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Mao Z, Mu J, Gao Z, Huang S, Chen L. Biological Functions and Potential Therapeutic Significance of O-GlcNAcylation in Hepatic Cellular Stress and Liver Diseases. Cells 2024; 13:805. [PMID: 38786029 PMCID: PMC11119800 DOI: 10.3390/cells13100805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/07/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
O-linked-β-D-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation), which is dynamically regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), is a post-translational modification involved in multiple cellular processes. O-GlcNAcylation of proteins can regulate their biological functions via crosstalk with other post-translational modifications, such as phosphorylation, ubiquitination, acetylation, and methylation. Liver diseases are a major cause of death worldwide; yet, key pathological features of the disease, such as inflammation, fibrosis, steatosis, and tumorigenesis, are not fully understood. The dysregulation of O-GlcNAcylation has been shown to be involved in some severe hepatic cellular stress, viral hepatitis, liver fibrosis, nonalcoholic fatty acid liver disease (NAFLD), malignant progression, and drug resistance of hepatocellular carcinoma (HCC) through multiple molecular signaling pathways. Here, we summarize the emerging link between O-GlcNAcylation and hepatic pathological processes and provide information about the development of therapeutic strategies for liver diseases.
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Affiliation(s)
- Zun Mao
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China; (Z.M.); (Z.G.)
| | - Junpeng Mu
- Department of Clinical Medicine, Xuzhou Medical University, Xuzhou 221004, China;
| | - Zhixiang Gao
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China; (Z.M.); (Z.G.)
| | - Shile Huang
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA
- Department of Hematology and Oncology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, LA 71130-3932, USA
| | - Long Chen
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China; (Z.M.); (Z.G.)
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2
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Jóźwiak P, Oracz J, Dziedzic A, Szelenberger R, Żyżelewicz D, Bijak M, Krześlak A. Increased O-GlcNAcylation by Upregulation of Mitochondrial O-GlcNAc Transferase (mOGT) Inhibits the Activity of Respiratory Chain Complexes and Controls Cellular Bioenergetics. Cancers (Basel) 2024; 16:1048. [PMID: 38473405 DOI: 10.3390/cancers16051048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/24/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
O-linked β-N-acetylglucosamine (O-GlcNAc) is a reversible post-translational modification involved in the regulation of cytosolic, nuclear, and mitochondrial proteins. The interplay between O-GlcNAcylation and phosphorylation is critical to control signaling pathways and maintain cellular homeostasis. The addition of O-GlcNAc moieties to target proteins is catalyzed by O-linked N-acetylglucosamine transferase (OGT). Of the three splice variants of OGT described, one is destined for the mitochondria (mOGT). Although the effects of O-GlcNAcylation on the biology of normal and cancer cells are well documented, the role of mOGT remains poorly understood. In this manuscript, the effects of mOGT on mitochondrial protein phosphorylation, electron transport chain (ETC) complex activity, and the expression of VDAC porins were investigated. We performed studies using normal and breast cancer cells with upregulated mOGT or its catalytically inactive mutant. Proteomic approaches included the isolation of O-GlcNAc-modified proteins of the electron transport chain, followed by their analysis using mass spectrometry. We found that mitochondrial OGT regulates the activity of complexes I-V of the respiratory chain and identified a group of 19 ETC components as mOGT substrates in mammary cells. Furthermore, we observed that the upregulation of mOGT inhibited the interaction of VDAC1 with hexokinase II. Our results suggest that the deregulation of mOGT reprograms cellular energy metabolism via interaction with and O-GlcNAcylation of proteins involved in ATP production in mitochondria and its exchange between mitochondria and the cytosol.
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Affiliation(s)
- Paweł Jóźwiak
- Department of Cytobiochemistry, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
| | - Joanna Oracz
- Institute of Food Technology and Analysis, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 90-924 Lodz, Poland
| | - Angela Dziedzic
- Department of General Biochemistry, Institute of Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
| | - Rafał Szelenberger
- Biohazard Prevention Centre, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
| | - Dorota Żyżelewicz
- Institute of Food Technology and Analysis, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 90-924 Lodz, Poland
| | - Michał Bijak
- Biohazard Prevention Centre, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
| | - Anna Krześlak
- Department of Cytobiochemistry, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
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He D, Zeng L, Chen P. Research progress in pharmacological effects of Aralia elata. Zhejiang Da Xue Xue Bao Yi Xue Ban 2023; 52:616-626. [PMID: 37916310 PMCID: PMC10630058 DOI: 10.3724/zdxbyxb-2023-0147] [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: 03/29/2023] [Accepted: 08/24/2023] [Indexed: 10/08/2023]
Abstract
The traditional Chinese medicine Aralia elata (Miq.) Seem., also known as Aralia mandshurica, has the effect of "tonifying Qi and calming the mind, strengthening the essence and tonifying the kidneys, and dispelling wind and invigorating blood circulation". It is used in the treatment of neurasthenia, Yang deficiency and Qi deficiency, kidney Qi deficiency, spleen Yang deficiency, water-dampness stagnation, thirst, and bruises. Aralia elata saponins are the main components for the pharmacological effects. From the perspective of modern pharmacological science, Aralia elata has a wide range of effects, including anti-myocardial ischaemia and alleviation of secondary myocardium ischemic reperfusion injury by regulating ionic homeostasis, anti-tumor activity by inhibiting proliferation, promoting apoptosis and enhancing immunity, hypoglycemia and lipid lowering effects by regulating glucose and lipid metabolism, and hepato-protective, neuroprotective, anti-inflammatory/analgesic effects. The studies on pharmacological mechanisms of Aralia elata will be conducive to its development and application in the future. This article reviews the research progress of Aralia elata domestically and internationally in the last two decades and proposes new directions for further research.
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Affiliation(s)
- Dahong He
- School of Medicine, Hangzhou City University, Hangzhou 310015, China.
| | - Linghui Zeng
- School of Medicine, Hangzhou City University, Hangzhou 310015, China.
| | - Peng Chen
- School of Medicine, Hangzhou City University, Hangzhou 310015, China.
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Sitosari H, Morimoto I, Weng Y, Zheng Y, Fukuhara Y, Ikegame M, Okamura H. Inhibition of protein phosphatase 2A by okadaic acid induces translocation of nucleocytoplasmic O-GlcNAc transferase. Biochem Biophys Res Commun 2023; 646:50-55. [PMID: 36706705 DOI: 10.1016/j.bbrc.2023.01.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 01/15/2023]
Abstract
Post-translational modification (PTM) is crucial for many biological events, such as the modulation of bone metabolism. Phosphorylation and O-GlcNAcylation are two examples of PTMs that can occur at the same site in the protein: serine and threonine residues. This phenomenon may cause crosstalk and possible interactions between the molecules involved. Protein phosphatase 2 A (PP2A) is widely expressed throughout the body and plays a major role in dephosphorylation. At the same location where PP2A acts, O-GlcNAc transferase (OGT) can introduce uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) molecules and mediates O-GlcNAc modifications. To examine the effects of PP2A inhibition on OGT localization and expression, osteoblastic MC3T3-E1 cells were treated with Okadaic Acid (OA), a potent PP2A inhibitor. In the control cells, OGT was strictly localized in the nucleus. However, OGT was observed diffusely in the cytoplasm of the OA-treated cells. This change in localization from the nucleus to the cytoplasm resulted from an increase in mitochondrial OGT expression and translocation of the nucleocytoplasmic isoform. Furthermore, knockdown of PP2A catalytic subunit α isoform (PP2A Cα) significantly affected OGT expression (p < 0.05), and there was a correlation between PP2A Cα and OGT expression (r = 0.93). These results suggested a possible interaction between PP2A and OGT, which strengthens the notion of an interaction between phosphorylation and O-GlcNAcylation.
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Affiliation(s)
- Heriati Sitosari
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan; Department of Oral Biology, Faculty of Dentistry, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
| | - Ikkei Morimoto
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan
| | - Yao Weng
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan; Department of Oral Rehabilitation and Implantology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan
| | - Yilin Zheng
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan
| | - Yoko Fukuhara
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan
| | - Mika Ikegame
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan
| | - Hirohiko Okamura
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan.
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Wong A, Akhaphong B, Baumann D, Alejandro EU. Genetic Ablation of the Nutrient Sensor Ogt in Endocrine Progenitors Is Dispensable for β-Cell Development but Essential for Maintenance of β-Cell Mass. Biomedicines 2022; 11:105. [PMID: 36672613 PMCID: PMC9855876 DOI: 10.3390/biomedicines11010105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 12/20/2022] [Accepted: 12/29/2022] [Indexed: 01/03/2023] Open
Abstract
Previously we utilized a murine model to demonstrate that Ogt deletion in pancreatic progenitors (OgtKOPanc) causes pancreatic hypoplasia, partly mediated by a reduction in the Pdx1-expressing pancreatic progenitor pool. Here, we continue to explore the role of Ogt in pancreas development by deletion of Ogt in the endocrine progenitors (OgtKOEndo). At birth OgtKOEndo, were normoglycemic and had comparable pancreas weight and α-cell, and β-cell mass to littermate controls. At postnatal day 23, OgtKOEndo displayed wide ranging but generally elevated blood glucose levels, with histological analyses showing aberrant islet architecture with α-cells invading the islet core. By postnatal day 60, these mice were overtly diabetic and showed significant loss of both α-cell and β-cell mass. Together, these results highlight the indispensable role of Ogt in maintenance of β-cell mass and glucose homeostasis.
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Affiliation(s)
- Alicia Wong
- Department of Genetics, Cell Biology, and Development, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Brian Akhaphong
- Department of Integrative Biology and Physiology, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Daniel Baumann
- Department of Integrative Biology and Physiology, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Emilyn U. Alejandro
- Department of Integrative Biology and Physiology, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
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6
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Hu CW, Xie J, Jiang J. The Emerging Roles of Protein Interactions with O-GlcNAc Cycling Enzymes in Cancer. Cancers (Basel) 2022; 14:5135. [PMID: 36291918 PMCID: PMC9600386 DOI: 10.3390/cancers14205135] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/18/2022] [Accepted: 10/18/2022] [Indexed: 09/11/2023] Open
Abstract
The dynamic O-GlcNAc modification of intracellular proteins is an important nutrient sensor for integrating metabolic signals into vast networks of highly coordinated cellular activities. Dysregulation of the sole enzymes responsible for O-GlcNAc cycling, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), and the associated cellular O-GlcNAc profile is a common feature across nearly every cancer type. Many studies have investigated the effects of aberrant OGT/OGA expression on global O-GlcNAcylation activity in cancer cells. However, recent studies have begun to elucidate the roles of protein-protein interactions (PPIs), potentially through regions outside of the immediate catalytic site of OGT/OGA, that regulate greater protein networks to facilitate substrate-specific modification, protein translocalization, and the assembly of larger biomolecular complexes. Perturbation of OGT/OGA PPI networks makes profound changes in the cell and may directly contribute to cancer malignancies. Herein, we highlight recent studies on the structural features of OGT and OGA, as well as the emerging roles and molecular mechanisms of their aberrant PPIs in rewiring cancer networks. By integrating complementary approaches, the research in this area will aid in the identification of key protein contacts and functional modules derived from OGT/OGA that drive oncogenesis and will illuminate new directions for anti-cancer drug development.
