1
|
Lam D, Arroyo B, Liberchuk AN, Wolfe AL. Effects of N361 Glycosylation on Epidermal Growth Factor Receptor Biological Function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.12.603279. [PMID: 39071333 PMCID: PMC11275927 DOI: 10.1101/2024.07.12.603279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase that is frequently modified by glycosylation post-translationally. In cancer, EGFR amplifications and hotspot mutations such as L858R that promote proliferation have been detected in a significant fraction of non-small cell lung carcinomas and breast adenocarcinomas. Molecular dynamic simulations suggested that glycosylation at asparagine residue 361 (N361) promotes dimerization and ligand binding. We stably expressed glycosylation-deficient mutant EGFR N361A, with or without the oncogenic mutation L858R. Immunofluorescence and flow cytometry demonstrated that the mutants were each well expressed at the cell membrane. N361A decreased proliferation relative to wild-type EGFR as well as decreased sensitivity to ligands. Proximity ligation assays measuring co-localization of EGFR with its binding partner HER2 in cells revealed that N361A mutations increased co-localization. N361A, located near the binding interface for the EGFR inhibitor necitumumab, desensitized cells expressing the oncogenic EGFR L858R to antibody-based inhibition. These findings underline the critical relevance of post-translational modifications on oncogene function.
Collapse
Affiliation(s)
- Dennis Lam
- Department of Biological Sciences, Hunter College of the City University of New York
- Department of Pharmacology, Weill Cornell Medicine
| | - Brandon Arroyo
- Department of Biological Sciences, Hunter College of the City University of New York
- Maximizing Access to Research Careers Program, Hunter College of the City University of New York
| | - Ariel N. Liberchuk
- Department of Biological Sciences, Hunter College of the City University of New York
- Macaulay Honors College, Hunter College of the City University of New York
| | - Andrew L. Wolfe
- Department of Biological Sciences, Hunter College of the City University of New York
- Department of Pharmacology, Weill Cornell Medicine
- Biochemistry Ph.D. Program, Graduate Center of the City University of New York
- Molecular, Cellular, and Developmental Biology Ph.D. Subprogram, Graduate Center of the City University of New York
| |
Collapse
|
2
|
Grozdanić M, Sobotič B, Biasizzo M, Sever T, Vidmar R, Vizovišek M, Turk B, Fonović M. Cathepsin L-mediated EGFR cleavage affects intracellular signalling pathways in cancer. Biol Chem 2024; 405:283-296. [PMID: 37889671 DOI: 10.1515/hsz-2023-0213] [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: 05/12/2023] [Accepted: 10/12/2023] [Indexed: 10/29/2023]
Abstract
Proteolytic activity in the tumour microenvironment is an important factor in cancer development since it can also affect intracellular signalling pathways via positive feedback loops that result in either increased tumour growth or resistance to anticancer mechanisms. In this study, we demonstrated extracellular cathepsin L-mediated cleavage of epidermal growth factor receptor (EGFR) and identified the cleavage site in the extracellular domain after R224. To further evaluate the relevance of this cleavage, we cloned and expressed a truncated version of EGFR, starting at G225, in HeLa cells. We confirmed the constitutive activation of the truncated protein in the absence of ligand binding and determined possible changes in intracellular signalling. Furthermore, we determined the effect of truncated EGFR protein expression on HeLa cell viability and response to the EGFR inhibitors, tyrosine kinase inhibitor (TKI) erlotinib and monoclonal antibody (mAb) cetuximab. Our data reveal the nuclear localization and phosphorylation of EGFR and signal trancducer and activator of transcription 3 (STAT3) in cells that express the truncated EGFR protein and suggest that these phenomena cause resistance to EGFR inhibitors.
