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Yang S, He Z, Wu T, Wang S, Dai H. Glycobiology in osteoclast differentiation and function. Bone Res 2023; 11:55. [PMID: 37884496 PMCID: PMC10603120 DOI: 10.1038/s41413-023-00293-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 08/20/2023] [Accepted: 09/07/2023] [Indexed: 10/28/2023] Open
Abstract
Glycans, either alone or in complex with glycan-binding proteins, are essential structures that can regulate cell biology by mediating protein stability or receptor dimerization under physiological and pathological conditions. Certain glycans are ligands for lectins, which are carbohydrate-specific receptors. Bone is a complex tissue that provides mechanical support for muscles and joints, and the regulation of bone mass in mammals is governed by complex interplay between bone-forming cells, called osteoblasts, and bone-resorbing cells, called osteoclasts. Bone erosion occurs when bone resorption notably exceeds bone formation. Osteoclasts may be activated during cancer, leading to a range of symptoms, including bone pain, fracture, and spinal cord compression. Our understanding of the role of protein glycosylation in cells and tissues involved in osteoclastogenesis suggests that glycosylation-based treatments can be used in the management of diseases. The aims of this review are to clarify the process of bone resorption and investigate the signaling pathways mediated by glycosylation and their roles in osteoclast biology. Moreover, we aim to outline how the lessons learned about these approaches are paving the way for future glycobiology-focused therapeutics.
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Affiliation(s)
- Shufa Yang
- Prenatal Diagnostic Center, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, 100026, China
| | - Ziyi He
- Department of Immunology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Peking University, Beijing, 100191, China
| | - Tuo Wu
- Department of Immunology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Peking University, Beijing, 100191, China
| | - Shunlei Wang
- Department of Immunology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Peking University, Beijing, 100191, China
| | - Hui Dai
- Department of Immunology, School of Basic Medical Sciences, NHC Key Laboratory of Medical Immunology, Peking University, Beijing, 100191, China.
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2
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Noborn F, Nilsson J, Sihlbom C, Nikpour M, Kjellén L, Larson G. Mapping the Human Chondroitin Sulfate Glycoproteome Reveals an Unexpected Correlation Between Glycan Sulfation and Attachment Site Characteristics. Mol Cell Proteomics 2023; 22:100617. [PMID: 37453717 PMCID: PMC10424144 DOI: 10.1016/j.mcpro.2023.100617] [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: 12/08/2022] [Revised: 07/07/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023] Open
Abstract
Chondroitin sulfate proteoglycans (CSPGs) control key events in human health and disease and are composed of chondroitin sulfate (CS) polysaccharide(s) attached to different core proteins. Detailed information on the biological effects of site-specific CS structures is scarce as the polysaccharides are typically released from their core proteins prior to analysis. Here we present a novel glycoproteomic approach for site-specific sequencing of CS modifications from human urine. Software-assisted and manual analysis revealed that certain core proteins carried CS with abundant sulfate modifications, while others carried CS with lower levels of sulfation. Inspection of the amino acid sequences surrounding the attachment sites indicated that the acidity of the attachment site motifs increased the levels of CS sulfation, and statistical analysis confirmed this relationship. However, not only the acidity but also the sequence and characteristics of specific amino acids in the proximity of the serine glycosylation site correlated with the degree of sulfation. These results demonstrate attachment site-specific characteristics of CS polysaccharides of CSPGs in human urine and indicate that this novel method may assist in elucidating the biosynthesis and functional roles of CSPGs in cellular physiology.
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Affiliation(s)
- Fredrik Noborn
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jonas Nilsson
- Proteomics Core Facility, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Carina Sihlbom
- Proteomics Core Facility, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Mahnaz Nikpour
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lena Kjellén
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Göran Larson
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Laboratory of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden.
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3
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Ly TD, Wolny M, Lindenkamp C, Birschmann I, Hendig D, Knabbe C, Faust-Hinse I. The Human Myofibroblast Marker Xylosyltransferase-I: A New Indicator for Macrophage Polarization. Biomedicines 2022; 10:2869. [PMID: 36359389 PMCID: PMC9687871 DOI: 10.3390/biomedicines10112869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/29/2022] [Accepted: 11/05/2022] [Indexed: 09/04/2023] Open
Abstract
Chronic inflammation and excessive synthesis of extracellular matrix components, such as proteoglycans (PG), by fibroblast- or macrophage-derived myofibroblasts are the hallmarks of fibrotic diseases, including systemic sclerosis (SSc). Human xylosyltransferase-I (XT-I), which is encoded by the gene XYLT1, is the key enzyme that is involved in PG biosynthesis. Increased cellular XYLT1 expression and serum XT-I activity were measured in SSc. Nothing is known so far about the regulation of XT-I in immune cells, and their contribution to the increase in measurable serum XT-I activity. We utilized an in vitro model, with primary human CD14+CD16+ monocyte-derived macrophages (MΦ), in order to investigate the role of macrophage polarization on XT-I regulation. The MΦ generated were polarized towards two macrophage phenotypes that were associated with SSc, which were classified as classical pro-inflammatory (M1-like), and alternative pro-fibrotic (M2-like) MΦ. The fully characterized M1- and M2-like MΦ cultures showed differential XT-I gene and protein expressions. The fibrotic M2-like MΦ cultures exhibited higher XT-I secretion, as well as increased expression of myofibroblast marker α-smooth muscle actin, indicating the onset of macrophage-to-myofibroblast transition (MMT). Thus, we identified XT-I as a novel macrophage polarization marker for in vitro generated M1- and M2-like MΦ subtypes, and broadened the view of XT-I as a myofibroblast marker in the process of MMT.
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Affiliation(s)
| | | | | | | | | | | | - Isabel Faust-Hinse
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum NRW, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
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4
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Noborn F, Nilsson J, Larson G. Site-specific glycosylation of proteoglycans: a revisited frontier in proteoglycan research. Matrix Biol 2022; 111:289-306. [PMID: 35840015 DOI: 10.1016/j.matbio.2022.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 06/11/2022] [Accepted: 07/11/2022] [Indexed: 11/29/2022]
Abstract
Proteoglycans (PGs), a class of carbohydrate-modified proteins, are present in essentially all metazoan organisms investigated to date. PGs are composed of glycosaminoglycan (GAG) chains attached to various core proteins and are important for embryogenesis and normal homeostasis. PGs exert many of their functions via their GAG chains and understanding the details of GAG-ligand interactions has been an essential part of PG research. Although PGs are also involved in many diseases, the number of GAG-related drugs used in the clinic is yet very limited, indicating a lack of detailed structure-function understanding. Structural analysis of PGs has traditionally been obtained by first separating the GAG chains from the core proteins, after which the two components are analyzed separately. While this strategy greatly facilitates the analysis, it precludes site-specific information and introduces either a "GAG" or a "core protein" perspective on the data interpretation. Mass-spectrometric (MS) glycoproteomic approaches have recently been introduced, providing site-specific information on PGs. Such methods have revealed a previously unknown structural complexity of the GAG linkage regions and resulted in identification of several novel CSPGs and HSPGs in humans and in model organisms, thereby expanding our view on PG complexity. In light of these findings, we discuss here if the use of such MS-based techniques, in combination with various functional assays, can also be used to expand our functional understanding of PGs. We have also summarized the site-specific information of all human PGs known to date, providing a theoretical framework for future studies on site-specific functional analysis of PGs in human pathophysiology.
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Affiliation(s)
- Fredrik Noborn
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; Department of Laboratory Medicine, Sundsvall County Hospital, Sweden.
| | - Jonas Nilsson
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; Proteomics Core Facility, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Göran Larson
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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5
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Gao J, Huang X. Recent advances on glycosyltransferases involved in the biosynthesis of the proteoglycan linkage region. Adv Carbohydr Chem Biochem 2021; 80:95-119. [PMID: 34872657 DOI: 10.1016/bs.accb.2021.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Proteoglycans (PGs) are an essential family of glycoproteins, which can play roles in many important biological events including cell proliferation, cancer development, and pathogen infections. Proteoglycans consist of a core protein with one or multiple glycosaminoglycan (GAG) chains, which are covalently attached to serine residues of serine-glycine dipeptide within the core protein through a common tetrasaccharide linkage. In the past three decades, four key glycosyl transferases involved in the biosynthesis of PG linkage have been discovered and investigated. This review aims to provide an overview on progress made on these four enzymes, with foci on enzyme expression/purification, substrate specificity, activity determination, product characterization, and structure-activity relationship analysis.
