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Ramakrishnan P. O-GlcNAcylation and immune cell signaling: A review of known and a preview of unknown. J Biol Chem 2024; 300:107349. [PMID: 38718861 PMCID: PMC11180344 DOI: 10.1016/j.jbc.2024.107349] [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: 10/30/2023] [Revised: 04/25/2024] [Accepted: 04/27/2024] [Indexed: 06/06/2024] Open
Abstract
The dynamic and reversible modification of nuclear and cytoplasmic proteins by O-GlcNAcylation significantly impacts the function and dysfunction of the immune system. O-GlcNAcylation plays crucial roles under both physiological and pathological conditions in the biochemical regulation of all immune cell functions. Three and a half decades of knowledge acquired in this field is merely sufficient to perceive that what we know is just the prelude. This review attempts to mark out the known regulatory roles of O-GlcNAcylation in key signal transduction pathways and specific protein functions in the immune system and adumbrate ensuing questions toward the unknown functions.
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Affiliation(s)
- Parameswaran Ramakrishnan
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA; The Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA; Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, USA; University Hospitals-Cleveland Medical Center, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA.
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Chen YH, Cheng WH. Hexosamine biosynthesis and related pathways, protein N-glycosylation and O-GlcNAcylation: their interconnection and role in plants. FRONTIERS IN PLANT SCIENCE 2024; 15:1349064. [PMID: 38510444 PMCID: PMC10951099 DOI: 10.3389/fpls.2024.1349064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 02/05/2024] [Indexed: 03/22/2024]
Abstract
N-Acetylglucosamine (GlcNAc), a fundamental amino sugar moiety, is essential for protein glycosylation, glycolipid, GPI-anchor protein, and cell wall components. Uridine diphosphate-GlcNAc (UDP-GlcNAc), an active form of GlcNAc, is synthesized through the hexosamine biosynthesis pathway (HBP). Although HBP is highly conserved across organisms, the enzymes involved perform subtly distinct functions among microbes, mammals, and plants. A complete block of HBP normally causes lethality in any life form, reflecting the pivotal role of HBP in the normal growth and development of organisms. Although HBP is mainly composed of four biochemical reactions, HBP is exquisitely regulated to maintain the homeostasis of UDP-GlcNAc content. As HBP utilizes substrates including fructose-6-P, glutamine, acetyl-CoA, and UTP, endogenous nutrient/energy metabolites may be integrated to better suit internal growth and development, and external environmental stimuli. Although the genes encoding HBP enzymes are well characterized in microbes and mammals, they were less understood in higher plants in the past. As the HBP-related genes/enzymes have largely been characterized in higher plants in recent years, in this review we update the latest advances in the functions of the HBP-related genes in higher plants. In addition, HBP's salvage pathway and GlcNAc-mediated two major co- or post-translational modifications, N-glycosylation and O-GlcNAcylation, are also included in this review. Further knowledge on the function of HBP and its product conjugates, and the mechanisms underlying their response to deleterious environments might provide an alternative strategy for agricultural biofortification in the future.
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Affiliation(s)
| | - Wan-Hsing Cheng
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
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3
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Whitham D, Bruno P, Haaker N, Arcaro KF, Pentecost BT, Darie CC. Deciphering a proteomic signature for the early detection of breast cancer from breast milk: the role of quantitative proteomics. Expert Rev Proteomics 2024; 21:81-98. [PMID: 38376826 DOI: 10.1080/14789450.2024.2320158] [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: 09/05/2023] [Accepted: 12/26/2023] [Indexed: 02/21/2024]
Abstract
INTRODUCTION Breast cancer is one of the most prevalent cancers among women in the United States. Current research regarding breast milk has been focused on the composition and its role in infant growth and development. There is little information about the proteins, immune cells, and epithelial cells present in breast milk which can be indicative of the emergence of BC cells and tumors. AREAS COVERED We summarize all breast milk studies previously done in our group using proteomics. These studies include 1D-PAGE and 2D-PAGE analysis of breast milk samples, which include within woman and across woman comparisons to identify dysregulated proteins in breast milk and the roles of these proteins in both the development of BC and its diagnosis. Our projected outlook for the use of milk for cancer detection is also discussed. EXPERT OPINION Analyzing the samples by multiple methods allows one to interrogate a set of samples with various biochemical methods that complement each other, thus providing a more comprehensive proteome. Complementing methods like 1D-PAGE, 2D-PAGE, in-solution digestion and proteomics analysis with PTM-omics, peptidomics, degradomics, or interactomics will provide a better understanding of the dysregulated proteins, but also the modifications or interactions between these proteins.
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Affiliation(s)
- Danielle Whitham
- Department of Chemistry and Biochemistry, Clarkson University, Potsdam, NY, USA
| | - Pathea Bruno
- Department of Chemistry and Biochemistry, Clarkson University, Potsdam, NY, USA
| | - Norman Haaker
- Department of Chemistry and Biochemistry, Clarkson University, Potsdam, NY, USA
| | - Kathleen F Arcaro
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, MA, USA
| | - Brian T Pentecost
- Department of Chemistry and Biochemistry, Clarkson University, Potsdam, NY, USA
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, MA, USA
| | - Costel C Darie
- Department of Chemistry and Biochemistry, Clarkson University, Potsdam, NY, USA
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4
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Lu Q, Zhang X, Liang T, Bai X. O-GlcNAcylation: an important post-translational modification and a potential therapeutic target for cancer therapy. Mol Med 2022; 28:115. [PMID: 36104770 PMCID: PMC9476278 DOI: 10.1186/s10020-022-00544-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/07/2022] [Indexed: 02/07/2023] Open
Abstract
O-linked β-d-N-acetylglucosamine (O-GlcNAc) is an important post-translational modification of serine or threonine residues on thousands of proteins in the nucleus and cytoplasm of all animals and plants. In eukaryotes, only two conserved enzymes are involved in this process. O-GlcNAc transferase is responsible for adding O-GlcNAc to proteins, while O-GlcNAcase is responsible for removing it. Aberrant O-GlcNAcylation is associated with a variety of human diseases, such as diabetes, cancer, neurodegenerative diseases, and cardiovascular diseases. Numerous studies have confirmed that O-GlcNAcylation is involved in the occurrence and progression of cancers in multiple systems throughout the body. It is also involved in regulating multiple cancer hallmarks, such as metabolic reprogramming, proliferation, invasion, metastasis, and angiogenesis. In this review, we first describe the process of O-GlcNAcylation and the structure and function of O-GlcNAc cycling enzymes. In addition, we detail the occurrence of O-GlcNAc in various cancers and the role it plays. Finally, we discuss the potential of O-GlcNAc as a promising biomarker and novel therapeutic target for cancer diagnosis, treatment, and prognosis.
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Suban S, Sendersky E, Golden SS, Schwarz R. Impairment of a cyanobacterial glycosyltransferase that modifies a pilin results in biofilm development. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:218-229. [PMID: 35172394 PMCID: PMC9306852 DOI: 10.1111/1758-2229.13050] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 02/03/2022] [Indexed: 05/03/2023]
Abstract
A biofilm inhibiting mechanism operates in the cyanobacterium Synechococcus elongatus. Here, we demonstrate that the glycosyltransferase homologue, Ogt, participates in the inhibitory process - inactivation of ogt results in robust biofilm formation. Furthermore, a mutational approach shows requirement of the glycosyltransferase activity for biofilm inhibition. This enzyme is necessary for glycosylation of the pilus subunit and for adequate pilus formation. In contrast to wild-type culture in which most cells exhibit several pili, only 25% of the mutant cells are piliated, half of which possess a single pilus. In spite of this poor piliation, natural DNA competence was similar to that of wild-type; therefore, we propose that the unglycosylated pili facilitate DNA transformation. Additionally, conditioned medium from wild-type culture, which contains a biofilm inhibiting substance(s), only partially blocks biofilm development by the ogt-mutant. Thus, we suggest that inactivation of ogt affects multiple processes including production or secretion of the inhibitor as well as the ability to sense or respond to it.
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Affiliation(s)
- Shiran Suban
- The Mina and Everard Goodman Faculty of Life SciencesBar‐Ilan UniversityRamat‐Gan5290002Israel
| | - Eleonora Sendersky
- The Mina and Everard Goodman Faculty of Life SciencesBar‐Ilan UniversityRamat‐Gan5290002Israel
| | - Susan S. Golden
- Division of Biological SciencesUniversity of California, San DiegoLa JollaCA92093USA
- Center for Circadian BiologyUniversity of California, San DiegoLa JollaCA92093USA
| | - Rakefet Schwarz
- The Mina and Everard Goodman Faculty of Life SciencesBar‐Ilan UniversityRamat‐Gan5290002Israel
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6
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Lam C, Low JY, Tran PT, Wang H. The hexosamine biosynthetic pathway and cancer: Current knowledge and future therapeutic strategies. Cancer Lett 2021; 503:11-18. [PMID: 33484754 DOI: 10.1016/j.canlet.2021.01.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 01/07/2021] [Accepted: 01/11/2021] [Indexed: 12/28/2022]
Abstract
The hexosamine biosynthetic pathway (HBP) is a glucose metabolism pathway that results in the synthesis of a nucleotide sugar UDP-GlcNAc, which is subsequently used for the post-translational modification (O-GlcNAcylation) of intracellular proteins that regulate nutrient sensing and stress response. The HBP is carried out by a series of enzymes, many of which have been extensively implicated in cancer pathophysiology. Increasing evidence suggests that elevated activation of the HBP may act as a cancer biomarker. Inhibition of HBP enzymes could suppress tumor cell growth, modulate the immune response, reduce resistance, and sensitize tumor cells to conventional cancer therapy. Therefore, targeting the HBP may serve as a novel strategy for treating cancer patients. Here, we review the current findings on the significance of HBP enzymes in various cancers and discuss future approaches for exploiting HBP inhibition for cancer treatment.
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Affiliation(s)
- Christine Lam
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States
| | - Jin-Yih Low
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States
| | - Phuoc T Tran
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States
| | - Hailun Wang
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, United States.
