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Hassan N, Gregson CL, Tang H, van der Kamp M, Leo P, McInerney‐Leo AM, Zheng J, Brandi ML, Tang JCY, Fraser W, Stone MD, Grundberg E, Brown MA, Duncan EL, Tobias JH. Rare and Common Variants in GALNT3 May Affect Bone Mass Independently of Phosphate Metabolism. J Bone Miner Res 2023; 38:678-691. [PMID: 36824040 PMCID: PMC10729283 DOI: 10.1002/jbmr.4795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 02/15/2023] [Accepted: 02/22/2023] [Indexed: 02/25/2023]
Abstract
Anabolic treatment options for osteoporosis remain limited. One approach to discovering novel anabolic drug targets is to identify genetic causes of extreme high bone mass (HBM). We investigated a pedigree with unexplained HBM within the UK HBM study, a national cohort of probands with HBM and their relatives. Whole exome sequencing (WES) in a family with HBM identified a rare heterozygous missense variant (NM_004482.4:c.1657C > T, p.Arg553Trp) in GALNT3, segregating appropriately. Interrogation of data from the UK HBM study and the Anglo-Australasian Osteoporosis Genetics Consortium (AOGC) revealed an unrelated individual with HBM with another rare heterozygous variant (NM_004482.4:c.831 T > A, p.Asp277Glu) within the same gene. In silico protein modeling predicted that p.Arg553Trp would disrupt salt-bridge interactions, causing instability of GALNT3, and that p.Asp277Glu would disrupt manganese binding and consequently GALNT3 catalytic function. Bi-allelic loss-of-function GALNT3 mutations alter FGF23 metabolism, resulting in hyperphosphatemia and causing familial tumoral calcinosis (FTC). However, bone mineral density (BMD) in FTC cases, when reported, has been either normal or low. Common variants in the GALNT3 locus show genome-wide significant associations with lumbar, femoral neck, and total body BMD. However, no significant associations with BMD are observed at loci coding for FGF23, its receptor FGFR1, or coreceptor klotho. Mendelian randomization analysis, using expression quantitative trait loci (eQTL) data from primary human osteoblasts and genome-wide association studies data from UK Biobank, suggested increased expression of GALNT3 reduces total body, lumbar spine, and femoral neck BMD but has no effect on phosphate concentrations. In conclusion, rare heterozygous loss-of-function variants in GALNT3 may cause HBM without altering phosphate concentration. These findings suggest that GALNT3 may affect BMD through pathways other than FGF23 regulation, the identification of which may yield novel anabolic drug targets for osteoporosis. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Neelam Hassan
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
| | - Celia L. Gregson
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
| | - Haotian Tang
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
| | | | - Paul Leo
- Faculty of Health, Translational Genomics Group, Institute of Health and Biomedical InnovationQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Aideen M. McInerney‐Leo
- The Faculty of Medicine, Frazer InstituteThe University of QueenslandWoolloongabbaQueenslandAustralia
| | - Jie Zheng
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai National Clinical Research Center for metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR ChinaShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory for Endocrine Tumor, State Key Laboratory of Medical Genomics, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | | | - Jonathan C. Y. Tang
- Norwich Medical SchoolUniversity of East AngliaNorwichUK
- Clinical Biochemistry, Departments of Laboratory MedicineNorfolk and Norwich University Hospital NHS Foundation TrustNorwichUK
| | - William Fraser
- Norwich Medical SchoolUniversity of East AngliaNorwichUK
- Department of Diabetes, Endocrinology and Clinical BiochemistryNorfolk and Norwich University Hospital NHS Foundation TrustNorwichUK
| | - Michael D. Stone
- University Hospital LlandoughCardiff & Vale University Health BoardCardiffUK
| | - Elin Grundberg
- Genomic Medicine CenterChildren's Mercy Kansas CityKansas CityMissouriUSA
| | | | | | - Emma L. Duncan
- Department of Twin Research and Genetic Epidemiology, School of Life Course & Population Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
| | - Jonathan H. Tobias
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
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2
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Garay YC, Cejas RB, Lorenz V, Zlocowski N, Parodi P, Ferrero FA, Angeloni G, García VA, Sendra VG, Lardone RD, Irazoqui FJ. Polypeptide N-acetylgalactosamine transferase 3: a post-translational writer on human health. J Mol Med (Berl) 2022; 100:1387-1403. [PMID: 36056254 DOI: 10.1007/s00109-022-02249-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 08/10/2022] [Accepted: 08/17/2022] [Indexed: 10/14/2022]
