1
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Das S, Hegde S, Wagh N, Sudhakaran J, Roy AE, Deshpande G, Ratnaparkhi GS. Caspar specifies primordial germ cell count and identity in Drosophila melanogaster. eLife 2024; 13:RP98584. [PMID: 39671304 PMCID: PMC11643641 DOI: 10.7554/elife.98584] [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] [Indexed: 12/15/2024] Open
Abstract
Repurposing of pleiotropic factors during execution of diverse cellular processes has emerged as a regulatory paradigm. Embryonic development in metazoans is controlled by maternal factors deposited in the egg during oogenesis. Here, we explore maternal role(s) of Caspar (Casp), the Drosophila orthologue of human Fas-associated factor-1 (FAF1) originally implicated in host-defense as a negative regulator of NF-κB signaling. Maternal loss of either Casp or it's protein partner, transitional endoplasmic reticulum 94 (TER94) leads to partial embryonic lethality correlated with aberrant centrosome behavior, cytoskeletal abnormalities, and defective gastrulation. Although ubiquitously distributed, both proteins are enriched in the primordial germ cells (PGCs), and in keeping with the centrosome problems, mutant embryos display a significant reduction in the PGC count. Moreover, the total number of pole buds is directly proportional to the level of Casp. Consistently, it's 'loss' and 'gain' results in respective reduction and increase in the Oskar protein levels, the master determinant of PGC fate. To elucidate this regulatory loop, we analyzed several known components of mid-blastula transition and identify the translational repressor Smaug, a zygotic regulator of germ cell specification, as a potential critical target. We present a detailed structure-function analysis of Casp aimed at understanding its novel involvement during PGC development.
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Affiliation(s)
- Subhradip Das
- Department of Biology, Indian Institute of Science Education & ResearchPuneIndia
| | - Sushmitha Hegde
- Department of Biology, Indian Institute of Science Education & ResearchPuneIndia
| | - Neel Wagh
- Department of Biology, Indian Institute of Science Education & ResearchPuneIndia
| | - Jyothish Sudhakaran
- Department of Biology, Indian Institute of Science Education & ResearchPuneIndia
| | - Adheena Elsa Roy
- Department of Biology, Indian Institute of Science Education & ResearchPuneIndia
| | - Girish Deshpande
- Department of Biology, Indian Institute of Science Education & ResearchPuneIndia
- Department of Molecular Biology, Princeton UniversityPrincetonUnited States
| | - Girish S Ratnaparkhi
- Department of Biology, Indian Institute of Science Education & ResearchPuneIndia
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2
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Vanderhaeghe S, Prerad J, Tharkeshwar AK, Goethals E, Vints K, Beckers J, Scheveneels W, Debroux E, Princen K, Van Damme P, Fivaz M, Griffioen G, Van Den Bosch L. A pathogenic mutation in the ALS/FTD gene VCP induces mitochondrial hypermetabolism by modulating the permeability transition pore. Acta Neuropathol Commun 2024; 12:161. [PMID: 39390590 PMCID: PMC11465669 DOI: 10.1186/s40478-024-01866-0] [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: 08/14/2024] [Accepted: 09/23/2024] [Indexed: 10/12/2024] Open
Abstract
Valosin-containing protein (VCP) is a ubiquitously expressed type II AAA+ ATPase protein, implicated in both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). This study aimed to explore the impact of the disease-causing VCPR191Q/wt mutation on mitochondrial function using a CRISPR/Cas9-engineered neuroblastoma cell line. Mitochondria in these cells are enlarged, with a depolarized mitochondrial membrane potential associated with increased respiration and electron transport chain activity. Our results indicate that mitochondrial hypermetabolism could be caused, at least partially, by increased calcium-induced opening of the permeability transition pore (mPTP), leading to mild mitochondrial uncoupling. In conclusion, our findings reveal a central role of the ALS/FTD gene VCP in maintaining mitochondrial homeostasis and suggest a model of pathogenesis based on progressive alterations in mPTP physiology and mitochondrial energetics.
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Affiliation(s)
- Silke Vanderhaeghe
- Laboratory of Neurobiology, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, Leuven, Belgium
- Laboratory of Neurobiology, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- reMYND, Leuven, Belgium
| | | | - Arun Kumar Tharkeshwar
- Department of Human Genetics, KU Leuven - University of Leuven, Leuven, Belgium
- KU Leuven Institute for Single Cell Omics (LISCO), KU Leuven - University of Leuven, Leuven, Belgium
| | - Elien Goethals
- Laboratory of Neurobiology, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, Leuven, Belgium
- reMYND, Leuven, Belgium
| | - Katlijn Vints
- Electron Microscopy Platform and VIB-Bioimaging Core, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
| | - Jimmy Beckers
- Laboratory of Neurobiology, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, Leuven, Belgium
- Laboratory of Neurobiology, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
| | - Wendy Scheveneels
- Laboratory of Neurobiology, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, Leuven, Belgium
- Laboratory of Neurobiology, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
| | | | | | - Philip Van Damme
- Laboratory of Neurobiology, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, Leuven, Belgium
- Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | | | | | - Ludo Van Den Bosch
- Laboratory of Neurobiology, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, Leuven, Belgium.
- Laboratory of Neurobiology, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
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3
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Thulasidharan A, Garg L, Tendulkar S, Ratnaparkhi GS. Age-dependent dynamics of neuronal VAPB ALS inclusions in the adult brain. Neurobiol Dis 2024; 196:106517. [PMID: 38679111 DOI: 10.1016/j.nbd.2024.106517] [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: 02/12/2024] [Revised: 04/01/2024] [Accepted: 04/25/2024] [Indexed: 05/01/2024] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a relentlessly progressive and fatal disease, caused by the degeneration of upper and lower motor neurons within the brain and spinal cord in the ageing human. The dying neurons contain cytoplasmic inclusions linked to the onset and progression of the disease. Here, we use a Drosophila model of ALS8 (VAPP58S) to understand the modulation of these inclusions in the ageing adult brain. The adult VAPP58S fly shows progressive deterioration in motor function till its demise 25 days post-eclosion. The density of VAPP58S-positive brain inclusions is stable for 5-15 days of age. In contrast, adding a single copy of VAPWT to the VAPP58S animal leads to a large decrease in inclusion density with concomitant rescue of motor function and lifespan. ER stress, a contributing factor in disease, shows reduction with ageing for the disease model. Autophagy, rather than the Ubiquitin Proteasome system, is the dominant mechanism for aggregate clearance. We explored the ability of Drosophila Valosin-containing protein (VCP/TER94), the ALS14 locus, which is involved in cellular protein clearance, to regulate age-dependent aggregation. Contrary to expectation, TER94 overexpression increased VAPP58S punctae density, while its knockdown led to enhanced clearance. Expression of a dominant positive allele, TER94R152H, further stabilised VAPP58S puncta, cementing roles for an ALS8-ALS14 axis. Our results are explained by a mechanism where autophagy is modulated by TER94 knockdown. Our study sheds light on the complex regulatory events involved in the neuronal maintenance of ALS8 aggregates, suggesting a context-dependent switch between proteasomal and autophagy-based mechanisms as the larvae develop into an adult. A deeper understanding of the nucleation and clearance of the inclusions, which affect cellular stress and function, is essential for understanding the initiation and progression of ALS.
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Affiliation(s)
- Aparna Thulasidharan
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India
| | - Lovleen Garg
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India
| | - Shweta Tendulkar
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India
| | - Girish S Ratnaparkhi
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India.
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4
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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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5
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Pontifex CS, Zaman M, Fanganiello RD, Shutt TE, Pfeffer G. Valosin-Containing Protein (VCP): A Review of Its Diverse Molecular Functions and Clinical Phenotypes. Int J Mol Sci 2024; 25:5633. [PMID: 38891822 PMCID: PMC11172259 DOI: 10.3390/ijms25115633] [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: 03/19/2024] [Revised: 05/20/2024] [Accepted: 05/20/2024] [Indexed: 06/21/2024] Open
Abstract
In this review we examine the functionally diverse ATPase associated with various cellular activities (AAA-ATPase), valosin-containing protein (VCP/p97), its molecular functions, the mutational landscape of VCP and the phenotypic manifestation of VCP disease. VCP is crucial to a multitude of cellular functions including protein quality control, endoplasmic reticulum-associated degradation (ERAD), autophagy, mitophagy, lysophagy, stress granule formation and clearance, DNA replication and mitosis, DNA damage response including nucleotide excision repair, ATM- and ATR-mediated damage response, homologous repair and non-homologous end joining. VCP variants cause multisystem proteinopathy, and pathology can arise in several tissue types such as skeletal muscle, bone, brain, motor neurons, sensory neurons and possibly cardiac muscle, with the disease course being challenging to predict.
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Affiliation(s)
- Carly S. Pontifex
- Hotchkiss Brain Institute, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.S.P.); (M.Z.); (T.E.S.)
| | - Mashiat Zaman
- Hotchkiss Brain Institute, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.S.P.); (M.Z.); (T.E.S.)
- Alberta Child Health Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB T2N 1N4, Canada
| | | | - Timothy E. Shutt
- Hotchkiss Brain Institute, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.S.P.); (M.Z.); (T.E.S.)
- Alberta Child Health Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Gerald Pfeffer
- Hotchkiss Brain Institute, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.S.P.); (M.Z.); (T.E.S.)
- Alberta Child Health Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
- Heritage Medical Research Building 155, 3330 Hospital Dr NW, Calgary, AB T2N 4N1, Canada
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6
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Li M, Ding W, Deng Y, Zhao Y, Liu Q, Zhou Z. The AAA-ATPase Ter94 regulates wing size in Drosophila by suppressing the Hippo pathway. Commun Biol 2024; 7:533. [PMID: 38710747 PMCID: PMC11074327 DOI: 10.1038/s42003-024-06246-x] [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: 09/30/2023] [Accepted: 04/25/2024] [Indexed: 05/08/2024] Open
Abstract
Insect wing development is a fascinating and intricate process that involves the regulation of wing size through cell proliferation and apoptosis. In this study, we find that Ter94, an AAA-ATPase, is essential for proper wing size dependently on its ATPase activity. Loss of Ter94 enables the suppression of Hippo target genes. When Ter94 is depleted, it results in reduced wing size and increased apoptosis, which can be rescued by inhibiting the Hippo pathway. Biochemical experiments reveal that Ter94 reciprocally binds to Mer, a critical upstream component of the Hippo pathway, and disrupts its interaction with Ex and Kib. This disruption prevents the formation of the Ex-Mer-Kib complex, ultimately leading to the inactivation of the Hippo pathway and promoting proper wing development. Finally, we show that hVCP, the human homolog of Ter94, is able to substitute for Ter94 in modulating Drosophila wing size, underscoring their functional conservation. In conclusion, Ter94 plays a positive role in regulating wing size by interfering with the Ex-Mer-Kib complex, which results in the suppression of the Hippo pathway.
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Affiliation(s)
- Mingming Li
- College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Wenhao Ding
- College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Yanran Deng
- Key Laboratory of Biodiversity Conservation and Bioresource Utilization of Jiangxi Province, College of Life Sciences, Jiangxi Normal University, Nanchang, China
| | - Yunhe Zhao
- College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Qingxin Liu
- College of Life Sciences, Shandong Agricultural University, Tai'an, China.
| | - Zizhang Zhou
- College of Life Sciences, Shandong Agricultural University, Tai'an, China.
