1
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Boerrigter MM, Duijzer R, te Morsche RHM, Drenth JPH. Heterozygosity of ALG9 in Association with Autosomal Dominant Polycystic Liver Disease. Genes (Basel) 2023; 14:1755. [PMID: 37761895 PMCID: PMC10530326 DOI: 10.3390/genes14091755] [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: 08/03/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023] Open
Abstract
α-1,2-mannosyltransferase (ALG9) germline variants are linked to autosomal dominant polycystic kidney disease (ADPKD). Many individuals affected with ADPKD possess polycystic livers as a common extrarenal manifestation. We performed whole exome sequencing in a female with autosomal dominant polycystic liver disease (ADPLD) without kidney cysts and established the presence of a heterozygous missense variant (c.677G>C p.(Gly226Ala)) in ALG9. In silico pathogenicity prediction and 3D protein modeling determined this variant as pathogenic. Loss of heterozygosity is regularly seen in liver cyst walls. Immunohistochemistry indicated the absence of ALG9 in liver tissue from this patient. ALG9 expression was absent in cyst wall lining from ALG9- and PRKCSH-caused ADPLD patients but present in the liver cyst lining derived from an ADPKD patient with a PKD2 variant. Thus, heterozygous pathogenic variants in ALG9 are also associated with ADPLD. Somatic loss of heterozygosity of the ALG9 enzyme was seen in the ALG9 patient but also in ADPLD patients with a different genetic background. This expanded the phenotypic spectrum of ADPLD to ALG9.
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Affiliation(s)
- Melissa M. Boerrigter
- Department of Gastroenterology and Hepatology, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Renée Duijzer
- Department of Gastroenterology and Hepatology, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- European Reference Network RARE-LIVER, D-20246 Hamburg, Germany
| | - René H. M. te Morsche
- Department of Gastroenterology and Hepatology, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Joost P. H. Drenth
- Department of Gastroenterology and Hepatology, Research Institute for Medical Innovation, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- European Reference Network RARE-LIVER, D-20246 Hamburg, Germany
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2
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Kaymak D, Alpay V, Davutoğlu EA, Elçi O, Yiğin AK, Tüysüz B, Madazlı R. Gillessen-Kaesbach-Nishimura syndrome in two fetuses from Turkey. Am J Med Genet A 2023; 191:617-623. [PMID: 36326140 DOI: 10.1002/ajmg.a.63024] [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: 06/11/2022] [Revised: 10/04/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022]
Abstract
Gillessen-Kaesbach-Nishimura syndrome (GIKANIS) is a congenital disease of glycosylation (CDG) linked to the ALG9 gene. GIKANIS is a lethal disorder characterized by atypical facial features, generalized skeletal changes with shortening of the long bones with broad, round metaphyses, round ilia, and deficient ossification of the skull, cervical spine and pubic bones, and visceral abnormalities including polycystic kidneys and congenital cardiac defects. GIKANIS is caused by a homozygous splicing variant (c.1173 + 2 T > A) leading to skipping of exon 10, frameshift, and premature termination codon of the ALG9 gene. To our best knowledge, only two affected families with confirmed molecular analyses have been reported. We present an additional report on two siblings with the same mutation, emphasizing the prenatal ultrasonographic features. Their facial and skeletal manifestations recapitulated those previously reported. Ultrasonography revealed polycystic kidneys and unbalanced atrioventricular septal defect (AVSD) with transposition of the great arteries.
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Affiliation(s)
- Didem Kaymak
- Department of Obstetrics and Gynecology, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Verda Alpay
- Department of Obstetrics and Gynecology, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Ebru Alıcı Davutoğlu
- Department of Obstetrics and Gynecology, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Oguzhan Elçi
- Department of Obstetrics and Gynecology, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Aysel Kalaycı Yiğin
- Department of Medical Genetics, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Beyhan Tüysüz
- Department of Pediatric Genetics, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Riza Madazlı
- Department of Obstetrics and Gynecology, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
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Himmelreich N, Dimitrov B, Zielonka M, Hüllen A, Hoffmann GF, Juenger H, Müller H, Lorenz I, Busse B, Marschall C, Schlüter G, Thiel C. Missense variant c.1460 T > C (p.L487P) enhances protein degradation of ER mannosyltransferase ALG9 in two new ALG9-CDG patients presenting with West syndrome and review of the literature. Mol Genet Metab 2022; 136:274-281. [PMID: 35839600 DOI: 10.1016/j.ymgme.2022.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 12/01/2022]
Abstract
ALG9-CDG is a CDG-I defect within the group of Congenital Disorders of Glycosylation (CDG). We here describe the clinical symptoms of two new and unrelated ALG9-CDG patients, both carrying the novel homozygous missense variant c.1460 T > C (p.L487P) in the ALG9 gene which led to global developmental delay, psychomotor disability, facial dysmorphisms, brain and heart defects, hearing loss, hypotonia, as well as feeding problems. New clinical symptoms comprised West syndrome with hypsarrhythmia. Quantitative RT-PCR analysis revealed a significantly enhanced ALG9 mRNA transcript level, whereas the protein amount in fibroblasts was significantly reduced. This could be ascribed to a stronger degradation of the mutated ALG9 protein in patient fibroblasts. Lipid-linked oligosaccharide analysis showed an ALG9-CDG characteristic accumulation of Man6GlcNAc2-PP-dolichol and Man8GlcNAc2-PP-dolichol in patient cells. The clinical findings of our patients and of all previously published ALG9-CDG patients are brought together to further expand the knowledge about this rare N-glycosylation disorder. SYNOPSIS: Homozygosity for p.L487P in ALG9 causes protein degradation and leads to West syndrome.
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Affiliation(s)
- Nastassja Himmelreich
- Center for Child and Adolescent Medicine, Pediatrics I, University of Heidelberg, Analysezentrum 3, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany
| | - Bianca Dimitrov
- Center for Child and Adolescent Medicine, Pediatrics I, University of Heidelberg, Analysezentrum 3, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany
| | - Matthias Zielonka
- Center for Child and Adolescent Medicine, Pediatrics I, University of Heidelberg, Analysezentrum 3, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany
| | - Andreas Hüllen
- Center for Child and Adolescent Medicine, Pediatrics I, University of Heidelberg, Analysezentrum 3, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany
| | - Georg Friedrich Hoffmann
- Center for Child and Adolescent Medicine, Pediatrics I, University of Heidelberg, Analysezentrum 3, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany
| | - Hendrik Juenger
- Klinik für Kinderheilkunde und Jugendmedizin, Neonatologie, Klinikum Kempten, Robert-Weixler-Straße 50, 87439 Kempten, Germany
| | - Herbert Müller
- Klinik für Kinderheilkunde und Jugendmedizin, Neonatologie, Klinikum Kempten, Robert-Weixler-Straße 50, 87439 Kempten, Germany
| | - Imke Lorenz
- Klinik für Kinder und Jugendliche der Universität Erlangen, Abteilung für Neuropädiatrie und Sozialpädiatrie, Loschgestraße 15, 91054 Erlangen, Germany
| | - Birgit Busse
- MVZ Martinsried, Lochhamer Str.29, 82152 Martinsried, Germany
| | | | - Gregor Schlüter
- Pränatalmedizin, Gynäkologie und Genetik (MVZ), Bankgasse 3, 90402 Nürnberg, Germany
| | - Christian Thiel
- Center for Child and Adolescent Medicine, Pediatrics I, University of Heidelberg, Analysezentrum 3, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany.
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4
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Senum SR, Li Y(SM, Benson KA, Joli G, Olinger E, Lavu S, Madsen CD, Gregory AV, Neatu R, Kline TL, Audrézet MP, Outeda P, Nau CB, Meijer E, Ali H, Steinman TI, Mrug M, Phelan PJ, Watnick TJ, Peters DJ, Ong AC, Conlon PJ, Perrone RD, Cornec-Le Gall E, Hogan MC, Torres VE, Sayer JA, Harris PC, Harris PC. Monoallelic IFT140 pathogenic variants are an important cause of the autosomal dominant polycystic kidney-spectrum phenotype. Am J Hum Genet 2022; 109:136-156. [PMID: 34890546 DOI: 10.1016/j.ajhg.2021.11.016] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 11/15/2021] [Indexed: 12/18/2022] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD), characterized by progressive cyst formation/expansion, results in enlarged kidneys and often end stage kidney disease. ADPKD is genetically heterogeneous; PKD1 and PKD2 are the common loci (∼78% and ∼15% of families) and GANAB, DNAJB11, and ALG9 are minor genes. PKD is a ciliary-associated disease, a ciliopathy, and many syndromic ciliopathies have a PKD phenotype. In a multi-cohort/-site collaboration, we screened ADPKD-diagnosed families that were naive to genetic testing (n = 834) or for whom no PKD1 and PKD2 pathogenic variants had been identified (n = 381) with a PKD targeted next-generation sequencing panel (tNGS; n = 1,186) or whole-exome sequencing (WES; n = 29). We identified monoallelic IFT140 loss-of-function (LoF) variants in 12 multiplex families and 26 singletons (1.9% of naive families). IFT140 is a core component of the intraflagellar transport-complex A, responsible for retrograde ciliary trafficking and ciliary entry of membrane proteins; bi-allelic IFT140 variants cause the syndromic ciliopathy, short-rib thoracic dysplasia (SRTD9). The distinctive monoallelic phenotype is mild PKD with large cysts, limited kidney insufficiency, and few liver cysts. Analyses of the cystic kidney disease probands of Genomics England 100K showed that 2.1% had IFT140 LoF variants. Analysis of the UK Biobank cystic kidney disease group showed probands with IFT140 LoF variants as the third most common group, after PKD1 and PKD2. The proximity of IFT140 to PKD1 (∼0.5 Mb) in 16p13.3 can cause diagnostic confusion, and PKD1 variants could modify the IFT140 phenotype. Importantly, our studies link a ciliary structural protein to the ADPKD spectrum.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA.
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5
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Gallo GL, Valko A, Aguilar NH, Weisz AD, D'Alessio C. A novel fission yeast platform to model N-glycosylation and the bases of congenital disorders of glycosylation Type I. J Cell Sci 2021; 135:274232. [PMID: 34851357 DOI: 10.1242/jcs.259167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 11/18/2021] [Indexed: 11/20/2022] Open
Abstract
Congenital Disorders of Glycosylation Type I (CDG-I) are inherited human diseases caused by deficiencies in lipid-linked oligosaccharide (LLO) synthesis or the glycan transfer to proteins during N-glycosylation. We constructed a platform of 16 Schizosaccharomyces pombe mutant strains that synthesize all possible theoretical combinations of LLOs containing three to zero Glc and nine to five Man. The occurrence of unexpected LLOs suggested the requirement of specific Man residues for glucosyltransferases activities. We then quantified protein hypoglycosylation in each strain and found that in S. pombe the presence of Glc in the LLO is more relevant to the transfer efficiency than the amount of Man residues. Surprisingly, a decrease in the number of Man in glycans somehow improved the glycan transfer. The most severe hypoglycosylation was produced in cells completely lacking Glc and having a high number of Man. This deficiency could be reverted by expressing a single subunit OST with a broad range of substrate specificity. Our work shows the usefulness of this new S. pombe set of mutants as a platform to model the molecular bases of human CDG-I diseases.
