1
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Rossmanith W, Giegé P, Hartmann RK. Discovery, structure, mechanisms, and evolution of protein-only RNase P enzymes. J Biol Chem 2024; 300:105731. [PMID: 38336295 PMCID: PMC10941002 DOI: 10.1016/j.jbc.2024.105731] [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: 08/01/2023] [Revised: 01/22/2024] [Accepted: 01/24/2024] [Indexed: 02/12/2024] Open
Abstract
The endoribonuclease RNase P is responsible for tRNA 5' maturation in all domains of life. A unique feature of RNase P is the variety of enzyme architectures, ranging from dual- to multi-subunit ribonucleoprotein forms with catalytic RNA subunits to protein-only enzymes, the latter occurring as single- or multi-subunit forms or homo-oligomeric assemblies. The protein-only enzymes evolved twice: a eukaryal protein-only RNase P termed PRORP and a bacterial/archaeal variant termed homolog of Aquifex RNase P (HARP); the latter replaced the RNA-based enzyme in a small group of thermophilic bacteria but otherwise coexists with the ribonucleoprotein enzyme in a few other bacteria as well as in those archaea that also encode a HARP. Here we summarize the history of the discovery of protein-only RNase P enzymes and review the state of knowledge on structure and function of bacterial HARPs and eukaryal PRORPs, including human mitochondrial RNase P as a paradigm of multi-subunit PRORPs. We also describe the phylogenetic distribution and evolution of PRORPs, as well as possible reasons for the spread of PRORPs in the eukaryal tree and for the recruitment of two additional protein subunits to metazoan mitochondrial PRORP. We outline potential applications of PRORPs in plant biotechnology and address diseases associated with mutations in human mitochondrial RNase P genes. Finally, we consider possible causes underlying the displacement of the ancient RNA enzyme by a protein-only enzyme in a small group of bacteria.
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Affiliation(s)
- Walter Rossmanith
- Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna, Austria.
| | - Philippe Giegé
- Institute for Plant Molecular Biology, IBMP-CNRS, University of Strasbourg, Strasbourg, France.
| | - Roland K Hartmann
- Institute of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany.
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2
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Wilhelm CA, Kaitany K, Kelly A, Yacoub M, Koutmos M. The protein-only RNase Ps, endonucleases that cleave pre-tRNA: Biological relevance, molecular architectures, substrate recognition and specificity, and protein interactomes. WILEY INTERDISCIPLINARY REVIEWS. RNA 2024; 15:e1836. [PMID: 38453211 DOI: 10.1002/wrna.1836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/27/2024] [Accepted: 02/06/2024] [Indexed: 03/09/2024]
Abstract
Protein-only RNase P (PRORP) is an essential enzyme responsible for the 5' maturation of precursor tRNAs (pre-tRNAs). PRORPs are classified into three categories with unique molecular architectures, although all three classes of PRORPs share a mechanism and have similar active sites. Single subunit PRORPs, like those found in plants, have multiple isoforms with different localizations, substrate specificities, and temperature sensitivities. Most recently, Arabidopsis thaliana PRORP2 was shown to interact with TRM1A and B, highlighting a new potential role between these enzymes. Work with At PRORPs led to the development of a ribonuclease that is being used to protect against plant viruses. The mitochondrial RNase P complex, found in metazoans, consists of PRORP, TRMT10C, and SDR5C1, and has also been shown to have substrate specificity, although the cause is unknown. Mutations in mitochondrial tRNA and mitochondrial RNase P have been linked to human disease, highlighting the need to continue understanding this complex. The last class of PRORPs, homologs of Aquifex RNase P (HARPs), is found in thermophilic archaea and bacteria. This most recently discovered type of PRORP forms a large homo-oligomer complex. Although numerous structures of HARPs have been published, it is still unclear how HARPs bind pre-tRNAs and in what ratio. There is also little investigation into the substrate specificity and ideal conditions for HARPs. Moving forward, further work is required to fully characterize each of the three classes of PRORP, the pre-tRNA binding recognition mechanism, the rules of substrate specificity, and how these three distinct classes of PRORP evolved. This article is categorized under: RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
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Affiliation(s)
| | - Kipchumba Kaitany
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan, USA
| | - Abigail Kelly
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Matthew Yacoub
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Markos Koutmos
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan, USA
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3
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Sridhara S. Multiple structural flavors of RNase P in precursor tRNA processing. WILEY INTERDISCIPLINARY REVIEWS. RNA 2024; 15:e1835. [PMID: 38479802 DOI: 10.1002/wrna.1835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 06/06/2024]
Abstract
The precursor transfer RNAs (pre-tRNAs) require extensive processing to generate mature tRNAs possessing proper fold, structural stability, and functionality required to sustain cellular viability. The road to tRNA maturation follows an ordered process: 5'-processing, 3'-processing, modifications at specific sites, if any, and 3'-CCA addition before aminoacylation and recruitment to the cellular protein synthesis machinery. Ribonuclease P (RNase P) is a universally conserved endonuclease in all domains of life, performing the hydrolysis of pre-tRNA sequences at the 5' end by the removal of phosphodiester linkages between nucleotides at position -1 and +1. Except for an archaeal species: Nanoarchaeum equitans where tRNAs are transcribed from leaderless-position +1, RNase P is indispensable for life and displays fundamental variations in terms of enzyme subunit composition, mechanism of substrate recognition and active site architecture, utilizing in all cases a two metal ion-mediated conserved catalytic reaction. While the canonical RNA-based ribonucleoprotein RNase P has been well-known to occur in bacteria, archaea, and eukaryotes, the occurrence of RNA-free protein-only RNase P in eukaryotes and RNA-free homologs of Aquifex RNase P in prokaryotes has been discovered more recently. This review aims to provide a comprehensive overview of structural diversity displayed by various RNA-based and RNA-free RNase P holoenzymes towards harnessing critical RNA-protein and protein-protein interactions in achieving conserved pre-tRNA processing functionality. Furthermore, alternate roles and functional interchangeability of RNase P are discussed in the context of its employability in several clinical and biotechnological applications. This article is categorized under: RNA Processing > tRNA Processing RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
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Affiliation(s)
- Sagar Sridhara
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
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4
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He XY, Dobkin C, Brown WT, Yang SY. Infantile Neurodegeneration Results from Mutants of 17β-Hydroxysteroid Dehydrogenase Type 10 Rather Than Aβ-Binding Alcohol Dehydrogenase. Int J Mol Sci 2023; 24:ijms24108487. [PMID: 37239833 DOI: 10.3390/ijms24108487] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/28/2023] Open
Abstract
Type 10 17β-hydroxysteroid dehydrogenase (17β-HSD10), a homo-tetrameric multifunctional protein with 1044 residues encoded by the HSD17B10 gene, is necessary for brain cognitive function. Missense mutations result in infantile neurodegeneration, an inborn error in isoleucine metabolism. A 5-methylcytosine hotspot underlying a 388-T transition leads to the HSD10 (p.R130C) mutant to be responsible for approximately half of all cases suffering with this mitochondrial disease. Fewer females suffer with this disease due to X-inactivation. The binding capability of this dehydrogenase to Aβ-peptide may play a role in Alzheimer's disease, but it appears unrelated to infantile neurodegeneration. Research on this enzyme was complicated by reports of a purported Aβ-peptide-binding alcohol dehydrogenase (ABAD), formerly referred to as endoplasmic-reticulum-associated Aβ-binding protein (ERAB). Reports concerning both ABAD and ERAB in the literature reflect features inconsistent with the known functions of 17β-HSD10. It is clarified here that ERAB is reportedly a longer subunit of 17β-HSD10 (262 residues). 17β-HSD10 exhibits L-3-hydroxyacyl-CoA dehydrogenase activity and is thus also referred to in the literature as short-chain 3-hydorxyacyl-CoA dehydrogenase or type II 3-hydorxyacyl-CoA dehydrogenase. However, 17β-HSD10 is not involved in ketone body metabolism, as reported in the literature for ABAD. Reports in the literature referring to ABAD (i.e., 17β-HSD10) as a generalized alcohol dehydrogenase, relying on data underlying ABAD's activities, were found to be unreproducible. Furthermore, the rediscovery of ABAD/ERAB's mitochondrial localization did not cite any published research on 17β-HSD10. Clarification of the purported ABAD/ERAB function derived from these reports on ABAD/ERAB may invigorate this research field and encourage new approaches to the understanding and treatment of HSD17B10-gene-related disorders. We establish here that infantile neurodegeneration is caused by mutants of 17β-HSD10 but not ABAD, and so we conclude that ABAD represents a misnomer employed in high-impact journals.
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Affiliation(s)
- Xue-Ying He
- Department of Molecular Biology, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA
| | - Carl Dobkin
- Department of Human Genetics, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA
| | - William Ted Brown
- Central Clinical School, University of Sydney, Sydney 2006, Australia
| | - Song-Yu Yang
- Department of Molecular Biology, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA
- Ph.D. Program in Biology-Neuroscience, Graduate Center, City University of New York, New York, NY 10016, USA
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5
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Novel ELAC2 Mutations in Individuals Presenting with Variably Severe Neurological Disease in the Presence or Absence of Cardiomyopathy. Life (Basel) 2023; 13:life13020445. [PMID: 36836802 PMCID: PMC9958991 DOI: 10.3390/life13020445] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/30/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
Transcription of mitochondrial DNA generates long polycistronic precursors whose nucleolytic cleavage yields the individual mtDNA-encoded transcripts. In most cases, this cleavage occurs at the 5'- and 3'-ends of tRNA sequences by the concerted action of RNAseP and RNaseZ/ELAC2 endonucleases, respectively. Variants in the ELAC2 gene have been predominantly linked to severe to mild cardiomyopathy that, in its milder forms, is accompanied by variably severe neurological presentations. Here, we report five patients from three unrelated families. Four of the patients presented mild to moderate cardiomyopathy and one died at 1 year of age, one patient had no evidence of cardiomyopathy. The patients had variable neurological presentations that included intellectual disability, ataxia, refractory epilepsy, neuropathy and deafness. All patients carried previously unreported missense and nonsense variants. Enzymatic analyses showed multiple OXPHOS deficiencies in biopsies from two patients, whereas immunoblot analyses revealed a decreased abundance of ELAC2 in fibroblasts from three patients. Northern blot analysis revealed an accumulation of unprocessed mt-tRNAVal-precursor consistent with the role of ELAC2 in transcript processing. Our study expands the genetic spectrum of ELAC2-linked disease and suggests that cardiomyopathy is not an invariably present clinical hallmark of this pathology.
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Wu Meyers N, Karasik A, Kaitany K, Fierke CA, Koutmos M. Gambogic acid and juglone inhibit RNase P through distinct mechanisms. J Biol Chem 2022; 298:102683. [PMID: 36370850 PMCID: PMC9731865 DOI: 10.1016/j.jbc.2022.102683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 11/02/2022] [Accepted: 11/05/2022] [Indexed: 11/11/2022] Open
Abstract
The first step in transfer RNA (tRNA) maturation is the cleavage of the 5' end of precursor tRNA (pre-tRNA) catalyzed by ribonuclease P (RNase P). RNase P is either a ribonucleoprotein complex with a catalytic RNA subunit or a protein-only RNase P (PRORP). In most land plants, algae, and Euglenozoa, PRORP is a single-subunit enzyme. There are currently no inhibitors of PRORP for use as tools to study the biological function of this enzyme. Therefore, we screened for compounds that inhibit the activity of a model PRORP from A. thaliana organelles (PRORP1) using a high throughput fluorescence polarization cleavage assay. Two compounds, gambogic acid and juglone (5-hydroxy-1,4-naphthalenedione) that inhibit PRORP1 in the 1 μM range were identified and analyzed. We found these compounds similarly inhibit human mtRNase P, a multisubunit protein enzyme and are 50-fold less potent against bacterial RNA-dependent RNase P. Our biochemical measurements indicate that gambogic acid is a rapid-binding, uncompetitive inhibitor targeting the PRORP1-substrate complex, while juglone acts as a time-dependent PRORP1 inhibitor. Additionally, X-ray crystal structures of PRORP1 in complex with juglone demonstrate the formation of a covalent complex with cysteine side chains on the surface of the protein. Finally, we propose a model consistent with the kinetic data that involves juglone binding to PRORP1 rapidly to form an inactive enzyme-inhibitor complex and then undergoing a slow step to form an inactive covalent adduct with PRORP1. These inhibitors have the potential to be developed into tools to probe PRORP structure and function relationships.
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Affiliation(s)
- Nancy Wu Meyers
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Agnes Karasik
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Kipchumba Kaitany
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Carol A Fierke
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA; Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA.
| | - Markos Koutmos
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA; Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA; Program in Biophysics, University of Michigan, Ann Arbor, Michigan, USA.
