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Morgenstern R. Kinetic Behavior of Glutathione Transferases: Understanding Cellular Protection from Reactive Intermediates. Biomolecules 2024; 14:641. [PMID: 38927045 PMCID: PMC11201704 DOI: 10.3390/biom14060641] [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: 05/14/2024] [Revised: 05/24/2024] [Accepted: 05/28/2024] [Indexed: 06/28/2024] Open
Abstract
Glutathione transferases (GSTs) are the primary catalysts protecting from reactive electrophile attack. In this review, the quantitative levels and distribution of glutathione transferases in relation to physiological function are discussed. The catalytic properties (random sequential) tell us that these enzymes have evolved to intercept reactive intermediates. High concentrations of enzymes (up to several hundred micromolar) ensure efficient protection. Individual enzyme molecules, however, turn over only rarely (estimated as low as once daily). The protection of intracellular protein and DNA targets is linearly proportional to enzyme levels. Any lowering of enzyme concentration, or inhibition, would thus result in diminished protection. It is well established that GSTs also function as binding proteins, potentially resulting in enzyme inhibition. Here the relevance of ligand inhibition and catalytic mechanisms, such as negative co-operativity, is discussed. There is a lack of knowledge pertaining to relevant ligand levels in vivo, be they exogenous or endogenous (e.g., bile acids and bilirubin). The stoichiometry of active sites in GSTs is well established, cytosolic enzyme dimers have two sites. It is puzzling that a third of the site's reactivity is observed in trimeric microsomal glutathione transferases (MGSTs). From a physiological point of view, such sub-stoichiometric behavior would appear to be wasteful. Over the years, a substantial amount of detailed knowledge on the structure, distribution, and mechanism of purified GSTs has been gathered. We still lack knowledge on exact cell type distribution and levels in vivo however, especially in relation to ligand levels, which need to be determined. Such knowledge must be gathered in order to allow mathematical modeling to be employed in the future, to generate a holistic understanding of reactive intermediate protection.
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Affiliation(s)
- Ralf Morgenstern
- Institute of Environmental Medicine, Division of Biochemical Toxicology, Karolinska Institutet, P.O. Box 210, SE-171 77 Stockholm, Sweden
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2
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Zhang J, Ye ZW, Bräutigam L, Chakraborty P, Luo Z, Culpepper J, Aslam M, Zhang L, Johansson K, Haeggström JZ, Xu J, Olsson M, Townsend DM, Mehrotra S, Morgenstern R, Tew KD. A role for microsomal glutathione transferase 1 in melanin biosynthesis and melanoma progression. J Biol Chem 2023; 299:104920. [PMID: 37321450 PMCID: PMC10372821 DOI: 10.1016/j.jbc.2023.104920] [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: 10/26/2022] [Revised: 03/31/2023] [Accepted: 05/06/2023] [Indexed: 06/17/2023] Open
Abstract
Recent advancements in the treatment of melanoma are encouraging, but there remains a need to identify additional therapeutic targets. We identify a role for microsomal glutathione transferase 1 (MGST1) in biosynthetic pathways for melanin and as a determinant of tumor progression. Knockdown (KD) of MGST1 depleted midline-localized, pigmented melanocytes in zebrafish embryos, while in both mouse and human melanoma cells, loss of MGST1 resulted in a catalytically dependent, quantitative, and linear depigmentation, associated with diminished conversion of L-dopa to dopachrome (eumelanin precursor). Melanin, especially eumelanin, has antioxidant properties, and MGST1 KD melanoma cells are under higher oxidative stress, with increased reactive oxygen species, decreased antioxidant capacities, reduced energy metabolism and ATP production, and lower proliferation rates in 3D culture. In mice, when compared to nontarget control, Mgst1 KD B16 cells had less melanin, more active CD8+ T cell infiltration, slower growing tumors, and enhanced animal survival. Thus, MGST1 is an integral enzyme in melanin synthesis and its inhibition adversely influences tumor growth.
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Affiliation(s)
- Jie Zhang
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, United States.
| | - Zhi-Wei Ye
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Lars Bräutigam
- Department of Comparative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Paramita Chakraborty
- Department of Surgery, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Zhenwu Luo
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - John Culpepper
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Muhammad Aslam
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Leilei Zhang
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, United States
| | | | - Jesper Z Haeggström
- Divisions of Biochemistry and Chemistry 2, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Jianqiang Xu
- School of Life and Pharmaceutical Sciences (LPS) & Panjin Institute of Industrial Technology (PIIT), Dalian University of Technology, Panjin, China
| | - Magnus Olsson
- Division of Biochemical Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Danyelle M Townsend
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Shikhar Mehrotra
- Department of Surgery, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Ralf Morgenstern
- Division of Biochemical Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Kenneth D Tew
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, United States.
