1
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Hommel U, Hurth K, Rondeau JM, Vulpetti A, Ostermeier D, Boettcher A, Brady JP, Hediger M, Lehmann S, Koch E, Blechschmidt A, Yamamoto R, Tundo Dottorello V, Haenni-Holzinger S, Kaiser C, Lehr P, Lingel A, Mureddu L, Schleberger C, Blank J, Ramage P, Freuler F, Eder J, Bornancin F. Discovery of a selective and biologically active low-molecular weight antagonist of human interleukin-1β. Nat Commun 2023; 14:5497. [PMID: 37679328 PMCID: PMC10484922 DOI: 10.1038/s41467-023-41190-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Human interleukin-1β (hIL-1β) is a pro-inflammatory cytokine involved in many diseases. While hIL-1β directed antibodies have shown clinical benefit, an orally available low-molecular weight antagonist is still elusive, limiting the applications of hIL-1β-directed therapies. Here we describe the discovery of a low-molecular weight hIL-1β antagonist that blocks the interaction with the IL-1R1 receptor. Starting from a low affinity fragment-based screening hit 1, structure-based optimization resulted in a compound (S)-2 that binds and antagonizes hIL-1β with single-digit micromolar activity in biophysical, biochemical, and cellular assays. X-ray analysis reveals an allosteric mode of action that involves a hitherto unknown binding site in hIL-1β encompassing two loops involved in hIL-1R1/hIL-1β interactions. We show that residues of this binding site are part of a conformationally excited state of the mature cytokine. The compound antagonizes hIL-1β function in cells, including primary human fibroblasts, demonstrating the relevance of this discovery for future development of hIL-1β directed therapeutics.
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Affiliation(s)
- Ulrich Hommel
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland.
| | - Konstanze Hurth
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland.
| | - Jean-Michel Rondeau
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Anna Vulpetti
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Daniela Ostermeier
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Andreas Boettcher
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Jacob Peter Brady
- Novartis Institutes for BioMedical Research, 250 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Michael Hediger
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Sylvie Lehmann
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Elke Koch
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Anke Blechschmidt
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Rina Yamamoto
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | | | | | - Christian Kaiser
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Philipp Lehr
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Andreas Lingel
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Luca Mureddu
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Christian Schleberger
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Jutta Blank
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Paul Ramage
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Felix Freuler
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Joerg Eder
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Frédéric Bornancin
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland.
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2
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Tozzi A, Coelho R, Disler M, Lombardo F, Fedier A, Nunez Lopez M, Freuler F, Jacob F, Heinzelmann-Schwarz V. 1P Comprehensive assessment of gene mutations revealed overlapping responses for PARPi and chemotherapy in ovarian cancer cells. Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.04.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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3
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Bleu M, Mermet-Meillon F, Apfel V, Barys L, Holzer L, Bachmann Salvy M, Lopes R, Amorim Monteiro Barbosa I, Delmas C, Hinniger A, Chau S, Kaufmann M, Haenni S, Berneiser K, Wahle M, Moravec I, Vissières A, Poetsch T, Ahrné E, Carte N, Voshol J, Bechter E, Hamon J, Meyerhofer M, Erdmann D, Fischer M, Stachyra T, Freuler F, Gutmann S, Fernández C, Schmelzle T, Naumann U, Roma G, Lawrenson K, Nieto-Oberhuber C, Cobos-Correa A, Ferretti S, Schübeler D, Galli GG. PAX8 and MECOM are interaction partners driving ovarian cancer. Nat Commun 2021; 12:2442. [PMID: 33903593 PMCID: PMC8076227 DOI: 10.1038/s41467-021-22708-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 03/26/2021] [Indexed: 11/25/2022] Open
Abstract
The transcription factor PAX8 is critical for the development of the thyroid and urogenital system. Comprehensive genomic screens furthermore indicate an additional oncogenic role for PAX8 in renal and ovarian cancers. While a plethora of PAX8-regulated genes in different contexts have been proposed, we still lack a mechanistic understanding of how PAX8 engages molecular complexes to drive disease-relevant oncogenic transcriptional programs. Here we show that protein isoforms originating from the MECOM locus form a complex with PAX8. These include MDS1-EVI1 (also called PRDM3) for which we map its interaction with PAX8 in vitro and in vivo. We show that PAX8 binds a large number of genomic sites and forms transcriptional hubs. At a subset of these, PAX8 together with PRDM3 regulates a specific gene expression module involved in adhesion and extracellular matrix. This gene module correlates with PAX8 and MECOM expression in large scale profiling of cell lines, patient-derived xenografts (PDXs) and clinical cases and stratifies gynecological cancer cases with worse prognosis. PRDM3 is amplified in ovarian cancers and we show that the MECOM locus and PAX8 sustain in vivo tumor growth, further supporting that the identified function of the MECOM locus underlies PAX8-driven oncogenic functions in ovarian cancer.
