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Abstract
The cause of Crohn’s disease (CD) has posed a conundrum for at least a century. A large body of work coupled with recent technological advances in genome research have at last started to provide some of the answers. Initially this review seeks to explain and to differentiate between bowel inflammation in the primary immunodeficiencies that generally lead to very early onset diffuse bowel inflammation in humans and in animal models, and the real syndrome of CD. In the latter, a trigger, almost certainly enteric infection by one of a multitude of organisms, allows the faeces access to the tissues, at which stage the response of individuals predisposed to CD is abnormal. Direct investigation of patients’ inflammatory response together with genome-wide association studies (GWAS) and DNA sequencing indicate that in CD the failure of acute inflammation and the clearance of bacteria from the tissues, and from within cells, is defective. The retained faecal products result in the characteristic chronic granulomatous inflammation and adaptive immune response. In this review I will examine the contemporary evidence that has led to this understanding, and look for explanations for the recent dramatic increase in the incidence of this disease.
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2
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Abstract
The cause of Crohn's disease (CD) has posed a conundrum for at least a century. A large body of work coupled with recent technological advances in genome research have at last started to provide some of the answers. Initially this review seeks to explain and to differentiate between bowel inflammation in the primary immunodeficiencies that generally lead to very early onset diffuse bowel inflammation in humans and in animal models, and the real syndrome of CD. In the latter, a trigger, almost certainly enteric infection by one of a multitude of organisms, allows the faeces access to the tissues, at which stage the response of individuals predisposed to CD is abnormal. Direct investigation of patients' inflammatory response together with genome-wide association studies (GWAS) and DNA sequencing indicate that in CD the failure of acute inflammation and the clearance of bacteria from the tissues, and from within cells, is defective. The retained faecal products result in the characteristic chronic granulomatous inflammation and adaptive immune response. In this review I will examine the contemporary evidence that has led to this understanding, and look for explanations for the recent dramatic increase in the incidence of this disease.
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3
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Borrull A, Allard B, Wijkhuisen A, Herbet A, Lamourette P, Birouk W, Leiber D, Tanfin Z, Ducancel F, Boquet D, Couraud JY, Robin P. Rendomab B4, a monoclonal antibody that discriminates the human endothelin B receptor of melanoma cells and inhibits their migration. MAbs 2016; 8:1371-1385. [PMID: 27390909 DOI: 10.1080/19420862.2016.1208865] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Metastatic melanoma is an aggressive cancer with a poor prognostic, and the design of new targeted drugs to treat melanoma is a therapeutic challenge. A promising approach is to produce monoclonal antibodies (mAbs) against the endothelin B receptor (ETB), which is known to be overexpressed in melanoma and to contribute to proliferation, migration and vasculogenic mimicry associated with invasiveness of this cancer. We previously described rendomab-B1, a mAb produced by DNA immunization. It is endowed with remarkable characteristics in term of affinity, specificity and antagonist properties against human ETB expressed by the endothelial cells, but, surprisingly, had poor affinity for ETB expressed by melanoma cells. This characteristic strongly suggested the existence of a tumor-specific ETB form. In the study reported here, we identified a new mAb, rendomab-B4, which, in contrast to rendomab-B1, binds ETB expressed on UACC-257, WM-266-4 and SLM8 melanoma cells. Moreover, after binding to UACC-257 cells, rendomab-B4 is internalized and colocalizes with the endosomal protein EEA-1. Interestingly, rendomab-B4, despite its inability to compete with endothelin binding, is able to inhibit phospholipase C pathway and migration induced by endothelin. By contrast, rendomab-B4 fails to decrease ERK1/2 phosphorylation induced by endothelin, suggesting a biased effect on ETB. These particular properties make rendomab-B4 an interesting tool to analyze ETB-structure/function and a promising starting point for the development of new immunological tools in the field of melanoma therapeutics.
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Affiliation(s)
- Aurélie Borrull
- a CEA, iBiTec-S, SPI, Laboratoire d'Ingénierie des Anticorps pour la Santé , Gif-sur-Yvette , France.,b Université Paris Sud-11 , CNRS, UMR 8619, IBBMC , Orsay , France
| | - Bertrand Allard
- a CEA, iBiTec-S, SPI, Laboratoire d'Ingénierie des Anticorps pour la Santé , Gif-sur-Yvette , France
| | - Anne Wijkhuisen
- a CEA, iBiTec-S, SPI, Laboratoire d'Ingénierie des Anticorps pour la Santé , Gif-sur-Yvette , France.,c Université Paris Diderot, Sorbonne Paris Cité , Gif-sur-Yvette , France
| | - Amaury Herbet
- a CEA, iBiTec-S, SPI, Laboratoire d'Ingénierie des Anticorps pour la Santé , Gif-sur-Yvette , France
| | - Patricia Lamourette
- d CEA, iBiTec-S, SPI, Laboratoire d'Etude et de Recherche en Immunoanalyse , Gif-sur-Yvette , France
| | - Wided Birouk
- b Université Paris Sud-11 , CNRS, UMR 8619, IBBMC , Orsay , France
| | - Denis Leiber
- b Université Paris Sud-11 , CNRS, UMR 8619, IBBMC , Orsay , France
| | - Zahra Tanfin
- b Université Paris Sud-11 , CNRS, UMR 8619, IBBMC , Orsay , France
| | - Frédéric Ducancel
- a CEA, iBiTec-S, SPI, Laboratoire d'Ingénierie des Anticorps pour la Santé , Gif-sur-Yvette , France
| | - Didier Boquet
- a CEA, iBiTec-S, SPI, Laboratoire d'Ingénierie des Anticorps pour la Santé , Gif-sur-Yvette , France
| | - Jean-Yves Couraud
- a CEA, iBiTec-S, SPI, Laboratoire d'Ingénierie des Anticorps pour la Santé , Gif-sur-Yvette , France.,c Université Paris Diderot, Sorbonne Paris Cité , Gif-sur-Yvette , France
| | - Philippe Robin
- b Université Paris Sud-11 , CNRS, UMR 8619, IBBMC , Orsay , France
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4
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Godovac-Zimmermann J. High-throughput, big data and complexity in clinical proteomics: an interview with Jasminka Godovac-Zimmermann. Expert Rev Mol Diagn 2015; 15:1241-4. [DOI: 10.1586/14737159.2015.1091543] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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5
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Ji Y, Leymarie N, Haeussler DJ, Bachschmid MM, Costello CE, Lin C. Direct detection of S-palmitoylation by mass spectrometry. Anal Chem 2013; 85:11952-9. [PMID: 24279456 DOI: 10.1021/ac402850s] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Direct detection and quantification of protein/peptide palmitoylation by mass spectrometry (MS) is a challenging task because of the tendency of palmitoyl loss during sample preparation and tandem MS analysis. In addition, the large difference in hydrophobicity between the palmitoyl peptides and their unmodified counterparts could prevent their simultaneous analysis in a single liquid chromatography-MS experiment. Here, the stability of palmitoylation in several model palmitoyl peptides under different incubation and fragmentation conditions was investigated. It was found that the usual trypsin digestion protocol using dithiothreitol as the reducing agent in ammonium bicarbonate buffer could result in significant palmitoyl losses. Instead, it is recommended that sample preparation be performed in neutral tris buffer with tris(2-carboxyethyl)phosphine as the reducing agent, conditions under which palmitoylation was largely preserved. For tandem MS analysis, collision-induced dissociation often led to facile palmitoyl loss, and electron capture dissociation frequently produced secondary side-chain losses remote from the backbone cleavage site, thus discouraging their use for accurate palmitoylation site determination. In contrast, the palmitoyl group was mostly preserved during electron transfer dissociation, which produced extensive inter-residue cleavage coverage, making it the ideal fragmentation method for palmitoyl peptide analysis. Finally, derivatization of the unmodified peptides with a perfluoroalkyl tag, N-[(3-perfluorooctyl)propyl] iodoacetamide, significantly increased their hydrophobicity, allowing them to be simultaneously analyzed with palmitoyl peptides for relative quantification of palmitoylation.