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Affiliation(s)
- Giovanna L Gallo
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Buenos Aires C1428EGA, Argentina.,Consejo Nacional de investigaciones Científicas y Técnicas (CONICET), Argentina.,Fundación Instituto Leloir, Buenos Aires, C1405BWE, Argentina
| | - Ayelen Valko
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Buenos Aires C1428EGA, Argentina.,Consejo Nacional de investigaciones Científicas y Técnicas (CONICET), Argentina.,Fundación Instituto Leloir, Buenos Aires, C1405BWE, Argentina
| | - Nathalia Herrera Aguilar
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Buenos Aires C1428EGA, Argentina.,Fundación Instituto Leloir, Buenos Aires, C1405BWE, Argentina
| | - Ariel D Weisz
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Buenos Aires C1428EGA, Argentina
| | - Cecilia D'Alessio
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Instituto de Biociencias, Biotecnología y Biología Traslacional (iB3), Buenos Aires C1428EGA, Argentina.,Consejo Nacional de investigaciones Científicas y Técnicas (CONICET), Argentina
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6
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The evolving genetic landscape of congenital disorders of glycosylation. Biochim Biophys Acta Gen Subj 2021; 1865:129976. [PMID: 34358634 DOI: 10.1016/j.bbagen.2021.129976] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 07/30/2021] [Indexed: 01/01/2023]
Abstract
Congenital Disorders of Glycosylation (CDG) are an expanding and complex group of rare genetic disorders caused by defects in the glycosylation of proteins and lipids. The genetic spectrum of CDG is extremely broad with mutations in over 140 genes leading to a wide variety of symptoms ranging from mild to severe and life-threatening. There has been an expansion in the genetic complexity of CDG in recent years. More specifically several examples of alternate phenotypes in recessive forms of CDG and new types of CDG following an autosomal dominant inheritance pattern have been identified. In addition, novel genetic mechanisms such as expansion repeats have been reported and several already known disorders have been classified as CDG as their pathophysiology was better elucidated. Furthermore, we consider the future and outlook of CDG genetics, with a focus on exploration of the non-coding genome using whole genome sequencing, RNA-seq and multi-omics technology.
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Kwak C, Shin S, Park JS, Jung M, Nhung TTM, Kang MG, Lee C, Kwon TH, Park SK, Mun JY, Kim JS, Rhee HW. Contact-ID, a tool for profiling organelle contact sites, reveals regulatory proteins of mitochondrial-associated membrane formation. Proc Natl Acad Sci U S A 2020; 117:12109-12120. [PMID: 32414919 PMCID: PMC7275737 DOI: 10.1073/pnas.1916584117] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mitochondria-associated membrane (MAM) has emerged as a cellular signaling hub regulating various cellular processes. However, its molecular components remain unclear owing to lack of reliable methods to purify the intact MAM proteome in a physiological context. Here, we introduce Contact-ID, a split-pair system of BioID with strong activity, for identification of the MAM proteome in live cells. Contact-ID specifically labeled proteins proximal to the contact sites of the endoplasmic reticulum (ER) and mitochondria, and thereby identified 115 MAM-specific proteins. The identified MAM proteins were largely annotated with the outer mitochondrial membrane (OMM) and ER membrane proteins with MAM-related functions: e.g., FKBP8, an OMM protein, facilitated MAM formation and local calcium transport at the MAM. Furthermore, the definitive identification of biotinylation sites revealed membrane topologies of 85 integral membrane proteins. Contact-ID revealed regulatory proteins for MAM formation and could be reliably utilized to profile the proteome at any organelle-membrane contact sites in live cells.
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Affiliation(s)
- Chulhwan Kwak
- Department of Chemistry, Seoul National University, 08826 Seoul, Korea
- Department of Chemistry, Ulsan National Institute of Science and Technology, 44919 Ulsan, Korea
| | - Sanghee Shin
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, 08826 Seoul, Korea
| | - Jong-Seok Park
- Department of Chemistry, Ulsan National Institute of Science and Technology, 44919 Ulsan, Korea
| | - Minkyo Jung
- Neural Circuit Research Group, Korea Brain Research Institute, 41062 Daegu, Korea
| | - Truong Thi My Nhung
- Department of Life Sciences, Pohang University of Science and Technology, 37673 Pohang, Korea
| | - Myeong-Gyun Kang
- Department of Chemistry, Seoul National University, 08826 Seoul, Korea
- Department of Chemistry, Ulsan National Institute of Science and Technology, 44919 Ulsan, Korea
| | - Chaiheon Lee
- Department of Chemistry, Ulsan National Institute of Science and Technology, 44919 Ulsan, Korea
| | - Tae-Hyuk Kwon
- Department of Chemistry, Ulsan National Institute of Science and Technology, 44919 Ulsan, Korea
| | - Sang Ki Park
- Department of Life Sciences, Pohang University of Science and Technology, 37673 Pohang, Korea
| | - Ji Young Mun
- Neural Circuit Research Group, Korea Brain Research Institute, 41062 Daegu, Korea;
| | - Jong-Seo Kim
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea;
- School of Biological Sciences, Seoul National University, 08826 Seoul, Korea
| | - Hyun-Woo Rhee
- Department of Chemistry, Seoul National University, 08826 Seoul, Korea;
- School of Biological Sciences, Seoul National University, 08826 Seoul, Korea
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8
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Yu Y, Kou D, Liu B, Huang Y, Li S, Qi Y, Guo Y, Huang T, Qi X, Jia L. LncRNA MEG3 contributes to drug resistance in acute myeloid leukemia by positively regulating ALG9 through sponging miR-155. Int J Lab Hematol 2020; 42:464-472. [PMID: 32359033 DOI: 10.1111/ijlh.13225] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 04/07/2020] [Accepted: 04/11/2020] [Indexed: 12/17/2022]
Abstract
INTRODUCTION The development of drug resistance is the main obstacle for successful treatment in acute myeloid leukemia (AML). Noncoding RNAs have been implicated in biological function in AML drug resistance. Aberrant protein glycosylation is associated with AML progression. The aim of the study was to explore the potential regulatory mechanism of lncRNA MEG3/miR-155/ALG9 axis in drug resistance of AML. METHODS QRT-PCR and Western blot were used for comparison analyses of ALG9, MEG3, and miR-155 levels. CCK-8 and colony formation assays were determined for drug sensitivity and proliferative capability of AML cells. Luciferase reporter assay was used to confirm the targets of miR-155. RESULTS The mannosyltransferase ALG9 and MEG3 was downregulated in peripheral blood mononuclear cells (PBMCs) of M5/multidrug resistance (MDR) AML patients and adriamycin (ADR)-resistant AML cell lines, which determined a positive correlation in AML patients. Low expression of ALG9 and MEG3 predicted poor prognosis of AML patients. The altered level of ALG9 was found corresponding to the drug-resistant phenotype and sphere formation of AML cells. MiR-155 was overexpressed in M5/MDR patients and ADR-resistant AML cells, as well as inversely correlated to ALG9 expression. MEG3 was a direct target of miR-155 and could sponge miR-155 in AML cells. MEG3 interacted with miR-155 to regulate ALG9 expression, which reversed the effects of ALG9 regulation on proliferation and drug resistance in AML cells. CONCLUSION MEG3 sponged miR-155 by competing endogenous RNA (ceRNA) mechanism, which further modulated ALG9 expression and AML procession, providing a novel therapeutic target for AML chemoresistance.
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Affiliation(s)
- Yanan Yu
- College of Laboratory Medicine, Dalian Medical University, Dalian, China.,Department of Emergency, Affiliated Dalian Friend-ship Hospital of Dalian Medical University, Dalian, China
| | - Daqing Kou
- Department of Clinical Laboratory, the First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Bing Liu
- College of Laboratory Medicine, Dalian Medical University, Dalian, China
| | - Yiran Huang
- College of Laboratory Medicine, Dalian Medical University, Dalian, China
| | - Shuangda Li
- College of Laboratory Medicine, Dalian Medical University, Dalian, China
| | - Yu Qi
- College of Laboratory Medicine, Dalian Medical University, Dalian, China
| | - Yanru Guo
- College of Laboratory Medicine, Dalian Medical University, Dalian, China
| | - Tong Huang
- College of Laboratory Medicine, Dalian Medical University, Dalian, China
| | - Xia Qi
- College of Laboratory Medicine, Dalian Medical University, Dalian, China
| | - Li Jia
- College of Laboratory Medicine, Dalian Medical University, Dalian, China
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Yeast Models of Phosphomannomutase 2 Deficiency, a Congenital Disorder of Glycosylation. G3-GENES GENOMES GENETICS 2019; 9:413-423. [PMID: 30530630 PMCID: PMC6385982 DOI: 10.1534/g3.118.200934] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Phosphomannomutase 2 Deficiency (PMM2-CDG) is the most common monogenic congenital disorder of glycosylation (CDG) affecting at least 800 patients globally. PMM2 orthologs are present in model organisms, including the budding yeast Saccharomyces cerevisiae gene SEC53. Here we describe conserved genotype-phenotype relationships across yeast and human patients between five PMM2 loss-of-function missense mutations and their orthologous SEC53 mutations. These alleles range in severity from folding defective (hypomorph) to dimerization defective (severe hypomorph) to catalytic dead (null). We included the first and second most common missense mutations – R141H, F119L respectively– and the most common compound heterozygote genotype – PMM2R141H/F119L – observed in PMM2-CDG patients. Each mutation described is expressed in haploid as well as homozygous and heterozygous diploid yeast cells at varying protein expression levels as either SEC53 protein variants or PMM2 protein variants. We developed a 384-well-plate, growth-based assay for use in a screen of the 2,560-compound Microsource Spectrum library of approved drugs, experimental drugs, tool compounds and natural products. We identified three compounds that suppress growth defects of SEC53 variants, F126L and V238M, based on the biochemical defect of the allele, protein abundance or ploidy. The rare PMM2 E139K protein variant is fully functional in yeast cells, suggesting that its pathogenicity in humans is due to the underlying DNA mutation that results in skipping of exon 5 and a nonfunctional truncated protein. Together, these results demonstrate that yeast models can be used to characterize known and novel PMM2 patient alleles in quantitative growth and enzymatic activity assays, and used as patient avatars for PMM2-CDG drug screens yielding compounds that could be rapidly cross-validated in zebrafish, rodent and human organoid models.
