and literature review. RESULTS The onset and evolution of epilepsy in Menkes disease is marked by different stages. Early presentations typically involve focal seizures, with progression to epileptic spasms and a chronic late stage of epilepsy characterized by tonic seizures, myoclonic jerks, and multifocal epileptiform activity on the EEG. Morphological correlates in the brain include evidence of atrophy of grey matter, ventriculomegaly, tortuous intracranial vasculature, and white matter signal changes consistent with loss of myelin and axons. The presence of significant lactic acidosis in brain and cerebrospinal fluid suggests widespread disturbance in oxidative metabolism. Molecular consequences of the pathogenic ATP7A gene mutation lead to impairment in copper transport, which in turn causes deficiencies of key copper containing enzymes (dopamine β hydroxylase and cytochrome c oxidase). Microarray studies suggest widespread effects in dysregulation of genes involved in cellular responses to oxidative stress, ribosomal translation, signal transduction, mitochondrial function, and immune responses. Impairment of copper mediated NMDA receptor function further enhances neuronal excitability, excitotoxic neuronal injury, setting up a cascade that creates conditions for epileptogenesis to follow. CONCLUSION Neurological manifestations are likely related to perturbations in copper dependent enzymatic pathways involved in neurotransmitter and energy metabolism. Early diagnosis and institution of copper supplementation has been shown to be beneficial particularly in patients with residual ATP7A activity.
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Affiliation(s)
- Asuri N Prasad
- Department of Pediatrics, University of Western Ontario, London, Ontario, Canada.
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Vonk WIM, de Bie P, Wichers CGK, van den Berghe PVE, van der Plaats R, Berger R, Wijmenga C, Klomp LWJ, van de Sluis B. The copper-transporting capacity of ATP7A mutants associated with Menkes disease is ameliorated by COMMD1 as a result of improved protein expression. Cell Mol Life Sci 2011; 69:149-63. [PMID: 21667063 PMCID: PMC3249196 DOI: 10.1007/s00018-011-0743-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 05/26/2011] [Accepted: 05/30/2011] [Indexed: 01/02/2023]
Abstract
Menkes disease (MD) is an X-linked recessive disorder characterized by copper deficiency resulting in a diminished function of copper-dependent enzymes. Most MD patients die in early childhood, although mild forms of MD have also been described. A diversity of mutations in the gene encoding of the Golgi-resident copper-transporting P1B-type ATPase ATP7A underlies MD. To elucidate the molecular consequences of the ATP7A mutations, various mutations in ATP7A associated with distinct phenotypes of MD (L873R, C1000R, N1304S, and A1362D) were analyzed in detail. All mutants studied displayed changes in protein expression and intracellular localization parallel to a dramatic decline in their copper-transporting capacity compared to ATP7A the wild-type. We restored these observed defects in ATP7A mutant proteins by culturing the cells at 30°C, which improves the quality of protein folding, similar to that which as has recently has been demonstrated for misfolded ATP7B, a copper transporter homologous to ATP7A. Further, the effect of the canine copper toxicosis protein COMMD1 on ATP7A function was examined as COMMD1 has been shown to regulate the proteolysis of ATP7B proteins. Interestingly, in addition to adjusted growth temperature, binding of COMMD1 partially restored the expression, subcellular localization, and copper-exporting activities of the ATP7A mutants. However, no effect of pharmacological chaperones was observed. Together, the presented data might provide a new direction for developing therapies to improve the residual exporting activity of unstable ATP7A mutant proteins, and suggests a potential role for COMMD1 in this process.
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Affiliation(s)
- Willianne I M Vonk
- Department of Metabolic and Endocrine Diseases, Netherlands Metabolomics Center, University Medical Center Utrecht, 3584 EA Utrecht, The Netherlands
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Skjørringe T, Tümer Z, Møller LB. Splice site mutations in the ATP7A gene. PLoS One 2011; 6:e18599. [PMID: 21494555 PMCID: PMC3073976 DOI: 10.1371/journal.pone.0018599] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Accepted: 03/06/2011] [Indexed: 01/20/2023] Open
Abstract
Menkes disease (MD) is caused by mutations in the ATP7A gene. We describe 33 novel splice site mutations detected in patients with MD or the milder phenotypic form, Occipital Horn Syndrome. We review these 33 mutations together with 28 previously published splice site mutations. We investigate 12 mutations for their effect on the mRNA transcript in vivo. Transcriptional data from another 16 mutations were collected from the literature. The theoretical consequences of splice site mutations, predicted with the bioinformatics tool Human Splice Finder, were investigated and evaluated in relation to in vivo results. Ninety-six percent of the mutations identified in 45 patients with classical MD were predicted to have a significant effect on splicing, which concurs with the absence of any detectable wild-type transcript in all 19 patients investigated in vivo. Sixty-seven percent of the mutations identified in 12 patients with milder phenotypes were predicted to have no significant effect on splicing, which concurs with the presence of wild-type transcript in 7 out of 9 patients investigated in vivo. Both the in silico predictions and the in vivo results support the hypothesis previously suggested by us and others, that the presence of some wild-type transcript is correlated to a milder phenotype.