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Affiliation(s)
- Jia Gao
- Department of Chemistry, Michigan State University, East Lansing, MI, United States; Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
| | - Xuefei Huang
- Department of Chemistry, Michigan State University, East Lansing, MI, United States; Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States; Department of Biomedical Engineering, Michigan State University, East Lansing, MI, United States.
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6
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Montoliu-Gaya L, Tietze D, Kaminski D, Mirgorodskaya E, Tietze AA, Sterky FH. CA10 regulates neurexin heparan sulfate addition via a direct binding in the secretory pathway. EMBO Rep 2021; 22:e51349. [PMID: 33586859 PMCID: PMC8024894 DOI: 10.15252/embr.202051349] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 12/21/2020] [Accepted: 01/13/2021] [Indexed: 12/29/2022] Open
Abstract
Neurexins are presynaptic adhesion molecules that shape the molecular composition of synapses. Diversification of neurexins in numerous isoforms is believed to confer synapse-specific properties by engaging with distinct ligands. For example, a subset of neurexin molecules carry a heparan sulfate (HS) glycosaminoglycan that controls ligand binding, but how this post-translational modification is controlled is not known. Here, we observe that CA10, a ligand to neurexin in the secretory pathway, regulates neurexin-HS formation. CA10 is exclusively found on non-HS neurexin and CA10 expressed in neurons is sufficient to suppress HS addition and attenuate ligand binding and synapse formation induced by ligands known to recruit HS. This effect is mediated by a direct interaction in the secretory pathway that blocks the primary step of HS biosynthesis: xylosylation of the serine residue. NMR reveals that CA10 engages residues on either side of the serine that can be HS-modified, suggesting that CA10 sterically blocks xylosyltransferase access in Golgi. These results suggest a mechanism for the regulation of HS on neurexins and exemplify a new mechanism to regulate site-specific glycosylations.
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Affiliation(s)
- Laia Montoliu-Gaya
- Department of Laboratory Medicine, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Daniel Tietze
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden.,Department of Chemistry and Molecular Biology, Faculty of Science, University of Gothenburg, Gothenburg, Sweden
| | - Debora Kaminski
- Department of Laboratory Medicine, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden.,Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden
| | | | - Alesia A Tietze
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden.,Department of Chemistry and Molecular Biology, Faculty of Science, University of Gothenburg, Gothenburg, Sweden
| | - Fredrik H Sterky
- Department of Laboratory Medicine, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden.,Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden
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7
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Meng T, Wong SM, Chua KB. Sulfonated azo dyes enhance the genome release of enterovirus A71 VP1-98K variants by preventing the virions from being trapped by sulfated glycosaminoglycans at acidic pH. Virology 2021; 555:19-34. [PMID: 33422703 DOI: 10.1016/j.virol.2020.12.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/22/2020] [Accepted: 12/29/2020] [Indexed: 12/23/2022]
Abstract
Enterovirus A71 (EV-A71) is a causative agent of hand, foot and mouth disease and occasionally causes death in children. Its infectivity and pathogenesis, however, remain to be better understood. Three sulfonated azo dyes, including acid red 88 (Ar88), were identified to enhance the infectivity of EV-A71, especially isolates with VP1-98K, 145E (-KE), by mainly promoting viral genome release in vitro. Enzymatic removal of sulfated glycosaminoglycans (GAGs) or knockout of xylosyltransferase II (XT2) responsible for biosynthesis of sulfated GAGs weakened the Ar88 enhanced EV-A71 infection. Ar88 is proposed to prevent the -KE variants from being trapped by sulfated GAGs at acidic pH and to facilitate the viral interaction with uncoating factors for genome release in endosomes. The results suggest dual roles of sulfated GAGs as attachment factors and as decoys during host interaction of EV-A71 and caution that these artificial dyes in our environment can enhance viral infection.
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Affiliation(s)
- Tao Meng
- Temasek Life Sciences Laboratory Limited, Republic of Singapore; Department of Biological Sciences, National University of Singapore, Republic of Singapore
| | - Sek-Man Wong
- Temasek Life Sciences Laboratory Limited, Republic of Singapore; Department of Biological Sciences, National University of Singapore, Republic of Singapore; NUS Suzhou Research Institute, Suzhou, People's Republic of China.
| | - Kaw-Bing Chua
- Temasek Life Sciences Laboratory Limited, Republic of Singapore.
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8
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Ferencz B, Condac E, Poudel N, Munteanu MC, Sivasami P, Choudhury B, Naidu NN, Zhang F, Breshears M, Linhardt RJ, Hinsdale ME. Xylosyltransferase 2 deficiency and organ homeostasis. Glycoconj J 2020; 37:755-765. [PMID: 32965647 PMCID: PMC9248025 DOI: 10.1007/s10719-020-09945-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 08/13/2020] [Accepted: 09/04/2020] [Indexed: 12/19/2022]
Abstract
In this paper we characterize the function of Xylosyltransferase 2 (XylT2) in different tissues to investigate the role XylT2 has in the proteoglycan (PG) biochemistry of multiple organs. The results show that in all organs examined there is a widespread and significant decrease in total XylT activity in Xylt2 knock out mice (Xylt2-/-). This decrease results in increased organ weight differences in lung, heart, and spleen. These findings, in addition to our previous findings of increased liver and kidney weight with loss of serum XylT activity, suggest systemic changes in organ function due to loss of XylT2 activity. The Xylt2-/- mice have splenomegaly due to enlargement of the red pulp area and enhanced pulmonary response to bacterial liposaccharide. Tissue glycosaminoglycan composition changes are also found. These results demonstrate a role of XylT2 activity in multiple organs and their PG content. Because the residual XylT activity in the Xylt2-/- is due to xylosyltransferase 1 (XylT1), these studies indicate that both XylT1 and XylT2 have important roles in PG biosynthesis and organ homeostasis.
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Affiliation(s)
- Beatrix Ferencz
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Eduard Condac
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Nabin Poudel
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | | | - Pulavendran Sivasami
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Biswa Choudhury
- Glycotechnology Core Lab, Cellular and Molecular Medicine East, University of California, San Diego, La Jolla, CA, 92093-0687, USA
| | | | - Fuming Zhang
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180-3590, USA
| | - Melanie Breshears
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Robert J Linhardt
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180-3590, USA
| | - Myron E Hinsdale
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA.
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
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9
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Global view of human protein glycosylation pathways and functions. Nat Rev Mol Cell Biol 2020; 21:729-749. [PMID: 33087899 DOI: 10.1038/s41580-020-00294-x] [Citation(s) in RCA: 502] [Impact Index Per Article: 125.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2020] [Indexed: 02/07/2023]
Abstract
Glycosylation is the most abundant and diverse form of post-translational modification of proteins that is common to all eukaryotic cells. Enzymatic glycosylation of proteins involves a complex metabolic network and different types of glycosylation pathways that orchestrate enormous amplification of the proteome in producing diversity of proteoforms and its biological functions. The tremendous structural diversity of glycans attached to proteins poses analytical challenges that limit exploration of specific functions of glycosylation. Major advances in quantitative transcriptomics, proteomics and nuclease-based gene editing are now opening new global ways to explore protein glycosylation through analysing and targeting enzymes involved in glycosylation processes. In silico models predicting cellular glycosylation capacities and glycosylation outcomes are emerging, and refined maps of the glycosylation pathways facilitate genetic approaches to address functions of the vast glycoproteome. These approaches apply commonly available cell biology tools, and we predict that use of (single-cell) transcriptomics, genetic screens, genetic engineering of cellular glycosylation capacities and custom design of glycoprotein therapeutics are advancements that will ignite wider integration of glycosylation in general cell biology.
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10
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CDG biochemical screening: Where do we stand? Biochim Biophys Acta Gen Subj 2020; 1864:129652. [DOI: 10.1016/j.bbagen.2020.129652] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/18/2020] [Accepted: 05/28/2020] [Indexed: 12/22/2022]
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11
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Fischer B, Ly TD, Schmidt V, Hendig D, Kuhn J, Knabbe C, Faust I. Xylosyltransferase-deficient human HEK293 cells show a strongly reduced proliferation capacity and viability. Biochem Biophys Res Commun 2020; 521:507-513. [PMID: 31677793 DOI: 10.1016/j.bbrc.2019.10.148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 10/22/2019] [Indexed: 01/08/2023]
Abstract
Human xylosyltransferases-I and -II (XT-I and XT-II) catalyze the initial and rate-limiting step in proteoglycan (PG)-biosynthesis. Because PG are major components of the extracellular matrix (ECM), an alternated XT expression is associated with the manifestation of ECM-related diseases. While Drosophila melanogaster and Caenorhabditis elegans only harbor one XT-isoform, all higher organisms contain two isoforms, which are expressed in a tissue-specific manner. The reason for the appearance of two isoenzymes remains unexplained and remarkable, as all other enzymes involved in the synthesis of the tetrasaccharid linker, which connects the PG core protein with attached glycosaminoglycans, only show one isoform. In human, mutations in the XYLT genes cause diseases affecting the homeostasis of the ECM, such as skeletal dysplasias. We investigated for the first time whether already XT-I-deficient human embryonic kidney (HEK293) cells can compensate for decreased expression levels of both XT-isoforms. A siRNA-mediated XYLT2 mRNA knockdown led to reduced cellular proliferation rates and a partially increased cellular senescence of treated HEK293 cells. These results were verified by conducting a stable CRISPR/Cas9-mediated XYLT2 knockout, which revealed that only cells expressing at least partially functional XT-II proteins remain proliferative. Our study, therefore, shows for the first time that cells lacking both XT-isoforms are not viable and clearly indicates the importance of the XT concerning the cellular metabolism.
