1
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Kundu S, Jaiswal M, Babu Mullapudi V, Guo J, Kamat M, Basso KB, Guo Z. Investigation of Glycosylphosphatidylinositol (GPI)-Plasma Membrane Interaction in Live Cells and the Influence of GPI Glycan Structure on the Interaction. Chemistry 2024; 30:e202303047. [PMID: 37966101 PMCID: PMC10922586 DOI: 10.1002/chem.202303047] [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: 09/19/2023] [Revised: 11/05/2023] [Accepted: 11/15/2023] [Indexed: 11/16/2023]
Abstract
Glycosylphosphatidylinositols (GPIs) need to interact with other components in the cell membrane to transduce transmembrane signals. A bifunctional GPI probe was employed for photoaffinity-based proximity labelling and identification of GPI-interacting proteins in the cell membrane. This probe contained the entire core structure of GPIs and was functionalized with photoreactive diazirine and clickable alkyne to facilitate its crosslinking with proteins and attachment of an affinity tag. It was disclosed that this probe was more selective than our previously reported probe containing only a part structure of the GPI core for cell membrane incorporation and an improved probe for studying GPI-cell membrane interaction. Eighty-eight unique membrane proteins, many of which are related to GPIs/GPI-anchored proteins, were identified utilizing this probe. The proteomics dataset is a valuable resource for further analyses and data mining to find new GPI-related proteins and signalling pathways. A comparison of these results with those of our previous probe provided direct evidence for the profound impact of GPI glycan structure on its interaction with the cell membrane.
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Affiliation(s)
- Sayan Kundu
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Mohit Jaiswal
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | | | - Jiatong Guo
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Manasi Kamat
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Kari B Basso
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Zhongwu Guo
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
- UF Health Cancer Centre, University of Florida, Gainesville, FL 32611, USA
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2
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Rao XS, Cong XX, Gao XK, Shi YP, Shi LJ, Wang JF, Ni CY, He MJ, Xu Y, Yi C, Meng ZX, Liu J, Lin P, Zheng LL, Zhou YT. AMPK-mediated phosphorylation enhances the auto-inhibition of TBC1D17 to promote Rab5-dependent glucose uptake. Cell Death Differ 2021; 28:3214-3234. [PMID: 34045668 PMCID: PMC8630067 DOI: 10.1038/s41418-021-00809-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 02/04/2023] Open
Abstract
Dysregulation of glucose homeostasis contributes to insulin resistance and type 2 diabetes. Whilst exercise stimulated activation of AMP-activated protein kinase (AMPK), an important energy sensor, has been highlighted for its potential to promote insulin-stimulated glucose uptake, the underlying mechanisms for this remain largely unknown. Here we found that AMPK positively regulates the activation of Rab5, a small GTPase which is involved in regulating Glut4 translocation, in both myoblasts and skeletal muscles. We further verified that TBC1D17, identified as a potential interacting partner of Rab5 in our recent study, is a novel GTPase activating protein (GAP) of Rab5. TBC1D17-Rab5 axis regulates transport of Glut1, Glut4, and transferrin receptor. TBC1D17 interacts with Rab5 or AMPK via its TBC domain or N-terminal 1-306 region (N-Ter), respectively. Moreover, AMPK phosphorylates the Ser 168 residue of TBC1D17 which matches the predicted AMPK consensus motif. N-Ter of TBC1D17 acts as an inhibitory region by directly interacting with the TBC domain. Ser168 phosphorylation promotes intra-molecular interaction and therefore enhances the auto-inhibition of TBC1D17. Our findings reveal that TBC1D17 acts as a molecular bridge that links AMPK and Rab5 and delineate a previously unappreciated mechanism by which the activation of TBC/RabGAP is regulated.
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Affiliation(s)
- Xi Sheng Rao
- grid.13402.340000 0004 1759 700XDepartment of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XKey Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiao Xia Cong
- grid.13402.340000 0004 1759 700XDepartment of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XKey Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiu Kui Gao
- grid.13402.340000 0004 1759 700XDepartment of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XKey Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Yin Pu Shi
- grid.13402.340000 0004 1759 700XDepartment of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XKey Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Lin Jing Shi
- grid.13402.340000 0004 1759 700XDepartment of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jian Feng Wang
- grid.13402.340000 0004 1759 700XDepartment of Respiratory Medicine, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chen-Yao Ni
- grid.35403.310000 0004 1936 9991The School of Molecular and Cellular Biology, University of Illinois at Urbana Champaign, Urbana, IL USA
| | - Ming Jie He
- grid.13402.340000 0004 1759 700XDepartment of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XKey Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Yingke Xu
- grid.13402.340000 0004 1759 700XDepartment of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, China ,grid.13402.340000 0004 1759 700XDepartment of Endocrinology, the Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Cong Yi
- grid.13402.340000 0004 1759 700XDepartment of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhuo-Xian Meng
- grid.13402.340000 0004 1759 700XDepartment of Pathology and Pathophysiology and Zhejiang Provincial Key Laboratory of Pancreatic Disease of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jinling Liu
- grid.13402.340000 0004 1759 700XDepartment of Pulmonology, the Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Peng Lin
- grid.13402.340000 0004 1759 700XDepartment of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Li Ling Zheng
- grid.13402.340000 0004 1759 700XKey Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XDepartment of Biochemistry and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yi Ting Zhou
- grid.13402.340000 0004 1759 700XDepartment of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XKey Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XZJU-UoE Institute, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XCancer Center, Zhejiang University, Hangzhou, China
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3
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Ayagama T, Bose SJ, Capel RA, Priestman DA, Berridge G, Fischer R, Galione A, Platt FM, Kramer H, Burton RA. A modified density gradient proteomic-based method to analyze endolysosomal proteins in cardiac tissue. iScience 2021; 24:102949. [PMID: 34466782 PMCID: PMC8384914 DOI: 10.1016/j.isci.2021.102949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 03/04/2021] [Accepted: 08/02/2021] [Indexed: 11/22/2022] Open
Abstract
The importance of lysosomes in cardiac physiology and pathology is well established, and evidence for roles in calcium signaling is emerging. We describe a label-free proteomics method suitable for small cardiac tissue biopsies based on density-separated fractionation, which allows study of endolysosomal (EL) proteins. Density gradient fractions corresponding to tissue lysate; sarcoplasmic reticulum (SR), mitochondria (Mito) (1.3 g/mL); and EL with negligible contamination from SR or Mito (1.04 g/mL) were analyzed using Western blot, enzyme activity assay, and liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis (adapted discontinuous Percoll and sucrose differential density gradient). Kyoto Encyclopedia of Genes and Genomes, Reactome, Panther, and Gene Ontology pathway analysis showed good coverage of RAB proteins and lysosomal cathepsins (including cardiac-specific cathepsin D) in the purified EL fraction. Significant EL proteins recovered included catalytic activity proteins. We thus present a comprehensive protocol and data set of guinea pig atrial EL organelle proteomics using techniques also applicable for non-cardiac tissue.
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Affiliation(s)
- Thamali Ayagama
- University of Oxford, Department of Pharmacology, Oxford, OX1 3QT UK
| | - Samuel J. Bose
- University of Oxford, Department of Pharmacology, Oxford, OX1 3QT UK
| | - Rebecca A. Capel
- University of Oxford, Department of Pharmacology, Oxford, OX1 3QT UK
| | | | - Georgina Berridge
- Target Discovery Institute, University of Oxford, Oxford, OX3 7FZ UK
| | - Roman Fischer
- Target Discovery Institute, University of Oxford, Oxford, OX3 7FZ UK
| | - Antony Galione
- University of Oxford, Department of Pharmacology, Oxford, OX1 3QT UK
| | - Frances M. Platt
- University of Oxford, Department of Pharmacology, Oxford, OX1 3QT UK
| | - Holger Kramer
- Biological Mass Spectrometry and Proteomics Facility, MRC London Institute of Medical Sciences, Imperial College London, London, W12 0NN UK
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4
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Pandey P, Leary AY, Tumtas Y, Savage Z, Dagvadorj B, Duggan C, Yuen EL, Sanguankiattichai N, Tan E, Khandare V, Connerton AJ, Yunusov T, Madalinski M, Mirkin FG, Schornack S, Dagdas Y, Kamoun S, Bozkurt TO. An oomycete effector subverts host vesicle trafficking to channel starvation-induced autophagy to the pathogen interface. eLife 2021; 10:65285. [PMID: 34424198 PMCID: PMC8382295 DOI: 10.7554/elife.65285] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 07/20/2021] [Indexed: 12/14/2022] Open
Abstract
Eukaryotic cells deploy autophagy to eliminate invading microbes. In turn, pathogens have evolved effector proteins to counteract antimicrobial autophagy. How adapted pathogens co-opt autophagy for their own benefit is poorly understood. The Irish famine pathogen Phytophthora infestans secretes the effector protein PexRD54 that selectively activates an unknown plant autophagy pathway that antagonizes antimicrobial autophagy at the pathogen interface. Here, we show that PexRD54 induces autophagosome formation by bridging vesicles decorated by the small GTPase Rab8a with autophagic compartments labeled by the core autophagy protein ATG8CL. Rab8a is required for pathogen-triggered and starvation-induced but not antimicrobial autophagy, revealing specific trafficking pathways underpin selective autophagy. By subverting Rab8a-mediated vesicle trafficking, PexRD54 utilizes lipid droplets to facilitate biogenesis of autophagosomes diverted to pathogen feeding sites. Altogether, we show that PexRD54 mimics starvation-induced autophagy to subvert endomembrane trafficking at the host-pathogen interface, revealing how effectors bridge distinct host compartments to expedite colonization. With its long filaments reaching deep inside its prey, the tiny fungi-like organism known as Phytophthora infestans has had a disproportionate impact on human history. Latching onto plants and feeding on their cells, it has caused large-scale starvation events such as the Irish or Highland potato famines. Many specialized proteins allow the parasite to accomplish its feat. For instance, PexRD54 helps P. infestans hijack a cellular process known as autophagy. Healthy cells use this ‘self-eating’ mechanism to break down invaders or to recycle their components, for example when they require specific nutrients. The process is set in motion by various pathways of molecular events that result in specific sac-like ‘vesicles’ filled with cargo being transported to specialized compartments for recycling. PexRD54 can take over this mechanism by activating one of the plant autophagy pathways, directing cells to form autophagic vesicles that Phytophthora could then possibly use to feed on or to destroy antimicrobial components. How or why this is the case remains poorly understood. To examine these questions, Pandey, Leary et al. used a combination of genetic and microscopy techniques and tracked how PexRD54 alters autophagy as P. infestans infects a tobacco-related plant. The results show that PexRD54 works by bridging two proteins: one is present on cellular vesicles filled with cargo, and the other on autophagic structures surrounding the parasite. This allows PexRD54 to direct the vesicles to the feeding sites of P. infestans so the parasite can potentially divert nutrients. Pandey, Leary et al. then went on to develop a molecule called the AIM peptide, which could block autophagy by mimicking part of PexRD54. These results help to better grasp how a key disease affects crops, potentially leading to new ways to protect plants without the use of pesticides. They also shed light on autophagy: ultimately, a deeper understanding of this fundamental biological process could allow the development of plants which can adapt to changing environments.
