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Bekele BM, Gazzerro E, Schoenrath F, Falk V, Rost S, Hoerning S, Jelting Y, Zaum AK, Spuler S, Knierim J. Undetected Neuromuscular Disease in Patients after Heart Transplantation. Int J Mol Sci 2024; 25:7819. [PMID: 39063061 PMCID: PMC11277526 DOI: 10.3390/ijms25147819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 07/10/2024] [Accepted: 07/15/2024] [Indexed: 07/28/2024] Open
Abstract
(1) Heart transplantation (HTX) improves the overall survival and functional status of end-stage heart failure patients with cardiomyopathies (CMPs). The majority of CMPs have genetic causes, and the overlap between CMPs and inherited myopathies is well documented. However, the long-term outcome in skeletal muscle function and possibility of an undiagnosed underlying genetic cause of both a cardiac and skeletal pathology remain unknown. (2) Thirty-nine patients were assessed using open and standardized interviews on muscle function, a quality-of-life (EuroQol EQ-5D-3L) questionnaire, and a physical examination (Medical Research Council Muscle scale). Whole-exome sequencing was completed in three stages for those with skeletal muscle weakness. (3) Seven patients (17.9%) reported new-onset muscle weakness and motor limitations. Objective muscle weakness in the upper and lower extremities was seen in four patients. In three of them, exome sequencing revealed pathogenic/likely pathogenic variants in the genes encoding nexilin, myosin heavy chain, titin, and SPG7. (4) Our findings support a positive long-term outcome of skeletal muscle function in HTX patients. However, 10% of patients showed clinical signs of myopathy due to a possible genetic cause. The integration of genetic testing and standardized neurological assessment of motor function during the peri-HTX period should be considered.
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Affiliation(s)
- Biniam Melese Bekele
- Muscle Research Unit, ECRC Experimental and Clinical Research Center, Charité—Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Lindenberger Weg 80, 13125 Berlin, Germany; (B.M.B.); (E.G.)
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
- Charité—Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany (J.K.)
- Deutsches Herzzentrum der Charité—Medical Heart Center of Charité and German Heart Institute Berlin, Department of Cardiothoracic and Vascular Surgery, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Elisabetta Gazzerro
- Muscle Research Unit, ECRC Experimental and Clinical Research Center, Charité—Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Lindenberger Weg 80, 13125 Berlin, Germany; (B.M.B.); (E.G.)
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
| | - Felix Schoenrath
- Charité—Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany (J.K.)
- Deutsches Herzzentrum der Charité—Medical Heart Center of Charité and German Heart Institute Berlin, Department of Cardiothoracic and Vascular Surgery, Augustenburger Platz 1, 13353 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner site Berlin, 13125 Berlin, Germany
| | - Volkmar Falk
- Charité—Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany (J.K.)
- Deutsches Herzzentrum der Charité—Medical Heart Center of Charité and German Heart Institute Berlin, Department of Cardiothoracic and Vascular Surgery, Augustenburger Platz 1, 13353 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner site Berlin, 13125 Berlin, Germany
- Translational Cardiovascular Technologies, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland
| | - Simone Rost
- Institute for Human Genetics, University of Würzburg, 97074 Würzburg, Germany
| | - Selina Hoerning
- Institute for Human Genetics, University of Würzburg, 97074 Würzburg, Germany
| | - Yvonne Jelting
- Institute for Human Genetics, University of Würzburg, 97074 Würzburg, Germany
| | - Ann-Kathrin Zaum
- Institute for Human Genetics, University of Würzburg, 97074 Würzburg, Germany
| | - Simone Spuler
- Muscle Research Unit, ECRC Experimental and Clinical Research Center, Charité—Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Lindenberger Weg 80, 13125 Berlin, Germany; (B.M.B.); (E.G.)
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
- Berlin Institute of Health at Charité—Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Jan Knierim
- Charité—Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany (J.K.)
- Sana Paulinenkrankenhaus, Department of Internal Medicine and Cardiology, Dickensweg 25-39, 14055 Berlin, Germany
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2
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Seo Y, Lim HT, Lee BJ, Han J. Expanding SPG7 dominant optic atrophy phenotype: Infantile nystagmus and optic atrophy without spastic paraplegia. Am J Med Genet A 2023; 191:582-585. [PMID: 36367250 DOI: 10.1002/ajmg.a.63037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/19/2022] [Accepted: 10/13/2022] [Indexed: 11/13/2022]
Abstract
Spastic paraplegia is a neurodegenerative disorder characterized by progressive leg weakness and spasticity due to degeneration of corticospinal axons. SPG7 encodes paraplegin, and pathogenic variants in the gene cause hereditary spastic paraplegia as an autosomal recessive trait. Various ophthalmological findings including optic atrophy, ophthalmoplegia, or nystagmus have been reported in patients with spastic paraplegia type 7. We report a 15-year-old male patient with a novel heterozygous variant, c.1224T>G:p.(Asp408Glu) in SPG7 (NM_003119.3) causing early onset isolated optic atrophy and infantile nystagmus prior to the onset of neurological symptoms. Therefore, SPG7 should be considered a cause of infantile nystagmus with optic atrophy.
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Affiliation(s)
- Yuri Seo
- Department of Ophthalmology, Institute of Vision Research, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, South Korea
| | | | - Byung Joo Lee
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Jinu Han
- Department of Ophthalmology, Institute of Vision Research, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
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3
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Boyenle ID, Oyedele AK, Ogunlana AT, Adeyemo AF, Oyelere FS, Akinola OB, Adelusi TI, Ehigie LO, Ehigie AF. Targeting the mitochondrial permeability transition pore for drug discovery: Challenges and opportunities. Mitochondrion 2022; 63:57-71. [PMID: 35077882 DOI: 10.1016/j.mito.2022.01.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 12/22/2021] [Accepted: 01/17/2022] [Indexed: 12/29/2022]
Abstract
Several drug targets have been amenable to drug discovery pursuit not until the characterization of the mitochondrial permeability transition pore (MPTP), a pore with an undefined molecular identity that forms on the inner mitochondrial membrane upon mitochondrial permeability transition (MPT) under the influence of calcium overload and oxidative stress. The opening of the pore which is presumed to cause cell death in certain human diseases also has implications under physiological parlance. Different models for this pore have been postulated following its first identification in the last six decades. The mitochondrial community has witnessed many protein candidates such as; voltage-dependent anion channel (VDAC), adenine nucleotide translocase (ANT), Mitochondrial phosphate carrier (PiC), Spastic Paralegin (SPG7), disordered proteins, and F1Fo ATPase. However, genetic studies have cast out most of these candidates with only F1Fo ATPase currently under intense argument. Cyclophilin D (CyPD) remains the widely accepted positive regulator of the MPTP known to date, but no drug candidate has emerged as its inhibitor, raising concern issues for therapeutics. Thus, in this review, we discuss various models of MPTP reported with the hope of stimulating further research in this field. We went beyond the classical description of the MPTP to ascribe a 'two-edged sword property' to the pore for therapeutic function in human disease because its inhibition and activation have pharmacological relevance. We suggested putative proteins upstream to CyPD that can regulate its activity and prevent cell deaths in neurodegenerative disease and ischemia-reperfusion injury.