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Affiliation(s)
- Bastian Fischer
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany.
| | - Thanh-Diep Ly
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany
| | - Vanessa Schmidt
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany
| | - Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany
| | - Joachim Kuhn
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany
| | - Cornelius Knabbe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany
| | - Isabel Faust
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany
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12
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Sivasami P, Poudel N, Munteanu MC, Hudson J, Lovern P, Liu L, Griffin T, Hinsdale ME. Adipose tissue loss and lipodystrophy in xylosyltransferase II deficient mice. Int J Obes (Lond) 2019; 43:1783-1794. [PMID: 30778123 PMCID: PMC7067554 DOI: 10.1038/s41366-019-0324-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 10/21/2018] [Accepted: 11/22/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND/OBJECTIVES The cellular and extracellular matrix (ECM) interactions that regulate adipose tissue homeostasis are incompletely understood. Proteoglycans (PGs) and their sulfated glycosaminoglycans (GAGs) provide spatial and temporal signals for ECM organization and interactions with resident cells by impacting growth factor and cytokine activity. Therefore, PGs and their GAGs could be significant to adipose tissue homeostasis. The purpose of this study was to determine the role of ECM sulfated GAGs in adipose tissue homeostasis. METHODS Adipose tissue and metabolic homeostasis in mice deficient in xylosyltransferase 2 (Xylt2-/-) were examined by histologic analyses, gene expression analyses, whole body fat composition measurements, and glucose tolerance test. Adipose tissue inflammation and adipocyte precursors were characterized by flow cytometry and in vitro culture of mesenchymal stem cells. RESULTS Xylt2-/- mice have low body weight due to overall reductions in abdominal fat deposition. Histologically, the adipocytes are reduced in size and number in both gonadal and mesenteric fat depots of Xylt2-/- mice. In addition, these mice are glucose intolerant, insulin resistant, and have increased serum triglycerides as compared to Xylt2 + / + control mice. Furthermore, the adipose tissue niche has increased inflammatory cells and enrichment of proinflammatory factors IL6 and IL1β, and these mice also have a loss of adipose tissue vascular endothelial cells. Lastly, xylosyltransferease-2 (XylT2) deficient mesenchymal stem cells from gonadal adipose tissue and bone marrow exhibit impaired adipogenic differentiation in vitro. CONCLUSIONS Decreased GAGs due to the loss of the key GAG assembly enzyme XylT2 causes reduced steady state adipose tissue stores leading to a unique lipodystrophic model. Accumulation of an adipocytic precursor pool of cells is discovered indicating an interruption in differentiation. Therefore, adipose tissue GAGs are important in the homeostasis of adipose tissue by mediating control of adipose precursor development, tissue inflammation, and vascular development.
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Affiliation(s)
- Pulavendran Sivasami
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Nabin Poudel
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | | | - Joanna Hudson
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Pamela Lovern
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Lin Liu
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Tim Griffin
- Aging and Metabolism Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Myron E Hinsdale
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK, 74078, USA.
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
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13
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Bruneel A, Dubail J, Roseau C, Prada P, Haouari W, Huber C, Dupré T, Poüs C, Cormier-Daire V, Seta N. Serum bikunin is a biomarker of linkeropathies. Clin Chim Acta 2018; 485:178-180. [DOI: 10.1016/j.cca.2018.06.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 06/27/2018] [Accepted: 06/28/2018] [Indexed: 11/16/2022]
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14
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Matsuo K, Atsumi G. Xylosylation of proteins by expression of human xylosyltransferase 2 in plants. J Biosci Bioeng 2018; 126:371-378. [PMID: 29657126 DOI: 10.1016/j.jbiosc.2018.03.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 03/04/2018] [Accepted: 03/19/2018] [Indexed: 10/17/2022]
Abstract
Through the years, the post-translational modification of plant-made recombinant proteins has been a considerable problem. Protein glycosylation is arguably the most important post-translational modification; thus, for the humanization of protein glycosylation in plants, the introduction, repression, and knockout of many glycosylation-related genes has been carried out. In addition, plants lack mammalian-type protein O-glycosylation pathways; thus, for the synthesis of mammalian O-glycans in plants, the construction of these pathways is necessary. In this study, we successfully xylosylated the recombinant human proteoglycan core protein, serglycin, by transient expression of human xylosyltransferase 2 in Nicotiana benthamiana plants. When human serglycin was co-expressed with human xylosyltransferase 2 in plants, multiple serine residues of eight xylosylation candidates were xylosylated. From the results of carbohydrate assays for total soluble proteins, some endogenous plant proteins also appeared to be xylosylated, likely through the actions of xylosyltransferase 2. The xylosylation of core proteins is the initial step of the glycosaminoglycan part of the synthesis of proteoglycans. In the future, these novel findings may lead to whole mammalian proteoglycan synthesis in plants.
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Affiliation(s)
- Kouki Matsuo
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan.
| | - Go Atsumi
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan
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15
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Abstract
Xylosyltransferase initiates glycosaminoglycan synthesis on the proteoglycan core protein. In this issue of Structure, Briggs and Hohenester (2018) determined the crystal structure of xylosyltransferase 1 and its structure in ternary complex with UDP-xylose donor and peptide acceptors, providing a mechanistic insight into the role of xylosyltransferase for glycosaminoglycan site selection.
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Affiliation(s)
- Yanlei Yu
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Robert J Linhardt
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA; Department of Chemical and Biological Engineering, Department of Biomedical Engineering, Department of Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
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16
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Briggs DC, Hohenester E. Structural Basis for the Initiation of Glycosaminoglycan Biosynthesis by Human Xylosyltransferase 1. Structure 2018; 26:801-809.e3. [PMID: 29681470 PMCID: PMC5992326 DOI: 10.1016/j.str.2018.03.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/15/2018] [Accepted: 03/20/2018] [Indexed: 01/10/2023]
Abstract
Proteoglycans (PGs) are essential components of the animal extracellular matrix and are required for cell adhesion, migration, signaling, and immune function. PGs are composed of a core protein and long glycosaminoglycan (GAG) chains, which often specify PG function. GAG biosynthesis is initiated by peptide O-xylosyltransferases, which transfer xylose onto selected serine residues in the core proteins. We have determined crystal structures of human xylosyltransferase 1 (XT1) in complex with the sugar donor, UDP-xylose, and various acceptor peptides. The structures reveal unique active-site features that, in conjunction with functional experiments, explain the substrate specificity of XT1. A constriction within the peptide binding cleft requires the acceptor serine to be followed by glycine or alanine. The remainder of the cleft can accommodate a wide variety of sequences, but with a general preference for acidic residues. These findings provide a framework for understanding the selectivity of GAG attachment.
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Affiliation(s)
- David C Briggs
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
| | - Erhard Hohenester
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
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Faust I, Donhauser E, Fischer B, Ibold B, Kuhn J, Knabbe C, Hendig D. Characterization of dermal myofibroblast differentiation in pseudoxanthoma elasticum. Exp Cell Res 2017; 360:153-162. [PMID: 28882457 DOI: 10.1016/j.yexcr.2017.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/30/2017] [Accepted: 09/01/2017] [Indexed: 02/06/2023]
Abstract
Pseudoxanthoma elasticum (PXE) is a rare hereditary disorder which is caused by ABCC6 (ATP-binding cassette subfamily C member 6) gene mutations. Characteristic hallmarks of PXE are progressive calcification and degradation of the elastic fibers in skin, cardiovascular system and ocular fundus. Since the underlying pathomechanisms of PXE remain unidentified, the aim of this study was to get new insights into PXE pathophysiology by characterizing dermal myofibroblast differentiation. Fibroblasts are the key cells of extracellular matrix (ECM) remodeling and, therefore, participate not only in physiological processes, such as calcification or wound healing, but also in pathologic events, such as fibrotization. We revealed that human dermal PXE fibroblasts possess exaggerated migration capability in wound healing and attenuated myofibroblast contractility in comparison to controls. Subsequent analyses reinforced these observations and indicated a diminished induction of the myofibroblast differentiation markers α-smooth muscle actin and xylosyltransferase-I as well as poor transforming growth factor-β1 responsiveness in PXE fibroblasts. In summary, we describe pathological deviations of dermal myofibroblast differentiation in PXE which might be mediated by aberrant supramolecular ECM organization. These results not only improve our insights into cellular PXE pathophysiology, but might also qualify us to interfere with ECM remodeling in the future.
