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Stadlmann J, Helm J, Mereiter S, Oliveira T, Gattinger A, Markovitz D, Penninger J, Altmann F. Non-targeted isomer-sensitive N-glycome analysis reveals new layers of organ-specific diversity in mice. RESEARCH SQUARE 2024:rs.3.rs-4130712. [PMID: 38659835 PMCID: PMC11042426 DOI: 10.21203/rs.3.rs-4130712/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
N-glycosylation is one of the most common protein modifications in eukaryotes, with immense importance at the molecular, cellular, and organismal level. Accurate and reliable N-glycan analysis is essential to obtain a systems-wide understanding of fundamental biological processes. Due to the structural complexity of glycans, their analysis is still highly challenging. Here we make publicly available a consistent N-glycome dataset of 20 different mouse tissues and demonstrate a multimodal data analysis workflow that allows for unprecedented depth and coverage of N-glycome features. This highly scalable, LC-MS/MS data-driven method integrates the automated identification of N-glycan spectra, the application of non-targeted N-glycome profiling strategies and the isomer-sensitive analysis of glycan structures. Our delineation of critical sub-structural determinants and glycan isomers across the mouse N-glycome uncovered tissue-specific glycosylation patterns, the expression of non-canonical N-glycan structures and highlights multiple layers of N-glycome complexity that derive from organ-specific regulations of glycobiological pathways.
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Affiliation(s)
| | - Johannes Helm
- University of Natural Resources and Life Sciences Vienna
| | | | - Tiago Oliveira
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA)
| | - Anna Gattinger
- Bioinformatics Research Group, University of Applied Sciences Upper Austria
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2
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Li J, Qiu Y, Zhang C, Wang H, Bi R, Wei Y, Li Y, Hu B. The role of protein glycosylation in the occurrence and outcome of acute ischemic stroke. Pharmacol Res 2023; 191:106726. [PMID: 36907285 DOI: 10.1016/j.phrs.2023.106726] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/03/2023] [Accepted: 03/09/2023] [Indexed: 03/12/2023]
Abstract
Acute ischemic stroke (AIS) is a serious and life-threatening disease worldwide. Despite thrombolysis or endovascular thrombectomy, a sizeable fraction of patients with AIS have adverse clinical outcomes. In addition, existing secondary prevention strategies with antiplatelet and anticoagulant drugs therapy are not able to adequately decrease the risk of ischemic stroke recurrence. Thus, exploring novel mechanisms for doing so represents an urgent need for the prevention and treatment of AIS. Recent studies have discovered that protein glycosylation plays a critical role in the occurrence and outcome of AIS. As a common co- and post-translational modification, protein glycosylation participates in a wide variety of physiological and pathological processes by regulating the activity and function of proteins or enzymes. Protein glycosylation is involved in two causes of cerebral emboli in ischemic stroke: atherosclerosis and atrial fibrillation. Following ischemic stroke, the level of brain protein glycosylation becomes dynamically regulated, which significantly affects stroke outcome through influencing inflammatory response, excitotoxicity, neuronal apoptosis, and blood-brain barrier disruption. Drugs targeting glycosylation in the occurrence and progression of stroke may represent a novel therapeutic idea. In this review, we focus on possible perspectives about how glycosylation affects the occurrence and outcome of AIS. We then propose the potential of glycosylation as a therapeutic drug target and prognostic marker for AIS patients in the future.
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Affiliation(s)
- Jianzhuang Li
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yanmei Qiu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chunlin Zhang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hailing Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rentang Bi
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yanhao Wei
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yanan Li
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Bo Hu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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3
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Peptide Sequence Mapping around Bisecting GlcNAc-Bearing N-Glycans in Mouse Brain. Int J Mol Sci 2021; 22:ijms22168579. [PMID: 34445285 PMCID: PMC8395275 DOI: 10.3390/ijms22168579] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 02/08/2023] Open
Abstract
N-glycosylation is essential for many biological processes in mammals. A variety of N-glycan structures exist, of which, the formation of bisecting N-acetylglucosamine (GlcNAc) is catalyzed by N-acetylglucosaminyltransferase-III (GnT-III, encoded by the Mgat3 gene). We previously identified various bisecting GlcNAc-modified proteins involved in Alzheimer's disease and cancer. However, the mechanisms by which GnT-III acts on the target proteins are unknown. Here, we performed comparative glycoproteomic analyses using brain membranes of wild type (WT) and Mgat3-deficient mice. Target glycoproteins of GnT-III were enriched with E4-phytohemagglutinin (PHA) lectin, which recognizes bisecting GlcNAc, and analyzed by liquid chromatograph-mass spectrometry. We identified 32 N-glycosylation sites (Asn-Xaa-Ser/Thr, Xaa ≠ Pro) that were modified with bisecting GlcNAc. Sequence alignment of identified N-glycosylation sites that displayed bisecting GlcNAc suggested that GnT-III does not recognize a specific primary amino acid sequence. The molecular modeling of GluA1 as one of the good cell surface substrates for GnT-III in the brain, indicated that GnT-III acts on N-glycosylation sites located in a highly flexible and mobile loop of GluA1. These results suggest that the action of GnT-III is partially affected by the tertiary structure of target proteins, which can accommodate bisecting GlcNAc that generates a bulky flipped-back conformation of the modified glycans.
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Syed BA, Patel M, Patel A, Gami B, Patel B. Regulation of antioxidant enzymes and osmo-protectant molecules by salt and drought responsive genes in Bambusa balcooa. JOURNAL OF PLANT RESEARCH 2021; 134:165-175. [PMID: 33411148 DOI: 10.1007/s10265-020-01242-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 11/17/2020] [Indexed: 06/12/2023]
Abstract
Bio-energy crops need to be grown on marginal salt and drought lands in India as per policy. Understanding environmental stress response in bio-energy crops might help in promoting cultivation of bio-energy feedstock on marginal salty and drought land. This is one of the first report for vegetative propagation of Bamboo (Bambusa balcooa) under salt and drought stress to understand antioxidant enzymes' gene regulations to combat stress through activation of antioxidant enzymes and osmo-protectant molecules to scavenge reactive oxygen species as measured by physiological changes. Morphological, physiological, and biochemical traits were noted as indicators of plant health upon different sodium chloride (NaCl) salt-stress while various drought conditions with correlation analysis. A significant up-regulation of genes related to most of the antioxidant enzymes was observed up to salinity of 14 mS cm- 1 electric conductivity (EC) at 150 mM NaCl experimental salt stress which declined with higher salt-stress. While in the case of drought-stress, all genes remained up-regulated while proline dehydrogenase (PDH) remained down-regulated up-to 100% drought-stress having 4% soil moisture. The gene expressions of antioxidant enzymes were significantly correlated with their corresponding gene-products namely super-oxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and ascorbate peroxidase (APX) activities. Biochemical parameters such as, soluble sugar, proline, malondialdehyde (MDA), total amino acids, hydrogen peroxide and electrolyte leakage ratio also showed positive correlation (p = 0.001) with salt condition. Genetic and biochemical test parameters were significantly correlated with physiological attributes of plant health at soil EC of 14 mS cm- 1 shown as 150 mM NaCl salt stress and 60% drought-stress having 17% soil moisture content, were the optimum stress tolerance limits observed. Application of these data would be useful to cultivate 0.63 million ha of salinity affected land and 10.05 million ha of drought affected land among wastelands in India to meet biofuel need.
