1
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Wardman JF, Withers SG. Carbohydrate-active enzyme (CAZyme) discovery and engineering via (Ultra)high-throughput screening. RSC Chem Biol 2024; 5:595-616. [PMID: 38966674 PMCID: PMC11221537 DOI: 10.1039/d4cb00024b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 05/16/2024] [Indexed: 07/06/2024] Open
Abstract
Carbohydrate-active enzymes (CAZymes) constitute a diverse set of enzymes that catalyze the assembly, degradation, and modification of carbohydrates. These enzymes have been fashioned into potent, selective catalysts by millennia of evolution, and yet are also highly adaptable and readily evolved in the laboratory. To identify and engineer CAZymes for different purposes, (ultra)high-throughput screening campaigns have been frequently utilized with great success. This review provides an overview of the different approaches taken in screening for CAZymes and how mechanistic understandings of CAZymes can enable new approaches to screening. Within, we also cover how cutting-edge techniques such as microfluidics, advances in computational approaches and synthetic biology, as well as novel assay designs are leading the field towards more informative and effective screening approaches.
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Affiliation(s)
- Jacob F Wardman
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver BC V6T 1Z3 Canada
- Michael Smith Laboratories, University of British Columbia Vancouver BC V6T 1Z4 Canada
| | - Stephen G Withers
- Department of Biochemistry and Molecular Biology, University of British Columbia Vancouver BC V6T 1Z3 Canada
- Michael Smith Laboratories, University of British Columbia Vancouver BC V6T 1Z4 Canada
- Department of Chemistry, University of British Columbia Vancouver BC V6T 1Z1 Canada
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2
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Mazuca LG, Mohl JE. ISOGlyP: O-Glycosylation Site Prediction Using Peptide Sequences and GALNTs. Methods Mol Biol 2024; 2763:237-247. [PMID: 38347415 DOI: 10.1007/978-1-0716-3670-1_20] [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] [Indexed: 02/15/2024]
Abstract
Mucin-type O-glycosylation is one of the most common posttranslational modifications of proteins. The abnormal expression of various polypeptide GalNAc-transferases (GALNTs) which initiate and define sites of O-glycosylation is linked to many cancers and other diseases. Many current O-glycosylation prediction programs utilize O-glycoproteomics data obtained without using the transferase isoform(s) responsible for the glycosylation. With 20 different GALNTs in humans, having the ability to predict and interpret O-glycosylation sites in terms of specific GALNT isoforms is invaluable.To fill this gap, ISOGlyP (isoform-specific O-glycosylation prediction) has been developed. Using position-specific enhancement values generated based on GalNAc-T isoform-specific amino acid preferences, ISOGlyP predicts the propensity that a site would be glycosylated by a specific transferase. ISOGlyP gave an overall prediction accuracy of 70% against in vivo data, which is comparable to that of the NetOGlyc4.0 predictor. Additionally, ISOGlyP can identify the known effects of long- and short-range prior glycosylation and can generate potential peptide sequences selectively glycosylated by specific isoforms. ISOGlyP is freely available for use at https://ISOGlyP.utep.edu . The code is also available on GitHub ( https://github.com/jonmohl/ISOGlyP ).
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3
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Berkel C, Cacan E. The expression of O-linked glycosyltransferase GALNT7 in breast cancer is dependent on estrogen-, progesterone-, and HER2-receptor status, with prognostic implications. Glycoconj J 2023; 40:631-644. [PMID: 37947928 DOI: 10.1007/s10719-023-10137-4] [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: 04/04/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023]
Abstract
GALNT7 is a glycosyltransferase enzyme transferring N-acetylgalactosamine to initiate O-linked glycosylation in the Golgi apparatus. Breast cancer is the most common cancer in women globally. Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2; ERBB2) are important biomarkers in the prognosis and molecular subtyping of breast cancer. Here, we showed that ER-positive, PR-positive or HER2-positive breast tumors have higher expression of GALNT7 compared to ER-negative, PR-negative or HER2-negative breast tumors, respectively. We found that CpG-aggregated methylation of GALNT7 gene is decreased, and in parallel, its transcript levels are increased in breast cancer compared to healthy breast tissue. We observed that the difference in the expression of GALNT7 between negative and positive status of the receptors is the highest for HER2, followed by ER and PR, pointing that HER2 might be relatively more influential than ER and PR on the expression of GALNT7 in breast cancer. We reported that basal-like breast tumors have decreased expression of GALNT7 compared to non-basal-like tumors, and that high GALNT7 expression is associated with favorable relapse-free and distant metastasis-free survival in HER2 status-dependent manner in breast cancer patients. Moreover, we showed that GALNT7 expression in breast cancer is cell type- (epithelial vs stromal cells), tumor grade- and ethnicity-dependent. Combined, we propose that GALNT7 might contribute to different clinical outcomes depending on the receptor status in breast cancer, and that a better understanding of GALNT7 and its function in the context of breast cancer is needed.
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Affiliation(s)
- Caglar Berkel
- Department of Molecular Biology and Genetics, Tokat Gaziosmanpasa University, Tokat, Turkey.
| | - Ercan Cacan
- Department of Molecular Biology and Genetics, Tokat Gaziosmanpasa University, Tokat, Turkey
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4
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Ballard CJ, Paserba MR, Paul Daniel EJ, Hurtado-Guerrero R, Gerken TA. Polypeptide N-acetylgalactosaminyltransferase (GalNAc-T) isozyme surface charge governs charge substrate preferences to modulate mucin type O-glycosylation. Glycobiology 2023; 33:817-836. [PMID: 37555669 PMCID: PMC10629720 DOI: 10.1093/glycob/cwad066] [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: 05/31/2023] [Revised: 07/21/2023] [Accepted: 08/03/2023] [Indexed: 08/10/2023] Open
Abstract
A large family of polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) initiate mucin type O-glycosylation transferring α-GalNAc from a UDP-GalNAc donor to the hydroxyl groups of Ser and Thr residues of peptides and proteins, thereby defining sites of O-glycosylation. Mutations and differential expression of several GalNAc-Ts are associated with many disease states including cancers. The mechanisms by which these isozymes choose their targets and their roles in disease are not fully understood. We previously showed that the GalNAc-Ts possess common and unique specificities for acceptor type, peptide sequence and prior neighboring, and/or remote substrate GalNAc glycosylation. In the present study, the role of flanking charged residues was investigated using a library of charged peptide substrates containing the central -YAVTPGP- acceptor sequence. Eleven human and one bird GalNAc-T were initially characterized revealing a range of preferences for net positive, net negative, or unique combinations of flanking N- and/or C-terminal charge, correlating to each isozyme's different electrostatic surface potential. It was further found that isoforms with high sequence identity (>70%) within a subfamily can possess vastly different charge specificities. Enzyme kinetics, activities obtained at elevated ionic strength, and molecular dynamics simulations confirm that the GalNAc-Ts differently recognize substrate charge outside the common +/-3 residue binding site. These electrostatic interactions impact how charged peptide substrates bind/orient on the transferase surface, thus modulating their activities. In summary, we show the GalNAc-Ts utilize more extended surfaces than initially thought for binding substrates based on electrostatic, and likely other hydrophobic/hydrophilic interactions, furthering our understanding of how these transferases select their target.
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Affiliation(s)
- Collin J Ballard
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Miya R Paserba
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | - Ramón Hurtado-Guerrero
- Department of Biomedical Engineering, The Institute for Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza 50018, Spain
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark
- Fundación ARAID, Zaragoza 50018, Spain
| | - Thomas A Gerken
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
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5
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Dang X, Liu J, Zhang Z, Luo XJ. Mendelian Randomization Study Using Dopaminergic Neuron-Specific eQTL Identifies Novel Risk Genes for Schizophrenia. Mol Neurobiol 2023; 60:1537-1546. [PMID: 36517655 DOI: 10.1007/s12035-022-03160-3] [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: 06/06/2022] [Accepted: 12/04/2022] [Indexed: 12/23/2022]
Abstract
Multiple integrative studies have been performed to identify the potential target genes of the non-coding schizophrenia (SCZ) risk variants. However, all the integrative studies used expression quantitative trait loci (eQTL) data from bulk tissues. Considering the cell type-specific regulatory effect of many genetic variants, it is important to conduct integrative studies using cell type-specific eQTL data. Here, we conduct a Mendelian randomization (MR) study by integrating genome-wide associations of SCZ (74,776 cases and 101,023 controls) and eQTL data (N = 215) from dopaminergic neurons, which were differentiated from human-induced pluripotent stem cell (iPSC) lines. For eQTL from young post-mitotic dopaminergic neurons (differentiation of iPSC for 30 days, D30), we identified 34 genes whose genetically regulated expression in dopaminergic neurons may have a causal role in SCZ. Among which, ARL3 showed the most significant associations with SCZ. For eQTL from more mature dopaminergic neurons (D52), we identified 37 potential SCZ causal genes, and ARL3 and GNL3 showed the most significant associations. Only 12 genes showed significant associations with SCZ in both D30 and D52 eQTL datasets, indicating the time point-specific genetic regulatory effects in young post-mitotic dopaminergic neurons and more mature dopaminergic neurons. Comparing the results from dopaminergic neurons with bulk brain tissues prioritized 2 high-confidence risk genes, including DDHD2 and GALNT10. Our study identifies multiple risk genes whose genetically regulated expression in dopaminergic neurons may have a causal role in SCZ. Further mechanistic investigation will provide pivotal insights into SCZ pathophysiology.
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Affiliation(s)
- Xinglun Dang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, Yunnan, China
| | - Jiewei Liu
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, Yunnan, China
| | - Zhijun Zhang
- Zhongda Hospital, Advanced Institute for Life and Health, Southeast University, Nanjing, 210096, China
- Department of Neurology, School of Medicine, Affiliated Zhongda Hospital, Research Institution of Neuropsychiatry, Southeast University, Nanjing, 210009, Jiangsu Province, China
| | - Xiong-Jian Luo
- Zhongda Hospital, Advanced Institute for Life and Health, Southeast University, Nanjing, 210096, China.
- Department of Neurology, School of Medicine, Affiliated Zhongda Hospital, Research Institution of Neuropsychiatry, Southeast University, Nanjing, 210009, Jiangsu Province, China.
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6
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Barchi JJ, Strain CN. The effect of a methyl group on structure and function: Serine vs. threonine glycosylation and phosphorylation. Front Mol Biosci 2023; 10:1117850. [PMID: 36845552 PMCID: PMC9950641 DOI: 10.3389/fmolb.2023.1117850] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/30/2023] [Indexed: 02/12/2023] Open
Abstract
A variety of glycan structures cover the surface of all cells and are involved in myriad biological processes, including but not limited to, cell adhesion and communication, protein quality control, signal transduction and metabolism, while also being intimately involved in innate and adaptive immune functions. Immune surveillance and responses to foreign carbohydrate antigens, such as capsular polysaccharides on bacteria and surface protein glycosylation of viruses, are the basis of microbial clearance, and most antimicrobial vaccines target these structures. In addition, aberrant glycans on tumors called Tumor-Associated Carbohydrate Antigens (TACAs) elicit immune responses to cancer, and TACAs have been used in the design of many antitumor vaccine constructs. A majority of mammalian TACAs are derived from what are referred to as mucin-type O-linked glycans on cell-surface proteins and are linked to the protein backbone through the hydroxyl group of either serine or threonine residues. A small group of structural studies that have compared mono- and oligosaccharides attached to each of these residues have shown that there are distinct differences in conformational preferences assumed by glycans attached to either "unmethylated" serine or ß-methylated threonine. This suggests that the linkage point of antigenic glycans will affect their presentation to the immune system as well as to various carbohydrate binding molecules (e.g., lectins). This short review, followed by our hypothesis, will examine this possibility and extend the concept to the presentation of glycans on surfaces and in assay systems where recognition of glycans by proteins and other binding partners can be defined by different attachment points that allow for a range of conformational presentations.
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Affiliation(s)
| | - Caitlin N. Strain
- Center for Cancer Research, Chemical Biology Laboratory, National Cancer Institute at Frederick, Frederick, MD, United States
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7
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Mahajan SP, Srinivasan Y, Labonte JW, DeLisa MP, Gray JJ. Structural basis for peptide substrate specificities of glycosyltransferase GalNAc-T2. ACS Catal 2021; 11:2977-2991. [PMID: 34322281 DOI: 10.1021/acscatal.0c04609] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The polypeptide N-acetylgalactosaminyl transferase (GalNAc-T) enzyme family initiates O-linked mucin-type glycosylation. The family constitutes 20 isoenzymes in humans. GalNAc-Ts exhibit both redundancy and finely tuned specificity for a wide range of peptide substrates. In this work, we deciphered the sequence and structural motifs that determine the peptide substrate preferences for the GalNAc-T2 isoform. Our approach involved sampling and characterization of peptide-enzyme conformations obtained from Rosetta Monte Carlo-minimization-based flexible docking. We computationally scanned 19 amino acid residues at positions -1 and +1 of an eight-residue peptide substrate, which comprised a dataset of 361 (19x19) peptides with previously characterized experimental GalNAc-T2 glycosylation efficiencies. The calculations recapitulated experimental specificity data, successfully discriminating between glycosylatable and non-glycosylatable peptides with a probability of 96.5% (ROC-AUC score), a balanced accuracy of 85.5% and a false positive rate of 7.3%. The glycosylatable peptide substrates viz. peptides with proline, serine, threonine, and alanine at the -1 position of the peptide preferentially exhibited cognate sequon-like conformations. The preference for specific residues at the -1 position of the peptide was regulated by enzyme residues R362, K363, Q364, H365 and W331, which modulate the pocket size and specific enzyme-peptide interactions. For the +1 position of the peptide, enzyme residues K281 and K363 formed gating interactions with aromatics and glutamines at the +1 position of the peptide, leading to modes of peptide-binding sub-optimal for catalysis. Overall, our work revealed enzyme features that lead to the finely tuned specificity observed for a broad range of peptide substrates for the GalNAc-T2 enzyme. We anticipate that the key sequence and structural motifs can be extended to analyze specificities of other isoforms of the GalNAc-T family and can be used to guide design of variants with tailored specificity.