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Affiliation(s)
- Melusine Bleu
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Fanny Mermet-Meillon
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Verena Apfel
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Louise Barys
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Laura Holzer
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | | | - Rui Lopes
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | | | - Cecile Delmas
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Alexandra Hinniger
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Suzanne Chau
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Markus Kaufmann
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Simon Haenni
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Karolin Berneiser
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
- Biozentrum, University of Basel, Basel, Switzerland
| | - Maria Wahle
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Ivana Moravec
- Analytical Sciences and Imaging, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Alexandra Vissières
- Analytical Sciences and Imaging, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Tania Poetsch
- Analytical Sciences and Imaging, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Erik Ahrné
- Analytical Sciences and Imaging, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Nathalie Carte
- Analytical Sciences and Imaging, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Johannes Voshol
- Analytical Sciences and Imaging, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Elisabeth Bechter
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Jacques Hamon
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Marco Meyerhofer
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Dirk Erdmann
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Matteo Fischer
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Therese Stachyra
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Felix Freuler
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Sascha Gutmann
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - César Fernández
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Tobias Schmelzle
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Ulrike Naumann
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Guglielmo Roma
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Kate Lawrenson
- Cedars-Sinai Women's Cancer Program at the Samuel Oschin Cancer Center, Los Angeles, CA, USA
| | | | - Amanda Cobos-Correa
- Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Stephane Ferretti
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Dirk Schübeler
- Friedrich Miescher Institute for Biomedical Research, University of Basel, Basel, Switzerland
- Faculty of Science, University of Basel, Basel, Switzerland
| | - Giorgio Giacomo Galli
- Disease area Oncology, Novartis Institutes for Biomedical Research, Basel, Switzerland.
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4
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Haffke M, Fehlmann D, Rummel G, Boivineau J, Duckely M, Gommermann N, Cotesta S, Sirockin F, Freuler F, Littlewood-Evans A, Kaupmann K, Jaakola VP. Structural basis of species-selective antagonist binding to the succinate receptor. Nature 2019; 574:581-585. [DOI: 10.1038/s41586-019-1663-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 09/17/2019] [Indexed: 02/06/2023]
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5
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Kallen J, Bergsdorf C, Arnaud B, Bernhard M, Brichet M, Cobos-Correa A, Elhajouji A, Freuler F, Galimberti I, Guibourdenche C, Haenni S, Holzinger S, Hunziker J, Izaac A, Kaufmann M, Leder L, Martus HJ, von Matt P, Polyakov V, Roethlisberger P, Roma G, Stiefl N, Uteng M, Lerchner A. X-ray Structures and Feasibility Assessment of CLK2 Inhibitors for Phelan-McDermid Syndrome. ChemMedChem 2018; 13:1997-2007. [PMID: 29985556 DOI: 10.1002/cmdc.201800344] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Indexed: 01/15/2023]
Abstract
CLK2 inhibition has been proposed as a potential mechanism to improve autism and neuronal functions in Phelan-McDermid syndrome (PMDS). Herein, the discovery of a very potent indazole CLK inhibitor series and the CLK2 X-ray structure of the most potent analogue are reported. This new indazole series was identified through a biochemical CLK2 Caliper assay screen with 30k compounds selected by an in silico approach. Novel high-resolution X-ray structures of all CLKs, including the first CLK4 X-ray structure, bound to known CLK2 inhibitor tool compounds (e.g., TG003, CX-4945), are also shown and yield insight into inhibitor selectivity in the CLK family. The efficacy of the new CLK2 inhibitors from the indazole series was demonstrated in the mouse brain slice assay, and potential safety concerns were investigated. Genotoxicity findings in the human lymphocyte micronucleus test (MNT) assay are shown by using two structurally different CLK inhibitors to reveal a major concern for pan-CLK inhibition in PMDS.
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Affiliation(s)
- Joerg Kallen
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Christian Bergsdorf
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Bertrand Arnaud
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Mario Bernhard
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Murielle Brichet
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Amanda Cobos-Correa
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Azeddine Elhajouji
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Felix Freuler
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Ivan Galimberti
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Christel Guibourdenche
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Simon Haenni
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Sandra Holzinger
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Juerg Hunziker
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Aude Izaac
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Markus Kaufmann
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Lukas Leder
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Hans-Joerg Martus
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Peter von Matt
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Valery Polyakov
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Patrik Roethlisberger
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Guglielmo Roma
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Nikolaus Stiefl
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Marianne Uteng
- Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
| | - Andreas Lerchner
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, Novartis Campus, 4002, Basel, Switzerland
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6
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Ginster S, Bardet M, Unterreiner A, Malinverni C, Renner F, Lam S, Freuler F, Gerrits B, Voshol J, Calzascia T, Régnier CH, Renatus M, Nikolay R, Israël L, Bornancin F. Two Antagonistic MALT1 Auto-Cleavage Mechanisms Reveal a Role for TRAF6 to Unleash MALT1 Activation. PLoS One 2017; 12:e0169026. [PMID: 28052131 PMCID: PMC5214165 DOI: 10.1371/journal.pone.0169026] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 12/09/2016] [Indexed: 11/18/2022] Open
Abstract
The paracaspase MALT1 has arginine-directed proteolytic activity triggered by engagement of immune receptors. Recruitment of MALT1 into activation complexes is required for MALT1 proteolytic function. Here, co-expression of MALT1 in HEK293 cells, either with activated CARD11 and BCL10 or with TRAF6, was used to explore the mechanism of MALT1 activation at the molecular level. This work identified a prominent self-cleavage site of MALT1 isoform A (MALT1A) at R781 (R770 in MALT1B) and revealed that TRAF6 can activate MALT1 independently of the CBM. Intramolecular cleavage at R781/R770 removes a C-terminal TRAF6-binding site in both MALT1 isoforms, leaving MALT1B devoid of the two key interaction sites with TRAF6. A previously identified auto-proteolysis site of MALT1 at R149 leads to deletion of the death-domain, thereby abolishing interaction with BCL10. By using MALT1 isoforms and cleaved fragments thereof, as well as TRAF6 WT and mutant forms, this work shows that TRAF6 induces N-terminal auto-proteolytic cleavage of MALT1 at R149 and accelerates MALT1 protein turnover. The MALT1 fragment generated by N-terminal self-cleavage at R149 was labile and displayed enhanced signaling properties that required an intact K644 residue, previously shown to be a site for mono-ubiquitination of MALT1. Conversely, C-terminal self-cleavage at R781/R770 hampered the ability for self-cleavage at R149 and stabilized MALT1 by hindering interaction with TRAF6. C-terminal self-cleavage had limited impact on MALT1A but severely reduced MALT1B proteolytic and signaling functions. It also abrogated NF-κB activation by N-terminally cleaved MALT1A. Altogether, this study provides further insights into mechanisms that regulate the scaffolding and activation cycle of MALT1. It also emphasizes the reduced functional capacity of MALT1B as compared to MALT1A.