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Affiliation(s)
- Bakhtiyar Alam Syed
- SN Gene Labs Private Limited, A-President Plaza, Nanpura, Surat, 395001, Gujarat, India
| | - Meghana Patel
- Gujarat Ecological Education and Research (GEER) Foundation, Indroda Nature Park, P.O. Sector -7, Gandhinagar, 382007, Gujarat, India
| | - Akash Patel
- Abellon Cleanenergy Limited, Sangeeta Complex, Nr. Parimal Crossing, Ellisbridge, Ahmedabad, Gujarat, 380006, India
| | - Bharat Gami
- Abellon Cleanenergy Limited, Sangeeta Complex, Nr. Parimal Crossing, Ellisbridge, Ahmedabad, Gujarat, 380006, India
| | - Beena Patel
- Abellon Cleanenergy Limited, Sangeeta Complex, Nr. Parimal Crossing, Ellisbridge, Ahmedabad, Gujarat, 380006, India.
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5
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Wongtrakul-Kish K, Herbert BR, Packer NH. Bisecting GlcNAc Protein N-Glycosylation Is Characteristic of Human Adipogenesis. J Proteome Res 2020; 20:1313-1327. [PMID: 33383989 DOI: 10.1021/acs.jproteome.0c00702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human adipose tissue contains a major source of adipose-derived stem cells (ADSCs) that have the ability to differentiate into various cell types: in vitro, ADSCs can differentiate into mesenchymal lineages including adipocytes, while in vivo, ADSCs become mature adipocytes. Protein glycosylation has been shown to change in stem cell differentiation, and while ADSCs have been acknowledged for their therapeutic potential, little is known about protein glycosylation during human ADSC adipogenic differentiation. In the present study, the global membrane protein glycosylation of native adipocytes was compared to ADSCs from the same individuals as a model of in vivo adipogenesis. For in vitro adipogenesis, ADSCs were adipogenically differentiated in cell culture using an optimized, large-scale differentiation procedure. The membrane glycome of the differentiated ADSCs (dADSCs) was compared with mature adipocytes and the progenitor ADSCs. A total of 137 glycan structures were characterized across the three cell types using PGC-LC coupled with negative-ion electrospray ionization mass spectrometry (ESI-MS)/MS. Significantly higher levels of bisecting GlcNAc-type N-glycans were detected in mature adipocytes (32.1% of total glycans) and in in vitro dADSC progeny (1.9% of total glycans) compared to ADSCs. This was further correlated by the mRNA expression of the MGAT3 gene responsible for the enzymatic synthesis of this structural type. The bisecting GlcNAc structures were found on the majority of human native adipocyte membrane proteins, suggesting an important role in human adipocyte biology. Core fucosylation was also significantly increased during in vivo adipogenesis but did not correlate with an increase in Fut8 gene transcript. Unexpectedly, low abundance structures carrying rare β-linked Gal-Gal termini were also detected. Overall, the N-glycan profiles of the in vitro differentiated progeny did not reflect native adipocytes, and the results show that bisecting GlcNAc structures are a characteristic feature of human adipocyte membrane protein N-glycosylation. Raw MS files are available on GlycoPOST (ID: GPST000153 https://glycopost.glycosmos.org/).
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Affiliation(s)
- Katherine Wongtrakul-Kish
- Biomolecular Discovery Research Centre, Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia.,ARC Centre for Nanoscale BioPhotonics, Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Benjamin R Herbert
- Biomolecular Discovery Research Centre, Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Nicolle H Packer
- Biomolecular Discovery Research Centre, Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia.,ARC Centre for Nanoscale BioPhotonics, Department of Molecular Sciences, Macquarie University, Sydney, NSW 2109, Australia
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6
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Matsumoto K, Luther KB, Haltiwanger RS. Diseases related to Notch glycosylation. Mol Aspects Med 2020; 79:100938. [PMID: 33341260 DOI: 10.1016/j.mam.2020.100938] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/30/2020] [Accepted: 12/03/2020] [Indexed: 12/15/2022]
Abstract
The Notch receptors are a family of transmembrane proteins that mediate direct cell-cell interactions and control numerous cell-fate specifications in humans. The extracellular domains of mammalian Notch proteins contain 29-36 tandem epidermal growth factor-like (EGF) repeats, most of which have O-linked glycan modifications: O-glucose added by POGLUT1, O-fucose added by POFUT1 and elongated by Fringe enzymes, and O-GlcNAc added by EOGT. The extracellular domain is also N-glycosylated. Mutations in the glycosyltransferases modifying Notch have been identified in several diseases, including Dowling-Degos Disease (haploinsufficiency of POFUT1 or POGLUT1), a form of limb-girdle muscular dystrophy (autosomal recessive mutations in POGLUT1), Spondylocostal Dysostosis 3 (autosomal recessive mutations in LFNG), Adams-Oliver syndrome (autosomal recessive mutations in EOGT), and some cancers (amplification, gain or loss-of-function of POFUT1, Fringe enzymes, POGLUT1, MGAT3). Here we review the characteristics of these diseases and potential molecular mechanisms.
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Affiliation(s)
- Kenjiroo Matsumoto
- Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, 315 Riverbend Road, Athens, GA, 30602, USA
| | - Kelvin B Luther
- Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, 315 Riverbend Road, Athens, GA, 30602, USA
| | - Robert S Haltiwanger
- Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, 315 Riverbend Road, Athens, GA, 30602, USA.
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7
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Li J, Xu J, Li L, Ianni A, Kumari P, Liu S, Sun P, Braun T, Tan X, Xiang R, Yue S. MGAT3-mediated glycosylation of tetraspanin CD82 at asparagine 157 suppresses ovarian cancer metastasis by inhibiting the integrin signaling pathway. Am J Cancer Res 2020; 10:6467-6482. [PMID: 32483464 PMCID: PMC7255015 DOI: 10.7150/thno.43865] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 05/04/2020] [Indexed: 12/15/2022] Open
Abstract
Background: Tetraspanins constitute a family of transmembrane spanning proteins that function mainly by organizing the plasma membrane into micro-domains. CD82, a member of tetraspanins, is a potent inhibitor of cancer metastasis in numerous malignancies. CD82 is a highly glycosylated protein, however, it is still unknown whether and how this post-translational modification affects CD82 function and cancer metastasis. Methods: The glycosylation of CD82 profiles are checked in the paired human ovarian primary and metastatic cancer tissues. The functional studies on the various glycosylation sites of CD82 are performed in vitro and in vivo. Results: We demonstrate that CD82 glycosylation at Asn157 is necessary for CD82-mediated inhibition of ovarian cancer cells migration and metastasis in vitro and in vivo. Mechanistically, we discover that CD82 glycosylation is pivotal to disrupt integrin α5β1-mediated cellular adhesion to the abundant extracellular matrix protein fibronectin. Thereby the glycosylated CD82 inhibits the integrin signaling pathway responsible for the induction of the cytoskeleton rearrangements required for cellular migration. Furthermore, we reveal that the glycosyltransferase MGAT3 is responsible for CD82 glycosylation in ovarian cancer cells. Metastatic ovarian cancers express reduced levels of MGAT3 which in turn may result in impaired CD82 glycosylation. Conclusions: Our work implicates a pathway for ovarian cancers metastasis regulation via MGAT3 mediated glycosylation of tetraspanin CD82 at asparagine 157.
