1
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Melo EP, El-Guendouz S, Correia C, Teodoro F, Lopes C, Martel PJ. A Conformational-Dependent Interdomain Redox Relay at the Core of Protein Disulfide Isomerase Activity. Antioxid Redox Signal 2024. [PMID: 38497737 DOI: 10.1089/ars.2023.0288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Aims: Protein disulfide isomerases (PDIs) are a family of chaperones resident in the endoplasmic reticulum (ER). In addition to holdase function, some members catalyze disulfide bond formation and isomerization, a crucial step for native folding and prevention of aggregation of misfolded proteins. PDIs are characterized by an arrangement of thioredoxin-like domains, with the canonical protein disulfide isomerase A1 (PDIA1) organized as four thioredoxin-like domains forming a horseshoe with two active sites, a and a', at the extremities. We aimed to clarify important aspects underlying the catalytic cycle of PDIA1 in the context of the full pathways of oxidative protein folding operating in the ER. Results: Using two fluorescent redox sensors, redox green fluorescent protein 2 (roGFP2) and HyPer (circularly permutated yellow fluorescent protein containing the regulatory domain of the H2O2-sensing protein OxyR), either unfolded or native, as client substrates, we identified the N-terminal a active site of PDIA1 as the main oxidant of thiols. From there, electrons can flow to the C-terminal a' active site, with the redox-dependent conformational flexibility of PDIA1 allowing the formation of an interdomain disulfide bond. The a' active site then acts as a crossing point to redirect electrons to ER downstream oxidases or back to client proteins to reduce scrambled disulfide bonds. Innovation and Conclusions: The two active sites of PDIA1 work cooperatively as an interdomain redox relay mechanism that explains PDIA1 oxidative activity to form native disulfides and PDIA1 reductase activity to resolve scrambled disulfides. This mechanism suggests a new rationale for shutting down oxidative protein folding under ER redox imbalance. Whether it applies to physiological substrates in cells remains to be shown.
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Affiliation(s)
- Eduardo P Melo
- Centro de Ciências do Mar (CCMAR), University of Algarve, Faro, Portugal
| | | | - Cátia Correia
- Centro de Ciências do Mar (CCMAR), University of Algarve, Faro, Portugal
| | - Fernando Teodoro
- Centro de Ciências do Mar (CCMAR), University of Algarve, Faro, Portugal
| | - Carlos Lopes
- Centro de Ciências do Mar (CCMAR), University of Algarve, Faro, Portugal
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2
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Tang XH, Li X, Zhou Y, He YT, Wang ZY, Yang X, Wang W, Guo K, Zhang W, Sun Y, Li HQ, Li XF. Golgi anti-apoptotic proteins redundantly counteract cell death by inhibiting production of reactive oxygen species under endoplasmic reticulum stress. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2601-2617. [PMID: 35034107 DOI: 10.1093/jxb/erac011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Maintaining proteostasis in the endoplasmic reticulum (ER) is critical for cell viability and plant survival under adverse conditions. The unfolded protein response (UPR) pathways interact with reactive oxygen species (ROS) to precisely trigger adaptive outputs or cell death under ER stress with varying degrees. However, little information is known about the relationship between UPR signalling and ROS regulation. Here, Arabidopsis GOLGI ANTI-APOPTOTIC PROTEIN1 (GAAP1)-GAAP4 were found to play redundant positive roles under ER stress. Genetic analysis showed that GAAP4 played a role in INOSITOL-REQUIRING ENZYME (IRE1)-dependent and -independent pathways. In addition, GAAPs played negative roles to activate the adaptive UPR under conditions of stress. Quantitative biochemical analysis showed that mutations in GAAP genes decreased the oxidised glutathione content and altered the pattern of ROS and glutathione in early ER stress. When plants were challenged with unmitigated ER stress, mutations in GAAP advanced ROS accumulation, which was associated with a decline in adaptive UPR. These data indicated that GAAPs resist cell death by regulating glutathione content to inhibit ROS accumulation and maintain UPR during ER stress. They provide a basis for further analysis of the regulation of cell fate decision under ER stress.
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Affiliation(s)
- Xiao-Han Tang
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Xin Li
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Yan Zhou
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Yu-Ting He
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Zhi-Ying Wang
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Xue Yang
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Wei Wang
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Kun Guo
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Wei Zhang
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Yue Sun
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Hong-Qing Li
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
| | - Xiao-Fang Li
- School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai, P R China
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3
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Teratani T, Tomita K, Toma-Fukai S, Nakamura Y, Itoh T, Shimizu H, Shiraishi Y, Sugihara N, Higashiyama M, Shimizu T, Inoue I, Takenaka Y, Hokari R, Adachi T, Shimizu T, Miura S, Kanai T. Redox-dependent PPARγ/Tnpo1 complex formation enhances PPARγ nuclear localization and signaling. Free Radic Biol Med 2020; 156:45-56. [PMID: 32553752 DOI: 10.1016/j.freeradbiomed.2020.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/30/2020] [Accepted: 06/04/2020] [Indexed: 02/06/2023]
Abstract
The nuclear receptor peroxisome proliferator-activated receptor (PPAR)γ has been implicated in the pathogenesis of various human diseases including fatty liver. Although nuclear translocation of PPARγ plays an important role in PPARγ signaling, details of the translocation mechanisms have not been elucidated. Here we demonstrate that PPARγ2 translocates to the nucleus and activates signal transduction through H2O2-dependent formation of a PPARγ2 and transportin (Tnpo)1 complex via redox-sensitive disulfide bonds between cysteine (Cys)176 and Cys180 of the former and Cys512 of the latter. Using hepatocyte cultures and mouse models, we show that cytosolic H2O2/Tnpo1-dependent nuclear translocation enhances the amount of DNA-bound PPARγ and downstream signaling, leading to triglyceride accumulation in hepatocytes and liver. These findings expand our understanding of the mechanism underlying the nuclear translocation of PPARγ, and suggest that the PPARγ and Tnpo1 complex and surrounding redox environment are potential therapeutic targets in the treatment of PPARγ-related diseases.
