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Ben Ahmed A, Scache J, Mortuaire M, Lefebvre T, Vercoutter-Edouart AS. Downregulation of O-GlcNAc transferase activity impairs basal autophagy and late endosome positioning under nutrient-rich conditions in human colon cells. Biochem Biophys Res Commun 2024; 724:150198. [PMID: 38852504 DOI: 10.1016/j.bbrc.2024.150198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/23/2024] [Accepted: 05/29/2024] [Indexed: 06/11/2024]
Abstract
Autophagy is a critical catabolic pathway that enables cells to survive and adapt to stressful conditions, especially nutrient deprivation. The fusion of autophagic vacuoles with lysosomes is the final step of autophagy, which degrades the engulfed contents into metabolic precursors for re-use by the cell. O-GlcNAc transferase (OGT) plays a crucial role in regulating autophagy flux in response to nutrient stress, particularly by targeting key proteins involved in autophagosome-lysosome fusion. However, the role of OGT in basal autophagy, which occurs at a low and constitutive levels under growth conditions, remains poorly understood. Silencing or inhibition of OGT was used to compare the effect of OGT downregulation on autophagy flux in the non-cancerous CCD841CoN and cancerous HCT116 human colon cell lines under nutrient-rich conditions. We provide evidence that the reduction of OGT activity impairs the maturation of autophagosomes, thereby blocking the completion of basal autophagy in both cell lines. Additionally, OGT inhibition results in the accumulation of lysosomes and enlarged late endosomes in the perinuclear region, as demonstrated by confocal imaging. This is associated with a defect in the localization of the small GTPase Rab7 to these organelles. The regulation of transport and fusion events between the endosomal and lysosomal compartments is crucial for maintaining the autophagic flux. These findings suggest an interplay between OGT and the homeostasis of the endolysosomal network in human cells.
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Affiliation(s)
- Awatef Ben Ahmed
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Jodie Scache
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Marlène Mortuaire
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Tony Lefebvre
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
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2
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Li S, Ren W, Zheng J, Li S, Zhi K, Gao L. Role of O-linked N-acetylglucosamine protein modification in oxidative stress-induced autophagy: a novel target for bone remodeling. Cell Commun Signal 2024; 22:358. [PMID: 38987770 PMCID: PMC11238385 DOI: 10.1186/s12964-024-01734-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Accepted: 07/04/2024] [Indexed: 07/12/2024] Open
Abstract
O-linked N-acetylglucosamine protein modification (O-GlcNAcylation) is a dynamic post-translational modification (PTM) involving the covalent binding of serine and/or threonine residues, which regulates bone cell homeostasis. Reactive oxygen species (ROS) are increased due to oxidative stress in various pathological contexts related to bone remodeling, such as osteoporosis, arthritis, and bone fracture. Autophagy serves as a scavenger for ROS within bone marrow-derived mesenchymal stem cells, osteoclasts, and osteoblasts. However, oxidative stress-induced autophagy is affected by the metabolic status, leading to unfavorable clinical outcomes. O-GlcNAcylation can regulate the autophagy process both directly and indirectly through oxidative stress-related signaling pathways, ultimately improving bone remodeling. The present interventions for the bone remodeling process often focus on promoting osteogenesis or inhibiting osteoclast absorption, ignoring the effect of PTM on the overall process of bone remodeling. This review explores how O-GlcNAcylation synergizes with autophagy to exert multiple regulatory effects on bone remodeling under oxidative stress stimulation, indicating the application of O-GlcNAcylation as a new molecular target in the field of bone remodeling.
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Affiliation(s)
- Shengqian Li
- Department of Oral and Maxillofacial Reconstruction, the Affiliated Hospital of Qingdao University, Qingdao, 266555, China
- School of Stomatology, Qingdao University, Qingdao, 266003, China
| | - Wenhao Ren
- Department of Oral and Maxillofacial Reconstruction, the Affiliated Hospital of Qingdao University, Qingdao, 266555, China
- School of Stomatology, Qingdao University, Qingdao, 266003, China
- Department of Oral and Maxillofacial Surgery, the Affiliated Hospital of Qingdao University, Qingdao, 266555, China
| | - Jingjing Zheng
- Department of Endodontics, the Affiliated Hospital of Qingdao University, Qingdao, 266003, China
| | - Shaoming Li
- Department of Oral and Maxillofacial Reconstruction, the Affiliated Hospital of Qingdao University, Qingdao, 266555, China
| | - Keqian Zhi
- Department of Oral and Maxillofacial Reconstruction, the Affiliated Hospital of Qingdao University, Qingdao, 266555, China.
- School of Stomatology, Qingdao University, Qingdao, 266003, China.
- Key Laboratory of Oral Clinical Medicine, the Affiliated Hospital of Qingdao University, Qingdao, 266003, China.
- Department of Oral and Maxillofacial Surgery, the Affiliated Hospital of Qingdao University, Qingdao, 266555, China.
| | - Ling Gao
- Department of Oral and Maxillofacial Reconstruction, the Affiliated Hospital of Qingdao University, Qingdao, 266555, China.
- Key Laboratory of Oral Clinical Medicine, the Affiliated Hospital of Qingdao University, Qingdao, 266003, China.
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Sun C, Chen Y, Gu Q, Fu Y, Wang Y, Liu C, Xie H, Liao Y, Zheng Z, Liu P, Li M. UBE3C tunes autophagy via ATG4B ubiquitination. Autophagy 2024; 20:645-658. [PMID: 38146933 PMCID: PMC10936621 DOI: 10.1080/15548627.2023.2299514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/20/2023] [Indexed: 12/27/2023] Open
Abstract
ATG4B is a core protein and essential for cleaving precursor MAP1LC3/LC3 or deconjugating lipidated LC3-II to drive the formation of autophagosomes. The protein stability and activity of ATG4B regulated by post-translational modification (ubiquitination) will directly affect macroautophagy/autophagy. However, the mechanism involved in ATG4B ubiquitination is largely unclear. In this study, a new E3 ligase of ATG4B, UBE3C, was identified by mass spectra. UBE3C mainly assembles K33-branched ubiquitin chains on ATG4B at Lys119 without causing ATG4B degradation. In addition, the increased ubiquitination of ATG4B caused by UBE3C overexpression inhibits autophagy flux in both normal and starvation conditions, which might be due to the reduced activity of ATG4B and ATG4B-LC3 interaction. This reduction could be reversed once the lysine 119 of ATG4B was mutated to arginine. More important, under starvation conditions the interaction between ATG4B and UBE3C apparently decreased followed by the removal of the K33-branched ubiquitin chain of ATG4B. Thus, starvation-induced autophagy could be partially suppressed by an increased ubiquitination level of ATG4B. In conclusion, our research reveals a novel modification mode of ATG4B in which UBE3C can fine tune ATG4B activity by specific ubiquitination regulating autophagy without causing ATG4B degradation.Abbreviation: ATG: autophagy-related; Baf: bafilomycin A1; CBB: Coomassie Brilliant Blue; CM: complete medium; CQ: chloroquine; GFP: green fluorescent protein; HA-Ub: HA-tagged ubiquitin; IF: immunofluorescence; IP: immunoprecipitation; K: lysine; KO: knockout; K0: all K-to-R mutant; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MS: mass spectrometry; NC: negative control; R: arginine; WCL: whole cell lysate; WT: wild-type.
