1
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Netto LES, Machado LESF. Preferential redox regulation of cysteine‐based protein tyrosine phosphatases: structural and biochemical diversity. FEBS J 2022; 289:5480-5504. [DOI: 10.1111/febs.16466] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 03/20/2022] [Accepted: 04/28/2022] [Indexed: 12/30/2022]
Affiliation(s)
- Luís Eduardo S. Netto
- Departamento de Genética e Biologia Evolutiva Instituto de Biociências Universidade de São Paulo Brazil
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2
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Yang Y, Zhao Y, Zheng W, Zhao Y, Zhao S, Wang Q, Bai L, Zhang T, Huang S, Song C, Yuan M, Guo Y. Phosphatidylinositol 3-phosphate regulates SCAB1-mediated F-actin reorganization during stomatal closure in Arabidopsis. THE PLANT CELL 2022; 34:477-494. [PMID: 34850207 PMCID: PMC8773959 DOI: 10.1093/plcell/koab264] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 10/22/2021] [Indexed: 05/20/2023]
Abstract
Stomatal movement is critical for plant responses to environmental changes and is regulated by the important signaling molecule phosphatidylinositol 3-phosphate (PI3P). However, the molecular mechanism underlying this process is not well understood. In this study, we show that PI3P binds to stomatal closure-related actin-binding protein1 (SCAB1), a plant-specific F-actin-binding and -bundling protein, and inhibits the oligomerization of SCAB1 to regulate its activity on F-actin in guard cells during stomatal closure in Arabidopsis thaliana. SCAB1 binds specifically to PI3P, but not to other phosphoinositides. Treatment with wortmannin, an inhibitor of phosphoinositide kinase that generates PI3P, leads to an increase of the intermolecular interaction and oligomerization of SCAB1, stabilization of F-actin, and retardation of F-actin reorganization during abscisic acid (ABA)-induced stomatal closure. When the binding activity of SCAB1 to PI3P is abolished, the mutated proteins do not rescue the stability and realignment of F-actin regulated by SCAB1 and the stomatal closure in the scab1 mutant. The expression of PI3P biosynthesis genes is consistently induced when the plants are exposed to drought and ABA treatments. Furthermore, the binding of PI3P to SCAB1 is also required for vacuolar remodeling during stomatal closure. Our results illustrate a PI3P-regulated pathway during ABA-induced stomatal closure, which involves the mediation of SCAB1 activity in F-actin reorganization.
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Affiliation(s)
| | | | | | - Yang Zhao
- Shanghai Center for Plant Stress Biology, CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Shuangshuang Zhao
- Key Life Science College, Laboratory of Plant Stress, Shandong Normal University, Jinan 250014, China
| | - Qiannan Wang
- School of Life Sciences, Center for Plant Biology, Tsinghua University, Beijing 100084, China
| | - Li Bai
- College of Biological Sciences, State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100193, China
| | - Tianren Zhang
- College of Biological Sciences, State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100193, China
| | - Shanjin Huang
- School of Life Sciences, Center for Plant Biology, Tsinghua University, Beijing 100084, China
| | - Chunpeng Song
- Collaborative Innovation Center of Crop Stress Biology, Henan Province, Institute of Plant Stress Biology, Henan University, Kaifeng 475001, China
| | - Ming Yuan
- College of Biological Sciences, State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100193, China
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3
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Taheri-Ledari R, Fazeli A, Kashtiaray A, Salek Soltani S, Maleki A, Zhang W. Cefixime-Containing Silica Nanoseeds Coated by a Hybrid PVA-Gold Network with a Cys-Arg Dipeptide Conjugation: Enhanced Antimicrobial and Drug Release Properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 38:132-146. [PMID: 34961315 DOI: 10.1021/acs.langmuir.1c02233] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Therapeutic nano-bioconjugates (TNBCs) as an advanced class of drug delivery systems have attracted much attention due to more efficacy than the individual medications. Hence, in this study, a novel anti-infection TNBC system is designed based on highly porous silica nanoparticles, gold nanoparticles (AuNPs), and hybridized polyvinyl alcohol (PVA) for the efficient delivery of cefixime (CFM). Furthermore, a conjugation of cysteine-arginine (CR) dipeptide is made onto the surfaces for the enhancement of cell adhesion. Concisely, the AuNPs incorporated inside the PVA network play the key role in the controlled release process triggered by localized surface plasmon resonance (LSPR) heating. The drug content of the CFM-containing cargo (named as CFM@SiO2/PVA/Au-CR) and related release profile have been precisely studied by the confirmed analytical methods. Eventually, confocal microscopy on the stained cells has revealed that the TNBC particles are capable of entering the Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) bacterial cells better than the individual CFM. Also, optical density experiments (OD600) have corroborated that the prepared CFM@SiO2/PVA/Au-CR TNBC includes a high antimicrobial effect on K. pneumoniae and E. coli cells with (93.0 ± 1.5) % and (86.8 ± 1.0) % success rates, respectively, whereas the same dosage of the individual CFM has shown a lower effect on the cell growth rate. Also, estimation of minimum inhibitory/bactericidal concentrations (MIC/MBC) confirmed the enhanced antibacterial property of the CFM through the presented delivery method. Overall, this product is suggested to be clinically administrated instead of the individual CFM due to its high efficacy and containing lower dosage of the antibiotic drug.
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Affiliation(s)
- Reza Taheri-Ledari
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
| | - Atefeh Fazeli
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
| | - Amir Kashtiaray
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
| | - Siavash Salek Soltani
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
| | - Ali Maleki
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
| | - Wenjie Zhang
- Department of Nuclear Medicine, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu 610041, Sichuan Province, P. R. China
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4
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Hay IM, Fearnley GW, Rios P, Köhn M, Sharpe HJ, Deane JE. The receptor PTPRU is a redox sensitive pseudophosphatase. Nat Commun 2020; 11:3219. [PMID: 32591542 PMCID: PMC7320164 DOI: 10.1038/s41467-020-17076-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 06/05/2020] [Indexed: 01/06/2023] Open
Abstract
The receptor-linked protein tyrosine phosphatases (RPTPs) are key regulators of cell-cell communication through the control of cellular phosphotyrosine levels. Most human RPTPs possess an extracellular receptor domain and tandem intracellular phosphatase domains: comprising an active membrane proximal (D1) domain and an inactive distal (D2) pseudophosphatase domain. Here we demonstrate that PTPRU is unique amongst the RPTPs in possessing two pseudophosphatase domains. The PTPRU-D1 displays no detectable catalytic activity against a range of phosphorylated substrates and we show that this is due to multiple structural rearrangements that destabilise the active site pocket and block the catalytic cysteine. Upon oxidation, this cysteine forms an intramolecular disulphide bond with a vicinal "backdoor" cysteine, a process thought to reversibly inactivate related phosphatases. Importantly, despite the absence of catalytic activity, PTPRU binds substrates of related phosphatases strongly suggesting that this pseudophosphatase functions in tyrosine phosphorylation by competing with active phosphatases for the binding of substrates.
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Affiliation(s)
- Iain M Hay
- Cambridge Institute for Medical Research, Hills Road, Cambridge, CB2 0XY, UK
- Signalling Programme, Babraham Institute, Cambridge, CB22 3AT, UK
| | - Gareth W Fearnley
- Cambridge Institute for Medical Research, Hills Road, Cambridge, CB2 0XY, UK
- Signalling Programme, Babraham Institute, Cambridge, CB22 3AT, UK
| | - Pablo Rios
- Signalling Research Centres BIOSS and CIBSS, and Faculty of Biology, University of Freiburg, Schänzlestr. 18, Freiburg, D-79104, Germany
| | - Maja Köhn
- Signalling Research Centres BIOSS and CIBSS, and Faculty of Biology, University of Freiburg, Schänzlestr. 18, Freiburg, D-79104, Germany
| | - Hayley J Sharpe
- Cambridge Institute for Medical Research, Hills Road, Cambridge, CB2 0XY, UK.
- Signalling Programme, Babraham Institute, Cambridge, CB22 3AT, UK.
| | - Janet E Deane
- Cambridge Institute for Medical Research, Hills Road, Cambridge, CB2 0XY, UK.
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5
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Reiterer V, Pawłowski K, Desrochers G, Pause A, Sharpe HJ, Farhan H. The dead phosphatases society: a review of the emerging roles of pseudophosphatases. FEBS J 2020; 287:4198-4220. [PMID: 32484316 DOI: 10.1111/febs.15431] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/12/2020] [Accepted: 05/27/2020] [Indexed: 12/11/2022]
Abstract
Phosphatases are a diverse family of enzymes, comprising at least 10 distinct protein folds. Like most other enzyme families, many have sequence variations that predict an impairment or loss of catalytic activity classifying them as pseudophosphatases. Research on pseudoenzymes is an emerging area of interest, with new biological functions repurposed from catalytically active relatives. Here, we provide an overview of the pseudophosphatases identified to date in all major phosphatase families. We will highlight the degeneration of the various catalytic sequence motifs and discuss the challenges associated with the experimental determination of catalytic inactivity. We will also summarize the role of pseudophosphatases in various diseases and discuss the major challenges and future directions in this field.
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Affiliation(s)
| | | | - Guillaume Desrochers
- Department of Biochemistry, McGill University, Montréal, QC, Canada.,Goodman Cancer Research Centre, McGill University, Montréal, QC, Canada
| | - Arnim Pause
- Department of Biochemistry, McGill University, Montréal, QC, Canada.,Goodman Cancer Research Centre, McGill University, Montréal, QC, Canada
| | | | - Hesso Farhan
- Institute of Basic Medical Sciences, University of Oslo, Norway
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6
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Deweirdt J, Quignard JF, Lacomme S, Gontier E, Mornet S, Savineau JP, Marthan R, Guibert C, Baudrimont I. In vitro study of carbon black nanoparticles on human pulmonary artery endothelial cells: effects on calcium signaling and mitochondrial alterations. Arch Toxicol 2020; 94:2331-2348. [PMID: 32394085 DOI: 10.1007/s00204-020-02764-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 04/22/2020] [Indexed: 02/06/2023]
Abstract
Human exposure to manufactured nanoparticles (NPs) is a public health concern. Endothelial cells lining the inner surface of arteries could be one of the primary targets for inhaled nanoparticles. Moreover, it is well known that alteration in calcium signaling is a critical event involved in the physiopathology of cardiovascular diseases. The objective of this study was to assess the role of oxidative stress in carbon black FW2 NPs-induced alteration in calcium signaling and mitochondria in human pulmonary artery endothelial cells. To this end, cells were exposed for 4 or 24 h to FW2 NPs (1-10 μg/cm2) and the following endpoints were studied: (i) production of ROS by fluorimetry and electron paramagnetic resonance, (ii) variation in intracellular calcium concentration by confocal microscopy, and (iii) mitochondrial alteration and apoptosis by confocal microscopy and transmission electronic microscopy. Exposure to FW2 NPs concentration-dependently increases oxidative stress, evidenced by the production of superoxide anion leading to an alteration in calcium content of intracellular organelles, such as endoplasmic reticulum and mitochondria activating, in turn, intrinsic apoptosis. This study provides evidence that FW2 NPs exposure impairs calcium signaling and mitochondria triggered by oxidative stress, and, thus, could act as a cardiovascular disease risk owing to the key role of calcium homeostasis in the control of vascular tone.