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7
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Saoji M, Petersen CE, Sen A, Tripoli BA, Smyth JT, Cox RT. Reduction of Drosophila Mitochondrial RNase P in Skeletal and Heart Muscle Causes Muscle Degeneration, Cardiomyopathy, and Heart Arrhythmia. Front Cell Dev Biol 2022; 10:788516. [PMID: 35663400 PMCID: PMC9162060 DOI: 10.3389/fcell.2022.788516] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 04/14/2022] [Indexed: 11/19/2022] Open
Abstract
In this study, we examine the cause and progression of mitochondrial diseases linked to the loss of mtRNase P, a three-protein complex responsible for processing and cleaving mitochondrial transfer RNAs (tRNA) from their nascent transcripts. When mtRNase P function is missing, mature mitochondrial tRNA levels are decreased, resulting in mitochondrial dysfunction. mtRNase P is composed of Mitochondrial RNase P Protein (MRPP) 1, 2, and 3. MRPP1 and 2 have their own enzymatic activity separate from MRPP3, which is the endonuclease responsible for cleaving tRNA. Human mutations in all subunits cause mitochondrial disease. The loss of mitochondrial function can cause devastating, often multisystemic failures. When mitochondria do not provide enough energy and metabolites, the result can be skeletal muscle weakness, cardiomyopathy, and heart arrhythmias. These symptoms are complex and often difficult to interpret, making disease models useful for diagnosing disease onset and progression. Previously, we identified Drosophila orthologs of each mtRNase P subunit (Roswell/MRPP1, Scully/MRPP2, Mulder/MRPP3) and found that the loss of each subunit causes lethality and decreased mitochondrial tRNA processing in vivo. Here, we use Drosophila to model mtRNase P mitochondrial diseases by reducing the level of each subunit in skeletal and heart muscle using tissue-specific RNAi knockdown. We find that mtRNase P reduction in skeletal muscle decreases adult eclosion and causes reduced muscle mass and function. Adult flies exhibit significant age-progressive locomotor defects. Cardiac-specific mtRNase P knockdowns reduce fly lifespan for Roswell and Scully, but not Mulder. Using intravital imaging, we find that adult hearts have impaired contractility and exhibit substantial arrhythmia. This occurs for roswell and mulder knockdowns, but with little effect for scully. The phenotypes shown here are similar to those exhibited by patients with mitochondrial disease, including disease caused by mutations in MRPP1 and 2. These findings also suggest that skeletal and cardiac deficiencies induced by mtRNase P loss are differentially affected by the three subunits. These differences could have implications for disease progression in skeletal and heart muscle and shed light on how the enzyme complex functions in different tissues.
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Affiliation(s)
- Maithili Saoji
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD, United States
- Henry M. Jackson Foundation, Bethesda, MD, United States.
| | - Courtney E. Petersen
- Henry M. Jackson Foundation, Bethesda, MD, United States.
- Department of Anatomy, Physiology and Genetics, Uniformed Services University, Bethesda, MD, United States
| | - Aditya Sen
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD, United States
- Henry M. Jackson Foundation, Bethesda, MD, United States.
| | - Benjamin A. Tripoli
- Department of Anatomy, Physiology and Genetics, Uniformed Services University, Bethesda, MD, United States
| | - Jeremy T. Smyth
- Department of Anatomy, Physiology and Genetics, Uniformed Services University, Bethesda, MD, United States
| | - Rachel T. Cox
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD, United States
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8
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Organization and expression of the mammalian mitochondrial genome. Nat Rev Genet 2022; 23:606-623. [PMID: 35459860 DOI: 10.1038/s41576-022-00480-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2022] [Indexed: 02/07/2023]
Abstract
The mitochondrial genome encodes core subunits of the respiratory chain that drives oxidative phosphorylation and is, therefore, essential for energy conversion. Advances in high-throughput sequencing technologies and cryoelectron microscopy have shed light on the structure and organization of the mitochondrial genome and revealed unique mechanisms of mitochondrial gene regulation. New animal models of impaired mitochondrial protein synthesis have shown how the coordinated regulation of the cytoplasmic and mitochondrial translation machineries ensures the correct assembly of the respiratory chain complexes. These new technologies and disease models are providing a deeper understanding of mitochondrial genome organization and expression and of the diseases caused by impaired energy conversion, including mitochondrial, neurodegenerative, cardiovascular and metabolic diseases. They also provide avenues for the development of treatments for these conditions.
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ost in promiscuity? An evolutionary and biochemical evaluation of HSD10 function in cardiolipin metabolism. Cell Mol Life Sci 2022; 79:562. [PMID: 36271951 PMCID: PMC9587951 DOI: 10.1007/s00018-022-04579-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 09/20/2022] [Accepted: 09/28/2022] [Indexed: 01/12/2023]
Abstract
Multifunctional proteins are challenging as it can be difficult to confirm pathomechanisms associated with disease-causing genetic variants. The human 17β-hydroxysteroid dehydrogenase 10 (HSD10) is a moonlighting enzyme with at least two structurally and catalytically unrelated functions. HSD10 disease was originally described as a disorder of isoleucine metabolism, but the clinical manifestations were subsequently shown to be linked to impaired mtDNA transcript processing due to deficient function of HSD10 in the mtRNase P complex. A surprisingly large number of other, mostly enzymatic and potentially clinically relevant functions have been attributed to HSD10. Recently, HSD10 was reported to exhibit phospholipase C-like activity towards cardiolipins (CL), important mitochondrial phospholipids. To assess the physiological role of the proposed CL-cleaving function, we studied CL architectures in living cells and patient fibroblasts in different genetic backgrounds and lipid environments using our well-established LC-MS/MS cardiolipidomic pipeline. These experiments revealed no measurable effect on CLs, indicating that HSD10 does not have a physiologically relevant function towards CL metabolism. Evolutionary constraints could explain the broad range of reported substrates for HSD10 in vitro. The combination of an essential structural with a non-essential enzymatic function in the same protein could direct the evolutionary trajectory towards improvement of the former, thereby increasing the flexibility of the binding pocket, which is consistent with the results presented here.
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10
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Hochberg I, Demain LA, Richer J, Thompson K, Urquhart JE, Rea A, Pagarkar W, Rodríguez-Palmero A, Schlüter A, Verdura E, Pujol A, Quijada-Fraile P, Amberger A, Deutschmann AJ, Demetz S, Gillespie M, Belyantseva IA, McMillan HJ, Barzik M, Beaman GM, Motha R, Ng KY, O’Sullivan J, Williams SG, Bhaskar SS, Lawrence IR, Jenkinson EM, Zambonin JL, Blumenfeld Z, Yalonetsky S, Oerum S, Rossmanith W, Yue WW, Zschocke J, Munro KJ, Battersby BJ, Friedman TB, Taylor RW, O’Keefe RT, Newman WG, Newman WG. Bi-allelic variants in the mitochondrial RNase P subunit PRORP cause mitochondrial tRNA processing defects and pleiotropic multisystem presentations. Am J Hum Genet 2021; 108:2195-2204. [PMID: 34715011 PMCID: PMC8595931 DOI: 10.1016/j.ajhg.2021.10.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 10/07/2021] [Indexed: 02/03/2023] Open
Abstract
Human mitochondrial RNase P (mt-RNase P) is responsible for 5′ end processing of mitochondrial precursor tRNAs, a vital step in mitochondrial RNA maturation, and is comprised of three protein subunits: TRMT10C, SDR5C1 (HSD10), and PRORP. Pathogenic variants in TRMT10C and SDR5C1 are associated with distinct recessive or x-linked infantile onset disorders, resulting from defects in mitochondrial RNA processing. We report four unrelated families with multisystem disease associated with bi-allelic variants in PRORP, the metallonuclease subunit of mt-RNase P. Affected individuals presented with variable phenotypes comprising sensorineural hearing loss, primary ovarian insufficiency, developmental delay, and brain white matter changes. Fibroblasts from affected individuals in two families demonstrated decreased steady state levels of PRORP, an accumulation of unprocessed mitochondrial transcripts, and decreased steady state levels of mitochondrial-encoded proteins, which were rescued by introduction of the wild-type PRORP cDNA. In mt-tRNA processing assays performed with recombinant mt-RNase P proteins, the disease-associated variants resulted in diminished mitochondrial tRNA processing. Identification of disease-causing variants in PRORP indicates that pathogenic variants in all three subunits of mt-RNase P can cause mitochondrial dysfunction, each with distinct pleiotropic clinical presentations.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - William G Newman
- Division of Evolution, Infection, and Genomics, School of Biological Sciences, University of Manchester, Manchester M13 9PL, UK; Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester M13 9WL, UK.
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11
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Shaukat AN, Kaliatsi EG, Skeparnias I, Stathopoulos C. The Dynamic Network of RNP RNase P Subunits. Int J Mol Sci 2021; 22:ijms221910307. [PMID: 34638646 PMCID: PMC8509007 DOI: 10.3390/ijms221910307] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 11/17/2022] Open
Abstract
Ribonuclease P (RNase P) is an important ribonucleoprotein (RNP), responsible for the maturation of the 5′ end of precursor tRNAs (pre-tRNAs). In all organisms, the cleavage activity of a single phosphodiester bond adjacent to the first nucleotide of the acceptor stem is indispensable for cell viability and lies within an essential catalytic RNA subunit. Although RNase P is a ribozyme, its kinetic efficiency in vivo, as well as its structural variability and complexity throughout evolution, requires the presence of one protein subunit in bacteria to several protein partners in archaea and eukaryotes. Moreover, the existence of protein-only RNase P (PRORP) enzymes in several organisms and organelles suggests a more complex evolutionary timeline than previously thought. Recent detailed structures of bacterial, archaeal, human and mitochondrial RNase P complexes suggest that, although apparently dissimilar enzymes, they all recognize pre-tRNAs through conserved interactions. Interestingly, individual protein subunits of the human nuclear and mitochondrial holoenzymes have additional functions and contribute to a dynamic network of elaborate interactions and cellular processes. Herein, we summarize the role of each RNase P subunit with a focus on the human nuclear RNP and its putative role in flawless gene expression in light of recent structural studies.
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12
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Saoji M, Sen A, Cox RT. Loss of Individual Mitochondrial Ribonuclease P Complex Proteins Differentially Affects Mitochondrial tRNA Processing In Vivo. Int J Mol Sci 2021; 22:ijms22116066. [PMID: 34199774 PMCID: PMC8200052 DOI: 10.3390/ijms22116066] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 11/16/2022] Open
Abstract
Over a thousand nucleus-encoded mitochondrial proteins are imported from the cytoplasm; however, mitochondrial (mt) DNA encodes for a small number of critical proteins and the entire suite of mt:tRNAs responsible for translating these proteins. Mitochondrial RNase P (mtRNase P) is a three-protein complex responsible for cleaving and processing the 5'-end of mt:tRNAs. Mutations in any of the three proteins can cause mitochondrial disease, as well as mutations in mitochondrial DNA. Great strides have been made in understanding the enzymology of mtRNase P; however, how the loss of each protein causes mitochondrial dysfunction and abnormal mt:tRNA processing in vivo has not been examined in detail. Here, we used Drosophila genetics to selectively remove each member of the complex in order to assess their specific contributions to mt:tRNA cleavage. Using this powerful model, we find differential effects on cleavage depending on which complex member is lost and which mt:tRNA is being processed. These data revealed in vivo subtleties of mtRNase P function that could improve understanding of human diseases.
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Affiliation(s)
- Maithili Saoji
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814, USA; (M.S.); (A.S.)
- Henry M. Jackson Foundation, Bethesda, MD 20817, USA
- Alector Inc., 131 Oyster Point Blvd, San Francisco, CA 94080, USA
| | - Aditya Sen
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814, USA; (M.S.); (A.S.)
- Henry M. Jackson Foundation, Bethesda, MD 20817, USA
| | - Rachel T. Cox
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD 20814, USA; (M.S.); (A.S.)
- Correspondence:
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13
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Karasik A, Wilhelm CA, Fierke CA, Koutmos M. Disease-associated mutations in mitochondrial precursor tRNAs affect binding, m1R9 methylation, and tRNA processing by mtRNase P. RNA (NEW YORK, N.Y.) 2021; 27:420-432. [PMID: 33380464 PMCID: PMC7962481 DOI: 10.1261/rna.077198.120] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 12/16/2020] [Indexed: 06/12/2023]
Abstract
Mitochondrial diseases linked to mutations in mitochondrial (mt) tRNA sequences are common. However, the contributions of these tRNA mutations to the development of diseases is mostly unknown. Mutations may affect interactions with (mt)tRNA maturation enzymes or protein synthesis machinery leading to mitochondrial dysfunction. In human mitochondria, in most cases the first step of tRNA processing is the removal of the 5' leader of precursor tRNAs (pre-tRNA) catalyzed by the three-component enzyme, mtRNase P. Additionally, one component of mtRNase P, mitochondrial RNase P protein 1 (MRPP1), catalyzes methylation of the R9 base in pre-tRNAs. Despite the central role of 5' end processing in mitochondrial tRNA maturation, the link between mtRNase P and diseases is mostly unexplored. Here, we investigate how 11 different human disease-linked mutations in (mt)pre-tRNAIle, (mt)pre-tRNALeu(UUR), and (mt)pre-tRNAMet affect the activities of mtRNase P. We find that several mutations weaken the pre-tRNA binding affinity (KD s are approximately two- to sixfold higher than that of wild-type), while the majority of mutations decrease 5' end processing and methylation activity catalyzed by mtRNase P (up to ∼55% and 90% reduction, respectively). Furthermore, all of the investigated mutations in (mt)pre-tRNALeu(UUR) alter the tRNA fold which contributes to the partial loss of function of mtRNase P. Overall, these results reveal an etiological link between early steps of (mt)tRNA-substrate processing and mitochondrial disease.
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Affiliation(s)
- Agnes Karasik
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, USA
| | - Catherine A Wilhelm
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Carol A Fierke
- Department of Chemistry, Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Chemistry, Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA
| | - Markos Koutmos
- Department of Chemistry, Program in Biophysics, University of Michigan, Ann Arbor, Michigan 48109, USA
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14
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Zhang L, Chen J, Ma J, Liu H. HN-CNN: A Heterogeneous Network Based on Convolutional Neural Network for m 7 G Site Disease Association Prediction. Front Genet 2021; 12:655284. [PMID: 33747055 PMCID: PMC7970120 DOI: 10.3389/fgene.2021.655284] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 02/15/2021] [Indexed: 12/24/2022] Open
Abstract
N7-methylguanosine (m7G) is a typical positively charged RNA modification, playing a vital role in transcriptional regulation. m7G can affect the biological processes of mRNA and tRNA and has associations with multiple diseases including cancers. Wet-lab experiments are cost and time ineffective for the identification of disease-related m7G sites. Thus, a heterogeneous network method based on Convolutional Neural Networks (HN-CNN) has been proposed to predict unknown associations between m7G sites and diseases. HN-CNN constructs a heterogeneous network with m7G site similarity, disease similarity, and disease-associated m7G sites to formulate features for m7G site-disease pairs. Next, a convolutional neural network (CNN) obtains multidimensional and irrelevant features prominently. Finally, XGBoost is adopted to predict the association between m7G sites and diseases. The performance of HN-CNN is compared with Naive Bayes (NB), Random Forest (RF), Support Vector Machine (SVM), as well as Gradient Boosting Decision Tree (GBDT) through 10-fold cross-validation. The average AUC of HN-CNN is 0.827, which is superior to others.