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3
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Quanrud GM, Lyu Z, Balamurugan SV, Canizal C, Wu HT, Genereux JC. Cellular Exposure to Chloroacetanilide Herbicides Induces Distinct Protein Destabilization Profiles. ACS Chem Biol 2023; 18:1661-1676. [PMID: 37427419 PMCID: PMC10367052 DOI: 10.1021/acschembio.3c00338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 06/23/2023] [Indexed: 07/11/2023]
Abstract
Herbicides in the widely used chloroacetanilide class harbor a potent electrophilic moiety, which can damage proteins through nucleophilic substitution. In general, damaged proteins are subject to misfolding. Accumulation of misfolded proteins compromises cellular integrity by disrupting cellular proteostasis networks, which can further destabilize the cellular proteome. While direct conjugation targets can be discovered through affinity-based protein profiling, there are few approaches to probe how cellular exposure to toxicants impacts the stability of the proteome. We apply a quantitative proteomics methodology to identify chloroacetanilide-destabilized proteins in HEK293T cells based on their binding to the H31Q mutant of the human Hsp40 chaperone DNAJB8. We find that a brief cellular exposure to the chloroacetanilides acetochlor, alachlor, and propachlor induces misfolding of dozens of cellular proteins. These herbicides feature distinct but overlapping profiles of protein destabilization, highly concentrated in proteins with reactive cysteine residues. Consistent with the recent literature from the pharmacology field, reactivity is driven by neither inherent nucleophilic nor electrophilic reactivity but is idiosyncratic. We discover that propachlor induces a general increase in protein aggregation and selectively targets GAPDH and PARK7, leading to a decrease in their cellular activities. Hsp40 affinity profiling identifies a majority of propachlor targets identified by competitive activity-based protein profiling (ABPP), but ABPP can only identify about 10% of protein targets identified by Hsp40 affinity profiling. GAPDH is primarily modified by the direct conjugation of propachlor at a catalytic cysteine residue, leading to global destabilization of the protein. The Hsp40 affinity strategy is an effective technique to profile cellular proteins that are destabilized by cellular toxin exposure. Raw proteomics data is available through the PRIDE Archive at PXD030635.
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Affiliation(s)
- Guy M. Quanrud
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Ziqi Lyu
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Sunil V. Balamurugan
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Carolina Canizal
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Hoi-Ting Wu
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Joseph C. Genereux
- Department of Chemistry, University of California, Riverside, California 92521, United States
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Zhang J, Ye ZW, Morgenstern R, Townsend DM, Tew KD. Microsomal glutathione transferase 1 in cancer and the regulation of ferroptosis. Adv Cancer Res 2023; 160:107-132. [PMID: 37704286 PMCID: PMC10586476 DOI: 10.1016/bs.acr.2023.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
Microsomal glutathione transferase 1 (MGST1) is a member of the MAPEG family (membrane associated proteins in eicosanoid and glutathione metabolism), defined according to enzymatic activities, sequence motifs, and structural properties. MGST1 is a homotrimer which can bind three molecules of glutathione (GSH), with one modified to a thiolate anion displaying one-third-of-sites-reactivity. MGST1 has both glutathione transferase and peroxidase activities. Each is based on stabilizing the GSH thiolate in the same active site. MGST1 is abundant in the liver and displays a broad subcellular distribution with high levels in endoplasmic reticulum and mitochondrial membranes, consistent with a physiological role in protection from reactive electrophilic intermediates and oxidative stress. In this review paper, we particularly focus on recent advances made in understanding MGST1 activation, induction, broad subcellular distribution, and the role of MGST1 in apoptosis, ferroptosis, cancer progression, and therapeutic responses.