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Affiliation(s)
| | | | - Jiaoyang Jiang
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, USA
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7
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Liu Y, Chen C, Wang X, Sun Y, Zhang J, Chen J, Shi Y. An Epigenetic Role of Mitochondria in Cancer. Cells 2022; 11:cells11162518. [PMID: 36010594 PMCID: PMC9406960 DOI: 10.3390/cells11162518] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/03/2022] [Accepted: 08/09/2022] [Indexed: 12/14/2022] Open
Abstract
Mitochondria are not only the main energy supplier but are also the cell metabolic center regulating multiple key metaborates that play pivotal roles in epigenetics regulation. These metabolites include acetyl-CoA, α-ketoglutarate (α-KG), S-adenosyl methionine (SAM), NAD+, and O-linked beta-N-acetylglucosamine (O-GlcNAc), which are the main substrates for DNA methylation and histone post-translation modifications, essential for gene transcriptional regulation and cell fate determination. Tumorigenesis is attributed to many factors, including gene mutations and tumor microenvironment. Mitochondria and epigenetics play essential roles in tumor initiation, evolution, metastasis, and recurrence. Targeting mitochondrial metabolism and epigenetics are promising therapeutic strategies for tumor treatment. In this review, we summarize the roles of mitochondria in key metabolites required for epigenetics modification and in cell fate regulation and discuss the current strategy in cancer therapies via targeting epigenetic modifiers and related enzymes in metabolic regulation. This review is an important contribution to the understanding of the current metabolic-epigenetic-tumorigenesis concept.
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Affiliation(s)
- Yu’e Liu
- Tongji University Cancer Center, Shanghai Tenth People’s Hospital of Tongji University, School of Medicine, Tongji University, Shanghai 200092, China
| | - Chao Chen
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Shanghai 200433, China
| | - Xinye Wang
- Tongji University Cancer Center, Shanghai Tenth People’s Hospital of Tongji University, School of Medicine, Tongji University, Shanghai 200092, China
| | - Yihong Sun
- Tongji University Cancer Center, Shanghai Tenth People’s Hospital of Tongji University, School of Medicine, Tongji University, Shanghai 200092, China
| | - Jin Zhang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Juxiang Chen
- Department of Neurosurgery, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Shanghai 200433, China
- Correspondence: (J.C.); (Y.S.)
| | - Yufeng Shi
- Tongji University Cancer Center, Shanghai Tenth People’s Hospital of Tongji University, School of Medicine, Tongji University, Shanghai 200092, China
- Clinical Center for Brain and Spinal Cord Research, Tongji University, Shanghai 200092, China
- Correspondence: (J.C.); (Y.S.)
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8
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Short O-GlcNAcase Is Targeted to the Mitochondria and Regulates Mitochondrial Reactive Oxygen Species Level. Cells 2022; 11:cells11111827. [PMID: 35681522 PMCID: PMC9180253 DOI: 10.3390/cells11111827] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/18/2022] [Accepted: 05/26/2022] [Indexed: 02/01/2023] Open
Abstract
O-GlcNAcylation is a reversible post-translational modification involved in the regulation of cytosolic, nuclear, and mitochondrial proteins. Only two enzymes, OGT (O-GlcNAc transferase) and OGA (O-GlcNAcase), control the attachment and removal of O-GlcNAc on proteins, respectively. Whereas a variant OGT (mOGT) has been proposed as the main isoform that O-GlcNAcylates proteins in mitochondria, identification of a mitochondrial OGA has not been performed yet. Two splice variants of OGA (short and long isoforms) have been described previously. In this work, using cell fractionation experiments, we show that short-OGA is preferentially recovered in mitochondria-enriched fractions from HEK-293T cells and RAW 264.7 cells, as well as mouse embryonic fibroblasts. Moreover, fluorescent microscopy imaging confirmed that GFP-tagged short-OGA is addressed to mitochondria. In addition, using a Bioluminescence Resonance Energy Transfer (BRET)-based mitochondrial O-GlcNAcylation biosensor, we show that co-transfection of short-OGA markedly reduced O-GlcNAcylation of the biosensor, whereas long-OGA had no significant effect. Finally, using genetically encoded or chemical fluorescent mitochondrial probes, we show that short-OGA overexpression increases mitochondrial ROS levels, whereas long-OGA has no significant effect. Together, our work reveals that the short-OGA isoform is targeted to the mitochondria where it regulates ROS homoeostasis.
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9
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Xue Q, Yan R, Ji S, Yu S. Regulation of mitochondrial network homeostasis by O-GlcNAcylation. Mitochondrion 2022; 65:45-55. [DOI: 10.1016/j.mito.2022.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 03/30/2022] [Accepted: 04/27/2022] [Indexed: 12/20/2022]
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Abstract
Post-translational modification with O-linked β-N-acetylglucosamine (O-GlcNAc), a process referred to as O-GlcNAcylation, occurs on a vast variety of proteins. Mounting evidence in the past several decades has clearly demonstrated that O-GlcNAcylation is a unique and ubiquitous modification. Reminiscent of a code, protein O-GlcNAcylation functions as a crucial regulator of nearly all cellular processes studied. The primary aim of this review is to summarize the developments in our understanding of myriad protein substrates modified by O-GlcNAcylation from a systems perspective. Specifically, we provide a comprehensive survey of O-GlcNAcylation in multiple species studied, including eukaryotes (e.g., protists, fungi, plants, Caenorhabditis elegans, Drosophila melanogaster, murine, and human), prokaryotes, and some viruses. We evaluate features (e.g., structural properties and sequence motifs) of O-GlcNAc modification on proteins across species. Given that O-GlcNAcylation functions in a species-, tissue-/cell-, protein-, and site-specific manner, we discuss the functional roles of O-GlcNAcylation on human proteins. We focus particularly on several classes of relatively well-characterized human proteins (including transcription factors, protein kinases, protein phosphatases, and E3 ubiquitin-ligases), with representative O-GlcNAc site-specific functions presented. We hope the systems view of the great endeavor in the past 35 years will help demystify the O-GlcNAc code and lead to more fascinating studies in the years to come.
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Affiliation(s)
- Junfeng Ma
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington, DC 20057, United States
| | - Chunyan Hou
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington, DC 20057, United States
| | - Ci Wu
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington, DC 20057, United States
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11
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Bisnett BJ, Condon BM, Linhart NA, Lamb CH, Huynh DT, Bai J, Smith TJ, Hu J, Georgiou GR, Boyce M. Evidence for nutrient-dependent regulation of the COPII coat by O-GlcNAcylation. Glycobiology 2021; 31:1102-1120. [PMID: 34142147 PMCID: PMC8457363 DOI: 10.1093/glycob/cwab055] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 06/01/2021] [Accepted: 06/03/2021] [Indexed: 12/18/2022] Open
Abstract
O-linked β-N-acetylglucosamine (O-GlcNAc) is a dynamic form of intracellular glycosylation common in animals, plants and other organisms. O-GlcNAcylation is essential in mammalian cells and is dysregulated in myriad human diseases, such as cancer, neurodegeneration and metabolic syndrome. Despite this pathophysiological significance, key aspects of O-GlcNAc signaling remain incompletely understood, including its impact on fundamental cell biological processes. Here, we investigate the role of O-GlcNAcylation in the coat protein II complex (COPII), a system universally conserved in eukaryotes that mediates anterograde vesicle trafficking from the endoplasmic reticulum. We identify new O-GlcNAcylation sites on Sec24C, Sec24D and Sec31A, core components of the COPII system, and provide evidence for potential nutrient-sensitive pathway regulation through site-specific glycosylation. Our work suggests a new connection between metabolism and trafficking through the conduit of COPII protein O-GlcNAcylation.
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Affiliation(s)
- Brittany J Bisnett
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Brett M Condon
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Noah A Linhart
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Caitlin H Lamb
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Duc T Huynh
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Jingyi Bai
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Timothy J Smith
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Jimin Hu
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - George R Georgiou
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Michael Boyce
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
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12
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Mitochondrial O-GlcNAc Transferase Interacts with and Modifies Many Proteins and Its Up-Regulation Affects Mitochondrial Function and Cellular Energy Homeostasis. Cancers (Basel) 2021; 13:cancers13122956. [PMID: 34204801 PMCID: PMC8231590 DOI: 10.3390/cancers13122956] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 05/31/2021] [Accepted: 06/08/2021] [Indexed: 02/06/2023] Open
Abstract
O-GlcNAcylation is a cell glucose sensor. The addition of O-GlcNAc moieties to target protein is catalyzed by the O-Linked N-acetylglucosamine transferase (OGT). OGT is encoded by a single gene that yields differentially spliced OGT isoforms. One of them is targeted to mitochondria (mOGT). Although the impact of O-GlcNAcylation on cancer cells biology is well documented, mOGT's role remains poorly investigated. We performed studies using breast cancer cells with up-regulated mOGT or its catalytic inactive mutant to identify proteins specifically modified by mOGT. Proteomic approaches included isolation of mOGT protein partners and O-GlcNAcylated proteins from mitochondria-enriched fraction followed by their analysis by mass spectrometry. Moreover, we analyzed the impact of mOGT dysregulation on mitochondrial activity and cellular metabolism using a variety of biochemical assays. We found that mitochondrial OGT expression is glucose-dependent. Elevated mOGT expression affected the mitochondrial transmembrane potential and increased intramitochondrial ROS generation. Moreover, mOGT up-regulation caused a decrease in cellular ATP level. We identified many mitochondrial proteins as mOGT substrates. Most of these proteins are localized in the mitochondrial matrix and the inner mitochondrial membrane and participate in mitochondrial respiration, fatty acid metabolism, transport, translation, apoptosis, and mtDNA processes. Our findings suggest that mOGT interacts with and modifies many mitochondrial proteins, and its dysregulation affects cellular bioenergetics and mitochondria function.