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Affiliation(s)
- Sai Pooja Mahajan
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Yashes Srinivasan
- Department of Bioengineering, University of California—Los Angeles, Los Angeles, California 90095, United States
| | - Jason W. Labonte
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Department of Chemistry, Franklin & Marshall College, Lancaster, Pennsylvania 17604, United States
| | - Matthew P. DeLisa
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Department of Microbiology, and Nancy E. and Peter C. Meinig School of Biomedical Engineering, Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York 14853, United States
| | - Jeffrey J. Gray
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland 21224, United States
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8
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Al Rifai O, Julien C, Lacombe J, Faubert D, Lira-Navarrete E, Narimatsu Y, Clausen H, Ferron M. The half-life of the bone-derived hormone osteocalcin is regulated through O-glycosylation in mice, but not in humans. eLife 2020; 9:61174. [PMID: 33284103 PMCID: PMC7822592 DOI: 10.7554/elife.61174] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/06/2020] [Indexed: 12/14/2022] Open
Abstract
Osteocalcin (OCN) is an osteoblast-derived hormone with pleiotropic physiological functions. Like many peptide hormones, OCN is subjected to post-translational modifications (PTMs) which control its activity. Here, we uncover O-glycosylation as a novel PTM present on mouse OCN and occurring on a single serine (S8) independently of its carboxylation and endoproteolysis, two other PTMs regulating this hormone. We also show that O-glycosylation increases OCN half-life in plasma ex vivo and in the circulation in vivo. Remarkably, in human OCN (hOCN), the residue corresponding to S8 is a tyrosine (Y12), which is not O-glycosylated. Yet, the Y12S mutation is sufficient to O-glycosylate hOCN and to increase its half-life in plasma compared to wildtype hOCN. These findings reveal an important species difference in OCN regulation, which may explain why serum concentrations of OCN are higher in mouse than in human. Bones provide support and protection for organs in the body. However, over the last 15 years researchers have discovered that bones also release chemicals known as hormones, which can travel to other parts of the body and cause an effect. The cells responsible for making bone, known as osteoblasts, produce a hormone called osteocalcin which communicates with a number of different organs, including the pancreas and brain. When osteocalcin reaches the pancreas, it promotes the release of another hormone called insulin which helps regulate the levels of sugar in the blood. Osteocalcin also travels to other organs such as muscle, where it helps to degrade fats and sugars that can be converted into energy. It also has beneficial effects on the brain, and has been shown to aid memory and reduce depression. Osteocalcin has largely been studied in mice where levels are five to ten times higher than in humans. But it is unclear why this difference exists or how it alters the role of osteocalcin in humans. To answer this question, Al Rifai et al. used a range of experimental techniques to compare the structure and activity of osteocalcin in mice and humans. The experiments showed that mouse osteocalcin has a group of sugars attached to its protein structure, which prevent the hormone from being degraded by an enzyme in the blood. Human osteocalcin has a slightly different protein sequence and is therefore unable to bind to this sugar group. As a result, the osteocalcin molecules in humans are less stable and cannot last as long in the blood. Al Rifai et al. showed that when human osteocalcin was modified so the sugar group could attach, the hormone was able to stick around for much longer and reach higher levels when added to blood in the laboratory. These findings show how osteocalcin differs between human and mice. Understanding this difference is important as the effects of osteocalcin mean this hormone can be used to treat diabetes and brain disorders. Furthermore, the results reveal how the stability of osteocalcin could be improved in humans, which could potentially enhance its therapeutic effect.
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Affiliation(s)
- Omar Al Rifai
- Molecular Physiology Research unit, Institut de Recherches Cliniques de Montréal, Montréal, Canada.,Programme de biologie moléculaire, Université de Montréal, Montréal, Canada
| | - Catherine Julien
- Molecular Physiology Research unit, Institut de Recherches Cliniques de Montréal, Montréal, Canada
| | - Julie Lacombe
- Molecular Physiology Research unit, Institut de Recherches Cliniques de Montréal, Montréal, Canada
| | - Denis Faubert
- Proteomics Discovery Platform, Institut de Recherches Cliniques de Montréal, Montréal, Canada
| | - Erandi Lira-Navarrete
- University of Copenhagen, Faculty of Health Sciences, Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine, Copenhagen, Denmark
| | - Yoshiki Narimatsu
- University of Copenhagen, Faculty of Health Sciences, Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine, Copenhagen, Denmark
| | - Henrik Clausen
- University of Copenhagen, Faculty of Health Sciences, Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine, Copenhagen, Denmark
| | - Mathieu Ferron
- Molecular Physiology Research unit, Institut de Recherches Cliniques de Montréal, Montréal, Canada.,Programme de biologie moléculaire, Université de Montréal, Montréal, Canada.,Département de Médecine, Université de Montréal, Montréal, Canada.,Division of Experimental Medicine, McGill University, Montréal, Canada
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9
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Akasaka-Manya K, Manya H. The Role of APP O-Glycosylation in Alzheimer's Disease. Biomolecules 2020; 10:biom10111569. [PMID: 33218200 PMCID: PMC7699271 DOI: 10.3390/biom10111569] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/16/2020] [Accepted: 11/16/2020] [Indexed: 12/13/2022] Open
Abstract
The number of people with dementia is increasing rapidly due to the increase in the aging population. Alzheimer’s disease (AD) is a type of neurodegenerative dementia caused by the accumulation of abnormal proteins. Genetic mutations, smoking, and several other factors have been reported as causes of AD, but alterations in glycans have recently been demonstrated to play a role in AD. Amyloid-β (Aβ), a cleaved fragment of APP, is the source of senile plaque, a pathological feature of AD. APP has been reported to undergo N- and O-glycosylation, and several Polypeptide N-acetylgalactosaminyltransferases (ppGalNAc-Ts) have been shown to have catalytic activity for the transfer of GalNAc to APP. Since O-glycosylation in the proximity of a cleavage site in many proteins has been reported to be involved in protein processing, O-glycans may affect the cleavage of APP during the Aβ production process. In this report, we describe new findings on the O-glycosylation of APP and Aβ production.
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10
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Mohl JE, Gerken TA, Leung MY. ISOGlyP: de novo prediction of isoform-specific mucin-type O-glycosylation. Glycobiology 2020; 31:168-172. [PMID: 32681163 DOI: 10.1093/glycob/cwaa067] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/09/2020] [Accepted: 07/12/2020] [Indexed: 02/07/2023] Open
Abstract
Mucin-type O-glycosylation is one of the most common posttranslational modifications of proteins. The abnormal expression of various polypeptide GalNAc-transferases (GalNAc-Ts) which initiate and define sites of O-glycosylation are linked to many cancers and other diseases. Current O-glycosyation prediction programs utilize O-glycoproteomics data obtained without regard to the transferase isoform (s) responsible for the glycosylation. With 20 different GalNAc-Ts in humans, having an ability to predict and interpret O-glycosylation sites in terms of specific GalNAc-T isoforms is invaluable. To fill this gap, ISOGlyP (Isoform-Specific O-Glycosylation Prediction) has been developed. Using position-specific enhancement values generated based on GalNAc-T isoform-specific amino acid preferences, ISOGlyP predicts the propensity that a site would be glycosylated by a specific transferase. ISOGlyP gave an overall prediction accuracy of 70% against in vivo data, which is comparable to that of the NetOGlyc4.0 predictor. Additionally, ISOGlyP can identify the known effects of long- and short-range prior glycosylation and can generate potential peptide sequences selectively glycosylated by specific isoforms. ISOGlyP is freely available for use at ISOGlyP.utep.edu. The code is also available on GitHub (https://github.com/jonmohl/ISOGlyP).
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Affiliation(s)
- Jonathon E Mohl
- Department of Mathematical Sciences and Border Biomedical Research Center, The University of Texas at El Paso, W University, El Paso, TX 79968, USA
| | - Thomas A Gerken
- Departments of Biochemistry and Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ming-Ying Leung
- Department of Mathematical Sciences and Border Biomedical Research Center, The University of Texas at El Paso, W University, El Paso, TX 79968, USA
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11
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Choi J, Wagner LJS, Timmermans SBPE, Malaker SA, Schumann B, Gray MA, Debets MF, Takashima M, Gehring J, Bertozzi CR. Engineering Orthogonal Polypeptide GalNAc-Transferase and UDP-Sugar Pairs. J Am Chem Soc 2019; 141:13442-13453. [PMID: 31373799 PMCID: PMC6813768 DOI: 10.1021/jacs.9b04695] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
O-Linked α-N-acetylgalactosamine (O-GalNAc) glycans constitute a major part of the human glycome. They are difficult to study because of the complex interplay of 20 distinct glycosyltransferase isoenzymes that initiate this form of glycosylation, the polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts). Despite proven disease relevance, correlating the activity of individual GalNAc-Ts with biological function remains challenging due to a lack of tools to probe their substrate specificity in a complex biological environment. Here, we develop a "bump-hole" chemical reporter system for studying GalNAc-T activity in vitro. Individual GalNAc-Ts were rationally engineered to contain an enlarged active site (hole) and probed with a newly synthesized collection of 20 (bumped) uridine diphosphate N-acetylgalactosamine (UDP-GalNAc) analogs to identify enzyme-substrate pairs that retain peptide specificities but are otherwise completely orthogonal to native enzyme-substrate pairs. The approach was applicable to multiple GalNAc-T isoenzymes, including GalNAc-T1 and -T2 that prefer nonglycosylated peptide substrates and GalNAcT-10 that prefers a preglycosylated peptide substrate. A detailed investigation of enzyme kinetics and specificities revealed the robustness of the approach to faithfully report on GalNAc-T activity and paves the way for studying substrate specificities in living systems.
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Affiliation(s)
- Junwon Choi
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Chemical Kinomics Research Center, Korea Institute of Science and Technology (KIST), 5 Hwarangro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Lauren J. S. Wagner
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Suzanne B. P. E. Timmermans
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Bio-Organic Chemistry Research Group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
| | - Stacy A. Malaker
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Benjamin Schumann
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Melissa A. Gray
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Marjoke F. Debets
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Megumi Takashima
- Department of Nutritional Sciences, University of California, Berkeley, California 94720, United States
| | - Jase Gehring
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
| | - Carolyn R. Bertozzi
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, United States
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12
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Stewart TJ, Takahashi K, Whitaker RH, Raska M, Placzek WJ, Novak J, Renfrow MB. IgA1 hinge-region clustered glycan fidelity is established early during semi-ordered glycosylation by GalNAc-T2. Glycobiology 2019; 29:543-556. [PMID: 30759204 PMCID: PMC6583770 DOI: 10.1093/glycob/cwz007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 01/13/2019] [Accepted: 02/04/2019] [Indexed: 01/03/2023] Open
Abstract
GalNAc-type O-glycans are often added to proteins post-translationally in a clustered manner in repeat regions of proteins, such as mucins and IgA1. Observed IgA1 glycosylation patterns show that glycans occur at similar sites with similar structures. It is not clear how the sites and number of glycans added to IgA1, or other proteins, can follow a conservative process. GalNAc-transferases initiate GalNAc-type glycosylation. In IgA nephropathy, an autoimmune disease, the sites and O-glycan structures of IgA1 hinge-region are altered, giving rise to a glycan autoantigen. To better understand how GalNAc-transferases determine sites and densities of clustered O-glycans, we used IgA1 hinge-region (HR) segment as a probe. Using LC-MS, we demonstrated a semi-ordered process of glycosylation by GalNAc-T2 towards the IgA1 HR. The catalytic domain was responsible for selection of four initial sites based on amino-acid sequence recognition. Both catalytic and lectin domains were involved in multiple second site-selections, each dependent on initial site-selection. Our data demonstrated that multiple start-sites and follow-up pathways were key to increasing the number of glycans added. The lectin domain predominately enhanced IgA1 HR glycan density by increasing synthesis pathway exploration by GalNAc-T2. Our data indicated a link between site-specific glycan addition and clustered glycan density that defines a mechanism of how conserved clustered O-glycosylation patterns and glycoform populations of IgA1 can be controlled by GalNAc-T2. Together, these findings characterized a correlation between glycosylation pathway diversity and glycosylation density, revealing mechanisms by which a single GalNAc-T isozyme can limit and define glycan heterogeneity in a disease-relevant context.