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Gupta R, Leon F, Thompson CM, Nimmakayala R, Karmakar S, Nallasamy P, Chugh S, Prajapati DR, Rachagani S, Kumar S, Ponnusamy MP. Global analysis of human glycosyltransferases reveals novel targets for pancreatic cancer pathogenesis. Br J Cancer 2020; 122:1661-1672. [PMID: 32203219 PMCID: PMC7251111 DOI: 10.1038/s41416-020-0772-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 02/12/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Several reports have shown the role of glycosylation in pancreatic cancer (PC), but a global systematic screening of specific glycosyltransferases (glycoTs) in its progression remains unknown. METHODS We demonstrate a rigorous top-down approach using TCGA-based RNA-Seq analysis, multi-step validation using RT-qPCR, immunoblots and immunohistochemistry. We identified six unique glycoTs (B3GNT3, B4GALNT3, FUT3, FUT6, GCNT3 and MGAT3) in PC pathogenesis and studied their function using CRISPR/Cas9-based KD systems. RESULTS Serial metastatic in vitro models using T3M4 and HPAF/CD18, generated in house, exhibited decreases in B3GNT3, FUT3 and GCNT3 expression on increasing metastatic potential. Immunohistochemistry identified clinical significance for GCNT3, B4GALNT3 and MGAT3 in PC. Furthermore, the effects of B3GNT3, FUT3, GCNT3 and MGAT3 were shown on proliferation, migration, EMT and stem cell markers in CD18 cell line. Talniflumate, GCNT3 inhibitor, reduced colony formation and migration in T3M4 and CD18 cells. Moreover, we found that loss of GCNT3 suppresses PC progression and metastasis by downregulating cell cycle genes and β-catenin/MUC4 axis. For GCNT3, proteomics revealed downregulation of MUC5AC, MUC1, MUC5B including many other proteins. CONCLUSIONS Collectively, we demonstrate a critical role of O- and N-linked glycoTs in PC progression and delineate the mechanism encompassing the role of GCNT3 in PC.
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Affiliation(s)
- Rohitesh Gupta
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Frank Leon
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Christopher M Thompson
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Ramakrishna Nimmakayala
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Saswati Karmakar
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Palanisamy Nallasamy
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Seema Chugh
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Dipakkumar R Prajapati
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Satyanarayana Rachagani
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Sushil Kumar
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Moorthy P Ponnusamy
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA.
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9
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Lu Z, Kamat K, Johnson BP, Yin CC, Scholler N, Abbott KL. Generation of a Fully Human scFv that binds Tumor-Specific Glycoforms. Sci Rep 2019; 9:5101. [PMID: 30911061 PMCID: PMC6433917 DOI: 10.1038/s41598-019-41567-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 03/08/2019] [Indexed: 12/13/2022] Open
Abstract
Tumor-specific glycosylation changes are an attractive target for the development of diagnostic and therapeutic applications. Periostin is a glycoprotein with high expression in many tumors of epithelial origin including ovarian cancer. Strategies to target the peptide portion of periostin as a diagnostic or therapeutic biomarker for cancer are limited due to increased expression of periostin in non-cancerous inflammatory conditions. Here, we have screened for antibody fragments that recognize the tumor-specific glycosylation present on glycoforms of periostin containing bisecting N-glycans in ovarian cancer using a yeast-display library of antibody fragments, while subtracting those that bind to the periostin protein with glycoforms found in non-malignant cell types. We generated a biotinylated form of a fully human scFv antibody (scFvC9) that targets the bisecting N-glycans expressed by cancer cells. Validation studies in vitro and in vivo using scFvC9 indicate this antibody can be useful for the development of diagnostic, imaging, and therapeutic applications for cancers that express the antigen.
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Affiliation(s)
- Zhongpeng Lu
- University of Arkansas for Medical Sciences, Department of Biochemistry and Molecular Biology, Little Rock, AR, 72205, USA
| | - Kalika Kamat
- SRI International Biosciences Division, Center for Cancer and Metabolism, Menlo Park, CA, 94025-3493, USA
| | - Blake P Johnson
- Ouachita Baptist University, Department of Biology, Arkadelphia, AR, 71998, USA
| | - Catherin C Yin
- SRI International Biosciences Division, Center for Cancer and Metabolism, Menlo Park, CA, 94025-3493, USA
| | - Nathalie Scholler
- SRI International Biosciences Division, Center for Cancer and Metabolism, Menlo Park, CA, 94025-3493, USA
| | - Karen L Abbott
- University of Arkansas for Medical Sciences, Department of Biochemistry and Molecular Biology, Little Rock, AR, 72205, USA.
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10
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Kohler RS, Anugraham M, López MN, Xiao C, Schoetzau A, Hettich T, Schlotterbeck G, Fedier A, Jacob F, Heinzelmann-Schwarz V. Epigenetic activation of MGAT3 and corresponding bisecting GlcNAc shortens the survival of cancer patients. Oncotarget 2018; 7:51674-51686. [PMID: 27429195 PMCID: PMC5239506 DOI: 10.18632/oncotarget.10543] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 06/26/2016] [Indexed: 12/21/2022] Open
Abstract
Bisecting GlcNAc on N-glycoproteins is described in E-cadherin-, EGF-, Wnt- and integrin- cancer-associated signaling pathways. However, the mechanisms regulating bisecting GlcNAc expression are not clear. Bisecting GlcNAc is attached to N-glycans through beta 1-4 N-acetylglucosaminyl transferase III (MGAT3), which is encoded by two exons flanked by high-density CpG islands. Despite a recently described correlation of MGAT3 and bisecting GlcNAc in ovarian cancer cells, it remains unknown whether DNA methylation is causative for the presence of bisecting GlcNAc. Here, we narrow down the regulatory genomic region and show that reconstitution of MGAT3 expression with 5-Aza coincides with reduced DNA methylation at the MGAT3 transcription start site. The presence of bisecting GlcNAc on released N-glycans was detected by mass spectrometry (LC-ESI-qTOF-MS/MS) in serous ovarian cancer cells upon DNA methyltransferase inhibition. The regulatory impact of DNA methylation on MGAT3 was further evaluated in 18 TCGA cancer types (n = 6118 samples) and the results indicate an improved overall survival in patients with reduced MGAT3 expression, thereby identifying long-term survivors of high-grade serous ovarian cancers (HGSOC). Epigenetic activation of MGAT3 was also confirmed in basal-like breast cancers sharing similar molecular and genetic features with HGSOC. These results provide novel insights into the epigenetic regulation of MGAT3/bisecting GlcNAc and demonstrate the importance of N-glycosylation in cancer progression.