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7
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Minati R, Perreault C, Thibault P. A Roadmap Toward the Definition of Actionable Tumor-Specific Antigens. Front Immunol 2020; 11:583287. [PMID: 33424836 PMCID: PMC7793940 DOI: 10.3389/fimmu.2020.583287] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/30/2020] [Indexed: 12/15/2022] Open
Abstract
The search for tumor-specific antigens (TSAs) has considerably accelerated during the past decade due to the improvement of proteogenomic detection methods. This provides new opportunities for the development of novel antitumoral immunotherapies to mount an efficient T cell response against one or multiple types of tumors. While the identification of mutated antigens originating from coding exons has provided relatively few TSA candidates, the possibility of enlarging the repertoire of targetable TSAs by looking at antigens arising from non-canonical open reading frames opens up interesting avenues for cancer immunotherapy. In this review, we outline the potential sources of TSAs and the mechanisms responsible for their expression strictly in cancer cells. In line with the heterogeneity of cancer, we propose that discrete families of TSAs may be enriched in specific cancer types.
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Affiliation(s)
- Robin Minati
- École Normale Supérieure de Lyon, Université Claude Bernard Lyon I, Université de Lyon, Lyon, France
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
| | - Claude Perreault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Pierre Thibault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Department of Chemistry, Université de Montréal, Montréal, QC, Canada
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Deng JJ, Li ZQ, Mo ZQ, Xu S, Mao HH, Shi D, Li ZW, Dan XM, Luo XC. Immunomodulatory Effects of N-Acetyl Chitooligosaccharides on RAW264.7 Macrophages. Mar Drugs 2020; 18:md18080421. [PMID: 32806493 PMCID: PMC7460392 DOI: 10.3390/md18080421] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/05/2020] [Accepted: 08/07/2020] [Indexed: 02/06/2023] Open
Abstract
The ongoing development of new production methods may lead to the commercialization of N-acetyl chitooligosaccharides (NACOS), such as chitosan oligosaccharides (COS). The bioactivity of NACOS, although not well detailed, differs from that of COS, as they have more acetyl groups than COS. We used two enzymatically produced NACOS with different molecular compositions and six NACOS (NACOS1–6) with a single degree of polymerization to verify their immunomodulatory effects on the RAW264.7 macrophage cell line. We aimed to identify any differences between COS and various NACOS with a single degree of polymerization. The results showed that NACOS had similar immune enhancement effects on RAW264.7 cells as COS, including the generation of reactive oxygen species (ROS), phagocytotic activity, and the production of pro-inflammation cytokines (IL-1β, IL-6, and TNF-α). However, unlike COS and lipopolysaccharide (LPS), NACOS1 and NACOS6 significantly inhibited nitric oxide (NO) production. Besides their immune enhancement effects, NACOS also significantly inhibited the LPS-induced RAW264.7 inflammatory response with some differences between various polymerization degrees. We confirmed that the NF-κB pathway is associated with the immunomodulatory effects of NACOS on RAW264.7 cells. This study could inform the application of NACOS with varying different degrees of polymerization in human health.
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Affiliation(s)
- Jun-Jin Deng
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Panyu District, Guangzhou 510006, China; (J.-J.D.); (Z.-Q.L.); (S.X.); (H.-H.M.); (D.S.); (Z.-W.L.)
- Institute of Animal Sciences, Guangdong Academy of Agricultural Sciences, No. 1 Dafeng Street, Wushan Road, Tianhe District, Guangzhou 510640, China
| | - Zong-Qiu Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Panyu District, Guangzhou 510006, China; (J.-J.D.); (Z.-Q.L.); (S.X.); (H.-H.M.); (D.S.); (Z.-W.L.)
| | - Ze-Quan Mo
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China; (Z.-Q.M.); (X.-M.D.)
| | - Shun Xu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Panyu District, Guangzhou 510006, China; (J.-J.D.); (Z.-Q.L.); (S.X.); (H.-H.M.); (D.S.); (Z.-W.L.)
| | - He-Hua Mao
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Panyu District, Guangzhou 510006, China; (J.-J.D.); (Z.-Q.L.); (S.X.); (H.-H.M.); (D.S.); (Z.-W.L.)
| | - Dan Shi
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Panyu District, Guangzhou 510006, China; (J.-J.D.); (Z.-Q.L.); (S.X.); (H.-H.M.); (D.S.); (Z.-W.L.)
| | - Zhi-Wei Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Panyu District, Guangzhou 510006, China; (J.-J.D.); (Z.-Q.L.); (S.X.); (H.-H.M.); (D.S.); (Z.-W.L.)
| | - Xue-Ming Dan
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China; (Z.-Q.M.); (X.-M.D.)
| | - Xiao-Chun Luo
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Panyu District, Guangzhou 510006, China; (J.-J.D.); (Z.-Q.L.); (S.X.); (H.-H.M.); (D.S.); (Z.-W.L.)
- Correspondence: ; Tel./Fax: +86-(0)20-3938-0609
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Authier F, Muha V, van Aalten DMF. A mouse model for functional dissection of TAB1 O-GlcNAcylation. Wellcome Open Res 2020; 4:128. [PMID: 32676538 PMCID: PMC7333360 DOI: 10.12688/wellcomeopenres.15394.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2020] [Indexed: 01/02/2023] Open
Abstract
Background: O-GlcNAcylation is a posttranslational modification associated with various physiological and pathophysiological processes including diabetes, cancer, neurodegeneration and inflammation. However, the biological mechanisms underlying the role of specific O-GlcNAc sites and their link to phenotypes remain largely unexplored due to lack of suitable
in vivo models. TGF-β activated kinase-1 binding protein-1 (TAB1) is a scaffolding protein required for TGF-β activated kinase-1 (TAK1) mediated signalling. A single O-GlcNAc site has been identified on human TAB1 that modulates TAK1-mediated cytokine release in cells. Methods: Here, we report the generation of the
Tab1
S393A mouse model using a constitutive knock-in strategy. The
Tab1
S393A mice carry a Ser393Ala (S393A) mutation that leads to loss of O-GlcNAcylation site on TAB1. Results: We did not observe any obvious phenotype in
Tab1
S393A mice. Loss of O-GlcNAcylation on TAB1 has no consequences on TAB1 protein level or on TAB1-TAK1 interaction. Conclusions: The homozygous
Tab1
S393A mice are viable and develop with no obvious abnormalities, providing a powerful tool to further investigate the role of O-GlcNAc on TAB1 in the inflammatory response in the context of a whole organism.
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Affiliation(s)
- Florence Authier
- Division of Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Villő Muha
- Division of Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Daan M F van Aalten
- Division of Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
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Nagy T, Fisi V, Frank D, Kátai E, Nagy Z, Miseta A. Hyperglycemia-Induced Aberrant Cell Proliferation; A Metabolic Challenge Mediated by Protein O-GlcNAc Modification. Cells 2019; 8:E999. [PMID: 31466420 PMCID: PMC6769692 DOI: 10.3390/cells8090999] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 08/26/2019] [Accepted: 08/26/2019] [Indexed: 12/13/2022] Open
Abstract
Chronic hyperglycemia has been associated with an increased prevalence of pathological conditions including cardiovascular disease, cancer, or various disorders of the immune system. In some cases, these associations may be traced back to a common underlying cause, but more often, hyperglycemia and the disturbance in metabolic balance directly facilitate pathological changes in the regular cellular functions. One such cellular function crucial for every living organism is cell cycle regulation/mitotic activity. Although metabolic challenges have long been recognized to influence cell proliferation, the direct impact of diabetes on cell cycle regulatory elements is a relatively uncharted territory. Among other "nutrient sensing" mechanisms, protein O-linked β-N-acetylglucosamine (O-GlcNAc) modification emerged in recent years as a major contributor to the deleterious effects of hyperglycemia. An increasing amount of evidence suggest that O-GlcNAc may significantly influence the cell cycle and cellular proliferation. In our present review, we summarize the current data available on the direct impact of metabolic changes caused by hyperglycemia in pathological conditions associated with cell cycle disorders. We also review published experimental evidence supporting the hypothesis that O-GlcNAc modification may be one of the missing links between metabolic regulation and cellular proliferation.
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Affiliation(s)
- Tamás Nagy
- Department of Laboratory Medicine, Medical School, University of Pécs, H-7624 Pécs, Hungary.
| | - Viktória Fisi
- Department of Laboratory Medicine, Medical School, University of Pécs, H-7624 Pécs, Hungary
| | - Dorottya Frank
- Department of Dentistry, Oral and Maxillofacial Surgery, Medical School, University of Pécs, H-7621 Pécs, Hungary
| | - Emese Kátai
- Department of Laboratory Medicine, Medical School, University of Pécs, H-7624 Pécs, Hungary
| | - Zsófia Nagy
- Department of Laboratory Medicine, Medical School, University of Pécs, H-7624 Pécs, Hungary
| | - Attila Miseta
- Department of Laboratory Medicine, Medical School, University of Pécs, H-7624 Pécs, Hungary
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Authier F, Muha V, van Aalten DM. A mouse model for functional dissection of TAB1 O-GlcNAcylation. Wellcome Open Res 2019; 4:128. [DOI: 10.12688/wellcomeopenres.15394.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2019] [Indexed: 11/20/2022] Open
Abstract
Background: O-GlcNAcylation is a posttranslational modification associated with various physiological and pathophysiological processes including diabetes, cancer, neurodegeneration and inflammation. However, the biological mechanisms underlying the role of specific O-GlcNAc sites and their link to phenotypes remain largely unexplored due to lack of suitable in vivo models. TGF-β activated kinase-1 binding protein-1 (TAB1) is a scaffolding protein required for TGF-β activated kinase-1 (TAK1) mediated signalling. A single O-GlcNAc site has been identified on TAB1 that modulates TAK1-mediated cytokine release in cells. Methods: Here, we report the generation of the Tab1S393A mouse model using a constitutive knock-in strategy. The Tab1S393A mice carry a Ser393Ala (S393A) mutation that leads to loss of the single O-GlcNAcylation site on TAB1. Results: We did not observe any obvious phenotype in Tab1S393A mice. Loss of O-GlcNAcylation on TAB1 has no consequences on TAB1 protein level or on TAB1-TAK1 interaction. Conclusions: The homozygous Tab1S393A mice are viable and develop with no obvious abnormalities, providing a powerful tool to further investigate the role of O-GlcNAc on TAB1 in the inflammatory response in the context of a whole organism.