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Affiliation(s)
- Isabel Faust
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany.
| | - Elfi Donhauser
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
| | - Bastian Fischer
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
| | - Bettina Ibold
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
| | - Joachim Kuhn
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
| | - Cornelius Knabbe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
| | - Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
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18
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Liu H, Wang J, Ren G, Zhang Y, Dong F. The relationship between proteoglycan inhibition via xylosyltransferase II silencing and the implantation of salivary pleomorphic adenoma. J Oral Pathol Med 2017; 46:504-512. [PMID: 27732748 DOI: 10.1111/jop.12510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To study the relationship between proteoglycan inhibition and the implantation of salivary pleomorphic adenoma (SPA). METHODS SPA fresh tissue was primitively cultured and identified. The Ad-shRNA-XT-II adenovirus vector was constructed and transfected into SPA cells to silence the XT-II gene. The expression of the XT-II gene and protein was detected using real-time PCR and Western blotting, respectively. The proteoglycan content of the cells was determined 48 h after transfection. The invasion and migration of SPA cells were observed using Matrigel invasion and wound-healing assays. Fibroblasts from the tumour capsule of the same patient were obtained, cultured and seeded onto an acellular dermal matrix (ADM) scaffold. Tumour cells were seeded onto the scaffold with the fibroblasts and then transferred to BALB/C-nu nude mice and allowed to grow in vivo for 3 months. RESULTS The SPA cells cultures were positive for human calponin, S-100 protein, α-SMA and CK. XT-II gene and protein expression was decreased by 42.72% and 34%, respectively. The proteoglycan content was downregulated by 41.15%. XT-II gene silencing decreased the invasion and migration abilities of SPA cells. The assessment of SPA growth in nude mice indicated an absence of tumour growth in the SPA-XT-II group (in which the XT-II gene was silenced), whereas SPA growth was observed in the other two groups (in which the XT-II gene was not silenced), and the tumour tissue was positive for the human S-100 protein, α-SMA and CK8&18. CONCLUSION Proteoglycan inhibition induced via XT-II gene silencing inhibited the implantation of SPA.
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Affiliation(s)
- Huijuan Liu
- Department of Oral Pathology, College and Hospital of Stomatology, Key Laboratory of Stomatology, Hebei Medical University, Hebei Province, China
| | - Jie Wang
- Department of Oral Pathology, College and Hospital of Stomatology, Key Laboratory of Stomatology, Hebei Medical University, Hebei Province, China
| | - Guiyun Ren
- Department of Oral & Maxillofacial Surgery, College and Hospital of Stomatology, Key Laboratory of Stomatology, Hebei Medical University, Hebei Province, China
| | - Yanning Zhang
- Department of Oral Pathology, College and Hospital of Stomatology, Key Laboratory of Stomatology, Hebei Medical University, Hebei Province, China
| | - Fusheng Dong
- Department of Oral & Maxillofacial Surgery, College and Hospital of Stomatology, Key Laboratory of Stomatology, Hebei Medical University, Hebei Province, China
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19
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Li C, Wang LX. Endoglycosidases for the Synthesis of Polysaccharides and Glycoconjugates. Adv Carbohydr Chem Biochem 2016; 73:73-116. [PMID: 27816108 DOI: 10.1016/bs.accb.2016.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Recent advances in glycobiology have implicated essential roles of oligosaccharides and glycoconjugates in many important biological recognition processes, including intracellular signaling, cell adhesion, cell differentiation, cancer progression, host-pathogen interactions, and immune responses. A detailed understanding of the biological functions, as well as the development of carbohydrate-based therapeutics, often requires structurally well-defined oligosaccharides and glycoconjugates, which are usually difficult to isolate in pure form from natural sources. To meet with this urgent need, chemical and chemoenzymatic synthesis has become increasingly important as the major means to provide homogeneous compounds for functional glycocomics studies and for drug/vaccine development. Chemoenzymatic synthesis, an approach that combines chemical synthesis and enzymatic manipulations, is often the method of choice for constructing complex oligosaccharides and glycoconjugates that are otherwise difficult to achieve by purely chemical synthesis. Among these, endoglycosidases, a class of glycosidases that hydrolyze internal glycosidic bonds in glycoconjugates and polysaccharides, are emerging as a very attractive class of enzymes for synthetic purposes, due to their transglycosylation activity and their capability of transferring oligosaccharide units en bloc in a single step, in contrast to the limitation of monosaccharide transfers by common glycosyltransferases. In this chapter, we provide an overview on the application of endoglycosidases for the synthesis of complex carbohydrates, including oligosaccharides, polysaccharides, glycoproteins, glycolipids, proteoglycans, and other biologically relevant polysaccharides. The scope, limitation, and future directions of endoglycosidase-catalyzed synthesis are discussed.
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Affiliation(s)
- Chao Li
- University of Maryland, College Park, MD, United States
| | - Lai-Xi Wang
- University of Maryland, College Park, MD, United States
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20
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Munns CF, Fahiminiya S, Poudel N, Munteanu MC, Majewski J, Sillence DO, Metcalf JP, Biggin A, Glorieux F, Fassier F, Rauch F, Hinsdale ME. Homozygosity for frameshift mutations in XYLT2 result in a spondylo-ocular syndrome with bone fragility, cataracts, and hearing defects. Am J Hum Genet 2015; 96:971-8. [PMID: 26027496 PMCID: PMC4457947 DOI: 10.1016/j.ajhg.2015.04.017] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 04/24/2015] [Indexed: 01/05/2023] Open
Abstract
Heparan and chondroitin/dermatan sulfated proteoglycans have a wide range of roles in cellular and tissue homeostasis including growth factor function, morphogen gradient formation, and co-receptor activity. Proteoglycan assembly initiates with a xylose monosaccharide covalently attached by either xylosyltransferase I or II. Three individuals from two families were found that exhibited similar phenotypes. The index case subjects were two brothers, individuals 1 and 2, who presented with osteoporosis, cataracts, sensorineural hearing loss, and mild learning defects. Whole exome sequence analyses showed that both individuals had a homozygous c.692dup mutation (GenBank: NM_022167.3) in the xylosyltransferase II locus (XYLT2) (MIM: 608125), causing reduced XYLT2 mRNA and low circulating xylosyltransferase (XylT) activity. In an unrelated boy (individual 3) from the second family, we noted low serum XylT activity. Sanger sequencing of XYLT2 in this individual revealed a c.520del mutation in exon 2 that resulted in a frameshift and premature stop codon (p.Ala174Profs(∗)35). Fibroblasts from individuals 1 and 2 showed a range of defects including reduced XylT activity, GAG incorporation of (35)SO4, and heparan sulfate proteoglycan assembly. These studies demonstrate that human XylT2 deficiency results in vertebral compression fractures, sensorineural hearing loss, eye defects, and heart defects, a phenotype that is similar to the autosomal-recessive disorder spondylo-ocular syndrome of unknown cause. This phenotype is different from what has been reported in individuals with other linker enzyme deficiencies. These studies illustrate that the cells of the lens, retina, heart muscle, inner ear, and bone are dependent on XylT2 for proteoglycan assembly in humans.
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Affiliation(s)
- Craig F Munns
- Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Westmead, NSW 2145, Australia
| | - Somayyeh Fahiminiya
- Department of Human Genetics, Faculty of Medicine, McGill University and Genome Quebec Innovation Center, Montréal, QC H3A 1B1, Canada
| | - Nabin Poudel
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | | | - Jacek Majewski
- Department of Human Genetics, Faculty of Medicine, McGill University and Genome Quebec Innovation Center, Montréal, QC H3A 1B1, Canada
| | - David O Sillence
- Discipline of Genetic Medicine, The Children's Hospital at Westmead Clinical School, Sydney Medicine, Westmead, NSW 2145, Australia
| | - Jordan P Metcalf
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73126, USA
| | - Andrew Biggin
- Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Westmead, NSW 2145, Australia
| | | | | | - Frank Rauch
- Shriners Hospital for Children, Montréal, QC H3G 1A6, Canada
| | - Myron E Hinsdale
- Department of Physiological Sciences, Oklahoma State University, Stillwater, OK 74078, USA; Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73126, USA.