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Affiliation(s)
- Yuhuan Ji
- Center for Biomedical Mass Spectrometry, ‡Department of Biochemistry, and §Department of Medicine, Boston University School of Medicine , Boston, Massachusetts 02118, United States
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6
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Zhang X, Chien EY, Chalmers MJ, Pascal BD, Gatchalian J, Stevens RC, Griffin PR. Dynamics of the beta2-adrenergic G-protein coupled receptor revealed by hydrogen-deuterium exchange. Anal Chem 2010; 82:1100-8. [PMID: 20058880 PMCID: PMC2829980 DOI: 10.1021/ac902484p] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To examine the molecular details of ligand activation of G-protein coupled receptors (GPCRs), emphasis has been placed on structure determination of these receptors with stabilizing ligands. Here we present the methodology for receptor dynamics characterization of the GPCR human beta(2) adrenergic receptor bound to the inverse agonist carazolol using the technique of amide hydrogen/deuterium exchange coupled with mass spectrometry (HDX MS). The HDX MS profile of receptor bound to carazolol is consistent with thermal parameter observations in the crystal structure and provides additional information in highly dynamic regions of the receptor and chemical modifications demonstrating the highly complementary nature of the techniques. After optimization of HDX experimental conditions for this membrane protein, better than 89% sequence coverage was obtained for the receptor. The methodology presented paves the way for future analysis of beta(2)AR bound to pharmacologically distinct ligands as well as analysis of other GPCR family members.
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Affiliation(s)
- Xi Zhang
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458
| | - Ellen Y.T. Chien
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Michael J. Chalmers
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458
| | - Bruce D. Pascal
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458
| | - Jovylyn Gatchalian
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Raymond C. Stevens
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Patrick R. Griffin
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458
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Ramalingam JK, Hunke C, Gao X, Grüber G, Preiser PR. ATP/ADP binding to a novel nucleotide binding domain of the reticulocyte-binding protein Py235 of Plasmodium yoelii. J Biol Chem 2008; 283:36386-96. [PMID: 18957411 DOI: 10.1074/jbc.m803102200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mechanism by which a malaria merozoite recognizes a suitable host cell is mediated by a cascade of receptor-ligand interactions. In addition to the availability of the appropriate receptors, intracellular ATP plays an important role in determining whether erythrocytes are suitable for merozoite invasion. Recent work has shown that ATP secreted from erythrocytes signals a number of cellular processes. To determine whether ATP signaling might be involved in merozoite invasion, we investigated whether known plasmodium invasion proteins contain nucleotide binding motifs. Domain mapping identified a putative nucleotide binding region within all members of the reticulocyte-binding protein homologue (RBL) family analyzed. A representative domain, termed here nucleotide binding domain 94 (NBD94), was expressed and demonstrated to specifically bind to ATP. Nucleotide affinities of NBD94 were determined by fluorescence correlation spectroscopy, where an increase in the binding of ATP is observed compared with ADP analogues. ATP binding was reduced by the known F1F0-ATP synthase inhibitor 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole. Fluorescence quenching and circular dichroism spectroscopy of NBD94 after binding of different nucleotides provide evidence for structural changes in this protein. Our data suggest that different structural changes induced by ATP/ADP binding to RBL could play an important role during the invasion process.
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Affiliation(s)
- Jeya Kumar Ramalingam
- Division of Genomics and Genetics, School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
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8
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Ho JTC, White JF, Grisshammer R, Hess S. Analysis of a G protein-coupled receptor for neurotensin by liquid chromatography-electrospray ionization-mass spectrometry. Anal Biochem 2007; 376:13-24. [PMID: 18294946 DOI: 10.1016/j.ab.2007.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Revised: 11/29/2007] [Accepted: 12/21/2007] [Indexed: 11/17/2022]
Abstract
The type 1 neurotensin receptor (NTS1) belongs to the G protein-coupled receptor (GPCR) family. GPCRs are involved in important physiological processes, but for many GPCRs ligand binding sites and other structural features have yet to be elucidated. Comprehensive analyses by mass spectrometry (MS) could address such issues, but they are complicated by the hydrophobic nature of the receptors. Recombinant NTS1 must be purified in the presence of detergents to maintain solubility and functionality of the receptor, to allow testing of ligand, or to allow G protein interaction. However, detergents are detrimental to MS analyses. Hence, steps need to be taken to substitute the detergents with MS-compatible polar/organic solvents. Here we report the characterization of NTS1 by electrospray ionization (ESI)-MS with emphasis on methods to transfer intact NTS1 or its proteolytic peptides into compatible solvents by protein precipitation and liquid chromatography (LC) prior to ESI-MS analyses. Molecular mass measurement of intact recombinant NTS1 was performed using a mixture of chloroform/methanol/aqueous trifluoroacetic acid as the mobile phase for size exclusion chromatography-ESI-MS analysis. In a separate experiment, NTS1 was digested with a combination of cyanogen bromide and trypsin and/or chymotrypsin. Subsequent reversed phase LC-ESI-tandem MS analysis resulted in greater than 80% sequence coverage of the NTS1 protein, including all seven transmembrane domains. This work represents the first comprehensive analysis of recombinant NTS1 using MS.