Collapse
Affiliation(s)
- Marija Grozdanić
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- International Postgraduate School Jožef Stefan, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Barbara Sobotič
- Kymab Ltd, The Bennet Building (B930), Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Monika Biasizzo
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- International Postgraduate School Jožef Stefan, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Tilen Sever
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- International Postgraduate School Jožef Stefan, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Robert Vidmar
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Matej Vizovišek
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Boris Turk
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Marko Fonović
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| |
Collapse
|
3
|
Role of Glycans on Key Cell Surface Receptors That Regulate Cell Proliferation and Cell Death. Cells 2021; 10:cells10051252. [PMID: 34069424 PMCID: PMC8159107 DOI: 10.3390/cells10051252] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/13/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
Cells undergo proliferation and apoptosis, migration and differentiation via a number of cell surface receptors, most of which are heavily glycosylated. This review discusses receptor glycosylation and the known roles of glycans on the functions of receptors expressed in diverse cell types. We included growth factor receptors that have an intracellular tyrosine kinase domain, growth factor receptors that have a serine/threonine kinase domain, and cell-death-inducing receptors. N- and O-glycans have a wide range of functions including roles in receptor conformation, ligand binding, oligomerization, and activation of signaling cascades. A better understanding of these functions will enable control of cell survival and cell death in diseases such as cancer and in immune responses.
Collapse
|
4
|
Martin-Fernandez ML, Clarke DT, Roberts SK, Zanetti-Domingues LC, Gervasio FL. Structure and Dynamics of the EGF Receptor as Revealed by Experiments and Simulations and Its Relevance to Non-Small Cell Lung Cancer. Cells 2019; 8:E316. [PMID: 30959819 PMCID: PMC6523254 DOI: 10.3390/cells8040316] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 03/29/2019] [Accepted: 03/30/2019] [Indexed: 12/25/2022] Open
Abstract
The epidermal growth factor receptor (EGFR) is historically the prototypical receptor tyrosine kinase, being the first cloned and the first where the importance of ligand-induced dimer activation was ascertained. However, many years of structure determination has shown that EGFR is not completely understood. One challenge is that the many structure fragments stored at the PDB only provide a partial view because full-length proteins are flexible entities and dynamics play a key role in their functionality. Another challenge is the shortage of high-resolution data on functionally important higher-order complexes. Still, the interest in the structure/function relationships of EGFR remains unabated because of the crucial role played by oncogenic EGFR mutants in driving non-small cell lung cancer (NSCLC). Despite targeted therapies against EGFR setting a milestone in the treatment of this disease, ubiquitous drug resistance inevitably emerges after one year or so of treatment. The magnitude of the challenge has inspired novel strategies. Among these, the combination of multi-disciplinary experiments and molecular dynamic (MD) simulations have been pivotal in revealing the basic nature of EGFR monomers, dimers and multimers, and the structure-function relationships that underpin the mechanisms by which EGFR dysregulation contributes to the onset of NSCLC and resistance to treatment.
Collapse
Affiliation(s)
- Marisa L Martin-Fernandez
- Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX, UK.
| | - David T Clarke
- Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX, UK.
| | - Selene K Roberts
- Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX, UK.
| | - Laura C Zanetti-Domingues
- Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX, UK.
| | | |
Collapse
|
5
|
Azimzadeh Irani M. Correlation between experimentally indicated and atomistically simulated roles of EGFR N-glycosylation. MOLECULAR SIMULATION 2018. [DOI: 10.1080/08927022.2018.1447108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Maryam Azimzadeh Irani
- Bioinformatics Institute, A*-STAR, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore
| |
Collapse
|
6
|
Vega JF, Ramos J, Cruz VL, Vicente-Alique E, Sánchez-Sánchez E, Sánchez-Fernández A, Wang Y, Hu P, Cortés J, Martínez-Salazar J. Molecular and hydrodynamic properties of human epidermal growth factor receptor HER2 extracellular domain and its homodimer: Experiments and multi-scale simulations. Biochim Biophys Acta Gen Subj 2017. [PMID: 28642126 DOI: 10.1016/j.bbagen.2017.06.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND In a broad range of human carcinomas gene amplification leads to HER2 overexpression, which has been proposed to cause spontaneous dimerization and activation in the absence of ligand. This makes HER2 attractive as a therapeutic target. However, the HER2 homodimerization mechanism remains unexplored. It has been suggested that the "back-to-back" homodimer does not form in solution. Notwithstanding, very recently the crystal structure of the HER2 extracellular domain homodimer formed with a "back-to-head" interaction has been resolved. We intend to explore the existence of such interactions. METHODS A combination of experiments, molecular dynamics and hydrodynamic modeling were used to monitor the transport properties of HER2 in solution. RESULTS & CONCLUSIONS We have detected the HER2 extracellular domain homodimer in solution. The results show a high degree of molecular flexibility, which ultimately leads to quite higher values of the intrinsic viscosity and lower values of diffusion coefficient than those corresponding to globular proteins. This flexibility obeys to the open conformation of the receptor and to the large fluctuations of the different domains. We also report that for obtaining the correct hydrodynamic constants from the modeling one must consider the glycosylation of the systems. GENERAL SIGNIFICANCE Conformational features of epidermal growth factor receptors regulate their hydrodynamic properties and control their activity. It is essential to understand the dynamics of these systems and the role of the specific domains involved. To find biophysical correlations between dynamics and macroscopic transport properties is of general interest for researches working in this area. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue.