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Affiliation(s)
- Stefanie Ginster
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Maureen Bardet
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Adeline Unterreiner
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Claire Malinverni
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Florian Renner
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Stephen Lam
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Felix Freuler
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Bertran Gerrits
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Johannes Voshol
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Thomas Calzascia
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Catherine H. Régnier
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Martin Renatus
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Rainer Nikolay
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Laura Israël
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
| | - Frédéric Bornancin
- Novartis Institutes for BioMedical Research, Novartis Campus, Basel, Switzerland
- * E-mail:
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7
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Groot-Kormelink PJ, Ferrand S, Kelley N, Bill A, Freuler F, Imbert PE, Marelli A, Gerwin N, Sivilotti LG, Miraglia L, Orth AP, Oakeley EJ, Schopfer U, Siehler S. High Throughput Random Mutagenesis and Single Molecule Real Time Sequencing of the Muscle Nicotinic Acetylcholine Receptor. PLoS One 2016; 11:e0163129. [PMID: 27649498 PMCID: PMC5029940 DOI: 10.1371/journal.pone.0163129] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/03/2016] [Indexed: 12/15/2022] Open
Abstract
High throughput random mutagenesis is a powerful tool to identify which residues are important for the function of a protein, and gain insight into its structure-function relation. The human muscle nicotinic acetylcholine receptor was used to test whether this technique previously used for monomeric receptors can be applied to a pentameric ligand-gated ion channel. A mutant library for the α1 subunit of the channel was generated by error-prone PCR, and full length sequences of all 2816 mutants were retrieved using single molecule real time sequencing. Each α1 mutant was co-transfected with wildtype β1, δ, and ε subunits, and the channel function characterized by an ion flux assay. To test whether the strategy could map the structure-function relation of this receptor, we attempted to identify mutations that conferred resistance to competitive antagonists. Mutant hits were defined as receptors that responded to the nicotinic agonist epibatidine, but were not inhibited by either α-bungarotoxin or tubocurarine. Eight α1 subunit mutant hits were identified, six of which contained mutations at position Y233 or V275 in the transmembrane domain. Three single point mutations (Y233N, Y233H, and V275M) were studied further, and found to enhance the potencies of five channel agonists tested. This suggests that the mutations made the channel resistant to the antagonists, not by impairing antagonist binding, but rather by producing a gain-of-function phenotype, e.g. increased agonist sensitivity. Our data show that random high throughput mutagenesis is applicable to multimeric proteins to discover novel functional mutants, and outlines the benefits of using single molecule real time sequencing with regards to quality control of the mutant library as well as downstream mutant data interpretation.
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Affiliation(s)
- Paul J. Groot-Kormelink
- Musculoskeletal Disease Area, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Sandrine Ferrand
- Center for Proteomic Chemistry, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Nicholas Kelley
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Anke Bill
- Center for Proteomic Chemistry, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, United States of America
| | - Felix Freuler
- Center for Proteomic Chemistry, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Pierre-Eloi Imbert
- Center for Proteomic Chemistry, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Anthony Marelli
- Genomics Institute of the Novartis Research Foundation, Novartis Institutes for BioMedical Research, San Diego, California, United States of America
| | - Nicole Gerwin
- Musculoskeletal Disease Area, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Lucia G. Sivilotti
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Loren Miraglia
- Genomics Institute of the Novartis Research Foundation, Novartis Institutes for BioMedical Research, San Diego, California, United States of America
| | - Anthony P. Orth
- Genomics Institute of the Novartis Research Foundation, Novartis Institutes for BioMedical Research, San Diego, California, United States of America
| | - Edward J. Oakeley
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Ulrich Schopfer
- Center for Proteomic Chemistry, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Sandra Siehler
- Center for Proteomic Chemistry, Novartis Institutes for BioMedical Research, Basel, Switzerland
- * E-mail:
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8
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Bürstner N, Roggo S, Ostermann N, Blank J, Delmas C, Freuler F, Gerhartz B, Hinniger A, Hoepfner D, Liechty B, Mihalic M, Murphy J, Pistorius D, Rottmann M, Thomas JR, Schirle M, Schmitt EK. Inside Cover: Gift from Nature: Cyclomarin A Kills Mycobacteria and Malaria Parasites by Distinct Modes of Action (ChemBioChem 17/2015). Chembiochem 2015. [DOI: 10.1002/cbic.201500579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nathalie Bürstner
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Silvio Roggo
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Nils Ostermann
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Jutta Blank
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Cecile Delmas
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Felix Freuler
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Bernd Gerhartz
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Alexandra Hinniger
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Dominic Hoepfner
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Brigitta Liechty
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Manuel Mihalic
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Jason Murphy
- Novartis Institutes for BioMedical Research Inc; 250 Massachusetts Avenue Cambridge MA 02139 USA
| | - Dominik Pistorius
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Matthias Rottmann
- Swiss Tropical and Public Health Institute; Socinstrasse 57 4051 Basel Switzerland
| | - Jason R. Thomas