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13
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Fang N, Li P. O-linked N-acetylglucosaminyltransferase OGT inhibits diabetic nephropathy by stabilizing histone methyltransferases EZH2 via the HES1/PTEN axis. Life Sci 2021; 274:119226. [PMID: 33609540 DOI: 10.1016/j.lfs.2021.119226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/26/2021] [Accepted: 02/07/2021] [Indexed: 01/01/2023]
Abstract
BACKGROUND O-linked N-acetylglucosaminyltransferase (OGT) is involved in diabetes-related diseases including diabetic nephropathy (DN), and responsible for O-GlcNAcylation. Moreover, O-GlcNAcylation and OGT could be induced by high glucose. Thus, we sought to explore the molecular mechanism of OGT in DN. METHODS Loss- and gain-functions were conducted to determine the roles of OGT, enhancer of zeste homolog 2 (EZH2), hairy and enhancer of split 1 (HES1) and phosphatase and tensin homolog (PTEN) in the viability, cell cycle and fibrosis of mesangial cells (MCs), followed by the assessment using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and Western blot assay (fibrosis-related proteins). The interaction between OGT and EZH2 and the effect on EZH2 glycosylation were verified by chromatin immunoprecipitation (ChIP) and glutathione S-transferase (GST) pull-down assays. EZH2 stability was checked by treatment with cycloheximide. RESULTS Expression of OGT was repressed in the DN mice and high glucose-treated MCs. Elevated OGT suppressed viability of high glucose-treated MCs, blocked proliferation characterized by repressed cyclin D1, but enhanced p21 levels, and inhibited fibrosis evidenced by reduced levels of fibronectin (FN) and collagen-4 (col-4). OGT interacted with EZH2 and promoted its glycosylation thus stabilizing the EZH2. EZH2 overexpression enhanced the enrichment of EZH2 and histone H3 Lys27 trimethylation (H3K27me3) in the HES1 promoter. HES1 was upregulated and PTEN was downregulated in DN mice. Transduction of lentivirus vector containing overexpression (oe)-OGT alleviated renal injury in DN mice. CONCLUSIONS Collectively, OGT stabilizes histone methyltransferases EZH2 to regulate HES1/PTEN thus inhibiting DN.
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Affiliation(s)
- Na Fang
- Department of Nephrology, The Fifth People's Hospital of Jinan, Jinan 250022, PR China.
| | - Ping Li
- Special Inspection Section, The Fifth People's Hospital of Jinan, Jinan 250022, PR China
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14
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Ma J, Wu C, Hart GW. Analytical and Biochemical Perspectives of Protein O-GlcNAcylation. Chem Rev 2021; 121:1513-1581. [DOI: 10.1021/acs.chemrev.0c00884] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Junfeng Ma
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington D.C. 20057, United States
| | - Ci Wu
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington D.C. 20057, United States
| | - Gerald W. Hart
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, United States
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15
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Flax J, Wilkins HM, Miller R, Griffith S, Cork GK, Qiang A, Thompson J, Swerdlow RH, Slawson C. OGA Inhibition Alters Energetics and Nutrient Sensing in Alzheimer's Disease Cytoplasmic Hybrids. J Alzheimers Dis 2020; 78:1743-1753. [PMID: 33285636 DOI: 10.3233/jad-200996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) features reductions in key bioenergetic fluxes and perturbed mitochondrial function. Cytoplasmic hybrids (cybrids) generated through the transfer of AD subject mitochondria to mtDNA-depleted SH-SY5Y neuroblastoma cells recapitulate some of these features in an in vitro setting. OBJECTIVE For this study, we used the AD cybrid model to assess the impact of a nutrient-excess like-state via increasing O-GlcNAcylation on whole cell and mitochondrial homeostasis. METHODS We induced increased O-GlcNAc by treating AD and control cybrid cell lines with Thiamet G (TMG), an inhibitor of the O-GlcNAcase enzyme that mediates removal of the nutrient-dependent O-GlcNAc modification. RESULTS Relative to control cybrid cell lines, AD cybrid lines showed a blunted response to TMG-induced O-GlcNAcylation. At baseline, AD cybrid cell line mitochondria showed partial activation of several proteins that help maintain bioenergetic homeostasis such as AMP-Regulated Kinase suggesting that AD mitochondria initiate a state of nutrient stress promoting energetic compensation; however, this compensation reduces the capacity of cells to respond to additional nutrient-related stresses such as TMG treatment. Also, TMG caused disruptions in acetylation and Sirtuin 3 expression, while lowing total energetic output of the cell. CONCLUSION Together, these findings suggest that modulation of O-GlcNAc is essential for proper energetic function of the mitochondria, and AD mitochondrial capacity to handle nutrient-excess is limited.
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Affiliation(s)
- Jarrod Flax
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Heather M Wilkins
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA.,Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Reegan Miller
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Sarah Griffith
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Gentry K Cork
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Amy Qiang
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Jeffrey Thompson
- Department of Biostatistics and Data Science, University of Kansas Medical Center, Kansas City, KS, USA
| | - Russell H Swerdlow
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Chad Slawson
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA
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16
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Wu D, Jin J, Qiu Z, Liu D, Luo H. Functional Analysis of O-GlcNAcylation in Cancer Metastasis. Front Oncol 2020; 10:585288. [PMID: 33194731 PMCID: PMC7653022 DOI: 10.3389/fonc.2020.585288] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 10/06/2020] [Indexed: 12/21/2022] Open
Abstract
One common and reversible type of post-translational modification (PTM) is the addition of O-linked β-N-acetylglucosamine (O-GlcNAc) modification (O-GlcNAcylation), and its dynamic balance is controlled by O-GlcNAc transferase (OGT) and glycoside hydrolase O-GlcNAcase (OGA) through the addition or removal of O-GlcNAc groups. A large amount of research data confirms that proteins regulated by O-GlcNAcylation play a pivotal role in cells. In particularly, imbalanced levels of OGT and O-GlcNAcylation have been found in various types of cancers. Recently, increasing evidence shows that imbalanced O-GlcNAcylation directly or indirectly impacts the process of cancer metastasis. This review summarizes the current understanding of the influence of O-GlcNAc-proteins on the regulation of cancer metastasis. It will provide a theoretical basis to further elucidate of the molecular mechanisms underlying cancer emergence and progression.
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Affiliation(s)
- Donglu Wu
- School of Clinical Medical, Changchun University of Chinese Medicine, Changchun, China.,Key Laboratory of Effective Components of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Jingji Jin
- School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Zhidong Qiu
- Key Laboratory of Effective Components of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China.,School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Da Liu
- Key Laboratory of Effective Components of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China.,School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Haoming Luo
- Key Laboratory of Effective Components of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China.,School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
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17
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Chen PH, Hu J, Wu J, Huynh DT, Smith TJ, Pan S, Bisnett BJ, Smith AB, Lu A, Condon BM, Chi JT, Boyce M. Gigaxonin glycosylation regulates intermediate filament turnover and may impact giant axonal neuropathy etiology or treatment. JCI Insight 2019; 5:127751. [PMID: 31944090 DOI: 10.1172/jci.insight.127751] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Gigaxonin (also known as KLHL16) is an E3 ligase adaptor protein that promotes the ubiquitination and degradation of intermediate filament (IF) proteins. Mutations in human gigaxonin cause the fatal neurodegenerative disease giant axonal neuropathy (GAN), in which IF proteins accumulate and aggregate in axons throughout the nervous system, impairing neuronal function and viability. Despite this pathophysiological significance, the upstream regulation and downstream effects of normal and aberrant gigaxonin function remain incompletely understood. Here, we report that gigaxonin is modified by <italic>O</italic>-linked β-<italic>N</italic>-acetylglucosamine (O-GlcNAc), a prevalent form of intracellular glycosylation, in a nutrient- and growth factor–dependent manner. MS analyses of human gigaxonin revealed 9 candidate sites of O-GlcNAcylation, 2 of which — serine 272 and threonine 277 — are required for its ability to mediate IF turnover in gigaxonin-deficient human cell models that we created. Taken together, the results suggest that nutrient-responsive gigaxonin O-GlcNAcylation forms a regulatory link between metabolism and IF proteostasis. Our work may have significant implications for understanding the nongenetic modifiers of GAN phenotypes and for the optimization of gene therapy for this disease.
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Affiliation(s)
- Po-Han Chen
- Department of Biochemistry.,Department of Molecular Genetics and Microbiology, and.,Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | | | - Jianli Wu
- Department of Molecular Genetics and Microbiology, and.,Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | | | | | - Samuel Pan
- Department of Molecular Genetics and Microbiology, and.,Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | | | - Alexander B Smith
- Department of Molecular Genetics and Microbiology, and.,Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Annie Lu
- Department of Molecular Genetics and Microbiology, and.,Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | | | - Jen-Tsan Chi
- Department of Molecular Genetics and Microbiology, and.,Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, North Carolina, USA
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18
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Hu CW, Worth M, Li H, Jiang J. Chemical and Biochemical Strategies To Explore the Substrate Recognition of O-GlcNAc-Cycling Enzymes. Chembiochem 2019; 20:312-318. [PMID: 30199580 PMCID: PMC6433133 DOI: 10.1002/cbic.201800481] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Indexed: 12/11/2022]
Abstract
The O-linked N-acetylglucosamine (O-GlcNAc) modification is an essential component in cell regulation. A single pair of human enzymes conducts this modification dynamically on a broad variety of proteins: O-GlcNAc transferase (OGT) adds the GlcNAc residue and O-GlcNAcase (OGA) hydrolyzes it. This modification is dysregulated in many diseases, but its exact effect on particular substrates remains unclear. In addition, no apparent sequence motif has been found in the modified proteins, and the factors controlling the substrate specificity of OGT and OGA are largely unknown. In this minireview, we will discuss recent developments in chemical and biochemical methods toward addressing the challenge of OGT and OGA substrate recognition. We hope that the new concepts and knowledge from these studies will promote research in this area to advance understanding of O-GlcNAc regulation in health and disease.
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Affiliation(s)
- Chia-Wei Hu
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin–Madison, 777 Highland Avenue, Madison, WI 53705 (USA)
| | - Matthew Worth
- Department of Chemistry, University of Wisconsin–Madison, 101 University Avenue, Madison, WI 53706 (USA)
| | - Hao Li
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin–Madison, 777 Highland Avenue, Madison, WI 53705 (USA)
| | - Jiaoyang Jiang
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin–Madison, 777 Highland Avenue, Madison, WI 53705 (USA)
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19
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O-deGlcNAcylation is required for Entamoeba histolytica-induced HepG2 cell death. Microb Pathog 2018; 123:285-295. [DOI: 10.1016/j.micpath.2018.07.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 07/12/2018] [Accepted: 07/12/2018] [Indexed: 11/17/2022]
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20
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Pinho TS, Verde DM, Correia SC, Cardoso SM, Moreira PI. O-GlcNAcylation and neuronal energy status: Implications for Alzheimer's disease. Ageing Res Rev 2018; 46:32-41. [PMID: 29787816 DOI: 10.1016/j.arr.2018.05.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 04/03/2018] [Accepted: 05/14/2018] [Indexed: 02/05/2023]
Abstract
Since the first clinical case reported more than 100 years ago, it has been a long and winding road to demystify the initial pathological events underling the onset of Alzheimer's disease (AD). Fortunately, advanced imaging techniques extended the knowledge regarding AD origin, being well accepted that a decline in brain glucose metabolism occurs during the prodromal phases of AD and is aggravated with the progression of the disease. In this sense, in the last decades, the post-translational modification O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) has emerged as a potential causative link between hampered brain glucose metabolism and AD pathology. This is not surprising taking into account that this dynamic post-translational modification acts as a metabolic sensor that links glucose metabolism to normal neuronal functioning. Within this scenario, the present review aims to summarize the current understanding on the role of O-GlcNAcylation in neuronal physiology and AD pathology, emphasizing the close association of this post-translational modification with the emergence of AD-related hallmarks and its potential as a therapeutic target.
