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Casas-Martinez JC, Samali A, McDonagh B. Redox regulation of UPR signalling and mitochondrial ER contact sites. Cell Mol Life Sci 2024; 81:250. [PMID: 38847861 PMCID: PMC11335286 DOI: 10.1007/s00018-024-05286-0] [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: 02/08/2024] [Revised: 04/11/2024] [Accepted: 05/18/2024] [Indexed: 06/13/2024]
Abstract
Mitochondria and the endoplasmic reticulum (ER) have a synergistic relationship and are key regulatory hubs in maintaining cell homeostasis. Communication between these organelles is mediated by mitochondria ER contact sites (MERCS), allowing the exchange of material and information, modulating calcium homeostasis, redox signalling, lipid transfer and the regulation of mitochondrial dynamics. MERCS are dynamic structures that allow cells to respond to changes in the intracellular environment under normal homeostatic conditions, while their assembly/disassembly are affected by pathophysiological conditions such as ageing and disease. Disruption of protein folding in the ER lumen can activate the Unfolded Protein Response (UPR), promoting the remodelling of ER membranes and MERCS formation. The UPR stress receptor kinases PERK and IRE1, are located at or close to MERCS. UPR signalling can be adaptive or maladaptive, depending on whether the disruption in protein folding or ER stress is transient or sustained. Adaptive UPR signalling via MERCS can increase mitochondrial calcium import, metabolism and dynamics, while maladaptive UPR signalling can result in excessive calcium import and activation of apoptotic pathways. Targeting UPR signalling and the assembly of MERCS is an attractive therapeutic approach for a range of age-related conditions such as neurodegeneration and sarcopenia. This review highlights the emerging evidence related to the role of redox mediated UPR activation in orchestrating inter-organelle communication between the ER and mitochondria, and ultimately the determination of cell function and fate.
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Affiliation(s)
- Jose C Casas-Martinez
- Discipline of Physiology, School of Medicine, University of Galway, Galway, Ireland
- Apoptosis Research Centre, University of Galway, Galway, Ireland
| | - Afshin Samali
- Apoptosis Research Centre, University of Galway, Galway, Ireland
- School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Brian McDonagh
- Discipline of Physiology, School of Medicine, University of Galway, Galway, Ireland.
- Apoptosis Research Centre, University of Galway, Galway, Ireland.
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2
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Stolyarchuk M, Botnari M, Tchertanov L. Vitamin K Epoxide Reductase Complex-Protein Disulphide Isomerase Assemblies in the Thiol-Disulphide Exchange Reactions: Portrayal of Precursor-to-Successor Complexes. Int J Mol Sci 2024; 25:4135. [PMID: 38673722 PMCID: PMC11050172 DOI: 10.3390/ijms25084135] [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: 03/06/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024] Open
Abstract
The human Vitamin K Epoxide Reductase Complex (hVKORC1), a key enzyme that converts vitamin K into the form necessary for blood clotting, requires for its activation the reducing equivalents supplied by its redox partner through thiol-disulphide exchange reactions. The functionally related molecular complexes assembled during this process have never been described, except for a proposed de novo model of a 'precursor' complex of hVKORC1 associated with protein disulphide isomerase (PDI). Using numerical approaches (in silico modelling and molecular dynamics simulation), we generated alternative 3D models for each molecular complex bonded either covalently or non-covalently. These models differ in the orientation of the PDI relative to hVKORC1 and in the cysteine residue involved in forming protein-protein disulphide bonds. Based on a comparative analysis of these models' shape, folding, and conformational dynamics, the most probable putative complexes, mimicking the 'precursor', 'intermediate', and 'successor' states, were suggested. In addition, we propose using these complexes to develop the 'allo-network drugs' necessary for treating blood diseases.
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Affiliation(s)
| | | | - Luba Tchertanov
- Centre Borelli, ENS Paris-Saclay, CNRS, Université Paris-Saclay, 4 Avenue des Sciences, 91190 Gif-sur-Yvette, France; (M.S.); (M.B.)
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3
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Moretti AIS, Baksheeva VE, Roman AY, De Bessa TC, Devred F, Kovacic H, Tsvetkov PO. Exploring the Influence of Zinc Ions on the Conformational Stability and Activity of Protein Disulfide Isomerase. Int J Mol Sci 2024; 25:2095. [PMID: 38396772 PMCID: PMC10889200 DOI: 10.3390/ijms25042095] [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: 11/28/2023] [Revised: 01/22/2024] [Accepted: 02/02/2024] [Indexed: 02/25/2024] Open
Abstract
The interplay between metal ion binding and the activity of thiol proteins, particularly within the protein disulfide isomerase family, remains an area of active investigation due to the critical role that these proteins play in many vital processes. This research investigates the interaction between recombinant human PDIA1 and zinc ions, focusing on the subsequent implications for PDIA1's conformational stability and enzymatic activity. Employing isothermal titration calorimetry and differential scanning calorimetry, we systematically compared the zinc binding capabilities of both oxidized and reduced forms of PDIA1 and assessed the structural consequences of this interaction. Our results demonstrate that PDIA1 can bind zinc both in reduced and oxidized states, but with significantly different stoichiometry and more pronounced conformational effects in the reduced form of PDIA1. Furthermore, zinc binding was observed to inhibit the catalytic activity of reduced-PDIA1, likely due to induced alterations in its conformation. These findings unveil a potential regulatory mechanism in PDIA1, wherein metal ion binding under reductive conditions modulates its activity. Our study highlights the potential role of zinc in regulating the catalytic function of PDIA1 through conformational modulation, suggesting a nuanced interplay between metal binding and protein stability in the broader context of cellular redox regulation.
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Affiliation(s)
- Ana Iochabel Soares Moretti
- Vascular Biology Laboratory (LIM64), School of Medicine, Heart Institute (InCor), Cardiopneumology Department, University of São Paulo, Campus Sao Paulo, Sao Paulo 05403-000, Brazil
| | - Viktoria E. Baksheeva
- Aix Marseille Univ, CNRS, UMR 7051, INP, Inst Neurophysiopathol, Fac Sciences Médicales et Paramédicales, 13005 Marseille, France (F.D.); (H.K.)
| | - Andrei Yu. Roman
- Aix Marseille Univ, CNRS, UMR 7051, INP, Inst Neurophysiopathol, Fac Sciences Médicales et Paramédicales, 13005 Marseille, France (F.D.); (H.K.)
| | - Tiphany Coralie De Bessa
- Vascular Biology Laboratory (LIM64), School of Medicine, Heart Institute (InCor), Cardiopneumology Department, University of São Paulo, Campus Sao Paulo, Sao Paulo 05403-000, Brazil
| | - François Devred
- Aix Marseille Univ, CNRS, UMR 7051, INP, Inst Neurophysiopathol, Fac Sciences Médicales et Paramédicales, 13005 Marseille, France (F.D.); (H.K.)
| | - Hervé Kovacic
- Aix Marseille Univ, CNRS, UMR 7051, INP, Inst Neurophysiopathol, Fac Sciences Médicales et Paramédicales, 13005 Marseille, France (F.D.); (H.K.)
| | - Philipp O. Tsvetkov
- Aix Marseille Univ, CNRS, UMR 7051, INP, Inst Neurophysiopathol, Fac Sciences Médicales et Paramédicales, 13005 Marseille, France (F.D.); (H.K.)
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Liu S, Shen G, Li W. Structural and cellular basis of vitamin K antagonism. J Thromb Haemost 2022; 20:1971-1983. [PMID: 35748323 DOI: 10.1111/jth.15800] [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: 05/02/2022] [Revised: 06/15/2022] [Accepted: 06/20/2022] [Indexed: 11/30/2022]
Abstract
Vitamin K antagonists (VKAs), such as warfarin, are oral anticoagulants widely used to treat and prevent thromboembolic diseases. Therapeutic use of these drugs requires frequent monitoring and dose adjustments, whereas overdose often causes severe bleeding. Addressing these drawbacks requires mechanistic understandings at cellular and structural levels. As the target of VKAs, vitamin K epoxide reductase (VKOR) generates the active, hydroquinone form of vitamin K, which in turn drives the γ-carboxylation of several coagulation factors required for their activity. Crystal structures revealed that VKAs inhibit VKOR via mimicking its catalytic process. At the active site, two strong hydrogen bonds that facilitate the catalysis also afford the binding specificity for VKAs. Binding of VKAs induces a global change from open to closed conformation. Similar conformational change is induced by substrate binding to promote an electron transfer process that reduces the VKOR active site. In the cellular environment, reducing partner proteins or small reducing molecules may afford electrons to maintain the VKOR activity. The catalysis and VKA inhibition require VKOR in different cellular redox states, explaining the complex kinetics behavior of VKAs. Recent studies also revealed the mechanisms underlying warfarin resistance, warfarin dose variation, and antidoting by vitamin K. These mechanistic understandings may lead to improved anticoagulation strategies targeting the vitamin K cycle.
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Affiliation(s)
- Shixuan Liu
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Guomin Shen
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
- Henan International Joint Laboratory of Thrombosis and Hemostasis, School of Basic Medical Science, Henan University of Science and Technology, Luoyang, China
- Department of Cell Biology, Harbin Medical University, Harbin, China
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
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5
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Functions and mechanisms of protein disulfide isomerase family in cancer emergence. Cell Biosci 2022; 12:129. [PMID: 35965326 PMCID: PMC9375924 DOI: 10.1186/s13578-022-00868-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/03/2022] [Indexed: 11/13/2022] Open
Abstract
The endoplasmic reticulum (ER) is a multi-layered organelle that is essential for the synthesis, folding, and structural maturation of almost one-third of the cellular proteome. It houses several resident proteins for these functions including the 21 members of the protein disulfide isomerase (PDI) family. The signature of proteins belonging to this family is the presence of the thioredoxin domain which mediates the formation, and rearrangement of disulfide bonds of substrate proteins in the ER. This process is crucial not only for the proper folding of ER substrates but also for maintaining a balanced ER proteostasis. The inclusion of new PDI members with a wide variety of structural determinants, size and enzymatic activity has brought additional epitomes of how PDI functions. Notably, some of them do not carry the thioredoxin domain and others have roles outside the ER. This also reflects that PDIs may have specialized functions and their functions are not limited within the ER. Large-scale expression datasets of human clinical samples have identified that the expression of PDI members is elevated in pathophysiological states like cancer. Subsequent functional interrogations using structural, molecular, cellular, and animal models suggest that some PDI members support the survival, progression, and metastasis of several cancer types. Herein, we review recent research advances on PDIs, vis-à-vis their expression, functions, and molecular mechanisms in supporting cancer growth with special emphasis on the anterior gradient (AGR) subfamily. Last, we posit the relevance and therapeutic strategies in targeting the PDIs in cancer.