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Affiliation(s)
- Ibrahim Damilare Boyenle
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria; Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Abdulquddus Kehinde Oyedele
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Abdeen Tunde Ogunlana
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Aishat Folashade Adeyemo
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | | | - Olateju Balikis Akinola
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Temitope Isaac Adelusi
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Leonard Ona Ehigie
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Adeola Folasade Ehigie
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
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4
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Yi L, Liu B, Nixon PJ, Yu J, Chen F. Recent Advances in Understanding the Structural and Functional Evolution of FtsH Proteases. FRONTIERS IN PLANT SCIENCE 2022; 13:837528. [PMID: 35463435 PMCID: PMC9020784 DOI: 10.3389/fpls.2022.837528] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/24/2022] [Indexed: 05/18/2023]
Abstract
The FtsH family of proteases are membrane-anchored, ATP-dependent, zinc metalloproteases. They are universally present in prokaryotes and the mitochondria and chloroplasts of eukaryotic cells. Most bacteria bear a single ftsH gene that produces hexameric homocomplexes with diverse house-keeping roles. However, in mitochondria, chloroplasts and cyanobacteria, multiple FtsH homologs form homo- and heterocomplexes with specialized functions in maintaining photosynthesis and respiration. The diversification of FtsH homologs combined with selective pairing of FtsH isomers is a versatile strategy to enable functional adaptation. In this article we summarize recent progress in understanding the evolution, structure and function of FtsH proteases with a focus on the role of FtsH in photosynthesis and respiration.
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Affiliation(s)
- Lanbo Yi
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing, China
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, China
| | - Bin Liu
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, China
| | - Peter J. Nixon
- Sir Ernst Chain Building-Wolfson Laboratories, Department of Life Sciences, Imperial College London, London, United Kingdom
- *Correspondence: Peter J. Nixon, ; orcid.org/0000-0003-1952-6937
| | - Jianfeng Yu
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
- Sir Ernst Chain Building-Wolfson Laboratories, Department of Life Sciences, Imperial College London, London, United Kingdom
- Jianfeng Yu, ; orcid.org/0000-0001-7174-3803
| | - Feng Chen
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, China
- Feng Chen, ; orcid.org/0000-0002-9054-943X
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5
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The Pseudomonas aeruginosa substrate-binding protein Ttg2D functions as a general glycerophospholipid transporter across the periplasm. Commun Biol 2021; 4:448. [PMID: 33837253 PMCID: PMC8035174 DOI: 10.1038/s42003-021-01968-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 03/04/2021] [Indexed: 11/19/2022] Open
Abstract
In Pseudomonas aeruginosa, Ttg2D is the soluble periplasmic phospholipid-binding component of an ABC transport system thought to be involved in maintaining the asymmetry of the outer membrane. Here we use the crystallographic structure of Ttg2D at 2.5 Å resolution to reveal that this protein can accommodate four acyl chains. Analysis of the available structures of Ttg2D orthologs shows that they conform a new substrate-binding-protein structural cluster. Native and denaturing mass spectrometry experiments confirm that Ttg2D, produced both heterologously and homologously and isolated from the periplasm, can carry two diacyl glycerophospholipids as well as one cardiolipin. Binding is notably promiscuous, allowing the transport of various molecular species. In vitro binding assays coupled to native mass spectrometry show that binding of cardiolipin is spontaneous. Gene knockout experiments in P. aeruginosa multidrug-resistant strains reveal that the Ttg2 system is involved in low-level intrinsic resistance against certain antibiotics that use a lipid-mediated pathway to permeate through membranes. Yero et al. elucidate the function of Ttg2D, a Pseudomonas aeruginosa periplasmic protein, in maintaining phospholipid asymmetry between the outer and inner membrane. Gram negative bacteria have inner and outer membranes that differ in phospholipd composition. Using X-ray crystallography and mass spectrometry, the authors show that Ttg2D can carry two diacyl glycerophospholipids or a cardiolipin. The authors also identify a role for Ttg2D in resistance against antibiotics that use a lipid-mediated pathway into the cell.
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Lallemant-Dudek P, Darios F, Durr A. Recent advances in understanding hereditary spastic paraplegias and emerging therapies. Fac Rev 2021; 10:27. [PMID: 33817696 PMCID: PMC8009193 DOI: 10.12703/r/10-27] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Hereditary spastic paraplegias (HSPs) are a group of rare, inherited, neurological diseases characterized by broad clinical and genetic heterogeneity. Lower-limb spasticity with first motoneuron involvement is the core symptom of all HSPs. As spasticity is a syndrome and not a disease, it develops on top of other neurological signs (ataxia, dystonia, and parkinsonism). Indeed, the definition of genes responsible for HSPs goes beyond the 79 identified SPG genes. In order to avoid making a catalog of the different genes involved in HSP in any way, we have chosen to focus on the HSP with cerebellar ataxias since this is a frequent association described for several genes. This overlap leads to an intermediary group of spastic ataxias which is actively genetically and clinically studied. The most striking example is SPG7, which is responsible for HSP or cerebellar ataxia or both. There are no specific therapies against HSPs, and there is a dearth of randomized trials in patients with HSP, especially on spasticity when it likely results from other mechanisms. Thus far, no gene-specific therapy has been developed for HSP, but emerging therapies in animal models and neurons derived from induced pluripotent stem cells are potential treatments for patients.