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Affiliation(s)
| | | | | | | | | | - Cian Duggan
- Imperial College London, London, United Kingdom
| | | | | | - Emily Tan
- Imperial College London, London, United Kingdom
| | | | | | - Temur Yunusov
- Sainsbury Laboratory Cambridge University (SLCU), Cambridge, United Kingdom
| | - Mathias Madalinski
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Federico Gabriel Mirkin
- Imperial College London, London, United Kingdom.,Sainsbury Laboratory Cambridge University (SLCU), Cambridge, United Kingdom.,Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria.,INGEBI-CONICET, Ciudad Autonoma de Buenos Aires, Buenos Aires, Argentina
| | | | - Yasin Dagdas
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
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5
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Pandey P, Leary AY, Tumtas Y, Savage Z, Dagvadorj B, Duggan C, Yuen EL, Sanguankiattichai N, Tan E, Khandare V, Connerton AJ, Yunusov T, Madalinski M, Mirkin FG, Schornack S, Dagdas Y, Kamoun S, Bozkurt TO. An oomycete effector subverts host vesicle trafficking to channel starvation-induced autophagy to the pathogen interface. eLife 2021; 10:65285. [PMID: 34424198 DOI: 10.1101/2020.03.20.000117] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 07/20/2021] [Indexed: 05/26/2023] Open
Abstract
Eukaryotic cells deploy autophagy to eliminate invading microbes. In turn, pathogens have evolved effector proteins to counteract antimicrobial autophagy. How adapted pathogens co-opt autophagy for their own benefit is poorly understood. The Irish famine pathogen Phytophthora infestans secretes the effector protein PexRD54 that selectively activates an unknown plant autophagy pathway that antagonizes antimicrobial autophagy at the pathogen interface. Here, we show that PexRD54 induces autophagosome formation by bridging vesicles decorated by the small GTPase Rab8a with autophagic compartments labeled by the core autophagy protein ATG8CL. Rab8a is required for pathogen-triggered and starvation-induced but not antimicrobial autophagy, revealing specific trafficking pathways underpin selective autophagy. By subverting Rab8a-mediated vesicle trafficking, PexRD54 utilizes lipid droplets to facilitate biogenesis of autophagosomes diverted to pathogen feeding sites. Altogether, we show that PexRD54 mimics starvation-induced autophagy to subvert endomembrane trafficking at the host-pathogen interface, revealing how effectors bridge distinct host compartments to expedite colonization.
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Affiliation(s)
| | | | | | | | | | - Cian Duggan
- Imperial College London, London, United Kingdom
| | | | | | - Emily Tan
- Imperial College London, London, United Kingdom
| | | | | | - Temur Yunusov
- Sainsbury Laboratory Cambridge University (SLCU), Cambridge, United Kingdom
| | - Mathias Madalinski
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Federico Gabriel Mirkin
- Imperial College London, London, United Kingdom
- Sainsbury Laboratory Cambridge University (SLCU), Cambridge, United Kingdom
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
- INGEBI-CONICET, Ciudad Autonoma de Buenos Aires, Buenos Aires, Argentina
| | | | - Yasin Dagdas
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
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6
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Phosphorylation regulates the binding of autophagy receptors to FIP200 Claw domain for selective autophagy initiation. Nat Commun 2021; 12:1570. [PMID: 33692357 PMCID: PMC7946963 DOI: 10.1038/s41467-021-21874-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 02/17/2021] [Indexed: 12/20/2022] Open
Abstract
The ULK complex initiates the autophagosome formation, and has recently been implicated in selective autophagy by interacting with autophagy receptors through its FIP200 subunit. However, the structural mechanism underlying the interactions of autophagy receptors with FIP200 and the relevant regulatory mechanism remain elusive. Here, we discover that the interactions of FIP200 Claw domain with autophagy receptors CCPG1 and Optineurin can be regulated by the phosphorylation in their respective FIP200-binding regions. We determine the crystal structures of FIP200 Claw in complex with the phosphorylated CCPG1 and Optineurin, and elucidate the detailed molecular mechanism governing the interactions of FIP200 Claw with CCPG1 and Optineurin as well as their potential regulations by kinase-mediated phosphorylation. In addition, we define the consensus FIP200 Claw-binding motif, and find other autophagy receptors that contain this motif within their conventional LC3-interacting regions. In all, our findings uncover a general and phosphoregulatable binding mode shared by many autophagy receptors to interact with FIP200 Claw for autophagosome biogenesis, and are valuable for further understanding the molecular mechanism of selective autophagy.
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7
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Adams V, Gußen V, Zozulya S, Cruz A, Moriscot A, Linke A, Labeit S. Small-Molecule Chemical Knockdown of MuRF1 in Melanoma Bearing Mice Attenuates Tumor Cachexia Associated Myopathy. Cells 2020; 9:E2272. [PMID: 33050629 PMCID: PMC7600862 DOI: 10.3390/cells9102272] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/17/2020] [Accepted: 09/21/2020] [Indexed: 12/13/2022] Open
Abstract
: Patients with malignant tumors frequently suffer during disease progression from a syndrome referred to as cancer cachexia (CaCax): CaCax includes skeletal muscle atrophy and weakness, loss of bodyweight, and fat tissues. Currently, there are no FDA (Food and Drug Administration) approved treatments available for CaCax. Here, we studied skeletal muscle atrophy and dysfunction in a murine CaCax model by injecting B16F10 melanoma cells into mouse thighs and followed mice during melanoma outgrowth. Skeletal muscles developed progressive weakness as detected by wire hang tests (WHTs) during days 13-23. Individual muscles analyzed at day 24 had atrophy, mitochondrial dysfunction, augmented metabolic reactive oxygen species (ROS) stress, and a catabolically activated ubiquitin proteasome system (UPS), including upregulated MuRF1. Accordingly, we tested as an experimental intervention of recently identified small molecules, Myomed-205 and -946, that inhibit MuRF1 activity and MuRF1/MuRF2 expression. Results indicate that MuRF1 inhibitor fed attenuated induction of MuRF1 in tumor stressed muscles. In addition, the compounds augmented muscle performance in WHTs and attenuated muscle weight loss. Myomed-205 and -946 also rescued citrate synthase and complex-1 activities in tumor-stressed muscles, possibly suggesting that mitochondrial-metabolic and muscle wasting effects in this CaCax model are mechanistically connected. Inhibition of MuRF1 during tumor cachexia may represent a suitable strategy to attenuate skeletal muscle atrophy and dysfunction.
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Affiliation(s)
- Volker Adams
- Laboratory of Molecular and Experimental Cardiology, TU Dresden, Heart Center Dresden, 1307 Dresden, Germany; (V.G.); (A.L.)
- Dresden Cardiovascular Research Institute and Core Laboratories GmbH, 01067 Dresden, Germany
| | - Victoria Gußen
- Laboratory of Molecular and Experimental Cardiology, TU Dresden, Heart Center Dresden, 1307 Dresden, Germany; (V.G.); (A.L.)
| | - Sergey Zozulya
- Department of Drug Research, Enamine-Bienta Ltd., 02000 Kiev, Ukraine;
| | - André Cruz
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (A.C.); (A.M.)
| | - Anselmo Moriscot
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (A.C.); (A.M.)
| | - Axel Linke
- Laboratory of Molecular and Experimental Cardiology, TU Dresden, Heart Center Dresden, 1307 Dresden, Germany; (V.G.); (A.L.)
- Dresden Cardiovascular Research Institute and Core Laboratories GmbH, 01067 Dresden, Germany
| | - Siegfried Labeit
- Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany;
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8
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Guo Q, Wang J, Weng Q. The diverse role of optineurin in pathogenesis of disease. Biochem Pharmacol 2020; 180:114157. [PMID: 32687832 DOI: 10.1016/j.bcp.2020.114157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/11/2020] [Accepted: 07/14/2020] [Indexed: 02/07/2023]
Abstract
Optineurin is a widely expressed protein that possesses multiple functions. Growing evidence suggests that mutation or dysregulation of optineurin can cause several neurodegenerative diseases, including amyotrophic lateral sclerosis, primary open-angle glaucoma, and Huntington's disease, as well as inflammatory digestive disorders such as Crohn's disease. Optineurin engages in vesicular trafficking, receptor regulation, immune reactions, autophagy, and distinct signaling pathways including nuclear factor kappa beta, by which optineurin contributes to cellular death and related diseases, indicating its potential as a therapeutic target. In this review, we discuss the major functions and signaling pathways of optineurin. Furthermore, we illustrate the influence of optineurin mutation or dysregulation to region-specific pathogenesis as well as potential applications of optineurin in therapeutic strategies.
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Affiliation(s)
- Qingyi Guo
- Center for Drug Safety Evaluation and Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jincheng Wang
- Center for Drug Safety Evaluation and Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Qinjie Weng
- Center for Drug Safety Evaluation and Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China.