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Affiliation(s)
- J Deweirdt
- Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U 1045, 33604, Pessac, France.,Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, 33600, Pessac, France
| | - J F Quignard
- Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U 1045, 33604, Pessac, France.,Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, 33600, Pessac, France
| | - S Lacomme
- CNRS, Bordeaux Imaging Center UMS 3420 CNRS-US4 INSERM, 33000, Bordeaux, France
| | - E Gontier
- CNRS, Bordeaux Imaging Center UMS 3420 CNRS-US4 INSERM, 33000, Bordeaux, France
| | - S Mornet
- CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB, UMR 5026, 33076, Bordeaux, France
| | - J P Savineau
- Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U 1045, 33604, Pessac, France.,Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, 33600, Pessac, France
| | - R Marthan
- Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U 1045, 33604, Pessac, France.,Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, 33600, Pessac, France.,CHU de Bordeaux, Service d'Exploration Fonctionnelle Respiratoire, 33000, Bordeaux, France
| | - C Guibert
- Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, 33600, Pessac, France
| | - I Baudrimont
- Univ. Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux U 1045, 33604, Pessac, France. .,Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux U1045, 33600, Pessac, France.
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7
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Henderson CF, Bica I, Long FT, Irwin DD, Stull CH, Baker BW, Suarez Vega V, Taugher ZM, Fletes ED, Bartleson JM, Humphrey ML, Álvarez L, Akiyama M, Kumagai Y, Fukuto JM, Lin J. Cysteine Trisulfide Protects E. coli from Electrophile-Induced Death through the Generation of Cysteine Hydropersulfide. Chem Res Toxicol 2020; 33:678-686. [PMID: 31977195 DOI: 10.1021/acs.chemrestox.9b00494] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hydropersulfide and polysulfide species have recently been shown to elicit a wide variety of biological and physiological responses. In this study, we examine the effects of cysteine trisulfide (Cys-SSS-Cys; also known as thiocystine) treatment on E. coli. Previous studies in mammalian cells have shown that Cys-SSS-Cys treatment results in protection from the electrophiles. Here, we show that the protective effect of Cys-SSS-Cys treatment against electrophile-induced cell death is conserved in E. coli. This protection correlates with the rapid generation of cysteine hydropersulfide (Cys-SSH) in the culture media. We go on to demonstrate that an exogenous phosphatase expressed in E. coli, containing only a single catalytic cysteine, is protected from electrophile-induced inactivation in the presence of hydropersulfides. These data together demonstrate that E. coli can utilize Cys-SSS-Cys to generate Cys-SSH and that the Cys-SSH can protect cellular thiols from reactivity with the electrophiles.
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Affiliation(s)
- Catherine F Henderson
- Department of Biology , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Iris Bica
- Department of Biology , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Faith T Long
- Department of Biology , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Drew D Irwin
- Department of Biology , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Christine H Stull
- Department of Chemistry , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Blaine W Baker
- Department of Chemistry , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Valeria Suarez Vega
- Department of Chemistry , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Zachary M Taugher
- Department of Biology , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Eliza D Fletes
- Department of Biology , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Juliet M Bartleson
- Department of Biology , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Megan L Humphrey
- Department of Biology , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Lucía Álvarez
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , INQUIMAE-CONICET, Ciudad Universitaria, C1428EGA Buenos Aires , Argentina
| | - Masahiro Akiyama
- Environmental Biology Section, Faculty of Medicine , University of Tsukuba , Tsukuba , Ibaraki 305-8575 , Japan
| | - Yoshito Kumagai
- Environmental Biology Section, Faculty of Medicine , University of Tsukuba , Tsukuba , Ibaraki 305-8575 , Japan
| | - Jon M Fukuto
- Department of Chemistry , Sonoma State University , Rohnert Park , California 94928 , United States
| | - Joseph Lin
- Department of Biology , Sonoma State University , Rohnert Park , California 94928 , United States
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8
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He R, Pan J, Mayer JP, Liu F. The Chemical Methods of Disulfide Bond Formation and Their Applications to Drug Conjugates. CURR ORG CHEM 2020. [DOI: 10.2174/1385272823666191202111723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
:
The disulfide bond possesses unique chemical and biophysical properties which
distinguish it as one of the key structural elements of bioactive proteins and peptides, important
drugs and other materials. The chemo-selective synthesis of these structures and
the exploration of their function have been of longstanding interest to the chemistry community.
The past decades have witnessed significant progress in both areas. This review
will summarize the historically established and recently developed chemical methods in
disulfide bond formation. The discussion will also be extended to the use of the disulfide
linkers in small molecules, and peptide- and protein-drug conjugates. It is hoped that the
combined overview of the fundamental chemistries and applications to drug discovery
will inspire creative thinking and stimulate future novel uses of these versatile chemistries.
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Affiliation(s)
- Rongjun He
- Novo Nordisk Research Center Indianapolis, 5225 Exploration Drive, Indianapolis, IN 46241, United States
| | - Jia Pan
- Novo Nordisk Research Centre China, 20 Life Science Road, Beijing, China
| | - John P. Mayer
- Department of Molecular, Developmental & Cell Biology, University of Colorado, Boulder, CO 80309, United States
| | - Fa Liu
- Novo Nordisk Research Center, 530 Fairview Avenue North, Seattle, WA 98109, United States
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9
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Protein Redox State Monitoring Studies of Thiol Reactivity. Antioxidants (Basel) 2019; 8:antiox8050143. [PMID: 31121865 PMCID: PMC6563020 DOI: 10.3390/antiox8050143] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/08/2019] [Accepted: 05/20/2019] [Indexed: 01/07/2023] Open
Abstract
Protein cysteine thiol status is a major determinant of oxidative stress and oxidant signaling. The -SulfoBiotics- Protein Redox State Monitoring Kit provides a unique opportunity to investigate protein thiol states. This system adds a 15-kDa Protein-SHifter to reduced cysteine residues, and this molecular mass shift can be detected by gel electrophoresis. Even in biological samples, Protein-SHifter Plus allows the thiol states of specific proteins to be studied using Western blotting. Peroxiredoxin 6 (Prx6) is a unique one-cysteine peroxiredoxin that scavenges peroxides by utilizing conserved Cysteine-47. Human Prx6 also contains an additional non-conserved cysteine residue, while rat Prx6 only has the catalytic cysteine. In cultured cells, cysteine residues of Prx6 were found to be predominantly fully reduced. The treatment of human cells with hydrogen peroxide (H2O2) formed Prx6 with one cysteine reduced. Since catalytic cysteine becomes oxidized in rat cells by the same H2O2 treatment and treating denatured human Prx6 with H2O2 results in the oxidation of both cysteines, non-conserved cysteine may not be accessible to H2O2 in human cells. We also found that untreated cells contained Prx6 multimers bound through disulfide bonds. Surprisingly, treating cells with H2O2 eliminated these Prx6 multimers. In contrast, treating cell lysates with H2O2 promoted the formation of Prx6 multimers. Similarly, treating purified preparations of the recombinant cyclic nucleotide-binding domain of the human hyperpolarization-activated cyclic nucleotide-modulated channels with H2O2 promoted the formation of multimers. These studies revealed that the cellular environment defines the susceptibility of protein cysteines to H2O2 and determines whether H2O2 acts as a facilitator or a disrupter of disulfide bonds.
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10
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Seidel L, Zarzycka B, Katritch V, Coin I. Exploring Pairwise Chemical Crosslinking To Study Peptide-Receptor Interactions. Chembiochem 2019; 20:683-692. [PMID: 30565820 DOI: 10.1002/cbic.201800582] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Indexed: 01/29/2023]
Abstract
Pairwise crosslinking is a powerful technique to characterize interactions between G protein coupled receptors and their ligands in the live cell. In this work, the "thiol trapping" method, which exploits the proximity-enhanced reaction between haloacetamides and cysteine, is examined to identify intermolecular pairs of vicinal positions. By incorporating cysteine into the corticotropin-releasing factor receptor and either α-chloro- or α-bromoacetamide groups into its ligands, it is shown that thiol trapping provides highly reproducible signals and a low background, and represents a valid alternative to classical "disulfide trapping". The method is advantageous if reducing agents are required during sample analysis. Moreover, it can provide partially distinct spatial constraints, thus giving access to a wider dataset for molecular modeling. Finally, by applying recombinant mini-Gs, GTPγS, and Gαs-depleted HEK293 cells to modulate Gs coupling, it is shown that yields of crosslinking increase in the presence of elevated levels of Gs.
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Affiliation(s)
- Lisa Seidel
- Faculty of Life Sciences, Institute of Biochemistry, University of Leipzig, Bruederstrasse 34, 04103, Leipzig, Germany
| | - Barbara Zarzycka
- Department of Biological Sciences, Bridge Institute, University of Southern California, 1002 Childs Way, MCB 317, Los Angeles, CA, 90089-3502, USA
| | - Vsevolod Katritch
- Department of Biological Sciences, Bridge Institute, University of Southern California, 1002 Childs Way, MCB 317, Los Angeles, CA, 90089-3502, USA.,Department of Chemistry, Bridge Institute, University of Southern California, 1002 Childs Way, MCB 317, Los Angeles, CA, 90089-3502, USA
| | - Irene Coin
- Faculty of Life Sciences, Institute of Biochemistry, University of Leipzig, Bruederstrasse 34, 04103, Leipzig, Germany
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11
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Aarnio-Peterson M, Zhao P, Yu SH, Christian C, Flanagan-Steet H, Wells L, Steet R. Altered Met receptor phosphorylation and LRP1-mediated uptake in cells lacking carbohydrate-dependent lysosomal targeting. J Biol Chem 2017; 292:15094-15104. [PMID: 28724630 DOI: 10.1074/jbc.m117.790139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/14/2017] [Indexed: 11/06/2022] Open
Abstract
Acid hydrolases utilize a carbohydrate-dependent mechanism for lysosomal targeting. These hydrolases acquire a mannose 6-phosphate tag by the action of the GlcNAc-1-phosphotransferase enzyme, allowing them to bind receptors and traffic to endosomes. Loss of GlcNAc-1-phosphotransferase results in hydrolase hypersecretion and profound lysosomal storage. Little, however, is known about how these cellular phenotypes affect the trafficking, activity, and localization of surface glycoproteins. To address this question, we profiled the abundance of surface glycoproteins in WT and CRISPR-mediated GNPTAB-/- HeLa cells and identified changes in numerous glycoproteins, including the uptake receptor LRP1 and multiple receptor tyrosine kinases. Decreased cell surface LRP1 in GNPTAB-/- cells corresponded with a reduction in its steady-state level and less amyloid-β-40 (Aβ40) peptide uptake. GNPTAB-/- cells displayed elevated activation of several kinases including Met receptor. We found increased Met phosphorylation within both the kinase and the docking domains and observed that lower concentrations of pervanadate were needed to cause an increase in phospho-Met in GNPTAB-/- cells. Together, these data suggested a decrease in the activity of the receptor and non-receptor protein-tyrosine phosphatases that down-regulate Met phosphorylation. GNPTAB-/- cells exhibited elevated levels of reactive oxygen species, known to inactivate cell surface and cytosolic phosphatases by oxidation of active site cysteine residues. Consistent with this mode of action, peroxide treatment of parental HeLa cells elevated phospho-Met levels whereas antioxidant treatment of GNPTAB-/- cells reduced phospho-Met levels. Collectively, these findings identify new mechanisms whereby impaired lysosomal targeting can impact the activity and recycling of receptors.