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21
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Kuhn J, Götting C, Beahm BJ, Bertozzi CR, Faust I, Kuzaj P, Knabbe C, Hendig D. Xylosyltransferase II is the predominant isoenzyme which is responsible for the steady-state level of xylosyltransferase activity in human serum. Biochem Biophys Res Commun 2015; 459:469-74. [PMID: 25748573 PMCID: PMC6598695 DOI: 10.1016/j.bbrc.2015.02.129] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 02/22/2015] [Indexed: 01/13/2023]
Abstract
In mammals, two active xylosyltransferase isoenzymes (EC 2.4.2.16) exist. Both xylosyltransferases I and II (XT-I and XT-II) catalyze the transfer of xylose from UDP-xylose to select serine residues in the proteoglycan core protein. Altered XT activity in human serum was found to correlate directly with various diseases such as osteoarthritis, systemic sclerosis, liver fibrosis, and pseudoxanthoma elasticum. To interpret the significance of the enzyme activity alteration observed in disease states it is important to know which isoenzyme is responsible for the XT activity in serum. Until now it was impossible for a specific measurement of XT-I or XT-II activity, respectively, because of the absence of a suitable enzyme substrate. This issue has now been solved and the following experimental study demonstrates for the first time, via the enzyme activity that XT-II is the predominant isoenzyme responsible for XT activity in human serum. The proof was performed using natural UDP-xylose as the xylose donor, as well as the artificial compound UDP-4-azido-4-deoxyxylose, which is a selective xylose donor for XT-I.
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Affiliation(s)
- Joachim Kuhn
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany.
| | - Christian Götting
- MVZ Labor Limbach Nürnberg, Lina-Ammon-Strasse 28, 90471 Nürnberg, Germany
| | - Brendan J Beahm
- Department of Chemistry and Molecular and Cell Biology Howard Hughes Medical Institute University of California, Berkeley, CA 94720, USA
| | - Carolyn R Bertozzi
- Department of Chemistry and Molecular and Cell Biology Howard Hughes Medical Institute University of California, Berkeley, CA 94720, USA
| | - Isabel Faust
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
| | - Patricia Kuzaj
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
| | - Cornelius Knabbe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
| | - Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Georgstraße 11, 32545 Bad Oeynhausen, Germany
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22
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Faust I, Böker KO, Eirich C, Akkermann D, Kuhn J, Knabbe C, Hendig D. Identification and characterization of human xylosyltransferase II promoter single nucleotide variants. Biochem Biophys Res Commun 2015; 458:901-7. [PMID: 25704086 DOI: 10.1016/j.bbrc.2015.02.056] [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: 01/21/2015] [Accepted: 02/11/2015] [Indexed: 10/24/2022]
Abstract
The human isoenzymes xylosyltransferase-I and -II (XT-I, XT-II) catalyze the rate-limiting step in proteoglycan biosynthesis. Therefore, serum XT activity, mainly representing XT-II activity, displays a powerful biomarker to quantify the actual proteoglycan synthesis rate. Serum XT activity is increased up to 44% in disorders which are characterized by an altered proteoglycan metabolism, whereby underlying regulatory mechanisms remain unclear. The aim of this study was to investigate new regulatory pathways by identifying and characterizing naturally occurring XYLT2 promoter sequence variants as well as their potential influence on promoter activity and serum XT activity. XYLT2 promoter single nucleotide variants (SNVs) were identified and genotyped in the genomic DNA of 100 healthy blood donors by promoter amplification and sequencing or restriction fragment length polymorphism analysis. The SNVs were characterized by an in silico analysis considering genetic linkage and transcription factor binding sites (TBSs). The influence of SNVs on promoter activity and serum XT activity was determined by dual luciferase reporter assay and HPLC-ESI mass spectrometry. Allele frequencies of seven XYLT2 promoter sequence variants identified were investigated. In silico analyses revealed a strong genetic linkage of SNVs c.-80delG and c.-188G > A, c.-80delG and c.-1443G > A, as well as c.-188G > A and c.-1443G > A. However, despite the generation of several SNV-associated changes in TBSs in silico, XYLT2 promoter SNVs did not significantly affect promoter activity. Serum XT activities of SNV carriers deviated up to 8% from the wild-type, whereby the differences were also not statistically significant. This is the first study which identifies, genotypes and characterizes XYLT2 promoter SNVs. Our results reveal a weak genetic heterogeneity and a strong conservation of the human XYLT2 promoter region. Since the SNVs detected could be excluded as causatives for strong interindividual variabilities in serum XT activity, our data provide increasing evidence that XT-II activity is obviously regulated by hitherto unknown complex genetic pathways, such as cis- or trans-acting enhancers, silencers or miRNAs.
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Affiliation(s)
- Isabel Faust
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Kai Oliver Böker
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Christina Eirich
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Dagmar Akkermann
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Joachim Kuhn
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Cornelius Knabbe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
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23
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Faust I, Böker KO, Lichtenberg C, Kuhn J, Knabbe C, Hendig D. First description of the complete human xylosyltransferase-I promoter region. BMC Genet 2014; 15:129. [PMID: 25480529 PMCID: PMC4264549 DOI: 10.1186/s12863-014-0129-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 11/17/2014] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Human xylosyltransferase-I (XT-I) catalyzes the rate-limiting step in proteoglycan glycosylation. An increase in XYLT1 mRNA expression and serum XT activity is associated with diseases characterized by abnormal extracellular matrix accumulation like, for instance, fibrosis. Nevertheless, physiological and pathological mechanisms of transcriptional XT regulation remain elusive. RESULTS To elucidate whether promoter variations might affect the naturally occurring variability in serum XT activity, a complete sequence analysis of the XYLT1 promoter was performed in genomic DNA of healthy blood donors. Based on promoter amplification by a specialized PCR technique, sequence analysis revealed a fragment of 238 bp, termed XYLT1 238*, which has never been described in the human XYLT1 reference sequence so far. In silico characterization of this unconsidered fragment depicted an evolutionary conservation between sequences of Homo sapiens and Pan troglodytes (chimpanzee) or Mus musculus (mouse), respectively. Promoter activity studies indicated that XYLT1 238* harbors various transcription factor binding sites affecting basal XYLT1 expression and inducibility by transforming growth factor-β1, the key fibrotic mediator. A microsatellite and two single nucleotide variants (SNV), c.-403C>T and c.-1088C>A, were identified and genotyped in 100 healthy blood donors. Construct associated changes in XYLT1 promoter activity were detected for several sequence variants, whereas serum XT activity was only marginally affected. CONCLUSIONS Our findings describe for the first time the entire XYLT1 promoter sequence and provide new insights into transcriptional regulation of XT-I. Future studies should analyze the impact of regulatory XYLT1 promoter variations on XT-associated diseases.
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Affiliation(s)
- Isabel Faust
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Kai Oliver Böker
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Christoph Lichtenberg
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Joachim Kuhn
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Cornelius Knabbe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
| | - Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
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Bui C, Huber C, Tuysuz B, Alanay Y, Bole-Feysot C, Leroy JG, Mortier G, Nitschke P, Munnich A, Cormier-Daire V. XYLT1 mutations in Desbuquois dysplasia type 2. Am J Hum Genet 2014; 94:405-14. [PMID: 24581741 PMCID: PMC3951945 DOI: 10.1016/j.ajhg.2014.01.020] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 01/31/2014] [Indexed: 12/31/2022] Open
Abstract
Desbuquois dysplasia (DBQD) is a severe condition characterized by short stature, joint laxity, and advanced carpal ossification. Based on the presence of additional hand anomalies, we have previously distinguished DBQD type 1 and identified CANT1 (calcium activated nucleotidase 1) mutations as responsible for DBQD type 1. We report here the identification of five distinct homozygous xylosyltransferase 1 (XYLT1) mutations in seven DBQD type 2 subjects from six consanguineous families. Among the five mutations, four were expected to result in loss of function and a drastic reduction of XYLT1 cDNA level was demonstrated in two cultured individual fibroblasts. Because xylosyltransferase 1 (XT-I) catalyzes the very first step in proteoglycan (PG) biosynthesis, we further demonstrated in the two individual fibroblasts a significant reduction of cellular PG content. Our findings of XYLT1 mutations in DBQD type 2 further support a common physiological basis involving PG synthesis in the multiple dislocation group of disorders. This observation sheds light on the key role of the XT-I during the ossification process.