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Affiliation(s)
- Chaonan Sun
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Yuxin Chen
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Qianqian Gu
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Yuanyuan Fu
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Yao Wang
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Cui Liu
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Huazhong Xie
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Yong Liao
- Chongqing Medical and Pharmaceutical College, Chongqing, China
| | - Zhihua Zheng
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Peiqing Liu
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Min Li
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, Guangdong, China
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4
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Pratt MR, Vocadlo DJ. Understanding and exploiting the roles of O-GlcNAc in neurodegenerative diseases. J Biol Chem 2023; 299:105411. [PMID: 37918804 PMCID: PMC10687168 DOI: 10.1016/j.jbc.2023.105411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/18/2023] [Accepted: 10/23/2023] [Indexed: 11/04/2023] Open
Abstract
O-GlcNAc is a common modification found on nuclear and cytoplasmic proteins. Determining the catalytic mechanism of the enzyme O-GlcNAcase (OGA), which removes O-GlcNAc from proteins, enabled the creation of potent and selective inhibitors of this regulatory enzyme. Such inhibitors have served as important tools in helping to uncover the cellular and organismal physiological roles of this modification. In addition, OGA inhibitors have been important for defining the augmentation of O-GlcNAc as a promising disease-modifying approach to combat several neurodegenerative diseases including both Alzheimer's disease and Parkinson's disease. These studies have led to development and optimization of OGA inhibitors for clinical application. These compounds have been shown to be well tolerated in early clinical studies and are steadily advancing into the clinic. Despite these advances, the mechanisms by which O-GlcNAc protects against these various types of neurodegeneration are a topic of continuing interest since improved insight may enable the creation of more targeted strategies to modulate O-GlcNAc for therapeutic benefit. Relevant pathways on which O-GlcNAc has been found to exert beneficial effects include autophagy, necroptosis, and processing of the amyloid precursor protein. More recently, the development and application of chemical methods enabling the synthesis of homogenous proteins have clarified the biochemical effects of O-GlcNAc on protein aggregation and uncovered new roles for O-GlcNAc in heat shock response. Here, we discuss the features of O-GlcNAc in neurodegenerative diseases, the application of inhibitors to identify the roles of this modification, and the biochemical effects of O-GlcNAc on proteins and pathways associated with neurodegeneration.
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Affiliation(s)
- Matthew R Pratt
- Department of Chemistry and Department of Biological Sciences, University of Southern California, Los Angeles, California, USA.
| | - David J Vocadlo
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada; Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.
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5
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Abstract
O-linked β-N-acetylglucosamine (O-GlcNAc) is a ubiquitous post-translational modification in mammals, decorating thousands of intracellular proteins. O-GlcNAc cycling is an essential regulator of myriad aspects of cell physiology and is dysregulated in numerous human diseases. Notably, O-GlcNAcylation is abundant in the brain and numerous studies have linked aberrant O-GlcNAc signaling to various neurological conditions. However, the complexity of the nervous system and the dynamic nature of protein O-GlcNAcylation have presented challenges for studying of neuronal O-GlcNAcylation. In this context, chemical approaches have been a particularly valuable complement to conventional cellular, biochemical, and genetic methods to understand O-GlcNAc signaling and to develop future therapeutics. Here we review selected recent examples of how chemical tools have empowered efforts to understand and rationally manipulate O-GlcNAcylation in mammalian neurobiology.
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Affiliation(s)
- Duc Tan Huynh
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Michael Boyce
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
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6
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Pan Z, Zheng J, Zhang J, Lin J, Lai J, Lyu Z, Feng H, Wang J, Wu D, Li Y. A Novel Protein Encoded by Exosomal CircATG4B Induces Oxaliplatin Resistance in Colorectal Cancer by Promoting Autophagy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2204513. [PMID: 36285810 PMCID: PMC9762280 DOI: 10.1002/advs.202204513] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/12/2022] [Indexed: 05/23/2023]
Abstract
Oxaliplatin is commonly used in chemotherapeutic regimens for colorectal cancer (CRC) after surgical resection. However, acquired chemoresistance seriously affects the curative effect in CRC patients, and the mechanism is still unclear. Here, a circular RNA, circATG4B is identified, which plays an important role in oxaliplatin resistance in CRC. circATG4B expression is found to be increased in exosomes secreted by oxaliplatin-resistant CRC cells. In addition, the results suggest that circATG4B induces oxaliplatin resistance by promoting autophagy. Further in vivo and in vitro studies indicate that the effect of circATG4B is attributed to its potential to encode a novel protein, circATG4B-222aa. Next, circATG4B-222aa is found to function as a decoy to competitively interact with TMED10 and prevent TMED10 from binding to ATG4B, which leads to increased autophagy followed by induction of chemoresistance. Therefore, this study reveals that exosomal circATG4B participates in the decreased chemosensitivity of CRC cells, providing a new rationale for a potential therapeutic target for oxaliplatin resistance in CRC.
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Affiliation(s)
- Zihao Pan
- Department of Gastrointestinal SurgeryDepartment of General SurgeryGuangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou510080China
- The Second School of Clinical MedicineSouthern Medical UniversityGuangzhou510080China
| | - Jun Zheng
- Department of Hepatic Surgery and Liver Transplantation Center of the Third Affiliated Hospital of Sun Yat‐sen UniversityOrgan Transplantation Research Center of Guangdong ProvinceGuangdong Province Engineering Laboratory for Transplantation MedicineGuangzhou510630China
| | - Jiebin Zhang
- Department of Hepatic Surgery and Liver Transplantation Center of the Third Affiliated Hospital of Sun Yat‐sen UniversityOrgan Transplantation Research Center of Guangdong ProvinceGuangdong Province Engineering Laboratory for Transplantation MedicineGuangzhou510630China
| | - Jiatong Lin
- Department of Gastrointestinal SurgeryDepartment of General SurgeryGuangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou510080China
- School of medicineSouth China University of TechnologyGuangzhouGuangdong Province510006China
| | - Jianguo Lai
- Department of Breast CancerCancer CenterGuangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou510080China
| | - Zejian Lyu
- Department of Gastrointestinal SurgeryDepartment of General SurgeryGuangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou510080China
- The Second School of Clinical MedicineSouthern Medical UniversityGuangzhou510080China
| | - Huolun Feng
- Department of Gastrointestinal SurgeryDepartment of General SurgeryGuangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou510080China
- School of medicineSouth China University of TechnologyGuangzhouGuangdong Province510006China
| | - Junjiang Wang
- Department of Gastrointestinal SurgeryDepartment of General SurgeryGuangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou510080China
- The Second School of Clinical MedicineSouthern Medical UniversityGuangzhou510080China
| | - Deqing Wu
- Department of Gastrointestinal SurgeryDepartment of General SurgeryGuangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou510080China
- The Second School of Clinical MedicineSouthern Medical UniversityGuangzhou510080China
| | - Yong Li
- Department of Gastrointestinal SurgeryDepartment of General SurgeryGuangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou510080China
- The Second School of Clinical MedicineSouthern Medical UniversityGuangzhou510080China
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7
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Fahie KMM, Papanicolaou KN, Zachara NE. Integration of O-GlcNAc into Stress Response Pathways. Cells 2022; 11:3509. [PMID: 36359905 PMCID: PMC9654274 DOI: 10.3390/cells11213509] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
The modification of nuclear, mitochondrial, and cytosolic proteins by O-linked βN-acetylglucosamine (O-GlcNAc) has emerged as a dynamic and essential post-translational modification of mammalian proteins. O-GlcNAc is cycled on and off over 5000 proteins in response to diverse stimuli impacting protein function and, in turn, epigenetics and transcription, translation and proteostasis, metabolism, cell structure, and signal transduction. Environmental and physiological injury lead to complex changes in O-GlcNAcylation that impact cell and tissue survival in models of heat shock, osmotic stress, oxidative stress, and hypoxia/reoxygenation injury, as well as ischemic reperfusion injury. Numerous mechanisms that appear to underpin O-GlcNAc-mediated survival include changes in chaperone levels, impacts on the unfolded protein response and integrated stress response, improvements in mitochondrial function, and reduced protein aggregation. Here, we discuss the points at which O-GlcNAc is integrated into the cellular stress response, focusing on the roles it plays in the cardiovascular system and in neurodegeneration.