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MESH Headings
- Chromatography, Gel
- Chromatography, Liquid/methods
- Chymotrypsin/metabolism
- Cyanogen Bromide/chemistry
- Receptors, G-Protein-Coupled/analysis
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Neurotensin/analysis
- Receptors, Neurotensin/chemistry
- Receptors, Neurotensin/metabolism
- Spectrometry, Mass, Electrospray Ionization/methods
- Trypsin/metabolism
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Affiliation(s)
- Jenny T C Ho
- Proteome Exploration Laboratory, Beckman Institute, MC 139-74, California Institute of Technology, Pasadena, CA 91125, USA
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9
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Thaker YR, Roessle M, Grüber G. The boxing glove shape of subunit d of the yeast V-ATPase in solution and the importance of disulfide formation for folding of this protein. J Bioenerg Biomembr 2007; 39:275-89. [PMID: 17896169 DOI: 10.1007/s10863-007-9089-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Accepted: 05/15/2007] [Indexed: 10/22/2022]
Abstract
The low resolution structure of subunit d (Vma6p) of the Saccharomyces cerevisiae V-ATPase was determined from solution X-ray scattering data. The protein is a boxing glove-shaped molecule consisting of two distinct domains, with a width of about 6.5 nm and 3.5 nm, respectively. To understand the importance of the N- and C-termini inside the protein, four truncated forms of subunit d (d (11-345), d (38-345), d (1-328) and d (1-298)) and mutant subunit d, with a substitution of Cys329 against Ser, were expressed, and only d (11-345), containing all six cysteine residues was soluble. The structural properties of d depends strongly on the presence of a disulfide bond. Changes in response to disulfide formation have been studied by fluorescence- and CD spectroscopy, and biochemical approaches. Cysteins, involved in disulfide bridges, were analyzed by MALDI-TOF mass spectrometry. Finally, the solution structure of subunit d will be discussed in terms of the topological arrangement of the V(1)V(O) ATPase.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Circular Dichroism
- DNA Primers/genetics
- DNA, Fungal/genetics
- Disulfides/chemistry
- Models, Molecular
- Molecular Sequence Data
- Molecular Weight
- Mutagenesis, Site-Directed
- Nuclear Magnetic Resonance, Biomolecular
- Protein Folding
- Protein Structure, Tertiary
- Protein Subunits
- Saccharomyces cerevisiae/enzymology
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae Proteins/chemistry
- Saccharomyces cerevisiae Proteins/genetics
- Scattering, Small Angle
- Sequence Homology, Amino Acid
- Spectrometry, Fluorescence
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Vacuolar Proton-Translocating ATPases/chemistry
- Vacuolar Proton-Translocating ATPases/genetics
- X-Ray Diffraction
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Affiliation(s)
- Youg R Thaker
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
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10
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Kumar A, Tyagi NK, Arevalo E, Miller KW, Kinne RKH. A proteomic study of sodium/d-glucose cotransporter 1 (SGLT1): Topology of loop 13 and coverage of other functionally important domains. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2007; 1774:968-74. [PMID: 17588833 DOI: 10.1016/j.bbapap.2007.05.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 05/04/2007] [Accepted: 05/08/2007] [Indexed: 11/16/2022]
Abstract
In order to obtain further information about the structure and function of human sodium/D-glucose cotransporter 1 (hSGLT1), the recombinant protein was subjected, either after reconstitution into liposomes or in its free form, to proteolysis followed by nanoscale microcapillary liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS/MS). The peptides released from SGLT1 proteoliposomes by trypsin bead digestion represented the early N-terminal, loop 7, and loop 9, supporting topology models that place these domains on the extracellular side of the protein. Trypsin bead digestion generated, however, also a number of peptides derived from loop 13 whose topology with regard to the membrane is hitherto a point of debate. Sequence coverage was provided from amino acids 559 to 644, suggesting that loop 13 is almost completely accessible at the extravesicular face of the proteoliposomes. These results support the notion that major parts of loop 13, essential for the interaction with transport inhibitors in vivo, are located extracellularly in intact cells. In-gel trypsin, chymotrypsin, and in particular trypsin/chymotrypsin digestion of recombinant SGLT1 in combination with LC-MS/MS provide extensive sequence coverage of the protein, including domains involved in sugar and inhibitor binding and potential phosphorylation sites. These studies demonstrate that proteomic analysis combined with mass spectrometry is a useful tool to characterize regions of SGLT1 that are important for its function and regulation.
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Affiliation(s)
- Azad Kumar
- Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, Dortmund 44227, Germany
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11
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Schäfer I, Rössle M, Biuković G, Müller V, Grüber G. Structural and functional analysis of the coupling subunit F in solution and topological arrangement of the stalk domains of the methanogenic A1AO ATP synthase. J Bioenerg Biomembr 2006; 38:83-92. [PMID: 16897437 DOI: 10.1007/s10863-006-9015-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Accepted: 04/07/2006] [Indexed: 11/28/2022]
Abstract
The first low-resolution shape of subunit F of the A(1)A(O) ATP synthase from the archaeon Methanosarcina mazei Gö1 in solution was determined by small angle X-ray scattering. Independent to the concentration used, the protein is monomeric and has an elongated shape, divided in a main globular part with a length of about 4.5 nm, and a hook-like domain of about 3.0 nm in length. The subunit-subunit interaction of subunit F inside the A(1)A(O) ATP synthase in the presence of 1-ethyl-3-(dimethylaminopropyl)-carbodiimide EDC was studied as a function of nucleotide binding, demonstrating movements of subunits F relative to the nucleotide-binding subunit B. Furthermore, in the intact A(1)A(O) complex, crosslinking of subunits D-E, A-H and A-B-D was obtained and the peptides, involved, were analyzed by MALDI-TOF mass spectrometry. Based on these data the surface of contact of B-F could be mapped in the high-resolution structure of subunit B of the A(1)A(O) ATP synthase.
