1
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Cheng H, Schwell V, Curtis BR, Fazlieva R, Roder H, Campbell KS. Conformational Changes in the Cytoplasmic Region of KIR3DL1 upon Interaction with SHP-2. Structure 2019; 27:639-650.e2. [PMID: 30773397 DOI: 10.1016/j.str.2019.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 11/07/2018] [Accepted: 01/18/2019] [Indexed: 12/29/2022]
Abstract
KIR3DL1 is an inhibitory killer cell immunoglobulin-like receptor (KIR) that negatively regulates natural killer cell cytotoxicity. The KIR3DL1 cytoplasmic region (3DL1-cyto) is disordered and can be dissected into three segments: (I) H340-V351; (II) M352-D371; and (III) P372-P423. NMR studies indicate that segment II can dynamically adopt a loop-like conformation, and segments I and III can form dynamic helices that may mediate binding to membranes, particularly in the region around the N-terminal (N) immunoreceptor tyrosine-based inhibitory motif (ITIM), consistent with its role in signaling. Furthermore, individual SH2 domains of SHP-2 strongly engage with the unphosphorylated N-ITIM of 3DL1-cyto, while binding of the tandem SHP-2 SH2 domains to the bis-phosphorylated ITIMs results in more extensive conformational changes in segments I and III. The findings enhance our understanding of KIR function and how ITIMs in a target receptor operate in concert to engage the tandem SH2 domains of SHP-2.
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Affiliation(s)
- Hong Cheng
- Institute for Cancer Research, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA.
| | - Vered Schwell
- Institute for Cancer Research, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Brett R Curtis
- Institute for Cancer Research, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Ruzaliya Fazlieva
- Institute for Cancer Research, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Heinrich Roder
- Institute for Cancer Research, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Kerry S Campbell
- Institute for Cancer Research, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
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2
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Zimmermann K, Eells R, Heinrich F, Rintoul S, Josey B, Shekhar P, Lösche M, Stern LJ. The cytosolic domain of T-cell receptor ζ associates with membranes in a dynamic equilibrium and deeply penetrates the bilayer. J Biol Chem 2017; 292:17746-17759. [PMID: 28893902 PMCID: PMC5663876 DOI: 10.1074/jbc.m117.794370] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 08/21/2017] [Indexed: 11/06/2022] Open
Abstract
Interactions between lipid bilayers and the membrane-proximal regions of membrane-associated proteins play important roles in regulating membrane protein structure and function. The T-cell antigen receptor is an assembly of eight single-pass membrane-spanning subunits on the surface of T lymphocytes that initiates cytosolic signaling cascades upon binding antigens presented by MHC-family proteins on antigen-presenting cells. Its ζ-subunit contains multiple cytosolic immunoreceptor tyrosine-based activation motifs involved in signal transduction, and this subunit by itself is sufficient to couple extracellular stimuli to intracellular signaling events. Interactions of the cytosolic domain of ζ (ζcyt) with acidic lipids have been implicated in the initiation and regulation of transmembrane signaling. ζcyt is unstructured in solution. Interaction with acidic phospholipids induces structure, but its disposition when bound to lipid bilayers is controversial. Here, using surface plasmon resonance and neutron reflection, we characterized the interaction of ζcyt with planar lipid bilayers containing mixtures of acidic and neutral lipids. We observed two binding modes of ζcyt to the bilayers in dynamic equilibrium: one in which ζcyt is peripherally associated with lipid headgroups and one in which it penetrates deeply into the bilayer. Such an equilibrium between the peripherally bound and embedded forms of ζcyt apparently controls accessibility of the immunoreceptor tyrosine-based activation signal transduction pathway. Our results reconcile conflicting findings of the ζ structure reported in previous studies and provide a framework for understanding how lipid interactions regulate motifs to tyrosine kinases and may regulate the T-cell antigen receptor biological activities for this cell-surface receptor system.