Abstract
Polypeptide N-acetylgalactosamine transferase 3 (ppGalNAc-T3) is an enzyme involved in the initiation of O-GalNAc glycan biosynthesis. Acting as a writer of frequent post-translational modification (PTM) on human proteins, ppGalNAc-T3 has key functions in the homeostasis of human cells and tissues. We review the relevant roles of this molecule in the biosynthesis of O-GalNAc glycans, as well as in biological functions related to human physiological and pathological conditions. With main emphasis in ppGalNAc-T3, we draw attention to the different ways involved in the modulation of ppGalNAc-Ts enzymatic activity. In addition, we take notice on recent reports of ppGalNAc-T3 having different subcellular localizations, highlight critical intrinsic and extrinsic functions in cellular physiology that are exerted by ppGalNAc-T3-synthesized PTMs, and provide an update on several human pathologies associated with dysfunctional ppGalNAc-T3. Finally, we propose biotechnological tools as new therapeutic options for the treatment of pathologies related to altered ppGalNAc-T3. KEY MESSAGES: ppGalNAc-T3 is a key enzyme in the human O-GalNAc glycans biosynthesis. enzyme activity is regulated by PTMs, lectin domain and protein-protein interactions. ppGalNAc-T3 is located in human Golgi apparatus and cell nucleus. ppGalNAc-T3 has a central role in cell physiology as well as in several pathologies. Biotechnological tools for pathological management are proposed.
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Affiliation(s)
- Yohana Camila Garay
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET and Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina
| | - Romina Beatriz Cejas
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Virginia Lorenz
- Facultad de Bioquímica Y Ciencias Biológicas, Instituto de Salud Y Ambiente del Litoral (ISAL), Universidad Nacional del Litoral (UNL) - Consejo Nacional de Investigaciones Científicas Y Técnicas (CONICET), Santa Fe, Argentina
| | - Natacha Zlocowski
- Centro de Microscopía Electrónica, Facultad de Ciencias Médicas, Instituto de Investigaciones en Ciencias de La Salud (INICSA-CONICET), Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Pedro Parodi
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET and Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina
| | - Franco Alejandro Ferrero
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET and Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina
| | - Genaro Angeloni
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET and Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina
| | - Valentina Alfonso García
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET and Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina
| | - Victor German Sendra
- Center for Translational Ocular Immunology, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - Ricardo Dante Lardone
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET and Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina
| | - Fernando José Irazoqui
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET and Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina.
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3
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Deryusheva EI, Machulin AV, Galzitskaya OV. Structural, Functional, and Evolutionary Characteristics of Proteins with Repeats. Mol Biol 2021. [DOI: 10.1134/s0026893321040038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Kato K, Hansen L, Clausen H. Polypeptide N-acetylgalactosaminyltransferase-Associated Phenotypes in Mammals. Molecules 2021; 26:5504. [PMID: 34576978 PMCID: PMC8472655 DOI: 10.3390/molecules26185504] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 01/31/2023] Open
Abstract
Mucin-type O-glycosylation involves the attachment of glycans to an initial O-linked N-acetylgalactosamine (GalNAc) on serine and threonine residues on proteins. This process in mammals is initiated and regulated by a large family of 20 UDP-GalNAc: polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) (EC 2.4.1.41). The enzymes are encoded by a large gene family (GALNTs). Two of these genes, GALNT2 and GALNT3, are known as monogenic autosomal recessive inherited disease genes with well characterized phenotypes, whereas a broad spectrum of phenotypes is associated with the remaining 18 genes. Until recently, the overlapping functionality of the 20 members of the enzyme family has hindered characterizing the specific biological roles of individual enzymes. However, recent evidence suggests that these enzymes do not have full functional redundancy and may serve specific purposes that are found in the different phenotypes described. Here, we summarize the current knowledge of GALNT and associated phenotypes.