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9
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Rivero-Ríos P, Romo-Lozano M, Fasiczka R, Naaldijk Y, Hilfiker S. LRRK2-Related Parkinson's Disease Due to Altered Endolysosomal Biology With Variable Lewy Body Pathology: A Hypothesis. Front Neurosci 2020; 14:556. [PMID: 32581693 PMCID: PMC7287096 DOI: 10.3389/fnins.2020.00556] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 05/06/2020] [Indexed: 12/14/2022] Open
Abstract
Mutations in the gene encoding for leucine-rich repeat kinase 2 (LRRK2) are associated with both familial and sporadic Parkinson's disease (PD). LRRK2 encodes a large protein comprised of a GTPase and a kinase domain. All pathogenic variants converge on enhancing LRRK2 kinase substrate phosphorylation, and distinct LRRK2 kinase inhibitors are currently in various stages of clinical trials. Although the precise pathophysiological functions of LRRK2 remain largely unknown, PD-associated mutants have been shown to alter various intracellular vesicular trafficking pathways, especially those related to endolysosomal protein degradation events. In addition, biochemical studies have identified a subset of Rab proteins, small GTPases required for all vesicular trafficking steps, as substrate proteins for the LRRK2 kinase activity in vitro and in vivo. Therefore, it is crucial to evaluate the impact of such phosphorylation on neurodegenerative mechanisms underlying LRRK2-related PD, especially with respect to deregulated Rab-mediated endolysosomal membrane trafficking and protein degradation events. Surprisingly, a significant proportion of PD patients due to LRRK2 mutations display neuronal cell loss in the substantia nigra pars compacta in the absence of any apparent α-synuclein-containing Lewy body neuropathology. These findings suggest that endolysosomal alterations mediated by pathogenic LRRK2 per se are not sufficient to cause α-synuclein aggregation. Here, we will review current knowledge about the link between pathogenic LRRK2, Rab protein phosphorylation and endolysosomal trafficking alterations, and we will propose a testable working model whereby LRRK2-related PD may present with variable LB pathology.
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Affiliation(s)
- Pilar Rivero-Ríos
- Institute of Parasitology and Biomedicine "López-Neyra", Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain.,Life Sciences Institute, University of Michigan, Ann Arbor, MI, United States
| | - María Romo-Lozano
- Institute of Parasitology and Biomedicine "López-Neyra", Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Rachel Fasiczka
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | - Yahaira Naaldijk
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | - Sabine Hilfiker
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States
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10
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Autophagy and Age-Related Eye Diseases. BIOMED RESEARCH INTERNATIONAL 2019; 2019:5763658. [PMID: 31950044 PMCID: PMC6948295 DOI: 10.1155/2019/5763658] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 08/08/2019] [Accepted: 08/26/2019] [Indexed: 12/12/2022]
Abstract
Background Autophagy is a catabolic process that depends on the lysosome. It is usually used to maintain cellular homeostasis, survival and development by degrading abnormal substances and dysfunctional organelles, especially when the cell is exposed to starvation or other stresses. Increasing studies have reported that autophagy is associated with various eye diseases, of which aging is one of the important factors. Objective To summarize the functional and regulatory role of autophagy in ocular diseases with aging, and discuss the possibility of autophagy-targeted therapy in age-related diseases. Methods PubMed searches were performed to identify relevant articles published mostly in the last 5 years. The key words were used to retrieve including “autophagy”, “aging”, “oxidative stress AND autophagy”, “dry eye AND autophagy”, “corneal disease AND autophagy”, “glaucoma AND autophagy”, “cataract AND autophagy”, “AMD AND autophagy”, “cardiovascular diseases AND autophagy”, “diabetes AND autophagy”. After being classified and assessed, the most relevant full texts in English were chosen. Results Apart from review articles, more than two research articles for each age-related eye diseases related to autophagy were retrieved. We only included the most relevant and recent studies for summary and discussion. Conclusion Autophagy has both protective and detrimental effects on the progress of age-related eye diseases. Different types of studies based on certain situations in vitro showed distinct results, which do not necessarily coincide with the actual situation in human bodies completely. It means the exact role and regulatory function of autophagy in ocular diseases remains largely unknown. Although autophagy as a potential therapeutic target has been proposed, many problems still need to be solved before it applies to clinical practice.
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11
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Ferrucci V, de Antonellis P, Pennino FP, Asadzadeh F, Virgilio A, Montanaro D, Galeone A, Boffa I, Pisano I, Scognamiglio I, Navas L, Diana D, Pedone E, Gargiulo S, Gramanzini M, Brunetti A, Danielson L, Carotenuto M, Liguori L, Verrico A, Quaglietta L, Errico ME, Del Monaco V, D'Argenio V, Tirone F, Mastronuzzi A, Donofrio V, Giangaspero F, Picard D, Remke M, Garzia L, Daniels C, Delattre O, Swartling FJ, Weiss WA, Salvatore F, Fattorusso R, Chesler L, Taylor MD, Cinalli G, Zollo M. Metastatic group 3 medulloblastoma is driven by PRUNE1 targeting NME1-TGF-β-OTX2-SNAIL via PTEN inhibition. Brain 2019; 141:1300-1319. [PMID: 29490009 DOI: 10.1093/brain/awy039] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 01/16/2018] [Indexed: 01/23/2023] Open
Abstract
Genetic modifications during development of paediatric groups 3 and 4 medulloblastoma are responsible for their highly metastatic properties and poor patient survival rates. PRUNE1 is highly expressed in metastatic medulloblastoma group 3, which is characterized by TGF-β signalling activation, c-MYC amplification, and OTX2 expression. We describe the process of activation of the PRUNE1 signalling pathway that includes its binding to NME1, TGF-β activation, OTX2 upregulation, SNAIL (SNAI1) upregulation, and PTEN inhibition. The newly identified small molecule pyrimido-pyrimidine derivative AA7.1 enhances PRUNE1 degradation, inhibits this activation network, and augments PTEN expression. Both AA7.1 and a competitive permeable peptide that impairs PRUNE1/NME1 complex formation, impair tumour growth and metastatic dissemination in orthotopic xenograft models with a metastatic medulloblastoma group 3 cell line (D425-Med cells). Using whole exome sequencing technology in metastatic medulloblastoma primary tumour cells, we also define 23 common 'non-synonymous homozygous' deleterious gene variants as part of the protein molecular network of relevance for metastatic processes. This PRUNE1/TGF-β/OTX2/PTEN axis, together with the medulloblastoma-driver mutations, is of relevance for future rational and targeted therapies for metastatic medulloblastoma group 3.10.1093/brain/awy039_video1awy039media15742053534001.
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Affiliation(s)
- Veronica Ferrucci
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy.,European School of Molecular Medicine (SEMM), Milan, Italy
| | - Pasqualino de Antonellis
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy.,Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Ontario, Canada
| | - Francesco Paolo Pennino
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy
| | | | - Antonella Virgilio
- Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, Naples, Italy
| | | | - Aldo Galeone
- Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, Naples, Italy
| | | | - Ida Pisano
- CEINGE Biotecnologie Avanzate, Naples, Italy
| | | | - Luigi Navas
- Department of Veterinary Medicine and Animal Productions, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Donatella Diana
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale della Ricerca, Naples, Italy
| | - Emilia Pedone
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale della Ricerca, Naples, Italy
| | - Sara Gargiulo
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale della Ricerca, Naples, Italy
| | - Matteo Gramanzini
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale della Ricerca, Naples, Italy
| | - Arturo Brunetti
- CEINGE Biotecnologie Avanzate, Naples, Italy.,Dipartimento di Scienze Biomediche Avanzate, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Laura Danielson
- Division of Clinical Studies, The Institute of Cancer Research, London SM2 5NG, UK
| | - Marianeve Carotenuto
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy
| | | | - Antonio Verrico
- Paediatric Neurosurgery, Ospedale Santobono-Pausilipon, Naples, Italy
| | - Lucia Quaglietta
- Paediatric Neurosurgery, Ospedale Santobono-Pausilipon, Naples, Italy
| | | | | | - Valeria D'Argenio
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy
| | - Felice Tirone
- Genetic Control of Development-URT, Institute of Cell Biology and Neurobiology, National Research Council, Fondazione Santa Lucia, Rome, Italy
| | - Angela Mastronuzzi
- Dipartimento di Onco-Ematologia, IRCCS Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | | | - Felice Giangaspero
- Dipartimento di Scienze Radiologiche, Oncologiche e Anatomo Patologiche, Università La Sapienza, Rome, Italy.,IRCCS Neuromed, Pozzilli, Italy
| | - Daniel Picard
- German Cancer Consortium (DKTK), Department of Paediatric Oncology, Haematology, and Clinical Immunology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Marc Remke
- German Cancer Consortium (DKTK), Department of Paediatric Oncology, Haematology, and Clinical Immunology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Livia Garzia
- Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto ON, Canada
| | - Craig Daniels
- Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Ontario, Canada
| | - Olivier Delattre
- PSL Research University, Inserm U830, Equipe Labellisée Ligue contre le Cancer, Institut Curie, Paris, France
| | - Fredrik J Swartling
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - William A Weiss
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Francesco Salvatore
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy
| | - Roberto Fattorusso
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Caserta, Italy
| | - Louis Chesler
- Division of Clinical Studies, The Institute of Cancer Research, London SM2 5NG, UK
| | - Michael D Taylor
- Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto ON, Canada
| | - Giuseppe Cinalli
- Paediatric Neurosurgery, Ospedale Santobono-Pausilipon, Naples, Italy
| | - Massimo Zollo
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy.,European School of Molecular Medicine (SEMM), Milan, Italy.,DAI-Medicina Trasfusionale-Azienda Ospedaliera Universitaria Federico II, Naples, Italy
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12
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Rivero-Ríos P, Romo-Lozano M, Madero-Pérez J, Thomas AP, Biosa A, Greggio E, Hilfiker S. The G2019S variant of leucine-rich repeat kinase 2 (LRRK2) alters endolysosomal trafficking by impairing the function of the GTPase RAB8A. J Biol Chem 2019; 294:4738-4758. [PMID: 30709905 PMCID: PMC6442034 DOI: 10.1074/jbc.ra118.005008] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 01/30/2019] [Indexed: 12/25/2022] Open
Abstract
Mutations in the gene encoding for leucine-rich repeat kinase 2 (LRRK2) are a common cause of hereditary Parkinson's disease. LRRK2 regulates various intracellular vesicular trafficking pathways, including endolysosomal degradative events such as epidermal growth factor receptor (EGFR) degradation. Recent studies have revealed that a subset of RAB proteins involved in secretory and endocytic recycling are LRRK2 kinase substrates in vivo. However, the effects of LRRK2-mediated phosphorylation of these substrates on membrane trafficking remain unknown. Here, using an array of immunofluorescence and pulldown assays, we report that expression of active or phosphodeficient RAB8A variants rescues the G2019S LRRK2–mediated effects on endolysosomal membrane trafficking. Similarly, up-regulation of the RAB11–Rabin8–RAB8A cascade, which activates RAB8A, also reverted these trafficking deficits. Loss of RAB8A mimicked the effects of G2019S LRRK2 on endolysosomal trafficking and decreased RAB7A activity. Expression of pathogenic G2019S LRRK2 or loss of RAB8A interfered with EGFR degradation by causing its accumulation in a RAB4-positive endocytic compartment, which was accompanied by a deficit in EGFR recycling and was rescued upon expression of active RAB7A. Dominant-negative RAB7A expression resulted in similar deficits in EGF degradation, accumulation in a RAB4 compartment, and deficits in EGFR recycling, which were all rescued upon expression of active RAB8A. Taken together, these findings suggest that, by impairing RAB8A function, pathogenic G2019S LRRK2 deregulates endolysosomal transport and endocytic recycling events.