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Affiliation(s)
- Tyler J Stewart
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kazuo Takahashi
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Nephrology, Fujita Health University, Toyoake, Japan
| | - Robert H Whitaker
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Milan Raska
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Immunology, Palacky University and University Hospital, Olomouc, Czech Republic
| | - William J Placzek
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Matthew B Renfrow
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
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13
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Narimatsu Y, Joshi HJ, Schjoldager KT, Hintze J, Halim A, Steentoft C, Nason R, Mandel U, Bennett EP, Clausen H, Vakhrushev SY. Exploring Regulation of Protein O-Glycosylation in Isogenic Human HEK293 Cells by Differential O-Glycoproteomics. Mol Cell Proteomics 2019; 18:1396-1409. [PMID: 31040225 PMCID: PMC6601209 DOI: 10.1074/mcp.ra118.001121] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 03/26/2019] [Indexed: 02/04/2023] Open
Abstract
Most proteins trafficking the secretory pathway of metazoan cells will acquire GalNAc-type O-glycosylation. GalNAc-type O-glycosylation is differentially regulated in cells by the expression of a repertoire of up to twenty genes encoding polypeptide GalNAc-transferase isoforms (GalNAc-Ts) that initiate O-glycosylation. These GalNAc-Ts orchestrate the positions and patterns of O-glycans on proteins in coordinated, but poorly understood ways - guided partly by the kinetic properties and substrate specificities of their catalytic domains, as well as by modulatory effects of their unique GalNAc-binding lectin domains. Here, we provide the hereto most comprehensive characterization of nonredundant contributions of individual GalNAc-T isoforms to the O-glycoproteome of the human HEK293 cell using quantitative differential O-glycoproteomics on a panel of isogenic HEK293 cells with knockout of GalNAc-T genes (GALNT1, T2, T3, T7, T10, or T11). We confirm that a major part of the O-glycoproteome is covered by redundancy, whereas distinct O-glycosite subsets are covered by nonredundant GalNAc-T isoform-specific functions. We demonstrate that the GalNAc-T7 and T10 isoforms function in follow-up of high-density O-glycosylated regions, and that GalNAc-T11 has highly restricted functions and essentially only serves the low-density lipoprotein-related receptors in linker regions (C6XXXTC1) between the ligand-binding repeats.
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Affiliation(s)
- Yoshiki Narimatsu
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
| | - Hiren J Joshi
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Katrine T Schjoldager
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - John Hintze
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Adnan Halim
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Catharina Steentoft
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Rebecca Nason
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Ulla Mandel
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Eric P Bennett
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Henrik Clausen
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Sergey Y Vakhrushev
- From the ‡Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
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14
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de Las Rivas M, Lira-Navarrete E, Gerken TA, Hurtado-Guerrero R. Polypeptide GalNAc-Ts: from redundancy to specificity. Curr Opin Struct Biol 2019; 56:87-96. [PMID: 30703750 PMCID: PMC6656595 DOI: 10.1016/j.sbi.2018.12.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Revised: 12/12/2018] [Accepted: 12/19/2018] [Indexed: 12/11/2022]
Abstract
Mucin-type O-glycosylation is a post-translational modification (PTM) that is predicted to occur in more than the 80% of the proteins that pass through the Golgi apparatus. This PTM is initiated by a family of polypeptide GalNAc-transferases (GalNAc-Ts) that modify Ser and Thr residues of proteins through the addition of a GalNAc moiety. These enzymes are type II membrane proteins that consist of a Golgi luminal catalytic domain connected by a flexible linker to a ricin type lectin domain. Together, both domains account for the different glycosylation preferences observed among isoenzymes. Although it is well accepted that most of the family members share some degree of redundancy toward their protein and glycoprotein substrates, it has been recently found that several GalNAc-Ts also possess activity toward specific targets. Despite the high similarity between isoenzymes, structural differences have recently been reported that are key to understanding the molecular basis of both their redundancy and specificity. The present review focuses on the molecular aspects of the protein substrate recognition and the different glycosylation preferences of these enzymes, which in turn will serve as a roadmap to the rational design of specific modulators of mucin-type O-glycosylation.
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Affiliation(s)
- Matilde de Las Rivas
- BIFI, University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza, Spain
| | - Erandi Lira-Navarrete
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, School of Dentistry, University of Copenhagen, Copenhagen, Denmark
| | - Thomas A Gerken
- Departments of Biochemistry, Chemistry and Pediatrics Case Western Reserve University, Cleveland, OH, USA.
| | - Ramon Hurtado-Guerrero
- BIFI, University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza, Spain; Fundación ARAID, 50018, Zaragoza, Spain.
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15
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de las Rivas M, Paul Daniel EJ, Coelho H, Lira-Navarrete E, Raich L, Compañón I, Diniz A, Lagartera L, Jiménez-Barbero J, Clausen H, Rovira C, Marcelo F, Corzana F, Gerken TA, Hurtado-Guerrero R. Structural and Mechanistic Insights into the Catalytic-Domain-Mediated Short-Range Glycosylation Preferences of GalNAc-T4. ACS CENTRAL SCIENCE 2018; 4:1274-1290. [PMID: 30276263 PMCID: PMC6161044 DOI: 10.1021/acscentsci.8b00488] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 05/03/2023]
Abstract
Mucin-type O-glycosylation is initiated by a family of polypeptide GalNAc-transferases (GalNAc-Ts) which are type-II transmembrane proteins that contain Golgi luminal catalytic and lectin domains that are connected by a flexible linker. Several GalNAc-Ts, including GalNAc-T4, show both long-range and short-range prior glycosylation specificity, governed by their lectin and catalytic domains, respectively. While the mechanism of the lectin-domain-dependent glycosylation is well-known, the molecular basis for the catalytic-domain-dependent glycosylation of glycopeptides is unclear. Herein, we report the crystal structure of GalNAc-T4 bound to the diglycopeptide GAT*GAGAGAGT*TPGPG (containing two α-GalNAc glycosylated Thr (T*), the PXP motif and a "naked" Thr acceptor site) that describes its catalytic domain glycopeptide GalNAc binding site. Kinetic studies of wild-type and GalNAc binding site mutant enzymes show the lectin domain GalNAc binding activity dominates over the catalytic domain GalNAc binding activity and that these activities can be independently eliminated. Surprisingly, a flexible loop protruding from the lectin domain was found essential for the optimal activity of the catalytic domain. This work provides the first structural basis for the short-range glycosylation preferences of a GalNAc-T.
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Affiliation(s)
- Matilde de las Rivas
- BIFI, University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit,
Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza 50018, Spain
| | - Earnest James Paul Daniel
- Departments
of Biochemistry, Pediatrics and Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Helena Coelho
- UCIBIO,
REQUIMTE, Departamento de Química, Faculdade de Ciências
e Tecnologia, Universidade de Nova de Lisboa, Caparica 2825-149, Portugal
- CIC
bioGUNE, Bizkaia Technology
Park, Building 801A, 48170 Derio, Spain
- Departament
of Organic Chemistry II, Faculty of Science
& Technology, University of the Basque
Country, Leioa, 48940 Bizkaia, Spain
| | - Erandi Lira-Navarrete
- Copenhagen
Center for Glycomics, Department of Cellular and Molecular Medicine,
School of Dentistry, University of Copenhagen, Copenhagen 1165, Denmark
| | - Lluis Raich
- Departament
de Química Inorgànica i Orgànica (secció
de Química Orgànica) & Institut de Química
Teòrica i Computacional (IQTCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Ismael Compañón
- Departamento
de Química, Universidad de La Rioja,
Centro de Investigación en Síntesis Química, E-26006 Logroño, Spain
| | - Ana Diniz
- UCIBIO,
REQUIMTE, Departamento de Química, Faculdade de Ciências
e Tecnologia, Universidade de Nova de Lisboa, Caparica 2825-149, Portugal
| | | | - Jesús Jiménez-Barbero
- CIC
bioGUNE, Bizkaia Technology
Park, Building 801A, 48170 Derio, Spain
- Departament
of Organic Chemistry II, Faculty of Science
& Technology, University of the Basque
Country, Leioa, 48940 Bizkaia, Spain
- Ikerbasque,
Basque Foundation for Science, Maria Diaz de Haro 13, 48009 Bilbao, Spain
| | - Henrik Clausen
- Copenhagen
Center for Glycomics, Department of Cellular and Molecular Medicine,
School of Dentistry, University of Copenhagen, Copenhagen 1165, Denmark
| | - Carme Rovira
- Departament
de Química Inorgànica i Orgànica (secció
de Química Orgànica) & Institut de Química
Teòrica i Computacional (IQTCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
- Institució
Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08010 Barcelona, Spain
| | - Filipa Marcelo
- UCIBIO,
REQUIMTE, Departamento de Química, Faculdade de Ciências
e Tecnologia, Universidade de Nova de Lisboa, Caparica 2825-149, Portugal
| | - Francisco Corzana
- Departamento
de Química, Universidad de La Rioja,
Centro de Investigación en Síntesis Química, E-26006 Logroño, Spain
| | - Thomas A. Gerken
- Departments
of Biochemistry, Pediatrics and Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
- E-mail:
| | - Ramon Hurtado-Guerrero
- BIFI, University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit,
Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza 50018, Spain
- Fundación ARAID, 50018 Zaragoza, Spain
- E-mail:
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16
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EFEMP2 Mediates GALNT14-Dependent Breast Cancer Cell Invasion. Transl Oncol 2018; 11:346-352. [PMID: 29428518 PMCID: PMC5884205 DOI: 10.1016/j.tranon.2018.01.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 01/09/2018] [Accepted: 01/16/2018] [Indexed: 01/21/2023] Open
Abstract
N-Acetylgalactosaminyltransferase-14 (GALNT14) is a member of acetylgalactosaminyltransferases family. We have shown that GALNT14 could promote breast cancer cell invasion. However, the underlying molecular mechanism is unclear. Here, using yeast two hybrid, we find that EGF-containing fibulin-like extracellular matrix protein 2 (EFEMP2) interacts with GALNT14. Both in vitro and in vivo binding assays show that EFEMP2 is associated with GALNT14. Moreover, we find that GALNT14 mediates glycosylation of EFEMP2. EFEMP2 significantly increased the invasion ability of breast cancer cells including MCF-7 and MBA-MD-231 cells, and this phenomenon is suppressed by knockdown expression of GALNT14. In addition, the GALNT14-dependent O-glycosylation of EFEMP-2 regulates the stability of EFEMP-2 protein in breast cancer cells. Taken together, our results demonstrate a novel molecular mechanism underlying breast cancer invasion.
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17
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Mao L, Fang Y, Campbell M, Southerland WM. Population differentiation in allele frequencies of obesity-associated SNPs. BMC Genomics 2017; 18:861. [PMID: 29126384 PMCID: PMC5681842 DOI: 10.1186/s12864-017-4262-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 11/02/2017] [Indexed: 08/11/2023] Open
Abstract
BACKGROUND Obesity is emerging as a global health problem, with more than one-third of the world's adult population being overweight or obese. In this study, we investigated worldwide population differentiation in allele frequencies of obesity-associated SNPs (single nucleotide polymorphisms). RESULTS We collected a total of 225 obesity-associated SNPs from a public database. Their population-level allele frequencies were derived based on the genotype data from 1000 Genomes Project (phase 3). We used hypergeometric model to assess whether the effect allele at a given SNP is significantly enriched or depleted in each of the 26 populations surveyed in the 1000 Genomes Project with respect to the overall pooled population. Our results indicate that 195 out of 225 SNPs (86.7%) possess effect alleles significantly enriched or depleted in at least one of the 26 populations. Populations within the same continental group exhibit similar allele enrichment/depletion patterns whereas inter-continental populations show distinct patterns. Among the 225 SNPs, 15 SNPs cluster in the first intron region of the FTO gene, which is a major gene associated with body-mass index (BMI) and fat mass. African populations exhibit much smaller blocks of LD (linkage disequilibrium) among these15 SNPs while European and Asian populations have larger blocks. To estimate the cumulative effect of all variants associated with obesity, we developed the personal composite genetic risk score for obesity. Our results indicate that the East Asian populations have the lowest averages of the composite risk scores, whereas three European populations have the highest averages. In addition, the population-level average of composite genetic risk scores is significantly correlated (R2 = 0.35, P = 0.0060) with obesity prevalence. CONCLUSIONS We have detected substantial population differentiation in allele frequencies of obesity-associated SNPs. The results will help elucidate the genetic basis which may contribute to population disparities in obesity prevalence.