- Novartis Institutes for BioMedical Research Inc; 250 Massachusetts Avenue Cambridge MA 02139 USA
| | - Markus Schirle
- Novartis Institutes for BioMedical Research Inc; 250 Massachusetts Avenue Cambridge MA 02139 USA
| | - Esther K. Schmitt
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
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9
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Bürstner N, Roggo S, Ostermann N, Blank J, Delmas C, Freuler F, Gerhartz B, Hinniger A, Hoepfner D, Liechty B, Mihalic M, Murphy J, Pistorius D, Rottmann M, Thomas JR, Schirle M, Schmitt EK. Gift from Nature: Cyclomarin A Kills Mycobacteria and Malaria Parasites by Distinct Modes of Action. Chembiochem 2015; 16:2433-6. [DOI: 10.1002/cbic.201500472] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Nathalie Bürstner
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Silvio Roggo
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Nils Ostermann
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Jutta Blank
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Cecile Delmas
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Felix Freuler
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Bernd Gerhartz
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Alexandra Hinniger
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Dominic Hoepfner
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Brigitta Liechty
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Manuel Mihalic
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Jason Murphy
- Novartis Institutes for BioMedical Research Inc; 250 Massachusetts Avenue Cambridge MA 02139 USA
| | - Dominik Pistorius
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
| | - Matthias Rottmann
- Swiss Tropical and Public Health Institute; Socinstrasse 57 4051 Basel Switzerland
| | - Jason R. Thomas
- Novartis Institutes for BioMedical Research Inc; 250 Massachusetts Avenue Cambridge MA 02139 USA
| | - Markus Schirle
- Novartis Institutes for BioMedical Research Inc; 250 Massachusetts Avenue Cambridge MA 02139 USA
| | - Esther K. Schmitt
- Novartis Institutes for BioMedical Research; Novartis Campus 4056 Basel Switzerland
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10
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Didiot MC, Hewett J, Varin T, Freuler F, Selinger D, Nick H, Reinhardt J, Buckler A, Myer V, Schuffenhauer A, Guy CT, Parker CN. Identification of cardiac glycoside molecules as inhibitors of c-Myc IRES-mediated translation. ACTA ACUST UNITED AC 2012; 18:407-19. [PMID: 23150017 DOI: 10.1177/1087057112466698] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Translation initiation is a fine-tuned process that plays a critical role in tumorigenesis. The use of small molecules that modulate mRNA translation provides tool compounds to explore the mechanism of translational initiation and to further validate protein synthesis as a potential pharmaceutical target for cancer therapeutics. This report describes the development and use of a click beetle, dual luciferase cell-based assay multiplexed with a measure of compound toxicity using resazurin to evaluate the differential effect of natural products on cap-dependent or internal ribosome entry site (IRES)-mediated translation initiation and cell viability. This screen identified a series of cardiac glycosides as inhibitors of IRES-mediated translation using, in particular, the oncogene mRNA c-Myc IRES. Treatment of c-Myc-dependent cancer cells with these compounds showed a decrease in c-Myc protein associated with a significant modulation of cell viability. These findings suggest that inhibition of IRES-mediated translation initiation may be a strategy to inhibit c-Myc-driven tumorigenesis.
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11
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Siehler S, Yamamoto R, Bergsdorf C, Leder L, Reinhardt J, Freuler F, Scheel G. Novel pharmacological insights for adenylyl cyclase 5, a gatekeeper of GPCR signaling. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.lb477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sandra Siehler
- Center for Proteomic ChemistryNovartis Institutes for BioMedical Research (NIBR)BaselSwitzerland
| | - Rina Yamamoto
- Center for Proteomic ChemistryNovartis Institutes for BioMedical Research (NIBR)BaselSwitzerland
| | - Christian Bergsdorf
- Center for Proteomic ChemistryNovartis Institutes for BioMedical Research (NIBR)BaselSwitzerland
| | - Lukas Leder
- Center for Proteomic ChemistryNovartis Institutes for BioMedical Research (NIBR)BaselSwitzerland
| | - Juergen Reinhardt
- Center for Proteomic ChemistryNovartis Institutes for BioMedical Research (NIBR)BaselSwitzerland
| | - Felix Freuler
- Center for Proteomic ChemistryNovartis Institutes for BioMedical Research (NIBR)BaselSwitzerland
| | - Guenther Scheel
- Center for Proteomic ChemistryNovartis Institutes for BioMedical Research (NIBR)BaselSwitzerland
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12
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Abstract
G protein-coupled receptors (GPCRs) are important targets for medicinal agents. Four different G protein families, G(s), G(i), G(q), and G(12), engage in their linkage to activation of receptor-specific signal transduction pathways. G(12) proteins were more recently studied, and upon activation by GPCRs they mediate activation of RhoGTPase guanine nucleotide exchange factors (RhoGEFs), which in turn activate the small GTPase RhoA. RhoA is involved in many cellular and physiological aspects, and a dysfunction of the G(12/13)-Rho pathway can lead to hypertension, cardiovascular diseases, stroke, impaired wound healing and immune cell functions, cancer progression and metastasis, or asthma. In this study, regulator of G protein signaling (RGS) domain-containing RhoGEFs were tagged with enhanced green fluorescent protein (EGFP) to detect their subcellular localization and translocation upon receptor activation. Constitutively active Galpha(12) and Galpha(13) mutants induced redistribution of these RhoGEFs from the cytosol to the plasma membrane. Furthermore, a pronounced and rapid translocation of p115-RhoGEF from the cytosol to the plasma membrane was observed upon activation of several G(12/13)-coupled GPCRs in a cell type-independent fashion. Plasma membrane translocation of p115-RhoGEF stimulated by a GPCR agonist could be completely and rapidly reversed by subsequent application of an antagonist for the respective GPCR, that is, p115-RhoGEF relocated back to the cytosol. The translocation of RhoGEF by G(12/13)-linked GPCRs can be quantified and therefore used for pharmacological studies of the pathway, and to discover active compounds in a G(12/13)-related disease context.