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Matsuo Y. Introducing Thioredoxin-Related Transmembrane Proteins: Emerging Roles of Human TMX and Clinical Implications. Antioxid Redox Signal 2022; 36:984-1000. [PMID: 34465218 PMCID: PMC9127828 DOI: 10.1089/ars.2021.0187] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Significance: The presence of a large number of thioredoxin superfamily members suggests a complex mechanism of redox-based regulation in mammalian cells. However, whether these members are functionally redundant or play separate and distinct roles in each cellular compartment remains to be elucidated. Recent Advances: In the mammalian endoplasmic reticulum (ER), ∼20 thioredoxin-like proteins have been identified. Most ER oxidoreductases are soluble proteins located in the luminal compartment, whereas a small family of five thioredoxin-related transmembrane proteins (TMX) also reside in the ER membrane and play crucial roles with specialized functions. Critical Issues: In addition to the predicted function of ER protein quality control, several independent studies have suggested the diverse roles of TMX family proteins in the regulation of cellular processes, including calcium homeostasis, bioenergetics, and thiol-disulfide exchange in the extracellular space. Moreover, recent studies have provided evidence of their involvement in the pathogenesis of various diseases. Future Directions: Extensive research is required to unravel the physiological roles of TMX family proteins. Given that membrane-associated proteins are prime targets for drug discovery in a variety of human diseases, expanding our knowledge on the mechanistic details of TMX action on the cell membrane will provide the molecular basis for developing novel diagnostic and therapeutic approaches as a potent molecular target in a clinical setting. Antioxid. Redox Signal. 36, 984-1000.
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Affiliation(s)
- Yoshiyuki Matsuo
- Department of Human Stress Response Science, Institute of Biomedical Science, Kansai Medical University, Hirakata, Osaka, Japan
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Human Vitamin K Epoxide Reductase as a Target of Its Redox Protein. Int J Mol Sci 2022; 23:ijms23073899. [PMID: 35409257 PMCID: PMC8998853 DOI: 10.3390/ijms23073899] [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: 03/14/2022] [Revised: 03/29/2022] [Accepted: 03/30/2022] [Indexed: 02/05/2023] Open
Abstract
Human vitamin K epoxide reductase (hVKORC1) enzymatic activity requires an initial activation by a specific redox protein, a less studied step in the hVKORC1 vital cycle. Significant steric conditions must be met by enzymes, being that to adapt their configurations is mandatory for hVKORC1 activation. We studied, by molecular dynamics (MD) simulations, the folding and conformational plasticity of hVKORC1 in its inactive (fully oxidised) state using available structures, crystallographic and from de novo modelling. According to the obtained results, hVKORC1 is a modular protein composed of the stable transmembrane domain (TMD) and intrinsically disordered luminal (L) loop, possessing the great plasticity/adaptability required to perform various steps of the activation process. The docking (HADDOCK) of Protein Disulfide Isomerase (PDI) onto different hVKORC1 conformations clearly indicated that the most interpretable solutions were found on the target closed L-loop form, a prevalent conformation of hVKORC1’s oxidised state. We also suggest that the cleaved L-loop is an appropriate entity to study hVKORC1 recognition/activation by its redox protein. Additionally, the application of hVKORC1 (membrane protein) in aqueous solution is likely to prove to be very useful in practice in either in silico studies or in vitro experiments.
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Chetot T, Benoit E, Lambert V, Lattard V. Overexpression of protein disulfide isomerase enhances vitamin K epoxide reductase activity. Biochem Cell Biol 2022; 100:152-161. [PMID: 35007172 DOI: 10.1139/bcb-2021-0441] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Vitamin K epoxide reductase (VKOR) activity is catalyzed by the VKORC1 enzyme. It is the target of vitamin K antagonists (VKA). Numerous mutations of VKORC1 have been reported and have been suspected to confer resistance to VKA and/or affect its velocity. Nevertheless, the results between studies have been conflicting, the functional characterization of these mutations in a cell system being complex due to the interweaving of VKOR activity in the vitamin K cycle. In this study, a new cellular approach was implemented to globally evaluate the vitamin K cycle in the HEK293 cells. This global approach was based on the vitamin K quinone/vitamin K epoxide (K/KO) balance. In the presence of VKA or when the VKORC1/VKORC1L1 were knocked out, the K/KO balance decreased significantly due to an accumulation of vitamin KO. On the contrary, when VKORC1 was overexpressed, the balance remained unchanged, demonstrating a limitation of the VKOR activity. This limitation was shown to be due to an insufficient expression of the activation partner of VKORC1, as overexpressing the protein disulfide isomerase (PDI) overcomes the limitation. This study is the first to demonstrate a functional interaction between VKORC1 and the PDI enzyme.
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Affiliation(s)
| | | | | | - Virginie Lattard
- VetAgro Sup, 88622, USC1233 INRAe-VetAgroSup, Marcy-l'Etoile, France, 69280;
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9
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Aksoy A, Al Zaidi M, Repges E, Becher MU, Müller C, Oldenburg J, Zimmer S, Nickenig G, Tiyerili V. Vitamin K Epoxide Reductase Complex Subunit 1-Like 1 (VKORC1L1) Inhibition Induces a Proliferative and Pro-inflammatory Vascular Smooth Muscle Cell Phenotype. Front Cardiovasc Med 2021; 8:708946. [PMID: 34778390 PMCID: PMC8578699 DOI: 10.3389/fcvm.2021.708946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 10/05/2021] [Indexed: 01/07/2023] Open
Abstract
Background: Vitamin K antagonists (VKA) are known to promote adverse cardiovascular remodeling. Contrarily, vitamin K supplementation has been discussed to decelerate cardiovascular disease. The recently described VKOR-isoenzyme Vitamin K epoxide reductase complex subunit 1-like 1 (VKORC1L1) is involved in vitamin K maintenance and exerts antioxidant properties. In this study, we sought to investigate the role of VKORC1L1 in neointima formation and on vascular smooth muscle cell (VSMC) function. Methods and Results: Treatment of wild-type mice with Warfarin, a well-known VKA, increased maladaptive neointima formation after carotid artery injury. This was accompanied by reduced vascular mRNA expression of VKORC1L1. In vitro, Warfarin was found to reduce VKORC1L1 mRNA expression in VSMC. VKORC1L1-downregulation by siRNA promoted viability, migration and formation of reactive oxygen species. VKORC1L1 knockdown further increased expression of key markers of vascular inflammation (NFκB, IL-6). Additionally, downregulation of the endoplasmic reticulum (ER) membrane resident VKORC1L1 increased expression of the main ER Stress moderator, glucose-regulated protein 78 kDa (GRP78). Moreover, treatment with the ER Stress inducer tunicamycin promoted VKORC1L1, but not VKORC1 expression. Finally, we sought to investigate, if treatment with vitamin K can exert protective properties on VSMC. Thus, we examined effects of menaquinone-7 (MK7) on VSMC phenotype switch. MK7 treatment dose-dependently alleviated PDGF-induced proliferation and migration. In addition, we detected a reduction in expression of inflammatory and ER Stress markers. Conclusion: VKA treatment promotes neointima formation after carotid wire injury. In addition, VKA treatment reduces aortal VKORC1L1 mRNA expression. VKORC1L1 inhibition contributes to an adverse VSMC phenotype, while MK7 restores VSMC function. Thus, MK7 supplementation might be a feasible therapeutic option to modulate vitamin K- and VKORC1L1-mediated vasculoprotection.
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Affiliation(s)
- Adem Aksoy
- Department of Cardiology, Heart Centre, University of Bonn, Bonn, Germany
| | - Muntadher Al Zaidi
- Department of Cardiology, Heart Centre, University of Bonn, Bonn, Germany
| | - Elena Repges
- Department of Cardiology, Heart Centre, University of Bonn, Bonn, Germany
| | - Marc Ulrich Becher
- Department of Cardiology, Heart Centre, University of Bonn, Bonn, Germany
| | - Cornelius Müller
- Department of Cardiology, Heart Centre, University of Bonn, Bonn, Germany
| | - Johannes Oldenburg
- Institute of Experimental Haematology and Transfusion Medicine, University of Bonn, Bonn, Germany
| | - Sebastian Zimmer
- Department of Cardiology, Heart Centre, University of Bonn, Bonn, Germany
| | - Georg Nickenig
- Department of Cardiology, Heart Centre, University of Bonn, Bonn, Germany
| | - Vedat Tiyerili
- Department of Cardiology, Heart Centre, University of Bonn, Bonn, Germany
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Ershov P, Kaluzhskiy L, Mezentsev Y, Yablokov E, Gnedenko O, Ivanov A. Enzymes in the Cholesterol Synthesis Pathway: Interactomics in the Cancer Context. Biomedicines 2021; 9:biomedicines9080895. [PMID: 34440098 PMCID: PMC8389681 DOI: 10.3390/biomedicines9080895] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 02/06/2023] Open
Abstract
A global protein interactome ensures the maintenance of regulatory, signaling and structural processes in cells, but at the same time, aberrations in the repertoire of protein-protein interactions usually cause a disease onset. Many metabolic enzymes catalyze multistage transformation of cholesterol precursors in the cholesterol biosynthesis pathway. Cancer-associated deregulation of these enzymes through various molecular mechanisms results in pathological cholesterol accumulation (its precursors) which can be disease risk factors. This work is aimed at systematization and bioinformatic analysis of the available interactomics data on seventeen enzymes in the cholesterol pathway, encoded by HMGCR, MVK, PMVK, MVD, FDPS, FDFT1, SQLE, LSS, DHCR24, CYP51A1, TM7SF2, MSMO1, NSDHL, HSD17B7, EBP, SC5D, DHCR7 genes. The spectrum of 165 unique and 21 common protein partners that physically interact with target enzymes was selected from several interatomic resources. Among them there were 47 modifying proteins from different protein kinases/phosphatases and ubiquitin-protein ligases/deubiquitinases families. A literature search, enrichment and gene co-expression analysis showed that about a quarter of the identified protein partners was associated with cancer hallmarks and over-represented in cancer pathways. Our results allow to update the current fundamental view on protein-protein interactions and regulatory aspects of the cholesterol synthesis enzymes and annotate of their sub-interactomes in term of possible involvement in cancers that will contribute to prioritization of protein targets for future drug development.
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Redox and Inflammatory Signaling, the Unfolded Protein Response, and the Pathogenesis of Pulmonary Hypertension. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1304:333-373. [PMID: 34019276 DOI: 10.1007/978-3-030-68748-9_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Protein folding overload and oxidative stress disrupt endoplasmic reticulum (ER) homeostasis, generating reactive oxygen species (ROS) and activating the unfolded protein response (UPR). The altered ER redox state induces further ROS production through UPR signaling that balances the cell fates of survival and apoptosis, contributing to pulmonary microvascular inflammation and dysfunction and driving the development of pulmonary hypertension (PH). UPR-induced ROS production through ER calcium release along with NADPH oxidase activity results in endothelial injury and smooth muscle cell (SMC) proliferation. ROS and calcium signaling also promote endothelial nitric oxide (NO) synthase (eNOS) uncoupling, decreasing NO production and increasing vascular resistance through persistent vasoconstriction and SMC proliferation. C/EBP-homologous protein further inhibits eNOS, interfering with endothelial function. UPR-induced NF-κB activity regulates inflammatory processes in lung tissue and contributes to pulmonary vascular remodeling. Conversely, UPR-activated nuclear factor erythroid 2-related factor 2-mediated antioxidant signaling through heme oxygenase 1 attenuates inflammatory cytokine levels and protects against vascular SMC proliferation. A mutation in the bone morphogenic protein type 2 receptor (BMPR2) gene causes misfolded BMPR2 protein accumulation in the ER, implicating the UPR in familial pulmonary arterial hypertension pathogenesis. Altogether, there is substantial evidence that redox and inflammatory signaling associated with UPR activation is critical in PH pathogenesis.