Collapse
Affiliation(s)
- J F Vega
- BIOPHYM, Department of Macromolecular Physics, Instituto de Estructura de la Materia, IEM-CSIC, C/ Serrano 113 bis, 28006 Madrid, Spain.
| | - J Ramos
- BIOPHYM, Department of Macromolecular Physics, Instituto de Estructura de la Materia, IEM-CSIC, C/ Serrano 113 bis, 28006 Madrid, Spain
| | - V L Cruz
- BIOPHYM, Department of Macromolecular Physics, Instituto de Estructura de la Materia, IEM-CSIC, C/ Serrano 113 bis, 28006 Madrid, Spain
| | - E Vicente-Alique
- BIOPHYM, Department of Macromolecular Physics, Instituto de Estructura de la Materia, IEM-CSIC, C/ Serrano 113 bis, 28006 Madrid, Spain
| | - E Sánchez-Sánchez
- BIOPHYM, Department of Macromolecular Physics, Instituto de Estructura de la Materia, IEM-CSIC, C/ Serrano 113 bis, 28006 Madrid, Spain
| | - A Sánchez-Fernández
- BIOPHYM, Department of Macromolecular Physics, Instituto de Estructura de la Materia, IEM-CSIC, C/ Serrano 113 bis, 28006 Madrid, Spain
| | - Y Wang
- Sino Biological, Inc., Beijing, People's Republic of China
| | - P Hu
- Sino Biological, Inc., Beijing, People's Republic of China
| | - J Cortés
- Ramon y Cajal University Hospital, Ctra. de Colmenar Viejo, km 9,100, 28034 Madrid, Spain; Vall D'Hebron Institute of Oncology (VHIO), Paseo Vall Hebron 119-129, 08035 Barcelona, Spain
| | - J Martínez-Salazar
- BIOPHYM, Department of Macromolecular Physics, Instituto de Estructura de la Materia, IEM-CSIC, C/ Serrano 113 bis, 28006 Madrid, Spain
| |
Collapse
|
7
|
Azimzadeh Irani M, Kannan S, Verma C. Role of N-glycosylation in EGFR ectodomain ligand binding. Proteins 2017; 85:1529-1549. [DOI: 10.1002/prot.25314] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/25/2017] [Accepted: 05/02/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Maryam Azimzadeh Irani
- Bioinformatics Institute, A*STAR; 30 Biopolis Street, #07-01 Matrix Singapore 138671 Singapore
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
| | | | - Chandra Verma
- Bioinformatics Institute, A*STAR; 30 Biopolis Street, #07-01 Matrix Singapore 138671 Singapore
- School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
- Department of Biological Sciences; National University of Singapore; Singapore 117543 Singapore
| |
Collapse
|
8
|
Taylor ES, Pol-Fachin L, Lins RD, Lower SK. Conformational stability of the epidermal growth factor (EGF) receptor as influenced by glycosylation, dimerization and EGF hormone binding. Proteins 2017; 85:561-570. [PMID: 28019699 PMCID: PMC5835389 DOI: 10.1002/prot.25220] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 11/03/2016] [Accepted: 11/21/2016] [Indexed: 12/18/2022]
Abstract
The epidermal growth factor receptor (EGFR) is an important transmembrane glycoprotein kinase involved the initiation or perpetuation of signal transduction cascades within cells. These processes occur after EGFR binds to a ligand [epidermal growth factor (EGF)], thus inducing its dimerization and tyrosine autophosphorylation. Previous publications have highlighted the importance of glycosylation and dimerization for promoting proper function of the receptor and conformation in membranes; however, the effects of these associations on the protein conformational stability have not yet been described. Molecular dynamics simulations were performed to characterize the conformational preferences of the monomeric and dimeric forms of the EGFR extracellular domain upon binding to EGF in the presence and absence of N-glycan moieties. Structural stability analyses revealed that EGF provides the most conformational stability to EGFR, followed by glycosylation and dimerization, respectively. The findings also support that EGF-EGFR binding takes place through a large-scale induced-fitting mechanism. Proteins 2017; 85:561-570. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Eric S. Taylor
- Department of Geology, Kent State University, North Canton, Ohio 44720
| | - Laercio Pol-Fachin
- Aggeu Magalhães Research Center, Oswaldo Cruz Foundation, Recife, Pernambuco 50740-465, Brazil