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Affiliation(s)
- Megan Aarnio-Peterson
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Peng Zhao
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Seok-Ho Yu
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Courtney Christian
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Heather Flanagan-Steet
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Lance Wells
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Richard Steet
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
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12
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Differential oxidation of protein-tyrosine phosphatases during zebrafish caudal fin regeneration. Sci Rep 2017; 7:8460. [PMID: 28814789 PMCID: PMC5559610 DOI: 10.1038/s41598-017-07109-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 06/22/2017] [Indexed: 11/17/2022] Open
Abstract
Zebrafish have the capacity to regenerate lost tissues and organs. Amputation of the caudal fin results in a rapid, transient increase in H2O2 levels emanating from the wound margin, which is essential for regeneration, because quenching of reactive oxygen species blocks regeneration. Protein-tyrosine phosphatases (PTPs) have a central role in cell signalling and are susceptible to oxidation, which results in transient inactivation of their catalytic activity. We hypothesized that PTPs may become oxidized in response to amputation of the caudal fin. Using the oxidized PTP-specific (ox-PTP) antibody and liquid chromatography-mass spectrometry, we identified 33 PTPs in adult zebrafish fin clips of the total of 44 PTPs that can theoretically be detected based on sequence conservation. Of these 33 PTPs, 8 were significantly more oxidized 40 min after caudal fin amputation. Surprisingly, Shp2, one of the PTPs that were oxidized in response to caudal fin amputation, was required for caudal fin regeneration. In contrast, Rptpα, which was not oxidized upon amputation, was dispensable for caudal fin regeneration. Our results demonstrate that PTPs are differentially oxidized in response to caudal fin amputation and that there is a differential requirement for PTPs in regeneration.
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13
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Garcia FJ, Carroll KS. An immunochemical approach to detect oxidized protein tyrosine phosphatases using a selective C-nucleophile tag. MOLECULAR BIOSYSTEMS 2017; 12:1790-8. [PMID: 26757830 DOI: 10.1039/c5mb00847f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Protein tyrosine phosphatases are crucial regulators of signal transduction and function as antagonists towards protein tyrosine kinases to control reversible tyrosine phosphorylation, thereby regulating fundamental physiological processes. Growing evidence has supported the notion that reversible oxidative inactivation of the catalytic cysteine residue in protein tyrosine phosphatases serves as an oxidative post-translational modification that regulates its activity to influence downstream signaling by promoting phosphorylation and induction of the signaling cascade. The oxidation of cysteine to the sulfenic acid is often transient and difficult to detect, thus making it problematic in understanding the role that this oxidative post-translational modification plays in redox-biology and pathogenesis. Several methods to detect cysteine oxidation in biological systems have been developed, though targeted approaches to directly detect oxidized phosphatases are still lacking. Herein we describe the development of a novel immunochemical approach to directly profile oxidized phosphatases. This immunochemical approach consists of an antibody designed to recognize the conserved sequence of the PTP active site (VHCDMDSAG) harboring the catalytic cysteine modified with dimedone (CDMD), a nucleophile that chemoselectively reacts with cysteine sulfenic acids to form a stable thioether adduct. Additionally, we provide biochemical and mass spectrometry workflows to be used in conjugation with this newly developed immunochemical approach to assist in the identification and quantification of basal and oxidized phosphatases.
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Affiliation(s)
- Francisco J Garcia
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
| | - Kate S Carroll
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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14
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Protocols and pitfalls in obtaining fatty acid-binding proteins for biophysical studies of ligand-protein and protein-protein interactions. Biochem Biophys Rep 2017; 10:318-324. [PMID: 28955759 PMCID: PMC5614677 DOI: 10.1016/j.bbrep.2017.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 04/26/2017] [Accepted: 05/03/2017] [Indexed: 01/22/2023] Open
Abstract
Adipocyte fatty acid-binding protein (AFABP: FABP4) is a member of the intracellular lipid-binding protein family that is thought to target long-chain fatty acids to nuclear receptors such as peroxisome proliferator-activated receptor gamma (PPARγ), which in turn plays roles in insulin resistance and obesity. A molecular understanding of AFABP function requires robust isolation of the protein in liganded and free forms as well as characterization of its oligomerization state(s) under physiological conditions. We report development of a protocol to optimize the production of members of this protein family in pure form, including removal of their bound lipids by mixing with hydrophobically functionalized hydroxypropyl dextran beads and validation by two-dimensional NMR spectroscopy. The formation of self-associated or covalently bonded protein dimers was evaluated critically using gel filtration chromatography, revealing conditions that promote or prevent formation of disulfide-linked homodimers. The resulting scheme provides a solid foundation for future investigations of AFABP interactions with key ligand and protein partners involved in lipid metabolism.
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Key Words
- AFABP, adipose fatty acid-binding protein
- Delipidation
- Disulfide bond
- ESI-MS, Electrospray Ionization Mass Spectrometry
- FABP, fatty acid-binding protein
- Fatty acid-binding protein
- GF, Gel filtration chromatography
- HSQC, [1H–15N] heteronuclear single quantum correlation spectroscopy
- Homodimer
- LCFA, Long-chain fatty acid
- Ligand
- MALDI-TOF, Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
- NMR, Nuclear Magnetic Resonance
- NOESY, 2D nuclear Overhauser spectroscopy
- PPAR, peroxisome proliferator-activated receptor
- Protein
- TCEP, tris(2-carboxyethyl)phosphine
- TEV, Tobacco Etch Virus
- TOCSY, 2D Total correlation spectroscopy
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15
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Machado LESF, Shen TL, Page R, Peti W. The KIM-family protein-tyrosine phosphatases use distinct reversible oxidation intermediates: Intramolecular or intermolecular disulfide bond formation. J Biol Chem 2017; 292:8786-8796. [PMID: 28389559 DOI: 10.1074/jbc.m116.774174] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Revised: 04/07/2017] [Indexed: 11/06/2022] Open
Abstract
The kinase interaction motif (KIM) family of protein-tyrosine phosphatases (PTPs) includes hematopoietic protein-tyrosine phosphatase (HePTP), striatal-enriched protein-tyrosine phosphatase (STEP), and protein-tyrosine phosphatase receptor type R (PTPRR). KIM-PTPs bind and dephosphorylate mitogen-activated protein kinases (MAPKs) and thereby critically modulate cell proliferation and differentiation. PTP activity can readily be diminished by reactive oxygen species (ROS), e.g. H2O2, which oxidize the catalytically indispensable active-site cysteine. This initial oxidation generates an unstable sulfenic acid intermediate that is quickly converted into either a sulfinic/sulfonic acid (catalytically dead and irreversible inactivation) or a stable sulfenamide or disulfide bond intermediate (reversible inactivation). Critically, our understanding of ROS-mediated PTP oxidation is not yet sufficient to predict the molecular responses of PTPs to oxidative stress. However, identifying distinct responses will enable novel routes for PTP-selective drug design, important for managing diseases such as cancer and Alzheimer's disease. Therefore, we performed a detailed biochemical and molecular study of all KIM-PTP family members to determine their H2O2 oxidation profiles and identify their reversible inactivation mechanism(s). We show that despite having nearly identical 3D structures and sequences, each KIM-PTP family member has a unique oxidation profile. Furthermore, we also show that whereas STEP and PTPRR stabilize their reversibly oxidized state by forming an intramolecular disulfide bond, HePTP uses an unexpected mechanism, namely, formation of a reversible intermolecular disulfide bond. In summary, despite being closely related, KIM-PTPs significantly differ in oxidation profiles. These findings highlight that oxidation protection is critical when analyzing PTPs, for example, in drug screening.
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Affiliation(s)
| | | | - Rebecca Page
- Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912
| | - Wolfgang Peti
- From the Departments of Molecular Pharmacology, Physiology and Biotechnology, .,Chemistry, and
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16
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Multiple myeloma cells' capacity to decompose H 2O 2 determines lenalidomide sensitivity. Blood 2016; 129:991-1007. [PMID: 28028022 DOI: 10.1182/blood-2016-09-738872] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 12/12/2016] [Indexed: 12/18/2022] Open
Abstract
Lenalidomide is an immunomodulatory drug (IMiDs) with clinical efficacy in multiple myeloma (MM) and other late B-cell neoplasms. Although cereblon (CRBN) is an essential requirement for IMiD action, the complete molecular and biochemical mechanisms responsible for lenalidomide-mediated sensitivity or resistance remain unknown. Here, we report that IMiDs work primarily via inhibition of peroxidase-mediated intracellular H2O2 decomposition in MM cells. MM cells with lower H2O2-decomposition capacity were more vulnerable to lenalidomide-induced H2O2 accumulation and associated cytotoxicity. CRBN-dependent degradation of IKZF1 and IKZF3 was a consequence of H2O2-mediated oxidative stress. Lenalidomide increased intracellular H2O2 levels by inhibiting thioredoxin reductase (TrxR) in cells expressing CRBN, causing accumulation of immunoglobulin light-chain dimers, significantly increasing endoplasmic reticulum stress and inducing cytotoxicity by activation of BH3-only protein Bim in MM. Other direct inhibitors of TrxR and thioredoxin (Trx) caused similar cytotoxicity, but in a CRBN-independent fashion. Our findings could help identify patients most likely to benefit from IMiDs and suggest direct TrxR or Trx inhibitors for MM therapy.