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Affiliation(s)
- Kamau M. M. Fahie
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kyriakos N. Papanicolaou
- Department of Medicine, Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Natasha E. Zachara
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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O-GlcNAc modification of leucyl-tRNA synthetase 1 integrates leucine and glucose availability to regulate mTORC1 and the metabolic fate of leucine. Nat Commun 2022; 13:2904. [PMID: 35614056 PMCID: PMC9133088 DOI: 10.1038/s41467-022-30696-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 05/12/2022] [Indexed: 12/11/2022] Open
Abstract
All living organisms have the ability to sense nutrient levels to coordinate cellular metabolism. Despite the importance of nutrient-sensing pathways that detect the levels of amino acids and glucose, how the availability of these two types of nutrients is integrated is unclear. Here, we show that glucose availability regulates the central nutrient effector mTORC1 through intracellular leucine sensor leucyl-tRNA synthetase 1 (LARS1). Glucose starvation results in O-GlcNAcylation of LARS1 on residue S1042. This modification inhibits the interaction of LARS1 with RagD GTPase and reduces the affinity of LARS1 for leucine by promoting phosphorylation of its leucine-binding site by the autophagy-activating kinase ULK1, decreasing mTORC1 activity. The lack of LARS1 O-GlcNAcylation constitutively activates mTORC1, supporting its ability to sense leucine, and deregulates protein synthesis and leucine catabolism under glucose starvation. This work demonstrates that LARS1 integrates leucine and glucose availability to regulate mTORC1 and the metabolic fate of leucine. Leucyl-tRNA synthetase 1 (LARS1) is a leucine sensor for mTORC1 signaling and regulates leucine utilization depending on glucose availability. Here, the author show that O-GlcNAcylation of LARS1 is crucial for its ability to regulate mTORC1 activity and leucine metabolism upon glucose starvation.
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9
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Post-Translational Modifications of ATG4B in the Regulation of Autophagy. Cells 2022; 11:cells11081330. [PMID: 35456009 PMCID: PMC9025542 DOI: 10.3390/cells11081330] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 11/16/2022] Open
Abstract
Autophagy plays a key role in eliminating and recycling cellular components in response to stress, including starvation. Dysregulation of autophagy is observed in various diseases, including neurodegenerative diseases, cancer, and diabetes. Autophagy is tightly regulated by autophagy-related (ATG) proteins. Autophagy-related 4 (ATG4) is the sole cysteine protease, and four homologs (ATG4A–D) have been identified in mammals. These proteins have two domains: catalytic and short fingers. ATG4 facilitates autophagy by promoting autophagosome maturation through reversible lipidation and delipidation of seven autophagy-related 8 (ATG8) homologs, including microtubule-associated protein 1-light chain 3 (LC3) and GABA type A receptor-associated protein (GABARAP). Each ATG4 homolog shows a preference for a specific ATG8 homolog. Post-translational modifications of ATG4, including phosphorylation/dephosphorylation, O-GlcNAcylation, oxidation, S-nitrosylation, ubiquitination, and proteolytic cleavage, regulate its activity and ATG8 processing, thus modulating its autophagic activity. We reviewed recent advances in our understanding of the effect of post-translational modification on the regulation, activity, and function of ATG4, the main protease that controls autophagy.
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10
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Xia F, Fu Y, Xie H, Chen Y, Fang D, Zhang W, Liu P, Li M. Suppression of ATG4B by copper inhibits autophagy and involves in Mallory body formation. Redox Biol 2022; 52:102284. [PMID: 35349929 PMCID: PMC8965161 DOI: 10.1016/j.redox.2022.102284] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/01/2022] [Accepted: 03/10/2022] [Indexed: 12/19/2022] Open
Abstract
Autophagy is an evolutionarily conserved self-protecting mechanism implicated in cellular homeostasis. ATG4B plays a vital role in autophagy process via undertaking priming and delipidation of LC3. Chemical inhibitors and regulative modifications such as oxidation of ATG4B have been demonstrated to modulate autophagy function. Whether and how ATG4B could be regulated by metal ions is largely unknown. Copper is an essential trace metal served as static co-factors in redox reactions in physiology process. Excessive accumulation of copper in ATP7B mutant cells leads to pathology progression such as insoluble Mallory body (MB) in Wilson disease (WD). The clearance of MB via autophagy pathway was thought as a promising strategy for WD. Here, we discovered that copper ion instead of other ions could inhibit the activity of ATG4B followed by autophagy suppression. In addition, copper could induce ATG4B oligomers depending on cysteine oxidation which could be abolished in reduced condition. Copper also promotes the formation of insoluble ATG4B aggregates, as well as p62-and ubiquitin-positive aggregates, which is consistent with the components of MB caused by copper overload in WD cell model. Importantly, overexpression of ATG4B could partially reduce the formation of MB and rescue impaired autophagy. Taken together, our results uncovered for the first time a new damage mechanism mediated by copper and implied new insights of the crosstalk between the toxicity of copper and autophagy in the pathogenesis of WD.
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Affiliation(s)
- Fan Xia
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Yuanyuan Fu
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Huazhong Xie
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Yuxin Chen
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Dongmei Fang
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Wei Zhang
- Laboratory Animal Center, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Peiqing Liu
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Min Li
- School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local Joint Engineering Laboratory of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drugs Evaluation, Sun Yat-Sen University, Guangzhou, 510006, China.
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11
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Abstract
Detection of protein O-GlcNAcylation could be challenging. By using the host-cell factor 1 (HCF-1), a known O-GlcNAcylated protein, we immunoprecipitated HCF-1 from transfected HEK293T cells or endogenous HCF-1 from HeLa cells to detect its O-GlcNAc levels by Western blotting. We also take advantage of RNAi or chemical inhibitors to modulate OGT and OGA activities before HCF-1 immunoprecipitation. For complete details on the use and execution of this protocol, please refer to Daou et al. (2011).
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12
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Mechanistic roles for altered O-GlcNAcylation in neurodegenerative disorders. Biochem J 2021; 478:2733-2758. [PMID: 34297044 DOI: 10.1042/bcj20200609] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 01/02/2023]
Abstract
Neurodegenerative diseases such as Alzheimer's and Parkinson's remain highly prevalent and incurable disorders. A major challenge in fully understanding and combating the progression of these diseases is the complexity of the network of processes that lead to progressive neuronal dysfunction and death. An ideal therapeutic avenue is conceivably one that could address many if not all of these multiple misregulated mechanisms. Over the years, chemical intervention for the up-regulation of the endogenous posttranslational modification (PTM) O-GlcNAc has been proposed as a potential strategy to slow down the progression of neurodegeneration. Through the development and application of tools that allow dissection of the mechanistic roles of this PTM, there is now a growing body of evidence that O-GlcNAc influences a variety of important neurodegeneration-pertinent mechanisms, with an overall protective effect. As a PTM that is appended onto numerous proteins that participate in protein quality control and homeostasis, metabolism, bioenergetics, neuronal communication, inflammation, and programmed death, O-GlcNAc has demonstrated beneficence in animal models of neurodegenerative diseases, and its up-regulation is now being pursued in multiple clinical studies.
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Melia TJ, Lystad AH, Simonsen A. Autophagosome biogenesis: From membrane growth to closure. J Cell Biol 2021; 219:151729. [PMID: 32357219 PMCID: PMC7265318 DOI: 10.1083/jcb.202002085] [Citation(s) in RCA: 158] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/04/2020] [Accepted: 04/06/2020] [Indexed: 12/14/2022] Open
Abstract
Autophagosome biogenesis involves de novo formation of a membrane that elongates to sequester cytoplasmic cargo and closes to form a double-membrane vesicle (an autophagosome). This process has remained enigmatic since its initial discovery >50 yr ago, but our understanding of the mechanisms involved in autophagosome biogenesis has increased substantially during the last 20 yr. Several key questions do remain open, however, including, What determines the site of autophagosome nucleation? What is the origin and lipid composition of the autophagosome membrane? How is cargo sequestration regulated under nonselective and selective types of autophagy? This review provides key insight into the core molecular mechanisms underlying autophagosome biogenesis, with a specific emphasis on membrane modeling events, and highlights recent conceptual advances in the field.