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Affiliation(s)
- Tiffany S Pinho
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Diogo M Verde
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Sónia C Correia
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Susana M Cardoso
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Paula I Moreira
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal; Laboratory of Physiology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
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21
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Kim YS, Kim M, Choi MY, Lee DH, Roh GS, Kim HJ, Kang SS, Cho GJ, Hong EK, Choi WS. Alpha-lipoic acid reduces retinal cell death in diabetic mice. Biochem Biophys Res Commun 2018; 503:1307-1314. [PMID: 30017190 DOI: 10.1016/j.bbrc.2018.07.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 07/08/2018] [Indexed: 12/30/2022]
Abstract
Oxidative stress plays an important role in the development of diabetic retinopathy. Here, we examined whether α-lipoic acid (α-LA), a natural antioxidant, attenuated retinal injury in diabetic mice. The α-LA was orally administered to control mice or mice with streptozotocin-induced diabetes. We found that α-LA reduced oxidative stress, decreased and increased retinal 4-hydroxy-2-nonenal and glutathione peroxidase, respectively, and inhibited retinal cell death. Concomitantly, α-LA reversed the decreased activation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase, and increased the levels of peroxisome proliferator-activated receptor delta and sirtuin3 in diabetic mouse retinas, similar to results shown after metformin treatment of retinal pigment epithelial cells (RPE) exposed to high glucose. Moreover, α-LA lowered the levels of O-linked β-N-acetylglucosamine transferase (OGT) and thioredoxin-interacting protein (TXNIP) in diabetic retinas that were more pronounced after metformin treatment of RPE cells. Importantly, α-LA lowered interactions between AMPK and OGT as shown by co-immunoprecipitation analyses, and this was accompanied by less cell death as measured by double immunofluorescence staining by terminal deoxynucleotide transferase-mediated dUTP nick-end labelling and OGT or TXNIP in retinal ganglion cells. Consistently, α-LA lowered the levels of cleaved poly(ADP-ribose) polymerase and pro-apoptotic marker cleaved caspase-3 in diabetic retinas. Our results indicated that α-LA reduced retinal cell death partly through AMPK activation or OGT inhibition in diabetic mice.
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Affiliation(s)
- Yoon Sook Kim
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, Republic of Korea
| | - Minjun Kim
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, Republic of Korea
| | - Mee Young Choi
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, Republic of Korea
| | - Dong Hoon Lee
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, Republic of Korea
| | - Gu Seob Roh
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, Republic of Korea
| | - Hyun Joon Kim
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, Republic of Korea
| | - Sang Soo Kang
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, Republic of Korea
| | - Gyeong Jae Cho
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, Republic of Korea
| | - Eun-Kyung Hong
- Medvill Co., Ltd, 1606 Daeryung Post Tower 5th, 68 Digitalro 9gil, Guemcheon-gu, Seoul, 08512, Republic of Korea
| | - Wan Sung Choi
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, Republic of Korea.
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22
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O-GlcNAc in cancer: An Oncometabolism-fueled vicious cycle. J Bioenerg Biomembr 2018; 50:155-173. [PMID: 29594839 DOI: 10.1007/s10863-018-9751-2] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 03/15/2018] [Indexed: 12/17/2022]
Abstract
Cancer cells exhibit unregulated growth, altered metabolism, enhanced metastatic potential and altered cell surface glycans. Fueled by oncometabolism and elevated uptake of glucose and glutamine, the hexosamine biosynthetic pathway (HBP) sustains glycosylation in the endomembrane system. In addition, the elevated pools of UDP-GlcNAc drives the O-GlcNAc modification of key targets in the cytoplasm, nucleus and mitochondrion. These targets include transcription factors, kinases, key cytoplasmic enzymes of intermediary metabolism, and electron transport chain complexes. O-GlcNAcylation can thereby alter epigenetics, transcription, signaling, proteostasis, and bioenergetics, key 'hallmarks of cancer'. In this review, we summarize accumulating evidence that many cancer hallmarks are linked to dysregulation of O-GlcNAc cycling on cancer-relevant targets. We argue that onconutrient and oncometabolite-fueled elevation increases HBP flux and triggers O-GlcNAcylation of key regulatory enzymes in glycolysis, Kreb's cycle, pentose-phosphate pathway, and the HBP itself. The resulting rerouting of glucose metabolites leads to elevated O-GlcNAcylation of oncogenes and tumor suppressors further escalating elevation in HBP flux creating a 'vicious cycle'. Downstream, elevated O-GlcNAcylation alters DNA repair and cellular stress pathways which influence oncogenesis. The elevated steady-state levels of O-GlcNAcylated targets found in many cancers may also provide these cells with a selective advantage for sustained growth, enhanced metastatic potential, and immune evasion in the tumor microenvironment.
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23
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O-Linked β- N-acetylglucosamine (O-GlcNAc) modification: a new pathway to decode pathogenesis of diabetic retinopathy. Clin Sci (Lond) 2018; 132:185-198. [PMID: 29352075 DOI: 10.1042/cs20171454] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/13/2017] [Accepted: 12/18/2017] [Indexed: 01/08/2023]
Abstract
The incidence of diabetes continues to rise among all ages and ethnic groups worldwide. Diabetic retinopathy (DR) is a complication of diabetes that affects the retinal neurovasculature causing serious vision problems, including blindness. Its pathogenesis and severity is directly linked to the chronic exposure to high glucose conditions. No treatments are currently available to stop the development and progression of DR. To develop new and effective therapeutic approaches, it is critical to better understand how hyperglycemia contributes to the pathogenesis of DR at the cellular and molecular levels. We propose alterations in O-GlcNAc modification of target proteins during diabetes contribute to the development and progression of DR. The O-GlcNAc modification is regulated through hexosamine biosynthetic pathway. We showed this pathway is differentially activated in various retinal vascular cells under high glucose conditions perhaps due to their selective metabolic activity. O-GlcNAc modification can alter protein stability, activity, interactions, and localization. By targeting the same amino acid residues (serine and threonine) as phosphorylation, O-GlcNAc modification can either compete or cooperate with phosphorylation. Here we will summarize the effects of hyperglycemia-induced O-GlcNAc modification on the retinal neurovasculature in a cell-specific manner, providing new insight into the role of O-GlcNAc modification in early loss of retinal pericytes and the pathogenesis of DR.
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24
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Akan I, Olivier-Van Stichelen S, Bond MR, Hanover JA. Nutrient-driven O-GlcNAc in proteostasis and neurodegeneration. J Neurochem 2017; 144:7-34. [PMID: 29049853 DOI: 10.1111/jnc.14242] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 09/28/2017] [Accepted: 10/11/2017] [Indexed: 12/14/2022]
Abstract
Proteostasis is essential in the mammalian brain where post-mitotic cells must function for decades to maintain synaptic contacts and memory. The brain is dependent on glucose and other metabolites for proper function and is spared from metabolic deficits even during starvation. In this review, we outline how the nutrient-sensitive nucleocytoplasmic post-translational modification O-linked N-acetylglucosamine (O-GlcNAc) regulates protein homeostasis. The O-GlcNAc modification is highly abundant in the mammalian brain and has been linked to proteopathies, including neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's. C. elegans, Drosophila, and mouse models harboring O-GlcNAc transferase- and O-GlcNAcase-knockout alleles have helped define the role O-GlcNAc plays in development as well as age-associated neurodegenerative disease. These enzymes add and remove the single monosaccharide from protein serine and threonine residues, respectively. Blocking O-GlcNAc cycling is detrimental to mammalian brain development and interferes with neurogenesis, neural migration, and proteostasis. Findings in C. elegans and Drosophila model systems indicate that the dynamic turnover of O-GlcNAc is critical for maintaining levels of key transcriptional regulators responsible for neurodevelopment cell fate decisions. In addition, pathways of autophagy and proteasomal degradation depend on a transcriptional network that is also reliant on O-GlcNAc cycling. Like the quality control system in the endoplasmic reticulum which uses a 'mannose timer' to monitor protein folding, we propose that cytoplasmic proteostasis relies on an 'O-GlcNAc timer' to help regulate the lifetime and fate of nuclear and cytoplasmic proteins. O-GlcNAc-dependent developmental alterations impact metabolism and growth of the developing mouse embryo and persist into adulthood. Brain-selective knockout mouse models will be an important tool for understanding the role of O-GlcNAc in the physiology of the brain and its susceptibility to neurodegenerative injury.
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Affiliation(s)
- Ilhan Akan
- Laboratory of Cell and Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Michelle R Bond
- Laboratory of Cell and Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, USA
| | - John A Hanover
- Laboratory of Cell and Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, USA
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25
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Kim YS, Kim M, Choi MY, Lee DH, Roh GS, Kim HJ, Kang SS, Cho GJ, Park KH, Kim SJ, Yoo JM, Choi WS. Aralia elata (Miq) Seem Extract Decreases O-GlcNAc Transferase Expression and Retinal Cell Death in Diabetic Mice. J Med Food 2017; 20:989-1001. [DOI: 10.1089/jmf.2016.3891] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Yoon Sook Kim
- Department of Anatomy and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Minjun Kim
- Department of Anatomy and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Mee Young Choi
- Department of Anatomy and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Dong Hoon Lee
- Department of Anatomy and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Gu Seob Roh
- Department of Anatomy and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Hyun Joon Kim
- Department of Anatomy and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Sang Soo Kang
- Department of Anatomy and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Gyeong Jae Cho
- Department of Anatomy and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Ki Hun Park
- Division of Applied Life Science, Institute of Agriculture Life Science, Graduate School of Gyeongsang National University, Jinju, South Korea
| | - Seong-Jae Kim
- Department of Ophthalmology, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Ji-Myong Yoo
- Department of Ophthalmology, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Wan Sung Choi
- Department of Anatomy and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, South Korea
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26
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Kim G, Cao L, Reece EA, Zhao Z. Impact of protein O-GlcNAcylation on neural tube malformation in diabetic embryopathy. Sci Rep 2017; 7:11107. [PMID: 28894244 PMCID: PMC5593976 DOI: 10.1038/s41598-017-11655-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 08/25/2017] [Indexed: 01/15/2023] Open
Abstract
Diabetes mellitus in early pregnancy can cause neural tube defects (NTDs) in embryos by perturbing protein activity, causing cellular stress, and increasing programmed cell death (apoptosis) in the tissues required for neurulation. Hyperglycemia augments a branch pathway in glycolysis, the hexosamine biosynthetic pathway (HBP), to increase uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc). GlcNAc can be added to proteins by O-GlcNAc transferase (OGT) to regulate protein activity. In the embryos of diabetic mice, OGT is highly activated in association with increases in global protein O-GlcNAcylation. In neural stem cells in vitro, high glucose elevates O-GlcNAcylation and reactive oxygen species, but the elevations can be suppressed by an OGT inhibitor. Inhibition of OGT in diabetic pregnant mice in vivo decreases NTD rate in the embryos. This effect is associated with reduction in global O-GlcNAcylation, alleviation of intracellular stress, and decreases in apoptosis in the embryos. These suggest that OGT plays an important role in diabetic embryopathy via increasing protein O-GlcNAcylation, and that inhibiting OGT could be a candidate approach to prevent birth defects in diabetic pregnancies.