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Affiliation(s)
- Ingmar Schäfer
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
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12
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Pluder F, Mörl K, Beck-Sickinger AG. Proteome analysis to study signal transduction of G protein-coupled receptors. Pharmacol Ther 2006; 112:1-11. [PMID: 16644018 DOI: 10.1016/j.pharmthera.2006.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2006] [Accepted: 03/01/2006] [Indexed: 12/28/2022]
Abstract
G protein-coupled receptors (GPCR) play an important role in drug development. Although many classical signal transduction pathways have been elucidated, more and more cross-talk to other cascades, e.g. MAP-kinase have been reported. In order to identify the overall function of receptor stimulation in a specific cell type or under certain conditions proteome analysis has been shown to be a very successful and powerful approach. Here, we will summarize the current state of the art of proteome analysis applied to GPCR.
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Affiliation(s)
- Franka Pluder
- Institute of Biochemistry, University of Leipzig, Brüderstrasse 34, D-04103, Leipzig, Germany
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13
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Schäfer IB, Bailer SM, Düser MG, Börsch M, Bernal RA, Stock D, Grüber G. Crystal structure of the archaeal A1Ao ATP synthase subunit B from Methanosarcina mazei Gö1: Implications of nucleotide-binding differences in the major A1Ao subunits A and B. J Mol Biol 2006; 358:725-40. [PMID: 16563431 DOI: 10.1016/j.jmb.2006.02.057] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Revised: 02/20/2006] [Accepted: 02/21/2006] [Indexed: 11/19/2022]
Abstract
The A1Ao ATP synthase from archaea represents a class of chimeric ATPases/synthases, whose function and general structural design share characteristics both with vacuolar V1Vo ATPases and with F1Fo ATP synthases. The primary sequences of the two large polypeptides A and B, from the catalytic part, are closely related to the eukaryotic V1Vo ATPases. The chimeric nature of the A1Ao ATP synthase from the archaeon Methanosarcina mazei Gö1 was investigated in terms of nucleotide interaction. Here, we demonstrate the ability of the overexpressed A and B subunits to bind ADP and ATP by photoaffinity labeling. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to map the peptide of subunit B involved in nucleotide interaction. Nucleotide affinities in both subunits were determined by fluorescence correlation spectroscopy, indicating a weaker binding of nucleotide analogues to subunit B than to A. In addition, the nucleotide-free crystal structure of subunit B is presented at 1.5 A resolution, providing the first view of the so-called non-catalytic subunit of the A1Ao ATP synthase. Superposition of the A-ATP synthase non-catalytic B subunit and the F-ATP synthase non-catalytic alpha subunit provides new insights into the similarities and differences of these nucleotide-binding ATPase subunits in particular, and into nucleotide binding in general. The arrangement of subunit B within the intact A1Ao ATP synthase is presented.
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Affiliation(s)
- Ingmar B Schäfer
- Universität des Saarlandes, Fachrichtung 2.3 & 2.5, D-66421 Homburg, Germany
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14
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Hong-Hermesdorf A, Brüx A, Grüber A, Grüber G, Schumacher K. A WNK kinase binds and phosphorylates V-ATPase subunit C. FEBS Lett 2006; 580:932-9. [PMID: 16427632 DOI: 10.1016/j.febslet.2006.01.018] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 12/14/2005] [Accepted: 01/04/2006] [Indexed: 10/25/2022]
Abstract
WNK (with no lysine (K)) protein kinases are found in many eukaryotes and share a unique active site. Here, we report that a member of the Arabidopsis WNK family (AtWNK8) interacts with subunit C of the vacuolar H+-ATPase (V-ATPase) via a short C-terminal domain. AtWNK8 is shown to autophosphorylate intermolecularly and to phosphorylate Arabidopsis subunit C (AtVHA-C) at multiple sites as determined by MALDI-TOF MS analysis. Furthermore, we show that AtVHA-C and other V-ATPase subunits are phosphorylated when V1-complexes are used as substrates for AtWNK8. Taken together, our results provide evidence that V-ATPases are potential targets of WNK kinases and their associated signaling pathways.
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Affiliation(s)
- Anne Hong-Hermesdorf
- Universität Tübingen, ZMBP-Plant Physiology, Auf der Morgenstelle 1, 72076 Tübingen, Germany
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15
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Conclusions. Proteomics 2005. [DOI: 10.1007/0-306-46895-6_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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16
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Soufir N, Meziani R, Lacapère JJ, Bertrand G, Fumeron F, Bourillon A, Gérard B, Descamps V, Crickx B, Ollivaud L, Archimbaud A, Lebbe C, Basset-Seguin N, Saiag P, Grandchamp B. Association Between Endothelin Receptor B Nonsynonymous Variants and Melanoma Risk. ACTA ACUST UNITED AC 2005; 97:1297-301. [PMID: 16145050 DOI: 10.1093/jnci/dji253] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The endothelin signaling pathway plays a crucial role in melanocyte differentiation and migration. In this study, we investigated whether germline mutations of endothelin receptor B (EDNRB), a gene involved in Hirschsprung disease (HSCR), could also predispose for malignant melanoma (MM). The coding region of EDNRB was sequenced in 137 MM patients and in 130 ethnically matched Caucasian control subjects. Six nonsynonymous EDNRB variants were found in 15 patients (11%), but only two were found in four control subjects (3%, odds ratio [OR] = 3.87, 95% confidence interval [CI] = 1.25 to 12; P = .012). Overall, 14 out of 15 MM patients carried EDNRB mutations reported in HSCR, some of which had previously been shown to lead to loss of function. In multivariable logistic regression analysis including skin type, eye and hair color, number of nevi, and dorsal lentigines (freckles), the association between EDNRB mutations and MM risk remained statistically significant (OR = 19.9, 95% CI = 1.34 to 296.2; P = .03). Our data strongly suggest that EDNRB is involved in predisposition for two different multigenic disorders, HSCR and melanoma.
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Affiliation(s)
- Nadem Soufir
- Laboratoire de Biochimie Hormonale et Génétique, Hôpital Bichat-Claude Bernard, AP-HP, Faculté de Médecine, Paris VII, Paris, France.