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Affiliation(s)
- Thomas J Melia
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT
| | - Alf H Lystad
- Department of Molecular Medicine, Institute of Basic Medical Sciences and Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Anne Simonsen
- Department of Molecular Medicine, Institute of Basic Medical Sciences and Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
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14
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Li X, Sun L, Yan G, Yan X. PFKP facilitates ATG4B phosphorylation during amino acid deprivation-induced autophagy. Cell Signal 2021; 82:109956. [PMID: 33607258 DOI: 10.1016/j.cellsig.2021.109956] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 01/29/2021] [Accepted: 02/13/2021] [Indexed: 12/09/2022]
Abstract
ATG4B facilitates autophagy by promoting autophagosome maturation through the reversible lipidation and delipidation of LC3. Recent reports have shown that phosphorylation of ATG4B regulates its activity and LC3 processing, leading to modulate autophagy activity. However, the mechanism about how ATG4B phosphorylation is involved in amino acid deprivation-induced autophagy is unclear. Here, we combined the tandem affinity purification with mass spectrometry (MS) and identified the ATG4B-interacting proteins including its well-known partner gamma-aminobutyric acid receptor-associated protein (GABARAP, a homolog of LC3) and phosphofructokinase 1 platelet isoform (PFKP). Further immunoprecipitation assays showed that amino acid deprivation strengthened the interaction between ATG4B and PFKP. By genetic depletion of PFKP using CRISPR/Cas9, we uncovered that PFKP loss reduced the degradation of LC3-II and p62 due to a partial block in autophagic flux. Furthermore, MS analysis of Flag-tagged ATG4B immunoprecipitates identified phosphorylation of ATG4B serine 34 residue (S34) and PFKP serine 386 residue (S386) under amino acid deprivation condition. In vitro kinase assay validated that PFKP functioning as a protein kinase phosphorylated ATG4B at S34. This phosphorylation could enhance ATG4B activity and p62 degradation. In addition, PFKP S386 phosphorylation was important to ATG4B S34 phosphorylation and autophagy in HEK293T cells. In brief, our findings describe that PFKP, a rate-limiting enzyme in the glycolytic pathway, functions as a protein kinase for ATG4B to regulate ATG4B activity and autophagy under amino acid deprivation condition.
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Affiliation(s)
- Xiuzhi Li
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China; Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei 430070, China
| | - Lingling Sun
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China; Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei 430070, China
| | - Guokai Yan
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China; Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei 430070, China
| | - Xianghua Yan
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China; Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei 430070, China.
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Park SJ, Bae JE, Jo DS, Kim JB, Park NY, Fang J, Jung YK, Jo DG, Cho DH. Increased O-GlcNAcylation of Drp1 by amyloid-beta promotes mitochondrial fission and dysfunction in neuronal cells. Mol Brain 2021; 14:6. [PMID: 33422108 PMCID: PMC7797154 DOI: 10.1186/s13041-020-00727-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 12/29/2020] [Indexed: 11/15/2022] Open
Abstract
As a dynamic organelle, mitochondria continuously fuse and divide with adjacent mitochondria. Imbalance in mitochondria dynamics leads to their dysfunction, which implicated in neurodegenerative diseases. However, how mitochondria alteration and glucose defect contribute to pathogenesis of Alzheimer’s disease (AD) is still largely unknown. Dynamin‐related protein 1 (Drp1) is an essential regulator for mitochondria fission. Among various posttranslational modifications, O-GlcNAcylation plays a role as a sensor for nutrient and oxidative stress. In this study, we identified that Drp1 is regulated by O-GlcNAcylation in AD models. Treatment of Aβ as well as PugNAc resulted in mitochondrial fragmentation in neuronal cells. Moreover, we found that AD mice brain exhibits an upregulated Drp1 O-GlcNAcylation. However, depletion of OGT inhibited Drp1 O-GlcNAcylation in Aβ-treated cells. In addition, overexpression of O-GlcNAc defective Drp1 mutant (T585A and T586A) decreased Drp1 O-GlcNAcylation and Aβ-induced mitochondria fragmentation. Taken together, these finding suggest that Aβ regulates mitochondrial fission by increasing O-GlcNAcylation of Drp1.
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Affiliation(s)
- So Jung Park
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Ji-Eun Bae
- Brain Science and Engineering Institute, Graduate School of Life Science, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Doo Sin Jo
- Graduate School of Life Science, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, 80 Daehakro Bukgu, Daegu, 41566, Republic of Korea
| | - Joon Bum Kim
- Graduate School of Life Science, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, 80 Daehakro Bukgu, Daegu, 41566, Republic of Korea
| | - Na Yeon Park
- Graduate School of Life Science, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, 80 Daehakro Bukgu, Daegu, 41566, Republic of Korea
| | - Jianguo Fang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Yong-Keun Jung
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dong Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Dong-Hyung Cho
- Brain Science and Engineering Institute, Graduate School of Life Science, Kyungpook National University, Daegu, 41566, Republic of Korea. .,Graduate School of Life Science, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, 80 Daehakro Bukgu, Daegu, 41566, Republic of Korea.
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16
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Zuliani I, Lanzillotta C, Tramutola A, Francioso A, Pagnotta S, Barone E, Perluigi M, Di Domenico F. The Dysregulation of OGT/OGA Cycle Mediates Tau and APP Neuropathology in Down Syndrome. Neurotherapeutics 2021; 18:340-363. [PMID: 33258073 PMCID: PMC8116370 DOI: 10.1007/s13311-020-00978-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2020] [Indexed: 12/12/2022] Open
Abstract
Protein O-GlcNAcylation is a nutrient-related post-translational modification that, since its discovery some 30 years ago, has been associated with the development of neurodegenerative diseases. As reported in Alzheimer's disease (AD), flaws in the cerebral glucose uptake translate into reduced hexosamine biosynthetic pathway flux and subsequently lead to aberrant protein O-GlcNAcylation. Notably, the reduction of O-GlcNAcylated proteins involves also tau and APP, thus promoting their aberrant phosphorylation in AD brain and the onset of AD pathological markers. Down syndrome (DS) individuals are characterized by the early development of AD by the age of 60 and, although the two conditions present the same pathological hallmarks and share the alteration of many molecular mechanisms driving brain degeneration, no evidence has been sought on the implication of O-GlcNAcylation in DS pathology. Our study aimed to unravel for the first time the role of protein O-GlcNacylation in DS brain alterations positing the attention of potential trisomy-related mechanisms triggering the aberrant regulation of OGT/OGA cycle. We demonstrate the disruption of O-GlcNAcylation homeostasis, as an effect of altered OGT and OGA regulatory mechanism, and confirm the relevance of O-GlcNAcylation in the appearance of AD hallmarks in the brain of a murine model of DS. Furthermore, we provide evidence for the neuroprotective effects of brain-targeted OGA inhibition. Indeed, the rescue of OGA activity was able to restore protein O-GlcNAcylation, and reduce AD-related hallmarks and decreased protein nitration, possibly as effect of induced autophagy.
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Affiliation(s)
- Ilaria Zuliani
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - Chiara Lanzillotta
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - Antonella Tramutola
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - Antonio Francioso
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - Sara Pagnotta
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - Eugenio Barone
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - Marzia Perluigi
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - Fabio Di Domenico
- Department of Biochemical Sciences "A. Rossi Fanelli", Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy.