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Affiliation(s)
- Bruno H Meyer
- Center for Proteomic Chemistry, Novartis Institutes for BioMedical Research Basel, Novartis Pharma AG, 4002 Basel, Switzerland
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13
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Freuler F, Stettler T, Meyerhofer M, Leder L, Mayr LM. Development of a novel Gateway-based vector system for efficient, multiparallel protein expression in Escherichia coli. Protein Expr Purif 2008; 59:232-41. [DOI: 10.1016/j.pep.2008.02.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 02/04/2008] [Accepted: 02/13/2008] [Indexed: 11/30/2022]
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14
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Leder L, Freuler F, Forstner M, Mayr LM. New methods for efficient protein production in drug discovery. Curr Opin Drug Discov Devel 2007; 10:193-202. [PMID: 17436555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The requirement for high levels of stable and functional proteins remains a bottleneck in many processes of modern drug discovery, including the high-throughput screening for novel active compounds or the determination of protein structures. Recently, numerous developments have been made to improve the production of soluble and active proteins in heterologous expression systems. These include versatile expression vectors, new methods for quick cloning, the introduction of novel and/or improved prokaryotic and eukaryotic expression systems, and more efficient and faster chromatographic procedures that result in highly pure proteins. In addition, several techniques allow the attachment of small molecular labels to proteins in a site-specific manner, which can be highly useful for various important experimental techniques in current drug discovery.
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Affiliation(s)
- Lukas Leder
- Novartis Institutes for BioMedical Research, Center for Proteomic Chemistry, WSJ-88.6.02A, Lichtstrasse 35, CH-4056 Basel, Switzerland.
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15
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Tirat A, Freuler F, Stettler T, Mayr LM, Leder L. Evaluation of two novel tag-based labelling technologies for site-specific modification of proteins. Int J Biol Macromol 2006; 39:66-76. [PMID: 16503347 DOI: 10.1016/j.ijbiomac.2006.01.012] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Revised: 01/23/2006] [Accepted: 01/23/2006] [Indexed: 11/21/2022]
Abstract
Modern drug discovery strongly depends on the availability of target proteins in sufficient amounts and with desired properties. For some applications, proteins have to be produced with specific modifications such as tags for protein purification, fluorescent or radiometric labels for detection, glycosylation and phosphorylation for biological activity, and many more. It is well known that covalent modifications can have adverse effects on the biological activity of some target proteins. It is therefore one of the major challenges in protein chemistry to generate covalent modifications without affecting the biological activity of the target protein. Current procedures for modification mostly rely on non-specific labelling of lysine or cysteine residues on the protein of interest, but alternative approaches dedicated to site-specific protein modification are being developed and might replace most of the commonly used methodologies. In this study, we investigated two novel methods where target proteins can be expressed in E. coli with a fusion partner that allows protein modification in a covalent and highly selective manner. Firstly, we explored a method based on the human DNA repair protein O6-alkylguanine-DNA alkyltransferase (hAGT) as a fusion tag for site-directed attachment of small molecules. The AGT-tag (SNAP-tag) can accept almost any chemical moiety when it is attached to the guanine base through a benzyl group. In our experiments we were able to label a target protein fused to the AGT-tag with various fluorophores coupled to O6-benzylguanine. Secondly, we tested in vivo and in vitro site-directed biotinylation with two different tags, consisting of either 15 (AviTag) or 72 amino acids (BioEase tag), which serve as a substrate for bacterial biotin ligase birA. When birA protein was co-expressed in E. coli biotin was incorporated almost completely into a model protein which carried these recognition tags at its C-terminus. The same findings were also obtained with in vitro biotinylation assays using pure birA independently over-expressed in E. coli and added to the biotinylation reaction in the test tube. For both biotinylation methods, peptide mapping and LC-MS proved the highly site-specific modification of the corresponding tags. Our results indicate that these novel site-specific labelling reactions work in a highly efficient manner, allow almost quantitative labelling of the target proteins, have no deleterious effect on the biological activity and are easy to perform in standard laboratories.
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Affiliation(s)
- Aline Tirat
- Novartis Institutes for Biomedical Research, Discovery Technologies, CH-4056 Basel, Switzerland
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16
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Tirat A, Schilb A, Riou V, Leder L, Gerhartz B, Zimmermann J, Worpenberg S, Eidhoff U, Freuler F, Stettler T, Mayr L, Ottl J, Leuenberger B, Filipuzzi I. Synthesis and characterization of fluorescent ubiquitin derivatives as highly sensitive substrates for the deubiquitinating enzymes UCH-L3 and USP-2. Anal Biochem 2005; 343:244-55. [PMID: 15963938 DOI: 10.1016/j.ab.2005.04.023] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2005] [Revised: 04/07/2005] [Accepted: 04/13/2005] [Indexed: 10/25/2022]
Abstract
Deubiquitinating enzymes (DUBs) catalyze the removal of attached ubiquitin molecules from amino groups of target proteins. The large family of DUBs plays an important role in the regulation of the intracellular homeostasis of different proteins and influences therefore key events such as cell division, apoptosis, etc. The DUB family members UCH-L3 and USP2 are believed to inhibit the degradation of various tumor-growth-promoting proteins by removing the trigger for degradation. Inhibitors of these enzymes should therefore lead to enhanced degradation of oncoproteins and may thus stop tumor growth. To develop an enzymatic assay for the search of UCH-L3 and USP2 inhibitors, C-terminally labeled ubiquitin substrates were enzymatically synthesized. We have used the ubiquitin-activating enzyme E1 and one of the ubiquitin-conjugating enzymes E2 to attach a fluorescent lysine derivative to the C terminus of ubiquitin. Since only the epsilon-NH(2) group of the lysine derivatives was free and reactive, the conjugates closely mimic the isopeptide bond between the ubiquitin and the lysine side chains of the targeted proteins. Various substrates were synthesized by this approach and characterized enzymatically with the two DUBs. The variant consisting of the fusion protein between the large N-terminal NusA tag and the ubiquitin which was modified with alpha-NH(2)-tetramethylrhodamin-lysine, was found to give the highest dynamic range in a fluorescence polarization readout. Therefore we have chosen this substrate for the development of a miniaturized, fluorescence-polarization-based high-throughput screening assay.