- Key Laboratory of Biodiversity Conservation and Bioresource Utilization of Jiangxi Province, College of Life Sciences, Jiangxi Normal University, Nanchang, China.
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7
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Ziff OJ, Harley J, Wang Y, Neeves J, Tyzack G, Ibrahim F, Skehel M, Chakrabarti AM, Kelly G, Patani R. Nucleocytoplasmic mRNA redistribution accompanies RNA binding protein mislocalization in ALS motor neurons and is restored by VCP ATPase inhibition. Neuron 2023; 111:3011-3027.e7. [PMID: 37480846 DOI: 10.1016/j.neuron.2023.06.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 05/09/2023] [Accepted: 06/22/2023] [Indexed: 07/24/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is characterized by nucleocytoplasmic mislocalization of the RNA-binding protein (RBP) TDP-43. However, emerging evidence suggests more widespread mRNA and protein mislocalization. Here, we employed nucleocytoplasmic fractionation, RNA sequencing, and mass spectrometry to investigate the localization of mRNA and protein in induced pluripotent stem cell-derived motor neurons (iPSMNs) from ALS patients with TARDBP and VCP mutations. ALS mutant iPSMNs exhibited extensive nucleocytoplasmic mRNA redistribution, RBP mislocalization, and splicing alterations. Mislocalized proteins exhibited a greater affinity for redistributed transcripts, suggesting a link between RBP mislocalization and mRNA redistribution. Notably, treatment with ML240, a VCP ATPase inhibitor, partially restored mRNA and protein localization in ALS mutant iPSMNs. ML240 induced changes in the VCP interactome and lysosomal localization and reduced oxidative stress and DNA damage. These findings emphasize the link between RBP mislocalization and mRNA redistribution in ALS motor neurons and highlight the therapeutic potential of VCP inhibition.
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Affiliation(s)
- Oliver J Ziff
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK; National Hospital for Neurology and Neurosurgery, University College London NHS Foundation Trust, WC1N 3BG London, UK.
| | - Jasmine Harley
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK; Institute of Molecular and Cell Biology, A(∗)STAR Research Entities, Singapore 138673, Singapore
| | - Yiran Wang
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK
| | - Jacob Neeves
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK
| | - Giulia Tyzack
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK
| | - Fairouz Ibrahim
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK
| | - Mark Skehel
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK
| | | | - Gavin Kelly
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK
| | - Rickie Patani
- The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, WC1N 3BG London, UK; National Hospital for Neurology and Neurosurgery, University College London NHS Foundation Trust, WC1N 3BG London, UK.
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8
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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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9
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Zheng J, Cao Y, Yang J, Jiang H. UBXD8 mediates mitochondria-associated degradation to restrain apoptosis and mitophagy. EMBO Rep 2022; 23:e54859. [PMID: 35979733 PMCID: PMC9535754 DOI: 10.15252/embr.202254859] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 07/20/2022] [Accepted: 08/04/2022] [Indexed: 08/08/2023] Open
Abstract
The hexameric AAA-ATPase valosin-containing protein (VCP) is essential for mitochondrial protein quality control. How VCP is recruited to mammalian mitochondria remains obscure. Here we report that UBXD8, an ER- and lipid droplet-localized VCP adaptor, also localizes to mitochondria and locally recruits VCP. UBXD8 associates with mitochondrial and ER ubiquitin E3 ligases and targets their substrates for degradation. Remarkably, both mitochondria- and ER-localized UBXD8 can degrade mitochondrial and ER substrates in cis and in trans. UBXD8 also associates with the TOM complex but is dispensable for translocation-associated degradation. UBXD8 knockout impairs the degradation of the pro-survival protein Mcl1 but surprisingly sensitizes cells to apoptosis and mitochondrial stresses. UBXD8 knockout also hyperactivates mitophagy. We identify pro-apoptotic BH3-only proteins Noxa, Bik, and Bnip3 as novel UBXD8 substrates and determine that UBXD8 inhibits apoptosis via degrading Noxa and restrains mitophagy via degrading Bnip3. Collectively, our characterizations reveal UBXD8 as the major mitochondrial adaptor of VCP and unveil its role in apoptosis and mitophagy regulation.
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Affiliation(s)
- Jing Zheng
- School of Life SciencesPeking UniversityBeijingChina
- National Institute of Biological SciencesBeijingChina
- Beijing Key Laboratory of Cell Biology for Animal AgingBeijingChina
| | - Yu Cao
- National Institute of Biological SciencesBeijingChina
- Beijing Key Laboratory of Cell Biology for Animal AgingBeijingChina
- College of Life SciencesBeijing Normal UniversityBeijingChina
| | - Jun Yang
- National Institute of Biological SciencesBeijingChina
- Beijing Key Laboratory of Cell Biology for Animal AgingBeijingChina
- School of Life SciencesTsinghua UniversityBeijingChina
| | - Hui Jiang
- School of Life SciencesPeking UniversityBeijingChina
- National Institute of Biological SciencesBeijingChina
- Beijing Key Laboratory of Cell Biology for Animal AgingBeijingChina
- Tsinghua Institute of Multidisciplinary Biomedical ResearchTsinghua UniversityBeijingChina
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10
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Cozzi M, Ferrari V. Autophagy Dysfunction in ALS: from Transport to Protein Degradation. J Mol Neurosci 2022; 72:1456-1481. [PMID: 35708843 PMCID: PMC9293831 DOI: 10.1007/s12031-022-02029-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/17/2022] [Indexed: 01/18/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting upper and lower motor neurons (MNs). Since the identification of the first ALS mutation in 1993, more than 40 genes have been associated with the disorder. The most frequent genetic causes of ALS are represented by mutated genes whose products challenge proteostasis, becoming unable to properly fold and consequently aggregating into inclusions that impose proteotoxic stress on affected cells. In this context, increasing evidence supports the central role played by autophagy dysfunctions in the pathogenesis of ALS. Indeed, in early stages of disease, high levels of proteins involved in autophagy are present in ALS MNs; but at the same time, with neurodegeneration progression, autophagy-mediated degradation decreases, often as a result of the accumulation of toxic protein aggregates in affected cells. Autophagy is a complex multistep pathway that has a central role in maintaining cellular homeostasis. Several proteins are involved in its tight regulation, and importantly a relevant fraction of ALS-related genes encodes products that directly take part in autophagy, further underlining the relevance of this key protein degradation system in disease onset and progression. In this review, we report the most relevant findings concerning ALS genes whose products are involved in the several steps of the autophagic pathway, from phagophore formation to autophagosome maturation and transport and finally to substrate degradation.
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Affiliation(s)
- Marta Cozzi
- Dipartimento Di Scienze Farmacologiche E Biomolecolari, Università Degli Studi Di Milano, 20133, Milan, Italy.
| | - Veronica Ferrari
- Dipartimento Di Scienze Farmacologiche E Biomolecolari, Università Degli Studi Di Milano, 20133, Milan, Italy.
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11
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Tendulkar S, Hegde S, Garg L, Thulasidharan A, Kaduskar B, Ratnaparkhi A, Ratnaparkhi GS. Caspar, an adapter for VAPB and TER94, modulates the progression of ALS8 by regulating IMD/NFκB mediated glial inflammation in a drosophila model of human disease. Hum Mol Genet 2022; 31:2857-2875. [PMID: 35377453 PMCID: PMC9433731 DOI: 10.1093/hmg/ddac076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/25/2022] [Accepted: 03/29/2022] [Indexed: 11/16/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal, late-onset, progressive motor neurodegenerative disorder. A key pathological feature of the disease is the presence of heavily ubiquitinated protein inclusions. Both the unfolded protein response and the ubiquitin–proteasome system appear significantly impaired in patients and animal models of ALS. We have studied cellular and molecular mechanisms involved in ALS using a vesicle-associated membrane protein-associated protein B (VAPB/ALS8) Drosophila model [Moustaqim-Barrette, A., Lin, Y.Q., Pradhan, S., Neely, G.G., Bellen, H.J. and Tsuda, H. (2014) The ALS 8 protein, VAP, is required for ER protein quality control. Hum. Mol. Genet., 23, 1975–1989], which mimics many systemic aspects of the human disease. Here, we show that VAPB, located on the cytoplasmic face of the endoplasmic reticulum membrane, interacts with Caspar, an orthologue of human fas associated factor 1 (FAF1). Caspar, in turn, interacts with transitional endoplasmic reticulum ATPase (TER94), a fly orthologue of ALS14 (VCP/p97, valosin-containing protein). Caspar overexpression in the glia extends lifespan and also slows the progression of motor dysfunction in the ALS8 disease model, a phenomenon that we ascribe to its ability to restrain age-dependent inflammation, which is modulated by Relish/NFκB signalling. Caspar binds to VAPB via an FFAT motif, and we find that Caspar’s ability to negatively regulate NFκB signalling is not dependent on the VAPB:Caspar interaction. We hypothesize that Caspar is a key molecule in the pathogenesis of ALS. The VAPB:Caspar:TER94 complex appears to be a candidate for regulating both protein homeostasis and NFκB signalling, with our study highlighting a role for Caspar in glial inflammation. We project human FAF1 as an important protein target to alleviate the progression of motor neuron disease.
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Affiliation(s)
- Shweta Tendulkar
- Indian Institute of Science Education & Research (IISER) Pune 411008, India
| | - Sushmitha Hegde
- Indian Institute of Science Education & Research (IISER) Pune 411008, India
| | - Lovleen Garg
- Indian Institute of Science Education & Research (IISER) Pune 411008, India
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12
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Neurons undergo pathogenic metabolic reprogramming in models of familial ALS. Mol Metab 2022; 60:101468. [PMID: 35248787 PMCID: PMC8958550 DOI: 10.1016/j.molmet.2022.101468] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 02/25/2022] [Accepted: 02/25/2022] [Indexed: 11/21/2022] Open
Abstract
Objectives Methods Results Conclusions Our work is the first to perform a comprehensive and quantitative analysis of intermediary metabolism in neurons in the setting of fALS causing gene products. Because the cardinal feature of ALS is death of motor neurons, these new studies are directly relevant to the pathogenesis of ALS. Our functional interrogations begin to unpack how metabolic re-wiring is induced by fALS genes and it will be very interesting, in the future, to gain insight in amino acid fueling of the TCA cycle. We suspect pleiotropic effects of amino acid fueling, and this may lead to very targeted therapeutic interventions.