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Affiliation(s)
- Pilar Rivero-Ríos
- From the Institute of Parasitology and Biomedicine "López-Neyra," Consejo Superior de Investigaciones Científicas (CSIC), Avda del Conocimiento s/n, 18016 Granada, Spain
| | - María Romo-Lozano
- From the Institute of Parasitology and Biomedicine "López-Neyra," Consejo Superior de Investigaciones Científicas (CSIC), Avda del Conocimiento s/n, 18016 Granada, Spain
| | - Jesús Madero-Pérez
- From the Institute of Parasitology and Biomedicine "López-Neyra," Consejo Superior de Investigaciones Científicas (CSIC), Avda del Conocimiento s/n, 18016 Granada, Spain
| | - Andrew P Thomas
- the Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103, and
| | - Alice Biosa
- the Department of Biology, University of Padova, Padova 35121, Italy
| | - Elisa Greggio
- the Department of Biology, University of Padova, Padova 35121, Italy
| | - Sabine Hilfiker
- From the Institute of Parasitology and Biomedicine "López-Neyra," Consejo Superior de Investigaciones Científicas (CSIC), Avda del Conocimiento s/n, 18016 Granada, Spain,
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13
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Morimoto S, Hatsuta H, Motoyama R, Kokubo Y, Ishiura H, Tsuji S, Kuzuhara S, Murayama S. Optineurin pathology in the spinal cord of amyotrophic lateral sclerosis/parkinsonism-dementia complex patients in Kii Peninsula, Japan. Brain Pathol 2019; 28:422-426. [PMID: 28960710 DOI: 10.1111/bpa.12558] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Satoru Morimoto
- Department of Neuropathology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan.,Department of Neurology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Hiroyuki Hatsuta
- Department of Neuropathology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Rie Motoyama
- Department of Neurology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Yasumasa Kokubo
- Kii ALS/PDC Research Center, Mie University Graduate School of Regional Innovation Studies, Mie, Japan
| | - Hiroyuki Ishiura
- Department of Neurology, Tokyo University Graduate School of Medicine, Tokyo, Japan
| | - Shoji Tsuji
- Department of Neurology, Tokyo University Graduate School of Medicine, Tokyo, Japan
| | - Shigeki Kuzuhara
- Neurology and Medicine, School of Nursing, Suzuka University of Medical Science, Mie, Japan
| | - Shigeo Murayama
- Department of Neuropathology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan.,Department of Neurology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
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14
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Madero-Pérez J, Fernández B, Lara Ordóñez AJ, Fdez E, Lobbestael E, Baekelandt V, Hilfiker S. RAB7L1-Mediated Relocalization of LRRK2 to the Golgi Complex Causes Centrosomal Deficits via RAB8A. Front Mol Neurosci 2018; 11:417. [PMID: 30483055 PMCID: PMC6243087 DOI: 10.3389/fnmol.2018.00417] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 10/25/2018] [Indexed: 11/30/2022] Open
Abstract
Mutations in the LRRK2 gene cause autosomal-dominant Parkinson’s disease (PD), and both LRRK2 as well as RAB7L1 have been implicated in increased susceptibility to idiopathic PD. RAB7L1 has been shown to increase membrane-association and kinase activity of LRRK2, and both seem to be mechanistically implicated in the same pathway. Another RAB protein, RAB8A, has been identified as a prominent LRRK2 kinase substrate, and our recent work demonstrates that aberrant LRRK2-mediated phosphorylation of RAB8A leads to centrosomal alterations. Here, we show that RAB7L1 recruits LRRK2 to the Golgi complex, which causes accumulation of phosphorylated RAB8A in a pericentrosomal/centrosomal location as well as centrosomal deficits identical to those observed with pathogenic LRRK2. The centrosomal alterations induced by wildtype LRRK2 in the presence of RAB7L1 depend on Golgi integrity. This is in contrast to pathogenic LRRK2 mutants, which cause centrosomal deficits independent of Golgi integrity or largely independent on RAB7L1 expression. Furthermore, centrosomal alterations in the presence of wildtype LRRK2 and RAB7L1 are at least in part mediated by aberrant LRRK2-mediated RAB8A phosphorylation, as abolished by kinase inhibitors and reduced upon knockdown of RAB8A. These results indicate that pathogenic LRRK2, as well as increased levels of RAB7L1, cause centrosomal deficits in a manner dependent on aberrant RAB8A phosphorylation and centrosomal/pericentrosomal accumulation, suggesting that centrosomal cohesion deficits may comprise a useful cellular readout for a broader spectrum of the disease.
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Affiliation(s)
- Jesús Madero-Pérez
- Institute of Parasitology and Biomedicine "López-Neyra", Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Belén Fernández
- Institute of Parasitology and Biomedicine "López-Neyra", Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Antonio Jesús Lara Ordóñez
- Institute of Parasitology and Biomedicine "López-Neyra", Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Elena Fdez
- Institute of Parasitology and Biomedicine "López-Neyra", Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Evy Lobbestael
- Laboratory for Neurobiology and Gene Therapy, KU Leuven, Leuven, Belgium
| | - Veerle Baekelandt
- Laboratory for Neurobiology and Gene Therapy, KU Leuven, Leuven, Belgium
| | - Sabine Hilfiker
- Institute of Parasitology and Biomedicine "López-Neyra", Consejo Superior de Investigaciones Científicas, Granada, Spain
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15
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Swarup G, Sayyad Z. Altered Functions and Interactions of Glaucoma-Associated Mutants of Optineurin. Front Immunol 2018; 9:1287. [PMID: 29951055 PMCID: PMC6008547 DOI: 10.3389/fimmu.2018.01287] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/22/2018] [Indexed: 12/13/2022] Open
Abstract
Optineurin (OPTN) is an adaptor protein that is involved in mediating a variety of cellular processes such as signaling, vesicle trafficking, and autophagy. Certain mutations in OPTN (gene OPTN) are associated with primary open angle glaucoma, a leading cause of irreversible blindness, and amyotrophic lateral sclerosis, a fatal motor neuron disease. Glaucoma-associated mutations of OPTN are mostly missense mutations. OPTN mediates its functions by interacting with various proteins and altered interactions of OPTN mutants with various proteins primarily contribute to functional defects. It interacts with Rab8, myosin VI, Huntigtin, TBC1D17, and transferrin receptor to mediate various membrane vesicle trafficking pathways. It is an autophagy receptor that mediates cargo-selective as well as non-selective autophagy. Glaucoma-associated mutants of OPTN, E50K, and M98K, cause defective vesicle trafficking, autophagy, and signaling that contribute to death of retinal ganglion cells (RGCs). Transgenic mice expressing E50K-OPTN show loss of RGCs and persistent reactive gliosis. TBK1 protein kinase, which mediates E50K-OPTN and M98K-OPTN induced cell death, is emerging as a potential drug target. Autoimmunity has been implicated in glaucoma but involvement of OPTN or its mutants in autoimmnity has not been explored. In this review, we highlight the main functions of OPTN and how glaucoma-associated mutants alter these functions. We also discuss some of the controversies, such as the role of OPTN in signaling to transcription factor NF-κB, interferon signaling, and use of RGC-5 cell line as a cell culture model.
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Affiliation(s)
- Ghanshyam Swarup
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
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16
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Toth RP, Atkin JD. Dysfunction of Optineurin in Amyotrophic Lateral Sclerosis and Glaucoma. Front Immunol 2018; 9:1017. [PMID: 29875767 PMCID: PMC5974248 DOI: 10.3389/fimmu.2018.01017] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 04/23/2018] [Indexed: 12/11/2022] Open
Abstract
Neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia, and glaucoma, affect millions of people worldwide. ALS is caused by the loss of motor neurons in the spinal cord, brainstem, and brain, and genetic mutations are responsible for 10% of all ALS cases. Glaucoma is characterized by the loss of retinal ganglion cells and is the most common cause of irreversible blindness. Interestingly, mutations in OPTN, encoding optineurin, are associated with both ALS and glaucoma. Optineurin is a highly abundant protein involved in a wide range of cellular processes, including the inflammatory response, autophagy, Golgi maintenance, and vesicular transport. In this review, we summarize the role of optineurin in cellular mechanisms implicated in neurodegenerative disorders, including neuroinflammation, autophagy, and vesicular trafficking, focusing in particular on the consequences of expression of mutations associated with ALS and glaucoma. This review, therefore showcases the impact of optineurin dysfunction in ALS and glaucoma.