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Affiliation(s)
- Aline Tirat
- Discovery Technologies, Novartis Institutes for Biomedical Research, CH-4058 Basel, Switzerland
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17
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Vallon R, Freuler F, Desta-Tsedu N, Robeva A, Dawson J, Wenner P, Engelhardt P, Boes L, Schnyder J, Tschopp C, Urfer R, Baumann G. Serum amyloid A (apoSAA) expression is up-regulated in rheumatoid arthritis and induces transcription of matrix metalloproteinases. J Immunol 2001; 166:2801-7. [PMID: 11160347 DOI: 10.4049/jimmunol.166.4.2801] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The acute-phase reactant rabbit serum amyloid A 3 (SAA3) was identified as the major difference product in Ag-induced arthritis in the rabbit, a model resembling in many aspects the clinical characteristics of rheumatoid arthritis (RA) in humans. In Ag-induced arthritis, up-regulated SAA3 transcription in vivo was detected in cells infiltrating into the inflamed joint, in the area where pannus formation starts and, most notably, also in chondrocytes. The proinflammatory cytokine IL-1beta induced SAA3 transcription in primary rabbit chondrocytes in vitro. Furthermore, rSAA3 protein induced transcription of matrix metalloproteinases in rabbit chondrocytes in vitro. In the human experimental system, IL-1beta induced transcription of acute-phase SAA (A-SSA; encoded by SAA1/SAA2) in primary chondrocytes. Similar to the rabbit system, recombinant human A-SAA protein was able to induce matrix metalloproteinases' transcription in chondrocytes. Further, immunohistochemistry demonstrated that A-SAA was highly expressed in human RA synovium. A new finding of our study is that A-SSA expression was also detected in cartilage in osteoarthritis. Our data, together with previous findings of SAA expression in RA synovium, suggest that A-SAA may play a role in cartilage destruction in arthritis.
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Affiliation(s)
- R Vallon
- Arthritis Biology, Department of Arthritis and Bone Metabolism, Novartis Pharma AG, Basle, Switzerland.
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18
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Heilker R, Freuler F, Vanek M, Pulfer R, Kobel T, Peter J, Zerwes HG, Hofstetter H, Eder J. The kinetics of association and phosphorylation of IkappaB isoforms by IkappaB kinase 2 correlate with their cellular regulation in human endothelial cells. Biochemistry 1999; 38:6231-8. [PMID: 10320352 DOI: 10.1021/bi990220t] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Activation of the transcription factor NF-kappaB depends on the specific dual phosphorylation of its inhibitor protein IkappaB by the homologous cytokine-inducible IkappaB kinases 1 and 2 (IKK1/2). Various IkappaB isoforms exist: IkappaBalpha, IkappaBbeta1/2 (two alternative splice variants), and IkappaBepsilon. However, the individual relevance and the specific regulation of these isoforms is not well-understood. We have studied the direct interaction of recombinant IkappaBalpha, IkappaBbeta1, IkappaBbeta2, and IkappaBepsilon with the recombinant homodimeric IKK2. Fluorescence-based active site titration revealed that each IKK2 dimer contains two binding sites for IkappaB. By using surface plasmon resonance analysis, we found that all IkappaB proteins interact with the IKK2 dimer following a noncooperative binding mechanism. Further, the four IkappaB proteins bind to the kinase with equilibrium dissociation constants (KD) in the range of 50-300 nM; the association rate constants for all IkappaB isoforms with IKK2 were between 6.0 x 10(3) and 22.5 x 10(3) M-1 s-1, and the dissociation rate constants were between 1.25 x 10(-3) and 1.75 x 10(-3) s-1. This high-affinity binding suggests that the previously observed preassociation of all analyzed IkappaB proteins with the biochemically purified 700 kDa IkappaB kinase (IKK) complex is based on a direct enzyme-substrate association between the various IkappaB isoforms and the IKK proteins. The apparent catalytic efficiencies (kcat/KM) of IKK2 for IkappaBalpha, IkappaBbeta1, IkappaBbeta2, and IkappaBepsilon were 22 x 10(3), 10 x 10(3), 5.4 x 10(3), and 8.5 x 10(3) s-1 M-1, respectively, with KM values ranging between 1.7 x 10(-6) and 3.2 x 10(-6) M and kcat values ranging between 1.5 x 10(-2) and 3.7 x 10(-2) s-1. The relative affinities and catalytic efficiencies of IKK2 for the IkappaB isoforms were also reflected by the kinetics observed for the TNF-induced, phosphorylation-dependent degradation of the alpha, beta1, beta2, and epsilon isoforms of IkappaB in human umbilical vein endothelial cells. Therefore, differential regulation of the IkappaB isoforms in some cell types is not a direct result of the IKK activity, but appears to be due to parallel events.