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17
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Xia F, Liu P, Li M. The regulatory factors and pathological roles of autophagy-related protein 4 in diverse diseases: Recent research advances. Med Res Rev 2020; 41:1644-1675. [PMID: 33314291 DOI: 10.1002/med.21772] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 12/12/2022]
Abstract
Macroautophagy (autophagy) is an evolutionarily conserved and dynamic degradation/recycling pathway in which portions of the cytoplasm, such as dysfunctional proteins and surplus organelles, are engulfed by double-membrane bound vesicles through a lysosome-dependent process. As the only proteolytic enzyme of the core mammalian autophagy proteins, autophagy-related protein 4 (ATG4) primes newly synthesized pro-light chain 3 (LC3) to form LC3-I that attaches to phosphatidylethanolamine and delipidates LC3-PE to LC3-I for recycling. Besides autophagy, ATG4 has been shown to be involved in regulating various biological and pathological processes. The roles of ATG4 in cancer therapy, a methodology for ATG4 activity detection, and the discovery of chemical modulators have been well-reviewed. However, a comprehensive summary on how ATG4 is regulated by multiple factors and, thereby, how ATG4 influences autophagy or other pathways remains lacking. In this paper, we summarize multiple processes and molecules that regulate the activity of ATG4, such as micro-RNAs, posttranslational modifications, and small molecules. Additionally, we focus on the relationship between ATG4 and diverse diseases, including cancer, neurodegeneration, microbial infection, and other diseases. It provides insight regarding potential ATG4-targeted therapeutic opportunities, which could be beneficial for future studies and human health.
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Affiliation(s)
- Fan Xia
- Department of Pharmacology and Toxicology, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Peiqing Liu
- Department of Pharmacology and Toxicology, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Min Li
- Department of Pharmacology and Toxicology, Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
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18
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Chatham JC, Zhang J, Wende AR. Role of O-Linked N-Acetylglucosamine Protein Modification in Cellular (Patho)Physiology. Physiol Rev 2020; 101:427-493. [PMID: 32730113 DOI: 10.1152/physrev.00043.2019] [Citation(s) in RCA: 148] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In the mid-1980s, the identification of serine and threonine residues on nuclear and cytoplasmic proteins modified by a N-acetylglucosamine moiety (O-GlcNAc) via an O-linkage overturned the widely held assumption that glycosylation only occurred in the endoplasmic reticulum, Golgi apparatus, and secretory pathways. In contrast to traditional glycosylation, the O-GlcNAc modification does not lead to complex, branched glycan structures and is rapidly cycled on and off proteins by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. Since its discovery, O-GlcNAcylation has been shown to contribute to numerous cellular functions, including signaling, protein localization and stability, transcription, chromatin remodeling, mitochondrial function, and cell survival. Dysregulation in O-GlcNAc cycling has been implicated in the progression of a wide range of diseases, such as diabetes, diabetic complications, cancer, cardiovascular, and neurodegenerative diseases. This review will outline our current understanding of the processes involved in regulating O-GlcNAc turnover, the role of O-GlcNAcylation in regulating cellular physiology, and how dysregulation in O-GlcNAc cycling contributes to pathophysiological processes.
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Affiliation(s)
- John C Chatham
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama; and Birmingham Veterans Affairs Medical Center, Birmingham, Alabama
| | - Jianhua Zhang
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama; and Birmingham Veterans Affairs Medical Center, Birmingham, Alabama
| | - Adam R Wende
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama; and Birmingham Veterans Affairs Medical Center, Birmingham, Alabama
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19
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Zheng X, Yang Z, Gu Q, Xia F, Fu Y, Liu P, Yin XM, Li M. The protease activity of human ATG4B is regulated by reversible oxidative modification. Autophagy 2020; 16:1838-1850. [PMID: 31880198 DOI: 10.1080/15548627.2019.1709763] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Macroautophagy/autophagy plays a pivotal role in cytoplasmic material recycling and metabolic turnover, in which ATG4B functions as a "scissor" for processing pro-LC3 and lipidated LC3 to drive the autophagy progress. Mounting evidence has demonstrated the tight connection between ROS and autophagy during various pathological situations. Coincidentally, several studies have shown that ATG4B is potentially regulated by redox modification, but the underlying molecular mechanism and its relationship with autophagy is ambiguous. In this study, we verified that ATG4B activity was definitely regulated in a reversible redox manner. We also determined that Cys292 and Cys361 are essential sites of ATG4B to form reversible intramolecular disulfide bonds that respond to oxidative stress. Interestingly, we unraveled a new phenomenon that ATG4B concurrently formed disulfide-linked oligomers at Cys292 and Cys361, and that both sites underwent redox modifications thereby modulating ATG4B activity. Finally, increased autophagic flux and decreased oxidation sensitivity were observed in Cys292 and Cys361 double site-mutated cells under normal growth conditions. In conclusion, our research reveals a novel molecular mechanism that oxidative modification at Cys292 and Cys361 sites regulates ATG4B function, which modulates autophagy.Abbreviations: Air-ox: air-oxidation; ATG4B: autophagy related 4B cysteine peptidase; BCNU: 1,3-bis(2-chloroethyl)-1-nitrosourea; CBB: Coomassie Brilliant Blue; CM: complete medium; CQ: chloroquine; DTT: dithiothreitol; GSH: reduced glutathione; GSNO: S-nitrosoglutathione; GSSG: oxidized glutathione; HMW: high molecular weight; H2O2: hydrogen peroxide; NAC: N-acetyl-L-cysteine; NEM: N-ethylmaleimide; PE: phosphatidylethanolamine; PTM: post-translational modification; ROS, reactive oxygen species; WT: wild type.
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Affiliation(s)
- Xueping Zheng
- School of Pharmaceutical Sciences, Sun Yat-Sen University, National-Local Joint Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drug Evaluation, Provincial Key Laboratory of New Drug Design and Evaluation , Guangzhou, Guangdong, China
| | - Zuolong Yang
- School of Pharmaceutical Sciences, Sun Yat-Sen University, National-Local Joint Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drug Evaluation, Provincial Key Laboratory of New Drug Design and Evaluation , Guangzhou, Guangdong, China
| | - Qianqian Gu
- School of Pharmaceutical Sciences, Sun Yat-Sen University, National-Local Joint Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drug Evaluation, Provincial Key Laboratory of New Drug Design and Evaluation , Guangzhou, Guangdong, China
| | - Fan Xia
- School of Pharmaceutical Sciences, Sun Yat-Sen University, National-Local Joint Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drug Evaluation, Provincial Key Laboratory of New Drug Design and Evaluation , Guangzhou, Guangdong, China
| | - Yuanyuan Fu
- School of Pharmaceutical Sciences, Sun Yat-Sen University, National-Local Joint Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drug Evaluation, Provincial Key Laboratory of New Drug Design and Evaluation , Guangzhou, Guangdong, China
| | - Peiqing Liu
- School of Pharmaceutical Sciences, Sun Yat-Sen University, National-Local Joint Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drug Evaluation, Provincial Key Laboratory of New Drug Design and Evaluation , Guangzhou, Guangdong, China
| | - Xiao-Ming Yin
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine , Indianapolis, IN, USA
| | - Min Li
- School of Pharmaceutical Sciences, Sun Yat-Sen University, National-Local Joint Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Engineering Laboratory of Druggability and New Drug Evaluation, Provincial Key Laboratory of New Drug Design and Evaluation , Guangzhou, Guangdong, China
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20
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Agrotis A, Ketteler R. On ATG4B as Drug Target for Treatment of Solid Tumours-The Knowns and the Unknowns. Cells 2019; 9:cells9010053. [PMID: 31878323 PMCID: PMC7016753 DOI: 10.3390/cells9010053] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 12/17/2019] [Accepted: 12/19/2019] [Indexed: 12/13/2022] Open
Abstract
Autophagy is an evolutionary conserved stress survival pathway that has been shown to play an important role in the initiation, progression, and metastasis of multiple cancers; however, little progress has been made to date in translation of basic research to clinical application. This is partially due to an incomplete understanding of the role of autophagy in the different stages of cancer, and also to an incomplete assessment of potential drug targets in the autophagy pathway. While drug discovery efforts are on-going to target enzymes involved in the initiation phase of the autophagosome, e.g., unc51-like autophagy activating kinase (ULK)1/2, vacuolar protein sorting 34 (Vps34), and autophagy-related (ATG)7, we propose that the cysteine protease ATG4B is a bona fide drug target for the development of anti-cancer treatments. In this review, we highlight some of the recent advances in our understanding of the role of ATG4B in autophagy and its relevance to cancer, and perform a critical evaluation of ATG4B as a druggable cancer target.