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10
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Abstract
Congenital disorders of glycosylation (CDG) is a genetically heterogeneous and clinically polymorphic group of diseases caused by defects in various enzymes, the synthesis and processing of N-linked glycans or oligosaccharides into glycoproteins. Approximately half of all proteins expressed in cells are glycosylated to achieve their full functionality. Basically there are 2 variants of glycosylation: N-glycosylation and O-glycosylation. N-glycans are bound to the amide group of aspartine, whereas O-glycans are bonded to the hydroxyl group of serine or threonine. Synthesis of N-glycans occurs in 3 stages: the formation of nucleotide-linked sugars, assembly (in the cytosol and endoplasmic reticulum) and treatment (in the Golgi apparatus). Synthesis of O-glycans occurs mainly in the Golgi apparatus. The most frequently identified types of CDG are associated with a defect in the N-glycosylation pathway. CDGs are typically multisystem disorders with varying clinical manifestations such as hepatomegaly, cholestasis, liver failure, developmental delay, hypotonia, convulsions, facial dysmorphism and gastrointestinal disorders. Also histological findings showed liver fibrosis, malformation of the ducts, cirrhosis, and steatosis. CDGs typically present in the first months of life, and about 20% of patients do not survive to 5 years. The first line of CDG screening is based on the analysis of N-glycosylation of transf ferin. Exome sequencing or targeted gene panel is used for diagnosis. Several CDG subtypes are amenable to teraphy with mannose and galactose.
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11
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ALG9 Associated Gillessen-Kaesbach–Nishimura Syndrome (GIKANIS): An Uncommon Aetiology of Enlarged Foetal Kidneys. JOURNAL OF FETAL MEDICINE 2018. [DOI: 10.1007/s40556-018-0183-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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ALG9-CDG: New clinical case and review of the literature. Mol Genet Metab Rep 2017; 13:55-63. [PMID: 28932688 PMCID: PMC5596360 DOI: 10.1016/j.ymgmr.2017.08.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/19/2017] [Accepted: 08/20/2017] [Indexed: 12/18/2022] Open
Abstract
Congenital disorders of glycosylation (CDG) are a group of metabolic diseases resulting from defects in glycan synthesis or processing. The number of subgroups and their phenotypic spectrums continue to expand with most related to deficiencies of N-glycosylation. ALG9-CDG (previously CDG-IL) is the result of a mutation in ALG9. This gene encodes the enzyme alpha-1,2-mannosyltransferase. To date, a total of 10 patients from 6 different families have been reported with one of four ALG9 mutations. Seven of these patients had a similar phenotype with failure to thrive, dysmorphic features, seizures, hepatic and/or renal cysts; the other three patients died in utero from a lethal skeletal dysplasia. This report describes an additional patient with ALG9-CDG who has a milder phenotype. This patient is a term female born to Caucasian, Canadian, non-consanguineous parents of Scottish decent. Prenatally, dysmorphic features, numerous renal cysts and minor cardiac malformations were detected. Post-natally, dysmorphic features included shallow orbits, micrognathia, hypoplastic nipples, talipes equinovarus, lipodystrophy and cutis marmorata. She developed failure to thrive and seizures. The metabolic work-up included analysis of a transferrin isoelectric focusing, which showed a type 1 pattern. This was confirmed by glycan profiling, which identified ahomozygous mutation in ALG9, c.860A > G (p.Tyr287Cys) (NM_1234567890). This had been previously published as a pathogenic mutation in two Canadian patients. Our goal is to contribute to the growing body of knowledge for this disorder by describing the phenotypic spectrum and providing further insight on prognosis.
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Alsubhi S, Alhashem A, Faqeih E, Alfadhel M, Alfaifi A, Altuwaijri W, Alsahli S, Aldhalaan H, Alkuraya FS, Hundallah K, Mahmoud A, Alasmari A, Mutairi FA, Abduraouf H, AlRasheed L, Alshahwan S, Tabarki B. Congenital disorders of glycosylation: The Saudi experience. Am J Med Genet A 2017; 173:2614-2621. [DOI: 10.1002/ajmg.a.38358] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/10/2017] [Accepted: 06/14/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Sarah Alsubhi
- Division of Pediatric Neurology; Department of Pediatrics, Prince Sultan Military Medical City; Riyadh Saudi Arabia
| | - Amal Alhashem
- Division of Genetics; Department of Pediatrics; Prince Sultan Military Medical City; Riyadh Saudi Arabia
| | - Eissa Faqeih
- Department of Pediatric Subspecialties; Children's Hospital, King Fahad Medical City; Riyadh Saudi Arabia
| | - Majid Alfadhel
- Division of Genetics; Department of Pediatrics, King Abdulaziz Medical City; Riyadh Saudi Arabia
| | - Abdullah Alfaifi
- Division of Genetics; Department of Pediatrics, King Abdulaziz Medical City; Riyadh Saudi Arabia
| | - Waleed Altuwaijri
- Division of Pediatric Neurology; Department of Pediatrics, King Abdulaziz Medical City; Riyadh Saudi Arabia
| | - Saud Alsahli
- Division of Genetics; Department of Pediatrics, King Abdulaziz Medical City; Riyadh Saudi Arabia
| | - Hesham Aldhalaan
- Division of Pediatric Neurology; Department of Neurosciences, King Faisal Specialist Hospital and Research Center; Riyadh Saudi Arabia
| | - Fowzan S. Alkuraya
- Department of Genetics; King Faisal Specialist Hospital and Research Center; Riyadh Saudi Arabia
- Department of Anatomy and Cell Biology; College of Medicine, Alfaisal University; Riyadh Saudi Arabia
| | - Khalid Hundallah
- Division of Pediatric Neurology; Department of Pediatrics, Prince Sultan Military Medical City; Riyadh Saudi Arabia
| | - Adel Mahmoud
- Department of Pediatric Subspecialties; Children's Hospital, King Fahad Medical City; Riyadh Saudi Arabia
| | - Ali Alasmari
- Department of Pediatric Subspecialties; Children's Hospital, King Fahad Medical City; Riyadh Saudi Arabia
| | - Fuad Al Mutairi
- Division of Genetics; Department of Pediatrics, King Abdulaziz Medical City; Riyadh Saudi Arabia
| | - Hanem Abduraouf
- Division of Genetics; Department of Pediatrics; Prince Sultan Military Medical City; Riyadh Saudi Arabia
| | - Layan AlRasheed
- Division of Genetics; Department of Pediatrics; Prince Sultan Military Medical City; Riyadh Saudi Arabia
| | - Saad Alshahwan
- Division of Pediatric Neurology; Department of Pediatrics, Prince Sultan Military Medical City; Riyadh Saudi Arabia
| | - Brahim Tabarki
- Division of Pediatric Neurology; Department of Pediatrics, Prince Sultan Military Medical City; Riyadh Saudi Arabia
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14
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Al Teneiji A, Bruun TUJ, Sidky S, Cordeiro D, Cohn RD, Mendoza-Londono R, Moharir M, Raiman J, Siriwardena K, Kyriakopoulou L, Mercimek-Mahmutoglu S. Phenotypic and genotypic spectrum of congenital disorders of glycosylation type I and type II. Mol Genet Metab 2017; 120:235-242. [PMID: 28122681 DOI: 10.1016/j.ymgme.2016.12.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/28/2016] [Accepted: 12/29/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND Congenital disorders of glycosylation (CDG) are inborn defects of glycan metabolism. They are multisystem disorders. Analysis of transferrin isoforms is applied as a screening test for CDG type I (CDG-I) and type II (CDG-II). We performed a retrospective cohort study to determine spectrum of phenotype and genotype and prevalence of the different subtypes of CDG-I and CDG-II. MATERIAL AND METHODS All patients with CDG-I and CDG-II evaluated in our institution's Metabolic Genetics Clinics were included. Electronic and paper patient charts were reviewed. We set-up a high performance liquid chromatography transferrin isoelectric focusing (TIEF) method to measure transferrin isoforms in our Institution. We reviewed the literature for the rare CDG-I and CDG-II subtypes seen in our Institution. RESULTS Fifteen patients were included: 9 with PMM2-CDG and 6 with non-PMM2-CDG (one ALG3-CDG, one ALG9-CDG, two ALG11-CDG, one MPDU1-CDG and one ATP6V0A2-CDG). All patients with PMM2-CDG and 5 patients with non-PMM2-CDG showed abnormal TIEF suggestive of CDG-I or CDG-II pattern. In all patients, molecular diagnosis was confirmed either by single gene testing, targeted next generation sequencing for CDG genes, or by whole exome sequencing. CONCLUSION We report 15 new patients with CDG-I and CDG-II. Whole exome sequencing will likely identify more patients with normal TIEF and expand the phenotypic spectrum of CDG-I and CDG-II.
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Affiliation(s)
- Amal Al Teneiji
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Theodora U J Bruun
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Sarah Sidky
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Dawn Cordeiro
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ronald D Cohn
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Roberto Mendoza-Londono
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mahendranath Moharir
- Division of Neurology, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | - Lianna Kyriakopoulou
- Division of Genome Diagnostics, Department of Paediatric Laboratory Medicine, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Saadet Mercimek-Mahmutoglu
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada; Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada.
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15
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Marques-da-Silva D, Dos Reis Ferreira V, Monticelli M, Janeiro P, Videira PA, Witters P, Jaeken J, Cassiman D. Liver involvement in congenital disorders of glycosylation (CDG). A systematic review of the literature. J Inherit Metab Dis 2017; 40:195-207. [PMID: 28108845 DOI: 10.1007/s10545-016-0012-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 12/20/2016] [Accepted: 12/22/2016] [Indexed: 12/15/2022]
Abstract
Congenital disorders of glycosylation (CDG) are a rapidly growing family of genetic diseases caused by defects in glycosylation. Nearly 100 CDG types are known so far. Patients present a great phenotypic diversity ranging from poly- to mono-organ/system involvement and from very mild to extremely severe presentation. In this literature review, we summarize the liver involvement reported in CDG patients. Although liver involvement is present in only a minority of the reported CDG types (22 %), it can be debilitating or even life-threatening. Sixteen of the patients we collated here developed cirrhosis, 10 had liver failure. We distinguish two main groups: on the one hand, the CDG types with predominant or isolated liver involvement including MPI-CDG, TMEM199-CDG, CCDC115-CDG, and ATP6AP1-CDG, and on the other hand, the CDG types associated with liver disease but not as a striking, unique or predominant feature, including PMM2-CDG, ALG1-CDG, ALG3-CDG, ALG6-CDG, ALG8-CDG, ALG9-CDG, PGM1-CDG, and COG-CDG. This review aims to facilitate CDG patient identification and to understand CDG liver involvement, hopefully leading to earlier diagnosis, and better management and treatment.