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17
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Jagannadham MV, Nagaraj R. Detection of peptides covalently modified with multiple fatty acids by MALDI-TOF mass spectrometry. ACTA ACUST UNITED AC 2005; 66:94-100. [PMID: 16000123 DOI: 10.1111/j.1399-3011.2005.00277.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Analysis and characterization of membrane proteins and hydrophobic peptides by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is a considerable challenge because of their lower ionization efficiency. Detergents are used to solubilize hydrophobic peptides and proteins. However, in MALDI-MS, the presence of detergents can cause considerable loss of signal intensity. The extent of interference depends on the matrix/sample preparation method and experimental conditions. In the present study, we have analyzed the MALDI response of multiple fatty acylated peptides in the presence of the matrices alpha-cyano-4-hydroxy cinnamic acid (HCCA) and 2,5-dihydroxy benzoic acid (DHB). The effect of adding the nonionic detergent n-octylglucoside (OG) was also examined. The presence of OG facilitated detection of tetrapalmitoylated peptide, particularly when HCCA was used as the matrix. When DHB was used as the matrix, good signal intensity was observed in the absence of OG. Lower laser pulse rate in the linear mode of analysis resulted in good signal intensity for the tetrapalmitoylated peptide. Conditions for obtaining good signal intensities for dipalmitoylated and N-myristoyl peptides with both HCCA and DHB as matrices were also investigated.
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Affiliation(s)
- M V Jagannadham
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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18
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Wendel M, Kummer W, Knels L, Schmeck J, Koch T. Muscular ETB receptors develop postnatally and are differentially distributed in specific segments of the rat vasculature. J Histochem Cytochem 2005; 53:187-96. [PMID: 15684331 DOI: 10.1369/jhc.4a6474.2005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The endothelin/endothelin-receptor system is a key player in the regulation of vascular tone in mammals. We raised and characterized an antiserum against rat ETB receptor and investigated the distribution of ETB receptors in different vascular beds during postnatal development (day 0 through day 28) and in the adult rat. We report the tissue-specific and age-dependent presence of vasoconstrictor ETB receptors. At the time of birth, vascular smooth muscle cells from all tissues examined did not exhibit ETB receptor immunoreactivity. The occurrence of ETB receptor immunoreactivity in the postnatal development was time dependent and started in small coronary and meningeal arteries at day 5, followed by small mesenteric arteries as well as brachial artery and vein at day 14. At day 21, ETB receptors were present in the media of muscular segments of pulmonary artery, large coronary arteries, and intracerebral arterioles. At day 28, ETB receptor immunoreactivity was evident in interlobular renal arteries, vas afferens, and efferens. Large renal arteries, mesenteric artery, and elastic segments of pulmonary arteries, as well as coronary and mesenteric veins, did not exhibit ETB receptor immunoreactivity. These data demonstrate the age-dependent and tissue-specific presence of ETB receptors, mainly on arterial smooth muscle cells in the vascular system of the rat.
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Affiliation(s)
- Martina Wendel
- Department of Anesthesiology and Intensive Care Medicine, Technical University of Dresden, Dresden, Germany.
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19
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Foster N, Loi TH, Owe-Young R, Stanley KK. Lysosomal traffic of liganded endothelin B receptor. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1642:45-52. [PMID: 12972292 DOI: 10.1016/s0167-4889(03)00097-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The endothelin B receptor (ETB) is an endothelial cell receptor found in caveolae. Studies with GFP-tagged ETB have suggested that the protein is constitutively endocytosed and targeted to lysosomes where it is rapidly degraded. We report that iodinated endothelin-1 ligand (ET-1) is taken up by cells transfected with ETB and remains undegraded for at least 17 h. Analysis of the intracellular traffic of endocytosed ET-1 on isotonic Ficoll gradients shows that it is rapidly internalised to lysosomes by a chloroquine sensitive and cholesterol dependent pathway. Low-temperature nonreducing SDS gels show that the ET-1 initially binds to full-length GFP-tagged ETB, which is rapidly clipped at the amino-terminus and is then stable for at least 6 h. Analysis of GFP tagged ETB on reducing SDS gels shows that it is proteolytically cleaved with a half time of approximately 3 h. However, nonreducing gels show that the receptor is virtually intact, suffering only a similar cleavage to the liganded receptor. We conclude that the ETB receptor shows remarkable stability in lysosomes, held together by disulfide bonds, and maintaining ligand binding for long periods of time.
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Affiliation(s)
- Natasha Foster
- Centre for Immunology, St. Vincent's Hospital, University of NSW, Cnr West and Boundary Street, Darlinghurst NSW 2010, Sydney, Australia
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20
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Armbrüster A, Bailer SM, Koch MHJ, Godovac-Zimmermann J, Grüber G. Dimer formation of subunit G of the yeast V-ATPase. FEBS Lett 2003; 546:395-400. [PMID: 12832076 DOI: 10.1016/s0014-5793(03)00643-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The G subunit of the vacuolar ATPase (V-ATPase) is a component of the stalk connecting the V(1) and V(O) sectors of the enzyme and is essential for normal assembly and function. Subunit G (Vma10p) of the yeast V-ATPase was expressed in Escherichia coli as a soluble protein and was purified to homogeneity. The molecular mass of subunit G, determined by Native-polyacrylamide gel electrophoresis, gel filtration analysis and small-angle X-ray scattering, was approximately 28+/-2 kDa, indicating that this protein is dimeric. With a radius of gyration (R(g)) and a maximum size (D(max)) of 2.7+/-0.2 nm and 8.0+/-0.3 nm, respectively, the G-dimer is rather elongated. To understand which region of subunit G is required to mediate dimerization, a G(38-144) form (the carboxyl-terminus) was expressed and purified. G(38-144) is homogeneous, with a molecular mass of approximately 12+/-3 kDa, indicating a monomeric form in solution.
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Affiliation(s)
- Andrea Armbrüster
- Universität des Saarlandes, Fachrichtung 2.5 - Biophysik, D-66421 Homburg, Germany
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21
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Lee YJ, Hoaglund-Hyzera CS, Srebalus Barnes CA, Hilderbrand AE, Valentine SJ, Clemmer DE. Development of high-throughput liquid chromatography injected ion mobility quadrupole time-of-flight techniques for analysis of complex peptide mixtures. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 782:343-51. [PMID: 12458017 DOI: 10.1016/s1570-0232(02)00569-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The development of a multidimensional approach involving high-performance liquid chromatography (LC), ion mobility spectrometry (IMS) and tandem mass spectrometry is described for the analysis of complex peptide mixtures. In this approach, peptides are separated based on differences in their LC retention times and mobilities (as ions drift through He) prior to being introduced into a quadrupole/octopole/time-of-flight mass spectrometer. The initial LC separation and IMS dispersion of ions is used to label ions for subsequent fragmentation studies that are carried out for mixtures of ions. The approach is demonstrated by examining a mixture of peptides generated from tryptic digestion of 18 commercially available proteins. Current limitations of this initial study and potential advantages of the experimental approach are discussed.