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Affiliation(s)
| | | | - Frank Heinrich
- the Departments of Physics and
- the National Institute of Standards and Technology (NIST) Center for Neutron Research, Gaithersburg, Maryland 20899
| | | | | | | | - Mathias Lösche
- the Departments of Physics and
- the National Institute of Standards and Technology (NIST) Center for Neutron Research, Gaithersburg, Maryland 20899
- Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, and
| | - Lawrence J Stern
- From the Departments of Pathology and
- Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655
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3
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Structural biology of intrinsically disordered proteins: Revisiting unsolved mysteries. Biochimie 2016; 125:112-8. [PMID: 27004461 DOI: 10.1016/j.biochi.2016.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 03/17/2016] [Indexed: 01/30/2023]
Abstract
The emergence of intrinsically disordered proteins (IDPs) has challenged the classical protein structure-function paradigm by introducing a new paradigm of "coupled binding and folding". This paradigm suggests that IDPs fold upon binding to their partners. Further studies, however, revealed a novel and previously unrecognized phenomenon of "uncoupled binding and folding" suggesting that IDPs do not necessarily fold upon interaction with their lipid and protein partners. The complex and often unusual biophysics of IDPs makes structural characterization of these proteins and their complexes not only challenging but often resulting in opposite conclusions. For this reason, some crucial questions in this field remain unsolved for well over a decade. Considering an important role of IDPs in cellular regulation, signaling and control in health and disease, more efforts are needed to solve these mysteries. Here, I focus on two long-standing contradictions in the literature concerning dimerization and membrane-binding activities of IDPs. Molecular explanation of these discrepancies is provided. I also demonstrate how resolution of these critical issues in the field of IDPs results in our expanded understanding of cell function and has multiple applications in biology and medicine.
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4
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Sigalov AB. Interplay Between Protein Order, Disorder and Oligomericity in Receptor Signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 725:50-73. [DOI: 10.1007/978-1-4614-0659-4_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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5
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Sigalov AB. Uncoupled binding and folding of immune signaling-related intrinsically disordered proteins. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2011; 106:525-36. [DOI: 10.1016/j.pbiomolbio.2011.08.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 08/10/2011] [Indexed: 10/17/2022]
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6
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Sigalov AB. The SCHOOL of nature: II. Protein order, disorder and oligomericity in transmembrane signaling. SELF/NONSELF 2010; 1:89-102. [PMID: 21487511 PMCID: PMC3065667 DOI: 10.4161/self.1.2.11590] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 02/20/2010] [Accepted: 02/22/2010] [Indexed: 11/19/2022]
Abstract
Recent reports have revealed that many proteins that do not adopt globular structures under native conditions, thus termed intrinsically disordered proteins (IDPs), are involved in cell signaling. Intriguingly, physiologically relevant oligomerization of IDPs has been recently observed and shown to exhibit unique biophysical characteristics, including the lack of significant changes in chemical shift and peak intensity upon binding. In this work, I summarize several distinct features of protein disorder that are especially important as related to receptor-mediated transmembrane signal transduction. I also hypothesize that interactions of IDPs with their protein or lipid partners represent a general biphasic process with the "no disorder-to-order" fast interaction which, depending on the interacting partner, may or may not be accompanied by the slow formation of a secondary structure. Further, I suggest signaling-related functional connections between protein order, disorder, and oligomericity and hypothesize that receptor oligomerization induced or tuned upon ligand binding outside the cell is translated across the membrane into protein oligomerization inside the cell, thus providing a general platform, the Signaling Chain HOmoOLigomerization (SCHOOL) platform, for receptor-mediated signaling. This structures our current multidisciplinary knowledge and views of the mechanisms governing the coupling of recognition to signal transduction and cell response. Importantly, this approach not only reveals previously unrecognized striking similarities in the basic mechanistic principles of function of numerous functionally diverse and unrelated surface membrane receptors, but also suggests the similarity between therapeutic targets, thus opening new horizons for both fundamental and clinically relevant studies.
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7
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Sigalov AB. Membrane binding of intrinsically disordered proteins: Critical importance of an appropriate membrane model. SELF NONSELF 2010; 1:129-132. [PMID: 21487515 DOI: 10.4161/self.1.2.11547] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Revised: 02/17/2010] [Accepted: 02/17/2010] [Indexed: 11/19/2022]
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8
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Sigalov AB. Protein intrinsic disorder and oligomericity in cell signaling. ACTA ACUST UNITED AC 2010; 6:451-61. [DOI: 10.1039/b916030m] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Sigalov AB, Hendricks GM. Membrane binding mode of intrinsically disordered cytoplasmic domains of T cell receptor signaling subunits depends on lipid composition. Biochem Biophys Res Commun 2009; 389:388-93. [PMID: 19733547 DOI: 10.1016/j.bbrc.2009.09.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 09/01/2009] [Indexed: 02/08/2023]
Abstract
Intrinsically disordered cytoplasmic domains of T cell receptor (TCR) signaling subunits including zeta(cyt) and CD3epsilon(cyt) all contain one or more copies of an immunoreceptor tyrosine-based activation motif (ITAM), tyrosine residues of which are phosphorylated upon receptor triggering. Membrane binding-induced helical folding of zeta(cyt) and CD3epsilon(cyt) ITAMs is thought to control TCR activation. However, the question whether or not lipid binding of zeta(cyt) and CD3epsilon(cyt) is necessarily accompanied by a folding transition of ITAMs remains open. In this study, we investigate whether the membrane binding mechanisms of zeta(cyt) and CD3epsilon(cyt) depend on the membrane model used. Circular dichroic and fluorescence data indicate that binding of zeta(cyt) and CD3epsilon(cyt) to detergent micelles and unstable vesicles is accompanied by a disorder-to-order transition, whereas upon binding to stable vesicles these proteins remain unfolded. Using electron microscopy and dynamic light scattering, we show that upon protein binding, unstable vesicles fuse and rupture. In contrast, stable vesicles remain intact under these conditions. This suggests different membrane binding modes for zeta(cyt) and CD3epsilon(cyt) depending on the bilayer stability: (1) coupled binding and folding, and (2) binding without folding. These findings explain the long-standing puzzle in the literature and highlight the importance of the choice of an appropriate membrane model for protein-lipid interactions studies.