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Affiliation(s)
- Toshiaki Teratani
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Kengo Tomita
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa-shi, Saitama, 359-8513, Japan.
| | - Sachiko Toma-Fukai
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan; Complex Molecular Systems Laboratory, Nara Institute of Science and Technology, Takayama-cho, Ikoma-shi, Nara, 630-0192, Japan
| | - Yutaro Nakamura
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Toshimasa Itoh
- Laboratory of Drug Design and Medicinal Chemistry, Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo, 194-8543, Japan
| | - Hikaru Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yasunaga Shiraishi
- Division of Environmental Medicine, National Defense Medical College Research Institute, 3-2 Namiki, Tokorozawa-shi, Saitama, 359-8513, Japan
| | - Nao Sugihara
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa-shi, Saitama, 359-8513, Japan
| | - Masaaki Higashiyama
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa-shi, Saitama, 359-8513, Japan
| | - Takahiko Shimizu
- Department of Advanced Aging Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan
| | - Ikuo Inoue
- Department of Endocrinology and Diabetes, Saitama Medical University, Moroyama, 350-0495, Japan
| | - Yasuhiro Takenaka
- Department of Endocrinology and Diabetes, Saitama Medical University, Moroyama, 350-0495, Japan; Department of Physiology, Graduate School of Medicine, Nippon Medical School, 1-25-16 Nezu, Bunkyo-ku, Tokyo, 113-8602, Japan
| | - Ryota Hokari
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa-shi, Saitama, 359-8513, Japan
| | - Takeshi Adachi
- Division of Cardiology, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa-shi, Saitama, 359-8513, Japan
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Soichiro Miura
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa-shi, Saitama, 359-8513, Japan; International University of Health and Welfare Graduate School, 1-24-1 Minami-Aoyama, Minato-ku, Tokyo, 107-0062, Japan
| | - Takanori Kanai
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
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4
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Scirè A, Cianfruglia L, Minnelli C, Bartolini D, Torquato P, Principato G, Galli F, Armeni T. Glutathione compartmentalization and its role in glutathionylation and other regulatory processes of cellular pathways. Biofactors 2019; 45:152-168. [PMID: 30561781 DOI: 10.1002/biof.1476] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/23/2018] [Accepted: 10/24/2018] [Indexed: 12/20/2022]
Abstract
Glutathione is considered the major non-protein low molecular weight modulator of redox processes and the most important thiol reducing agent of the cell. The biosynthesis of glutathione occurs in the cytosol from its constituent amino acids, but this tripeptide is also present in the most important cellular districts, such as mitochondria, nucleus, and endoplasmic reticulum, thus playing a central role in several metabolic pathways and cytoprotection mechanisms. Indeed, glutathione is involved in the modulation of various cellular processes and, not by chance, it is a ubiquitous determinant for redox signaling, xenobiotic detoxification, and regulation of cell cycle and death programs. The balance between its concentration and redox state is due to a complex series of interactions between biosynthesis, utilization, degradation, and transport. All these factors are of great importance to understand the significance of cellular redox balance and its relationship with physiological responses and pathological conditions. The purpose of this review is to give an overview on glutathione cellular compartmentalization. Information on its subcellular distribution provides a deeper understanding of glutathione-dependent processes and reflects the importance of compartmentalization in the regulation of specific cellular pathways. © 2018 BioFactors, 45(2):152-168, 2019.