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17
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Oxidative Dimerization of PHD2 is Responsible for its Inactivation and Contributes to Metabolic Reprogramming via HIF-1α Activation. Sci Rep 2016; 6:18928. [PMID: 26740011 PMCID: PMC4703963 DOI: 10.1038/srep18928] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/30/2015] [Indexed: 12/20/2022] Open
Abstract
Prolyl hydroxylase domain protein 2 (PHD2) belongs to an evolutionarily conserved superfamily of 2-oxoglutarate and Fe(II)-dependent dioxygenases that mediates homeostatic responses to oxygen deprivation by mediating hypoxia-inducible factor-1α (HIF-1α) hydroxylation and degradation. Although oxidative stress contributes to the inactivation of PHD2, the precise molecular mechanism of PHD2 inactivation independent of the levels of co-factors is not understood. Here, we identified disulfide bond-mediated PHD2 homo-dimer formation in response to oxidative stress caused by oxidizing agents and oncogenic H-rasV12 signalling. Cysteine residues in the double-stranded β-helix fold that constitutes the catalytic site of PHD isoforms appeared responsible for the oxidative dimerization. Furthermore, we demonstrated that disulfide bond-mediated PHD2 dimerization is associated with the stabilization and activation of HIF-1α under oxidative stress. Oncogenic H-rasV12 signalling facilitates the accumulation of HIF-1α in the nucleus and promotes aerobic glycolysis and lactate production. Moreover, oncogenic H-rasV12 does not trigger aerobic glycolysis in antioxidant-treated or PHD2 knocked-down cells, suggesting the participation of the ROS-mediated PHD2 inactivation in the oncogenic H-rasV12-mediated metabolic reprogramming. We provide here a better understanding of the mechanism by which disulfide bond-mediated PHD2 dimerization and inactivation result in the activation of HIF-1α and aerobic glycolysis in response to oxidative stress.
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18
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Pinto A, Mace Y, Drouet F, Bony E, Boidot R, Draoui N, Lobysheva I, Corbet C, Polet F, Martherus R, Deraedt Q, Rodríguez J, Lamy C, Schicke O, Delvaux D, Louis C, Kiss R, Kriegsheim AV, Dessy C, Elias B, Quetin-Leclercq J, Riant O, Feron O. A new ER-specific photosensitizer unravels (1)O2-driven protein oxidation and inhibition of deubiquitinases as a generic mechanism for cancer PDT. Oncogene 2015; 35:3976-85. [PMID: 26686091 DOI: 10.1038/onc.2015.474] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 10/29/2015] [Accepted: 11/17/2015] [Indexed: 12/19/2022]
Abstract
Photosensitizers (PS) are ideally devoid of any activity in the absence of photoactivation, and rely on molecular oxygen for the formation of singlet oxygen ((1)O2) to produce cellular damage. Off-targets and tumor hypoxia therefore represent obstacles for the use of PS for cancer photodynamic therapy. Herein, we describe the characterization of OR141, a benzophenazine compound identified through a phenotypic screening for its capacity to be strictly activated by light and to kill a large variety of tumor cells under both normoxia and hypoxia. This new class of PS unraveled an unsuspected common mechanism of action for PS that involves the combined inhibition of the mammalian target of rapamycin (mTOR) signaling pathway and proteasomal deubiquitinases (DUBs) USP14 and UCH37. Oxidation of mTOR and other endoplasmic reticulum (ER)-associated proteins drives the early formation of high molecular weight (MW) complexes of multimeric proteins, the concomitant blockade of DUBs preventing their degradation and precipitating cell death. Furthermore, we validated the antitumor effects of OR141 in vivo and documented its highly selective accumulation in the ER, further increasing the ER stress resulting from (1)O2 generation upon light activation.
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Affiliation(s)
- A Pinto
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - Y Mace
- Institute of Condensed Matter and Nanosciences Molecules, Solids and Reactivity (IMCN/MOST), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - F Drouet
- Institute of Condensed Matter and Nanosciences Molecules, Solids and Reactivity (IMCN/MOST), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - E Bony
- Pharmacognosy Research Group (GNOS), Louvain Drug Research Institute (LDRI), Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - R Boidot
- Institute of Condensed Matter and Nanosciences Molecules, Solids and Reactivity (IMCN/MOST), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - N Draoui
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - I Lobysheva
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - C Corbet
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - F Polet
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - R Martherus
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - Q Deraedt
- Institute of Condensed Matter and Nanosciences Molecules, Solids and Reactivity (IMCN/MOST), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - J Rodríguez
- Systems Biology Ireland, Conway Institute, Belfield, Dublin 4, Ireland
| | - C Lamy
- Institute of Condensed Matter and Nanosciences Molecules, Solids and Reactivity (IMCN/MOST), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - O Schicke
- Institute of Condensed Matter and Nanosciences Molecules, Solids and Reactivity (IMCN/MOST), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - D Delvaux
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - C Louis
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - R Kiss
- Laboratoire de Cancérologie et de Toxicologie Expérimentale, Faculté de Pharmacie, Université Libre de Bruxelles, Brussels, Belgium
| | - A V Kriegsheim
- Systems Biology Ireland, Conway Institute, Belfield, Dublin 4, Ireland
| | - C Dessy
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - B Elias
- Institute of Condensed Matter and Nanosciences Molecules, Solids and Reactivity (IMCN/MOST), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - J Quetin-Leclercq
- Pharmacognosy Research Group (GNOS), Louvain Drug Research Institute (LDRI), Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - O Riant
- Institute of Condensed Matter and Nanosciences Molecules, Solids and Reactivity (IMCN/MOST), Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - O Feron
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
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19
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Liu T, Yang Y, Wang D, Xiao Y, Du G, Wu L, Ding M, Li L, Wu C. Human eukaryotic elongation factor 1A forms oligomers through specific cysteine residues. Acta Biochim Biophys Sin (Shanghai) 2015; 47:1011-7. [PMID: 26515794 DOI: 10.1093/abbs/gmv113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 08/15/2015] [Indexed: 12/29/2022] Open
Abstract
Eukaryotic elongation factor 1A (eEF1A) is a multifunctional protein involved in bundling actin, severing microtubule, activating the phosphoinositol-4 kinase, and recruiting aminoacyl-tRNAs to ribosomes during protein biosynthesis. Although evidence has shown the presence of the isoform eEF1A1 oligomers, the substantial mechanism of the self-association remains unclear. Herein, we found that human eEF1A1 could spontaneously form oligomers. Specifically, mutagenesis screen on cysteine residues demonstrated that Cys(234) was essential for eEF1A1 oligomerization. In addition, we also found that hydrogen peroxide treatment could induce the formation of eEF1A oligomers in cells. By cysteine replacement, eEF1A2 isoform displayed the ability to oligomerize in cells under the oxidative environment. In summary, in this study we characterized eEF1A1 oligomerization and demonstrated that specific cysteine residues are required for this oligomerization activity.
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Affiliation(s)
- Tao Liu
- School of Life Sciences and Key Laboratory of Bio-Resources and Eco-Environment, Sichuan University, Ministry of Education, Chengdu 610064, China
| | - Yu Yang
- School of Life Sciences and Key Laboratory of Bio-Resources and Eco-Environment, Sichuan University, Ministry of Education, Chengdu 610064, China
| | - Di Wang
- School of Life Sciences and Key Laboratory of Bio-Resources and Eco-Environment, Sichuan University, Ministry of Education, Chengdu 610064, China
| | - Yan Xiao
- School of Life Sciences and Key Laboratory of Bio-Resources and Eco-Environment, Sichuan University, Ministry of Education, Chengdu 610064, China
| | - Guangshi Du
- School of Life Sciences and Key Laboratory of Bio-Resources and Eco-Environment, Sichuan University, Ministry of Education, Chengdu 610064, China
| | - Lei Wu
- School of Life Sciences and Key Laboratory of Bio-Resources and Eco-Environment, Sichuan University, Ministry of Education, Chengdu 610064, China
| | - Muran Ding
- School of Life Sciences and Key Laboratory of Bio-Resources and Eco-Environment, Sichuan University, Ministry of Education, Chengdu 610064, China
| | - Ling Li
- School of Life Sciences and Key Laboratory of Bio-Resources and Eco-Environment, Sichuan University, Ministry of Education, Chengdu 610064, China
| | - Chuanfang Wu
- School of Life Sciences and Key Laboratory of Bio-Resources and Eco-Environment, Sichuan University, Ministry of Education, Chengdu 610064, China
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20
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Bretón-Romero R, Lamas S. Hydrogen peroxide signaling in vascular endothelial cells. Redox Biol 2014; 2:529-34. [PMID: 24634835 PMCID: PMC3953958 DOI: 10.1016/j.redox.2014.02.005] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 02/20/2014] [Indexed: 12/27/2022] Open
Abstract
Redox signaling is implicated in different physiological and pathological events in the vasculature. Among the different reactive oxygen species, hydrogen peroxide (H2O2) is a very good candidate to perform functions as an intracellular messenger in the regulation of several biological events. In this review, we summarize the main physiological sources of H2O2 in the endothelium and the molecular mechanisms by which it is able to act as a signaling mediator in the vasculature.
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Affiliation(s)
- Rosa Bretón-Romero
- Centro de Biología Molecular 'Severo Ochoa' CSIC-UAM, Campus Universidad Autónoma, Nicolás Cabrera 1, Madrid E-28049, Spain
| | - Santiago Lamas
- Centro de Biología Molecular 'Severo Ochoa' CSIC-UAM, Campus Universidad Autónoma, Nicolás Cabrera 1, Madrid E-28049, Spain
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21
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Haase H, Rink L. Zinc signals and immune function. Biofactors 2014; 40:27-40. [PMID: 23804522 DOI: 10.1002/biof.1114] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/23/2013] [Accepted: 04/25/2013] [Indexed: 12/21/2022]
Abstract
For more than 50 years, it has been known that zinc deficiency compromises immune function. During this time, knowledge about the biochemistry of zinc has continued to grow, but only recent years have provided in-depth molecular insights into the multiple aspects of zinc as a regulator of immunity. A network based on ZnT and ZIP proteins for transport and metallothionein for storage tightly regulates zinc availability, and virtually all aspects of innate and adaptive immunity are affected by zinc. In vivo, zinc deficiency alters the number and function of neutrophil granulocytes, monocytes, natural killer (NK)-, T-, and B-cells. T cell functions and balance between the different subsets are particularly susceptible to changes in zinc status. This article focuses in particular on the main mechanisms by which zinc ions exert essential functions in the immune system. On the one hand, this includes tightly protein bound zinc ions serving catalytic or structural functions in a multitude of different proteins, in particular enzymes and transcription factors. On the other hand, increasing evidence arises for a regulatory role of free zinc ions in signal transduction, especially in cells of the immune system. Identification of several molecular targets, including phosphatases, phosphodiesterases, caspases, and kinases suggest that zinc ions are a second messenger regulating signal transduction in various kinds of immune cells.