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Affiliation(s)
- Jie Zhang
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States.
| | - Zhi-Wei Ye
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States
| | - Ralf Morgenstern
- Institute of Environmental Medicine, Division of Biochemical Toxicology, Karolinska Institutet, Stockholm, Sweden
| | - Danyelle M Townsend
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Kenneth D Tew
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States
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Cebula M, Morgenstern R. Enzymology of reactive intermediate protection: kinetic analysis and temperature dependence of the mesophilic membrane protein catalyst MGST1. FEBS J 2023. [PMID: 36808476 DOI: 10.1111/febs.16754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/25/2023] [Accepted: 02/16/2023] [Indexed: 02/23/2023]
Abstract
Glutathione transferases (GSTs) are a class of phase II detoxifying enzymes catalysing the conjugation of glutathione (GSH) to endogenous and exogenous electrophilic molecules, with microsomal glutathione transferase 1 (MGST1) being one of its key members. MGST1 forms a homotrimer displaying third-of-the-sites-reactivity and up to 30-fold activation through modification of its Cys-49 residue. It has been shown that the steady-state behaviour of the enzyme at 5 °C can be accounted for by its pre-steady-state behaviour if the presence of a natively activated subpopulation (~ 10%) is assumed. Low temperature was used as the ligand-free enzyme is unstable at higher temperatures. Here, we overcame enzyme lability through stop-flow limited turnover analysis, whereby kinetic parameters at 30 °C were obtained. The acquired data are more physiologically relevant and enable confirmation of the previously established enzyme mechanism (at 5 °C), yielding parameters relevant for in vivo modelling. Interestingly, the kinetic parameter defining toxicant metabolism, kcat /KM , is strongly dependent on substrate reactivity (Hammett value 4.2), underscoring that glutathione transferases function as efficient and responsive interception catalysts. The temperature behaviour of the enzyme was also analysed. Both the KM and KD values decreased with increasing temperature, while the chemical step k3 displayed modest temperature dependence (Q10 : 1.1-1.2), mirrored in that of the nonenzymatic reaction (Q10 : 1.1-1.7). Unusually high Q10 values for GSH thiolate anion formation (k2 : 3.9), kcat (2.7-5.6) and kcat /KM (3.4-5.9) support that large structural transitions govern GSH binding and deprotonation, which limits steady-state catalysis.
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Affiliation(s)
- Marcus Cebula
- Division of Biochemical Toxicology, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden
| | - Ralf Morgenstern
- Division of Biochemical Toxicology, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden
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A High-Throughput Search for SFXN1 Physical Partners Led to the Identification of ATAD3, HSD10 and TIM50. BIOLOGY 2022; 11:biology11091298. [PMID: 36138777 PMCID: PMC9495560 DOI: 10.3390/biology11091298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/23/2022] [Accepted: 08/28/2022] [Indexed: 11/25/2022]
Abstract
Simple Summary Mitochondria are central players in cell fate and cell death. Indeed, mitochondrial dysfunction has been observed in many diseases, including neurodegenerative diseases. The activity of these organelles relies on numerous mitochondrial transporters, among which the sideroflexins have received little attention to date despite their emerging importance in human health. To better understand the cellular functions of these transporters and their associations with diseases, we herein investigated the molecular partners of one human sideroflexin, SFXN1. Several proteins capable of interacting with SFXN1 were identified, including ATAD3 and HSD10, two mitochondrial proteins linked to neuronal disorders. Abstract Sideroflexins (SFXN, SLC56) are a family of evolutionarily conserved mitochondrial carriers potentially involved in iron homeostasis. One member of the SFXN family is SFXN1, recently identified as a human mitochondrial serine transporter. However, little is known about the SFXN1 interactome, necessitating a high-throughput search to better characterize SFXN1 mitochondrial functions. Via co-immunoprecipitation followed by shotgun mass spectrometry (coIP-MS), we identified 96 putative SFXN1 interactors in the MCF7 human cell line. Our in silico analysis of the SFXN1 interactome highlights biological processes linked to mitochondrial organization, electron transport chains and transmembrane transport. Among the potential physical partners, ATAD3A and 17β-HSD10, two proteins associated with neurological disorders, were confirmed using different human cell lines. Nevertheless, further work will be needed to investigate the significance of these interactions.