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Affiliation(s)
- Andrea Scirè
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Ancona, Italy
| | - Laura Cianfruglia
- Department of Clinical Sciences, Section of Biochemistry, Biology and Physics, Università Politecnica delle Marche, Ancona, Italy
| | - Cristina Minnelli
- Department of Clinical Sciences, Section of Biochemistry, Biology and Physics, Università Politecnica delle Marche, Ancona, Italy
| | - Desirée Bartolini
- Clinical Biochemistry and Human Nutrition Labs, Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Pierangelo Torquato
- Clinical Biochemistry and Human Nutrition Labs, Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Giovanni Principato
- Department of Clinical Sciences, Section of Biochemistry, Biology and Physics, Università Politecnica delle Marche, Ancona, Italy
| | - Francesco Galli
- Clinical Biochemistry and Human Nutrition Labs, Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Tatiana Armeni
- Department of Clinical Sciences, Section of Biochemistry, Biology and Physics, Università Politecnica delle Marche, Ancona, Italy
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5
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Redox crosstalk at endoplasmic reticulum (ER) membrane contact sites (MCS) uses toxic waste to deliver messages. Cell Death Dis 2018; 9:331. [PMID: 29491367 PMCID: PMC5832433 DOI: 10.1038/s41419-017-0033-4] [Citation(s) in RCA: 147] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 09/29/2017] [Accepted: 10/03/2017] [Indexed: 12/17/2022]
Abstract
Many cellular redox reactions housed within mitochondria, peroxisomes and the endoplasmic reticulum (ER) generate hydrogen peroxide (H2O2) and other reactive oxygen species (ROS). The contribution of each organelle to the total cellular ROS production is considerable, but varies between cell types and also over time. Redox-regulatory enzymes are thought to assemble at a “redox triangle” formed by mitochondria, peroxisomes and the ER, assembling “redoxosomes” that sense ROS accumulations and redox imbalances. The redoxosome enzymes use ROS, potentially toxic by-products made by some redoxosome members themselves, to transmit inter-compartmental signals via chemical modifications of downstream proteins and lipids. Interestingly, important components of the redoxosome are ER chaperones and oxidoreductases, identifying ER oxidative protein folding as a key ROS producer and controller of the tri-organellar membrane contact sites (MCS) formed at the redox triangle. At these MCS, ROS accumulations could directly facilitate inter-organellar signal transmission, using ROS transporters. In addition, ROS influence the flux of Ca2+ ions, since many Ca2+ handling proteins, including inositol 1,4,5 trisphosphate receptors (IP3Rs), SERCA pumps or regulators of the mitochondrial Ca2+ uniporter (MCU) are redox-sensitive. Fine-tuning of these redox and ion signaling pathways might be difficult in older organisms, suggesting a dysfunctional redox triangle may accompany the aging process.
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6
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Zhong X, He T, Prashad AS, Wang W, Cohen J, Ferguson D, Tam AS, Sousa E, Lin L, Tchistiakova L, Gatto S, D'Antona A, Luan YT, Ma W, Zollner R, Zhou J, Arve B, Somers W, Kriz R. Mechanistic understanding of the cysteine capping modifications of antibodies enables selective chemical engineering in live mammalian cells. J Biotechnol 2017; 248:48-58. [PMID: 28300660 DOI: 10.1016/j.jbiotec.2017.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 03/02/2017] [Accepted: 03/06/2017] [Indexed: 12/21/2022]
Abstract
Protein modifications by intricate cellular machineries often redesign the structure and function of existing proteins to impact biological networks. Disulfide bond formation between cysteine (Cys) pairs is one of the most common modifications found in extracellularly-destined proteins, key to maintaining protein structure. Unpaired surface cysteines on secreted mammalian proteins are also frequently found disulfide-bonded with free Cys or glutathione (GSH) in circulation or culture, the mechanism for which remains unknown. Here we report that these so-called Cys-capping modifications take place outside mammalian cells, not in the endoplasmic reticulum (ER) where oxidoreductase-mediated protein disulfide formation occurs. Unpaired surface cysteines of extracellularly-arrived proteins such as antibodies are uncapped upon secretion before undergoing disulfide exchange with cystine or oxidized GSH in culture medium. This observation has led to a feasible way to selectively modify the nucleophilic thiol side-chain of cell-surface or extracellular proteins in live mammalian cells, by applying electrophiles with a chemical handle directly into culture medium. These findings provide potentially an effective approach for improving therapeutic conjugates and probing biological systems.
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Affiliation(s)
- Xiaotian Zhong
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States.
| | - Tao He
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Amar S Prashad
- Pharmaceutical Sciences, Medicinal Sciences, Pfizer Worldwide R&D, Pearl River, NY 10965,United States
| | | | - Justin Cohen
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Darren Ferguson
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Amy S Tam
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Eric Sousa
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Laura Lin
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Lioudmila Tchistiakova
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Scott Gatto
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Aaron D'Antona
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | | | - Weijun Ma
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Richard Zollner
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Jing Zhou
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Bo Arve
- Pharmaceutical Sciences, Medicinal Sciences, Pfizer Worldwide R&D, Pearl River, NY 10965,United States
| | - Will Somers
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
| | - Ronald Kriz
- BioMedicine Design, Medicinal Sciences, Pfizer Worldwide R&D, Cambridge, MA 02139, United States
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7
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Protein folding alterations in amyotrophic lateral sclerosis. Brain Res 2016; 1648:633-649. [PMID: 27064076 DOI: 10.1016/j.brainres.2016.04.010] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/04/2016] [Accepted: 04/05/2016] [Indexed: 02/07/2023]
Abstract
Protein misfolding leads to the formation of aggregated proteins and protein inclusions, which are associated with synaptic loss and neuronal death in neurodegenerative diseases. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that targets motor neurons in the brain, brainstem and spinal cord. Several proteins misfold and are associated either genetically or pathologically in ALS, including superoxide dismutase 1 (SOD1), Tar DNA binding protein-43 (TDP-43), Ubiquilin-2, p62, VCP, and dipeptide repeat proteins produced by unconventional repeat associated non-ATG translation of the repeat expansion in C9ORF72. Chaperone proteins, including heat shock proteins (Hsp׳s) and the protein disulphide isomerase (PDI) family, assist in protein folding and therefore can prevent protein misfolding, and have been implicated as being protective in ALS. In this review we provide an overview of the current literature regarding the molecular mechanisms of protein misfolding and aggregation in ALS, and the role of chaperones as potential targets for therapeutic intervention. This article is part of a Special Issue entitled SI:ER stress.
