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Jones NH, Liu Q, Urnavicius L, Dahan NE, Vostal LE, Kapoor TM. Allosteric activation of VCP, an AAA unfoldase, by small molecule mimicry. Proc Natl Acad Sci U S A 2024; 121:e2316892121. [PMID: 38833472 PMCID: PMC11181084 DOI: 10.1073/pnas.2316892121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 04/17/2024] [Indexed: 06/06/2024] Open
Abstract
The loss of function of AAA (ATPases associated with diverse cellular activities) mechanoenzymes has been linked to diseases, and small molecules that activate these proteins can be powerful tools to probe mechanisms and test therapeutic hypotheses. Unlike chemical inhibitors that can bind a single conformational state to block enzyme function, activator binding must be permissive to different conformational states needed for mechanochemistry. However, we do not know how AAA proteins can be activated by small molecules. Here, we focus on valosin-containing protein (VCP)/p97, an AAA unfoldase whose loss of function has been linked to protein aggregation-based disorders, to identify druggable sites for chemical activators. We identified VCP ATPase Activator 1 (VAA1), a compound that dose-dependently stimulates VCP ATPase activity up to ~threefold. Our cryo-EM studies resulted in structures (ranging from ~2.9 to 3.7 Å-resolution) of VCP in apo and ADP-bound states and revealed that VAA1 binds an allosteric pocket near the C-terminus in both states. Engineered mutations in the VAA1-binding site confer resistance to VAA1, and furthermore, modulate VCP activity. Mutation of a phenylalanine residue in the VCP C-terminal tail that can occupy the VAA1 binding site also stimulates ATPase activity, suggesting that VAA1 acts by mimicking this interaction. Together, our findings uncover a druggable allosteric site and a mechanism of enzyme regulation that can be tuned through small molecule mimicry.
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Affiliation(s)
- Natalie H. Jones
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY10065
- Tri-Institutional PhD Program in Chemical Biology, New York, NY10065
| | - Qiwen Liu
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY10065
| | - Linas Urnavicius
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY10065
| | - Noa E. Dahan
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY10065
- The David Rockefeller Graduate Program in Bioscience, The Rockefeller University, New York, NY10065
| | - Lauren E. Vostal
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY10065
- Tri-Institutional PhD Program in Chemical Biology, New York, NY10065
| | - Tarun M. Kapoor
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY10065
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Chen X, Tsvetkov AS, Shen HM, Isidoro C, Ktistakis NT, Linkermann A, Koopman WJ, Simon HU, Galluzzi L, Luo S, Xu D, Gu W, Peulen O, Cai Q, Rubinsztein DC, Chi JT, Zhang DD, Li C, Toyokuni S, Liu J, Roh JL, Dai E, Juhasz G, Liu W, Zhang J, Yang M, Liu J, Zhu LQ, Zou W, Piacentini M, Ding WX, Yue Z, Xie Y, Petersen M, Gewirtz DA, Mandell MA, Chu CT, Sinha D, Eftekharpour E, Zhivotovsky B, Besteiro S, Gabrilovich DI, Kim DH, Kagan VE, Bayir H, Chen GC, Ayton S, Lünemann JD, Komatsu M, Krautwald S, Loos B, Baehrecke EH, Wang J, Lane JD, Sadoshima J, Yang WS, Gao M, Münz C, Thumm M, Kampmann M, Yu D, Lipinski MM, Jones JW, Jiang X, Zeh HJ, Kang R, Klionsky DJ, Kroemer G, Tang D. International consensus guidelines for the definition, detection, and interpretation of autophagy-dependent ferroptosis. Autophagy 2024; 20:1213-1246. [PMID: 38442890 PMCID: PMC11210914 DOI: 10.1080/15548627.2024.2319901] [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: 08/25/2023] [Accepted: 10/19/2023] [Indexed: 03/07/2024] Open
Abstract
Macroautophagy/autophagy is a complex degradation process with a dual role in cell death that is influenced by the cell types that are involved and the stressors they are exposed to. Ferroptosis is an iron-dependent oxidative form of cell death characterized by unrestricted lipid peroxidation in the context of heterogeneous and plastic mechanisms. Recent studies have shed light on the involvement of specific types of autophagy (e.g. ferritinophagy, lipophagy, and clockophagy) in initiating or executing ferroptotic cell death through the selective degradation of anti-injury proteins or organelles. Conversely, other forms of selective autophagy (e.g. reticulophagy and lysophagy) enhance the cellular defense against ferroptotic damage. Dysregulated autophagy-dependent ferroptosis has implications for a diverse range of pathological conditions. This review aims to present an updated definition of autophagy-dependent ferroptosis, discuss influential substrates and receptors, outline experimental methods, and propose guidelines for interpreting the results.Abbreviation: 3-MA:3-methyladenine; 4HNE: 4-hydroxynonenal; ACD: accidentalcell death; ADF: autophagy-dependentferroptosis; ARE: antioxidant response element; BH2:dihydrobiopterin; BH4: tetrahydrobiopterin; BMDMs: bonemarrow-derived macrophages; CMA: chaperone-mediated autophagy; CQ:chloroquine; DAMPs: danger/damage-associated molecular patterns; EMT,epithelial-mesenchymal transition; EPR: electronparamagnetic resonance; ER, endoplasmic reticulum; FRET: Försterresonance energy transfer; GFP: green fluorescent protein;GSH: glutathione;IF: immunofluorescence; IHC: immunohistochemistry; IOP, intraocularpressure; IRI: ischemia-reperfusion injury; LAA: linoleamide alkyne;MDA: malondialdehyde; PGSK: Phen Green™ SK;RCD: regulatedcell death; PUFAs: polyunsaturated fatty acids; RFP: red fluorescentprotein;ROS: reactive oxygen species; TBA: thiobarbituricacid; TBARS: thiobarbituric acid reactive substances; TEM:transmission electron microscopy.