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Affiliation(s)
- Kentaro Kato
- Department of Eco-Epidemiology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
- School of Tropical Medicine and Global Health, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Lars Hansen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark;
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark;
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Herrmann J, Gummi MR, Xia M, van der Giet M, Tölle M, Schuchardt M. Vascular Calcification in Rodent Models-Keeping Track with an Extented Method Assortment. BIOLOGY 2021; 10:biology10060459. [PMID: 34067504 PMCID: PMC8224561 DOI: 10.3390/biology10060459] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/12/2021] [Accepted: 05/20/2021] [Indexed: 02/07/2023]
Abstract
Simple Summary Arterial vessel diseases are the leading cause of death in the elderly and their accelerated pathogenesis is responsible for premature death in patients with chronic renal failure. Since no functioning therapy concepts exist so far, the identification of the main signaling pathways is of current research interest. To develop therapeutic concepts, different experimental rodent models are needed, which should be subject to the 3R principle of Russel and Burch: “Replace, Reduce and Refine”. This review aims to summarize the current available experimental rodent models for studying vascular calcification and their quantification methods. Abstract Vascular calcification is a multifaceted disease and a significant contributor to cardiovascular morbidity and mortality. The calcification deposits in the vessel wall can vary in size and localization. Various pathophysiological pathways may be involved in disease progression. With respect to the calcification diversity, a great number of research models and detection methods have been established in basic research, relying mostly on rodent models. The aim of this review is to provide an overview of the currently available rodent models and quantification methods for vascular calcification, emphasizing animal burden and assessing prospects to use available methods in a way to address the 3R principles of Russel and Burch: “Replace, Reduce and Refine”.
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Affiliation(s)
- Jaqueline Herrmann
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (J.H.); (M.R.G.); (M.X.); (M.v.d.G.); (M.T.)
- Department of Chemistry, Biochemistry and Pharmacy, Freie Universität Berlin, Königin-Luise-Straße 2+4, 14195 Berlin, Germany
| | - Manasa Reddy Gummi
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (J.H.); (M.R.G.); (M.X.); (M.v.d.G.); (M.T.)
| | - Mengdi Xia
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (J.H.); (M.R.G.); (M.X.); (M.v.d.G.); (M.T.)
| | - Markus van der Giet
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (J.H.); (M.R.G.); (M.X.); (M.v.d.G.); (M.T.)
| | - Markus Tölle
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (J.H.); (M.R.G.); (M.X.); (M.v.d.G.); (M.T.)
| | - Mirjam Schuchardt
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (J.H.); (M.R.G.); (M.X.); (M.v.d.G.); (M.T.)
- Correspondence: ; Tel.: +49-30-450-514-690
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6
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Research Models for Studying Vascular Calcification. Int J Mol Sci 2020; 21:ijms21062204. [PMID: 32210002 PMCID: PMC7139511 DOI: 10.3390/ijms21062204] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/17/2020] [Accepted: 03/18/2020] [Indexed: 12/14/2022] Open
Abstract
Calcification of the vessel wall contributes to high cardiovascular morbidity and mortality. Vascular calcification (VC) is a systemic disease with multifaceted contributing and inhibiting factors in an actively regulated process. The exact underlying mechanisms are not fully elucidated and reliable treatment options are lacking. Due to the complex pathophysiology, various research models exist evaluating different aspects of VC. This review aims to give an overview of the cell and animal models used so far to study the molecular processes of VC. Here, in vitro cell culture models of different origins, ex vivo settings using aortic tissue and various in vivo disease-induced animal models are summarized. They reflect different aspects and depict the (patho)physiologic mechanisms within the VC process.
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7
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Boyce AM, Lee AE, Roszko KL, Gafni RI. Hyperphosphatemic Tumoral Calcinosis: Pathogenesis, Clinical Presentation, and Challenges in Management. Front Endocrinol (Lausanne) 2020; 11:293. [PMID: 32457699 PMCID: PMC7225339 DOI: 10.3389/fendo.2020.00293] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/20/2020] [Indexed: 02/02/2023] Open
Abstract
Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare and disabling disorder of fibroblast growth factor 23 (FGF23) deficiency or resistance. The disorder is manifest by hyperphosphatemia, inappropriately increased tubular reabsorption of phosphate and 1,25-dihydroxy-Vitamin D, and ectopic calcifications. HFTC has been associated with autosomal recessive pathogenic variants in: (1) the gene encoding FGF23; (2) GALNT3, which encodes a protein responsible for FGF23 glycosylation; and (3) KL, the gene encoding KLOTHO, a critical co-receptor for FGF23 signaling. An acquired autoimmune form of hyperphosphatemic tumoral calcinosis has also been reported. Periarticular tumoral calcinosis is the primary cause of disability in HFTC, leading to pain, reduced range-of-motion, and impaired physical function. Inflammatory disease is also prominent, including diaphysitis with cortical hyperostosis. Multiple treatment strategies have attempted to manage blood phosphate, reduce pain and inflammation, and address calcifications and their complications. Unfortunately, efficacy data are limited to case reports and small cohorts, and no clearly effective therapies have been identified. The purpose of this review is to provide a background on pathogenesis and clinical presentation in HFTC, discuss current approaches to clinical management, and outline critical areas of need for future research.