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Targeting ATG4 in Cancer Therapy. Cancers (Basel) 2019; 11:cancers11050649. [PMID: 31083460 PMCID: PMC6562779 DOI: 10.3390/cancers11050649] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/06/2019] [Accepted: 05/08/2019] [Indexed: 12/30/2022] Open
Abstract
Autophagy is a lysosome-mediated degradation pathway that enables the degradation and recycling of cytoplasmic components to sustain metabolic homoeostasis. Recently, autophagy has been reported to have an astonishing number of connections to cancer, as tumor cells require proficient autophagy in response to metabolic and therapeutic stresses to sustain cell proliferation. Autophagy-related gene 4 (ATG4) is essential for autophagy by affecting autophagosome formation through processing full-length microtubule-associated protein 1A/1B-light chain 3 (pro-LC3) and lipidated LC3. An increasing amount of evidence suggests that ATG4B expression is elevated in certain types of cancer, implying that ATG4B is a potential anticancer target. In this review, we address the central roles of ATG4B in the autophagy machinery and in targeted cancer therapy. Specifically, we discuss how pharmacologically inhibiting ATG4B can benefit cancer therapies.
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22
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Shin JH, Park SJ, Jo DS, Park NY, Kim JB, Bae JE, Jo YK, Hwang JJ, Lee JA, Jo DG, Kim JC, Jung YK, Koh JY, Cho DH. Down-regulated TMED10 in Alzheimer disease induces autophagy via ATG4B activation. Autophagy 2019; 15:1495-1505. [PMID: 30821607 DOI: 10.1080/15548627.2019.1586249] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Several studies have shown that dysfunction of macroautophagy/autophagy is associated with many human diseases, including neurodegenerative disease and cancer. To explore the molecular mechanisms of autophagy, we performed a cell-based functional screening with SH-SY5Y cells stably expressing GFP-LC3, using an siRNA library and identified TMED10 (transmembrane p24 trafficking protein 10), previously known as the γ-secretase-modulating protein, as a novel regulator of autophagy. Further investigations revealed that depletion of TMED10 induced the activation of autophagy. Interestingly, protein-protein interaction assays showed that TMED10 directly binds to ATG4B (autophagy related gene 4B cysteine peptidase), and the interaction is diminished under autophagy activation conditions such as rapamycin treatment and serum deprivation. In addition, inhibition of TMED10 significantly enhanced the proteolytic activity of ATG4B for LC3 cleavage. Importantly, the expression of TMED10 in AD (Alzheimer disease) patients was considerably decreased, and downregulation of TMED10 increased amyloid-β (Aβ) production. Treatment with Aβ increased ATG4B proteolytic activity as well as dissociation of TMED10 and ATG4B. Taken together, our results suggest that the AD-associated protein TMED10 negatively regulates autophagy by inhibiting ATG4B activity.Abbreviations: Aβ: amyloid-β; AD: Alzheimer disease; ATG: autophagy related; BECN1: beclin 1; BiFC: bimolecular fluorescence complementation; CD: cytosolic domain; GFP: green fluorescent protein; GLUC: Gaussia luciferase; IP: immunoprecipitation; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; LD: luminal domain; PD: Parkinson disease; ROS: reactive oxygen species; siRNA: small interfering RNA; SNP: single-nucleotide polymorphisms; TD: transmembrane domain; TMED10: transmembrane p24 trafficking protein 10; VC: C terminus of Venus fluorescent protein; VN: N terminus of Venus fluorescent protein.
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Affiliation(s)
- Ji Hyun Shin
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea.,b Department of Gerontology, Graduate School of E-W Medical Science, Kyung Hee University , Yongin , South Korea
| | - So Jung Park
- b Department of Gerontology, Graduate School of E-W Medical Science, Kyung Hee University , Yongin , South Korea
| | - Doo Sin Jo
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea
| | - Na Yeon Park
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea
| | - Joon Bum Kim
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea
| | - Ji-Eun Bae
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea.,b Department of Gerontology, Graduate School of E-W Medical Science, Kyung Hee University , Yongin , South Korea
| | - Yoon Kyung Jo
- b Department of Gerontology, Graduate School of E-W Medical Science, Kyung Hee University , Yongin , South Korea
| | - Jung Jin Hwang
- c Asan Institute for Life Sciences, Asan Medical Center , Seoul , South Korea
| | - Jin-A Lee
- d College of Life Sciences and Nanotechnology, Hannam University , Daejeon , South Korea
| | - Dong-Gyu Jo
- e School of Pharmacy, Sungkyunkwan University , Suwon , South Korea
| | - Jin Cheon Kim
- f Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center , Seoul , South Korea
| | - Yong Keun Jung
- g School of Biological Sciences, Seoul National University , Seoul , South Korea
| | - Jae-Young Koh
- h Department of Neurology, University of Ulsan College of Medicine, Asan Medical Center , Seoul , South Korea
| | - Dong-Hyung Cho
- a School of Life Sciences, Kyungpook National University , Daegu , Republic of Korea
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Pengo N, Prak K, Costa JR, Luft C, Agrotis A, Freeman J, Gewinner CA, Chan AWE, Selwood DL, Kriston-Vizi J, Ketteler R. Identification of Kinases and Phosphatases That Regulate ATG4B Activity by siRNA and Small Molecule Screening in Cells. Front Cell Dev Biol 2018; 6:148. [PMID: 30443548 PMCID: PMC6221980 DOI: 10.3389/fcell.2018.00148] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/10/2018] [Indexed: 12/15/2022] Open
Abstract
Autophagy protease ATG4B is a key regulator of the LC3/GABARAP conjugation system required for autophagosome formation, maturation and closure. Members of the ATG4 and the LC3/GABARAP family have been implicated in various diseases including cancer, and targeting the ATG4B protease has been suggested as a potential therapeutic anti-cancer strategy. Recently, it has been demonstrated that ATG4B is regulated by multiple post-translational modifications, including phosphorylation and de-phosphorylation. In order to identify regulators of ATG4B activity, we optimized a cell-based luciferase assay based on ATG4B-dependent release of Gaussia luciferase. We applied this assay in a proof-of-concept small molecule compound screen and identified activating compounds that increase cellular ATG4B activity. Next, we performed a high-throughput screen to identify kinases and phosphatases that regulate cellular ATG4B activity using siRNA mediated knockdown and cDNA overexpression. Of these, we provide preliminary evidence that the kinase AKT2 enhances ATG4B activity in cells. We provide all raw and processed data from the screens as a resource for further analysis. Overall, our findings provide novel insights into the regulation of ATG4B and highlight the importance of post-translational modifications of ATG4B.