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Affiliation(s)
- Xin Chen
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Andrey S. Tsvetkov
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX, USA
| | - Han-Ming Shen
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Macau, Macau, China
| | - Ciro Isidoro
- Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | | | - Andreas Linkermann
- Division of Nephrology, Department of Internal Medicine 3, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Germany
- Division of Nephrology, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Werner J.H. Koopman
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
- Human and Animal Physiology, Wageningen University, Wageningen, The Netherlands
| | - Hans-Uwe Simon
- Institute of Pharmacology, University of Bern, Bern, Switzerland
- Institute of Biochemistry, Brandenburg Medical School, Neuruppin, Germany
| | - Lorenzo Galluzzi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA
- Sandra and Edward Meyer Cancer Center, New York, NY, USA
- Caryl and Israel Englander Institute for Precision Medicine, New York, NY, USA
| | - Shouqing Luo
- Peninsula Medical School, University of Plymouth, Plymouth, UK
| | - Daqian Xu
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Institute of Translational Medicine, Zhejiang University School of Medicine, Zhejiang University, Hangzhou, China
| | - Wei Gu
- Institute for Cancer Genetics, and Department of Pathology and Cell Biology, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY, USA
| | - Olivier Peulen
- Metastasis Research Laboratory, GIGA Cancer-University of Liège, Liège, Belgium
| | - Qian Cai
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - David C. Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
- UK Dementia Research Institute, University of Cambridge, Cambridge, UK
| | - Jen-Tsan Chi
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
| | - Donna D. Zhang
- Pharmacology and Toxicology, R. Ken Coit College of Pharmacy, University of Arizona, Tucson, AZ, USA
| | - Changfeng Li
- Department of Endoscopy Center, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Shinya Toyokuni
- Department of Pathology and Biological Response, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Center for Low-temperature Plasma Sciences, Nagoya University, Nagoya, Japan
| | - Jinbao Liu
- Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, State Key Laboratory of Respiratory Disease, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Jong-Lyel Roh
- Department of Otorhinolaryngology-Head and Neck Surgery, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea
| | - Enyong Dai
- The Second Department of Hematology and Oncology, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China
| | - Gabor Juhasz
- Biological Research Center, Institute of Genetics, Szeged, Hungary
- Department of Anatomy, Cell and Developmental Biology, Eotvos Lorand University, Budapest, Hungary
| | - Wei Liu
- Department of Orthopedics, Changzheng Hospital, Second Affiliated Hospital of Naval Medical University, Shanghai, China
| | - Jianhua Zhang
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Minghua Yang
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
- Hunan Clinical Research Center of Pediatric Cancer, Changsha, China
| | - Jiao Liu
- DAMP Laboratory, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Ling-Qiang Zhu
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Weiping Zou
- Departments of Surgery and Pathology, University of Michigan Medical School, Ann Arbor, USA
| | - Mauro Piacentini
- Department of Biology, University of Rome “Tor Vergata”, Rome, Italy
- National Institute for Infectious Diseases IRCCS “Lazzaro Spallanzani”, Rome, Italy
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS, USA
| | - Zhenyu Yue
- Department of Neurology, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yangchun Xie
- Department of Oncology, Central South University, Changsha, Hunan, China
| | - Morten Petersen
- Functional genomics, Department of Biology, Copenhagen University, Denmark
| | - David A. Gewirtz
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Massey Cancer Center, Richmond, VA, USA
| | - Michael A. Mandell
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, USA
| | - Charleen T. Chu
- Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Debasish Sinha
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA; Wilmer Eye lnstitute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Eftekhar Eftekharpour
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer, Villejuif, France; Gustave Roussy Cancer, Villejuif, France
| | - Boris Zhivotovsky
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden, Europe
- Faculty of Medicine, Lomonosov Moscow State University, Moscow, Russia
- Engelhardt Institute of Molecular Biology, Moscow, Russia
| | - Sébastien Besteiro
- LPHI, University Montpellier, CNRS, Montpellier, France
- Institut du Cancer Paris CARPEM, Department of Biology, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