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Raghu D, Mobley RJ, Shendy NAM, Perry CH, Abell AN. GALNT3 Maintains the Epithelial State in Trophoblast Stem Cells. Cell Rep 2019; 26:3684-3697.e7. [PMID: 30917321 PMCID: PMC6501849 DOI: 10.1016/j.celrep.2019.02.093] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 09/27/2018] [Accepted: 02/22/2019] [Indexed: 01/06/2023] Open
Abstract
O-GalNAc glycosylation is initiated in the Golgi by glycosyltransferases called GALNTs. Proteomic screens identified >600 O-GalNAc-modified proteins, but the biological relevance of these modifications has been difficult to determine. We have discovered a conserved function for GALNT3 in trophoblast stem (TS) cells, blastocyst trophectoderm, and human mammary epithelial cells (HMECs). The loss of GALNT3 expression in these systems reduces O-GalNAc glycosylation and induces epithelial-mesenchymal transition. Furthermore, Galnt3 expression is reduced in aggressive, mesenchymal claudin-low breast cancer cells. We show that GALNT3 expression controls the O-GalNAc glycosylation of multiple proteins, including E-cadherin in both TS cells and HMECs. The loss of GALNT3 results in the intracellular retention of E-cadherin in the Golgi. Significantly, re-expression of GALNT3 in TS cells increases O-GalNAc glycosylation and restores the epithelial state. Together, these data demonstrate the critical biological role of GALNT3 O-GalNAc glycosylation to promote the epithelial phenotype in TS cells, blastocyst trophectoderm, and HMECs.
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Affiliation(s)
- Deepthi Raghu
- Department of Biological Sciences, University of Memphis, Memphis, TN 38152, USA
| | - Robert J Mobley
- Department of Biological Sciences, University of Memphis, Memphis, TN 38152, USA
| | - Noha A M Shendy
- Department of Biological Sciences, University of Memphis, Memphis, TN 38152, USA; Department of Chemistry, Faculty of Science, Mansoura University, Mansoura 35516, Egypt
| | - Charles H Perry
- Department of Biological Sciences, University of Memphis, Memphis, TN 38152, USA
| | - Amy N Abell
- Department of Biological Sciences, University of Memphis, Memphis, TN 38152, USA; Department of Biomedical Engineering, University of Memphis, Memphis, TN 38152, USA.
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Lorenz V, Cejas RB, Bennett EP, Nores GA, Irazoqui FJ. Functional control of polypeptide GalNAc-transferase 3 through an acetylation site in the C-terminal lectin domain. Biol Chem 2017; 398:1237-1246. [PMID: 28672761 DOI: 10.1515/hsz-2017-0130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 06/21/2017] [Indexed: 11/15/2022]
Abstract
O-GalNAc glycans are important structures in cellular homeostasis. Their biosynthesis is initiated by members of the polypeptide GalNAc-transferase (ppGalNAc-T) enzyme family. Mutations in ppGalNAc-T3 isoform cause diseases (congenital disorders of glycosylation) in humans. The K626 residue located in the C-terminal β-trefoil fold of ppGalNAc-T3 was predicted to be a site with high likelihood of acetylation by CBP/p300 acetyltransferase. We used a site-directed mutagenesis approach to evaluate the role of this acetylation site in biological properties of the enzyme. Two K626 mutants of ppGalNAc-T3 (T3K626Q and T3K626A) had GalNAc-T activities lower than that of wild-type enzyme. Direct and competitive interaction assays revealed that GalNAc recognition by the lectin domain was altered in the mutants. The presence of GlcNAc glycosides affected the interaction of the three enzymes with mucin-derived peptides. In GalNAc-T activity assays, the presence of GlcNAc glycosides significantly inhibited activity of the mutant (T3K626Q) that mimicked acetylation. Our findings, taken together, reveal the crucial role of the K626 residue in the C-terminal β-trefoil fold in biological properties of human ppGalNAc-T3. We propose that acetylated residues on ppGalNAc-T3 function as control points for enzyme activity, and high level of GlcNAc glycosides promote a synergistic regulatory mechanism, leading to a metabolically disordered state.
