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Abstract
The cysteinyl leukotrienes (cys-LTs), leukotriene C4, (LTC4), LTD4, and LTE4, are lipid mediators of inflammation. LTC4 is the only intracellularly synthesized cys-LT through the 5-lipoxygenase and LTC4 synthase pathway and after transport is metabolized to LTD4 and LTE4 by specific extracellular peptidases. Each cys-LT has a preferred functional receptor in vivo; LTD4 to the type 1 cys-LT receptor (CysLT1R), LTC4 to CysLT2R, and LTE4 to CysLT3R (OXGR1 or GPR99). Recent studies in mouse models revealed that there are multiple regulatory mechanisms for these receptor functions and each receptor plays a distinct role as observed in different mouse models of inflammation and immune responses. This review focuses on the integrated host responses to the cys-LT/CysLTR pathway composed of sequential ligands with preferred receptors as seen from mouse models. It also discusses potential therapeutic targets for LTC4 synthase, CysLT2R, and CysLT3R.
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Affiliation(s)
- Yoshihide Kanaoka
- Department of Medicine, Harvard Medical School and Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA, United States.
| | - K Frank Austen
- Department of Medicine, Harvard Medical School and Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA, United States.
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2
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Roblin G, Octave S, Faucher M, Fleurat-Lessard P, Berjeaud JM. Cysteine: A multifaceted amino acid involved in signaling, plant resistance and antifungal development. Plant Physiol Biochem 2018; 129:77-89. [PMID: 29852365 DOI: 10.1016/j.plaphy.2018.05.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/04/2018] [Accepted: 05/22/2018] [Indexed: 06/08/2023]
Abstract
Early effects induced by cysteine were monitored using the model of Mimosa pudica pulvinar cells. Rapid dose-dependent membrane depolarization (within seconds) and modification of proton secretion (within minutes) were triggered at cysteine concentrations higher than 0.1 mM. These effects did not result from a modification of the plasma membrane H+-ATPase activity nor from a protonophore effect as shown by assays on plasma membrane vesicles isolated from pulvinar tissues. In a 0.5-10 mM range, cysteine inhibited the ion-driven turgor-mediated seismonastic reaction of Mimosa pudica primary pulvini and the dark-induced movement of Cassia fasciculata leaflets. At concentrations higher than 1 mM, it induced a long-lasting leaflet necrosis dependent on the concentration and treatment duration. Electron microscopy showed that cysteine induced important damage in the nucleus, mitochondria, endoplasmic reticulum and Golgi of the M. pudica motor cell. Cysteine inhibited in a concentration-dependent manner, from 0.5 to 20 mM, both the mycelial growth and the spore germination of the fungal pathogens Phaeomoniella chlamydospora and Phaeoacremonium minimum implicated in esca disease of grapevines. Using [35S] cysteine, we showed that the amino acid was absorbed following leaf spraying, translocated from leaves to other parts of grapevine cuttings and accumulated within trunks and roots. Therefore, cysteine showed relevant properties to be a candidate able to control fungal diseases either by acting as an early signal directing plant host reaction or/and by acting directly on fungal development.
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Affiliation(s)
- Gabriel Roblin
- Université de Poitiers, Ecologie & Biologie des Interactions, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 Poitiers cedex 9, France
| | - Stéphane Octave
- Université de Poitiers, Ecologie & Biologie des Interactions, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 Poitiers cedex 9, France; Current address: Sorbonne Universités, Université de Technologie de Compiègne, UMR CNRS 7025, Génie Enzymatique et Cellulaire, Rue du Docteur Schweitzer CS 60319, 60203 Compiègne Cedex, France
| | - Mireille Faucher
- Université de Poitiers, Ecologie & Biologie des Interactions, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 Poitiers cedex 9, France
| | - Pierrette Fleurat-Lessard
- Université de Poitiers, Ecologie & Biologie des Interactions, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 Poitiers cedex 9, France
| | - Jean-Marc Berjeaud
- Université de Poitiers, Ecologie & Biologie des Interactions, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 Poitiers cedex 9, France.
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3
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Cardi M, Zaffagnini M, De Lillo A, Castiglia D, Chibani K, Gualberto JM, Rouhier N, Jacquot JP, Esposito S. Plastidic P2 glucose-6P dehydrogenase from poplar is modulated by thioredoxin m-type: Distinct roles of cysteine residues in redox regulation and NADPH inhibition. Plant Sci 2016; 252:257-266. [PMID: 27717462 DOI: 10.1016/j.plantsci.2016.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/01/2016] [Accepted: 08/07/2016] [Indexed: 05/03/2023]
Abstract
A cDNA coding for a plastidic P2-type G6PDH isoform from poplar (Populus tremula x tremuloides) has been used to express and purify to homogeneity the mature recombinant protein with a N-terminus His-tag. The study of the kinetic properties of the recombinant enzyme showed an in vitro redox sensing modulation exerted by reduced DTT. The interaction with thioredoxins (TRXs) was then investigated. Five cysteine to serine variants (C145S - C175S - C183S - C195S - C242S) and a variant with a double substitution for Cys175 and Cys183 (C175S/C183S) have been generated, purified and biochemically characterized in order to investigate the specific role(s) of cysteines in terms of redox regulation and NADPH-dependent inhibition. Three cysteine residues (C145, C194, C242) are suggested to have a role in controlling the NADP+ access to the active site, and in stabilizing the NADPH regulatory binding site. Our results also indicate that the regulatory disulfide involves residues Cys175 and Cys183 in a position similar to those of chloroplastic P1-G6PDHs, but the modulation is exerted primarily by TRX m-type, in contrast to P1-G6PDH, which is regulated by TRX f. This unexpected specificity indicates differences in the mechanism of regulation, and redox sensing of plastidic P2-G6PDH compared to chloroplastic P1-G6PDH in higher plants.
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Affiliation(s)
- Manuela Cardi
- Dipartimento di Biologia, Univ. di Napoli "Federico II", I-80126 Napoli, Italy
| | - Mirko Zaffagnini
- Dipartimento di Farmacia e Biotecnologie, Univ. di Bologna, I-40126 Bologna, Italy
| | - Alessia De Lillo
- Dipartimento di Biologia, Univ. di Napoli "Federico II", I-80126 Napoli, Italy
| | - Daniela Castiglia
- Dipartimento di Biologia, Univ. di Napoli "Federico II", I-80126 Napoli, Italy
| | - Kamel Chibani
- Université de Lorraine, UMR 1136 Interactions Arbres/Microorganismes, Faculté des Sciences et Technologies, 54506, Vandoeuvre-lès-Nancy, France; INRA, UMR 1136 Interactions Arbres/Microorganismes, Centre INRA Nancy Lorraine, 54280, Champenoux, France
| | - José Manuel Gualberto
- Université de Strasbourg, Institut de Biologie Moléculaire Des Plantes (IBMP), CNRS-UPR 2357, 67084 Strasbourg, France
| | - Nicolas Rouhier
- Université de Lorraine, UMR 1136 Interactions Arbres/Microorganismes, Faculté des Sciences et Technologies, 54506, Vandoeuvre-lès-Nancy, France; INRA, UMR 1136 Interactions Arbres/Microorganismes, Centre INRA Nancy Lorraine, 54280, Champenoux, France
| | - Jean-Pierre Jacquot
- Université de Lorraine, UMR 1136 Interactions Arbres/Microorganismes, Faculté des Sciences et Technologies, 54506, Vandoeuvre-lès-Nancy, France; INRA, UMR 1136 Interactions Arbres/Microorganismes, Centre INRA Nancy Lorraine, 54280, Champenoux, France
| | - Sergio Esposito
- Dipartimento di Biologia, Univ. di Napoli "Federico II", I-80126 Napoli, Italy.
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Watanabe Y. [Regulation of calcium signals via redox modification]. Nihon Yakurigaku Zasshi 2016; 147:285-289. [PMID: 27181723 DOI: 10.1254/fpj.147.285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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5
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Abstract
Cysteinyl leukotrienes (CysLTs) are lipid mediators that have been implicated in the pathogenesis of allergic rhinitis. Pharmacological studies using CysLTs indicate that two classes of receptor exist: CysLT1 receptor (CysLT1R) and CysLT2 receptor (CysLT2R). The CysLT1R is a high-affinity leukotriene D4 receptor with lower affinity for leukotriene C4 that is sensitive to the CysLT1R antagonist currently used to treat asthma and allergic rhinitis. Our previous immunohistochemical and autoradiographic studies have demonstrated the presence of anti-CysLT1R antibodies labeled in eosinophils, mast cells, macrophages, neutrophils and vascular endothelial cells in human nasal mucosa. Furthermore, we have revealed that the novel radioactive CysLT1R antagonist [3H]-pranlukast bound specifically to CysLT1R in human inferior turbinates and its binding sites were localized to vascular endothelium and the interstitial cells. These data suggest that the major targets of CysLT1R antagonists in allergic rhinitis are the vascular bed and infiltrated leukocytes such as mast cells, eosinophils and macrophages. Clinical trials have demonstrated that CysLT1R antagonists are as effective as antihistamines for the treatment of allergic rhinitis; however, they are less effective than intranasal steroids. The use of CysLT1R antagonists in combination with antihistamines has generally resulted in greater efficacy than when these agents were used alone.
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Liu T, Schroeder HJ, Wilson SM, Terry MH, Romero M, Longo LD, Power GG, Blood AB. Local and systemic vasodilatory effects of low molecular weight S-nitrosothiols. Free Radic Biol Med 2016; 91:215-23. [PMID: 26686469 PMCID: PMC4761500 DOI: 10.1016/j.freeradbiomed.2015.12.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 10/02/2015] [Accepted: 12/10/2015] [Indexed: 12/21/2022]
Abstract
S-nitrosothiols (SNOs) such as S-nitroso-L-cysteine (L-cysNO) are endogenous compounds with potent vasodilatory activity. During circulation in the blood, the NO moiety can be exchanged among various thiol-containing compounds by S-transnitrosylation, resulting in SNOs with differing capacities to enter the cell (membrane permeability). To determine whether the vasodilating potency of SNOs is dependent upon membrane permeability, membrane-permeable L-cysNO and impermeable S-nitroso-D-cysteine (D-cysNO) and S-nitroso-glutathione (GSNO) were infused into one femoral artery of anesthetized adult sheep while measuring bilateral femoral and systemic vascular conductances. L-cysNO induced vasodilation in the infused hind limb, whereas D-cysNO and GSNO did not. L-cysNO also increased intracellular NO in isolated arterial smooth muscle cells, whereas GSNO did not. The infused SNOs remained predominantly in a low molecular weight form during first-passage through the hind limb vasculature, but were converted into high molecular weight SNOs upon systemic recirculation. At systemic concentrations of ~0.6 μmol/L, all three SNOs reduced mean arterial blood pressure by ~50%, with pronounced vasodilation in the mesenteric bed. Pharmacokinetics of L-cysNO and GSNO were measured in vitro and in vivo and correlated with their hemodynamic effects, membrane permeability, and S-transnitrosylation. These results suggest local vasodilation by SNOs in the hind limb requires membrane permeation, whereas systemic vasodilation does not. The systemic hemodynamic effects of SNOs occur after equilibration of the NO moiety amongst the plasma thiols via S-transnitrosylation.