| | | | - Do-Hyung Kim
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Valerian E. Kagan
- Department of Environmental Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hülya Bayir
- Department of Pediatrics, Columbia University, New York, USA
| | - Guang-Chao Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Scott Ayton
- Florey Institute, University of Melbourne, Parkville, Australia
| | - Jan D. Lünemann
- Department of Neurology with Institute of Translational Neurology, University of Münster, Münster, Germany
| | - Masaaki Komatsu
- Department of Physiology, Juntendo University School of Medicine, Bunkyo-ku Tokyo, Japan
| | - Stefan Krautwald
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Ben Loos
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Eric H. Baehrecke
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jiayi Wang
- Department of Clinical Laboratory, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Thoracic Oncology Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- College of Medical Technology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jon D. Lane
- School of Biochemistry, University of Bristol, Bristol, UK
| | - Junichi Sadoshima
- Rutgers New Jersey Medical School, Department of Cell Biology and Molecular Medicine, Newark, USA
| | - Wan Seok Yang
- Department of Biological Sciences, St. John’s University, New York City, NY, USA
| | - Minghui Gao
- The HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Christian Münz
- Institute of Experimental Immunology, University of Zürich, Zürich, Switzerland
| | - Michael Thumm
- Department of Cellular Biochemistry, University Medical Center Goettingen, Goettingen, Germany
| | - Martin Kampmann
- Department of Biochemistry & Biophysics, University of California, San Francisco, USA
- Institute for Neurodegenerative Diseases, University of California, San Francisco, USA
| | - Di Yu
- Faculty of Medicine, Frazer Institute, University of Queensland, Brisbane, Australia
- Faculty of Medicine, Ian Frazer Centre for Children’s Immunotherapy Research, Child Health Research Centre, University of Queensland, Brisbane, Australia
| | - Marta M. Lipinski
- Department of Anesthesiology & Department of Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jace W. Jones
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD, USA
| | - Xuejun Jiang
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Herbert J. Zeh
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA
| | - Rui Kang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA
| | - Daniel J. Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Guido Kroemer
- Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, INSERM U1138, Institut Universitaire de France, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer, Villejuif, France; Gustave Roussy Cancer, Villejuif, France
- Institut du Cancer Paris CARPEM, Department of Biology, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
| | - Daolin Tang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA
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3
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Phan JM, Creekmore BC, Nguyen AT, Bershadskaya DD, Darwich NF, Mann CN, Lee EB. VCP activator reverses nuclear proteostasis defects and enhances TDP-43 aggregate clearance in multisystem proteinopathy models. J Clin Invest 2024; 134:e169039. [PMID: 38787785 PMCID: PMC11257039 DOI: 10.1172/jci169039] [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: 01/20/2023] [Accepted: 05/17/2024] [Indexed: 05/26/2024] Open
Abstract
Pathogenic variants in valosin-containing protein (VCP) cause multisystem proteinopathy (MSP), a disease characterized by multiple clinical phenotypes including inclusion body myopathy, Paget's disease of the bone, and frontotemporal dementia (FTD). How such diverse phenotypes are driven by pathogenic VCP variants is not known. We found that these diseases exhibit a common pathologic feature: ubiquitinated intranuclear inclusions affecting myocytes, osteoclasts, and neurons. Moreover, knock-in cell lines harboring MSP variants show a reduction in nuclear VCP. Given that MSP is associated with neuronal intranuclear inclusions comprised of TDP-43 protein, we developed a cellular model whereby proteostatic stress results in the formation of insoluble intranuclear TDP-43 aggregates. Consistent with a loss of nuclear VCP function, cells harboring MSP variants or cells treated with VCP inhibitor exhibited decreased clearance of insoluble intranuclear TDP-43 aggregates. Moreover, we identified 4 compounds that activate VCP primarily by increasing D2 ATPase activity, where pharmacologic VCP activation appears to enhance clearance of insoluble intranuclear TDP-43 aggregate. Our findings suggest that VCP function is important for nuclear protein homeostasis, that impaired nuclear proteostasis may contribute to MSP, and that VCP activation may be a potential therapeutic by virtue of enhancing the clearance of intranuclear protein aggregates.