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12
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O-Glycosylation with O-linked β-N-acetylglucosamine increases vascular contraction: Possible modulatory role on Interleukin-10 signaling pathway. Life Sci 2018; 209:78-84. [PMID: 30075176 DOI: 10.1016/j.lfs.2018.07.058] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/27/2018] [Accepted: 07/30/2018] [Indexed: 01/29/2023]
Abstract
AIMS The interleukin-10 (IL-10) is an immuno-regulatory cytokine that plays a protective effect in the vasculature. IL-10 binding to its receptor, activating the IL-10/JAK1/STAT3 cascade to exert its effects. Therefore, STAT3 phosphorylation is essential for IL-10 actions. O-Glycosylation with linked β-N-acetylglucosamine (O-GlcNAc) is a post-translational modification able to regulate many proteins by interfering with protein on a phosphorylation level. Our aim was to determine whether O-GlcNAc promotes the inhibition of IL-10-pathway (JAK1/STAT3/IL-10), inactivationg its action in the vasculature. MAIN METHODS Mice (C57BL/6) aortic segments were incubated with vehicle or Thiamet G (0.1 mM, for 24 h) to increase global O-GlcNAc levels. Aortas from knockout mice for IL-10 were also used. Vascular reactivity and western blot tests were performed to evaluate protein expression. KEY FINDINGS High levels of O-GlcNAc, induced by Thiamet G incubation, increased vascular expression of JAK1, but decreased expression and activity of STAT3. In addition, IL-10 levels were diminished in arteries treated with Thiamet G. Absence of IL-10, as well as augmented O-GlcNAcylation, increased vascular reactivity to constrictor stimuli, an effect that was abolished by ERK 1/2 inhibitor. High levels of O-GlcNAc and the absence of IL-10 also leads to increased vascular expression of ERK1/2. SIGNIFICANCE Our data suggest that O-GlcNAc modification seems to (dys)regulate IL-10 signaling pathway and consequently, compromise the protective effect of this cytokine in vasculature. It is possible that there is a promising relationship in pathophysiological conditions where changes in O-GlcNAcylation and IL-10 levels are observed, such as hypertension and diabetes.
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Nagy T, Kátai E, Fisi V, Takács TT, Stréda A, Wittmann I, Miseta A. Protein O-GlcNAc Modification Increases in White Blood Cells After a Single Bout of Physical Exercise. Front Immunol 2018; 9:970. [PMID: 29774032 PMCID: PMC5943509 DOI: 10.3389/fimmu.2018.00970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 04/18/2018] [Indexed: 01/24/2023] Open
Abstract
Background Protein O-linked N-acetylglucosamine (O-GlcNAc) is a dynamic posttranslational modification influencing the function of many intracellular proteins. Recently it was revealed that O-GlcNAc regulation is modified under various stress states, including ischemia and oxidative stress. Aside from a few contradictory studies based on animal models, the effect of exercise on O-GlcNAc is unexplored. Purpose To evaluate O-GlcNAc levels in white blood cells (WBC) of human volunteers following physical exercise. Methods Young (age 30 ± 5.2), healthy male volunteers (n = 6) were enlisted for the study. Blood parameters including metabolites, ions, “necro”-enzymes, and cell counts were measured before and after a single bout of exercise (2-mile run). From WBC samples, we performed western blots to detect O-GlcNAc modified proteins. The distribution of O-GlcNAc in WBC subpopulations was assessed by flow cytometry. Results Elevation of serum lactic acid (increased from 1.3 ± 0.4 to 6.9 ± 1.7 mM), creatinine (from 77.5 ± 6.3 U/L to 102.2 ± 7.0 μM), and lactate dehydrogenase (from 318.5 ± 26.2 to 380.5 ± 33.2 U/L) confirmed the effect of exercise. WBC count also significantly increased (from 6.6 ± 1.0 to 8.4 ± 1.4 G/L). The level of O-GlcNAc modified proteins in WBCs showed significant elevation after exercise (85 ± 51%, p < 0.05). Flow cytometry revealed that most of this change could be attributed to lymphocytes and monocytes. Conclusion Our results indicate that short-term exercise impacts the O-GlcNAc status of WBCs. O-GlcNAc modification could be a natural process by which physical activity modulates the immune system. Further research could elucidate the role of O-GlcNAc during exercise and validate O-GlcNAc as a biomarker for fitness assessment.
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Affiliation(s)
- Tamás Nagy
- Department of Laboratory Medicine, Medical School, University of Pécs, Pécs, Hungary.,János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Emese Kátai
- Department of Laboratory Medicine, Medical School, University of Pécs, Pécs, Hungary
| | - Viktória Fisi
- Department of Laboratory Medicine, Medical School, University of Pécs, Pécs, Hungary
| | - Tamás Tibor Takács
- Department of Laboratory Medicine, Medical School, University of Pécs, Pécs, Hungary
| | - Antal Stréda
- Department of Internal Medicine and Nephrology Center, Medical School, University of Pécs, Pécs, Hungary
| | - István Wittmann
- Department of Internal Medicine and Nephrology Center, Medical School, University of Pécs, Pécs, Hungary
| | - Attila Miseta
- Department of Laboratory Medicine, Medical School, University of Pécs, Pécs, Hungary
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14
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Lopez Aguilar A, Gao Y, Hou X, Lauvau G, Yates JR, Wu P. Profiling of Protein O-GlcNAcylation in Murine CD8 + Effector- and Memory-like T Cells. ACS Chem Biol 2017; 12:3031-3038. [PMID: 29125738 DOI: 10.1021/acschembio.7b00869] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
During an acute infection, antigenic stimulation leads to activation, expansion, and differentiation of naïve CD8+ T cells, first into cytotoxic effector cells and eventually into long-lived memory cells. T cell antigen receptors (TCRs) detect antigens on antigen-presenting cells (APCs) in the form of antigenic peptides bound to major histocompatibility complex I (MHC-I)-encoded molecules and initiate TCR signal transduction network. This process is mediated by phosphorylation of many intracellular signaling proteins. Protein O-GlcNAc modification is another post-translational modification involved in this process, which often has either reciprocal or synergistic roles with phosphorylation. In this study, using a chemoenzymatic glycan labeling technique and proteomics analysis, we compared protein O-GlcNAcylation of murine effector and memory-like CD8+ T cells differentiated in vitro. By quantitative proteomics analysis, we identified 445 proteins that are significantly regulated in either effector- or memory-like T cell subsets. Furthermore, qualitative and quantitative analysis identified highly regulated protein clusters that suggest involvement of this post-translational modification in specific cellular processes. In effector-like T cells, protein O-GlcNAcylation is heavily involved in transcriptional and translational processes that drive fast effector T cells proliferation. During the formation of memory-like T cells, protein O-GlcNAcylation is involved in a more specific, perhaps more targeted regulation of transcription, mRNA processing, and translation. Significantly, O-GlcNAc plays a critical role as part of the "histone code" in both CD8+ T cells subgroups.
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Affiliation(s)
- Aime Lopez Aguilar
- Department
of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Yu Gao
- Department
of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Xiaomeng Hou
- Department
of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Gregoire Lauvau
- Department
of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - John R. Yates
- Department
of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Peng Wu
- Department
of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States
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15
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Palestinian Arab ethnicity is associated with an adverse metabolic phenotype. Clin Chim Acta 2017; 475:56-63. [PMID: 28987777 DOI: 10.1016/j.cca.2017.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 10/03/2017] [Indexed: 01/16/2023]
Abstract
Urban-dwelling Palestinians have been shown to have higher cardiovascular morbidity and mortality and prevalence of diabetes than urban Israelis. Inflammation is implicated in the etiology of these conditions. We hypothesized that increased inflammatory activation, manifested as increased GlycA, a novel biomarker of global inflammation, would be evident in Palestinians. We compared GlycA concentrations between Palestinians and Israelis and assessed the associations of GlycA with anthropometric, health behavioral and clinical variables in a sample of 1674 Palestinians and Israelis aged 25-74, residing in Jerusalem. The main outcome measure was GlycA concentration. GlycA was higher in Palestinians than Israelis (p<0.001). This finding persisted in young Palestinians with normal glucose tolerance. GlycA, total white blood cell count, the triglyceride to HDL-cholesterol ratio and small LDL-cholesterol particles were all significantly higher in Palestinians compared to Israelis across obesity and glucose tolerance categories. Palestinian women had greater GlycA compared to Israeli women and men of both ethnicities. GlycA as well as adverse cardiovascular biomarkers are all higher in Palestinian Arabs than Israeli Jews, even in young healthy adults. This propensity to inflammation may be a driver of the higher risk of cardiovascular disease, insulin resistance and diabetes observed in this population.
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16
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Abstract
One of the fundamental traits of immune cells in rheumatoid arthritis (RA) is their ability to proliferate, a property shared with the joint-resident cells that form the synovial pannus. The building of biomass imposes high demands for energy and biosynthetic precursors, implicating metabolic control as a basic disease mechanism. During preclinical RA, when autoreactive T cells expand and immunological tolerance is broken, the main sites of disease are the secondary lymphoid tissues. Naive CD4+ T cells from patients with RA have a distinct metabolic signature, characterized by dampened glycolysis, low ATP levels and enhanced shunting of glucose into the pentose phosphate pathway. Equipped with high levels of NADPH and depleted of intracellular reactive oxygen species, such T cells hyperproliferate and acquire proinflammatory effector functions. During clinical RA, immune cells coexist with stromal cells in the acidic milieu of the inflamed joint. This microenvironment is rich in metabolic intermediates that are released into the extracellular space to shape cell-cell communication and the functional activity of tissue-resident cells. Increasing awareness of how metabolites regulate signalling pathways, guide post-translational modifications and condition the tissue microenvironment will help to connect environmental factors with the pathogenic behaviour of T cells in RA.