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Abstract
PURPOSE OF REVIEW We give an update on the etiology and potential treatment options of rare inherited monogenic disorders associated with arterial calcification and calcific cardiac valve disease. RECENT FINDINGS Genetic studies of rare inherited syndromes have identified key regulators of ectopic calcification. Based on the pathogenic principles causing the diseases, these can be classified into three groups: (1) disorders of an increased extracellular inorganic phosphate/inorganic pyrophosphate ratio (generalized arterial calcification of infancy, pseudoxanthoma elasticum, arterial calcification and distal joint calcification, progeria, idiopathic basal ganglia calcification, and hyperphosphatemic familial tumoral calcinosis; (2) interferonopathies (Singleton-Merten syndrome); and (3) others, including Keutel syndrome and Gaucher disease type IIIC. Although some of the identified causative mechanisms are not easy to target for treatment, it has become clear that a disturbed serum phosphate/pyrophosphate ratio is a major force triggering arterial and cardiac valve calcification. Further studies will focus on targeting the phosphate/pyrophosphate ratio to effectively prevent and treat these calcific disease phenotypes.
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MESH Headings
- Abnormalities, Multiple/drug therapy
- Abnormalities, Multiple/genetics
- Abnormalities, Multiple/metabolism
- Aortic Diseases/drug therapy
- Aortic Diseases/genetics
- Aortic Diseases/metabolism
- Basal Ganglia Diseases/drug therapy
- Basal Ganglia Diseases/genetics
- Basal Ganglia Diseases/metabolism
- Calcinosis/drug therapy
- Calcinosis/genetics
- Calcinosis/metabolism
- Cartilage Diseases/drug therapy
- Cartilage Diseases/genetics
- Cartilage Diseases/metabolism
- Dental Enamel Hypoplasia/drug therapy
- Dental Enamel Hypoplasia/genetics
- Dental Enamel Hypoplasia/metabolism
- Diphosphates/metabolism
- Enzyme Replacement Therapy
- Gaucher Disease/drug therapy
- Gaucher Disease/genetics
- Gaucher Disease/metabolism
- Hand Deformities, Congenital/drug therapy
- Hand Deformities, Congenital/genetics
- Hand Deformities, Congenital/metabolism
- Humans
- Hyperostosis, Cortical, Congenital/drug therapy
- Hyperostosis, Cortical, Congenital/genetics
- Hyperostosis, Cortical, Congenital/metabolism
- Hyperphosphatemia/drug therapy
- Hyperphosphatemia/genetics
- Hyperphosphatemia/metabolism
- Interferons/metabolism
- Metacarpus/abnormalities
- Metacarpus/metabolism
- Muscular Diseases/drug therapy
- Muscular Diseases/genetics
- Muscular Diseases/metabolism
- Odontodysplasia/drug therapy
- Odontodysplasia/genetics
- Odontodysplasia/metabolism
- Osteoporosis/drug therapy
- Osteoporosis/genetics
- Osteoporosis/metabolism
- Phosphates/metabolism
- Progeria/drug therapy
- Progeria/genetics
- Progeria/metabolism
- Pseudoxanthoma Elasticum/drug therapy
- Pseudoxanthoma Elasticum/genetics
- Pseudoxanthoma Elasticum/metabolism
- Pulmonary Valve Stenosis/drug therapy
- Pulmonary Valve Stenosis/genetics
- Pulmonary Valve Stenosis/metabolism
- Vascular Calcification/drug therapy
- Vascular Calcification/genetics
- Vascular Calcification/metabolism
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Affiliation(s)
- Yvonne Nitschke
- Department of General Pediatrics, Münster University Children's Hospital, Albert-Schweitzer-Campus 1, D-48149, Münster, Germany
| | - Frank Rutsch
- Department of General Pediatrics, Münster University Children's Hospital, Albert-Schweitzer-Campus 1, D-48149, Münster, Germany.
