51
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Meekrathok P, Thongsom S, Aunkham A, Kaewmaneewat A, Kitaoku Y, Choowongkomon K, Suginta W. Novel GH-20 β-N-acetylglucosaminidase inhibitors: Virtual screening, molecular docking, binding affinity, and anti-tumor activity. Int J Biol Macromol 2020; 142:503-512. [DOI: 10.1016/j.ijbiomac.2019.09.122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 09/15/2019] [Accepted: 09/16/2019] [Indexed: 01/05/2023]
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52
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Park J, Lai MKP, Arumugam TV, Jo DG. O-GlcNAcylation as a Therapeutic Target for Alzheimer's Disease. Neuromolecular Med 2020; 22:171-193. [PMID: 31894464 DOI: 10.1007/s12017-019-08584-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 12/13/2019] [Indexed: 02/06/2023]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia and the number of elderly patients suffering from AD has been steadily increasing. Despite worldwide efforts to cope with this disease, little progress has been achieved with regard to identification of effective therapeutics. Thus, active research focusing on identification of new therapeutic targets of AD is ongoing. Among the new targets, post-translational modifications which modify the properties of mature proteins have gained attention. O-GlcNAcylation, a type of PTM that attaches O-linked β-N-acetylglucosamine (O-GlcNAc) to a protein, is being sought as a new target to treat AD pathologies. O-GlcNAcylation has been known to modify the two important components of AD pathological hallmarks, amyloid precursor protein, and tau protein. In addition, elevating O-GlcNAcylation levels in AD animal models has been shown to be effective in alleviating AD-associated pathology. Although studies investigating the precise mechanism of reversal of AD pathologies by targeting O-GlcNAcylation are not yet complete, it is clearly important to examine O-GlcNAcylation regulation as a target of AD therapeutics. This review highlights the mechanisms of O-GlcNAcylation and its role as a potential therapeutic target under physiological and pathological AD conditions.
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Affiliation(s)
- Jinsu Park
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea
- Department of Health Science and Technology, Sungkyunkwan University, Seoul, 06351, Korea
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Thiruma V Arumugam
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea.
- Department of Physiology, Yong Loo Lin School Medicine, National University of Singapore, Singapore, 117593, Singapore.
- Department of Physiology, Anatomy & Microbiology, School of Life Sciences, La Trobe University, Bundoora, VIC, Australia.
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea.
- Department of Health Science and Technology, Sungkyunkwan University, Seoul, 06351, Korea.
- Biomedical Institute for Convergence, Sungkyunkwan University, Suwon, 16419, Korea.
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53
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Ferron M, Cadiet J, Persello A, Prat V, Denis M, Erraud A, Aillerie V, Mevel M, Bigot E, Chatham JC, Gauthier C, Rozec B, Lauzier B. O-GlcNAc stimulation: A new metabolic approach to treat septic shock. Sci Rep 2019; 9:18751. [PMID: 31822776 PMCID: PMC6904741 DOI: 10.1038/s41598-019-55381-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 11/21/2019] [Indexed: 12/14/2022] Open
Abstract
Septic shock is a systemic inflammation associated with cell metabolism disorders and cardiovascular dysfunction. Increases in O-GlcNAcylation have shown beneficial cardiovascular effects in acute pathologies. We used two different rat models to evaluate the beneficial effects of O-GlcNAc stimulation at the early phase of septic shock. Rats received lipopolysaccharide (LPS) to induce endotoxemic shock or saline (control) and fluid resuscitation (R) with or without O-GlcNAc stimulation (NButGT-10 mg/kg) 1 hour after shock induction. For the second model, rats received cecal ligature and puncture (CLP) surgery and fluid therapy with or without NButGT. Cardiovascular function was evaluated and heart and blood samples were collected and analysed. NButGT treatment efficiently increased total O-GlcNAc without modification of HBP enzyme expression.Treatment improved circulating parameters and cardiovascular function in both models, and restored SERCA2a expression levels. NButGT treatment also reduced animal mortality. In this study, we demonstrate that in septic shock O-GlcNAc stimulation improves global animal and cardiovascular function outcomes associated with a restoration of SERCA2a levels. This pre-clinical study opens avenues for a potential therapy of early-stage septic shock.
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Affiliation(s)
- Marine Ferron
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France.
| | - Julien Cadiet
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | | | - Valentine Prat
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - Manon Denis
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | | | | | - Mathieu Mevel
- INSERM UMR 1089, Université de Nantes, CHU de Nantes, Nantes, France
| | - Edith Bigot
- Biochemistry Department, Laënnec Hospital, CHU Nantes, Nantes, France
| | - John C Chatham
- Division of Molecular and Cellular Pathology, Birmingham, United States
| | | | - Bertrand Rozec
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France
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Dong L, Shen S, Chen W, Xu D, Yang Q, Lu H, Zhang J. Discovery of Novel Inhibitors Targeting Human O-GlcNAcase: Docking-Based Virtual Screening, Biological Evaluation, Structural Modification, and Molecular Dynamics Simulation. J Chem Inf Model 2019; 59:4374-4382. [DOI: 10.1021/acs.jcim.9b00479] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Lili Dong
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Shengqiang Shen
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Wei Chen
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Dongdong Xu
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Qing Yang
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huizhe Lu
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Jianjun Zhang
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
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56
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Selnick HG, Hess JF, Tang C, Liu K, Schachter JB, Ballard JE, Marcus J, Klein DJ, Wang X, Pearson M, Savage MJ, Kaul R, Li TS, Vocadlo DJ, Zhou Y, Zhu Y, Mu C, Wang Y, Wei Z, Bai C, Duffy JL, McEachern EJ. Discovery of MK-8719, a Potent O-GlcNAcase Inhibitor as a Potential Treatment for Tauopathies. J Med Chem 2019; 62:10062-10097. [DOI: 10.1021/acs.jmedchem.9b01090] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Harold G. Selnick
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - J. Fred Hess
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Cuyue Tang
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Kun Liu
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Joel B. Schachter
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Jeanine E. Ballard
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Jacob Marcus
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Daniel J. Klein
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Xiaohai Wang
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Michelle Pearson
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Mary J. Savage
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Ramesh Kaul
- Alectos Therapeutics Inc., 8999 Nelson Way, Burnaby, British Columbia V5A 4B5, Canada
| | - Tong-Shuang Li
- Alectos Therapeutics Inc., 8999 Nelson Way, Burnaby, British Columbia V5A 4B5, Canada
| | - David J. Vocadlo
- Alectos Therapeutics Inc., 8999 Nelson Way, Burnaby, British Columbia V5A 4B5, Canada
| | - Yuanxi Zhou
- Alectos Therapeutics Inc., 8999 Nelson Way, Burnaby, British Columbia V5A 4B5, Canada
| | - Yongbao Zhu
- Alectos Therapeutics Inc., 8999 Nelson Way, Burnaby, British Columbia V5A 4B5, Canada
| | - Changwei Mu
- Pharmaron Beijing Co. Ltd., 6 Taihe Road, BDA, Beijing 100176, P. R. China
| | - Yaode Wang
- Pharmaron Beijing Co. Ltd., 6 Taihe Road, BDA, Beijing 100176, P. R. China
| | - Zhongyong Wei
- Pharmaron Beijing Co. Ltd., 6 Taihe Road, BDA, Beijing 100176, P. R. China
| | - Chang Bai
- Pharmaron Beijing Co. Ltd., 6 Taihe Road, BDA, Beijing 100176, P. R. China
| | - Joseph L. Duffy
- Merck & Co., Inc., 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States
| | - Ernest J. McEachern
- Alectos Therapeutics Inc., 8999 Nelson Way, Burnaby, British Columbia V5A 4B5, Canada
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57
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β-N-Acetylhexosaminidases-the wizards of glycosylation. Appl Microbiol Biotechnol 2019; 103:7869-7881. [PMID: 31401752 DOI: 10.1007/s00253-019-10065-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/23/2019] [Accepted: 07/24/2019] [Indexed: 12/27/2022]
Abstract
β-N-Acetylhexosaminidases (EC 3.2.1.52) are a unique family of glycoside hydrolases with dual substrate specificity and a particular reaction mechanism. Though hydrolytic enzymes per se, their good stability, easy recombinant production, absolute stereoselectivity, and a broad substrate specificity predestine these enzymes for challenging applications in carbohydrate synthesis. This mini-review aims to demonstrate the catalytic potential of β-N-acetylhexosaminidases in a range of unusual reactions, processing of unnatural substrates, formation of unexpected products, and demanding reaction designs. The use of unconventional media can considerably alter the progress of transglycosylation reactions. By means of site-directed mutagenesis, novel catalytic machineries can be constructed. Glycosylation of difficult substrates such as sugar nucleotides was accomplished, and the range of afforded glycosidic bonds comprises unique non-reducing sugars. Specific functional groups may be tolerated in the substrate molecule, which makes β-N-acetylhexosaminidases invaluable allies in difficult synthetic problems.