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Affiliation(s)
- Niccolo Pengo
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Krisna Prak
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Joana R. Costa
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Christin Luft
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Alexander Agrotis
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Jamie Freeman
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | | | - A. W. Edith Chan
- Wolfson Institute for Biomedical Research, University College London, London, United Kingdom
| | - David L. Selwood
- Wolfson Institute for Biomedical Research, University College London, London, United Kingdom
| | - Janos Kriston-Vizi
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Robin Ketteler
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
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24
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Zhu Y, Shan X, Safarpour F, Erro Go N, Li N, Shan A, Huang MC, Deen M, Holicek V, Ashmus R, Madden Z, Gorski S, Silverman MA, Vocadlo DJ. Pharmacological Inhibition of O-GlcNAcase Enhances Autophagy in Brain through an mTOR-Independent Pathway. ACS Chem Neurosci 2018; 9:1366-1379. [PMID: 29460617 DOI: 10.1021/acschemneuro.8b00015] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The glycosylation of nucleocytoplasmic proteins with O-linked N-acetylglucosamine residues (O-GlcNAc) is conserved among metazoans and is particularly abundant within brain. O-GlcNAc is involved in diverse cellular processes ranging from the regulation of gene expression to stress response. Moreover, O-GlcNAc is implicated in various diseases including cancers, diabetes, cardiac dysfunction, and neurodegenerative diseases. Pharmacological inhibition of O-GlcNAcase (OGA), the sole enzyme that removes O-GlcNAc, reproducibly slows neurodegeneration in various Alzheimer's disease (AD) mouse models manifesting either tau or amyloid pathology. These data have stimulated interest in the possibility of using OGA-selective inhibitors as pharmaceuticals to alter the progression of AD. The mechanisms mediating the neuroprotective effects of OGA inhibitors, however, remain poorly understood. Here we show, using a range of methods in neuroblastoma N2a cells, in primary rat neurons, and in mouse brain, that selective OGA inhibitors stimulate autophagy through an mTOR-independent pathway without obvious toxicity. Additionally, OGA inhibition significantly decreased the levels of toxic protein species associated with AD pathogenesis in the JNPL3 tauopathy mouse model as well as the 3×Tg-AD mouse model. These results strongly suggest that OGA inhibitors act within brain through a mechanism involving enhancement of autophagy, which aids the brain in combatting the accumulation of toxic protein species. Our study supports OGA inhibition being a feasible therapeutic strategy for hindering the progression of AD and other neurodegenerative diseases. Moreover, these data suggest more targeted strategies to stimulate autophagy in an mTOR-independent manner may be found within the O-GlcNAc pathway. These findings should aid the advancement of OGA inhibitors within the clinic.
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Affiliation(s)
- 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
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Xiaoyang Shan
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Farzaneh Safarpour
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Nancy Erro Go
- The Genome Sciences Centre, BC Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
| | - Nancy Li
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Alice Shan
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Mina C. Huang
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Matthew Deen
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Viktor Holicek
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Roger Ashmus
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Zarina Madden
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Sharon Gorski
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- The Genome Sciences Centre, BC Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
| | - Michael A. Silverman
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - David J. 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
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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25
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Kauffman KJ, Yu S, Jin J, Mugo B, Nguyen N, O'Brien A, Nag S, Lystad AH, Melia TJ. Delipidation of mammalian Atg8-family proteins by each of the four ATG4 proteases. Autophagy 2018; 14:992-1010. [PMID: 29458288 DOI: 10.1080/15548627.2018.1437341] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
During macroautophagy/autophagy, mammalian Atg8-family proteins undergo 2 proteolytic processing events. The first exposes a COOH-terminal glycine used in the conjugation of these proteins to lipids on the phagophore, the precursor to the autophagosome, whereas the second releases the lipid. The ATG4 family of proteases drives both cleavages, but how ATG4 proteins distinguish between soluble and lipid-anchored Atg8 proteins is not well understood. In a fully reconstituted delipidation assay, we establish that the physical anchoring of mammalian Atg8-family proteins in the membrane dramatically shifts the way ATG4 proteases recognize these substrates. Thus, while ATG4B is orders of magnitude faster at processing a soluble unprimed protein, all 4 ATG4 proteases can be activated to similar enzymatic activities on lipid-attached substrates. The recognition of lipidated but not soluble substrates is sensitive to a COOH-terminal LIR motif both in vitro and in cells. We suggest a model whereby ATG4B drives very fast priming of mammalian Atg8 proteins, whereas delipidation is inherently slow and regulated by all ATG4 homologs.
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Affiliation(s)
- Karlina J Kauffman
- a Department of Cell Biology , Yale University School of Medicine , New Haven , CT , USA
| | - Shenliang Yu
- a Department of Cell Biology , Yale University School of Medicine , New Haven , CT , USA
| | - Jiaxin Jin
- a Department of Cell Biology , Yale University School of Medicine , New Haven , CT , USA.,b Lanzhou University Second Hospital , Lanzhou , Gansu Province , China
| | - Brian Mugo
- a Department of Cell Biology , Yale University School of Medicine , New Haven , CT , USA
| | - Nathan Nguyen
- a Department of Cell Biology , Yale University School of Medicine , New Haven , CT , USA
| | - Aidan O'Brien
- a Department of Cell Biology , Yale University School of Medicine , New Haven , CT , USA
| | - Shanta Nag
- a Department of Cell Biology , Yale University School of Medicine , New Haven , CT , USA
| | - Alf Håkon Lystad
- c Department of Molecular Medicine , Institute of Basic Medical Sciences, University of Oslo , Norway
| | - Thomas J Melia
- a Department of Cell Biology , Yale University School of Medicine , New Haven , CT , USA
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26
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Zhang J, Culp ML, Craver JG, Darley-Usmar V. Mitochondrial function and autophagy: integrating proteotoxic, redox, and metabolic stress in Parkinson's disease. J Neurochem 2018; 144:691-709. [PMID: 29341130 PMCID: PMC5897151 DOI: 10.1111/jnc.14308] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/04/2018] [Accepted: 01/09/2018] [Indexed: 12/14/2022]
Abstract
Parkinson's disease (PD) is a movement disorder with widespread neurodegeneration in the brain. Significant oxidative, reductive, metabolic, and proteotoxic alterations have been observed in PD postmortem brains. The alterations of mitochondrial function resulting in decreased bioenergetic health is important and needs to be further examined to help develop biomarkers for PD severity and prognosis. It is now becoming clear that multiple hits on metabolic and signaling pathways are likely to exacerbate PD pathogenesis. Indeed, data obtained from genetic and genome association studies have implicated interactive contributions of genes controlling protein quality control and metabolism. For example, loss of key proteins that are responsible for clearance of dysfunctional mitochondria through a process called mitophagy has been found to cause PD, and a significant proportion of genes associated with PD encode proteins involved in the autophagy-lysosomal pathway. In this review, we highlight the evidence for the targeting of mitochondria by proteotoxic, redox and metabolic stress, and the role autophagic surveillance in maintenance of mitochondrial quality. Furthermore, we summarize the role of α-synuclein, leucine-rich repeat kinase 2, and tau in modulating mitochondrial function and autophagy. Among the stressors that can overwhelm the mitochondrial quality control mechanisms, we will discuss 4-hydroxynonenal and nitric oxide. The impact of autophagy is context depend and as such can have both beneficial and detrimental effects. Furthermore, we highlight the potential of targeting mitochondria and autophagic function as an integrated therapeutic strategy and the emerging contribution of the microbiome to PD susceptibility.