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17
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Kulkarni P, Dunker AK, Weninger K, Orban J. Prostate-associated gene 4 (PAGE4), an intrinsically disordered cancer/testis antigen, is a novel therapeutic target for prostate cancer. Asian J Androl 2017; 18:695-703. [PMID: 27270343 PMCID: PMC5000790 DOI: 10.4103/1008-682x.181818] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Prostate-associated gene 4 (PAGE4) is a remarkably prostate-specific Cancer/Testis Antigen that is highly upregulated in the human fetal prostate and its diseased states but not in the adult normal gland. PAGE4 is an intrinsically disordered protein (IDP) that functions as a stress-response protein to suppress reactive oxygen species as well as prevent DNA damage. In addition, PAGE4 is also a transcriptional regulator that potentiates transactivation by the oncogene c-Jun. c-Jun forms the AP-1 complex by heterodimerizing with members of the Fos family and plays an important role in the development and pathology of the prostate gland, underscoring the importance of the PAGE4/c-Jun interaction. HIPK1, also a component of the stress-response pathway, phosphorylates PAGE4 at T51 which is critical for its transcriptional activity. Phosphorylation induces conformational and dynamic switching in the PAGE4 ensemble leading to a new cellular function. Finally, bioinformatics evidence suggests that the PAGE4 mRNA could be alternatively spliced resulting in four potential isoforms of the polypeptide alluding to the possibility of a range of conformational ensembles with latent functions. Considered together, the data suggest that PAGE4 may represent the first molecular link between stress and prostate cancer (PCa). Thus, pharmacologically targeting PAGE4 may be a novel opportunity for treating and managing patients with PCa, especially patients with low-risk disease.
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Affiliation(s)
- Prakash Kulkarni
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA
| | - A Keith Dunker
- Center for Computational Biology and Bioinformatics, Department of Biochemistry and Molecular Biology, Indiana University School of Medicine and Informatics, Indianapolis, IN 46202, USA
| | - Keith Weninger
- Department of Physics, North Carolina State University, Raleigh, NC 27695, USA
| | - John Orban
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850; Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
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18
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Liu R, Ma X, Chen L, Yang Y, Zeng Y, Gao J, Jiang W, Zhang F, Li D, Han B, Han R, Qiu R, Huang W, Wang Y, Hao J. MicroRNA-15b Suppresses Th17 Differentiation and Is Associated with Pathogenesis of Multiple Sclerosis by Targeting O-GlcNAc Transferase. THE JOURNAL OF IMMUNOLOGY 2017; 198:2626-2639. [PMID: 28228555 DOI: 10.4049/jimmunol.1601727] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 01/30/2017] [Indexed: 12/16/2022]
Abstract
IL-17-producing Th17 cells have gradually become considered as key factors in the pathogenesis of many autoimmune diseases, including multiple sclerosis (MS). Although the involvement of certain microRNAs in the development of MS has been reported, their role in Th17-driven autoimmunity is still poorly understood. In this study, we identified microRNA (miR)-15b as an important factor in Th17-associated effects and determined that the expression of miR-15b is significantly downregulated in MS patients and in mice with experimental autoimmune encephalomyelitis. Overexpression of miR-15b alleviated experimental autoimmune encephalomyelitis, whereas knockdown of miR-15b aggravated it. We demonstrated that miR-15b suppressed Th17 differentiation both in vivo and in vitro. We also found that O-linked N-acetylglucosamine transferase is a potential target of miR-15b, enabling it to affect the transcriptional regulation of retinoic acid-related orphan receptor γT through O-linked N-acetylglucosamine glycosylation of NF-κB. These results contribute to the importance of miR-15b in Th17 differentiation and the pathogenesis of MS.
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Affiliation(s)
- Ruiqiong Liu
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.,Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China
| | - Xiaofeng Ma
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Li Chen
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin 300350, China
| | - Yang Yang
- Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China
| | - Yi Zeng
- Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China
| | - Jie Gao
- Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China
| | - Wei Jiang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Fang Zhang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Daojing Li
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Bin Han
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Ranran Han
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Rongfang Qiu
- Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China
| | - Wei Huang
- Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China
| | - Yan Wang
- Tianjin Key Laboratory of Medical Epigenetics, Department of Biochemistry and Molecular Biology, Tianjin Medical University, Tianjin 300070, China;
| | - Junwei Hao
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China;
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19
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20
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Pro-Dopamine Regulator - (KB220) to Balance Brain Reward Circuitry in Reward Deficiency Syndrome (RDS). JOURNAL OF REWARD DEFICIENCY SYNDROME AND ADDICTION SCIENCE 2017; 3:3-13. [PMID: 28804788 PMCID: PMC5551501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
We are faced with a worldwide opiate/opioid epidemic that is devastating. According to the Centers for Disease Control and Prevention (CDC), at least 127 people, young and old, are dying every day in America due to narcotic overdose. The Food and Drug Administration (FDA) has approved Medication-Assisted Treatments (MATs) for opiate/opioids as well as alcohol and nicotine. The mechanism of action of most MATS favors either blocking of dopaminergic function or a form of Opiate Substitution Therapy (OST). These treatment options are adequate for short-term treatment of the symptoms of addiction and harm reduction but fail long-term to deal with the cause or lead to recovery. There is a need to continue to seek better treatment options. This mini-review is the history of the development of one such treatment; a glutaminergic-dopaminergic optimization complex called KB220. Growing evidence indicates that brain reward circuitry controls drug addiction, in conjunction with "anti-reward systems" as the "anti-reward systems" can be affected by both glutaminergic and dopaminergic transmission. KB220 may likely alter the function of these regions and provide for the possible eventual balancing the brain reward system and the induction of "dopamine homeostasis." Many of these concepts have been reported elsewhere and have become an integral part of the addiction science literature. However, the concise review may encourage readership to reconsider these facts and stimulate further research focused on the impact that the induction of "dopamine homeostasis" may have on recovery and relapse prevention.
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21
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Wu JL, Wu HY, Tsai DY, Chiang MF, Chen YJ, Gao S, Lin CC, Lin CH, Khoo KH, Chen YJ, Lin KI. Temporal regulation of Lsp1 O-GlcNAcylation and phosphorylation during apoptosis of activated B cells. Nat Commun 2016; 7:12526. [PMID: 27555448 PMCID: PMC4999498 DOI: 10.1038/ncomms12526] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 07/11/2016] [Indexed: 01/08/2023] Open
Abstract
Crosslinking of B-cell receptor (BCR) sets off an apoptosis programme, but the underlying pathways remain obscure. Here we decipher the molecular mechanisms bridging B-cell activation and apoptosis mediated by post-translational modification (PTM). We find that O-GlcNAcase inhibition enhances B-cell activation and apoptosis induced by BCR crosslinking. This proteome-scale analysis of the functional interplay between protein O-GlcNAcylation and phosphorylation in stimulated mouse primary B cells identifies 313 O-GlcNAcylation-dependent phosphosites on 224 phosphoproteins. Among these phosphoproteins, temporal regulation of the O-GlcNAcylation and phosphorylation of lymphocyte-specific protein-1 (Lsp1) is a key switch that triggers apoptosis in activated B cells. O-GlcNAcylation at S209 of Lsp1 is a prerequisite for the recruitment of its kinase, PKC-β1, to induce S243 phosphorylation, leading to ERK activation and downregulation of BCL-2 and BCL-xL. Thus, we demonstrate the critical PTM interplay of Lsp1 that transmits signals for initiating apoptosis after BCR ligation. B cell receptor (BCR) activation can trigger signalling causing apoptosis in order to eliminate auto-reactive B cells. Here the authors show that the O-GlcNAcylation and phosphorylation of lymphocyte-specific protein-1 are involved in a switch that regulates the initiation of apoptosis induced by BCR cross-linking.
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Affiliation(s)
- Jung-Lin Wu
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei 112, Taiwan.,Genomics Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Hsin-Yi Wu
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Dong-Yan Tsai
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan.,Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
| | | | - Yi-Ju Chen
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Shijay Gao
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Chun-Cheng Lin
- Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Chun-Hung Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Kay-Hooi Khoo
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Yu-Ju Chen
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Kuo-I Lin
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan
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22
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Banerjee PS, Lagerlöf O, Hart GW. Roles of O-GlcNAc in chronic diseases of aging. Mol Aspects Med 2016; 51:1-15. [PMID: 27259471 DOI: 10.1016/j.mam.2016.05.005] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/18/2016] [Accepted: 05/30/2016] [Indexed: 12/22/2022]
Abstract
O-GlcNAcylation, a dynamic nutrient and stress sensitive post-translational modification, occurs on myriad proteins in the cell nucleus, cytoplasm and mitochondria. O-GlcNAcylation serves as a nutrient sensor to regulate signaling, transcription, translation, cell division, metabolism, and stress sensitivity in all cells. Aberrant protein O-GlcNAcylation plays a critical role both in the development, as well as in the progression of a variety of age related diseases. O-GlcNAcylation underlies the etiology of diabetes, and changes in specific protein O-GlcNAc levels and sites are responsible for insulin expression and sensitivity and glucose toxicity. Abnormal O-GlcNAcylation contributes directly to diabetes related dysfunction of the heart, kidney and eyes and affects progression of cardiomyopathy, nephropathy and retinopathy. O-GlcNAcylation is a critical modification in the brain and plays a role in both plaque and tangle formation, thus making its study important in neurodegenerative disorders. O-GlcNAcylation also affects cellular growth and metabolism during the development and metastasis of cancer. Finally, alterations in O-GlcNAcylation of transcription factors in macrophages and lymphocytes affect inflammation and cytokine production. Thus, O-GlcNAcylation plays key roles in many of the major diseases associated with aging. Elucidation of its specific functions in both normal and diseased tissues is likely to uncover totally novel avenues for therapeutic intervention.
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Affiliation(s)
- Partha S Banerjee
- Department of Biological Chemistry, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205-2185
| | - Olof Lagerlöf
- Department of Biological Chemistry, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205-2185
| | - Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205-2185.