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Affiliation(s)
- Young Jin Lee
- Department of Chemistry, Indiana University, Bloomington 47405, USA
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22
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Grüber G, Godovac-Zimmermann J, Link TA, Coskun U, Rizzo VF, Betz C, Bailer SM. Expression, purification, and characterization of subunit E, an essential subunit of the vacuolar ATPase. Biochem Biophys Res Commun 2002; 298:383-91. [PMID: 12413952 DOI: 10.1016/s0006-291x(02)02468-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A recombinant form of subunit E (Vma4p) from yeast vacuolar ATPases (V-ATPases) has been overexpressed in Escherichia coli, purified to homogeneity, and explored by mass spectrometry. Analysis of the secondary structure of Vma4p by circular dichroism spectroscopy indicated 32% alpha-helix and 23% beta-sheet content. Vma4p formed a hybrid-complex with the nucleotide-binding subunits alpha and beta of the closely related F(1) ATPase of the thermophilic bacterium PS3 (TF(1)). The alpha(3)beta(3)E-hybrid-complex had 56% of the ATPase activity of the native TF(1). By comparison, an alpha(3)beta(3)-formation without Vma4p showed about 24% of total TF(1) ATPase activity. This is the first demonstration of a hydrolytically active hybrid-complex consisting of F(1) and V(1) subunits. The arrangement of subunit E in V(1) has been probed using the recombinant Vma4p, the alpha(3)beta(3)E-hybrid-complex together with V(1) and an A(3)B(3)HEG-subcomplex of the V(1) ATPase from Manduca sexta, respectively, indicating that subunit E is shielded in V(1).
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Affiliation(s)
- Gerhard Grüber
- Fachrichtung 2.5-Biophysik, Universität des Saarlandes, D-66421 Homburg, Germany.
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23
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van Montfort BA, Doeven MK, Canas B, Veenhoff LM, Poolman B, Robillard GT. Combined in-gel tryptic digestion and CNBr cleavage for the generation of peptide maps of an integral membrane protein with MALDI-TOF mass spectrometry. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1555:111-5. [PMID: 12206901 DOI: 10.1016/s0005-2728(02)00264-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A limitation of the in-gel approaches for the generation of peptides of membrane proteins is the size and hydrophobicity of the fragments generated. For membrane proteins like the lactose transporter (LacS) of Streptococcus thermophilus, tryptic digestion or CNBr cleavage yields several hydrophobic fragments larger than 3.5 kDa. As a result, the sequence coverage of the membrane domain is low when the in-gel tryptic-digested or CNBr-cleaved fragments are analyzed by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry (MS). The combination of tryptic digestion and subsequent CNBr cleavage on the same gel pieces containing LacS approximately doubled the coverage of the hydrophobic membrane domain compared to the individual cleavage methods, while the coverage of the soluble domain remained complete. The fragments formed are predominantly below m/z 2500, which allows accurate mass measurement.
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Affiliation(s)
- Bart A van Montfort
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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24
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Coskun U, Grüber G, Koch MHJ, Godovac-Zimmermann J, Lemker T, Müller V. Cross-talk in the A1-ATPase from Methanosarcina mazei Go1 due to nucleotide binding. J Biol Chem 2002; 277:17327-33. [PMID: 11854274 DOI: 10.1074/jbc.m110407200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Changes in the A(3)B(3)CDF-complex of the Methanosarcina mazei Gö1 A(1)-ATPase in response to ligand binding have been studied by small-angle x-ray scattering, protease digestion, fluorescence spectroscopy, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, and CuCl(2)-induced disulfide formation. The value of the radius of gyration, R(g), increases slightly when MgATP, MgADP, or MgADP + P(i) (but not MgAMP-PNP) is present. The nucleotide-binding subunits A and B were reacted with N-4[4-[7-(dimethylamino)-4-methyl]coumarin-3-yl]maleimide, and spectral shifts and changes in fluorescence intensity were detected upon addition of MgAMP-PNP, MgATP, MgADP + P(i), or MgADP. Trypsin treatment of A(1) resulted in cleavage of the stalk subunits C and F, which was rapid in the presence of MgAMP-PNP but slow when MgATP or MgADP were added to the enzyme. When A(1) was supplemented with CuCl(2) a clear nucleotide dependence of an A-A-D cross-linking product was generated in the presence of MgADP and MgATP but not when MgAMP-PNP or MgADP + P(i) was added. The site of cross-link formation was located in the region of the N and C termini of subunit D. The data suggest that the stalk subunits C, D, and F in A(1) undergo conformational changes during ATP hydrolysis.
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Affiliation(s)
- Unal Coskun
- Universität des Saarlandes, Fachrichtung 2.5-Biophysik, D-66421 Homburg, Germany
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25
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van Montfort BA, Canas B, Duurkens R, Godovac-Zimmermann J, Robillard GT. Improved in-gel approaches to generate peptide maps of integral membrane proteins with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2002; 37:322-330. [PMID: 11921374 DOI: 10.1002/jms.288] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This paper reports studies of in-gel digestion procedures to generate MALDI-MS peptide maps of integral membrane proteins. The methods were developed for the membrane domain of the mannitol permease of E. coli. In-gel digestion of this domain with trypsin, followed by extraction of the peptides from the gel, yields only 44% sequence coverage. Since lysines and arginines are seldomly found in the membrane-spanning regions, complete tryptic cleavage will generate large hydrophobic fragments, many of which are poorly soluble and most likely contribute to the low sequence coverage. Addition of the detergent octyl-beta-glucopyranoside (OBG), at 0.1% concentration, to the extraction solvent increases the total number of peptides detected to at least 85% of the total protein sequence. OBG facilitates the recovery of hydrophobic peptides when they are SpeedVac dried during the extraction procedure. Many of the newly recovered peptides are partial cleavage products. This seems to be advantageous since it generates hydrophobic fragments with a hydrophilic solubilizing part. In-gel CNBr cleavage resulted in 5-10-fold more intense spectra, 83% sequence coverage, fully cleaved fragments and no effect of OBG. In contrast to tryptic cleavage sites, the CNBr cleavage sites are found in transmembrane segments; cleavage at these sites generates smaller hydrophobic fragments, which are more soluble and do not need OBG. With the results of both cleavages, a complete sequence coverage of the membrane domain of the mannitol permease of E. coli is obtained without the necessity of using HPLC separation. The protocols were applied to two other integral membrane proteins, which confirmed the general applicability of CNBr cleavage and the observed effects of OBG in peptide recovery after tryptic digestion.