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4
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Wrobel L, Hoffmann JL, Li X, Rubinsztein DC. p37 regulates VCP/p97 shuttling and functions in the nucleus and cytosol. SCIENCE ADVANCES 2024; 10:eadl6082. [PMID: 38701207 PMCID: PMC11068011 DOI: 10.1126/sciadv.adl6082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 04/02/2024] [Indexed: 05/05/2024]
Abstract
The AAA+-ATPase valosin-containing protein (VCP; also called p97 or Cdc48), a major protein unfolding machinery with a variety of essential functions, localizes to different subcellular compartments where it has different functions. However, the processes regulating the distribution of VCP between the cytosol and nucleus are not understood. Here, we identified p37 (also called UBXN2B) as a major factor regulating VCP nucleocytoplasmic shuttling. p37-dependent VCP localization was crucial for local cytosolic VCP functions, such as autophagy, and nuclear functions in DNA damage repair. Mutations in VCP causing multisystem proteinopathy enhanced its association with p37, leading to decreased nuclear localization of VCP, which enhanced susceptibility to DNA damage accumulation. Both VCP localization and DNA damage susceptibility in cells with such mutations were normalized by lowering p37 levels. Thus, we uncovered a mechanism by which VCP nucleocytoplasmic distribution is fine-tuned, providing a means for VCP to respond appropriately to local needs.
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Affiliation(s)
- Lidia Wrobel
- Department of Medical Genetics, Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
- UK Dementia Research Institute, University of Cambridge, Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Johanna L. Hoffmann
- Department of Medical Genetics, Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
- UK Dementia Research Institute, University of Cambridge, Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Xinyi Li
- Department of Medical Genetics, Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
- UK Dementia Research Institute, University of Cambridge, Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - David C. Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
- UK Dementia Research Institute, University of Cambridge, Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
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5
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Hu J, Fu S, Zhan Z, Zhang J. Advancements in dual-target inhibitors of PI3K for tumor therapy: Clinical progress, development strategies, prospects. Eur J Med Chem 2024; 265:116109. [PMID: 38183777 DOI: 10.1016/j.ejmech.2023.116109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 12/24/2023] [Accepted: 12/28/2023] [Indexed: 01/08/2024]
Abstract
Phosphoinositide 3-kinases (PI3Ks) modify lipids by the phosphorylation of inositol phospholipids at the 3'-OH position, thereby participating in signal transduction and exerting effects on various physiological processes such as cell growth, metabolism, and organism development. PI3K activation also drives cancer cell growth, survival, and metabolism, with genetic dysregulation of this pathway observed in diverse human cancers. Therefore, this target is considered a promising potential therapeutic target for various types of cancer. Currently, several selective PI3K inhibitors and one dual-target PI3K inhibitor have been approved and launched on the market. However, the majority of these inhibitors have faced revocation or voluntary withdrawal of indications due to concerns regarding their adverse effects. This article provides a comprehensive review of the structure and biological functions, and clinical status of PI3K inhibitors, with a specific emphasis on the development strategies and structure-activity relationships of dual-target PI3K inhibitors. The findings offer valuable insights and future directions for the development of highly promising dual-target drugs targeting PI3K.
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Affiliation(s)
- Jiarui Hu
- Department of Neurology, Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Siyu Fu
- Department of Neurology, Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Zixuan Zhan
- Department of Neurology, Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jifa Zhang
- Department of Neurology, Joint Research Institution of Altitude Health and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China.
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6
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Son SM, Park SJ, Breusegem SY, Larrieu D, Rubinsztein DC. p300 nucleocytoplasmic shuttling underlies mTORC1 hyperactivation in Hutchinson-Gilford progeria syndrome. Nat Cell Biol 2024; 26:235-249. [PMID: 38267537 PMCID: PMC10866696 DOI: 10.1038/s41556-023-01338-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 12/14/2023] [Indexed: 01/26/2024]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is a master regulator of cell growth, metabolism and autophagy. Multiple pathways modulate mTORC1 in response to nutrients. Here we describe that nucleus-cytoplasmic shuttling of p300/EP300 regulates mTORC1 activity in response to amino acid or glucose levels. Depletion of these nutrients causes cytoplasm-to-nucleus relocalization of p300 that decreases acetylation of the mTORC1 component raptor, thereby reducing mTORC1 activity and activating autophagy. This is mediated by AMP-activated protein kinase-dependent phosphorylation of p300 at serine 89. Nutrient addition to starved cells results in protein phosphatase 2A-dependent dephosphorylation of nuclear p300, enabling its CRM1-dependent export to the cytoplasm to mediate mTORC1 reactivation. p300 shuttling regulates mTORC1 in most cell types and occurs in response to altered nutrients in diverse mouse tissues. Interestingly, p300 cytoplasm-nucleus shuttling is altered in cells from patients with Hutchinson-Gilford progeria syndrome. p300 mislocalization by the disease-causing protein, progerin, activates mTORC1 and inhibits autophagy, phenotypes that are normalized by modulating p300 shuttling. These results reveal how nutrients regulate mTORC1, a cytoplasmic complex, by shuttling its positive regulator p300 in and out of the nucleus, and how this pathway is misregulated in Hutchinson-Gilford progeria syndrome, causing mTORC1 hyperactivation and defective autophagy.