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11
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Yao X, Yang H, Zhang Y, Ren C, Nie H, Fan Y, Zhou W, Wang S, Feng X, Wang F. Characterization of GALNTL5 gene sequence and expression in ovine testes and sperm. Theriogenology 2017; 95:54-61. [PMID: 28460680 DOI: 10.1016/j.theriogenology.2017.02.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 02/22/2017] [Accepted: 02/27/2017] [Indexed: 12/14/2022]
Abstract
The polypeptide N-acetylgalactosaminyltransferase-like protein 5 (GALNTL5), which belongs to the polypeptide N-acetylgalactosaminyltransferase (pp-GalNAc-T) gene family, is a newly identified gene that is specifically expressed in testis and involved in spermatogenesis. However, there is no data showing the existence of GALNTL5 in ram testis at various developmental stages and its influence on sperm motility. Therefore, the objectives of the present study were to evaluate the presence of GALNTL5 in the testis of 3-24 months (M) ram and to investigate the expression of GALNTL5 in spermatozoa with different motilities. We detected a 1602 bp cDNA fragment of GALNTL5 that included a 1326 bp coding sequence, encoding 441 amino acids and 90 and 185 bp of the 5' and 3' untranslated regions, respectively. The GALNTL5 amino acid sequence showed 51.87-83.48% identity with the sequences of proteins from other species. It was detected exclusively in the testis and the levels of both the mRNA and protein were progressively increased with age. Immunohistochemistry further revealed that GALNTL5 specifically localized in the elongating spermatids and spermatozoa, and it was demonstrated to be strongly concentrated in the head, neck, and mid-piece region of spermatozoa by immunocytochemistry. The sperm density and the percentage of live sperm in the high motility group (≥80%) were significantly higher than in the low motility group (≤50%), and the reverse trend was observed with the abnormal sperm. Western blot analysis showed that the protein expression of PGK2, ALDOA, and GALNTL5 were significantly higher in the high motility group than in the low motility group. Overall, the data suggest that GALNTL5 is an important functional molecule during spermatogenesis. Moreover, it is the first to suggest that the expression level of GALNTL5 is positively correlated with the sperm motility.
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Affiliation(s)
- Xiaolei Yao
- Jiangsu Engineering Technology Research Center of Mutton Sheep and Goat Industry, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Hua Yang
- Jiangsu Engineering Technology Research Center of Mutton Sheep and Goat Industry, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yanli Zhang
- Jiangsu Engineering Technology Research Center of Mutton Sheep and Goat Industry, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Caifang Ren
- Jiangsu Engineering Technology Research Center of Mutton Sheep and Goat Industry, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Haitao Nie
- Jiangsu Engineering Technology Research Center of Mutton Sheep and Goat Industry, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yixuan Fan
- Jiangsu Engineering Technology Research Center of Mutton Sheep and Goat Industry, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Wenjun Zhou
- Jiangsu Engineering Technology Research Center of Mutton Sheep and Goat Industry, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Shuting Wang
- Jiangsu Engineering Technology Research Center of Mutton Sheep and Goat Industry, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Xu Feng
- Jiangsu Engineering Technology Research Center of Mutton Sheep and Goat Industry, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Feng Wang
- Jiangsu Engineering Technology Research Center of Mutton Sheep and Goat Industry, Nanjing Agricultural University, Nanjing 210095, PR China.
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Schjoldager KT, Joshi HJ, Kong Y, Goth CK, King SL, Wandall HH, Bennett EP, Vakhrushev SY, Clausen H. Deconstruction of O-glycosylation--GalNAc-T isoforms direct distinct subsets of the O-glycoproteome. EMBO Rep 2015; 16:1713-22. [PMID: 26566661 PMCID: PMC4693523 DOI: 10.15252/embr.201540796] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 10/05/2015] [Accepted: 10/16/2015] [Indexed: 12/20/2022] Open
Abstract
GalNAc-type O-glycosylation is found on most proteins trafficking through the secretory pathway in metazoan cells. The O-glycoproteome is regulated by up to 20 polypeptide GalNAc-Ts and the contributions and biological functions of individual GalNAc-Ts are poorly understood. Here, we used a zinc-finger nuclease (ZFN)-directed knockout strategy to probe the contributions of the major GalNAc-Ts (GalNAc-T1 and GalNAc-T2) in liver cells and explore how the GalNAc-T repertoire quantitatively affects the O-glycoproteome. We demonstrate that the majority of the O-glycoproteome is covered by redundancy, whereas distinct subsets of substrates are modified by non-redundant functions of GalNAc-T1 and GalNAc-T2. The non-redundant O-glycoproteome subsets and specific transcriptional responses for each isoform are related to different cellular processes; for the GalNAc-T2 isoform, these support a role in lipid metabolism. The results demonstrate that GalNAc-Ts have different non-redundant glycosylation functions, which may affect distinct cellular processes. The data serves as a comprehensive resource for unique GalNAc-T substrates. Our study provides a new view of the differential regulation of the O-glycoproteome, suggesting that the plurality of GalNAc-Ts arose to regulate distinct protein functions and cellular processes.