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Affiliation(s)
- Catherine Bui
- Department of Genetics, INSERM U781, Université Paris Descartes- Sorbonne Paris Cité, Institut Imagine, Hôpital Necker Enfants Malades (AP-HP), Paris 75015, France
| | - Céline Huber
- Department of Genetics, INSERM U781, Université Paris Descartes- Sorbonne Paris Cité, Institut Imagine, Hôpital Necker Enfants Malades (AP-HP), Paris 75015, France
| | - Beyhan Tuysuz
- Department of Pediatric Genetics, Cerrahpasa Medical Faculty, Istanbul University, Istanbul 34098, Turkey
| | - Yasemin Alanay
- Pediatric Genetics Unit, Department of Pediatrics, School of Medicine, Acibadem University, Istanbul 34457, Turkey
| | | | | | - Geert Mortier
- Department of Medical Genetics, Antwerp University Hospital and University of Antwerp, Edegem 2650, Belgium
| | - Patrick Nitschke
- Plateforme de Bioinformatique, Université Paris Descartes, Paris 75015, France
| | - Arnold Munnich
- Department of Genetics, INSERM U781, Université Paris Descartes- Sorbonne Paris Cité, Institut Imagine, Hôpital Necker Enfants Malades (AP-HP), Paris 75015, France
| | - Valérie Cormier-Daire
- Department of Genetics, INSERM U781, Université Paris Descartes- Sorbonne Paris Cité, Institut Imagine, Hôpital Necker Enfants Malades (AP-HP), Paris 75015, France.
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25
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Superina S, Borovina A, Ciruna B. Analysis of maternal-zygotic ugdh mutants reveals divergent roles for HSPGs in vertebrate embryogenesis and provides new insight into the initiation of left-right asymmetry. Dev Biol 2014; 387:154-66. [PMID: 24462977 DOI: 10.1016/j.ydbio.2014.01.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/20/2013] [Accepted: 01/14/2014] [Indexed: 11/25/2022]
Abstract
Growth factors and morphogens regulate embryonic patterning, cell fate specification, cell migration, and morphogenesis. The activity and behavior of these signaling molecules are regulated in the extracellular space through interactions with proteoglycans (Bernfield et al., 1999; Perrimon and Bernfield 2000; Lander and Selleck 2000; Selleck 2000). Proteoglycans are high molecular-weight proteins consisting of a core protein with covalently linked glycosaminoglycan (GAG) side chains, which are thought to mediate ligand interaction. Drosophila mutant embryos deficient for UDP-glucose dehydrogenase activity (Ugdh, required for GAG synthesis) exhibit abnormal Fgf, Wnt and TGFß signaling and die during gastrulation, indicating a broad and critical role for proteoglycans during early embryonic development (Lin et al., 1999; Lin and Perrimon 2000) (Hacker et al., 1997). Mouse Ugdh mutants also die at gastrulation, however, only Fgf signaling appears disrupted (Garcia-Garcia and Anderson, 2003). These findings suggested a possible divergence in the requirement for proteoglycans during Drosophila and mouse embryogenesis, and that mammals may have evolved alternative means of regulating Wnt and TGFß activity. To further examine the function of proteoglycans in vertebrate development, we have characterized zebrafish mutants devoid of both maternal and zygotic Ugdh/Jekyll activity (MZjekyll). We demonstrate that MZjekyll mutant embryos display abnormal Fgf, Shh, and Wnt signaling activities, with concomitant defects in central nervous system patterning, cardiac ventricular fate specification and axial morphogenesis. Furthermore, we uncover a novel role for proteoglycans in left-right pattern formation. Our findings resolve longstanding questions into the evolutionary conservation of Ugdh function and provide new mechanistic insights into the initiation of left-right asymmetry.
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Affiliation(s)
- Simone Superina
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, Toronto, Ont., Canada M5G 1X8; Department of Molecular Genetics, The University of Toronto, Toronto, Ont., Canada M5S 1A8
| | - Antonia Borovina
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, Toronto, Ont., Canada M5G 1X8; Department of Molecular Genetics, The University of Toronto, Toronto, Ont., Canada M5S 1A8
| | - Brian Ciruna
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, Toronto, Ont., Canada M5G 1X8; Department of Molecular Genetics, The University of Toronto, Toronto, Ont., Canada M5S 1A8.
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26
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Schreml J, Durmaz B, Cogulu O, Keupp K, Beleggia F, Pohl E, Milz E, Coker M, Ucar SK, Nürnberg G, Nürnberg P, Kuhn J, Ozkinay F. The missing "link": an autosomal recessive short stature syndrome caused by a hypofunctional XYLT1 mutation. Hum Genet 2014; 133:29-39. [PMID: 23982343 DOI: 10.1007/s00439-013-1351-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 08/10/2013] [Indexed: 12/31/2022]
Abstract
Proteoglycan (PG) synthesis begins with the sequential addition of a "linker chain", made up of four sugar residues, to a specific region of a core protein. Defects in the enzymes catalyzing steps two to four of the linker chain synthesis have been shown to cause autosomal recessive human phenotypes while no mutation has yet been reported in humans for the xylosyltransferases 1 and 2 (XT1 and XT2), the initiating enzymes in the linker chain formation. Here, we present a consanguineous Turkish family with two affected individuals presenting with short stature, distinct facial features, alterations of fat distribution, and moderate intellectual disability. X-rays showed only mild skeletal changes in the form of a short femoral neck, stocky and plump long bones and thickened ribs. Using a combination of whole-exome sequencing (WES), determination of homozygous stretches by WES variants, and classical linkage analysis, we identified the homozygous missense mutation c.C1441T in XYLT1, encoding XT1, within a large homozygous stretch on chromosome 16p13.12-p12.1. The mutation co-segregated with the phenotype in the family, is not found in over 13,000 alleles in the exome variant server and is predicted to change a highly conserved arginine at position 481 (p.R481W) located in the putative catalytical domain. Immunostaining of primary patient fibroblasts showed a loss of predominance of Golgi localization in mutant cells. Moreover, western blot analysis of decorin in cell culture supernatant demonstrated glycosylation differences between patient and control cells. Our data provide evidence that functional alterations of XT1 cause an autosomal recessive short stature syndrome associated with intellectual disability.
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Affiliation(s)
- Julia Schreml
- Institute of Human Genetics, University of Cologne, Cologne, Germany,
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27
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Mis EK, Liem KF, Kong Y, Schwartz NB, Domowicz M, Weatherbee SD. Forward genetics defines Xylt1 as a key, conserved regulator of early chondrocyte maturation and skeletal length. Dev Biol 2014; 385:67-82. [PMID: 24161523 PMCID: PMC3895954 DOI: 10.1016/j.ydbio.2013.10.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/11/2013] [Accepted: 10/14/2013] [Indexed: 12/12/2022]
Abstract
The long bones of the vertebrate body are built by the initial formation of a cartilage template that is later replaced by mineralized bone. The proliferation and maturation of the skeletal precursor cells (chondrocytes) within the cartilage template and their replacement by bone is a highly coordinated process which, if misregulated, can lead to a number of defects including dwarfism and other skeletal deformities. This is exemplified by the fact that abnormal bone development is one of the most common types of human birth defects. Yet, many of the factors that initiate and regulate chondrocyte maturation are not known. We identified a recessive dwarf mouse mutant (pug) from an N-ethyl-N-nitrosourea (ENU) mutagenesis screen. pug mutant skeletal elements are patterned normally during development, but display a ~20% length reduction compared to wild-type embryos. We show that the pug mutation does not lead to changes in chondrocyte proliferation but instead promotes premature maturation and early ossification, which ultimately leads to disproportionate dwarfism. Using sequence capture and high-throughput sequencing, we identified a missense mutation in the Xylosyltransferase 1 (Xylt1) gene in pug mutants. Xylosyltransferases catalyze the initial step in glycosaminoglycan (GAG) chain addition to proteoglycan core proteins, and these modifications are essential for normal proteoglycan function. We show that the pug mutation disrupts Xylt1 activity and subcellular localization, leading to a reduction in GAG chains in pug mutants. The pug mutant serves as a novel model for mammalian dwarfism and identifies a key role for proteoglycan modification in the initiation of chondrocyte maturation.