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23
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Abstract
O-Linked N-acetylglucosamine, or O-GlcNAc, is a dynamic post-translational modification that cycles on and off serine and threonine residues of nucleocytoplasmic and mitochondrial proteins. In addition to cancer and inflammation diseases, O-GlcNAc modification appears to play a critical role during cell apoptosis and stress response, although the precise mechanisms are still not very clear. Here we found that nitric oxide synthase adaptor (NOS1AP), which plays an important part in glutamate-induced neuronal apoptosis, carries the modification of O-GlcNAc. Mass spectrometry analysis identified Ser47, Ser183, Ser204, Ser269, Ser271 as O-GlcNAc sites. Higher O-GlcNAc of NOS1AP was detected during glutamate-induced neuronal apoptosis. Furthermore, with O-GlcNAc sites of NOS1AP mutated, the interaction of NOS1AP and neuronal nitric oxide syntheses (nNOS) decreases. Finally, during glutamate-induced neuronal apoptosis, decreasing the O-GlcNAc modification of NOS1AP results in more severe neuronal apoptosis. All these results suggest that O-GlcNAc modification of NOS1AP exerts protective effects during glutamate-induced neuronal apoptosis.
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24
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Santos AS, Finlay BB. Bringing down the host: enteropathogenic and enterohaemorrhagic Escherichia coli effector-mediated subversion of host innate immune pathways. Cell Microbiol 2015; 17:318-32. [PMID: 25588886 DOI: 10.1111/cmi.12412] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 12/17/2014] [Accepted: 12/22/2014] [Indexed: 12/14/2022]
Abstract
Enteric bacterial pathogens commonly use a type III secretion system (T3SS) to successfully infect intestinal epithelial cells and survive and proliferate in the host. Enteropathogenic and enterohaemorrhagic Escherichia coli (EPEC; EHEC) colonize the human intestinal mucosa, form characteristic histological lesions on the infected epithelium and require the T3SS for full virulence. T3SS effectors injected into host cells subvert cellular pathways to execute a variety of functions within infected host cells. The EPEC and EHEC effectors that subvert innate immune pathways--specifically those involved in phagocytosis, host cell survival, apoptotic cell death and inflammatory signalling--are all required to cause disease. These processes are reviewed within, with a focus on recent work that has provided insights into the functions and host cell targets of these effectors.
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Affiliation(s)
- Andrew S Santos
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, BC, Canada; Michael Smith Laboratories, The University of British Columbia, Vancouver, BC, Canada
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25
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Karababa A, Görg B, Schliess F, Häussinger D. O-GlcNAcylation as a novel ammonia-induced posttranslational protein modification in cultured rat astrocytes. Metab Brain Dis 2014; 29:975-82. [PMID: 24292976 DOI: 10.1007/s11011-013-9454-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 11/12/2013] [Indexed: 12/12/2022]
Abstract
Hepatic encephalopathy (HE) is a clinical manifestation of a low grade cerebral edema with a mutual interrelationship between osmotic- and oxidative stress. This leads to RNA oxidation and posttranslational protein modifications such as protein tyrosine nitration with pathophysiological relevance. Here, we report on O-GlcNAcylation as another ammonia-induced posttranslational protein modification in cultured rat astrocytes. NH4Cl induced O-GlcNAcylation of distinct proteins (25-250 kDa) in astrocytes in a dose- and time-dependent manner. Exposure of astrocytes to NH4Cl (5 mmol/l) for 48 h and 72 h significantly increased protein O-GlcNAcylation by about 2-fold and 4-fold, respectively. NH4Cl at a concentration of 1 mmol/l was sufficient to double protein O-GlcNAcylation in astrocytes after 72 h as compared to untreated controls. Ammonia-induced protein O-GlcNAcylation was sensitive towards glutamine-synthetase inhibition by methionine sulfoximine (MSO), but was not induced by hypoosmolarity (205 mosmol/l) or CH3NH3Cl (5 mmol/l). Increased protein O-GlcNAcylation in NH4Cl (5 mmol/l, 48 h)-treated astrocytes was fully reversible within 24 h after withdrawal of NH4Cl from culture medium. Amongst the proteins which are O-GlcNAcylated in response to ammonia, GAPDH was identified. It is concluded that ammonia induces reversible protein O-GlcNAcylation in astrocytes that depends on glutamine synthesis but not on astrocyte swelling per se or ammonia-induced pH-changes. In view of the complex involvement of O-GlcNAcylation in cell regulation, such as energy metabolism, apoptosis and circadian rhythmicity and in pathologies, such as neurodegenerative diseases, O-GlcNAcylation might contribute to the pathophysiology of hepatic encephalopathy.
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Affiliation(s)
- Ayşe Karababa
- Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich-Heine University, 40225, Düsseldorf, Germany
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26
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Jiang S, Gavrikova TA, Messina JL. Regulation of hepatic insulin receptor activity following injury. Am J Physiol Gastrointest Liver Physiol 2014; 306:G886-92. [PMID: 24699331 PMCID: PMC4024725 DOI: 10.1152/ajpgi.00128.2013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Impaired insulin receptor (IR) activity has been found in various models of insulin resistance, including models of injury or critical illness and Type 2 diabetes. However, mechanisms that modulate IR function remain unclear. With an animal model of critical-illness diabetes, we found insulin-induced IR tyrosine phosphorylation in the liver was impaired as early as 15 min following trauma and hemorrhage. Possible mechanisms for this defect were examined, including IR protein levels and IR posttranslational modifications. The total amounts of hepatic IRα and IRβ subunits and the membrane localization of the IR were not altered by trauma and hemorrhage, and, likewise, no change in IR tyrosine nitration was found in the liver. However, there was a decrease in the level of protein O-linked β-N-acetlyglucosamine (O-GlcNac) modification on Ser/Thr in the liver following trauma and hemorrhage. Inhibition of JNK increased IR O-GlcNac modification, implicating an involvement of JNK. These findings suggest that a balance between O-GlcNac modification and JNK-induced phosphorylation may exist, with decreased Ser/Thr O-GlcNac modification following trauma and hemorrhage, allowing JNK to phosphorylate the IR on neighboring Ser/Thr residues, which subsequently inhibits IR activity. The present studies suggest potential mechanisms of hemorrhage-induced defects in IR activity and a potential role for acutely decreased O-GlcNac and increased serine phosphorylation of the IR.
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Affiliation(s)
- Shaoning Jiang
- 1Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Tatyana A. Gavrikova
- 1Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Joseph L. Messina
- 1Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, Alabama; and ,2Veterans Affairs Medical Center, Birmingham, Alabama
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27
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Malaney P, Uversky VN, Davé V. The PTEN Long N-tail is intrinsically disordered: increased viability for PTEN therapy. MOLECULAR BIOSYSTEMS 2014; 9:2877-88. [PMID: 24056727 DOI: 10.1039/c3mb70267g] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Aberrant activation of the PI3K/Akt/mTOR pathway is observed in several cancers and hyper proliferative disorders. PTEN, a tumor suppressor gene, negatively regulates the PI3K/Akt/mTOR pathway. Inhibitors of various components of this pathway are currently being used for cancer therapy. However, the use of these small molecule inhibitors remains limited due to the presence of compensatory feedback loops within the pathway such that inhibition of one oncogenic molecule often results in the activation of another oncogenic molecule resulting in the development of chemoresistance. One novel strategy that has emerged as a means to circumvent the problem of feedback signaling is by activating tumor suppressor genes that abrogate oncogenic pathways and regress tumor growth. In this regard, a newly identified isoform of the PTEN protein shows promise for use in tumors with elevated PI3K/Akt/mTOR signaling. This isoform is a translational variant of PTEN, termed as PTEN Long, and has additional 173 amino acids at its N-terminus (N-173) than normal PTEN. The N-173 region is required for PTEN secretion and transport across the body. Given the potential of this N-173 region to act as a drug delivery system for PTEN, we herein analyze the structural properties of this region. This N-173 tail has a large intrinsically disordered region (IDR) and is composed of highly charged basic residues. Further, the region is enriched in potential linear binding motifs, protein-binding sites and post-translational modifications (PTMs) indicating its probable role in PTEN function and transport across cells. An extensive analysis of this region is warranted to better exploit its structural and biophysical peculiarities to drug discovery and drug delivery applications.
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Affiliation(s)
- Prerna Malaney
- Morsani College of Medicine, MDC 64, Department of Pathology and Cell Biology, University of South Florida, 12901 Bruce B Downs Blvd, Tampa, FL 33612, USA.
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28
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Borghgraef P, Menuet C, Theunis C, Louis JV, Devijver H, Maurin H, Smet-Nocca C, Lippens G, Hilaire G, Gijsen H, Moechars D, Van Leuven F. Increasing brain protein O-GlcNAc-ylation mitigates breathing defects and mortality of Tau.P301L mice. PLoS One 2013; 8:e84442. [PMID: 24376810 PMCID: PMC3871570 DOI: 10.1371/journal.pone.0084442] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 11/18/2013] [Indexed: 01/12/2023] Open
Abstract
The microtubule associated protein tau causes primary and secondary tauopathies by unknown molecular mechanisms. Post-translational O-GlcNAc-ylation of brain proteins was demonstrated here to be beneficial for Tau.P301L mice by pharmacological inhibition of O-GlcNAc-ase. Chronic treatment of ageing Tau.P301L mice mitigated their loss in body-weight and improved their motor deficits, while the survival was 3-fold higher at the pre-fixed study endpoint at age 9.5 months. Moreover, O-GlcNAc-ase inhibition significantly improved the breathing parameters of Tau.P301L mice, which underpinned pharmacologically the close correlation of mortality and upper-airway defects. O-GlcNAc-ylation of brain proteins increased rapidly and stably by systemic inhibition of O-GlcNAc-ase. Conversely, biochemical evidence for protein Tau.P301L to become O-GlcNAc-ylated was not obtained, nor was its phosphorylation consistently or markedly affected. We conclude that increasing O-GlcNAc-ylation of brain proteins improved the clinical condition and prolonged the survival of ageing Tau.P301L mice, but not by direct biochemical action on protein tau. The pharmacological effect is proposed to be located downstream in the pathological cascade initiated by protein Tau.P301L, opening novel venues for our understanding, and eventually treating the neurodegeneration mediated by protein tau.