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Nakada EM, Sun R, Fujii U, Martin JG. The Impact of Endoplasmic Reticulum-Associated Protein Modifications, Folding and Degradation on Lung Structure and Function. Front Physiol 2021; 12:665622. [PMID: 34122136 PMCID: PMC8188853 DOI: 10.3389/fphys.2021.665622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/23/2021] [Indexed: 12/15/2022] Open
Abstract
The accumulation of unfolded/misfolded proteins in the endoplasmic reticulum (ER) causes ER stress and induces the unfolded protein response (UPR) and other mechanisms to restore ER homeostasis, including translational shutdown, increased targeting of mRNAs for degradation by the IRE1-dependent decay pathway, selective translation of proteins that contribute to the protein folding capacity of the ER, and activation of the ER-associated degradation machinery. When ER stress is excessive or prolonged and these mechanisms fail to restore proteostasis, the UPR triggers the cell to undergo apoptosis. This review also examines the overlooked role of post-translational modifications and their roles in protein processing and effects on ER stress and the UPR. Finally, these effects are examined in the context of lung structure, function, and disease.
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Affiliation(s)
- Emily M. Nakada
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre (RI-MUHC), McGill University, Montreal, QC, Canada
- McGill University, Montreal, QC, Canada
| | - Rui Sun
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre (RI-MUHC), McGill University, Montreal, QC, Canada
- McGill University, Montreal, QC, Canada
| | - Utako Fujii
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre (RI-MUHC), McGill University, Montreal, QC, Canada
- McGill University, Montreal, QC, Canada
| | - James G. Martin
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre (RI-MUHC), McGill University, Montreal, QC, Canada
- McGill University, Montreal, QC, Canada
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Identification of the Primary Factors Determining theSpecificity of Human VKORC1 Recognition by Thioredoxin-Fold Proteins. Int J Mol Sci 2021; 22:ijms22020802. [PMID: 33466919 PMCID: PMC7835823 DOI: 10.3390/ijms22020802] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 12/28/2020] [Accepted: 01/11/2021] [Indexed: 01/25/2023] Open
Abstract
Redox (reduction-oxidation) reactions control many important biological processes in all organisms, both prokaryotes and eukaryotes. This reaction is usually accomplished by canonical disulphide-based pathways involving a donor enzyme that reduces the oxidised cysteine residues of a target protein, resulting in the cleavage of its disulphide bonds. Focusing on human vitamin K epoxide reductase (hVKORC1) as a target and on four redoxins (protein disulphide isomerase (PDI), endoplasmic reticulum oxidoreductase (ERp18), thioredoxin-related transmembrane protein 1 (Tmx1) and thioredoxin-related transmembrane protein 4 (Tmx4)) as the most probable reducers of VKORC1, a comparative in-silico analysis that concentrates on the similarity and divergence of redoxins in their sequence, secondary and tertiary structure, dynamics, intraprotein interactions and composition of the surface exposed to the target is provided. Similarly, hVKORC1 is analysed in its native state, where two pairs of cysteine residues are covalently linked, forming two disulphide bridges, as a target for Trx-fold proteins. Such analysis is used to derive the putative recognition/binding sites on each isolated protein, and PDI is suggested as the most probable hVKORC1 partner. By probing the alternative orientation of PDI with respect to hVKORC1, the functionally related noncovalent complex formed by hVKORC1 and PDI was found, which is proposed to be a first precursor to probe thiol-disulphide exchange reactions between PDI and hVKORC1.
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Okuda A, Matsusaki M, Masuda T, Morishima K, Sato N, Inoue R, Sugiyama M, Urade R. A novel soybean protein disulphide isomerase family protein possesses dithiol oxidation activity: identification and characterization of GmPDIL6. J Biochem 2020; 168:393-405. [PMID: 32458972 DOI: 10.1093/jb/mvaa058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/02/2020] [Indexed: 01/04/2023] Open
Abstract
Secretory and membrane proteins synthesized in the endoplasmic reticulum (ER) are folded with intramolecular disulphide bonds, viz. oxidative folding, catalysed by the protein disulphide isomerase (PDI) family proteins. Here, we identified a novel soybean PDI family protein, GmPDIL6. GmPDIL6 has a single thioredoxin-domain with a putative N-terminal signal peptide and an active centre (CKHC). Recombinant GmPDIL6 forms various oligomers binding iron. Oligomers with or without iron binding and monomers exhibited a dithiol oxidase activity level comparable to those of other soybean PDI family proteins. However, they displayed no disulphide reductase and extremely low oxidative refolding activity. Interestingly, GmPDIL6 was mainly expressed in the cotyledon during synthesis of seed storage proteins and GmPDIL6 mRNA was up-regulated under ER stress. GmPDIL6 may play a role in the formation of disulphide bonds in nascent proteins for oxidative folding in the ER.
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Affiliation(s)
- Aya Okuda
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Motonori Matsusaki
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Taro Masuda
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Ken Morishima
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Sennan-gun, Osaka 590-0494, Japan
| | - Nobuhiro Sato
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Sennan-gun, Osaka 590-0494, Japan
| | - Rintaro Inoue
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Sennan-gun, Osaka 590-0494, Japan
| | - Masaaki Sugiyama
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Sennan-gun, Osaka 590-0494, Japan
| | - Reiko Urade
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
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15
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Chen X, Li C, Jin DY, Ingram B, Hao Z, Bai X, Stafford DW, Hu K, Tie JK. A cell-based high-throughput screen identifies drugs that cause bleeding disorders by off-targeting the vitamin K cycle. Blood 2020; 136:898-908. [PMID: 32374827 PMCID: PMC7426647 DOI: 10.1182/blood.2019004234] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 04/16/2020] [Indexed: 12/11/2022] Open
Abstract
Drug-induced bleeding disorders contribute to substantial morbidity and mortality. Antithrombotic agents that cause unintended bleeding of obvious cause are relatively easy to control. However, the mechanisms of most drug-induced bleeding disorders are poorly understood, which makes intervention more difficult. As most bleeding disorders are associated with the dysfunction of coagulation factors, we adapted our recently established cell-based assay to identify drugs that affect the biosynthesis of active vitamin K-dependent (VKD) coagulation factors with possible adverse off-target results. The National Institutes of Health (NIH) Clinical Collection (NCC) library containing 727 drugs was screened, and 9 drugs were identified, including the most commonly prescribed anticoagulant warfarin. Bleeding complications associated with most of these drugs have been clinically reported, but the pathogenic mechanisms remain unclear. Further characterization of the 9 top-hit drugs on the inhibition of VKD carboxylation suggests that warfarin, lansoprazole, and nitazoxanide mainly target vitamin K epoxide reductase (VKOR), whereas idebenone, clofazimine, and AM404 mainly target vitamin K reductase (VKR) in vitamin K redox cycling. The other 3 drugs mainly affect vitamin K availability within the cells. The molecular mechanisms underlying the inactivation of VKOR and VKR by these drugs are clarified. Results from both cell-based and animal model studies suggest that the anticoagulation effect of drugs that target VKOR, but not VKR, can be rescued by the administration of vitamin K. These findings provide insights into the prevention and management of drug-induced bleeding disorders. The established cell-based, high-throughput screening approach provides a powerful tool for identifying new vitamin K antagonists that function as anticoagulants.
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Affiliation(s)
- Xuejie Chen
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC; and
| | - Caihong Li
- Research Center for Integrative Medicine, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Da-Yun Jin
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC; and
| | - Brian Ingram
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC; and
| | - Zhenyu Hao
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC; and
| | - Xue Bai
- Research Center for Integrative Medicine, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Darrel W Stafford
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC; and
| | - Keping Hu
- Research Center for Integrative Medicine, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Jian-Ke Tie
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC; and
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16
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Kanemura S, Sofia EF, Hirai N, Okumura M, Kadokura H, Inaba K. Characterization of the endoplasmic reticulum-resident peroxidases GPx7 and GPx8 shows the higher oxidative activity of GPx7 and its linkage to oxidative protein folding. J Biol Chem 2020; 295:12772-12785. [PMID: 32719007 DOI: 10.1074/jbc.ra120.013607] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/17/2020] [Indexed: 12/13/2022] Open
Abstract
Oxidative protein folding occurs primarily in the mammalian endoplasmic reticulum, enabled by a diverse network comprising more than 20 members of the protein disulfide isomerase (PDI) family and more than five PDI oxidases. Although the canonical disulfide bond formation pathway involving Ero1α and PDI has been well-studied so far, the physiological roles of the newly identified PDI oxidases, glutathione peroxidase-7 (GPx7) and -8 (GPx8), are only poorly understood. We here demonstrated that human GPx7 has much higher reactivity with H2O2 and hence greater PDI oxidation activity than human GPx8. The high reactivity of GPx7 is due to the presence of a catalytic tetrad at the redox-active site, which stabilizes the sulfenylated species generated upon the reaction with H2O2 Although it was previously postulated that GPx7 catalysis involved a highly reactive peroxidatic cysteine that can be sulfenylated by H2O2, we revealed that a resolving cysteine instead regulates the PDI oxidation activity of GPx7. We also determined that GPx7 formed complexes preferentially with PDI and P5 in H2O2-treated cells. Altogether, these results suggest that human GPx7 functions as an H2O2-dependent PDI oxidase in cells, whereas PDI oxidation may not be the central physiological role of human GPx8.
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Affiliation(s)
- Shingo Kanemura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira, Aoba-ku, Sendai, Miyagi, Japan.,School of Science and Technology, Kwansei Gakuin University, Gakuen, Sanda, Hyogo, Japan.,Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramaki, Aza, Aoba-ku, Sendai, Miyagi, Japan
| | - Elza Firdiani Sofia
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira, Aoba-ku, Sendai, Miyagi, Japan
| | - Naoya Hirai
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira, Aoba-ku, Sendai, Miyagi, Japan
| | - Masaki Okumura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira, Aoba-ku, Sendai, Miyagi, Japan.,Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramaki, Aza, Aoba-ku, Sendai, Miyagi, Japan
| | - Hiroshi Kadokura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira, Aoba-ku, Sendai, Miyagi, Japan
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira, Aoba-ku, Sendai, Miyagi, Japan
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17
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Petsophonsakul P, Furmanik M, Forsythe R, Dweck M, Schurink GW, Natour E, Reutelingsperger C, Jacobs M, Mees B, Schurgers L. Role of Vascular Smooth Muscle Cell Phenotypic Switching and Calcification in Aortic Aneurysm Formation. Arterioscler Thromb Vasc Biol 2019; 39:1351-1368. [PMID: 31144989 DOI: 10.1161/atvbaha.119.312787] [Citation(s) in RCA: 197] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Aortic aneurysm is a vascular disease whereby the ECM (extracellular matrix) of a blood vessel degenerates, leading to dilation and eventually vessel wall rupture. Recently, it was shown that calcification of the vessel wall is involved in both the initiation and progression of aneurysms. Changes in aortic wall structure that lead to aneurysm formation and vascular calcification are actively mediated by vascular smooth muscle cells. Vascular smooth muscle cells in a healthy vessel wall are termed contractile as they maintain vascular tone and remain quiescent. However, in pathological conditions they can dedifferentiate into a synthetic phenotype, whereby they secrete extracellular vesicles, proliferate, and migrate to repair injury. This process is called phenotypic switching and is often the first step in vascular pathology. Additionally, healthy vascular smooth muscle cells synthesize VKDPs (vitamin K-dependent proteins), which are involved in inhibition of vascular calcification. The metabolism of these proteins is known to be disrupted in vascular pathologies. In this review, we summarize the current literature on vascular smooth muscle cell phenotypic switching and vascular calcification in relation to aneurysm. Moreover, we address the role of vitamin K and VKDPs that are involved in vascular calcification and aneurysm. Visual Overview- An online visual overview is available for this article.