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Affiliation(s)
- Pauline Lallemant-Dudek
- Paris Brain Institute (ICM), Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Frederic Darios
- Paris Brain Institute (ICM), Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Alexandra Durr
- Paris Brain Institute (ICM), Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
- Assistance Publique-Hôpitaux de Paris (AP-HP), Genetic Department, Pitié-Salpêtrière University Hospital, Paris, France
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7
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Ringman JM, Qiao Y, Garbin A, Fisher BE, Fogel B, Watari Knoell K, Chui HC, Shi Y, Rexach JE. Emotional detachment, gait ataxia, and cerebellar dysconnectivity associated with compound heterozygous mutations in the SPG7 gene. Neurocase 2020; 26:299-304. [PMID: 32893728 PMCID: PMC7530119 DOI: 10.1080/13554794.2020.1817493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 08/17/2020] [Indexed: 12/22/2022]
Abstract
We report a patient with autism-like deficits in emotional connectedness, executive dysfunction, and ataxia beginning at age 39. He had compound heterozygous variants in SPG7 (A510V and 1552+1 G>T substitutions), mutation of which is classically associated with spastic paraparesis. Diffusion MRI demonstrated abnormalities in the cerebellar outflow tracts. Transcranial magnetic stimulation showed a prolonged cortical silent period representing exaggerated cortical inhibition, as previously described with pure cerebellar degeneration. The acquired cerebellar cognitive affective syndrome in association with specific anatomic and neurophysiological abnormalities in the cerebellum expand the spectrum of SPG7-related neurodegeneration and support a role for cerebellar output in socio-emotional behavior.
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Affiliation(s)
- John M Ringman
- Memory and Aging Center, Department of Neurology, Keck School of Medicine, University of Southern California , Los Angeles, CA, USA
| | - Yuchuan Qiao
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California , Los Angeles, CA, USA
| | - Alexander Garbin
- Division of Biokinesiology and Physical Therapy, University of Southern California , Los Angeles, CA, USA
| | - Beth E Fisher
- Division of Biokinesiology and Physical Therapy, University of Southern California , Los Angeles, CA, USA
| | - Brent Fogel
- Neurogenetics Program, Department of Neurology, UCLA , Los Angeles, CA, USA
| | - Kecia Watari Knoell
- Memory and Aging Center, Department of Neurology, Keck School of Medicine, University of Southern California , Los Angeles, CA, USA
| | - Helena C Chui
- Memory and Aging Center, Department of Neurology, Keck School of Medicine, University of Southern California , Los Angeles, CA, USA
| | - Yonggang Shi
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California , Los Angeles, CA, USA
| | - Jessica E Rexach
- Neurogenetics Program, Department of Neurology, UCLA , Los Angeles, CA, USA
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8
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Wali G, Kumar KR, Liyanage E, Davis RL, Mackay-Sim A, Sue CM. Mitochondrial Function in Hereditary Spastic Paraplegia: Deficits in SPG7 but Not SPAST Patient-Derived Stem Cells. Front Neurosci 2020; 14:820. [PMID: 32973427 PMCID: PMC7469654 DOI: 10.3389/fnins.2020.00820] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/14/2020] [Indexed: 12/22/2022] Open
Abstract
Mutations in SPG7 and SPAST are common causes of hereditary spastic paraplegia (HSP). While some SPG7 mutations cause paraplegin deficiency, other SPG7 mutations cause increased paraplegin expression. Mitochondrial function has been studied in models that are paraplegin-deficient (human, mouse, and Drosophila models with large exonic deletions, null mutations, or knockout models) but not in models of mutations that express paraplegin. Here, we evaluated mitochondrial function in olfactory neurosphere-derived cells, derived from patients with a variety of SPG7 mutations that express paraplegin and compared them to cells derived from healthy controls and HSP patients with SPAST mutations, as a disease control. We quantified paraplegin expression and an extensive range of mitochondrial morphology measures (fragmentation, interconnectivity, and mass), mitochondrial function measures (membrane potential, oxidative phosphorylation, and oxidative stress), and cell proliferation. Compared to control cells, SPG7 patient cells had increased paraplegin expression, fragmented mitochondria with low interconnectivity, reduced mitochondrial mass, decreased mitochondrial membrane potential, reduced oxidative phosphorylation, reduced ATP content, increased mitochondrial oxidative stress, and reduced cellular proliferation. Mitochondrial dysfunction was specific to SPG7 patient cells and not present in SPAST patient cells, which displayed mitochondrial functions similar to control cells. The mitochondrial dysfunction observed here in SPG7 patient cells that express paraplegin was similar to the dysfunction reported in cell models without paraplegin expression. The p.A510V mutation was common to all patients and was the likely species associated with increased expression, albeit seemingly non-functional. The lack of a mitochondrial phenotype in SPAST patient cells indicates genotype-specific mechanisms of disease in these HSP patients.
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Affiliation(s)
- Gautam Wali
- Department of Neurogenetics, Royal North Shore Hospital, Kolling Institute of Medical Research, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Kishore Raj Kumar
- Department of Neurogenetics, Royal North Shore Hospital, Kolling Institute of Medical Research, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.,Molecular Medicine Laboratory, Department of Neurology, Concord Hospital, Sydney, NSW, Australia.,Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW, Australia.,Department of Neurology, Royal North Shore Hospital, Northern Sydney Local Health District, Sydney, NSW, Australia
| | - Erandhi Liyanage
- Department of Neurogenetics, Royal North Shore Hospital, Kolling Institute of Medical Research, The University of Sydney, Sydney, NSW, Australia
| | - Ryan L Davis
- Department of Neurogenetics, Royal North Shore Hospital, Kolling Institute of Medical Research, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.,Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Alan Mackay-Sim
- Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.,Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, Australia
| | - Carolyn M Sue
- Department of Neurogenetics, Royal North Shore Hospital, Kolling Institute of Medical Research, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.,Department of Neurology, Royal North Shore Hospital, Northern Sydney Local Health District, Sydney, NSW, Australia
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9
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SPG7 mutations in amyotrophic lateral sclerosis: a genetic link to hereditary spastic paraplegia. J Neurol 2020; 267:2732-2743. [PMID: 32447552 PMCID: PMC7419373 DOI: 10.1007/s00415-020-09861-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) and hereditary spastic paraplegia (HSP) are motor neuron diseases sharing clinical, pathological, and genetic similarities. While biallelic SPG7 mutations are known to cause recessively inherited HSP, heterozygous SPG7 mutations have repeatedly been identified in HSP and recently also in ALS cases. However, the frequency and clinical impact of rare SPG7 variants have not been studied in a larger ALS cohort. Here, whole-exome (WES) or targeted SPG7 sequencing was done in a cohort of 214 European ALS patients. The consequences of a splice site variant were analyzed on the mRNA level. The resulting protein alterations were visualized in a crystal structure model. All patients were subjected to clinical, electrophysiological, and neuroradiological characterization. In 9 of 214 (4.2%) ALS cases, we identified five different rare heterozygous SPG7 variants, all of which were previously reported in patients with HSP or ALS. All detected SPG7 variants affect the AAA+ domain of the encoded mitochondrial metalloprotease paraplegin and impair its stability or function according to predictions from mRNA analysis or crystal structure modeling. ALS patients with SPG7 mutations more frequently presented with cerebellar symptoms, flail arm or leg syndrome compared to those without SPG7 mutations, and showed a partial clinical overlap with HSP. Brain MRI findings in SPG7 mutation carriers included cerebellar atrophy and patterns suggestive of frontotemporal dementia. Collectively, our findings suggest that SPG7 acts as a genetic risk factor for ALS. ALS patients carrying SPG7 mutations present with distinct features overlapping with HSP, particularly regarding cerebellar findings.