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Choi BS, Kim DH, Kim MS, Park JC, Lee YH, Kim HJ, Jeong CB, Hagiwara A, Souissi S, Lee JS. The genome of the European estuarine calanoid copepod Eurytemora affinis: Potential use in molecular ecotoxicology. MARINE POLLUTION BULLETIN 2021; 166:112190. [PMID: 33711609 DOI: 10.1016/j.marpolbul.2021.112190] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 02/02/2021] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
In this study, we sequenced and assembled the genome of a European estuarine calanoid copepod using Oxford Nanopore PromethION and Illumina HiSeq 2500 platforms. The length of the assembled genome was 776.1 Mb with N50 = 474.9 kb (BUSCO 85.9%), and the genome consisted of 2473 contigs. A total of 18,014 genes were annotated and orthologous gene clusters were analyzed in comparison to other copepods. In addition, genome-wide identification of cytochrome P450s, glutathione S-transferases, and ATP-binding cassette transporters in E. affinis was performed to determine gene repertoire of these detoxification-related gene families. Results revealed the presence of species-specific gene inventories, indicating that these gene families have evolved through species-specific gene loss/expansion processes, possibly due to adaptation to different environmental stressors. Our study provides a new inventory of the European estuarine calanoid copepod E. affinis genome with emphasis on phase I, II, and III detoxification systems.
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Affiliation(s)
| | - Duck-Hyun Kim
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Min-Sub Kim
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Jun Chul Park
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Young Hwan Lee
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Hee-Jin Kim
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852-8521, Japan
| | - Chang-Bum Jeong
- Department of Marine Science, College of Nature Science, Incheon National University, Incheon 22012, South Korea
| | - Atsushi Hagiwara
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852-8521, Japan; Organization for Marine Science and Technology, Nagasaki University, Nagasaki 852-8521, Japan
| | - Sami Souissi
- Université de Lille, CNRS, Université du Littoral Côte d'Opale, UMR 8187 LOG, Laboratoire d'Océanologie et de Géosciences, Station marine de Wimereux, F-59000 Lille, France
| | - Jae-Seong Lee
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 16419, South Korea.
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Thulasingam M, Orellana L, Nji E, Ahmad S, Rinaldo-Matthis A, Haeggström JZ. Crystal structures of human MGST2 reveal synchronized conformational changes regulating catalysis. Nat Commun 2021; 12:1728. [PMID: 33741927 PMCID: PMC7979937 DOI: 10.1038/s41467-021-21924-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 02/16/2021] [Indexed: 11/23/2022] Open
Abstract
Microsomal glutathione S-transferase 2 (MGST2) produces leukotriene C4, key for intracrine signaling of endoplasmic reticulum (ER) stress, oxidative DNA damage and cell death. MGST2 trimer restricts catalysis to only one out of three active sites at a time, but the molecular basis is unknown. Here, we present crystal structures of human MGST2 combined with biochemical and computational evidence for a concerted mechanism, involving local unfolding coupled to global conformational changes that regulate catalysis. Furthermore, synchronized changes in the biconical central pore modulate the hydrophobicity and control solvent influx to optimize reaction conditions at the active site. These unique mechanistic insights pertain to other, structurally related, drug targets. Microsomal glutathione S-transferase 2 (MGST2) produces leukotriene C4, an intracrine mediator of cell death. Structural, biochemical and computational analyses of human MGST2 suggest a mechanism employed by the enzyme to restrict catalysis to only one active site within the MGST2 trimer.
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Affiliation(s)
- Madhuranayaki Thulasingam
- Department of Medical Biochemistry and Biophysics, Division of Chemistry II, Karolinska Institutet, Solnavägen 9, 171 65 Stockholm, Sweden.
| | - Laura Orellana
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16, 106 91 Stockholm, Sweden.,Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Emmanuel Nji
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16, 106 91 Stockholm, Sweden.,BioStruct-Africa, Stockholm, Sweden
| | - Shabbir Ahmad
- Department of Medical Biochemistry and Biophysics, Division of Chemistry II, Karolinska Institutet, Solnavägen 9, 171 65 Stockholm, Sweden.,Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Agnes Rinaldo-Matthis
- Department of Medical Biochemistry and Biophysics, Division of Chemistry II, Karolinska Institutet, Solnavägen 9, 171 65 Stockholm, Sweden
| | - Jesper Z Haeggström
- Department of Medical Biochemistry and Biophysics, Division of Chemistry II, Karolinska Institutet, Solnavägen 9, 171 65 Stockholm, Sweden.