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Affiliation(s)
- Reto S Kohler
- Ovarian Cancer Research, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Merrina Anugraham
- Ovarian Cancer Research, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Mónica Núñez López
- Ovarian Cancer Research, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Christina Xiao
- Ovarian Cancer Research, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Andreas Schoetzau
- Ovarian Cancer Research, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Timm Hettich
- School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland
| | - Goetz Schlotterbeck
- School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland
| | - André Fedier
- Ovarian Cancer Research, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Francis Jacob
- Ovarian Cancer Research, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland.,Glyco-Oncology, Ovarian Cancer Research, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Viola Heinzelmann-Schwarz
- Ovarian Cancer Research, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland.,Hospital for Women, Department of Gynecology and Gynecological Oncology, University Hospital Basel, Basel, Switzerland
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11
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de Haan N, Reiding KR, Krištić J, Hipgrave Ederveen AL, Lauc G, Wuhrer M. The N-Glycosylation of Mouse Immunoglobulin G (IgG)-Fragment Crystallizable Differs Between IgG Subclasses and Strains. Front Immunol 2017; 8:608. [PMID: 28620376 PMCID: PMC5449507 DOI: 10.3389/fimmu.2017.00608] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 05/09/2017] [Indexed: 12/30/2022] Open
Abstract
N-linked glycosylation of the fragment crystallizable (Fc)-region of immunoglobulin G (IgG) is known to have a large influence on the activity of the antibody, an effect reported to be IgG subclass specific. This situation applies both to humans and mice. The mouse is often used as experimental animal model to study the effects of Fc-glycosylation on IgG effector functions, and results are not uncommonly translated back to the human situation. However, while human IgG Fc-glycosylation has been extensively characterized in both health and disease, this is not the case for mice. To characterize the glycosylation profile of murine IgG-Fc and in addition evaluate the systematic glycosylation differences between mouse strains, sexes, and IgG subclasses, we used nanoliquid chromatography mass spectrometry (nanoLC-MS(/MS)) to look at the subclass-specific IgG Fc-glycopeptides of male and female mice from the strains BALB/c, C57BL/6, CD-1, and Swiss Webster. The structural analysis revealed the presence of predominantly fucosylated, diantennary glycans, with varying amounts of galactosylation and α2,6-sialylation. In addition, we report glycosylation features not previously reported in an Fc-specific way on murine IgG, including monoantennary, hybrid, and high mannose structures, as well as diantennary structures without a core fucose, with a bisecting N-acetylglucosamine, or with α1,3-galactosylation. Pronounced differences were detected between strains and the IgG subclasses within each strain. Especially the large spread in galactosylation and sialylation levels found between both strains and subclasses may vastly influence IgG effector functions. Mouse strain-based and subclass-specific glycosylation differences should be taken into account when designing and interpreting immunological and glycobiological mouse studies involving IgG effector functions.
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Affiliation(s)
- Noortje de Haan
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, Netherlands
| | - Karli R Reiding
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, Netherlands
| | | | | | - Gordan Lauc
- Glycoscience Research Laboratory, Genos, Zagreb, Croatia
| | - Manfred Wuhrer
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, Netherlands
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12
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Hamanoue M, Ikeda Y, Ogata T, Takamatsu K. Predominant expression of N-acetylglucosaminyltransferase V (GnT-V) in neural stem/progenitor cells. Stem Cell Res 2015; 14:68-78. [DOI: 10.1016/j.scr.2014.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 10/27/2014] [Accepted: 11/24/2014] [Indexed: 10/24/2022] Open
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13
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Allam H, Aoki K, Benigno BB, McDonald JF, Mackintosh SG, Tiemeyer M, Abbott KL. Glycomic analysis of membrane glycoproteins with bisecting glycosylation from ovarian cancer tissues reveals novel structures and functions. J Proteome Res 2014; 14:434-46. [PMID: 25437919 PMCID: PMC4286206 DOI: 10.1021/pr501174p] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
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Biomarkers capable of detecting and
targeting epithelial ovarian
cancer cells for diagnostics and therapeutics would be extremely valuable.
Ovarian cancer is the deadliest reproductive malignancy among women
in the U.S., killing over 14 000 women each year. Both the
lack of presenting symptoms and high mortality rates illustrate the
need for earlier diagnosis and improved treatment of this disease.
The glycosyltransferase enzyme GnT-III encoded by the Mgat3 gene is responsible for the addition of GlcNAc (N-acetylglucosamine) to form bisecting N-linked glycan structures.
GnT-III mRNA expression is amplified in ovarian cancer tissues compared
with normal ovarian tissue. We use a lectin capture strategy coupled
to nano-ESI–RPLC–MS/MS to isolate and identify the membrane
glycoproteins and unique glycan structures associated with GnT-III
amplification in human ovarian cancer tissues. Our data illustrate
that the majority of membrane glycoproteins with bisecting glycosylation
are common to both serous and endometrioid histological subtypes of
ovarian cancer, and several have been reported to participate in signaling
pathways such as Notch, Wnt, and TGFβ.
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Affiliation(s)
- Heba Allam
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, University of Georgia , 315 Riverbend Road, Athens, Georgia 30602, United States
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14
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Nagae M, Yamanaka K, Hanashima S, Ikeda A, Morita-Matsumoto K, Satoh T, Matsumoto N, Yamamoto K, Yamaguchi Y. Recognition of bisecting N-acetylglucosamine: structural basis for asymmetric interaction with the mouse lectin dendritic cell inhibitory receptor 2. J Biol Chem 2013; 288:33598-33610. [PMID: 24108122 DOI: 10.1074/jbc.m113.513572] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Dendritic cell inhibitory receptor 2 (DCIR2) is a C-type lectin expressed on classical dendritic cells. We recently identified the unique ligand specificity of mouse DCIR2 (mDCIR2) toward biantennary complex-type glycans containing bisecting N-acetylglucosamine (GlcNAc). Here, we report the crystal structures of the mDCIR2 carbohydrate recognition domain in unliganded form as well as in complex with an agalactosylated complex-type N-glycan unit carrying a bisecting GlcNAc residue. Bisecting GlcNAc and the α1-3 branch of the biantennary oligosaccharide asymmetrically interact with canonical and non-canonical mDCIR2 residues. Ligand-protein interactions occur directly through mDCIR2-characteristic amino acid residues as well as via a calcium ion and water molecule. Our structural and biochemical data elucidate for the first time the unique binding mode of mDCIR2 for bisecting GlcNAc-containing glycans, a mode that contrasts sharply with that of other immune C-type lectin receptors such as DC-SIGN.