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8
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Helander L, Sharma A, Krokan HE, Plaetzer K, Krammer B, Tortik N, Gederaas OA, Slupphaug G, Hagen L. Photodynamic treatment with hexyl-aminolevulinate mediates reversible thiol oxidation in core oxidative stress signaling proteins. MOLECULAR BIOSYSTEMS 2016; 12:796-805. [DOI: 10.1039/c5mb00744e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
HAL-PDT mediates reversible cysteine oxidation in core proteins involved in oxidative stress and apoptotic signalling.
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Affiliation(s)
- Linda Helander
- Department of Cancer Research and Molecular Medicine
- Norwegian University of Science and Technology
- Norway
| | - Animesh Sharma
- Department of Cancer Research and Molecular Medicine
- Norwegian University of Science and Technology
- Norway
- PROMEC Core Facility for Proteomics and Metabolomics
- Norwegian University of Science and Technology
| | - Hans E. Krokan
- Department of Cancer Research and Molecular Medicine
- Norwegian University of Science and Technology
- Norway
| | - Kristjan Plaetzer
- Laboratory of Photodynamic Inactivation of Microorganisms
- Department of Materials Science and Physics
- University of Salzburg
- Austria
| | - Barbara Krammer
- Division of Molecular Tumor Biology
- Department of Molecular Biology
- University of Salzburg
- Austria
| | - Nicole Tortik
- Laboratory of Photodynamic Inactivation of Microorganisms
- Department of Materials Science and Physics
- University of Salzburg
- Austria
| | - Odrun A. Gederaas
- Department of Cancer Research and Molecular Medicine
- Norwegian University of Science and Technology
- Norway
| | - Geir Slupphaug
- Department of Cancer Research and Molecular Medicine
- Norwegian University of Science and Technology
- Norway
- PROMEC Core Facility for Proteomics and Metabolomics
- Norwegian University of Science and Technology
| | - Lars Hagen
- Department of Cancer Research and Molecular Medicine
- Norwegian University of Science and Technology
- Norway
- PROMEC Core Facility for Proteomics and Metabolomics
- Norwegian University of Science and Technology
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9
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Ramming T, Kanemura S, Okumura M, Inaba K, Appenzeller-Herzog C. Cysteines 208 and 241 in Ero1α are required for maximal catalytic turnover. Redox Biol 2015; 7:14-20. [PMID: 26609561 PMCID: PMC4683387 DOI: 10.1016/j.redox.2015.11.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 11/11/2015] [Accepted: 11/12/2015] [Indexed: 12/31/2022] Open
Abstract
Endoplasmic reticulum (ER) oxidoreductin 1α (Ero1α) is a disulfide producer in the ER of mammalian cells. Besides four catalytic cysteines (Cys94, Cys99, Cys394, Cys397), Ero1α harbors four regulatory cysteines (Cys104, Cys131, Cys208, Cys241). These cysteines mediate the formation of inhibitory intramolecular disulfide bonds, which adapt the activation state of the enzyme to the redox environment in the ER through feedback signaling. Accordingly, disulfide production by Ero1α is accelerated by reducing conditions, which minimize the formation of inhibitory disulfides, or by mutations of regulatory cysteines. Here we report that reductive stimulation enhances Ero1α activity more potently than the mutation of cysteines. Specifically, mutation of Cys208/Cys241 does not mechanistically mimic reductive stimulation, as it lowers the turnover rate of Ero1α in presence of a reducing agent. The Cys208/Cys241 pair therefore fulfills a function during catalysis that reaches beyond negative regulation. In agreement, we identify a reciprocal crosstalk between the stabilities of the Cys208–Cys241 disulfide and the inhibitory disulfide bonds involving Cys104 and Cys131, which also controls the recruitment of the H2O2 scavenger GPx8 to Ero1α. Two possible mechanisms by which thiol–disulfide exchange at the Cys208/Cys241 pair stimulates the catalytic turnover under reducing conditions are discussed. Reductive stimulation enhances Ero1α more potently than cysteine mutations. Cys208/Cys241 controls Ero1α activity beyond negative regulation. Other regulatory cysteines communicate with Cys208/Cys241 within Ero1α. Other regulatory cysteines control the binding of GPx8 to Ero1α through Cys208/Cys241.