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Affiliation(s)
- Reka P Toth
- Motor Neuron Disease Research Centre, Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Julie D Atkin
- Motor Neuron Disease Research Centre, Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia.,Department of Biochemistry, La Trobe Institute for Molecular Science, Melbourne, VIC, Australia
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17
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Bansal M, Moharir SC, Swarup G. Autophagy receptor optineurin promotes autophagosome formation by potentiating LC3-II production and phagophore maturation. Commun Integr Biol 2018; 11:1-4. [PMID: 30083281 PMCID: PMC6067844 DOI: 10.1080/19420889.2018.1467189] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/17/2018] [Indexed: 10/27/2022] Open
Abstract
Autophagy is an essential physiological process that maintains cellular homeostasis by eliminating harmful protein aggregates, damaged organelles and certain pathogens through lysosomal degradation. During autophagy specialized structures, known as autophagosomes are formed that recruit the cargo through autophagy receptors, and deliver it to lysosomes. Optineurin (Optn) is an autophagy receptor that mediates cargo selective autophagy. Recently, we have identified a novel function of Optn that promotes autophagosome formation during non-selective autophagy. Optn-deficient cells show reduced formation of autophagosomal protein LC3-II and lower number of autophagosomes as well as autolysosomes. Interestingly, formation of phagophores is increased in Optn-deficient cells. This suggests that Optn promotes autophagosome formation by potentiating LC3-II production and phagophore maturation. Phosphorylation of Optn at Ser-177 is required for promoting autophagosome formation. Here, we discuss various aspects of the role of Optn in the formation of autophagosomes and Atg16L1-positive vesicles. We also discuss the potential role of Rab1a-Optn interaction.
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Affiliation(s)
- Megha Bansal
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | - Ghanshyam Swarup
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
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18
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Ryan TA, Tumbarello DA. Optineurin: A Coordinator of Membrane-Associated Cargo Trafficking and Autophagy. Front Immunol 2018; 9:1024. [PMID: 29867991 PMCID: PMC5962687 DOI: 10.3389/fimmu.2018.01024] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/24/2018] [Indexed: 12/13/2022] Open
Abstract
Optineurin is a multifunctional adaptor protein intimately involved in various vesicular trafficking pathways. Through interactions with an array of proteins, such as myosin VI, huntingtin, Rab8, and Tank-binding kinase 1, as well as via its oligomerisation, optineurin has the ability to act as an adaptor, scaffold, or signal regulator to coordinate many cellular processes associated with the trafficking of membrane-delivered cargo. Due to its diverse interactions and its distinct functions, optineurin is an essential component in a number of homeostatic pathways, such as protein trafficking and organelle maintenance. Through the binding of polyubiquitinated cargoes via its ubiquitin-binding domain, optineurin also serves as a selective autophagic receptor for the removal of a wide range of substrates. Alternatively, it can act in an ubiquitin-independent manner to mediate the clearance of protein aggregates. Regarding its disease associations, mutations in the optineurin gene are associated with glaucoma and have more recently been found to correlate with Paget’s disease of bone and amyotrophic lateral sclerosis (ALS). Indeed, ALS-associated mutations in optineurin result in defects in neuronal vesicular localisation, autophagosome–lysosome fusion, and secretory pathway function. More recent molecular and functional analysis has shown that it also plays a role in mitophagy, thus linking it to a number of other neurodegenerative conditions, such as Parkinson’s. Here, we review the role of optineurin in intracellular membrane trafficking, with a focus on autophagy, and describe how upstream signalling cascades are critical to its regulation. Current data and contradicting reports would suggest that optineurin is an important and selective autophagy receptor under specific conditions, whereby interplay, synergy, and functional redundancy with other receptors occurs. We will also discuss how dysfunction in optineurin-mediated pathways may lead to perturbation of critical cellular processes, which can drive the pathologies of number of diseases. Therefore, further understanding of optineurin function, its target specificity, and its mechanism of action will be critical in fully delineating its role in human disease.
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Affiliation(s)
- Thomas A Ryan
- Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - David A Tumbarello
- Biological Sciences, University of Southampton, Southampton, United Kingdom
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19
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Bansal M, Moharir SC, Sailasree SP, Sirohi K, Sudhakar C, Sarathi DP, Lakshmi BJ, Buono M, Kumar S, Swarup G. Optineurin promotes autophagosome formation by recruiting the autophagy-related Atg12-5-16L1 complex to phagophores containing the Wipi2 protein. J Biol Chem 2017; 293:132-147. [PMID: 29133525 DOI: 10.1074/jbc.m117.801944] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/31/2017] [Indexed: 01/09/2023] Open
Abstract
Autophagy is a quality-control mechanism that helps to maintain cellular homeostasis by removing damaged proteins and organelles through lysosomal degradation. During autophagy, signaling events lead to the formation of a cup-shaped structure called the phagophore that matures into the autophagosome. Recruitment of the autophagy-associated Atg12-5-16L1 complex to Wipi2-positive phagophores is crucial for producing microtubule-associated protein 1 light chain 3-II (LC3-II), which is required for autophagosome formation. Here, we explored the role of the autophagy receptor optineurin (Optn) in autophagosome formation. Fibroblasts from Optn knock-out mouse showed reduced LC3-II formation and a lower number of autophagosomes and autolysosomes during both basal and starvation-induced autophagy. However, the number of Wipi2-positive phagophores was not decreased in Optn-deficient cells. We also found that the number of Atg12/16L1-positive puncta and recruitment of the Atg12-5-16L1 complex to Wipi2-positive puncta are reduced in Optn-deficient cells. Of note, Optn was recruited to Atg12-5-16L1-positive puncta, and interacted with Atg5 and also with Atg12-5 conjugate. A disease-associated Optn mutant, E478G, defective in ubiquitin binding, was also defective in autophagosome formation and recruitment to the Atg12-5-16L1-positive puncta. Moreover, we noted that Optn phosphorylation at Ser-177 was required for autophagosome formation but not for Optn recruitment to the phagophore. These results suggest that Optn potentiates LC3-II production and maturation of the phagophore into the autophagosome, by facilitating the recruitment of the Atg12-5-16L1 complex to Wipi2-positive phagophores.
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Affiliation(s)
- Megha Bansal
- Council of Scientific and Industrial Research (CSIR), Centre for Cellular and Molecular Biology, Hyderabad-500007, India
| | - Shivranjani C Moharir
- Council of Scientific and Industrial Research (CSIR), Centre for Cellular and Molecular Biology, Hyderabad-500007, India
| | - S Purnima Sailasree
- Council of Scientific and Industrial Research (CSIR), Centre for Cellular and Molecular Biology, Hyderabad-500007, India
| | - Kapil Sirohi
- Council of Scientific and Industrial Research (CSIR), Centre for Cellular and Molecular Biology, Hyderabad-500007, India
| | - Cherukuri Sudhakar
- Council of Scientific and Industrial Research (CSIR), Centre for Cellular and Molecular Biology, Hyderabad-500007, India
| | - D Partha Sarathi
- Council of Scientific and Industrial Research (CSIR), Centre for Cellular and Molecular Biology, Hyderabad-500007, India
| | - B Jyothi Lakshmi
- Council of Scientific and Industrial Research (CSIR), Centre for Cellular and Molecular Biology, Hyderabad-500007, India
| | - Mario Buono
- MRC Molecular Hematology Unit, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Satish Kumar
- Council of Scientific and Industrial Research (CSIR), Centre for Cellular and Molecular Biology, Hyderabad-500007, India
| | - Ghanshyam Swarup
- Council of Scientific and Industrial Research (CSIR), Centre for Cellular and Molecular Biology, Hyderabad-500007, India.
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20
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Human protein secretory pathway genes are expressed in a tissue-specific pattern to match processing demands of the secretome. NPJ Syst Biol Appl 2017; 3:22. [PMID: 28845240 PMCID: PMC5562915 DOI: 10.1038/s41540-017-0021-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 06/17/2017] [Accepted: 06/22/2017] [Indexed: 02/05/2023] Open
Abstract
Protein secretory pathway in eukaryal cells is responsible for delivering functional secretory proteins. The dysfunction of this pathway causes a range of important human diseases from congenital disorders to cancer. Despite the piled-up knowledge on the molecular biology and biochemistry level, the tissue-specific expression of the secretory pathway genes has not been analyzed on the transcriptome level. Based on the recent RNA-sequencing studies, the largest fraction of tissue-specific transcriptome encodes for the secretome (secretory proteins). Here, the question arises that if the expression levels of the secretory pathway genes have a tissue-specific tuning. In this study, we tackled this question by performing a meta-analysis of the recently published transcriptome data on human tissues. As a result, we detected 68 as called “extreme genes” which show an unusual expression pattern in specific gene families of the secretory pathway. We also inspected the potential functional link between detected extreme genes and the corresponding tissues enriched secretome. As a result, the detected extreme genes showed correlation with the enrichment of the nature and number of specific post-translational modifications in each tissue’s secretome. Our findings conciliate both the housekeeping and tissue-specific nature of the protein secretory pathway, which we attribute to a fine-tuned regulation of defined gene families to support the diversity of secreted proteins and their modifications. The secretory pathway, an ubiquitous cellular machinery in human cells, is here shown to have tissue-specific characteristics. A research team led by Prof. Jens Nielsen at the Chalmers University of Technology performed a meta-analysis of the gene expressions of the secretory pathway’ component. They detected that even though most of these components are expressed in all tissues, there exist distinct components with fine-tuned expression. They further evaluated the functional link between the detected tuning and the processes that are demanded to make a set of tissue-specific proteins such as endocrine system hormones or their receptors. These findings open up a new avenue to understand the function of the secretion pathway in human tissues with possible applications for improving production of pharmaceutical proteins and getting more insight into the mechanisms underlying diseases such as diabetes that are connected with the endocrine system.