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13
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Harley J, Hagemann C, Serio A, Patani R. TDP-43 and FUS mislocalization in VCP mutant motor neurons is reversed by pharmacological inhibition of the VCP D2 ATPase domain. Brain Commun 2021; 3:fcab166. [PMID: 34396115 PMCID: PMC8361416 DOI: 10.1093/braincomms/fcab166] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 05/06/2021] [Accepted: 05/14/2021] [Indexed: 12/02/2022] Open
Abstract
RNA binding proteins have been shown to play a key role in the pathogenesis of amyotrophic lateral sclerosis (ALS). Mutations in valosin-containing protein (VCP/p97) cause ALS and exhibit the hallmark nuclear-to-cytoplasmic mislocalization of RNA binding proteins (RBPs). However, the mechanism by which mutations in VCP lead to this mislocalization of RBPs remains incompletely resolved. To address this, we used human-induced pluripotent stem cell-derived motor neurons carrying VCP mutations. We first demonstrate reduced nuclear-to-cytoplasmic ratios of transactive response DNA-binding protein 43 (TDP-43), fused in sarcoma/translocated in liposarcoma (FUS) and splicing factor proline and glutamine rich (SFPQ) in VCP mutant motor neurons. Upon closer analysis, we also find these RBPs are mislocalized to motor neuron neurites themselves. To address the hypothesis that altered function of the D2 ATPase domain of VCP causes RBP mislocalization, we used pharmacological inhibition of this domain in control motor neurons and found this does not recapitulate RBP mislocalization phenotypes. However, D2 domain inhibition in VCP mutant motor neurons was able to robustly reverse mislocalization of both TDP-43 and FUS, in addition to partially relocalizing SFPQ from the neurites. Together these results argue for a gain-of-function of D2 ATPase in VCP mutant human motor neurons driving the mislocalization of TDP-43 and FUS. Our data raise the intriguing possibility of harnessing VCP D2 ATPase inhibitors in the treatment of VCP-related ALS.
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Affiliation(s)
- Jasmine Harley
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK.,The Francis Crick Institute, London NW1 1AT, UK
| | - Cathleen Hagemann
- The Francis Crick Institute, London NW1 1AT, UK.,Centre for Craniofacial & Regenerative Biology, King's College London, London WC2R 2LS, UK
| | - Andrea Serio
- The Francis Crick Institute, London NW1 1AT, UK.,Centre for Craniofacial & Regenerative Biology, King's College London, London WC2R 2LS, UK
| | - Rickie Patani
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK.,The Francis Crick Institute, London NW1 1AT, UK
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14
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VCP maintains nuclear size by regulating the DNA damage-associated MDC1-p53-autophagy axis in Drosophila. Nat Commun 2021; 12:4258. [PMID: 34253734 PMCID: PMC8275807 DOI: 10.1038/s41467-021-24556-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 06/24/2021] [Indexed: 12/20/2022] Open
Abstract
The maintenance of constant karyoplasmic ratios suggests that nuclear size has physiological significance. Nuclear size anomalies have been linked to malignant transformation, although the mechanism remains unclear. By expressing dominant-negative TER94 mutants in Drosophila photoreceptors, here we show disruption of VCP (valosin-containing protein, human TER94 ortholog), a ubiquitin-dependent segregase, causes progressive nuclear size increase. Loss of VCP function leads to accumulations of MDC1 (mediator of DNA damage checkpoint protein 1), connecting DNA damage or associated responses to enlarged nuclei. TER94 can interact with MDC1 and decreases MDC1 levels, suggesting that MDC1 is a VCP substrate. Our evidence indicates that MDC1 accumulation stabilizes p53A, leading to TER94K2A-associated nuclear size increase. Together with a previous report that p53A disrupts autophagic flux, we propose that the stabilization of p53A in TER94K2A-expressing cells likely hinders the removal of nuclear content, resulting in aberrant nuclear size increase. Cells maintain a constant cytoplasm to nucleus volume ratio, although the role of DNA damage is not well explored. Here, the authors use Drosophila to connect TER94, the fly homolog of VCP, to disruption of DNA damage repair, leading to ubiquitinated Mu2 protein accumulation and enlarged nuclei.
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15
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Wall JM, Basu A, Zunica ERM, Dubuisson OS, Pergola K, Broussard JP, Kirwan JP, Axelrod CL, Johnson AE. CRISPR/Cas9-engineered Drosophila knock-in models to study VCP diseases. Dis Model Mech 2021; 14:dmm048603. [PMID: 34160014 PMCID: PMC8325010 DOI: 10.1242/dmm.048603] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 06/11/2021] [Indexed: 01/08/2023] Open
Abstract
Mutations in Valosin Containing Protein (VCP) are associated with several degenerative diseases, including multisystem proteinopathy (MSP-1) and amyotrophic lateral sclerosis. However, patients with VCP mutations vary widely in their pathology and clinical penetrance, making it difficult to devise effective treatment strategies. A deeper understanding of how each mutation affects VCP function could enhance the prediction of clinical outcomes and design of personalized treatment options. The power of a genetically tractable model organism coupled with well-established in vivo assays and a relatively short life cycle make Drosophila an attractive system to study VCP disease pathogenesis. Using CRISPR/Cas9, we have generated individual Drosophila knock-in mutants that include nine hereditary VCP disease mutations. Our models display many hallmarks of VCP-mediated degeneration, including progressive decline in mobility, protein aggregate accumulation and defects in lysosomal and mitochondrial function. We also made some novel and unexpected findings, including nuclear morphology defects and sex-specific phenotypic differences in several mutants. Taken together, the Drosophila VCP disease models generated in this study will be useful for studying the etiology of individual VCP patient mutations and testing potential genetic and/or pharmacological therapies.
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Affiliation(s)
- Jordan M. Wall
- Louisiana State University, Department of Biological Sciences, Baton Rouge, LA 70803, USA
| | - Ankita Basu
- Louisiana State University, Department of Biological Sciences, Baton Rouge, LA 70803, USA
| | - Elizabeth R. M. Zunica
- Integrated Physiology and Molecular Medicine Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Olga S. Dubuisson
- Louisiana State University, Department of Biological Sciences, Baton Rouge, LA 70803, USA
| | - Kathryn Pergola
- Integrated Physiology and Molecular Medicine Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
- Department of Translational Services, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Joshua P. Broussard
- Louisiana State University, Department of Biological Sciences, Baton Rouge, LA 70803, USA
| | - John P. Kirwan
- Integrated Physiology and Molecular Medicine Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Christopher L. Axelrod
- Integrated Physiology and Molecular Medicine Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
- Department of Translational Services, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Alyssa E. Johnson
- Louisiana State University, Department of Biological Sciences, Baton Rouge, LA 70803, USA
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16
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Johnson AE, Orr BO, Fetter RD, Moughamian AJ, Primeaux LA, Geier EG, Yokoyama JS, Miller BL, Davis GW. SVIP is a molecular determinant of lysosomal dynamic stability, neurodegeneration and lifespan. Nat Commun 2021; 12:513. [PMID: 33479240 PMCID: PMC7820495 DOI: 10.1038/s41467-020-20796-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 12/17/2020] [Indexed: 12/12/2022] Open
Abstract
Missense mutations in Valosin-Containing Protein (VCP) are linked to diverse degenerative diseases including IBMPFD, amyotrophic lateral sclerosis (ALS), muscular dystrophy and Parkinson's disease. Here, we characterize a VCP-binding co-factor (SVIP) that specifically recruits VCP to lysosomes. SVIP is essential for lysosomal dynamic stability and autophagosomal-lysosomal fusion. SVIP mutations cause muscle wasting and neuromuscular degeneration while muscle-specific SVIP over-expression increases lysosomal abundance and is sufficient to extend lifespan in a context, stress-dependent manner. We also establish multiple links between SVIP and VCP-dependent disease in our Drosophila model system. A biochemical screen identifies a disease-causing VCP mutation that prevents SVIP binding. Conversely, over-expression of an SVIP mutation that prevents VCP binding is deleterious. Finally, we identify a human SVIP mutation and confirm the pathogenicity of this mutation in our Drosophila model. We propose a model for VCP disease based on the differential, co-factor-dependent recruitment of VCP to intracellular organelles.
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Affiliation(s)
- Alyssa E Johnson
- Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, 94158, USA
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Brian O Orr
- Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Richard D Fetter
- Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Armen J Moughamian
- Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, 94158, USA
- Department of Neurology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Logan A Primeaux
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Ethan G Geier
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Jennifer S Yokoyama
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Bruce L Miller
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Graeme W Davis
- Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, 94158, USA.
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17
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Escobar-Henriques M, Anton V. Mitochondrial Surveillance by Cdc48/p97: MAD vs. Membrane Fusion. Int J Mol Sci 2020; 21:E6841. [PMID: 32961852 PMCID: PMC7555132 DOI: 10.3390/ijms21186841] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 11/16/2022] Open
Abstract
Cdc48/p97 is a ring-shaped, ATP-driven hexameric motor, essential for cellular viability. It specifically unfolds and extracts ubiquitylated proteins from membranes or protein complexes, mostly targeting them for proteolytic degradation by the proteasome. Cdc48/p97 is involved in a multitude of cellular processes, reaching from cell cycle regulation to signal transduction, also participating in growth or death decisions. The role of Cdc48/p97 in endoplasmic reticulum-associated degradation (ERAD), where it extracts proteins targeted for degradation from the ER membrane, has been extensively described. Here, we present the roles of Cdc48/p97 in mitochondrial regulation. We discuss mitochondrial quality control surveillance by Cdc48/p97 in mitochondrial-associated degradation (MAD), highlighting the potential pathologic significance thereof. Furthermore, we present the current knowledge of how Cdc48/p97 regulates mitofusin activity in outer membrane fusion and how this may impact on neurodegeneration.
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Affiliation(s)
- Mafalda Escobar-Henriques
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Straße 26, 50931 Cologne, Germany;
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18
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Chi H, Sun L, Shiu RH, Han R, Hsieh CP, Wei TM, Lo CC, Chang HY, Sang TK. Cleavage of human tau at Asp421 inhibits hyperphosphorylated tau induced pathology in a Drosophila model. Sci Rep 2020; 10:13482. [PMID: 32778728 PMCID: PMC7417559 DOI: 10.1038/s41598-020-70423-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 07/29/2020] [Indexed: 11/09/2022] Open
Abstract
Hyperphosphorylated and truncated tau variants are enriched in neuropathological aggregates in diseases known as tauopathies. However, whether the interaction of these posttranslational modifications affects tau toxicity as a whole remains unresolved. By expressing human tau with disease-related Ser/Thr residues to simulate hyperphosphorylation, we show that despite severe neurodegeneration in full-length tau, with the truncation at Asp421, the toxicity is ameliorated. Cytological and biochemical analyses reveal that hyperphosphorylated full-length tau distributes in the soma, the axon, and the axonal terminal without evident distinction, whereas the Asp421-truncated version is mostly restricted from the axonal terminal. This discrepancy is correlated with the fact that fly expressing hyperphosphorylated full-length tau, but not Asp421-cleaved one, develops axonopathy lesions, including axonal spheroids and aberrant actin accumulations. The reduced presence of hyperphosphorylated tau in the axonal terminal is corroborated with the observation that flies expressing Asp421-truncated variants showed less motor deficit, suggesting synaptic function is preserved. The Asp421 cleavage of tau is a proteolytic product commonly found in the neurofibrillary tangles. Our finding suggests the coordination of different posttranslational modifications on tau may have an unexpected impact on the protein subcellular localization and cytotoxicity, which may be valuable when considering tau for therapeutic purposes.
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Affiliation(s)
- Hao Chi
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Lee Sun
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Ren-Huei Shiu
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Rui Han
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Chien-Ping Hsieh
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Tzu-Min Wei
- Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Chung-Chuan Lo
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, 30013, Taiwan.,Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, 30013, Taiwan.,Brain Research Center, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Hui-Yun Chang
- Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, 30013, Taiwan.,Department of Medical Science, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Tzu-Kang Sang
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan. .,Brain Research Center, National Tsing Hua University, Hsinchu, 30013, Taiwan. .,Department of Life Science, National Tsing Hua University, Hsinchu, 30013, Taiwan.