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Affiliation(s)
- Lin Zhang
- Engineering Research Center of Intelligent Control for Underground Space, Ministry of Education, China University of Mining and Technology, Xuzhou, China.,School of Information and Control Engineering, China University of Mining and Technology, Xuzhou, China
| | - Jin Chen
- School of Information and Control Engineering, China University of Mining and Technology, Xuzhou, China
| | - Jiani Ma
- School of Information and Control Engineering, China University of Mining and Technology, Xuzhou, China
| | - Hui Liu
- Engineering Research Center of Intelligent Control for Underground Space, Ministry of Education, China University of Mining and Technology, Xuzhou, China.,School of Information and Control Engineering, China University of Mining and Technology, Xuzhou, China
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15
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Isokallio MA, Stewart JB. High-Throughput Detection of mtDNA Mutations Leading to tRNA Processing Errors. Methods Mol Biol 2021; 2192:117-132. [PMID: 33230770 DOI: 10.1007/978-1-0716-0834-0_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Some mutations in the tRNA genes of mitochondrial DNA (mtDNA) have been demonstrated to affect the processing of the mitochondrial transcriptome in human patients with mitochondrial disease. A recent analysis of mtDNA mutations in 527 human tumors revealed that approximately a quarter of the somatic mt-tRNA gene mutations lead to aberrant processing of the mitochondrial transcriptome in these tumors. Here, we describe a method, based on mtDNA mutations induced by the mtDNA mutator mouse, to map the sites that lead to transcript processing abnormalities. Mutations in the mtDNA are identified and quantified by amplicon-based mtDNA sequencing, and compared to the allelic ratios observed in matched RNASeq data. Strong deviation in the variant allele frequencies between the amplicon and RNASeq data suggests that such mutations lead to disruptions in mitochondrial transcript processing.
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16
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Vinklarova L, Schmidt M, Benek O, Kuca K, Gunn-Moore F, Musilek K. Friend or enemy? Review of 17β-HSD10 and its role in human health or disease. J Neurochem 2020; 155:231-249. [PMID: 32306391 DOI: 10.1111/jnc.15027] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/26/2020] [Accepted: 04/10/2020] [Indexed: 12/17/2022]
Abstract
17β-hydroxysteroid dehydrogenase (17β-HSD10) is a multifunctional human enzyme with important roles both as a structural component and also as a catalyst of many metabolic pathways. This mitochondrial enzyme has important functions in the metabolism, development and aging of the neural system, where it is involved in the homeostasis of neurosteroids, especially in regard to estradiol, changes in which make it an essential part of neurodegenerative pathology. These roles therefore, indicate that 17β-HSD10 may be a possible druggable target for neurodegenerative diseases including Alzheimer's disease (AD), and in hormone-dependent cancer. The objective of this review was to provide a summary about physiological functions and pathological roles of 17β-HSD10 and the modulators of its activity.
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Affiliation(s)
- Lucie Vinklarova
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Monika Schmidt
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Ondrej Benek
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | | | - Kamil Musilek
- Faculty of Science, Department of Chemistry, University of Hradec Kralove, Hradec Kralove, Czech Republic
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17
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Ccm1p is a 15S rRNA primary transcript processing factor as elucidated by a novel in vivo system in Saccharomyces cerevisiae. Curr Genet 2020; 66:775-789. [PMID: 32152734 DOI: 10.1007/s00294-020-01064-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 02/15/2020] [Accepted: 02/24/2020] [Indexed: 10/24/2022]
Abstract
In Saccharomyces cerevisiae, the mitoribosomal RNA of the minor subunit, 15S rRNA, is transcribed as a bicistronic transcript along with tRNAW. 5' and 3' sequences flanking the mature transcript must be removed by cleavage at the respective junctions before incorporating it into the mitoribosome. An in vivo dose-response triphasic system was created to elucidate the role of Ccm1p in the processing of 15S rRNA: Ccm1p supply ("On"), deprivation ("Off"), and resupply ("Back on"). After 72 h under "Off" status, the cells started to exhibit a complete mutant phenotype as assessed by their lack of growth in glycerol medium, while keeping their mitochondrial DNA integrity (ρ+). Full functionality of mitochondria was reacquired upon "Back on." 15S rRNA levels and phenotype followed the Ccm1p intramitochondrial concentrations throughout the "On-Off-Back on" course. Under "Off" status, cells gradually accumulated unprocessed 5' and 3' junctions, which reached significant levels at 72-96 h, probably due to a saturation of the mitochondrial degradosome (mtEXO). The Ccm1p/mtEXO mutant (Δccm1/Δdss1) showed a copious accumulation of 15S rRNA primary transcript forms, which were cleaved upon Ccm1p resupply. The gene that codes for the RNA component of RNase P was conserved in wild-type and mutant strains. Our results indicate that Ccm1p is crucial in processing the 15S rRNA primary transcript and does not stabilize the already mature 15S rRNA. Consequently, failure of this function in Δccm1 cells results, as it happens to any other unprocessed primary transcripts, in total degradation of 15S rRNA by mtEXO, whose mechanism of action is discussed.
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18
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Karasik A, Fierke CA, Koutmos M. Interplay between substrate recognition, 5' end tRNA processing and methylation activity of human mitochondrial RNase P. RNA (NEW YORK, N.Y.) 2019; 25:1646-1660. [PMID: 31455609 PMCID: PMC6859853 DOI: 10.1261/rna.069310.118] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 08/16/2019] [Indexed: 05/07/2023]
Abstract
Human mitochondrial ribonuclease P (mtRNase P) is an essential three-protein complex that catalyzes the 5' end maturation of mitochondrial precursor tRNAs (pre-tRNAs). Mitochondrial RNase P Protein 3 (MRPP3), a protein-only RNase P (PRORP), is the nuclease component of the mtRNase P complex and requires a two-protein S-adenosyl-methionine (SAM)-dependent methyltransferase MRPP1/2 subcomplex to function. Dysfunction of mtRNase P is linked to several human mitochondrial diseases, such as mitochondrial myopathies. Despite its central role in mitochondrial RNA processing, little is known about how the protein subunits of mtRNase P function synergistically. Here, we use purified mtRNase P to demonstrate that mtRNase P recognizes, cleaves, and methylates some, but not all, mitochondrial pre-tRNAs in vitro. Additionally, mtRNase P does not process all mitochondrial pre-tRNAs uniformly, suggesting the possibility that some pre-tRNAs require additional factors to be cleaved in vivo. Consistent with this, we found that addition of the TRMT10C (MRPP1) cofactor SAM enhances the ability of mtRNase P to bind and cleave some mitochondrial pre-tRNAs. Furthermore, the presence of MRPP3 can enhance the methylation activity of MRPP1/2. Taken together, our data demonstrate that the subunits of mtRNase P work together to efficiently recognize, process, and methylate human mitochondrial pre-tRNAs.
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Affiliation(s)
- Agnes Karasik
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, USA
| | - Carol A Fierke
- Department of Chemistry, Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Markos Koutmos
- Department of Chemistry, Program in Biophysics, University of Michigan, Ann Arbor, Michigan 48109, USA
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19
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Waters PJ, Lace B, Buhas D, Gravel S, Cyr D, Boucher RM, Bernard G, Lévesque S, Maranda B. HSD10 mitochondrial disease: p.Leu122Val variant, mild clinical phenotype, and founder effect in French-Canadian patients from Quebec. Mol Genet Genomic Med 2019; 7:e1000. [PMID: 31654490 PMCID: PMC6900358 DOI: 10.1002/mgg3.1000] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/28/2019] [Accepted: 09/03/2019] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND HSD10 mitochondrial disease (HSD10MD), originally described as a deficiency of 2-methyl-3-hydroxybutyryl-CoA dehydrogenase (MHBD), is a rare X-linked disorder of a moonlighting protein encoded by the HSD17B10. The diagnosis is usually first suspected on finding elevated isoleucine degradation metabolites in urine, reflecting decreased MHBD activity. However, it is now known that clinical disease pathogenesis reflects other independent functions of the HSD10 protein; particularly its essential role in mitochondrial transcript processing and tRNA maturation. The classical phenotype of HSD10MD in affected males is an infantile-onset progressive neurodegenerative disorder associated with severe mitochondrial dysfunction. PATIENTS, METHODS, AND RESULTS In four unrelated families, we identified index patients with MHBD deficiency, which implied a diagnosis of HSD10MD. Each index patient was independently investigated because of neurological or developmental concerns. All had persistent elevations of urinary 2-methyl-3-hydroxybutyric acid and tiglylglycine. Analysis of HSD17B10 identified a single missense variant, c.364C>G, p.Leu122Val, in each case. This rare variant (1/183336 alleles in gnomAD) was previously reported in one Dutch patient and was described as pathogenic. The geographic origins of our families and results of haplotype analysis together provide evidence of a founder effect for this variant in Quebec. Notably, we identified an asymptomatic hemizygous adult male in one family, while a second independent genetic disorder contributed substantially to the clinical phenotypes observed in probands from two other families. CONCLUSION The phenotype associated with p.Leu122Val in HSD17B10 currently appears to be attenuated and nonprogressive. This report widens the spectrum of phenotypic severity of HSD10MD and contributes to genotype-phenotype correlation. At present, we consider p.Leu122Val a "variant of uncertain significance." Nonetheless, careful follow-up of our patients remains advisable, to assess long-term clinical course and ensure appropriate management. It will also be important to identify other potential patients in our population and to characterize their phenotype.
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Affiliation(s)
- Paula J Waters
- Medical Genetics, Department of Pediatrics, Université de Sherbrooke-CHUS, Sherbrooke, QC, Canada.,CRCHUS, Sherbrooke, QC, Canada
| | - Baiba Lace
- Medical Genetics, Department of Pediatrics, CHU de Québec-Université Laval, Quebec, Canada
| | - Daniela Buhas
- Medical Genetics, Department of Specialized Medicine, MUHC, Montreal, Canada.,Department of Human Genetics, McGill University, Montreal, Canada
| | - Serge Gravel
- Medical Genetics, Department of Pediatrics, Université de Sherbrooke-CHUS, Sherbrooke, QC, Canada.,CRCHUS, Sherbrooke, QC, Canada
| | - Denis Cyr
- Medical Genetics, Department of Pediatrics, Université de Sherbrooke-CHUS, Sherbrooke, QC, Canada.,CRCHUS, Sherbrooke, QC, Canada
| | - Renée-Myriam Boucher
- Neurology, Department of Pediatrics, CHU de Québec-Université Laval, Quebec, QC, Canada
| | - Geneviève Bernard
- Medical Genetics, Department of Specialized Medicine, MUHC, Montreal, Canada.,Department of Human Genetics, McGill University, Montreal, Canada.,Departments of Neurology/Neurosurgery and Pediatrics, McGill University, Montreal, Canada.,RI-MUHC, Montreal, Canada
| | - Sébastien Lévesque
- Medical Genetics, Department of Pediatrics, Université de Sherbrooke-CHUS, Sherbrooke, QC, Canada.,CRCHUS, Sherbrooke, QC, Canada
| | - Bruno Maranda
- Medical Genetics, Department of Pediatrics, Université de Sherbrooke-CHUS, Sherbrooke, QC, Canada.,CRCHUS, Sherbrooke, QC, Canada
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20
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Saoura M, Powell CA, Kopajtich R, Alahmad A, AL‐Balool HH, Albash B, Alfadhel M, Alston CL, Bertini E, Bonnen PE, Bratkovic D, Carrozzo R, Donati MA, Di Nottia M, Ghezzi D, Goldstein A, Haan E, Horvath R, Hughes J, Invernizzi F, Lamantea E, Lucas B, Pinnock K, Pujantell M, Rahman S, Rebelo‐Guiomar P, Santra S, Verrigni D, McFarland R, Prokisch H, Taylor RW, Levinger L, Minczuk M. Mutations in ELAC2 associated with hypertrophic cardiomyopathy impair mitochondrial tRNA 3'-end processing. Hum Mutat 2019; 40:1731-1748. [PMID: 31045291 PMCID: PMC6764886 DOI: 10.1002/humu.23777] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 04/09/2019] [Accepted: 04/29/2019] [Indexed: 12/16/2022]
Abstract
Mutations in either the mitochondrial or nuclear genomes are associated with a diverse group of human disorders characterized by impaired mitochondrial respiration. Within this group, an increasing number of mutations have been identified in nuclear genes involved in mitochondrial RNA metabolism, including ELAC2. The ELAC2 gene codes for the mitochondrial RNase Z, responsible for endonucleolytic cleavage of the 3' ends of mitochondrial pre-tRNAs. Here, we report the identification of 16 novel ELAC2 variants in individuals presenting with mitochondrial respiratory chain deficiency, hypertrophic cardiomyopathy (HCM), and lactic acidosis. We provide evidence for the pathogenicity of the novel missense variants by studying the RNase Z activity in an in vitro system. We also modeled the residues affected by a missense mutation in solved RNase Z structures, providing insight into enzyme structure and function. Finally, we show that primary fibroblasts from the affected individuals have elevated levels of unprocessed mitochondrial RNA precursors. Our study thus broadly confirms the correlation of ELAC2 variants with severe infantile-onset forms of HCM and mitochondrial respiratory chain dysfunction. One rare missense variant associated with the occurrence of prostate cancer (p.Arg781His) impairs the mitochondrial RNase Z activity of ELAC2, suggesting a functional link between tumorigenesis and mitochondrial RNA metabolism.