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Affiliation(s)
- Taiming Liu
- Department of Pediatrics, Division of Neonatology, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
| | - Hobe J Schroeder
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
| | - Sean M Wilson
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
| | - Michael H Terry
- Department of Respiratory Care, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
| | - Monica Romero
- Advanced Microscopy Imaging Core, Loma Linda University School of Medicine, Loma Linda, CA 92354
| | - Lawrence D Longo
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
| | - Gordon G Power
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
| | - Arlin B Blood
- Department of Pediatrics, Division of Neonatology, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA; Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
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7
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Uehara T. [Regulation of intracellular signal pathways via sensor proteins by oxidative stress]. Clin Calcium 2013; 23:1613-1619. [PMID: 24162601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
It has been known that reactive oxygen species (ROS) control the enzymatic and transcriptional activity of proteins via direct modification of cysteine residues. Hence, oxidation of cysteine thiol could be a vital modulator of signal transduction pathways. These findings indicate that some proteins serve as the sensor proteins highly sensitive to ROS. In this review, I show the relationship between intracellular ROS sensor and the regulation of protein function via oxidation.
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Affiliation(s)
- Takashi Uehara
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Japan
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8
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Abstract
The thyroid hormone (TH) transporter monocarboxylate transporter 8 (MCT8) is crucial for brain development as demonstrated by the severe psychomotor retardation in patients with MCT8 mutations. MCT8 contains 10 residues of the reactive amino acid cysteine (Cys) whose functional roles were studied using the Cys-specific reagent p-chloromercurybenzenesulfonate (pCMBS) and by site-directed mutagenesis. Pretreatment of JEG3 cells with pCMBS resulted in a dose- and time-dependent decrease of subsequent T3 uptake. Pretreatment with dithiothreitol did not affect TH transport or its inhibition by pCMBS. However, pCMBS inhibition of MCT8 was reversed by dithiothreitol. Inhibition of MCT8 by pCMBS was prevented in the presence of T3. The single and double mutation of C481A and C497A did not affect T3 transport, but the single mutants were less sensitive and the double mutant was completely insensitive to pCMBS. Similar effects on MCT8 were obtained using HgCl2 instead of pCMBS. In conclusion, we have identified Cys481 and Cys497 in MCT8 as the residues modified by pCMBS or HgCl2. These residues are probably located at or near the substrate-recognition site in MCT8. It remains to be investigated whether MCT8 function is regulated by modification of these Cys residues under pathophysiological conditions.
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Affiliation(s)
- Elaine C Lima de Souza
- PhD, Department of Internal Medicine, Erasmus University Medical Center, BO Box 2040, 3000 CA Rotterdam, The Netherlands
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Jin HF, Zhao MM, Geng B. [Endogenous sulfur-containing amino acids and cardiovascular injury and repair]. Sheng Li Ke Xue Jin Zhan 2012; 43:330-333. [PMID: 23316602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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10
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Haglund E, Sułkowska JI, He Z, Feng GS, Jennings PA, Onuchic JN. The unique cysteine knot regulates the pleotropic hormone leptin. PLoS One 2012; 7:e45654. [PMID: 23029163 PMCID: PMC3454405 DOI: 10.1371/journal.pone.0045654] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 08/20/2012] [Indexed: 11/30/2022] Open
Abstract
Leptin plays a key role in regulating energy intake/expenditure, metabolism and hypertension. It folds into a four-helix bundle that binds to the extracellular receptor to initiate signaling. Our work on leptin revealed a hidden complexity in the formation of a previously un-described, cysteine-knotted topology in leptin. We hypothesized that this unique topology could offer new mechanisms in regulating the protein activity. A combination of in silico simulation and in vitro experiments was used to probe the role of the knotted topology introduced by the disulphide-bridge on leptin folding and function. Our results surprisingly show that the free energy landscape is conserved between knotted and unknotted protein, however the additional complexity added by the knot formation is structurally important. Native state analyses led to the discovery that the disulphide-bond plays an important role in receptor binding and thus mediate biological activity by local motions on distal receptor-binding sites, far removed from the disulphide-bridge. Thus, the disulphide-bridge appears to function as a point of tension that allows dissipation of stress at a distance in leptin.
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Affiliation(s)
- Ellinor Haglund
- Department of Chemistry and Biochemistry and Center for theoretical Biological Physics (CTBP), University of California San Diego, La Jolla, California, United States of America
| | - Joanna I. Sułkowska
- Department of Chemistry and Biochemistry and Center for theoretical Biological Physics (CTBP), University of California San Diego, La Jolla, California, United States of America
| | - Zhao He
- Department of Pathology; School of Medicine and Molecular Biology Section, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Gen-Sheng Feng
- Department of Pathology; School of Medicine and Molecular Biology Section, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Patricia A. Jennings
- Department of Chemistry and Biochemistry and Center for theoretical Biological Physics (CTBP), University of California San Diego, La Jolla, California, United States of America
| | - José N. Onuchic
- Center for Theoretical Biological physics and Department of Physics and Astronomy, Chemistry, and Biochemistry and Cell Biology, Rice University, Houston, Texas, United States of America
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Schiedel AC, Hinz S, Thimm D, Sherbiny F, Borrmann T, Maass A, Müller CE. The four cysteine residues in the second extracellular loop of the human adenosine A2B receptor: role in ligand binding and receptor function. Biochem Pharmacol 2011; 82:389-99. [PMID: 21620804 DOI: 10.1016/j.bcp.2011.05.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 05/09/2011] [Accepted: 05/11/2011] [Indexed: 11/17/2022]
Abstract
The adenosine A(2B) receptor is of considerable interest as a new drug target for the treatment of asthma, inflammatory diseases, pain, and cancer. In the present study we investigated the role of the cysteine residues in the extracellular loop 2 (ECL2) of the receptor, which is particularly cysteine-rich, by a combination of mutagenesis, molecular modeling, chemical and pharmacological experiments. Pretreatment of CHO cells recombinantly expressing the human A(2B) receptor with dithiothreitol led to a 74-fold increase in the EC(50) value of the agonist NECA in cyclic AMP accumulation. In the C78(3.25)S and the C171(45.50)S mutant high-affinity binding of the A(2B) antagonist radioligand [(3)H]PSB-603 was abolished and agonists were virtually inactive in cAMP assays. This indicates that the C3.25-C45.50 disulfide bond, which is highly conserved in GPCRs, is also important for binding and function of A(2B) receptors. In contrast, the C166(45.45)S and the C167(45.46)S mutant as well as the C166(45.45)S-C167(45.46)S double mutant behaved like the wild-type receptor, while in the C154(45.33)S mutant significant, although more subtle effects on cAMP accumulation were observed - decrease (BAY60-6583) or increase (NECA) - depending on the structure of the investigated agonist. In contrast to the X-ray structure of the closely related A(2A) receptor, which showed four disulfide bonds, the present data indicate that in the A(2B) receptor only the C3.25-C45.50 disulfide bond is essential for ligand binding and receptor activation. Thus, the cysteine residues in the ECL2 of the A(2B) receptor not involved in stabilization of the receptor structure may have other functions.
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Affiliation(s)
- Anke C Schiedel
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany.
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Prise KM, Davies S, Stratford MR, Michael BD. The Role of Non-protein Sulphydryls in Determining the Chemical Repair Rates of Free Radical Precursors of DNA Damage and Cell Killing in Chinese Hamster V79 Cells. Int J Radiat Biol 2009; 62:297-306. [PMID: 1356131 DOI: 10.1080/09553009214552141] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Chinese hamster V79 fibroblasts were irradiated in the gas explosion apparatus and the chemical repair rates of the oxygen-dependent free radical precursors of DNA double-strand breaks (dsb) and lethal lesions measured using filter elution (pH 9.6) and a clonogenic assay. Depletion of cellular GSH levels, from 4.16 fmol/cell to 0.05 fmol/cell, by treatment with buthionine sulphoximine (50 mumol dm-3; 18 h), led to sensitization as regards DNA dsb induction and cell killing. This was evident at all time settings but was particularly pronounced when the oxygen shot was given 1 ms after the irradiation pulse. A detailed analysis of the chemical repair kinetics showed that depletion of GSH led to a reduction in the first-order rate constant for dsb precursors from 385 s-1 to 144 s-1, and for lethal lesion precursors from 533 s-1 to 165 s-1. This is generally consistent with the role of GSH in the repair-fixation model of radiation damage at the critical DNA lesions. However, the reduction in chemical repair rate was not proportional to the severe thiol depletion (down to approximately 1% for GSH) and a residual repair capacity remained (approximately 30%). This was found not to be due to compartmentalization of residual GSH in the nucleus, as the repair rate for dsb precursors in isolated nuclei, washed virtually free of GSH, was identical to that found in GSH-depleted cells (144 s-1), also the OER remained substantially above unity. This suggests that other reducing agents may have a role to play in the chemical repair of oxygen-dependent damage. One possible candidate is the significant level of protein sulphydryls present in isolated nuclei.