- Department of Fundamental Chemistry, Federal University of Pernambuco, Recife, Pernambuco 50740-560, Brazil
| | - Roberto D. Lins
- Aggeu Magalhães Research Center, Oswaldo Cruz Foundation, Recife, Pernambuco 50740-465, Brazil
- Department of Fundamental Chemistry, Federal University of Pernambuco, Recife, Pernambuco 50740-560, Brazil
| | - Steven K. Lower
- School of Environment and Natural Resources, Ohio State University, 275 Mendenhall Laboratory, Columbus, Ohio 43210
| |
Collapse
|
9
|
Kovacs E, Zorn JA, Huang Y, Barros T, Kuriyan J. A structural perspective on the regulation of the epidermal growth factor receptor. Annu Rev Biochem 2015; 84:739-64. [PMID: 25621509 DOI: 10.1146/annurev-biochem-060614-034402] [Citation(s) in RCA: 225] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that plays a critical role in the pathogenesis of many cancers. The structure of intact forms of this receptor has yet to be determined, but intense investigations of fragments of the receptor have provided a detailed view of its activation mechanism, which we review here. Ligand binding converts the receptor to a dimeric form, in which contacts are restricted to the receptor itself, allowing heterodimerization of the four EGFR family members without direct ligand involvement. Activation of the receptor depends on the formation of an asymmetric dimer of kinase domains, in which one kinase domain allosterically activates the other. Coupling between the extracellular and intracellular domains may involve a switch between alternative crossings of the transmembrane helices, which form dimeric structures. We also discuss how receptor regulation is compromised by oncogenic mutations and the structural basis for negative cooperativity in ligand binding.
Collapse
|
10
|
Hasegawa Y, Takahashi M, Ariki S, Asakawa D, Tajiri M, Wada Y, Yamaguchi Y, Nishitani C, Takamiya R, Saito A, Uehara Y, Hashimoto J, Kurimura Y, Takahashi H, Kuroki Y. Surfactant protein D suppresses lung cancer progression by downregulation of epidermal growth factor signaling. Oncogene 2014; 34:838-45. [DOI: 10.1038/onc.2014.20] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 12/18/2013] [Accepted: 01/06/2014] [Indexed: 12/28/2022]
|
11
|
Abstract
Glycosylation of proteins, lipids and mucins has gained increasing complexity in the course of evolution. Metazoans and mammals exhibit extensively exploited pathways of N-glycan biosynthesis, with unique features that are not found in plants or protozoans.Paralleling the complexity of N-glycan structure, their impact on regulatory processes has become very diverse and has evolved into a multidimensional lattice imprinting modes of cellular communication. Processes that are regulated by N-glycans are cellular adhesion and motility, growth factor and cytokine signalling, metabolic homeostasis, and binding of certain pathogens. Consequently, alterations in N-glycan biosynthesis interfere with cellular proliferation and differentiation and may produce disturbances in embryonic development, trigger inflammatory processes, favour tumour development and enhance the metastastic dissemination of primary tumours. Particular N-glycans that have been causally related to these pathological scenarios are the complex-type N-glycans, branching from oligomannosidic core structures into β-glycosidic linkages, connected to acetylated glucosamine and galactose, and yield extended lactosamine chains of variable length. These N-acetyllactosamines are preferred building blocks for further modification by fucosylation, sialylation, and sulphation, thus creating binding sites for different galectins or selectins. The focus of this review will be on the b1,6-N -acetylglucosaminyltransferase-V/GnT-V/MGAT5, a phylogenically conserved enzyme that is required for the synthesis of β1,6-branched complex-type oligosaccharides in the medial Golgi compartment, and its implications in metabolism and cancer progression.