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58
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Huang G, Huang H. Synthesis, antiasthmatic, and insecticidal/antifungal activities of allosamidins. J Enzyme Inhib Med Chem 2019; 34:1226-1232. [PMID: 31307248 PMCID: PMC6691824 DOI: 10.1080/14756366.2019.1623208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2022] Open
Abstract
Allosamidins come from the secondary metabolites of Streptomyces species, and they have the pseudotrisaccharide structures. Allosamidins are chitinase inhibitors that can be used to study the physiological effects of chitinases in a variety of organisms. They have the novel antiasthmatic activity and insecticidal/antifungal activities. Herein, the synthesis and activities of allosamidins were summarized and analyzed.
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Affiliation(s)
- Gangliang Huang
- a Chongqing Key Laboratory of Green Synthesis and Application , Active Carbohydrate Research Institute, Chongqing Normal University , Chongqing , China
| | - Hualiang Huang
- b School of Chemistry and Environmental Engineering , Wuhan Institute of Technology , Wuhan , China
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59
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Shen S, Dong L, Chen W, Wu R, Lu H, Yang Q, Zhang J. Design and Optimization of Thioglycosyl-naphthalimides as Efficient Inhibitors Against Human O-GlcNAcase. Front Chem 2019; 7:533. [PMID: 31403045 PMCID: PMC6669961 DOI: 10.3389/fchem.2019.00533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/12/2019] [Indexed: 12/26/2022] Open
Abstract
β-N-acetylhexosaminidases represent an important class of exoglycosidases and have emerged as the promising targets for drug and pesticide discovery. Among these, human O-GlcNAcase (hOGA) has been reported to be closely linked to several diseases such as Alzheimer's disease, diabetes, and cancer. Potent hOGA inhibitors with high selectivity are therefore of great significance for the regulation of the corresponding physiological processes. In this study, several classes of novel and readily available thioglycosyl-naphthalimides bearing the amide linker were designed and synthesized. To investigate their potency and selectivity, the inhibitory efficiencies toward hOGA and human β-N-acetylhexosaminidase B (HsHexB) were assayed. Especially, compounds 10a (K i = 0.61 μM) and 16l (K i = 0.72 μM) exhibited excellent inhibitory potency against hOGA and high selectivity (HsHexB, K i > 100 μM). In addition, during the preparation of these thioglycosyl-naphthalimides, a new practical method was developed for the synthesis of ureido glycosides from trichloroethyl carbamates at room temperature and normal pressure without catalyst. Furthermore, the possible binding modes of hOGA with 10a, 10d, and 16j were studied using molecular docking and molecular dynamics simulations to explore the molecular basis for the potency of these thioglycosides. This work present here provides useful clues for the further structural optimization toward hOGA.
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Affiliation(s)
- Shengqiang Shen
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Lili Dong
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Wei Chen
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Renjie Wu
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Huizhe Lu
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Qing Yang
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jianjun Zhang
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
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60
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Gu YX, Liang XX, Yin NY, Yang Y, Wan B, Guo LH, Faiola F. New insights into mechanism of bisphenol analogue neurotoxicity: implications of inhibition of O-GlcNAcase activity in PC12 cells. Arch Toxicol 2019; 93:2661-2671. [DOI: 10.1007/s00204-019-02525-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 07/18/2019] [Indexed: 01/25/2023]
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61
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Steady state kinetic analysis of O-linked GalNAc glycan release catalyzed by endo-α-N-acetylgalactosaminidase. Carbohydr Res 2019; 480:54-60. [DOI: 10.1016/j.carres.2019.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/20/2019] [Accepted: 05/21/2019] [Indexed: 11/17/2022]
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62
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Coyle T, Wu L, Debowski AW, Davies GJ, Stubbs KA. Synthetic and Crystallographic Insight into Exploiting sp 2 Hybridization in the Development of α-l-Fucosidase Inhibitors. Chembiochem 2019; 20:1365-1368. [PMID: 30663832 PMCID: PMC6589914 DOI: 10.1002/cbic.201800710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 01/20/2019] [Indexed: 11/25/2022]
Abstract
The sugar fucose plays a myriad of roles in biological recognition. Enzymes hydrolyzing fucose from glycoconjugates, α-l-fucosidases, are important targets for inhibitor and probe development. Here we describe the synthesis and evaluation of novel α-l-fucosidase inhibitors, with X-ray crystallographic analysis using an α-l-fucosidase from Bacteroides thetaiotamicron helping to lay a foundation for future development of inhibitors for this important enzyme class.
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Affiliation(s)
- Travis Coyle
- School of Molecular SciencesUniversity of Western Australia35 Stirling HighwayCrawleyWA6009Australia
- Present address: School of ChemistryUniversity College DublinStillorgan RoadBelfield, Dublin4Ireland
| | - Liang Wu
- Department of Chemistry, York Structural LaboratoryUniversity of YorkHeslingtonYorkYO10 5DDUK
| | - Aleksandra W. Debowski
- School of Molecular SciencesUniversity of Western Australia35 Stirling HighwayCrawleyWA6009Australia
| | - Gideon J. Davies
- Department of Chemistry, York Structural LaboratoryUniversity of YorkHeslingtonYorkYO10 5DDUK
| | - Keith A. Stubbs
- School of Molecular SciencesUniversity of Western Australia35 Stirling HighwayCrawleyWA6009Australia
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63
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Dong L, Shen S, Xu Y, Wang L, Feng R, Zhang J, Lu H. Computational Studies on the Potency and Selectivity of PUGNAc Derivatives Against GH3, GH20, and GH84 β-N-acetyl-D-hexosaminidases. Front Chem 2019; 7:235. [PMID: 31111026 PMCID: PMC6499197 DOI: 10.3389/fchem.2019.00235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/25/2019] [Indexed: 02/05/2023] Open
Abstract
β-N-acetyl-D-hexosaminidases have attracted significant attention due to their crucial role in diverse physiological functions including antibacterial synergists, pathogen defense, virus infection, lysosomal storage, and protein glycosylation. In particular, the GH3 β-N-acetyl-D-hexosaminidase of V. cholerae (VcNagZ), human GH20 β-N-acetyl-D-hexosaminidase B (HsHexB), and human GH84 β-N-acetyl-D-hexosaminidase (hOGA) are three important representative glycosidases. These have been found to be implicated in β-lactam resistance (VcNagZ), lysosomal storage disorders (HsHexB) and Alzheimer's disease (hOGA). Considering the profound effects of these three enzymes, many small molecule inhibitors with good potency and selectivity have been reported to regulate the corresponding physiological functions. In this paper, the best-known inhibitors PUGNAc and two of its derivatives (N-valeryl-PUGNAc and EtBuPUG) were selected as model compounds and docked into the active pockets of VcNagZ, HsHexB, and hOGA, respectively. Subsequently, molecular dynamics simulations of the nine systems were performed to systematically compare their binding modes from active pocket architecture and individual interactions. Furthermore, the binding free energy and free energy decomposition are calculated using the MM/GBSA methods to predict the binding affinities of enzyme-inhibitor systems and to quantitatively analyze the contribution of each residue. The results show that PUGNAc is deeply-buried in the active pockets of all three enzymes, which indicates its potency (but not selectivity) against VcNagZ, HsHexB, and hOGA. However, EtBuPUG, bearing branched 2-isobutamido, adopted strained conformations and was only located in the active pocket of VcNagZ. It has completely moved out of the pocket of HsHexB and lacks interactions with HsHexB. This indicates why the selectivity of EtBuPUG to VcNagZ/HsHexB is the largest, reaching 968-fold. In addition, the contributions of the catalytic residue Asp253 (VcNagZ), Asp254 (VcNagZ), Asp175 (hOGA), and Asp354 (HsHexB) are important to distinguish the activity and selectivity of these inhibitors. The results of this study provide a helpful structural guideline to promote the development of novel and selective inhibitors against specific β-N-acetyl-D-hexosaminidases.
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Affiliation(s)
- Lili Dong
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Shengqiang Shen
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Yefei Xu
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Leng Wang
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Ruirui Feng
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Jianjun Zhang
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Huizhe Lu
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
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64
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Shi J, Ruijtenbeek R, Pieters RJ. Demystifying O-GlcNAcylation: hints from peptide substrates. Glycobiology 2019; 28:814-824. [PMID: 29635275 DOI: 10.1093/glycob/cwy031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 03/21/2018] [Indexed: 12/20/2022] Open
Abstract
O-GlcNAcylation, analogous to phosphorylation, is an essential post-translational modification of proteins at Ser/Thr residues with a single β-N-acetylglucosamine moiety. This dynamic protein modification regulates many fundamental cellular processes and its deregulation has been linked to chronic diseases such as cancer, diabetes and neurodegenerative disorders. Reversible attachment and removal of O-GlcNAc is governed only by O-GlcNAc transferase and O-GlcNAcase, respectively. Peptide substrates, derived from natural O-GlcNAcylation targets, function in the catalytic cores of these two enzymes by maintaining interactions between enzyme and substrate, which makes them ideal models for the study of O-GlcNAcylation and deglycosylation. These peptides provide valuable tools for a deeper understanding of O-GlcNAc processing enzymes. By taking advantage of peptide chemistry, recent progress in the study of activity and regulatory mechanisms of these two enzymes has advanced our understanding of their fundamental specificities as well as their potential as therapeutic targets. Hence, this review summarizes the recent achievements on this modification studied at the peptide level, focusing on enzyme activity, enzyme specificity, direct function, site-specific antibodies and peptide substrate-inspired inhibitors.