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Affiliation(s)
- Hajo Haase
- Institute of Immunology, Medical Faculty, RWTH Aachen University, Pauwelsstrasse 30, Aachen, Germany
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22
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Tonks NK. Protein tyrosine phosphatases--from housekeeping enzymes to master regulators of signal transduction. FEBS J 2013; 280:346-78. [PMID: 23176256 DOI: 10.1111/febs.12077] [Citation(s) in RCA: 340] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/13/2012] [Accepted: 11/15/2012] [Indexed: 12/12/2022]
Abstract
There are many misconceptions surrounding the roles of protein phosphatases in the regulation of signal transduction, perhaps the most damaging of which is the erroneous view that these enzymes exert their effects merely as constitutively active housekeeping enzymes. On the contrary, the phosphatases are critical, specific regulators of signalling in their own right and serve an essential function, in a coordinated manner with the kinases, to determine the response to a physiological stimulus. This review is a personal perspective on the development of our understanding of the protein tyrosine phosphatase family of enzymes. I have discussed various aspects of the structure, regulation and function of the protein tyrosine phosphatase family, which I hope will illustrate the fundamental importance of these enzymes in the control of signal transduction.
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Affiliation(s)
- Nicholas K Tonks
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724-2208, USA.
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23
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Burgoyne JR, Eaton P. Detecting disulfide-bound complexes and the oxidative regulation of cyclic nucleotide-dependent protein kinases by H2O2. Methods Enzymol 2013; 528:111-28. [PMID: 23849862 DOI: 10.1016/b978-0-12-405881-1.00007-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Hydrogen peroxide regulates intracellular signaling by oxidatively converting susceptible cysteine thiols to a modified state, which includes the formation of intermolecular disulfides. This type of oxidative modification can occur within the cAMP- and cGMP-dependent protein kinases often referred to as PKA and PKG, which have important roles in regulating cardiac contractility and systemic blood pressure. Both kinases are stimulated through conical pathways that elevate their respective cyclic nucleotides leading to direct kinase stimulation. However, PKA and PKG can also be functionally modulated independently of cyclic nucleotide stimulation through direct cysteine thiol oxidation leading to intermolecular disulfide formation. In the case of PKG, the formation of an intermolecular disulfide between two parallel dimeric subunits leads to enhanced kinase affinity for substrate. For PKA, the formation of two intermolecular disulfides between antiparallel dimeric regulatory RI subunits increases the affinity of this kinase for its binding partners, the A-kinase anchoring proteins, leading to increased PKA localization to its substrates. In this chapter, we describe the methods for detecting intermolecular disulfide-bound proteins and monitoring PKA and PKG oxidation within biological samples.
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Affiliation(s)
- Joseph R Burgoyne
- King's College London, Cardiovascular Division, The Rayne Institute, London, United Kingdom
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24
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Abstract
cGMP-dependent protein kinase, also known as protein kinase G (PKG), is activated independently of cGMP by a novel thiol-reactive mechanism involving the formation of an intermolecular disulfide. This oxidative modification within PKG is generally not detected by conventional Western immunoblot analysis due to the experimental conditions used. Here, we describe the proteomic approach that lead to PKG being identified as a kinase susceptible to oxidant-dependent disulfide dimer formation, these methods being applicable for the identification of other disulfide bound protein complexes. In addition a nonreducing Western immunoblot method for routinely measuring PKG oxidation in complex protein mixtures generated from cell lysates or tissue homogenates is also described.
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Affiliation(s)
- Joseph Robert Burgoyne
- Cardiovascular Division, The Rayne Institute, St. Thomas' Hospital, King's College London, London, UK
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25
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Chien PN, Ryu SE. Protein Tyrosine Phosphatase σ in Proteoglycan-Mediated Neural Regeneration Regulation. Mol Neurobiol 2012; 47:220-7. [DOI: 10.1007/s12035-012-8346-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 08/27/2012] [Indexed: 12/25/2022]
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Abstract
Reactive oxygen species (ROS), particularly hydrogen peroxide (H(2)O(2)), act as intracellular second messengers in many signaling pathways. Protein-tyrosine phosphatases (PTPs) are now believed to be important targets of ROS. PTPs contain a conserved catalytic cysteine with an unusually low pK(a). This property allows PTPs to execute nucleophilic attack on substrate phosphotyrosyl residues, but also renders them highly susceptible to oxidation. Reversible oxidation, which inactivates PTPs, is emerging as an important cellular regulatory mechanism and might contribute to human diseases, including cancer. Given their potential toxicity, it seems likely that ROS generation is highly controlled within cells to restrict oxidation to those PTPs that must be inactivated for signaling to proceed. Thus, identifying ROS-inactivated PTPs could be tantamount to finding the PTP(s) that critically regulate a specific signaling pathway. This article provides an overview of the methods currently available to identify and quantify PTP oxidation and outlines future challenges in redox signaling.
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Affiliation(s)
- Robert Karisch
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.
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27
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Primo ME, Jakoncic J, Noguera ME, Risso VA, Sosa L, Sica MP, Solimena M, Poskus E, Ermácora MR. Protein-protein interactions in crystals of the human receptor-type protein tyrosine phosphatase ICA512 ectodomain. PLoS One 2011; 6:e24191. [PMID: 21935384 PMCID: PMC3174154 DOI: 10.1371/journal.pone.0024191] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 08/02/2011] [Indexed: 11/19/2022] Open
Abstract
ICA512 (or IA-2) is a transmembrane protein-tyrosine phosphatase located in secretory granules of neuroendocrine cells. Initially, it was identified as one of the main antigens of autoimmune diabetes. Later, it was found that during insulin secretion, the cytoplasmic domain of ICA512 is cleaved and relocated to the nucleus, where it stimulates the transcription of the insulin gene. The role of the other parts of the receptor in insulin secretion is yet to be unveiled. The structures of the intracellular pseudocatalytic and mature extracellular domains are known, but the transmembrane domain and several intracellular and extracellular parts of the receptor are poorly characterized. Moreover the overall structure of the receptor remains to be established. We started to address this issue studying by X-ray crystallography the structure of the mature ectodomain of ICA512 (ME ICA512) and variants thereof. The variants and crystallization conditions were chosen with the purpose of exploring putative association interfaces, metal binding sites and all other structural details that might help, in subsequent works, to build a model of the entire receptor. Several structural features were clarified and three main different association modes of ME ICA512 were identified. The results provide essential pieces of information for the design of new experiments aimed to assess the structure in vivo.
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Affiliation(s)
- María E. Primo
- Consejo Nacional de Investigaciones Científicas y Técnicas (Conicet), Ciudad Autónoma de Buenos Aires, Argentina
- Cátedra de Inmunología de la Facultad de Farmacia y Bioquímica, Idehu, and División Endocrinología del Hospital de Clínicas J. de San Martín, Universidad de Buenos Aires—Conicet, Ciudad Autónoma de Buenos Aires, Argentina
| | - Jean Jakoncic
- Photon Science Directorate, Brookhaven National Laboratory, Upton, New York, United States of America
| | - Martín E. Noguera
- Consejo Nacional de Investigaciones Científicas y Técnicas (Conicet), Ciudad Autónoma de Buenos Aires, Argentina
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina
| | - Valeria A. Risso
- Consejo Nacional de Investigaciones Científicas y Técnicas (Conicet), Ciudad Autónoma de Buenos Aires, Argentina
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina
| | - Laura Sosa
- Consejo Nacional de Investigaciones Científicas y Técnicas (Conicet), Ciudad Autónoma de Buenos Aires, Argentina
- Cátedra de Inmunología de la Facultad de Farmacia y Bioquímica, Idehu, and División Endocrinología del Hospital de Clínicas J. de San Martín, Universidad de Buenos Aires—Conicet, Ciudad Autónoma de Buenos Aires, Argentina
| | - Mauricio P. Sica
- Consejo Nacional de Investigaciones Científicas y Técnicas (Conicet), Ciudad Autónoma de Buenos Aires, Argentina
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina
| | - Michele Solimena
- Paul Langerhans Institute Dresden, Molecular Diabetology, Universitätsklinikum “Carl Gustav Carus”, University of Technology Dresden, Dresden, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics Dresden, Dresden, Germany
| | - Edgardo Poskus
- Consejo Nacional de Investigaciones Científicas y Técnicas (Conicet), Ciudad Autónoma de Buenos Aires, Argentina
- Cátedra de Inmunología de la Facultad de Farmacia y Bioquímica, Idehu, and División Endocrinología del Hospital de Clínicas J. de San Martín, Universidad de Buenos Aires—Conicet, Ciudad Autónoma de Buenos Aires, Argentina
| | - Mario R. Ermácora
- Consejo Nacional de Investigaciones Científicas y Técnicas (Conicet), Ciudad Autónoma de Buenos Aires, Argentina
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina
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Schröder K, Schütz S, Schlöffel I, Bätz S, Takac I, Weissmann N, Michaelis UR, Koyanagi M, Brandes RP. Hepatocyte growth factor induces a proangiogenic phenotype and mobilizes endothelial progenitor cells by activating Nox2. Antioxid Redox Signal 2011; 15:915-23. [PMID: 21050133 DOI: 10.1089/ars.2010.3533] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Hepatocyte growth factor (HGF) by stimulating the receptor tyrosine kinase c-Met induces angiogenesis and tissue regeneration. HGF has been shown to antagonize the angiotensin II-induced senescence of endothelial progenitor cells (EPCs), which is mediated by NADPH oxidase-dependent reactive oxygen species (ROS) formation. As growth factors, however, usually require ROS for their signaling, we hypothesized that the proangiogenic effects of HGF require NADPH oxidases and focused on the homolog Nox2, which is most abundantly expressed in EPCs and endothelial cells. Indeed, HGF increased the H(2)O(2) formation in EPCs and human umbilical vein endothelial cells (HUVECs), and this effect was not observed in Nox2-deficient cells. HGF induced the mobilization of EPCs and vascular outgrowth from aortic explants in wild-type (WT) but not Nox2(y/-) mice. HGF also stimulated migration and tube formation in HUVECs, and antisense oligonucleotides against Nox2 prevented this effect. To identify the signal transduction underlying these effects, we focused on the kinases Jak2 and Jnk. In HUVECs, HGF increased the phosphorylation of these in a Nox2-dependent manner as demonstrated by antisense oligonucleotides. Also, the HGF-induced Jak2-dependent activation of a STAT3 reporter construct was attenuated after downregulation of Nox2. Accordingly, the HGF-stimulated tube formation of HUVEC was blocked by inhibitors of Jak2 and Jnk. In vivo treatment with the Jnk inhibitor SP600125 blocked the HGF-induced mobilization of EPCs. Ex vivo, SP600125 blocked HGF-induced migration and tube formation. We conclude that HGF-induced mobilization of EPCs and the proangiogenic effects of the growth factor require a Nox2-dependent ROS-mediated activation of Jak2 and Jnk.