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10
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Mancini C, Giorgio E, Rubegni A, Pradotto L, Bagnoli S, Rubino E, Prontera P, Cavalieri S, Di Gregorio E, Ferrero M, Pozzi E, Riberi E, Ferrero P, Nigro P, Mauro A, Zibetti M, Tessa A, Barghigiani M, Antenora A, Sirchia F, Piacentini S, Silvestri G, De Michele G, Filla A, Orsi L, Santorelli FM, Brusco A. Prevalence and phenotype of the c.1529C>T SPG7 variant in adult-onset cerebellar ataxia in Italy. Eur J Neurol 2018; 26:80-86. [PMID: 30098094 DOI: 10.1111/ene.13768] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 08/07/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND PURPOSE Hereditary ataxias are heterogeneous groups of neurodegenerative disorders, characterized by cerebellar syndromes associated with dysarthria, oculomotor and corticospinal signs, neuropathy and cognitive impairment. Recent reports have suggested mutations in the SPG7 gene, causing the most common form of autosomal recessive spastic paraplegia (MIM#607259), as a main cause of ataxias. The majority of described patients were homozygotes or compound heterozygotes for the c.1529C>T (p.Ala510Val) change. We screened a cohort of 895 Italian patients with ataxia for p.Ala510Val in order to define the prevalence and genotype-phenotype correlation of this variant. METHODS We set up a rapid assay for c.1529C>T using restriction enzyme analysis after polymerase chain reaction amplification. We confirmed the diagnosis with Sanger sequencing. RESULTS We identified eight homozygotes and 13 compound heterozygotes, including two novel variants affecting splicing. Mutated patients showed a pure cerebellar ataxia at onset, evolving in mild spastic ataxia (alternatively) associated with dysarthria (~80% of patients), urinary urgency (~30%) and pyramidal signs (~70%). Comparing homozygotes and compound heterozygotes, we noted a difference in age at onset and Scale for the Assessment and Rating of Ataxia score between the two groups, supporting an earlier and more severe phenotype in compound heterozygotes versus homozygotes. CONCLUSIONS The SPG7 c.1529C>T (p.Ala510Val) mutants accounted for 2.3% of cerebellar ataxia cases in Italy, suggesting that this variant should be considered as a priority test in the presence of late-onset pure ataxia. Moreover, the heterozygous/homozygous genotype appeared to predict the onset of clinical manifestation and disease progression.
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Affiliation(s)
- C Mancini
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - E Giorgio
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - A Rubegni
- Molecular Medicine, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - L Pradotto
- Division of Neurology and Neurorehabilitation, San Giuseppe Hospital, IRCCS Istituto Auxologico Italiano, Piancavallo, Italy
| | - S Bagnoli
- Department of Neuroscience, Psychology, Drug Research and Child's Health, University of Florence, Florence, Italy
| | - E Rubino
- Department of Neuroscience and Mental Health, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - P Prontera
- Medical Genetics Unit, Hospital S. Maria della Misericordia, Perugia, Italy
| | - S Cavalieri
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - E Di Gregorio
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - M Ferrero
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - E Pozzi
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - E Riberi
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - P Ferrero
- Department of Neuroscience and Mental Health, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - P Nigro
- Clinica Neurologica, Azienda Ospedaliera - Università di Perugia, Perugia, Italy
| | - A Mauro
- Department of Neurosciences, University of Torino, Turin, Italy
| | - M Zibetti
- Department of Neuroscience and Mental Health, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - A Tessa
- Molecular Medicine, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - M Barghigiani
- Molecular Medicine, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - A Antenora
- Department of Neurosciences, Federico II University, Naples, Italy
| | - F Sirchia
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - S Piacentini
- Department of Neuroscience, Psychology, Drug Research and Child's Health, University of Florence, Florence, Italy
| | - G Silvestri
- Fondazione Policlinico Universitario IRCCS, A. Gemelli, Rome, Italy.,Università Cattolica del Sacro Cuore, Rome, Italy
| | - G De Michele
- Department of Neurosciences, Federico II University, Naples, Italy
| | - A Filla
- Department of Neurosciences, Federico II University, Naples, Italy
| | - L Orsi
- Department of Neuroscience and Mental Health, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - F M Santorelli
- Molecular Medicine, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - A Brusco
- Department of Medical Sciences, University of Torino, Turin, Italy.,Medical Genetics Unit, Città della Salute e della Scienza Hospital, Turin, Italy
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11
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ATPase and Protease Domain Movements in the Bacterial AAA+ Protease FtsH Are Driven by Thermal Fluctuations. J Mol Biol 2018; 430:4592-4602. [PMID: 30044948 DOI: 10.1016/j.jmb.2018.07.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/10/2018] [Accepted: 07/17/2018] [Indexed: 01/27/2023]
Abstract
AAA+ proteases are essential players in cellular pathways of protein degradation. Elucidating their conformational behavior is key for understanding their reaction mechanism and, importantly, for elaborating our understanding of mutation-induced protease deficiencies. Here, we study the structural dynamics of the Thermotoga maritima AAA+ hexameric ring metalloprotease FtsH (TmFtsH). Using a single-molecule Förster resonance energy transfer approach to monitor ATPase and protease inter-domain conformational changes in real time, we show that TmFtsH-even in the absence of nucleotide-is a highly dynamic protease undergoing sequential transitions between five states on the second timescale. Addition of ATP does not influence the number of states or change the timescale of domain motions but affects the state occupancy distribution leading to an inter-domain compaction. These findings suggest that thermal energy, but not chemical energy, provides the major driving force for conformational switching, while ATP, through a state reequilibration, introduces directionality into this process. The TmFtsH A359V mutation, a homolog of the human pathogenic A510V mutation of paraplegin (SPG7) causing hereditary spastic paraplegia, does not affect the dynamic behavior of the protease but impairs the ATP-coupled domain compaction and, thus, may account for protease malfunctioning and pathogenesis in hereditary spastic paraplegia.