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Affiliation(s)
- R Heilker
- Novartis Pharma AG, CH-4002 Basel, Switzerland
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19
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Heilker R, Freuler F, Pulfer R, Di Padova F, Eder J. All three IkappaB isoforms and most Rel family members are stably associated with the IkappaB kinase 1/2 complex. Eur J Biochem 1999; 259:253-61. [PMID: 9914500 DOI: 10.1046/j.1432-1327.1999.00028.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Nuclear factor kappa B (NF-kappaB) is an important transcription factor for the genes of many pro-inflammatory proteins and is strongly activated by the cytokines interleukin-1 and tumor necrosis factor (TNF)alpha under various pathological conditions. In nonstimulated cells, NF-kappaB is present in the cytosol where it is complexed to its inhibitor IkappaB. Activation of NF-kappaB depends on the signal-induced phosphorylation of IkappaB by specific IkappaB kinases which initiates the inhibitor's conjugation to ubiquitin and subsequent degradation by the proteasome. We used both TNF-stimulated and okadaic-acid-stimulated HeLa cells to purify three biochemically distinct kinase activities targeting one or both of the two serines (S32 and S36) in IkappaBalpha which induce its rapid degradation upon cytokine stimulation. All three activities correspond to known IkappaB kinases: the mitogen-activated 90 kDa ribosomal S6 kinase (p90rsk1), the IkappaB kinase 1/2 complex (IKK1/2) and casein kinase II (CK II). However, we found that only one of the activities, namely the IKK1/2 complex, exists as a pre-assembled kinase-substrate complex in which the IKKs are directly or indirectly associated with several NF-kappaB-related and IkappaB-related proteins: RelA, RelB, cRel, p100, p105, Ikappa Balpha, Ikappa Bbeta and Ikappa Bepsilon. The existence of stable kinase-substrate complexes, the presence of all three known IkappaB isoforms in these complexes and our observation that the IKK complex is capable of phosphorylating Ikappa Balpha-, Ikappa Bbeta- and Ikappa Bepsilon-derived peptides at the respective degradation-relevant serines suggests that the IKK complex exerts a broad regulatory role for the activation of different NF-kappaB species. In contrast to previous studies, which locate CK II phosphorylation sites exclusively to the C-terminal PEST sequence of Ikappa Balpha, we observed efficient phosphorylation of serine 32 in Ikappa Balpha by the purified endogenous CK II complex. Therefore, both p90rsk1 and CK II have the same preference for phosphorylating only one of the two serines which are relevant for inducible degradation.
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Affiliation(s)
- R Heilker
- Novartis Pharma AG, Arthritis and Bone Metabolism Research, Basel, Switzerland
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20
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Müller K, Gombert FO, Manning U, Grossmüller F, Graff P, Zaegel H, Zuber JF, Freuler F, Tschopp C, Baumann G. Rapid identification of phosphopeptide ligands for SH2 domains. Screening of peptide libraries by fluorescence-activated bead sorting. J Biol Chem 1996; 271:16500-5. [PMID: 8663178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A method for the identification of high-affinity ligands to SH2 domains by fluorescence-activated bead sorting (FABS) was established. Recombinant SH2 domains, expressed as glutathione S-transferase (GST) fusion proteins, were incubated with a phosphotyrosine (Y*)-containing peptide library. 6.4 x 10(5) individual peptides of nine amino acids in length (EPX6Y*X19X7X19X7X6) were each displayed on beads. Phosphopeptide interaction of a given SH2 domain was monitored by binding of fluorescein isothiocyanate-labeled antibodies directed against GST. High-fluorescence beads were isolated by flow cytometric sorting. Subsequent pool sequencing of the selected beads revealed a distinct pattern of phosphotyrosine-containing motifs for each individual SH2 domain: the SH2 domain of the adapter protein Grb2 predominantly selected beads with the sequence Y*ENDP, whereas the C-terminal SH2 domain of the tyrosine kinase Syk selected Y*EELD, each motif representing the most frequently found residues C-terminal to the phosphotyrosine. For deconvolution studies, soluble phosphopeptides comprising variations of the Grb2 motifs were resynthesized and analyzed by surface plasmon resonance.
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Affiliation(s)
- K Müller
- Sandoz Pharma Ltd., Preclinical Research, CH-4002 Basel, Switzerland
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21
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Müller K, Gombert FO, Manning U, Grossmüller F, Graff P, Zaegel H, Zuber JF, Freuler F, Tschopp C, Baumann G. Rapid Identification of Phosphopeptide Ligands for SH2 Domains. J Biol Chem 1996. [DOI: 10.1074/jbc.271.28.16500] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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22
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Wienands J, Freuler F, Baumann G. Tyrosine-phosphorylated forms of Ig beta, CD22, TCR zeta and HOSS are major ligands for tandem SH2 domains of Syk. Int Immunol 1995; 7:1701-8. [PMID: 8580068 DOI: 10.1093/intimm/7.11.1701] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The protein tyrosine kinase Syk plays an important role in signal transduction from the B cell antigen receptor and possibly also from the TCR. We have examined the binding specificity of Syk-derived SH2 domains in vitro and found that the tandem SH2 domains have two major ligands in activated Ramos B cells as well as in activated Jurkat T cells. The SH2-binding proteins in Ramos B cells were identified as the tyrosine-phosphorylated forms of the Ig alpha beta heterodimer and of CD22. Binding to the Ig alpha beta heterodimer seems to occur predominantly via Ig beta, indicating that the two receptor components might couple to distinct signaling pathways. In Jurkat T cells one of the SH2-binding proteins represents the tyrosine-phosphorylated TCR zeta chain. The identity of the second SH2 ligand, called HOSS, is not known. HOSS is discussed as a putative member of the receptor family characterized by the immunoreceptor tyrosine-based activation motif.