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Affiliation(s)
- Katrin Schröder
- Institut für Kardiovaskuläre Physiologie, Goethe-Universität, Frankfurt am Main, Germany.
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29
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Tanner JJ, Parsons ZD, Cummings AH, Zhou H, Gates KS. Redox regulation of protein tyrosine phosphatases: structural and chemical aspects. Antioxid Redox Signal 2011; 15:77-97. [PMID: 20919935 DOI: 10.1089/ars.2010.3611] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Protein tyrosine phosphatases (PTPs) are important targets of the H(2)O(2) that is produced during mammalian signal transduction. H(2)O(2)-mediated inactivation of PTPs also may be important in various pathophysiological conditions involving oxidative stress. Here we review the chemical and structural biology of redox-regulated PTPs. Reactions of H(2)O(2) with PTPs convert the catalytic cysteine thiol to a sulfenic acid. In PTPs, the initially generated sulfenic acid residues have the potential to undergo secondary reactions with a neighboring amide nitrogen or cysteine thiol residue to yield a sulfenyl amide or disulfide, respectively. The chemical mechanisms by which formation of sulfenyl amide and disulfide linkages can protect the catalytic cysteine residue against irreversible overoxidation to sulfinic and sulfonic oxidation states are described. Due to the propensity for back-door and distal cysteine residues to engage with the active-site cysteine after oxidative inactivation, differences in the structures of the oxidatively inactivated PTPs may stem, to a large degree, from differences in the number and location of cysteine residues surrounding the active site of the enzymes. PTPs with key cysteine residues in structurally similar locations may be expected to share similar mechanisms of oxidative inactivation.
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Affiliation(s)
- John J Tanner
- Department of Chemistry, University of Missouri, Columbia, 65211, USA.
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30
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Deb I, Poddar R, Paul S. Oxidative stress-induced oligomerization inhibits the activity of the non-receptor tyrosine phosphatase STEP61. J Neurochem 2011; 116:1097-111. [PMID: 21198639 DOI: 10.1111/j.1471-4159.2010.07165.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The neuron-specific tyrosine phosphatase STriatal Enriched Phosphatase (STEP) is emerging as an important mediator of glutamatergic transmission in the brain. STEP is also thought to be involved in the etiology of neurodegenerative disorders that are linked to oxidative stress such as Alzheimer's disease and cerebral ischemia. However, the mechanism by which oxidative stress can modulate STEP activity is still unclear. In this study, we have investigated whether dimerization may play a role in regulating the activity of STEP. Our findings show that STEP(61), the membrane associated isoform, can undergo homodimerization under basal conditions in neurons. Dimerization of STEP(61) involves intermolecular disulfide bond formation between two cysteine residues (Cys 65 and Cys 76 respectively) present in the hydrophobic region at the N-terminus specific to STEP(61). Oxidative stress induced by hydrogen peroxide leads to a significant increase in the formation of dimers and higher-order oligomers of STEP(61). Using two substrates, para-nitrophenylphosphate and extracellular-regulated kinase MAPK we further demonstrate that oligomerization leads to a significant reduction in its enzymatic activity.
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Affiliation(s)
- Ishani Deb
- Department of Neurology, University of New Mexico Health Sciences Center, 1 University of New Mexico, Albuquerque, New Mexico 87131, USA
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31
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Zheng X, Ying L, Liu J, Dou D, He Q, Leung SWS, Man RYK, Vanhoutte PM, Gao Y. Role of sulfhydryl-dependent dimerization of soluble guanylyl cyclase in relaxation of porcine coronary artery to nitric oxide. Cardiovasc Res 2011; 90:565-72. [PMID: 21248051 DOI: 10.1093/cvr/cvr016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Soluble guanylyl cyclase (sGC) is a heterodimer. The dimerization of the enzyme is obligatory for its function in mediating actions caused by agents that elevate cyclic guanosine monophosphate (cGMP). The present study aimed to determine whether sGC dimerization is modulated by thiol-reducing agents and whether its dimerization influences relaxations in response to nitric oxide (NO). METHODS AND RESULTS The dimers and monomers of sGC and cGMP-dependent protein kinase (PKG) were analysed by western blotting. The intracellular cGMP content was measured by enzyme-linked immunosorbent assay. Changes in isometric tension were determined in organ chambers. In isolated porcine coronary arteries, the protein levels of sGC dimer were decreased by the thiol reductants dithiothreitol, l-cysteine, reduced l-glutathione and tris(2-carboxyethyl) phosphine. The effect was associated with reduced cGMP elevation and attenuated relaxations in response to nitric oxide donors. The dimerization of sGC and activation of the enzyme were also decreased by dihydrolipoic acid, an endogenous thiol antioxidant. Dithiothreitol at concentrations markedly affecting the dimerization of sGC had no significant effect on the dimerization of PKG or relaxation in response to 8-Br-cGMP. Relaxation of the coronary artery in response to a NO donor was potentiated by hypoxia when sGC was partly inhibited, coincident with an increase in sGC dimer and enhanced cGMP production. These effects were prevented by dithiothreitol and tris(2-carboxyethyl) phosphine. CONCLUSION These results demonstrate that the dimerization of sGC is exquisitely sensitive to thiol reductants compared with that of PKG, which may provide a novel mechanism for thiol-dependent modulation of NO-mediated vasodilatation in conditions such as hypoxia.
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Affiliation(s)
- Xiaoxu Zheng
- Department of Physiology and Pathophysiology, Peking University Health Science Center, 38 Xue Yuan Road, Beijing 100191, China
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32
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Törnvall U, Hedström M, Schillén K, Hatti-Kaul R. Structural, functional and chemical changes in Pseudozyma antarctica lipase B on exposure to hydrogen peroxide. Biochimie 2010; 92:1867-75. [DOI: 10.1016/j.biochi.2010.07.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Accepted: 07/12/2010] [Indexed: 11/29/2022]
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Abstract
The unique chemistry of oxygen has been both a resource and threat for life on Earth for at least the last 2.4 billion years. Reduction of oxygen to water allows extraction of more metabolic energy from organic fuels than is possible through anaerobic glycolysis. On the other hand, partially reduced oxygen can react indiscriminately with biomolecules to cause genetic damage, disease, and even death. Organisms in all three superkingdoms of life have developed elaborate mechanisms to protect against such oxidative damage and to exploit reactive oxygen species as sensors and signals in myriad processes. The sulfur amino acids, cysteine and methionine, are the main targets of reactive oxygen species in proteins. Oxidative modifications to cysteine and methionine can have profound effects on a protein's activity, structure, stability, and subcellular localization. Non-reversible oxidative modifications (oxidative damage) may contribute to molecular, cellular, and organismal aging and serve as signals for repair, removal, or programmed cell death. Reversible oxidation events can function as transient signals of physiological status, extracellular environment, nutrient availability, metabolic state, cell cycle phase, immune function, or sensory stimuli. Because of its chemical similarity to sulfur and stronger nucleophilicity and acidity, selenium is an extremely efficient catalyst of reactions between sulfur and oxygen. Most of the biological activity of selenium is due to selenoproteins containing selenocysteine, the 21st genetically encoded protein amino acid. The most abundant selenoproteins in mammals are the glutathione peroxidases (five to six genes) that reduce hydrogen peroxide and lipid hydroperoxides at the expense of glutathione and serve to limit the strength and duration of reactive oxygen signals. Thioredoxin reductases (three genes) use nicotinamide adenine dinucleotide phosphate to reduce oxidized thioredoxin and its homologs, which regulate a plethora of redox signaling events. Methionine sulfoxide reductase B1 reduces methionine sulfoxide back to methionine using thioredoxin as a reductant. Several selenoproteins in the endoplasmic reticulum are involved in the regulation of protein disulfide formation and unfolded protein response signaling, although their precise biological activities have not been determined. The most widely distributed selenoprotein family in Nature is represented by the highly conserved thioredoxin-like selenoprotein W and its homologs that have not yet been assigned specific biological functions. Recent evidence suggests selenoprotein W and the six other small thioredoxin-like mammalian selenoproteins may serve to transduce hydrogen peroxide signals into regulatory disulfide bonds in specific target proteins.
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Affiliation(s)
- Wayne Chris Hawkes
- USDA Agricultural Research Service, Western Human Nutrition Research Center, University of California at Davis, Davis, USA
| | - Zeynep Alkan
- USDA Agricultural Research Service, Western Human Nutrition Research Center, University of California at Davis, Davis, USA
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Samet JM, Tal TL. Toxicological disruption of signaling homeostasis: tyrosine phosphatases as targets. Annu Rev Pharmacol Toxicol 2010; 50:215-35. [PMID: 20055703 DOI: 10.1146/annurev.pharmtox.010909.105841] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The protein tyrosine phosphatases (PTPs) consist of a diverse group of enzymes whose activity opposes that of the tyrosine kinases. As such, the PTPs have critical roles in maintaining signaling quiescence in resting cells and in restoring homeostasis by effecting signal termination. Interest in these enzymes has increased in recent years following the discovery that the activity of PTPs is modulated through redox mechanisms during signaling. The molecular features that enable redox regulation of PTPs during physiological signaling also render them highly susceptible to oxidative and electrophilic inactivation by a broad spectrum of structurally disparate xenobiotic compounds. The loss of PTP activity results in a profound disregulation of protein phosphotyrosine metabolism, leading to widespread and persistent activation of signaling cascades in the cell.
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Affiliation(s)
- James M Samet
- U.S. Environmental Protection Agency, Chapel Hill, North Carolina, USA.