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Affiliation(s)
| | | | - Robert Kopajtich
- Genetics of Mitochondrial Disorders, Institute of Human GeneticsTechnische Universität MünchenMunichGermany
- Genetics of Mitochondrial Disorders, Institute of Human GeneticsHelmholtz Zentrum MünchenNeuherbergGermany
| | - Ahmad Alahmad
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
- Kuwait Medical Genetics CenterKuwait CityKuwait
| | | | | | - Majid Alfadhel
- Genetics Division, Department of Pediatrics, King Abdullah International Medical Research CentreKing Saud bin Abdulaziz University for Health SciencesRiyadhSaudi Arabia
| | - Charlotte L. Alston
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Enrico Bertini
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular MedicineBambino Gesu' Children's Research Hospital, IRCCSRomeItaly
| | - Penelope E. Bonnen
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexas
| | - Drago Bratkovic
- Metabolic ClinicWomen's and Children's HospitalNorth AdelaideSouth AustraliaAustralia
| | - Rosalba Carrozzo
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular MedicineBambino Gesu' Children's Research Hospital, IRCCSRomeItaly
| | | | - Michela Di Nottia
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular MedicineBambino Gesu' Children's Research Hospital, IRCCSRomeItaly
| | - Daniele Ghezzi
- Unit of Medical Genetics and NeurogeneticsFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
- Department of Pathophysiology and TransplantationUniversity of MilanMilanItaly
| | - Amy Goldstein
- Mitochondrial Medicine Frontier ProgramChildren's Hospital of PhiladelphiaPhiladelphiaUSA
| | - Eric Haan
- Metabolic ClinicWomen's and Children's HospitalNorth AdelaideSouth AustraliaAustralia
| | - Rita Horvath
- Wellcome Centre for Mitochondrial Research, Institute of Genetic MedicineNewcastle UniversityNewcastle upon TyneUK
| | - Joanne Hughes
- National Centre for Inherited Metabolic DisordersTemple Street Children's University HospitalDublinIreland
| | - Federica Invernizzi
- Unit of Medical Genetics and NeurogeneticsFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
| | - Eleonora Lamantea
- Unit of Medical Genetics and NeurogeneticsFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
| | - Benjamin Lucas
- York CollegeThe City University of New YorkJamaicaNew York
| | | | | | - Shamima Rahman
- Mitochondrial Research GroupUCL Great Ormond Street Institute of Child HealthLondonUK
| | - Pedro Rebelo‐Guiomar
- MRC Mitochondrial Biology UnitUniversity of CambridgeCambridgeUK
- Graduate Program in Areas of Basic and Applied BiologyUniversity of PortoPortoPortugal
| | - Saikat Santra
- Department of Clinical Inherited Metabolic DisordersBirmingham Children's HospitalBirminghamUK
| | - Daniela Verrigni
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular MedicineBambino Gesu' Children's Research Hospital, IRCCSRomeItaly
| | - Robert McFarland
- Genetics of Mitochondrial Disorders, Institute of Human GeneticsHelmholtz Zentrum MünchenNeuherbergGermany
| | - Holger Prokisch
- Genetics of Mitochondrial Disorders, Institute of Human GeneticsTechnische Universität MünchenMunichGermany
- Genetics of Mitochondrial Disorders, Institute of Human GeneticsHelmholtz Zentrum MünchenNeuherbergGermany
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Institute of NeuroscienceNewcastle UniversityNewcastle upon TyneUK
| | - Louis Levinger
- York CollegeThe City University of New YorkJamaicaNew York
| | - Michal Minczuk
- MRC Mitochondrial Biology UnitUniversity of CambridgeCambridgeUK
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21
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Hiltunen JK, Kastaniotis AJ, Autio KJ, Jiang G, Chen Z, Glumoff T. 17B-hydroxysteroid dehydrogenases as acyl thioester metabolizing enzymes. Mol Cell Endocrinol 2019; 489:107-118. [PMID: 30508570 DOI: 10.1016/j.mce.2018.11.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 11/23/2018] [Accepted: 11/23/2018] [Indexed: 01/10/2023]
Abstract
17β-Hydroxysteroid dehydrogenases (HSD17B) catalyze the oxidation/reduction of 17β-hydroxy/keto group in position C17 in C18- and C19 steroids. Most HSD17Bs are also catalytically active with substrates other than steroids. A subset of these enzymes is able to process thioesters of carboxylic acids. This group of enzymes includes HSD17B4, HSD17B8, HSD17B10 and HSD17B12, which execute reactions in intermediary metabolism, participating in peroxisomal β-oxidation of fatty acids, mitochondrial oxidation of 3R-hydroxyacyl-groups, breakdown of isoleucine and fatty acid chain elongation in endoplasmic reticulum. Divergent substrate acceptance capabilities exemplify acquirement of catalytic site adaptiveness during evolution. As an additional common feature these HSD17Bs are multifunctional enzymes that arose either via gene fusions (HSD17B4) or are incorporated as subunits into multifunctional protein complexes (HSD17B8 and HSD17B10). Crystal structures of HSD17B4, HSD17B8 and HSD17B10 give insight into their structure-function relationships. Thus far, deficiencies of HSD17B4 and HSD17B10 have been assigned to inborn errors in humans, underlining their significance as enzymes of metabolism.
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Affiliation(s)
- J Kalervo Hiltunen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland; State Key Laboratory of Supramolecular Structure and Materials and Institute of Theoretical Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, PR China.
| | | | - Kaija J Autio
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Guangyu Jiang
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Zhijun Chen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland; State Key Laboratory of Supramolecular Structure and Materials and Institute of Theoretical Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, PR China
| | - Tuomo Glumoff
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
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22
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Tsachaki M, Odermatt A. Subcellular localization and membrane topology of 17β-hydroxysteroid dehydrogenases. Mol Cell Endocrinol 2019; 489:98-106. [PMID: 30864548 DOI: 10.1016/j.mce.2018.07.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 06/18/2018] [Accepted: 07/03/2018] [Indexed: 01/09/2023]
Abstract
The 17β-hydroxysteroid dehydrogenases (17β-HSDs) comprise enzymes initially identified by their ability to interconvert active and inactive forms of sex steroids, a vital process for the tissue-specific control of estrogen and androgen balance. However, most 17β-HSDs have now been shown to accept substrates other than sex steroids, including bile acids, retinoids and fatty acids, thereby playing unanticipated roles in cell physiology. This functional divergence is often reflected by their different subcellular localization, with 17β-HSDs found in the cytosol, peroxisome, mitochondria, endoplasmic reticulum and in lipid droplets. Moreover, a subset of 17β-HSDs are integral membrane proteins, with their specific topology dictating the cellular compartment in which they exert their enzymatic activity. Here, we summarize the present knowledge on the subcellular localization and membrane topology of the 17β-HSD enzymes and discuss the correlation with their biological functions.
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Affiliation(s)
- Maria Tsachaki
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Alex Odermatt
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland.
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23
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Oerum S, Roovers M, Rambo RP, Kopec J, Bailey HJ, Fitzpatrick F, Newman JA, Newman WG, Amberger A, Zschocke J, Droogmans L, Oppermann U, Yue WW. Structural insight into the human mitochondrial tRNA purine N1-methyltransferase and ribonuclease P complexes. J Biol Chem 2018; 293:12862-12876. [PMID: 29880640 PMCID: PMC6102140 DOI: 10.1074/jbc.ra117.001286] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 04/24/2018] [Indexed: 01/17/2023] Open
Abstract
Mitochondrial tRNAs are transcribed as long polycistronic transcripts of precursor tRNAs and undergo posttranscriptional modifications such as endonucleolytic processing and methylation required for their correct structure and function. Among them, 5'-end processing and purine 9 N1-methylation of mitochondrial tRNA are catalyzed by two proteinaceous complexes with overlapping subunit composition. The Mg2+-dependent RNase P complex for 5'-end cleavage comprises the methyltransferase domain-containing protein tRNA methyltransferase 10C, mitochondrial RNase P subunit (TRMT10C/MRPP1), short-chain oxidoreductase hydroxysteroid 17β-dehydrogenase 10 (HSD17B10/MRPP2), and metallonuclease KIAA0391/MRPP3. An MRPP1-MRPP2 subcomplex also catalyzes the formation of 1-methyladenosine/1-methylguanosine at position 9 using S-adenosyl-l-methionine as methyl donor. However, a lack of structural information has precluded insights into how these complexes methylate and process mitochondrial tRNA. Here, we used a combination of X-ray crystallography, interaction and activity assays, and small angle X-ray scattering (SAXS) to gain structural insight into the two tRNA modification complexes and their components. The MRPP1 N terminus is involved in tRNA binding and monomer-monomer self-interaction, whereas the C-terminal SPOUT fold contains key residues for S-adenosyl-l-methionine binding and N1-methylation. The entirety of MRPP1 interacts with MRPP2 to form the N1-methylation complex, whereas the MRPP1-MRPP2-MRPP3 RNase P complex only assembles in the presence of precursor tRNA. This study proposes low-resolution models of the MRPP1-MRPP2 and MRPP1-MRPP2-MRPP3 complexes that suggest the overall architecture, stoichiometry, and orientation of subunits and tRNA substrates.
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Affiliation(s)
- Stephanie Oerum
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
| | | | - Robert P Rambo
- Diamond Light Source, Harwell Science and Innovation Center, Didcot OX11 0QG, United Kingdom
| | - Jola Kopec
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Henry J Bailey
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Fiona Fitzpatrick
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Joseph A Newman
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - William G Newman
- Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, University of Manchester, Manchester, M13 9WL, United Kingdom
| | - Albert Amberger
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Johannes Zschocke
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Louis Droogmans
- Laboratoire de Microbiologie, Universite libre de Bruxelles, 1050 Belgium
| | - Udo Oppermann
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom; Botnar Research Centre, NIHR Oxford Biomedical Research Unit, Oxford OX3 7LD, United Kingdom.
| | - Wyatt W Yue
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom.
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24
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Abstract
Transcription of the mitochondrial genome yields three large polycistronic transcripts that undergo multiple endonucleolytic processing steps, before resulting in functional mRNAs, tRNAs, and rRNAs. Cleavage of the large precursor transcripts is mainly performed by the RNase P complex and RNase Z that cleave mitochondrial pre-tRNAs at their 5' and 3' ends respectively. Most likely there are additional enzymes involved that still await identification and characterization. Defects in mitochondrial RNA processing have been associated with human disease. There are published cases of patients carrying mutations in either HSD17B10/MRPP2 (encoding a subunit of RNase P complex) or ELAC2 (coding for RNase Z). In addition, several mtDNA mutations within tRNA genes have been shown to affect RNA processing. Here, we describe detailed protocols for analyzing RNA processing of mitochondrial tRNAs, in particular their 3'-ends that are processed by RNase Z. These protocols should serve as a guide to extract RNA for quantitative real-time PCR and RNAseq analysis.
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25
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Reinhard L, Sridhara S, Hällberg BM. The MRPP1/MRPP2 complex is a tRNA-maturation platform in human mitochondria. Nucleic Acids Res 2017; 45:12469-12480. [PMID: 29040705 PMCID: PMC5716156 DOI: 10.1093/nar/gkx902] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/25/2017] [Indexed: 11/22/2022] Open
Abstract
Mitochondrial polycistronic transcripts are extensively processed to give rise to functional mRNAs, rRNAs and tRNAs; starting with the release of tRNA elements through 5′-processing by RNase P (MRPP1/2/3-complex) and 3′-processing by RNase Z (ELAC2). Here, we show using in vitro experiments that MRPP1/2 is not only a component of the mitochondrial RNase P but that it retains the tRNA product from the 5′-processing step and significantly enhances the efficiency of ELAC2-catalyzed 3′-processing for 17 of the 22 tRNAs encoded in the human mitochondrial genome. Furthermore, MRPP1/2 retains the tRNA product after ELAC2 processing and presents the nascent tRNA to the mitochondrial CCA-adding enzyme. Thus, in addition to being an essential component of the RNase P reaction, MRPP1/2 serves as a processing platform for several down-stream tRNA maturation steps in human mitochondria. These findings are of fundamental importance for our molecular understanding of disease-related mutations in MRPP1/2, ELAC2 and mitochondrial tRNA genes.
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Affiliation(s)
- Linda Reinhard
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.,Röntgen-Ångström-Cluster, Karolinska Institutet Outstation, Centre for Structural Systems Biology (CSSB), DESY-Campus, 22607 Hamburg, Germany
| | - Sagar Sridhara
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.,Röntgen-Ångström-Cluster, Karolinska Institutet Outstation, Centre for Structural Systems Biology (CSSB), DESY-Campus, 22607 Hamburg, Germany
| | - B Martin Hällberg
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.,Röntgen-Ångström-Cluster, Karolinska Institutet Outstation, Centre for Structural Systems Biology (CSSB), DESY-Campus, 22607 Hamburg, Germany.,European Molecular Biology Laboratory, Hamburg Unit, 22603 Hamburg, Germany
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26
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Frazier AE, Thorburn DR, Compton AG. Mitochondrial energy generation disorders: genes, mechanisms, and clues to pathology. J Biol Chem 2017; 294:5386-5395. [PMID: 29233888 DOI: 10.1074/jbc.r117.809194] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Inherited disorders of oxidative phosphorylation cause the clinically and genetically heterogeneous diseases known as mitochondrial energy generation disorders, or mitochondrial diseases. Over the last three decades, mutations causing these disorders have been identified in almost 290 genes, but many patients still remain without a molecular diagnosis. Moreover, while our knowledge of the genetic causes is continually expanding, our understanding into how these defects lead to cellular dysfunction and organ pathology is still incomplete. Here, we review recent developments in disease gene discovery, functional characterization, and shared pathogenic parameters influencing disease pathology that offer promising avenues toward the development of effective therapies.