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Affiliation(s)
- Emily K. Mis
- Department of Genetics, Yale University, New Haven, CT 06520
| | - Karel F. Liem
- Department of Pediatrics, Yale University, New Haven, CT 06520
| | - Yong Kong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520
- W.M. Keck Foundation Biotechnology Resource Laboratory, Yale University, New Haven, CT 06520
| | | | - Miriam Domowicz
- Department of Pediatrics, University of Chicago, Chicago, IL 60637
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28
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Spahr C, Kim JJ, Deng S, Kodama P, Xia Z, Tang J, Zhang R, Siu S, Nuanmanee N, Estes B, Stevens J, Zhou M, Lu HS. Recombinant human lecithin-cholesterol acyltransferase Fc fusion: analysis of N- and O-linked glycans and identification and elimination of a xylose-based O-linked tetrasaccharide core in the linker region. Protein Sci 2013; 22:1739-53. [PMID: 24115046 PMCID: PMC3843628 DOI: 10.1002/pro.2373] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 09/05/2013] [Accepted: 09/06/2013] [Indexed: 11/06/2022]
Abstract
Recombinant human lecithin-cholesterol acyltransferase Fc fusion (huLCAT-Fc) is a chimeric protein produced by fusing human Fc to the C-terminus of the human enzyme via a linker sequence. The huLCAT-Fc homodimer contains five N-linked glycosylation sites per monomer. The heterogeneity and site-specific distribution of the various glycans were examined using enzymatic digestion and LC-MS/MS, followed by automatic processing. Almost all of the N-linked glycans in human LCAT are fucosylated and sialylated. The predominant LCAT N-linked glycoforms are biantennary glycans, followed by triantennary sugars, whereas the level of tetraantennary glycans is much lower. Glycans at the Fc N-linked site exclusively contain typical asialobiantennary structures. HuLCAT-Fc was also confirmed to have mucin-type glycans attached at T407 and S409 . When LCAT-Fc fusions were constructed using a G-S-G-G-G-G linker, an unexpected +632 Da xylose-based glycosaminoglycan (GAG) tetrasaccharide core of Xyl-Gal-Gal-GlcA was attached to S418 . Several minor intermediate species including Xyl, Xyl-Gal, Xyl-Gal-Gal, and a phosphorylated GAG core were also present. The mucin-type O-linked glycans can be effectively released by sialidase and O-glycanase; however, the GAG could only be removed and localized using chemical alkaline β-elimination and targeted LC-MS/MS. E416 (the C-terminus of LCAT) combined with the linker sequence is likely serving as a substrate for peptide O-xylosyltransferase. HuLCAT-Fc shares some homology with the proposed consensus site near the linker sequence, in particular, the residues underlined PPPE416 GS418 GGGGDK. GAG incorporation can be eliminated through engineering by shifting the linker Ser residue downstream in the linker sequence.
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Affiliation(s)
- Chris Spahr
- Biologics Optimization, Therapeutic Discovery, Amgen Inc.Thousand Oaks, California, 91320
| | - Justin J Kim
- Drug Substance Development, Amgen Inc.Seattle, Washington, 98119
| | - Sihong Deng
- Drug Substance Development, Amgen Inc.Seattle, Washington, 98119
| | - Paul Kodama
- Drug Substance Development, Amgen Inc.Seattle, Washington, 98119
| | - Zhen Xia
- Protein Technologies, Therapeutic Discovery, Amgen Inc.South San Francisco, California, 94080
| | - Jay Tang
- Protein Technologies, Therapeutic Discovery, Amgen Inc.South San Francisco, California, 94080
| | - Richard Zhang
- Protein Technologies, Therapeutic Discovery, Amgen Inc.South San Francisco, California, 94080
| | - Sophia Siu
- Biologics Optimization, Therapeutic Discovery, Amgen Inc.Seattle, Washington, 98119
| | - Noi Nuanmanee
- Biologics Optimization, Therapeutic Discovery, Amgen Inc.Thousand Oaks, California, 91320
| | - Bram Estes
- Biologics Optimization, Therapeutic Discovery, Amgen Inc.Thousand Oaks, California, 91320
| | - Jennitte Stevens
- Biologics Optimization, Therapeutic Discovery, Amgen Inc.Thousand Oaks, California, 91320
| | - Mingyue Zhou
- Metabolic Disorders, Amgen Inc.South San Francisco, California, 94080
| | - Hsieng S Lu
- Biologics Optimization, Therapeutic Discovery, Amgen Inc.Thousand Oaks, California, 91320
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29
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Spencer D, Novarra S, Zhu L, Mugabe S, Thisted T, Baca M, Depaz R, Barton C. O-xylosylation in a Recombinant Protein is Directed at a Common Motif on Glycine–Serine Linkers. J Pharm Sci 2013; 102:3920-4. [DOI: 10.1002/jps.23733] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 08/30/2013] [Accepted: 09/03/2013] [Indexed: 11/10/2022]
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30
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Faust I, Roch C, Kuhn J, Prante C, Knabbe C, Hendig D. Human xylosyltransferase-I - a new marker for myofibroblast differentiation in skin fibrosis. Biochem Biophys Res Commun 2013; 436:449-54. [PMID: 23747722 DOI: 10.1016/j.bbrc.2013.05.125] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 05/29/2013] [Indexed: 01/09/2023]
Abstract
Skin fibrosis is a severe type of fibrotic disorder emerging in terms of hypertrophic scars or systemic sclerosis. Key event of fibrogenesis is the transition of fibroblasts to matrix-producing myofibroblasts. In the presence of fibrotic triggers, for instance secretion of profibrotic growth factors like transforming growth factor-β1 (TGF-β1) or mechanical strain, myofibroblasts persist. Current research focuses on discovering innovative myofibroblast biomarkers which are regulated in fibrotic development and accessible for antifibrotic inhibition. Here, we consider the suitability of xylosyltransferase-I (XT-I) as a myofibroblast biomarker in skin fibrosis. XT-I catalyzes the initial step of glycosaminoglycan biosynthesis. Its increase in enzymatic activity is known to refer only to manifested diseases which are characterized by an abnormal rate of proteoglycan biosynthesis. In this study, treatment of normal human dermal fibroblasts (NHDF) with TGF-β1 was followed by increased relative XYLT1 mRNA expression. Remarkably, this upregulation was strongly dependent on myofibroblast content, increasing during fibrogenesis. Moreover, XT activity increased time-dependently in response to progressive myofibroblast transformation. XYLT1 expression was inhibited by TGF-β receptor I (ALK5) inhibitor SB431542. In contrast, XYLT2 expression was only marginally affected by TGF-β1 as well as ALK5 inhibition. Our results strengthen the significance of XT expression and activity in fibrotic remodeling. Therefore, we propose XT activity, in addition to α-SMA expression, as a new biomarker for myofibroblast differentiation and fibrotic development. Further studies are now needed to evaluate the option to control and inhibit fibrotic remodeling by interfering with XT expression.
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Affiliation(s)
- I Faust
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
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31
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Wen D, Foley SF, Hronowski XL, Gu S, Meier W. Discovery and Investigation of O-Xylosylation in Engineered Proteins Containing a (GGGGS)n Linker. Anal Chem 2013; 85:4805-12. [DOI: 10.1021/ac400596g] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Dingyi Wen
- Analytical Biochemistry, Department
of Biologics Drug
Discovery, Biogen Idec, 12 Cambridge Center,
Cambridge, Massachusetts 02142, United States
| | - Susan F. Foley
- Analytical Biochemistry, Department
of Biologics Drug
Discovery, Biogen Idec, 12 Cambridge Center,
Cambridge, Massachusetts 02142, United States
| | - Xiaoping L. Hronowski
- Analytical Biochemistry, Department
of Biologics Drug
Discovery, Biogen Idec, 12 Cambridge Center,
Cambridge, Massachusetts 02142, United States
| | - Sheng Gu
- Analytical Biochemistry, Department
of Biologics Drug
Discovery, Biogen Idec, 12 Cambridge Center,
Cambridge, Massachusetts 02142, United States
| | - Werner Meier
- Analytical Biochemistry, Department
of Biologics Drug
Discovery, Biogen Idec, 12 Cambridge Center,
Cambridge, Massachusetts 02142, United States
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32
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Müller B, Prante C, Knabbe C, Kleesiek K, Götting C. First identification and functional analysis of the human xylosyltransferase II promoter. Glycoconj J 2013; 30:237-45. [PMID: 22886070 DOI: 10.1007/s10719-012-9439-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 07/25/2012] [Accepted: 07/27/2012] [Indexed: 12/26/2022]
Abstract
Recently, we demonstrated that the human xylosyltransferase II (XT-II) has enzymatic activity and is able to catalyze the initial and rate-limiting step in the biosynthesis of glycosaminoglycans (GAGs) like chondroitin and dermatan sulfate, as well as heparan sulfate and heparin. Therefore, this enzyme also very likely assumes a crucial regulatory role in the biosynthesis of proteoglycans (PGs). In this study, we identified and characterized for the first time the XYLT2 gene promoter region and transcription factors involved in its regulation. Several binding sites for members of the Sp1 family of transcription factors were identified as being necessary for transcriptional regulation of the XYLT2 gene. This was determined by mithramycin A treatment, electrophoretic mobility shift and supershift assays, as well as numerous site-directed mutagenesis experiments. Different 5' and 3' deletion constructs of the predicted GC rich promoter region, which lacks a canonical TATA and CAAT box, revealed that a 177 nts proximal promoter element is sufficient and indispensable to drive the constitutive transcription in full strength in HepG2 hepatoma cells. In addition, we also detected the transcriptional start site using 5'-RACE (rapid amplification of cDNA ends). Our results provide an insight into transcriptional regulation of the XYLT2 gene and may contribute to understanding the manifold GAG-involving processes in health and disease.