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Affiliation(s)
- Thomas Ramming
- Division of Molecular & Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, 4056, Basel, Switzerland
| | - Shingo Kanemura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Katahira 2-1-1, Sendai, 980-8577, Japan
| | - Masaki Okumura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Katahira 2-1-1, Sendai, 980-8577, Japan
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Katahira 2-1-1, Sendai, 980-8577, Japan.
| | - Christian Appenzeller-Herzog
- Division of Molecular & Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, 4056, Basel, Switzerland.
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10
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Anelli T, Sannino S, Sitia R. Proteostasis and "redoxtasis" in the secretory pathway: Tales of tails from ERp44 and immunoglobulins. Free Radic Biol Med 2015; 83:323-30. [PMID: 25744412 DOI: 10.1016/j.freeradbiomed.2015.02.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/20/2015] [Accepted: 02/22/2015] [Indexed: 01/09/2023]
Abstract
In multicellular organisms, some cells are given the task of secreting huge quantities of proteins. To comply with their duty, they generally equip themselves with a highly developed endoplasmic reticulum (ER) and downstream organelles in the secretory pathway. These professional secretors face paramount proteostatic challenges in that they need to couple efficiency and fidelity in their secretory processes. On one hand, stringent quality control (QC) mechanisms operate from the ER onward to check the integrity of the secretome. On the other, the pressure to secrete can be overwhelming, as for instance on antibody-producing cells during infection. Maintaining homeostasis is particularly hard when the products to be released contain disulfide bonds, because oxidative folding entails production of reactive oxygen species. How are redox homeostasis ("redoxtasis") and proteostasis maintained despite the massive fluxes of cargo proteins traversing the pathway? Here we describe recent findings on how ERp44, a multifunctional chaperone of the secretory pathway, can modulate these processes integrating protein QC, redoxtasis, and calcium signaling.
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Affiliation(s)
- Tiziana Anelli
- Divisions of Genetics and Cell Biology, IRCCS Ospedale San Raffaele and Università Vita-Salute San Raffaele, 20132 Milan, Italy
| | - Sara Sannino
- Divisions of Genetics and Cell Biology, IRCCS Ospedale San Raffaele and Università Vita-Salute San Raffaele, 20132 Milan, Italy
| | - Roberto Sitia
- Divisions of Genetics and Cell Biology, IRCCS Ospedale San Raffaele and Università Vita-Salute San Raffaele, 20132 Milan, Italy.
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11
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Hudson DA, Gannon SA, Thorpe C. Oxidative protein folding: from thiol-disulfide exchange reactions to the redox poise of the endoplasmic reticulum. Free Radic Biol Med 2015; 80:171-82. [PMID: 25091901 PMCID: PMC4312752 DOI: 10.1016/j.freeradbiomed.2014.07.037] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Accepted: 07/23/2014] [Indexed: 12/21/2022]
Abstract
This review examines oxidative protein folding within the mammalian endoplasmic reticulum (ER) from an enzymological perspective. In protein disulfide isomerase-first (PDI-first) pathways of oxidative protein folding, PDI is the immediate oxidant of reduced client proteins and then addresses disulfide mispairings in a second isomerization phase. In PDI-second pathways the initial oxidation is PDI-independent. Evidence for the rapid reduction of PDI by reduced glutathione is presented in the context of PDI-first pathways. Strategies and challenges are discussed for determination of the concentrations of reduced and oxidized glutathione and of the ratios of PDI(red):PDI(ox). The preponderance of evidence suggests that the mammalian ER is more reducing than first envisaged. The average redox state of major PDI-family members is largely to almost totally reduced. These observations are consistent with model studies showing that oxidative protein folding proceeds most efficiently at a reducing redox poise consistent with a stoichiometric insertion of disulfides into client proteins. After a discussion of the use of natively encoded fluorescent probes to report the glutathione redox poise of the ER, this review concludes with an elaboration of a complementary strategy to discontinuously survey the redox state of as many redox-active disulfides as can be identified by ratiometric LC-MS-MS methods. Consortia of oxidoreductases that are in redox equilibrium can then be identified and compared to the glutathione redox poise of the ER to gain a more detailed understanding of the factors that influence oxidative protein folding within the secretory compartment.
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Affiliation(s)
- Devin A Hudson
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Shawn A Gannon
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Colin Thorpe
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA.