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MESH Headings
- Antigens, CD/chemistry
- Antigens, CD/metabolism
- Antigens, Differentiation, B-Lymphocyte/chemistry
- Antigens, Differentiation, B-Lymphocyte/metabolism
- Base Sequence
- Cell Adhesion Molecules
- Enzyme Precursors/metabolism
- Humans
- Immunoglobulins/metabolism
- Intracellular Signaling Peptides and Proteins
- Lectins
- Lymphocyte Activation
- Membrane Proteins/metabolism
- Molecular Sequence Data
- Phosphoproteins/chemistry
- Phosphoproteins/metabolism
- Phosphorylation
- Protein Binding
- Protein-Tyrosine Kinases/metabolism
- Receptors, Antigen, B-Cell/chemistry
- Receptors, Antigen, B-Cell/metabolism
- Receptors, Antigen, T-Cell/metabolism
- Sialic Acid Binding Ig-like Lectin 2
- Syk Kinase
- Tumor Cells, Cultured
- src Homology Domains
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Affiliation(s)
- J Wienands
- Max-Planck-Institut für Immunobiologie, Freiburg, Germany
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23
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Baumann G, Maier D, Freuler F, Tschopp C, Baudisch K, Wienands J. In vitro characterization of major ligands for Src homology 2 domains derived from protein tyrosine kinases, from the adaptor protein SHC and from GTPase-activating protein in Ramos B cells. Eur J Immunol 1994; 24:1799-807. [PMID: 7519995 DOI: 10.1002/eji.1830240812] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Antigen receptors of B lymphocytes transmit their activation signal to the cell interior by associating with and activation of specific non-receptor tyrosine kinases. Most of these kinases as well as other cytoplasmic effectors contain at least one Src homology 2 (SH2) domain, known to bind tyrosine-phosphorylated proteins. We examined the binding specificity of SH2 domains from different signaling molecules in B cells and found that each of the SH2 domains tested bound distinct subsets of stimulation-dependent phosphoproteins in vitro. SH2 domains from Src-like tyrosine kinases bound predominantly to the HS1 phosphoprotein. The tandem SH2 domains of the ZAP-70 tyrosine kinase bound to phosphorylated Ig-beta but only weakly to Ig-alpha. Also the SHC-derived SH2 domain formed complexes with the tyrosine-phosphorylated Ig-alpha/beta heterodimer, while the C- and N-terminal SH2 domains of GTPase-activating protein displayed completely different binding preferences. These results suggest that cytoplasmic effector molecules can be recruited to the activated B cell receptor in an SH2-phosphotyrosine-mediated manner. The data also provide a possible explanation for the notion that Ig-alpha and Ig-beta might couple to different biochemical pathways.
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Affiliation(s)
- G Baumann
- Sandoz Pharma Ltd., Preclinical Research, Basel, Germany
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24
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Holmes IB, Freuler F. Use of the Technicon Autocounter for animal platelet counting and for continuous monitoring of circulating platelet number. Pharmacol Ther B 1979; 5:257-65. [PMID: 386369 DOI: 10.1016/0163-7258(79)90094-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Holmes IB, Smith GM, Freuler F. The effect of intravenous adenosine diphosphate on the number of circulating platelets in experimental animals: inhibition by prostaglandin E1, dipyridamole, SH-869 and VK-774. Thromb Haemost 1977; 37:36-46. [PMID: 402707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The number of circulating platelets was monitored in anaesthetized animals by a continuous flow technique, using a Technicon Autocounter. Intravenous infusions of adenosine diphosphate (ADP) produced transient, dose-dependent falls in circulating platelet numbers in rabbits, dogs, rats, pigs and squirrel monkeys. The rat was the most sensitive of the species investigated. In the rabbit, the effect of a submaximal dose of ADP was inhibited in a dose-dependent manner by intravenous infusions of prostaglandin E1 (PGE1), dipyridamole, and two derivatives of dipyridamole (SH-869 and VK-774). The dose-response curves for PGE1, SH-869 and VK-774 were approximately parallel, whereas that for dipyridamole was considerably less steep. PGE1 was the most potent inhibitor, but the duration of action was very short. Dipyridamole and SH-869 produced inhibition of long duration. The duration of action of VK-774 was intermediate. All inhibitors produced marked and often long-lasting hypotension. The fact no inhibition of ADP effects could be demonstrated with dibenzyline and hexamethonium, which also produced marked hypotension of long duration, indicated that inhibition of the ADP effect by the four antagonists studied was not due to changes in blood pressure.
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Spring R, Magrel F, Freuler F. [Late results of surgical therapy in tibial head fractures]. Helv Chir Acta 1976; 43:437-8. [PMID: 1002493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Spring R, Magerl F, Freuler F. [Late results of surgical therapy in tibial-head fractures]. Hefte Unfallheilkd 1975:315-6. [PMID: 1234194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Blatter R, Schönenberger F, Freuler F. [Orthopedic emergencies]. Ther Umsch 1973; 30:270-3. [PMID: 4695273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Marti R, Freuler F. [Knee-distorsion]. Ther Umsch 1973; 30:246-51. [PMID: 4695270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Stalder GR, Buhler EM, Gadola G, Widmer R, Freuler F. A family with balanced D1-Cs-translocation carriers and unbalanced offspring. Humangenetik 1964; 1:197-200. [PMID: 5869480 DOI: 10.1007/bf00389637] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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