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10
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Liu T, Chen F, Tang N, Feng J, Zhao D, Wei K, Zhu Y, He F, Liu S. CD247 can bind SHC1, no matter if CD247 is phosphorylated. J Mol Recognit 2009; 22:205-14. [PMID: 19229850 DOI: 10.1002/jmr.933] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
On T cell receptor (TCR) stimulation, src homology 2 domain-containing transforming protein C1 (SHC1) had been found to bind the tyrosine-phosphorylated CD247 chain of the receptor via its src homology 2 (SH2) domain, delivering signals that control T cell development and activation. However, how the phosphorylation of CD247 led to the instant binding has not been characterized clearly. To study the binding process in detail, we simulated and compared the interaction processes of the SH2 domain with CD247 and phosphorylated CD247, respectively. Unexpectedly, the simulation revealed that SHC1 can also bind the nonphosphorylated CD247 peptide, which was further validated to be a weak binding by affinity pull-down experiment. The molecular dynamics (MD) simulation also revealed that the CD247 peptide formed a folding conformation with its Leu209 inserted into the hydrophobic binding pocket in SHC1. And on phosphorylation, it was the electrostatic attraction between the CD247 Tyr(P)206 and the SHC1 Tyr(P)-binding pocket that destroyed the folding conformation of the nonphosphorylated CD247 and, aided by the electrostatic attraction between SHC1 and the Asp203 of CD247, led to the extended conformation of the phosphorylated CD247 binding to SHC1 strongly. The results suggest that nonphosphorylated CD247 can recruit SHC1 in advance to prepare for the instant needs for SHC1 on TCR stimulation. In view of the ubiquity of phosphorylation in protein interaction regulation, we think this study also exemplified the usefulness of MD in more interactome research involving phosphorylation.
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Affiliation(s)
- Tao Liu
- State Key Laboratory of Proteomics, Department of Neurobiology, Institute of Basic Medical Sciences, Beijing 100850, PR China
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11
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Risueño RM, Ortiz AR, Alarcón B. Conformational Model. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 640:103-12. [DOI: 10.1007/978-0-387-09789-3_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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12
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Risueño RM, Schamel WWA, Alarcón B. T cell receptor engagement triggers its CD3epsilon and CD3zeta subunits to adopt a compact, locked conformation. PLoS One 2008; 3:e1747. [PMID: 18320063 PMCID: PMC2254190 DOI: 10.1371/journal.pone.0001747] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Accepted: 10/08/2007] [Indexed: 11/24/2022] Open
Abstract
How the T cell antigen receptor (TCR) discriminates between molecularly related peptide/Major Histocompatibility Complex (pMHC) ligands and converts this information into different possible signaling outcomes is still not understood. One current model proposes that strong pMHC ligands, but not weak ones, induce a conformational change in the TCR. Evidence supporting this comes from a pull-down assay that detects ligand-induced binding of the TCR to the N-terminal SH3 domain of the adapter protein Nck, and also from studies with a neoepitope-specific antibody. Both methods rely on the exposure of a polyproline sequence in the CD3ε subunit of the TCR, and neither indicates whether the conformational change is transmitted to other CD3 subunits. Using a protease-sensitivity assay, we now show that the cytoplasmic tails of CD3ε and CD3ζ subunits become fully protected from degradation upon TCR triggering. These results suggest that the TCR conformational change is transmitted to the tails of CD3ε and CD3ζ, and perhaps all CD3 subunits. Furthermore, the resistance to protease digestion suggests that CD3 cytoplasmic tails adopt a compact structure in the triggered TCR. These results are consistent with a model in which transduction of the conformational change induced upon TCR triggering promotes condensation and shielding of the CD3 cytoplasmic tails.