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12
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Hydrogen peroxide administered into the rat spinal cord at the level elevated by contusion spinal cord injury oxidizes proteins, DNA and membrane phospholipids, and induces cell death: attenuation by a metalloporphyrin. Neuroscience 2014; 285:81-96. [PMID: 25451281 DOI: 10.1016/j.neuroscience.2014.10.063] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Revised: 10/24/2014] [Accepted: 10/28/2014] [Indexed: 01/23/2023]
Abstract
We previously demonstrated that hydrogen peroxide concentration ([H2O2]) significantly increases after spinal cord injury (SCI). The present study explored (1) whether SCI-elevated [H2O2] is sufficient to induce oxidation and cell death, (2) if apoptosis is a pathway of H2O2-induced cell death, and (3) whether H2O2-induced oxidation and cell death could be reversed by treatment with the catalytic antioxidant Mn (III) tetrakis (4-benzoic acid) porphyrin (MnTBAP). H2O2 was perfused through a microcannula into the uninjured rat spinal cord to mimic the conditions induced by SCI. Protein and DNA oxidation, membrane phospholipids peroxidation (MLP), cell death and apoptosis were characterized by histochemical and immunohistochemical staining with antibodies against markers of oxidation and apoptosis. Stained cells were quantified in sections of H2O2-, or artificial cerebrospinal fluid (ACSF)-exposed with vehicle-, or MnTBAP-treated groups. Compared with ACSF-exposed animals, SCI-elevated [H2O2] significantly increased intracellular protein and DNA oxidation by threefold and MLP by eightfold in neurons, respectively. H2O2-elevated extracellular malondialdehyde was measured by microdialysis sampling. We demonstrated that SCI-elevated [H2O2] significantly increased extracellular malondialdehyde above pre-injury levels. H2O2 also significantly increased cell loss and the numbers of terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate-(dUTP)-biotin nick end labeling (TUNEL)-positive and active caspase-3-positive neurons by 2.3-, 2.8-, and 5.6-fold compared to ACSF controls, respectively. Our results directly and unequivocally demonstrate that SCI-elevated [H2O2] contributes to post-SCI MLP, protein, and DNA oxidation to induce cell death. Therefore, we conclude that (1) the role of H2O2 in secondary SCI is pro-oxidation and pro-cell death, (2) apoptosis is a pathway for SCI-elevated [H2O2] to induce cell death, (3) caspase activation is a mechanism of H2O2-induced apoptosis after SCI, and (4) MnTBAP treatment significantly decreased H2O2-induced oxidation, cell loss, and apoptosis to the levels of ACSF controls, further supporting MnTBAP's ability to scavenge H2O2 by in vivo evidence.
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13
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Balancing oxidative protein folding: The influences of reducing pathways on disulfide bond formation. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:1383-90. [DOI: 10.1016/j.bbapap.2014.02.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 01/31/2014] [Accepted: 02/07/2014] [Indexed: 11/20/2022]
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14
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Stocki P, Chapman DC, Beach LA, Williams DB. Depletion of cyclophilins B and C leads to dysregulation of endoplasmic reticulum redox homeostasis. J Biol Chem 2014; 289:23086-23096. [PMID: 24990953 DOI: 10.1074/jbc.m114.570911] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Protein folding within the endoplasmic reticulum is assisted by molecular chaperones and folding catalysts that include members of the protein-disulfide isomerase and peptidyl-prolyl isomerase families. In this report, we examined the contributions of the cyclophilin subset of peptidyl-prolyl isomerases to protein folding and identified cyclophilin C as an endoplasmic reticulum (ER) cyclophilin in addition to cyclophilin B. Using albumin and transferrin as models of cis-proline-containing proteins in human hepatoma cells, we found that combined knockdown of cyclophilins B and C delayed transferrin secretion but surprisingly resulted in more efficient oxidative folding and secretion of albumin. Examination of the oxidation status of ER protein-disulfide isomerase family members revealed a shift to a more oxidized state. This was accompanied by a >5-fold elevation in the ratio of oxidized to total glutathione. This "hyperoxidation" phenotype could be duplicated by incubating cells with the cyclophilin inhibitor cyclosporine A, a treatment that triggered efficient ER depletion of cyclophilins B and C by inducing their secretion to the medium. To identify the pathway responsible for ER hyperoxidation, we individually depleted several enzymes that are known or suspected to deliver oxidizing equivalents to the ER: Ero1αβ, VKOR, PRDX4, or QSOX1. Remarkably, none of these enzymes contributed to the elevated oxidized to total glutathione ratio induced by cyclosporine A treatment. These findings establish cyclophilin C as an ER cyclophilin, demonstrate the novel involvement of cyclophilins B and C in ER redox homeostasis, and suggest the existence of an additional ER oxidative pathway that is modulated by ER cyclophilins.
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Affiliation(s)
- Pawel Stocki
- Department of Biochemistry, University of Toronto, Toronto M5S 1A8, Canada
| | - Daniel C Chapman
- Department of Biochemistry, University of Toronto, Toronto M5S 1A8, Canada
| | - Lori A Beach
- Department of Biochemistry, University of Toronto, Toronto M5S 1A8, Canada
| | - David B Williams
- Department of Biochemistry, University of Toronto, Toronto M5S 1A8, Canada.