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Affiliation(s)
- Katrine T Schjoldager
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Hiren J Joshi
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Yun Kong
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Christoffer K Goth
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Sarah Louise King
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Hans H Wandall
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Eric P Bennett
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Sergey Y Vakhrushev
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N, Denmark
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13
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Esapa CT, Hannan FM, Babinsky VN, Potter P, Thomas GP, Croucher PI, Brown MA, Brown SDM, Cox RD, Thakker RV. N-ethyl-N-Nitrosourea (ENU) induced mutations within the klotho gene lead to ectopic calcification and reduced lifespan in mouse models. PLoS One 2015; 10:e0122650. [PMID: 25860694 PMCID: PMC4393098 DOI: 10.1371/journal.pone.0122650] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 02/11/2015] [Indexed: 11/18/2022] Open
Abstract
Ectopic calcification (EC), which is the pathological deposition of calcium and phosphate in extra-skeletal tissues, may be associated with hypercalcaemic and hyperphosphataemic disorders, or it may occur in the absence of metabolic abnormalities. In addition, EC may be inherited as part of several monogenic disorders and studies of these have provided valuable insights into the metabolic pathways regulating mineral metabolism. For example, studies of tumoural calcinosis, a disorder characterised by hyperphosphataemia and progressive EC, have revealed mutations of fibroblast growth factor 23 (FGF23), polypeptide N-acetyl galactosaminyltransferase 3 (GALNT3) and klotho (KL), which are all part of a phosphate-regulating pathway. However, such studies in humans are limited by the lack of available large families with EC, and to facilitate such studies we assessed the progeny of mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for EC. This identified two mutants with autosomal recessive forms of EC, and reduced lifespan, designated Ecalc1 and Ecalc2. Genetic mapping localized the Ecalc1 and Ecalc2 loci to a 11.0 Mb region on chromosome 5 that contained the klotho gene (Kl), and DNA sequence analysis identified nonsense (Gln203Stop) and missense (Ile604Asn) Kl mutations in Ecalc1 and Ecalc2 mice, respectively. The Gln203Stop mutation, located in KL1 domain, was severely hypomorphic and led to a 17-fold reduction of renal Kl expression. The Ile604Asn mutation, located in KL2 domain, was predicted to impair klotho protein stability and in vitro expression studies in COS-7 cells revealed endoplasmic reticulum retention of the Ile604Asn mutant. Further phenotype studies undertaken in Ecalc1 (kl203X/203X) mice demonstrated elevations in plasma concentrations of phosphate, FGF23 and 1,25-dihydroxyvitamin D. Thus, two allelic variants of Kl that develop EC and represent mouse models for tumoural calcinosis have been established.
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Affiliation(s)
- Christopher T. Esapa
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford, United Kingdom
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, Harwell, United Kingdom
| | - Fadil M. Hannan
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford, United Kingdom
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Valerie N. Babinsky
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford, United Kingdom
| | - Paul Potter
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, Harwell, United Kingdom
| | - Gethin P. Thomas
- University of Queensland Diamantina Institute, Translational Research Institute, Princess Alexandra Hospital, University of Queensland, Brisbane, Australia
| | | | - Matthew A. Brown
- University of Queensland Diamantina Institute, Translational Research Institute, Princess Alexandra Hospital, University of Queensland, Brisbane, Australia
| | - Steve D. M. Brown
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, Harwell, United Kingdom
| | - Roger D. Cox
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, Harwell, United Kingdom
| | - Rajesh V. Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford, United Kingdom
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14
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Levery SB, Steentoft C, Halim A, Narimatsu Y, Clausen H, Vakhrushev SY. Advances in mass spectrometry driven O-glycoproteomics. Biochim Biophys Acta Gen Subj 2014; 1850:33-42. [PMID: 25284204 DOI: 10.1016/j.bbagen.2014.09.026] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND Global analyses of proteins and their modifications by mass spectrometry are essential tools in cell biology and biomedical research. Analyses of glycoproteins represent particular challenges and we are only at the beginnings of the glycoproteomic era. Some of the challenges have been overcome with N-glycoproteins and proteome-wide analysis of N-glycosylation sites is accomplishable today but only by sacrificing information of structures at individual glycosites. More recently advances in analysis of O-glycoproteins have been made and proteome-wide analysis of O-glycosylation sites is becoming available as well. SCOPE OF REVIEW Here we discuss the challenges of analysis of O-glycans and new O-glycoproteomics strategies focusing on O-GalNAc and O-Man glycoproteomes. MAJOR CONCLUSIONS A variety of strategies are now available for proteome-wide analysis of O-glycosylation sites enabling functional studies. However, further developments are still needed for complete analysis of glycan structures at individual sites for both N- and O-glycoproteomics strategies. GENERAL SIGNIFICANCE The advances in O-glycoproteomics have led to identification of new biological functions of O-glycosylation and a new understanding of the importance of where O-glycans are positioned on proteins.