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Affiliation(s)
- Masamichi Nagae
- Structural Glycobiology Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, RIKEN Global Research Cluster, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kousuke Yamanaka
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562, Japan
| | - Shinya Hanashima
- Structural Glycobiology Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, RIKEN Global Research Cluster, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Akemi Ikeda
- Structural Glycobiology Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, RIKEN Global Research Cluster, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kana Morita-Matsumoto
- Structural Glycobiology Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, RIKEN Global Research Cluster, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tadashi Satoh
- Structural Glycobiology Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, RIKEN Global Research Cluster, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Naoki Matsumoto
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562, Japan
| | - Kazuo Yamamoto
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562, Japan
| | - Yoshiki Yamaguchi
- Structural Glycobiology Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, RIKEN Global Research Cluster, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
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15
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Miwa HE, Song Y, Alvarez R, Cummings RD, Stanley P. The bisecting GlcNAc in cell growth control and tumor progression. Glycoconj J 2012; 29:609-18. [PMID: 22476631 DOI: 10.1007/s10719-012-9373-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 03/11/2012] [Indexed: 11/30/2022]
Abstract
The bisecting GlcNAc is transferred to the core mannose residue of complex or hybrid N-glycans on glycoproteins by the β1,4-N-acetylglucosaminyltransferase III (GlcNAcT-III) or MGAT3. The addition of the bisecting GlcNAc confers unique lectin recognition properties to N-glycans. Thus, LEC10 gain-of-function Chinese hamster ovary (CHO) cells selected for the acquisition of ricin resistance, carry N-glycans with a bisecting GlcNAc, which enhances the binding of the erythroagglutinin E-PHA, but reduces the binding of ricin and galectins-1, -3 and -8. The altered interaction with galactose-binding lectins suggests that the bisecting GlcNAc affects N-glycan conformation. LEC10 mutants expressing polyoma middle T antigen (PyMT) exhibit reduced growth factor signaling. Furthermore, PyMT-induced mammary tumors lacking MGAT3, progress more rapidly than tumors with the bisecting GlcNAc on N-glycans of cell surface glycoproteins. In recent years, evidence for a new paradigm of cell growth control has emerged involving regulation of cell surface residency of growth factor and cytokine receptors via interactions and cross-linking of their branched N-glycans with a lattice of galectin(s). Specific cross-linking of glycoprotein receptors in the lattice regulates their endocytosis, leading to effects on growth factor-induced signaling. This review will describe evidence that the bisecting GlcNAc of N-glycans regulates cellular signaling and tumor progression, apparently through modulating N-glycan/galectin interactions.
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Affiliation(s)
- Hazuki E Miwa
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY 10461, USA
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16
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Patankar MS, Gubbels JAA, Felder M, Connor JP. The immunomodulating roles of glycoproteins in epithelial ovarian cancer. Front Biosci (Elite Ed) 2012; 4:631-50. [PMID: 22201900 DOI: 10.2741/405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The complexity of the immune system demands an intricate defense mechanism by tumors. Ovarian and other tumors employ specific glycoproteins and the associated glycan sequences to modulate immune responses. Glycoproteins enable tumor cells that express or secrete these molecules to evade immune cell attack and induce the immune system to promote tumor growth. This review focuses first on the immune environment in ovarian cancer, and the mechanisms of activation and inhibition that immune cells undergo in order to either attack or ignore a target cell. Next we illustrate the immunomodulatory roles of ovarian cancer-associated glycans and glycoproteins in 1. preventing immune synapse formation, 2. serving as ligands of immune cell receptors, 3. scavenging cytokines and chemokines, and 4. participating in the formation of autoantibodies against the tumor. The importance of these immunomodulating strategies from the view points of understanding the tumor immunology of ovarian tumors, potential origin of such mechanisms, and specific strategies to circumvent the glycoconjugate-mediated suppression of immune responses is discussed in this review.
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Affiliation(s)
- Manish S Patankar
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, WI 53792-6188, USA.
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17
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Nett JH, Stadheim TA, Li H, Bobrowicz P, Hamilton SR, Davidson RC, Choi BK, Mitchell T, Bobrowicz B, Rittenhour A, Wildt S, Gerngross TU. A combinatorial genetic library approach to target heterologous glycosylation enzymes to the endoplasmic reticulum or the Golgi apparatus of Pichia pastoris. Yeast 2011; 28:237-52. [DOI: 10.1002/yea.1835] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 11/18/2010] [Indexed: 11/08/2022] Open
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18
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dos Reis Almeida FB, de Oliveira LL, Valle de Sousa M, Roque Barreira MC, Hanna ES. Paracoccin from Paracoccidioides brasiliensis; purification through affinity with chitin and identification of N-acetyl-beta-D-glucosaminidase activity. Yeast 2010; 27:67-76. [PMID: 19908201 DOI: 10.1002/yea.1731] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The dimorphic fungus Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis, the most frequent systemic mycosis in Latin America. Our group has been working with paracoccin, a P. brasiliensis lectin with MM 70 kDa, which is purified by affinity with immobilized N-acetylglucosamine (GlcNAc). Paracoccin has been described to play a role in fungal adhesion to extracellular matrix components and to induce high and persistent levels of TNFalpha and nitric oxide production by macrophages. In the cell wall, paracoccin colocalizes with the beta-1,4-homopolymer of GlcNAc into the budding sites of the P. brasiliensis yeast cell. In this paper we present a protocol for the chitin-affinity purification of paracoccin. This procedure provided higher yields than those achieved by means of the technique based on the affinity of this lectin with GlcNAc and had an impact on downstream assays. SDS-PAGE and Western blot analysis revealed similarities between the N-acetylglucosamine- and chitin-bound fractions, confirmed by MALDI-TOF-MS of trypsinic peptides. Western blot of two-dimensional gel electrophoresis of the yeast extract showed a major spot with M(r) 70,000 and pI approximately 5.63. Moreover, an N-acetyl-beta-D-glucosaminidase activity was reported for paracoccin, thereby providing new insights into the mechanisms that lead to cell wall remodelling and opening new perspectives for its structural characterization.
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Affiliation(s)
- Fausto Bruno dos Reis Almeida
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14049-900, Brazil
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19
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Nairn AV, York WS, Harris K, Hall EM, Pierce JM, Moremen KW. Regulation of glycan structures in animal tissues: transcript profiling of glycan-related genes. J Biol Chem 2008; 283:17298-313. [PMID: 18411279 DOI: 10.1074/jbc.m801964200] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Glycan structures covalently attached to proteins and lipids play numerous roles in mammalian cells, including protein folding, targeting, recognition, and adhesion at the molecular or cellular level. Regulating the abundance of glycan structures on cellular glycoproteins and glycolipids is a complex process that depends on numerous factors. Most models for glycan regulation hypothesize that transcriptional control of the enzymes involved in glycan synthesis, modification, and catabolism determines glycan abundance and diversity. However, few broad-based studies have examined correlations between glycan structures and transcripts encoding the relevant biosynthetic and catabolic enzymes. Low transcript abundance for many glycan-related genes has hampered broad-based transcript profiling for comparison with glycan structural data. In an effort to facilitate comparison with glycan structural data and to identify the molecular basis of alterations in glycan structures, we have developed a medium-throughput quantitative real time reverse transcriptase-PCR platform for the analysis of transcripts encoding glycan-related enzymes and proteins in mouse tissues and cells. The method employs a comprehensive list of >700 genes, including enzymes involved in sugar-nucleotide biosynthesis, transporters, glycan extension, modification, recognition, catabolism, and numerous glycosylated core proteins. Comparison with parallel microarray analyses indicates a significantly greater sensitivity and dynamic range for our quantitative real time reverse transcriptase-PCR approach, particularly for the numerous low abundance glycan-related enzymes. Mapping of the genes and transcript levels to their respective biosynthetic pathway steps allowed a comparison with glycan structural data and provides support for a model where many, but not all, changes in glycan abundance result from alterations in transcript expression of corresponding biosynthetic enzymes.