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Affiliation(s)
- Peter Borghgraef
- Experimental Genetics Group - LEGTEGG, KULeuven, Leuven, Belgium
| | - Clément Menuet
- MP3-Respiration, UMR CNRS 6231, Faculté Saint-Jérôme, Marseille, France
| | - Clara Theunis
- Experimental Genetics Group - LEGTEGG, KULeuven, Leuven, Belgium
| | - Justin V. Louis
- Experimental Genetics Group - LEGTEGG, KULeuven, Leuven, Belgium
| | - Herman Devijver
- Experimental Genetics Group - LEGTEGG, KULeuven, Leuven, Belgium
| | - Hervé Maurin
- Experimental Genetics Group - LEGTEGG, KULeuven, Leuven, Belgium
| | - Caroline Smet-Nocca
- Groupe RMN-Glycobiologie, CNRS, University de Lille, Villeneuve d'Ascq, France
| | - Guy Lippens
- Groupe RMN-Glycobiologie, CNRS, University de Lille, Villeneuve d'Ascq, France
| | - Gerard Hilaire
- MP3-Respiration, UMR CNRS 6231, Faculté Saint-Jérôme, Marseille, France
| | - Harrie Gijsen
- Department Neuroscience, Janssen Research & Development, Beerse, Belgium
| | - Dieder Moechars
- Department Neuroscience, Janssen Research & Development, Beerse, Belgium
| | - Fred Van Leuven
- Experimental Genetics Group - LEGTEGG, KULeuven, Leuven, Belgium
- * E-mail:
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Springhorn C, Matsha TE, Erasmus RT, Essop MF. Exploring leukocyte O-GlcNAcylation as a novel diagnostic tool for the earlier detection of type 2 diabetes mellitus. J Clin Endocrinol Metab 2012; 97:4640-9. [PMID: 23066116 DOI: 10.1210/jc.2012-2229] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
CONTEXT Because current tests available for the diagnosis of diabetes have shortcomings, a novel screening method for the earlier and more efficient detection of type 2 diabetes would be a significant clinical advance. OBJECTIVE The hexosamine biosynthetic pathway usually acts as a fuel sensor, and its activation leads to O-linked β-N-acetylglucosamine (O-GlcNAc) modification of target proteins (O-GlcNAcylation) in a glucose-responsive manner. O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) are responsible for O-GlcNAc addition and removal, respectively. Because higher hexosamine biosynthetic pathway flux is linked to insulin resistance/type 2 diabetes, we hypothesized that increased O-GlcNAcylation of leukocyte proteins can detect the onset of pre- and overt diabetes. DESIGN, SETTING AND PATIENTS Seventy-four participants from Bellville and Stellenbosch (Western Cape, South Africa) were recruited and classified as normal, prediabetic, and diabetic individuals (American Diabetes Association criteria). MAIN OUTCOME MEASURES Leukocytes isolated from study subjects were evaluated for O-GlcNAc, OGA, and O-GlcNAc transferase expression by flow cytometry and immunofluorescence microscopy. RESULTS Flow cytometric analysis of leukocyte subtypes revealed increased O-GlcNAcylation in granulocytes vs. lymphocytes (P < 0.001). Diabetic individuals displayed higher leukocyte O-GlcNAcylation (P < 0.01), whereas granulocyte analysis showed an increase for prediabetic subjects (P < 0.01). However, OGA expression increased in leukocytes of diabetic subjects and is likely an adaptation to attenuate higher O-GlcNAcylation observed (P < 0.001). CONCLUSIONS Together our data demonstrate that leukocyte (particularly granulocyte) O-GlcNAcylation could help detect pre- and overt diabetes and offer clinical value as unique markers for the earlier and more efficient detection of type 2 diabetes.
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Affiliation(s)
- Clare Springhorn
- Cardio-Metabolic Research Group, Department of Physiological Sciences, Stellenbosch University, Room 2005, Mike De Vries Building, Merriman Avenue, Stellenbosch 7600, South Africa
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p38 and OGT sequestration into viral inclusion bodies in cells infected with human respiratory syncytial virus suppresses MK2 activities and stress granule assembly. J Virol 2012; 87:1333-47. [PMID: 23152511 DOI: 10.1128/jvi.02263-12] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Respiratory syncytial virus (RSV) forms cytoplasmic inclusion bodies (IBs) that are thought to be sites of nucleocapsid accumulation and viral RNA synthesis. The present study found that IBs also were the sites of major sequestration of two proteins involved in cellular signaling pathways. These are phosphorylated p38 mitogen-activated protein kinase (MAPK) (p38-P), a key regulator of cellular inflammatory and stress responses, and O-linked N-acetylglucosamine (OGN) transferase (OGT), an enzyme that catalyzes the posttranslational addition of OGN to protein targets to regulate cellular processes, including signal transduction, transcription, translation, and the stress response. The virus-induced sequestration of p38-P in IBs resulted in a substantial reduction in the accumulation of a downstream signaling substrate, MAPK-activated protein kinase 2 (MK2). Sequestration of OGT in IBs was associated with suppression of stress granule (SG) formation. Thus, while the RSV IBs are thought to play an essential role in viral replication, the present results show that they also play a role in suppressing the cellular response to viral infection. The sequestration of p38-P and OGT in IBs appeared to be reversible: oxidative stress resulting from arsenite treatment transformed large IBs into a scattering of smaller bodies, suggestive of partial disassembly, and this was associated with MK2 phosphorylation and OGN addition. Unexpectedly, the RSV M2-1 protein was found to localize in SGs that formed during oxidative stress. This protein was previously shown to be a viral transcription elongation factor, and the present findings provide the first evidence of possible involvement in SG activities during RSV infection.
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O-GlcNAcylation and oxidation of proteins: is signalling in the cardiovascular system becoming sweeter? Clin Sci (Lond) 2012; 123:473-86. [PMID: 22757958 PMCID: PMC3389386 DOI: 10.1042/cs20110638] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
O-GlcNAcylation is an unusual form of protein glycosylation, where a single-sugar [GlcNAc (N-acetylglucosamine)] is added (via β-attachment) to the hydroxyl moiety of serine and threonine residues of nuclear and cytoplasmic proteins. A complex and extensive interplay exists between O-GlcNAcylation and phosphorylation. Many phosphorylation sites are also known glycosylation sites, and this reciprocal occupancy may produce different activities or alter the stability in a target protein. The interplay between these two post-translational modifications is not always reciprocal, as some proteins can be concomitantly phosphorylated and O-GlcNAcylated, and the adjacent phosphorylation or O-GlcNAcylation can regulate the addition of either moiety. Increased cardiovascular production of ROS (reactive oxygen species), termed oxidative stress, has been consistently reported in various chronic diseases and in conditions where O-GlcNAcylation has been implicated as a contributing mechanism for the associated organ injury/protection (for example, diabetes, Alzheimer's disease, arterial hypertension, aging and ischaemia). In the present review, we will briefly comment on general aspects of O-GlcNAcylation and provide an overview of what has been reported for this post-translational modification in the cardiovascular system. We will then specifically address whether signalling molecules involved in redox signalling can be modified by O-GlcNAc (O-linked GlcNAc) and will discuss the critical interplay between O-GlcNAcylation and ROS generation. Experimental evidence indicates that the interactions between O-GlcNAcylation and oxidation of proteins are important not only for cell regulation in physiological conditions, but also under pathological states where the interplay may become dysfunctional and thereby exacerbate cellular injury.
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Miura Y, Sakurai Y, Endo T. O-GlcNAc modification affects the ATM-mediated DNA damage response. Biochim Biophys Acta Gen Subj 2012; 1820:1678-85. [PMID: 22759405 DOI: 10.1016/j.bbagen.2012.06.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 06/19/2012] [Accepted: 06/20/2012] [Indexed: 11/16/2022]
Abstract
BACKGROUND O-Linked β-N-acetylglucosamine (O-GlcNAc) is a reversible, post-translational, and regulatory modification of nuclear, mitochondrial, and cytoplasmic proteins that is responsive to cellular stress. The role of O-GlcNAcylation in the ataxia-telangiectasia mutated (ATM)-mediated DNA damage response is unknown. It is unclear whether ATM, which is an early acting and central component of the signal transduction system activated by DNA double strand breaks, is an O-GlcNAc-modified protein. METHODS The effect of O-GlcNAc modification on ATM activation was examined using two inhibitors, PUGNAc and DON that increase and decrease, respectively, levels of protein O-GlcNAcylation. To assess O-GlcNAcylation of ATM, immunoprecipitation and immunoblot analyses using anti-ATM or anti-O-GlcNAc antibody were performed in HeLa cells and primary cultured neurons. Interaction of ATM with O-GlcNAc transferase (OGT), the enzyme that adds O-GlcNAc to target proteins, was examined by immunoprecipitation and immunoblot analyses using anti-ATM. RESULTS Enhancement of protein O-GlcNAcylation increased levels of X-irradiation-induced ATM activation. However, decreases in protein O-GlcNAcylation did not affect levels of ATM activation, but these decreases did delay ATM activation and ATM recovery processes based on assessment of de-phosphorylation of phospho-ATM. Thus, activation and recovery of ATM were affected by O-GlcNAcylation. ATM was subjected to O-GlcNAcylation, and ATM interacted with OGT. The steady-state O-GlcNAc level of ATM was not significantly responsive to X-irradiation or oxidative stress. GENERAL SIGNIFICANCE ATM is an O-GlcNAc modified protein, and dynamic O-GlcNAc modification affects the ATM-mediated DNA damage response.
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Affiliation(s)
- Yuri Miura
- Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan.