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Affiliation(s)
- K M Prise
- Gray Laboratory, Mount Vernon Hospital, Northwood, Middlesex, UK
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Li MS, Demsey AFA, Qi J, Linsdell P. Cysteine-independent inhibition of the CFTR chloride channel by the cysteine-reactive reagent sodium (2-sulphonatoethyl) methanethiosulphonate. Br J Pharmacol 2009; 157:1065-71. [PMID: 19466983 PMCID: PMC2737665 DOI: 10.1111/j.1476-5381.2009.00258.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Revised: 01/15/2009] [Accepted: 02/17/2009] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND PURPOSE Methanethiosulphonate (MTS) reagents are used extensively to modify covalently cysteine side chains in ion channel structure-function studies. We have investigated the interaction between a widely used negatively charged MTS reagent, (2-sulphonatoethyl) methanethiosulphonate (MTSES), and the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel. EXPERIMENTAL APPROACH Patch clamp recordings were used to study a 'cys-less' variant of human CFTR, in which all 18 endogenous cysteine residues have been removed by mutagenesis, expressed in mammalian cell lines. Use of excised inside-out membrane patches allowed MTS reagents to be applied to the cytoplasmic face of active channels. KEY RESULTS Intracellular application of MTSES, but not the positively charged MTSET, inhibited the function of cys-less CFTR. Inhibition was voltage dependent, with a K(d) of 1.97 mmol x L(-1) at -80 mV increasing to 36 mmol x L(-1) at +80 mV. Inhibition was completely reversed on washout of MTSES, inconsistent with covalent modification of the channel protein. At the single channel level, MTSES caused a concentration-dependent reduction in unitary current amplitude. This inhibition was strengthened when extracellular Cl(-) concentration was decreased. CONCLUSIONS AND IMPLICATIONS Our results indicate that MTSES inhibits the function of CFTR in a manner that is independent of its ability to modify cysteine residues covalently. Instead, we suggest that MTSES functions as an open channel blocker that enters the CFTR channel pore from its cytoplasmic end to physically occlude Cl(-) permeation. Given the very widespread use of MTS reagents in functional studies, our findings offer a broadly applicable caveat to the interpretation of results obtained from such studies.
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Affiliation(s)
- M-S Li
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada
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Zarros A, Liapi C, Galanopoulou P, Marinou K, Mellios Z, Skandali N, Al-Humadi H, Anifantaki F, Gkrouzman E, Tsakiris S. Effects of adult-onset streptozotocin-induced diabetes on the rat brain antioxidant status and the activities of acetylcholinesterase, (Na(+),K (+))- and Mg(2+)-ATPase: modulation by L-cysteine. Metab Brain Dis 2009; 24:337-48. [PMID: 19296211 DOI: 10.1007/s11011-009-9133-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2008] [Accepted: 11/19/2008] [Indexed: 01/28/2023]
Abstract
Uncontrolled diabetes is known to affect the nervous system. The aim of this study was to investigate the effect of the antioxidant L: -cysteine (Cys) on the changes caused by adult-onset streptozotocin (STZ)-induced diabetes on the rat brain total antioxidant status (TAS) and the activities of acetylcholinesterase (AChE), (Na(+),K(+))-ATPase and Mg(2+)-ATPase. Thirty-eight male Wistar rats were divided into six groups: C(A) (8-week-control), C(B) (8-week-control + 1-week-saline-treated), C + Cys (8-week-control + 1-week-Cys-treated), D(A) (8-week-diabetic), D(B) (8-week-diabetic + 1-week-saline-treated) and D + Cys (8-week-diabetic + 1-week-Cys-treated). All diabetic rats were once treated with an intraperitoneal (i.p.) STZ injection (50 mg/kg body weight) at the beginning of the experiment, while all Cys-treated groups received i.p. injections of Cys 7 mg/kg body weight (daily, for 1-week, during the 9th-week). Whole rat brain parameters were measured spectrophotometrically. In vitro incubation with 0.83 mM of Cys or 10 mM of STZ for 3 h was performed on brain homogenate samples from groups C(B) and D(B), in order to study the enzymes' activities. Diabetic rats exhibited a statistically significant reduction in brain TAS (-28%, D(A) vs C(A);-30%, D(B) vs C(B)) that was reversed after 1-week-Cys-administration into basal levels. Diabetes caused a significant increase in AChE activity (+27%, D(A) vs C(A); +15%, D(B) vs C(B)), that was further enhanced by Cys-administration (+57%, D + Cys vs C(B)). The C + Cys group exhibited no significant difference compared to the C(B) group in TAS (+2%), but showed a significantly increased AChE activity (+66%, C + Cys vs C(B)). Diabetic rats exhibited a significant reduction in the activity of Na(+),K(+)-ATPase (-36%, D(A) vs C(A);-48%, D(B) vs C(B)) that was not reversed after 1-week Cys administration. However, in vitro incubation with Cys partially reversed the diabetes-induced Na(+),K(+)-ATPase inhibition. Mg(2+)-ATPase activity was not affected by STZ-induced diabetes, while Cys caused a significant inhibition of the enzyme, both in vivo (-14%, C + Cys vs C(B);-17%, D + Cys vs C(B)) and in vitro (-16%, D(B) + in vitro Cys vs C(B)). In vitro incubation with STZ had no effect on the studied enzymes. The present data revealed a protective role for Cys towards the oxidative effect of diabetes on the adult rat brain. Moreover, an increase in whole brain AChE activity due to diabetes was recorded (not repeatedly established in the literature, since contradictory findings exist), that was further increased by Cys. The inhibition of Na(+),K(+)-ATPase reflects a possible mechanism through which untreated diabetes could affect neuronal excitability, metabolic energy production and certain systems of neurotransmission. As concerns the use of Cys as a neuroprotective agent against diabetes, our in vitro findings could be indicative of a possible protective role of Cys under different in vivo experimental conditions.
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Affiliation(s)
- Apostolos Zarros
- Department of Pharmacology, Medical School, University of Athens, Athens, Greece
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15
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He X, Ma Q. Induction of metallothionein I by arsenic via metal-activated transcription factor 1: critical role of C-terminal cysteine residues in arsenic sensing. J Biol Chem 2009; 284:12609-21. [PMID: 19276070 PMCID: PMC2675990 DOI: 10.1074/jbc.m901204200] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 03/09/2009] [Indexed: 11/06/2022] Open
Abstract
Metal-activated transcription factor 1 (MTF1) mediates the induction of metallothioneins I and II by zinc and stress signals. The mechanism of MTF1 activation has not been well understood. We analyzed the interaction between arsenic (As(3+)) and MTF1 for Mt1 induction. As(3+) potently induces Mt1 mRNA expression in mouse hepa1c1c7 cells. Induction is dependent upon functional MTF1 as induction is lost in Mtf1 knockout cells but is restored upon reconstitution with Mtf1; moreover, As(3+) induces the binding of MTF1 to the metal response elements of endogenous Mt1. Induction is not affected by modulating zinc concentrations but is markedly enhanced by cycloheximide. Phenylarsine oxide (PAO), which covalently binds to vicinal protein cysteine thiol groups, induces Mt1 with a magnitude of higher potency than that of As(3+). PAO affinity beads effectively pulls down the carboxyl half of MTF1 (MTF1(321-675)) by binding to a cluster of five cysteine residues near the terminus. Preincubation with As(3+), Cd(2+), Co(2+), Ni(2+), Ag(+), Hg(2+), and Bi(3+) blocks pulldown of MTF1(321-675) by PAO beads in vitro and in vivo, indicating that binding of the metal inducers to the same C-terminal cysteine cluster as PAO occurs. Deletion of the C-terminal cysteine cluster or mutation of the cysteine residues abolishes or markedly reduces the transcription activation activity of MTF1 and the ability of MTF1 to restore Mt1 induction in Mtf1 knockout cells. The findings demonstrate a critical role of the C-terminal cysteine cluster of MTF1 in arsenic sensing and gene transcription via arsenic-cysteine thiol interaction.
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MESH Headings
- Animals
- Arsenic/pharmacology
- Blotting, Northern
- Cells, Cultured
- Chromatin Immunoprecipitation
- Cysteine/physiology
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Embryo, Mammalian/drug effects
- Embryo, Mammalian/metabolism
- Fibroblasts/drug effects
- Fibroblasts/metabolism
- Immunoblotting
- Liver Neoplasms, Experimental/drug therapy
- Liver Neoplasms, Experimental/metabolism
- Liver Neoplasms, Experimental/pathology
- Luciferases/metabolism
- Metallothionein/biosynthesis
- Mice
- Mice, Knockout
- NF-E2-Related Factor 2/metabolism
- Promoter Regions, Genetic
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reactive Oxygen Species/metabolism
- Response Elements/genetics
- Sulfhydryl Compounds/metabolism
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcriptional Activation
- Zinc/pharmacology
- beta-Galactosidase/metabolism
- Transcription Factor MTF-1
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Affiliation(s)
- Xiaoqing He
- Receptor Biology Laboratory, Toxicology and Molecular Biology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA
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16
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17
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Abstract
Background The interactions of the voltage-gated Ca2+ channel (VGCC) with syntaxin 1A (Sx 1A), Synaptosome-associated protein of 25 kD (SNAP-25), and synaptotagmin, couple electrical excitation to evoked secretion. Two vicinal Cys residues, Cys 271 and Cys 272 in the Sx 1A transmembrane domain, are highly conserved and participate in modulating channel kinetics. Each of the Sx1A Cys mutants, differently modify the kinetics of Cav1.2, and neuronal Cav2.2 calcium channel. Methodology/Principle Findings We examined the effects of various Sx1A Cys mutants and the syntaxin isoforms 2, 3, and 4 each of which lack vicinal Cys residues, on evoked secretion, monitoring capacitance transients in a functional release assay. Membrane capacitance in Xenopus oocytes co-expressing Cav1.2, Sx1A, SNAP-25 and synaptotagmin, which is Bot C- and Bot A-sensitive, was elicited by a double 500 ms depolarizing pulse to 0 mV. The evoked-release was obliterated when a single Cys Sx1A mutant or either one of the Sx isoforms were substituted for Sx 1A, demonstrating the essential role of vicinal Cys residues in the depolarization mediated process. Protein expression and confocal imaging established the level of the mutated proteins in the cell and their targeting to the plasma membrane. Conclusions/Significance We propose a model whereby the two adjacent transmembranal Cys residues of Sx 1A, lash two calcium channels. Consistent with the necessity of a minimal fusion complex termed the excitosome, each Sx1A is in a complex with SNAP-25, Syt1, and the Ca2+ channel. A Hill coefficient >2 imply that at least three excitosome complexes are required for generating a secreting hetero-oligomer protein complex. This working model suggests that a fusion pore that opens during membrane depolarization could be lined by alternating transmembrane segments of Sx1A and VGCC. The functional coupling of distinct amino acids of Sx 1A with VGCC appears to be essential for depolarization-evoked secretion.