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Affiliation(s)
- Benjamin Müller
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum NRW, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
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33
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Frankenberger C, Borgia JA, Edirisinghe PD, Oegema TR. Incomplete elongation of the chondroitin sulfate linkage region on aggrecan and response to interleukin-1β. Connect Tissue Res 2013; 54:123-31. [PMID: 23237500 DOI: 10.3109/03008207.2012.756871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Aggrecan is the prominent proteoglycan in cartilage and is modified with approximately 100 chondroitin sulfate (CS) chains through a tetrasaccharide linkage structure. In osteoarthritis (OA), the viscoelastic properties of cartilage are compromised on both the quantity and integrity of aggrecan core protein expressed as well as reduced overall CS chain length. Herein, we postulated that chronic low-level inflammation may also contribute to OA progression by promoting regulatory mechanisms in early CS biosynthesis that yield incomplete linkage structures on aggrecan. To test this idea, chondrocytes extracted from human tali were cultured in alginate beads and challenged with 5 ng/mL IL-1β as a model for chronic inflammation leading to OA progression. Novel mass spectrometry-based methods were devised to detect and quantify partially elongated linkage structures relative to control cultures. The total mole fraction of unelongated xylose residues per aggrecan was significantly less (p = 0.03) after IL-1β treatment compared to control cultures, with unelongated xylose residues constituting between 6% and 12% of the fraction of total CS measured. A portion (<1%) of the partially elongated linkage structures was found to be either phosphorylated or sulfated. These results establish quantitative mass spectrometry as a very sensitive and effective platform for evaluating truncated proteoglycan linkage structures. Our observations using this method suggest a possible role for aberrant linkage structure elongation in OA progression.
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Affiliation(s)
- Casey Frankenberger
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612-3823, USA
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34
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Abstract
Protein glycosylation is a ubiquitous post-translational modification found in all domains of life. Despite their significant complexity in animal systems, glycan structures have crucial biological and physiological roles, from contributions in protein folding and quality control to involvement in a large number of biological recognition events. As a result, they impart an additional level of 'information content' to underlying polypeptide structures. Improvements in analytical methodologies for dissecting glycan structural diversity, along with recent developments in biochemical and genetic approaches for studying glycan biosynthesis and catabolism, have provided a greater understanding of the biological contributions of these complex structures in vertebrates.
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35
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Abstract
Glycosylation is a very common modification of protein and lipid, and most glycosylation reactions occur in the Golgi. Although the transfer of initial sugar(s) to glycoproteins or glycolipids occurs in the ER or on the ER membrane, the subsequent addition of the many different sugars that make up a mature glycan is accomplished in the Golgi. Golgi membranes are studded with glycosyltransferases, glycosidases, and nucleotide sugar transporters arrayed in a generally ordered manner from the cis-Golgi to the trans-Golgi network (TGN), such that each activity is able to act on specific substrate(s) generated earlier in the pathway. The spectrum of glycosyltransferases and other activities that effect glycosylation may vary with cell type, and thus the final complement of glycans on glycoconjugates is variable. In addition, glycan synthesis is affected by Golgi pH, the integrity of Golgi peripheral membrane proteins, growth factor signaling, Golgi membrane dynamics, and cellular stress. Knowledge of Golgi glycosylation has fostered the development of assays to identify mechanisms of intracellular vesicular trafficking and facilitated glycosylation engineering of recombinant glycoproteins.
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Affiliation(s)
- Pamela Stanley
- Department of Cell Biology, Albert Einstein College of Medicine, New York, New York 10461, USA.
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36
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Yamakoshi Y, Nagano T, Hu JC, Yamakoshi F, Simmer JP. Porcine dentin sialoprotein glycosylation and glycosaminoglycan attachments. BMC BIOCHEMISTRY 2011; 12:6. [PMID: 21291557 PMCID: PMC3039539 DOI: 10.1186/1471-2091-12-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 02/03/2011] [Indexed: 01/04/2023]
Abstract
Background Dentin sialophosphoprotein (Dspp) is a multidomain, secreted protein that is critical for the formation of tooth dentin. Mutations in DSPP cause inherited dentin defects categorized as dentin dysplasia type II and dentinogenesis imperfecta type II and type III. Dentin sialoprotein (Dsp), the N-terminal domain of dentin sialophosphoprotein (Dspp), is a highly glycosylated proteoglycan, but little is known about the number, character, and attachment sites of its carbohydrate moieties. Results To identify its carbohydrate attachment sites we isolated Dsp from developing porcine molars and digested it with endoproteinase Glu-C or pronase, fractionated the digestion products, identified fractions containing glycosylated peptides using a phenol sulfuric acid assay, and characterized the glycopeptides by N-terminal sequencing, amino acid analyses, or LC/MSMS. To determine the average number of sialic acid attachments per N-glycosylation, we digested Dsp with glycopeptidase A, labeled the released N-glycosylations with 2-aminobenzoic acid, and quantified the moles of released glycosylations by comparison to labeled standards of known concentration. Sialic acid was released by sialidase digestion and quantified by measuring β-NADH reduction of pyruvic acid, which was generated stoichiometrically from sialic acid by aldolase. To determine its forms, sialic acid released by sialidase digestion was labeled with 1,2-diamino-4,5-methyleneoxybenzene (DMB) and compared to a DMB-labeled sialic acid reference panel by RP-HPLC. To determine the composition of Dsp glycosaminoglycan (GAG) attachments, we digested Dsp with chondroitinase ABC and compared the chromotagraphic profiles of the released disaccharides to commercial standards. N-glycosylations were identified at Asn37, Asn77, Asn136, Asn155, Asn161, and Asn176. Dsp averages one sialic acid per N-glycosylation, which is always in the form of N-acetylneuraminic acid. O-glycosylations were tentatively assigned at Thr200, Thr216 and Thr316. Porcine Dsp GAG attachments were found at Ser238 and Ser250 and were comprised of chondroitin 6-sulfate and chondroitin 4-sulfate in a ratio of 7 to 3, respectively. Conclusions The distribution of porcine Dsp posttranslational modifications indicate that porcine Dsp has an N-terminal domain with at least six N-glycosylations and a C-terminal domain with two GAG attachments and at least two O-glycosylations.
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Affiliation(s)
- Yasuo Yamakoshi
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Place, Ann Arbor, MI 48108, USA
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37
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Kramer KL. Specific sides to multifaceted glycosaminoglycans are observed in embryonic development. Semin Cell Dev Biol 2010; 21:631-7. [PMID: 20599516 PMCID: PMC2923045 DOI: 10.1016/j.semcdb.2010.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 06/21/2010] [Accepted: 06/24/2010] [Indexed: 11/19/2022]
Abstract
Ubiquitously found in the extracellular matrix and attached to the surface of most cells, glycosaminoglycans (GAGs) mediate many intercellular interactions. Originally described in 1889 as the primary carbohydrate in cartilage and then in 1916 as a coagulation inhibitor from liver, various GAGs have since been identified as key regulators of normal physiology. GAGs are critical mediators of differentiation, migration, tissue morphogenesis, and organogenesis during embryonic development. While GAGs are simple polysaccharide chains, many GAGs acquire a considerable degree of complexity by extensive modifications involving sulfation and epimerization. Embryos that lack specific GAG modifying enzymes have distinct developmental defects, illuminating the importance of GAG complexity. Revealing how these complex molecules specifically function in the embryo has often required additional approaches, the results of which suggest that GAG modifications might instructively mediate embryonic development.
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Affiliation(s)
- Kenneth L Kramer
- Genetics and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1583, USA.
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