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19
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Zhang T, Hay BA, Guo M. Generation, Analyzing and in-vivo Drug Treatment of Drosophila Models with IBMPFD. Bio Protoc 2020; 10:e3621. [PMID: 33659294 DOI: 10.21769/bioprotoc.3621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 02/16/2020] [Accepted: 03/10/2020] [Indexed: 11/02/2022] Open
Abstract
Missense mutations of p97/cdc48/Valosin-containing protein (VCP) cause inclusion body myopathy, Paget disease with frontotemporal dementia (IBMPFD) and other neurodegenerative diseases. The pathological mechanism of IBMPFD is not clear and there is no treatment. We generated Drosophila models of IBMPFD in adult flight muscle in vivo. Here we describe a variety of assays to characterize disease pathology and dissect disease mechanism, and the consequences of in vivo feeding of VCP inhibitors.
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Affiliation(s)
- Ting Zhang
- Department of Neurology, UCLA David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Bruce A Hay
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Ming Guo
- Department of Neurology, UCLA David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.,Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.,California Nanosystems Institute at UCLA, Los Angeles, CA 90095, USA
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20
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Rycenga HB, Wolfe KB, Yeh ES, Long DT. Uncoupling of p97 ATPase activity has a dominant negative effect on protein extraction. Sci Rep 2019; 9:10329. [PMID: 31316150 PMCID: PMC6637110 DOI: 10.1038/s41598-019-46949-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 07/04/2019] [Indexed: 12/13/2022] Open
Abstract
p97 is a highly abundant, homohexameric AAA+ ATPase that performs a variety of essential cellular functions. Characterized as a ubiquitin-selective chaperone, p97 recognizes proteins conjugated to K48-linked polyubiquitin chains and promotes their removal from chromatin and other molecular complexes. Changes in p97 expression or activity are associated with the development of cancer and several related neurodegenerative disorders. Although pathogenic p97 mutations cluster in and around p97’s ATPase domains, mutant proteins display normal or elevated ATPase activity. Here, we show that one of the most common p97 mutations (R155C) retains ATPase activity, but is functionally defective. p97-R155C can be recruited to ubiquitinated substrates on chromatin, but is unable to promote substrate removal. As a result, p97-R155C acts as a dominant negative, blocking protein extraction by a similar mechanism to that observed when p97’s ATPase activity is inhibited or inactivated. However, unlike ATPase-deficient proteins, p97-R155C consumes excess ATP, which can hinder high-energy processes. Together, our results shed new insight into how pathogenic mutations in p97 alter its cellular function, with implications for understanding the etiology and treatment of p97-associated diseases.
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Affiliation(s)
- Halley B Rycenga
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Kelly B Wolfe
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Elizabeth S Yeh
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - David T Long
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, 29425, USA.
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21
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Ubiquitin- and ATP-dependent unfoldase activity of P97/VCP•NPLOC4•UFD1L is enhanced by a mutation that causes multisystem proteinopathy. Proc Natl Acad Sci U S A 2017; 114:E4380-E4388. [PMID: 28512218 DOI: 10.1073/pnas.1706205114] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
p97 is a "segregase" that plays a key role in numerous ubiquitin (Ub)-dependent pathways such as ER-associated degradation. It has been hypothesized that p97 extracts proteins from membranes or macromolecular complexes to enable their proteasomal degradation; however, the complex nature of p97 substrates has made it difficult to directly observe the fundamental basis for this activity. To address this issue, we developed a soluble p97 substrate-Ub-GFP modified with K48-linked ubiquitin chains-for in vitro p97 activity assays. We demonstrate that WT p97 can unfold proteins and that this activity is dependent on the p97 adaptor NPLOC4-UFD1L, ATP hydrolysis, and substrate ubiquitination, with branched chains providing maximal stimulation. Furthermore, we show that a p97 mutant that causes inclusion body myopathy, Paget's disease of bone, and frontotemporal dementia in humans unfolds substrate faster, suggesting that excess activity may underlie pathogenesis. This work overcomes a significant barrier in the study of p97 and will allow the future dissection of p97 mechanism at a level of detail previously unattainable.
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22
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Liu YJ, Tsai PY, Chern Y. Energy Homeostasis and Abnormal RNA Metabolism in Amyotrophic Lateral Sclerosis. Front Cell Neurosci 2017; 11:126. [PMID: 28522961 PMCID: PMC5415567 DOI: 10.3389/fncel.2017.00126] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/18/2017] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease that is clinically characterized by progressive muscle weakness and impaired voluntary movement due to the loss of motor neurons in the brain, brain stem and spinal cord. To date, no effective treatment is available. Ample evidence suggests that impaired RNA homeostasis and abnormal energy status are two major pathogenesis pathways in ALS. In the present review article, we focus on recent studies that report molecular insights of both pathways, and discuss the possibility that energy dysfunction might negatively regulate RNA homeostasis via the impairment of cytoplasmic-nuclear shuttling in motor neurons and subsequently contribute to the development of ALS.
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Affiliation(s)
- Yu-Ju Liu
- Division of Neuroscience, Institute of Biomedical Sciences, Academia SinicaTaipei, Taiwan
| | - Po-Yi Tsai
- Division of Neuroscience, Institute of Biomedical Sciences, Academia SinicaTaipei, Taiwan
| | - Yijuang Chern
- Division of Neuroscience, Institute of Biomedical Sciences, Academia SinicaTaipei, Taiwan
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23
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Zhang T, Mishra P, Hay BA, Chan D, Guo M. Valosin-containing protein (VCP/p97) inhibitors relieve Mitofusin-dependent mitochondrial defects due to VCP disease mutants. eLife 2017; 6. [PMID: 28322724 PMCID: PMC5360448 DOI: 10.7554/elife.17834] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 02/13/2017] [Indexed: 11/13/2022] Open
Abstract
Missense mutations of valosin-containing protein (VCP) cause an autosomal dominant disease known as inclusion body myopathy, Paget disease with frontotemporal dementia (IBMPFD) and other neurodegenerative disorders. The pathological mechanism of IBMPFD is not clear and there is no treatment. We show that endogenous VCP negatively regulates Mitofusin, which is required for outer mitochondrial membrane fusion. Because 90% of IBMPFD patients have myopathy, we generated an in vivo IBMPFD model in adult Drosophila muscle, which recapitulates disease pathologies. We show that common VCP disease mutants act as hyperactive alleles with respect to regulation of Mitofusin. Importantly, VCP inhibitors suppress mitochondrial defects, muscle tissue damage and cell death associated with IBMPFD models in Drosophila. These inhibitors also suppress mitochondrial fusion and respiratory defects in IBMPFD patient fibroblasts. These results suggest that VCP disease mutants cause IBMPFD through a gain-of-function mechanism, and that VCP inhibitors have therapeutic value.
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Affiliation(s)
- Ting Zhang
- Department of Neurology, UCLA David Geffen School of Medicine, University of California, Los Angele, United States
| | - Prashant Mishra
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Bruce A Hay
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - David Chan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Ming Guo
- Department of Neurology, UCLA David Geffen School of Medicine, University of California, Los Angele, United States.,Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, University of California, Los Angeles, United States
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24
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Guo X, Sun X, Hu D, Wang YJ, Fujioka H, Vyas R, Chakrapani S, Joshi AU, Luo Y, Mochly-Rosen D, Qi X. VCP recruitment to mitochondria causes mitophagy impairment and neurodegeneration in models of Huntington's disease. Nat Commun 2016; 7:12646. [PMID: 27561680 PMCID: PMC5007466 DOI: 10.1038/ncomms12646] [Citation(s) in RCA: 160] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 07/20/2016] [Indexed: 02/06/2023] Open
Abstract
Mutant Huntingtin (mtHtt) causes neurodegeneration in Huntington's disease (HD) by evoking defects in the mitochondria, but the underlying mechanisms remains elusive. Our proteomic analysis identifies valosin-containing protein (VCP) as an mtHtt-binding protein on the mitochondria. Here we show that VCP is selectively translocated to the mitochondria, where it is bound to mtHtt in various HD models. Mitochondria-accumulated VCP elicits excessive mitophagy, causing neuronal cell death. Blocking mtHtt/VCP mitochondrial interaction with a peptide, HV-3, abolishes VCP translocation to the mitochondria, corrects excessive mitophagy and reduces cell death in HD mouse- and patient-derived cells and HD transgenic mouse brains. Treatment with HV-3 reduces behavioural and neuropathological phenotypes of HD in both fragment- and full-length mtHtt transgenic mice. Our findings demonstrate a causal role of mtHtt-induced VCP mitochondrial accumulation in HD pathogenesis and suggest that the peptide HV-3 might be a useful tool for developing new therapeutics to treat HD.
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Affiliation(s)
- Xing Guo
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | - XiaoYan Sun
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | - Di Hu
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | - Ya-Juan Wang
- Center for Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | - Hisashi Fujioka
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | - Rajan Vyas
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | - Sudha Chakrapani
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | - Amit Umesh Joshi
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94043, USA
| | - Yu Luo
- Department of Neurosurgery, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | - Daria Mochly-Rosen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94043, USA
| | - Xin Qi
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
- Center for Mitochondrial Disease, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
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Carrì MT, D'Ambrosi N, Cozzolino M. Pathways to mitochondrial dysfunction in ALS pathogenesis. Biochem Biophys Res Commun 2016; 483:1187-1193. [PMID: 27416757 DOI: 10.1016/j.bbrc.2016.07.055] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 07/10/2016] [Indexed: 12/20/2022]
Abstract
Alterations in the structure and functions of mitochondria are a typical trait of Amyotrophic Lateral Sclerosis, a neurodegenerative disease characterized by a prominent degeneration of upper and lower motor neurons. The known gene mutations that are responsible for a small fraction of ALS cases point to a complex interplay between different mechanisms in the disease pathogenesis. Here we will briefly overview the genetic and mechanistic evidence that make dysfunction of mitochondria a candidate major player in this process.
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Affiliation(s)
- Maria Teresa Carrì
- Department of Biology, Università di Roma "Tor Vergata", Via della Ricerca Scientifica, 00133, Rome, Italy; Fondazione Santa Lucia, IRCCS, Via del Fosso di Fiorano 64, 00143, Rome, Italy.
| | - Nadia D'Ambrosi
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168, Rome, Italy.
| | - Mauro Cozzolino
- Institute of Translational Pharmacology, CNR, Via del Fosso del Cavaliere 100, 00133, Rome, Italy.