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Thulasingam M, Haeggström JZ. Integral Membrane Enzymes in Eicosanoid Metabolism: Structures, Mechanisms and Inhibitor Design. J Mol Biol 2020; 432:4999-5022. [PMID: 32745470 DOI: 10.1016/j.jmb.2020.07.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 12/14/2022]
Abstract
Eicosanoids are potent lipid mediators involved in central physiological processes such as hemostasis, renal function and parturition. When formed in excess, eicosanoids become critical players in a range of pathological conditions, in particular pain, fever, arthritis, asthma, cardiovascular disease and cancer. Eicosanoids are generated via oxidative metabolism of arachidonic acid along the cyclooxygenase (COX) and lipoxygenase (LOX) pathways. Specific lipid species are formed downstream of COX and LOX by specialized synthases, some of which reside on the nuclear and endoplasmic reticulum, including mPGES-1, FLAP, LTC4 synthase, and MGST2. These integral membrane proteins are members of the family "membrane-associated proteins in eicosanoid and glutathione metabolism" (MAPEG). Here we focus on this enzyme family, which encompasses six human members typically catalyzing glutathione dependent transformations of lipophilic substrates. Enzymes of this family have evolved to combat the topographical challenge and unfavorable energetics of bringing together two chemically different substrates, from cytosol and lipid bilayer, for catalysis within a membrane environment. Thus, structural understanding of these enzymes are of utmost importance to unravel their molecular mechanisms, mode of substrate entry and product release, in order to facilitate novel drug design against severe human diseases.
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Affiliation(s)
- Madhuranayaki Thulasingam
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
| | - Jesper Z Haeggström
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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Abstract
The mercapturic acid pathway is a major route for the biotransformation of xenobiotic and endobiotic electrophilic compounds and their metabolites. Mercapturic acids (N-acetyl-l-cysteine S-conjugates) are formed by the sequential action of the glutathione transferases, γ-glutamyltransferases, dipeptidases, and cysteine S-conjugate N-acetyltransferase to yield glutathione S-conjugates, l-cysteinylglycine S-conjugates, l-cysteine S-conjugates, and mercapturic acids; these metabolites constitute a "mercapturomic" profile. Aminoacylases catalyze the hydrolysis of mercapturic acids to form cysteine S-conjugates. Several renal transport systems facilitate the urinary elimination of mercapturic acids; urinary mercapturic acids may serve as biomarkers for exposure to chemicals. Although mercapturic acid formation and elimination is a detoxication reaction, l-cysteine S-conjugates may undergo bioactivation by cysteine S-conjugate β-lyase. Moreover, some l-cysteine S-conjugates, particularly l-cysteinyl-leukotrienes, exert significant pathophysiological effects. Finally, some enzymes of the mercapturic acid pathway are described as the so-called "moonlighting proteins," catalytic proteins that exert multiple biochemical or biophysical functions apart from catalysis.
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Affiliation(s)
- Patrick E Hanna
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - M W Anders
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA
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11
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CryoEM: a crystals to single particles round-trip. Curr Opin Struct Biol 2019; 58:59-67. [DOI: 10.1016/j.sbi.2019.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 04/15/2019] [Accepted: 05/09/2019] [Indexed: 01/17/2023]
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12
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Yuan P, Huang S, Yang Z, Xie L, Wang K, Yang Y, Ran L, Yu Q, Song Z. UBXN1 interacts with the S1 protein of transmissible gastroenteritis coronavirus and plays a role in viral replication. Vet Res 2019; 50:28. [PMID: 31029162 PMCID: PMC6487014 DOI: 10.1186/s13567-019-0648-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/04/2019] [Indexed: 11/10/2022] Open
Abstract
Transmissible gastroenteritis coronavirus (TGEV) is an enteropathogenic coronavirus that causes diarrhea in pigs and is associated with high morbidity and mortality in sucking piglets. S1 is one of two protein domains in the spike (S) glycoprotein and is responsible for enteric tropism, sialic acid recognition, and host receptor binding. Although there has been extensive research on the S1 protein of TGEV, little is known about the intracellular role of TGEV-S1. In the present study, we used yeast two-hybrid screening of a cDNA library from porcine intestinal cells to identify proteins that interact with TGEV-S1. Among 120 positive clones from the library, 12 intracellular proteins were identified after sequencing and a BLAST search. These intracellular proteins are involved in protein synthesis and degradation, biological signal transduction, and negative control of signaling pathways. Using a glutathione-S-transferase (GST) pulldown assay and Co-IP, we found that UBXN1 interacts with the S1 protein. Here, we observed that TGEV infection led to increased UBXN1 expression levels during the late phase of infection in IPEC-J2 cells. Inhibition of UBXN1 in IPEC-J2 cells via siRNA interference significantly decreased the viral titer and downregulated the expression of S1. UBXN1 overexpression significantly increased the viral copy number. Additionally, we provided data suggesting that UBXN1 negatively regulates IFN-β expression after TGEV infection. Finally, our research indicated that UBXN1 plays a vital role in the process of TGEV infection, making it a candidate target for the development of a novel antiviral method.