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Affiliation(s)
- Ann E Frazier
- From the Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, and
| | - David R Thorburn
- From the Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, and.,Victorian Clinical Genetic Services, Royal Children's Hospital, Melbourne, Victoria 3052, Australia
| | - Alison G Compton
- From the Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, and
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27
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Su L, Li X, Lin R, Sheng H, Feng Z, Liu L. Clinical and molecular analysis of 6 Chinese patients with isoleucine metabolism defects: identification of 3 novel mutations in the HSD17B10 and ACAT1 gene. Metab Brain Dis 2017; 32:2063-2071. [PMID: 28875337 DOI: 10.1007/s11011-017-0097-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 08/16/2017] [Indexed: 01/16/2023]
Abstract
Hydroxysteroid (17β) dehydrogenase 10 (HSD10) and mitochondrial acetoacetyl-CoA thiolase (β-KT) are two adjacent enzymes for the degradation of isoleucine, thus HSD10 and β-KT deficiencies are confusing at an early stage because of nearly the same elevation of typical metabolites in urine, such as 2-methyl-3-hydroxybutyric acid (2M3HBA) and tiglylglycine (TG). In order to better understand the differences between these two disorders, we described the clinical and molecular characteristics of two HSD10 deficiency patients and four β-KT deficiency patients. β-KT deficiency patients had a much more favorable outcome than that of HSD10 deficiency patients, indicating that the multifunction of HSD10, especially neurosteroid metabolic activity, other than only enzymatic degradation of isoleucine, is involved in the pathogenesis of HSD10 deficiency. Two different mutations, a novel mutation p.Ile175Met and a reported mutation p.Arg226Gln, were detected in the HSD17B10 gene of HSD10 deficiency patients. Six different mutations, including four known mutations: p.Ala333Pro, p.Thr297Lys, c.83_84delAT, c.1006-1G > C, and two novel mutations: p.Thr277Pro and c.121-3C > G were identified in the ACAT1 gene of β-KT deficiency patients. In general, DNA diagnosis played an important role in distinguishing between these two disorders.
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MESH Headings
- 3-Hydroxyacyl CoA Dehydrogenases/genetics
- Acetyl-CoA C-Acetyltransferase/genetics
- Acetyl-CoA C-Acyltransferase/deficiency
- Acetyl-CoA C-Acyltransferase/genetics
- Acetyl-CoA C-Acyltransferase/metabolism
- Amino Acid Metabolism, Inborn Errors/diagnosis
- Amino Acid Metabolism, Inborn Errors/diagnostic imaging
- Amino Acid Metabolism, Inborn Errors/genetics
- Amino Acid Metabolism, Inborn Errors/metabolism
- Brain/diagnostic imaging
- Child, Preschool
- China
- Diagnosis, Differential
- Dyskinesias/diagnosis
- Dyskinesias/diagnostic imaging
- Dyskinesias/genetics
- Dyskinesias/metabolism
- Epilepsy/genetics
- Epilepsy/metabolism
- Female
- Humans
- Infant
- Isoleucine/metabolism
- Male
- Mental Retardation, X-Linked/diagnosis
- Mental Retardation, X-Linked/diagnostic imaging
- Mental Retardation, X-Linked/genetics
- Mental Retardation, X-Linked/metabolism
- Models, Molecular
- Mutation
- Retrospective Studies
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Affiliation(s)
- Ling Su
- Southern Medical University, Guangzhou, 510515, China
| | - Xiuzhen Li
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China
| | - Ruizhu Lin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China
| | - Huiying Sheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China
| | - Zhichun Feng
- Southern Medical University, Guangzhou, 510515, China.
- Department of Neonatology, Affiliated Bayi Children's Hospital, Clinical Medical College in PLA Army General Hospital, Southern Medical University, Beijing, 100007, China.
| | - Li Liu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China.
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28
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Garone C, D’Souza AR, Dallabona C, Lodi T, Rebelo-Guiomar P, Rorbach J, Donati MA, Procopio E, Montomoli M, Guerrini R, Zeviani M, Calvo SE, Mootha VK, DiMauro S, Ferrero I, Minczuk M. Defective mitochondrial rRNA methyltransferase MRM2 causes MELAS-like clinical syndrome. Hum Mol Genet 2017; 26:4257-4266. [PMID: 28973171 PMCID: PMC5886288 DOI: 10.1093/hmg/ddx314] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/01/2017] [Accepted: 08/03/2017] [Indexed: 02/02/2023] Open
Abstract
Defects in nuclear-encoded proteins of the mitochondrial translation machinery cause early-onset and tissue-specific deficiency of one or more OXPHOS complexes. Here, we report a 7-year-old Italian boy with childhood-onset rapidly progressive encephalomyopathy and stroke-like episodes. Multiple OXPHOS defects and decreased mtDNA copy number (40%) were detected in muscle homogenate. Clinical features combined with low level of plasma citrulline were highly suggestive of mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome, however, the common m.3243 A > G mutation was excluded. Targeted exome sequencing of genes encoding the mitochondrial proteome identified a damaging mutation, c.567 G > A, affecting a highly conserved amino acid residue (p.Gly189Arg) of the MRM2 protein. MRM2 has never before been linked to a human disease and encodes an enzyme responsible for 2'-O-methyl modification at position U1369 in the human mitochondrial 16S rRNA. We generated a knockout yeast model for the orthologous gene that showed a defect in respiration and the reduction of the 2'-O-methyl modification at the equivalent position (U2791) in the yeast mitochondrial 21S rRNA. Complementation with the mrm2 allele carrying the equivalent yeast mutation failed to rescue the respiratory phenotype, which was instead completely rescued by expressing the wild-type allele. Our findings establish that defective MRM2 causes a MELAS-like phenotype, and suggests the genetic screening of the MRM2 gene in patients with a m.3243 A > G negative MELAS-like presentation.
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Affiliation(s)
- Caterina Garone
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - Aaron R D’Souza
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability - University of Parma, Parma 43121, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability - University of Parma, Parma 43121, Italy
| | - Pedro Rebelo-Guiomar
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
- Graduate Program in Areas of Basic and Applied Biology (GABBA), University of Porto, 4099-002, Portugal
| | - Joanna Rorbach
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | | | - Elena Procopio
- Metabolic Unit, A. Meyer Children's Hospital, Florence 50139, Italy
| | - Martino Montomoli
- Pediatric Neurology Unit and Laboratories, “A. Meyer” Children's Hospital, University of Florence, 50139, Italy
| | - Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, “A. Meyer” Children's Hospital, University of Florence, 50139, Italy
| | - Massimo Zeviani
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Sarah E Calvo
- Broad Institute of MIT & Harvard, Cambridge, MA 02142, USA
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, and Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Vamsi K Mootha
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, and Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Salvatore DiMauro
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - Ileana Ferrero
- Department of Chemistry, Life Sciences and Environmental Sustainability - University of Parma, Parma 43121, Italy
| | - Michal Minczuk
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
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29
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Houten SM. Protein moonlighting in inborn errors of metabolism: the case of the mitochondrial acylglycerol kinase. J Inherit Metab Dis 2017; 40:755-756. [PMID: 29290639 PMCID: PMC5743438 DOI: 10.1007/s10545-017-0090-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
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30
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Litim N, Morissette M, Caruso D, Melcangi RC, Di Paolo T. Effect of the 5α-reductase enzyme inhibitor dutasteride in the brain of intact and parkinsonian mice. J Steroid Biochem Mol Biol 2017; 174:242-256. [PMID: 28982631 DOI: 10.1016/j.jsbmb.2017.09.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 09/08/2017] [Accepted: 09/30/2017] [Indexed: 12/15/2022]
Abstract
Dutasteride is a 5alpha-reductase inhibitor in clinical use to treat endocrine conditions. The present study investigated the neuroprotective mechanisms of action of dutasteride in intact and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mice using a low dose of MPTP not affecting motor activity modeling early stages of Parkinson's disease (PD). We hypothesized that dutasteride neuroprotection is due to altered steroids levels. Dutasteride pre-treatment prevented loss of striatal dopamine (DA) and its metabolite DOPAC. Dutasteride decreased effects of MPTP on striatal dopamine transporter (DAT), vesicular monoamine transporter 2 (VMAT2) and D2 DA receptor specific binding while D1 receptor specific binding remained unchanged. Dutasteride enhanced DAT specific binding and the glycosylated form of DAT in intact mice. MPTP-lesioned mice had plasma and brain testosterone and dihydrotestosterone levels lower than control mice whereas progesterone and its metabolites (dihydroprogesterone, isopregnanolone and tetrahydroprogesterone) pathway showed increases. Dutasteride treatment by inhibiting transformation of progesterone and testosterone to its metabolites elevated plasma and brain concentrations of testosterone compared to MPTP mice and decreased DHT levels in intact mice. Plasma and brain estradiol levels were low and remained unchanged by MPTP and/or dutasteride treatment. Dutasteride treatment did not affect striatal phosphorylation of Akt and its downstream substrate GSK3β as well as phosphorylation of ERK1/2 in intact and MPTP lesioned MPTP mice. Striatal glial fibrillary acidic protein (GFAP) levels were markedly elevated in MPTP compared to control mice and dutasteride reduced GFAP levels in MPTP mice. Treatment with dutasteride post-lesion left unchanged striatal DA levels. These results suggest dutasteride as promising drug for PD neuroprotection.
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Affiliation(s)
- Nadhir Litim
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada; Faculty of Pharmacy, Laval University, Quebec City, Canada
| | - Marc Morissette
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada
| | - Donatella Caruso
- Department of Pharmacological and Biomolecular Sciences, Center of Excellence on Neurodegenerative Diseases, Università degli Studi di Milano, Milan, Italy
| | - Roberto C Melcangi
- Department of Pharmacological and Biomolecular Sciences, Center of Excellence on Neurodegenerative Diseases, Università degli Studi di Milano, Milan, Italy
| | - Thérèse Di Paolo
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada; Faculty of Pharmacy, Laval University, Quebec City, Canada.
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31
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Oerum S, Roovers M, Leichsenring M, Acquaviva-Bourdain C, Beermann F, Gemperle-Britschgi C, Fouilhoux A, Korwitz-Reichelt A, Bailey HJ, Droogmans L, Oppermann U, Sass JO, Yue WW. Novel patient missense mutations in the HSD17B10 gene affect dehydrogenase and mitochondrial tRNA modification functions of the encoded protein. Biochim Biophys Acta Mol Basis Dis 2017; 1863:3294-3302. [PMID: 28888424 DOI: 10.1016/j.bbadis.2017.09.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 08/16/2017] [Accepted: 09/05/2017] [Indexed: 10/18/2022]
Abstract
MRPP2 (also known as HSD10/SDR5C1) is a multifunctional protein that harbours both catalytic and non-catalytic functions. The protein belongs to the short-chain dehydrogenase/reductases (SDR) family and is involved in the catabolism of isoleucine in vivo and steroid metabolism in vitro. MRPP2 also moonlights in a complex with the MRPP1 (also known as TRMT10C) protein for N1-methylation of purines at position 9 of mitochondrial tRNA, and in a complex with MRPP1 and MRPP3 (also known as PRORP) proteins for 5'-end processing of mitochondrial precursor tRNA. Inherited mutations in the HSD17B10 gene encoding MRPP2 protein lead to a childhood disorder characterised by progressive neurodegeneration, cardiomyopathy or both. Here we report two patients with novel missense mutations in the HSD17B10 gene (c.34G>C and c.526G>A), resulting in the p.V12L and p.V176M substitutions. Val12 and Val176 are highly conserved residues located at different regions of the MRPP2 structure. Recombinant mutant proteins were expressed and characterised biochemically to investigate their effects towards the functions of MRPP2 and associated complexes in vitro. Both mutant proteins showed significant reduction in the dehydrogenase, methyltransferase and tRNA processing activities compared to wildtype, associated with reduced stability for protein with p.V12L, whereas the protein carrying p.V176M showed impaired kinetics and complex formation. This study therefore identified two distinctive molecular mechanisms to explain the biochemical defects for the novel missense patient mutations.
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Affiliation(s)
- Stephanie Oerum
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Martine Roovers
- Institut de Recherches Microbiologiques Jean-Marie Wiame, Bruxelles, Belgium
| | - Michael Leichsenring
- Department for Children and Adolescent Medicine, Ulm University Medical School, Ulm, Germany
| | - Cécile Acquaviva-Bourdain
- Groupement Hospitalier Est, Centre de Biologie Est, Service Maladies Héréditaires du Métabolisme, Bron, France
| | - Frauke Beermann
- University of Freiburg Children's Hospital, Laboratory of Clinical Biochemistry and Metabolism, Freiburg, Germany
| | - Corinne Gemperle-Britschgi
- University Children's Hospital and Children's Research Center, Clinical Chemistry & Biochemistry, Zürich, Switzerland
| | - Alain Fouilhoux
- Centre de Référence des Maladies Héréditaires du Métabolisme, HCL, Bron, France
| | - Anne Korwitz-Reichelt
- Bonn-Rhein-Sieg University of Applied Sciences, Department of Natural Sciences, von-Liebig-Str. 20, 53359 Rheinbach, Germany
| | - Henry J Bailey
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Louis Droogmans
- Laboratoire de Microbiologie, Universite libre de Bruxelles, Belgium
| | - Udo Oppermann
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, OX3 7DQ Oxford, UK; Botnar Research Centre, NIHR Oxford Biomedical Research Unit, Oxford, UK
| | - Jörn Oliver Sass
- University of Freiburg Children's Hospital, Laboratory of Clinical Biochemistry and Metabolism, Freiburg, Germany; University Children's Hospital and Children's Research Center, Clinical Chemistry & Biochemistry, Zürich, Switzerland; Bonn-Rhein-Sieg University of Applied Sciences, Department of Natural Sciences, von-Liebig-Str. 20, 53359 Rheinbach, Germany.
| | - Wyatt W Yue
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, OX3 7DQ Oxford, UK.