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Affiliation(s)
- Sung Min Son
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
- UK Dementia Research Institute, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - So Jung Park
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
- UK Dementia Research Institute, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Sophia Y Breusegem
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Delphine Larrieu
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - David C Rubinsztein
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
- UK Dementia Research Institute, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
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7
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Jones NH, Liu Q, Urnavicius L, Dahan NE, Vostal LE, Kapoor TM. Allosteric activation of VCP, a AAA unfoldase, by small molecule mimicry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.02.560478. [PMID: 37873168 PMCID: PMC10592943 DOI: 10.1101/2023.10.02.560478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The loss of function of AAA (ATPases associated with diverse cellular activities) mechanoenzymes has been linked to diseases, and small molecules that activate these proteins can be powerful tools to probe mechanisms and test therapeutic hypotheses. Unlike chemical inhibitors that can bind a single conformational state to block enzyme activity, activator binding must be permissive to different conformational states needed for enzyme function. However, we do not know how AAA proteins can be activated by small molecules. Here, we focus on valosin-containing protein (VCP)/p97, a AAA unfoldase whose loss of function has been linked to protein aggregation-based disorders, to identify druggable sites for chemical activators. We identified VCP Activator 1 (VA1), a compound that dose-dependently stimulates VCP ATPase activity up to ∼3-fold. Our cryo-EM studies resulted in structures (∼2.9-3.5 Å-resolution) of VCP in apo and ADP-bound states, and revealed VA1 binding an allosteric pocket near the C-terminus in both states. Engineered mutations in the VA1 binding site confer resistance to VA1, and furthermore, modulate VCP activity to a similar level as VA1-mediated activation. The VA1 binding site can alternatively be occupied by a phenylalanine residue in the VCP C-terminal tail, a motif that is post-translationally modified and interacts with cofactors. Together, our findings uncover a druggable allosteric site and a mechanism of enzyme regulation that can be tuned through small molecule mimicry. Significance The loss of function of valosin-containing protein (VCP/p97), a mechanoenzyme from the AAA superfamily that hydrolyzes ATP and uses the released energy to extract or unfold substrate proteins, is linked to protein aggregation-based disorders. However, druggable allosteric sites to activate VCP, or any AAA mechanoenzyme, have not been identified. Here, we report cryo-EM structures of VCP in two states in complex with VA1, a compound we identified that dose-dependently stimulates VCP's ATP hydrolysis activity. The VA1 binding site can also be occupied by a phenylalanine residue in the VCP C-terminal tail, suggesting that VA1 acts through mimicry of this interaction. Our study reveals a druggable allosteric site and a mechanism of enzyme regulation.
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Ishtayeh H, Galves M, Barnatan TT, Berdichevsky Y, Amer‐Sarsour F, Pasmanik‐Chor M, Braverman I, Blumen SC, Ashkenazi A. Oculopharyngeal muscular dystrophy mutations link the RNA-binding protein HNRNPQ to autophagosome biogenesis. Aging Cell 2023; 22:e13949. [PMID: 37559347 PMCID: PMC10577562 DOI: 10.1111/acel.13949] [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: 02/25/2023] [Revised: 06/22/2023] [Accepted: 07/15/2023] [Indexed: 08/11/2023] Open
Abstract
Autophagy is an intracellular degradative process with an important role in cellular homeostasis. Here, we show that the RNA binding protein (RBP), heterogeneous nuclear ribonucleoprotein Q (HNRNPQ)/SYNCRIP is required to stimulate early events in autophagosome biogenesis, in particular the induction of VPS34 kinase by ULK1-mediated beclin 1 phosphorylation. The RBPs HNRNPQ and poly(A) binding protein nuclear 1 (PABPN1) form a regulatory network that controls the turnover of distinct autophagy-related (ATG) proteins. We also show that oculopharyngeal muscular dystrophy (OPMD) mutations engender a switch from autophagosome stimulation to autophagosome inhibition by impairing PABPN1 and HNRNPQ control of the level of ULK1. The overexpression of HNRNPQ in OPMD patient-derived cells rescues the defective autophagy in these cells. Our data reveal a regulatory mechanism of autophagy induction that is compromised by PABPN1 disease mutations, and may thus further contribute to their deleterious effects.
