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Ikeda Y, Fujii J. The Emerging Roles of γ-Glutamyl Peptides Produced by γ-Glutamyltransferase and the Glutathione Synthesis System. Cells 2023; 12:2831. [PMID: 38132151 PMCID: PMC10741565 DOI: 10.3390/cells12242831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/03/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
L-γ-Glutamyl-L-cysteinyl-glycine is commonly referred to as glutathione (GSH); this ubiquitous thiol plays essential roles in animal life. Conjugation and electron donation to enzymes such as glutathione peroxidase (GPX) are prominent functions of GSH. Cellular glutathione balance is robustly maintained via regulated synthesis, which is catalyzed via the coordination of γ-glutamyl-cysteine synthetase (γ-GCS) and glutathione synthetase, as well as by reductive recycling by glutathione reductase. A prevailing short supply of L-cysteine (Cys) tends to limit glutathione synthesis, which leads to the production of various other γ-glutamyl peptides due to the unique enzymatic properties of γ-GCS. Extracellular degradation of glutathione by γ-glutamyltransferase (GGT) is a dominant source of Cys for some cells. GGT catalyzes the hydrolytic removal of the γ-glutamyl group of glutathione or transfers it to amino acids or to dipeptides outside cells. Such processes depend on an abundance of acceptor substrates. However, the physiological roles of extracellularly preserved γ-glutamyl peptides have long been unclear. The identification of γ-glutamyl peptides, such as glutathione, as allosteric modulators of calcium-sensing receptors (CaSRs) could provide insights into the significance of the preservation of γ-glutamyl peptides. It is conceivable that GGT could generate a new class of intercellular messaging molecules in response to extracellular microenvironments.
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Affiliation(s)
- Yoshitaka Ikeda
- Division of Molecular Cell Biology, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata City 990-9585, Japan
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Marjanovic A, Rozeboom HJ, de Vries MS, Mayer C, Otzen M, Wijma HJ, Janssen DB. Catalytic and structural properties of ATP-dependent caprolactamase from Pseudomonas jessenii. Proteins 2021; 89:1079-1098. [PMID: 33826169 PMCID: PMC8453981 DOI: 10.1002/prot.26082] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 03/04/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022]
Abstract
Caprolactamase is the first enzyme in the caprolactam degradation pathway of Pseudomonas jessenii. It is composed of two subunits (CapA and CapB) and sequence-related to other ATP-dependent enzymes involved in lactam hydrolysis, like 5-oxoprolinases and hydantoinases. Low sequence similarity also exists with ATP-dependent acetone- and acetophenone carboxylases. The caprolactamase was produced in Escherichia coli, isolated by His-tag affinity chromatography, and subjected to functional and structural studies. Activity toward caprolactam required ATP and was dependent on the presence of bicarbonate in the assay buffer. The hydrolysis product was identified as 6-aminocaproic acid. Quantum mechanical modeling indicated that the hydrolysis of caprolactam was highly disfavored (ΔG0 '= 23 kJ/mol), which explained the ATP dependence. A crystal structure showed that the enzyme exists as an (αβ)2 tetramer and revealed an ATP-binding site in CapA and a Zn-coordinating site in CapB. Mutations in the ATP-binding site of CapA (D11A and D295A) significantly reduced product formation. Mutants with substitutions in the metal binding site of CapB (D41A, H99A, D101A, and H124A) were inactive and less thermostable than the wild-type enzyme. These residues proved to be essential for activity and on basis of the experimental findings we propose possible mechanisms for ATP-dependent lactam hydrolysis.