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32
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Bohnsack MT, Sloan KE. The mitochondrial epitranscriptome: the roles of RNA modifications in mitochondrial translation and human disease. Cell Mol Life Sci 2017; 75:241-260. [PMID: 28752201 PMCID: PMC5756263 DOI: 10.1007/s00018-017-2598-6] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 07/08/2017] [Accepted: 07/17/2017] [Indexed: 11/28/2022]
Abstract
Mitochondrial protein synthesis is essential for the production of components of the oxidative phosphorylation system. RNA modifications in the mammalian mitochondrial translation apparatus play key roles in facilitating mitochondrial gene expression as they enable decoding of the non-conventional genetic code by a minimal set of tRNAs, and efficient and accurate protein synthesis by the mitoribosome. Intriguingly, recent transcriptome-wide analyses have also revealed modifications in mitochondrial mRNAs, suggesting that the concept of dynamic regulation of gene expression by the modified RNAs (the “epitranscriptome”) extends to mitochondria. Furthermore, it has emerged that defects in RNA modification, arising from either mt-DNA mutations or mutations in nuclear-encoded mitochondrial modification enzymes, underlie multiple mitochondrial diseases. Concomitant advances in the identification of the mitochondrial RNA modification machinery and recent structural views of the mitochondrial translation apparatus now allow the molecular basis of such mitochondrial diseases to be understood on a mechanistic level.
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Affiliation(s)
- Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
- Göttingen Centre for Molecular Biosciences, University of Göttingen, Justus-von-Liebig-Weg 11, 37077, Göttingen, Germany.
| | - Katherine E Sloan
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
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33
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Periodontal Ehlers-Danlos Syndrome Is Caused by Mutations in C1R and C1S, which Encode Subcomponents C1r and C1s of Complement. Am J Hum Genet 2016; 99:1005-1014. [PMID: 27745832 PMCID: PMC5097948 DOI: 10.1016/j.ajhg.2016.08.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 08/26/2016] [Indexed: 12/31/2022] Open
Abstract
Periodontal Ehlers-Danlos syndrome (pEDS) is an autosomal-dominant disorder characterized by early-onset periodontitis leading to premature loss of teeth, joint hypermobility, and mild skin findings. A locus was mapped to an approximately 5.8 Mb region at 12p13.1 but no candidate gene was identified. In an international consortium we recruited 19 independent families comprising 107 individuals with pEDS to identify the locus, characterize the clinical details in those with defined genetic causes, and try to understand the physiological basis of the condition. In 17 of these families, we identified heterozygous missense or in-frame insertion/deletion mutations in C1R (15 families) or C1S (2 families), contiguous genes in the mapped locus that encode subunits C1r and C1s of the first component of the classical complement pathway. These two proteins form a heterotetramer that then combines with six C1q subunits. Pathogenic variants involve the subunit interfaces or inter-domain hinges of C1r and C1s and are associated with intracellular retention and mild endoplasmic reticulum enlargement. Clinical features of affected individuals in these families include rapidly progressing periodontitis with onset in the teens or childhood, a previously unrecognized lack of attached gingiva, pretibial hyperpigmentation, skin and vascular fragility, easy bruising, and variable musculoskeletal symptoms. Our findings open a connection between the inflammatory classical complement pathway and connective tissue homeostasis.
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34
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Liao Y, Castello A, Fischer B, Leicht S, Föehr S, Frese CK, Ragan C, Kurscheid S, Pagler E, Yang H, Krijgsveld J, Hentze MW, Preiss T. The Cardiomyocyte RNA-Binding Proteome: Links to Intermediary Metabolism and Heart Disease. Cell Rep 2016; 16:1456-1469. [PMID: 27452465 PMCID: PMC4977271 DOI: 10.1016/j.celrep.2016.06.084] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 04/06/2016] [Accepted: 06/07/2016] [Indexed: 11/30/2022] Open
Abstract
RNA functions through the dynamic formation of complexes with RNA-binding proteins (RBPs) in all clades of life. We determined the RBP repertoire of beating cardiomyocytic HL-1 cells by jointly employing two in vivo proteomic methods, mRNA interactome capture and RBDmap. Together, these yielded 1,148 RBPs, 391 of which are shared with all other available mammalian RBP repertoires, while 393 are thus far unique to cardiomyocytes. RBDmap further identified 568 regions of RNA contact within 368 RBPs. The cardiomyocyte mRNA interactome composition reflects their unique biology. Proteins with roles in cardiovascular physiology or disease, mitochondrial function, and intermediary metabolism are all highly represented. Notably, we identified 73 metabolic enzymes as RBPs. RNA-enzyme contacts frequently involve Rossmann fold domains with examples in evidence of both, mutual exclusivity of, or compatibility between RNA binding and enzymatic function. Our findings raise the prospect of previously hidden RNA-mediated regulatory interactions among cardiomyocyte gene expression, physiology, and metabolism. mRNA interactome capture and RBDmap reveal the cardiomyocyte RNA-binding proteome 1,148 RBPs are identified, 393 of which are thus far unique to cardiomyocytes Many cardiac RBPs have links to heart disease and mitochondrial metabolism Contacts of metabolic enzymes with RNA frequently involve Rossmann fold domains
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Affiliation(s)
- Yalin Liao
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research (JCSMR), The Australian National University, Acton (Canberra) ACT 2601, Australia
| | - Alfredo Castello
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Bernd Fischer
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Stefan Leicht
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Sophia Föehr
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Christian K Frese
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Chikako Ragan
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research (JCSMR), The Australian National University, Acton (Canberra) ACT 2601, Australia
| | - Sebastian Kurscheid
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research (JCSMR), The Australian National University, Acton (Canberra) ACT 2601, Australia
| | - Eloisa Pagler
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research (JCSMR), The Australian National University, Acton (Canberra) ACT 2601, Australia
| | - Hao Yang
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research (JCSMR), The Australian National University, Acton (Canberra) ACT 2601, Australia
| | - Jeroen Krijgsveld
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Matthias W Hentze
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Thomas Preiss
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research (JCSMR), The Australian National University, Acton (Canberra) ACT 2601, Australia; Victor Chang Cardiac Research Institute, Darlinghurst (Sydney), NSW 2010, Australia.
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Kristofikova Z, Ricny J, Vyhnalek M, Hort J, Laczo J, Sirova J, Klaschka J, Ripova D. Levels of 17β-Hydroxysteroid Dehydrogenase Type 10 in Cerebrospinal Fluid of People with Mild Cognitive Impairment and Various Types of Dementias. J Alzheimers Dis 2016; 48:105-14. [PMID: 26401932 DOI: 10.3233/jad-142898] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Overexpression of the mitochondrial enzyme 17β-hydroxysteroid dehydrogenase type 10 (17β-HSD10, which is also known as the intracellular amyloid-β peptide (Aβ) binding protein) is observed in cortical or hippocampal regions of patients with Alzheimer's disease (AD). It appears that 17β-HSD10 may play a role in the pathogenesis of AD. OBJECTIVE We investigated the possibility that levels of 17β-HSD10 in cerebrospinal fluid could be a prospective biomarker of AD. METHODS We estimated the enzyme levels in 161 people (15 non-demented controls, 52 people with mild cognitive impairment (MCI), 35 people with probable AD, or 59 people with other types of dementia) and compared them with those of Aβ(1- 42), tau, and phospho-tau. RESULTS We found significantly higher levels of 17β-HSD10 in people with MCI due to AD (to 109.9% ), with AD (to 120.0% ), or with other types of dementia (to 110.9% ) when compared to the control group. The sensitivity of the new biomarker to AD was 80.0% , and the specificity was 73.3% (compared to controls) or 52.5-59.1% (compared to other types of dementia). Results of multiple linear regression and of correlation analysis revealed AD-mediated changes in links between 17β-HSD10 and Mini Mental State Examination score. CONCLUSION It seems that changes in 17β-HSD10 start many years before symptom onset, analogous to those in Aβ1 - 42, tau, or phospho-tau and that the levels are a relatively highly sensitive but unfortunately less specific biomarker of AD. A role of 17β-HSD10 overexpression in AD is discussed.
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Affiliation(s)
| | - Jan Ricny
- National Institute of Mental Health, Klecany, Czech Republic
| | - Martin Vyhnalek
- Memory Disorders Clinic, Department of Neurology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague 5, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Jakub Hort
- Memory Disorders Clinic, Department of Neurology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague 5, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Jan Laczo
- Memory Disorders Clinic, Department of Neurology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague 5, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Jana Sirova
- National Institute of Mental Health, Klecany, Czech Republic
| | - Jan Klaschka
- Institute of Computer Science, Academy of Sciences, Praha 8, Czech Republic
| | - Daniela Ripova
- National Institute of Mental Health, Klecany, Czech Republic
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36
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Richardson A, Berry GT, Garganta C, Abbott MA. Hydroxysteroid 17-Beta Dehydrogenase Type 10 Disease in Siblings. JIMD Rep 2016; 32:25-32. [PMID: 27295195 PMCID: PMC5355379 DOI: 10.1007/8904_2016_547] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/11/2016] [Accepted: 02/12/2016] [Indexed: 01/30/2023] Open
Abstract
Hydroxysteroid 17-beta dehydrogenase type 10 (HSD10) deficiency (HSD10 disease) is a rare X-linked neurodegenerative condition caused by abnormalities in the HSD17B10 gene. A total of 10 mutations have been reported in the literature since 2000. Described phenotypes include a severe neonatal or progressive infantile form with hypotonia, choreoathetosis, seizures, cardiomyopathy, neurodegeneration, and death, as well as an attenuated form with variable regression. Here we present the second report of a c.194T>C (p.V65A) mutation in two half-brothers with a clinical phenotype characterized by neurodevelopmental delay, choreoathetosis, visual loss, cardiac findings, and behavioral abnormalities, with regressions now noted in the older sibling. Neither has experienced a metabolic crisis. Both of the siblings had normal tandem mass spectroscopy analysis of their newborn screening samples. The older brother's phenotype may be complicated by the presence of a 3q29 microduplication. Diagnosis requires a high index of suspicion, as the characteristic urine organic acid pattern may escape detection. The exact pathogenic mechanism of disease remains to be elucidated, but may involve the non-dehydrogenase functionalities of the HSD10 protein. Our report highlights clinical features of two patients with the less fulminant phenotype associated with a V65A mutation, compares the reported phenotypes to date, and reviews recent findings regarding the potential pathophysiology of this condition.Summary Sentence Hydroxysteroid 17-beta dehydrogenase type 10 (HSD10) disease (HSD10 disease) is a rare X-linked neurodegenerative condition with a variable clinical phenotype; diagnosis requires a high index of suspicion.
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Affiliation(s)
- Annely Richardson
- Department of Pediatrics, Baystate Children's Hospital, Springfield, MA, 01199, USA.
| | | | | | - Mary-Alice Abbott
- Department of Pediatrics, Baystate Children's Hospital, Springfield, MA, 01199, USA
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Metodiev M, Thompson K, Alston C, Morris A, He L, Assouline Z, Rio M, Bahi-Buisson N, Pyle A, Griffin H, Siira S, Filipovska A, Munnich A, Chinnery P, McFarland R, Rötig A, Taylor R. Recessive Mutations in TRMT10C Cause Defects in Mitochondrial RNA Processing and Multiple Respiratory Chain Deficiencies. Am J Hum Genet 2016; 98:993-1000. [PMID: 27132592 PMCID: PMC4863561 DOI: 10.1016/j.ajhg.2016.03.010] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/14/2016] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial disorders are clinically and genetically diverse, with mutations in mitochondrial or nuclear genes able to cause defects in mitochondrial gene expression. Recently, mutations in several genes encoding factors involved in mt-tRNA processing have been identified to cause mitochondrial disease. Using whole-exome sequencing, we identified mutations in TRMT10C (encoding the mitochondrial RNase P protein 1 [MRPP1]) in two unrelated individuals who presented at birth with lactic acidosis, hypotonia, feeding difficulties, and deafness. Both individuals died at 5 months after respiratory failure. MRPP1, along with MRPP2 and MRPP3, form the mitochondrial ribonuclease P (mt-RNase P) complex that cleaves the 5′ ends of mt-tRNAs from polycistronic precursor transcripts. Additionally, a stable complex of MRPP1 and MRPP2 has m1R9 methyltransferase activity, which methylates mt-tRNAs at position 9 and is vital for folding mt-tRNAs into their correct tertiary structures. Analyses of fibroblasts from affected individuals harboring TRMT10C missense variants revealed decreased protein levels of MRPP1 and an increase in mt-RNA precursors indicative of impaired mt-RNA processing and defective mitochondrial protein synthesis. The pathogenicity of the detected variants—compound heterozygous c.542G>T (p.Arg181Leu) and c.814A>G (p.Thr272Ala) changes in subject 1 and a homozygous c.542G>T (p.Arg181Leu) variant in subject 2—was validated by the functional rescue of mt-RNA processing and mitochondrial protein synthesis defects after lentiviral transduction of wild-type TRMT10C. Our study suggests that these variants affect MRPP1 protein stability and mt-tRNA processing without affecting m1R9 methyltransferase activity, identifying mutations in TRMT10C as a cause of mitochondrial disease and highlighting the importance of RNA processing for correct mitochondrial function.