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Affiliation(s)
- Alison V Nairn
- Complex Carbohydrate Research Center and the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
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20
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Lee J, Song EY, Chung TW, Kang SK, Kim KS, Chung TH, Yeom YI, Kim CH. Hyperexpression of N-acetylglucosaminyltransferase-III in liver tissues of transgenic mice causes fatty body and obesity through severe accumulation of Apo A-I and Apo B. Arch Biochem Biophys 2004; 426:18-31. [PMID: 15130779 DOI: 10.1016/j.abb.2003.12.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2003] [Revised: 12/01/2003] [Indexed: 11/18/2022]
Abstract
N-Acetylglucosaminyltransferase (GnT)-III catalyzes the attachment of an N-acetylglucosamine (GlcNAc) residue to mannose in beta(1-4) configuration in the region of N-glycans and forms a bisecting GlcNAc. To investigate the pathophysiological role of dysregulated glycosylation mediated by aberrantly expressed GnT-III, we generated transgenic mice hyperexpressing the human GnT-III in the liver by introducing human GnT-III cDNA under the control of mouse albumin enhancer/promoter. Total five transgenic founder mice (pGnTSVTpA-10, -14, -20, -25, and -51) expressed the human GnT-III in their livers and were characterized by molecular genetic means. The copy number of transgene integrated into the genome of these mice ranged between 1 and 3 copies per haploid genome. Northern and Western blot analyses showed that the transgene is specifically expressed in the liver but not in any other tissues tested. The triglyceride level in GnT-III transgenic mice was significantly decreased, however, no significant differences in the levels of glucose, cholesterol, or albumin were observed between transgenic and nontransgenic mice. Although glutamate oxaloacetic transaminase and glutamic pyruvic transaminase activities of transgenic mice were also higher than those of nontransgenic mice, no differences in total bililubin and total protein were observed between the two animal lines. Large amounts of apolipoprotein (Apo) A-I and Apo B were specifically detected in the intracellular liver of transgenic mice. The accumulation of Apo A-I in hepatocytes may be due to aberrant glycosylation, since glycosylated Apo A-I was not observed in transgenic mice. However, the accumulated Apo B was severely glycosylated. Therefore, it is suggested that highly expressed transgenic GnT-III allowed unknown target proteins to be glycosylated in large amounts, and the resulting target protein(s) disrupted in assembly formation of Apo A-I in the hepatocytes and cause a decrease in the release of lipoproteins and accumulations of Apo A-I and Apo B in the liver. The transgenic mice showed aberrant glycosylation by GnT-III, resulting in numerous lipid droplets in liver tissues and the obesity. These mice showed microvesicular fatty changes with abnormal lipid accumulation in the hepatocytes. Our study provides the basis for future analysis of the role of glycosylation in hepatic pathogenesis. In the transgenic mice, Apo A-I and Apo B were significantly increased compared with levels in nontransgenic liver tissues.
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Affiliation(s)
- Jungwoong Lee
- National Research Laboratory for Glycobiology, Korean Ministry of Science and Technology, Kyungbuk 780-714, Republic of Korea
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21
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Abstract
The four essential building blocks of cells are proteins, nucleic acids, lipids, and glycans. Also referred to as carbohydrates, glycans are composed of saccharides that are typically linked to lipids and proteins in the secretory pathway. Glycans are highly abundant and diverse biopolymers, yet their functions have remained relatively obscure. This is changing with the advent of genetic reagents and techniques that in the past decade have uncovered many essential roles of specific glycan linkages in living organisms. Glycans appear to modulate biological processes in the development and function of multiple physiologic systems, in part by regulating protein-protein and cell-cell interactions. Moreover, dysregulation of glycan synthesis represents the etiology for a growing number of human genetic diseases. The study of glycans, known as glycobiology, has entered an era of renaissance that coincides with the acquisition of complete genome sequences for multiple organisms and an increased focus upon how posttranslational modifications to protein contribute to the complexity of events mediating normal and disease physiology. Glycan production and modification comprise an estimated 1% of genes in the mammalian genome. Many of these genes encode enzymes termed glycosyltransferases and glycosidases that reside in the Golgi apparatus where they play the major role in constructing the glycan repertoire that is found at the cell surface and among extracellular compartments. We present a review of the recently established functions of glycan structures in the context of mammalian genetic studies focused upon the mouse and human species. Nothing tends so much to the advancement of knowledge as the application of a new instrument. The native intellectual powers of men in different times are not so much the causes of the different success of their labours, as the peculiar nature of the means and artificial resources in their possession. T. Hager: Force of Nature (1)
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Affiliation(s)
- John B Lowe
- Department of Pathology and Howard Hughes Medical Institute, University of Michigan, Ann Arbor, Michigan 48109, USA.
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22
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Stanley P. Biological consequences of overexpressing or eliminating N-acetylglucosaminyltransferase-TIII in the mouse. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1573:363-8. [PMID: 12417419 DOI: 10.1016/s0304-4165(02)00404-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
N-acetylglucosaminyltransferase III (GlcNAc-TIII), a product of the human MGAT3 gene, was discovered as a glycosyltransferase activity in hen oviduct. GlcNAc-TIII transfers GlcNAc in beta4-linkage to the core Man of complex or hybrid N-glycans, and thereby alters not only the composition, but also the conformation of the N-glycan. The dramatic consequences of the addition of this bisecting GlcNAc residue are reflected in the altered binding of lectins that recognize Gal residues on N-glycans. Changes in GlcNAc-TIII expression correlate with hepatoma and leukemia in rodents and humans, and the bisecting GlcNAc on Asn 297 of human IgG antibodies enhances their effector functions. Overexpression of a cDNA encoding GlcNAc-TIII alters growth control and cell-cell interactions in cultured cells, and in transgenic mice. While mice lacking GlcNAc-TIII are viable and fertile, they exhibit retarded progression of diethylnitrosamine (DEN)-induced liver tumors. Further biological functions of GlcNAc-TIII are expected to be uncovered as mice with a null mutation in the Mgat3 gene are challenged.
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Affiliation(s)
- Pamela Stanley
- Department of Cell Biology, Albert Einstein College Medicine, Yeshiva University, Bronx, New York, NY 10461, USA.