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Affiliation(s)
- Ploingarm Petsophonsakul
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands (P.P., M.F., C.R., L.S.)
| | - Malgorzata Furmanik
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands (P.P., M.F., C.R., L.S.)
| | - Rachael Forsythe
- Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (R.F., M.D.)
| | - Marc Dweck
- Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (R.F., M.D.)
| | - Geert Willem Schurink
- Department of Vascular Surgery (G.W.S., M.J., B.M.), Maastricht University Medical Center (MUMC), Maastricht, the Netherlands
| | - Ehsan Natour
- Department of Cardiovascular Surgery (E.N.), Maastricht University Medical Center (MUMC), Maastricht, the Netherlands.,European Vascular Center Aachen-Maastricht, Maastricht, the Netherlands (E.N., M.J., B.M.)
| | - Chris Reutelingsperger
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands (P.P., M.F., C.R., L.S.)
| | - Michael Jacobs
- Department of Vascular Surgery (G.W.S., M.J., B.M.), Maastricht University Medical Center (MUMC), Maastricht, the Netherlands.,European Vascular Center Aachen-Maastricht, Maastricht, the Netherlands (E.N., M.J., B.M.)
| | - Barend Mees
- Department of Vascular Surgery (G.W.S., M.J., B.M.), Maastricht University Medical Center (MUMC), Maastricht, the Netherlands.,European Vascular Center Aachen-Maastricht, Maastricht, the Netherlands (E.N., M.J., B.M.)
| | - Leon Schurgers
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands (P.P., M.F., C.R., L.S.)
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18
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Abstract
ABSTRACT
For most of the proteins synthesized in the endoplasmic reticulum (ER), disulfide bond formation accompanies protein folding in a process called oxidative folding. Oxidative folding is catalyzed by a number of enzymes, including the family of protein disulfide isomerases (PDIs), as well as other proteins that supply oxidizing equivalents to PDI family proteins, like ER oxidoreductin 1 (Ero1). Oxidative protein folding in the ER is a basic vital function, and understanding its molecular mechanism is critical for the application of plants as protein production tools. Here, I review the recent research and progress related to the enzymes involved in oxidative folding in the plant ER. Firstly, nine groups of plant PDI family proteins are introduced. Next, the enzymatic properties of plant Ero1 are described. Finally, the cooperative folding by multiple PDI family proteins and Ero1 is described.
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Affiliation(s)
- Reiko Urade
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
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19
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Zhang Z, Zhang L, Zhou L, Lei Y, Zhang Y, Huang C. Redox signaling and unfolded protein response coordinate cell fate decisions under ER stress. Redox Biol 2018; 25:101047. [PMID: 30470534 PMCID: PMC6859529 DOI: 10.1016/j.redox.2018.11.005] [Citation(s) in RCA: 215] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 11/05/2018] [Accepted: 11/07/2018] [Indexed: 02/05/2023] Open
Abstract
Endoplasmic reticulum (ER) is a dynamic organelle orchestrating the folding and post-translational maturation of almost all membrane proteins and most secreted proteins. These proteins synthesized in the ER, need to form disulfide bridge to acquire specific three-dimensional structures for function. The formation of disulfide bridge is mediated via protein disulfide isomerase (PDI) family and other oxidoreductases, which contribute to reactive oxygen species (ROS) generation and consumption in the ER. Therefore, redox regulation of ER is delicate and sensitive to perturbation. Deregulation in ER homeostasis, usually called ER stress, can provoke unfolded protein response (UPR) pathways with an aim to initially restore homeostasis by activating genes involved in protein folding and antioxidative machinery. Over time, however, activated UPR involves a variety of cellular signaling pathways which determine the state and fate of cell in large part (like autophagy, apoptosis, ferroptosis, inflammation, senescence, stemness, and cell cycle, etc.). This review will describe the regulation of UPR from the redox perspective in controlling the cell survival or death, emphasizing the redox modifications of UPR sensors/transducers in the ER.
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Affiliation(s)
- Zhe Zhang
- Department of Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, PR China
| | - Lu Zhang
- Department of Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, PR China
| | - Li Zhou
- Department of Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, PR China
| | - Yunlong Lei
- Department of Biochemistry and Molecular Biology, and Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, PR China
| | - Yuanyuan Zhang
- Department of Pharmacology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu 610041, PR China.
| | - Canhua Huang
- Department of Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, PR China.
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20
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Dahlberg S, Ede J, Schött U. Vitamin K and cancer. Scandinavian Journal of Clinical and Laboratory Investigation 2017; 77:555-567. [PMID: 28933567 DOI: 10.1080/00365513.2017.1379090] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Subclinical vitamin K deficits refer to carboxylation defects of different types of vitamin K-dependent hepatic and extrahepatic so-called Gla proteins without prolongation of the prothrombin time. This condition has been reported in different clinical situations due to insufficient supply or malabsorption of vitamin K as well as drug interactions. This review discusses the effects of different vitamin K subspecies on tumour growth and the possible anti-tumour effects of increased vitamin K intake. Blocking carboxylation of vitamin K-dependent proteins with warfarin anticoagulation - what are the risks/benefits for carcinogenesis? Previous studies on both heparin and low molecular weight heparin blocking of the vitamin K-dependent factors X and II have shown tumour suppressive effects. Vitamin K has anti-inflammatory effects that could also impact carcinogenesis, but little data exists on this subject.
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Affiliation(s)
- Sofia Dahlberg
- a Department of Anaesthesia and Intensive Care, Institution of Clinical Science Lund, Medical Faculty , Lund University , Lund , Sweden
| | - Jacob Ede
- a Department of Anaesthesia and Intensive Care, Institution of Clinical Science Lund, Medical Faculty , Lund University , Lund , Sweden
| | - Ulf Schött
- a Department of Anaesthesia and Intensive Care, Institution of Clinical Science Lund, Medical Faculty , Lund University , Lund , Sweden.,b Department of Anaesthesia and Intensive Care , Skåne University Hospital Lund , Lund , Sweden
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21
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Neal SE, Dabir DV, Wijaya J, Boon C, Koehler CM. Osm1 facilitates the transfer of electrons from Erv1 to fumarate in the redox-regulated import pathway in the mitochondrial intermembrane space. Mol Biol Cell 2017; 28:2773-2785. [PMID: 28814504 PMCID: PMC5638582 DOI: 10.1091/mbc.e16-10-0712] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 08/10/2017] [Accepted: 08/10/2017] [Indexed: 11/18/2022] Open
Abstract
Osm1 transfers electrons from fumarate to succinate and functions with Mia40 and Erv1 in the redox-regulated import pathway for proteins that form disulfide bonds in the mitochondrial intermembrane space. Expression of Osm1 and cytochrome c is reciprocally regulated, indicating that the cell has strategies to coordinate expression of terminal electron acceptors. Prokaryotes have aerobic and anaerobic electron acceptors for oxidative folding of periplasmic proteins. The mitochondrial intermembrane space has an analogous pathway with the oxidoreductase Mia40 and sulfhydryl oxidase Erv1, termed the mitochondrial intermembrane space assembly (MIA) pathway. The aerobic electron acceptors include oxygen and cytochrome c, but an acceptor that can function under anaerobic conditions has not been identified. Here we show that the fumarate reductase Osm1, which facilitates electron transfer from fumarate to succinate, fills this gap as a new electron acceptor. In addition to microsomes, Osm1 localizes to the mitochondrial intermembrane space and assembles with Erv1 in a complex. In reconstitution studies with reduced Tim13, Mia40, and Erv1, the addition of Osm1 and fumarate completes the disulfide exchange pathway that results in Tim13 oxidation. From in vitro import assays, mitochondria lacking Osm1 display decreased import of MIA substrates, Cmc1 and Tim10. Comparative reconstitution assays support that the Osm1/fumarate couple accepts electrons with similar efficiency to cytochrome c and that the cell has strategies to coordinate expression of the terminal electron acceptors. Thus Osm1/fumarate is a new electron acceptor couple in the mitochondrial intermembrane space that seems to function in both aerobic and anaerobic conditions.
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Affiliation(s)
- Sonya E Neal
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095
| | - Deepa V Dabir
- Department of Biology, Loyola Marymount University, Los Angeles, CA 90045
| | - Juwina Wijaya
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095
| | - Cennyana Boon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095
| | - Carla M Koehler
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095 .,Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095.,Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA 90095
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22
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Abstract
Cysteine thiols are among the most reactive functional groups in proteins, and their pairing in disulfide linkages is a common post-translational modification in proteins entering the secretory pathway. This modest amino acid alteration, the mere removal of a pair of hydrogen atoms from juxtaposed cysteine residues, contrasts with the substantial changes that characterize most other post-translational reactions. However, the wide variety of proteins that contain disulfides, the profound impact of cross-linking on the behavior of the protein polymer, the numerous and diverse players in intracellular pathways for disulfide formation, and the distinct biological settings in which disulfide bond formation can take place belie the simplicity of the process. Here we lay the groundwork for appreciating the mechanisms and consequences of disulfide bond formation in vivo by reviewing chemical principles underlying cysteine pairing and oxidation. We then show how enzymes tune redox-active cofactors and recruit oxidants to improve the specificity and efficiency of disulfide formation. Finally, we discuss disulfide bond formation in a cellular context and identify important principles that contribute to productive thiol oxidation in complex, crowded, dynamic environments.
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Affiliation(s)
- Deborah Fass
- Department of Structural Biology, Weizmann Institute of Science , Rehovot 7610001, Israel
| | - Colin Thorpe
- Department of Chemistry and Biochemistry, University of Delaware , Newark, Delaware 19716, United States
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23
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Selles B, Zannini F, Couturier J, Jacquot JP, Rouhier N. Atypical protein disulfide isomerases (PDI): Comparison of the molecular and catalytic properties of poplar PDI-A and PDI-M with PDI-L1A. PLoS One 2017; 12:e0174753. [PMID: 28362814 PMCID: PMC5375154 DOI: 10.1371/journal.pone.0174753] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 03/14/2017] [Indexed: 11/18/2022] Open
Abstract
Protein disulfide isomerases are overwhelmingly multi-modular redox catalysts able to perform the formation, reduction or isomerisation of disulfide bonds. We present here the biochemical characterization of three different poplar PDI isoforms. PDI-A is characterized by a single catalytic Trx module, the so-called a domain, whereas PDI-L1a and PDI-M display an a-b-b’-a’ and a°-a-b organisation respectively. Their activities have been tested in vitro using purified recombinant proteins and a series of model substrates as insulin, NADPH thioredoxin reductase, NADP malate dehydrogenase (NADP-MDH), peroxiredoxins or RNase A. We demonstrated that PDI-A exhibited none of the usually reported activities, although the cysteines of the WCKHC active site signature are able to form a disulfide with a redox midpoint potential of -170 mV at pH 7.0. The fact that it is able to bind a [Fe2S2] cluster upon Escherichia coli expression and anaerobic purification might indicate that it does not have a function in dithiol-disulfide exchange reactions. The two other proteins were able to catalyze oxidation or reduction reactions, PDI-L1a being more efficient in most cases, except that it was unable to activate the non-physiological substrate NADP-MDH, in contrast to PDI-M. To further evaluate the contribution of the catalytic domains of PDI-M, the dicysteinic motifs have been independently mutated in each a domain. The results indicated that the two a domains seem interconnected and that the a° module preferentially catalyzed oxidation reactions whereas the a module catalyzed reduction reactions, in line with the respective redox potentials of -170 mV and -190 mV at pH 7.0. Overall, these in vitro results illustrate that the number and position of a and b domains influence the redox properties and substrate recognition (both electron donors and acceptors) of PDI which contributes to understand why this protein family expanded along evolution.