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38
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Sen A, Karasik A, Shanmuganathan A, Mirkovic E, Koutmos M, Cox RT. Loss of the mitochondrial protein-only ribonuclease P complex causes aberrant tRNA processing and lethality in Drosophila. Nucleic Acids Res 2016; 44:6409-22. [PMID: 27131785 PMCID: PMC5291253 DOI: 10.1093/nar/gkw338] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 04/14/2016] [Indexed: 12/26/2022] Open
Abstract
Proteins encoded by mitochondrial DNA are translated using mitochondrially encoded tRNAs and rRNAs. As with nuclear encoded tRNAs, mitochondrial tRNAs must be processed to become fully functional. The mitochondrial form of ribonuclease P (mt:RNase P) is responsible for 5′-end maturation and is comprised of three proteins; mitochondrial RNase P protein (MRPP) 1 and 2 together with proteinaceous RNase P (PRORP). However, its mechanism and impact on development is not yet known. Using homology searches, we have identified the three proteins composing Drosophila mt:RNase P: Mulder (PRORP), Scully (MRPP2) and Roswell (MRPP1). Here, we show that each protein is essential and localizes with mitochondria. Furthermore, reducing levels of each causes mitochondrial deficits, which appear to be due at least in part to defective mitochondrial tRNA processing. Overexpressing two members of the complex, Mulder and Roswell, is also lethal, and in the case of Mulder, causes abnormal mitochondrial morphology. These data are the first evidence that defective mt:RNase P causes mitochondrial dysfunction, lethality and aberrant mitochondrial tRNA processing in vivo, underscoring its physiological importance. This in vivo mt:RNase P model will advance our understanding of how loss of mitochondrial tRNA processing causes tissue failure, an important aspect of human mitochondrial disease.
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Affiliation(s)
- Aditya Sen
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD, 20814, USA
| | - Agnes Karasik
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD, 20814, USA
| | | | | | - Markos Koutmos
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD, 20814, USA
| | - Rachel T Cox
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, MD, 20814, USA
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39
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Amberger A, Deutschmann AJ, Traunfellner P, Moser P, Feichtinger RG, Kofler B, Zschocke J. 17β-Hydroxysteroid dehydrogenase type 10 predicts survival of patients with colorectal cancer and affects mitochondrial DNA content. Cancer Lett 2016; 374:149-155. [PMID: 26884257 DOI: 10.1016/j.canlet.2016.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 02/03/2016] [Accepted: 02/04/2016] [Indexed: 02/04/2023]
Abstract
Mitochondrial energy production is reduced in tumor cells, and altered mitochondrial respiration contributes to tumor progression. Synthesis of proteins coded by mitochondrial DNA (mtDNA) requires the correct processing of long polycistronic precursor RNA molecules. Mitochondrial RNase P, composed of three different proteins (MRPP1, HSD10, and MRPP3), is necessary for correct RNA processing. Here we analyzed the role of RNase P proteins in colorectal cancer. High HSD10 expression was found in 28%; high MRPP1 expression in 40% of colorectal cancers, respectively. Expression of both proteins was not significantly associated with clinicopathological parameters. Survival analysis revealed that loss of HSD10 expression is associated with poor prognosis. Cox regression demonstrated that patients with high HSD10 tumors are at lower risk. High HSD10 expression was significantly associated with high mtDNA content in tumor tissue. A causal effect of HSD10 overexpression or knock down with increased or reduced mtDNA levels, respectively, was confirmed in tumor cell lines. Our data suggest that HSD10 plays a role in alterations of energy metabolism by regulating mtDNA content in colorectal carcinomas, and HSD10 protein analysis may be of prognostic value.
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Affiliation(s)
- Albert Amberger
- Division of Human Genetics, Medical University Innsbruck, Peter Mayr Straße 1, 6020 Innsbruck, Austria.
| | - Andrea J Deutschmann
- Division of Human Genetics, Medical University Innsbruck, Peter Mayr Straße 1, 6020 Innsbruck, Austria
| | - Pia Traunfellner
- Division of Human Genetics, Medical University Innsbruck, Peter Mayr Straße 1, 6020 Innsbruck, Austria
| | - Patrizia Moser
- Institute of General Pathology, Medical University Innsbruck, Müllerstraße 44, 6020 Innsbruck, Austria
| | - René G Feichtinger
- Laura-Bassi Centre of Expertise-THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University Salzburg, Müllner Hauptstraße 48, 5020 Salzburg, Austria
| | - Barbara Kofler
- Laura-Bassi Centre of Expertise-THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University Salzburg, Müllner Hauptstraße 48, 5020 Salzburg, Austria
| | - Johannes Zschocke
- Division of Human Genetics, Medical University Innsbruck, Peter Mayr Straße 1, 6020 Innsbruck, Austria.
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40
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Castello A, Hentze MW, Preiss T. Metabolic Enzymes Enjoying New Partnerships as RNA-Binding Proteins. Trends Endocrinol Metab 2015; 26:746-757. [PMID: 26520658 PMCID: PMC4671484 DOI: 10.1016/j.tem.2015.09.012] [Citation(s) in RCA: 183] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 09/26/2015] [Accepted: 09/28/2015] [Indexed: 12/21/2022]
Abstract
In the past century, few areas of biology advanced as much as our understanding of the pathways of intermediary metabolism. Initially considered unimportant in terms of gene regulation, crucial cellular fate changes, cell differentiation, or malignant transformation are now known to involve 'metabolic remodeling' with profound changes in the expression of many metabolic enzyme genes. This review focuses on the recent identification of RNA-binding activity of numerous metabolic enzymes. We discuss possible roles of this unexpected second activity in feedback gene regulation ('moonlighting') and/or in the control of enzymatic function. We also consider how metabolism-driven post-translational modifications could regulate enzyme-RNA interactions. Thus, RNA emerges as a new partner of metabolic enzymes with far-reaching possible consequences to be unraveled in the future.
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Affiliation(s)
- Alfredo Castello
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Matthias W Hentze
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
| | - Thomas Preiss
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Acton (Canberra), ACT 2601, Australia; Victor Chang Cardiac Research Institute, Darlinghurst (Sydney), New South Wales 2010, Australia
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41
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Boynton TO, Shimkets LJ. Myxococcus CsgA, Drosophila Sniffer, and human HSD10 are cardiolipin phospholipases. Genes Dev 2015; 29:1903-14. [PMID: 26338420 PMCID: PMC4579348 DOI: 10.1101/gad.268482.115] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/17/2015] [Indexed: 11/25/2022]
Abstract
Myxococcus xanthus development requires CsgA, a member of the short-chain alcohol dehydrogenase (SCAD) family of proteins. Boynton and Shimkets show that CsgA and SocA oxidize the 2′-OH glycerol moiety on cardiolipin and phosphatidylglycerol to produce diacylglycerol, dihydroxyacetone, and orthophosphate. SCADs that prevent neurodegenerative disorders, such as Drosophila Sniffer and human HSD17B10, oxidize cardiolipin with similar kinetic parameters. Myxococcus xanthus development requires CsgA, a member of the short-chain alcohol dehydrogenase (SCAD) family of proteins. We show that CsgA and SocA, a protein that can replace CsgA function in vivo, oxidize the 2′-OH glycerol moiety on cardiolipin and phosphatidylglycerol to produce diacylglycerol (DAG), dihydroxyacetone, and orthophosphate. A lipid extract enriched in DAGs from wild-type cells initiates development and lipid body production in a csgA mutant to bypass the mutational block. This novel phospholipase C-like reaction is widespread. SCADs that prevent neurodegenerative disorders, such as Drosophila Sniffer and human HSD10, oxidize cardiolipin with similar kinetic parameters. HSD10 exhibits a strong preference for cardiolipin with oxidized fatty acids. This activity is inhibited in the presence of the amyloid β peptide. Three HSD10 variants associated with neurodegenerative disorders are inactive with cardiolipin. We suggest that HSD10 protects humans from reactive oxygen species by removing damaged cardiolipin before it induces apoptosis.
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Affiliation(s)
- Tye O'Hara Boynton
- Department of Microbiology, University of Georgia, Athens, Georgia 30602, USA
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42
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Powell C, Kopajtich R, D’Souza AR, Rorbach J, Kremer L, Husain R, Dallabona C, Donnini C, Alston C, Griffin H, Pyle A, Chinnery P, Strom T, Meitinger T, Rodenburg R, Schottmann G, Schuelke M, Romain N, Haller R, Ferrero I, Haack T, Taylor R, Prokisch H, Minczuk M. TRMT5 Mutations Cause a Defect in Post-transcriptional Modification of Mitochondrial tRNA Associated with Multiple Respiratory-Chain Deficiencies. Am J Hum Genet 2015; 97:319-28. [PMID: 26189817 PMCID: PMC4573257 DOI: 10.1016/j.ajhg.2015.06.011] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/16/2015] [Indexed: 10/29/2022] Open
Abstract
Deficiencies in respiratory-chain complexes lead to a variety of clinical phenotypes resulting from inadequate energy production by the mitochondrial oxidative phosphorylation system. Defective expression of mtDNA-encoded genes, caused by mutations in either the mitochondrial or nuclear genome, represents a rapidly growing group of human disorders. By whole-exome sequencing, we identified two unrelated individuals carrying compound heterozygous variants in TRMT5 (tRNA methyltransferase 5). TRMT5 encodes a mitochondrial protein with strong homology to members of the class I-like methyltransferase superfamily. Both affected individuals presented with lactic acidosis and evidence of multiple mitochondrial respiratory-chain-complex deficiencies in skeletal muscle, although the clinical presentation of the two affected subjects was remarkably different; one presented in childhood with failure to thrive and hypertrophic cardiomyopathy, and the other was an adult with a life-long history of exercise intolerance. Mutations in TRMT5 were associated with the hypomodification of a guanosine residue at position 37 (G37) of mitochondrial tRNA; this hypomodification was particularly prominent in skeletal muscle. Deficiency of the G37 modification was also detected in human cells subjected to TRMT5 RNAi. The pathogenicity of the detected variants was further confirmed in a heterologous yeast model and by the rescue of the molecular phenotype after re-expression of wild-type TRMT5 cDNA in cells derived from the affected individuals. Our study highlights the importance of post-transcriptional modification of mitochondrial tRNAs for faithful mitochondrial function.
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43
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Mayr JA, Haack TB, Freisinger P, Karall D, Makowski C, Koch J, Feichtinger RG, Zimmermann FA, Rolinski B, Ahting U, Meitinger T, Prokisch H, Sperl W. Spectrum of combined respiratory chain defects. J Inherit Metab Dis 2015; 38:629-40. [PMID: 25778941 PMCID: PMC4493854 DOI: 10.1007/s10545-015-9831-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/20/2015] [Accepted: 02/23/2015] [Indexed: 01/22/2023]
Abstract
Inherited disorders of mitochondrial energy metabolism form a large and heterogeneous group of metabolic diseases. More than 250 gene defects have been reported to date and this number continues to grow. Mitochondrial diseases can be grouped into (1) disorders of oxidative phosphorylation (OXPHOS) subunits and their assembly factors, (2) defects of mitochondrial DNA, RNA and protein synthesis, (3) defects in the substrate-generating upstream reactions of OXPHOS, (4) defects in relevant cofactors and (5) defects in mitochondrial homeostasis. Deficiency of more than one respiratory chain enzyme is a common finding. Combined defects are found in 49 % of the known disease-causing genes of mitochondrial energy metabolism and in 57 % of patients with OXPHOS defects identified in our diagnostic centre. Combined defects of complexes I, III, IV and V are typically due to deficiency of mitochondrial DNA replication, RNA metabolism or translation. Defects in cofactors can result in combined defects of various combinations, and defects of mitochondrial homeostasis can result in a generalised decrease of all OXPHOS enzymes. Noteworthy, identification of combined defects can be complicated by different degrees of severity of each affected enzyme. Furthermore, even defects of single respiratory chain enzymes can result in combined defects due to aberrant formation of respiratory chain supercomplexes. Combined OXPHOS defects have a great variety of clinical manifestations in terms of onset, course severity and tissue involvement. They can present as classical encephalomyopathy but also with hepatopathy, nephropathy, haematologic findings and Perrault syndrome in a subset of disorders.
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Affiliation(s)
- Johannes A Mayr
- Department of Paediatrics, Paracelsus Medical University, SALK Salzburg, Salzburg, 5020, Austria,
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44
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Van Haute L, Pearce SF, Powell CA, D’Souza AR, Nicholls TJ, Minczuk M. Mitochondrial transcript maturation and its disorders. J Inherit Metab Dis 2015; 38:655-80. [PMID: 26016801 PMCID: PMC4493943 DOI: 10.1007/s10545-015-9859-z] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/27/2015] [Accepted: 04/29/2015] [Indexed: 11/03/2022]
Abstract
Mitochondrial respiratory chain deficiencies exhibit a wide spectrum of clinical presentations owing to defective mitochondrial energy production through oxidative phosphorylation. These defects can be caused by either mutations in the mitochondrial DNA (mtDNA) or mutations in nuclear genes coding for mitochondrially-targeted proteins. The underlying pathomechanisms can affect numerous pathways involved in mitochondrial biology including expression of mtDNA-encoded genes. Expression of the mitochondrial genes is extensively regulated at the post-transcriptional stage and entails nucleolytic cleavage of precursor RNAs, RNA nucleotide modifications, RNA polyadenylation, RNA quality and stability control. These processes ensure proper mitochondrial RNA (mtRNA) function, and are regulated by dedicated, nuclear-encoded enzymes. Recent growing evidence suggests that mutations in these nuclear genes, leading to incorrect maturation of RNAs, are a cause of human mitochondrial disease. Additionally, mutations in mtDNA-encoded genes may also affect RNA maturation and are frequently associated with human disease. We review the current knowledge on a subset of nuclear-encoded genes coding for proteins involved in mitochondrial RNA maturation, for which genetic variants impacting upon mitochondrial pathophysiology have been reported. Also, primary pathological mtDNA mutations with recognised effects upon RNA processing are described.