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12
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Saha N, Dutta S, Datta SP, Sarkar S. The minimal ESCRT machinery of Giardia lamblia has altered inter-subunit interactions within the ESCRT-II and ESCRT-III complexes. Eur J Cell Biol 2017; 97:44-62. [PMID: 29224850 DOI: 10.1016/j.ejcb.2017.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 11/29/2017] [Accepted: 11/30/2017] [Indexed: 11/19/2022] Open
Abstract
The ESCRT pathway functions at different subcellular membranes to induce their negative curvature, and it has been largely characterized in model eukaryotes belonging to Opisthokonta. But searches of the genomes of many nonopisthokonts belonging to various supergroups indicate that some of them may harbour fewer ESCRT components. Of the genomes explored thus far, one of the most minimal set of ESCRT components was identified in the human pathogen Giardia lamblia, which belongs to Excavata. Here we report that an ESCRT-mediated pathway most likely operates at the peripheral vesicles, which are located at the cell periphery and the bare zone of this protist. Functional comparison of all the identified putative giardial ESCRT components, with the corresponding well-characterized orthologues from Saccharomyces cerevisiae, indicated that only some of the ESCRT components could functionally substitute for the corresponding yeast proteins. While GlVps25, GlVps2, and all three paralogues of GlVps4, tested positive in functional complementation assays, GlVps22, GlVps20, and GlVps24 did not. Binary interactions of either GlVps22 or GlVps25, with other ESCRT-II components from Giardia or yeast indicate that the giardial Vps36 orthologue is either completely missing or highly diverged. Interactions within the giardial ESCRT-III components also differ from those in yeast; while GlVps46a interacts preferentially with Vps24 compared to Vps2, GlVps46b, like the yeast orthologue, interacts with both.
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Affiliation(s)
- Nabanita Saha
- Department of Biochemistry, Bose Institute, P 1/12 CIT Road Scheme VII M, Kolkata 700054, West Bengal, India.
| | - Somnath Dutta
- Department of Biochemistry, Bose Institute, P 1/12 CIT Road Scheme VII M, Kolkata 700054, West Bengal, India.
| | - Shankari P Datta
- Department of Biochemistry, Bose Institute, P 1/12 CIT Road Scheme VII M, Kolkata 700054, West Bengal, India.
| | - Srimonti Sarkar
- Department of Biochemistry, Bose Institute, P 1/12 CIT Road Scheme VII M, Kolkata 700054, West Bengal, India.
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13
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Levytskyy RM, Bohovych I, Khalimonchuk O. Metalloproteases of the Inner Mitochondrial Membrane. Biochemistry 2017; 56:4737-4746. [PMID: 28806058 DOI: 10.1021/acs.biochem.7b00663] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The inner mitochondrial membrane (IM) is among the most protein-rich cellular compartments. The metastable IM subproteome where the concentration of proteins is approaching oversaturation creates a challenging protein folding environment with a high probability of protein malfunction or aggregation. Failure to maintain protein homeostasis in such a setting can impair the functional integrity of the mitochondria and drive clinical manifestations. The IM is equipped with a series of highly conserved, proteolytic complexes dedicated to the maintenance of normal protein homeostasis within this mitochondrial subcompartment. Particularly important is a group of membrane-anchored metallopeptidases commonly known as m-AAA and i-AAA proteases, and the ATP-independent Oma1 protease. Herein, we will summarize the current biochemical knowledge of these proteolytic machines and discuss recent advances in our understanding of mechanistic aspects of their functioning.
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Affiliation(s)
- Roman M Levytskyy
- Department of Biochemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0664, United States
| | - Iryna Bohovych
- Department of Biochemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0664, United States
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0664, United States.,Nebraska Redox Biology Center, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0662, United States.,Fred & Pamela Buffett Cancer Center , Omaha, Nebraska 68106, United States
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14
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Glynn SE. Multifunctional Mitochondrial AAA Proteases. Front Mol Biosci 2017; 4:34. [PMID: 28589125 PMCID: PMC5438985 DOI: 10.3389/fmolb.2017.00034] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/08/2017] [Indexed: 11/28/2022] Open
Abstract
Mitochondria perform numerous functions necessary for the survival of eukaryotic cells. These activities are coordinated by a diverse complement of proteins encoded in both the nuclear and mitochondrial genomes that must be properly organized and maintained. Misregulation of mitochondrial proteostasis impairs organellar function and can result in the development of severe human diseases. ATP-driven AAA+ proteins play crucial roles in preserving mitochondrial activity by removing and remodeling protein molecules in accordance with the needs of the cell. Two mitochondrial AAA proteases, i-AAA and m-AAA, are anchored to either face of the mitochondrial inner membrane, where they engage and process an array of substrates to impact protein biogenesis, quality control, and the regulation of key metabolic pathways. The functionality of these proteases is extended through multiple substrate-dependent modes of action, including complete degradation, partial processing, or dislocation from the membrane without proteolysis. This review discusses recent advances made toward elucidating the mechanisms of substrate recognition, handling, and degradation that allow these versatile proteases to control diverse activities in this multifunctional organelle.
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Affiliation(s)
- Steven E Glynn
- Department of Biochemistry and Cell Biology, Stony Brook UniversityStony Brook, NY, United States
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15
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Levytskyy RM, Germany EM, Khalimonchuk O. Mitochondrial Quality Control Proteases in Neuronal Welfare. J Neuroimmune Pharmacol 2016; 11:629-644. [PMID: 27137937 PMCID: PMC5093085 DOI: 10.1007/s11481-016-9683-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 04/27/2016] [Indexed: 01/01/2023]
Abstract
The functional integrity of mitochondria is a critical determinant of neuronal health and compromised mitochondrial function is a commonly recognized factor that underlies a plethora of neurological and neurodegenerative diseases. Metabolic demands of neural cells require high bioenergetic outputs that are often associated with enhanced production of reactive oxygen species. Unopposed accumulation of these respiratory byproducts over time leads to oxidative damage and imbalanced protein homeostasis within mitochondrial subcompartments, which in turn may result in cellular demise. The post-mitotic nature of neurons and their vulnerability to these stress factors necessitate strict protein homeostatic control to prevent such scenarios. A series of evolutionarily conserved proteases is one of the central elements of mitochondrial quality control. These versatile proteolytic enzymes conduct a multitude of activities to preserve normal mitochondrial function during organelle biogenesis, metabolic remodeling and stress. In this review we discuss neuroprotective aspects of mitochondrial quality control proteases and neuropathological manifestations arising from defective proteolysis within the mitochondrion.