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Affiliation(s)
- Ruth M. Risueño
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Balbino Alarcón
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
- * To whom correspondence should be addressed. E-mail:
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13
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Duchardt E, Sigalov AB, Aivazian D, Stern LJ, Schwalbe H. Structure induction of the T-cell receptor zeta-chain upon lipid binding investigated by NMR spectroscopy. Chembiochem 2007; 8:820-7. [PMID: 17410622 DOI: 10.1002/cbic.200600413] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The conformation of the cytoplasmic part of the zeta-chain of the T-cell receptor (TCR) in its free form and bound to detergent micelles has been investigated by heteronuclear NMR spectroscopy. The zeta-chain is considered to be a mediator between the extracellular antigen and the intracellular signal-transduction cascade leading to T-cell activation. Earlier studies suggested a T-cell activation mechanism that involved a TCR-state-dependent lipid incorporation propensity of the zeta-chain accompanied by a helical folding transition. In order to support this proposed mechanism, standard protein NMR assignment and secondary-structure-elucidation techniques have been applied to the free TCR zeta-chain and to the zeta-chain bound to the detergent LMPG, which forms a micelle, in order to obtain the structural characteristics of this folding transition in a residue-resolved manner. We could assign the resonances of the free zeta-chain at 278 K, and this formed the basis for chemical-shift-perturbation studies to identify lipid binding sites. Our NMR results show that the free TCR zeta-chain is indeed intrinsically unstructured. Regions around the ITAM2 and ITAM3 sequences are involved in a highly dynamic binding of the free zeta-chain to a detergent micelle formed by the acidic lipid LMPG.
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Affiliation(s)
- Elke Duchardt
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe University Frankfurt, 60439 Frankfurt, Germany
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14
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Sigalov AB, Aivazian DA, Uversky VN, Stern LJ. Lipid-binding activity of intrinsically unstructured cytoplasmic domains of multichain immune recognition receptor signaling subunits. Biochemistry 2006; 45:15731-9. [PMID: 17176095 PMCID: PMC2528957 DOI: 10.1021/bi061108f] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Multichain immune recognition receptors (MIRRs) found on the surface of T cells, B cells, mast cells, natural killer cells, basophils, and other immune cells are formed by the association of several single-pass transmembrane proteins, with immunoglobulin-like ligand recognition domains and signal-transducing domains present on separate subunits. The MIRR signaling subunits all have cytoplasmic domains containing one or more copies of an immunoreceptor tyrosine-based activation motif (ITAM), tyrosine residues of which are phosphorylated upon receptor engagement in an early and obligatory event in the signaling cascade. Despite the proximity to the cell membrane and crucial role in transmembrane signal transduction, little is known about the structure and lipid-binding activity of the ITAM-containing cytoplasmic domains. Here we investigate the conformation and lipid-binding activity of several MIRR cytoplasmic domains, namely, T cell receptor zetacyt, CD3epsiloncyt, CD3deltacyt, and CD3gammacyt, B cell receptor Igalphacyt and Igbetacyt, and Fc receptor FcepsilonRIgammacyt, using purified recombinant proteins. Secondary structure prediction analysis and experimental circular dichroism spectra identify each of these cytoplasmic domains as natively unfolded proteins. We also report that zetacyt, CD3epsiloncyt, and FcepsilonRIgammacyt bind to acidic and mixed phospholipid vesicles and that the binding strength correlates with the protein net charge and the presence of clustered basic amino acid residues. Circular dichroism analysis reveals the lack of secondary structure for these domains in lipid-bound form. Phosphorylation of zetacyt and FcepsilonRIgammacyt does not alter their random-coil conformation but weakens binding to membranes. The implications of these results for transmembrane signal transduction by immune receptors are discussed.
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MESH Headings
- Amino Acid Sequence
- CD3 Complex/chemistry
- CD3 Complex/metabolism
- Cytoplasm/chemistry
- Cytoplasm/metabolism
- Humans
- Membrane Proteins/chemistry
- Membrane Proteins/metabolism
- Molecular Sequence Data
- Phospholipids/chemistry
- Phospholipids/metabolism
- Protein Binding
- Protein Structure, Tertiary
- Protein Subunits/chemistry
- Protein Subunits/metabolism
- Protein Subunits/physiology
- Receptors, Antigen, B-Cell/chemistry
- Receptors, Antigen, B-Cell/metabolism
- Receptors, Antigen, B-Cell/physiology
- Receptors, Antigen, T-Cell/chemistry
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/physiology
- Receptors, Antigen, T-Cell, gamma-delta/chemistry
- Receptors, Antigen, T-Cell, gamma-delta/metabolism
- Receptors, Immunologic/chemistry
- Receptors, Immunologic/metabolism
- Receptors, Immunologic/physiology
- Signal Transduction/physiology
- Unilamellar Liposomes/chemistry
- Unilamellar Liposomes/metabolism
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Affiliation(s)
- Alexander B Sigalov
- Department of Pathology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA.