Collapse
Affiliation(s)
- A K Horst
- Diagnostic Center: Institute of Clinical Chemistry, University Medical Center Hamburg-Eppendorf, Martinistraβe 52, D-20246, Hamburg,
| | | |
Collapse
|
12
|
Przybyło M, Martuszewska D, Pocheć E, Hoja-Łukowicz D, Lityńska A. Identification of proteins bearing beta1-6 branched N-glycans in human melanoma cell lines from different progression stages by tandem mass spectrometry analysis. Biochim Biophys Acta Gen Subj 2007; 1770:1427-35. [PMID: 17600626 DOI: 10.1016/j.bbagen.2007.05.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2007] [Revised: 04/24/2007] [Accepted: 05/15/2007] [Indexed: 01/01/2023]
Abstract
The common structural alterations in the cell-surface glycoproteins concern the highly elevated expression of tri- and tetra-antennary beta1-6-N-acetylglucosamine (beta1-6 GlcNAc) bearing N-glycans, which are recognised by Phaseolus vulgaris agglutinin (PHA-L). In this report we identified proteins bearing beta1-6 GlcNAc branched N-glycans in three human melanoma cell lines: WM35--from the primary tumour site, as well as WM239 and WM9 from different metastatic sites: the skin and the lymph node, respectively, by tandem mass spectrometry (MS/MS) on PHA-L agarose bound material, followed by immunochemical identification. Our results show that melanoma cell lines differ from each other in the number of N-glycoproteins bearing beta1-6 GlcNAc branched oligosaccharides. Among identified proteins the largest group consists of integrin subunits. In addition, L1-CAM, Mac-2 binding protein, melanoma cell adhesion molecule, intercellular adhesion molecule, melanoma associated antigen, tumour rejection antigen-1, melanoma-associated chondroitin sulfate proteoglycan 4 and lysosome-associated membrane protein (LAMP-1) were found. It was indicated that WM35 cell line showed the lowest number of proteins possessing beta1-6 GlcNAc branched N-glycans in comparison to metastatic WM9 and WM239 cell lines. Our data suggest that changes in the number of proteins being a substrate for GlcNAc-TV are better correlated with melanoma development and progression than with expression of cell adhesion molecules.
Collapse
Affiliation(s)
- Małgorzata Przybyło
- Department of Glycoconjugate Biochemistry, Institute of Zoology, Jagiellonian University, Ingardena 6, 30-060 Kraków, Poland
| | | | | | | | | |
Collapse
|
13
|
Abstract
Secreted proteins and membrane proteins are frequently post-translationally modified by oligosaccharides. Therefore, many glycoproteins are involved in signal transduction. One example is growth factor receptors, which are membrane proteins that often contain oligosaccharides. The oligosaccharides in those growth factor receptors play crucial roles in receptor functions. An analysis of glycosyltransferase-transfectants revealed that the branching structures of oligosaccharide also serve as important determinants. For example, N-glycans of epidermal growth factor receptor (EGFR) are involved in receptor sorting, ligand binding and dimerization. The addition of a bisecting GlcNAc to N-glycans increases the endocytosis of EGFR. N-glycans of Trk, a high affinity nerve growth factor receptor, also affect its function. Thus, oligosaccharides play an important role in growth factor signaling.
Collapse
Affiliation(s)
- Motoko Takahashi
- Department of Biochemistry, Osaka Univerisity Graduate School of Medicine, B1, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | | | | | | | | |
Collapse
|
14
|
Zhen Y, Caprioli RM, Staros JV. Characterization of glycosylation sites of the epidermal growth factor receptor. Biochemistry 2003; 42:5478-92. [PMID: 12731890 PMCID: PMC2765783 DOI: 10.1021/bi027101p] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The epidermal growth factor receptor is a transmembrane glycoprotein that mediates the cellular responses to epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha). In this study of the human EGF receptor naturally expressed in A431 cells, the glycosylation sites of the full-length, membrane-bound receptor and of a secreted form of the receptor were characterized by mass spectrometry. Our data show that the naturally expressed human EGF receptor is fully glycosylated on eight of the 11 canonical sites; two of the sites are not glycosylated, and one is partially glycosylated, a pattern of site-usage similar but not identical to those reported for the recombinant human EGF receptor heterologously expressed in Chinese hamster ovary cells. We also confirm the partial glycosylation of an atypical NNC site first identified in the receptor expressed in Chinese hamster ovary cells. We show that an additional canonical site in the secreted form of the receptor is fully glycosylated. While the pattern of glycosylation is the same for the sites shared by the full-length and the secreted forms of the receptor, the oligosaccharides of the full-length receptor are more extensively processed. Finally, we provide evidence that in addition to the known secreted form of the receptor, a proteolytic cleavage product of the receptor corresponding to the full extracytoplasmic, ligand-binding domain is present in the conditioned medium.