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26
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Viswanathan MC, Blice-Baum AC, Sang TK, Cammarato A. Cardiac-Restricted Expression of VCP/TER94 RNAi or Disease Alleles Perturbs Drosophila Heart Structure and Impairs Function. J Cardiovasc Dev Dis 2016; 3. [PMID: 27500162 PMCID: PMC4973812 DOI: 10.3390/jcdd3020019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Valosin-containing protein (VCP) is a highly conserved mechanoenzyme that helps maintain protein homeostasis in all cells and serves specialized functions in distinct cell types. In skeletal muscle, it is critical for myofibrillogenesis and atrophy. However, little is known about VCP’s role(s) in the heart. Its functional diversity is determined by differential binding of distinct cofactors/adapters, which is likely disrupted during disease. VCP mutations cause multisystem proteinopathy (MSP), a pleiotropic degenerative disorder that involves inclusion body myopathy. MSP patients display progressive muscle weakness. They also exhibit cardiomyopathy and die from cardiac and respiratory failure, which are consistent with critical myocardial roles for the enzyme. Nonetheless, efficient models to interrogate VCP in cardiac muscle remain underdeveloped and poorly studied. Here, we investigated the significance of VCP and mutant VCP in the Drosophila heart. Cardiac-restricted RNAi-mediated knockdown of TER94, the Drosophila VCP homolog, severely perturbed myofibrillar organization and heart function in adult flies. Furthermore, expression of MSP disease-causing alleles engendered cardiomyopathy in adults and structural defects in embryonic hearts. Drosophila may therefore serve as a valuable model for examining role(s) of VCP in cardiogenesis and for identifying novel heart-specific VCP interactions, which when disrupted via mutation, contribute to or elicit cardiac pathology.
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Affiliation(s)
- Meera C. Viswanathan
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Ross 1050, 720 Rutland Avenue, Baltimore, MD 21205, USA; (M.C.V.); (A.C.B.-B.)
| | - Anna C. Blice-Baum
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Ross 1050, 720 Rutland Avenue, Baltimore, MD 21205, USA; (M.C.V.); (A.C.B.-B.)
| | - Tzu-Kang Sang
- Institute of Biotechnology & Department of Life Science, National Tsing Hua University, Hsinchu City 30013, Taiwan;
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Ross 1050, 720 Rutland Avenue, Baltimore, MD 21205, USA; (M.C.V.); (A.C.B.-B.)
- Department of Physiology, Johns Hopkins University, Ross 1050, 720 Rutland Avenue, Baltimore, MD 21205, USA
- Correspondence: ; Tel.: +1-410-955-1807; Fax: +1-410-502-2558
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Wang T, Xu W, Qin M, Yang Y, Bao P, Shen F, Zhang Z, Xu J. Pathogenic Mutations in the Valosin-containing Protein/p97(VCP) N-domain Inhibit the SUMOylation of VCP and Lead to Impaired Stress Response. J Biol Chem 2016; 291:14373-14384. [PMID: 27226613 DOI: 10.1074/jbc.m116.729343] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Indexed: 11/06/2022] Open
Abstract
Valosin-containing protein/p97(VCP) is a hexameric ATPase vital to protein degradation during endoplasmic reticulum stress. It regulates diverse cellular functions including autophagy, chromatin remodeling, and DNA repair. In addition, mutations in VCP cause inclusion body myopathy, Paget disease of the bone, and frontotemporal dementia (IBMPFD), as well as amyotrophic lateral sclerosis. Nevertheless, how the VCP activities were regulated and how the pathogenic mutations affect the function of VCP during stress are not unclear. Here we show that the small ubiquitin-like modifier (SUMO)-ylation of VCP is a normal stress response inhibited by the disease-causing mutations in the N-domain. Under oxidative and endoplasmic reticulum stress conditions, the SUMOylation of VCP facilitates the distribution of VCP to stress granules and nucleus, and promotes the VCP hexamer assembly. In contrast, pathogenic mutations in the VCP N-domain lead to reduced SUMOylation and weakened VCP hexamer formation upon stress. Defective SUMOylation of VCP also causes altered co-factor binding and attenuated endoplasmic reticulum-associated protein degradation. Furthermore, SUMO-defective VCP fails to protect against stress-induced toxicity in Drosophila Therefore, our results have revealed SUMOylation as a molecular signaling switch to regulate the distribution and functions of VCP during stress response, and suggest that deficiency in VCP SUMOylation caused by pathogenic mutations will render cells vulnerable to stress insults.
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Affiliation(s)
- Tao Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031
| | - Wangchao Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031,; University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Meiling Qin
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031
| | - Yi Yang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031,; University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Puhua Bao
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031
| | - Fuxiao Shen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031
| | - Zhenlin Zhang
- Department of Osteoporosis and Bone Diseases, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated People's No.6 Hospital, Shanghai 200233, China
| | - Jin Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031,.
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Wu X, Li L, Jiang H. Doa1 targets ubiquitinated substrates for mitochondria-associated degradation. J Cell Biol 2016; 213:49-63. [PMID: 27044889 PMCID: PMC4828692 DOI: 10.1083/jcb.201510098] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 03/02/2016] [Indexed: 02/07/2023] Open
Abstract
Wu et al. show that Doa1 recognizes and recruits ubiquitinated mitochondrial outer-membrane proteins to the Cdc48–proteasome degradation pathway. Doa1 deficiency sensitizes cells to mitochondrial oxidative stress. Mitochondria-associated degradation (MAD) mediated by the Cdc48 complex and proteasome degrades ubiquitinated mitochondrial outer-membrane proteins. MAD is critical for mitochondrial proteostasis, but it remains poorly characterized. We identified several mitochondrial Cdc48 substrates and developed a genetic screen assay to uncover regulators of the Cdc48-dependent MAD pathway. Surprisingly, we identified Doa1, a substrate-processing factor of Cdc48 that inhibits the degradation of some Cdc48 substrates, as a critical mediator of the turnover of mitochondrial Cdc48 substrates. Deletion of DOA1 causes the accumulation and mislocalization of substrates on mitochondria. Profiling of Cdc48 cofactors shows that Doa1 and Cdc48-Ufd1-Npl4 form a functional complex mediating MAD. Biochemically, Doa1 interacts with ubiquitinated substrates and facilitates substrate recruitment to the Cdc48-Ufd1-Npl4 complex. Functionally, Doa1 is critical for cell survival under mitochondrial oxidative stress, but not ER stress, conditions. Collectively, our results demonstrate the essential role of the Doa1–Cdc48-Ufd1-Npl4 complex in mitochondrial proteostasis and suggest that Doa1 plays dual roles on the Cdc48 complex.
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Affiliation(s)
- Xi Wu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Lanlan Li
- National Institute of Biological Sciences, Beijing 102206, China
| | - Hui Jiang
- National Institute of Biological Sciences, Beijing 102206, China
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29
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Johnson AE, Shu H, Hauswirth AG, Tong A, Davis GW. VCP-dependent muscle degeneration is linked to defects in a dynamic tubular lysosomal network in vivo. eLife 2015; 4. [PMID: 26167652 PMCID: PMC4574298 DOI: 10.7554/elife.07366] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Accepted: 07/11/2015] [Indexed: 12/25/2022] Open
Abstract
Lysosomes are classically viewed as vesicular structures to which cargos are delivered for degradation. Here, we identify a network of dynamic, tubular lysosomes that extends throughout Drosophila muscle, in vivo. Live imaging reveals that autophagosomes merge with tubular lysosomes and that lysosomal membranes undergo extension, retraction, fusion and fission. The dynamics and integrity of this tubular lysosomal network requires VCP, an AAA-ATPase that, when mutated, causes degenerative diseases of muscle, bone and neurons. We show that human VCP rescues the defects caused by loss of Drosophila VCP and overexpression of disease relevant VCP transgenes dismantles tubular lysosomes, linking tubular lysosome dysfunction to human VCP-related diseases. Finally, disruption of tubular lysosomes correlates with impaired autophagosome-lysosome fusion, increased cytoplasmic poly-ubiquitin aggregates, lipofuscin material, damaged mitochondria and impaired muscle function. We propose that VCP sustains sarcoplasmic proteostasis, in part, by controlling the integrity of a dynamic tubular lysosomal network. DOI:http://dx.doi.org/10.7554/eLife.07366.001 Mutations in a gene that produces a protein called Valosin-containing protein (VCP for short) causes degenerative diseases that affect the brain, muscle and bone. In nearly half of the individuals with these VCP-related diseases—which can also result in dementia, Paget's disease of the bone and amyotrophic lateral sclerosis (ALS)—the first symptom is muscle weakness. Currently, very little is known about how VCP affects muscles. Patients with VCP-related diseases often have problems clearing damaged proteins from their cells, and recent research suggests that VCP is important for forming a cellular structure known as a lysosome. Lysosomes contain powerful enzymes that destroy damaged proteins and other cellular structures that would otherwise accumulate in the cells. In most cells, lysosomes look like bubble-like compartments called vesicles. However, in some types of cells lysosomes have been observed to form a network of tubules that extend throughout the cell interior. However, it remains unclear what these tubules do, how they form in cells and whether they are altered in disease. Johnson et al. analyzed lysosomes in the muscle of the fruit fly species Drosophila melanogaster and discovered that lysosomes were in the form of a network of tubules that spread throughout each muscle cell. These tubules constantly changed in living muscles; extending, retracting, breaking and merging to form a large tubular lysosome network. When Johnson et al. reduced the amount of VCP produced by the muscle cells, via a method called RNA interference, the lysosome tubules broke down into vesicles that were no longer constantly changing. Modifying these defective fly muscle cells so that they produced the human VCP protein caused the tubules to form again. These results suggest that the human and fly VCP proteins are very similar and that they play a key role in either the ability of lysosomes to form tubules or the maintenance of existing tubules. Johnson et al. then engineered flies to produce a version of the VCP protein that had mutations commonly seen in individuals with degenerative diseases. Lysosome tubules did not form correctly in the muscle cells of these flies. These flies also had other abnormalities; for example, their cells showed a great build-up of damaged proteins, and their ability to move their muscles was weaker. These findings suggest that a network of lysosomal tubules is necessary for healthy muscle cells, but how and why these tubular networks are formed or maintained is still mysterious. What causes lysosomal membranes to form tubules? How do they break and fuse? And why are they necessary? Genetic experiments in fruit flies will be a great place to discover these mechanisms and understand the links to degenerative diseases in humans. DOI:http://dx.doi.org/10.7554/eLife.07366.002
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Affiliation(s)
- Alyssa E Johnson
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Huidy Shu
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Anna G Hauswirth
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Amy Tong
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Graeme W Davis
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
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Hatzihristidis T, Desai N, Hutchins AP, Meng TC, Tremblay ML, Miranda-Saavedra D. A Drosophila-centric view of protein tyrosine phosphatases. FEBS Lett 2015; 589:951-66. [PMID: 25771859 DOI: 10.1016/j.febslet.2015.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 12/30/2022]
Abstract
Most of our knowledge on protein tyrosine phosphatases (PTPs) is derived from human pathologies and mouse knockout models. These models largely correlate well with human disease phenotypes, but can be ambiguous due to compensatory mechanisms introduced by paralogous genes. Here we present the analysis of the PTP complement of the fruit fly and the complementary view that PTP studies in Drosophila will accelerate our understanding of PTPs in physiological and pathological conditions. With only 44 PTP genes, Drosophila represents a streamlined version of the human complement. Our integrated analysis places the Drosophila PTPs into evolutionary and functional contexts, thereby providing a platform for the exploitation of the fly for PTP research and the transfer of knowledge onto other model systems.