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Affiliation(s)
- D Marques-da-Silva
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Lisboa, Portugal
- Portuguese Association for CDG, Lisboa, Portugal
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
| | - V Dos Reis Ferreira
- Portuguese Association for CDG, Lisboa, Portugal
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
| | - M Monticelli
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Lisboa, Portugal
- Dipartimento di Biologia, Università degli Studi di Napoli "Federico II", Napoli, Italy
| | - P Janeiro
- Departamento de Pediatria, Unidade de Doenças Metabólicas, CHLN, Hospital de Sta. Maria, Lisboa, Portugal
| | - P A Videira
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Lisboa, Portugal
- Portuguese Association for CDG, Lisboa, Portugal
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
| | - P Witters
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
- Center for Metabolic Diseases, UZ and KU Leuven, Leuven, Belgium
| | - J Jaeken
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal.
- Center for Metabolic Diseases, UZ and KU Leuven, Leuven, Belgium.
| | - D Cassiman
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal.
- Center for Metabolic Diseases, UZ and KU Leuven, Leuven, Belgium.
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16
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Maratha A, Colhoun HO, Knerr I, Coss KP, Doran P, Treacy EP. Classical Galactosaemia and CDG, the N-Glycosylation Interface. A Review. JIMD Rep 2016; 34:33-42. [PMID: 27502837 PMCID: PMC5509556 DOI: 10.1007/8904_2016_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 12/11/2022] Open
Abstract
Classical galactosaemia is a rare disorder of carbohydrate metabolism caused by galactose-1-phosphate uridyltransferase (GALT) deficiency (EC 2.7.7.12). The disease is life threatening if left untreated in neonates and the only available treatment option is a long-term galactose restricted diet. While this is lifesaving in the neonate, complications persist in treated individuals, and the cause of these, despite early initiation of treatment, and shared GALT genotypes remain poorly understood. Systemic abnormal glycosylation has been proposed to contribute substantially to the ongoing pathophysiology. The gross N-glycosylation assembly defects observed in the untreated neonate correct over time with treatment. However, N-glycosylation processing defects persist in treated children and adults.Congenital disorders of glycosylation (CDG) are a large group of over 100 inherited disorders affecting largely N- and O-glycosylation.In this review, we compare the clinical features observed in galactosaemia with a number of predominant CDG conditions.We also summarize the N-glycosylation abnormalities, which we have described in galactosaemia adult and paediatric patients, using an automated high-throughput HILIC-UPLC analysis of galactose incorporation into serum IgG with analysis of the corresponding N-glycan gene expression patterns and the affected pathways.
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Affiliation(s)
- Ashwini Maratha
- National Centre for Inherited Metabolic Disorders, Children's University Hospital, Temple Street, Dublin, Ireland
- University College Dublin Clinical Research Centre, Eccles Street, Dublin, Ireland
| | | | - Ina Knerr
- National Centre for Inherited Metabolic Disorders, Children's University Hospital, Temple Street, Dublin, Ireland
| | - Karen P Coss
- Faculty of Life Sciences and Medicine, Department of Infectious Diseases, King's College London, Guy's Hospital, London, UK
| | - Peter Doran
- University College Dublin Clinical Research Centre, Eccles Street, Dublin, Ireland
| | - Eileen P Treacy
- National Centre for Inherited Metabolic Disorders, Children's University Hospital, Temple Street, Dublin, Ireland.
- University College Dublin Clinical Research Centre, Eccles Street, Dublin, Ireland.
- Trinity College, Dublin, Ireland.
- Mater Misericordiae University Hospital, Eccles Street, Dublin, Ireland.
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17
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Analysis of transcriptional profiles of Saccharomyces cerevisiae exposed to bisphenol A. Curr Genet 2016; 63:253-274. [DOI: 10.1007/s00294-016-0633-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/14/2016] [Accepted: 07/16/2016] [Indexed: 01/06/2023]
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18
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Classical galactosaemia: novel insights in IgG N-glycosylation and N-glycan biosynthesis. Eur J Hum Genet 2016; 24:976-84. [PMID: 26733289 DOI: 10.1038/ejhg.2015.254] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 10/20/2015] [Accepted: 10/27/2015] [Indexed: 01/05/2023] Open
Abstract
Classical galactosaemia (OMIM #230400), a rare disorder of carbohydrate metabolism, is caused by a deficient activity of galactose-1-phosphate uridyltransferase (EC 2.7.7.12). The pathophysiology of the long-term complications, mainly cognitive, neurological and female fertility problems remains poorly understood. The lack of validated biomarkers to determine prognosis, monitor disease progression and responses to new therapies, pose a huge challenge. We report the detailed analysis of an automated robotic hydrophilic interaction ultra-performance liquid chromatography N-glycan analytical method of high glycan peak resolution applied to serum IgG. This has revealed specific N-glycan processing defects observed in 40 adult galactosaemia patients (adults and adolescents), in comparison with 81 matched healthy controls. We have identified a significant increase in core fucosylated neutral glycans (P<0.0001) and a significant decrease in core fucosylated (P<0.001), non-fucosylated (P<0.0001) bisected glycans and, of specific note, decreased N-linked mannose-5 glycans (P<0.0001), in galactosaemia patients. We also report the abnormal expression of a number of related relevant N-glycan biosynthesis genes in peripheral blood mononuclear cells from 32 adult galactosaemia patients. We have noted significant dysregulation of two key N-glycan biosynthesis genes: ALG9 upregulated (P<0.001) and MGAT1 downregulated (P<0.01) in galactosaemia patients, which may contribute to its ongoing pathophysiology. Our data suggest that the use of IgG N-glycosylation analysis with matched N-glycan biosynthesis gene profiles may provide useful biomarkers for monitoring response to therapy and interventions. They also indicate potential gene modifying steps in this N-glycan biosynthesis pathway, of relevance to galactosaemia and related N-glycan biosynthesis disorders.
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19
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Further Delineation of the ALG9-CDG Phenotype. JIMD Rep 2015; 27:107-12. [PMID: 26453364 DOI: 10.1007/8904_2015_504] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 09/14/2015] [Accepted: 09/18/2015] [Indexed: 12/13/2022] Open
Abstract
ALG9-CDG is one of the less frequently reported types of CDG. Here, we summarize the features of six patients with ALG9-CDG reported in the literature and report the features of four additional patients. The patients presented with drug-resistant infantile epilepsy, hypotonia, dysmorphic features, failure to thrive, global developmental disability, and skeletal dysplasia. One patient presented with nonimmune hydrops fetalis. A brain MRI revealed global atrophy with delayed myelination. Exome sequencing identified a novel homozygous mutation c.1075G>A, p.E359K of the ALG9 gene. The results of our analysis of these patients expand the knowledge of ALG9-CDG phenotype.
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20
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Harada Y, Hirayama H, Suzuki T. Generation and degradation of free asparagine-linked glycans. Cell Mol Life Sci 2015; 72:2509-33. [PMID: 25772500 PMCID: PMC11113800 DOI: 10.1007/s00018-015-1881-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 02/19/2015] [Accepted: 03/05/2015] [Indexed: 10/23/2022]
Abstract
Asparagine (N)-linked protein glycosylation, which takes place in the eukaryotic endoplasmic reticulum (ER), is important for protein folding, quality control and the intracellular trafficking of secretory and membrane proteins. It is known that, during N-glycosylation, considerable amounts of lipid-linked oligosaccharides (LLOs), the glycan donor substrates for N-glycosylation, are hydrolyzed to form free N-glycans (FNGs) by unidentified mechanisms. FNGs are also generated in the cytosol by the enzymatic deglycosylation of misfolded glycoproteins during ER-associated degradation. FNGs derived from LLOs and misfolded glycoproteins are eventually merged into one pool in the cytosol and the various glycan structures are processed to a near homogenous glycoform. This article summarizes the current state of our knowledge concerning the formation and catabolism of FNGs.
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Affiliation(s)
- Yoichiro Harada
- Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, Global Research Cluster, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 Japan
| | - Hiroto Hirayama
- Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, Global Research Cluster, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 Japan
| | - Tadashi Suzuki
- Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, Global Research Cluster, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 Japan
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21
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A novel phenotype in N-glycosylation disorders: Gillessen-Kaesbach-Nishimura skeletal dysplasia due to pathogenic variants in ALG9. Eur J Hum Genet 2015; 24:198-207. [PMID: 25966638 DOI: 10.1038/ejhg.2015.91] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 02/24/2015] [Accepted: 03/31/2015] [Indexed: 12/29/2022] Open
Abstract
A rare lethal autosomal recessive syndrome with skeletal dysplasia, polycystic kidneys and multiple malformations was first described by Gillessen-Kaesbach et al and subsequently by Nishimura et al. The skeletal features uniformly comprise a round pelvis, mesomelic shortening of the upper limbs and defective ossification of the cervical spine. We studied two unrelated families including three affected fetuses with Gillessen-Kaesbach-Nishimura syndrome using whole-exome and Sanger sequencing, comparative genome hybridization and homozygosity mapping. All affected patients were shown to have a novel homozygous splice variant NM_024740.2: c.1173+2T>A in the ALG9 gene, encoding alpha-1,2-mannosyltransferase, involved in the formation of the lipid-linked oligosaccharide precursor of N-glycosylation. RNA analysis demonstrated skipping of exon 10, leading to shorter RNA. Mass spectrometric analysis showed an increase in monoglycosylated transferrin as compared with control tissues, confirming that this is a congenital disorder of glycosylation (CDG). Only three liveborn children with ALG9-CDG have been previously reported, all with missense variants. All three suffered from intellectual disability, muscular hypotonia, microcephaly and renal cysts, but none had skeletal dysplasia. Our study shows that some pathogenic variants in ALG9 can present as a lethal skeletal dysplasia with visceral malformations as the most severe phenotype. The skeletal features overlap with that previously reported for ALG3- and ALG12-CDG, suggesting that this subset of glycosylation disorders constitutes a new diagnostic group of skeletal dysplasias.
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22
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Baycin-Hizal D, Gottschalk A, Jacobson E, Mai S, Wolozny D, Zhang H, Krag SS, Betenbaugh MJ. Physiologic and pathophysiologic consequences of altered sialylation and glycosylation on ion channel function. Biochem Biophys Res Commun 2014; 453:243-53. [PMID: 24971539 PMCID: PMC4544737 DOI: 10.1016/j.bbrc.2014.06.067] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 06/13/2014] [Indexed: 01/01/2023]
Abstract
Voltage-gated ion channels are transmembrane proteins that regulate electrical excitability in cells and are essential components of the electrically active tissues of nerves, muscle and the heart. Potassium channels are one of the largest subfamilies of voltage sensitive channels and are among the most-studied of the voltage-gated ion channels. Voltage-gated channels can be glycosylated and changes in the glycosylation pattern can affect ion channel function, leading to neurological and neuromuscular disorders and congenital disorders of glycosylation (CDG). Alterations in glycosylation can also be acquired and appear to play a role in development and aging. Recent studies have focused on the impact of glycosylation and sialylation on ion channels, particularly for voltage-gated potassium and sodium channels. The terminal step of sialylation often affects channel activation and inactivation kinetics. The presence of sialic acids on O or N-glycans can alter the gating mechanism and cause conformational changes in the voltage-sensing domains due to sialic acid's negative charges. This manuscript will provide an overview of sialic acids, potassium and sodium channel function, and the impact of sialylation on channel activation and deactivation.