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Affiliation(s)
- Bart A van Montfort
- Groningen Biomolecular Sciences and Biotechnology Institute and Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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26
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Knapp DR, Crouch RK, Ball LE, Gelasco AK, Ablonczy Z. Mass spectrometric analysis of G protein-coupled receptors. Methods Enzymol 2002; 343:157-61. [PMID: 11665563 DOI: 10.1016/s0076-6879(02)43132-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Affiliation(s)
- Daniel R Knapp
- Department of Pharmacology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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27
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Cramer H, Schmenger K, Heinrich K, Horstmeyer A, Böning H, Breit A, Piiper A, Lundstrom K, Müller-Esterl W, Schroeder C. Coupling of endothelin receptors to the ERK/MAP kinase pathway. Roles of palmitoylation and G(alpha)q. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:5449-59. [PMID: 11606208 DOI: 10.1046/j.0014-2956.2001.02486.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Endothelins are potent mitogens that stimulate extracellular signal-regulated kinases (ERK/MAP kinases) through their cognate G-protein-coupled receptors, ET(A) and ET(B). To address the role of post-translational ET receptor modifications such as acylation on ERK activation and to identify relevant downstream effectors coupling the ET receptor to the ERK signaling cascades we have constructed a panel of palmitoylation-deficient ET receptor mutants with differential G(alpha) protein binding capacity. Endothelin-1 stimulation of wild-type ET(A) or ET(B) induced a fivefold to sixfold increase in ERK in COS-7 and CHO cells whereas full-length nonpalmitoylated ET(A) and ET(B) mutants failed to stimulate ERK. A truncated ET(B) lacking the C-terminal tail domain including putative phosphorylation and arrestin binding site(s) but retaining the critical palmitoylation site(s) was still able to fully stimulate ERK activation. Using mutated ET receptors with selective G-protein-coupling we found that endothelin-induced stimulation of G(alpha)q, but not of G(alpha)i or G(alpha)s, is essential for endothelin-mediated ERK activation. Inhibition of protein kinases A and C or epidermal growth factor receptor kinase failed to prevent ET(A)- and ET(B)-mediated ERK activation whereas blockage of phospholipase C-beta completely abrogated endothelin-promoted ERK activation through ET(A) and ET(B) in recombinant COS-7 and native C6 cells. Complex formation of Ca2+ or inhibition of Src family tyrosine kinases prevented ET-1-induced ERK-2 activation in C6-cells. Our results indicate that endothelin-promoted ERK/MAPK activation criticially depends on palmitoylation but not on phosphorylation of ET receptors, and that the G(alpha)q/phospholipase C-beta/Ca2+/Src signaling cascade is necessary for efficient coupling of ET receptors to the ERK/MAPK pathway.
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Affiliation(s)
- H Cramer
- Institute for Biochemistry II, Johann Wolfgang Goethe University Frankfurt, Theodor-Stern-Kai7, Germany
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28
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Schäfer HJ, Eger O, Godovac-Zimmermann J, Wieczorek H, Kagawa Y, Grüber G. 8-N(3)-3'-biotinyl-ATP, a novel monofunctional reagent: differences in the F(1)- and V(1)-ATPases by means of the ATP analogue. Biochem Biophys Res Commun 2001; 286:1218-27. [PMID: 11527430 DOI: 10.1006/bbrc.2001.5502] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A novel photoaffinity label, 8-N(3)-3'-biotinyl-ATP, has been synthesized. The introduction of an additional biotin residue is advantageous for easy detection of labeled proteins. This could be first tested by reaction with the F(1)-ATPase from the thermophilic bacterium PS3 (TF(1)). UV irradiation of TF(1) in the presence of 8-N(3)-3'-biotinyl-ATP results in a nucleotide-dependent binding of the analogue in the noncatalytic alpha and the catalytic beta subunits of TF(1), demonstrating the suitability of this analogue as a potential photoaffinity label. Reaction with the V(1)-ATPase, however, led to labeling of subunit E, which has been suggested as a structural and functional homologue of the gamma subunit of the F-ATPases. MALDI-TOF mass spectrometry has been used to map the regions of subunit E involved in the binding of 8-N(3)-3'-biotinyl-ATP.
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Affiliation(s)
- H J Schäfer
- Institut für Biochemie, Johannes Gutenberg-Universität, Mainz, D-55099, Germany
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29
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Affiliation(s)
- J Godovac-Zimmermann
- Center for Molecular Medicine, Department of Medicine, University College London, 5 University Street, London WC1E 6JJ, United Kingdom.
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30
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Grüber G, Svergun DI, Godovac-Zimmermann J, Harvey WR, Wieczorek H, Koch MH. Evidence for major structural changes in the Manduca sexta midgut V1 ATPase due to redox modulation. A small angle X-ray scattering study. J Biol Chem 2000; 275:30082-7. [PMID: 10893230 DOI: 10.1074/jbc.m002976200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The shape and overall dimensions of the oxidized and reduced form of the V(1) ATPase from Manduca sexta were investigated by synchrotron radiation x-ray solution scattering. The radius of gyration of the oxidized and reduced complex differ noticeably, with dimensions of 6. 20 +/- 0.06 and 5.84 +/- 0.06 nm, respectively, whereas the maximum dimensions remain constant at 22.0 +/- 0.1 nm. Comparison of the low resolution shapes of both forms, determined ab initio, indicates that the main structural alteration occurs in the head piece, where the major subunits A and B are located, and at the bottom of the stalk. In conjunction with the solution scattering data, decreased susceptibility to tryptic digestion and tryptophan fluorescence of the reduced V(1) molecule provide the first strong evidence for major structural changes in the V(1) ATPase because of redox modulation.
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Affiliation(s)
- G Grüber
- Universität Osnabrück, Fachbereich Biologie/Chemie, D-49069 Osnabrück, Germany.