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Affiliation(s)
- Roy Cohen
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Merav Marom
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Daphne Atlas
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- * To whom correspondence should be addressed. E-mail:
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18
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Gruda R, Achdout H, Stern-Ginossar N, Gazit R, Betser-Cohen G, Manaster I, Katz G, Gonen-Gross T, Tirosh B, Mandelboim O. Intracellular cysteine residues in the tail of MHC class I proteins are crucial for extracellular recognition by leukocyte Ig-like receptor 1. J Immunol 2007; 179:3655-61. [PMID: 17785801 DOI: 10.4049/jimmunol.179.6.3655] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The activity of NK cells is regulated by activating receptors that recognize mainly stress-induced ligands and by inhibitory receptors that recognize mostly MHC class I proteins on target cells. Comparing the cytoplasmic tail sequences of various MHC class I proteins revealed the presence of unique cysteine residues in some of the MHC class I molecules which are absent in others. To study the role of these unique cysteines, we performed site specific mutagenesis, generating MHC class I molecules lacking these cysteines, and demonstrated that their expression on the cell surface was impaired. Surprisingly, we demonstrated that these cysteines are crucial for the surface binding of the leukocyte Ig-like receptor 1 inhibitory receptor to the MHC class I proteins, but not for the binding of the KIR2DL1 inhibitory receptor. In addition, we demonstrated that the cysteine residues in the cytoplasmic tail of MHC class I proteins are crucial for their egress from the endoplasmic reticulum and for their palmitoylation, thus probably affecting their expression on the cell surface. Finally, we show that the cysteine residues are important for proper extracellular conformation. Thus, although the interaction between leukocyte Ig-like receptor 1 and MHC class I proteins is formed between two extracellular surfaces, the intracellular components of MHC class I proteins play a crucial role in this recognition.
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Affiliation(s)
- Raizy Gruda
- Lautenberg Center for General and Tumor Immunology, Hebrew University, Hadassah Medical School, Jerusalem, Israel
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19
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D’Silva S, Xiao X, Lowe ME. A polymorphism in the gene encoding procolipase produces a colipase, Arg92Cys, with decreased function against long-chain triglycerides. J Lipid Res 2007; 48:2478-84. [PMID: 17715423 PMCID: PMC3684974 DOI: 10.1194/jlr.m700371-jlr200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Type 2 diabetes mellitus is a multifactorial and polygenic disorder with increasing prevalence. Recently, a polymorphism in the gene encoding procolipase, a cysteine for arginine substitution at position 92, was associated with type 2 diabetes in two human populations. Because procolipase plays a critical role in dietary fat metabolism, polymorphisms that affect the function of procolipase could influence the development of type 2 diabetes. We hypothesized that the Arg92Cys polymorphism has functional consequences. To test our hypothesis, we expressed recombinant cysteine 92 (Cys92) procolipase in a yeast expression system and compared the function and stability of purified Cys92 with that of the more common arginine 92 (Arg92) procolipase. Cys92 fully restored the activity of bile-salt inhibited lipase with short- and medium-chain triglycerides but only had 50% of Arg92 function with long-chain triglycerides. After storage at 4 degrees C, Cys92 lost the ability to restore pancreatic triglyceride lipase activity with medium- and long-chain triglycerides. The loss of function correlated with the inability of Cys92 to anchor lipase on an emulsion surface and oxidation of the cysteine. No detectable degradation or intramolecular disulfide formation occurred in Cys92 after storage. Our findings demonstrate that the Arg92Cys polymorphism decreases the function of Cys92 colipase. This change may contribute to the development of type 2 diabetes.
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Affiliation(s)
- Sheryl D’Silva
- Department of Pediatrics, Children’s Hospital of Pittsburgh at University of Pittsburgh Medical Center, Pittsburgh, PA 15213
| | - Xunjun Xiao
- Department of Pediatrics, Children’s Hospital of Pittsburgh at University of Pittsburgh Medical Center, Pittsburgh, PA 15213
| | - Mark E. Lowe
- Department of Pediatrics, Children’s Hospital of Pittsburgh at University of Pittsburgh Medical Center, Pittsburgh, PA 15213
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20
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Kaetsu Y, Yamamoto Y, Sugihara S, Matsuura T, Igawa G, Matsubara K, Igawa O, Shigemasa C, Hisatome I. Role of cysteinyl leukotrienes in the proliferation and the migration of murine vascular smooth muscle cells in vivo and in vitro. Cardiovasc Res 2007; 76:160-6. [PMID: 17588553 DOI: 10.1016/j.cardiores.2007.05.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 05/10/2007] [Accepted: 05/10/2007] [Indexed: 11/18/2022] Open
Affiliation(s)
- Yasuhiro Kaetsu
- Department of Multidisciplinary Internal Medicine, Tottori University Faculty of Medicine, Yonago, Japan
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21
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Meliton AY, Munoz NM, Leff AR. Blockade of avidity and focal clustering of beta 2-integrin by cysteinyl leukotriene antagonism attenuates eosinophil adhesion. J Allergy Clin Immunol 2007; 120:1316-23. [PMID: 17904626 DOI: 10.1016/j.jaci.2007.07.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Revised: 06/08/2007] [Accepted: 07/23/2007] [Indexed: 12/19/2022]
Abstract
BACKGROUND Cysteinyl leukotriene (cysLT) antagonism attenuates migration of eosinophils into airways during immune challenge in human subjects and animal models. The intracellular signaling mechanism by which this occurs has not been elucidated. OBJECTIVE We sought to determine the relative efficacy and mechanism by which 5-lipoxygenase (5-LO) inhibition and cysLT(1) receptor (cysLT(1)R) antagonism block beta(2)-integrin adhesion in isolated human eosinophils in vitro. METHODS Human blood eosinophils were isolated by means of immunomagnetic separation. Upregulation of CD11b expression, active conformation of CD11b, and focal clustering of beta(2)-integrin caused by IL-5, eotaxin-1 or leukotriene (LT) B(4) was assessed by means of flow cytometry and confocal microscopy. The effect and mechanism of cysLT(1)R or 5-LO blockade on these components of beta(2)-integrin adhesion were determined. RESULTS Montelukast, a cysLT(1)R antagonist, and AA861, a 5-LO enzyme inhibitor, blocked (1) avidity of beta(2)-integrin, (2) beta(2)-integrin-mediated adhesion to intercellular adhesion molecule 1, and (3) focal clustering of CD11b elicited by LTB(4). However, adhesion caused by either IL-5 or eotaxin-1 was not attenuated for eosinophils pretreated with either montelukast or AA861. CONCLUSION Our data demonstrate that (1) LTB(4) causes autocrine upregulation of adhesion through secretion of cysLTs, and (2) blockade of cysLT(1)R blocks the avidity and focal clustering of CD11b/CD18 for eosinophils activated by LTB(4) but not by IL-5 or eotaxin-1. CLINICAL IMPLICATIONS Unlike cysLT-induced adhesion, adhesion caused by IL-5 or eotaxin-1 is not regulated through the cysLT(1)R, suggesting that cysLTs have specific but limited potential to upregulate eosinophil adhesion.
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Affiliation(s)
- Angelo Y Meliton
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
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22
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Abbas AK, Xia W, Tranberg M, Wigström H, Weber SG, Sandberg M. S-Sulfo-Cysteine is an Endogenous Amino Acid in Neonatal Rat Brain but an Unlikely Mediator of Cysteine Neurotoxicity. Neurochem Res 2007; 33:301-7. [PMID: 17764028 DOI: 10.1007/s11064-007-9441-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 07/10/2007] [Indexed: 11/25/2022]
Abstract
S-sulfo-cysteine (SSC) is an agonist of glutamate receptors which could be involved in cysteine-induced neurotoxicity. Here we analyzed SSC by HPLC and demonstrated that the concentration of SSC in cortex of cysteine-injected rats increased to 1.4 microM, about four times the value of control rats. The neurotoxic effect of SSC was evaluated in slice cultures of rat hippocampus and compared to NMDA and cysteine. The neurotoxicity threshold of SSC was well above the tissue concentration. Our results show that SSC increases in neonatal rat brain after cysteine injection but reaches a tissue concentration far below concentrations that induce neurotoxicity in vitro. Thus, even if all the tissue SSC after cysteine injection was extracellular it would be below the threshold for toxicity, indicating that SSC is not a main excitotoxin involved in cysteine toxicity.
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Affiliation(s)
- Abdul-Karim Abbas
- Institute of Neuroscience and Physiology, Goteborg University, Medicinerigatan 11, P.O. Box 433, Goteborg 40530, Sweden.
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23
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Liu XS, Zhang M, Jiang M, Wu DM, Tseng GN. Probing the interaction between KCNE2 and KCNQ1 in their transmembrane regions. J Membr Biol 2007; 216:117-27. [PMID: 17676362 DOI: 10.1007/s00232-007-9047-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Accepted: 05/23/2007] [Indexed: 11/25/2022]
Abstract
KCNE1-KCNE5 are single membrane-spanning proteins that associate with voltage-gated potassium channels to diversify their function. Other than the KCNQ1/KCNE1 complex, little is known about how KCNE proteins work. We focus on KCNE2, which associates with KCNQ1 to form K channels critical for gastric acid secretion in parietal cells. We use cysteine (Cys)-scanning mutagenesis to probe the functional role of residues along the KCNE2 transmembrane domain (TMD) in modulating KCNQ1 function. There is an alpha-helical periodicity in how Cys substitutions along the KCNE2 TMD perturb KCNQ1 pore conductance/ion selectivity. However, positions where Cys substitutions perturb KCNQ1 gating kinetics cluster to the extracellular end and cytoplasmic half of the KCNE2 TMD. This is the first systematic perturbation analysis of a KCNE TMD. We propose that the KCNE2 TMD adopts an alpha-helical secondary structure with one face making intimate contact with the KCNQ1 pore domain, while the contacts with the KCNQ1 voltage-sensing domain appear more dynamic.
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Affiliation(s)
- Xian-Sheng Liu
- Department of Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA 23298, USA
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24
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Kurejová M, Lacinová L, Pavlovicová M, Eschbach M, Klugbauer N. The effect of the outermost basic residues in the S4 segments of the Ca(V)3.1 T-type calcium channel on channel gating. Pflugers Arch 2007; 455:527-39. [PMID: 17638012 DOI: 10.1007/s00424-007-0302-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Accepted: 05/23/2007] [Indexed: 11/26/2022]
Abstract
The contribution of voltage-sensing S4 segments in domains I to IV of the T-type Ca(V)3.1 calcium channel to channel gating was investigated by the replacement of the uppermost charged arginine residues by neutral cysteines. In each construct, either a single (R180C, R834C, R1379C or R1717C) or a double (two adjacent domains) mutation was introduced. We found that the neutralisation of the uppermost arginines in the IS4, IIS4 and IIIS4 segments shifted the voltage dependence of channel activation in a hyperpolarising direction, with the most prominent effect in the IS4 mutant. In contrast, the voltage dependence of channel inactivation was shifted towards more negative membrane potentials in all four single mutant channels, and these effects were more pronounced than the effects on channel activation. Recovery from inactivation was affected by the IS4 and IIIS4 mutations. In double mutants, the effects on channel inactivation and recovery from inactivation, but not on channel activation, were additive. Exposure of mutant channels to the reducing agent dithiothreitol did not alter channel properties. In summary, our data indicate that the S4 segments in all four domains of the Ca(V)3.1 calcium channels contribute to voltage sensing during channel inactivation, while only the S4 segments in domains I, II and III play such role in channel activation. Furthermore, the removal of the outermost basic amino acids from the IVS4 and IIIS4 and, to a lesser extent, from IS4 segments stabilised the open state of the channel, whereas neutralization from that of IIS4 destabilised it.