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21
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Rasnitsyn A, Doucette L, Seifi M, Footz T, Raymond V, Walter MA. FOXC1 modulates MYOC secretion through regulation of the exocytic proteins RAB3GAP1, RAB3GAP2 and SNAP25. PLoS One 2017; 12:e0178518. [PMID: 28575017 PMCID: PMC5456087 DOI: 10.1371/journal.pone.0178518] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 05/15/2017] [Indexed: 11/19/2022] Open
Abstract
The neurodegenerative disease glaucoma is one of the leading causes of blindness in the world. Glaucoma is characterized by progressive visual field loss caused by retinal ganglion cell (RGC) death. Both surgical glaucoma treatments and medications are available, however, they only halt glaucoma progression and are unable to reverse damage. Furthermore, many patients do not respond well to treatments. It is therefore important to better understand the mechanisms involved in glaucoma pathogenesis. Patients with Axenfeld-Rieger syndrome (ARS) offer important insight into glaucoma progression. ARS patients are at 50% risk of developing early onset glaucoma and respond poorly to treatments, even when surgical treatments are combined with medications. Mutations in the transcription factor FOXC1 cause ARS. Alterations in FOXC1 levels cause ocular malformations and disrupt stress response in ocular tissues, thereby contributing to glaucoma progression. In this study, using biochemical and molecular techniques, we show that FOXC1 regulates the expression of RAB3GAP1, RAB3GAP2 and SNAP25, three genes with central roles in both exocytosis and endocytosis, responsible for extracellular trafficking. FOXC1 positively regulates RAB3GAP1 and RAB3GAP2, while either increase or decrease in FOXC1 levels beyond its normal range results in decreased SNAP25. In addition, we found that FOXC1 regulation of RAB3GAP1, RAB3GAP2 and SNAP25 affects secretion of Myocilin (MYOC), a protein associated with juvenile onset glaucoma and steroid-induced glaucoma. The present work reveals that FOXC1 is an important regulator of exocytosis and establishes a new link between FOXC1 and MYOC-associated glaucoma.
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Affiliation(s)
- Alexandra Rasnitsyn
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Lance Doucette
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Morteza Seifi
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Tim Footz
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Vincent Raymond
- Centre Hospitalier de l'Université Laval (CHUL) Quebec City, Québec, Canada
| | - Michael A. Walter
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
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22
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Liu Y, Allingham RR. Major review: Molecular genetics of primary open-angle glaucoma. Exp Eye Res 2017; 160:62-84. [PMID: 28499933 DOI: 10.1016/j.exer.2017.05.002] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 03/29/2017] [Accepted: 05/07/2017] [Indexed: 12/13/2022]
Abstract
Glaucoma is a leading cause of irreversible blindness worldwide. Primary open-angle glaucoma (POAG), the most common type, is a complex inherited disorder that is characterized by progressive retinal ganglion cell death, optic nerve head excavation, and visual field loss. The discovery of a large, and growing, number of genetic and chromosomal loci has been shown to contribute to POAG risk, which carry implications for disease pathogenesis. Differential gene expression analyses in glaucoma-affected tissues as well as animal models of POAG are enhancing our mechanistic understanding in this common, blinding disorder. In this review we summarize recent developments in POAG genetics and molecular genetics research.
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Affiliation(s)
- Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States; James & Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States; Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, GA, United States
| | - R Rand Allingham
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, United States; Duke - National University of Singapore (Duke-NUS), Singapore.
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23
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Ubiquitin and Parkinson's disease through the looking glass of genetics. Biochem J 2017; 474:1439-1451. [PMID: 28408429 PMCID: PMC5390927 DOI: 10.1042/bcj20160498] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 02/20/2017] [Accepted: 02/20/2017] [Indexed: 12/12/2022]
Abstract
Biochemical alterations found in the brains of Parkinson's disease (PD) patients indicate that cellular stress is a major driver of dopaminergic neuronal loss. Oxidative stress, mitochondrial dysfunction, and ER stress lead to impairment of the homeostatic regulation of protein quality control pathways with a consequent increase in protein misfolding and aggregation and failure of the protein degradation machinery. Ubiquitin signalling plays a central role in protein quality control; however, prior to genetic advances, the detailed mechanisms of how impairment in the ubiquitin system was linked to PD remained mysterious. The discovery of mutations in the α-synuclein gene, which encodes the main protein misfolded in PD aggregates, together with mutations in genes encoding ubiquitin regulatory molecules, including PTEN-induced kinase 1 (PINK1), Parkin, and FBX07, has provided an opportunity to dissect out the molecular basis of ubiquitin signalling disruption in PD, and this knowledge will be critical for developing novel therapeutic strategies in PD that target the ubiquitin system.
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24
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Mao J, Xia Q, Liu C, Ying Z, Wang H, Wang G. A critical role of Hrd1 in the regulation of optineurin degradation and aggresome formation. Hum Mol Genet 2017; 26:1877-1889. [DOI: 10.1093/hmg/ddx096] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/08/2017] [Indexed: 12/30/2022] Open
Affiliation(s)
- Jiahui Mao
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215021, China
- Department of Pathophysiology, Nantong University School of Medicine, Nantong, Jiangsu 226001, China
| | - Qin Xia
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215021, China
| | - Chunfeng Liu
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Zheng Ying
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215021, China
- Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215021, China
| | - Hongfeng Wang
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215021, China
| | - Guanghui Wang
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215021, China
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25
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Montecalvo A, Watkins SC, Orange J, Kane LP. Inducible turnover of optineurin regulates T cell activation. Mol Immunol 2017; 85:9-17. [PMID: 28192730 DOI: 10.1016/j.molimm.2017.01.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 01/13/2017] [Accepted: 01/28/2017] [Indexed: 12/28/2022]
Abstract
Optineurin (Optn) is an adaptor protein with homology to NF-κB essential modulator (NEMO), the regulatory subunit of the IκB kinase (IKK) complex. Dysregulation of Optn has been linked to neurodegenerative, autoimmune and bone diseases. Optn shares a high degree of homology with NEMO, but is not part of the same high-molecular weight complex containing IKKα and IKKβ. Despite its homology with NEMO and the fact that it has been the subject of extensive study in several cell types, there are no published studies addressing the role of Optn during T cell activation. Here we demonstrate that ectopic expression of Optn down-regulates TCR-induced NF-κB activation and TNF-α production, in a manner dependent on ubiquitin-binding. Conversely, knock-down of Optn enhances NF-κB activation and the production of TNF-α. Consistent with a negative regulatory role for this protein, we observed transient loss of Optn after TCR stimulation in both cell lines and in primary murine T cells. The acute loss of Optn appears to be due to both protein degradation and exocytosis, the latter via activation-induced exosomes. This study therefore provides novel information regarding the role of Optn during TCR activation, suggesting the possible importance of Optn during inflammation and/or autoimmune diseases.
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Affiliation(s)
- Angela Montecalvo
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, United States
| | - Simon C Watkins
- Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, United States
| | - Jordan Orange
- Texas Children's Hospital, Houston, TX 77030, United States
| | - Lawrence P Kane
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, United States.
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26
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Vidal-Quadras M, Holst MR, Francis MK, Larsson E, Hachimi M, Yau WL, Peränen J, Martín-Belmonte F, Lundmark R. Endocytic turnover of Rab8 controls cell polarization. J Cell Sci 2017; 130:1147-1157. [PMID: 28137756 PMCID: PMC5358338 DOI: 10.1242/jcs.195420] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 01/18/2017] [Indexed: 01/05/2023] Open
Abstract
Adaptation of cell shape and polarization through the formation and retraction of cellular protrusions requires balancing of endocytosis and exocytosis combined with fine-tuning of the local activity of small GTPases like Rab8. Here, we show that endocytic turnover of the plasma membrane at protrusions is directly coupled to surface removal and inactivation of Rab8. Removal is induced by reduced membrane tension and mediated by the GTPase regulator associated with focal adhesion kinase-1 (GRAF1, also known as ARHGAP26), a regulator of clathrin-independent endocytosis. GRAF1-depleted cells were deficient in multi-directional spreading and displayed elevated levels of GTP-loaded Rab8, which was accumulated at the tips of static protrusions. Furthermore, GRAF1 depletion impaired lumen formation and spindle orientation in a 3D cell culture system, indicating that GRAF1 activity regulates polarity establishment. Our data suggest that GRAF1-mediated removal of Rab8 from the cell surface restricts its activity during protrusion formation, thereby facilitating dynamic adjustment of the polarity axis.
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Affiliation(s)
| | - Mikkel R Holst
- Integrative Medical Biology, Umeå University, Umeå 901 87, Sweden
| | - Monika K Francis
- Integrative Medical Biology, Umeå University, Umeå 901 87, Sweden.,Medical Biochemistry and Biophysics, Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå 901 87, Sweden
| | - Elin Larsson
- Integrative Medical Biology, Umeå University, Umeå 901 87, Sweden.,Medical Biochemistry and Biophysics, Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå 901 87, Sweden
| | - Mariam Hachimi
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-UAM, Madrid 28049, Spain
| | - Wai-Lok Yau
- Medical Biochemistry and Biophysics, Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå 901 87, Sweden
| | - Johan Peränen
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki FIN-00014, Finland
| | - Fernando Martín-Belmonte
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-UAM, Madrid 28049, Spain
| | - Richard Lundmark
- Integrative Medical Biology, Umeå University, Umeå 901 87, Sweden .,Medical Biochemistry and Biophysics, Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå 901 87, Sweden
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27
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Minegishi Y, Nakayama M, Iejima D, Kawase K, Iwata T. Significance of optineurin mutations in glaucoma and other diseases. Prog Retin Eye Res 2016; 55:149-181. [DOI: 10.1016/j.preteyeres.2016.08.002] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 08/18/2016] [Accepted: 08/18/2016] [Indexed: 12/12/2022]
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28
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Abstract
Macroautophagy is a conserved degradative pathway in which a double-membrane compartment sequesters cytoplasmic cargo and delivers the contents to lysosomes for degradation. Efficient formation and maturation of autophagic vesicles, so-called phagophores that are precursors to autophagosomes, and their subsequent trafficking to lysosomes relies on the activity of small RAB GTPases, which are essential factors of cellular vesicle transport systems. The activity of RAB GTPases is coordinated by upstream factors, which include guanine nucleotide exchange factors (RAB GEFs) and RAB GTPase activating proteins (RAB GAPs). A role in macroautophagy regulation for different TRE2-BUB2-CDC16 (TBC) domain-containing RAB GAPs has been established. Recently, however, a positive modulation of macroautophagy has also been demonstrated for the TBC domain-free RAB3GAP1/2, adding to the family of RAB GAPs that coordinate macroautophagy and additional cellular trafficking pathways.