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Affiliation(s)
- Jie Shi
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, TB Utrecht, The Netherlands
| | - Rob Ruijtenbeek
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, TB Utrecht, The Netherlands.,PamGene International BV, HH's-Hertogenbosch, The Netherlands
| | - Roland J Pieters
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, TB Utrecht, The Netherlands
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65
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Abstract
In the early 1980s, while using purified glycosyltransferases to probe glycan structures on surfaces of living cells in the murine immune system, we discovered a novel form of serine/threonine protein glycosylation (O-linked β-GlcNAc; O-GlcNAc) that occurs on thousands of proteins within the nucleus, cytoplasm, and mitochondria. Prior to this discovery, it was dogma that protein glycosylation was restricted to the luminal compartments of the secretory pathway and on extracellular domains of membrane and secretory proteins. Work in the last 3 decades from several laboratories has shown that O-GlcNAc cycling serves as a nutrient sensor to regulate signaling, transcription, mitochondrial activity, and cytoskeletal functions. O-GlcNAc also has extensive cross-talk with phosphorylation, not only at the same or proximal sites on polypeptides, but also by regulating each other's enzymes that catalyze cycling of the modifications. O-GlcNAc is generally not elongated or modified. It cycles on and off polypeptides in a time scale similar to phosphorylation, and both the enzyme that adds O-GlcNAc, the O-GlcNAc transferase (OGT), and the enzyme that removes O-GlcNAc, O-GlcNAcase (OGA), are highly conserved from C. elegans to humans. Both O-GlcNAc cycling enzymes are essential in mammals and plants. Due to O-GlcNAc's fundamental roles as a nutrient and stress sensor, it plays an important role in the etiologies of chronic diseases of aging, including diabetes, cancer, and neurodegenerative disease. This review will present an overview of our current understanding of O-GlcNAc's regulation, functions, and roles in chronic diseases of aging.
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Affiliation(s)
- Gerald W Hart
- From the Complex Carbohydrate Research Center and Biochemistry and Molecular Biology Department, University of Georgia, Athens, Georgia 30602
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66
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Wang H, Guo J, Wang N, Wang J, Xue Q, Wang J, Liu W, Liu K, Cao X, Zhao W, Xi R, Niu Y, Wang P, Li J. Ac 4GlcNAcF 3, an OGT-tolerated but OGA-resistant regulator for O-GlcNAcylation. Bioorg Med Chem Lett 2019; 29:802-805. [PMID: 30713024 DOI: 10.1016/j.bmcl.2019.01.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 01/18/2019] [Accepted: 01/19/2019] [Indexed: 10/27/2022]
Abstract
O-Linked N-acetylglucosamine (O-GlcNAc) is an abundant posttranslationalmonosaccaride-modification found on Ser or Thr residues of intracellular proteins in most eukaryotes. The dynamic nature of O-GlcNAc has enabled researchers to modulate the stoichiometry of O-GlcNAc on proteins in order to investigate its function. Cell permeable small moleculars have proven invaluable tools to increase O-GlcNAc levels. Herein, using in vitro substrate screening, we identified GlcNAcF3 as an OGT-accepted but OGA-resistant sugar mimic. Cellular experiments with cell-permeable peracetylated-GlcNAcF3 (Ac4GlcNAcF3) displayed that Ac4GlcNAcF3 was a potent tool to increase O-GlcNAc levels in several cell lines. Further, NIH3T3 cells interfered with OGT (siOGT) showed significant decreasing of O-GlcNAc levels with Ac4GlcNAcF3 treatment, indicating O-GlcNAcF3 was an OGT-dependent modification. In addition, cellular toxic assay confirmed O-GlcNAcF3 production has no significant effect on cell proliferation or viability. Thus, Ac4GlcNAcF3 represents a safe and dual regulator for both OGT and OGA, which will benefit the study of O-GlcNAc.
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Affiliation(s)
- Haifeng Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Jianshuang Guo
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Nan Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Jiajia Wang
- School of Basic Medical Sciences, Henan University Joint National Laboratory for Antibody Drug Engineering, Kaifeng, Henan 475004, China
| | - Qingqing Xue
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Jiyan Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Wenjie Liu
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Kaihui Liu
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Xuefeng Cao
- Department of Chemistry & Center for Diagnostics & Therapeutics Georgia State University, Atlanta, GA 30303, USA
| | - Wei Zhao
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Rimo Xi
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Youhong Niu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking Univeristy, Xue Yuan Road No.38, Beijing 100191, China
| | - Peng Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Jing Li
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Reasearch, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China; College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100191, China.
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67
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Bojarová P, Kulik N, Slámová K, Hubálek M, Kotik M, Cvačka J, Pelantová H, Křen V. Selective β-N-acetylhexosaminidase from Aspergillus versicolor—a tool for producing bioactive carbohydrates. Appl Microbiol Biotechnol 2019; 103:1737-1753. [DOI: 10.1007/s00253-018-9534-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/05/2018] [Accepted: 11/17/2018] [Indexed: 12/21/2022]
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68
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Igual MO, Nunes PS, da Costa RM, Mantoani SP, Tostes RC, Carvalho I. Novel glucopyranoside C2-derived 1,2,3-triazoles displaying selective inhibition of O-GlcNAcase (OGA). Carbohydr Res 2019; 471:43-55. [DOI: 10.1016/j.carres.2018.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 10/19/2018] [Accepted: 10/22/2018] [Indexed: 01/13/2023]
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69
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Males A, Davies GJ. Structural studies of a surface-entropy reduction mutant of O-GlcNAcase. Acta Crystallogr D Struct Biol 2019; 75:70-78. [PMID: 30644846 PMCID: PMC6333286 DOI: 10.1107/s2059798318016595] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 11/21/2018] [Indexed: 11/18/2022] Open
Abstract
The enzyme O-GlcNAcase catalyses the removal of the O-GlcNAc co/post-translational modification in multicellular eukaryotes. The enzyme has become of acute interest given the intimate role of O-GlcNAcylation in tau modification and stability; small-molecular inhibitors of human O-GlcNAcase are under clinical assessment for the treatment of tauopathies. Given the importance of structure-based and mechanism-based inhibitor design for O-GlcNAcase, it was sought to test whether different crystal forms of the human enzyme could be achieved by surface mutagenesis. Guided by surface-entropy reduction, a Glu602Ala/Glu605Ala variant [on the Gly11-Gln396/Lys535-Tyr715 construct; Roth et al. (2017), Nature Chem. Biol. 13, 610-612] was obtained which led to a new crystal form of the human enzyme. An increase in crystal contacts stabilized disordered regions of the protein, enabling 88% of the structure to be modelled; only 83% was possible for the wild-type construct. Although the binding of the C-terminus was consistent with the wild type, Lys713 in monomer A was bound in the -1 subsite of the symmetry-related monomer A and the active sites of the B monomers were vacant. The new crystal form presents an opportunity for enhanced soaking experiments that are essential to understanding the binding mechanism and substrate specificity of O-GlcNAcase.
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Affiliation(s)
- Alexandra Males
- Department of Chemistry, University of York, York YO10 5DD, England
| | - Gideon J. Davies
- Department of Chemistry, University of York, York YO10 5DD, England
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70
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Coines J, Alfonso‐Prieto M, Biarnés X, Planas A, Rovira C. Oxazoline or Oxazolinium Ion? The Protonation State and Conformation of the Reaction Intermediate of Chitinase Enzymes Revisited. Chemistry 2018; 24:19258-19265. [DOI: 10.1002/chem.201803905] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/29/2018] [Indexed: 11/07/2022]
Affiliation(s)
- Joan Coines
- Departament de Química Inorgànica i Orgànica, (secció de Química Orgànica) and Institut de Química Teòrica i, Computacional (IQTCUB)Universitat de Barcelona, Martí i Franquès 1 08028 Barcelona Spain
| | - Mercedes Alfonso‐Prieto
- Departament de Química Inorgànica i Orgànica, (secció de Química Orgànica) and Institut de Química Teòrica i, Computacional (IQTCUB)Universitat de Barcelona, Martí i Franquès 1 08028 Barcelona Spain
- Current address: INM-9/IAS-5Forschungszentrum Jülich, 52425 Jülich (Germany) and C. and O. Vogt Institute for Brain Research, Heinrich Heine University Düsseldorf 40225 Düsseldorf Germany
| | - Xevi Biarnés
- Laboratory of BiochemistryInstitut Químic de SarriàUniversitat Ramon Llull Via Augusta, 390 08017 Barcelona Spain
| | - Antoni Planas
- Laboratory of BiochemistryInstitut Químic de SarriàUniversitat Ramon Llull Via Augusta, 390 08017 Barcelona Spain
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica, (secció de Química Orgànica) and Institut de Química Teòrica i, Computacional (IQTCUB)Universitat de Barcelona, Martí i Franquès 1 08028 Barcelona Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA) Passeig Lluís Companys 23 08010 Barcelona Spain
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71
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Lu D, Zhu S, Sobala LF, Bernardo-Seisdedos G, Millet O, Zhang Y, Jiménez-Barbero J, Davies GJ, Sollogoub M. From 1,4-Disaccharide to 1,3-Glycosyl Carbasugar: Synthesis of a Bespoke Inhibitor of Family GH99 Endo-α-mannosidase. Org Lett 2018; 20:7488-7492. [PMID: 30427198 DOI: 10.1021/acs.orglett.8b03260] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding the enzyme reaction mechanism can lead to the design of enzyme inhibitors. A Claisen rearrangement was used to allow conversion of an α-1,4-disaccharide into an α-1,3-linked glycosyl carbasugar to target the endo-α-mannosidase from the GH99 glycosidase family, which, unusually, is believed to act through a 1,2-anhydrosugar "epoxide" intermediate. Using NMR and X-ray crystallography, it is shown that glucosyl carbasugar α-aziridines can act as reasonably potent endo-α-mannosidase inhibitors, likely by virtue of their shape mimicry and the interactions of the aziridine nitrogen with the conserved catalytic acid/base of the enzyme active site.