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Affiliation(s)
- Martina Kurejová
- Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlárska 5, Bratislava, Slovakia
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25
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Walbott H, Husson C, Auxilien S, Golinelli-Pimpaneau B. Cysteine of sequence motif VI is essential for nucleophilic catalysis by yeast tRNA m5C methyltransferase. RNA 2007; 13:967-73. [PMID: 17475914 PMCID: PMC1894932 DOI: 10.1261/rna.515707] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Sequence comparison of several RNA m(5)C methyltransferases identifies two conserved cysteine residues that belong to signature motifs IV and VI of RNA and DNA methyltransferases. While the cysteine of motif IV is used as the nucleophilic catalyst by DNA m(5)C methyltransferases, this role is fulfilled by the cysteine of motif VI in Escherichia coli 16S rRNA m(5)C967 methyltransferase, but whether this conclusion applies to other RNA m(5)C methyltransferases remains to be verified. Yeast tRNA m(5)C methyltransferase Trm4p is a multisite-specific S-adenosyl-L-methionine-dependent enzyme that catalyzes the methylation of cytosine at C5 in several positions of tRNA. Here, we confirm that Cys310 of motif VI in Trm4p is essential for nucleophilic catalysis, presumably by forming a covalent link with carbon 6 of cytosine. Indeed, the enzyme is able to form a stable covalent adduct with the 5-fluorocytosine-containing RNA substrate analog, whereas the C310A mutant protein is inactive and unable to form the covalent complex.
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Affiliation(s)
- Hélène Walbott
- Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, Gif-sur-Yvette Cedex, France
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26
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Abstract
S-glutathionylation, the formation of mixed disulfides of glutathione with cysteine residues of proteins, is a broadly observed physiological modification that occurs in response to oxidative stress. Since cysteine residues are particularly susceptible to oxidative modification by reactive oxygen species, S-glutathionylation can protect proteins from irreversible oxidation. In this study, we show that the kinase activity of the non-receptor tyrosine kinase c-Abl is inhibited by in vitro thiol modification; specifically, the cysteine residues of c-Abl are modified by S-glutathionylation and by thiol alkylating agents such as 4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid and N-ethylmaleimide. Modification of cysteine residues of c-Abl tyrosine kinase using glutathione disulfide and thiol alkylating agents corresponds to a concomitant loss of kinase activity. We also demonstrate that S-glutathionylation of c-Abl can be reversed using a physiological system involving glutaredoxin and this reversal restores c-Abl kinase activity. To our knowledge, these are the first data to show S-glutathionylation of c-Abl, and this modification may represent a mechanism of regulation of c-Abl kinase activity in cells under oxidative stress.
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Affiliation(s)
- Amanda Kae Leonberg
- Department of Chemistry, John Carroll University, 20700 North Park Boulevard, University Heights, OH 44118, USA
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27
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Sawyer GW, Ehlert FJ, Shults CA. Cysteine Pairs in the Third Intracellular Loop of the Muscarinic M1Acetylcholine Receptor Play a Role in Agonist-Induced Internalization. J Pharmacol Exp Ther 2007; 324:196-205. [PMID: 17540859 DOI: 10.1124/jpet.107.123695] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We determined the functional role of a small domain in the third intracellular loop of the human muscarinic M(1) (hM(1)) receptor. Using site-directed mutagenesis, several mutant hM(1) receptors were made possessing either a deletion or point mutations within the third intracellular loop domain (252)PETPPGRCCRCC(263). Wild-type and mutant hM(1) receptors were transiently expressed in Chinese hamster ovary cells, and the effects of each mutation on radioligand binding, agonist-mediated phosphoinositide hydrolysis, and agonist-induced internalization were determined. The mutant receptors exhibited a modest reduction in affinity for [(3)H]N-methylscopolamine (pK(D) = approximately 9.0) and a moderately increased binding capacity relative to the wild-type receptor. This moderate increase in binding capacity was associated with small increases in the maximal response and potency of carbachol for eliciting phosphoinositide hydrolysis through the mutant receptors (pEC(50) = approximately 5.5) relative to wild-type (pEC(50) = 5.35 +/- 0.05). In contrast, carbachol-induced internalization of mutant hM(1) receptors possessing either C259A/C260A or C262A/C263A or both double point mutations was significantly reduced compared to the wild-type hM(1) receptor. Of the hM(1) receptor mutants tested, those possessing a C262D/C263D double point mutation had the least carbachol-induced internalization. The desensitization and down-regulation of receptors possessing either Cys/Ala or Cys/Asp double point mutations were similar to those observed for the wild-type hM(1) receptor. Collectively, these observations suggest that Cys pairs Cys259/Cys260 and Cys262/Cys263 play an important role in the agonist-induced internalization of hM(1) receptors.
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Affiliation(s)
- Gregory W Sawyer
- Department of Biochemistry and Microbiology, Center for Health Sciences, Oklahoma State University, 1111 W. 17th Street, Tulsa, OK 74107-1898, USA.
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28
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Martínez-Rodríguez S, Andújar-Sánchez M, Neira JL, Clemente-Jiménez JM, Jara-Pérez V, Rodríguez-Vico F, Las Heras-Vázquez FJ. Site-directed mutagenesis indicates an important role of cysteines 76 and 181 in the catalysis of hydantoin racemase from Sinorhizobium meliloti. Protein Sci 2007; 15:2729-38. [PMID: 17132860 PMCID: PMC2242435 DOI: 10.1110/ps.062452106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Hydantoin racemase enzyme plays a crucial role in the reaction cascade known as "hydantoinase process." In conjunction with a stereoselective hydantoinase and a stereospecific carbamoylase, it allows the total conversion from D,L-5-monosubstituted hydantoins, with a low rate of racemization, to optically pure D- or L-amino acids. Residues Cys76 and Cys181 belonging to hydantoin racemase from Sinorhizobium meliloti (SmeHyuA) have been proved to be involved in catalysis. Here, we report biophysical data of SmeHyuA Cys76 and Cys181 to alanine mutants, which point toward a two-base mechanism for the racemization of 5-monosubstituted hydantoins. The secondary and the tertiary structure of the mutants were not significantly affected, as shown by circular dichroism. Calorimetric and fluorescence experiments have shown that Cys76 is responsible for recognition and proton retrieval of D-isomers, while Cys181 is responsible for L-isomer recognition and racemization. This recognition process is further supported by measurements of protein stability followed by chemical denaturation in the presence of the corresponding compound.
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Affiliation(s)
- Sergio Martínez-Rodríguez
- Departamento Química Física, Bioquímica y Química Inorgánica, Universidad de Almería, 04120 Almería, Spain
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Takahashi H, Arai M, Takenawa T, Sota H, Xie QH, Iwakura M. Stabilization of Hyperactive Dihydrofolate Reductase by Cyanocysteine-mediated Backbone Cyclization. J Biol Chem 2007; 282:9420-9429. [PMID: 17264073 DOI: 10.1074/jbc.m610983200] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Stabilization of an enzyme while maintaining its activity has been a major challenge in protein chemistry. Although it is difficult to simultaneously improve stability and activity of a protein by amino acid substitutions due to the activity-stability trade-off, backbone cyclization by connecting the N and C termini with a linker is promising as a general method of stabilizing a protein without affecting its activity. Recently, we created a hyperactive, methionine- and cysteine-free mutant of dihydrofolate reductase from Escherichia coli, called ANLYF, by introducing seven amino acid substitutions, which, however, destabilized the protein. Here we show that ANLYF is stabilized without a loss of its high activity by a novel backbone cyclization method for unprotected proteins. The method is based on the in vitro cyanocysteine-mediated intramolecular ligation reaction, which can be conducted with relatively high efficiency by a simple procedure and under mild conditions. We also show that the reversibility of thermal denaturation is highly improved by the cyclization. Thus, activity and stability of the protein can be separately improved by amino acid substitutions and backbone cyclization, respectively. We suggest that the cyanocysteine-mediated cyclization method is complementary to the intein-mediated cyclization method in stabilizing a protein without affecting its activity.
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Affiliation(s)
- Hisashi Takahashi
- Protein Design Research Group, Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Munehito Arai
- Protein Design Research Group, Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Tatsuyuki Takenawa
- Protein Design Research Group, Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Hiroyuki Sota
- Protein Design Research Group, Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Qui Hong Xie
- Protein Design Research Group, Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Masahiro Iwakura
- Protein Design Research Group, Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
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Abstract
Trypanosoma brucei brucei infections which establish successfully in the tsetse fly midgut may subsequently mature into mammalian infective trypanosomes in the salivary glands. This maturation is not automatic and the control of these events is complex. Utilising direct in vivo feeding experiments, we report maturation of T. b. brucei infections in tsetse is regulated by antioxidants as well as environmental stimuli. Dissection of the maturation process provides opportunities to develop transmission blocking vaccines for trypanosomiasis. The present work suggests L-cysteine and/or nitric oxide are necessary for the differentiation of trypanosome midgut infections in tsetse.