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Affiliation(s)
- Gyuyoup Kim
- Department of Obstetrics, Gynecology and Reproductive Sciences,University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Lixue Cao
- Department of Obstetrics, Gynecology and Reproductive Sciences,University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - E Albert Reece
- Department of Obstetrics, Gynecology and Reproductive Sciences,University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Zhiyong Zhao
- Department of Obstetrics, Gynecology and Reproductive Sciences,University of Maryland School of Medicine, Baltimore, Maryland, USA.
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA.
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27
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Kim YS, Kim M, Choi MY, Lee DH, Roh GS, Kim HJ, Kang SS, Cho GJ, Kim SJ, Yoo JM, Choi WS. Metformin protects against retinal cell death in diabetic mice. Biochem Biophys Res Commun 2017; 492:397-403. [PMID: 28843855 DOI: 10.1016/j.bbrc.2017.08.087] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 08/22/2017] [Indexed: 10/19/2022]
Abstract
Retinal degeneration is an early feature of diabetic retinopathy, the major cause of blindness in the developed world. Here we investigated how the widely used antidiabetic drug metformin reduces retinal injury in diabetic mice. Metformin was orally administered to control mice or mice with streptozotocin-induced diabetes. Western blot analysis showed that levels of O-linked β-N-acetylglucosamine (O-GlcNAc) transferase (OGT) and other related proteins such as carbohydrate-responsive element-binding protein (ChREBP) and thioredoxin-interacting protein (TXNIP) were significantly increased, and nuclear factor kappaB (NF-κB) and poly (ADP-ribose) polymerase (PARP) were activated in the diabetic retinas or retinal pigment epithelial (RPE) cells exposed to high glucose compared to controls. More importantly, RPE cells exposed to high glucose and treated with thiamet-G had higher levels of those proteins, demonstrating the role of elevated O-GlcNAcylation. Double immunofluorescence analysis revealed increased co-localization of terminal deoxynucleotide transferase-mediated dUTP nick-end labelling (TUNEL)-positive ganglion cells and OGT, ChREBP, TXNIP, or NF-κB in diabetic retinas compared to control retinas. Co-immunoprecipitation analysis showed that interaction between OGT and ChREBP or NF-κB was increased in diabetic retinas compared to control retinas, and this was accompanied by more cell death. Notably, metformin attenuated the increases in protein levels; reduced co-localization of TUNEL-positive ganglion cells and OGT, ChREBP, TXNIP, or NF-κB; and reduced interaction between OGT and ChREBP or NF-κB. Our results indicate that OGT inhibition might be one of the mechanisms by which metformin decreases retinal cell death.
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Affiliation(s)
- Yoon Sook Kim
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea
| | - Minjun Kim
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea
| | - Mee Young Choi
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea
| | - Dong Hoon Lee
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea
| | - Gu Seob Roh
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea
| | - Hyun Joon Kim
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea
| | - Sang Soo Kang
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea
| | - Gyeong Jae Cho
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea
| | - Seong-Jae Kim
- Department of Ophthalmology, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea
| | - Ji-Myong Yoo
- Department of Ophthalmology, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea
| | - Wan Sung Choi
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Gyeongnam, South Korea.
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Kim EJ. In Vitro Biochemical Assays for O-GlcNAc-Processing Enzymes. Chembiochem 2017; 18:1462-1472. [PMID: 28474822 DOI: 10.1002/cbic.201700138] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Indexed: 12/27/2022]
Abstract
O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) are the only enzymes that regulate the dynamics of protein O-GlcNAcylation. Protein O-GlcNAcylation is an important post-translational modification (PTM) of nuclear and cytoplasmic proteins with O-linked β-N-acetyl-glucosamine (O-GlcNAc). O-GlcNAc and its enzymes are involved in a wide variety of cellular processes and are linked to the pathological progression of chronic diseases. Considering their emerging biological significance, systematic and rapid methods to determine the activities of OGT and OGA have become essential, and several chemical/biochemical methods for measuring the activities of these enzymes have been developed. This minireview mainly focuses on the various biochemical assay methods developed to date, while also providing a description of the fundamental principles underlying the monitoring of O-GlcNAc enzyme activities.
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Affiliation(s)
- Eun Ju Kim
- Department of Science Education-Chemistry Major, Daegu University, 15, Jilyang, Gyeongsan-si, GyeongBuk, 712-714, Republic of Korea
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29
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Potential coordination role between O-GlcNAcylation and epigenetics. Protein Cell 2017; 8:713-723. [PMID: 28488246 PMCID: PMC5636747 DOI: 10.1007/s13238-017-0416-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 04/20/2017] [Indexed: 11/25/2022] Open
Abstract
Dynamic changes of the post-translational O-GlcNAc modification (O-GlcNAcylation) are controlled by O-linked β-N-acetylglucosamine (O-GlcNAc) transferase (OGT) and the glycoside hydrolase O-GlcNAcase (OGA) in cells. O-GlcNAcylation often occurs on serine (Ser) and threonine (Thr) residues of the specific substrate proteins via the addition of O-GlcNAc group by OGT. It has been known that O-GlcNAcylation is not only involved in many fundamental cellular processes, but also plays an important role in cancer development through various mechanisms. Recently, accumulating data reveal that O-GlcNAcylation at histones or non-histone proteins can lead to the start of the subsequent biological processes, suggesting that O-GlcNAcylation as ‘protein code’ or ‘histone code’ may provide recognition platforms or executive instructions for subsequent recruitment of proteins to carry out the specific functions. In this review, we summarize the interaction of O-GlcNAcylation and epigenetic changes, introduce recent research findings that link crosstalk between O-GlcNAcylation and epigenetic changes, and speculate on the potential coordination role of O-GlcNAcylation with epigenetic changes in intracellular biological processes.
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30
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O-GlcNAc Glycosylation of nNOS Promotes Neuronal Apoptosis Following Glutamate Excitotoxicity. Cell Mol Neurobiol 2017; 37:1465-1475. [DOI: 10.1007/s10571-017-0477-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 02/17/2017] [Indexed: 01/11/2023]
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31
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Sacoman JL, Dagda RY, Burnham-Marusich AR, Dagda RK, Berninsone PM. Mitochondrial O-GlcNAc Transferase (mOGT) Regulates Mitochondrial Structure, Function, and Survival in HeLa Cells. J Biol Chem 2017; 292:4499-4518. [PMID: 28100784 DOI: 10.1074/jbc.m116.726752] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 12/30/2016] [Indexed: 01/06/2023] Open
Abstract
O-Linked N-acetylglucosamine transferase (OGT) catalyzes O-GlcNAcylation of target proteins and regulates numerous biological processes. OGT is encoded by a single gene that yields nucleocytosolic and mitochondrial isoforms. To date, the role of the mitochondrial isoform of OGT (mOGT) remains largely unknown. Using high throughput proteomics, we identified 84 candidate mitochondrial glycoproteins, of which 44 are novel. Notably, two of the candidate glycoproteins identified (cytochrome oxidase 2 (COX2) and NADH:ubiquinone oxidoreductase core subunit 4 (MT-ND4)) are encoded by mitochondrial DNA. Using siRNA in HeLa cells, we found that reducing endogenous mOGT expression leads to alterations in mitochondrial structure and function, including Drp1-dependent mitochondrial fragmentation, reduction in mitochondrial membrane potential, and a significant loss of mitochondrial content in the absence of mitochondrial ROS. These defects are associated with a compensatory increase in oxidative phosphorylation per mitochondrion. mOGT is also critical for cell survival; siRNA-mediated knockdown of endogenous mOGT protected cells against toxicity mediated by rotenone, a complex I inhibitor. Conversely, reduced expression of both nucleocytoplasmic (ncOGT) and mitochondrial (mOGT) OGT isoforms is associated with increased mitochondrial respiration and elevated glycolysis, suggesting that ncOGT is a negative regulator of cellular bioenergetics. Last, we determined that mOGT is probably involved in the glycosylation of a restricted set of mitochondrial targets. We identified four proteins implicated in mitochondrial biogenesis and metabolism regulation as candidate substrates of mOGT, including leucine-rich PPR-containing protein and mitochondrial aconitate hydratase. Our findings suggest that mOGT is catalytically active in vivo and supports mitochondrial structure, health, and survival, whereas ncOGT predominantly regulates cellular bioenergetics.
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Affiliation(s)
- Juliana L Sacoman
- From the Department of Biology, University of Nevada, Reno, Nevada 89557 and
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32
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Qin CX, Sleaby R, Davidoff AJ, Bell JR, De Blasio MJ, Delbridge LM, Chatham JC, Ritchie RH. Insights into the role of maladaptive hexosamine biosynthesis and O-GlcNAcylation in development of diabetic cardiac complications. Pharmacol Res 2016; 116:45-56. [PMID: 27988387 DOI: 10.1016/j.phrs.2016.12.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 10/28/2016] [Accepted: 12/13/2016] [Indexed: 12/21/2022]
Abstract
Diabetes mellitus significantly increases the risk of heart failure, independent of coronary artery disease. The mechanisms implicated in the development of diabetic heart disease, commonly termed diabetic cardiomyopathy, are complex, but much of the impact of diabetes on the heart can be attributed to impaired glucose handling. It has been shown that the maladaptive nutrient-sensing hexosamine biosynthesis pathway (HBP) contributes to diabetic complications in many non-cardiac tissues. Glucose metabolism by the HBP leads to enzymatically-regulated, O-linked attachment of a sugar moiety molecule, β-N-acetylglucosamine (O-GlcNAc), to proteins, affecting their biological activity (similar to phosphorylation). In normal physiology, transient activation of HBP/O-GlcNAc mechanisms is an adaptive, protective means to enhance cell survival; interventions that acutely suppress this pathway decrease tolerance to stress. Conversely, chronic dysregulation of HBP/O-GlcNAc mechanisms has been shown to be detrimental in certain pathological settings, including diabetes and cancer. Most of our understanding of the impact of sustained maladaptive HBP and O-GlcNAc protein modifications has been derived from adipose tissue, skeletal muscle and other non-cardiac tissues, as a contributing mechanism to insulin resistance and progression of diabetic complications. However, the long-term consequences of persistent activation of cardiac HBP and O-GlcNAc are not well-understood; therefore, the goal of this timely review is to highlight current understanding of the role of the HBP pathway in development of diabetic cardiomyopathy.