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Affiliation(s)
- Steven B Levery
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Catharina Steentoft
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Adnan Halim
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Yoshiki Narimatsu
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Sergey Y Vakhrushev
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
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15
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Ichikawa S, Gray AK, Padgett LR, Reilly AM, Unsicker TR. High dietary phosphate intake induces development of ectopic calcifications in a murine model of familial tumoral calcinosis. J Bone Miner Res 2014; 29:2017-23. [PMID: 24692172 DOI: 10.1002/jbmr.2242] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 02/28/2014] [Accepted: 03/12/2014] [Indexed: 11/07/2022]
Abstract
Familial tumoral calcinosis is characterized by ectopic calcifications due to persistent hyperphosphatemia. The most common genetic cause of the disease is mutations in GALNT3, encoding a glycosyltransferase involved in a posttranslational modification of fibroblast growth factor 23 (FGF23). The Galnt3 knockout mouse we developed was hyperphosphatemic due to low intact Fgf23 levels, but did not develop any apparent calcifications on a standard rodent diet. We therefore tested the hypothesis that a further challenge with a high phosphate diet could induce ectopic calcifications in Galnt3 knockout mice. Mice were fed either normal (0.6%) or high (1.65%) phosphate diet for 20 weeks beginning from weaning at 3 weeks. The high phosphate diet did not affect serum phosphorus concentration. However, regardless of the dietary phosphate contents, serum phosphorus levels were consistently elevated in Galnt3 knockout mice. The mice on the high phosphate diet had slightly low serum calcium, but significantly high alkaline phosphatase, parathyroid hormone (PTH), and calcium in the kidney. Although none of Galnt3 knockout mice on the normal phosphate diet developed calcifications, calcifications appeared in approximately one-half of the mice on the high phosphate diet by 12 weeks. Calcified masses were most often found around the neck and on the back and as large as 9.9 mm in length. These data indicate that dietary phosphate load has major impact on the development of ectopic calcifications in tumoral calcinosis.
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Affiliation(s)
- Shoji Ichikawa
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
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Gaynor KU, Grigorieva IV, Allen MD, Esapa CT, Head RA, Gopinath P, Christie PT, Nesbit MA, Jones JL, Thakker RV. GATA3 mutations found in breast cancers may be associated with aberrant nuclear localization, reduced transactivation and cell invasiveness. Discov Oncol 2013; 4:123-39. [PMID: 23435732 DOI: 10.1007/s12672-013-0138-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 02/08/2013] [Indexed: 01/05/2023] Open
Abstract
Somatic and germline mutations in the dual zinc-finger transcription factor GATA3 are associated with breast cancers expressing the estrogen receptor (ER) and the autosomal dominant hypoparathyroidism-deafness-renal dysplasia syndrome, respectively. To elucidate the role of GATA3 in breast tumorigenesis, we investigated 40 breast cancers that expressed ER, for GATA3 mutations. Six different heterozygous GATA3 somatic mutations were identified in eight tumors, and these consisted of: a frameshifting deletion/insertion (944_945delGGinsAGC), an in-frame deletion of a key arginine residue (991_993delAGG), a seven-nucleotide frameshifting insertion (991_992insTGGAGGA), a frameshifting deletion (1196_1197delGA), and two frameshifting single nucleotide insertions (1224_1225insG found in three tumors and 1224_1225insA). Five of the eight mutations occurred in tumors that retained GATA3 immunostaining, indicating that absence of GATA3 immunostaining is an unreliable predictor of the presence of GATA3 mutations. Luciferase reporter assays, electrophoretic mobility shift assays, immunofluorescence, invasion and proliferation assays demonstrated that the GATA3 mutations resulted in loss (or reduction) of DNA binding, decrease in transactivational activity, and alterations in invasiveness but not proliferation. The 991_992insTGGAGGA (Arg330 frameshift) mutation led to a loss of nuclear localization, yet the 991_993delAGG (Arg330deletion) retained nuclear localization. Investigation of the putative nuclear localization signal (NLS) sites showed that the NLS of GATA3 does not conform to either a classical mono- or bi-partite signal, but contains multiple cooperative NLS elements residing around the N-terminal zinc-finger which comprises residues 264-288. Thus, approximately 20 % ER-positive breast cancers have somatic GATA3 mutations that lead to a loss of GATA3 transactivation activity and altered cell invasiveness.
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Affiliation(s)
- Katherine U Gaynor
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Oxford, OX3 7LJ, UK
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