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Affiliation(s)
- Ewan Thomas Macleod
- Centre for Infectious Diseases, College of Medicine and Veterinary Medicine, The University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian, United Kindgom
| | - Alistair Charles Darby
- Centre for Infectious Diseases, College of Medicine and Veterinary Medicine, The University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian, United Kindgom
| | - Ian Maudlin
- Centre for Infectious Diseases, College of Medicine and Veterinary Medicine, The University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian, United Kindgom
| | - Sue Christina Welburn
- Centre for Infectious Diseases, College of Medicine and Veterinary Medicine, The University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian, United Kindgom
- * To whom correspondence should be addressed. E-mail:
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Byun MS, Choi J, Jue DM. Cysteine-179 of IkappaB kinase beta plays a critical role in enzyme activation by promoting phosphorylation of activation loop serines. Exp Mol Med 2007; 38:546-52. [PMID: 17079871 DOI: 10.1038/emm.2006.64] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
IkappaB kinase beta (IKKbeta) subunit of IKK complex is essential for the activation of NF-kappaB in response to various proinflammatory signals. Cys-179 in the activation loop of IKKbeta is known to be the target site for IKK inhibitors such as cyclopentenone prostaglandins, arsenite, and antirheumatic gold compounds. Here we show that a mutant IKKbeta in which Cys-179 is substituted with alanine had decreased activity when it was expressed in HEK-293 cells, and TNF stimulation did not restore the activity. Phosphorylation of activation loop serines (Ser-177 and Ser-181) which is required for IKKbeta activation was reduced in the IKKbeta (C179A) mutant. The activity of IKKbeta (C179A) was partially recovered when its phosphorylation was enforced by coexpression with mitogen-activated protein kinase kinase kinases (MAPKKK) such as NF-kappaB inducing kinase (NIK) and MAPK/extracellular signal-regulated kinase kinase kinase 1(MEKK1) or when the serine residues were replaced with phospho-mimetic glutamate. The IKKbeta (C179A) mutant was normal in dimer formation, while its activity abnormally responded to the change in the concentration of substrate ATP in reaction mixture. Our results suggest that Cys-179 of IKKbeta plays a critical role in enzyme activation by promoting phosphorylation of activation-loop serines and interaction with ATP.
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Affiliation(s)
- Mi-Sun Byun
- Department of Biochemistry, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
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Abstract
Although T-type Ca(2+) channels in the reticular thalamic nucleus (nRT) have a central function in tuning neuronal excitability and are implicated in sensory processing, sleep, and epilepsy, the mechanisms involved in their regulation are poorly understood. Here we recorded T-type Ca(2+) currents from intact nRT neurons in brain slices from young rats and investigated the mechanisms of T-type channel modulation by S-nitrosothiols (SNOs). We found that extracellular application of S-nitrosoglutathione (GSNO), S-nitrosocysteine (CSNO) and S-nitroso-N-acetyl-penicillamin (SNAP) rapidly and reversibly reduced T-type currents. The effects of SNOs are strongly stereoselective at physiological concentrations: (L)-CSNO was fourfold more effective in inhibiting T-type current than was (D)-CSNO. The effects of GSNO were abolished if cells had been treated with free hemoglobin or N-ethylmaleimide, an irreversible alkylating agent but not by 8-bromoguanosine-3',5'-cyclomonophosphate sodium salt, a membrane-permeant cGMP analogue or 1H-(1,2,4) oxadiazolo (4,3-a) quinoxalin-1-one, a specific soluble guanylyl cyclase inhibitor. In addition, bath applications of GSNO inhibited T-type currents in nucleated outside-out patches and whole cell recordings to a similar extent, with minimal effect on cell-attached recordings, suggesting a direct effect of GSNO on putative extracellular thiol residues on T-type channels. Biophysical studies indicate that GSNO decreased the availability of T-type channels at physiological potentials by modifying gating and stabilizing inactive states of the channels. In current-clamp experiments, GSNO diminished the amplitude of low-threshold calcium spikes and frequency of spike firing with minimal effects on the passive membrane properties. Collectively, the results indicate that SNOs may be a class of endogenous agents that control the functional states of the thalamus.
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Affiliation(s)
- Pavle M Joksovic
- Dept. of Anesthesiology, University of Virginia Health System, Mail Box 800710, Charlottesville, VA 22908-0710, USA
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Satoh T. [Cysteine-mediated signaling pathway by a novel electrophilic compound, NEPP11]. Seikagaku 2007; 79:28-34. [PMID: 17319510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Affiliation(s)
- Takumi Satoh
- Department of Welfare Engineering, Faculty of Engineering, Iwate University, Morioka, Japan
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Abstract
FKBP-12 mediates the immunosuppressive actions of FK506 and rapamycin, and modulates the activities of the ryanodine, IP3 and type 1 TGF-ss receptors. Additionally, FKBP-12 possesses cis-trans peptidylprolyl isomerase (rotamase) activity. We have discovered that recombinant FKBP-12 readily forms a dimer and a small amount of trimer under nonreducing conditions. A mutant with substitution at the sole cysteine residue of FKBP-12 (C23S) did not form dimers or trimers. Using mutants with 5% or less rotamase activity, the formation of dimers was independent of enzymatic activity. The formation of trimers was abrogated by a F36Y substitution, even though dimer formation was preserved. Dimers were also observed with native FKBP-12 that was detached from rabbit skeletal muscle ryanodine receptors using FK590. The multimers of FKBP-12 could interact with molecular targets distinctly from the FKBP-12 monomer, for example, by facilitating the assembly of multimeric receptors or coordinating the activity of receptor subunits.
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Affiliation(s)
- Barbara Schories
- Section of Cardiology, Department of Internal Medicine and Wake Forest University School of Medicine, Winston-Salem, NC 27157-1045, USA
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35
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Serrano SMT, Kim J, Wang D, Dragulev B, Shannon JD, Mann HH, Veit G, Wagener R, Koch M, Fox JW. The cysteine-rich domain of snake venom metalloproteinases is a ligand for von Willebrand factor A domains: role in substrate targeting. J Biol Chem 2006; 281:39746-56. [PMID: 17040908 DOI: 10.1074/jbc.m604855200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Snake venom metalloproteinases (SVMPs) are members of the Reprolysin family of metalloproteinases to which the ADAM (a disintegrin and metalloproteinase) proteins also belong. The disintegrin-like/cysteine-rich domains of the ADAMs have been implicated in their function. In the case of the SVMPs, we hypothesized that these domains could function to target the metalloproteinases to key extracellular matrix proteins or cell surface proteins. Initially we detected interaction of collagen XIV, a fibril-associated collagen with interrupted triple helices containing von Willebrand factor A (VWA) domains, with the PIII SVMP catrocollastatin. Next we investigated whether other VWA domain-containing matrix proteins could support the binding of PIII SVMPs. Using surface plasmon resonance, the PIII SVMP jararhagin and a recombinant cysteine-rich domain from a PIII SVMP were demonstrated to bind to collagen XIV, collagen XII, and matrilins 1, 3, and 4. Jararhagin was shown to cleave these proteins predominantly at sites localized at or near the VWA domains suggesting that it is the VWA domains to which the PIII SVMPs are binding via their cysteine-rich domain. In light of the fact that these extracellular matrix proteins function to stabilize matrix, targeting the SVMPs to these proteins followed by their specific cleavage could promote the destabilization of extracellular matrix and cell-matrix interactions and in the case of capillaries could contribute to their disruption and hemorrhage. Although there is only limited structural homology shared by the cysteine-rich domains of the PIII SVMPs and the ADAMs our results suggest an analogous function for the cysteine-rich domains in certain members of the expanded ADAM family of proteins to target them to VWA domain-containing proteins.
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Affiliation(s)
- Solange M T Serrano
- Laboratório Especial de Toxinologia Aplicada/Center for Applied Toxinology, Instituto Butantan, 05503-900 Sao Paulo, Brazil
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Payabvash S, Ghahremani MH, Goliaei A, Mandegary A, Shafaroodi H, Amanlou M, Dehpour AR. Nitric oxide modulates glutathione synthesis during endotoxemia. Free Radic Biol Med 2006; 41:1817-28. [PMID: 17157184 DOI: 10.1016/j.freeradbiomed.2006.09.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 08/16/2006] [Accepted: 09/09/2006] [Indexed: 11/22/2022]
Abstract
Nitric oxide is known to modulate intracellular glutathione levels, but the relationship between nitric oxide synthesis and glutathione metabolism during endotoxemia is unknown. The present study was designed to examine the effects of increased nitric oxide formation on hepatic glutathione synthesis and antioxidant defense in endotoxemic mice. Our results demonstrate that hepatic glutathione synthesis is decreased for 24 h following injection of lipopolysaccharide (LPS). Administration of the cysteine precursor, L-2-oxothiazolidine-4-carboxylic acid (OTZ), failed to normalize hepatic glutathione concentration, and suggests that decreased gamma-glutamylcysteine ligase activity is primarily responsible for the decrease in hepatic glutathione levels during endotoxemia. Inhibition of nitric oxide synthesis prevented the endotoxin-induced changes in hepatic and plasma glutathione status and up-regulated liver glutathione and cysteine synthesis pathways at the level of gene expression. Furthermore, whereas the activity of glutathione peroxidase and glutathione S-transferase decreased during endotoxemia, both of these changes were prevented by inhibition of nitric oxide synthesis. In conclusion, increased nitric oxide synthesis during endotoxemia causes marked changes in glutathione flux and defenses against oxidative stress in the liver.
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Affiliation(s)
- Seyedmehdi Payabvash
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, PO Box 13145-784, Tehran, Iran
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Petit CM, Chouljenko VN, Iyer A, Colgrove R, Farzan M, Knipe DM, Kousoulas KG. Palmitoylation of the cysteine-rich endodomain of the SARS-coronavirus spike glycoprotein is important for spike-mediated cell fusion. Virology 2006; 360:264-74. [PMID: 17134730 PMCID: PMC7103323 DOI: 10.1016/j.virol.2006.10.034] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 08/14/2006] [Accepted: 10/18/2006] [Indexed: 11/21/2022]
Abstract
The SARS–coronavirus (SARS–CoV) is the etiological agent of the severe acute respiratory syndrome (SARS). The SARS–CoV spike (S) glycoprotein mediates membrane fusion events during virus entry and virus-induced cell-to-cell fusion. The cytoplasmic portion of the S glycoprotein contains four cysteine-rich amino acid clusters. Individual cysteine clusters were altered via cysteine-to-alanine amino acid replacement and the modified S glycoproteins were tested for their transport to cell-surfaces and ability to cause cell fusion in transient transfection assays. Mutagenesis of the cysteine cluster I, located immediately proximal to the predicted transmembrane, domain did not appreciably reduce cell-surface expression, although S-mediated cell fusion was reduced by more than 50% in comparison to the wild-type S. Similarly, mutagenesis of the cysteine cluster II located adjacent to cluster I reduced S-mediated cell fusion by more than 60% compared to the wild-type S, while cell-surface expression was reduced by less than 20%. Mutagenesis of cysteine clusters III and IV did not appreciably affect S cell-surface expression or S-mediated cell fusion. The wild-type S was palmitoylated as evidenced by the efficient incorporation of 3H-palmitic acid in wild-type S molecules. S glycoprotein palmitoylation was significantly reduced for mutant glycoproteins having cluster I and II cysteine changes, but was largely unaffected for cysteine cluster III and IV mutants. These results show that the S cytoplasmic domain is palmitoylated and that palmitoylation of the membrane proximal cysteine clusters I and II may be important for S-mediated cell fusion.