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O-GlcNAcylation of TAB1 modulates TAK1-mediated cytokine release. EMBO J 2012; 31:1394-404. [PMID: 22307082 PMCID: PMC3321193 DOI: 10.1038/emboj.2012.8] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Accepted: 12/08/2011] [Indexed: 12/30/2022] Open
Abstract
The protein kinase TAK1 plays an important role in pro-inflammatory cytokine signalling. Interleukin-1- and osmotic stress-induced O-GlcNAcylation of its regulatory subunit TAB1 is required for full TAK1 activation to induce downstream cytokine production, linking this protein modification to innate immunity signalling. Transforming growth factor (TGF)-β-activated kinase 1 (TAK1) is a key serine/threonine protein kinase that mediates signals transduced by pro-inflammatory cytokines such as transforming growth factor-β, tumour necrosis factor (TNF), interleukin-1 (IL-1) and wnt family ligands. TAK1 is found in complex with binding partners TAB1–3, phosphorylation and ubiquitination of which has been found to regulate TAK1 activity. In this study, we show that TAB1 is modified with N-acetylglucosamine (O-GlcNAc) on a single site, Ser395. With the help of a novel O-GlcNAc site-specific antibody, we demonstrate that O-GlcNAcylation of TAB1 is induced by IL-1 and osmotic stress, known inducers of the TAK1 signalling cascade. By reintroducing wild-type or an O-GlcNAc-deficient mutant TAB1 (S395A) into Tab1−/− mouse embryonic fibroblasts, we determined that O-GlcNAcylation of TAB1 is required for full TAK1 activation upon stimulation with IL-1/osmotic stress, for downstream activation of nuclear factor κB and finally production of IL-6 and TNFα. This is one of the first examples of a single O-GlcNAc site on a signalling protein modulating a key innate immunity signalling pathway.
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O-GlcNAc modification of the anti-malarial vaccine candidate PfAMA1: in silico-defined structural changes and potential to generate a better vaccine. Mol Biol Rep 2011; 39:4663-72. [PMID: 22020851 DOI: 10.1007/s11033-011-1258-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 09/14/2011] [Indexed: 10/16/2022]
Abstract
The complex life cycle of plasmodial parasites makes the selection of a single subunit protein a less than optimal strategy to generate an efficient vaccinal protection against malaria. Moreover, the full protection afforded by malarial proteins carried by intact parasites implies that immune responses against different antigens expressed in different phases of the cycle are required, but also suggests that native malarial antigens are presented to the host immune system in a manner that recombinant proteins do not achieve. The malarial apical membrane antigen 1 (AMA1) represents a suitable vaccine candidate because AMA1 is expressed on sporozoites and merozoites and allows them to invade hepatocytes and erythrocytes, respectively. Anti-AMA1 antibodies and cytotoxic T-cells are therefore expected to interfere both with the primary invasion of hepatocytes by sporozoites and with the later propagation of merozoites in erythrocytes, and thus efficiently counteract parasite development in its human host. AMA1 bears potential glycosylation sites and the human erythrocytic O-linked N-acetylglucosamine transferase (OGT) could glycosylate AMA1 through combinatorial metabolism. This hypothesis was tested in silico by developing binding models of AMA1 with human OGT complexed with UDP-GlcNc, and followed by the binding of O-GlcNAc with the hydroxyl group of AMA1 serine and threonine residues. Our results suggests that AMA1 shows potential for glycosylation at Thr517 and Ser498 and that O-GlcNAc AMA1 may constitute a conformationally more appropriate antigen for developing a protective anti-malarial immune response.
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Ryu IH, Do SI. Denitrosylation of S-nitrosylated OGT is triggered in LPS-stimulated innate immune response. Biochem Biophys Res Commun 2011; 408:52-7. [PMID: 21453677 DOI: 10.1016/j.bbrc.2011.03.115] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 03/25/2011] [Indexed: 11/18/2022]
Abstract
O-linked N-acetylglucosaminyltransferase (OGT)-mediated protein O-GlcNAcylation has been revealing various aspects of functional significance in biological processes, such as cellular signaling and activation of immune system. We found that OGT is maintained as S-nitrosylated form in resting cells, and its denitrosylation is triggered in innate immune response of lipopolysaccharide (LPS)-treated macrophage cells. S-nitrosylation of OGT strongly inhibits its catalytic activity up to more than 80% of native OGT, and denitrosylation of OGT leads to protein hyper-O-GlcNAcylation. Furthermore, blockage of increased protein O-GlcNAcylation results in significant loss of nitric oxide and cytokine production. We propose that denitrosylation of S-nitrosylated OGT is a direct mechanism for upregulation of OGT activity by which immune defense is critically controlled in LPS-stimulated innate immune response.
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Affiliation(s)
- In-Hyun Ryu
- Department of Life Science, Laboratory of Functional Glycomics, Ajou University, San 5, Wonchon-dong, Suwon 443-749, Republic of Korea
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GlaxoSmithKline Award Lecture. The O-GlcNAc modification: three-dimensional structure, enzymology and the development of selective inhibitors to probe disease. Biochem Soc Trans 2011; 38:1179-88. [PMID: 20863281 DOI: 10.1042/bst0381179] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Carbohydrates, their structures and the enzymes responsible for their synthesis and degradation, offer numerous possibilities for the design and application of probes with which to study and treat disease. The intracellular dynamic O-GlcNAc (O-linked β-N-acetylglucosamine) modification is one such glycosylation with considerable medical interest, reflecting its implication in diseases such as Type 2 diabetes and neurodegeneration. In the present paper, we review recent structural and mechanistic studies into the enzymes responsible for this modification, highlighting how mechanism-inspired small-molecule probes may be applied to study potential disease processes. Such studies have questioned a causal link between O-GlcNAc and Type 2 diabetes, but do offer potential for the study, and perhaps the treatment, of tauopathies.
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Shirakawa T, Kawazoe Y, Tsujikawa T, Jung D, Sato SI, Uesugi M. Deactivation of STAT6 through serine 707 phosphorylation by JNK. J Biol Chem 2010; 286:4003-10. [PMID: 21123173 DOI: 10.1074/jbc.m110.168435] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signal transducer and activator of transcription 6 (STAT6), which plays a critical role in immune responses, is activated by interleukin-4 (IL-4). Activity of STAT family members is regulated primarily by tyrosine phosphorylations and possibly also by serine phosphorylations. Here, we report a previously undescribed serine phosphorylation of STAT6, which is activated by cell stress or by the pro-inflammatory cytokine, interleukin-1β (IL-1β). Our analyses suggest that Ser-707 is phosphorylated by c-Jun N-terminal kinase (JNK). Phosphorylation decreases the DNA binding ability of IL-4-stimulated STAT6, thereby inhibiting the transcription of STAT6-responsive genes. Inactivation of STAT6 by JNK-dependent Ser-707 phosphorylation may be one mechanism of controlling the balance between IL-1β and IL-4 signals.
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Affiliation(s)
- Takashi Shirakawa
- Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 611-0011, Japan
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Martínez-Florensa M, García-Blesa A, Yélamos J, Muñoz-Suano A, Domínguez-Villar M, Valdor R, Alonso A, García-Cózar F, Aparicio P, Malissen B, Aguado E. Serine residues in the LAT adaptor are essential for TCR-dependent signal transduction. J Leukoc Biol 2010; 89:63-73. [PMID: 20940326 DOI: 10.1189/jlb.0509342] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The adaptor protein LAT has a prominent role in the transduction of intracellular signals elicited by the TCR/CD3 complex. Upon TCR engagement, LAT becomes tyrosine-phosphorylated and thereby, recruits to the membrane several proteins implicated in the activation of downstream signaling pathways. However, little is known about the role of other conserved motifs present in the LAT sequence. Here, we report that the adaptor LAT contains several conserved serine-based motifs, which are essential for proper signal transduction through the TCR. Mutation of these serine motifs in the human T cell line Jurkat prevents proper calcium influx, MAPK activation, and IL-2 production in response to TCR/CD3 stimulation. Moreover, this mutant form of LAT has a reduced ability to bind to PLC-γ1 and SLP-76, although phosphorylation of tyrosine residues 132, 171, and 191 is not decreased, raising a possible role for the serine-based motifs of LAT for the binding of important partners. The functional role of LAT serine-based motifs in signal transduction could be mediated by an effect on tyrosine phosphorylation, as their mutation significantly diminishes the phosphorylation of tyrosine residue 226. In addition, these serine motifs seem to have a regulatory role, given that upon their mutation, ZAP-70 shows enhanced phosphorylation. Therefore, the LAT serine-based motifs likely regulate signaling pathways that are essential for T cell physiology.
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Affiliation(s)
- Mario Martínez-Florensa
- Departamento de Bioquimíca, Biología Molecular B e Inmunología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
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Müller D, Hildebrand M, Lübberstedt J, Kuhn M, Middendorff R. The membrane receptors guanylyl cyclase-A and -B undergo distinctive changes in post-translational modification during brain development. J Neurochem 2010; 115:1024-34. [PMID: 20880010 DOI: 10.1111/j.1471-4159.2010.06985.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Temporal carbohydrate expression patterns at cell surfaces are thought to be of crucial regulatory significance during developmental processes. Hitherto, however, data on individual membrane proteins undergoing development-associated changes in glycosylation are sparsely. Here, we show that the two natriuretic peptide receptors, guanylyl cyclase-A (GC-A) and GC-B are subject to pronounced size alterations in the rat brain between postnatal day 1 and adult. Comparable size changes were not detectable for GC-A and GC-B in peripheral tissues and for three other membrane proteins (insulin receptor, insulin-like growth factor-II/mannose-6-phoshate receptor, neutral endopeptidase) in brain, indicating remarkable specificity. As revealed by treatments with carbohydrate-digesting enzymes, both GC-A and GC-B are hyperglycosylated at N-linked glycosylation sites in the developing brain. At postnatal day 1, the vast majority of GC-B (but not GC-A) molecules contain additionally an O-linked carbohydrate modification of about 1 kDa in mass and a further modification of similar size which is resistant to enzymatic removal. The glycoforms exhibited functional activity in membrane GC assays, indicating proper folding and signaling capability. These data link recently reported roles of natriuretic peptides during brain development for the first time with specific glycosylation states of their cyclic GMP-generating receptors.
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Affiliation(s)
- Dieter Müller
- Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany.