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Affiliation(s)
- Dan Lu
- Sorbonne Université , CNRS, Institut Parisien de Chimie Moléculaire, UMR 8232 , 4 place Jussieu , 75005 Paris , France
| | - Sha Zhu
- Sorbonne Université , CNRS, Institut Parisien de Chimie Moléculaire, UMR 8232 , 4 place Jussieu , 75005 Paris , France
| | - Lukasz F Sobala
- York Structural Biology Laboratory, Department of Chemistry , University of York , York YO10 5DD , U.K
| | | | | | - Yongmin Zhang
- Sorbonne Université , CNRS, Institut Parisien de Chimie Moléculaire, UMR 8232 , 4 place Jussieu , 75005 Paris , France
| | - Jesus Jiménez-Barbero
- Ikerbasque, Basque Foundation for Science , Maria Diaz de Haro 3 , 48013 Bilbao , Spain
| | - Gideon J Davies
- York Structural Biology Laboratory, Department of Chemistry , University of York , York YO10 5DD , U.K
| | - Matthieu Sollogoub
- Sorbonne Université , CNRS, Institut Parisien de Chimie Moléculaire, UMR 8232 , 4 place Jussieu , 75005 Paris , France
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72
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Tan HY, Eskandari R, Shen D, Zhu Y, Liu TW, Willems LI, Alteen MG, Madden Z, Vocadlo DJ. Direct One-Step Fluorescent Labeling of O-GlcNAc-Modified Proteins in Live Cells Using Metabolic Intermediates. J Am Chem Soc 2018; 140:15300-15308. [PMID: 30296064 DOI: 10.1021/jacs.8b08260] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The modification of proteins with O-linked N-acetylglucosamine ( O-GlcNAc) by the enzyme O-GlcNAc transferase (OGT) has emerged as an important regulator of cellular physiology. Metabolic labeling strategies to monitor O-GlcNAcylation in cells have proven of great value for uncovering the molecular roles of O-GlcNAc. These strategies rely on two-step labeling procedures, which limits the scope of experiments that can be performed. Here, we report on the creation of fluorescent uridine 5'-diphospho- N-acetylglucosamine (UDP-GlcNAc) analogues in which the N-acyl group of glucosamine is modified with a suitable linker and fluorophore. Using human OGT, we show these donor sugar substrates permit direct monitoring of OGT activity on protein substrates in vitro. We show that feeding cells with a corresponding fluorescent metabolic precursor for the last step of the hexosamine biosynthetic pathway (HBP) leads to its metabolic assimilation and labeling of O-GlcNAcylated proteins within live cells. This one-step metabolic feeding strategy permits labeling of O-GlcNAcylated proteins with a fluorescent glucosamine-nitrobenzoxadiazole (GlcN-NBD) conjugate that accumulates in a time- and dose-dependent manner. Because no genetic engineering of cells is required, we anticipate this strategy should be generally amenable to studying the roles of O-GlcNAc in cellular physiology as well as to gain an improved understanding of the regulation of OGT within cells. The further expansion of this one-step in-cell labeling strategy should enable performing a range of experiments including two-color pulse chase experiments and monitoring OGT activity on specific protein substrates in live cells.
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73
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Ho LA, Winogrodzki JL, Debowski AW, Madden Z, Vocadlo DJ, Mark BL, Stubbs KA. A mechanism-based GlcNAc-inspired cyclophellitol inactivator of the peptidoglycan recycling enzyme NagZ reverses resistance to β-lactams in Pseudomonas aeruginosa. Chem Commun (Camb) 2018; 54:10630-10633. [PMID: 30178799 DOI: 10.1039/c8cc05281f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The development of a potent mechanism-based inactivator of NagZ, an enzyme critical to the production of inducible AmpC β-lactamase in Gram-negative bacteria, is presented. This inactivator significantly reduces MIC values for important β-lactams against a clinically relevant strain of Pseudomonas aeruginosa.
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Affiliation(s)
- Louisa A Ho
- School of Molecular Sciences, University of Western Australia, Crawley, WA 6009, Australia.
| | - Judith L Winogrodzki
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba R3T2N2, Canada.
| | - Aleksandra W Debowski
- School of Molecular Sciences, University of Western Australia, Crawley, WA 6009, Australia. and School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - Zarina Madden
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A1S6, Canada
| | - David J Vocadlo
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A1S6, Canada
| | - Brian L Mark
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba R3T2N2, Canada.
| | - Keith A Stubbs
- School of Molecular Sciences, University of Western Australia, Crawley, WA 6009, Australia.
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74
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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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75
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Meekrathok P, Stubbs KA, Suginta W. Potent inhibition of a GH20 exo-β-N-acetylglucosaminidase from marine Vibrio bacteria by reaction intermediate analogues. Int J Biol Macromol 2018; 115:1165-1173. [DOI: 10.1016/j.ijbiomac.2018.04.193] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 04/14/2018] [Accepted: 04/30/2018] [Indexed: 02/04/2023]
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76
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Constable S, Lim JM, Vaidyanathan K, Wells L. O-GlcNAc transferase regulates transcriptional activity of human Oct4. Glycobiology 2018; 27:927-937. [PMID: 28922739 DOI: 10.1093/glycob/cwx055] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 06/10/2017] [Indexed: 01/06/2023] Open
Abstract
O-linked β-N-acetylglucosamine (O-GlcNAc) is a single sugar modification found on many different classes of nuclear and cytoplasmic proteins. Addition of this modification, by the enzyme O-linked N-acetylglucosamine transferase (OGT), is dynamic and inducible. One major class of proteins modified by O-GlcNAc is transcription factors. O-GlcNAc regulates transcription factor properties through a variety of different mechanisms including localization, stability and transcriptional activation. Maintenance of embryonic stem (ES) cell pluripotency requires tight regulation of several key transcription factors, many of which are modified by O-GlcNAc. Octamer-binding protein 4 (Oct4) is one of the key transcription factors required for pluripotency of ES cells and more recently, the generation of induced pluripotent stem (iPS) cells. The action of Oct4 is modulated by the addition of several post-translational modifications, including O-GlcNAc. Previous studies in mice found a single site of O-GlcNAc addition responsible for transcriptional regulation. This study was designed to determine if this mechanism is conserved in humans. We mapped 10 novel sites of O-GlcNAc attachment on human Oct4, and confirmed a role for OGT in transcriptional activation of Oct4 at a site distinct from that found in mouse that allows distinction between different Oct4 target promoters. Additionally, we uncovered a potential new role for OGT that does not include its catalytic function. These results confirm that human Oct4 activity is being regulated by OGT by a mechanism that is distinct from mouse Oct4.
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Affiliation(s)
- Sandii Constable
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, The University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA
| | - Jae-Min Lim
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, The University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA.,Department of Chemistry, Changwon National University, Changwon, Gyeongnam 641-773, South Korea
| | - Krithika Vaidyanathan
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, The University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA
| | - Lance Wells
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, The University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA
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77
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Borodkin VS, Rafie K, Selvan N, Aristotelous T, Navratilova I, Ferenbach AT, van Aalten DMF. O-GlcNAcase Fragment Discovery with Fluorescence Polarimetry. ACS Chem Biol 2018; 13:1353-1360. [PMID: 29641181 DOI: 10.1021/acschembio.8b00183] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The attachment of the sugar N-acetyl-D-glucosamine (GlcNAc) to specific serine and threonine residues on proteins is referred to as protein O-GlcNAcylation. O-GlcNAc transferase (OGT) is the enzyme responsible for carrying out the modification, while O-GlcNAcase (OGA) reverses it. Protein O-GlcNAcylation has been implicated in a wide range of cellular processes including transcription, proteostasis, and stress response. Dysregulation of O-GlcNAc has been linked to diabetes, cancer, and neurodegenerative and cardiovascular disease. OGA has been proposed to be a drug target for the treatment of Alzheimer's and cardiovascular disease given that increased O-GlcNAc levels appear to exert a protective effect. The search for specific, potent, and drug-like OGA inhibitors with bioavailability in the brain is therefore a field of active research, requiring orthogonal high-throughput assay platforms. Here, we describe the synthesis of a novel probe for use in a fluorescence polarization based assay for the discovery of inhibitors of OGA. We show that the probe is suitable for use with both human OGA, as well as the orthologous bacterial counterpart from Clostridium perfringens, CpOGA, and the lysosomal hexosaminidases HexA/B. We structurally characterize CpOGA in complex with a ligand identified from a fragment library screen using this assay. The versatile synthesis procedure could be adapted for making fluorescent probes for the assay of other glycoside hydrolases.