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Affiliation(s)
- Teri Hatzihristidis
- Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue, Montreal, Québec H3A 1A3, Canada; Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Nikita Desai
- Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue, Montreal, Québec H3A 1A3, Canada; Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Andrew P Hutchins
- Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, Guangdong 510530, China
| | - Tzu-Ching Meng
- Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan; Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Michel L Tremblay
- Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue, Montreal, Québec H3A 1A3, Canada; Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada; Department of Biochemistry, McGill University, Montreal, Quebec, Canada.
| | - Diego Miranda-Saavedra
- World Premier International (WPI) Immunology Frontier Research Center (IFReC), Osaka University, 3-1 Yamadaoka, Suita 565-0871, Osaka, Japan; Centro de Biología Molecular Severo Ochoa, CSIC/Universidad Autónoma de Madrid, 28049 Madrid, Spain; IE Business School, IE University, María de Molina 31 bis, 28006 Madrid, Spain.
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31
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Zeng Z, de Gorter DJJ, Kowalski M, ten Dijke P, Shimmi O. Ter94/VCP is a novel component involved in BMP signaling. PLoS One 2014; 9:e114475. [PMID: 25469707 PMCID: PMC4255028 DOI: 10.1371/journal.pone.0114475] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 11/10/2014] [Indexed: 11/18/2022] Open
Abstract
Bone morphogenetic proteins (BMPs), a subgroup of the transforming growth factor (TGF)-β family, transduce their signal through multiple components downstream of their receptors. Even though the components involved in the BMP signaling pathway have been intensely studied, many molecules mediating BMP signaling remain to be addressed. To identify novel components that participate in BMP signaling, RNA interference (RNAi)-based screening was established by detecting phosphorylated Mad (pMad) in Drosophila S2 cells. Ter94, a member of the family of AAA ATPases, was identified as a novel mediator of BMP signaling, which is required for the phosphorylation of Mad in Drosophila S2 cells. Moreover, the mammalian orthlog of Ter94 valosin-containing protein (VCP) plays a critical role in the BMP-Smad1/5/8 signaling pathway in mammalian cells. Genetic evidence suggests that Ter94 is involved in the dorsal-ventral patterning of the Drosophila early embryo through regulating decapentaplegic (Dpp)/BMP signals. Taken together, our data suggest that Ter94/VCP appears to be an evolutionarily conserved component that regulates BMP-Smad1/5/8 signaling.
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Affiliation(s)
- Zhao Zeng
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - David J. J. de Gorter
- Department of Molecular Cell Biology and Cancer Genomics Centre Netherlands, Leiden University Medical Centre, Leiden, The Netherlands
| | - Maria Kowalski
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Peter ten Dijke
- Department of Molecular Cell Biology and Cancer Genomics Centre Netherlands, Leiden University Medical Centre, Leiden, The Netherlands
| | - Osamu Shimmi
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- * E-mail:
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32
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Delabaere L, Orsi G, Sapey-Triomphe L, Horard B, Couble P, Loppin B. The Spartan Ortholog Maternal Haploid Is Required for Paternal Chromosome Integrity in the Drosophila Zygote. Curr Biol 2014; 24:2281-7. [DOI: 10.1016/j.cub.2014.08.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 07/05/2014] [Accepted: 08/06/2014] [Indexed: 11/28/2022]
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Liang CJ, Chang YC, Chang HC, Wang CK, Hung YC, Lin YE, Chan CC, Chen CH, Chang HY, Sang TK. Derlin-1 regulates mutant VCP-linked pathogenesis and endoplasmic reticulum stress-induced apoptosis. PLoS Genet 2014; 10:e1004675. [PMID: 25255315 PMCID: PMC4177747 DOI: 10.1371/journal.pgen.1004675] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 08/14/2014] [Indexed: 12/13/2022] Open
Abstract
Mutations in VCP (Valosin-containing protein), an AAA ATPase critical for ER-associated degradation, are linked to IBMPFD (Inclusion body myopathy with Paget disease and frontotemporal dementia). Using a Drosophila IBMPFD model, we have identified the ER protein Derlin-1 as a modifier of pathogenic TER94 (the fly VCP homolog) mutants. Derlin-1 binds to TER94 directly, and this interaction is essential for Derlin-1 overexpression to suppress the pathogenic TER94-induced neurodegeneration. Derlin-1 overexpression reduces the elevated ATPase activity of pathogenic TER94, implying that IBMPFD is caused by ATPase hyper-activation. Under physiological condition, Derlin-1 expression is increased upon ER stress to recruit TER94 to the ER. However, in response to severe ER stress, Derlin-1 is required for activating apoptosis to eliminate damaged cells. This pro-apoptotic response is mimicked by Derlin-1 overexpression, which elicits acute ER stress and triggers apoptosis via a novel C-terminal motif (α). As this Derlin-1-dependent cell death is negated by TER94 overexpression, we propose that while Derlin-1 and VCP work cooperatively in ER stress response, their imbalance has a role in removing cells suffering prolonged ER stress. We have previously developed a fly model for IBMPFD (inclusion body myopathy with Paget disease and frontotemporal dementia) and demonstrated that specific mutations in VCP gene, a highly conserved ATPase, cause muscle and neuron degeneration by depleting cellular ATP level. Using this model, we show that expression of Derlin-1, an ER membrane protein capable of directly interacting with VCP, restores the normal cellular ATP level and suppresses IBMPFD-like neurodegeneration. As Derlin-1 expression can be induced by tunicamycin (an antibiotic) in experimental systems, our findings may yield new therapeutic strategies for VCP-linked diseases. In addition, we have obtained important insights regarding Derlin-1 function under physiological conditions. ER stress, caused by accumulation of improperly folded proteins, results in increased Derlin-1 expression, which is important for ER stress-induced cell death. We propose that Derlin-1 promotes ER homeostasis through multiple mechanisms. In addition to cooperating with VCP to extract improperly folded proteins from the ER, elevated Derlin-1 expression removes cells suffering from irreparable ER stress, thus preventing these damaged cells from further harming the organisms.
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Affiliation(s)
- Cyong-Jhih Liang
- Institute of Biotechnology, Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Ya-Chu Chang
- Institute of Biotechnology, Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Henry C. Chang
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Chung-Kang Wang
- Institute of Biotechnology, Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Yu-Chien Hung
- Institute of Biotechnology, Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Ying-Er Lin
- Institute of Biotechnology, Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Chia-Ching Chan
- Institute of Biotechnology, Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Chun-Hong Chen
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli County, Taiwan
| | - Hui-Yun Chang
- Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan
- Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, Taiwan
| | - Tzu-Kang Sang
- Institute of Biotechnology, Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
- Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan
- * E-mail:
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Hsu TC, Wang CK, Yang CY, Lee LC, Hsieh-Li HM, Ro LS, Chen CM, Lee-Chen GJ, Su MT. Deactivation of TBP contributes to SCA17 pathogenesis. Hum Mol Genet 2014; 23:6878-93. [PMID: 25104854 DOI: 10.1093/hmg/ddu410] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Spinocerebellar ataxia type 17 (SCA17) is an autosomal dominant cerebellar ataxia caused by the expansion of polyglutamine (polyQ) within the TATA box-binding protein (TBP). Previous studies have shown that polyQ-expanded TBP forms neurotoxic aggregates and alters downstream genes. However, how expanded polyQ tracts affect the function of TBP and the link between dysfunctional TBP and SCA17 is not clearly understood. In this study, we generated novel Drosophila models for SCA17 that recapitulate pathological features such as aggregate formation, mobility defects and premature death. In addition to forming neurotoxic aggregates, we determined that polyQ-expanded TBP reduces its own intrinsic DNA-binding and transcription abilities. Dysfunctional TBP also disrupts normal TBP function. Furthermore, heterozygous dTbp amorph mutant flies exhibited SCA17-like phenotypes and flies expressing polyQ-expanded TBP exhibited enhanced retinal degeneration, suggesting that loss of TBP function may contribute to SCA17 pathogenesis. We further determined that the downregulation of TBP activity enhances retinal degeneration in SCA3 and Huntington's disease fly models, indicating that the deactivation of TBP is likely to play a common role in polyQ-induced neurodegeneration.
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Affiliation(s)
- Tun-Chieh Hsu
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Cheng-Kuang Wang
- Department of Laboratory Medicine, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli 35664, Taiwan and
| | - Chun-Yen Yang
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Li-Ching Lee
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Hsiu-Mei Hsieh-Li
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Long-Sun Ro
- Department of Neurology, Chang Gung Memorial Hospital, College of Medicine, Chang-Gung University, Taoyuan 33305, Taiwan
| | - Chiung-Mei Chen
- Department of Neurology, Chang Gung Memorial Hospital, College of Medicine, Chang-Gung University, Taoyuan 33305, Taiwan
| | - Guey-Jen Lee-Chen
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Ming-Tsan Su
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
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Chuang CL, Lu YN, Wang HC, Chang HY. Genetic dissection reveals that Akt is the critical kinase downstream of LRRK2 to phosphorylate and inhibit FOXO1, and promotes neuron survival. Hum Mol Genet 2014; 23:5649-58. [PMID: 24916379 DOI: 10.1093/hmg/ddu281] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Leucine-rich repeat kinase 2 (LRRK2) is a complex kinase and mutations in LRRK2 are perhaps the most common genetic cause of Parkinson's disease (PD). However, the identification of the normal physiological function of LRRK2 remains elusive. Here, we show that LRRK2 protects neurons against apoptosis induced by the Drosophila genes grim, hid and reaper. Genetic dissection reveals that Akt is the critical downstream kinase of LRRK2 that phosphorylates and inhibits FOXO1, and thereby promotes survival. Like human LRRK2, Drosophila lrrk also promotes neuron survival; lrrk loss-of-function mutant displays reduced cell numbers, which can be rescued by LRRK2 expression. Importantly, LRRK2 G2019S and LRRK2 R1441C mutants impair the ability of LRRK2 to activate Akt, and fail to prevent apoptotic death. Ectopic expression of a constitutive active form of Akt hence is sufficient to rescue this functional deficit. These data establish that LRRK2 can protect neurons from apoptotic insult through a survival pathway in which LRRK2 signals to activate Akt, and then inhibits FOXO1. These results might indicate that a LRRK-Akt therapeutic pathway to promote neuron survival and to prevent neurodegeneration in Parkinson's disease.
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Affiliation(s)
- Chia-Lung Chuang
- Institute of Systems Neuroscience, Department of Medical Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan and Brain Research Center, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Yu-Ning Lu
- Institute of Systems Neuroscience, Department of Medical Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan and Brain Research Center, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Hung-Cheng Wang
- Institute of Systems Neuroscience, Department of Medical Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan and Brain Research Center, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Hui-Yun Chang
- Institute of Systems Neuroscience, Department of Medical Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan and Brain Research Center, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
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Drosophila Valosin-Containing Protein is required for dendrite pruning through a regulatory role in mRNA metabolism. Proc Natl Acad Sci U S A 2014; 111:7331-6. [PMID: 24799714 DOI: 10.1073/pnas.1406898111] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The dendritic arbors of the larval Drosophila peripheral class IV dendritic arborization neurons degenerate during metamorphosis in an ecdysone-dependent manner. This process-also known as dendrite pruning-depends on the ubiquitin-proteasome system (UPS), but the specific processes regulated by the UPS during pruning have been largely elusive. Here, we show that mutation or inhibition of Valosin-Containing Protein (VCP), a ubiquitin-dependent ATPase whose human homolog is linked to neurodegenerative disease, leads to specific defects in mRNA metabolism and that this role of VCP is linked to dendrite pruning. Specifically, we find that VCP inhibition causes an altered splicing pattern of the large pruning gene molecule interacting with CasL and mislocalization of the Drosophila homolog of the human RNA-binding protein TAR-DNA-binding protein of 43 kilo-Dalton (TDP-43). Our data suggest that VCP inactivation might lead to specific gain-of-function of TDP-43 and other RNA-binding proteins. A similar combination of defects is also seen in a mutant in the ubiquitin-conjugating enzyme ubcD1 and a mutant in the 19S regulatory particle of the proteasome, but not in a 20S proteasome mutant. Thus, our results highlight a proteolysis-independent function of the UPS during class IV dendritic arborization neuron dendrite pruning and link the UPS to the control of mRNA metabolism.