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15
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Góngora-Benítez M, Tulla-Puche J, Albericio F. Multifaceted Roles of Disulfide Bonds. Peptides as Therapeutics. Chem Rev 2013; 114:901-26. [DOI: 10.1021/cr400031z] [Citation(s) in RCA: 388] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Miriam Góngora-Benítez
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
| | - Judit Tulla-Puche
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
| | - Fernando Albericio
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
- Department
of Organic Chemistry, University of Barcelona, Barcelona, 08028 Spain
- School of Chemistry & Physics, University of KwaZulu-Natal, 4001 Durban, South Africa
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16
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Battle DM, Gunasekara SD, Watson GR, Ahmed EM, Saysell CG, Altaf N, Sanusi AL, Munipalle PC, Scoones D, Walker J, Viswanath Y, Benham AM. Expression of the endoplasmic reticulum oxidoreductase Ero1α in gastro-intestinal cancer reveals a link between homocysteine and oxidative protein folding. Antioxid Redox Signal 2013; 19:24-35. [PMID: 23373818 DOI: 10.1089/ars.2012.4651] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AIM Ero proteins are central to oxidative protein folding in the endoplasmic reticulum (ER), but their expression varies in a tissue-specific manner. The aim of this work was to establish the expression of Ero1α in the digestive system and to examine the behavior of Ero1α in premalignant Barrett's esophagus, esophageal (OE) and gastric cancers and esophageal cancer cell lines. RESULTS Ero1α is expressed in the columnar epithelium of Barrett's tissue, and in OE tumors and gastric tumors. Homocysteine, a precursor in the metabolism of cysteine and methionine, induces the active Ox1 form of Ero1α in the OE cancer cell line OE33. INNOVATION These results demonstrate for the first time that Ero1α can sense the level of an amino acid precursor, identifying a potential link between diet, antioxidants, and oxidative protein folding in the ER. CONCLUSION The high expression of Ero1α in cancers of the esophagus and stomach demonstrates the importance of ER redox regulation in the gastro-intestinal (GI) tract in health and disease. Proteins and metabolites involved in disulfide bond formation and redox regulation may be suitable targets for both biomarker and drug development in GI cancer.
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Affiliation(s)
- Danielle M Battle
- School of Biological and Biomedical Sciences, Durham University, Durham, England
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17
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Birk J, Ramming T, Odermatt A, Appenzeller-Herzog C. Green fluorescent protein-based monitoring of endoplasmic reticulum redox poise. Front Genet 2013; 4:108. [PMID: 23781233 PMCID: PMC3680709 DOI: 10.3389/fgene.2013.00108] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 05/27/2013] [Indexed: 01/08/2023] Open
Abstract
Pathological endoplasmic reticulum (ER) stress is tightly linked to the accumulation of reactive oxidants, which can be both upstream and downstream of ER stress. Accordingly, detrimental intracellular stress signals are amplified through establishment of a vicious cycle. An increasing number of human diseases are characterized by tissue atrophy in response to ER stress and oxidative injury. Experimental monitoring of stress-induced, time-resolved changes in ER reduction-oxidation (redox) states is therefore important. Organelle-specific examination of redox changes has been facilitated by the advent of genetically encoded, fluorescent probes, which can be targeted to different subcellular locations by means of specific amino acid extensions. These probes include redox-sensitive green fluorescent proteins (roGFPs) and the yellow fluorescent protein-based redox biosensor HyPer. In the case of roGFPs, variants with known specificity toward defined redox couples are now available. Here, we review the experimental framework to measure ER redox changes using ER-targeted fluorescent biosensors. Advantages and drawbacks of plate-reader and microscopy-based measurements are discussed, and the power of these techniques demonstrated in the context of selected cell culture models for ER stress.
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Affiliation(s)
- Julia Birk
- Division of Molecular & Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel Basel, Switzerland
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18
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Avezov E, Cross BCS, Kaminski Schierle GS, Winters M, Harding HP, Melo EP, Kaminski CF, Ron D. Lifetime imaging of a fluorescent protein sensor reveals surprising stability of ER thiol redox. ACTA ACUST UNITED AC 2013; 201:337-49. [PMID: 23589496 PMCID: PMC3628511 DOI: 10.1083/jcb.201211155] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Interfering with disulfide bond formation impedes protein folding and promotes endoplasmic reticulum (ER) stress. Due to limitations in measurement techniques, the relationships of altered thiol redox and ER stress have been difficult to assess. We report that fluorescent lifetime measurements circumvented the crippling dimness of an ER-tuned fluorescent redox-responsive probe (roGFPiE), faithfully tracking the activity of the major ER-localized protein disulfide isomerase, PDI. In vivo lifetime imaging by time-correlated single-photon counting (TCSPC) recorded subtle changes in ER redox poise induced by exposure of mammalian cells to a reducing environment but revealed an unanticipated stability of redox to fluctuations in unfolded protein load. By contrast, TCSPC of roGFPiE uncovered a hitherto unsuspected reductive shift in the mammalian ER upon loss of luminal calcium, whether induced by pharmacological inhibition of calcium reuptake into the ER or by physiological activation of release channels. These findings recommend fluorescent lifetime imaging as a sensitive method to track ER redox homeostasis in mammalian cells.