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Affiliation(s)
- Linyong Mao
- Department of Biochemistry and Molecular Biology, Howard University College of Medicine, 520 W Street NW, Washington, DC 20059 USA
| | - Yayin Fang
- Department of Biochemistry and Molecular Biology, Howard University College of Medicine, 520 W Street NW, Washington, DC 20059 USA
| | - Michael Campbell
- Department of Biology, Howard University, 415 College Street NW, Washington, 20059 DC USA
| | - William M. Southerland
- Department of Biochemistry and Molecular Biology, Howard University College of Medicine, 520 W Street NW, Washington, DC 20059 USA
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18
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Qiu H, Xu X, Liu M, Wang Z, Yuan Y, Liu C, Xu L, Wu S. RNA interference-mediated silencing of ppGalNAc-T1 and ppGalNAc-T2 inhibits invasion and increases chemosensitivity potentially by reducing terminal α2,3 sialylation and MMP14 expression in triple‑negative breast cancer cells. Mol Med Rep 2017; 15:3724-3734. [PMID: 28393207 DOI: 10.3892/mmr.2017.6449] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 11/08/2016] [Indexed: 11/06/2022] Open
Abstract
Glycopeptide-preferring polypeptide N-acetylgalactosamine transferase (ppGalNAc‑T) is a key enzyme that initiates the formation of the first GalNAc monosaccharide to polypeptides at Thr/Ser residues by O‑linked glycosylation. In order to investigate the effects of ppGalNAc‑T1 and ppGalNAc‑T2 on the initiation of O‑glycosylation, siRNA‑ppGalNAc‑T1 (si‑T1) and siRNA‑ppGalNAc‑T2 (si‑T2) were transfected into highly‑invasive estrogen receptor‑negative MDA‑MB‑231 cells to inhibit O‑glycosylation. Downregulation of ppGalNAc‑T1 demonstrated a significant reduction in the number of terminal α2,3 sialic acids, when compared to cells transfected with si‑T2 or si‑T1/T2. This downregulation led to a decrease in the invasion capabilities of the breast carcinoma cells, as well as enhanced chemosensitivity, which was the result antineoplastic drug effects. In addition, immunoprecipitation assays demonstrated that downregulation of ppGalNAc‑T1 led to a reduction in the number of terminal α2,3 sialic acids on O‑linked glycans of the matrix metalloproteinase‑14 (MMP14) glycoprotein. Furthermore, MMP14 and vascular endothelial growth factor were downregulated in the si‑T1 groups when compared with the si‑T2 and si‑T1/T2 groups. In conclusion, the results of the present study suggest that ppGalNAc‑T1 may serve a pivotal role in the initiation of O‑glycosylation, which may lead to a low density of α2,3 sialic acids on O‑linked glycans of MMP14 when downregulated. Glycosylation serves a significant role in regulating the sensitivity of MMP14 to self‑proteolysis, which ultimately decreases the invasion capabilities of breast cancer cells. The results of the present study may be useful in establishing the function of ppGalNAc‑T1 during breast cancer invasion and metastasis.
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Affiliation(s)
- Hao Qiu
- Department of Biochemistry and Molecular Biology, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Xu Xu
- Department of Biochemistry and Molecular Biology, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Min Liu
- Department of Oncology, Nanjing University of Traditional Chinese Medicine Affiliated Suzhou Hospital of Traditional Chinese Medicine, Suzhou, Jiangsu 215128, P.R. China
| | - Zerong Wang
- Department of Biochemistry and Molecular Biology, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Yaqin Yuan
- Department of Biochemistry and Molecular Biology, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Chunliang Liu
- Department of Biochemistry and Molecular Biology, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Lan Xu
- Department of Biochemistry and Molecular Biology, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Shiliang Wu
- Department of Biochemistry and Molecular Biology, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
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19
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Tomita T, Sugi T, Yakubu R, Tu V, Ma Y, Weiss LM. Making Home Sweet and Sturdy: Toxoplasma gondii ppGalNAc-Ts Glycosylate in Hierarchical Order and Confer Cyst Wall Rigidity. mBio 2017; 8:e02048-16. [PMID: 28074022 PMCID: PMC5225312 DOI: 10.1128/mbio.02048-16] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 12/08/2016] [Indexed: 12/20/2022] Open
Abstract
The protozoan intracellular parasite Toxoplasma gondii forms latent cysts in the central nervous system (CNS) and persists for the lifetime of the host. This cyst is cloaked with a glycosylated structure called the cyst wall. Previously, we demonstrated that a mucin-like glycoprotein, CST1, localizes to the cyst wall and confers structural rigidity on brain cysts in a mucin-like domain-dependent manner. The mucin-like domain of CST1 is composed of 20 units of threonine-rich tandem repeats that are O-GalNAc glycosylated. A family of enzymes termed polypeptide N-acetylgalactosaminyltransferases (ppGalNAc-Ts) initiates O-GalNAc glycosylation. To identify which isoforms of ppGalNAc-Ts are responsible for the glycosylation of the CST1 mucin-like domain and to evaluate the function of each ppGalNAc-T in the overall glycosylation of the cyst wall, all five ppGalNAc-T isoforms were deleted individually from the T. gondii genome. The ppGalNAc-T2 and -T3 deletion mutants produced various glycosylation defects on the cyst wall, implying that many cyst wall glycoproteins are glycosylated by T2 and T3. Both T2 and T3 glycosylate the CST1 mucin-like domain, and this glycosylation is necessary for CST1 to confer structural rigidity on the cyst wall. We established that T2 is required for the initial glycosylation of the mucin-like domain and that T3 is responsible for the sequential glycosylation on neighboring acceptor sites, demonstrating hierarchical glycosylation by two distinct initiating and filling-in ppGalNAc-Ts in an intact organism. IMPORTANCE Toxoplasma gondii is an obligate intracellular parasite that infects a third of the world's population. It can cause severe congenital disease and devastating encephalitis in immunocompromised individuals. We identified two glycosyltransferases, ppGalNAc-T2 and -T3, which are responsible for glycosylating cyst wall proteins in a hierarchical fashion. This glycosylation confers structural rigidity on the brain cyst. Our studies provide new insights into the mechanisms of O-GalNAc glycosylation in T. gondii.
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Affiliation(s)
- Tadakimi Tomita
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Tatsuki Sugi
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Rama Yakubu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Vincent Tu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Yanfen Ma
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Louis M Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
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20
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Festari MF, Trajtenberg F, Berois N, Pantano S, Revoredo L, Kong Y, Solari-Saquieres P, Narimatsu Y, Freire T, Bay S, Robello C, Bénard J, Gerken TA, Clausen H, Osinaga E. Revisiting the human polypeptide GalNAc-T1 and T13 paralogs. Glycobiology 2017; 27:140-153. [PMID: 27913570 PMCID: PMC5224595 DOI: 10.1093/glycob/cww111] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/30/2016] [Accepted: 11/02/2016] [Indexed: 11/13/2022] Open
Abstract
Polypeptide GalNAc-transferases (GalNAc-Ts) constitute a family of 20 human glycosyltransferases (comprising 9 subfamilies), which initiate mucin-type O-glycosylation. The O-glycoproteome is thought to be differentially regulated via the different substrate specificities and expression patterns of each GalNAc-T isoforms. Here, we present a comprehensive in vitro analysis of the peptide substrate specificity of GalNAc-T13, showing that it essentially overlaps with the ubiquitous expressed GalNAc-T1 isoform found in the same subfamily as T13. We have also identified and partially characterized nine splice variants of GalNAc-T13, which add further complexity to the GalNAc-T family. Two variants with changes in their lectin domains were characterized by in vitro glycosylation assays, and one (Δ39Ex9) was inactive while the second one (Ex10b) had essentially unaltered activity. We used reverse transcription-polymerase chain reaction analysis of human neuroblastoma cell lines, normal brain and a small panel of neuroblastoma tumors to demonstrate that several splice variants (Ex10b, ΔEx9, ΔEx2-7 and ΔEx6/8-39bpEx9) were highly expressed in tumor cell lines compared with normal brain, although the functional implications remain to be unveiled. In summary, the GalNAc-T13 isoform is predicted to function similarly to GalNAc-T1 against peptide substrates in vivo, in contrast to a prior report, but is unique by being selectively expressed in the brain.
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Affiliation(s)
- María Florencia Festari
- Laboratory of Tumor Immunology and Glycobiology, Institut Pasteur de Montevideo, Mataojo 2020 (C.P. 11400), Montevideo, Uruguay
- Departamento de Inmunobiología, Facultad de Medicina, Universidad de la República, Avenida General Flores 2125 (C.P. 11800), Montevideo, Uruguay
| | | | - Nora Berois
- Laboratory of Tumor Immunology and Glycobiology, Institut Pasteur de Montevideo, Mataojo 2020 (C.P. 11400), Montevideo, Uruguay
| | - Sergio Pantano
- Grupo de Simulaciones Biomoleculares, Institut Pasteur de Montevideo, Mataojo 2020 (C.P. 11400), Montevideo, Uruguay
| | - Leslie Revoredo
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Yun Kong
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Patricia Solari-Saquieres
- Laboratory of Tumor Immunology and Glycobiology, Institut Pasteur de Montevideo, Mataojo 2020 (C.P. 11400), Montevideo, Uruguay
| | - Yoshiki Narimatsu
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Teresa Freire
- Departamento de Inmunobiología, Facultad de Medicina, Universidad de la República, Avenida General Flores 2125 (C.P. 11800), Montevideo, Uruguay
| | - Sylvie Bay
- Unité de Chimie de Biomoleculares, CNRS UMR 3523 Institut Pasteur, Paris, France
| | - Carlos Robello
- Unidad de Biología Molecular, Institut Pasteur de Montevideo, Mataojo 2020 (C.P. 11400), Montevideo, Uruguay
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Avenida General Flores 2125 (C.P. 11800), Montevideo, Uruguay
| | - Jean Bénard
- CNRS UMR 8126, Université Paris-Sud 11, and Département de Biologie et Pathologie Médicales Institut Gustave Roussy, Villejuif Cedex, France
| | - Thomas A Gerken
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
- Departments of Pediatrics and Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Henrik Clausen
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Eduardo Osinaga
- Laboratory of Tumor Immunology and Glycobiology, Institut Pasteur de Montevideo, Mataojo 2020 (C.P. 11400), Montevideo, Uruguay
- Departamento de Inmunobiología, Facultad de Medicina, Universidad de la República, Avenida General Flores 2125 (C.P. 11800), Montevideo, Uruguay
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21
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Li Y, Li Y, Chen D, Jin L, Su Z, Liu J, Duan H, Li X, Qi Z, Shi M, Ni L, Yang S, Gui Y, Mao X, Chen Y, Lai Y. miR‑30a‑5p in the tumorigenesis of renal cell carcinoma: A tumor suppressive microRNA. Mol Med Rep 2016; 13:4085-94. [PMID: 27035333 DOI: 10.3892/mmr.2016.5024] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 03/07/2016] [Indexed: 02/05/2023] Open
Abstract
Renal cell carcinoma (RCC) is the most common type of malignant tumor of the adult kidney and has a poor prognosis. MicroRNAs (miRs) are important in a wide range of biological and pathological processes, including cell differentiation, migration, growth, proliferation, apoptosis and metabolism. The present study aimed to determine the role exerted by miR‑30a‑5p in the tumorigenesis of RCC. The expression levels of miR‑30a‑5p in RCC tissues and RCC‑derived cells were demonstrated to be significantly downregulated by real‑time quantitative polymerase chain reaction (RT‑qPCR). Wound scratch assay, cell proliferation assay and flow cytometric analysis revealed that the abilities of migration and proliferation of the RCC‑derived cells were suppressed, whereas cell apoptosis was promoted, when miR‑30a‑5p was overexpressed in these cells. N‑acetylgalactosaminyltransferase 7 (GALNT7) was predicted to be one target gene of miR‑30a‑5p by bioinformatics analysis. Luciferase reporter assay, RT‑qPCR and western blotting were performed to confirm that GALNT7 is the direct conserved target of miR‑30a‑5p. These results suggested that miR‑30a‑5p has a tumor‑suppressive role in the tumorigenesis of RCC.