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Affiliation(s)
- Jianhua Zhang
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
- Department of Veterans Affairs, Birmingham VA Medical Center
| | - M Lillian Culp
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Jason G Craver
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Victor Darley-Usmar
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
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27
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Ni Z, He J, Wu Y, Hu C, Dai X, Yan X, Li B, Li X, Xiong H, Li Y, Li S, Xu L, Li Y, Lian J, He F. AKT-mediated phosphorylation of ATG4B impairs mitochondrial activity and enhances the Warburg effect in hepatocellular carcinoma cells. Autophagy 2018; 14:685-701. [PMID: 29165041 DOI: 10.1080/15548627.2017.1407887] [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] [Indexed: 02/06/2023] Open
Abstract
Phosphorylation is a major type of post-translational modification, which can influence the cellular physiological function. ATG4B, a key macroautophagy/autophagy-related protein, has a potential effect on the survival of tumor cells. However, the role of ATG4B phosphorylation in cancers is still unknown. In this study, we identified a novel phosphorylation site at Ser34 of ATG4B induced by AKT in HCC cells. The phosphorylation of ATG4B at Ser34 had little effect on autophagic flux, but promoted the Warburg effect including the increase of L-lactate production and glucose consumption, and the decrease of oxygen consumption in HCC cells. The Ser34 phosphorylation of ATG4B also contributed to the impairment of mitochondrial activity including the inhibition of F1Fo-ATP synthase activity and the elevation of mitochondrial ROS in HCC cells. Moreover, the phosphorylation of ATG4B at Ser34 enhanced its mitochondrial location and the subsequent colocalization with F1Fo-ATP synthase in HCC cells. Furthermore, recombinant human ATG4B protein suppressed the activity of F1Fo-ATP synthase in MgATP submitochondrial particles from patient-derived HCC tissues in vitro. In brief, our results demonstrate for the first time that the phosphorylation of ATG4B at Ser34 participates in the metabolic reprogramming of HCC cells via repressing mitochondrial function, which possibly results from the Ser34 phosphorylation-induced mitochondrial enrichment of ATG4B and the subsequent inhibition of F1Fo-ATP synthase activity. Our findings reveal a noncanonical working pattern of ATG4B under pathological conditions, which may provide a scientific basis for developing novel strategies for HCC treatment by targeting ATG4B and its Ser34 phosphorylation.
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Affiliation(s)
- Zhenhong Ni
- a Department of Biochemistry and Molecular Biology , College of Basic Medical Sciences, Third Military Medical University , Chongqing, China
| | - Jintao He
- b Battalion 17 of Students , College of Preventive Medicine, Third Military Medical University , Chongqing, China
| | - Yaran Wu
- a Department of Biochemistry and Molecular Biology , College of Basic Medical Sciences, Third Military Medical University , Chongqing, China
| | - Changjiang Hu
- c Department of Gastroenterology , Xinqiao Hospital, Third Military Medical University , Chongqing , China
| | - Xufang Dai
- d College of Educational Science, Chongqing Normal University , Chongqing , China
| | - Xiaojing Yan
- a Department of Biochemistry and Molecular Biology , College of Basic Medical Sciences, Third Military Medical University , Chongqing, China
| | - Bo Li
- a Department of Biochemistry and Molecular Biology , College of Basic Medical Sciences, Third Military Medical University , Chongqing, China
| | - Xinzhe Li
- a Department of Biochemistry and Molecular Biology , College of Basic Medical Sciences, Third Military Medical University , Chongqing, China
| | - Haojun Xiong
- a Department of Biochemistry and Molecular Biology , College of Basic Medical Sciences, Third Military Medical University , Chongqing, China
| | - Yuming Li
- e Department of Hepatobiliary Surgery , Xinqiao Hospital, Third Military Medical University , Chongqing , China
| | - Song Li
- f Center for Pharmacogenetics , Department of Pharmaceutical Sciences, School of Pharmacy , University of Pittsburgh , Pittsburgh , PA , USA
| | - Liang Xu
- g Department of Molecular Biosciences and Department of Radiation Oncology , University of Kansas Cancer Center, University of Kansas , Lawrence , KS , USA
| | - Yongsheng Li
- h Institute of Cancer, Xinqiao Hospital, Third Military Medical University , Chongqing , China
| | - Jiqin Lian
- a Department of Biochemistry and Molecular Biology , College of Basic Medical Sciences, Third Military Medical University , Chongqing, China
| | - Fengtian He
- a Department of Biochemistry and Molecular Biology , College of Basic Medical Sciences, Third Military Medical University , Chongqing, China
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28
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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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29
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Akan I, Olivier-Van Stichelen S, Bond MR, Hanover JA. Nutrient-driven O-GlcNAc in proteostasis and neurodegeneration. J Neurochem 2017; 144:7-34. [PMID: 29049853 DOI: 10.1111/jnc.14242] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 09/28/2017] [Accepted: 10/11/2017] [Indexed: 12/14/2022]
Abstract
Proteostasis is essential in the mammalian brain where post-mitotic cells must function for decades to maintain synaptic contacts and memory. The brain is dependent on glucose and other metabolites for proper function and is spared from metabolic deficits even during starvation. In this review, we outline how the nutrient-sensitive nucleocytoplasmic post-translational modification O-linked N-acetylglucosamine (O-GlcNAc) regulates protein homeostasis. The O-GlcNAc modification is highly abundant in the mammalian brain and has been linked to proteopathies, including neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's. C. elegans, Drosophila, and mouse models harboring O-GlcNAc transferase- and O-GlcNAcase-knockout alleles have helped define the role O-GlcNAc plays in development as well as age-associated neurodegenerative disease. These enzymes add and remove the single monosaccharide from protein serine and threonine residues, respectively. Blocking O-GlcNAc cycling is detrimental to mammalian brain development and interferes with neurogenesis, neural migration, and proteostasis. Findings in C. elegans and Drosophila model systems indicate that the dynamic turnover of O-GlcNAc is critical for maintaining levels of key transcriptional regulators responsible for neurodevelopment cell fate decisions. In addition, pathways of autophagy and proteasomal degradation depend on a transcriptional network that is also reliant on O-GlcNAc cycling. Like the quality control system in the endoplasmic reticulum which uses a 'mannose timer' to monitor protein folding, we propose that cytoplasmic proteostasis relies on an 'O-GlcNAc timer' to help regulate the lifetime and fate of nuclear and cytoplasmic proteins. O-GlcNAc-dependent developmental alterations impact metabolism and growth of the developing mouse embryo and persist into adulthood. Brain-selective knockout mouse models will be an important tool for understanding the role of O-GlcNAc in the physiology of the brain and its susceptibility to neurodegenerative injury.
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Affiliation(s)
- Ilhan Akan
- Laboratory of Cell and Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Michelle R Bond
- Laboratory of Cell and Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, USA
| | - John A Hanover
- Laboratory of Cell and Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland, USA
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30
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Maruyama T, Noda NN. Autophagy-regulating protease Atg4: structure, function, regulation and inhibition. J Antibiot (Tokyo) 2017; 71:ja2017104. [PMID: 28901328 PMCID: PMC5799747 DOI: 10.1038/ja.2017.104] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 07/19/2017] [Accepted: 07/27/2017] [Indexed: 12/15/2022]
Abstract
Autophagy is an intracellular degradation system that contributes to cellular homeostasis through degradation of various targets such as proteins, organelles and microbes. Since autophagy is related to various diseases such as infection, neurodegenerative diseases and cancer, it is attracting attention as a new therapeutic target. Autophagy is mediated by dozens of autophagy-related (Atg) proteins, among which Atg4 is the sole protease that regulates autophagy through the processing and deconjugating of Atg8. As the Atg4 activity is essential and highly specific to autophagy, Atg4 is a prospective target for developing autophagy-specific inhibitors. In this review article, we summarize our current knowledge of the structure, function and regulation of Atg4 including efforts to develop Atg4-specific inhibitors.The Journal of Antibiotics advance online publication, 13 September 2017; doi:10.1038/ja.2017.104.
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Affiliation(s)
- Tatsuro Maruyama
- Laboratory of Structural Biology, Institute of Microbial Chemistry, Tokyo, Japan
| | - Nobuo N Noda
- Laboratory of Structural Biology, Institute of Microbial Chemistry, Tokyo, Japan
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