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Affiliation(s)
- Benjamin Selles
- UMR 1136 Interactions Arbres/Microorganismes, Université de Lorraine/ INRA, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, France
| | - Flavien Zannini
- UMR 1136 Interactions Arbres/Microorganismes, Université de Lorraine/ INRA, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, France
| | - Jérémy Couturier
- UMR 1136 Interactions Arbres/Microorganismes, Université de Lorraine/ INRA, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, France
| | - Jean-Pierre Jacquot
- UMR 1136 Interactions Arbres/Microorganismes, Université de Lorraine/ INRA, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, France
| | - Nicolas Rouhier
- UMR 1136 Interactions Arbres/Microorganismes, Université de Lorraine/ INRA, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, France
- * E-mail:
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24
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Chatron N, Chalmond B, Trouvé A, Benoît E, Caruel H, Lattard V, Tchertanov L. Identification of the functional states of human vitamin K epoxide reductase from molecular dynamics simulations. RSC Adv 2017. [DOI: 10.1039/c7ra07463h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The functionally-related states of hVKORC1 predicted from MD conformations were assigned by probing their affinity to vitamin K and validated through analysis of its binding energy with VKAs.
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Affiliation(s)
- N. Chatron
- Centre de Mathématiques et de Leurs Applications (CMLA)
- ENS Cachan
- CNRS
- Université Paris-Saclay
- Cachan
| | - B. Chalmond
- Centre de Mathématiques et de Leurs Applications (CMLA)
- ENS Cachan
- CNRS
- Université Paris-Saclay
- Cachan
| | - A. Trouvé
- Centre de Mathématiques et de Leurs Applications (CMLA)
- ENS Cachan
- CNRS
- Université Paris-Saclay
- Cachan
| | - E. Benoît
- USC 1233 INRA-Vetagro Sup
- Veterinary School of Lyon
- Marcy l'Etoile
- France
| | | | - V. Lattard
- USC 1233 INRA-Vetagro Sup
- Veterinary School of Lyon
- Marcy l'Etoile
- France
| | - L. Tchertanov
- Centre de Mathématiques et de Leurs Applications (CMLA)
- ENS Cachan
- CNRS
- Université Paris-Saclay
- Cachan
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25
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Dufrisne MB, Petrou VI, Clarke OB, Mancia F. Structural basis for catalysis at the membrane-water interface. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:1368-1385. [PMID: 27913292 DOI: 10.1016/j.bbalip.2016.11.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 11/27/2022]
Abstract
The membrane-water interface forms a uniquely heterogeneous and geometrically constrained environment for enzymatic catalysis. Integral membrane enzymes sample three environments - the uniformly hydrophobic interior of the membrane, the aqueous extramembrane region, and the fuzzy, amphipathic interfacial region formed by the tightly packed headgroups of the components of the lipid bilayer. Depending on the nature of the substrates and the location of the site of chemical modification, catalysis may occur in each of these environments. The availability of structural information for alpha-helical enzyme families from each of these classes, as well as several beta-barrel enzymes from the bacterial outer membrane, has allowed us to review here the different ways in which each enzyme fold has adapted to the nature of the substrates, products, and the unique environment of the membrane. Our focus here is on enzymes that process lipidic substrates. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop.
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Affiliation(s)
- Meagan Belcher Dufrisne
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA
| | - Vasileios I Petrou
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA
| | - Oliver B Clarke
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Filippo Mancia
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA.
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Soares Moretti AI, Martins Laurindo FR. Protein disulfide isomerases: Redox connections in and out of the endoplasmic reticulum. Arch Biochem Biophys 2016; 617:106-119. [PMID: 27889386 DOI: 10.1016/j.abb.2016.11.007] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/08/2016] [Accepted: 11/21/2016] [Indexed: 12/13/2022]
Abstract
Protein disulfide isomerases are thiol oxidoreductase chaperones from thioredoxin superfamily. As redox folding catalysts from the endoplasmic reticulum (ER), their roles in ER-related redox homeostasis and signaling are well-studied. PDIA1 exerts thiol oxidation/reduction and isomerization, plus chaperone effects. Also, substantial evidence indicates that PDIs regulate thiol-disulfide switches in other cell locations such as cell surface and possibly cytosol. Subcellular PDI translocation routes remain unclear and seem Golgi-independent. The list of signaling and structural proteins reportedly regulated by PDIs keeps growing, via thiol switches involving oxidation, reduction and isomerization, S-(de)nytrosylation, (de)glutathyonylation and protein oligomerization. PDIA1 is required for agonist-triggered Nox NADPH oxidase activation and cell migration in vascular cells and macrophages, while PDIA1-dependent cytoskeletal regulation appears a converging pathway. Extracellularly, PDIs crucially regulate thiol redox signaling of thrombosis/platelet activation, e.g., integrins, and PDIA1 supports expansive caliber remodeling during injury repair via matrix/cytoskeletal organization. Some proteins display regulatory PDI-like motifs. PDI effects are orchestrated by expression levels or post-translational modifications. PDI is redox-sensitive, although probably not a mass-effect redox sensor due to kinetic constraints. Rather, the "all-in-one" organization of its peculiar redox/chaperone properties likely provide PDIs with precision and versatility in redox signaling, making them promising therapeutic targets.
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Affiliation(s)
- Ana Iochabel Soares Moretti
- Vascular Biology Laboratory, Heart Institute (InCor), University of São Paulo, School of Medicine, São Paulo, Brazil
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27
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Abstract
Vitamin K-dependent carboxylation, an essential posttranslational modification catalyzed by gamma-glutamyl carboxylase, is required for the biological functions of proteins that control blood coagulation, vascular calcification, bone metabolism, and other important physiological processes. Concomitant with carboxylation, reduced vitamin K (KH2) is oxidized to vitamin K epoxide (KO). KO must be recycled back to KH2 by the enzymes vitamin K epoxide reductase and vitamin K reductase in a pathway known as the vitamin K cycle. Our current knowledge about the enzymes of the vitamin K cycle is mainly based on in vitro studies of each individual enzymes under artificial conditions, which are of limited usefulness in understanding how the complex carboxylation process is carried out in the physiological environment. In this chapter, we review the current in vitro activity assays for vitamin K cycle enzymes. We describe the rationale, establishment, and application of cell-based assays for the functional study of these enzymes in the native cellular milieu. In these cell-based assays, different vitamin K-dependent proteins were designed and stably expressed in mammalian cells as reporter proteins to accommodate the readily used enzyme-linked immunosorbent assay for carboxylation efficiency evaluation. Additionally, recently emerged genome-editing techniques TALENs and CRISPR-Cas9 were used to knock out the endogenous enzymes in the reporter cell lines to eliminate the background. These cell-based assays are easy to scale up for high-throughput screening of inhibitors of vitamin K cycle enzymes and have been successfully used to clarify the genotypes and their clinical phenotypes of enzymes of the vitamin K cycle.
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Affiliation(s)
- J-K Tie
- University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.
| | - D W Stafford
- University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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Kanemura S, Okumura M, Yutani K, Ramming T, Hikima T, Appenzeller-Herzog C, Akiyama S, Inaba K. Human ER Oxidoreductin-1α (Ero1α) Undergoes Dual Regulation through Complementary Redox Interactions with Protein-Disulfide Isomerase. J Biol Chem 2016; 291:23952-23964. [PMID: 27703014 DOI: 10.1074/jbc.m116.735662] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 10/04/2016] [Indexed: 11/06/2022] Open
Abstract
In the mammalian endoplasmic reticulum, oxidoreductin-1α (Ero1α) generates protein disulfide bonds and transfers them specifically to canonical protein-disulfide isomerase (PDI) to sustain oxidative protein folding. This oxidative process is coupled to the reduction of O2 to H2O2 on the bound flavin adenine dinucleotide cofactor. Because excessive thiol oxidation and H2O2 generation cause cell death, Ero1α activity must be properly regulated. In addition to the four catalytic cysteines (Cys94, Cys99, Cys104, and Cys131) that are located in the flexible active site region, the Cys208-Cys241 pair located at the base of another flexible loop is necessary for Ero1α regulation, although the mechanistic basis is not fully understood. The present study revealed that the Cys208-Cys241 disulfide was reduced by PDI and other PDI family members during PDI oxidation. Differential scanning calorimetry and small angle X-ray scattering showed that mutation of Cys208 and Cys241 did not grossly affect the thermal stability or overall shape of Ero1α, suggesting that redox regulation of this cysteine pair serves a functional role. Moreover, the flexible loop flanked by Cys208 and Cys241 provides a platform for functional interaction with PDI, which in turn enhances the oxidative activity of Ero1α through reduction of the Cys208-Cys241 disulfide. We propose a mechanism of dual Ero1α regulation by dynamic redox interactions between PDI and the two Ero1α flexible loops that harbor the regulatory cysteines.
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Affiliation(s)
- Shingo Kanemura
- From the Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Aoba-ku, Sendai 980-8577, Japan
| | - Masaki Okumura
- From the Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Aoba-ku, Sendai 980-8577, Japan.,RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan
| | | | - Thomas Ramming
- the Division of Molecular & Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, 4056 Basel, Switzerland
| | | | - Christian Appenzeller-Herzog
- the Division of Molecular & Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, 4056 Basel, Switzerland.,the Berufsfachschule Gesundheit Baselland, 4142 Münchenstein, Switzerland
| | - Shuji Akiyama
- RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan.,the Research Center of Integrative Molecular Systems (CIMoS), Institute for Molecular Science, Okazaki 444-8585, Japan.,the Department of Functional Molecular Science, SOKENDAI (Graduate University for Advanced Studies), Kanagawa 240-0193, Japan, and
| | - Kenji Inaba
- From the Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Aoba-ku, Sendai 980-8577, Japan, .,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, 102-0076, Japan
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Ayee MAA, Roth CW, Akpa BS. Structural perturbation of a dipalmitoylphosphatidylcholine (DPPC) bilayer by warfarin and its bolaamphiphilic analogue: A molecular dynamics study. J Colloid Interface Sci 2016; 468:227-237. [PMID: 26852346 PMCID: PMC4762473 DOI: 10.1016/j.jcis.2016.01.056] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 01/24/2016] [Accepted: 01/26/2016] [Indexed: 12/26/2022]
Abstract
Compounds with nominally similar biological activity may exhibit differential toxicity due to differences in their interactions with cell membranes. Many pharmaceutical compounds are amphiphilic and can be taken up by phospholipid bilayers, interacting strongly with the lipid-aqueous interface whether or not subsequent permeation through the bilayer is possible. Bolaamphiphilic compounds, which possess two hydrophilic ends and a hydrophobic linker, can likewise undergo spontaneous uptake by bilayers. While membrane-spanning bolaamphiphiles can stabilize membranes, small molecules with this characteristic have the potential to create membrane defects via disruption of bilayer structure and dynamics. When compared to the amphiphilic therapeutic anticoagulant, warfarin, the bolaamphiphilic analogue, brodifacoum, exhibits heightened toxicity that goes beyond superior inhibition of the pharmacological target enzyme. We explore, herein, the consequences of anticoagulant accumulation in a dipalmitoylphosphatidylcholine (DPPC) bilayer. Coarse-grained molecular dynamics simulations reveal that permeation of phospholipid bilayers by brodifacoum causes a disruption of membrane barrier function that is driven by the bolaamphiphilic nature and size of this molecule. We find that brodifacoum partitioning into bilayers causes membrane thinning and permeabilization and promotes lipid flip-flop - phenomena that are suspected to play a role in triggering cell death. These phenomena are either absent or less pronounced in the case of the less toxic, amphiphilic compound, warfarin.