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78
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Laarse SAM, Leney AC, Heck AJR. Crosstalk between phosphorylation and O‐Glc
NA
cylation: friend or foe. FEBS J 2018; 285:3152-3167. [DOI: 10.1111/febs.14491] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/27/2018] [Accepted: 04/26/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Saar A. M. Laarse
- Biomolecular Mass Spectrometry and Proteomics Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences Utrecht University The Netherlands
- Netherlands Proteomics Centre Utrecht The Netherlands
| | - Aneika C. Leney
- Biomolecular Mass Spectrometry and Proteomics Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences Utrecht University The Netherlands
- Netherlands Proteomics Centre Utrecht The Netherlands
| | - Albert J. R. Heck
- Biomolecular Mass Spectrometry and Proteomics Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences Utrecht University The Netherlands
- Netherlands Proteomics Centre Utrecht The Netherlands
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79
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Bouquet J, King DT, Vadlamani G, Benzie GR, Iorga B, Ide D, Adachi I, Kato A, Vocadlo DJ, Mark BL, Blériot Y, Désiré J. Selective trihydroxylated azepane inhibitors of NagZ, a glycosidase involved in Pseudomonas aeruginosa resistance to β-lactam antibiotics. Org Biomol Chem 2018; 15:4609-4619. [PMID: 28513749 DOI: 10.1039/c7ob00838d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of a series of d-gluco-like configured 4,5,6-trihydroxyazepanes bearing a triazole, a sulfonamide or a fluorinated acetamide moiety at C-3 is described. These synthetic derivatives have been tested for their ability to selectively inhibit the muropeptide recycling glucosaminidase NagZ and to thereby increase sensitivity of Pseudomonas aeruginosa to β-lactams, a pathway with substantial therapeutic potential. While introduction of triazole and sulfamide groups failed to lead to glucosaminidase inhibitors, the NHCOCF3 analog proved to be a selective inhibitor of NagZ over other glucosaminidases including human O-GlcNAcase and lysosomal hexosaminidases HexA and B.
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Affiliation(s)
- J Bouquet
- Equipe Synthèse Organique, Groupe Glycochimie, IC2MP, UMR CNRS 7285, Université de Poitiers, 4 rue Michel Brunet, 86073 Poitiers cedex 09, France.
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80
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Fjellaksel R, Dugalic D, Demissie TB, Riss PJ, Hjelstuen OK, Sundset R, Hansen JH. An acylation-Finkelstein approach to radioiodination of bioactives: The role of amide group anchimeric assistance. J PHYS ORG CHEM 2018. [DOI: 10.1002/poc.3835] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Richard Fjellaksel
- Medical Imaging Group, Department of Clinical Medicine; UiT The Arctic University of Norway; Tromsø Norway
- Drug Transport and Delivery Group, Department of Pharmacy; UiT The Arctic University of Norway; Tromsø Norway
- Organic Chemistry Group, Department of Chemistry; UiT The Arctic University of Norway; Tromsø Norway
| | - Damir Dugalic
- Drug Transport and Delivery Group, Department of Pharmacy; UiT The Arctic University of Norway; Tromsø Norway
- Organic Chemistry Group, Department of Chemistry; UiT The Arctic University of Norway; Tromsø Norway
| | - Taye B. Demissie
- Organic Chemistry Group, Department of Chemistry; UiT The Arctic University of Norway; Tromsø Norway
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry; UiT The Arctic University of Norway; Tromsø Norway
| | - Patrick J. Riss
- Department of neuropsychiatry and psychosomatic medicine; Oslo University Hospital; Oslo Norway
- Realomics SFI, Department of Chemistry; University of Oslo; Oslo Norway
- Norsk Medisinsk Syklotronsenter AS; Oslo Norway
| | - Ole-Kristian Hjelstuen
- Drug Transport and Delivery Group, Department of Pharmacy; UiT The Arctic University of Norway; Tromsø Norway
| | - Rune Sundset
- Medical Imaging Group, Department of Clinical Medicine; UiT The Arctic University of Norway; Tromsø Norway
- PET Imaging Center, Division of Diagnostics; University Hospital of North Norway; Tromsø Norway
| | - Jørn H. Hansen
- Organic Chemistry Group, Department of Chemistry; UiT The Arctic University of Norway; Tromsø Norway
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81
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Seo IK, Woo EH, Cecioni S, Vocadlo DJ. A divergent synthesis to generate targeted libraries of inhibitors for endo- N-acetylglucosaminidases. CAN J CHEM 2018. [DOI: 10.1139/cjc-2017-0461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cell active inhibitors of glycoside processing enzymes are valuable research tools that help us understand the physiological roles of this diverse class of enzymes. endo-N-Acetylglucosaminidases have gained increased attention for their important roles in both mammals and human pathogens; however, metabolically stable cell active inhibitors of these enzymes are lacking. Here, we describe a divergent synthetic strategy involving elaboration of a thiazoline core scaffold. We illustrate the potential of this approach by using the copper catalysed azide-alkyne click (CuAAC) reaction, in combination with a suitable catalyst to avoid poisoning by the thiazoline moiety, to generate a targeted panel of candidate inhibitors of endo-N-acetylglucosaminidases and chitinases.
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Affiliation(s)
- Isaac K. Seo
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Esther H. Woo
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Samy Cecioni
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - David J. Vocadlo
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
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82
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Ferron M, Denis M, Persello A, Rathagirishnan R, Lauzier B. Protein O-GlcNAcylation in Cardiac Pathologies: Past, Present, Future. Front Endocrinol (Lausanne) 2018; 9:819. [PMID: 30697194 PMCID: PMC6340935 DOI: 10.3389/fendo.2018.00819] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 12/31/2018] [Indexed: 01/22/2023] Open
Abstract
O-GlcNAcylation is a ubiquitous and reversible post-translational protein modification that has recently gained renewed interest due to the rapid development of analytical tools and new molecules designed to specifically increase the level of protein O-GlcNAcylation. The level of O-GlcNAc modification appears to have either deleterious or beneficial effects, depending on the context (exposure time, pathophysiological context). While high O-GlcNAcylation levels are mostly reported in chronic diseases, the increase in O-GlcNAc level in acute stresses such as during ischemia reperfusion or hemorrhagic shock is reported to be beneficial in vitro, ex vivo, or in vivo. In this context, an increase in O-GlcNAc levels could be a potential new cardioprotective therapy, but the ambivalent effects of protein O-GlcNAcylation augmentation remains as a key problem to be solved prior to their transfer to the clinic. The emergence of new analytical tools has opened new avenues to decipher the mechanisms underlying the beneficial effects associated with an O-GlcNAc level increase. A better understanding of the exact roles of O-GlcNAc on protein function, targeting or stability will help to develop more targeted approaches. The aim of this review is to discuss the mechanisms and potential beneficial impact of O-GlcNAc modulation, and its potential as a new clinical target in cardiology.
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Affiliation(s)
- Marine Ferron
- Montreal Heart Institute, Montreal, QC, Canada
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
- *Correspondence: Marine Ferron
| | - Manon Denis
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
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83
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Hwang H, Rhim H. Functional significance of O-GlcNAc modification in regulating neuronal properties. Pharmacol Res 2017; 129:295-307. [PMID: 29223644 DOI: 10.1016/j.phrs.2017.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/17/2017] [Accepted: 12/04/2017] [Indexed: 12/22/2022]
Abstract
Post-translational modifications (PTMs) covalently modify proteins and diversify protein functions. Along with protein phosphorylation, another common PTM is the addition of O-linked β-N-acetylglucosamine (O-GlcNAc) to serine and/or threonine residues. O-GlcNAc modification is similar to phosphorylation in that it occurs to serine and threonine residues and cycles on and off with a similar time scale. However, a striking difference is that the addition and removal of the O-GlcNAc moiety on all substrates are mediated by the two enzymes regardless of proteins, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. O-GlcNAcylation can interact or potentially compete with phosphorylation on serine and threonine residues, and thus serves as an important molecular mechanism to modulate protein functions and activation. However, it has been challenging to address the role of O-GlcNAc modification in regulating protein functions at the molecular level due to the lack of convenient tools to determine the sites and degrees of O-GlcNAcylation. Studies in this field have only begun to expand significantly thanks to the recent advances in detection and manipulation methods such as quantitative proteomics and highly selective small-molecule inhibitors for OGT and OGA. Interestingly, multiple brain regions, especially hippocampus, express high levels of both OGT and OGA, and a number of neuron-specific proteins have been reported to undergo O-GlcNAcylation. This review aims to discuss the recent updates concerning the impacts of O-GlcNAc modification on neuronal functions at multiple levels ranging from intrinsic neuronal properties to synaptic plasticity and animal behaviors.