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Affiliation(s)
- Antonija Marjanovic
- Biotransformation and Biocatalysis, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
| | - Henriëtte J. Rozeboom
- Biotransformation and Biocatalysis, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
| | - Meintje S. de Vries
- Biotransformation and Biocatalysis, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
| | - Clemens Mayer
- Biomolecular Chemistry and Catalysis, Stratingh Institute for ChemistryUniversity of GroningenGroningenThe Netherlands
| | - Marleen Otzen
- Biotransformation and Biocatalysis, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
| | | | - Dick B. Janssen
- Biotransformation and Biocatalysis, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
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Rumping L, Vringer E, Houwen RHJ, van Hasselt PM, Jans JJM, Verhoeven‐Duif NM. Inborn errors of enzymes in glutamate metabolism. J Inherit Metab Dis 2020; 43:200-215. [PMID: 31603991 PMCID: PMC7078983 DOI: 10.1002/jimd.12180] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 10/01/2019] [Accepted: 10/04/2019] [Indexed: 12/29/2022]
Abstract
Glutamate is involved in a variety of metabolic pathways. We reviewed the literature on genetic defects of enzymes that directly metabolise glutamate, leading to inborn errors of glutamate metabolism. Seventeen genetic defects of glutamate metabolising enzymes have been reported, of which three were only recently identified. These 17 defects affect the inter-conversion of glutamine and glutamate, amino acid metabolism, ammonia detoxification, and glutathione metabolism. We provide an overview of the clinical and biochemical phenotypes of these rare defects in an effort to ease their recognition. By categorising these by biochemical pathway, we aim to create insight into the contributing role of deviant glutamate and glutamine levels to the pathophysiology. For those disorders involving the inter-conversion of glutamine and glutamate, these deviant levels are postulated to play a pivotal pathophysiologic role. For the other IEM however-with the exception of urea cycle defects-abnormal glutamate and glutamine concentrations were rarely reported. To create insight into the clinical consequences of disturbed glutamate metabolism-rather than individual glutamate and glutamine levels-the prevalence of phenotypic abnormalities within the 17 IEM was compared to their prevalence within all Mendelian disorders and subsequently all disorders with metabolic abnormalities notated in the Human Phenotype Ontology (HPO) database. For this, a hierarchical database of all phenotypic abnormalities of the 17 defects in glutamate metabolism based on HPO was created. A neurologic phenotypic spectrum of developmental delay, ataxia, seizures, and hypotonia are common in the inborn errors of enzymes in glutamate metabolism. Additionally, ophthalmologic and skin abnormalities are often present, suggesting that disturbed glutamate homeostasis affects tissues of ectodermal origin: brain, eye, and skin. Reporting glutamate and glutamine concentrations in patients with inborn errors of glutamate metabolism would provide additional insight into the pathophysiology.
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Affiliation(s)
- Lynne Rumping
- Department of GeneticsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
- Center for Molecular MedicineUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
- Department of PediatricsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
| | - Esmee Vringer
- Department of GeneticsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
| | - Roderick H. J. Houwen
- Department of PediatricsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
| | - Peter M. van Hasselt
- Department of PediatricsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
| | - Judith J. M. Jans
- Department of GeneticsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
- Center for Molecular MedicineUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
| | - Nanda M. Verhoeven‐Duif
- Department of GeneticsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
- Center for Molecular MedicineUniversity Medical Center Utrecht, Utrecht UniversityUtrechtthe Netherlands
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Maroilley T, Tarailo-Graovac M. Uncovering Missing Heritability in Rare Diseases. Genes (Basel) 2019; 10:E275. [PMID: 30987386 PMCID: PMC6523881 DOI: 10.3390/genes10040275] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 03/29/2019] [Accepted: 04/01/2019] [Indexed: 12/14/2022] Open
Abstract
The problem of 'missing heritability' affects both common and rare diseases hindering: discovery, diagnosis, and patient care. The 'missing heritability' concept has been mainly associated with common and complex diseases where promising modern technological advances, like genome-wide association studies (GWAS), were unable to uncover the complete genetic mechanism of the disease/trait. Although rare diseases (RDs) have low prevalence individually, collectively they are common. Furthermore, multi-level genetic and phenotypic complexity when combined with the individual rarity of these conditions poses an important challenge in the quest to identify causative genetic changes in RD patients. In recent years, high throughput sequencing has accelerated discovery and diagnosis in RDs. However, despite the several-fold increase (from ~10% using traditional to ~40% using genome-wide genetic testing) in finding genetic causes of these diseases in RD patients, as is the case in common diseases-the majority of RDs are also facing the 'missing heritability' problem. This review outlines the key role of high throughput sequencing in uncovering genetics behind RDs, with a particular focus on genome sequencing. We review current advances and challenges of sequencing technologies, bioinformatics approaches, and resources.
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Affiliation(s)
- Tatiana Maroilley
- Departments of Biochemistry, Molecular Biology and Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.
| | - Maja Tarailo-Graovac
- Departments of Biochemistry, Molecular Biology and Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada.