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35
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Intermolecular disulfide bond to modulate protein function as a redox-sensing switch. Amino Acids 2010; 41:59-72. [DOI: 10.1007/s00726-010-0508-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 01/27/2010] [Indexed: 12/29/2022]
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36
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STAT3 is a substrate of SYK tyrosine kinase in B-lineage leukemia/lymphoma cells exposed to oxidative stress. Proc Natl Acad Sci U S A 2010; 107:2902-7. [PMID: 20133729 DOI: 10.1073/pnas.0909086107] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
We provide unprecedented genetic and biochemical evidence that the antiapoptotic transcription factor STAT3 serves as a substrate for SYK tyrosine kinase both in vitro and in vivo. Induction of SYK in an ecdysone-inducible mammalian expression system results in STAT3 activation, as documented by tyrosine phosphorylation and nuclear translocation of STAT3, as well as amplified expression of several STAT3 target genes. STAT3 activation after oxidative stress (OS) is strongly diminished in DT40 chicken B-lineage lymphoma cells rendered SYK-deficient by targeted disruption of the syk gene. Introduction of a wild-type, C-terminal or N-terminal SH2 domain-mutated, but not a kinase domain-mutated, syk gene into SYK-deficient DT40 cells restores OS-induced enhancement of STAT-3 activity. Thus, SYK plays an important and indispensable role in OS-induced STAT3 activation and its catalytic SH1 domain is critical for this previously unknown regulatory function. These results provide evidence for the existence of a novel mode of cytokine-independent cross-talk that operates between SYK and STAT3 pathways and regulates apoptosis during OS. We further provide experimental evidence that SYK is capable of associating with and phosphorylating STAT3 in human B-lineage leukemia/lymphoma cells challenged with OS. In agreement with a prerequisite role of SYK in OS-induced STAT3 activation, OS does not induce tyrosine phosphorylation of STAT3 in SYK-deficient human proB leukemia cells. Notably, inhibition of SYK with a small molecule drug candidate prevents OS-induced activation of STAT3 and overcomes the resistance of human B-lineage leukemia/lymphoma cells to OS-induced apoptosis.
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37
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Yan B, Yates Z, Balland A, Kleemann GR. Human IgG1 hinge fragmentation as the result of H2O2-mediated radical cleavage. J Biol Chem 2010; 284:35390-402. [PMID: 19850927 DOI: 10.1074/jbc.m109.064147] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hinge cleavage of a recombinant human IgG1 antibody, generated during production in a Chinese hamster ovary cell culture, was observed in the purified material. The cleavage products could be reproduced by incubation of the antibody with H(2)O(2) and featured complementary ladders of the C- and N-terminal residues (Asp(226)-Lys(227)-Thr(228)-His(229)-Thr(230)) in the heavy chain of the Fab domain and the upper hinge of one of the Fc domains, respectively. Two adducts of +45 and +71 Da were also observed at the N-terminal residues of some Fc fragments and were identified as isocyanate and alpha-ketoacyl derivatives generated by radical cleavage at the alpha-carbon position through the diamide and alpha-amidation pathways. We determined that the hinge cleavage was initiated by radical-induced breakage of the disulfide bond between the two hinge cysteines at position 231 (Cys(231)-Pro-Pro-Cys-Pro), followed by the formation of a thiyl radical (Cys(231)-S(*)) on one cysteine and sulfenic acid (Cys(231)-SOH) on the other. The location of the initial radical attack and the critical role of Cys(231) were demonstrated by the observation that 5,5-dimethyl-1-pyrroline N-oxide only reacted with the Cys(231) radical and completely blocked hinge cleavage, suggesting the necessity of an electron/radical transfer from the Cys(231) radical to the hinge residues where cleavage was observed. As a precursor of hydroxyl radicals, H(2)O(2) is widely produced in healthy cells and tissues and therefore could be the source for the radical-induced fragmentation of human IgG1 antibodies in vivo.
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Affiliation(s)
- Boxu Yan
- Department of Analytical and Formulation Science, Amgen Incorporated, Seattle, Washington 98119, USA.
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38
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Crystal structure of the catalytic domain of the tumor-associated human carbonic anhydrase IX. Proc Natl Acad Sci U S A 2009; 106:16233-8. [PMID: 19805286 DOI: 10.1073/pnas.0908301106] [Citation(s) in RCA: 389] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Carbonic anhydrase (CA) IX is a plasma membrane-associated member of the alpha-CA enzyme family, which is involved in solid tumor acidification. It is a marker of tumor hypoxia and a prognostic factor in several human cancers. An aberrant increase in CA IX expression in chronic hypoxia and during development of various carcinomas contributes to tumorigenesis through at least two mechanisms: pH regulation and cell adhesion control. Here we report the X-ray structure of the catalytic domain of CA IX in complex with a classical, clinically used sulfonamide inhibitor, acetazolamide. The structure reveals a typical alpha-CA fold, which significantly differs from the other CA isozymes when the protein quaternary structure is considered. Thus, two catalytic domains of CA IX associate to form a dimer, which is stabilized by the formation of an intermolecular disulfide bond. The active site clefts and the PG domains are located on one face of the dimer, while the C-termini are located on the opposite face to facilitate protein anchoring to the cell membrane. A correlation between the three-dimensional structure and the physiological role of the enzyme is here suggested, based on the measurement of the pH profile of the catalytic activity for the physiological reaction, CO(2) hydration to bicarbonate and protons. On the basis of the structural differences observed between CA IX and the other membrane-associated alpha-CAs, further prospects for the rational drug design of isozyme-specific CA inhibitors are proposed, given that inhibition of this enzyme shows antitumor activity both in vitro and in vivo.
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Hower AE, Beltran PJ, Bixby JL. Dimerization of tyrosine phosphatase PTPRO decreases its activity and ability to inactivate TrkC. J Neurochem 2009; 110:1635-47. [PMID: 19573017 DOI: 10.1111/j.1471-4159.2009.06261.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Receptor-protein tyrosine phosphatases (RPTPs), like receptor tyrosine kinases, regulate neuronal differentiation. While receptor tyrosine kinases are dimerized and activated by extracellular ligands, the extent to which RPTPs dimerize, and the effects of dimerization on phosphatase activity, are poorly understood. We have examined a neuronal type III RPTP, PTPRO; we find that PTPRO can form dimers in living cells, and that disulfide linkages in PTPROs intracellular domain likely regulate dimerization. Dimerization of PTPROs transmembrane and intracellular domains, achieved by ligand binding to a chimeric fusion protein, decreases activity toward artificial peptides and toward a putative substrate, tropomyosin-related kinase C (TrkC). Dephosphorylation of TrkC by PTPRO may be physiologically relevant, as it is efficient, and TrkC and PTPRO can be co-precipitated from transfected cells. Inhibition of PTPROs phosphatase activity by dimerization is interesting, as dimerization of a related RPTP, CD148/PTPRJ, increases activity. Thus, our results suggest a complex relationship between dimerization and activity in type III RPTPs.
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Identification of novel fibroblast growth factor receptor 3 gene mutations in actinic cheilitis and squamous cell carcinoma of the lip. ACTA ACUST UNITED AC 2009; 107:535-41. [PMID: 19327639 DOI: 10.1016/j.tripleo.2008.12.050] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Accepted: 12/18/2008] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Activating mutations in the fibroblast growth factor receptor 3 (FGFR3) gene are responsible for several craniosynostosis and chondrodysplasia syndromes as well as some human cancers, including bladder and cervical carcinoma. Despite a high frequency in some benign skin disorders, FGFR3 mutations have not been reported in cutaneous malignancies. Actinic cheilitis (AC) is a sun-induced premalignancy affecting the lower lip that frequently progresses to squamous cell carcinoma (SCC). The objective of this study was to determine if FGFR3 gene mutations are present in AC and SCC of the lip. STUDY DESIGN DNA was extracted and purified from microdissected, formalin-fixed, paraffin-embedded tissue sections of 20 cases of AC and SCC arising in AC. Exons 7, 15, and 17 were PCR amplified and direct sequenced. RESULTS Four novel somatic mutations in the FGFR3 gene were identified: exon 7 mutation 742C-->T (amino acid change R248C), exon 15 mutations 1850A-->G (D617G) and 1888G-->A (V630M), and exon 17 mutation 2056G-->A (E686K). Grade of dysplasia did not correlate with presence of mutations. CONCLUSION The frequency of FGFR3 receptor mutations suggests a functional role for the FGFR3 receptor in the development of epithelial disorders, and perhaps this change may contribute to the pathogenesis of some AC and SCC.
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41
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Karala AR, Lappi AK, Saaranen MJ, Ruddock LW. Efficient peroxide-mediated oxidative refolding of a protein at physiological pH and implications for oxidative folding in the endoplasmic reticulum. Antioxid Redox Signal 2009; 11:963-70. [PMID: 19117384 DOI: 10.1089/ars.2008.2326] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The majority of secreted and outer membrane eukaryotic proteins contain disulfide bonds, formed by complex interdependent pathways in the endoplasmic reticulum. The current model for the major route of disulfide formation is the regulated flow of oxidizing equivalents from molecular oxygen to the membrane-associated enzyme Ero1 to protein disulfide isomerase, and hence to substrate proteins. One molecule of hydrogen peroxide is produced by Ero1 per disulfide bond made. This peroxide is usually considered to be a dangerous by-product. Here we show that peroxide, added to a refolding buffer or generated enzymatically in situ, results in the efficient refolding of a model protein to the native state. At pH 7.0, the kinetics of obtaining the native folded state are more efficient using peroxide than by the use of a glutathione redox buffer. Disulfide bond formation by peroxide is kinetically favored over oxidation of cysteine to cysteine sulfinic acid and over the oxidation of other amino acids in the proteins such as methionine. Hence, unless peroxides are added in excess, oxidative damage to the folding protein is minimal. Our results offer insights into potential mechanisms for disulfide bond formation in vivo.
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42
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Differential impact of the CD45 juxtamembrane wedge on central and peripheral T cell receptor responses. Proc Natl Acad Sci U S A 2009; 106:546-51. [PMID: 19129486 DOI: 10.1073/pnas.0811647106] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The cooperative activity of protein tyrosine kinases and phosphatases plays a central role in regulation of T cell receptor (TCR) signal strength. Perturbing this balance, and thus the threshold for TCR signals, has profound impacts on T cell development and function. We previously generated mice containing a point mutation in the juxtamembrane wedge of the receptor-like protein tyrosine phosphatase CD45. Demonstrating the critical negative regulatory function of the wedge, the CD45 E613R (WEDGE) mutation led to a lymphoproliferative disorder (LPD) and a lupus-like autoimmune syndrome. Using genetic, cellular, and biochemical approaches, we now demonstrate that the CD45 wedge influences T cell development and function. Consistent with increased TCR signal strength, WEDGE mice have augmented positive selection and enhanced sensitivity to the CD4-mediated disease experimental autoimmune encephalitis (EAE). These correspond with hyperresponsive calcium and pERK responses to TCR stimulation in thymocytes, but surprisingly, not in peripheral T cells, where these responses are actually depressed. Together, the data support a role for the CD45 wedge in regulation of T cell responses in vivo and suggest that its effects depend on cellular context.