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Affiliation(s)
- Cheng Xue Qin
- Heart Failure Pharmacology, Baker IDI Heart & Diabetes Institute, Melbourne VIC 3004, Australia; Department of Pharmacology, University of Melbourne, VIC 3010, Australia
| | - Rochelle Sleaby
- Heart Failure Pharmacology, Baker IDI Heart & Diabetes Institute, Melbourne VIC 3004, Australia; Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Amy J Davidoff
- University of New England, Biddeford, ME, 04072, United States
| | - James R Bell
- Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Miles J De Blasio
- Heart Failure Pharmacology, Baker IDI Heart & Diabetes Institute, Melbourne VIC 3004, Australia; School of BioSciences, University of Melbourne, VIC 3010, Australia
| | | | - John C Chatham
- University of Alabama at Birmingham, Birmingham, AL, 35233, United States
| | - Rebecca H Ritchie
- Heart Failure Pharmacology, Baker IDI Heart & Diabetes Institute, Melbourne VIC 3004, Australia; Department of Pharmacology, University of Melbourne, VIC 3010, Australia; Department of Medicine, Monash University, Clayton 3800, VIC, Australia.
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33
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Stram AR, Payne RM. Post-translational modifications in mitochondria: protein signaling in the powerhouse. Cell Mol Life Sci 2016; 73:4063-73. [PMID: 27233499 PMCID: PMC5045789 DOI: 10.1007/s00018-016-2280-4] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 05/16/2016] [Accepted: 05/19/2016] [Indexed: 02/03/2023]
Abstract
There is an intimate interplay between cellular metabolism and the pathophysiology of disease. Mitochondria are essential to maintaining and regulating metabolic function of cells and organs. Mitochondrial dysfunction is implicated in diverse diseases, such as cardiovascular disease, diabetes and metabolic syndrome, neurodegeneration, cancer, and aging. Multiple reversible post-translational protein modifications are located in the mitochondria that are responsive to nutrient availability and redox conditions, and which can act in protein-protein interactions to modify diverse mitochondrial functions. Included in this are physiologic redox signaling via reactive oxygen and nitrogen species, phosphorylation, O-GlcNAcylation, acetylation, and succinylation, among others. With the advent of mass proteomic screening techniques, there has been a vast increase in the array of known mitochondrial post-translational modifications and their protein targets. The functional significance of these processes in disease etiology, and the pathologic response to their disruption, are still under investigation. However, many of these reversible modifications act as regulatory mechanisms in mitochondria and show promise for mitochondrial-targeted therapeutic strategies. This review addresses the current knowledge of post-translational processing and signaling mechanisms in mitochondria, and their implications in health and disease.
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Affiliation(s)
- Amanda R Stram
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, 1044 W. Walnut St., Room R4-302b, Indianapolis, IN, 46202, USA
| | - R Mark Payne
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, 1044 W. Walnut St., Room R4-302b, Indianapolis, IN, 46202, USA.
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34
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Zhao L, Feng Z, Yang X, Liu J. The regulatory roles of O-GlcNAcylation in mitochondrial homeostasis and metabolic syndrome. Free Radic Res 2016; 50:1080-1088. [PMID: 27646831 DOI: 10.1080/10715762.2016.1239017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Nutrients excess is one of the leading causes of metabolic syndrome globally. Protein post-translational O-GlcNAc modification has been recognized as an essential nutrient sensor of the cell. Emerging studies suggest that O-GlcNAcylation lies at the core linking nutritional stress to insulin resistance. Mitochondria are the major site for ATP production in most eukaryotes. Mitochondrial dysfunction and oxidative stress have long been considered as an important mechanism underlying insulin resistance. The metabolic process is under the influence of environmental and nutritional factors, thus sensing and transducing nutritional signals sit at the pivot of metabolism control. For a long time little was known about O-GlcNAcylation within mitochondria since mitochondrial O-GlcNAcylation was regarded rare. Recent findings have demonstrated that O-GlcNAcylation is widely spread among mitochondrial proteins, and that mitochondrial function and oxidative stress both can be regulated by O-GlcNAcylation, particularly under diabetic circumstances.
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Affiliation(s)
- Lin Zhao
- a Center for Mitochondrial Biology and Medicine, the Key Laboratory of Biomedical Information Engineering of Ministry of Education , School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University , Xi'an , China
| | - Zhihui Feng
- a Center for Mitochondrial Biology and Medicine, the Key Laboratory of Biomedical Information Engineering of Ministry of Education , School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University , Xi'an , China
| | - Xiaoyong Yang
- b Section of Comparative Medicine and Department of Cellular and Molecular Physiology , Yale University School of Medicine , New Haven , CT , USA
| | - Jiankang Liu
- a Center for Mitochondrial Biology and Medicine, the Key Laboratory of Biomedical Information Engineering of Ministry of Education , School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University , Xi'an , China
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35
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Nucleocytoplasmic human O-GlcNAc transferase is sufficient for O-GlcNAcylation of mitochondrial proteins. Biochem J 2016; 473:1693-702. [PMID: 27048592 PMCID: PMC4901358 DOI: 10.1042/bcj20160092] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 04/05/2016] [Indexed: 01/03/2023]
Abstract
O-linked N-acetylglucosamine modification (O-GlcNAcylation) is a nutrient-dependent protein post-translational modification (PTM), dynamically and reversibly driven by two enzymes: O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) that catalyse the addition and the removal of the O-GlcNAc moieties to/from serine and threonine residues of target proteins respectively. Increasing evidence suggests involvement of O-GlcNAcylation in many biological processes, including transcription, signalling, neuronal development and mitochondrial function. The presence of a mitochondrial O-GlcNAc proteome and a mitochondrial OGT (mOGT) isoform has been reported. We explored the presence of mOGT in human cell lines and mouse tissues. Surprisingly, analysis of genomic sequences indicates that this isoform cannot be expressed in most of the species analysed, except some primates. In addition, we were not able to detect endogenous mOGT in a range of human cell lines. Knockdown experiments and Western blot analysis of all the predicted OGT isoforms suggested the expression of only a single OGT isoform. In agreement with this, we demonstrate that overexpression of the nucleocytoplasmic OGT (ncOGT) isoform leads to increased O-GlcNAcylation of mitochondrial proteins, suggesting that ncOGT is necessary and sufficient for the generation of the O-GlcNAc mitochondrial proteome.
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36
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Gellai R, Hodrea J, Lenart L, Hosszu A, Koszegi S, Balogh D, Ver A, Banki NF, Fulop N, Molnar A, Wagner L, Vannay A, Szabo AJ, Fekete A. Role of O-linked N-acetylglucosamine modification in diabetic nephropathy. Am J Physiol Renal Physiol 2016; 311:F1172-F1181. [PMID: 27029430 DOI: 10.1152/ajprenal.00545.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 03/21/2016] [Indexed: 12/15/2022] Open
Abstract
Increased O-linked β-N-acetylglucosamine glycosylation (O-GlcNAcylation) is a known contributor to diabetes; however, its relevance in diabetic nephropathy (DN) is poorly elucidated. Here, we studied the process and enzymes of O-GlcNAcylation with a special emphasis on Akt-endothelial nitric oxide synthase (eNOS) and heat shock protein (HSP)72 signaling. Since tubular injury is the prominent site of DN, the effect of hyperglycemia was first measured in proximal tubular (HK2) cells cultured in high glucose. In vivo O-GlcNAcylation and protein levels of O-GlcNAc transferase (OGT), O-GlcNAcase (OGA), phosphorylated (p)Akt/Akt, peNOS/eNOS, and HSP72 were assessed in the kidney cortex of streptozotocin-induced diabetic rats. The effects of various renin-angiotensin-aldosterone system (RAAS) inhibitors were also evaluated. In proximal tubular cells, hyperglycemia-induced OGT expression led to increased O-GlcNAcylation, which was followed by a compensatory increase of OGA. In parallel, peNOS and pAkt levels decreased, whereas HSP72 increased. In diabetic rats, elevated O-GlcNAcylation was accompanied by decreased OGT and OGA. RAAS inhibitors ameliorated diabetes-induced kidney damage and prevented the elevation of O-GlcNAcylation and the decrement of pAkt, peNOS, and HSP72. In conclusion, hyperglycemia-induced elevation of O-GlcNAcylation contributes to the progression of DN via inhibition of Akt/eNOS phosphorylation and HSP72 induction. RAAS blockers successfully inhibit this process, suggesting a novel pathomechanism of their renoprotective action in the treatment of DN.
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Affiliation(s)
- Renata Gellai
- MTA-SE "Lendulet" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Judit Hodrea
- MTA-SE "Lendulet" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary.,MTA-SE Pediatrics and Nephrology Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Lilla Lenart
- MTA-SE "Lendulet" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Adam Hosszu
- MTA-SE "Lendulet" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Sandor Koszegi
- MTA-SE "Lendulet" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Dora Balogh
- MTA-SE "Lendulet" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Agota Ver
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Nora F Banki
- First Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Norbert Fulop
- Teaching Hospital Mór Kaposi, Kaposvar, Hungary; and
| | - Agnes Molnar
- MTA-SE "Lendulet" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Laszlo Wagner
- Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary
| | - Adam Vannay
- MTA-SE Pediatrics and Nephrology Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Attila J Szabo
- MTA-SE Pediatrics and Nephrology Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary.,First Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Andrea Fekete
- MTA-SE "Lendulet" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary; .,First Department of Pediatrics, Semmelweis University, Budapest, Hungary
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37
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Ma J, Liu T, Wei AC, Banerjee P, O'Rourke B, Hart GW. O-GlcNAcomic Profiling Identifies Widespread O-Linked β-N-Acetylglucosamine Modification (O-GlcNAcylation) in Oxidative Phosphorylation System Regulating Cardiac Mitochondrial Function. J Biol Chem 2015; 290:29141-53. [PMID: 26446791 DOI: 10.1074/jbc.m115.691741] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 11/06/2022] Open
Abstract
Dynamic cycling of O-linked β-N-acetylglucosamine (O-GlcNAc) on nucleocytoplasmic proteins serves as a nutrient sensor to regulate numerous biological processes. However, mitochondrial protein O-GlcNAcylation and its effects on function are largely unexplored. In this study, we performed a comparative analysis of the proteome and O-GlcNAcome of cardiac mitochondria from rats acutely (12 h) treated without or with thiamet-G (TMG), a potent and specific inhibitor of O-GlcNAcase. We then determined the functional consequences in mitochondria isolated from the two groups. O-GlcNAcomic profiling finds that over 88 mitochondrial proteins are O-GlcNAcylated, with the oxidative phosphorylation system as a major target. Moreover, in comparison with controls, cardiac mitochondria from TMG-treated rats did not exhibit altered protein abundance but showed overall elevated O-GlcNAcylation of many proteins. However, O-GlcNAc was unexpectedly down-regulated at certain sites of specific proteins. Concomitantly, TMG treatment resulted in significantly increased mitochondrial oxygen consumption rates, ATP production rates, and enhanced threshold for permeability transition pore opening by Ca(2+). Our data reveal widespread and dynamic mitochondrial protein O-GlcNAcylation, serving as a regulator to their function.