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Affiliation(s)
- Hasan Ishtayeh
- The Department of Cell and Developmental Biology, Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Margarita Galves
- The Department of Cell and Developmental Biology, Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Tania T. Barnatan
- The Department of Cell and Developmental Biology, Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Yevgeny Berdichevsky
- The Department of Cell and Developmental Biology, Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Fatima Amer‐Sarsour
- The Department of Cell and Developmental Biology, Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Metsada Pasmanik‐Chor
- Bioinformatics Unit, G.S. Wise Faculty of Life ScienceTel Aviv UniversityTel AvivIsrael
| | - Itzhak Braverman
- Department of Otolaryngology, Head and Neck SurgeryHillel Yaffe Medical CenterHaderaIsrael
- Rappaport Faculty of Medicine, TechnionHaifaIsrael
| | - Sergiu C. Blumen
- Rappaport Faculty of Medicine, TechnionHaifaIsrael
- Department of NeurologyHillel Yaffe Medical CenterHaderaIsrael
| | - Avraham Ashkenazi
- The Department of Cell and Developmental Biology, Faculty of MedicineTel Aviv UniversityTel AvivIsrael
- Sagol School of NeuroscienceTel Aviv UniversityTel AvivIsrael
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9
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Panagiotidou E, Gioran A, Bano D, Chondrogianni N. Neuron-specific proteasome activation exerts cell non-autonomous protection against amyloid-beta (Aβ) proteotoxicity in Caenorhabditis elegans. Redox Biol 2023; 65:102817. [PMID: 37473700 PMCID: PMC10404562 DOI: 10.1016/j.redox.2023.102817] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/11/2023] [Accepted: 07/11/2023] [Indexed: 07/22/2023] Open
Abstract
Proteostasis reinforcement is a promising approach in the design of therapeutic interventions against proteinopathies, including Alzheimer's disease. Understanding how and which parts of the proteostasis network should be enhanced is crucial in developing efficient therapeutic strategies. The ability of specific tissues to induce proteostatic responses in distal ones (cell non-autonomous regulation of proteostasis) is attracting interest. Although the proteasome is a major protein degradation node, nothing is known on its cell non-autonomous regulation. We show that proteasome activation in the nervous system can enhance the proteasome activity in the muscle of Caenorhabditis elegans. Mechanistically, this communication depends on Small Clear Vesicles, with glutamate as one of the neurotransmitters required for the distal regulation. More importantly, we demonstrate that this cell non-autonomous proteasome activation is translated into efficient prevention of amyloid-beta (Αβ)-mediated proteotoxic effects in the muscle of C. elegans but notably not to resistance against oxidative stress. Our in vivo data establish a mechanistic link between neuronal proteasome reinforcement and decreased Aβ proteotoxicity in the muscle. The identified distal communication may have serious implications in the design of therapeutic strategies based on tissue-specific proteasome manipulation.
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Affiliation(s)
- Eleni Panagiotidou
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635, Athens, Greece; Department of Biochemistry and Biotechnology, University of Thessaly, 41334, Larissa, Greece.
| | - Anna Gioran
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635, Athens, Greece.
| | - Daniele Bano
- German Center for Neurodegenerative Diseases (DZNE), 53127, Bonn, Germany.
| | - Niki Chondrogianni
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635, Athens, Greece.
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10
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Xu M, Zhong XZ, Huang P, Jaślan D, Wang P, Sun X, Weiden EM, EL Hiani Y, Grimm C, Dong XP. TRPML3/BK complex promotes autophagy and bacterial clearance by providing a positive feedback regulation of mTOR via PI3P. Proc Natl Acad Sci U S A 2023; 120:e2215777120. [PMID: 37585464 PMCID: PMC10450854 DOI: 10.1073/pnas.2215777120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 06/22/2023] [Indexed: 08/18/2023] Open
Abstract
TRPML3 is a Ca2+/Na+ release channel residing in both phagophores and endolysosomal membranes. It is activated by PI3P and PI3,5P2. Its activity can be enhanced by high luminal pH and by replacing luminal Na+ with K+. Here, we report that big-conductance Ca2+-activated potassium (BK) channels form a positive feedback loop with TRPML3. Ca2+ release via TRPML3 activates BK, which in turn facilitates TRPML3-mediated Ca2+ release, potentially through removing luminal Na+ inhibition. We further show that TRPML3/BK and mammalian target of rapamycin (mTOR) form another positive feedback loop to facilitate autophagy induction in response to nutrient starvation, i.e., mTOR inhibition upon nutrient starvation activates TRPML3/BK, and this further reduces mTOR activity, thereby increasing autophagy induction. Mechanistically, the feedback regulation between TRPML3/BK and mTOR is mediated by PI3P, an endogenous TRPML3 activator that is enriched in phagophores and is up-regulated by mTOR reduction. Importantly, bacterial infection activates TRPML3 in a BK-dependent manner, and both TRPML3 and BK are required for mTOR suppression and autophagy induction responding to bacterial infection. Suppressing either TRPML3 or BK helps bacteria survival whereas increasing either TRPML3 or BK favors bacterial clearance. Considering that TRPML3/BK is inhibited by low luminal pH but activated by high luminal pH and PI3P in phagophores, we suggest that TRPML3/BK and mTOR form a positive feedback loop via PI3P to ensure efficient autophagy induction in response to nutrient deprivation and bacterial infection. Our study reveals a role of TRPML3-BK coupling in controlling cellular homeostasis and intracellular bacterial clearance via regulating mTOR signaling.