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Affiliation(s)
- Roman M Levytskyy
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Edward M Germany
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.
- Nebraska Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.
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16
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Chen KB, Chen KC, Chang YL, Chang KL, Chang PC, Chang TT, Chen YC. In Silico Investigation of Traditional Chinese Medicine for Potential Lead Compounds as SPG7 Inhibitors against Coronary Artery Disease. Molecules 2016; 21:molecules21050588. [PMID: 27164068 PMCID: PMC6273800 DOI: 10.3390/molecules21050588] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 04/22/2016] [Accepted: 04/29/2016] [Indexed: 11/16/2022] Open
Abstract
Coronary artery disease (CAD) is the most common cause of heart attack and the leading cause of mortality in the world. It is associated with mitochondrial dysfunction and increased level of reactive oxygen species production. According to the Ottawa Heart Genomics Study genome-wide association study, a recent research identified that Q688 spastic paraplegia 7 (SPG7) variant is associated with CAD as it bypasses the regulation of tyrosine phosphorylation of AFG3L2 and enhances the processing and maturation of SPG7 protein. This study aims to identify potential compounds isolated from Traditional Chinese Medicines (TCMs) as potential lead compounds for paraplegin (SPG7) inhibitors. For the crystallographic structure of paraplegin, the disordered disposition of key amino acids in the binding site was predicted using the PONDR-Fit protocol before virtual screening. The TCM compounds saussureamine C and 3-(2-carboxyphenyl)-4(3H)-quinazolinone, have potential binding affinities with stable H-bonds and hydrophobic contacts with key residues of paraplegin. A molecular dynamics simulation was performed to validate the stability of the interactions between each candidate and paraplegin under dynamic conditions. Hence, we propose these compounds as potential candidates as lead drug from the compounds isolated from TCM for further study in drug development process with paraplegin protein for coronary artery disease.
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Affiliation(s)
- Kuen-Bao Chen
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan.
- School of Medicine, College of Medicine, China Medical University, Taichung 40402, Taiwan.
- Department of Anesthesiology, China Medical University Hospital, Taichung 40447, Taiwan.
| | - Kuan-Chung Chen
- School of Pharmacy, China Medical University, Taichung 40402, Taiwan.
| | - Ya-Lin Chang
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan.
| | - Kun-Lung Chang
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan.
- Department of Pharmacy, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan.
| | - Pei-Chun Chang
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan.
| | - Tung-Ti Chang
- School of Post-Baccalaureate Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 40402, Taiwan.
- Department of Chinese Pediatrics, China Medical University Hospital, Taichung 40402, Taiwan.
| | - Yu-Chian Chen
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan.
- Research Center for Chinese Medicine and Acupuncture, China Medical University, Taichung 40402, Taiwan.
- Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan.
- Computational and Systems Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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17
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Abstract
Torsin ATPases (Torsins) belong to the widespread AAA+ (ATPases associated with a variety of cellular activities) family of ATPases, which share structural similarity but have diverse cellular functions. Torsins are outliers in this family because they lack many characteristics of typical AAA+ proteins, and they are the only members of the AAA+ family located in the endoplasmic reticulum and contiguous perinuclear space. While it is clear that Torsins have essential roles in many, if not all metazoans, their precise cellular functions remain elusive. Studying Torsins has significant medical relevance since mutations in Torsins or Torsin-associated proteins result in a variety of congenital human disorders, the most frequent of which is early-onset torsion (DYT1) dystonia, a severe movement disorder. A better understanding of the Torsin system is needed to define the molecular etiology of these diseases, potentially enabling corrective therapy. Here, we provide a comprehensive overview of the Torsin system in metazoans, discuss functional clues obtained from various model systems and organisms and provide a phylogenetic and structural analysis of Torsins and their regulatory cofactors in relation to disease-causative mutations. Moreover, we review recent data that have led to a dramatically improved understanding of these machines at a molecular level, providing a foundation for investigating the molecular defects underlying the associated movement disorders. Lastly, we discuss our ideas on how recent progress may be utilized to inform future studies aimed at determining the cellular role(s) of these atypical molecular machines and their implications for dystonia treatment options.
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Affiliation(s)
- April E Rose
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and
| | - Rebecca S H Brown
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and
| | - Christian Schlieker
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and.,b Department of Cell Biology , Yale School of Medicine , New Haven , CT , USA
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18
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Yoshioka-Nishimura M, Yamamoto Y. Quality control of Photosystem II: the molecular basis for the action of FtsH protease and the dynamics of the thylakoid membranes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 137:100-6. [PMID: 24725639 DOI: 10.1016/j.jphotobiol.2014.02.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 02/17/2014] [Accepted: 02/17/2014] [Indexed: 01/20/2023]
Abstract
The reaction center-binding D1 protein of Photosystem II is damaged by excessive light, which leads to photoinhibition of Photosystem II. The damaged D1 protein is removed immediately by specific proteases, and a metalloprotease FtsH located in the thylakoid membranes is involved in the proteolytic process. According to recent studies on the distribution and organization of the protein complexes/supercomplexes in the thylakoid membranes, the grana of higher plant chloroplasts are crowded with Photosystem II complexes and light-harvesting complexes. For the repair of the photodamaged D1 protein, the majority of the active hexameric FtsH proteases should be localized in close proximity to the Photosystem II complexes. The unstacking of the grana may increase the area of the grana margin and facilitate easier access of the FtsH proteases to the damaged D1 protein. These results suggest that the structural changes of the thylakoid membranes by light stress increase the mobility of the membrane proteins and support the quality control of Photosystem II.