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Affiliation(s)
- Chad M Petit
- Division of Biotechnology and Molecular Medicine (BIOMMED), USA
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38
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Chiang N, Serhan CN, Dahlén SE, Drazen JM, Hay DWP, Rovati GE, Shimizu T, Yokomizo T, Brink C. The lipoxin receptor ALX: potent ligand-specific and stereoselective actions in vivo. Pharmacol Rev 2006; 58:463-87. [PMID: 16968948 DOI: 10.1124/pr.58.3.4] [Citation(s) in RCA: 357] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Lipoxins (LXs) and aspirin-triggered LX (ATL) are trihydroxytetraene-containing eicosanoids generated from arachidonic acid that are distinct in structure, formation, and function from the many other proinflammatory lipid-derived mediators. These endogenous eicosanoids have now emerged as founding members of the first class of lipid/chemical mediators involved in the resolution of the inflammatory response. Lipoxin A(4) (LXA(4)), ATL, and their metabolic stable analogs elicit cellular responses and regulate leukocyte trafficking in vivo by activating the specific receptor, ALX. ALX was the first receptor cloned and identified as a G protein-coupled receptor (GPCR) for lipoxygenase-derived eicosanoids with demonstrated cell type-specific signaling pathways. ALX at the level of DNA has sequence homology to the N-formylpeptide receptor and as an orphan GPCR was initially referred to as the N-formylpeptide receptor-like 1. Although LXA(4) is the endogenous potent ligand for ALX activation, a number of peptides can also activate this receptor to stimulate calcium mobilization and chemotaxis in vitro. In contrast with LXA(4), the counterparts of many of these peptides in vivo remain to be established. The purpose of this review is to highlight the molecular characterization of the ALX receptor and provide an overview of the ALX-LXA(4) axis responsible for anti-inflammatory and proresolving signals in vivo. The information in this review provides further support for the initial nomenclature proposition for this GPCR as ALX.
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Affiliation(s)
- Nan Chiang
- Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital/Harvard Medical School, Boston, MA, USA
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Bavec A, Jiang Y, Langel U, Zorko M. Role of cysteine 341 and arginine 348 of GLP-1 receptor in G-protein coupling. Mol Biol Rep 2006; 34:53-60. [PMID: 17103235 DOI: 10.1007/s11033-006-9015-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Accepted: 08/21/2006] [Indexed: 10/23/2022]
Abstract
We have demonstrated the ability of peptides derived from the third intracellular loop of GLP-1 receptor to differently modulate activity of four different types of G-proteins overexpressed in sf9 cells. In this respect, the involvement of Cys(341) in inhibition of G(s) and Cys(341) in activation of G(s) and in inhibition of G(i1,) G(o), and G(11), respectively, indicates their potential role in discrimination between different types of G-proteins. Moreover, these two amino acids from the third intracellular loop might represent an important novel targets for covalent modification by downstream regulators in signaling through GLP-1 receptor.
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Affiliation(s)
- Aljosa Bavec
- Institute of Biochemistry, Medical Faculty, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia.
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40
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Abstract
Cysteinyl leukotrienes (CysLTs) are a family of inflammatory lipid mediators synthesized from arachidonic acid by a variety of cells, including mast cells, eosinophils, basophils, and macrophages. This article reviews the data for the role of CysLTs as multi-functional mediators in allergic rhinitis (AR). We review the evidence that: (1) CysLTs are released from inflammatory cells that participate in AR, (2) receptors for CysLTs are located in nasal tissue, (3) CysLTs are increased in patients with AR and are released following allergen exposure, (4) administration of CysLTs reproduces the symptoms of AR, (5) CysLTs play roles in the maturation, as well as tissue recruitment, of inflammatory cells, and (6) a complex inter-regulation between CysLTs and a variety of other inflammatory mediators exists.
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Abstract
This study addresses the energetic coupling between the activation and slow inactivation gates of Shaker potassium channels. To track the status of the activation gate in inactivated channels that are nonconducting, we used two functional assays: the accessibility of a cysteine residue engineered into the protein lining the pore cavity (V474C) and the liberation by depolarization of a Cs+ ion trapped behind the closed activation gate. We determined that the rate of activation gate movement depends on the state of the inactivation gate. A closed inactivation gate favors faster opening and slower closing of the activation gate. We also show that hyperpolarization closes the activation gate long before a channel recovers from inactivation. Because activation and slow inactivation are ubiquitous gating processes in potassium channels, the cross talk between them is likely to be a fundamental factor in controlling ion flux across membranes.
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Affiliation(s)
- Gyorgy Panyi
- Department of Biophysics and Cell Biology, University of Debrecen, 4032 Debrecen, Hungary
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Letley DP, Rhead JL, Bishop K, Atherton JC. Paired cysteine residues are required for high levels of the Helicobacter pylori autotransporter VacA. Microbiology (Reading) 2006; 152:1319-1325. [PMID: 16622049 DOI: 10.1099/mic.0.28548-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The Helicobacter pylori vacuolating cytotoxin VacA shares homology in its C-terminal domain with many autotransporter proteins, suggesting a similar mechanism of secretion. Like most autotransporters, VacA contains a single pair of cysteine residues located near the C-terminus of the passenger domain. This study aimed to investigate the role of these conserved cysteine residues. This involved changing each cysteine in the VacA passenger domain to serine, quantifying the effect on VacA levels and assessing toxin activity in H. pylori. It was shown that both cysteine residues were required for high VacA levels, although mutation of each cysteine reduced toxin amounts to differing extents, implying that their importance was not simply for intramolecular disulphide bond formation. Although less VacA was observed for the cysteine mutants, vacuolating activity was detected, showing that the cysteines were not required for VacA function.
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Affiliation(s)
- Darren P Letley
- Institute of Infection, Immunity and Inflammation, University of Nottingham, Queen's Medical Centre, Clifton Boulevard, Nottingham NG7 2UH, UK
- Wolfson Digestive Diseases Centre, University of Nottingham, Queen's Medical Centre, Clifton Boulevard, Nottingham NG7 2UH, UK
| | - Joanne L Rhead
- Institute of Infection, Immunity and Inflammation, University of Nottingham, Queen's Medical Centre, Clifton Boulevard, Nottingham NG7 2UH, UK
- Wolfson Digestive Diseases Centre, University of Nottingham, Queen's Medical Centre, Clifton Boulevard, Nottingham NG7 2UH, UK
| | - Keith Bishop
- Institute of Infection, Immunity and Inflammation, University of Nottingham, Queen's Medical Centre, Clifton Boulevard, Nottingham NG7 2UH, UK
| | - John C Atherton
- Institute of Infection, Immunity and Inflammation, University of Nottingham, Queen's Medical Centre, Clifton Boulevard, Nottingham NG7 2UH, UK
- Wolfson Digestive Diseases Centre, University of Nottingham, Queen's Medical Centre, Clifton Boulevard, Nottingham NG7 2UH, UK
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Abstract
DsbD is a redox-active protein of the inner Escherichia coli membrane possessing an N-terminal (nDsbD) and a C-terminal (cDsbD) periplasmic domain. nDsbD interacts with four different redox proteins involved in the periplasmic disulfide isomerization and in the cytochrome c maturation systems. We review here the studies that led to the structural characterization of all soluble DsbD domains involved and, most importantly, of trapped disulfide intermediate complexes of nDsbD with three of its four redox partners. These results revealed the structural features enabling nDsbD, a 'redox hub' with an immunoglobulin-like fold, to interact efficiently with its different thioredoxin-like partners.
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Affiliation(s)
- C U Stirnimann
- Biochemisches Institut, Universität Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
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Singh AK, Haldar R, Mandal D, Kundu M. Analysis of the topology of Vibrio cholerae NorM and identification of amino acid residues involved in norfloxacin resistance. Antimicrob Agents Chemother 2006; 50:3717-23. [PMID: 16954325 PMCID: PMC1635172 DOI: 10.1128/aac.00460-06] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
NorM, a putative efflux pump of Vibrio cholerae, is a member of the multidrug and toxic compound extrusion family of transporters. We demonstrate that NorM confers resistance to norfloxacin, ciprofloxacin, and ethidium bromide. Inactivation of norM rendered V. cholerae hypersensitive towards these fluoroquinolones. Multiple sequence alignment of members of its family identified several regions of high sequence conservation. The topology of NorM was determined using beta-lactamase and chloramphenicol acetyltransferase fusions. The amino acid residues G(184), K(185), G(187), P(189), E(190), G(192), and G(195) in the periplasmic loops and L(381), R(382), G(383), Y(384), K(385), and D(386) in the cytoplasmic loops, as well as all the acidic and cysteine residues of NorM, were mutated. Mutants G184V, G184W, K185I, P189S, E190K, and E190A lost the norfloxacin resistance-imparting phenotype characteristic of NorM. Mutants E124V, D155V, G187V, G187R, C196S, Y384H, Y384S, and Y384F exhibited partial resistance to norfloxacin. Mutants with replacements of G(184) or G(187) by A, K(185) by R, and E(190) by D retained the norfloxacin resistance phenotype of NorM. Analysis of the accumulation of norfloxacin in intact cells of Escherichia coli expressing NorM or its mutants in the presence or absence of carbonyl cyanide m-chlorophenylhydrazone supported the results obtained through susceptibility testing and argued in favor of NorM-mediated efflux as the determining factor in norfloxacin susceptibility in the genetically manipulated strains. Taken together, these results suggested that E(124), D(155), G(184), K(185), G(187), P(189), E(190), C(196), and Y(384) are likely involved in NorM-dependent norfloxacin efflux. Except for D(155), C(196), and Y(384), all of these residues are located in periplasmic loops.