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Affiliation(s)
- Yifan Li
- Department of Urology, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
| | - Yuchi Li
- The Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Duqun Chen
- Department of Urology, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
| | - Lu Jin
- Department of Urology, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
| | - Zhengming Su
- Department of Urology, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
| | - Jiaju Liu
- Department of Urology, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
| | - Hongfang Duan
- Department of Otolaryngological, Guangzhou Medical University, Guangzhou, Guangdong 510000, P.R. China
| | - Xiaoqing Li
- Department of Urology, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China
| | - Zhengyu Qi
- The Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Min Shi
- The Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Liangchao Ni
- Department of Urology, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
| | - Shangqi Yang
- Department of Urology, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
| | - Yaoting Gui
- The Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Institute of Urology of Shenzhen PKU‑HKUST Medical Center, Shenzhen, Guangdong 518036, P.R. China
| | - Xiangming Mao
- Department of Urology, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
| | - Yun Chen
- Department of Ultrasound Division, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
| | - Yongqing Lai
- Department of Urology, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, P.R. China
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22
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Ahmad S, Zhao W, Renström F, Rasheed A, Samuel M, Zaidi M, Shah N, Mallick NH, Zaman KS, Ishaq M, Rasheed SZ, Memon FUR, Hanif B, Lakhani MS, Ahmed F, Kazmi SU, Frossard P, Franks PW, Saleheen D. Physical activity, smoking, and genetic predisposition to obesity in people from Pakistan: the PROMIS study. BMC MEDICAL GENETICS 2015; 16:114. [PMID: 26683835 PMCID: PMC4683724 DOI: 10.1186/s12881-015-0259-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 12/05/2015] [Indexed: 12/31/2022]
Abstract
Background Multiple genetic variants have been reliably associated with obesity-related traits in Europeans, but little is known about their associations and interactions with lifestyle factors in South Asians. Methods In 16,157 Pakistani adults (8232 controls; 7925 diagnosed with myocardial infarction [MI]) enrolled in the PROMIS Study, we tested whether: a) BMI-associated loci, individually or in aggregate (as a genetic risk score - GRS), are associated with BMI; b) physical activity and smoking modify the association of these loci with BMI. Analyses were adjusted for age, age2, sex, MI (yes/no), and population substructure. Results Of 95 SNPs studied here, 73 showed directionally consistent effects on BMI as reported in Europeans. Each additional BMI-raising allele of the GRS was associated with 0.04 (SE = 0.01) kg/m2 higher BMI (P = 4.5 × 10−14). We observed nominal evidence of interactions of CLIP1 rs11583200 (Pinteraction = 0.014), CADM2 rs13078960 (Pinteraction = 0.037) and GALNT10 rs7715256 (Pinteraction = 0.048) with physical activity, and PTBP2 rs11165643 (Pinteraction = 0.045), HIP1 rs1167827 (Pinteraction = 0.015), C6orf106 rs205262 (Pinteraction = 0.032) and GRID1 rs7899106 (Pinteraction = 0.043) with smoking on BMI. Conclusions Most BMI-associated loci have directionally consistent effects on BMI in Pakistanis and Europeans. There were suggestive interactions of established BMI-related SNPs with smoking or physical activity. Electronic supplementary material The online version of this article (doi:10.1186/s12881-015-0259-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shafqat Ahmad
- Genetic and Molecular Epidemiology Unit, Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden.
| | - Wei Zhao
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| | - Frida Renström
- Genetic and Molecular Epidemiology Unit, Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden.
| | - Asif Rasheed
- Center for Non-Communicable Diseases Pakistan, Karachi, Pakistan.
| | - Maria Samuel
- Center for Non-Communicable Diseases Pakistan, Karachi, Pakistan.
| | - Mozzam Zaidi
- Center for Non-Communicable Diseases Pakistan, Karachi, Pakistan.
| | - Nabi Shah
- Center for Non-Communicable Diseases Pakistan, Karachi, Pakistan. .,Department of Pharmacy, COMSATS Institute of Information Technology, Abbottabad, Pakistan.
| | | | - Khan Shah Zaman
- National Institute of Cardiovascular Diseases, Karachi, Pakistan.
| | | | | | | | | | | | - Faisal Ahmed
- Department of Cardiology, Liaquat National Hospital, Karachi, Pakistan.
| | | | - Philippe Frossard
- Center for Non-Communicable Diseases Pakistan, Karachi, Pakistan. .,Nazarbayev University, Astana, Kazakhstan.
| | - Paul W Franks
- Genetic and Molecular Epidemiology Unit, Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden. .,Department of Public Health and Clinical Medicine, Section for Medicine, Umeå University, Umeå, Sweden. .,Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.
| | - Danish Saleheen
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA. .,Center for Non-Communicable Diseases Pakistan, Karachi, Pakistan. .,Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, USA.
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23
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Revoredo L, Wang S, Bennett EP, Clausen H, Moremen KW, Jarvis DL, Ten Hagen KG, Tabak LA, Gerken TA. Mucin-type O-glycosylation is controlled by short- and long-range glycopeptide substrate recognition that varies among members of the polypeptide GalNAc transferase family. Glycobiology 2015; 26:360-76. [PMID: 26610890 DOI: 10.1093/glycob/cwv108] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 11/16/2015] [Indexed: 01/02/2023] Open
Abstract
A large family of UDP-GalNAc:polypeptide GalNAc transferases (ppGalNAc-Ts) initiates and defines sites of mucin-type Ser/Thr-O-GalNAc glycosylation. Family members have been classified into peptide- and glycopeptide-preferring subfamilies, although both families possess variable activities against glycopeptide substrates. All but one isoform contains a C-terminal carbohydrate-binding lectin domain whose roles in modulating glycopeptide specificity is just being understood. We have previously shown for several peptide-preferring isoforms that the presence of a remote Thr-O-GalNAc, 6-17 residues from a Ser/Thr acceptor site, may enhance overall catalytic activity in an N- or C-terminal direction. This enhancement varies with isoform and is attributed to Thr-O-GalNAc interactions at the lectin domain. We now report on the glycopeptide substrate utilization of a series of glycopeptide (human-ppGalNAc-T4, T7, T10, T12 and fly PGANT7) and peptide-preferring transferases (T2, T3 and T5) by exploiting a series of random glycopeptide substrates designed to probe the functions of their catalytic and lectin domains. Glycosylation was observed at the -3, -1 and +1 residues relative to a neighboring Thr-O-GalNAc, depending on isoform, which we attribute to specific Thr-O-GalNAc binding at the catalytic domain. Additionally, these glycopeptide-preferring isoforms show remote lectin domain-assisted Thr-O-GalNAc enhancements that vary from modest to none. We conclude that the glycopeptide specificity of the glycopeptide-preferring isoforms predominantly resides in their catalytic domain but may be further modulated by remote lectin domain interactions. These studies further demonstrate that both domains of the ppGalNAc-Ts have specialized and unique functions that work in concert to control and order mucin-type O-glycosylation.
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Affiliation(s)
| | - Shengjun Wang
- Copenhagen Center for Glycomics (CCG), Departments of Cellular and Molecular Medicine and Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N DK-2200, Denmark
| | - Eric Paul Bennett
- Copenhagen Center for Glycomics (CCG), Departments of Cellular and Molecular Medicine and Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N DK-2200, Denmark
| | - Henrik Clausen
- Copenhagen Center for Glycomics (CCG), Departments of Cellular and Molecular Medicine and Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen N DK-2200, Denmark
| | - Kelley W Moremen
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Donald L Jarvis
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA
| | | | - Lawrence A Tabak
- Section on Biological Chemistry, Department of Health and Human Services, NIDCR, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas A Gerken
- Department of Chemistry Department of Pediatrics and Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
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24
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Liu X, Xiong X, Yang J, Zhou L, Yang B, Ai H, Ma H, Xie X, Huang Y, Fang S, Xiao S, Ren J, Ma J, Huang L. Genome-wide association analyses for meat quality traits in Chinese Erhualian pigs and a Western Duroc × (Landrace × Yorkshire) commercial population. Genet Sel Evol 2015; 47:44. [PMID: 25962760 PMCID: PMC4427942 DOI: 10.1186/s12711-015-0120-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 04/09/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Understanding the genetic mechanisms that underlie meat quality traits is essential to improve pork quality. To date, most quantitative trait loci (QTL) analyses have been performed on F2 crosses between outbred pig strains and have led to the identification of numerous QTL. However, because linkage disequilibrium is high in such crosses, QTL mapping precision is unsatisfactory and only a few QTL have been found to segregate within outbred strains, which limits their use to improve animal performance. To detect QTL in outbred pig populations of Chinese and Western origins, we performed genome-wide association studies (GWAS) for meat quality traits in Chinese purebred Erhualian pigs and a Western Duroc × (Landrace × Yorkshire) (DLY) commercial population. METHODS Three hundred and thirty six Chinese Erhualian and 610 DLY pigs were genotyped using the Illumina PorcineSNP60K Beadchip and evaluated for 20 meat quality traits. After quality control, 35 985 and 56 216 single nucleotide polymorphisms (SNPs) were available for the Chinese Erhualian and DLY datasets, respectively, and were used to perform two separate GWAS. We also performed a meta-analysis that combined P-values and effects of 29 516 SNPs that were common to Erhualian, DLY, F2 and Sutai pig populations. RESULTS We detected 28 and nine suggestive SNPs that surpassed the significance level for meat quality in Erhualian and DLY pigs, respectively. Among these SNPs, ss131261254 on pig chromosome 4 (SSC4) was the most significant (P = 7.97E-09) and was associated with drip loss in Erhualian pigs. Our results suggested that at least two QTL on SSC12 and on SSC15 may have pleiotropic effects on several related traits. All the QTL that were detected by GWAS were population-specific, including 12 novel regions. However, the meta-analysis revealed seven novel QTL for meat characteristics, which suggests the existence of common underlying variants that may differ in frequency across populations. These QTL regions contain several relevant candidate genes. CONCLUSIONS These findings provide valuable insights into the molecular basis of convergent evolution of meat quality traits in Chinese and Western breeds that show divergent phenotypes. They may contribute to genetic improvement of purebreds for crossbred performance.
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Affiliation(s)
- Xianxian Liu
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Xinwei Xiong
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Jie Yang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Lisheng Zhou
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Bin Yang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Huashui Ai
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Huanban Ma
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Xianhua Xie
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Yixuan Huang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Shaoming Fang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Shijun Xiao
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Jun Ren
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Junwu Ma
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Lusheng Huang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, 330045, China.
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25
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update for 2009-2010. MASS SPECTROMETRY REVIEWS 2015; 34:268-422. [PMID: 24863367 PMCID: PMC7168572 DOI: 10.1002/mas.21411] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 07/16/2013] [Accepted: 07/16/2013] [Indexed: 05/07/2023]
Abstract
This review is the sixth update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2010. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, arrays and fragmentation are covered in the first part of the review and applications to various structural typed constitutes the remainder. The main groups of compound that are discussed in this section are oligo and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals. Many of these applications are presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions and applications to chemical synthesis.
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Affiliation(s)
- David J. Harvey
- Department of BiochemistryOxford Glycobiology InstituteUniversity of OxfordOxfordOX1 3QUUK
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26
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Kong Y, Joshi HJ, Schjoldager KTBG, Madsen TD, Gerken TA, Vester-Christensen MB, Wandall HH, Bennett EP, Levery SB, Vakhrushev SY, Clausen H. Probing polypeptide GalNAc-transferase isoform substrate specificities by in vitro analysis. Glycobiology 2015; 25:55-65. [PMID: 25155433 PMCID: PMC4245906 DOI: 10.1093/glycob/cwu089] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 08/13/2014] [Accepted: 08/19/2014] [Indexed: 12/16/2022] Open
Abstract
N-acetylgalactosaminyltransferase (GalNAc)-type (mucin-type) O-glycosylation is an abundant and highly diverse modification of proteins. This type of O-glycosylation is initiated in the Golgi by a large family of up to 20 homologous polypeptide GalNAc-T isoenzymes that transfer GalNAc to Ser, Thr and possibly Tyr residues. These GalNAc residues are then further elongated by a large set of glycosyltransferases to build a variety of complex O-glycan structures. What determines O-glycan site occupancy is still poorly understood, although it is clear that the substrate specificities of individual isoenzymes and the repertoire of GalNAc-Ts in cells are key parameters. The GalNAc-T isoenzymes are differentially expressed in cells and tissues in principle allowing cells to produce unique O-glycoproteomes dependent on the specific subset of isoforms present. In vitro analysis of acceptor peptide substrate specificities using recombinant expressed GalNAc-Ts has been the method of choice for probing activities of individual isoforms, but these studies have been hampered by biological validation of actual O-glycosylation sites in proteins and number of substrate testable. Here, we present a systematic analysis of the activity of 10 human GalNAc-T isoenzymes with 195 peptide substrates covering known O-glycosylation sites and provide a comprehensive dataset for evaluating isoform-specific contributions to the O-glycoproteome.