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Affiliation(s)
- Manuela Aseye Ayele Ayee
- Department of Chemical Engineering, University of Illinois at Chicago, 810 S. Clinton St., Chicago, IL 60607, USA; Department of Medicine, University of Illinois at Chicago, 909 S. Wolcott Ave., Chicago, IL 60612, USA.
| | - Charles William Roth
- Department of Chemical Engineering, University of Illinois at Chicago, 810 S. Clinton St., Chicago, IL 60607, USA.
| | - Belinda Sena Akpa
- Department of Chemical Engineering, University of Illinois at Chicago, 810 S. Clinton St., Chicago, IL 60607, USA; Department of Molecular Biomedical Sciences, North Carolina State University, 1060 William Moore Dr., Raleigh, NC 27607, USA.
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The membrane topology of vitamin K epoxide reductase is conserved between human isoforms and the bacterial enzyme. Biochem J 2016; 473:851-8. [PMID: 26772871 DOI: 10.1042/bj20151223] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/15/2016] [Indexed: 11/17/2022]
Abstract
The membrane topology of vitamin K epoxide reductase (VKOR) is controversial with data supporting both a three transmembrane and a four transmembrane model. The positioning of the transmembrane domains and the loops between these domains is critical if we are to understand the mechanism of vitamin K oxidation and its recycling by members of the thioredoxin family of proteins and the mechanism of action of warfarin, an inhibitor of VKOR. Here we show that both mammalian VKOR isoforms adopt the same topology, with the large loop between transmembrane one and two facing the lumen of the endoplasmic reticulum (ER). We used a redox sensitive green fluorescent protein (GFP) fused to the N- or C-terminus to show that these regions face the cytosol, and introduction of glycosylation sites along with mixed disulfide formation with thioredoxin-like transmembrane protein (TMX) to demonstrate ER localization of the major loop. The topology is identical with the bacterial homologue from Synechococcussp., for which the structure and mechanism of recycling has been characterized. Our results provide a resolution to the membrane topology controversy and support previous results suggesting a role for members of the ER protein disulfide isomerase (PDI) family in recycling VKOR.
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Liu S, Cheng W, Fowle Grider R, Shen G, Li W. Structures of an intramembrane vitamin K epoxide reductase homolog reveal control mechanisms for electron transfer. Nat Commun 2015; 5:3110. [PMID: 24477003 PMCID: PMC4360977 DOI: 10.1038/ncomms4110] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 12/13/2013] [Indexed: 01/19/2023] Open
Abstract
The intramembrane vitamin K epoxide reductase (VKOR) supports blood coagulation in humans and is the target of the anticoagulant warfarin. VKOR and its homologs generate disulfide bonds in organisms ranging from bacteria to humans. Here, to better understand the mechanism of VKOR catalysis, we report two crystal structures of a bacterial VKOR captured in different reaction states. These structures reveal a short helix at the hydrophobic active site of VKOR that alters between wound and unwound conformations. Motions of this “horizontal helix” promote electron transfer by regulating the positions of two cysteines in an adjacent loop. Winding of the helix separates these “loop cysteines” to prevent backward electron flow. Despite these motions, hydrophobicity at the active site is maintained to facilitate VKOR catalysis. Biochemical experiments suggest that several warfarin-resistant mutations act by changing the conformation of the horizontal helix. Taken together, these studies provide a comprehensive understanding of VKOR function.
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Affiliation(s)
- Shixuan Liu
- 1] Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri 63110, USA [2]
| | - Wei Cheng
- 1] Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri 63110, USA [2]
| | - Ronald Fowle Grider
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri 63110, USA
| | - Guomin Shen
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri 63110, USA
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri 63110, USA
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Structural Modeling Insights into Human VKORC1 Phenotypes. Nutrients 2015; 7:6837-51. [PMID: 26287237 PMCID: PMC4555152 DOI: 10.3390/nu7085313] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/03/2015] [Accepted: 08/06/2015] [Indexed: 11/17/2022] Open
Abstract
Vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) catalyses the reduction of vitamin K and its 2,3-epoxide essential to sustain γ-carboxylation of vitamin K-dependent proteins. Two different phenotypes are associated with mutations in human VKORC1. The majority of mutations cause resistance to 4-hydroxycoumarin- and indandione-based vitamin K antagonists (VKA) used in the prevention and therapy of thromboembolism. Patients with these mutations require greater doses of VKA for stable anticoagulation than patients without mutations. The second phenotype, a very rare autosomal-recessive bleeding disorder caused by combined deficiency of vitamin K dependent clotting factors type 2 (VKCFD2) arises from a homozygous Arg98Trp mutation. The bleeding phenotype can be corrected by vitamin K administration. Here, we summarize published experimental data and in silico modeling results in order to rationalize the mechanisms of VKA resistance and VKCFD2.
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Oldenburg J, Watzka M, Bevans CG. VKORC1 and VKORC1L1: Why do Vertebrates Have Two Vitamin K 2,3-Epoxide Reductases? Nutrients 2015; 7:6250-80. [PMID: 26264021 PMCID: PMC4555119 DOI: 10.3390/nu7085280] [Citation(s) in RCA: 21] [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: 05/18/2015] [Revised: 07/08/2015] [Accepted: 07/15/2015] [Indexed: 01/01/2023] Open
Abstract
Among all cellular life on earth, with the exception of yeasts, fungi, and some prokaryotes, VKOR family homologs are ubiquitously encoded in nuclear genomes, suggesting ancient and important biological roles for these enzymes. Despite single gene and whole genome duplications on the largest evolutionary timescales, and the fact that most gene duplications eventually result in loss of one copy, it is surprising that all jawed vertebrates (gnathostomes) have retained two paralogous VKOR genes. Both VKOR paralogs function as entry points for nutritionally acquired and recycled K vitamers in the vitamin K cycle. Here we present phylogenetic evidence that the human paralogs likely arose earlier than gnathostomes, possibly in the ancestor of crown chordates. We ask why gnathostomes have maintained these paralogs throughout evolution and present a current summary of what we know. In particular, we look to published studies about tissue- and developmental stage-specific expression, enzymatic function, phylogeny, biological roles and associated pathways that together suggest subfunctionalization as a major influence in evolutionary fixation of both paralogs. Additionally, we investigate on what evolutionary timescale the paralogs arose and under what circumstances in order to gain insight into the biological raison d’être for both VKOR paralogs in gnathostomes.
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Affiliation(s)
- Johannes Oldenburg
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Bonn 53105, Germany.
| | - Matthias Watzka
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Bonn 53105, Germany.
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Bevans CG, Krettler C, Reinhart C, Watzka M, Oldenburg J. Phylogeny of the Vitamin K 2,3-Epoxide Reductase (VKOR) Family and Evolutionary Relationship to the Disulfide Bond Formation Protein B (DsbB) Family. Nutrients 2015; 7:6224-49. [PMID: 26230708 PMCID: PMC4555120 DOI: 10.3390/nu7085281] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 06/25/2015] [Accepted: 07/09/2015] [Indexed: 12/04/2022] Open
Abstract
In humans and other vertebrate animals, vitamin K 2,3-epoxide reductase (VKOR) family enzymes are the gatekeepers between nutritionally acquired K vitamins and the vitamin K cycle responsible for posttranslational modifications that confer biological activity upon vitamin K-dependent proteins with crucial roles in hemostasis, bone development and homeostasis, hormonal carbohydrate regulation and fertility. We report a phylogenetic analysis of the VKOR family that identifies five major clades. Combined phylogenetic and site-specific conservation analyses point to clade-specific similarities and differences in structure and function. We discovered a single-site determinant uniquely identifying VKOR homologs belonging to human pathogenic, obligate intracellular prokaryotes and protists. Building on previous work by Sevier et al. (Protein Science 14:1630), we analyzed structural data from both VKOR and prokaryotic disulfide bond formation protein B (DsbB) families and hypothesize an ancient evolutionary relationship between the two families where one family arose from the other through a gene duplication/deletion event. This has resulted in circular permutation of primary sequence threading through the four-helical bundle protein folds of both families. This is the first report of circular permutation relating distant α-helical membrane protein sequences and folds. In conclusion, we suggest a chronology for the evolution of the five extant VKOR clades.
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Affiliation(s)
| | - Christoph Krettler
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, 60388 Frankfurt am Main, Germany.
| | - Christoph Reinhart
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, 60388 Frankfurt am Main, Germany.
| | - Matthias Watzka
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, 53105 Bonn, Germany.
| | - Johannes Oldenburg
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, 53105 Bonn, Germany.
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Dauti F, Hjaltalin Jonsson M, Hillarp A, Bentzer P, Schött U. Perioperative changes in PIVKA-II. Scandinavian Journal of Clinical and Laboratory Investigation 2015. [PMID: 26198297 DOI: 10.3109/00365513.2015.1058521] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND AND AIMS Proteins induced by vitamin K absence for factor II (PIVKA-II) is an enzyme-linked immunosorbent assay that monitors uncarboxylated prothrombin and responds to vitamin K deficits prior to changes in the prothrombin test. The aim of this project was to study perioperative PIVKA-II changes during various types of surgery in a prospective observational study. METHODS Patients undergoing abdominal or orthopaedic surgery were included. Blood was sampled on the day of surgery (preoperatively) and up to 5 days after surgery. The activated partial thromboplastin time, Quick and Owren prothrombin times were analyzed, together with PIVKA-II. RESULTS Thirty-nine patients were included, 27 +male and 12 +female. All but 7 +patients had elevated PIVKA-II levels preoperatively. PIVKA-II levels had already increased significantly (p < 0.017) on day 1 after surgery as compared to presurgery plasma levels. The median PIVKA-II was highest on day 5. Routine tests were mostly normal. No significant difference in PIVKA-II was seen when comparing patients undergoing abdominal versus orthopaedic surgeries. There was no significant correlation between PIVKA-II and routine coagulation tests. Patients with anterior resection, emergency laparotomy and emergency hip fractures had higher postoperative increases, which could be linked to increased gastrointestinal recovery times, paralytic ileus, peritonitis and comorbidities. CONCLUSIONS PIVKA-II levels increase during the perioperative period, despite mostly normal routine coagulation tests. Pre- and perioperative vitamin K supplementation in patients with elevated PIVKA-II levels should be studied, and its clinical significance be defined in future studies.