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Affiliation(s)
- Andreas Kern
- a Institute for Pathobiochemistry; University Medical Center of the Johannes Gutenberg University ; Mainz , Germany
| | - Ivan Dikic
- b Buchmann Institute for Molecular Life Sciences; Goethe University Frankfurt ; Frankfurt am Main , Germany
| | - Christian Behl
- a Institute for Pathobiochemistry; University Medical Center of the Johannes Gutenberg University ; Mainz , Germany
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29
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Zhu M, Li A, Chen J, Zhang S, Wu J. Effects of optineurin mutants on SH-SY5Y cell survival. Mol Cell Neurosci 2016; 74:18-24. [DOI: 10.1016/j.mcn.2016.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/17/2016] [Accepted: 03/04/2016] [Indexed: 10/22/2022] Open
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30
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Defects in autophagy caused by glaucoma-associated mutations in optineurin. Exp Eye Res 2016; 144:54-63. [DOI: 10.1016/j.exer.2015.08.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 07/14/2015] [Accepted: 08/18/2015] [Indexed: 11/30/2022]
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31
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A Glaucoma-Associated Variant of Optineurin, M98K, Activates Tbk1 to Enhance Autophagosome Formation and Retinal Cell Death Dependent on Ser177 Phosphorylation of Optineurin. PLoS One 2015; 10:e0138289. [PMID: 26376340 PMCID: PMC4574030 DOI: 10.1371/journal.pone.0138289] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 08/29/2015] [Indexed: 02/03/2023] Open
Abstract
Certain missense mutations in optineurin/OPTN and amplification of TBK1 are associated with normal tension glaucoma. A glaucoma-associated variant of OPTN, M98K, induces autophagic degradation of transferrin receptor (TFRC) and death in retinal cells. Here, we have explored the role of Tbk1 in M98K-OPTN-induced autophagy and cell death, and the effect of Tbk1 overexpression in retinal cells. Cell death induced by M98K-OPTN was dependent on Tbk1 as seen by the effect of Tbk1 knockdown and blocking of Tbk1 activity by a chemical inhibitor. Inhibition of Tbk1 also restores M98K-OPTN-induced transferrin receptor degradation. M98K-OPTN-induced autophagosome formation, autophagy and cell death were dependent on its phosphorylation at S177 by Tbk1. Knockdown of OPTN reduced starvation-induced autophagosome formation. M98K-OPTN expressing cells showed higher levels of Tbk1 activation and enhanced phosphorylation at Ser177 compared to WT-OPTN expressing cells. M98K-OPTN-induced activation of Tbk1 and its ability to be phosphorylated better by Tbk1 was dependent on ubiquitin binding. Phosphorylated M98K-OPTN localized specifically to autophagosomes and endogenous Tbk1 showed increased localization to autophagosomes in M98K-OPTN expressing cells. Overexpression of Tbk1 induced cell death and caspase-3 activation that were dependent on its catalytic activity. Tbk1-induced cell death possibly involves autophagy, as shown by the effect of Atg5 knockdown, and requirement of autophagic function of OPTN. Our results show that phosphorylation of Ser177 plays a crucial role in M98K-OPTN-induced autophagosome formation, autophagy flux and retinal cell death. In addition, we provide evidence for cross talk between two glaucoma associated proteins and their inter-dependence to mediate autophagy-dependent cell death.
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32
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Burtey A, Wagner M, Hodneland E, Skaftnesmo KO, Schoelermann J, Mondragon IR, Espedal H, Golebiewska A, Niclou SP, Bjerkvig R, Kögel T, Gerdes H. Intercellular transfer of transferrin receptor by a contact‐, Rab8‐dependent mechanism involving tunneling nanotubes. FASEB J 2015. [DOI: 10.1096/fj.14-268615] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Anne Burtey
- Department of BiomedicineUniversity of BergenBergenNorway
| | - Marek Wagner
- Department of BiomedicineUniversity of BergenBergenNorway
- Department of PathologyHaukeland University HospitalBergenNorway
| | - Erlend Hodneland
- Department of Clinical MedicineHaukeland University HospitalBergenNorway
| | | | - Julia Schoelermann
- Department of BiomedicineUniversity of BergenBergenNorway
- Biomaterials, Department of Clinical DentistryUniversity of BergenBergenNorway
| | | | - Heidi Espedal
- Department of BiomedicineUniversity of BergenBergenNorway
| | - Anna Golebiewska
- NorLux Neuro‐Oncology LaboratoryDepartment of OncologyLuxembourg Institute of Health (LIH)LuxembourgLuxembourg
| | - Simone P. Niclou
- K. G. Jebsen Brain Tumour Research CenterUniversity of BergenBergenNorway
- NorLux Neuro‐Oncology LaboratoryDepartment of OncologyLuxembourg Institute of Health (LIH)LuxembourgLuxembourg
| | - Rolf Bjerkvig
- Department of BiomedicineUniversity of BergenBergenNorway
- K. G. Jebsen Brain Tumour Research CenterUniversity of BergenBergenNorway
- NorLux Neuro‐Oncology LaboratoryDepartment of OncologyLuxembourg Institute of Health (LIH)LuxembourgLuxembourg
| | - Tanja Kögel
- Department of BiomedicineUniversity of BergenBergenNorway
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33
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Bansal M, Swarup G, Balasubramanian D. Functional analysis of optineurin and some of its disease-associated mutants. IUBMB Life 2015; 67:120-8. [DOI: 10.1002/iub.1355] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/07/2015] [Accepted: 01/16/2015] [Indexed: 12/27/2022]
Affiliation(s)
- Megha Bansal
- Centre for Cellular and Molecular Biology; Hyderabad Telangana India
| | - Ghanshyam Swarup
- Centre for Cellular and Molecular Biology; Hyderabad Telangana India
| | - Dorairajan Balasubramanian
- Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L.V. Prasad Eye Institute; Hyderabad Telangana India
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34
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Doucette LP, Rasnitsyn A, Seifi M, Walter MA. The interactions of genes, age, and environment in glaucoma pathogenesis. Surv Ophthalmol 2015; 60:310-26. [PMID: 25907525 DOI: 10.1016/j.survophthal.2015.01.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 12/30/2022]
Abstract
Glaucoma, a progressive degenerative condition that results in the death of retinal ganglion cells, is one of the leading causes of blindness, affecting millions worldwide. The mechanisms underlying glaucoma are not well understood, although years of studies have shown that the largest risk factors are elevated intraocular pressure, age, and genetics. Eleven genes and multiple loci have been identified as contributing factors. These genes act by a number of mechanisms, including mechanical stress, ischemic/oxidative stress, and neurodegeneration. We summarize the recent advances in the understanding of glaucoma and propose a unified hypothesis for glaucoma pathogenesis. Glaucoma does not result from a single pathological mechanism, but rather a combination of pathways that are influenced by genes, age, and environment. In particular, we hypothesize that, in the presence of genetic risk factors, exposure to environment stresses results in an earlier age of onset for glaucoma. This hypothesis is based upon the overlap of the molecular pathways in which glaucoma genes are involved. Because of the interactions between these processes, it is likely that there are common therapies that may be effective for different subtypes of glaucoma.
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Affiliation(s)
- Lance P Doucette
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada
| | - Alexandra Rasnitsyn
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada
| | - Morteza Seifi
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada
| | - Michael A Walter
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada.
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35
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Paulus JD, Link BA. Loss of optineurin in vivo results in elevated cell death and alters axonal trafficking dynamics. PLoS One 2014; 9:e109922. [PMID: 25329564 PMCID: PMC4199637 DOI: 10.1371/journal.pone.0109922] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 09/12/2014] [Indexed: 12/11/2022] Open
Abstract
Mutations in Optineurin have been associated with ALS, glaucoma, and Paget’s disease of bone in humans, but little is known about how these mutations contribute to disease. Most of the cellular consequences of Optineurin loss have come from in vitro studies, and it remains unclear whether these same defects would be seen in vivo. To answer this question, we assessed the cellular consequences of Optineurin loss in zebrafish embryos to determine if they showed the same defects as have been described in the in vitro studies. We found that loss of Optineurin resulted in increased cell death, as well as subtle cell morphology, cell migration and vesicle trafficking defects. However, unlike experiments on cells in culture, we found no indication that the Golgi apparatus was disrupted or that NF-κB target genes were upregulated. Therefore, we conclude that in vivo loss of Optineurin shows some, but not all, of the defects seen in in vitro work.
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Affiliation(s)
- Jeremiah D. Paulus
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, United States of America
| | - Brian A. Link
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, United States of America
- * E-mail:
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36
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E50K-OPTN-induced retinal cell death involves the Rab GTPase-activating protein, TBC1D17 mediated block in autophagy. PLoS One 2014; 9:e95758. [PMID: 24752605 PMCID: PMC3994150 DOI: 10.1371/journal.pone.0095758] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 03/28/2014] [Indexed: 12/18/2022] Open
Abstract
The protein optineurin coded by OPTN gene is involved in several functions including regulation of endocytic trafficking, autophagy and signal transduction. Certain missense mutations in the gene OPTN cause normal tension glaucoma. A glaucoma-causing mutant of optineurin, E50K, induces death selectively in retinal cells. This mutant induces defective endocytic recycling of transferrin receptor by causing inactivation of Rab8 mediated by the GTPase-activating protein, TBC1D17. Here, we have explored the mechanism of E50K-induced cell death. E50K-OPTN-induced cell death was inhibited by co-expression of a catalytically inactive mutant of TBC1D17 and also by shRNA mediated knockdown of TBC1D17. Endogenous TBC1D17 colocalized with E50K-OPTN in vesicular structures. Co-expression of transferrin receptor partially protected against E50K-induced cell death. Overexpression of the E50K-OPTN but not WT-OPTN inhibited autophagy flux. Treatment of cells with rapamycin, an inducer of autophagy, reduced E50K-OPTN-induced cell death. An LC3-binding-defective mutant of E50K-OPTN showed reduced cell death, further suggesting the involvement of autophagy. TBC1D17 localized to autophagosomes and inhibited autophagy flux dependent on its catalytic activity. Knockdown of TBC1D17 rescued cells from E50K-mediated inhibition of autophagy flux. Overall, our results suggest that E50K mutant induced death of retinal cells involves impaired autophagy as well as impaired transferrin receptor function. TBC1D17, a GTPase-activating protein for Rab GTPases, plays a crucial role in E50K-induced impaired autophagy and cell death.