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Affiliation(s)
- Mengnan Xu
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Xi Zoë Zhong
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Peng Huang
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
- Chongming Hospital, Shanghai University of Medicine and Health Sciences, Shanghai202150, China
| | - Dawid Jaślan
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich80336, Germany
| | - Pingping Wang
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Xue Sun
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
- Department of Developmental Cell Biology, China Medical University, Shenbei New District, Shenyang110122, China
| | - Eva-Maria Weiden
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich80336, Germany
| | - Yassine EL Hiani
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Christian Grimm
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich80336, Germany
- Immunology, Infection and Pandemic Research, Fraunhofer Institute for Translational Medicine and Pharmacology, Munich80799, Germany
| | - Xian-Ping Dong
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
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11
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Chu S, Xie X, Payan C, Stochaj U. Valosin containing protein (VCP): initiator, modifier, and potential drug target for neurodegenerative diseases. Mol Neurodegener 2023; 18:52. [PMID: 37545006 PMCID: PMC10405438 DOI: 10.1186/s13024-023-00639-y] [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: 02/20/2023] [Accepted: 06/27/2023] [Indexed: 08/08/2023] Open
Abstract
The AAA+ ATPase valosin containing protein (VCP) is essential for cell and organ homeostasis, especially in cells of the nervous system. As part of a large network, VCP collaborates with many cofactors to ensure proteostasis under normal, stress, and disease conditions. A large number of mutations have revealed the importance of VCP for human health. In particular, VCP facilitates the dismantling of protein aggregates and the removal of dysfunctional organelles. These are critical events to prevent malfunction of the brain and other parts of the nervous system. In line with this idea, VCP mutants are linked to the onset and progression of neurodegeneration and other diseases. The intricate molecular mechanisms that connect VCP mutations to distinct brain pathologies continue to be uncovered. Emerging evidence supports the model that VCP controls cellular functions on multiple levels and in a cell type specific fashion. Accordingly, VCP mutants derail cellular homeostasis through several mechanisms that can instigate disease. Our review focuses on the association between VCP malfunction and neurodegeneration. We discuss the latest insights in the field, emphasize open questions, and speculate on the potential of VCP as a drug target for some of the most devastating forms of neurodegeneration.
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Affiliation(s)
- Siwei Chu
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada
| | - Xinyi Xie
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada
| | - Carla Payan
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada
| | - Ursula Stochaj
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada.
- Quantitative Life Sciences Program, McGill University, Montreal, Canada.
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12
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Smith G, Sweeney ST, O’Kane CJ, Prokop A. How neurons maintain their axons long-term: an integrated view of axon biology and pathology. Front Neurosci 2023; 17:1236815. [PMID: 37564364 PMCID: PMC10410161 DOI: 10.3389/fnins.2023.1236815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/06/2023] [Indexed: 08/12/2023] Open
Abstract
Axons are processes of neurons, up to a metre long, that form the essential biological cables wiring nervous systems. They must survive, often far away from their cell bodies and up to a century in humans. This requires self-sufficient cell biology including structural proteins, organelles, and membrane trafficking, metabolic, signalling, translational, chaperone, and degradation machinery-all maintaining the homeostasis of energy, lipids, proteins, and signalling networks including reactive oxygen species and calcium. Axon maintenance also involves specialised cytoskeleton including the cortical actin-spectrin corset, and bundles of microtubules that provide the highways for motor-driven transport of components and organelles for virtually all the above-mentioned processes. Here, we aim to provide a conceptual overview of key aspects of axon biology and physiology, and the homeostatic networks they form. This homeostasis can be derailed, causing axonopathies through processes of ageing, trauma, poisoning, inflammation or genetic mutations. To illustrate which malfunctions of organelles or cell biological processes can lead to axonopathies, we focus on axonopathy-linked subcellular defects caused by genetic mutations. Based on these descriptions and backed up by our comprehensive data mining of genes linked to neural disorders, we describe the 'dependency cycle of local axon homeostasis' as an integrative model to explain why very different causes can trigger very similar axonopathies, providing new ideas that can drive the quest for strategies able to battle these devastating diseases.