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Wang L, Wang X, Wang CC. Protein disulfide-isomerase, a folding catalyst and a redox-regulated chaperone. Free Radic Biol Med 2015; 83:305-13. [PMID: 25697778 DOI: 10.1016/j.freeradbiomed.2015.02.007] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 02/04/2015] [Accepted: 02/07/2015] [Indexed: 01/08/2023]
Abstract
Protein disulfide-isomerase (PDI) was the first protein-folding catalyst to be characterized, half a century ago. It plays critical roles in a variety of physiological events by displaying oxidoreductase and redox-regulated chaperone activities. This review provides a brief history of the identification of PDI as both an enzyme and a molecular chaperone and of the recent advances in studies on the structure and dynamics of PDI, the substrate binding and release, and the cooperation with its partners to catalyze oxidative protein folding and maintain ER redox homeostasis. In this review, we highlight the structural features of PDI, including the high interdomain flexibility, the multiple binding sites, the two synergic active sites, and the redox-dependent conformational changes.
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Affiliation(s)
- Lei Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xi Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Chih-chen Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
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Margittai É, Enyedi B, Csala M, Geiszt M, Bánhegyi G. Composition of the redox environment of the endoplasmic reticulum and sources of hydrogen peroxide. Free Radic Biol Med 2015; 83:331-40. [PMID: 25678412 DOI: 10.1016/j.freeradbiomed.2015.01.032] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 01/30/2015] [Accepted: 01/31/2015] [Indexed: 12/22/2022]
Abstract
The endoplasmic reticulum (ER) is a metabolically active organelle, which has a central role in proteostasis by translating, modifying, folding, and occasionally degrading secretory and membrane proteins. The lumen of the ER represents a separate compartment of the eukaryotic cell, with a characteristic proteome and metabolome. Although the redox metabolome and proteome of the compartment have not been holistically explored, it is evident that proper redox conditions are necessary for the functioning of many luminal pathways. These redox conditions are defined by local oxidoreductases and the membrane transport of electron donors and acceptors. The main electron carriers of the compartment are identical with those of the other organelles: glutathione, pyridine and flavin nucleotides, ascorbate, and others. However, their composition, concentration, and redox state in the ER lumen can be different from those observed in other compartments. The terminal oxidases of oxidative protein folding generate and maintain an "oxidative environment" by oxidizing protein thiols and producing hydrogen peroxide. ER-specific mechanisms reutilize hydrogen peroxide as an electron acceptor of oxidative folding. These mechanisms, together with membrane and kinetic barriers, guarantee that redox systems in the reduced or oxidized state can be present simultaneously in the lumen. The present knowledge on the in vivo conditions of ER redox is rather limited; development of new genetically encoded targetable sensors for the measurement of the luminal state of redox systems other than thiol/disulfide will contribute to a better understanding of ER redox homeostasis.
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Affiliation(s)
- Éva Margittai
- Institute of Human Physiology and Clinical Experimental Research, Semmelweis University, Budapest 1444, Hungary
| | - Balázs Enyedi
- Department of Physiology, Semmelweis University, Budapest 1444, Hungary
| | - Miklós Csala
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest 1444, Hungary
| | - Miklós Geiszt
- Department of Physiology, Semmelweis University, Budapest 1444, Hungary; "Lendület" Peroxidase Enzyme Research Group of Semmelweis University and the Hungarian Academy of Sciences, Semmelweis University, Budapest 1444, Hungary
| | - Gábor Bánhegyi
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest 1444, Hungary.
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Okumura M, Kadokura H, Inaba K. Structures and functions of protein disulfide isomerase family members involved in proteostasis in the endoplasmic reticulum. Free Radic Biol Med 2015; 83:314-22. [PMID: 25697777 DOI: 10.1016/j.freeradbiomed.2015.02.010] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 01/22/2015] [Accepted: 02/09/2015] [Indexed: 12/16/2022]
Abstract
The endoplasmic reticulum (ER) is an essential cellular compartment in which an enormous number of secretory and cell surface membrane proteins are synthesized and subjected to cotranslational or posttranslational modifications, such as glycosylation and disulfide bond formation. Proper maintenance of ER protein homeostasis (sometimes termed proteostasis) is essential to avoid cellular stresses and diseases caused by abnormal proteins. Accumulating knowledge of cysteine-based redox reactions catalyzed by members of the protein disulfide isomerase (PDI) family has revealed that these enzymes play pivotal roles in productive protein folding accompanied by disulfide formation, as well as efficient ER-associated degradation accompanied by disulfide reduction. Each of PDI family members forms a protein-protein interaction with a preferential partner to fulfill a distinct function. Multiple redox pathways that utilize PDIs appear to function synergistically to attain the highest quality and productivity of the ER, even under various stress conditions. This review describes the structures, physiological functions, and cooperative actions of several essential PDIs, and provides important insights into the elaborate proteostatic mechanisms that have evolved in the extremely active and stress-sensitive ER.
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Affiliation(s)
- Masaki Okumura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Hiroshi Kadokura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
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Fernández I, Vijayakumar P, Marques C, Cancela ML, Gavaia PJ, Laizé V. Zebrafish vitamin K epoxide reductases: expression in vivo, along extracellular matrix mineralization and under phylloquinone and warfarin in vitro exposure. FISH PHYSIOLOGY AND BIOCHEMISTRY 2015; 41:745-759. [PMID: 25792234 DOI: 10.1007/s10695-015-0043-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 03/12/2015] [Indexed: 06/04/2023]
Abstract
Vitamin K (VK) acts as a cofactor driving the biological activation of VK-dependent proteins and conferring calcium-binding properties to them. As a result, VK is converted into VK epoxide, which must be recycled by VK epoxide reductases (Vkors) before it can be reused. Although VK has been shown to play a central role in fish development, particularly during skeletogenesis, pathways underlying VK actions are poorly understood, while good and reliable molecular markers for VK cycle/homeostasis are still lacking in fish. In the present work, expression of 2 zebrafish vkor genes was characterized along larval development and in adult tissues through qPCR analysis. Zebrafish cell line ZFB1 was used to evaluate in vitro regulation of vkors and other VK cycle-related genes during mineralization and upon 24 h exposure to 0.16 and 0.8 µM phylloquinone (VK1), 0.032 µM warfarin, or a combination of both molecules. Results showed that zebrafish vkors are differentially expressed during larval development, in adult tissues, and during cell differentiation/mineralization processes. Further, several VK cycle intermediates were differentially expressed in ZFB1 cells exposed to VK1 and/or warfarin. Present work provides data identifying different developmental stages and adult tissues where VK recycling is probably highly required, and shows how genes involved in VK cycle respond to VK nutritional status in skeletal cells. Expression of vkor genes can represent a reliable indicator to infer VK nutritional status in fish, while ZFB1 cells could represent a suitable in vitro tool to get insights into the mechanisms underlying VK action on fish bone.
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Affiliation(s)
- Ignacio Fernández
- Centre of Marine Sciences (CCMAR), University of Algarve, Campus of Gambelas, 8005-139, Faro, Portugal,
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Szarka A, Bánhegyi G. Oxidative folding: recent developments. Biomol Concepts 2015; 2:379-90. [PMID: 25962043 DOI: 10.1515/bmc.2011.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 07/21/2011] [Indexed: 01/29/2023] Open
Abstract
Disulfide bond formation in proteins is an effective tool of both structure stabilization and redox regulation. The prokaryotic periplasm and the endoplasmic reticulum of eukaryotes were long considered as the only compartments for enzyme mediated formation of stable disulfide bonds. Recently, the mitochondrial intermembrane space has emerged as the third protein-oxidizing compartment. The classic view on the mechanism of oxidative folding in the endoplasmic reticulum has also been reshaped by new observations. Moreover, besides the structure stabilizing function, reversible disulfide bridge formation in some proteins of the endoplasmic reticulum, seems to play a regulatory role. This review briefly summarizes the present knowledge of the redox systems supporting oxidative folding, emphasizing recent developments.
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Maternal nicotine exposure leads to impaired disulfide bond formation and augmented endoplasmic reticulum stress in the rat placenta. PLoS One 2015; 10:e0122295. [PMID: 25811377 PMCID: PMC4374683 DOI: 10.1371/journal.pone.0122295] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 02/17/2015] [Indexed: 12/16/2022] Open
Abstract
Maternal nicotine exposure has been associated with many adverse fetal and placental outcomes. Although underlying mechanisms remain elusive, recent studies have identified that augmented endoplasmic reticulum (ER) stress is linked to placental insufficiency. Moreover, ER function depends on proper disulfide bond formation—a partially oxygen-dependent process mediated by protein disulfide isomerase (PDI) and ER oxidoreductases. Given that nicotine compromised placental development in the rat, and placental insufficiency has been associated with poor disulfide bond formation and ER stress, we hypothesized that maternal nicotine exposure leads to both placental ER stress and impaired disulfide bond formation. To test this hypothesis, female Wistar rats received daily subcutaneous injections of either saline (vehicle) or nicotine bitartrate (1 mg/kg) for 14 days prior to mating and during pregnancy. Placentas were harvested on embryonic day 15 for analysis. Protein and mRNA expression of markers involved in ER stress (e.g., phosphorylated eIF2α, Grp78, Atf4, and CHOP), disulfide bond formation (e.g., PDI, QSOX1, VKORC1), hypoxia (Hif1α), and amino acid deprivation (GCN2) were quantified via Western blot and/or Real-time PCR. Maternal nicotine exposure led to increased expression of Grp78, phosphorylated eIF2α, Atf4, and CHOP (p<0.05) in the rat placenta, demonstrating the presence of augmented ER stress. Decreased expression of PDI and QSOX1 (p<0.05) reveal an impaired disulfide bond formation pathway, which may underlie nicotine-induced ER stress. Finally, elevated expression of Hif1α and GCN2 (p<0.05) indicate hypoxia and amino acid deprivation in nicotine-exposed placentas, respectively, which may also cause impaired disulfide bond formation and augmented ER stress. This study is the first to link maternal nicotine exposure with both placental ER stress and disulfide bond impairment in vivo, providing novel insight into the mechanisms underlying nicotine exposure during pregnancy on placental health.
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Okuda A, Matsusaki M, Higashino Y, Masuda T, Urade R. Disulfide bond formation activity of soybean quiescin sulfhydryl oxidase. FEBS J 2014; 281:5341-55. [PMID: 25265152 DOI: 10.1111/febs.13079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/22/2014] [Accepted: 09/25/2014] [Indexed: 12/23/2022]
Abstract
UNLABELLED Multiple enzymatic systems can catalyse protein disulfide bond formation in the endoplasmic reticulum (ER) of eukaryotic cells. The enzyme quiescin sulfhydryl oxidase (QSOX) catalyses disulfide bond formation in unfolded proteins via the reduction of oxygen. We found two QSOX homologues in the soybean genome database, Glycine max QSOX (GmQSOX)1 and GmQSOX2, which encode proteins composed of an N-terminal signal peptide, a thioredoxin-like domain, an FAD-binding domain, Erv/ALR, and a transmembrane region near the C terminus. We subsequently cloned two GmQSOX1 cDNAs, GmQSOX1a and GmQSOX1b, which may be generated by alternative splicing. The GmQSOX1a, GmQSOX1b and GmQSOX2 mRNA levels increased during seed storage protein synthesis in the cotyledon, and were also upregulated under conditions causing ER stress. Recombinant GmQSOX1 expressed in Escherichia coli formed disulfide bonds on reduced and denatured RNase A, but did not show any refolding activity. The reduced and denatured RNase A was effectively refolded by recombinant GmQSOX1 in the presence of the soybean protein disulfide isomerase family protein GmPDIL-2 in the absence of glutathione redox buffer, suggesting that GmQSOX1 plays a role in protein folding in the ER. DATABASES The nucleotide sequence data for the GmQSOX1a, GmQSOX1b, GmQSOX2a, GmQSOX2b and glycinin AaB1b cDNAs are available in the DDBJ/EMBL/GenBank databases under the accession numbers AB196647, AB195548, XM-006589586, XM-003536592, and AB113349, respectively.