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23
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Bhattacharyya R, Bhaumik M, Raju TS, Stanley P. Truncated, inactive N-acetylglucosaminyltransferase III (GlcNAc-TIII) induces neurological and other traits absent in mice that lack GlcNAc-TIII. J Biol Chem 2002; 277:26300-9. [PMID: 11986323 DOI: 10.1074/jbc.m202276200] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
N-Acetylglucosaminyltransferase III (GlcNAc-TIII), the product of the Mgat3 gene, transfers the bisecting GlcNAc to the core mannose of complex N-glycans. The addition of this residue is regulated during development and has functional consequences for receptor signaling, cell adhesion, and tumor progression. Mice homozygous for a null mutation at the Mgat3 locus (Mgat3(Delta)) or for a targeted mutation in the Mgat3 gene (previously called Mgat3(neo), but herein renamed Mgat3(T37) because the allele generates inactive GlcNAc-TIII of approximately 37 kDa) were found to exhibit retarded progression of liver tumors. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of neutral N-glycans from kidneys revealed no significant differences, and both mutants showed the expected lack of N-glycan species with an additional GlcNAc. However, the two mutants differed in several biological traits. Mgat3(T37/T37) homozygotes in a mixed or 129(SvJ) background were retarded in growth rate and exhibited an altered leg clasp reflex, an altered gait, and defective nursing behavior. Pups abandoned by Mgat3(T37/T37) mothers were rescued by wild-type foster mothers. None of these Mgat3(T37/T37) traits were exhibited by Mgat3(Delta/Delta) mice or by heterozygous mice carrying the Mgat3(T37) mutation. Similarly, no dominant-negative effect was observed in Chinese hamster ovary cells expressing truncated GlcNAc-TIII in the presence of wild-type GlcNAc-TIII. However, compound heterozygotes carrying both the Mgat3(T37) and Mgat3(Delta) mutations exhibited a marked leg clasp reflex, indicating that in the absence of wild-type GlcNAc-TIII, truncated GlcNAc-TIII causes this phenotype. The Mgat3 gene was expressed in brain at embryonic day 10.5 and thereafter and in neurons of adult cerebellum. The mutant Mgat3 gene was also highly expressed in Mgat3(T37/T37) brain. This may be the basis of the unexpected neurological phenotype induced by truncated, inactive GlcNAc-TIII in the mouse.
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Affiliation(s)
- Riddhi Bhattacharyya
- Department of Cell Biology, Albert Einstein College of Medicine, New York, New York 10461, USA
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24
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Lee J, Park SH, Stanley P. Antibodies that recognize bisected complex N-glycans on cell surface glycoproteins can be made in mice lacking N-acetylglucosaminyltransferase III. Glycoconj J 2002; 19:211-9. [PMID: 12815232 DOI: 10.1023/a:1024205925263] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The bisecting GlcNAc is transferred to complex or hybrid N-glycans by the action of N-acetylglucosaminyltransferase III (GlcNAc-TIII) encoded by the Mgat3 gene. CHO cells expressing mouse GlcNAc-TIII were shown by matrix-assisted laser desorption ionization (MALDI) mass spectrometry to produce mainly complex N-glycans with the predicted extra (bisecting) GlcNAc. In order to probe biological functions of the bisecting GlcNAc, antibodies that recognize this residue in the context of complex cell surface glycoconjugates were sought. The LEC10 gain-of-function Chinese hamster ovary (CHO) cell mutant that expresses GlcNAc-TIII and complex N-glycans with the bisecting GlcNAc was used to immunize Mgat3(+/+) and Mgat3(-/-) mice. ELISA of whole sera showed that polyclonal antibodies that bound specifically to LEC10 cells were obtained solely from Mgat3(-/-) mice. Fluorescence-activated cell cytometry of different CHO glycosylation mutants and western blotting after glycosidase treatments were used to show that anti-LEC10 cell antisera from Mgat3(-/-) mice recognize cellular glycoproteins with complex N-glycans containing both a bisecting GlcNAc and Gal residues. The polyclonal antibody specificity was similar to that of the lectin E-PHA. IgM-depleted serum containing IgG and IgA antibodies retained full binding activity. Therefore Mgat3(-/-) mice but not wild type mice can be used effectively to produce polyclonal antibodies that specifically recognize glycoproteins bearing complex N-glycans with a bisecting GlcNAc.
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Affiliation(s)
- JaeHoon Lee
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY 10461, USA
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25
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Abstract
This review covers discoveries made over the past 30-35 years that were important to our understanding of the synthetic pathway required for initiation of the antennae or branches on complex N-glycans and O-glycans. The review deals primarily with the author's contributions but the relevant work of other laboratories is also discussed. The focus of the review is almost entirely on the glycosyltransferases involved in the process. The following topics are discussed. (1) The localization of the synthesis of complex N-glycan antennae to the Golgi apparatus. (2) The "evolutionary boundary" at the stage in N-glycan processing where there is a change from oligomannose to complex N-glycans; this switch correlates with the appearance of multicellular organisms. (3) The discovery of the three enzymes which play a key role in this switch, N-acetylglucosaminyltransferases I and II and mannosidase II. (4) The "yellow brick road" which leads from oligomannose to highly branched complex N-glycans with emphasis on the enzymes involved in the process and the factors which control the routes of synthesis. (5) A short discussion of the characteristics of the enzymes involved and of the genes that encode them. (6) The role of complex N-glycans in mammalian and Caenorhabditis elegans development. (7) The crystal structure of N-acetylglucosaminyltransferase I. (8) The discovery of the enzymes which synthesize O-glycan cores 1, 2, 3 and 4 and their elongation.
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Affiliation(s)
- H Schachter
- Department of Structural Biology and Biochemistry, Research Institute, The Hospital for Sick Children, Faculty of Medicine, University of Toronto, Ont, Canada.
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26
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Raju TS, Stanley P. Gain-of-function Chinese hamster ovary mutants LEC18 and LEC14 each express a novel N-acetylglucosaminyltransferase activity. J Biol Chem 1998; 273:14090-8. [PMID: 9603907 DOI: 10.1074/jbc.273.23.14090] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
LEC18 and LEC14 cells are gain-of-function glycosylation mutants isolated from Chinese hamster ovary cells for resistance to pea lectin. Structural studies have shown that LEC18 cells synthesize complex N-glycans with a GlcNAc residue linked at the O-6 position of the core GlcNAc (Raju, T. S., Ray, M. K., and Stanley, P. (1995) J. Biol. Chem. 270, 30294-30302), whereas LEC14 cells synthesize complex N-glycans with a GlcNAc residue linked at the O-2 position of the core beta-linked Man residue (Raju, T. S., and Stanley, P. (1996) J. Biol. Chem. 271, 7484-7493). Both modifications are novel and have not been reported in glycoproteins from any other source. We now show that, in both LEC18 and LEC14 cells, GlcNAc transfer is mediated by a distinct N-acetylglucosaminyltransferase (GlcNAc-T) activity. The LEC18 activity, termed GlcNAc-TVIII, transfers GlcNAc to GlcNAcbeta1-O-pNP and to a GlcNAc-terminating, biantennary, complex N-glycan, with or without a core fucose. By contrast, the LEC14 transferase, termed GlcNAc-TVII, does not have significant activity with simple acceptors, and transfers GlcNAc preferentially to a GlcNAc-terminating biantennary glycopeptide that contains a core fucose residue. The acceptor specificities and other biochemical properties of GlcNAc-TVII and GlcNAc-TVIII differ from previously characterized GlcNAc-transferases including GlcNAc-TIII, indicating that they represent new members of the mammalian GlcNAc-T group of transferases.