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Affiliation(s)
- Hongik Hwang
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Hyewhon Rhim
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Republic of Korea.
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84
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Enzymatic properties of β-N-acetylglucosaminidases. Appl Microbiol Biotechnol 2017; 102:93-103. [PMID: 29143882 DOI: 10.1007/s00253-017-8624-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/02/2017] [Accepted: 11/02/2017] [Indexed: 01/27/2023]
Abstract
β-N-Acetylglucosaminidases (GlcNAcases) hydrolyse N-acetylglucosamine-containing oligosaccharides and proteins. These enzymes produce N-acetylglucosamine (GlcNAc) and have a wide range of promising applications in the food, energy, and pharmaceutical industries, such as synergistic degradation of chitin with endo-chitinases and using GlcNAc to produce sialic acid, bioethanol, single-cell proteins, and pharmaceutical therapeutics. GlcNAcases also play an important role in the dynamic balance of cellular O-linked GlcNAc levels, catabolism of ganglioside storage in Tay-Sachs disease, and bacterial cell wall recycling and flagellar assembly. In view of these important biological functions and the wide range of industrial applications of GlcNAcases, this review aims to provide a better understanding of various advances for these enzymes. It focuses on enzymatic properties of GlcNAcases, including substrate specificity, catalytic activity, pH optimum, temperature optimum, thermostability, the effects of various metal ions and organic reagents, and transglycosylation.
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85
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Ma X, Li H, He Y, Hao J. The emerging link between O-GlcNAcylation and neurological disorders. Cell Mol Life Sci 2017; 74:3667-3686. [PMID: 28534084 PMCID: PMC11107615 DOI: 10.1007/s00018-017-2542-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 04/23/2017] [Accepted: 05/16/2017] [Indexed: 12/15/2022]
Abstract
O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) is involved in the regulation of many cellular cascades and neurological diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. In the brain, the expression of O-GlcNAcylation is notably heightened, as is that of O-linked N-acetylglucosaminyltransferase (OGT) and β-N-acetylglucosaminidase (OGA), the presence of which is prominent in many regions of neurological importance. Most importantly, O-GlcNAcylation is believed to contribute to the normal functioning of neurons; conversely, its dysregulation participates in the pathogenesis of neurological disorders. In neurodegenerative diseases, O-GlcNAcylation of the brain's key proteins, such as tau and amyloid-β, interacts with their phosphorylation, thereby triggering the formation of neurofibrillary tangles and amyloid plaques. An increase of O-GlcNAcylation by pharmacological intervention prevents neuronal loss. Additionally, O-GlcNAcylation is stress sensitive, and its elevation is cytoprotective. Increased O-GlcNAcylation ameliorated brain damage in victims of both trauma-hemorrhage and stroke. In this review, we summarize the current understanding of O-GlcNAcylation's physiological and pathological roles in the nervous system and provide a foundation for development of a therapeutic strategy for neurological disorders.
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Affiliation(s)
- Xiaofeng Ma
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - He Li
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Yating He
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Junwei Hao
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China.
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86
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Li B, Li H, Hu CW, Jiang J. Structural insights into the substrate binding adaptability and specificity of human O-GlcNAcase. Nat Commun 2017; 8:666. [PMID: 28939839 PMCID: PMC5610315 DOI: 10.1038/s41467-017-00865-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 08/01/2017] [Indexed: 12/17/2022] Open
Abstract
The O-linked β-N-acetyl glucosamine (O-GlcNAc) modification dynamically regulates the functions of numerous proteins. A single human enzyme O-linked β-N-acetyl glucosaminase (O-GlcNAcase or OGA) hydrolyzes this modification. To date, it remains largely unknown how OGA recognizes various substrates. Here we report the structures of OGA in complex with each of four distinct glycopeptide substrates that contain a single O-GlcNAc modification on a serine or threonine residue. Intriguingly, these glycopeptides bind in a bidirectional yet conserved conformation within the substrate-binding cleft of OGA. This study provides fundamental insights into a general principle that confers the substrate binding adaptability and specificity to OGA in O-GlcNAc regulation. O-linked β-N-acetyl glucosamine (O-GlcNAc) is an important protein modification that is hydrolyzed by O-GlcNAcase (OGA). Here the authors give insights into OGA substrate recognition by presenting four human OGA structures complexed with glycopeptide substrates containing a single O-GlcNAc modification on either a serine or threonine.
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Affiliation(s)
- Baobin Li
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Hao Li
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Chia-Wei Hu
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Jiaoyang Jiang
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, 53705, USA.
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87
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Acute Increases in Protein O-GlcNAcylation Dampen Epileptiform Activity in Hippocampus. J Neurosci 2017; 37:8207-8215. [PMID: 28760863 DOI: 10.1523/jneurosci.0173-16.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 07/02/2017] [Accepted: 07/08/2017] [Indexed: 11/21/2022] Open
Abstract
O-GlcNAcylation is a ubiquitous and dynamic post-translational modification involving the O-linkage of β-N-acetylglucosamine to serine/threonine residues of membrane, cytosolic, and nuclear proteins. This modification is similar to phosphorylation and regarded as a key regulator of cell survival and homeostasis. Previous studies have shown that phosphorylation of serine residues on synaptic proteins is a major regulator of synaptic strength and long-term plasticity, suggesting that O-GlcNAcylation of synaptic proteins is likely as important as phosphorylation; however, few studies have investigated its role in synaptic efficacy. We recently demonstrated that acutely increasing O-GlcNAcylation induces a novel form of LTD at CA3-CA1 synapses, O-GlcNAc LTD. Here, using hippocampal slices from young adult male rats and mice, we report that epileptiform activity at CA3-CA1 synapses, generated by GABAAR inhibition, is significantly attenuated when protein O-GlcNAcylation is pharmacologically increased. This dampening effect is lost in slices from GluA2 KO mice, indicating a requirement of GluA2-containing AMPARs, similar to expression of O-GlcNAc LTD. Furthermore, we find that increasing O-GlcNAcylation decreases spontaneous CA3 pyramidal cell activity under basal and hyperexcitable conditions. This dampening effect was also observed on cortical hyperexcitability during in vivo EEG recordings in awake mice where the effects of the proconvulsant pentylenetetrazole are attenuated by acutely increasing O-GlcNAcylation. Collectively, these data demonstrate that the post-translational modification, O-GlcNAcylation, is a novel mechanism by which neuronal and synaptic excitability can be regulated, and suggest the possibility that increasing O-GlcNAcylation could be a novel therapeutic target to treat seizure disorders and epilepsy.SIGNIFICANCE STATEMENT We recently reported that an acute pharmacological increase in protein O-GlcNAcylation induces a novel form of long-term synaptic depression at hippocampal CA3-CA1 synapses (O-GlcNAc LTD). This synaptic dampening effect on glutamatergic networks suggests that increasing O-GlcNAcylation will depress pathological hyperexcitability. Using in vitro and in vivo models of epileptiform activity, we show that acutely increasing O-GlcNAc levels can significantly attenuate ongoing epileptiform activity and prophylactically dampen subsequent seizure activity. Together, our findings support the conclusion that protein O-GlcNAcylation is a regulator of neuronal excitability, and it represents a promising target for further research on seizure disorder therapeutics.
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88
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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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89
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Ma Z, Chalkley RJ, Vosseller K. Hyper- O-GlcNAcylation activates nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) signaling through interplay with phosphorylation and acetylation. J Biol Chem 2017; 292:9150-9163. [PMID: 28416608 DOI: 10.1074/jbc.m116.766568] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 03/23/2017] [Indexed: 01/08/2023] Open
Abstract
O-GlcNAcylation is the covalent addition of an O-linked β-N-acetylglucosamine (O-GlcNAc) sugar moiety to hydroxyl groups of serine/threonine residues of cytosolic and nuclear proteins. O-GlcNAcylation, analogous to phosphorylation, plays critical roles in gene expression through direct modification of transcription factors, such as NF-κB. Aberrantly increased NF-κB O-GlcNAcylation has been linked to NF-κB constitutive activation and cancer development. Therefore, it is of a great biological and clinical significance to dissect the molecular mechanisms that tune NF-κB activity. Recently, we and others have shown that O-GlcNAcylation affects the phosphorylation and acetylation of NF-κB subunit p65/RelA. However, the mechanism of how O-GlcNAcylation activates NF-κB signaling through phosphorylation and acetylation is not fully understood. In this study, we mapped O-GlcNAcylation sites of p65 at Thr-305, Ser-319, Ser-337, Thr-352, and Ser-374. O-GlcNAcylation of p65 at Thr-305 and Ser-319 increased CREB-binding protein (CBP)/p300-dependent activating acetylation of p65 at Lys-310, contributing to NF-κB transcriptional activation. Moreover, elevation of O-GlcNAcylation by overexpression of OGT increased the expression of p300, IKKα, and IKKβ and promoted IKK-mediated activating phosphorylation of p65 at Ser-536, contributing to NF-κB activation. In addition, we also identified phosphorylation of p65 at Thr-308, which might impair the O-GlcNAcylation of p65 at Thr-305. These results indicate mechanisms through which both non-pathological and oncogenic O-GlcNAcylation regulate NF-κB signaling through interplay with phosphorylation and acetylation.