Collapse
Affiliation(s)
| | - Richard M. Caprioli
- Correspondence may be addressed to the following authors. (R.M.C.) . Telephone: (615) 322-4336. (J.V.S.) . Telephone: (631) 632-6976
| | - James V. Staros
- Correspondence may be addressed to the following authors. (R.M.C.) . Telephone: (615) 322-4336. (J.V.S.) . Telephone: (631) 632-6976
| |
Collapse
|
15
|
Shaw DM, Woods AM, Myers KA, Westwater C, Rahi-Saund V, Davies MJ, Renouf DV, Hounsell EF, Stern PL. Glycosylation and epitope mapping of the 5T4 glycoprotein oncofoetal antigen. Biochem J 2002; 363:137-45. [PMID: 11903056 PMCID: PMC1222460 DOI: 10.1042/0264-6021:3630137] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The human 5T4 oncofoetal antigen is a focus for development of several antibody-directed therapies on the basis of the murine monoclonal antibody against 5T4 (mAb5T4), which recognizes a conformational epitope. 5T4 molecules are highly N-glycosylated transmembrane glycoproteins whose extracellular domain contains two regions of leucine-rich repeats (LRRs) and associated flanking regions, separated by an intervening hydrophilic sequence. Using a series of deletion and mutated cDNA constructs as well as chimaeras with the murine homologue, we have mapped the mAb5T4 epitope to the more membrane-proximal LRR2 or its flanking region. Analysis of the glycosylation of the seven consensus Asp-Xaa-Ser/Thr sites was consistent with all of the sites being glycosylated. A combination of two high-mannose chains (predominantly octasaccharide) and five mostly sialylated bi-, tri- and tetra-antennary complex chains with minor quantities of core fucose were detected. The two glycosylation sites, which are the most likely to have predominantly high-mannose chains, are in the only two regions that show significant differences between the human and the 81% identical mouse sequence. A site-directed mutation, which abolished glycosylation at one of these sites (position 192), did not alter antigenicity. The other, which is nearest to the N-terminus in the human, has an Asn-Leu-Thr to Asn-Leu-Leu conversion in the mouse, so cannot be glycosylated in the latter species. The large complex glycosylation at the other sites is likely to influence the antigenicity and tertiary structure generating the 5T4 epitope.
Collapse
Affiliation(s)
- David M Shaw
- CRC Immunology Group, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Wilmslow Road, Manchester M20 4BX, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Skinner MA, Wildeman AG. Suppression of tumor-related glycosylation of cell surface receptors by the 16-kDa membrane subunit of vacuolar H+-ATPase. J Biol Chem 2001; 276:48451-7. [PMID: 11604389 DOI: 10.1074/jbc.m103569200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The glycosylation of integrins and other cell surface receptors is altered in many transformed cells. Notably, an increase in the number of beta1,6-branched N-linked oligosaccharides correlates strongly with invasive growth of cells. An ectopic expression of the Golgi enzyme N-acetylglucosaminyltransferase V (GlcNAc-TV), which forms beta1,6 linkages, promotes metastasis of a number of cell types. It is shown here that the 16-kDa transmembrane subunit (16K) of vacuolar H(+)-ATPase suppresses beta1,6 branching of beta(1) integrin and the epidermal growth factor receptor. Overexpression of 16K inhibits cell adhesion and invasion. 16K contains four hydrophobic membrane-spanning alpha-helices, and its ability to influence glycosylation is localized primarily within the second and fourth membrane-spanning alpha-helices. 16K also interacts directly with the transmembrane domain of beta(1) integrin, but its effects on glycosylation were independent of its binding to beta(1) integrin. These data link cell surface tumor-related glycosylation to a component of the enzyme responsible for acidification of the exocytic pathway.
