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Schmidt G. Some Examples of Bacterial Toxins as Tools. Toxins (Basel) 2024; 16:202. [PMID: 38787054 PMCID: PMC11125981 DOI: 10.3390/toxins16050202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/18/2024] [Accepted: 04/20/2024] [Indexed: 05/25/2024] Open
Abstract
Pathogenic bacteria produce diverse protein toxins to disturb the host's defenses. This includes the opening of epithelial barriers to establish bacterial growth in deeper tissues of the host and to modulate immune cell functions. To achieve this, many toxins share the ability to enter mammalian cells, where they catalyze the modification of cellular proteins. The enzymatic activity is diverse and ranges from ribosyl- or glycosyl-transferase activity, the deamidation of proteins, and adenylate-cyclase activity to proteolytic cleavage. Protein toxins are highly active enzymes often with tight specificity for an intracellular protein or a protein family coupled with the intrinsic capability of entering mammalian cells. A broad understanding of their molecular mechanisms established bacterial toxins as powerful tools for cell biology. Both the enzymatic part and the pore-forming/protein transport capacity are currently used as tools engineered to study signaling pathways or to transport cargo like labeled compounds, nucleic acids, peptides, or proteins directly into the cytosol. Using several representative examples, this review is intended to provide a short overview of the state of the art in the use of bacterial toxins or parts thereof as tools.
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Affiliation(s)
- Gudula Schmidt
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Albertstr. 25, 79104 Freiburg, Germany
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Bao K, Jiao Y, Xing L, Zhang F, Tian F. The role of wnt signaling in diabetes-induced osteoporosis. Diabetol Metab Syndr 2023; 15:84. [PMID: 37106471 PMCID: PMC10141960 DOI: 10.1186/s13098-023-01067-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 04/24/2023] [Indexed: 04/29/2023] Open
Abstract
Osteoporosis, a chronic complication of diabetes mellitus, is characterized by a reduction in bone mass, destruction of bone microarchitecture, decreased bone strength, and increased bone fragility. Because of its insidious onset, osteoporosis renders patients highly susceptible to pathological fractures, leading to increased disability and mortality rates. However, the specific pathogenesis of osteoporosis induced by chronic hyperglycemia has not yet been fully elucidated. But it is currently known that the disruption of Wnt signaling triggered by chronic hyperglycemia is involved in the pathogenesis of diabetic osteoporosis. There are two main types of Wnt signaling pathways, the canonical Wnt signaling pathway (β-catenin-dependent) and the non-canonical Wnt signaling pathway (non-β-catenin-dependent), both of which play an important role in regulating the balance between bone formation and bone resorption. Therefore, this review systematically describes the effects of abnormal Wnt pathway signaling on bone homeostasis under hyperglycemia, hoping to reveal the relationship between Wnt signaling and diabetic osteoporosis to further improve understanding of this disease.
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Affiliation(s)
- Kairan Bao
- Department of Integrated Traditional & Western Medicine, Affiliated hospital of North, China University of Science and Technology, Jianshe South Road 73, Tangshan, 063000, Hebei, People's Republic of China.