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43
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A modified cysteinyl-labeling assay reveals reversible oxidation of protein tyrosine phosphatases in angiomyolipoma cells. Proc Natl Acad Sci U S A 2008; 105:9959-64. [PMID: 18632564 DOI: 10.1073/pnas.0804336105] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The production of reactive oxygen species (ROS) exerts an additional tier of control over tyrosine phosphorylation-dependent signal transduction by transiently inhibiting the catalytic activity of specific protein tyrosine phosphatases (PTPs). Hence, the ability to detect reversible oxidation of PTPs in vivo is critical to understanding the complex biological role of ROS in the control of cellular signaling. Here, we describe an assay for identifying those PTPs that are reversibly oxidized in vivo, which utilizes the unique chemistry of the invariant catalytic Cys residue in labeling the active site with biotinylated small molecules under mildly acidic conditions. We have applied this cysteinyl-labeling assay to the study of platelet-derived growth factor (PDGF) receptor signaling in an angiomyolipoma cell model. Doing so has allowed us to detect reversible oxidation of several proteins in response to sustained PDGF stimulation. As in other cell systems, we have observed the reversible oxidation of the classical PTP SHP2 and the tumor suppressor phosphatase PTEN in response to PDGF stimulation. Furthermore, we detected reversible oxidation of members of two other subclasses of PTPs, the receptor PTP LAR and the dual-specificity phosphatase MKP1. These data demonstrate the broad selectivity of the assay, allowing us to detect representatives of all of the major subgroups of the PTP superfamily. We anticipate that this cysteinyl-labeling enrichment strategy can be applied broadly to study reversible oxidation as a mechanism of harnessing PTP catalytic activity in a variety of signaling pathways.
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Khan IM, Gilbert SJ, Caterson B, Sandell LJ, Archer CW. Oxidative stress induces expression of osteoarthritis markers procollagen IIA and 3B3(-) in adult bovine articular cartilage. Osteoarthritis Cartilage 2008; 16:698-707. [PMID: 18255322 DOI: 10.1016/j.joca.2007.10.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Accepted: 10/01/2007] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Oxidative stress occurs when the metabolic balance of a cell is disrupted through exposure to excess pro-oxidant. Whilst it is known that unregulated production or exposure to exogenous sources of pro-oxidants induces chondrocyte cell death and degrades matrix components in vitro, relatively little is known of the effects of pro-oxidants on articular cartilage in situ. The objective of this study was to determine if a single exposure to the pro-oxidant hydrogen peroxide (H(2)O(2)) induces a degenerative phenotype. METHODS Articular cartilage explants were obtained from skeletally mature bovine steers and exposed to a single dose of hydrogen peroxide (0.1-1.0 mM) and cultured for up to 21 days. Cell death, and sulfated glycosaminoglycan loss into the medium and gene expression were quantitatively determined. Adoption of an abnormal chondrocyte phenotype was analyzed through the expression of 3B3(-), nitrotyrosine and procollagen type IIA epitopes in cartilage explants. RESULTS Cell death occurred primarily at the surface zone of cartilage in a dose-dependent manner in H(2)O(2) treated explants, and supplementation of standard serum-free medium with insulin-selenium-transferrin significantly reduced cell death (>fourfold). Nitric oxide synthase-2 gene expression and proteoglycan loss increased in oxidant treated explants in a concentration-dependent manner. Antibody labeling to 3B3(-), procollagen type IIA and nitrotyrosine was present in all treated explants but absent in untreated explants. CONCLUSIONS This study demonstrates that a single exposure to high levels of pro-oxidant causes the expression of genes and antibody epitopes that are associated with early degenerative changes observed in experimental osteoarthritis.
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Affiliation(s)
- I M Khan
- Connective Tissue Laboratories, Cardiff University, Cardiff, Wales, UK
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45
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Groen A, Overvoorde J, van der Wijk T, den Hertog J. Redox regulation of dimerization of the receptor protein-tyrosine phosphatases RPTPα, LAR, RPTPμ and CD45. FEBS J 2008; 275:2597-604. [DOI: 10.1111/j.1742-4658.2008.06407.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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46
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Abstract
Protein-tyrosine phosphatases are tightly controlled by various mechanisms, ranging from differential expression in specific cell types to restricted subcellular localization, limited proteolysis, post-translational modifications affecting intrinsic catalytic activity, ligand binding and dimerization. Here, we review the regulatory mechanisms found to control the classical protein-tyrosine phosphatases.
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47
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Primo ME, Klinke S, Sica MP, Goldbaum FA, Jakoncic J, Poskus E, Ermácora MR. Structure of the Mature Ectodomain of the Human Receptor-type Protein-tyrosine Phosphatase IA-2. J Biol Chem 2008; 283:4674-81. [DOI: 10.1074/jbc.m708144200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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48
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Kinns H, Howorka S. The surface location of individual residues in a bacterial S-layer protein. J Mol Biol 2008; 377:589-604. [PMID: 18262545 DOI: 10.1016/j.jmb.2008.01.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 12/22/2007] [Accepted: 01/08/2008] [Indexed: 10/22/2022]
Abstract
Bacterial surface layer (S-layer) proteins self-assemble into large two-dimensional crystalline lattices that form the outermost cell-wall component of all archaea and many eubacteria. Despite being a large class of self-assembling proteins, little is known about their molecular architecture. We investigated the S-layer protein SbsB from Geobacillus stearothermophilus PV72/p2 to identify residues located at the subunit-subunit interface and to determine the S-layer's topology. Twenty-three single cysteine mutants, which were previously mapped to the surface of the SbsB monomer, were subjected to a cross-linking screen using the photoactivatable, sulfhydryl-reactive reagent N-[4-(p-azidosalicylamido)butyl]-3'-(2'-pyridyldithio)propionamide. Gel electrophoretic analysis on the formation of cross-linked dimers indicated that 8 out of the 23 residues were located at the interface. In combination with surface accessibility data for the assembled protein, 10 residues were assigned to positions at the inner, cell-wall-facing lattice surface, while 5 residues were mapped to the outer, ambient-exposed lattice surface. In addition, the cross-linking screen identified six positions of intramolecular cross-linking within the assembled protein but not in the monomeric S-layer protein. Most likely, these intramolecular cross-links result from conformational changes upon self-assembly. The results are an important step toward the further structural elucidation of the S-layer protein via, for example, X-ray crystallography and cryo-electron microscopy. Our approach of identifying the surface location of residues is relevant to other planar supramolecular protein assemblies.
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Affiliation(s)
- Helen Kinns
- Department of Chemistry, University College London, Christopher Ingold Building, 20 Gordon Street, London WC1H 0AJ, England, UK
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49
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Noordman YE, Augustus ED, Schepens JTG, Chirivi RGS, Ríos P, Pulido R, Hendriks WJAJ. Multimerisation of receptor-type protein tyrosine phosphatases PTPBR7 and PTP-SL attenuates enzymatic activity. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1783:275-86. [PMID: 18068678 DOI: 10.1016/j.bbamcr.2007.10.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 10/22/2007] [Accepted: 10/30/2007] [Indexed: 11/16/2022]
Abstract
Dimerisation of receptor-type protein tyrosine phosphatases (RPTPs) represents an appealing mechanism to regulate their enzymatic activity. Studies thus far mostly concern the dimerisation behaviour of RPTPs possessing two tandemly oriented catalytic PTP domains. Mouse gene Ptprr encodes four different protein isoforms (i.e. PTPBR7, PTP-SL and PTPPBSgamma-42/37) that contain a single PTP domain. Using selective membrane permeabilisation we here demonstrate that PTP-SL, like PTPBR7, is a single membrane-spanning RPTP. Furthermore, these two receptor-type PTPs constitutively formed homo- and hetero-meric complexes as witnessed in chemical cross-linking and co-immunoprecipitation experiments, in sharp contrast to the cytosolic PTPPBSgamma-42 and PTPPBSgamma-37 PTPRR isoforms. This multimerisation occurs independently of the PTP domain and requires the transmembrane domain and/or the proximal hydrophobic region. Using overexpression of a PTPBR7 mutant that essentially lacks the intracellular PTP domain-containing segment, a monomer-mimicking state was forced upon full-length PTPBR7 immunoprecipitates. This resulted in a significant increase in the enzymatic activity of the PTPRR PTP domain, which strengthens the notion that multimerisation represents a general mechanism to tone down RPTP catalytic activity.
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Affiliation(s)
- Yvet E Noordman
- Department of Cell Biology, Radboud University Nijmegen Medical Centre, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands
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50
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Yang J, Groen A, Lemeer S, Jans A, Slijper M, Roe SM, den Hertog J, Barford D. Reversible oxidation of the membrane distal domain of receptor PTPalpha is mediated by a cyclic sulfenamide. Biochemistry 2007; 46:709-19. [PMID: 17223692 DOI: 10.1021/bi061546m] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein tyrosine phosphatases (PTPs) are fundamental to the regulation of cellular signalling cascades triggered by protein tyrosine kinases. Most receptor-like PTPs (RPTPs) comprise two tandem PTP domains, with only the membrane proximal domains (D1) having significant phosphatase activity; the membrane distal domains (D2) display little to no catalytic activity. Intriguingly, however, many RPTP D2s share the catalytically essential Cys and Arg residues of D1s. D2 of RPTPalpha may function as a redox sensor that mediates regulation of D1 via reactive oxygen species. Oxidation of Cys723 of RPTPalpha D2 (equivalent to PTP catalytic Cys residues) stabilizes RPTPalpha dimers, induces rotational coupling, and is required for inactivation of D1 phosphatase activity. Here, we investigated the structural consequences of RPTPalpha D2 oxidation. Exposure of RPTPalpha D2 to oxidants promotes formation of a cyclic sulfenamide species, a reversibly oxidized state of Cys723, accompanied by conformational changes of the D2 catalytic site. The cyclic sulfenamide is highly resistant to terminal oxidation to sulfinic and sulfonic acids. Conformational changes associated with RPTPalpha D2 oxidation have implications for RPTPalpha quaternary structure and allosteric regulation of D1 phosphatase activity.
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MESH Headings
- Amides/chemistry
- Amino Acid Sequence
- Animals
- Chromatography, Gel
- Crystallography, X-Ray
- Cysteine/chemistry
- Dimerization
- Hydrogen Peroxide/chemistry
- Mice
- Models, Molecular
- Oxidation-Reduction
- Protein Conformation/drug effects
- Protein Structure, Quaternary
- Protein Structure, Tertiary
- Protein Tyrosine Phosphatases/chemistry
- Protein Tyrosine Phosphatases/immunology
- Reactive Oxygen Species/chemistry
- Receptor-Like Protein Tyrosine Phosphatases, Class 4
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/immunology
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Sulfenic Acids/chemistry
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Affiliation(s)
- Jing Yang
- Section of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, United Kingdom
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