Collapse
Affiliation(s)
- M A Skinner
- Department of Molecular Biology and Genetics, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
| | | |
Collapse
|
17
|
Mares V, Brückner G. Fucosylated glycans in the periventricular structures and the cerebrospinal fluid of the fetal rat forebrain. An autoradiographic and lectin binding histiotopic study. Int J Dev Neurosci 2001; 19:297-303. [PMID: 11337198 DOI: 10.1016/s0736-5748(01)00013-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Our autoradiographic 3H-fucose incorporation study of the brains of 20-day-old rat fetuses showed that the synthesis of fucosylated glycans is significantly higher in the ventricular germinative zone of the forebrain hemisphere than in the more superficial layers, including the cortical plate. Intense incorporation of 3H-fucose also occurred in the choroid plexus, both its epithelial and stromal component, in the primordial ependymal lining of the lateral ventricles, meninges and capillaries of the forebrain parenchyma. In the lateral ventricles, densely labeled microprecipitates of the cerebrospinal fluid (CSF) were occasionally observed. The histiotopic differences in 3H-fucose labeling were absent, or were much less expressed, in the autoradiograms prepared from unfixed cryostat sections containing mainly unincorporated isotope. This indicates that the blood-mediated supply of 3H-fucose to the studied brain compartments was essentially equal and our incorporation data reflect actual differences in the rate of fucosylation within the forebrain hemispheres. The cytochemical lectin-binding assay, carried out with Ulex europaeus and Lotus tetragonolobus agglutinins, showed that regions with a higher rate of 3H-fucose incorporation were also richer in fucose-bearing glycoconjugates. The study revealed that the periventricular regions and the CSF of fetal rat forebrain form a fucosylated glycan-enriched complex, which represents a new chemoarchitectonic feature that may be of importance for maintaining the germinative properties of the ventricular neuroepithelium and the growth of the hemispheric ventricles.
Collapse
Affiliation(s)
- V Mares
- Institute of Physiology, Academy of Sciences, Vídenská 1083, CZ-142 00, Prague, Czech Republic.
| | | |
Collapse
|
18
|
Domagala T, Konstantopoulos N, Smyth F, Jorissen RN, Fabri L, Geleick D, Lax I, Schlessinger J, Sawyer W, Howlett GJ, Burgess AW, Nice EC. Stoichiometry, kinetic and binding analysis of the interaction between epidermal growth factor (EGF) and the extracellular domain of the EGF receptor. Growth Factors 2000; 18:11-29. [PMID: 10831070 DOI: 10.3109/08977190009003231] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The kinetics, binding equilibria and stoichiometry of the interaction between epidermal growth factor and the soluble extracellular domain of the epidermal growth factor receptor (sEGFR), produced in CHO cells using a bioreactor, have been studied by three methods: analytical ultracentrifugation, biosensor analysis using surface plasmon resonance detection (BIAcore 2000) and fluorescence anisotropy. These studies were performed with an sEGFR preparation purified in the absence of detergent using a mild two step chromatographic procedure employing anion exchange and size exclusion HPLC. The fluorescence anisotropy and analytical ultracentrifugation data indicated a 1:1 molar binding ratio between EGF and the sEGFR. Analytical ultracentrifugation further indicated that the complex comprised 2EGF:2sEGFR, consistent with the model proposed recently by Lemmon et al. (1997). Global analysis of the BIAcore binding data showed that a simple Langmuirian interaction does not adequately describe the EGF:sEGFR interaction and that more complex interaction mechanisms are operative. Furthermore, analysis of solution binding data using either fluorescence anisotropy or the biosensor, to determine directly the concentration of free sEGFR in solution competition experiments, yielded Scatchard plots which were biphasic and Hill coefficients of less than unity. Taken together our data indicate that in solution there are two sEGFR populations; one which binds EGF with a KD of 2-20 nM and the other with a KD of 400-550 nM.
Collapse
Affiliation(s)
- T Domagala
- The Ludwig Institute for Cancer Research, Melbourne Tumour Biology Branch, Victoria, Australia
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Affiliation(s)
- A L Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco 94143-0446, USA
| | | | | |
Collapse
|
20
|
Hounsell EF, Renouf DV. Oligosaccharide epitope diversity and therapeutic potential. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 435:251-60. [PMID: 9498083 DOI: 10.1007/978-1-4615-5383-0_24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- E F Hounsell
- Department of Biochemistry & Molecular Biology, University College London
| | | |
Collapse
|