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Affiliation(s)
- Junfeng Ma
- From the Department of Biological Chemistry and
| | - Ting Liu
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - An-Chi Wei
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | | | - Brian O'Rourke
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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38
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Shi J, Gu JH, Dai CL, Gu J, Jin X, Sun J, Iqbal K, Liu F, Gong CX. O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling. Sci Rep 2015; 5:14500. [PMID: 26412745 PMCID: PMC4585968 DOI: 10.1038/srep14500] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 09/02/2015] [Indexed: 01/13/2023] Open
Abstract
Apoptosis plays an important role in neural development and neurological disorders. In this study, we found that O-GlcNAcylation, a unique protein posttranslational modification with O-linked β-N-acetylglucosamine (GlcNAc), promoted apoptosis through attenuating phosphorylation/activation of AKT and Bad. By using co-immunoprecipitation and mutagenesis techniques, we identified O-GlcNAc modification at both Thr308 and Ser473 of AKT. O-GlcNAcylation-induced apoptosis was attenuated by over-expression of AKT. We also found a dynamic elevation of protein O-GlcNAcylation during the first four hours of cerebral ischemia, followed by continuous decline after middle cerebral artery occlusion (MCAO) in the mouse brain. The elevation of O-GlcNAcylation coincided with activation of cell apoptosis. Finally, we found a negative correlation between AKT phosphorylation and O-GlcNAcylation in ischemic brain tissue. These results indicate that cerebral ischemia induces a rapid increase of O-GlcNAcylation that promotes apoptosis through down-regulation of AKT activity. These findings provide a novel mechanism through which O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling.
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Affiliation(s)
- Jianhua Shi
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China.,Department of Biochemistry, Nantong University Medical School, Nantong, Jiangsu 226001, China.,Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, United States of America
| | - Jin-hua Gu
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, United States of America.,Department of Pathophysiology, Nantong University Medical School, Nantong, Jiangsu 226001, China
| | - Chun-ling Dai
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, United States of America
| | - Jianlan Gu
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China.,Department of Biochemistry, Nantong University Medical School, Nantong, Jiangsu 226001, China
| | - Xiaoxia Jin
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Jianming Sun
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, United States of America
| | - Fei Liu
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China.,Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, United States of America
| | - Cheng-Xin Gong
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China.,Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, United States of America
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Abstract
Unlike the complex glycans decorating the cell surface, the O-linked β-N-acetyl glucosamine (O-GlcNAc) modification is a simple intracellular Ser/Thr-linked monosaccharide that is important for disease-relevant signaling and enzyme regulation. O-GlcNAcylation requires uridine diphosphate-GlcNAc, a precursor responsive to nutrient status and other environmental cues. Alternative splicing of the genes encoding the O-GlcNAc cycling enzymes O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) yields isoforms targeted to discrete sites in the nucleus, cytoplasm, and mitochondria. OGT and OGA also partner with cellular effectors and act in tandem with other posttranslational modifications. The enzymes of O-GlcNAc cycling act preferentially on intrinsically disordered domains of target proteins impacting transcription, metabolism, apoptosis, organelle biogenesis, and transport.
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40
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Nagel AK, Ball LE. Intracellular protein O-GlcNAc modification integrates nutrient status with transcriptional and metabolic regulation. Adv Cancer Res 2015; 126:137-66. [PMID: 25727147 DOI: 10.1016/bs.acr.2014.12.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The inducible, nutrient-sensitive posttranslational modification of protein Ser/Thr residues with O-linked β-N-acetylglucosamine (O-GlcNAc) occurs on histones, transcriptional regulators, metabolic enzymes, oncogenes, tumor suppressors, and many critical intermediates of growth factor signaling. Cycling of O-GlcNAc modification on and off of protein substrates is catalyzed by the actions of O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. To date, there are less than 150 publications addressing the role of O-GlcNAc modification in cancer and over half were published in the last 2 years. These studies have clearly established that increased expression of OGT and hyper-O-GlcNAcylation is common to human cancers of breast, prostate, colon, lung, and pancreas. Furthermore, attenuating OGT activity reduces tumor growth in vitro and metastasis in vivo. This chapter discusses the structure and function of the O-GlcNAc cycling enzymes, mechanisms by which protein O-GlcNAc modification sense changes in nutrient status, the influence of O-GlcNAc cycling enzymes on glucose metabolism, and provides an overview of recent observations regarding the role of O-GlcNAcylation in cancer.
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41
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Abstract
O-GlcNAcylation is an abundant nutrient-driven modification linked to cellular signaling and regulation of gene expression. Utilizing precursors derived from metabolic flux, O-GlcNAc functions as a homeostatic regulator. The enzymes of O-GlcNAc cycling, OGT and O-GlcNAcase, act in mitochondria, the cytoplasm, and the nucleus in association with epigenetic "writers" and "erasers" of the histone code. Both O-GlcNAc and O-phosphate modify repeats within the RNA polymerase II C-terminal domain (CTD). By communicating with the histone and CTD codes, O-GlcNAc cycling provides a link between cellular metabolic status and the epigenetic machinery. Thus, O-GlcNAcylation is poised to influence trans-generational epigenetic inheritance.
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Affiliation(s)
| | - John A Hanover
- NIDDK, National Institutes of Health, Bethesda, Maryland 20892
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42
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Janetzko J, Walker S. The making of a sweet modification: structure and function of O-GlcNAc transferase. J Biol Chem 2014; 289:34424-32. [PMID: 25336649 DOI: 10.1074/jbc.r114.604405] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
O-GlcNAc transferase is an essential mammalian enzyme responsible for transferring a single GlcNAc moiety from UDP-GlcNAc to specific serine/threonine residues of hundreds of nuclear and cytoplasmic proteins. This modification is dynamic and has been implicated in numerous signaling pathways. An unexpected second function for O-GlcNAc transferase as a protease involved in cleaving the epigenetic regulator HCF-1 has also been reported. Recent structural and biochemical studies that provide insight into the mechanism of glycosylation and HCF-1 cleavage will be described, with outstanding questions highlighted.
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Affiliation(s)
- John Janetzko
- the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Suzanne Walker
- From the Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115 and
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43
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O-GlcNAc transferase and O-GlcNAcase: achieving target substrate specificity. Amino Acids 2014; 46:2305-16. [PMID: 25173736 DOI: 10.1007/s00726-014-1827-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 08/13/2014] [Indexed: 12/19/2022]
Abstract
O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) catalyze the dynamic cycling of intracellular, post-translational O-GlcNAc modification on thousands of Ser/Thr residues of cytosolic, nuclear, and mitochondrial signaling proteins. The identification of O-GlcNAc modified substrates has revealed a functionally diverse set of proteins, and the extent of O-GlcNAcylation fluctuates in response to nutrients and cellular stress. As a result, OGT and OGA are implicated in widespread, nutrient-responsive regulation of numerous signaling pathways and transcriptional programs. These enzymes are required for normal embryonic development and are dysregulated in metabolic and age-related disease states. While a recent surge of interest in the field has contributed to understanding the functional impacts of protein O-GlcNAcylation, little is known about the upstream mechanisms which modulate OGT and OGA substrate targeting. This review focuses on elements of enzyme structure among splice variants, post-translational modification, localization, and regulatory protein interactions which drive the specificity of OGT and OGA toward different subsets of the cellular proteome. Ongoing efforts in this rapidly advancing field are aimed at revealing mechanisms of OGT and OGA regulation to harness the potential therapeutic benefit of manipulating these enzymes' activities.
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44
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Lozano L, Lara-Lemus R, Zenteno E, Alvarado-Vásquez N. The mitochondrial O-linked N-acetylglucosamine transferase (mOGT) in the diabetic patient could be the initial trigger to develop Alzheimer disease. Exp Gerontol 2014; 58:198-202. [PMID: 25148700 DOI: 10.1016/j.exger.2014.08.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 08/14/2014] [Accepted: 08/18/2014] [Indexed: 12/15/2022]
Abstract
Diabetes mellitus (DM) is considered a risk factor for the development of Alzheimer disease (AD); however, how DM favors evolution of AD is still insufficiently understood. Hyperglycemia in DM is associated to an increase in mitochondrial reactive oxygen species (ROS) generation, as well as damage of hippocampal cells, reflected by changes in morphological and mitochondrial functionality. Similar mitochondrial damage has been observed when amyloid beta (Aβ) accumulates in the brain of AD patients. In DM, the excess of glucose in the brain induces higher activity of the hexosamine biosynthesis pathway (HBP), it synthesizes UDP-N-acetylglucosamine (UDP-GlcNAc), which is used by O-linked N-acetylglucosamine transferase (OGT) to catalyze O-GlcNAcylation of numerous proteins. Although O-GlcNAcylation plays an important role in maintaining structure and cellular functionality, chronic activity of this pathway has been associated with insulin resistance and hyperglycemia-induced glucose toxicity. Three different forms of OGT are known: nucleocytoplasmic (ncOGT), short (sOGT), and mitochondrial (mOGT). Previous reports showed that overexpression of ncOGT is not toxic to the cell; in contrast, overexpression of mOGT is associated with cellular apoptosis. In this work, we suggest that hyperglycemia in the diabetic patient could induce greater expression and activity of mOGT, modifying the structure and functionality of mitochondria in hippocampal cells, accelerating neuronal damage, and favoring the start of AD. In consequence, mOGT activity could be a key point for AD development in patients with DM.
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Affiliation(s)
- Liliana Lozano
- National Autonomous University of Mexico, Department of Biochemistry, Faculty of Medicine, Mexico
| | - Roberto Lara-Lemus
- National Institute of Respiratory Diseases, "Ismael Cosío Villegas", Mexico
| | - Edgar Zenteno
- National Autonomous University of Mexico, Department of Biochemistry, Faculty of Medicine, Mexico
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45
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de Queiroz RM, Carvalho E, Dias WB. O-GlcNAcylation: The Sweet Side of the Cancer. Front Oncol 2014; 4:132. [PMID: 24918087 PMCID: PMC4042083 DOI: 10.3389/fonc.2014.00132] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/18/2014] [Indexed: 12/31/2022] Open
Abstract
O-GlcNAcylation is an O-linked β-N-acetylglucosamine (O-GlcNAc) moiety linked to the serine or threonine residues in proteins. O-GlcNAcylation is a dynamic post-translational modification involved in a wide range of biological processes and diseases such as cancer. This modification can increase and decrease the activity of enzymes as well as interfere with protein stability and interaction. The modulatory capacity of O-GlcNAcylation, as well as protein phosphorylation, is of paramount importance in the regulation of metabolism and intracellular signaling of tumor cells. Thus, understanding the regulation of O-GlcNAcylation in tumor cells and their difference compared to non-tumor cells may elucidate new mechanisms related to tumor generation and development, could provide a new marker to diagnosis and prognosis in patients with cancer and indicate a new target to cancer chemotherapy.