| | - Yinghua Jiao
- Department of Integrated Traditional & Western Medicine, Affiliated hospital of North, China University of Science and Technology, Jianshe South Road 73, Tangshan, 063000, Hebei, People's Republic of China
- North China University of Science and Technology, Bohai Road 21, Caofeidian Dis, Tangshan, 063210, Hebei, People's Republic of China
| | - Lei Xing
- Department of Integrated Traditional & Western Medicine, Affiliated hospital of North, China University of Science and Technology, Jianshe South Road 73, Tangshan, 063000, Hebei, People's Republic of China
| | - Fang Zhang
- Department of Integrated Traditional & Western Medicine, Affiliated hospital of North, China University of Science and Technology, Jianshe South Road 73, Tangshan, 063000, Hebei, People's Republic of China
| | - Faming Tian
- Department of Integrated Traditional & Western Medicine, Affiliated hospital of North, China University of Science and Technology, Jianshe South Road 73, Tangshan, 063000, Hebei, People's Republic of China
- North China University of Science and Technology, Bohai Road 21, Caofeidian Dis, Tangshan, 063210, Hebei, People's Republic of China
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Chakraborty S, Handrick B, Yu D, Bode KA, Hafner A, Schenz J, Schaack D, Uhle F, Tachibana T, Kamitani S, Vogl T, Kubatzky KF. Gα q modulates the energy metabolism of osteoclasts. Front Cell Infect Microbiol 2023; 12:1016299. [PMID: 36699722 PMCID: PMC9869164 DOI: 10.3389/fcimb.2022.1016299] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 12/09/2022] [Indexed: 01/12/2023] Open
Abstract
Introduction The bacterial protein toxin Pasteurella multocida toxin (PMT) mediates RANKL-independent osteoclast differentiation. Although these osteoclasts are smaller, their resorptive activity is high which helps in efficient destruction of nasal turbinate bones of pigs. Methods The proteome of bone marrow-derived macrophages differentiated into osteoclasts with either RANKL or PMT was analysed. The results were verified by characterizing the metabolic activity using Seahorse analysis, a protein translation assay, immunoblots, real-time PCR as well as flow cytometry-based monitoring of mitochondrial activity and ROS production. A Gαq overexpression system using ER-Hoxb8 cells was used to identify Gαq-mediated metabolic effects on osteoclast differentiation and function. Results PMT induces the upregulation of metabolic pathways, which included strong glycolytic activity, increased expression of GLUT1 and upregulation of the mTOR pathway. As OxPhos components were expressed more efficiently, cells also displayed increased mitochondrial respiration. The heterotrimeric G protein Gαq plays a central role in this hypermetabolic cell activation as it triggers mitochondrial relocalisation of pSerSTAT3 and an increase in OPA1 expression. This seems to be caused by a direct interaction between STAT3 and OPA1 resulting in enhanced mitochondrial respiration. Overexpression of Gαq mimicked the hypermetabolic phenotype observed for PMT-induced osteoclasts and resulted in higher glycolytic and mitochondrial activity as well as increased bone resorptive activity. In addition, rheumatoid arthritis (RA) patients showed an increase in GNAQ expression, especially in the synovial fluid. Discussion Our study suggests that Gαq plays a key role in PMT-induced osteoclastogenesis. Enhanced expression of GNAQ at the site of inflammation in RA patients indicates its pathophysiological relevance in the context of inflammatory bone disorders.
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Affiliation(s)
- Sushmita Chakraborty
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University, Heidelberg, Germany
- Department of Transplant Immunology and Immunogenetics, All India Institute of Medical Sciences, New Delhi, India
| | - Bianca Handrick
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University, Heidelberg, Germany
| | - Dayoung Yu
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University, Heidelberg, Germany
| | - Konrad A. Bode
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University, Heidelberg, Germany
| | - Anna Hafner
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Judith Schenz
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Dominik Schaack
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Florian Uhle
- Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Taro Tachibana
- Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan
| | - Shigeki Kamitani
- Department of Nutrition, Graduate School of Human Life and Ecology, Osaka Metropolitan University, Osaka, Japan
| | - Thomas Vogl
- Institute of Immunology, University Hospital Münster, Münster, Germany
| | - Katharina F. Kubatzky
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University, Heidelberg, Germany
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Kubatzky KF. Pasteurella multocida toxin - lessons learned from a mitogenic toxin. Front Immunol 2022; 13:1058905. [PMID: 36591313 PMCID: PMC9800868 DOI: 10.3389/fimmu.2022.1058905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
The gram-negative, zoonotic bacterium Pasteurella multocida was discovered in 1880 and found to be the causative pathogen of fowl cholera. Pasteurella-related diseases can be found in domestic and wild life animals such as buffalo, sheep, goat, deer and antelope, cats, dogs and tigers and cause hemorrhagic septicemia in cattle, rhinitis or pneumonia in rabbits or fowl cholera in poultry and birds. Pasteurella multocida does not play a major role in the immune-competent human host, but can be found after animal bites or in people with close contact to animals. Toxigenic strains are most commonly found in pigs and express a phage-encoded 146 kDa protein, the Pasteurella multocida toxin (PMT). Toxin-expressing strains cause atrophic rhinitis where nasal turbinate bones are destroyed through the inhibition of bone building osteoblasts and the activation of bone resorbing osteoclasts. After its uptake through receptor-mediated endocytosis, PMT specifically targets the alpha subunit of several heterotrimeric G proteins and constitutively activates them through deamidation of a glutamine residue to glutamate in the alpha subunit. This results in cytoskeletal rearrangement, proliferation, differentiation and survival of cells. Because of the toxin's mitogenic effects, it was suggested that it might have carcinogenic properties, however, no link between Pasteurella infections and cell transformation could be established, neither in tissue culture models nor through epidemiological data. In the recent years it was shown that the toxin not only affects bone, but also the heart as well as basically all cells of innate and adaptive immunity. During the last decade the focus of research shifted from signal transduction processes to understanding how the bacteria might benefit from a bone-destroying toxin. The primary function of PMT seems to be the modulation of immune cell activation which at the same time creates an environment permissive for osteoclast formation. While the disease is restricted to pigs, the implications of the findings from PMT research can be used to explore human diseases and have a high translational potential. In this review our current knowledge will be summarized and it will be discussed what can be learned from using PMT as a tool to understand human pathologies.