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Ecdysone-induced receptor tyrosine phosphatase PTP52F regulates Drosophila midgut histolysis by enhancement of autophagy and apoptosis. Mol Cell Biol 2014; 34:1594-606. [PMID: 24550005 DOI: 10.1128/mcb.01391-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The rapid removal of larval midgut is a critical developmental process directed by molting hormone ecdysone during Drosophila metamorphosis. To date, it remains unclear how the stepwise events can link the onset of ecdysone signaling to the destruction of larval midgut. This study investigated whether ecdysone-induced expression of receptor protein tyrosine phosphatase PTP52F regulates this process. The mutation of the Ptp52F gene caused significant delay in larval midgut degradation. Transitional endoplasmic reticulum ATPase (TER94), a regulator of ubiquitin proteasome system, was identified as a substrate and downstream effector of PTP52F in the ecdysone signaling. The inducible expression of PTP52F at the puparium formation stage resulted in dephosphorylation of TER94 on its Y800 residue, ensuring the rapid degradation of ubiquitylated proteins. One of the proteins targeted by dephosphorylated TER94 was found to be Drosophila inhibitor of apoptosis 1 (DIAP1), which was rapidly proteolyzed in cells with significant expression of PTP52F. Importantly, the reduced level of DIAP1 in response to inducible PTP52F was essential not only for the onset of apoptosis but also for the initiation of autophagy. This study demonstrates a novel function of PTP52F in regulating ecdysone-directed metamorphosis via enhancement of autophagic and apoptotic cell death in doomed Drosophila midguts.
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38
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O'Sullivan NC, Dräger N, O'Kane CJ. Characterization of the Drosophila atlastin interactome reveals VCP as a functionally related interactor. J Genet Genomics 2013; 40:297-306. [PMID: 23790629 DOI: 10.1016/j.jgg.2013.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/29/2013] [Accepted: 04/30/2013] [Indexed: 01/19/2023]
Abstract
At least 25 genes, many involved in trafficking, localisation or shaping of membrane organelles, have been identified as causative genes for the neurodegenerative disorder hereditary spastic paraplegia (HSP). One of the most commonly mutated HSP genes, atlastin-1, encodes a dynamin-like GTPase that mediates homotypic fusion of endoplasmic reticulum (ER) membranes. However, the molecular mechanisms of atlastin-1-related membrane fusion and axonopathy remain unclear. To better understand its mode of action, we used affinity purification coupled with mass spectrometry to identify protein interactors of atlastin in Drosophila. Analysis of 72 identified proteins revealed that the atlastin interactome contains many proteins involved in protein processing and transport, in addition to proteins with roles in mRNA binding, metabolism and mitochondrial proteins. The highest confidence interactor from mass spectrometry analysis, the ubiquitin-selective AAA-ATPase valosin-containing protein (VCP), was validated as an atlastin-interacting protein, and VCP and atlastin showed overlapping subcellular distributions. Furthermore, VCP acted as a genetic modifier of atlastin: loss of VCP partially suppressed an eye phenotype caused by atlastin overexpression, whereas overexpression of VCP enhanced this phenotype. These interactions between atlastin and VCP suggest a functional relationship between these two proteins, and point to potential shared mechanisms between HSP and other forms of neurodegeneration.
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Affiliation(s)
- Niamh C O'Sullivan
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, United Kingdom.
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Loss of vesicular dopamine release precedes tauopathy in degenerative dopaminergic neurons in a Drosophila model expressing human tau. Acta Neuropathol 2013; 125:711-25. [PMID: 23494099 PMCID: PMC3631315 DOI: 10.1007/s00401-013-1105-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Revised: 02/07/2013] [Accepted: 03/02/2013] [Indexed: 11/18/2022]
Abstract
While a number of genome-wide association studies have identified microtubule-associated protein tau as a strong risk factor for Parkinson’s disease (PD), little is known about the mechanism through which human tau can predispose an individual to this disease. Here, we demonstrate that expression of human wild-type tau is sufficient to disrupt the survival of dopaminergic neurons in a Drosophila model. Tau triggers a synaptic pathology visualized by vesicular monoamine transporter-pHGFP that precedes both the age-dependent formation of tau-containing neurofibrillary tangle-like pathology and the progressive loss of DA neurons, thereby recapitulating the pathological hallmarks of PD. Flies overexpressing tau also exhibit progressive impairments of both motor and learning behaviors. Surprisingly, contrary to common belief that hyperphosphorylated tau could aggravate toxicity, DA neuron degeneration is alleviated by expressing the modified, hyperphosphorylated tauE14. Together, these results show that impairment of VMAT-containing synaptic vesicle, released to synapses before overt tauopathy may be the underlying mechanism of tau-associated PD and suggest that correction or prevention of this deficit may be appropriate targets for early therapeutic intervention.
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40
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Franz A, Ackermann L, Hoppe T. Create and preserve: proteostasis in development and aging is governed by Cdc48/p97/VCP. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1843:205-15. [PMID: 23583830 DOI: 10.1016/j.bbamcr.2013.03.031] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 03/08/2013] [Accepted: 03/25/2013] [Indexed: 12/24/2022]
Abstract
The AAA-ATPase Cdc48 (also called p97 or VCP) acts as a key regulator in proteolytic pathways, coordinating recruitment and targeting of substrate proteins to the 26S proteasome or lysosomal degradation. However, in contrast to the well-known function in ubiquitin-dependent cellular processes, the physiological relevance of Cdc48 in organismic development and maintenance of protein homeostasis is less understood. Therefore, studies on multicellular model organisms help to decipher how Cdc48-dependent proteolysis is regulated in time and space to meet developmental requirements. Given the importance of developmental regulation and tissue maintenance, defects in Cdc48 activity have been linked to several human pathologies including protein aggregation diseases. Thus, addressing the underlying disease mechanisms not only contributes to our understanding on the organism-wide function of Cdc48 but also facilitates the design of specific medical therapies. In this review, we will portray the role of Cdc48 in the context of multicellular organisms, pointing out its importance for developmental processes, tissue surveillance, and disease prevention. This article is part of a Special Issue entitled: Ubiquitin-Proteasome System. Guest Editors: Thomas Sommer and Dieter H. Wolf.
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Affiliation(s)
- André Franz
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Zülpicher Straße 47a, 50674 Cologne, Germany
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41
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Bartolome F, Wu HC, Burchell VS, Preza E, Wray S, Mahoney CJ, Fox NC, Calvo A, Canosa A, Moglia C, Mandrioli J, Chiò A, Orrell RW, Houlden H, Hardy J, Abramov AY, Plun-Favreau H. Pathogenic VCP mutations induce mitochondrial uncoupling and reduced ATP levels. Neuron 2013; 78:57-64. [PMID: 23498975 PMCID: PMC3843114 DOI: 10.1016/j.neuron.2013.02.028] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2013] [Indexed: 11/23/2022]
Abstract
Valosin-containing protein (VCP) is a highly expressed member of the type II AAA+ ATPase family. VCP mutations are the cause of inclusion body myopathy, Paget's disease of the bone, and frontotemporal dementia (IBMPFD) and they account for 1%-2% of familial amyotrophic lateral sclerosis (ALS). Using fibroblasts from patients carrying three independent pathogenic mutations in the VCP gene, we show that VCP deficiency causes profound mitochondrial uncoupling leading to decreased mitochondrial membrane potential and increased mitochondrial oxygen consumption. This mitochondrial uncoupling results in a significant reduction of cellular ATP production. Decreased ATP levels in VCP-deficient cells lower their energy capacity, making them more vulnerable to high energy-demanding processes such as ischemia. Our findings propose a mechanism by which pathogenic VCP mutations lead to cell death.
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MESH Headings
- Adenosine Triphosphatases/deficiency
- Adenosine Triphosphatases/genetics
- Adenosine Triphosphate/metabolism
- Adult
- Aged
- Analysis of Variance
- Animals
- Animals, Newborn
- Case-Control Studies
- Cell Cycle Proteins/deficiency
- Cell Cycle Proteins/genetics
- Cells, Cultured
- Cerebral Cortex/cytology
- Family Health
- Female
- Fibroblasts/metabolism
- Fibroblasts/pathology
- Frontotemporal Dementia/genetics
- Frontotemporal Dementia/metabolism
- Frontotemporal Dementia/pathology
- Humans
- Lipid Peroxidation/genetics
- Luminescent Proteins/genetics
- Magnesium/metabolism
- Male
- Membrane Potential, Mitochondrial/genetics
- Mice
- Mice, Inbred C57BL
- Middle Aged
- Mitochondria/genetics
- Mitochondria/metabolism
- Mitochondria/pathology
- Muscular Dystrophies, Limb-Girdle/genetics
- Muscular Dystrophies, Limb-Girdle/metabolism
- Muscular Dystrophies, Limb-Girdle/pathology
- Mutation/genetics
- Myositis, Inclusion Body/genetics
- Myositis, Inclusion Body/metabolism
- Myositis, Inclusion Body/pathology
- NAD/metabolism
- Neuroblastoma/pathology
- Neurons/ultrastructure
- Osteitis Deformans/genetics
- Osteitis Deformans/metabolism
- Osteitis Deformans/pathology
- Oxygen Consumption/genetics
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Transfection
- Valosin Containing Protein
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Affiliation(s)
- Fernando Bartolome
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
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VCP is essential for mitochondrial quality control by PINK1/Parkin and this function is impaired by VCP mutations. Neuron 2013; 78:65-80. [PMID: 23498974 DOI: 10.1016/j.neuron.2013.02.029] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/19/2013] [Indexed: 12/12/2022]
Abstract
Mutations in VCP cause multisystem degeneration impacting the nervous system, muscle, and/or bone. Patients may present with ALS, Parkinsonism, frontotemporal dementia, myopathy, Paget's disease, or a combination of these. The disease mechanism is unknown. We developed a Drosophila model of VCP mutation-dependent degeneration. The phenotype is reminiscent of PINK1 and parkin mutants, including a pronounced mitochondrial defect. Indeed, VCP interacts genetically with the PINK1/parkin pathway in vivo. Paradoxically, VCP complements PINK1 deficiency but not parkin deficiency. The basis of this paradox is resolved by mechanistic studies in vitro showing that VCP recruitment to damaged mitochondria requires Parkin-mediated ubiquitination of mitochondrial targets. VCP recruitment coincides temporally with mitochondrial fission, and VCP is required for proteasome-dependent degradation of Mitofusins in vitro and in vivo. Further, VCP and its adaptor Npl4/Ufd1 are required for clearance of damaged mitochondria via the PINK1/Parkin pathway, and this is impaired by pathogenic mutations in VCP.