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15
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Medgyesi D, Sárközi R, Koncz G, Arató K, Váradi G, Tóth GK, Sármay G. Functional consequences of a MAPK docking site on human FcgammaRIIb. Immunol Lett 2004; 92:83-90. [PMID: 15081531 DOI: 10.1016/j.imlet.2003.12.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Accepted: 12/02/2003] [Indexed: 11/24/2022]
Abstract
Type IIb Fcgamma receptors (FcgammaRIIb) have a major role in regulating B cell activation. Upon its co-aggregation with the B cell receptors (BCR) via immune complexes FcgammaRIIb become phosphorylated on tyrosine within its immunoreceptor tyrosine based inhibitory motif (ITIM) and in turn recruit protein- and inositol phosphatases, inhibiting thereby signal transduction. The intracellular domain of the human FcgammaRIIb has a membrane proximal motif that is very similar to those of MAPK docking site in MAPK-interacting molecules. Additionally, in contrast to the mouse, a serine residue is located next to this motif that is a potential phosphorylation site for Ser/Thr kinases. Our aim was to study the role of the putative MAPK docking motif on FcgammaRIIb mediated function. We report here that MAPKs bind to FcgammaRIIb affinity purified from the detergent extracts of anti-IgM activated and BCR-FcgammaRIIb co-clustered B cells. We detected extracellular signal regulated kinase (ERK) activity in FcgammaRIIb immunoprecipitates and identified the bound proteins as 85, 44 and 42kDa ERKs by Western blots. Active ERKs bound to the synthetic peptide representing the putative docking site of FcgammaRIIb on a Ser/Thr phosphatase dependent manner. The FcgammaRIIb-associated ERKs may phosphorylate the membrane proximal serine of the receptor. We examined the consequences of serine phosphorylation by comparing the proteins that interact with synthetic peptides comprising the combined sequences of the MAPK docking site and the ITIM either in phosphorylated or in non-phosphorylated forms. The results indicate that phosphorylation on serine modifies the binding of Lyn to FcgammaRIIb, thus might negatively regulate phosphorylation of ITIM.
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Affiliation(s)
- Dávid Medgyesi
- Research Group of the Hungarian Academy of Science at the Department of Immunology, Eötvös Loránd University, Budapest, Hungary
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16
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Vass E, Hollósi M, Besson F, Buchet R. Vibrational spectroscopic detection of beta- and gamma-turns in synthetic and natural peptides and proteins. Chem Rev 2003; 103:1917-54. [PMID: 12744696 DOI: 10.1021/cr000100n] [Citation(s) in RCA: 246] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Elemér Vass
- Department of Organic Chemistry, Eötvös Loránd University, H-1518 Budapest 112, P.O. Box 32, Hungary
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17
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Fujitani N, Kanagawa M, Aizawa T, Ohkubo T, Kaya S, Demura M, Kawano K, Nishimura SI, Taniguchi K, Nitta K. Structure determination and conformational change induced by tyrosine phosphorylation of the N-terminal domain of the alpha-chain of pig gastric H+/K+-ATPase. Biochem Biophys Res Commun 2003; 300:223-9. [PMID: 12480547 DOI: 10.1016/s0006-291x(02)02794-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
It has been well established that phosphorylation is an important reaction for the regulation of protein functions. In the N-terminal domain of the alpha-chain of pig gastric H(+)/K(+)-ATPase, reversible sequential phosphorylation occurs at Tyr 10 and Tyr 7. In this study, we determined the structure of the peptide involving the residues from Gly 2 to Gly 34 of pig gastric H(+)/K(+)-ATPase and investigated the tyrosine phosphorylation-induced conformational change using CD and NMR experiments. The solution structure showed that the N-terminal fragment has a helical conformation, and the peptide adopted two alpha-helices in 50% trifluoroethanol (TFE) solvent, suggesting that the peptide has a high helical propensity under hydrophobic conditions. Furthermore, the CD and NMR data suggested that the structure of the N-terminal fragment becomes more disordered as a result of phosphorylation of Tyr 10. This conformational change induced by the phosphorylation of Tyr 10 might be an advantageous reaction for sequential phosphorylation and may be important for regulating the function of H(+)/K(+)-ATPase.