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Affiliation(s)
- Yun Kong
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen, Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Hiren J Joshi
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen, Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Katrine Ter-Borch Gram Schjoldager
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen, Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Thomas Daugbjerg Madsen
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen, Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Thomas A Gerken
- Department of Pediatrics Department of Biochemistry and Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Malene B Vester-Christensen
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen, Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Hans H Wandall
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen, Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Eric Paul Bennett
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen, Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Steven B Levery
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen, Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Sergey Y Vakhrushev
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen, Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Henrik Clausen
- Department of Cellular and Molecular Medicine and Odontology, Copenhagen, Center for Glycomics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
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27
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Nordén R, Halim A, Nyström K, Bennett EP, Mandel U, Olofsson S, Nilsson J, Larson G. O-linked glycosylation of the mucin domain of the herpes simplex virus type 1-specific glycoprotein gC-1 is temporally regulated in a seed-and-spread manner. J Biol Chem 2014; 290:5078-5091. [PMID: 25548287 DOI: 10.1074/jbc.m114.616409] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The herpes simplex virus type 1 (HSV-1) glycoprotein gC-1, participating in viral receptor interactions and immunity interference, harbors a mucin-like domain with multiple clustered O-linked glycans. Using HSV-1-infected diploid human fibroblasts, an authentic target for HSV-1 infection, and a protein immunoaffinity procedure, we enriched fully glycosylated gC-1 and a series of its biosynthetic intermediates. This fraction was subjected to trypsin digestion and a LC-MS/MS glycoproteomics approach. In parallel, we characterized the expression patterns of the 20 isoforms of human GalNAc transferases responsible for initiation of O-linked glycosylation. The gC-1 O-glycosylation was regulated in an orderly manner initiated by synchronous addition of one GalNAc unit each to Thr-87 and Thr-91 and one GalNAc unit to either Thr-99 or Thr-101, forming a core glycopeptide for subsequent additions of in all 11 GalNAc residues to selected Ser and Thr residues of the Thr-76-Lys-107 stretch of the mucin domain. The expression patterns of GalNAc transferases in the infected cells suggested that initial additions of GalNAc were carried out by initiating GalNAc transferases, in particular GalNAc-T2, whereas subsequent GalNAc additions were carried out by followup transferases, in particular GalNAc-T10. Essentially all of the susceptible Ser or Thr residues had to acquire their GalNAc units before any elongation to longer O-linked glycans of the gC-1-associated GalNAc units was permitted. Because the GalNAc occupancy pattern is of relevance for receptor binding of gC-1, the data provide a model to delineate biosynthetic steps of O-linked glycosylation of the gC-1 mucin domain in HSV-1-infected target cells.
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Affiliation(s)
- Rickard Nordén
- From the Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, SE 413 45 Gothenburg, Sweden
| | - Adnan Halim
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, University of Copenhagen, DK-2200 Copenhagen, Denmark, and; Department of Clinical Chemistry and Transfusion Medicine, University of Gothenburg, SE 413 45 Gothenburg, Sweden
| | - Kristina Nyström
- From the Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, SE 413 45 Gothenburg, Sweden
| | - Eric P Bennett
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, University of Copenhagen, DK-2200 Copenhagen, Denmark, and
| | - Ulla Mandel
- Copenhagen Center for Glycomics, Departments of Cellular and Molecular Medicine and Odontology, University of Copenhagen, DK-2200 Copenhagen, Denmark, and
| | - Sigvard Olofsson
- From the Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, SE 413 45 Gothenburg, Sweden
| | - Jonas Nilsson
- Department of Clinical Chemistry and Transfusion Medicine, University of Gothenburg, SE 413 45 Gothenburg, Sweden
| | - Göran Larson
- Department of Clinical Chemistry and Transfusion Medicine, University of Gothenburg, SE 413 45 Gothenburg, Sweden.
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28
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Minai-Tehrani A, Chang SH, Park SB, Cho MH. The O‑glycosylation mutant osteopontin alters lung cancer cell growth and migration in vitro and in vivo. Int J Mol Med 2013; 32:1137-49. [PMID: 24008322 DOI: 10.3892/ijmm.2013.1483] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 08/27/2013] [Indexed: 11/05/2022] Open
Abstract
Osteopontin (OPN) is an acidic, glycosylated and phosphorylated protein that plays an essential role in determining the aggressiveness and oncogenic potential of several types of cancer, including lung cancer. The OPN function is highly dependent on post-translational modification (PTM) and regulation of the processes that involve OPN can be mediated through glycosylation. However, the connection between OPN function and its O-glycosylation in lung cancer cells has yet to be investigated. In the present study, this issue was addressed by studying the effects of wild-type (WT) OPN and a triple mutant (TM) of OPN, which was mutated at three O-glycosylation sites in lung cancer cells. It was shown that OPN WT rather than OPN TM induced the OPN‑mediated signaling pathway. The OPN WT expression enhanced cap-dependent protein translation, NF-κB activity and glucose uptake, whereas a reduction was observed in cells treated with OPN TM. The results clearly demonstrated that unlike OPN WT, OPN TM did not increase lung cancer cell growth and migration both in vitro and in a xenograft mouse model. Thus, results of the present study suggested that targeting OPN by introducing OPN TM may be a good strategy for treating lung cancer.
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Affiliation(s)
- Arash Minai-Tehrani
- Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul 151‑742, Japan
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Gerken TA, Revoredo L, Thome JJC, Tabak LA, Vester-Christensen MB, Clausen H, Gahlay GK, Jarvis DL, Johnson RW, Moniz HA, Moremen K. The lectin domain of the polypeptide GalNAc transferase family of glycosyltransferases (ppGalNAc Ts) acts as a switch directing glycopeptide substrate glycosylation in an N- or C-terminal direction, further controlling mucin type O-glycosylation. J Biol Chem 2013; 288:19900-14. [PMID: 23689369 PMCID: PMC3707691 DOI: 10.1074/jbc.m113.477877] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 05/17/2013] [Indexed: 01/22/2023] Open
Abstract
Mucin type O-glycosylation is initiated by a large family of polypeptide GalNAc transferases (ppGalNAc Ts) that add α-GalNAc to the Ser and Thr residues of peptides. Of the 20 human isoforms, all but one are composed of two globular domains linked by a short flexible linker: a catalytic domain and a ricin-like lectin carbohydrate binding domain. Presently, the roles of the catalytic and lectin domains in peptide and glycopeptide recognition and specificity remain unclear. To systematically study the role of the lectin domain in ppGalNAc T glycopeptide substrate utilization, we have developed a series of novel random glycopeptide substrates containing a single GalNAc-O-Thr residue placed near either the N or C terminus of the glycopeptide substrate. Our results reveal that the presence and N- or C-terminal placement of the GalNAc-O-Thr can be important determinants of overall catalytic activity and specificity that differ between transferase isoforms. For example, ppGalNAc T1, T2, and T14 prefer C-terminally placed GalNAc-O-Thr, whereas ppGalNAc T3 and T6 prefer N-terminally placed GalNAc-O-Thr. Several transferase isoforms, ppGalNAc T5, T13, and T16, display equally enhanced N- or C-terminal activities relative to the nonglycosylated control peptides. This N- and/or C-terminal selectivity is presumably due to weak glycopeptide binding to the lectin domain, whose orientation relative to the catalytic domain is dynamic and isoform-dependent. Such N- or C-terminal glycopeptide selectivity provides an additional level of control or fidelity for the O-glycosylation of biologically significant sites and suggests that O-glycosylation may in some instances be exquisitely controlled.
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Affiliation(s)
- Thomas A. Gerken
- From the Departments of Pediatrics (W. A. Bernbaum Center for Cystic Fibrosis Research)
- Biochemistry, and
- Chemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Leslie Revoredo
- Chemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Joseph J. C. Thome
- From the Departments of Pediatrics (W. A. Bernbaum Center for Cystic Fibrosis Research)
| | - Lawrence A. Tabak
- the Section on Biological Chemistry, NIDCR, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892
| | - Malene Bech Vester-Christensen
- the Copenhagen Center for Glycomics (CCG), Departments of Cellular and Molecular Medicine and Dentistry, Faculty of Health Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Henrik Clausen
- the Copenhagen Center for Glycomics (CCG), Departments of Cellular and Molecular Medicine and Dentistry, Faculty of Health Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Gagandeep K. Gahlay
- the Department of Molecular Biology, University of Wyoming, Laramie, Wyoming 82071, and
| | - Donald L. Jarvis
- the Department of Molecular Biology, University of Wyoming, Laramie, Wyoming 82071, and
| | - Roy W. Johnson
- the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Heather A. Moniz
- the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Kelley Moremen
- the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
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30
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Minai-Tehrani A, Chang SH, Kwon JT, Hwang SK, Kim JE, Shin JY, Yu KN, Park SJ, Jiang HL, Kim JH, Hong SH, Kang B, Kim D, Chae CH, Lee KH, Beck GR, Cho MH. Aerosol delivery of lentivirus-mediated O-glycosylation mutant osteopontin suppresses lung tumorigenesis in K-ras (LA1) mice. Cell Oncol (Dordr) 2013; 36:15-26. [PMID: 23070870 DOI: 10.1007/s13402-012-0107-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Osteopontin (OPN) is a secreted glycophosphoprotein that has been implicated in the regulation of cancer development. The function of OPN is primarily regulated through post-translational modification such as glycosylation. As yet, however, the relationship between OPN glycosylation and lung cancer development has not been investigated. In this study, we addressed this issue by studying the effect of a triple mutant (TM) of OPN, which is mutated at three O-glycosylation sites, on lung cancer development in K-ras (LA1) mice, a murine model for human non-small cell lung cancer. METHODS Aerosolized lentivirus-based OPN TM was delivered into the lungs of K-ras (LA1) mice using a nose-only-inhalation chamber 3 times/wk for 4 wks. Subsequently, the effects of repeated delivery of OPN TM on lung tumorigenesis and its concomitant OPN-mediated signaling pathways were investigated. RESULTS Aerosol-delivered OPN TM inhibited lung tumorigenesis. In addition, the OPN-mediated Akt signaling pathway was inhibited. OPN TM also decreased NF-κB activity and the phosphorylation of 4E-BP1, while facilitating apoptosis in the lungs of K-ras (LA1) mice. CONCLUSIONS Our results show that aerosol delivery of OPN TM successfully suppresses lung cancer development in the K-ras (LA1) mouse model and, therefore, warrant its further investigation as a possible therapeutic strategy for non-small cell lung cancer.
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Affiliation(s)
- Arash Minai-Tehrani
- Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
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31
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Halim A, Rüetschi U, Larson G, Nilsson J. LC-MS/MS characterization of O-glycosylation sites and glycan structures of human cerebrospinal fluid glycoproteins. J Proteome Res 2013; 12:573-84. [PMID: 23234360 DOI: 10.1021/pr300963h] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The GalNAc O-glycosylation on Ser/Thr residues of extracellular proteins has not been well characterized from a proteomics perspective. We previously reported a sialic acid capture-and-release protocol to enrich tryptic N- and O-glycopeptides from human cerebrospinal fluid glycoproteins using nano-LC-ESI-MS/MS with collision-induced dissociation (CID) for glycopeptide characterization. Here, we have introduced peptide N-glycosidase F (PNGase F) pretreatment of CSF samples to remove the N-glycans facilitating the selective characterization of O-glycopeptides and enabling the use of an automated CID-MS(2)/MS(3) search protocol for glycopeptide identification. We used electron-capture and -transfer dissociation (ECD/ETD) to pinpoint the glycosylation site(s) of the glycopeptides, identified as predominantly core-1-like HexHexNAc-O- structure attached to one to four Ser/Thr residues. We characterized 106 O-glycosylations and found Pro residues preferentially in the n - 1, n + 1, and/or n + 3 positions in relation to the Ser/Thr attachment site (n). The characterization of glycans and glycosylation sites in glycoproteins from human clinical samples provides a basis for future studies addressing the biological and diagnostic importance of specific protein glycosylations in relation to human disease.
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Affiliation(s)
- Adnan Halim
- Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg, 413 45 Gothenburg, Sweden
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32
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Bojarová P, Rosencrantz RR, Elling L, Křen V. Enzymatic glycosylation of multivalent scaffolds. Chem Soc Rev 2013; 42:4774-97. [DOI: 10.1039/c2cs35395d] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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33
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Bennett EP, Mandel U, Clausen H, Gerken TA, Fritz TA, Tabak LA. Control of mucin-type O-glycosylation: a classification of the polypeptide GalNAc-transferase gene family. Glycobiology 2012; 22:736-56. [PMID: 22183981 PMCID: PMC3409716 DOI: 10.1093/glycob/cwr182] [Citation(s) in RCA: 594] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 12/14/2011] [Accepted: 12/14/2011] [Indexed: 12/15/2022] Open
Abstract
Glycosylation of proteins is an essential process in all eukaryotes and a great diversity in types of protein glycosylation exists in animals, plants and microorganisms. Mucin-type O-glycosylation, consisting of glycans attached via O-linked N-acetylgalactosamine (GalNAc) to serine and threonine residues, is one of the most abundant forms of protein glycosylation in animals. Although most protein glycosylation is controlled by one or two genes encoding the enzymes responsible for the initiation of glycosylation, i.e. the step where the first glycan is attached to the relevant amino acid residue in the protein, mucin-type O-glycosylation is controlled by a large family of up to 20 homologous genes encoding UDP-GalNAc:polypeptide GalNAc-transferases (GalNAc-Ts) (EC 2.4.1.41). Therefore, mucin-type O-glycosylation has the greatest potential for differential regulation in cells and tissues. The GalNAc-T family is the largest glycosyltransferase enzyme family covering a single known glycosidic linkage and it is highly conserved throughout animal evolution, although absent in bacteria, yeast and plants. Emerging studies have shown that the large number of genes (GALNTs) in the GalNAc-T family do not provide full functional redundancy and single GalNAc-T genes have been shown to be important in both animals and human. Here, we present an overview of the GalNAc-T gene family in animals and propose a classification of the genes into subfamilies, which appear to be conserved in evolution structurally as well as functionally.
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Affiliation(s)
- Eric P Bennett
- Department of Odontology, Copenhagen Center for Glycomics, University of Copenhagen, Nørre Alle 20, DK-2200 Copenhagen N, Denmark.