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31
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Abe Y, Nakayama K, Yamanaka A, Sakurai T, Goto K. Subtype-specific trafficking of endothelin receptors. J Biol Chem 2000; 275:8664-71. [PMID: 10722707 DOI: 10.1074/jbc.275.12.8664] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We investigated the subcellular localization of two endothelin receptors (ET(A)R and ET(B)R). To visualize these receptors directly, the C terminus of each receptor was fused to the N terminus of enhanced green fluorescent protein (designated as ETR-EGFP). When transiently expressed in various mammalian cell lines, ET(A)R-EGFP was predominantly localized on the plasma membrane. By contrast, ET(B)R-EGFP was, independent of ligand stimulation, predominantly localized on the intracellular vesicular structures containing Lamp-1. Immunoblot analyses revealed that at steady state ET(B)R-EGFP was highly degraded, and its degradation was inhibited by bafilomycin A(1). Antibody uptake experiments suggested that the ET(B)R-EGFP molecules were internalized from the plasma membrane. It is therefore likely that ET(B)R is first transported to the plasma membrane and then internalized, irrespective of ligand stimulation, to lysosomes where it undergoes proteolytic degradation. Exchanging the C-terminal cytoplasmic tails of the two ETRs revealed that the cytoplasmic tail is responsible for both the intracellular localization and the degradation of the receptors. Deletion of the extreme C-terminal 35 amino acids from both receptors allowed the receptor proteins to localize predominantly in the intracellular vesicles and to degrade. These observations indicate that the cytoplasmic tail of ET(A)R determines its plasma membrane localization. Stimulation with endothelin-1 increased the amount of intact ETR-EGFP fusion proteins without increasing their de novo synthesis, suggesting that binding of endothelin-1 stabilizes the ETRs.
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Affiliation(s)
- Y Abe
- Department of Pharmacology, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
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32
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Abstract
Functional proteomic methods have been developed and applied to the investigation of signal transduction systems involving platelet-derived growth factor (PDGF), endothelin and bradykinin receptors. Mouse fibroblast cells have been stimulated with PDGF or endothelin. Phosphorylation/dephosphorylation of several hundred proteins has been followed as a function of time following stimulation using 2-D gel electrophoresis and anti-phosphotyrosine or anti-phosphoserine antibodies. Up to 100 of these proteins showed strong changes in phosphorylation with minutes of receptor stimulation. Identification of some of these proteins by mass fingerprinting using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry and by partial peptide sequencing with ion trap electrospray mass spectrometry has identified proteins which were previously known to be associated with PDGF signaling, proteins which have been shown to be involved in other signaling pathways, but not PDGF and proteins not previously associated with signal transduction. Parallel to these studies, new methods for rapid, single-step isolation of peptide receptors using a peptide coupled to a (dA)30 oligonucleotide have been developed and applied to mass spectrometric studies of post-translational modifications of the endothelin B and bradykinin B2 receptors under in vivo conditions. Both receptors have been shown to undergo extensive phosphorylation as well as palmitoylation. The patterns of post-translational modifications are more complex than previously recognized and provide new indications of possible roles for these modifications in the regulation and response of these receptors.
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33
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Auricchio A, Griseri P, Carpentieri ML, Betsos N, Staiano A, Tozzi A, Priolo M, Thompson H, Bocciardi R, Romeo G, Ballabio A, Ceccherini I. Double heterozygosity for a RET substitution interfering with splicing and an EDNRB missense mutation in Hirschsprung disease. Am J Hum Genet 1999; 64:1216-21. [PMID: 10090908 PMCID: PMC1377847 DOI: 10.1086/302329] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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34
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Soskic V, Nyakatura E, Roos M, Müller-Esterl W, Godovac-Zimmermann J. Correlations in palmitoylation and multiple phosphorylation of rat bradykinin B2 receptor in Chinese hamster ovary cells. J Biol Chem 1999; 274:8539-45. [PMID: 10085087 DOI: 10.1074/jbc.274.13.8539] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rat bradykinin B2 receptor from unstimulated Chinese hamster ovary cells transfected with the corresponding cDNA has been isolated, and subsequent mass spectrometric analysis of multiple phosphorylated species and of the palmitoylation attachment site is described. Bradykinin B2 receptor was isolated on oligo(dT)-cellulose using N-(epsilon-maleimidocaproyloxy)succinimide-Met-Lys-bradykinin coupled to a protected (dA)30-mer. This allowed a one-step isolation of the receptor on an oligo(dT)-cellulose column via variation solely of salt concentration. After enzymatic in-gel digestion, matrix-assisted laser desorption ionization and electrospray ion trap mass spectrometric analysis of the isolated rat bradykinin B2 receptor showed phosphorylation at Ser365, Ser371, Ser378, Ser380, and Thr374. Further phosphorylation at Tyr352 and Tyr161 was observed. Rat bradykinin receptor B2 receptor is also palmitoylated at Cys356. All of the phosphorylation sites except for Tyr161 cluster at the carboxyl-terminal domain of the receptor located on the cytoplasmic face of the cell membrane. Surprisingly, many of the post-translational modifications were shown by MSn mass spectroscopic analysis to be correlated pairwise, e.g. diphosphorylation at Ser365 and Ser371, at Ser378 and Ser380, and at Thr374 and Ser380 as well as mutually exclusive phosphorylation at Tyr352 and palmitoylation at Cys356. The last correlation may be involved in a receptor internalization motif. Pairwise correlations and mutual exclusion of phosphorylation and palmitoylation suggest critical roles of multiple post-translational modifications for the regulation of activity, coupling to intracelluar signaling pathways, and/or sequestration of the bradykinin receptor.
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Affiliation(s)
- V Soskic
- Institute of Molecular Biotechnology e.V., 07745 Jena, Germany
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35
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Abstract
Endothelin receptor type B (ETb) is one of the two ET receptor subtypes, both of which belong to the G protein-coupled receptor (GPCR) superfamily. The primary amino acid sequence of ETb, published in 1990, predicted potential posttranslational modifications of the receptor protein, and in the last couple of years, we and others presented direct experimental evidence for palmitoylation and phosphorylation of ETb. Functional evaluation of both substitution and deletion mutants indicated a negative role on the part of these modifications in the ligand binding capacities and cellular sequestrations of the receptors. At least one of them, palmitoylation, however, appears to be critically involved in the coupling with G proteins.
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Affiliation(s)
- Y Okamoto
- Department of Pharmacology, Faculty of Medicine, Kyoto University, Kyoto 606, Japan
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