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Affiliation(s)
- Naoki Fujitani
- Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
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18
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Gil D, Schamel WWA, Montoya M, Sánchez-Madrid F, Alarcón B. Recruitment of Nck by CD3 epsilon reveals a ligand-induced conformational change essential for T cell receptor signaling and synapse formation. Cell 2002; 109:901-12. [PMID: 12110186 DOI: 10.1016/s0092-8674(02)00799-7] [Citation(s) in RCA: 342] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
How membrane receptors initiate signal transduction upon ligand binding is a matter of intense scrutiny. The T cell receptor complex (TCR-CD3) is composed of TCR alpha/beta ligand binding subunits bound to the CD3 subunits responsible for signal transduction. Although it has long been speculated that TCR-CD3 may undergo a conformational change, confirmation is still lacking. We present strong evidence that ligand engagement of TCR-CD3 induces a conformational change that exposes a proline-rich sequence in CD3 epsilon and results in recruitment of the adaptor protein Nck. This occurs earlier than and independently of tyrosine kinase activation. Finally, by interfering with Nck-CD3 epsilon association in vivo, we demonstrate that TCR-CD3 recruitment of Nck is critical for maturation of the immune synapse and for T cell activation.
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Affiliation(s)
- Diana Gil
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Cantoblanco, Madrid 20849, Spain
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19
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Chiţu V, Fajka-Boja R, Tóth GK, Váradi G, Hegedüs Z, Frankó A, Szücs KS, Monostori E. Comparative study on the effect of phosphorylated TCR zeta chain ITAM sequences on early activation events in Jurkat T cells. Peptides 2001; 22:1963-71. [PMID: 11786178 DOI: 10.1016/s0196-9781(01)00543-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
One of the main dilemma in T cell receptor (TCR) signal transduction is whether the presence of multiple Immunoreceptor Tyrosine-based Activation Motifs (ITAMs) within the TCR signaling module serves for signal amplification or signal distribution. To contribute to answer this question, we analyzed the effect of synthetic oligopeptides representing the three bi-phosphorylated zeta chain-ITAMs on the early signaling events in permeabilized leukemia T cells. Our main observations were as follows: 1/Stimulation of the cells with the bi-phosphorylated membrane proximal and central ITAMs (zeta (1)y(p)y(p) and zeta (2)y(p)y(p), respectively) resulted in a strong phosphorylation of proteins with a similar pattern. In contrast, the membrane distal ITAM, zeta (3)y(p)y(p) had a reduced ability to promote tyrosine phosphorylation and failed to induce the phosphorylation of a number of proteins. 2/ The phospho-peptide induced tyrosine phosphorylation events were at least partially mediated by p56(lck) and Syk/ZAP70 protein tyrosine kinases as it was shown in p56(lck) and Syk/ZAP70 deficient Jurkat variants. 3/The patterns of the association of the adaptor protein, Grb2 with tyrosine phosphorylated proteins following cell stimulation with the bi-phosphorylated membrane proximal or the central ITAMs were similar, while the membrane distal ITAM was unable to induce any of these associations. Our data provide additional evidence that the three zetaITAMs differ in their capacity to induce tyrosine phosphorylation of intracellular proteins in permeabilized T cells, depending to their primary sequence. The first and second ITAM sequences of the zeta chain may have similar but not totally overlapping functions. This conclusion results from their similar but not identical abilities to induce tyrosine phosphorylation and association of Grb-2 with intracellular phosphoproteins. In contrast, the third ITAM (zeta3) may have distinct functions since this peptide fails to induce tyrosine phosphorylation of a number of proteins compared to the other two ITAMs, and it is unable to induce either new association or the increase in the amount of Grb-2 associated phosphoproteins.