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Affiliation(s)
- Deniz Baycin-Hizal
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States.
| | - Allan Gottschalk
- Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, United States
| | - Elena Jacobson
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States
| | - Sunny Mai
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States
| | - Daniel Wolozny
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States
| | - Hui Zhang
- Pathology, Johns Hopkins University, United States
| | - Sharon S Krag
- Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, United States
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23
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Tan Z, Lu W, Li X, Yang G, Guo J, Yu H, Li Z, Guan F. Altered N-Glycan Expression Profile in Epithelial-to-Mesenchymal Transition of NMuMG Cells Revealed by an Integrated Strategy Using Mass Spectrometry and Glycogene and Lectin Microarray Analysis. J Proteome Res 2014; 13:2783-95. [DOI: 10.1021/pr401185z] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
| | | | | | | | | | - Hanjie Yu
- Laboratory
for Functional Glycomics, College of Life Sciences, Northwest University, 229 Taibai Beilu, Xi’an 710069, China
| | - Zheng Li
- Laboratory
for Functional Glycomics, College of Life Sciences, Northwest University, 229 Taibai Beilu, Xi’an 710069, China
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24
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Wolfe LA, Krasnewich D. Congenital disorders of glycosylation and intellectual disability. ACTA ACUST UNITED AC 2014; 17:211-25. [PMID: 23798010 DOI: 10.1002/ddrr.1115] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/17/2012] [Indexed: 12/31/2022]
Abstract
The congenital disorders of glycosylation (CDG) are a rapidly growing group of inborn errors of metabolism that result from defects in the synthesis of glycans. Glycosylation is a major post-translational protein modification and an estimated 2% of the human genome encodes proteins for glycosylation. The molecular bases for the current 60 disorders, affecting approximately 800 individuals, have been identified, many in the last 5 years. CDG should be considered in any multi-system syndrome or single tissue disorder not explained by the identification of another disorder. The initial clinical presentation varies significantly among individuals, even between affected siblings. However, two thirds of the known CDGs are associated with intellectual disabilities and most affected individuals need support services throughout their lives. Additional disorders of glycosylation are likely to be characterized over time.
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Affiliation(s)
- Lynne A Wolfe
- Genetic Nurse Practitioner, Undiagnosed Diseases Program, National Human Genome Research Institute, Bethesda, Maryland 20892, USA.
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25
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Kouwenberg D, Gardeitchik T, Mohamed M, Lefeber DJ, Morava E. Wrinkled skin and fat pads in patients with ALG8-CDG: revisiting skin manifestations in congenital disorders of glycosylation. Pediatr Dermatol 2014; 31:e1-5. [PMID: 24555185 DOI: 10.1111/pde.12233] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Glycosylation is the posttranslational coupling of sugar chains to proteins or lipids. Proper glycosylation is essential for normal protein structure, function, and trafficking. Mutations in the glycosylation pathway lead to a phenotypically heterogeneous group of metabolic disorders, the congenital disorders of glycosylation (CDG). Some of these conditions, including PMM2-CDG, frequently present with recognizable skin abnormalities such as abnormal fat distribution, skin wrinkling, or peau d'orange, whereas others, such as COG7-CDG and ATP6V0A2-CDG, have been described in association with cutis laxa: wrinkled, inelastic, and sagging skin. Ichthyosis is also common in several types of CDG. ALG8-CDG is a severe disorder characterized by dysmorphic features, failure to thrive, protein-losing enteropathy, neurologic and ophthalmologic problems, and developmental delay. We reviewed the clinical features in all nine previously reported patients diagnosed with ALG8-CDG with a special focus on their skin signs. Three of the nine patients had abnormal fat distribution and skin wrinkling. As the spectrum of CDG presenting with skin signs expands further, we suggest screening for CDG in all patients presenting with any type of central nervous involvement and wrinkled skin, cutis laxa, severe ichthyosis, or abnormal fat distribution.
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Affiliation(s)
- Dorus Kouwenberg
- Department of Pediatrics; Radboud University Nijmegen Medical Center; Nijmegen the Netherlands
| | - Thatjana Gardeitchik
- Department of Pediatrics; Radboud University Nijmegen Medical Center; Nijmegen the Netherlands
| | - Miski Mohamed
- Department of Pediatrics; Radboud University Nijmegen Medical Center; Nijmegen the Netherlands
| | - Dirk J. Lefeber
- Laboratory of Genetic, Endocrine and Metabolic Disease; Radboud University Nijmegen Medical Center; Nijmegen the Netherlands
- Department of Neurology; Institute for Genetic and Metabolic Disease; Radboud University Nijmegen Medical Center; Nijmegen the Netherlands
| | - Eva Morava
- Department of Pediatrics; Radboud University Nijmegen Medical Center; Nijmegen the Netherlands
- Department of Pediatrics; Hayward Genetics Center; Tulane University Medical School; New Orleans Louisiana
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26
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Hykollari A, Balog CIA, Rendić D, Braulke T, Wilson IBH, Paschinger K. Mass spectrometric analysis of neutral and anionic N-glycans from a Dictyostelium discoideum model for human congenital disorder of glycosylation CDG IL. J Proteome Res 2013; 12:1173-87. [PMID: 23320427 PMCID: PMC3588589 DOI: 10.1021/pr300806b] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
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The HL241 mutant strain of the cellular slime mold Dictyostelium
discoideum is a potential model for human congenital disorder
of glycosylation type IL (ALG9-CDG) and has been previously predicted
to possess a lower degree of modification of its N-glycans with anionic
moieties than the parental wild-type. In this study, we first showed
that this strain has a premature stop codon in its alg9 mannosyltransferase gene compatible with the occurrence of truncated
N-glycans. These were subject to an optimized analytical workflow,
considering that the mass spectrometry of acidic glycans often presents
challenges due to neutral loss and suppression effects. Therefore,
the protein-bound N-glycans were first fractionated, after serial
enzymatic release, by solid phase extraction. Then primarily single
glycan species were isolated by mixed hydrophilic-interaction/anion-exchange
or reversed-phase HPLC and analyzed using chemical and enzymatic treatments
and MS/MS. We show that protein-linked N-glycans of the mutant are
of reduced size as compared to those of wild-type AX3, but still contain
core α1,3-fucose, intersecting N-acetylglucosamine,
bisecting N-acetylglucosamine, methylphosphate, phosphate,
and sulfate residues. We observe that a single N-glycan can carry
up to four of these six possible modifications. Due to the improved
analytical procedures, we reveal fuller details regarding the N-glycomic
potential of this fascinating model organism.
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Affiliation(s)
- Alba Hykollari
- Department für Chemie, Universität für Bodenkultur, A-1190 Wien, Austria
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Matthijs G, Rymen D, Millón MBB, Souche E, Race V. Approaches to homozygosity mapping and exome sequencing for the identification of novel types of CDG. Glycoconj J 2012; 30:67-76. [PMID: 22983704 DOI: 10.1007/s10719-012-9445-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Revised: 08/21/2012] [Accepted: 08/22/2012] [Indexed: 12/18/2022]
Abstract
In the past decade, the identification of most genes involved in Congenital Disorders of Glycosylation (CDG) (type I) was achieved by a combination of biochemical, cell biological and glycobiological investigations. This has been truly successful for CDG-I, because the candidate genes could be selected on the basis of the homology of the synthetic pathway of the dolichol linked oligosaccharide in human and yeast. On the contrary, only a few CDG-II defects were elucidated, be it that some of the discoveries represent wonderful breakthroughs, like e.g, the identification of the COG defects. In general, many rare genetic defects have been identified by positional cloning. However, only a few types of CDG have effectively been elucidated by linkage analysis and so-called reverse genetics. The reason is that the families were relatively small and could-except for CDG-PMM2-not be pooled for analysis. Hence, a large number of CDG cases has long remained unsolved because the search for the culprit gene was very laborious, due to the heterogeneous phenotype and the myriad of candidate defects. This has changed when homozygosity mapping came of age, because it could be applied to small (consanguineous) families. Many novel CDG genes have been discovered in this way. But the best has yet to come: what we are currently witnessing, is an explosion of novel CDG defects, thanks to exome sequencing: seven novel types were published over a period of only two years. It is expected that exome sequencing will soon become a diagnostic tool, that will continuously uncover new facets of this fascinating group of diseases.
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Affiliation(s)
- Gert Matthijs
- Center for Human Genetics, University of Leuven, Herestraat 49, 3000, Leuven, Belgium.
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Laboratory Diagnosis of Congenital Disorders of Glycosylation Type I by Analysis of Transferrin Glycoforms. Mol Diagn Ther 2012; 11:303-11. [DOI: 10.1007/bf03256251] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Evolutionarily conserved glycan signal to degrade aberrant brassinosteroid receptors in Arabidopsis. Proc Natl Acad Sci U S A 2012; 109:11437-42. [PMID: 22733738 DOI: 10.1073/pnas.1119173109] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Asparagine-linked glycans (N-glycans) are crucial signals for protein folding, quality control, and endoplasmic reticulum (ER)-associated degradation (ERAD) in yeast and mammals. Although similar ERAD processes were reported in plants, little is known about their biochemical mechanisms, especially their relationships with N-glycans. Here, we show that a missense mutation in the Arabidopsis EMS-mutagenized bri1 suppressor 3 (EBS3) gene suppresses a dwarf mutant, bri1-9, the phenotypes of which are caused by ER retention and ERAD of a brassinosteroid receptor, BRASSINOSTEROID-INSENSITIVE 1 (BR1). EBS3 encodes the Arabidopsis ortholog of the yeast asparagine-linked glycosylation 9 (ALG9), which catalyzes the ER luminal addition of two terminal α1,2 mannose (Man) residues in assembling the three-branched N-glycan precursor [glucose(Glc)](3)(Man)(9)[N-acetylglucosamine(GlcNAc)](2). Consistent with recent discoveries revealing the importance of the Glc(3)Man(9)GlcNAc(2) C-branch in generating an ERAD signal, the ebs3-1 mutation prevents the Glc(3)Man(9)GlcNAc(2) assembly and inhibits the ERAD of bri1-9. By contrast, overexpression of EBS4 in ebs3-1 bri1-9, which encodes the Arabidopsis ortholog of the yeast ALG12 catalyzing the ER luminal α1,6 Man addition, adds an α1,6 Man to the truncated N-glycan precursor accumulated in ebs3-1 bri1-9, promotes the bri1-9 ERAD, and neutralizes the ebs3-1 suppressor phenotype. Furthermore, a transfer (T)-DNA insertional alg3-T2 mutation, which causes accumulation of an even smaller N-glycan precursor carrying a different exposed α1,6 Man, promotes the ERAD of bri1-9 and enhances its dwarfism. Taken together, our results strongly suggest that the glycan signal to mark an ERAD client in Arabidopsis is likely conserved to be an α1,6 Man-exposed N-glycan.