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Yamano K, Fogel AI, Wang C, van der Bliek AM, Youle RJ. Mitochondrial Rab GAPs govern autophagosome biogenesis during mitophagy. eLife 2014; 3:e01612. [PMID: 24569479 PMCID: PMC3930140 DOI: 10.7554/elife.01612] [Citation(s) in RCA: 223] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Damaged mitochondria can be selectively eliminated by mitophagy. Although two gene products mutated in Parkinson’s disease, PINK1, and Parkin have been found to play a central role in triggering mitophagy in mammals, how the pre-autophagosomal isolation membrane selectively and accurately engulfs damaged mitochondria remains unclear. In this study, we demonstrate that TBC1D15, a mitochondrial Rab GTPase-activating protein (Rab-GAP), governs autophagosome biogenesis and morphology downstream of Parkin activation. To constrain autophagosome morphogenesis to that of the cargo, TBC1D15 inhibits Rab7 activity and associates with both the mitochondria through binding Fis1 and the isolation membrane through the interactions with LC3/GABARAP family members. Another TBC family member TBC1D17, also participates in mitophagy and forms homodimers and heterodimers with TBC1D15. These results demonstrate that TBC1D15 and TBC1D17 mediate proper autophagic encapsulation of mitochondria by regulating Rab7 activity at the interface between mitochondria and isolation membranes. DOI:http://dx.doi.org/10.7554/eLife.01612.001 Parkinson disease is a common degenerative brain disorder that causes tremors, muscle stiffening, and slowing down of movement. Scientists believe that these symptoms are caused by a progressive loss of brain cells called dopaminergic neurons, which help regulate movement. Most cases have no obvious genetic cause, but around 15% of people with the disease have a close relative who also has the disease, and mutations in the genes encoding two proteins—PINK1 and Parkin—have been identified as prime suspects in familial Parkinson disease. These proteins help to eliminate damaged mitochondria from cells. In addition to producing the energy that cells need to function, mitochondria also help to trigger cell death. Pesticides and other chemicals linked to non-familial cases of Parkinson disease also damage mitochondria. Taken together, this evidence suggests that the accumulation of damaged mitochondria may contribute to the excessive loss of dopaminergic neurons that is seen in both forms of the disease. Yamano et al. provide new details on the ways that autophagosomes—structures that help cells to recycle nutrients and remove debris—destroy mitochondria. Previous studies have shown that when a mitochondrion is damaged, PINK1 sends a signal to Parkin, which then helps to recruit the proteins that are needed to form an autophagosome around the damaged mitochondrion. However, the identity of the proteins that guide the formation of the autophagosome remained a mystery. Yamano et al. have now identified two of these proteins and helped to explain their specific roles in the assembly of autophagosomes. The two proteins, which are called TBC1D15 and TBC1D17, are both GAP proteins, which are well known for their role in deactivating enzymes called RAB GTPases. Yamano et al. show that TBC1D15 binds to the damaged mitochondrion and also to the autophagosome as it grows around the mitochondrion. TBC1D15 also inhibits the action of an enzyme called Rab7 to prevent excessive growth of the autophagosome. TBC1D17 has a similar role. The work of Yamano et al. indicates that Parkin activates Rab7, perhaps by placing chains of a protein called ubiquitin on mitochondria, which would mean that an unexpected new step in this pathway remains to be discovered. Understanding how Parkin activates Rab7 could help identify new targets for drugs that might treat Parkinson disease. DOI:http://dx.doi.org/10.7554/eLife.01612.002
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Affiliation(s)
- Koji Yamano
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
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Kanerva K, Uronen RL, Blom T, Li S, Bittman R, Lappalainen P, Peränen J, Raposo G, Ikonen E. LDL cholesterol recycles to the plasma membrane via a Rab8a-Myosin5b-actin-dependent membrane transport route. Dev Cell 2013; 27:249-62. [PMID: 24209575 DOI: 10.1016/j.devcel.2013.09.016] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 08/09/2013] [Accepted: 09/16/2013] [Indexed: 12/27/2022]
Abstract
Mammalian cells acquire cholesterol, a major membrane constituent, via low-density lipoprotein (LDL) uptake. However, the mechanisms by which LDL cholesterol reaches the plasma membrane (PM) have remained obscure. Here, we applied LDL labeled with BODIPY cholesteryl linoleate to identify this pathway in living cells. The egress of BODIPY cholesterol (BC) from late endosomal (LE) organelles was dependent on acid lipase and Niemann-Pick C1 (NPC1) protein, as for natural cholesterol. We show that NPC1 was needed to recruit Rab8a to BC-containing LEs, and Rab8a enhanced the motility and segregation of BC- and CD63-positive organelles from lysosomes. The BC carriers docked to the cortical actin by a Rab8a- and Myosin5b (Myo5b)-dependent mechanism, typically in the proximity of focal adhesions (FAs). LDL increased the number and dynamics of FAs and stimulated cell migration in an acid lipase, NPC1, and Rab8a-dependent fashion, providing evidence that this cholesterol delivery route to the PM is important for cell movement.
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Affiliation(s)
- Kristiina Kanerva
- Institute of Biomedicine, Anatomy, University of Helsinki, FI-00014 Helsinki, Finland; Minerva Foundation Institute for Medical Research, FI-00290 Helsinki, Finland
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IRF-1-binding site in the first intron mediates interferon-γ-induced optineurin promoter activation. Biochem Biophys Res Commun 2013; 437:179-84. [DOI: 10.1016/j.bbrc.2013.06.065] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 06/18/2013] [Indexed: 12/20/2022]
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Sirohi K, Chalasani MLS, Sudhakar C, Kumari A, Radha V, Swarup G. M98K-OPTN induces transferrin receptor degradation and RAB12-mediated autophagic death in retinal ganglion cells. Autophagy 2013; 9:510-27. [PMID: 23357852 DOI: 10.4161/auto.23458] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Mutations in the autophagy receptor OPTN/optineurin are associated with the pathogenesis of glaucoma and amyotrophic lateral sclerosis, but the underlying molecular basis is poorly understood. The OPTN variant, M98K has been described as a risk factor for normal tension glaucoma in some ethnic groups. Here, we examined the consequence of the M98K mutation in affecting cellular functions of OPTN. Overexpression of M98K-OPTN induced death of retinal ganglion cells (RGC-5 cell line), but not of other neuronal and non-neuronal cells. Enhanced levels of the autophagy marker, LC3-II, a post-translationally modified form of LC3, in M98K-OPTN-expressing cells and the inability of an LC3-binding-defective M98K variant of OPTN to induce cell death, suggested that autophagy contributes to cell death. Knockdown of Atg5 reduced M98K-induced death of RGC-5 cells, further supporting the involvement of autophagy. Overexpression of M98K-OPTN enhanced autophagosome formation and potentiated the delivery of transferrin receptor to autophagosomes for degradation resulting in reduced cellular transferrin receptor levels. Coexpression of transferrin receptor or supplementation of media with an iron donor reduced M98K-induced cell death. OPTN complexes with RAB12, a GTPase involved in vesicle trafficking, and M98K variant shows enhanced colocalization with RAB12. Knockdown of Rab12 increased transferrin receptor level and reduced M98K-induced cell death. RAB12 is present in autophagosomes and knockdown of Rab12 resulted in reduced formation of autolysosomes during starvation-induced autophagy, implicating a role for RAB12 in autophagy. These results also show that transferrin receptor degradation and autophagy play a crucial role in RGC-5 cell death induced by M98K variant of OPTN.
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Affiliation(s)
- Kapil Sirohi
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India
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Maruyama H, Kawakami H. Optineurin and amyotrophic lateral sclerosis. Geriatr Gerontol Int 2012; 13:528-32. [PMID: 23279185 DOI: 10.1111/ggi.12022] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2012] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis is a devastating disease, and thus it is important to identify the causative gene and resolve the mechanism of the disease. We identified optineurin as a causative gene for amyotrophic lateral sclerosis. We found three types of mutations: a homozygous deletion of exon 5, a homozygous Q398X nonsense mutation and a heterozygous E478G missense mutation within its ubiquitin-binding domain. Optineurin negatively regulates the tumor necrosis factor-α-induced activation of nuclear factor kappa B. Nonsense and missense mutations abolished this function. Mutations related to amyotrophic lateral sclerosis also negated the inhibition of interferon regulatory factor-3. The missense mutation showed a cyotoplasmic distribution different from that of the wild type. There are no specific clinical symptoms related to optineurin. However, severe brain atrophy was detected in patients with homozygous deletion. Neuropathologically, an E478G patient showed transactive response DNA-binding protein of 43 kDa-positive neuronal intracytoplasmic inclusions in the spinal and medullary motor neurons. Furthermore, Golgi fragmentation was identified in 73% of this patient's anterior horn cells. In addition, optineurin is colocalized with fused in sarcoma in the basophilic inclusions of amyotrophic lateral sclerosis with fused in sarcoma mutations, and in basophilic inclusion body disease. These findings strongly suggest that optineurin is involved in the pathogenesis of amyotrophic lateral sclerosis.
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Affiliation(s)
- Hirofumi Maruyama
- Department of Epidemiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
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