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Affiliation(s)
- V Chiţu
- Lymphocyte Signal Transduction Laboratory, Institute of Genetics, Biological Research Center, H-6726 Szeged, Temesvári krt. 62., Hungary
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Koncz G, Tóth GK, Bökönyi G, Kéri G, Pecht I, Medgyesi D, Gergely J, Sármay G. Co-clustering of Fcgamma and B cell receptors induces dephosphorylation of the Grb2-associated binder 1 docking protein. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:3898-906. [PMID: 11453982 DOI: 10.1046/j.1432-1327.2001.02295.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The immunoreceptor tyrosine-based inhibitory motif (ITIM) of human type IIb Fcgamma receptor (FcgammaRIIb) is phosphorylated on its tyrosine upon co-clustering with the B cell receptor (BCR). The phosphorylated ITIM (p-ITIM) binds to the SH2 domains of polyphosphoinositol 5-phosphatase (SHIP) and the tyrosine phosphatase, SHP-2. We investigated the involvement of the molecular complex composed of the phosphorylated SHIP and FcgammaRIIb in the activation of SHP-2. As a model compound, we synthesized a bisphosphopeptide, combining the sequences of p-ITIM and the N-terminal tyrosine phosphorylated motif of SHIP with a flexible spacer. This compound bound to the recombinant SH2 domains of SHP-2 with high affinity and activated the phosphatase in an in vitro assay. These data suggest that the phosphorylated FcgammaRII-SHIP complexes formed in the intact cells may also activate SHP-2. Grb2-associated binder 1 (Gab1) is a multisite docking protein, which becomes tyrosine-phosphorylated in response to various types of signaling, including BCR. In turn it binds to the SH2 domains of SHP-2, SHIP and the p85 subunit of phosphatidyl inositol 3-kinase (PtdIns3-K) and may regulate their activity. Gab1 is a potential substrate of SHP-2, thus its binding to FcgammaRIIb may modify the Gab1-bound signaling complex. We show here that Gab1 is part of the multiprotein complex assembled by FcgammaRIIb upon its co-clustering with BCR. Gab1 may recruit SH2 domain-containing molecules to the phosphorylated FcgammaRIIb. SHP-2, activated upon the binding to FcgammaRIIb-SHIP complex, partially dephosphorylates Gab1, resulting in the release of PtdIns3-K and ultimately in the inhibition of downstream activation pathways in BCR/FcgammaRIIb co-aggregated cells.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Adaptor Proteins, Vesicular Transport
- Amino Acid Motifs
- Antigens, CD/metabolism
- Intracellular Signaling Peptides and Proteins
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases
- Phosphopeptides/metabolism
- Phosphoproteins/metabolism
- Phosphoric Monoester Hydrolases/metabolism
- Protein Binding
- Protein Tyrosine Phosphatase, Non-Receptor Type 11
- Protein Tyrosine Phosphatase, Non-Receptor Type 6
- Protein Tyrosine Phosphatases/metabolism
- Proteins/metabolism
- Receptors, Antigen, B-Cell/metabolism
- Receptors, IgG/metabolism
- SH2 Domain-Containing Protein Tyrosine Phosphatases
- Shc Signaling Adaptor Proteins
- Signal Transduction
- Src Homology 2 Domain-Containing, Transforming Protein 1
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Affiliation(s)
- G Koncz
- Research Group of the Hungarian Academy of Science at the Department of Immunology, Loránd Eötvös University, Göd, Hungary
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Vass E, Besson F, Majer Z, Volpon L, Hollósi M. Ca(2+)-induced changes of surfactin conformation: a FTIR and circular dichroism study. Biochem Biophys Res Commun 2001; 282:361-7. [PMID: 11264016 DOI: 10.1006/bbrc.2001.4469] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous NMR studies on surfactin proposed two gamma or beta-turn-containing conformers while recent CD studies described beta-sheets and alpha-helices in surfactin. Since these data were not obtained in the same conditions, the conformation of surfactin was reinvestigated by FTIR spectroscopy, a diagnostic method for beta-sheets. In trifluoroethanol, the FTIR spectra of surfactin and its diester are compatible with gamma and/or beta-turn(s) and the differences in their CD spectra show the importance of the Glu(1) and Asp(5) COOH groups in stabilizing the lipopeptide conformation. The calcium-induced spectral changes of both lipopeptides suggest a first binding of the divalent ions to the surfactin COOH groups (until calcium-lipopeptide mole ratio reached 1) followed by bulk conformational changes (at higher mole ratios). In Tris buffer at pH 8.5, the FTIR amide I band shape, without the typical 1610-1628 and 1675-1695 cm(-1) bands, ascertains the absence of beta-sheets.
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Affiliation(s)
- E Vass
- Department of Organic Chemistry, Eötvös Loránd University, Budapest, H-1518, Hungary
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Kupihár Z, Váradi G, Monostori É, Tóth GK. Preparation of an asymmetrically protected phosphoramidite and its application in solid-phase synthesis of phosphopeptides. Tetrahedron Lett 2000. [DOI: 10.1016/s0040-4039(00)00615-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Wu J, Edberg JC, Gibson AW, Tsao B, Kimberly RP. Single-nucleotide polymorphisms of T cell receptor zeta chain in patients with systemic lupus erythematosus. ARTHRITIS AND RHEUMATISM 1999; 42:2601-5. [PMID: 10616006 DOI: 10.1002/1529-0131(199912)42:12<2601::aid-anr13>3.0.co;2-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Signaling molecules from the T cell receptor zeta/Fcepsilon receptor gamma (TCRzeta/FcRgamma) family play a critical role in the function of Fcgamma receptors and the TCR and are located on human chromosome 1, where lupus susceptibility genes are located. This study was undertaken to investigate the possibility of polymorphisms and/or mutations of TCRzeta in systemic lupus erythematosus (SLE). METHODS We amplified the whole coding region of TCRzeta by reverse transcriptase-polymerase chain reaction (PCR) and directly sequenced the PCR products with a dye primer technique to facilitate heterozygote detection. RESULTS An alternative splicing form of TCRzeta, with a CAG codon (glutamine) inserted at the splice junction of exons 4 and 5, was found both in SLE and in non-SLE subjects. Both splice isoforms of TCRzeta occurred in human mixed peripheral blood mononuclear cells, natural killer cells, and Jurkat T cells. In TCRzeta, 2 silent and 2 missense mutations were found, but neither coding change occurred in the immunoreceptor tyrosine-activation motif. No unique mutations were found in Caucasian, African American, Hispanic, Chinese, or Japanese SLE patients living in North America. CONCLUSION The uncommon and equal occurrence of novel single-nucleotide polymorphisms in both SLE patients and normal subjects makes it improbable that they play important roles in genetic susceptibility to SLE.