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34
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Tran DT, Lim JM, Liu M, Stalnaker SH, Wells L, Ten Hagen KG, Live D. Glycosylation of α-dystroglycan: O-mannosylation influences the subsequent addition of GalNAc by UDP-GalNAc polypeptide N-acetylgalactosaminyltransferases. J Biol Chem 2012; 287:20967-74. [PMID: 22549772 DOI: 10.1074/jbc.m112.370387] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
O-Linked glycosylation is a functionally and structurally diverse type of protein modification present in many tissues and across many species. α-Dystroglycan (α-DG), a protein linked to the extracellular matrix, whose glycosylation status is associated with human muscular dystrophies, displays two predominant types of O-glycosylation, O-linked mannose (O-Man) and O-linked N-acetylgalactosamine (O-GalNAc), in its highly conserved mucin-like domain. The O-Man is installed by an enzyme complex present in the endoplasmic reticulum. O-GalNAc modifications are initiated subsequently in the Golgi apparatus by the UDP-GalNAc polypeptide N-acetylgalactosaminyltransferase (ppGalNAc-T) enzymes. How the presence and position of O-Man influences the action of the ppGalNAc-Ts on α-DG and the distribution of the two forms of glycosylation in this domain is not known. Here, we investigated the interplay between O-Man and the addition of O-GalNAc by examining the activity of the ppGalNAc-Ts on peptides and O-Man-containing glycopeptides mimicking those found in native α-DG. These synthetic glycopeptides emulate intermediate structures, not otherwise readily available from natural sources. Through enzymatic and mass spectrometric methods, we demonstrate that the presence and specific location of O-Man can impact either the regional exclusion or the site of O-GalNAc addition on α-DG, elucidating the factors contributing to the glycosylation patterns observed in vivo. These results provide evidence that one form of glycosylation can influence another form of glycosylation in α-DG and suggest that in the absence of proper O-mannosylation, as is associated with certain forms of muscular dystrophy, aberrant O-GalNAc modifications may occur and could play a role in disease presentation.
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Affiliation(s)
- Duy T Tran
- Developmental Glycobiology Unit, NIDCR, National Institutes of Health, Bethesda, Maryland 20892, USA
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35
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Harrison R, Hitchen PG, Panico M, Morris HR, Mekhaiel D, Pleass RJ, Dell A, Hewitt JE, Haslam SM. Glycoproteomic characterization of recombinant mouse α-dystroglycan. Glycobiology 2012; 22:662-75. [PMID: 22241827 PMCID: PMC3311285 DOI: 10.1093/glycob/cws002] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 01/04/2012] [Accepted: 01/04/2012] [Indexed: 12/15/2022] Open
Abstract
α-Dystroglycan (DG) is a key component of the dystrophin-glycoprotein complex. Aberrant glycosylation of the protein has been linked to various forms of congenital muscular dystrophy. Unusually α-DG has previously been demonstrated to be modified with both O-N-acetylgalactosamine and O-mannose initiated glycans. In the present study, Fc-tagged recombinant mouse α-DG was expressed and purified from human embryonic kidney 293T cells. α-DG glycopeptides were characterized by glycoproteomic strategies using both nano-liquid chromatography matrix-assisted laser desorption ionization and electrospray tandem mass spectrometry. A total of 14 different peptide sequences and 38 glycopeptides were identified which displayed heterogeneous O-glycosylation. These data provide new insights into the complex domain-specific O-glycosylation of α-DG.
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Affiliation(s)
- Rebecca Harrison
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - Paul G Hitchen
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - Maria Panico
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - Howard R Morris
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - David Mekhaiel
- Centre for Genetics and Genomics, School of Biology, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Richard J Pleass
- Centre for Genetics and Genomics, School of Biology, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Anne Dell
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - Jane E Hewitt
- Centre for Genetics and Genomics, School of Biology, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Stuart M Haslam
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
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36
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Yoshimura Y, Nudelman AS, Levery SB, Wandall HH, Bennett EP, Hindsgaul O, Clausen H, Nishimura SI. Elucidation of the sugar recognition ability of the lectin domain of UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 3 by using unnatural glycopeptide substrates. Glycobiology 2012; 22:429-38. [PMID: 22042768 DOI: 10.1093/glycob/cwr159] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Mucin-type glycosylation [α-N-acetyl-D-galactosamine (α-GalNAc)-O-Ser/Thr] on proteins is initiated biosynthetically by 16 homologous isoforms of GalNAc-Ts (uridine diphosphate-GalNAc:polypeptide N-acetylgalactosaminyltransferases). All the GalNAc-Ts consist of a catalytic domain and a lectin domain. Previous reports of GalNAc-T assays toward peptides and α-GalNAc glycopeptides showed that the lectin domain recognized the sugar on the substrates and affected the reaction; however, the details are not clear. Here, we report a new strategy to give insight on the sugar recognition ability and the function of the GalNAc-T3 lectin domain using chemically synthesized natural-type (α-GalNAc-O-Thr) and unnatural-type [β-GalNAc-O-Thr, α-Fuc-O-Thr and β-GlcNAc-O-Thr] MUC5AC glycopeptides. GalNAc-T3 is one of isoforms expressed in various organs, its substrate specificity extensively characterized and its anomalous expression has been identified in several types of cancer (e.g. pancreas and stomach). The glycopeptides used in this study were designed based on a preliminary peptide assay with a sequence derived from the MUC5AC tandem repeat. Through GalNAc-T3 and lectin-inactivated GalNAc-T3, competition assays between the glycopeptide substrates and product analyses (MALDI-TOF MS, RP-HPLC and ETD-MS/MS), we show that the lectin domain strictly recognized GalNAc on the substrate and this specificity controlled the glycosylation pathway.
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Affiliation(s)
- Yayoi Yoshimura
- Graduate School of Life Science and Research Center for Post-Genome Science and Technology, Hokkaido University, Sapporo 001-0021, Japan.
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Ding MX, Wang HF, Wang JS, Zhan H, Zuo YG, Yang DL, Liu JY, Wang W, Ke CX, Yan RP. ppGalNAc T1 as a potential novel marker for human bladder cancer. Asian Pac J Cancer Prev 2012; 13:5653-7. [PMID: 23317233 DOI: 10.7314/apjcp.2012.13.11.5653] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVES To investigate the effect of glycopeptide-preferring polypeptide GalNAc transferase 1 (ppGalNAc T1) targeted RNA interference (RNAi) on the growth and migration of human bladder carcinoma EJ cells in vitro and in vivo. METHODS DNA microarray assays were performed to determine ppGalNAc Ts(ppGalNAc T1-9) expression in human bladder cancer and normal bladder tissues. We transfected the EJ bladder cancer cell line with well-designed ppGalNAc T1 siRNA. Boyden chamber and Wound healing assays were used to investigate changes of shppGalNAc T1-EJ cell migration. Proliferation of shppGalNAc T1-EJ cells in vitro was assessed using [3H]-thymidine incorporation assay and soft agar colony formation assays. Subcutaneous bladder tumors in BALB/c nude mice were induced by inoculation of shppGalNAc T1-EJ cells and after inoculation diameters of tumors were measured every 5 days to determine gross tumor volumes. RESULTS ppGalNAc T1 mRNA in bladder cancer tissues was 11.2-fold higher than in normal bladder tissues. When ppGalNAc T1 expression in EJ cells was knocked down through transfection by pSUPER-shppGalNAc T1 vector, markedly reduced incorporation of [3H]-thymidine into DNA of EJ cells was observed at all time points compared with the empty vector transfected control cells. However, ppGalNAc T1 knockdown did not significantly inhibited cell migration (only 12.3%). Silenced ppGalNAc T1 expression significantly inhibited subcutaneous tumor growth compared with the control groups injected with empty vector transfected control cells. At the end of observation course (40 days), the inhibitory rate of cancerous growth for ppGalNAc T1 knockdown was 52.5%. CONCLUSION ppGalNAc T1 might be a potential novel marker for human bladder cancer. Although ppGalNAc T1 knockdown caused no remarkable change in cell migration, silenced expression significantly inhibited proliferation and tumor growth of the bladder cancer EJ cell line.
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Affiliation(s)
- Ming-Xia Ding
- Department of Urology, The Second Affiliated Hospital of Kunming Medical University, Yunnan Institute of Urology, Kunming, China E-mail :
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Gerken TA. O-glycoprotein biosynthesis: site localization by Edman degradation and site prediction based on random peptide substrates. Methods Mol Biol 2012; 842:81-108. [PMID: 22259131 DOI: 10.1007/978-1-61779-513-8_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The characterization of mucin-type O-glycosylation is fraught with extreme difficulty at almost every level of analysis: from difficulties in obtaining glycopeptides suitable for study, their structural heterogeneity, lack of broad acting glycosidase tools capable of simplifying the glycans, and finally the vast complexity of performing analysis on multiply glycosylated glycopeptides. This, along with a lack of known peptide sequence motif(s) for the transferases that initiate mucin-type O-glycosylation, significantly hinders our understanding of mucin-type O-glycosylation at almost every level from their biosynthesis to their biological and biophysical properties. In this chapter, the use of partial chemical deglycosylation coupled with Edman amino acid sequencing is described to quantify sites of O-glycosylation. In addition, the use of oriented random peptide substrates is described for providing the specificities of the polypeptide α-N-acetylgalactosaminyltransferases, which can be used to estimate transferase-specific sites of O-glycosylation.
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Affiliation(s)
- Thomas A Gerken
- Department of Pediatrics and Biochemistry, Case Western Reserve University, School of Medicine, Cleveland, OH, USA,
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Raman J, Guan Y, Perrine CL, Gerken TA, Tabak LA. UDP-N-acetyl-α-D-galactosamine:polypeptide N-acetylgalactosaminyltransferases: completion of the family tree. Glycobiology 2011; 22:768-77. [PMID: 22186971 DOI: 10.1093/glycob/cwr183] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The formation of mucin-type O-glycans is initiated by an evolutionarily conserved family of enzymes, the UDP-N-acetyl-α-D-galactosamine:polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts). The human genome encodes 20 transferases; 17 of which have been characterized functionally. The complexity of the GalNAc-T family reflects the differential patterns of expression among the individual enzyme isoforms and the unique substrate specificities which are required to form the dense arrays of glycans that are essential for mucin function. We report the expression patterns and enzymatic activity of the remaining three members of the family and the further characterization of a recently reported isoform, GalNAc-T17. One isoform, GalNAcT-16 that is most homologous to GalNAc-T14, is widely expressed (abundantly in the heart) and has robust polypeptide transferase activity. The second isoform GalNAc-T18, most similar to GalNAc-T8, -T9 and -T19, completes a discrete subfamily of GalNAc-Ts. It is widely expressed and has low, albeit detectable, activity. The final isoform, GalNAc-T20, is most homologous to GalNAc-T11 but lacks a lectin domain and has no detectable transferase activity with the panel of substrates tested. We have also identified and characterized enzymatically active splice variants of GalNAc-T13 that differ in the sequence of their lectin domain. The variants differ in their affinities for glycopeptide substrates. Our findings provide a comprehensive view of the complexities of mucin-type O-glycan formation and provide insight into the underlying mechanisms employed to heavily decorate mucins and mucin-like domains with carbohydrate.
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Affiliation(s)
- Jayalakshmi Raman
- Department of Health and Human Services, Section on Biological Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Li X, Wang J, Li W, Xu Y, Shao D, Xie Y, Xie W, Kubota T, Narimatsu H, Zhang Y. Characterization of ppGalNAc-T18, a member of the vertebrate-specific Y subfamily of UDP-N-acetyl-α-D-galactosamine:polypeptide N-acetylgalactosaminyltransferases. Glycobiology 2011; 22:602-15. [PMID: 22171061 DOI: 10.1093/glycob/cwr179] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The first step of mucin-type O-glycosylation is catalyzed by members of the UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase (ppGalNAc-T; EC 2.4.1.41) family. Each member of this family has unique substrate specificity and expression profiles. In this report, we describe a new subfamily of ppGalNAc-Ts, designated the Y subfamily. The Y subfamily consists of four members, ppGalNAc-T8, -T9, -T17 and -T18, in which the conserved YDX(5)WGGENXE sequence in the Gal/GalNAc-T motif of ppGalNAc-Ts is mutated to LDX(5)YGGENXE. Phylogenetic analysis revealed that the Y subfamily members only exist in vertebrates. All four Y subfamily members lack in vitro GalNAc-transferase activity toward classical substrates possibly because of the UDP-GalNAc-binding pocket mutants. However, ppGalNAc-T18, the newly identified defining member, was localized in the endoplasmic reticulum rather than the Golgi apparatus in lung carcinoma cells. The knockdown of ppGalNAc-T18 altered cell morphology, proliferation potential and changed cell O-glycosylation. ppGalNAc-T18 can also modulate the in vitro GalNAc-transferase activity of ppGalNAc-T2 and -T10, suggesting that it may be a chaperone-like protein. These findings suggest that the new Y subfamily of ppGalNAc-Ts plays an important role in protein glycosylation; characterizing their functions will provide new insight into the role of ppGalNAc-Ts.