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Sass JO, Kalkan Uçar S, van Karnebeek CDM. From rodent heart to inborn errors of human metabolism. Mol Genet Metab 2018; 123:287-288. [PMID: 29429868 DOI: 10.1016/j.ymgme.2018.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 02/03/2018] [Indexed: 11/19/2022]
Affiliation(s)
- Jörn Oliver Sass
- Research Group Inborn Errors of Metabolism, Department of Natural Sciences, University of Applied Sciences, Rheinbach, Germany.
| | - Sema Kalkan Uçar
- Metabolism Unit, Department of Pediatrics, Ege University, Medical Faculty, Izmir, Turkey
| | - Clara D M van Karnebeek
- Centre for Molecular Medicine and Therapeutics, Vancouver, BC, Canada; Department of Pediatrics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada; Department of Pediatrics, Academic Medical Centre, Amsterdam, The Netherlands; Department of Clinical Genetics, Academic Medical Centre, Amsterdam, The Netherlands
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Niehaus TD, Elbadawi-Sidhu M, de Crécy-Lagard V, Fiehn O, Hanson AD. Discovery of a widespread prokaryotic 5-oxoprolinase that was hiding in plain sight. J Biol Chem 2017; 292:16360-16367. [PMID: 28830929 DOI: 10.1074/jbc.m117.805028] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/18/2017] [Indexed: 11/06/2022] Open
Abstract
5-Oxoproline (OP) is well-known as an enzymatic intermediate in the eukaryotic γ-glutamyl cycle, but it is also an unavoidable damage product formed spontaneously from glutamine and other sources. Eukaryotes metabolize OP via an ATP-dependent 5-oxoprolinase; most prokaryotes lack homologs of this enzyme (and the γ-glutamyl cycle) but are predicted to have some way to dispose of OP if its spontaneous formation in vivo is significant. Comparative analysis of prokaryotic genomes showed that the gene encoding pyroglutamyl peptidase, which removes N-terminal OP residues, clusters in diverse genomes with genes specifying homologs of a fungal lactamase (renamed prokaryotic 5-oxoprolinase A, pxpA) and homologs of allophanate hydrolase subunits (renamed pxpB and pxpC). Inactivation of Bacillus subtilis pxpA, pxpB, or pxpC genes slowed growth, caused OP accumulation in cells and medium, and prevented use of OP as a nitrogen source. Assays of cell lysates showed that ATP-dependent 5-oxoprolinase activity disappeared when pxpA, pxpB, or pxpC was inactivated. 5-Oxoprolinase activity could be reconstituted in vitro by mixing recombinant B. subtilis PxpA, PxpB, and PxpC proteins. In addition, overexpressing Escherichia coli pxpABC genes in E. coli increased 5-oxoprolinase activity in lysates ≥1700-fold. This work shows that OP is a major universal metabolite damage product and that OP disposal systems are common in all domains of life. Furthermore, it illustrates how easily metabolite damage and damage-control systems can be overlooked, even for central metabolites in model organisms.
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Affiliation(s)
- Thomas D Niehaus
- From the Horticultural Sciences Department, University of Florida, Gainesville, Florida 32611,
| | - Mona Elbadawi-Sidhu
- the West Coast Metabolomics Center, University of California Davis, Davis, California 95616, and
| | - Valérie de Crécy-Lagard
- the Microbiology and Cell Science Department, University of Florida, Gainesville, Florida 32611
| | - Oliver Fiehn
- the West Coast Metabolomics Center, University of California Davis, Davis, California 95616, and
| | - Andrew D Hanson
- From the Horticultural Sciences Department, University of Florida, Gainesville, Florida 32611,
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Tarailo-Graovac M, Wasserman WW, Van Karnebeek CDM. Impact of next-generation sequencing on diagnosis and management of neurometabolic disorders: current advances and future perspectives. Expert Rev Mol Diagn 2017; 17:307-309. [PMID: 28277145 DOI: 10.1080/14737159.2017.1293527] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Maja Tarailo-Graovac
- a Institute of Physiology and Biochemistry, Faculty of Biology , The University of Belgrade , Belgrade , Serbia.,b BC Children's Hospital Research Institute, Centre for Molecular Medicine and Therapeutics, and Department of Medical Genetics , University of British Columbia , Vancouver , Canada
| | - Wyeth W Wasserman
- b BC Children's Hospital Research Institute, Centre for Molecular Medicine and Therapeutics, and Department of Medical Genetics , University of British Columbia , Vancouver , Canada
| | - Clara D M Van Karnebeek
- c BC Children's Hospital Research Institute, Centre for Molecular Medicine and Therapeutics, Department of Pediatrics , University of British Columbia , Vancouver , Canada.,d Department of Pediatrics , Emma Children's Hospital, Academic Medical Centre , Amsterdam , The Netherlands
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