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Zhang X, Tong N, Li Y. Concurrently using rosiglitazone prevents glucosamine-induced islet β-Cell apoptosis and dysfunction. Cell Biochem Funct 2010; 28:509-14. [DOI: 10.1002/cbf.1684] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Teo CF, Ingale S, Wolfert MA, Elsayed GA, Nöt LG, Chatham JC, Wells L, Boons GJ. Glycopeptide-specific monoclonal antibodies suggest new roles for O-GlcNAc. Nat Chem Biol 2010; 6:338-43. [PMID: 20305658 DOI: 10.1038/nchembio.338] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Accepted: 01/22/2010] [Indexed: 12/26/2022]
Abstract
Studies of post-translational modification by beta-N-acetyl-D-glucosamine (O-GlcNAc) are hampered by a lack of efficient tools such as O-GlcNAc-specific antibodies that can be used for detection, isolation and site localization. We have obtained a large panel of O-GlcNAc-specific IgG monoclonal antibodies having a broad spectrum of binding partners by combining three-component immunogen methodology with hybridoma technology. Immunoprecipitation followed by large-scale shotgun proteomics led to the identification of more than 200 mammalian O-GlcNAc-modified proteins, including a large number of new glycoproteins. A substantial number of the glycoproteins were enriched by only one of the antibodies. This observation, combined with the results of inhibition ELISAs, suggests that the antibodies, in addition to their O-GlcNAc dependence, also appear to have different but overlapping local peptide determinants. The monoclonal antibodies made it possible to delineate differentially modified proteins of liver in response to trauma-hemorrhage and resuscitation in a rat model.
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Affiliation(s)
- Chin Fen Teo
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
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Ozcan S, Andrali SS, Cantrell JEL. Modulation of transcription factor function by O-GlcNAc modification. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1799:353-64. [PMID: 20202486 DOI: 10.1016/j.bbagrm.2010.02.005] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Revised: 02/19/2010] [Accepted: 02/25/2010] [Indexed: 12/22/2022]
Abstract
O-linked beta-N-acetylglucosamine (O-GlcNAc) modification of nuclear and cytoplasmic proteins is important for many cellular processes, and the number of proteins that contain this modification is steadily increasing. This modification is dynamic and reversible, and in some cases competes for phosphorylation of the same residues. O-GlcNAc modification of proteins is regulated by cell cycle, nutrient metabolism, and other extracellular signals. Compared to protein phosphorylation, which is mediated by a large number of kinases, O-GlcNAc modification is catalyzed only by one enzyme called O-linked N-acetylglucosaminyl transferase or OGT. Removal of O-GlcNAc from proteins is catalyzed by the enzyme beta-N-acetylglucosaminidase (O-GlcNAcase or OGA). Altered O-linked GlcNAc modification levels contribute to the establishment of many diseases, such as cancer, diabetes, cardiovascular disease, and neurodegeneration. Many transcription factors have been shown to be modified by O-linked GlcNAc modification, which can influence their transcriptional activity, DNA binding, localization, stability, and interaction with other co-factors. This review focuses on modulation of transcription factor function by O-linked GlcNAc modification.
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Affiliation(s)
- Sabire Ozcan
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA.
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Cheng Y, Li M, Wang S, Peng H, Reid S, Ni N, Fang H, Xu W, Wang B. Carbohydrate biomarkers for future disease detection and treatment. Sci China Chem 2010; 53:3-20. [PMID: 32214994 PMCID: PMC7089153 DOI: 10.1007/s11426-010-0021-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2009] [Accepted: 10/09/2009] [Indexed: 12/28/2022]
Abstract
Carbohydrates are considered as one of the most important classes of biomarkers for cell types, disease states, protein functions, and developmental states. Carbohydrate "binders" that can specifically recognize a carbohydrate biomarker can be used for developing novel types of site specific delivery methods and imaging agents. In this review, we present selected examples of important carbohydrate biomarkers and how they can be targeted for the development of therapeutic and diagnostic agents. Examples are arranged based on disease categories including (1) infectious diseases, (2) cancer, (3) inflammation and immune responses, (4) signal transduction, (5) stem cell transformation, (6) embryo development, and (7) cardiovascular diseases, though some issues cross therapeutic boundaries.
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Affiliation(s)
- YunFeng Cheng
- Department of Chemistry, Georgia State University, Atlanta, GA 30303 USA
| | - MinYong Li
- Department of Medicinal Chemistry, School of Pharmacy, Shandong University, Jinan, 250012 China
| | - ShaoRu Wang
- Department of Chemistry, Georgia State University, Atlanta, GA 30303 USA
| | - HanJing Peng
- Department of Chemistry, Georgia State University, Atlanta, GA 30303 USA
| | - Suazette Reid
- Department of Chemistry, Georgia State University, Atlanta, GA 30303 USA
| | - NanTing Ni
- Department of Chemistry, Georgia State University, Atlanta, GA 30303 USA
| | - Hao Fang
- Department of Medicinal Chemistry, School of Pharmacy, Shandong University, Jinan, 250012 China
| | - WenFang Xu
- Department of Medicinal Chemistry, School of Pharmacy, Shandong University, Jinan, 250012 China
| | - BingHe Wang
- Department of Chemistry, Georgia State University, Atlanta, GA 30303 USA
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Chung S, Kang DO, Yamzon J, Warburton D, Koh CJ. O-GlcNAc mediated glycosylation down-regulation in mice with cyclophosphamide induced cystitis. J Urol 2010; 183:351-6. [PMID: 19914650 DOI: 10.1016/j.juro.2009.08.102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Indexed: 01/05/2023]
Abstract
PURPOSE Cyclophosphamide induced cystitis is an established model for the study of bladder injury and wound healing. Glycosylation is an important modification mechanism that regulates the structure and function of secreted proteins and growth factors from inflammation sites. We determined the effect of cyclophosphamide induced cystitis on O-GlcNAc mediated glycosylation in the bladder. MATERIALS AND METHODS Cystitis in WT C57BL6 mice was induced with intraperitoneal cyclophosphamide. Retrieved bladders were analyzed using histology, immunohistochemistry, reverse transcriptase-polymerase chain reaction and Western blot for glycosylation associated factors. RESULTS Acute bladder injury was seen up to 168 hours (7 days) after injection. Reverse transcriptase-polymerase chain reaction revealed down-regulation of O-GlcNAc transferase, a key enzyme in O-GlcNAc mediated glycosylation, at the 8, 48 and 168-hour time points. Also, the glycosidase menangioma expressed antigen 5 was up-regulated at similar time points. Western blot analysis revealed decreased glycosylated protein during cyclophosphamide induced inflammation. CONCLUSIONS To our knowledge we report the first study of alterations in O-GlcNAc mediated glycosylation activity in bladders with cyclophosphamide induced cystitis. Glycosylation may have a significant role in the bladder wound healing process. Future studies of the glycosylation signaling pathways in the bladder would assist in future potential therapy for bladder inflammatory disease and cancer by elucidating pathways that guide bladder development and wound healing.
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Affiliation(s)
- Seyung Chung
- Developmental Biology, Regenerative Medicine and Surgery Program, Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, California, USA
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Abstract
A variety of post-translational protein modifications (PTMs) are known to be altered as a result of cancer development. Thus, these PTMs are potentially useful biomarkers for breast cancer. Mass spectrometry, antibody microarrays and immunohistochemistry techniques have shown promise for identifying changes in PTMs. In this review, we summarize the current literature on PTMs identified in the plasma and tumor tissue of breast-cancer patients or in breast cell lines. We also discuss some of the analytical techniques currently being used to evaluate PTMs.
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Affiliation(s)
- Hongjun Jin
- Cell Biology and Biochemistry Group, Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, PO Box 999, 902 Battelle Blvd, Richland, WA 99352
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Hanover JA, Krause MW, Love DC. The hexosamine signaling pathway: O-GlcNAc cycling in feast or famine. Biochim Biophys Acta Gen Subj 2009; 1800:80-95. [PMID: 19647043 DOI: 10.1016/j.bbagen.2009.07.017] [Citation(s) in RCA: 258] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 07/10/2009] [Accepted: 07/18/2009] [Indexed: 12/14/2022]
Abstract
The enzymes of O-GlcNAc cycling couple the nutrient-dependent synthesis of UDP-GlcNAc to O-GlcNAc modification of Ser/Thr residues of key nuclear and cytoplasmic targets. This series of reactions culminating in O-GlcNAcylation of targets has been termed the hexosamine signaling pathway (HSP). The evolutionarily ancient enzymes of O-GlcNAc cycling have co-evolved with other signaling effecter molecules; they are recruited to their targets by many of the same mechanisms used to organize canonic kinase-dependent signaling pathways. This co-recruitment of the enzymes of O-GlcNAc cycling drives a binary switch impacting pathways of anabolism and growth (nutrient uptake) and catabolic pathways (nutrient sparing and salvage). The hexosamine signaling pathway (HSP) has thus emerged as a versatile cellular regulator modulating numerous cellular signaling cascades influencing growth, metabolism, cellular stress, circadian rhythm, and host-pathogen interactions. In mammals, the nutrient-sensing HSP has been harnessed to regulate such cell-specific functions as neutrophil migration, and activation of B-cells and T-cells. This review summarizes the diverse approaches being used to examine O-GlcNAc cycling. It will emphasize the impact O-GlcNAcylation has upon signaling pathways that may be become deregulated in diseases of the immune system, diabetes mellitus, cancer, cardiovascular disease, and neurodegenerative diseases.
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Affiliation(s)
- John A Hanover
- Laboratory of Cell Biochemistry and Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA.
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Drosophila O-GlcNAc transferase (OGT) is encoded by the Polycomb group (PcG) gene, super sex combs (sxc). Proc Natl Acad Sci U S A 2009; 106:13427-32. [PMID: 19666537 DOI: 10.1073/pnas.0904638106] [Citation(s) in RCA: 187] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
O-linked N-acetylglucosamine transferase (OGT) reversibly modifies serine and threonine residues of many intracellular proteins with a single beta-O-linked N-acetylglucosamine residue (O-GlcNAc), and has been implicated in insulin signaling, neurodegenerative disease, cellular stress response, and other important processes in mammals. OGT also glycosylates RNA polymerase II and various transcription factors, which suggests that it might be directly involved in transcriptional regulation. We report here that the Drosophila OGT is encoded by the Polycomb group (PcG) gene, super sex combs (sxc). Furthermore, major sites of O-GlcNAc modification on polytene chromosomes correspond to PcG protein binding sites. Our results thus suggest a direct role for O-linked glycosylation by OGT in PcG-mediated epigenetic gene silencing, which is important in developmental regulation, stem cell maintenance, genomic imprinting, and cancer. In addition, we observe rescue of sxc lethality by a human Ogt cDNA transgene; thus Drosophila may provide an ideal model to study important functional roles of OGT in mammals.
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