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Affiliation(s)
- Tina Skjørringe
- Department of Applied Functional Human Genetics, The Kennedy Center, Glostrup, Denmark
| | - Zeynep Tümer
- Department of Applied Functional Human Genetics, The Kennedy Center, Glostrup, Denmark
| | - Lisbeth Birk Møller
- Department of Applied Functional Human Genetics, The Kennedy Center, Glostrup, Denmark
- * E-mail:
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Yan S, Wu G. Quantitative relationship between mutated amino-acid sequence of human copper-transporting ATPases and their related diseases. Mol Divers 2008; 12:119-29. [PMID: 18688737 DOI: 10.1007/s11030-008-9084-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Accepted: 07/19/2008] [Indexed: 02/03/2023]
Abstract
Copper-transporting ATPase 1 and 2 (ATP7A and ATP7B) are two highly homologous P-type copper ATPase exporters. Mutations in ATP7A can lead to Menkes disease which is an X-linked disorder of copper deficiency. Mutations in ATP7B can cause Wilson disease which is an autosomal recessive disorder of copper toxicity. In this study, we attempt to build a quantitative relationship between mutated ATPase and Menkes/Wilson disease. First, we use the amino-acid distribution probability as a measure to quantify the difference in ATPase before and after mutation. Second, we use the cross-impact analysis to define the quantitative relationship between mutant ATPase protein and Menkes/Wilson disease, and compute various probabilities. Finally, we use the Bayesian equation to determine the probability that Menkes/Wilson disease is diagnosed under a mutation. The results show (i) the vast majority of mutations lead to the amino-acid distribution probability increase in mutant ATP7As and decrease in ATP7Bs, and (ii) the probability that a mutation causes Menkes/Wilson disease is about nine tenth. Thus we provide a way to use the descriptively probabilistic method to couple the mutation with its clinical outcome after quantifying mutations in proteins.
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Affiliation(s)
- Shaomin Yan
- Guangxi Academy of Sciences, 98 Daling Road, Nanning, Guangxi, 530007, China
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Møller LB, Bukrinsky JT, Mølgaard A, Paulsen M, Lund C, Tümer Z, Larsen S, Horn N. Identification and analysis of 21 novel disease-causing amino acid substitutions in the conserved part of ATP7A. Hum Mutat 2006; 26:84-93. [PMID: 15981243 DOI: 10.1002/humu.20190] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ATP7A encodes a copper-translocating ATPase that belongs to the large family of P-type ATPases. Eight conserved regions define the core of the P-type ATPase superfamily. We report here the identification of 21 novel missense mutations in the conserved part of ATP7A that encodes the residues p.V842-p.S1404. Using the coordinates of X-ray crystal structures of the sarcoplasmic reticulum Ca(2+)-ATPase, as determined in the presence and absence of Ca(2+), we created structural homology models of ATP7A. By mapping the substituted residues onto the models, we found that these residues are more clustered three-dimensionally than expected from the primary sequence. The location of the substituted residues in conserved regions supports the functional similarities between the two types of P-type ATPases. An immunofluorescence analysis of Menkes fibroblasts suggested that the localization of a large number of the mutated ATP7A protein variants was correct. In the absence of copper, they were located in perinuclear regions of the cells, just like the wild type. However, two of the mutated ATP7A variants showed only partly correct localization, and in five cultures no ATP7A protein could be detected. These findings suggest that although a disease-causing mutation may indicate a functional significance of the affected residue, this is not always the case.
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Hsi G, Cox DW. A comparison of the mutation spectra of Menkes disease and Wilson disease. Hum Genet 2003; 114:165-72. [PMID: 14579150 DOI: 10.1007/s00439-003-1045-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2003] [Accepted: 09/22/2003] [Indexed: 01/23/2023]
Abstract
The genes for two copper-transporting ATPases, ATP7A and ATP7B, are defective in the heritable disorders of copper imbalance, Menkes disease (MNK) and Wilson disease (WND), respectively. A comparison of the two proteins shows extensive conservation in the signature domains, with amino acid identities outside of the conserved domains being limited. The mutation spectra of MNK and WND were compared to confirm and refine further regions critical for normal function. Mutations were found to be relatively widespread; however, the majority was concentrated within defined functional domains and membrane-spanning segments, reinforcing the importance of these regions for protein function. Of the total published point mutations in ATP7A, 23.0% are splice-site, 20.7% nonsense, 17.2% missense, and 39.1% small insertions/deletions. There is a high prevalence (58.2%) of missense mutations in ATP7B. For the other mutations in ATP7B, 7.4% are splice-site, 7.4% nonsense, and 27.0% small insertions/deletions. A region of possible importance is the intervening sequence between the last copper-binding domain and the first transmembrane helix, as this region has a high percentage of MNK mutations. Similarly, the region containing the ATP-binding domain has 24.6% of all WND mutations. The study of mutation locations is useful for defining critical regions or residues and for efficient molecular diagnosis.