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Affiliation(s)
- Edward Avezov
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Cambridge CB2 0QQ, England, UK
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19
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Sarkar DD, Edwards SK, Mauser JA, Suarez AM, Serowoky MA, Hudok NL, Hudok PL, Nuñez M, Weber CS, Lynch RM, Miyashita O, Tsao TS. Increased redox-sensitive green fluorescent protein reduction potential in the endoplasmic reticulum following glutathione-mediated dimerization. Biochemistry 2013; 52:3332-45. [PMID: 23594148 DOI: 10.1021/bi400052u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
As the endoplasmic reticulum (ER) is the compartment where disulfide bridges in secreted and cell surface proteins are formed, the disturbance of its redox state has profound consequences, yet regulation of ER redox potential remains poorly understood. To monitor the ER redox state in live cells, several fluorescence-based sensors have been developed. However, these sensors have yielded results that are inconsistent with each other and with earlier non-fluorescence-based studies. One particular green fluorescent protein (GFP)-based redox sensor, roGFP1-iL, could detect oxidizing changes in the ER despite having a reduction potential significantly lower than that previously reported for the ER. We have confirmed these observations and determined the mechanisms by which roGFP1-iL detects oxidizing changes. First, glutathione mediates the formation of disulfide-bonded roGFP1-iL dimers with an intermediate excitation fluorescence spectrum resembling a mixture of oxidized and reduced monomers. Second, glutathione facilitates dimerization of roGFP1-iL, which shifted the equilibrium from oxidized monomers to dimers, thereby increasing the molecule's reduction potential compared with that of a dithiol redox buffer. We conclude that the glutathione redox couple in the ER significantly increased the reduction potential of roGFP1-iL in vivo by facilitating its dimerization while preserving its ratiometric nature, which makes it suitable for monitoring oxidizing and reducing changes in the ER with a high degree of reliability in real time. The ability of roGFP1-iL to detect both oxidizing and reducing changes in ER and its dynamic response in glutathione redox buffer between approximately -190 and -130 mV in vitro suggests a range of ER redox potentials consistent with those determined by earlier approaches that did not involve fluorescent sensors.
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Affiliation(s)
- Deboleena Dipak Sarkar
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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20
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Birk J, Meyer M, Aller I, Hansen HG, Odermatt A, Dick TP, Meyer AJ, Appenzeller-Herzog C. Endoplasmic reticulum: reduced and oxidized glutathione revisited. J Cell Sci 2013; 126:1604-17. [PMID: 23424194 DOI: 10.1242/jcs.117218] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The reducing power of glutathione, expressed by its reduction potential EGSH, is an accepted measure for redox conditions in a given cell compartment. In the endoplasmic reticulum (ER), EGSH is less reducing than elsewhere in the cell. However, attempts to determine EGSH(ER) have been inconsistent and based on ineligible assumptions. Using a codon-optimized and evidently glutathione-specific glutaredoxin-coupled redox-sensitive green fluorescent protein (roGFP) variant, we determined EGSH(ER) in HeLa cells as -208±4 mV (at pH 7.0). At variance with existing models, this is not oxidizing enough to maintain the known redox state of protein disulfide isomerase family enzymes. Live-cell microscopy confirmed ER hypo-oxidation upon inhibition of ER Ca(2+) import. Conversely, stressing the ER with a glycosylation inhibitor did not lead to more reducing conditions, as reported for yeast. These results, which for the first time establish the oxidative capacity of glutathione in the ER, illustrate a context-dependent interplay between ER stress and EGSH(ER). The reported development of ER-localized EGSH sensors will enable more targeted in vivo redox analyses in ER-related disorders.
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Affiliation(s)
- Julia Birk
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, 4056 Basel, Switzerland
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21
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Zito E, Hansen H, Yeo G, Fujii J, Ron D. Endoplasmic reticulum thiol oxidase deficiency leads to ascorbic acid depletion and noncanonical scurvy in mice. Mol Cell 2012; 48:39-51. [PMID: 22981861 PMCID: PMC3473360 DOI: 10.1016/j.molcel.2012.08.010] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 07/16/2012] [Accepted: 08/07/2012] [Indexed: 12/16/2022]
Abstract
Endoplasmic reticulum (ER) thiol oxidases initiate a disulfide relay to oxidatively fold secreted proteins. We found that combined loss-of-function mutations in genes encoding the ER thiol oxidases ERO1α, ERO1β, and PRDX4 compromised the extracellular matrix in mice and interfered with the intracellular maturation of procollagen. These severe abnormalities were associated with an unexpectedly modest delay in disulfide bond formation in secreted proteins but a profound, 5-fold lower procollagen 4-hydroxyproline content and enhanced cysteinyl sulfenic acid modification of ER proteins. Tissue ascorbic acid content was lower in mutant mice, and ascorbic acid supplementation improved procollagen maturation and lowered sulfenic acid content in vivo. In vitro, the presence of a sulfenic acid donor accelerated the oxidative inactivation of ascorbate by an H(2)O(2)-generating system. Compromised ER disulfide relay thus exposes protein thiols to competing oxidation to sulfenic acid, resulting in depletion of ascorbic acid, impaired procollagen proline 4-hydroxylation, and a noncanonical form of scurvy.
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Affiliation(s)
- Ester Zito
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Cambridge CB2 0QQ, UK
| | - Henning Gram Hansen
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Cambridge CB2 0QQ, UK
| | - Giles S.H. Yeo
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Cambridge CB2 0QQ, UK
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan
| | - David Ron
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Cambridge CB2 0QQ, UK
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