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Affiliation(s)
- Gaynor Smith
- Cardiff University, School of Medicine, College of Biomedical and Life Sciences, Cardiff, United Kingdom
| | - Sean T. Sweeney
- Department of Biology, University of York and York Biomedical Research Institute, York, United Kingdom
| | - Cahir J. O’Kane
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Andreas Prokop
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biology, The University of Manchester, Manchester, United Kingdom
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13
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Wrobel L, Hill SM, Rubinsztein DC. SMER28 binding to VCP/p97 enhances both autophagic and proteasomal neurotoxic protein clearance. Autophagy 2023; 19:1348-1350. [PMID: 36036202 PMCID: PMC10012944 DOI: 10.1080/15548627.2022.2116832] [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: 08/18/2022] [Revised: 08/19/2022] [Accepted: 08/19/2022] [Indexed: 11/02/2022] Open
Abstract
The ability to maintain a functional proteome by clearing damaged or misfolded proteins is critical for cell survival, and aggregate-prone proteins accumulate in many neurodegenerative diseases, such as Huntington, Alzheimer, and Parkinson diseases. The removal of such proteins is mainly mediated by the ubiquitin-proteasome system and autophagy, and the activity of these systems declines in disease or with age. We recently found that targeting VCP/p97 with compounds like SMER28 enhances macroautophagy/autophagy flux mediated by the increased activity of the PtdIns3K complex I. Additionally, we found that SMER28 binding to VCP stimulates aggregate-prone protein clearance via the ubiquitin-proteasome system. This concurrent action of SMER28 on both degradation pathways resulted in the selective decrease in disease-causing proteins but not their wild-type counterparts. These results reveal a promising mode of VCP activation to counteract the toxicity caused by aggregate-prone proteins.
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Affiliation(s)
- Lidia Wrobel
- Department of Medical Genetics, Cambridge Institute for Medical Research, Cambridge, UK
- UK Dementia Research Institute, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK
| | - Sandra M. Hill
- Department of Medical Genetics, Cambridge Institute for Medical Research, Cambridge, UK
- UK Dementia Research Institute, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - David C. Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research, Cambridge, UK
- UK Dementia Research Institute, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK
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14
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Phan JM, Creekmore BC, Nguyen AT, Bershadskaya DD, Darwich NF, Lee EB. Novel VCP activator reverses multisystem proteinopathy nuclear proteostasis defects and enhances TDP-43 aggregate clearance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.15.532082. [PMID: 36993559 PMCID: PMC10055171 DOI: 10.1101/2023.03.15.532082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Pathogenic variants in VCP cause multisystem proteinopathy (MSP), a disease characterized by multiple clinical phenotypes including inclusion body myopathy, Paget's disease of the bone, and frontotemporal dementia (FTD). How such diverse phenotypes are driven by pathogenic VCP variants is not known. We found that these diseases exhibit a common pathologic feature, ubiquitinated intranuclear inclusions affecting myocytes, osteoclasts and neurons. Moreover, knock-in cell lines harboring MSP variants show a reduction in nuclear VCP. Given that MSP is associated with neuronal intranuclear inclusions comprised of TDP-43 protein, we developed a cellular model whereby proteostatic stress results in the formation of insoluble intranuclear TDP-43 aggregates. Consistent with a loss of nuclear VCP function, cells harboring MSP variants or cells treated with VCP inhibitor exhibited decreased clearance of insoluble intranuclear TDP-43 aggregates. Moreover, we identified four novel compounds that activate VCP primarily by increasing D2 ATPase activity whereby pharmacologic VCP activation appears to enhance clearance of insoluble intranuclear TDP-43 aggregate. Our findings suggest that VCP function is important for nuclear protein homeostasis, that MSP may be the result of impaired nuclear proteostasis, and that VCP activation may be potential therapeutic by virtue of enhancing the clearance of intranuclear protein aggregates.
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Affiliation(s)
- Jessica M Phan
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, PA, USA
| | - Benjamin C Creekmore
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, PA, USA
| | - Aivi T Nguyen
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, PA, USA
| | - Darya D Bershadskaya
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, PA, USA
| | - Nabil F Darwich
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, PA, USA
| | - Edward B Lee
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, PA, USA
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