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Affiliation(s)
- Peng Yuan
- Department of Veterinary Medicine, College of Animal Science, Southwest University, Chongqing, 402460, China
| | - Shilei Huang
- Department of Veterinary Medicine, College of Animal Science, Southwest University, Chongqing, 402460, China
| | - Zhou Yang
- Department of Veterinary Medicine, College of Animal Science, Southwest University, Chongqing, 402460, China
| | - Luyi Xie
- Department of Veterinary Medicine, College of Animal Science, Southwest University, Chongqing, 402460, China
| | - Kai Wang
- Department of Veterinary Medicine, College of Animal Science, Southwest University, Chongqing, 402460, China
| | - Yang Yang
- Department of Veterinary Medicine, College of Animal Science, Southwest University, Chongqing, 402460, China
| | - Lin Ran
- Department of Veterinary Medicine, College of Animal Science, Southwest University, Chongqing, 402460, China
| | - Qiuhan Yu
- Department of Veterinary Medicine, College of Animal Science, Southwest University, Chongqing, 402460, China
| | - Zhenhui Song
- Department of Veterinary Medicine, College of Animal Science, Southwest University, Chongqing, 402460, China.
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13
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Bräutigam L, Zhang J, Dreij K, Spahiu L, Holmgren A, Abe H, Tew KD, Townsend DM, Kelner MJ, Morgenstern R, Johansson K. MGST1, a GSH transferase/peroxidase essential for development and hematopoietic stem cell differentiation. Redox Biol 2018; 17:171-179. [PMID: 29702404 PMCID: PMC6006721 DOI: 10.1016/j.redox.2018.04.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/10/2018] [Accepted: 04/13/2018] [Indexed: 02/06/2023] Open
Abstract
We show for the first time that, in contrast to other glutathione transferases and peroxidases, deletion of microsomal glutathione transferase 1 (MGST1) in mice is embryonic lethal. To elucidate why, we used zebrafish development as a model system and found that knockdown of MGST1 produced impaired hematopoiesis. We show that MGST1 is expressed early during zebrafish development and plays an important role in hematopoiesis. High expression of MGST1 was detected in regions of active hematopoiesis and co-expressed with markers for hematopoietic stem cells. Further, morpholino-mediated knock-down of MGST1 led to a significant reduction of differentiated hematopoietic cells both from the myeloid and the lymphoid lineages. In fact, hemoglobin was virtually absent in the knock-down fish as revealed by diaminofluorene staining. The impact of MGST1 on hematopoiesis was also shown in hematopoietic stem/progenitor cells (HSPC) isolated from mice, where it was expressed at high levels. Upon promoting HSPC differentiation, lentiviral shRNA MGST1 knockdown significantly reduced differentiated, dedicated cells of the hematopoietic system. Further, MGST1 knockdown resulted in a significant lowering of mitochondrial metabolism and an induction of glycolytic enzymes, energetic states closely coupled to HSPC dynamics. Thus, the non-selenium, glutathione dependent redox regulatory enzyme MGST1 is crucial for embryonic development and for hematopoiesis in vertebrates.
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Affiliation(s)
- Lars Bräutigam
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Jie Zhang
- Departments of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Kristian Dreij
- Institute of Environmental Medicine, Division of Biochemical Toxicology, Karolinska Institutet, SE 17177 Stockholm, Sweden
| | - Linda Spahiu
- Institute of Environmental Medicine, Division of Biochemical Toxicology, Karolinska Institutet, SE 17177 Stockholm, Sweden
| | - Arne Holmgren
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Hiroshi Abe
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-Ku, Nagoya 464-8602, Japan
| | - Kenneth D Tew
- Departments of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Danyelle M Townsend
- Department of Pharmaceutical and Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Michael J Kelner
- Department of Pathology, University of California, San Diego, MC7721, La Jolla, CA 92093-7721, United States
| | - Ralf Morgenstern
- Institute of Environmental Medicine, Division of Biochemical Toxicology, Karolinska Institutet, SE 17177 Stockholm, Sweden.
| | - Katarina Johansson
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
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