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Affiliation(s)
- Zhiyuan Ma
- From the Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102 and
| | - Robert J Chalkley
- the Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158
| | - Keith Vosseller
- From the Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102 and
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90
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Roth C, Chan S, Offen WA, Hemsworth GR, Willems LI, King DT, Varghese V, Britton R, Vocadlo DJ, Davies GJ. Structural and functional insight into human O-GlcNAcase. Nat Chem Biol 2017; 13:610-612. [PMID: 28346405 PMCID: PMC5438047 DOI: 10.1038/nchembio.2358] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/09/2017] [Indexed: 12/24/2022]
Abstract
O-GlcNAc hydrolase, OGA, removes O-linked N-acetylglucosamine (O-GlcNAc) from myriad nucleocytoplasmic proteins. Through co-expression and assembly of OGA fragments we determined the 3-D structure of human OGA, revealing an unusual helix exchanged dimer that lays a structural foundation for an improved understanding of substrate recognition and regulation of OGA. Structures of OGA in complex with a series of inhibitors define a precise blueprint for the design of inhibitors having clinical value.
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Affiliation(s)
- Christian Roth
- York Structural Biology Laboratory, Department of Chemistry University of York, York, UK
| | - Sherry Chan
- York Structural Biology Laboratory, Department of Chemistry University of York, York, UK
| | - Wendy A Offen
- York Structural Biology Laboratory, Department of Chemistry University of York, York, UK
| | - Glyn R Hemsworth
- York Structural Biology Laboratory, Department of Chemistry University of York, York, UK
| | - Lianne I Willems
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Dustin T King
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Vimal Varghese
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Robert Britton
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - David J Vocadlo
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Gideon J Davies
- York Structural Biology Laboratory, Department of Chemistry University of York, York, UK
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91
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Elsen NL, Patel SB, Ford RE, Hall DL, Hess F, Kandula H, Kornienko M, Reid J, Selnick H, Shipman JM, Sharma S, Lumb KJ, Soisson SM, Klein DJ. Insights into activity and inhibition from the crystal structure of human O-GlcNAcase. Nat Chem Biol 2017; 13:613-615. [PMID: 28346407 DOI: 10.1038/nchembio.2357] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 03/09/2017] [Indexed: 12/13/2022]
Abstract
O-GlcNAc hydrolase (OGA) catalyzes removal of βα-linked N-acetyl-D-glucosamine from serine and threonine residues. We report crystal structures of Homo sapiens OGA catalytic domain in apo and inhibited states, revealing a flexible dimer that displays three unique conformations and is characterized by subdomain α-helix swapping. These results identify new structural features of the substrate-binding groove adjacent to the catalytic site and open new opportunities for structural, mechanistic and drug discovery activities.
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Affiliation(s)
- Nathaniel L Elsen
- Screening and Protein Sciences, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Sangita B Patel
- Structural Chemistry, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Rachael E Ford
- Screening and Protein Sciences, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Dawn L Hall
- Screening and Protein Sciences, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Fred Hess
- Department of Neurobiology, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Hari Kandula
- Screening and Protein Sciences, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Maria Kornienko
- Screening and Protein Sciences, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - John Reid
- Structural Chemistry, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Harold Selnick
- Discovery Chemistry, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Jennifer M Shipman
- Screening and Protein Sciences, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Sujata Sharma
- Screening and Protein Sciences, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Kevin J Lumb
- Screening and Protein Sciences, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Stephen M Soisson
- Structural Chemistry, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
| | - Daniel J Klein
- Structural Chemistry, MRL, Merck &Co., Inc., West Point, Pennsylvania, USA
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92
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Slámová K, Bojarová P. Engineered N-acetylhexosamine-active enzymes in glycoscience. Biochim Biophys Acta Gen Subj 2017; 1861:2070-2087. [PMID: 28347843 DOI: 10.1016/j.bbagen.2017.03.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 01/17/2023]
Abstract
BACKGROUND In recent years, enzymes modifying N-acetylhexosamine substrates have emerged in numerous theoretical studies as well as practical applications from biology, biomedicine, and biotechnology. Advanced enzyme engineering techniques converted them into potent synthetic instruments affording a variety of valuable glycosides. SCOPE OF REVIEW This review presents the diversity of engineered enzymes active with N-acetylhexosamine carbohydrates: from popular glycoside hydrolases and glycosyltransferases to less known oxidases, epimerases, kinases, sulfotransferases, and acetylases. Though hydrolases in natura, engineered chitinases, β-N-acetylhexosaminidases, and endo-β-N-acetylglucosaminidases were successfully employed in the synthesis of defined natural and derivatized chitooligomers and in the remodeling of N-glycosylation patterns of therapeutic antibodies. The genes of various N-acetylhexosaminyltransferases were cloned into metabolically engineered microorganisms for producing human milk oligosaccharides, Lewis X structures, and human-like glycoproteins. Moreover, mutant N-acetylhexosamine-active glycosyltransferases were applied, e.g., in the construction of glycomimetics and complex glycostructures, industrial production of low-lactose milk, and metabolic labeling of glycans. In the synthesis of biotechnologically important compounds, several innovative glycoengineered systems are presented for an efficient bioproduction of GlcNAc, UDP-GlcNAc, N-acetylneuraminic acid, and of defined glycosaminoglycans. MAJOR CONCLUSIONS The above examples demonstrate that engineering of N-acetylhexosamine-active enzymes was able to solve complex issues such as synthesis of tailored human-like glycoproteins or industrial-scale production of desired oligosaccharides. Due to the specific catalytic mechanism, mutagenesis of these catalysts was often realized through rational solutions. GENERAL SIGNIFICANCE Specific N-acetylhexosamine glycosylation is crucial in biological, biomedical and biotechnological applications and a good understanding of its details opens new possibilities in this fast developing area of glycoscience.
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Affiliation(s)
- Kristýna Slámová
- Laboratory of Biotransformation, Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, CZ 14220 Prague 4, Czech Republic
| | - Pavla Bojarová
- Laboratory of Biotransformation, Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, CZ 14220 Prague 4, Czech Republic.
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93
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Structures of human O-GlcNAcase and its complexes reveal a new substrate recognition mode. Nat Struct Mol Biol 2017; 24:362-369. [PMID: 28319083 DOI: 10.1038/nsmb.3390] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 02/16/2017] [Indexed: 02/07/2023]
Abstract
Human O-GlcNAcase (hOGA) is the unique enzyme responsible for the hydrolysis of the O-linked β-N-acetyl glucosamine (O-GlcNAc) modification, an essential protein glycosylation event that modulates the function of numerous cellular proteins in response to nutrients and stress. Here we report crystal structures of a truncated hOGA, which comprises the catalytic and stalk domains, in apo form, in complex with an inhibitor, and in complex with a glycopeptide substrate. We found that hOGA forms an unusual arm-in-arm homodimer in which the catalytic domain of one monomer is covered by the stalk domain of the sister monomer to create a substrate-binding cleft. Notably, the residues on the cleft surface afford extensive interactions with the peptide substrate in a recognition mode that is distinct from that of its bacterial homologs. These structures represent the first model of eukaryotic enzymes in the glycoside hydrolase 84 (GH84) family and provide a crucial starting point for understanding the substrate specificity of hOGA, which regulates a broad range of biological and pathological processes.
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94
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Zaro BW, Batt AR, Chuh KN, Navarro MX, Pratt MR. The Small Molecule 2-Azido-2-deoxy-glucose Is a Metabolic Chemical Reporter of O-GlcNAc Modifications in Mammalian Cells, Revealing an Unexpected Promiscuity of O-GlcNAc Transferase. ACS Chem Biol 2017; 12:787-794. [PMID: 28135057 DOI: 10.1021/acschembio.6b00877] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Glycans can be directly labeled using unnatural monosaccharide analogs, termed metabolic chemical reporters (MCRs). These compounds enable the secondary visualization and identification of glycoproteins by taking advantage of bioorthogonal reactions. Most widely used MCRs have azides or alkynes at the 2-N-acetyl position but are not selective for one class of glycoprotein over others. To address this limitation, we are exploring additional MCRs that have bioorthogonal functionality at other positions. Here, we report the characterization of 2-azido-2-deoxy-glucose (2AzGlc). We find that 2AzGlc selectively labels intracellular O-GlcNAc modifications, which further supports a somewhat unexpected, structural flexibility in this pathway. In contrast to the endogenous modification N-acetyl-glucosamine (GlcNAc), we find that 2AzGlc is not dynamically removed from protein substrates and that treatment with higher concentrations of per-acetylated 2AzGlc is toxic to cells. Finally, we demonstrate that this toxicity is an inherent property of the small-molecule, as removal of the 6-acetyl-group renders the corresponding reporter nontoxic but still results in protein labeling.