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Affiliation(s)
- Miho Yoshioka-Nishimura
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
| | - Yasusi Yamamoto
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
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19
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Wedding IM, Koht J, Tran GT, Misceo D, Selmer KK, Holmgren A, Frengen E, Bindoff L, Tallaksen CME, Tzoulis C. Spastic paraplegia type 7 is associated with multiple mitochondrial DNA deletions. PLoS One 2014; 9:e86340. [PMID: 24466038 PMCID: PMC3899233 DOI: 10.1371/journal.pone.0086340] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Accepted: 12/11/2013] [Indexed: 11/19/2022] Open
Abstract
Spastic paraplegia 7 is an autosomal recessive disorder caused by mutations in the gene encoding paraplegin, a protein located at the inner mitochondrial membrane and involved in the processing of other mitochondrial proteins. The mechanism whereby paraplegin mutations cause disease is unknown. We studied two female and two male adult patients from two Norwegian families with a combination of progressive external ophthalmoplegia and spastic paraplegia. Sequencing of SPG7 revealed a novel missense mutation, c.2102A>C, p.H 701P, which was homozygous in one family and compound heterozygous in trans with a known pathogenic mutation c.1454_1462del in the other. Muscle was examined from an additional, unrelated adult female patient with a similar phenotype caused by a homozygous c.1047insC mutation in SPG7. Immunohistochemical studies in skeletal muscle showed mosaic deficiency predominantly affecting respiratory complex I, but also complexes III and IV. Molecular studies in single, microdissected fibres showed multiple mitochondrial DNA deletions segregating at high levels (38-97%) in respiratory deficient fibres. Our findings demonstrate for the first time that paraplegin mutations cause accumulation of mitochondrial DNA damage and multiple respiratory chain deficiencies. While paraplegin is not known to be directly associated with the mitochondrial nucleoid, it is known to process other mitochondrial proteins and it is possible therefore that paraplegin mutations lead to mitochondrial DNA deletions by impairing proteins involved in the homeostasis of the mitochondrial genome. These studies increase our understanding of the molecular pathogenesis of SPG7 mutations and suggest that SPG7 testing should be included in the diagnostic workup of autosomal recessive, progressive external ophthalmoplegia, especially if spasticity is present.
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Affiliation(s)
- Iselin Marie Wedding
- Department of Neurology, Oslo University Hospital, Ullevål, Oslo, Norway
- University of Oslo, Faculty of Medicine, Oslo, Norway
| | - Jeanette Koht
- University of Oslo, Faculty of Medicine, Oslo, Norway
- Department of Neurology, Drammen Hospital, Vestre Viken Health Trust, Norway
| | - Gia Tuong Tran
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Doriana Misceo
- University of Oslo, Faculty of Medicine, Oslo, Norway
- Department of Medical Genetics, Oslo University Hospital, Ullevål, Oslo, Norway
| | - Kaja Kristine Selmer
- University of Oslo, Faculty of Medicine, Oslo, Norway
- Department of Medical Genetics, Oslo University Hospital, Ullevål, Oslo, Norway
| | - Asbjørn Holmgren
- University of Oslo, Faculty of Medicine, Oslo, Norway
- Department of Medical Genetics, Oslo University Hospital, Ullevål, Oslo, Norway
| | - Eirik Frengen
- University of Oslo, Faculty of Medicine, Oslo, Norway
- Department of Medical Genetics, Oslo University Hospital, Ullevål, Oslo, Norway
| | - Laurence Bindoff
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Chantal M. E. Tallaksen
- Department of Neurology, Oslo University Hospital, Ullevål, Oslo, Norway
- University of Oslo, Faculty of Medicine, Oslo, Norway
| | - Charalampos Tzoulis
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Neurology, Haukeland University Hospital, Bergen, Norway
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20
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Goard CA, Schimmer AD. Mitochondrial matrix proteases as novel therapeutic targets in malignancy. Oncogene 2013; 33:2690-9. [PMID: 23770858 DOI: 10.1038/onc.2013.228] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 04/23/2013] [Accepted: 04/30/2013] [Indexed: 12/30/2022]
Abstract
Although mitochondrial function is often altered in cancer, it remains essential for tumor viability. Tight control of protein homeostasis is required for the maintenance of mitochondrial function, and the mitochondrial matrix houses several coordinated protein quality control systems. These include three evolutionarily conserved proteases of the AAA+ superfamily-the Lon, ClpXP and m-AAA proteases. In humans, these proteases are proposed to degrade, process and chaperone the assembly of mitochondrial proteins in the matrix and inner membrane involved in oxidative phosphorylation, mitochondrial protein synthesis, mitochondrial network dynamics and nucleoid function. In addition, these proteases are upregulated by a variety of mitochondrial stressors, including oxidative stress, unfolded protein stress and imbalances in respiratory complex assembly. Given that tumor cells must survive and proliferate under dynamic cellular stress conditions, dysregulation of mitochondrial protein quality control systems may provide a selective advantage. The association of mitochondrial matrix AAA+ proteases with cancer and their potential for therapeutic modulation therefore warrant further consideration. Although our current knowledge of the endogenous human substrates of these proteases is limited, we highlight functional insights gained from cultured human cells, protease-deficient mouse models and other eukaryotic model organisms. We also review the consequences of disrupting mitochondrial matrix AAA+ proteases through genetic and pharmacological approaches, along with implications of these studies on the potential of these proteases as anticancer therapeutic targets.
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Affiliation(s)
- C A Goard
- Princess Margaret Cancer Centre, Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada
| | - A D Schimmer
- Princess Margaret Cancer Centre, Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada
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21
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Abstract
This review focuses on organellar AAA/FtsH proteases, whose proteolytic and chaperone-like activity is a crucial component of the protein quality control systems of mitochondrial and chloroplast membranes. We compare the AAA/FtsH proteases from yeast, mammals and plants. The nature of the complexes formed by AAA/FtsH proteases and the current view on their involvement in degradation of non-native organellar proteins or assembly of membrane complexes are discussed. Additional functions of AAA proteases not directly connected with protein quality control found in yeast and mammals but not yet in plants are also described shortly. Following an overview of the molecular functions of the AAA/FtsH proteases we discuss physiological consequences of their inactivation in yeast, mammals and plants. The molecular basis of phenotypes associated with inactivation of the AAA/FtsH proteases is not fully understood yet, with the notable exception of those observed in m-AAA protease-deficient yeast cells, which are caused by impaired maturation of mitochondrial ribosomal protein. Finally, examples of cytosolic events affecting protein quality control in mitochondria and chloroplasts are given. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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Affiliation(s)
- Hanna Janska
- Department of Biotechnology, University of Wroclaw, Przybyszewskiego 63/77, 51-148 Wroclaw, Poland.