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Affiliation(s)
- Anil Kumar Singh
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
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Cappello AR, Curcio R, Valeria Miniero D, Stipani I, Robinson AJ, Kunji ERS, Palmieri F. Functional and structural role of amino acid residues in the even-numbered transmembrane alpha-helices of the bovine mitochondrial oxoglutarate carrier. J Mol Biol 2006; 363:51-62. [PMID: 16962611 DOI: 10.1016/j.jmb.2006.08.041] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 08/02/2006] [Accepted: 08/14/2006] [Indexed: 11/21/2022]
Abstract
The mitochondrial oxoglutarate carrier exchanges cytosolic malate for 2-oxoglutarate from the mitochondrial matrix. Orthologs of the carrier have a high degree of amino acid sequence conservation, meaning that it is impossible to identify residues important for function on the basis of this criterion alone. Therefore, each amino acid residue in the transmembrane alpha-helices H2 and H6 was replaced by a cysteine in a functional mitochondrial oxoglutarate carrier that was otherwise devoid of cysteine residues. The effects of the cysteine replacement and subsequent modification by sulfhydryl reagents on the initial uptake rate of 2-oxoglutarate were determined. The results were evaluated using a structural model of the oxoglutarate carrier. Residues involved in inter-helical and lipid bilayer interactions tolerate cysteine replacements or their modifications with little effect on transport activity. In contrast, the majority of cysteine substitutions in the aqueous cavity had a severe effect on transport activity. Residues important for function of the carrier cluster in three regions of the transporter. The first consists of residues in the [YWLF]- [KR]-G-X-X-P sequence motif, which is highly conserved in all members of the mitochondrial carrier family. The residues may fulfill a structural role as a helix breaker or a dynamic role as a hinge region for conformational changes during translocation. The second cluster of important residues can be found at the carboxy-terminal end of the even-numbered transmembrane alpha-helices at the cytoplasmic side of the carrier. Residues in H6 at the interface with H1 are the most sensitive to mutation and modification, and may be essential for folding of the carrier during biogenesis. The third cluster is at the midpoint of the membrane and consists of residues that are proposed to be involved in substrate binding.
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Affiliation(s)
- Anna Rita Cappello
- Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari, Via E. Orabona 4, 70125 Bari, Italy
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Na HK, Surh YJ. Transcriptional regulation via cysteine thiol modification: a novel molecular strategy for chemoprevention and cytoprotection. Mol Carcinog 2006; 45:368-80. [PMID: 16673384 DOI: 10.1002/mc.20225] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Chemoprevention refers to the use of defined nontoxic chemical regimens to inhibit, reverse, or retard the process of multistage carcinogenesis that involves multiple signal transduction events. Identification of signaling molecules associated with carcinogenesis as prime targets of chemopreventive agents has become an area of great interest. Recent studies have implicated cysteine thiols present in various transcription factors, such as NF-kappaB, AP-1, and p53 as redox sensors in transcriptional regulation of many genes essential for maintaining cellular homeostasis. Some chemopreventive and cytoprotective agents have been found to target cysteine thiols present in key transcription factors or their regulators, thereby suppressing aberrant over-activation of carcinogenic signal transduction or restoring/normalizing or even potentiating cellular defense signaling. The focus of this review is the oxidation or covalent modification of thiol groups present in key representative redox-sensitive transcription factors and their regulating molecules as a unique strategy for molecular target-based chemoprevention and cytoprotection.
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Affiliation(s)
- Hye-Kyung Na
- National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Seoul, South Korea
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Abstract
Protons are potent physiological modifiers of voltage-gated Na(+) channels, shifting the voltage range of channel gating and reducing current magnitude (pK(a) approximately 6). We recently showed that proton block of the skeletal muscle isoform (Na(V)1.4) resulted from protonation of the four superficial carboxylates in the outer vestibule of the channel. We concluded that the large local negative electrostatic field shifted the outer vestibule carboxylate pK(a) into the physiological range. However, block was not complete; the best-fit titration curves yielded an acid pH asymptote of 10-15%, suggesting that the selectivity filter carboxylates may not be protonated. Using HEK 293 cells stably expressing different isoforms, each with varying channel density, we demonstrate that a pH-independent current is found in Na(V)1.4, but not in the cardiac isoform (Na(V)1.5). Mutational studies showed that absence of the pH-independent current in Na(V)1.5 could be ascribed to the cysteine in domain I, just above the selectivity filter aspartate (Cys373). We suggest that this cysteine can be protonated in acid solution to produce a positive charge that blocks the pore. Competition between protons and Na(+) did not exist for Na(+) concentrations between 1 and 140 mm. The residual current in acid solution, when the cysteine is absent, confirms that over the range of pH values that can be achieved physiologically, the selectivity filter carboxylates are not protonated. The pH-independent current helps to protect activation of skeletal muscle during the acidosis that occurs during exercise.
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Affiliation(s)
- A Khan
- The Cardiac Electrophysiology Laboratories, Department of Medicine, The University of Chicago, IL 60637, USA
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Uyguner ZO, Siva A, Kayserili H, Saip S, Altintaş A, Apak MY, Albayram S, Işik N, Akman-Demir G, Taşyürekli M, Oz B, Wollnik B. The R110C mutation in Notch3 causes variable clinical features in two Turkish families with CADASIL syndrome. J Neurol Sci 2006; 246:123-30. [PMID: 16730748 DOI: 10.1016/j.jns.2006.02.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2005] [Revised: 02/09/2006] [Accepted: 02/24/2006] [Indexed: 11/21/2022]
Abstract
Mutations in Notch3 gene are responsible for the cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). It is a late onset neurological disorder recognized by recurrent strokes and dementia. We describe here the clinical and molecular findings of three unrelated Turkish families with CADASIL syndrome. Two of the families were identified to have the same mutation, p.R110C (c.C328T), located in exon 3 of the Notch3 gene. Interestingly, the phenotypic expression of the disease in these two families was markedly different in severity and age of onset implicating additional genetic and/or non-genetic modulating factors involved in the pathogenesis. In addition, we identified the novel p.C201R (c.T601C) mutation in exon 4 of the Notch3 gene in a proband of the third family with two consecutive stroke-like episodes and typical MRI findings. Mutations described here cause an odd number of cysteines in the N-terminal of the EGF domain of Notch3 protein, which seems to have an important functional effect in the pathophysiology of CADASIL. The phenotypic variability in families carrying the same molecular defect as presented here makes the prediction of prognosis inconceivable. Although DNA analysis is effective and valuable in diagnosing approximately 90% of the CADASIL patients, lack of genotype-phenotype correlation and prognostic parameters makes the presymptomatic genetic counseling very difficult.
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Affiliation(s)
- Z O Uyguner
- Child Health Institute, Division of Medical Genetics, Istanbul University, Turkey.
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Romanyuk ND, Rigden DJ, Vatamaniuk OK, Lang A, Cahoon RE, Jez JM, Rea PA. Mutagenic definition of a papain-like catalytic triad, sufficiency of the N-terminal domain for single-site core catalytic enzyme acylation, and C-terminal domain for augmentative metal activation of a eukaryotic phytochelatin synthase. Plant Physiol 2006; 141:858-69. [PMID: 16714405 PMCID: PMC1489916 DOI: 10.1104/pp.106.082131] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Phytochelatin (PC) synthases are gamma-glutamylcysteine (gamma-Glu-Cys) dipeptidyl transpeptidases that catalyze the synthesis of heavy metal-binding PCs, (gamma-Glu-Cys)nGly polymers, from glutathione (GSH) and/or shorter chain PCs. Here it is shown through investigations of the enzyme from Arabidopsis (Arabidopsis thaliana; AtPCS1) that, although the N-terminal half of the protein, alone, is sufficient for core catalysis through the formation of a single-site enzyme acyl intermediate, it is not sufficient for acylation at a second site and augmentative stimulation by free Cd2+. A purified N-terminally hexahistidinyl-tagged AtPCS1 truncate containing only the first 221 N-terminal amino acid residues of the enzyme (HIS-AtPCS1_221tr) is competent in the synthesis of PCs from GSH in media containing Cd2+ or the synthesis of S-methyl-PCs from S-methylglutathione in media devoid of heavy metal ions. However, whereas its full-length hexahistidinyl-tagged equivalent, HIS-AtPCS1, undergoes gamma-Glu-Cys acylation at two sites during the Cd2+-dependent synthesis of PCs from GSH and is stimulated by free Cd2+ when synthesizing S-methyl-PCs from S-methylglutathione, HIS-AtPCS1_221tr undergoes gamma-Glu-Cys acylation at only one site when GSH is the substrate and is not directly stimulated, but instead inhibited, by free Cd2+ when S-methylglutathione is the substrate. Through the application of sequence search algorithms capable of detecting distant homologies, work we reported briefly before but not in its entirety, it has been determined that the N-terminal half of AtPCS1 and its equivalents from other sources have the hallmarks of a papain-like, Clan CA Cys protease. Whereas the fold assignment deduced from these analyses, which substantiates and is substantiated by the recent determination of the crystal structure of a distant prokaryotic PC synthase homolog from the cyanobacterium Nostoc, is capable of explaining the strict requirement for a conserved Cys residue, Cys-56 in the case of AtPCS1, for formation of the biosynthetically competent gamma-Glu-Cys enzyme acyl intermediate, the primary data from experiments directed at determining whether the other two residues, His-162 and Asp-180 of the putative papain-like catalytic triad of AtPCS1, are essential for catalysis have yet to be presented. This shortfall in our basic understanding of AtPCS1 is addressed here by the results of systematic site-directed mutagenesis studies that demonstrate that not only Cys-56 but also His-162 and Asp-180 are indeed required for net PC synthesis. It is therefore established experimentally that AtPCS1 and, by implication, other eukaryotic PC synthases are papain Cys protease superfamily members but ones, unlike their prokaryotic counterparts, which, in addition to having a papain-like N-terminal catalytic domain that undergoes primary gamma-Glu-Cys acylation, contain an auxiliary metal-sensing C-terminal domain that undergoes secondary gamma-Glu-Cys acylation.
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Affiliation(s)
- Nataliya D Romanyuk
- Plant Science Institute, Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Abstract
Although there are numerous investigations describing bone marrow cells or bone-marrow derived cells at the site of such injuries as bone fractures, infarction and subsequent ischemic reperfusion injury, or cutaneous wounds, little is know about the factors that affect the cells in those clinical situations. Cysteinyl leukotrienes have been extensively investigated in airway diseases that may eventually lead to lung fibrosis; while the engraftment of mesenchymal stem cells have been shown to reverse bleomycin-induced lung fibrosis in vivo. Therefore, we elucidated the involvement of cysteinyl leukotrienes in human mesenchymal stem cell proliferation and differentiation. Human mesenchymal stem cells express the cysteinyl leukotriene type 1 receptor. Various doses of pranlukast, which is a specific cysteinyl leukotriene type 1 receptor antagonist, failed to affect the proliferation of cells; however, 10(-6) M of pranlukast significantly induced cellular cytoplasmic differentiation by showing microvilli sprouting and the emersion of rough endoplasmic reticulum within a 16-hour(s) incubation. Additionally, pranlukast-induced fibronectin protein production by human mesenchymal stem cells. Therefore, attenuation of the cysteinyl leukotriene pathway contributes to human mesenchymal stem cell differentiation and may contribute to modulation of the local injury site.
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Affiliation(s)
- Kozo Akino
- Division of Anatomy, Department of Developmental and Reconstructive Medicine, Nagasaki University, Nagasaki, Japan
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