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43
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Chia WS, Chia DX, Rao F, Bar Nun S, Geifman Shochat S. ATP binding to p97/VCP D1 domain regulates selective recruitment of adaptors to its proximal N-domain. PLoS One 2012; 7:e50490. [PMID: 23226521 PMCID: PMC3513293 DOI: 10.1371/journal.pone.0050490] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 10/23/2012] [Indexed: 11/18/2022] Open
Abstract
p97/Valosin-containing protein (VCP) is a member of the AAA-ATPase family involved in many cellular processes including cell division, intracellular trafficking and extraction of misfolded proteins in endoplasmic reticulum-associated degradation (ERAD). It is a homohexamer with each subunit containing two tandem D1 and D2 ATPase domains and N- and C-terminal regions that function as adaptor protein binding domains. p97/VCP is directed to its many different functional pathways by associating with various adaptor proteins. The regulation of the recruitment of the adaptor proteins remains unclear. Two adaptor proteins, Ufd1/Npl4 and p47, which bind exclusively to the p97/VCP N-domain and direct p97/VCP to either ERAD-related processes or homotypic fusion of Golgi fragments, were studied here. Surface plasmon resonance biosensor-based assays allowed the study of binding kinetics in real time. In competition experiments, it was observed that in the presence of ATP, Ufd1/Npl4 was able to compete more effectively with p47 for binding to p97/VCP. By using non-hydrolysable ATP analogues and the hexameric truncated p97/N-D1 fragment, it was shown that binding rather than hydrolysis of ATP to the proximal D1 domain strengthened the Ufd1/Npl4 association with the N-domain, thus regulating the recruitment of either Ufd1/Npl4 or p47. This novel role of ATP and an assigned function to the D1 AAA-ATPase domain link the multiple functions of p97/VCP to the metabolic status of the cell.
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Affiliation(s)
- Wei Sheng Chia
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Diana Xueqi Chia
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Feng Rao
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Shoshana Bar Nun
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Susana Geifman Shochat
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail:
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44
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Guerriero CJ, Brodsky JL. The delicate balance between secreted protein folding and endoplasmic reticulum-associated degradation in human physiology. Physiol Rev 2012; 92:537-76. [PMID: 22535891 DOI: 10.1152/physrev.00027.2011] [Citation(s) in RCA: 314] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Protein folding is a complex, error-prone process that often results in an irreparable protein by-product. These by-products can be recognized by cellular quality control machineries and targeted for proteasome-dependent degradation. The folding of proteins in the secretory pathway adds another layer to the protein folding "problem," as the endoplasmic reticulum maintains a unique chemical environment within the cell. In fact, a growing number of diseases are attributed to defects in secretory protein folding, and many of these by-products are targeted for a process known as endoplasmic reticulum-associated degradation (ERAD). Since its discovery, research on the mechanisms underlying the ERAD pathway has provided new insights into how ERAD contributes to human health during both normal and diseases states. Links between ERAD and disease are evidenced from the loss of protein function as a result of degradation, chronic cellular stress when ERAD fails to keep up with misfolded protein production, and the ability of some pathogens to coopt the ERAD pathway. The growing number of ERAD substrates has also illuminated the differences in the machineries used to recognize and degrade a vast array of potential clients for this pathway. Despite all that is known about ERAD, many questions remain, and new paradigms will likely emerge. Clearly, the key to successful disease treatment lies within defining the molecular details of the ERAD pathway and in understanding how this conserved pathway selects and degrades an innumerable cast of substrates.
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Affiliation(s)
- Christopher J Guerriero
- Department of Biological Sciences, University of Pittsburgh, A320 Langley Hall, Pittsburgh, PA 15260, USA
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45
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Chan HT, Lee TR, Huang SH, Lee HY, Sang TK, Chan HL, Lyu PC. Proteomic analysis of a drosophila IBMPFD model reveals potential pathogenic mechanisms. MOLECULAR BIOSYSTEMS 2012; 8:1730-41. [PMID: 22481368 DOI: 10.1039/c2mb25037c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
IBMPFD, Inclusion body myopathy associated with Paget's disease of bone and frontotemporal dementia, is a hereditary degenerative disorder due to single missense mutations in VCP (Valosin-Containing Protein). The mechanisms of how mutations of VCP lead to IBMPFD remain mysterious. Here we utilize two-dimensional difference gel electrophoresis (2D-DIGE) combined with mass spectrometry to study the IBMPFD disorder at the protein level. With this set-up, we are able to employ comparative proteomics to analyze IBMPFD disease using Drosophila melanogaster as our disease model organism. Head proteome of transgenic D. melanogaster expressing wild type VCP is compared, respectively, with the head proteome of transgenic mutant type VCPs that correspond to human IBMPFD disease alleles (TER94(A229E), TER94(R188Q), and TER94(R152H)). Of all the proteins identified, a significant fraction of proteins altered in TER94(A229E) and TER94(R188Q) mutants belong to the same functional categories, i.e. apoptosis and metabolism. Among these, Drosophila transferrin is observed to be significantly up-regulated in mutant flies expressing TER94(A229E). A knock-down experiment suggests that fly transferrin might be a potential modifier in IBMPFD disease. The molecular analysis of IBMPFD disease may benefit from the proteomics approach which combines the advantages of high throughput analysis and the focus on protein levels.
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Affiliation(s)
- Hsin-Tzu Chan
- Institute of Bioinformatics and Structural Biology & Department of Medical Sciences, National Tsing Hua University, Hsinchu, Taiwan
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46
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d'Ydewalle C, Bogaert E, Van Den Bosch L. HDAC6 at the Intersection of Neuroprotection and Neurodegeneration. Traffic 2012; 13:771-9. [PMID: 22372633 DOI: 10.1111/j.1600-0854.2012.01347.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 02/23/2012] [Accepted: 02/28/2012] [Indexed: 12/14/2022]
Abstract
Histone deacetylase 6 (HDAC6) catalyzes multiple reactions. We summarize the current knowledge on HDAC6, its targets and functions. Among others, HDAC6 recognizes damaged proteins and assures that these proteins are destroyed by autophagy. On the other hand, HDAC6 also modifies the tracks used by the clearance mechanism so that axonal transport becomes less efficient. We hypothesize that a disturbance in the equilibrium between the different functions of HDAC6 could play an important role in neurodegeneration.
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47
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Wang CT, Chen YC, Wang YY, Huang MH, Yen TL, Li H, Liang CJ, Sang TK, Ciou SC, Yuh CH, Wang CY, Brummel TJ, Wang HD. Reduced neuronal expression of ribose-5-phosphate isomerase enhances tolerance to oxidative stress, extends lifespan, and attenuates polyglutamine toxicity in Drosophila. Aging Cell 2012; 11:93-103. [PMID: 22040003 DOI: 10.1111/j.1474-9726.2011.00762.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Aging and age-related diseases can be viewed as the result of the lifelong accumulation of stress insults. The identification of mutant strains and genes that are responsive to stress and can alter longevity profiles provides new therapeutic targets for age-related diseases. Here we reported that a Drosophila strain with reduced expression of ribose-5-phosphate isomerase (rpi), EP2456, exhibits increased resistance to oxidative stress and enhanced lifespan. In addition, the strain also displays higher levels of NADPH. The knockdown of rpi in neurons by double-stranded RNA interference recapitulated the lifespan extension and oxidative stress resistance in Drosophila. This manipulation was also found to ameliorate the effects of genetic manipulations aimed at creating a model for studying Huntington's disease by overexpression of polyglutamine in the eye, suggesting that modulating rpi levels could serve as a treatment for normal aging as well as for polyglutamine neurotoxicity.
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Affiliation(s)
- Ching-Tzu Wang
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, Taiwan, ROC
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48
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The Multiple Faces of Valosin-Containing Protein-Associated Diseases: Inclusion Body Myopathy with Paget’s Disease of Bone, Frontotemporal Dementia, and Amyotrophic Lateral Sclerosis. J Mol Neurosci 2011; 45:522-31. [DOI: 10.1007/s12031-011-9627-y] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Accepted: 08/08/2011] [Indexed: 12/11/2022]
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49
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Aroclor 1254, a developmental neurotoxicant, alters energy metabolism- and intracellular signaling-associated protein networks in rat cerebellum and hippocampus. Toxicol Appl Pharmacol 2011; 256:290-9. [PMID: 21791222 DOI: 10.1016/j.taap.2011.07.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 07/06/2011] [Accepted: 07/08/2011] [Indexed: 01/23/2023]
Abstract
The vast literature on the mode of action of polychlorinated biphenyls (PCBs) indicates that PCBs are a unique model for understanding the mechanisms of toxicity of environmental mixtures of persistent chemicals. PCBs have been shown to adversely affect psychomotor function and learning and memory in humans. Although the molecular mechanisms for PCB effects are unclear, several studies indicate that the disruption of Ca(2+)-mediated signal transduction plays significant roles in PCB-induced developmental neurotoxicity. Culminating events in signal transduction pathways include the regulation of gene and protein expression, which affects the growth and function of the nervous system. Our previous studies showed changes in gene expression related to signal transduction and neuronal growth. In this study, protein expression following developmental exposure to PCB is examined. Pregnant rats (Long Evans) were dosed with 0.0 or 6.0mg/kg/day of Aroclor-1254 from gestation day 6 through postnatal day (PND) 21, and the cerebellum and hippocampus from PND14 animals were analyzed to determine Aroclor 1254-induced differential protein expression. Two proteins were found to be differentially expressed in the cerebellum following PCB exposure while 18 proteins were differentially expressed in the hippocampus. These proteins are related to energy metabolism in mitochondria (ATP synthase, sub unit β (ATP5B), creatine kinase, and malate dehydrogenase), calcium signaling (voltage-dependent anion-selective channel protein 1 (VDAC1) and ryanodine receptor type II (RyR2)), and growth of the nervous system (dihydropyrimidinase-related protein 4 (DPYSL4), valosin-containing protein (VCP)). Results suggest that Aroclor 1254-like persistent chemicals may alter energy metabolism and intracellular signaling, which might result in developmental neurotoxicity.
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50
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Yamanaka K, Sasagawa Y, Ogura T. Recent advances in p97/VCP/Cdc48 cellular functions. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1823:130-7. [PMID: 21781992 DOI: 10.1016/j.bbamcr.2011.07.001] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 07/06/2011] [Accepted: 07/06/2011] [Indexed: 10/18/2022]
Abstract
p97/VCP/Cdc48 is one of the best-characterized type II AAA (ATPases associated with diverse cellular activities) ATPases. p97 is suggested to be a ubiquitin-selective chaperone and its key function is to disassemble protein complexes. p97 is involved in a wide variety of cellular activities. Recently, novel functions, namely autophagy and mitochondrial quality control, for p97 have been uncovered. p97 was identified as a causative factor for inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia (IBMPFD) and more recently as a causative factor for amyotrophic lateral sclerosis (ALS). In this review, we will summarize and discuss recent progress and topics in p97 functions and the relationship to its associated diseases.
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Affiliation(s)
- Kunitoshi Yamanaka
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan
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