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Affiliation(s)
| | - Sarah F. Pearce
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge, CB2 0XY UK
| | | | - Aaron R. D’Souza
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge, CB2 0XY UK
| | - Thomas J. Nicholls
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge, CB2 0XY UK
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, Hills Road, Cambridge, CB2 0XY UK
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45
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Stewart JB, Alaei-Mahabadi B, Sabarinathan R, Samuelsson T, Gorodkin J, Gustafsson CM, Larsson E. Simultaneous DNA and RNA Mapping of Somatic Mitochondrial Mutations across Diverse Human Cancers. PLoS Genet 2015; 11:e1005333. [PMID: 26125550 PMCID: PMC4488357 DOI: 10.1371/journal.pgen.1005333] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 06/03/2015] [Indexed: 12/30/2022] Open
Abstract
Somatic mutations in the nuclear genome are required for tumor formation, but the functional consequences of somatic mitochondrial DNA (mtDNA) mutations are less understood. Here we identify somatic mtDNA mutations across 527 tumors and 14 cancer types, using an approach that takes advantage of evidence from both genomic and transcriptomic sequencing. We find that there is selective pressure against deleterious coding mutations, supporting that functional mitochondria are required in tumor cells, and also observe a strong mutational strand bias, compatible with endogenous replication-coupled errors as the major source of mutations. Interestingly, while allelic ratios in general were consistent in RNA compared to DNA, some mutations in tRNAs displayed strong allelic imbalances caused by accumulation of unprocessed tRNA precursors. The effect was explained by altered secondary structure, demonstrating that correct tRNA folding is a major determinant for processing of polycistronic mitochondrial transcripts. Additionally, the data suggest that tRNA clusters are preferably processed in the 3′ to 5′ direction. Our study gives insights into mtDNA function in cancer and answers questions regarding mitochondrial tRNA biogenesis that are difficult to address in controlled experimental systems. According to the so-called “tRNA punctuation model”, tRNA processing is key to generating all mature mitochondrial mRNAs. However, the process is difficult to study in vivo, since standard tools for genetic manipulation are not applicable to mitochondria. Here, we circumvent this problem by using a large compendium of naturally occurring genetic perturbations, derived from human tumor sequencing data. We identify somatic mitochondrial mutations across hundreds of human tumors using an approach that simultaneously takes advantage of both genomic and transcriptomic sequencing. This enables us to compare the allele frequency in DNA and RNA for each mutation. Our data reveals that some mutations in mitochondrial tRNAs are associated with strong accumulation of immature tRNA precursors, indicative of impaired tRNA mutaration. We find that intact tRNA secondary structure is a major requirement for correct maturation, and that mutations affecting tRNA folding can impair maturation of not only the affected tRNA, but also neighboring gene transcripts. Mutations in mitochondrial tRNAs underlie a range of disease conditions, and our findings may help to explain why mutations in the same tRNA can present different phenotypes. Our results additionally support that there is selective pressure against mutations affecting oxidative phosphorylation, showing that functional mitochondria are required in many tumor cells.
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Affiliation(s)
| | - Babak Alaei-Mahabadi
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Radhakrishnan Sabarinathan
- Center for non-coding RNA in Technology and Health, IKVH, University of Copenhagen, Frederiksberg, Denmark
| | - Tore Samuelsson
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jan Gorodkin
- Center for non-coding RNA in Technology and Health, IKVH, University of Copenhagen, Frederiksberg, Denmark
| | - Claes M. Gustafsson
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Erik Larsson
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- * E-mail:
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46
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Vilardo E, Rossmanith W. Molecular insights into HSD10 disease: impact of SDR5C1 mutations on the human mitochondrial RNase P complex. Nucleic Acids Res 2015; 43:5112-9. [PMID: 25925575 PMCID: PMC4446446 DOI: 10.1093/nar/gkv408] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 04/16/2015] [Indexed: 11/25/2022] Open
Abstract
SDR5C1 is an amino and fatty acid dehydrogenase/reductase, moonlighting as a component of human mitochondrial RNase P, which is the enzyme removing 5′-extensions of tRNAs, an early and crucial step in tRNA maturation. Moreover, a subcomplex of mitochondrial RNase P catalyzes the N1-methylation of purines at position 9, a modification found in most mitochondrial tRNAs and thought to stabilize their structure. Missense mutations in SDR5C1 cause a disease characterized by progressive neurodegeneration and cardiomyopathy, called HSD10 disease. We have investigated the effect of selected mutations on SDR5C1's functions. We show that pathogenic mutations impair SDR5C1-dependent dehydrogenation, tRNA processing and methylation. Some mutations disrupt the homotetramerization of SDR5C1 and/or impair its interaction with TRMT10C, the methyltransferase subunit of the mitochondrial RNase P complex. We propose that the structural and functional alterations of SDR5C1 impair mitochondrial RNA processing and modification, leading to the mitochondrial dysfunction observed in HSD10 patients.
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Affiliation(s)
- Elisa Vilardo
- Center for Anatomy & Cell Biology, Medical University of Vienna, 1090 Vienna, Austria
| | - Walter Rossmanith
- Center for Anatomy & Cell Biology, Medical University of Vienna, 1090 Vienna, Austria
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47
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Powell CA, Nicholls TJ, Minczuk M. Nuclear-encoded factors involved in post-transcriptional processing and modification of mitochondrial tRNAs in human disease. Front Genet 2015; 6:79. [PMID: 25806043 PMCID: PMC4354410 DOI: 10.3389/fgene.2015.00079] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 02/16/2015] [Indexed: 11/29/2022] Open
Abstract
The human mitochondrial genome (mtDNA) encodes 22 tRNAs (mt-tRNAs) that are necessary for the intraorganellar translation of the 13 mtDNA-encoded subunits of the mitochondrial respiratory chain complexes. Maturation of mt-tRNAs involves 5′ and 3′ nucleolytic excision from precursor RNAs, as well as extensive post-transcriptional modifications. Recent data suggest that over 7% of all mt-tRNA residues in mammals undergo post-transcriptional modification, with over 30 different modified mt-tRNA positions so far described. These processing and modification steps are necessary for proper mt-tRNA function, and are performed by dedicated, nuclear-encoded enzymes. Recent growing evidence suggests that mutations in these nuclear genes (nDNA), leading to incorrect maturation of mt-tRNAs, are a cause of human mitochondrial disease. Furthermore, mtDNA mutations in mt-tRNA genes, which may also affect mt-tRNA function, processing, and modification, are also frequently associated with human disease. In theory, all pathogenic mt-tRNA variants should be expected to affect only a single process, which is mitochondrial translation, albeit to various extents. However, the clinical manifestations of mitochondrial disorders linked to mutations in mt-tRNAs are extremely heterogeneous, ranging from defects of a single tissue to complex multisystem disorders. This review focuses on the current knowledge of nDNA coding for proteins involved in mt-tRNA maturation that have been linked to human mitochondrial pathologies. We further discuss the possibility that tissue specific regulation of mt-tRNA modifying enzymes could play an important role in the clinical heterogeneity observed for mitochondrial diseases caused by mutations in mt-tRNA genes.
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Affiliation(s)
- Christopher A Powell
- Mitochondrial Genetics, Mitochondrial Biology Unit, Medical Research Council, Cambridge, UK
| | - Thomas J Nicholls
- Mitochondrial Genetics, Mitochondrial Biology Unit, Medical Research Council, Cambridge, UK
| | - Michal Minczuk
- Mitochondrial Genetics, Mitochondrial Biology Unit, Medical Research Council, Cambridge, UK
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Chatfield KC, Coughlin CR, Friederich MW, Gallagher RC, Hesselberth JR, Lovell MA, Ofman R, Swanson MA, Thomas JA, Wanders RJA, Wartchow EP, Van Hove JLK. Mitochondrial energy failure in HSD10 disease is due to defective mtDNA transcript processing. Mitochondrion 2015; 21:1-10. [PMID: 25575635 DOI: 10.1016/j.mito.2014.12.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 12/26/2014] [Accepted: 12/29/2014] [Indexed: 11/27/2022]
Abstract
Muscle, heart and liver were analyzed in a male subject who succumbed to HSD10 disease. Respiratory chain enzyme analysis and BN-PAGE showed reduced activities and assembly of complexes I, III, IV, and V. The mRNAs of all RNase P subunits were preserved in heart and overexpressed in muscle, but MRPP2 protein was severely decreased. RNase P upregulation correlated with increased expression of mitochondrial biogenesis factors and preserved mitochondrial enzymes in muscle, but not in heart where this compensatory mechanism was incomplete. We demonstrate elevated amounts of unprocessed pre-tRNAs and mRNA transcripts encoding mitochondrial subunits indicating deficient RNase P activity. This study provides evidence of abnormal mitochondrial RNA processing causing mitochondrial energy failure in HSD10 disease.
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Affiliation(s)
- Kathryn C Chatfield
- Pediatric Cardiology, Children's Hospital of Colorado, University of Colorado School of Medicine, Aurora, CO, USA
| | - Curtis R Coughlin
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado, Aurora, CO, USA
| | - Marisa W Friederich
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado, Aurora, CO, USA
| | - Renata C Gallagher
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado, Aurora, CO, USA
| | - Jay R Hesselberth
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Mark A Lovell
- Department of Pathology, University of Colorado, Aurora, CO, USA; Department of Pathology, Children's Hospital Colorado, Aurora, CO, USA
| | - Rob Ofman
- Laboratory of Genetic Metabolic Diseases, Academic Medical Centre, Amsterdam, The Netherlands
| | - Michael A Swanson
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado, Aurora, CO, USA
| | - Janet A Thomas
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado, Aurora, CO, USA
| | - Ronald J A Wanders
- Laboratory of Genetic Metabolic Diseases, Academic Medical Centre, Amsterdam, The Netherlands
| | - Eric P Wartchow
- Department of Pathology, Children's Hospital Colorado, Aurora, CO, USA
| | - Johan L K Van Hove
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado, Aurora, CO, USA.
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49
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Fukao T, Akiba K, Goto M, Kuwayama N, Morita M, Hori T, Aoyama Y, Venkatesan R, Wierenga R, Moriyama Y, Hashimoto T, Usuda N, Murayama K, Ohtake A, Hasegawa Y, Shigematsu Y, Hasegawa Y. The first case in Asia of 2-methyl-3-hydroxybutyryl-CoA dehydrogenase deficiency (HSD10 disease) with atypical presentation. J Hum Genet 2014; 59:609-14. [PMID: 25231369 DOI: 10.1038/jhg.2014.79] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 04/24/2014] [Accepted: 08/20/2014] [Indexed: 11/09/2022]
Abstract
2-Methyl-3-hydroxybutyryl-CoA dehydrogenase (2M3HBD) deficiency (HSD10 disease) is a rare inborn error of metabolism, and <30 cases have been reported worldwide. This disorder is typically characterized by progressive neurodegenerative disease from 6 to 18 months of age. Here, we report the first patient with this disorder in Asia, with atypical clinical presentation. A 6-year-old boy, who had been well, presented with severe ketoacidosis following a 5-day history of gastroenteritis. Urinary organic acid analysis showed elevated excretion of 2-methyl-3-hydroxybutyrate and tiglylglycine. He was tentatively diagnosed with β-ketothiolase (T2) deficiency. However, repeated enzyme assays using lymphocytes showed normal T2 activity and no T2 mutation was found. Instead, a hemizygous c.460G>A (p.A154T) mutation was identified in the HSD17B10 gene. This mutation was not found in 258 alleles from Japanese subjects (controls). A normal level of the HSD17B10 protein was found by immunoblot analysis but no 2M3HBD enzyme activity was detected in enzyme assays using the patient's fibroblasts. These data confirmed that this patient was affected with HSD10 disease. He has had no neurological regression until now. His fibroblasts showed punctate and fragmented mitochondrial organization by MitoTracker staining and had relatively low respiratory chain complex IV activity to those of other complexes.
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Affiliation(s)
- Toshiyuki Fukao
- 1] Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan [2] Medical Information Sciences Division, United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, Japan
| | - Kazuhisa Akiba
- Department of General Pediatrics, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Masahiro Goto
- Department of Endocrinology and Metabolism, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Nobuki Kuwayama
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Mikiko Morita
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Tomohiro Hori
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Yuka Aoyama
- Medical Information Sciences Division, United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, Japan
| | - Rajaram Venkatesan
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Rik Wierenga
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Yohsuke Moriyama
- Department of Anatomy and Cell Biology, Fujita Health University School of Medicine, Toyoake, Japan
| | - Takashi Hashimoto
- Department of Anatomy and Cell Biology, Fujita Health University School of Medicine, Toyoake, Japan
| | - Nobuteru Usuda
- Department of Anatomy and Cell Biology, Fujita Health University School of Medicine, Toyoake, Japan
| | - Kei Murayama
- Department of Metabolism, Chiba Children's Hospital, Chiba, Japan
| | - Akira Ohtake
- 1] Department of Endocrinology and Metabolism, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan [2] Department of Pediatrics, Saitama Medical University, Moroyama, Japan
| | - Yuki Hasegawa
- Department of Pediatrics, Shimane University School of Medicine, Izumo, Japan
| | - Yosuke Shigematsu
- Department of Health Science, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Japan
| | - Yukihiro Hasegawa
- Department of Endocrinology and Metabolism, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
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