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Abstract
Glycosylation is an essential process by which sugars are attached to proteins and lipids. Complete lack of glycosylation is not compatible with life. Because of the widespread function of glycosylation, inherited disorders of glycosylation are multisystemic. Since the identification of the first defect on N-linked glycosylation in the 1980s, there are over 40 different congenital protein hypoglycosylation diseases. This review will include defects of N-linked glycosylation, O-linked glycosylation and disorders of combined N- and O-linked glycosylation.
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Affiliation(s)
- Susan E Sparks
- Department of Pediatrics, Levine Children's Hospital at Carolinas Medical Center, Charlotte, NC, USA; Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, NC, USA
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Van Hove JLK, Lohr NJ. Metabolic and monogenic causes of seizures in neonates and young infants. Mol Genet Metab 2011; 104:214-30. [PMID: 21839663 DOI: 10.1016/j.ymgme.2011.04.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2011] [Revised: 04/20/2011] [Accepted: 04/20/2011] [Indexed: 11/22/2022]
Abstract
Seizures in neonates or young infants present a frequent diagnostic challenge. After exclusion of acquired causes, disturbances of the internal homeostasis and brain malformations, the physician must evaluate for inborn errors of metabolism and for other non-malformative genetic disorders as the cause of seizures. The metabolic causes can be categorized into disorders of neurotransmitter metabolism, disorders of energy production, and synthetic or catabolic disorders associated with brain malformation, dysfunction and degeneration. Other genetic conditions involve channelopathies, and disorders resulting in abnormal growth, differentiation and formation of neuronal populations. These conditions are important given their potential for treatment and the risk for recurrence in the family. In this paper, we will succinctly review the metabolic and genetic non-malformative causes of seizures in neonates and infants less than 6 months of age. We will then provide differential diagnostic clues and a practical paradigm for their evaluation.
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Affiliation(s)
- Johan L K Van Hove
- Department of Pediatrics, University of Colorado, Clinical Genetics, Aurora, CO 80045, USA.
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Vleugels W, Duvet S, Peanne R, Mir AM, Cacan R, Michalski JC, Matthijs G, Foulquier F. Identification of phosphorylated oligosaccharides in cells of patients with a congenital disorders of glycosylation (CDG-I). Biochimie 2011; 93:823-33. [PMID: 21315133 DOI: 10.1016/j.biochi.2011.01.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 01/29/2011] [Indexed: 11/24/2022]
Abstract
Protein N-glycosylation is initiated by the dolichol cycle in which the oligosaccharide precursor Glc(3)Man(9)GlcNAc(2)-PP-dolichol is assembled in the endoplasmic reticulum (ER). One critical step in the dolichol cycle concerns the availability of Dol-P at the cytosolic face of the ER membrane. In RFT1 cells, the lipid-linked oligosaccharide (LLO) intermediate Man(5)GlcNAc(2)-PP-Dol accumulates at the cytosolic face of the ER membrane. Since Dol-P is a rate-limiting intermediate during protein N-glycosylation, continuous accumulation of Man(5)GlcNAc(2)-PP-Dol would block the dolichol cycle. Hence, we investigated the molecular mechanisms by which accumulating Man(5)GlcNAc(2)-PP-Dol could be catabolized in RFT1 cells. On the basis of metabolic labeling experiments and in comparison to human control cells, we identified phosphorylated oligosaccharides (POS), not found in human control cells and present evidence that they originate from the accumulating LLO intermediates. In addition, POS were also detected in other CDG patients' cells accumulating specific LLO intermediates at different cellular locations. Moreover, the enzymatic activity that hydrolyses oligosaccharide-PP-Dol into POS was identified in human microsomal membranes and required Mn(2+) for optimal activity. In CDG patients' cells, we thus identified and characterized POS that could result from the catabolism of accumulating LLO intermediates.
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Affiliation(s)
- Wendy Vleugels
- Laboratory for Molecular Diagnosis, Center for Human Genetics, University of Leuven, B-3000 Leuven, Belgium
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Janssen MJ, Waanders E, Woudenberg J, Lefeber DJ, Drenth JPH. Congenital disorders of glycosylation in hepatology: the example of polycystic liver disease. J Hepatol 2010; 52:432-40. [PMID: 20138683 DOI: 10.1016/j.jhep.2009.12.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autosomal dominant polycystic liver disease (PCLD) is a rare progressive disorder characterized by an increased liver volume due to many (>20) fluid-filled cysts of biliary origin. Disease causing mutations in PRKCSH or SEC63 are found in approximately 25% of the PCLD patients. Both gene products function in the endoplasmic reticulum, however, the molecular mechanism behind cyst formation remains to be elucidated. As part of the translocon complex, SEC63 plays a role in protein import into the ER and is implicated in the export of unfolded proteins to the cytoplasm during ER-associated degradation (ERAD). PRKCSH codes for the beta-subunit of glucosidase II (hepatocystin), which cleaves two glucose residues of Glc(3)Man(9)GlcNAc(2) N-glycans on proteins. Hepatocystin is thereby directly involved in the protein folding process by regulating protein binding to calnexin/calreticulin in the ER. A separate group of genetic diseases affecting protein N-glycosylation in the ER is formed by the congenital disorders of glycosylation (CDG). In distinct subtypes of this autosomal recessive multisystem disease specific liver symptoms have been reported that overlap with PCLD. Recent research revealed novel insights in PCLD disease pathology such as the absence of hepatocystin from cyst epithelia indicating a two-hit model for PCLD cystogenesis. This opens the way to speculate about a recessive mechanism for PCLD pathophysiology and shared molecular pathways between CDG and PCLD. In this review we will discuss the clinical-genetic features of PCLD and CDG as well as their biochemical pathways with the aim to identify novel directions of research into cystogenesis.
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Affiliation(s)
- Manoe J Janssen
- Department of Gastroenterology and Hepatology, Institute for Genetic & Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Haeuptle MA, Hennet T. Congenital disorders of glycosylation: an update on defects affecting the biosynthesis of dolichol-linked oligosaccharides. Hum Mutat 2010; 30:1628-41. [PMID: 19862844 DOI: 10.1002/humu.21126] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Defects in the biosynthesis of the oligosaccharide precursor for N-glycosylation lead to decreased occupancy of glycosylation sites and thereby to diseases known as congenital disorders of glycosylation (CDG). In the last 20 years, approximately 1,000 CDG patients have been identified presenting with multiple organ dysfunctions. This review sets the state of the art by listing all mutations identified in the 15 genes (PMM2, MPI, DPAGT1, ALG1, ALG2, ALG3, ALG9, ALG12, ALG6, ALG8, DOLK, DPM1, DPM3, MPDU1, and RFT1) that yield a deficiency of dolichol-linked oligosaccharide biosynthesis. The present analysis shows that most mutations lead to substitutions of strongly conserved amino acid residues across eukaryotes. Furthermore, the comparison between the different forms of CDG affecting dolichol-linked oligosaccharide biosynthesis shows that the severity of the disease does not relate to the position of the mutated gene along this biosynthetic pathway.
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Affiliation(s)
- Micha A Haeuptle
- Institute of Physiology, University of Zürich, Zürich, Switzerland
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Vleugels W, Keldermans L, Jaeken J, Butters TD, Michalski JC, Matthijs G, Foulquier F. Quality control of glycoproteins bearing truncated glycans in an ALG9-defective (CDG-IL) patient. Glycobiology 2009; 19:910-7. [PMID: 19451548 DOI: 10.1093/glycob/cwp067] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We describe an ALG9-defective (congenital disorders of glycosylation type IL) patient who is homozygous for the p.Y286C (c.860A>G) mutation. This patient presented with psychomotor retardation, axial hypotonia, epilepsy, failure to thrive, inverted nipples, hepatomegaly, and pericardial effusion. Due to the ALG9 deficiency, the cells of this patient accumulated the lipid-linked oligosaccharides Man(6)GlcNAc(2)-PP-dolichol and Man(8)GlcNAc(2)-PP-dolichol. It is known that the oligosaccharide structure has a profound effect on protein glycosylation. Therefore, we investigated the influence of these truncated oligosaccharide structures on the protein transfer efficiency, the quality control of newly synthesized glycoproteins, and the eventual degradation of the truncated glycoproteins formed in this patient. We demonstrated that lipid-linked Man(6)GlcNAc(2) and Man(8)GlcNAc(2) are transferred onto proteins with the same efficiency. In addition, glycoproteins bearing these Man(6)GlcNAc(2) and Man(8)GlcNAc(2) structures efficiently entered in the glucosylation/deglucosylation cycle of the quality control system to assist in protein folding. We also showed that in comparison with control cells, patient's cells degraded misfolded glycoproteins at an increasing rate. The Man(8)GlcNAc(2) isomer C on the patient's glycoproteins was found to promote the degradation of misfolded glycoproteins.
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Affiliation(s)
- Wendy Vleugels
- Laboratory for Molecular Diagnosis, Center for Human Genetics, University of Leuven, Leuven, Belgium
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Jamroz E, Adamek D, Paprocka J, Adamowicz M, Marszał E, Wevers RA. CDG type Ia and congenital cytomegalovirus infection: two coexisting conditions. J Child Neurol 2009; 24:13-8. [PMID: 19168813 DOI: 10.1177/0883073808321041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Congenital disorders of glycosylation are a heterogeneous group of disorders with multisystemic involvement. The most common form is phosphomannomutase deficiency or congenital disorders of glycosylation type Ia with an autosomal recessive inheritance and incidence estimated at 1/20000-1/50000 live born. Congenital disorders of glycosylation Ia can manifest as severe multisystemic disease of infancy or milder disorder with only neurological problems including ataxia, hypotonia, and psychomotor retardation. The brain pathological findings in congenital disorders of glycosylation type Ia patients corroborate with cerebellar dysfunction. Usually the most affected part is the anterior lobe of the vermis. Microscopic analysis demonstrates the prominent Purkinje cell loss and subtotal loss of the external and internal granule cell layers. The authors present clinical and pathological picture of a 4-month-old girl with congenital disorders of glycosylation type Ia, additionally complicated by congenital cytomegalovirus infection. The diagnosis was confirmed by low phosphomannomutase activity in patient's fibroblasts and mutations on both alleles of phosphomannomutase 2 gene.