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22
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Protein quality control in organelles - AAA/FtsH story. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:381-7. [PMID: 22498346 DOI: 10.1016/j.bbamcr.2012.03.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 03/26/2012] [Accepted: 03/27/2012] [Indexed: 11/23/2022]
Abstract
This review focuses on organellar AAA/FtsH proteases, whose proteolytic and chaperone-like activity is a crucial component of the protein quality control systems of mitochondrial and chloroplast membranes. We compare the AAA/FtsH proteases from yeast, mammals and plants. The nature of the complexes formed by AAA/FtsH proteases and the current view on their involvement in degradation of non-native organellar proteins or assembly of membrane complexes are discussed. Additional functions of AAA proteases not directly connected with protein quality control found in yeast and mammals but not yet in plants are also described shortly. Following an overview of the molecular functions of the AAA/FtsH proteases we discuss physiological consequences of their inactivation in yeast, mammals and plants. The molecular basis of phenotypes associated with inactivation of the AAA/FtsH proteases is not fully understood yet, with the notable exception of those observed in m-AAA protease-deficient yeast cells, which are caused by impaired maturation of mitochondrial ribosomal protein. Finally, examples of cytosolic events affecting protein quality control in mitochondria and chloroplasts are given. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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23
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Human matrix metalloproteinases: an ubiquitarian class of enzymes involved in several pathological processes. Mol Aspects Med 2011; 33:119-208. [PMID: 22100792 DOI: 10.1016/j.mam.2011.10.015] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 10/29/2011] [Indexed: 02/07/2023]
Abstract
Human matrix metalloproteinases (MMPs) belong to the M10 family of the MA clan of endopeptidases. They are ubiquitarian enzymes, structurally characterized by an active site where a Zn(2+) atom, coordinated by three histidines, plays the catalytic role, assisted by a glutamic acid as a general base. Various MMPs display different domain composition, which is very important for macromolecular substrates recognition. Substrate specificity is very different among MMPs, being often associated to their cellular compartmentalization and/or cellular type where they are expressed. An extensive review of the different MMPs structural and functional features is integrated with their pathological role in several types of diseases, spanning from cancer to cardiovascular diseases and to neurodegeneration. It emerges a very complex and crucial role played by these enzymes in many physiological and pathological processes.
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24
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Gerdes F, Tatsuta T, Langer T. Mitochondrial AAA proteases--towards a molecular understanding of membrane-bound proteolytic machines. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1823:49-55. [PMID: 22001671 DOI: 10.1016/j.bbamcr.2011.09.015] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/13/2011] [Accepted: 09/15/2011] [Indexed: 10/16/2022]
Abstract
Mitochondrial AAA proteases play an important role in the maintenance of mitochondrial proteostasis. They regulate and promote biogenesis of mitochondrial proteins by acting as processing enzymes and ensuring the selective turnover of misfolded proteins. Impairment of AAA proteases causes pleiotropic defects in various organisms including neurodegeneration in humans. AAA proteases comprise ring-like hexameric complexes in the mitochondrial inner membrane and are functionally conserved from yeast to man, but variations are evident in the subunit composition of orthologous enzymes. Recent structural and biochemical studies revealed how AAA proteases degrade their substrates in an ATP dependent manner. Intersubunit coordination of the ATP hydrolysis leads to an ordered ATP hydrolysis within the AAA ring, which ensures efficient substrate dislocation from the membrane and translocation to the proteolytic chamber. In this review, we summarize recent findings on the molecular mechanisms underlying the versatile functions of mitochondrial AAA proteases and their relevance to those of the other AAA+ machines.
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Affiliation(s)
- Florian Gerdes
- Institute for Genetics, Centre for Molecular Medicine (CMMC), Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Zülpicher Str. 47a, 50674 Cologne, Germany.
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Langklotz S, Baumann U, Narberhaus F. Structure and function of the bacterial AAA protease FtsH. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1823:40-8. [PMID: 21925212 DOI: 10.1016/j.bbamcr.2011.08.015] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Revised: 08/24/2011] [Accepted: 08/30/2011] [Indexed: 10/17/2022]
Abstract
Proteolysis of regulatory proteins or key enzymes of biosynthetic pathways is a universal mechanism to rapidly adjust the cellular proteome to particular environmental needs. Among the five energy-dependent AAA(+) proteases in Escherichia coli, FtsH is the only essential protease. Moreover, FtsH is unique owing to its anchoring to the inner membrane. This review describes the structural and functional properties of FtsH. With regard to its role in cellular quality control and regulatory circuits, cytoplasmic and membrane substrates of the FtsH protease are depicted and mechanisms of FtsH-dependent proteolysis are discussed.
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Affiliation(s)
- Sina Langklotz
- Lehrstuhl für Biologie der Mikroorganismen, Ruhr-Universität Bochum, Germany
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Sacco T, Boda E, Hoxha E, Pizzo R, Cagnoli C, Brusco A, Tempia F. Mouse brain expression patterns of Spg7, Afg3l1, and Afg3l2 transcripts, encoding for the mitochondrial m-AAA protease. BMC Neurosci 2010; 11:55. [PMID: 20426821 PMCID: PMC2880309 DOI: 10.1186/1471-2202-11-55] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 04/28/2010] [Indexed: 11/10/2022] Open
Abstract
Background The m-AAA (ATPases Associated with a variety of cellular Activities) is an evolutionary conserved metalloprotease complex located in the internal mitochondrial membrane. In the mouse, it is a hetero-oligomer variably formed by the Spg7, Afg3l1, and Afg3l2 encoded proteins, or a homo-oligomer formed by either Afg3l1 or Afg3l2. In humans, AFG3L2 and SPG7 genes are conserved, whereas AFG3L1 became a pseudogene. Both AFG3L2 and SPG7 are involved in a neurodegenerative disease, namely the autosomal dominant spinocerebellar ataxia SCA28 and a recessive form of spastic paraplegia, respectively. Results Using quantitative RT-PCR, we measured the expression levels of Spg7, Afg3l1, and Afg3l2 in the mouse brain. In all regions Afg3l2 is the most abundant transcript, followed by Spg7, and Afg3l1, with a ratio of approximately 5:3:1 in whole-brain mRNA. Using in-situ hybridization, we showed that Spg7, Afg3l1 and Afg3l2 have a similar cellular pattern of expression, with high levels in mitral cells, Purkinje cells, deep cerebellar nuclei cells, neocortical and hippocampal pyramidal neurons, and brainstem motor neurons. However, in some neuronal types, differences in the level of expression of these genes were present, suggesting distinct degrees of contribution of their proteins. Conclusions Neurons involved in SCA28 and hereditary spastic paraplegia display high levels of expression, but similar or even higher expression is also present in other types of neurons, not involved in these diseases, suggesting that the selective cell sensitivity should be attributed to other, still unknown, mechanisms.
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Affiliation(s)
- Tiziana Sacco
- Section of Physiology of the Department of Neuroscience, University of Torino and National Institute of Neuroscience-Italy, Torino, Italy
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