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Affiliation(s)
- Balyn W. Zaro
- Department
of Chemistry and ‡Department of Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089-0744, United States
| | - Anna R. Batt
- Department
of Chemistry and ‡Department of Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089-0744, United States
| | - Kelly N. Chuh
- Department
of Chemistry and ‡Department of Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089-0744, United States
| | - Marisol X. Navarro
- Department
of Chemistry and ‡Department of Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089-0744, United States
| | - Matthew R. Pratt
- Department
of Chemistry and ‡Department of Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089-0744, United States
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95
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Abstract
O-GlcNAcylation is the modification of serine and threonine residues with β-N-acetylglucosamine (O-GlcNAc) on intracellular proteins. This dynamic modification is attached by O-GlcNAc transferase (OGT) and removed by O-GlcNAcase (OGA) and is a critical regulator of various cellular processes. Furthermore, O-GlcNAcylation is dysregulated in many diseases, such as diabetes, cancer, and Alzheimer's disease. However, the precise role of this modification and its cycling enzymes (OGT and OGA) in normal and disease states remains elusive. This is partially due to the difficulty in studying O-GlcNAcylation with traditional genetic and biochemical techniques. In this review, we will summarize recent progress in chemical approaches to overcome these obstacles. We will cover new inhibitors of OGT and OGA, advances in metabolic labeling and cellular imaging, synthetic approaches to access homogeneous O-GlcNAcylated proteins, and cross-linking methods to identify O-GlcNAc-protein interactions. We will also discuss remaining gaps in our toolbox for studying O-GlcNAcylation and questions of high interest that are yet to be answered.
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Affiliation(s)
- Matthew Worth
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53705, United States
| | - Hao Li
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin—Madison, Madison, Wisconsin 53705, United States
| | - Jiaoyang Jiang
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin—Madison, Madison, Wisconsin 53705, United States
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96
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Shen DL, Liu TW, Zandberg W, Clark T, Eskandari R, Alteen MG, Tan HY, Zhu Y, Cecioni S, Vocadlo D. Catalytic Promiscuity of O-GlcNAc Transferase Enables Unexpected Metabolic Engineering of Cytoplasmic Proteins with 2-Azido-2-deoxy-glucose. ACS Chem Biol 2017; 12:206-213. [PMID: 27935279 DOI: 10.1021/acschembio.6b00876] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
O-GlcNAc transferase (OGT) catalyzes the installation of N-acetylglucosamine (GlcNAc) O-linked to nucleocytoplasmic proteins (O-GlcNAc) within multicellular eukaryotes. OGT shows surprising tolerance for structural changes in the sugar component of its nucleotide sugar donor substrate, uridine diphosphate N-acetylglucosamine (UDP-GlcNAc). Here, we find that OGT uses UDP-glucose to install O-linked glucose (O-Glc) onto proteins only 25-fold less efficiently than O-GlcNAc. Spurred by this observation, we show that OGT transfers 2-azido-2-deoxy-d-glucose (GlcAz) in vitro from UDP-GlcAz to proteins. Further, feeding cells with per-O-acetyl GlcAz (AcGlcAz), in combination with inhibition or inducible knockout of OGT, shows OGT-dependent modification of nuclear and cytoplasmic proteins with O-GlcAz as detected using microscopy, immunoblot, and proteomics. We find that O-GlcAz is reversible within cells, and an unidentified cellular enzyme exists to cleave O-Glc that can also process O-GlcAz. We anticipate that AcGlcAz will prove to be a useful tool to study the O-GlcNAc modification. We also speculate that, given the high concentration of UDP-Glc within certain mammalian tissues, O-Glc may exist within mammals and serve as a physiologically relevant modification.
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Affiliation(s)
- David L. Shen
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Department
of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Ta-Wei Liu
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Department
of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Wesley Zandberg
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Tom Clark
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Razieh Eskandari
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Matthew G. Alteen
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Hong Yee Tan
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Yanping Zhu
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Department
of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Samy Cecioni
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - David Vocadlo
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Department
of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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97
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Balachandran N, To F, Berti PJ. Linear Free Energy Relationship Analysis of Transition State Mimicry by 3-Deoxy-d-arabino-heptulosonate-7-phosphate (DAHP) Oxime, a DAHP Synthase Inhibitor and Phosphate Mimic. Biochemistry 2017; 56:592-601. [PMID: 28045507 DOI: 10.1021/acs.biochem.6b01211] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Naresh Balachandran
- Department of Chemistry & Chemical Biology and ‡Department of Biochemistry & Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - Frederick To
- Department of Chemistry & Chemical Biology and ‡Department of Biochemistry & Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - Paul J. Berti
- Department of Chemistry & Chemical Biology and ‡Department of Biochemistry & Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
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98
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Montgomery AP, Xiao K, Wang X, Skropeta D, Yu H. Computational Glycobiology: Mechanistic Studies of Carbohydrate-Active Enzymes and Implication for Inhibitor Design. STRUCTURAL AND MECHANISTIC ENZYMOLOGY 2017; 109:25-76. [DOI: 10.1016/bs.apcsb.2017.04.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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99
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Li C, Zhu S, Tong X, Ou C, Wang LX. A facile synthesis of a complex type N-glycan thiazoline as an effective inhibitor against the antibody-deactivating endo-β-N-acetylglucosaminidases. J Carbohydr Chem 2017; 36:336-346. [PMID: 30930529 DOI: 10.1080/07328303.2017.1403616] [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: 10/18/2022]
Abstract
Endo-β-N-acetylglucosaminidases are a class of endoglycosidases that deglycosylate N-glycans from glycoproteins. We describe here a facile synthesis of a complex type N-glycan thiazoline as a new mechanism-based inhibitor for this class of enzymes. The synthesis started with the readily available sialoglycopeptide (SGP) and its conversion into the glycan thiazoline through several enzymatic and chemical reactions. The synthetic glycan thiazoline showed potent inhibitory activity against several endoglycosidases including the two antibody-deactivating enzymes, Endo-S and Endo-S2, from human pathogen Streptococcus pyogenes, which would be useful as tools for structural and functional studies of these enzymes.
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Affiliation(s)
- Chao Li
- Department of Chemistry and Biochemistry, University of Maryland, 8051 Regents Drive, College Park, Maryland 20742, USA
| | - Shilei Zhu
- Department of Chemistry and Biochemistry, University of Maryland, 8051 Regents Drive, College Park, Maryland 20742, USA
| | - Xin Tong
- Department of Chemistry and Biochemistry, University of Maryland, 8051 Regents Drive, College Park, Maryland 20742, USA
| | - Chong Ou
- Department of Chemistry and Biochemistry, University of Maryland, 8051 Regents Drive, College Park, Maryland 20742, USA
| | - Lai-Xi Wang
- Department of Chemistry and Biochemistry, University of Maryland, 8051 Regents Drive, College Park, Maryland 20742, USA
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100
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Teo CF, El-Karim EG, Wells L. Dissecting PUGNAc-mediated inhibition of the pro-survival action of insulin. Glycobiology 2016; 26:1198-1208. [PMID: 27072814 PMCID: PMC5884396 DOI: 10.1093/glycob/cww043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 04/01/2016] [Indexed: 01/02/2023] Open
Abstract
Previous studies utilizing PUGNAc, the most widely used β-N-acetylglucosaminidase (OGA) inhibitor to increase global O-N-acetylglucosamine (GlcNAc) levels, have reported a variety of effects including insulin resistance as a direct result of elevated O-GlcNAc levels. The notion of OGA inhibition causing insulin resistance was not replicated in studies in which elevated global O-GlcNAc levels were achieved using two other OGA inhibitors. Related to insulin action, work by others has suggested that O-GlcNAc elevation may inhibit the anti-apoptotic action of insulin. Thus, we examined the pro-survival action of insulin upon serum deprivation in the presence of PUGNAc as well as two selective OGA inhibitors (GlcNAcstatin-g and Thiamet-G), and a selective lysosomal hexosaminidase inhibitor (INJ2). We established that PUGNAc inhibits the pro-survival action of insulin but this effect is not recapitulated by the selective OGA inhibitors suggesting that elevation in O-GlcNAc levels alone is not responsible for PUGNAc's effect on the anti-apoptotic action of insulin. Further, we demonstrate that a selective hexosaminidase A/B (HexA/B) inhibitor does not impact insulin action suggesting that PUGNAc's effect is not due to inhibition of lysosomal hexosaminidase. Finally, we tested a combination of selective OGA and lysosomal hexosaminidase inhibitors but were not able to recapitulate the inhibition of insulin action generated by PUGNAc alone. These results strongly suggest that the defect in insulin action upon PUGNAc treatment does not derive from its inhibition of OGA or HexA/B, and that there is an unknown target of PUGNAc that is the likely culprit in inhibiting the protective effect of insulin from apoptosis.
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Affiliation(s)
- Chin Fen Teo
- Department of Biochemistry and Molecular Biology
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602-1516, USA
| | - Enas Gad El-Karim
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602-1516, USA
| | - Lance Wells
- Department of Biochemistry and Molecular Biology
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602-1516, USA
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