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Affiliation(s)
- Ewa Jamroz
- Child Neurology Department, Medical University of Silesia, Katowice, Poland
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Maeda Y, Kinoshita T. Dolichol-phosphate mannose synthase: Structure, function and regulation. Biochim Biophys Acta Gen Subj 2008; 1780:861-8. [DOI: 10.1016/j.bbagen.2008.03.005] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Revised: 02/11/2008] [Accepted: 03/06/2008] [Indexed: 11/30/2022]
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Haeuptle MA, Pujol FM, Neupert C, Winchester B, Kastaniotis AJ, Aebi M, Hennet T. Human RFT1 deficiency leads to a disorder of N-linked glycosylation. Am J Hum Genet 2008; 82:600-6. [PMID: 18313027 DOI: 10.1016/j.ajhg.2007.12.021] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 11/13/2007] [Accepted: 12/04/2007] [Indexed: 11/28/2022] Open
Abstract
N-linked glycosylation is an essential posttranslational modification of proteins in eukaryotes. The substrate of N-linked glycosylation, dolichol pyrophosphate (DolPP)-GlcNAc(2)Man(9)Glc(3), is assembled through a complex series of ordered reactions requiring the translocation of the intermediate DolPP-GlcNAc(2)Man(5) structure across the endoplasmic-reticulum membrane. A young patient diagnosed with a congenital disorder of glycosylation characterized by an intracellular accumulation of DolPP-GlcNAc(2)Man(5) was found to carry a homozygous point mutation in the RFT1 gene. The c.199C-->T mutation introduced the amino acid substitution p.R67C. The human RFT1 protein shares 22% identity with its yeast ortholog, which is involved in the translocation of DolPP-GlcNAc(2)Man(5) from the cytosolic into the lumenal side of the endoplasmic reticulum. Despite the low sequence similarity between the yeast and the human RFT1 proteins, we demonstrated both their functional orthology and the pathologic effect of the human p.R67C mutation by complementation assay in Deltarft1 yeast cells. The causality of the RFT1 p.R67C mutation was further established by restoration of normal glycosylation profiles in patient-derived fibroblasts after lentiviral expression of a normal RFT1 cDNA. The definition of the RFT1 defect establishes the functional conservation of the DolPP-GlcNAc(2)Man(5) translocation process in eukaryotes. RFT1 deficiency in both yeast and human cells leads to the accumulation of incomplete DolPP-GlcNAc(2)Man(5) and to a profound glycosylation disorder in humans.
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Affiliation(s)
- Micha A Haeuptle
- Institute of Physiology and Zürich Center for Integrative Human Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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Abstract
Congenital disorders of glycosylation (CDG) are a large family of genetic diseases resulting from defects in the synthesis of glycans and in the attachment of glycans to other compounds. These disorders cause a wide range of human diseases, with examples emanating from all medical subspecialties. Since our 2001 review on CDG ( 36 ), this field has seen substantial growth: The number of N-glycosylation defects has doubled (from 6 to 12), five new O-glycosylation defects have been added to the two previously known ones, three combined N- and O-glycosylation defects have been identified, the first lipid glycosylation defects have been discovered, and a new domain, that of the hyperglycosylation defects, has been introduced. A number of CDG are due to defects in enzymes with a putative glycosyltransferase function. There is also a growing group of patients with unidentified defects (CDG-x), some with typical clinical presentations and others with presentations not seen before in CDG. This review focuses on the clinical, biochemical, and genetic characteristics of CDG and on advances expected in their future study and clinical management.
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Affiliation(s)
- Jaak Jaeken
- Department of Pediatrics, Center for Metabolic Disease, University of Leuven, Leuven, Belgium.
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Heinicke S, Livstone MS, Lu C, Oughtred R, Kang F, Angiuoli SV, White O, Botstein D, Dolinski K. The Princeton Protein Orthology Database (P-POD): a comparative genomics analysis tool for biologists. PLoS One 2007; 2:e766. [PMID: 17712414 PMCID: PMC1942082 DOI: 10.1371/journal.pone.0000766] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 07/18/2007] [Indexed: 02/07/2023] Open
Abstract
Many biological databases that provide comparative genomics information and tools are now available on the internet. While certainly quite useful, to our knowledge none of the existing databases combine results from multiple comparative genomics methods with manually curated information from the literature. Here we describe the Princeton Protein Orthology Database (P-POD, http://ortholog.princeton.edu), a user-friendly database system that allows users to find and visualize the phylogenetic relationships among predicted orthologs (based on the OrthoMCL method) to a query gene from any of eight eukaryotic organisms, and to see the orthologs in a wider evolutionary context (based on the Jaccard clustering method). In addition to the phylogenetic information, the database contains experimental results manually collected from the literature that can be compared to the computational analyses, as well as links to relevant human disease and gene information via the OMIM, model organism, and sequence databases. Our aim is for the P-POD resource to be extremely useful to typical experimental biologists wanting to learn more about the evolutionary context of their favorite genes. P-POD is based on the commonly used Generic Model Organism Database (GMOD) schema and can be downloaded in its entirety for installation on one's own system. Thus, bioinformaticians and software developers may also find P-POD useful because they can use the P-POD database infrastructure when developing their own comparative genomics resources and database tools.
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Affiliation(s)
- Sven Heinicke
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Michael S. Livstone
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Charles Lu
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Rose Oughtred
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Fan Kang
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Samuel V. Angiuoli
- The Institute for Genomic Research, Rockville, Maryland, United States of America
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland, United States of America
| | - Owen White
- The Institute for Genomic Research, Rockville, Maryland, United States of America
| | - David Botstein
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Kara Dolinski
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- * To whom correspondence should be addressed. E-mail:
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Marklová E, Albahri Z. Screening and diagnosis of congenital disorders of glycosylation. Clin Chim Acta 2007; 385:6-20. [PMID: 17716641 DOI: 10.1016/j.cca.2007.07.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Revised: 06/22/2007] [Accepted: 07/02/2007] [Indexed: 02/07/2023]
Abstract
The aim of this paper is to review the diagnostics of congenital disorders of glycosylation (CDG), an ever expanding group of diseases. Development delay, neurological, and other clinical abnormalities as well as various non-specific laboratory changes can lead to the first suspicion of the disease. Still common screening test for most CDG types, including CDG Ia, is isoelectric focusing/polyacrylamide gel electrophoresis (IEF). IEF demonstrates the hypoglycosylation of various glycoproteins, usually serum transferrin. Other methods, such as agarose electrophoresis, capillary electrophoresis, high-performance liquid chromatography, micro-column separation combined with turbidimetry, enzyme-(EIA) and radioimmunoassay (RIA) have also been used for screening. However, these methods do not recognize all CDG defects, so other approaches including analysis of membrane-linked markers and urine oligosaccharides should be taken. Confirmation of diagnosis and detailed CDG subtyping starts with thorough structure analysis of the affected lipid-linked oligosaccharide or protein-(peptide)-linked-glycan using metabolic labeling and various (possibly mass-spectrometry combined) techniques. Decreased enzyme activity in peripheral leukocytes/cultured fibroblasts or analysis of affected transporters and other functional proteins combined with identification of specific gene mutations confirm the diagnosis. Prenatal diagnosis, based on enzyme assay or mutation analysis, is also available. Peri-/post-mortem investigations of fatal cases are important for genetic counseling. Evaluation of various analytical approaches and proposed algorithms for investigation complete the review.
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Affiliation(s)
- Eliska Marklová
- Charles University, Faculty of Medicine, Department of Pediatrics, Hradec Králové, Czech Republic.
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Carter CJ. Multiple genes and factors associated with bipolar disorder converge on growth factor and stress activated kinase pathways controlling translation initiation: implications for oligodendrocyte viability. Neurochem Int 2007; 50:461-90. [PMID: 17239488 DOI: 10.1016/j.neuint.2006.11.009] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 11/27/2006] [Indexed: 02/06/2023]
Abstract
Famine and viral infection, as well as interferon therapy have been reported to increase the risk of developing bipolar disorder. In addition, almost 100 polymorphic genes have been associated with this disease. Several form most of the components of a phosphatidyl-inositol signalling/AKT1 survival pathway (PIK3C3, PIP5K2A, PLCG1, SYNJ1, IMPA2, AKT1, GSK3B, TCF4) which is activated by growth factors (BDNF, NRG1) and also by NMDA receptors (GRIN1, GRIN2A, GRIN2B). Various other protein products of genes associated with bipolar disorder either bind to or are affected by phosphatidyl-inositol phosphate products of this pathway (ADBRK2, HIP1R, KCNQ2, RGS4, WFS1), are associated with its constituent elements (BCR, DUSP6, FAT, GNAZ) or are downstream targets of this signalling cascade (DPYSL2, DRD3, GAD1, G6PD, GCH1, KCNQ2, NOS3, SLC6A3, SLC6A4, SST, TH, TIMELESS). A further pathway relates to endoplasmic reticulum-stress (HSPA5, XBP1), caused by problems in protein glycosylation (ALG9), growth factor receptor sorting (PIK3C3, HIP1R, SYBL1), or aberrant calcium homoeostasis (WFS1). Key processes relating to these pathways appear to be under circadian control (ARNTL, CLOCK, PER3, TIMELESS). DISC1 can also be linked to many of these pathways. The growth factor pathway promotes protein synthesis, while the endoplasmic reticulum stress pathway, and other stress pathways activated by viruses and cytokines (IL1B, TNF, Interferons), oxidative stress or starvation, all factors associated with bipolar disorder risk, shuts down protein synthesis via control of the EIF2 alpha and beta translation initiation complex. For unknown reasons, oligodendrocytes appear to be particularly prone to defects in the translation initiation complex (EIF2B) and the convergence of these environmental and genomic signalling pathways on this area might well explain their vulnerability in bipolar disorder.
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McKenzie FA, Fietz M, Fletcher J, Smith RLL, Wright IMR, Jaeken J. A previously undescribed form of congenital disorder of glycosylation with variable presentation in siblings: Early fetal loss with hydrops fetalis, and infant death with hypoproteinemia. Am J Med Genet A 2007; 143A:2029-34. [PMID: 17663480 DOI: 10.1002/ajmg.a.31867] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We present two siblings with a previously undescribed congenital disorder of glycosylation (CDG). The first child died in utero with severe hydrops fetalis and the second presented following preterm delivery with respiratory insufficiency, generalised edema and a protein-losing enteropathy. Both had a similar pattern of facial dysmorphism and joint contractures. The diagnosis of CDG-I was made following the birth of the second child based on the serum transferrin isoform pattern. CDG-Ia and -Ib were excluded by specific enzyme analysis. Joint contractures are a relatively uncommon finding in CDG, although fetal hydrops (CDG-Ia) and protein-losing enteropathy (CDG-Ib) are well recognized. CDG must be considered in the differential diagnosis of hydrops fetalis, congenital hypoproteinemia and death in early infancy, particularly when associated with dysmorphic features.