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Affiliation(s)
- J Wu
- The University of Alabama at Birmingham, 35294-0006, USA
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Hegedûs Z, Chitu V, Tóth GK, Finta C, Váradi G, Andó I, Monostori E. Contribution of kinases and the CD45 phosphatase to the generation of tyrosine phosphorylation patterns in the T-cell receptor complex zeta chain. Immunol Lett 1999; 67:31-9. [PMID: 10217203 DOI: 10.1016/s0165-2478(98)00138-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The zeta subunit of the T-cell receptor complex plays a crucial role in coupling the antigen binding alphabeta and gammadelta heterodimers to the downstream activation pathways. Three tandem amino acid sequence motifs containing pairs of exactly spaced Tyr-X-X-Leu/Ile sequences, designated as Immunoreceptor Tyrosine-based Activation Motifs (ITAMs), control this function. The phosphorylated forms of ITAMs serve as docking sites for several src homology 2 (SH2) domain containing signaling proteins. The composition of the assembled signaling complex and the outcome of cell activation depends on the tyrosine phosphorylation pattern of the zeta polypeptide. The mechanism that conducts the generation of various phosphorylated forms has not yet been well established. In this study we have analyzed the ability of src family tyrosine kinases and the CD45 tyrosine phosphatase in determining the phosphorylation state of the different ITAMs and the individual tyrosine residues of the TCR zeta chain. The intracellular part of the zeta chain was phosphorylated by src family tyrosine kinases, p56lck and p59fyn in vitro. Synthetic oligopeptides representing full-length or half-sized ITAMs with a single tyrosine residue were also phosphorylated by both p56lck and p59fyn. In contrast, an additional membrane proximal tyrosine residue in the human zeta chain, located outside of the ITAMs, was not phosphorylated. We also examined the activity of the CD45 phosphatase, using a panel of ITAM derivatives, in which one or both tyrosines were phosphorylated. The efficiency of ITAM dephosphorylation by CD45 was dependent on the primary sequence of the oligopeptides and the position of the phosphotyrosine residues. The in vitro data suggest that the CD45 phosphatase rather than the tyrosine kinase(s) may control the generation of specific phosphorylation patterns of the zeta chain during cell activation.
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Affiliation(s)
- Z Hegedûs
- Institute of Genetics, Biological Research Center of Hungarian Academy of Sciences, Szeged
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Erhardt I, Lischke A, Sebald W, Friedrich K. Constitutive association of JAK1 and STAT5 in pro-B cells is dissolved by interleukin-4-induced tyrosine phosphorylation of both proteins. FEBS Lett 1998; 439:71-4. [PMID: 9849880 DOI: 10.1016/s0014-5793(98)01341-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The bipartite human interleukin-4 (IL-4) receptor was functionally expressed in murine pro-B cells and activated by human IL-4 to evoke intracellular signaling. Mutual association of signal transducing proteins within the receptor complex was then studied in dependence of ligand stimulation. Besides ligand-induced receptor heterodimerization and contacts of the two IL-4 receptor subunits alpha and gamma with Janus kinases JAK1 and JAK3 a prominent constitutive binding between JAK1 and signal transducer and activator of transcription STAT5 was detected. Since both these proteins become phosphorylated in response to IL-4 receptor stimulation, the influence of tyrosine phosphorylation on their mutual contact was analyzed. Association of JAK1 and STAT5 was found to occur exclusively between unphosphorylated proteins.
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Affiliation(s)
- I Erhardt
- Theodor-Boveri-Institut für Biowissenschaften (Biozentrum), Physiologische Chemie II, Am Hubland, Würzburg, Germany
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