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Affiliation(s)
- T S Raju
- Department of Cell Biology, Albert Einstein College of Medicine, New York, New York 10461, USA
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Yoshimura M, Ihara Y, Nishiura T, Okajima Y, Ogawa M, Yoshida H, Suzuki M, Yamamura K, Kanakura Y, Matsuzawa Y, Taniguchi N. Bisecting GlcNAc structure is implicated in suppression of stroma-dependent haemopoiesis in transgenic mice expressing N-acetylglucosaminyltransferase III. Biochem J 1998; 331 ( Pt 3):733-42. [PMID: 9560299 PMCID: PMC1219412 DOI: 10.1042/bj3310733] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Several sugar structures have been reported to be necessary for haemopoiesis. We analysed the haematological phenotypes of transgenic mice expressing beta-1,4 N-acetylglucosaminyltransferase III (GnT-III), which forms bisecting N-acetylglucosamine on asparagine-linked oligosaccharides. In the transgenic mice, the GnT-III activity was elevated in bone marrow, spleen and peripheral blood and in isolated mononuclear cells from these tissues, whereas no activity was found in these tissues of wild-type mice. Stromal cells after long-term cultures of transgenic-derived bone marrow and spleen cells also showed elevated GnT-III activity, compared with an undetectable activity in wild-type stromal cells. As judged by HPLC analysis, lectin blotting and lectin cytotoxicity assay, bisecting GlcNAc residues were increased on both blood cells and stromal cells from bone marrow and spleen in transgenic mice. The transgenic mice displayed spleen atrophy, hypocellular bone marrow and pancytopenia. Bone marrow cells and spleen cells from transgenic mice produced fewer haemopoietic colonies. After lethal irradiation followed by bone marrow transplantation, transgenic recipient mice showed pancytopenia compared with wild-type recipient mice. Bone marrow cells from transgenic donors gave haematological reconstitution at the same level as wild-type donor cells. In addition, non-adherent cell production was decreased in long-term bone marrow cell cultures of transgenic mice. Collectively these results indicate that the stroma-supported haemopoiesis is compromised in transgenic mice expressing GnT-III, providing the first demonstration that the N-glycans have some significant roles in stroma-dependent haemopoiesis.
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Affiliation(s)
- M Yoshimura
- Department of Biochemistry, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka 565, Japan
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Kukuruzinska MA, Lennon K. Protein N-glycosylation: molecular genetics and functional significance. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 1998; 9:415-48. [PMID: 9825220 DOI: 10.1177/10454411980090040301] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Protein N-glycosylation is a metabolic process that has been highly conserved in evolution. In all eukaryotes, N-glycosylation is obligatory for viability. It functions by modifying appropriate asparagine residues of proteins with oligosaccharide structures, thus influencing their properties and bioactivities. N-glycoprotein biosynthesis involves a multitude of enzymes, glycosyltransferases, and glycosidases, encoded by distinct genes. The majority of these enzymes are transmembrane proteins that function in the endoplasmic reticulum and Golgi apparatus in an ordered and well-orchestrated manner. The complexity of N-glycosylation is augmented by the fact that different asparagine residues within the same polypeptide may be modified with different oligosaccharide structures, and various proteins are distinguished from one another by the characteristics of their carbohydrate moieties. Furthermore, biological consequences of derivatization of proteins with N-glycans range from subtle to significant. In the past, all these features of N-glycosylation have posed a formidable challenge to an elucidation of the physiological role for this modification. Recent advances in molecular genetics, combined with the availability of diverse in vivo experimental systems ranging from yeast to transgenic mice, have expedited the identification, isolation, and characterization of N-glycosylation genes. As a result, rather unexpected information regarding relationships between N-glycosylation and other cellular functions--including secretion, cytoskeletal organization, proliferation, and apoptosis--has emerged. Concurrently, increased understanding of molecular details of N-glycosylation has facilitated the alignment between N-glycosylation deficiencies and human diseases, and has highlighted the possibility of using N-glycan expression on cells as potential determinants of disease and its progression. Recent studies suggest correlations between N-glycosylation capacities of cells and drug sensitivities, as well as susceptibility to infection. Therefore, knowledge of the regulatory features of N-glycosylation may prove useful in the design of novel therapeutics. While facing the demanding task of defining properties, functions, and regulation of the numerous, as yet uncharacterized, N-glycosylation genes, glycobiologists of the 21st century offer exciting possibilities for new approaches to disease diagnosis, prevention, and cure.
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Affiliation(s)
- M A Kukuruzinska
- Department of Molecular and Cell Biology, School of Dental Medicine, Boston University Medical Center, Massachusetts 02118, USA
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Ihara Y, Sakamoto Y, Mihara M, Shimizu K, Taniguchi N. Overexpression of N-acetylglucosaminyltransferase III disrupts the tyrosine phosphorylation of Trk with resultant signaling dysfunction in PC12 cells treated with nerve growth factor. J Biol Chem 1997; 272:9629-34. [PMID: 9092490 DOI: 10.1074/jbc.272.15.9629] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
beta-1,4-N-Acetylglucosaminyltransferase III (GnT-III: EC 2.4.1.144) is a pivotal glycosyltransferase which participates in branch formation by catalysis of the synthesis of a bisecting GlcNAc structure in N-glycans. These structures are thought to be one of the unique features of the N-glycans of neural tissues. To examine the intracellullar role of GnT-III expression and its product in neural cells, its gene was overexpressed in rat pheochromocytoma PC12 cells which normally express a low level of GnT-III. In the GnT-III gene-transfected cells, lectin blot analysis showed that some glycoproteins showed increased levels of bisecting GlcNAc structures. Following treatment with nerve growth factor (NGF) the control cells showed neurite outgrowth for differentiation whereas the transfectants showed no morphological response or change in the rate of cell growth. Transient tyrosine phosphorylation of the Trk/NGF receptor was detected at 5-15 min after NGF treatment in control cells, but not detected in the GnT-III gene-transfected cells despite the intact binding of NGF to the cells. Moreover the dimerization of Trk with NGF treatment was not induced in the GnT-III transfectant as compared with the dimerization seen in control cells. These results indicate that overexpression of GnT-III gene in PC12 cells affects some functions of glycoprotein receptors such as Trk by alteration of N-glycan structures, and results in changes in the intracellular signaling pathway of tyrosine phosphorylation modified by NGF.
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Affiliation(s)
- Y Ihara
- Department of Biochemistry, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka 565, Japan
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