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Affiliation(s)
- Xing Li
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 197 Rui Jin Road II, Shanghai 200025, China
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Tran DT, Zhang L, Zhang Y, Tian E, Earl LA, Ten Hagen KG. Multiple members of the UDP-GalNAc: polypeptide N-acetylgalactosaminyltransferase family are essential for viability in Drosophila. J Biol Chem 2011; 287:5243-52. [PMID: 22157008 DOI: 10.1074/jbc.m111.306159] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Mucin-type O-glycosylation represents a major form of post-translational modification that is conserved across most eukaryotic species. This type of glycosylation is initiated by a family of enzymes (GalNAc-Ts in mammals and PGANTs in Drosophila) whose members are expressed in distinct spatial and temporal patterns during development. Previous work from our group demonstrated that one member of this family is essential for viability and another member modulates extracellular matrix composition and integrin-mediated cell adhesion during development. To investigate whether other members of this family are essential, we employed RNA interference (RNAi) to each gene in vivo. Using this approach, we identified 4 additional pgant genes that are required for viability. Ubiquitous RNAi to pgant4, pgant5, pgant7, or the putative glycosyltransferase CG30463 resulted in lethality. Tissue-specific RNAi was also used to define the specific organ systems and tissues in which each essential family member is required. Interestingly, each essential pgant had a unique complement of tissues in which it was required. Additionally, certain tissues (mesoderm, digestive system, and tracheal system) required more than one pgant, suggesting unique functions for specific enzymes in these tissues. Expanding upon our RNAi results, we found that conventional mutations in pgant5 resulted in lethality and specific defects in specialized cells of the digestive tract, resulting in loss of proper digestive system acidification. In summary, our results highlight essential roles for O-glycosylation and specific members of the pgant family in many aspects of development and organogenesis.
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Affiliation(s)
- Duy T Tran
- Developmental Glycobiology Unit, NIDCR, National Institutes of Health, Bethesda, Maryland 20892-4370, USA
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Pedersen JW, Bennett EP, Schjoldager KTBG, Meldal M, Holmér AP, Blixt O, Cló E, Levery SB, Clausen H, Wandall HH. Lectin domains of polypeptide GalNAc transferases exhibit glycopeptide binding specificity. J Biol Chem 2011; 286:32684-96. [PMID: 21768105 PMCID: PMC3173194 DOI: 10.1074/jbc.m111.273722] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 07/09/2011] [Indexed: 11/06/2022] Open
Abstract
UDP-GalNAc:polypeptide α-N-acetylgalactosaminyltransferases (GalNAc-Ts) constitute a family of up to 20 transferases that initiate mucin-type O-glycosylation. The transferases are structurally composed of catalytic and lectin domains. Two modes have been identified for the selection of glycosylation sites by GalNAc-Ts: confined sequence recognition by the catalytic domain alone, and concerted recognition of acceptor sites and adjacent GalNAc-glycosylated sites by the catalytic and lectin domains, respectively. Thus far, only the catalytic domain has been shown to have peptide sequence specificity, whereas the primary function of the lectin domain is to increase affinity to previously glycosylated substrates. Whether the lectin domain also has peptide sequence selectivity has remained unclear. Using a glycopeptide array with a library of synthetic and recombinant glycopeptides based on sequences of mucins MUC1, MUC2, MUC4, MUC5AC, MUC6, and MUC7 as well as a random glycopeptide bead library, we examined the binding properties of four different lectin domains. The lectin domains of GalNAc-T1, -T2, -T3, and -T4 bound different subsets of small glycopeptides. These results indicate an additional level of complexity in the initiation step of O-glycosylation by GalNAc-Ts.
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Affiliation(s)
| | - Eric P. Bennett
- School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N and
| | | | - Morten Meldal
- the Carlsberg Laboratory and Nano Science Center, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | | | - Ola Blixt
- From the Department of Cellular and Molecular Medicine and
| | - Emiliano Cló
- From the Department of Cellular and Molecular Medicine and
| | | | - Henrik Clausen
- From the Department of Cellular and Molecular Medicine and
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Gill DJ, Clausen H, Bard F. Location, location, location: new insights into O-GalNAc protein glycosylation. Trends Cell Biol 2011; 21:149-58. [PMID: 21145746 DOI: 10.1016/j.tcb.2010.11.004] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/10/2010] [Accepted: 11/11/2010] [Indexed: 01/04/2023]
Abstract
O-GalNAc glycosylation of proteins confers essential structural, protective and signaling roles in eumetazoans. Addition of O-glycans onto proteins is an extremely complex process that regulates both sites of attachment and the types of oligosaccharides added. Twenty distinct polypeptide GalNAc-transferases (GalNAc-Ts) initiate O-glycosylation and fine-tuning their expression provides a mechanism for regulating this action. Recently, a new mode of regulation has emerged where activation of Src kinase selectively redistributes Golgi-localized GalNAc-Ts to the ER. This relocalization results in a strong increase in the density of O-glycan decoration. In this review, we discuss how different mechanisms can regulate the number and the types of O-glycans decorating proteins. In addition, we speculate how Src-dependent relocation of GalNAc-Ts could play an important role in cancerous cellular transformation.
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Affiliation(s)
- David J Gill
- Institute of Molecular and Cell Biology (IMCB), Proteos, 61 Biopolis Drive, Singapore, 138673
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Gerken TA, Jamison O, Perrine CL, Collette JC, Moinova H, Ravi L, Markowitz SD, Shen W, Patel H, Tabak LA. Emerging paradigms for the initiation of mucin-type protein O-glycosylation by the polypeptide GalNAc transferase family of glycosyltransferases. J Biol Chem 2011; 286:14493-507. [PMID: 21349845 DOI: 10.1074/jbc.m111.218701] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian mucin-type O-glycosylation is initiated by a large family of ∼20 UDP-GalNAc:polypeptide α-N-acetylgalactosaminyltransferases (ppGalNAc Ts) that transfer α-GalNAc from UDP-GalNAc to Ser and Thr residues of polypeptide acceptors. Characterizing the peptide substrate specificity of each isoform is critical to understanding their properties, biological roles, and significance. Presently, only the specificities of ppGalNAc T1, T2, and T10 and the fly orthologues of T1 and T2 have been systematically characterized utilizing random peptide substrates. We now extend these studies to ppGalNAc T3, T5, and T12, transferases variously associated with human disease. Our results reveal several common features; the most striking is the similar pattern of enhancements for the three residues C-terminal to the site of glycosylation for those transferases that contain a common conserved Trp. In contrast, residues N-terminal to the site of glycosylation show a wide range of isoform-specific enhancements, with elevated preferences for Pro, Val, and Tyr being the most common at the -1 position. Further analysis reveals that the ratio of positive (Arg, Lys, and His) to negative (Asp and Glu) charged residue enhancements varied among transferases, thus further modulating substrate preference in an isoform-specific manner. By utilizing the obtained transferase-specific preferences, the glycosylation patterns of the ppGalNAc Ts against a series of peptide substrates could roughly be reproduced, demonstrating the potential for predicting isoform-specific glycosylation. We conclude that each ppGalNAc T isoform may be uniquely sensitive to peptide sequence and overall charge, which together dictates the substrate sites that will be glycosylated.
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Affiliation(s)
- Thomas A Gerken
- Department of Pediatrics (W. A. Bernbaum Center for Cystic Fibrosis Research), Case Western Reserve University, Cleveland, Ohio 44106, USA.
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45
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Hashimoto R, Fujitani N, Takegawa Y, Kurogochi M, Matsushita T, Naruchi K, Ohyabu N, Hinou H, Gao XD, Manri N, Satake H, Kaneko A, Sakamoto T, Nishimura SI. An Efficient Approach for the Characterization of Mucin-Type Glycopeptides: The Effect of O-Glycosylation on the Conformation of Synthetic Mucin Peptides. Chemistry 2011; 17:2393-404. [DOI: 10.1002/chem.201002754] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Indexed: 01/19/2023]
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46
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Peng C, Togayachi A, Kwon YD, Xie C, Wu G, Zou X, Sato T, Ito H, Tachibana K, Kubota T, Noce T, Narimatsu H, Zhang Y. Identification of a novel human UDP-GalNAc transferase with unique catalytic activity and expression profile. Biochem Biophys Res Commun 2010; 402:680-6. [PMID: 20977886 DOI: 10.1016/j.bbrc.2010.10.084] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Accepted: 10/19/2010] [Indexed: 12/18/2022]
Abstract
A novel member of the human ppGalNAc-T family, ppGalNAc-T20, was identified and characterized. Amino acid alignment revealed a high sequence identity between ppGalNAc-T20 and -T10. In the GalNAc transfer assay towards mucin-derived peptide substrates, the recombinant ppGalNAc-T20 demonstrated to be a typical glycopeptide GalNAc-transferase that exhibits activity towards mono-GalNAc-glycosylated peptide EA2 derived from rat submandibular gland mucin but no activity towards non-modified EA2. The in vitro catalytic property of ppGalNAc-T20 was compared with that of ppGalNAc-T10 to show different acceptor substrate specificities and kinetic constants. The ppGalNAc-T20 transcript was found exclusively in testis and brain. In situ hybridization further reveals that ppGalNAc-T20 was specifically localized in primary and secondary spermatocytes of the two meiotic periods, suggesting that it may involve in O-glycosylation during mouse spermatogenesis.
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Affiliation(s)
- Can Peng
- Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine (SCSB), Shanghai Jiao Tong University, Shanghai, China
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Tabak LA. The role of mucin-type O-glycans in eukaryotic development. Semin Cell Dev Biol 2010; 21:616-21. [PMID: 20144722 DOI: 10.1016/j.semcdb.2010.02.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 01/22/2010] [Accepted: 02/01/2010] [Indexed: 01/09/2023]
Abstract
Newly emerging genetic studies have revealed that a subset of the family of glycosyltransferases responsible for the formation of mucin-type O glycans is essential for normal development. As additional genetic, biochemical and physical tools are developed to interrogate the complex structure and surface location of this under-studied class of carbohydrate, no doubt additional roles will be elucidated.
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Affiliation(s)
- Lawrence A Tabak
- Section on Biological Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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48
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Miwa HE, Gerken TA, Jamison O, Tabak LA. Isoform-specific O-glycosylation of osteopontin and bone sialoprotein by polypeptide N-acetylgalactosaminyltransferase-1. J Biol Chem 2010; 285:1208-19. [PMID: 19880513 PMCID: PMC2801249 DOI: 10.1074/jbc.m109.035436] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 10/08/2009] [Indexed: 11/06/2022] Open
Abstract
Mucin-type O-glycan biosynthesis is regulated by the family of UDP-GalNAc polypeptide:N-acetylgalactosaminlytransfersases (ppGalNAcTs) that catalyzes the first step in the pathway by transferring GalNAc to Ser or Thr residues in a protein from the sugar donor UDP-GalNAc. Because not all Ser/Thr residues are glycosylated, rules must exist that signal which hydroyxamino acids acquire sugar. To date, no universal consensus signal has emerged. Therefore, strategies to deduce the subset of proteins that will be glycosylated by distinct ppGalNAcTs must be developed. Mucin-type O-glycoproteins are present abundantly in bone, where we found multiple ppGalNAcT isoforms, including ppGalNAcT-1, to be highly expressed. Thus, we compared glycoproteins expressed in wild-type and Galnt1-null mice to identify bone-associated proteins that were glycosylated in a ppGalNAcT-1-dependent manner. A reduction in the apparent molecular masses of two SIBLINGs (small integrin binding ligand N-linked glycoproteins), osteopontin (OPN) and bone sialoprotein (BSP) in the Galnt1-null mice relative to those of the wild-type was observed. Several synthetic peptides derived from OPN and BSP sequences were designed to include either known or predicted (in silico) glycosylation sites. In vitro glycosylation assays of these peptides with recombinant ppGalNAcT-1, ppGalNAcT-2, or ppGalNAcT-3 demonstrated that both SIBLINGs contained Thr/Ser residues that were preferentially glycosylated by ppGalNAcT-1. In addition, lysates prepared from wild-type, but not those from Galnt1-null derived osteoblasts, could glycosylate these peptides efficiently, suggesting that OPN and BSP contain sites that are specific for ppGalNAcT-1. Our study presents a novel and systematic approach for identification of isoform-specific substrates of the ppGalNAcT family and suggests ppGalNAcT-1 to be indispensable for O-glycosylation at specific sites of the bone glycoproteins OPN and BSP.
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Affiliation(s)
- Hazuki E. Miwa
- From the Section on Biological Chemistry, NIDDK, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892 and
| | - Thomas A. Gerken
- the Departments of Pediatrics and Biochemistry, W. A. Bernbaum Center for Cystic Fibrosis Research, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
| | - Oliver Jamison
- the Departments of Pediatrics and Biochemistry, W. A. Bernbaum Center for Cystic Fibrosis Research, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
| | - Lawrence A. Tabak
- From the Section on Biological Chemistry, NIDDK, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892 and
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