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Affiliation(s)
- Aya Okuda
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, Japan
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Abstract
Severe deficiency of vitamin K-dependent proteins in patients not maintained on vitamin K antagonists is most commonly associated with poisoning by or surreptitious ingestion of warfarin, warfarin-like anticoagulants, or potent rodenticides ("superwarfarins"), such as brodifacoum. Serious bleeding manifestations are common. Superwarfarins are 2 orders of magnitude more potent than warfarin and have a half-life measured in weeks. These rodenticides are readily available household environmental hazards and are sometimes consumed accidentally or as manifestations of psychiatric disease. Immediate diagnosis and proper therapy is critically important to minimize morbidity and mortality because this condition, affecting thousands of patients annually, is reversible. Treatment with large doses of oral vitamin K1, often over months to years, to maintain a near-normal prothrombin time can reverse the coagulopathy associated with superwarfarins. Although these patients initially present to various medical specialties, the hematologist is often consulted to offer the definitive diagnosis and proper therapy.
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Regulating the level of intracellular hydrogen peroxide: the role of peroxiredoxin IV. Biochem Soc Trans 2014; 42:42-6. [PMID: 24450625 DOI: 10.1042/bst20130168] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hydrogen peroxide (H2O2) can act as a signalling molecule affecting the cell cycle as well as contributing towards the oxidative stress response. The primary target of this molecule is oxidation-sensitive cysteine residues in proteins such as protein tyrosine phosphatases. The cell has robust mechanisms to remove H2O2 that need to be regulated for H2O2 to react with and modify protein thiols. In particular, the family of peroxiredoxins are capable of the rapid removal of even trace amounts of this molecule. It has been suggested that the inactivation of peroxiredoxins by hyperoxidation may allow H2O2 levels to increase in cells and thereby modify critical thiol groups in proteins. We have been studying how the H2O2 produced during disulfide formation in the ER (endoplasmic reticulum) is metabolized and have shown that ER-resident peroxiredoxin IV not only can remove H2O2, but also contributes to de novo disulfide formation. In the present article, we review recent data on the structure and function of this enzyme as well as its sensitivity to hyperoxidation.
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Protein disulfide isomerase: a promising target for cancer therapy. Drug Discov Today 2014; 19:222-40. [DOI: 10.1016/j.drudis.2013.10.017] [Citation(s) in RCA: 168] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 09/12/2013] [Accepted: 10/22/2013] [Indexed: 12/15/2022]
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A cellular system for quantitation of vitamin K cycle activity: structure-activity effects on vitamin K antagonism by warfarin metabolites. Blood 2013; 123:582-9. [PMID: 24297869 DOI: 10.1182/blood-2013-05-505123] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Warfarin and other 4-hydroxycoumarins inhibit vitamin K epoxide reductase (VKOR) by depleting reduced vitamin K that is required for posttranslational modification of vitamin K-dependent clotting factors. In vitro prediction of the in vivo potency of vitamin K antagonists is complicated by the complex multicomponent nature of the vitamin K cycle. Here we describe a sensitive assay that enables quantitative analysis of γ-glutamyl carboxylation and its antagonism in live cells. We engineered a human embryonic kidney (HEK) 293-derived cell line (HEK 293-C3) to express a chimeric protein (F9CH) comprising the Gla domain of factor IX fused to the transmembrane and cytoplasmic regions of proline-rich Gla protein 2. Maximal γ-glutamyl carboxylation of F9CH required vitamin K supplementation, and was dose-dependently inhibited by racemic warfarin at a physiologically relevant concentration. Cellular γ-glutamyl carboxylation also exhibited differential VKOR inhibition by warfarin enantiomers (S > R) consistent with their in vivo potencies. We further analyzed the structure-activity relationship for inhibition of γ-glutamyl carboxylation by warfarin metabolites, observing tolerance to phenolic substitution at the C-5 and especially C-6, but not C-7 or C-8, positions on the 4-hydroxycoumarin nucleus. After correction for in vivo concentration and protein binding, 10-hydroxywarfarin and warfarin alcohols were predicted to be the most potent inhibitory metabolites in vivo.
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Boraldi F, Garcia-Fernandez M, Paolinelli-Devincenzi C, Annovi G, Schurgers L, Vermeer C, Cianciulli P, Ronchetti I, Quaglino D. Ectopic calcification in β-thalassemia patients is associated with increased oxidative stress and lower MGP carboxylation. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1832:2077-84. [PMID: 23899606 DOI: 10.1016/j.bbadis.2013.07.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/24/2013] [Accepted: 07/22/2013] [Indexed: 11/29/2022]
Abstract
A number of beta-thalassemia (β-thal) patients in the course of the disease exhibit ectopic calcification affecting skin, eyes and the cardiovascular system. Clinical and histopathological features have been described similar to those in pseudoxanthoma elasticum (PXE), although different genes are affected in the two diseases. Cultured dermal fibroblasts from β-thal patients with and without PXE-like clinical manifestations have been compared for parameters of redox balance and for the expression of proteins, which have been already associated with the pathologic mineralisation of soft connective tissues. Even though oxidative stress is a well-known condition of β-thal patients, our results indicate that the occurrence of mineralized elastin is associated with a more pronounced redox disequilibrium, as demonstrated by the intracellular increase of anion superoxide and of oxidized proteins and lipids. Moreover, fibroblasts from β-thal PXE-like patients are characterized by decreased availability of carboxylated matrix Gla protein (MGP), as well as by altered expression of proteins involved in the vitamin K-dependent carboxylation process. Results demonstrate that elastic fibre calcification is promoted when redox balance threshold levels are exceeded and the vitamin K-dependent carboxylation process is affected decreasing the activity of MGP, a well-known inhibitor of ectopic calcification. Furthermore, independently from the primary gene defect, these pathways are similarly involved in fibroblasts from PXE and from β-thal PXE-like patients as well as in other diseases leading to ectopic calcification, thus suggesting that can be used as markers of pathologic mineralisation.
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Affiliation(s)
- Federica Boraldi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy; PXELab, University of Modena and Reggio Emilia, Modena, Italy
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Koritzinsky M, Levitin F, van den Beucken T, Rumantir RA, Harding NJ, Chu KC, Boutros PC, Braakman I, Wouters BG. Two phases of disulfide bond formation have differing requirements for oxygen. ACTA ACUST UNITED AC 2013; 203:615-27. [PMID: 24247433 PMCID: PMC3840938 DOI: 10.1083/jcb.201307185] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Disulfide bonds introduced during or shortly after protein synthesis can occur without oxygen, whereas those introduced during post-translational folding or isomerization are oxygen dependent. Most proteins destined for the extracellular space require disulfide bonds for folding and stability. Disulfide bonds are introduced co- and post-translationally in endoplasmic reticulum (ER) cargo in a redox relay that requires a terminal electron acceptor. Oxygen can serve as the electron acceptor in vitro, but its role in vivo remains unknown. Hypoxia causes ER stress, suggesting a role for oxygen in protein folding. Here we demonstrate the existence of two phases of disulfide bond formation in living mammalian cells, with differential requirements for oxygen. Disulfide bonds introduced rapidly during protein synthesis can occur without oxygen, whereas those introduced during post-translational folding or isomerization are oxygen dependent. Other protein maturation processes in the secretory pathway, including ER-localized N-linked glycosylation, glycan trimming, Golgi-localized complex glycosylation, and protein transport, occur independently of oxygen availability. These results suggest that an alternative electron acceptor is available transiently during an initial phase of disulfide bond formation and that post-translational oxygen-dependent disulfide bond formation causes hypoxia-induced ER stress.
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Affiliation(s)
- Marianne Koritzinsky
- Ontario Cancer Institute and Campbell Family Institute for Cancer Research, University Health Network, Toronto, Ontario M5G 2M9, Canada
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Lu Y, Wang HR, Li H, Cui HR, Feng YG, Wang XY. A chloroplast membrane protein LTO1/AtVKOR involving in redox regulation and ROS homeostasis. PLANT CELL REPORTS 2013; 32:1427-40. [PMID: 23689258 DOI: 10.1007/s00299-013-1455-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/20/2013] [Accepted: 04/29/2013] [Indexed: 05/08/2023]
Abstract
The role of LTO1/ At VKOR-DsbA in ROS homeostasis and in redox regulation of cysteine-containing proteins in chloroplast was studied in lto1 - 2 mutant, and a potential target of LTO1 was captured. A chloroplast membrane protein LTO1/AtVKOR-DsbA encoded by the gene At4g35760 was recently found to be an oxidoreductase and involved in assembly of PSII. Here, the growth of a mutant lto1-2 line of Arabidopsis was found to be severely stunted and transgenic complementation ultimately demonstrated the phenotype changes were due to this gene. A proteomic experiment identified 23 proteins presenting a differential abundance in lto1-2 compared with wild-type plants, including components in PSII and proteins scavenging active oxygen. Three scavengers of active oxygen, L-ascorbate peroxidase 1, peroxisomal catalase 2, dehydroascorbate reductase 1, are reduced in lto1-2 plants, corresponding to high levels of accumulation of reactive oxygen species (ROS). The photosynthetic activities of PSII and the quantity of core protein D1 decreased significantly in lto1-2. Further investigation showed the synthesis of D1 was not affected in mutants both at transcription and translation levels. The soluble DsbA-like domain of LTO1 was found to have reduction, oxidation and isomerization activities, and could promote the formation of disulfide bonds in a lumenal protein, FKBP13. A potential target of LTO1 was captured which was involving in chlorophyll degradation and photooxidative stress response. Experimental results imply that LTO1 plays important roles in redox regulation, ROS homeostasis and maintenance of PSII.
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Affiliation(s)
- Ying Lu
- College of Life Science, Shandong Agricultural University, Taian 271018, Shandong, People's Republic of China
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Aller I, Meyer AJ. The oxidative protein folding machinery in plant cells. PROTOPLASMA 2013; 250:799-816. [PMID: 23090240 DOI: 10.1007/s00709-012-0463-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 10/02/2012] [Indexed: 06/01/2023]
Abstract
Formation of intra-molecular disulfides and concomitant oxidative protein folding is essential for stability and catalytic function of many soluble and membrane-bound proteins in the endomembrane system, the mitochondrial inter-membrane space and the thylakoid lumen. Disulfide generation from free cysteines in nascent polypeptide chains is generally a catalysed process for which distinct pathways exist in all compartments. A high degree of similarities between highly diverse eukaryotic and bacterial systems for generation of protein disulfides indicates functional conservation of key processes throughout evolution. However, while many aspects about molecular function of enzymatic systems promoting disulfide formation have been demonstrated for bacterial and non-plant eukaryotic organisms, it is now clear that the plant machinery for oxidative protein folding displays distinct details, suggesting that the different pathways have been adapted to plant-specific requirements in terms of compartmentation, molecular function and regulation. Here, we aim to evaluate biological diversity by comparing the plant systems for oxidative protein folding to the respective systems from non-plant eukaryotes.
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Affiliation(s)
- Isabel Aller
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, D-53113 Bonn, Germany
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