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Affiliation(s)
- F A McKenzie
- Hunter Genetics, Hunter New England Health, Newcastle, Australia.
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Abstract
The congenital disorders of N-glycosylation (CDG), a steadily increasing group of multi-systemic disorders, have severe clinical implications in infancy and early childhood. The various inborn errors responsible adversely affect N-glycosylation of lysosomal proteins because of either failing assembly of lipid-linked (LL) oligosaccharides (OS) in the endoplasmic reticulum, CDG Type I, or faulty processing of the asparagines (N)-linked OS in the ER and in the Golgi, CDG Type II. The overlap of phenotypes precludes specific clinical delineation. Isoelectric focusing (IEF) of plasma transferrin remains a valuable, albeit imperfect, screening tool. IEF of plasma ApoC-III protein, introduced O-glycosylation defects that delineated some new CDGs due to mutations of both N- and O-glycosylation. Only CDG-Ib is amenable to treatment with free mannose supplementation. Hence, early specific diagnosis of any one entity is crucial for genetic counseling and elective preventive measures.
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Affiliation(s)
- Jules G Leroy
- Department of Pediatrics, Ghent University School of Medicine and University, B-9000 Ghent, Belgium.
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Lehle L, Strahl S, Tanner W. Proteinglycosylierung, konserviert von der Bäckerhefe bis zum Menschen: Ein Modellorganismus hilft bei der Aufklärung menschlicher Erbkrankheiten. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200601645] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Lehle L, Strahl S, Tanner W. Protein Glycosylation, Conserved from Yeast to Man: A Model Organism Helps Elucidate Congenital Human Diseases. Angew Chem Int Ed Engl 2006; 45:6802-18. [PMID: 17024709 DOI: 10.1002/anie.200601645] [Citation(s) in RCA: 204] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Proteins can be modified by a large variety of covalently linked saccharides. The present review concentrates on two types, protein N-glycosylation and protein O-mannosylation, which, with only a few exceptions, are evolutionary conserved from yeast to man. They are also distinguished by some special features: The corresponding glycosylation processes start in the endoplasmatic reticulum, are continued in the Golgi apparatus, and require dolichol-activated precursors for the initial biosynthetic steps. With respect to the molecular biology of both types of protein glycosylation, the pathways and the genetic background of the reactions have most successfully been studied with the genetically easy-to-handle baker's yeast, Saccharomyces cerevisae. Many of the severe developmental disturbances in children are related to protein glycosylation, for example, the CDG syndrome (congenital disorders of glycosylation) as well as congenital muscular dystrophies with neuronal-cell-migration defects have been elucidated with the help of yeast.
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Affiliation(s)
- Ludwig Lehle
- Lehrstuhl für Zellbiologie und Pflanzenphysiologie, Universität Regensburg, Universitätstrasse 31, 93053 Regensburg, Germany.
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Cohn RD, Eklund E, Bergner AL, Casella JF, Woods SL, Althaus J, Blakemore KJ, Fox HE, Hoover-Fong JE, Hamosh A, Braverman NE, Freeze HH, Boyadjiev SA. Intracranial hemorrhage as the initial manifestation of a congenital disorder of glycosylation. Pediatrics 2006; 118:e514-21. [PMID: 16816004 DOI: 10.1542/peds.2005-1307] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Intracranial hemorrhage in a term neonate is a rare event in the absence of an identifiable precipitating factor such as severe thrombocytopenia, mechanical trauma, asphyxia, infections, or congenital vascular malformations. Congenital disorders of glycosylation are a genetically and clinically heterogeneous group of multisystem disorders characterized by the abnormal glycosylation of a number of glycoproteins. Although bleeding caused by abnormal glycosylation of various coagulation factors is a well-known clinical complication of several types of congenital disorders of glycosylation, intracranial hemorrhage has not been reported as an initial manifestation of this entity. Here we report the detailed history of a family with 2 consecutive male infants, both born at term with intracranial hemorrhage diagnosed within the first 24 hours of life. The diagnosis of a congenital disorder of glycosylation was established in the second infant by an abnormal glycosylation of serum transferrin detected by electrospray-ionization mass spectrometry. Both infants showed significant neurologic deterioration during the first month of life, and both died at 5 months of age. Intracranial hemorrhage in a term neonate without a potential precipitating factor represents yet another clinical feature that should raise the suspicion for a congenital disorder of glycosylation.
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Affiliation(s)
- Ronald D Cohn
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins Hospital, Children's Center, Johns Hopkins University School of Medicine, 600 N Wolfe St, Blalock 1008, Baltimore, Maryland 21205, USA.
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Baysal BE, Willett-Brozick JE, Bacanu SA, Detera-Wadleigh S, Nimgaonkar VL. Common variations in ALG9 are not associated with bipolar I disorder: a family-based study. Behav Brain Funct 2006; 2:25. [PMID: 16859551 PMCID: PMC1569366 DOI: 10.1186/1744-9081-2-25] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2006] [Accepted: 07/21/2006] [Indexed: 11/17/2022] Open
Abstract
Background A mannosyltransferase gene (ALG9, DIBD1) at chromosome band 11q23 was previously identified to be disrupted by a balanced chromosomal translocation t(9;11)(p24;q23) co-segregating with bipolar affective disorder in a small family. Inborn ALG9 deficiency (congenital disorders of glycosylation type IL) is associated with progressive microcephaly, seizures, developmental delay, and hepatomegaly. It is unknown whether common variations of ALG9 predispose to bipolar affective disorder. Methods We tested five polymorphic markers spanning ALG9 (three intragenic and one upstream microsatellite repeats and one common missense variation, V289I (rs10502151) for their association with bipolar I disorder in two pedigree series. The NIMH (National Institute of Mental Health) pedigrees had a total of 166 families showing transmissions to 250 affected offspring, whereas The PITT (The University of Pittsburgh) pedigrees had a total of 129 families showing transmissions to 135 cases. We used transmission disequilibrium test for the association analyses. Results We identified three common and distinct haplotypes spanning the ALG9 gene. We found no statistically-significant evidence of transmission disequilibrium of marker alleles or multi-marker haplotypes to the affected offspring with bipolar I disorder. Conclusion These results suggest that common variations in ALG9 do not play a major role in predisposition to bipolar affective disorder.
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Affiliation(s)
- Bora E Baysal
- Department of Obstetrics, Gynecology and Reproductive Sciences, The University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Joan E Willett-Brozick
- Department of Obstetrics, Gynecology and Reproductive Sciences, The University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Silviu-Alin Bacanu
- Department of Psychiatry, The University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
- GlaxoSmithKline, Moore Drive, Research Triangle Park, NC 27709, USA
| | | | - Vishwajit L Nimgaonkar
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Department of Psychiatry, The University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Abstract
The congenital disorders of glycosylation (CDG) are a rapidly expanding group of metabolic syndromes with a wide symptomatology and severity. They all stem from deficient N-glycosylation of proteins. To date the group contains 18 different subtypes: 12 of Type I (disrupted synthesis of the lipid-linked oligosaccharide precursor) and 6 of Type II (malfunctioning trimming/processing of the protein-bound oligosaccharide). Main features of CDG involve psychomotor retardation; ataxia; seizures; retinopathy; liver fibrosis; coagulopathies; failure to thrive; dysmorphic features, including inverted nipples and subcutaneous fat pads; and strabismus. No treatment currently is available for the vast majority of these syndromes (CDG-Ib and CDG-IIc are exceptions), even though attempts to synthesize drugs for the most common subtype, CDG-Ia, have been made. In this review we will discuss the individual syndromes, with focus on their neuronal involvement, available and possible treatments, and future directions.
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Affiliation(s)
- Erik A. Eklund
- />Department of Cell and Molecular Biology, Lund University, Lund, Sweden
- />Program for Glycobiology and Carbohydrate Chemistry, Burnham Institute for Medical Research, 92037 La Jolla, California
| | - Hudson H. Freeze
- />Program for Glycobiology and Carbohydrate Chemistry, Burnham Institute for Medical Research, 92037 La Jolla, California
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50
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Hesselberth JR, Miller JP, Golob A, Stajich JE, Michaud GA, Fields S. Comparative analysis of Saccharomyces cerevisiae WW domains and their interacting proteins. Genome Biol 2006; 7:R30. [PMID: 16606443 PMCID: PMC1557994 DOI: 10.1186/gb-2006-7-4-r30] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 02/10/2006] [Accepted: 03/09/2006] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The WW domain is found in a large number of eukaryotic proteins implicated in a variety of cellular processes. WW domains bind proline-rich protein and peptide ligands, but the protein interaction partners of many WW domain-containing proteins in Saccharomyces cerevisiae are largely unknown. RESULTS We used protein microarray technology to generate a protein interaction map for 12 of the 13 WW domains present in proteins of the yeast S. cerevisiae. We observed 587 interactions between these 12 domains and 207 proteins, most of which have not previously been described. We analyzed the representation of functional annotations within the network, identifying enrichments for proteins with peroxisomal localization, as well as for proteins involved in protein turnover and cofactor biosynthesis. We compared orthologs of the interacting proteins to identify conserved motifs known to mediate WW domain interactions, and found substantial evidence for the structural conservation of such binding motifs throughout the yeast lineages. The comparative approach also revealed that several of the WW domain-containing proteins themselves have evolutionarily conserved WW domain binding sites, suggesting a functional role for inter- or intramolecular association between proteins that harbor WW domains. On the basis of these results, we propose a model for the tuning of interactions between WW domains and their protein interaction partners. CONCLUSION Protein microarrays provide an appealing alternative to existing techniques for the construction of protein interaction networks. Here we built a network composed of WW domain-protein interactions that illuminates novel features of WW domain-containing proteins and their protein interaction partners.
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Affiliation(s)
- Jay R Hesselberth
- Department of Genome Sciences, University of Washington, Box 357730, Seattle, WA 98195, USA
| | - John P Miller
- Department of Genome Sciences, University of Washington, Box 357730, Seattle, WA 98195, USA
- Current address: Buck Institute, Redwood Boulevard, Novato, CA 94945, USA
| | - Anna Golob
- Department of Genome Sciences, University of Washington, Box 357730, Seattle, WA 98195, USA
| | - Jason E Stajich
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27710, USA
| | | | - Stanley Fields
- Department of Genome Sciences, University of Washington, Box 357730, Seattle, WA 98195, USA
- Department of Medicine, and Howard Hughes Medical Institute, University of Washington, Box 357730, Seattle, WA 98195, USA
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