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Affiliation(s)
- Gloria Hsi
- Department of Medical Genetics, 8-39 Medical Sciences Building, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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Petris MJ, Voskoboinik I, Cater M, Smith K, Kim BE, Llanos RM, Strausak D, Camakaris J, Mercer JFB. Copper-regulated trafficking of the Menkes disease copper ATPase is associated with formation of a phosphorylated catalytic intermediate. J Biol Chem 2002; 277:46736-42. [PMID: 12228238 DOI: 10.1074/jbc.m208864200] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Menkes protein (MNK; ATP7A) is a copper-transporting P-type ATPase that is defective in the copper deficiency disorder, Menkes disease. MNK is localized in the trans-Golgi network and transports copper to enzymes synthesized within secretory compartments. However, in cells exposed to excessive copper, MNK traffics to the plasma membrane where it functions in copper efflux. A conserved feature of all P-type ATPases is the formation of an acyl-phosphate intermediate, which occurs as part of the catalytic cycle during cation transport. In this study we investigated the effect of mutations within conserved catalytic regions of MNK on intracellular localization and trafficking from the trans-Golgi network (TGN). Our findings suggest that mutations that block formation of the phosphorylated catalytic intermediate also prevent copper-induced relocalization of MNK from the TGN. Furthermore, mutations in the phosphatase domain, which resulted in hyperphosphorylation of MNK, caused constitutive trafficking from the TGN to the plasma membrane. A similar effect on trafficking was observed with a phosphatase mutation in the closely related copper ATPase, ATP7B, affected in Wilson disease. These findings suggest that the copper-induced trafficking of the Menkes and Wilson disease copper ATPases is associated with the phosphorylated intermediate that is formed during the catalysis of these pumps. Our findings describe a novel mechanism for regulating the subcellular location of a transport protein involving the recognition of intermediate conformations during catalysis.
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Affiliation(s)
- Michael J Petris
- Department of Nutritional Sciences, University of Missouri, Columbia, Missouri 65211, USA
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Gu YH, Kodama H, Sato E, Mochizuki D, Yanagawa Y, Takayanagi M, Sato K, Ogawa A, Ushijima H, Lee CC. Prenatal diagnosis of Menkes disease by genetic analysis and copper measurement. Brain Dev 2002; 24:715-8. [PMID: 12427520 DOI: 10.1016/s0387-7604(02)00093-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Carrier detection for 12 women and prenatal diagnosis for six fetuses in Japanese families with a patient with Menkes disease (MNK) were performed by gene analysis and/or measurement of the copper concentration in cultured cells. Six out of eight mothers of MNK patients were carriers while two (25%) were not carriers. Two unrelated patients showed the same mutation (R986X): one patient's mother was a carrier while the other was not. One male and three female fetuses did not have the same mutant allele as the respective MNK proband and have been healthy since birth. One female fetus had the same mutant allele as her affected brother. Gene analysis is very useful and reliable, although such examination is only indicated in families in which a mutation has been identified. In one family in which a mutation in ATP7A was not found, cultured amniocytes from a male fetus had a high copper concentration. Thus after his birth, the biochemical findings confirmed the presence of MNK and early treatment was started. As his early treatment with parenteral copper-histidine prevented the neurological disorders effectively, prenatal diagnosis is very important.
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Affiliation(s)
- Yan-hong Gu
- Department of Pediatrics, School of Medicine, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8606, Japan
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Hahn S, Cho K, Ryu K, Kim J, Pai K, Kim M, Park H, Yoo O. Identification of four novel mutations in classical Menkes disease and successful prenatal DNA diagnosis. Mol Genet Metab 2001; 73:86-90. [PMID: 11350187 DOI: 10.1006/mgme.2001.3169] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Menkes disease is an X-linked recessive disorder of the copper metabolism and affected males suffer a systemic copper deficiency due to malabsorption and defective distribution of dietary copper. It is caused by a defect in the Menkes (ATP7A) gene, which encodes a transmembrane copper-transporting P-type ATPase. A variety of mutations were reported; however, only a few mutations were reported in Asian patients. We identified four novel mutations and one known mutation in five Korean patients. Arg646Ter in exon 8, a novel mutation transmitted from his carrier mother, was identified in one patient. Prenatal DNA diagnosis on an unaffected fetus in this carrier mother was successfully accomplished. An additional three novel mutations, Leu706Arg in exon 9, Gly1118Asp in exon 17, and Gly1255Arg in exon 19, were identified. Splicing mutation was not identified. Menkes disease in Korean patients appears to be caused by heterogeneous mutations with different spectrums from Caucasian patients.
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Affiliation(s)
- S Hahn
- Department of Pediatrics, Ajou University, School of Medicine, 5 Wonchon-dong, Paldal-gu, Suwon, Korea 442-721.
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