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Affiliation(s)
- Rafaela Muniz de Queiroz
- Laboratório de Glicobiologia Estrutural e Funcional, Centro de Ciências da Saúde - Bloco G, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil
| | - Erika Carvalho
- Instituto de Bioquimica Médica, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil
| | - Wagner Barbosa Dias
- Laboratório de Glicobiologia Estrutural e Funcional, Centro de Ciências da Saúde - Bloco G, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil
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46
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Gu Y, Gao J, Han C, Zhang X, Liu H, Ma L, Sun X, Yu W. O-GlcNAcylation is increased in prostate cancer tissues and enhances malignancy of prostate cancer cells. Mol Med Rep 2014; 10:897-904. [PMID: 24865644 DOI: 10.3892/mmr.2014.2269] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 03/14/2014] [Indexed: 11/06/2022] Open
Abstract
O-GlcNAc is an O-linked ?-N-acetylglucosamine moiety attached to the side-chain hydroxyl of a serine or threonine residue in numerous cytoplasmic and nuclear proteins. In this study, we detected the level of O-GlcNAc in prostate, liver and pancreatic cancer tissues, and found that the global O-GlcNAc modification also known as O-GlcNAcylation, is specifically increased in prostate cancer tissues compared to corresponding adjacent tissues. In addition, we found that global O-GlcNAcylation is increased in prostate cancer cells and not in benign prostatic hyperplasia (BPH) epithelial cells. O-GlcNAc enhanced the anchorage-independent growth and the migratory/invasive ability of prostate cancer cells. More importantly, we provide here, for the first time to the best of our knowledge, direct evidence that increased O-GlcNAcylation induces malignant transformation of nontumorigenic (BPH) cells. Furthermore, our study suggested that inhibiting the formation of the E-cadherin/catenin/cytoskeleton complex may underly the O-GlcNAc-induced prostate cancer progression. Overall, these findings indicated that O-GlcNAcylation is increased in prostate, but not in liver and pancreatic cancer tissues, and that O-GlcNAc can enhance the malignancy of prostate cancer cells.
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Affiliation(s)
- Yuchao Gu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Key Laboratory of Glycoscience and Glycotechnology of Shandong Province, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, P.R. China
| | - Jiangang Gao
- Department of Urology Surgery, Qingdao Municipal Hospital, Qingdao 266011, P.R. China
| | - Cuifang Han
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Key Laboratory of Glycoscience and Glycotechnology of Shandong Province, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, P.R. China
| | - Xinling Zhang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Key Laboratory of Glycoscience and Glycotechnology of Shandong Province, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, P.R. China
| | - Haiyan Liu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Key Laboratory of Glycoscience and Glycotechnology of Shandong Province, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, P.R. China
| | - Leina Ma
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Key Laboratory of Glycoscience and Glycotechnology of Shandong Province, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, P.R. China
| | - Xiaoqing Sun
- Department of Urology Surgery, Qingdao Municipal Hospital, Qingdao 266011, P.R. China
| | - Wengong Yu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, Key Laboratory of Glycoscience and Glycotechnology of Shandong Province, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, P.R. China
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47
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Tan EP, Villar MT, E L, Lu J, Selfridge JE, Artigues A, Swerdlow RH, Slawson C. Altering O-linked β-N-acetylglucosamine cycling disrupts mitochondrial function. J Biol Chem 2014; 289:14719-30. [PMID: 24713701 DOI: 10.1074/jbc.m113.525790] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Mitochondrial impairment is commonly found in many diseases such as diabetes, cancer, and Alzheimer disease. We demonstrate that the enzymes responsible for the addition or removal of the O-GlcNAc modification, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively, are critical regulators of mitochondrial function. Using a SILAC (stable isotope labeling of amino acids in cell culture)-based proteomics screen, we quantified the changes in mitochondrial protein expression in OGT- and OGA-overexpressing cells. Strikingly, overexpression of OGT or OGA showed significant decreases in mitochondria-localized proteins involved in the respiratory chain and the tricarboxylic acid cycle. Furthermore, mitochondrial morphology was altered in these cells. Both cellular respiration and glycolysis were reduced in OGT/OGA-overexpressing cells. These data demonstrate that alterations in O-GlcNAc cycling profoundly affect energy and metabolite production.
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Affiliation(s)
- Ee Phie Tan
- From the Department of Biochemistry and Molecular Biology
| | - Maria T Villar
- From the Department of Biochemistry and Molecular Biology
| | - Lezi E
- Department of Neurology, and
| | | | | | | | - Russell H Swerdlow
- From the Department of Biochemistry and Molecular Biology, Department of Neurology, and University of Kansas Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, Kansas 64108
| | - Chad Slawson
- From the Department of Biochemistry and Molecular Biology, University of Kansas Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, Kansas 64108 University of Kansas Cancer Center,
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48
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Maury JJP, Ng D, Bi X, Bardor M, Choo ABH. Multiple Reaction Monitoring Mass Spectrometry for the Discovery and Quantification of O-GlcNAc-Modified Proteins. Anal Chem 2013; 86:395-402. [DOI: 10.1021/ac401821d] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Julien Jean Pierre Maury
- Bioprocessing
Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #06-01 Centros, Singapore 138668
- Department
of Bioengineering, Faculty of Engineering, National University of Singapore, Singapore 119077
| | - Daniel Ng
- Bioprocessing
Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #06-01 Centros, Singapore 138668
| | - Xuezhi Bi
- Bioprocessing
Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #06-01 Centros, Singapore 138668
| | - Muriel Bardor
- Bioprocessing
Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #06-01 Centros, Singapore 138668
- Université de Rouen, Laboratoire Glycobiologie et Matrice
Extracellulaire Végétale (Glyco-MEV) EA 4358, Institut
de Recherche et d’Innovation Biomédicale (IRIB), Faculté
des Sciences et Techniques, 76821 Mont-Saint-Aignan Cédex, France
| | - Andre Boon-Hwa Choo
- Bioprocessing
Technology Institute, Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #06-01 Centros, Singapore 138668
- Department
of Bioengineering, Faculty of Engineering, National University of Singapore, Singapore 119077
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49
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Hanover JA, Wang P. O-GlcNAc cycling shows neuroprotective potential in C. elegans models of neurodegenerative disease. WORM 2013; 2:e27043. [PMID: 24744983 DOI: 10.4161/worm.27043] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 10/28/2013] [Accepted: 11/01/2013] [Indexed: 01/17/2023]
Abstract
C. elegans has proven to be an excellent organism in which to model human neurodegenerative disease.(1) (-) (7) The worm's simple nervous system, lineage, and neural maps, easily scored movement phenotypes, and robust forward and reverse genetics make it optimal for studying age-dependent processes on a reasonable time scale. A popular approach has been the introduction of transgenes expressing GFP-tagged proteotoxic human proteins into neurons leading to visible aggregation or movement phenotypes.(2) (,) (4) (,) (6) (,) (8) (-) (13) In addition, the maintenance of proteostasis networks has been extensively studied using the power of worm genetics.(8) (-) (13) These networks include genes involved in insulin-like signaling, the heat shock response, the response to hypoxia, and mTOR and AMPK pathways linked to aging.(14) Another pathway with suggestive links to neurodegeneration is the O-GlcNAc cycling pathway, a nutrient-dependent post-translational modification known to be altered in brains from patients with Alzheimer disease.(15) (-) (19) In this commentary, we summarize our recent findings showing that viable mutants of O-GlcNAc cycling in C. elegans dramatically alter the neurotoxicity of four distinct C. elegans models of neurodegenerative disease.(7) Mutants in O-GlcNAc cycling alter the toxicity of mutant tau, polyglutamine expansion reporters, and amyloid β-peptide. The findings further suggest that O-GlcNAc cycling acts at many steps in the lifecycle of aggregation-prone targets. The C. elegans system is likely to continue to provide insights into this complex problem. The involvement of O-GlcNAc cycling in the maintenance of proteostasis raises the possibility of targeting the enzymes catalyzing this critical post-translational modification for therapeutic intervention.
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50
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Groves JA, Lee A, Yildirir G, Zachara NE. Dynamic O-GlcNAcylation and its roles in the cellular stress response and homeostasis. Cell Stress Chaperones 2013; 18:535-58. [PMID: 23620203 PMCID: PMC3745259 DOI: 10.1007/s12192-013-0426-y] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 03/29/2013] [Accepted: 04/01/2013] [Indexed: 12/15/2022] Open
Abstract
O-linked N-acetyl-β-D-glucosamine (O-GlcNAc) is a ubiquitous and dynamic post-translational modification known to modify over 3,000 nuclear, cytoplasmic, and mitochondrial eukaryotic proteins. Addition of O-GlcNAc to proteins is catalyzed by the O-GlcNAc transferase and is removed by a neutral-N-acetyl-β-glucosaminidase (O-GlcNAcase). O-GlcNAc is thought to regulate proteins in a manner analogous to protein phosphorylation, and the cycling of this carbohydrate modification regulates many cellular functions such as the cellular stress response. Diverse forms of cellular stress and tissue injury result in enhanced O-GlcNAc modification, or O-GlcNAcylation, of numerous intracellular proteins. Stress-induced O-GlcNAcylation appears to promote cell/tissue survival by regulating a multitude of biological processes including: the phosphoinositide 3-kinase/Akt pathway, heat shock protein expression, calcium homeostasis, levels of reactive oxygen species, ER stress, protein stability, mitochondrial dynamics, and inflammation. Here, we will discuss the regulation of these processes by O-GlcNAc and the impact of such regulation on survival in models of ischemia reperfusion injury and trauma hemorrhage. We will also discuss the misregulation of O-GlcNAc in diseases commonly associated with the stress response, namely Alzheimer's and Parkinson's diseases. Finally, we will highlight recent advancements in the tools and technologies used to study the O-GlcNAc modification.
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Affiliation(s)
- Jennifer A. Groves
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe St, Baltimore, MD 21205-2185 USA
| | - Albert Lee
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe St, Baltimore, MD 21205-2185 USA
| | - Gokben Yildirir
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe St, Baltimore, MD 21205-2185 USA
| | - Natasha E. Zachara
- The Department of Biological Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe St, Baltimore, MD 21205-2185 USA
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