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Affiliation(s)
- Katharina F. Kubatzky
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University, Heidelberg, Germany
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Schoellkopf J, Mueller T, Hippchen L, Mueller T, Reuten R, Backofen R, Orth J, Schmidt G. Genome wide CRISPR screen for Pasteurella multocida toxin (PMT) binding proteins reveals LDL Receptor Related Protein 1 (LRP1) as crucial cellular receptor. PLoS Pathog 2022; 18:e1010781. [PMID: 36516199 PMCID: PMC9797058 DOI: 10.1371/journal.ppat.1010781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 12/28/2022] [Accepted: 11/15/2022] [Indexed: 12/15/2022] Open
Abstract
PMT is a protein toxin produced by Pasteurella multocida serotypes A and D. As causative agent of atrophic rhinitis in swine, it leads to rapid degradation of the nasal turbinate bone. The toxin acts as a deamidase to modify a crucial glutamine in heterotrimeric G proteins, which results in constitutive activation of the G proteins and permanent stimulation of numerous downstream signaling pathways. Using a lentiviral based genome wide CRISPR knockout screen in combination with a lethal toxin chimera, consisting of full length inactive PMT and the catalytic domain of diphtheria toxin, we identified the LRP1 gene encoding the Low-Density Lipoprotein Receptor-related protein 1 as a critical host factor for PMT function. Loss of LRP1 reduced PMT binding and abolished the cellular response and deamidation of heterotrimeric G proteins, confirming LRP1 to be crucial for PMT uptake. Expression of LRP1 or cluster 4 of LRP1 restored intoxication of the knockout cells. In summary our data demonstrate LRP1 as crucial host entry factor for PMT intoxication by acting as its primary cell surface receptor.
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Affiliation(s)
- Julian Schoellkopf
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Freiburg, Germany
| | - Thomas Mueller
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Freiburg, Germany
| | - Lena Hippchen
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Freiburg, Germany
| | - Teresa Mueller
- Bioinformatics—Department of Computer Science, Albert-Ludwigs-University, Freiburg, Germany
| | - Raphael Reuten
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Freiburg, Germany
| | - Rolf Backofen
- Bioinformatics—Department of Computer Science, Albert-Ludwigs-University, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University, Freiburg, Germany
| | - Joachim Orth
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Freiburg, Germany
| | - Gudula Schmidt
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Freiburg, Germany
- * E-mail:
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Banu A, Lax AJ, Grigoriadis AE. In Vivo Targets of Pasteurella Multocida Toxin. Int J Mol Sci 2020; 21:ijms21082739. [PMID: 32326543 PMCID: PMC7215291 DOI: 10.3390/ijms21082739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 01/03/2023] Open
Abstract
Many Pasteurella multocida strains are carried as commensals, while some cause disease in animals and humans. Some type D strains cause atrophic rhinitis in pigs, where the causative agent is known to be the Pasteurella multocida toxin (PMT). PMT activates three families of G-proteins—Gq/11, G12/13, and Gi/o—leading to cellular mitogenesis and other sequelae. The effects of PMT on whole animals in vivo have been investigated previously, but only at the level of organ-specific pathogenesis. We report here the first study to screen all the organs targeted by the toxin by using the QE antibody that recognizes only PMT-modified G-proteins. Under our experimental conditions, short-term treatment of PMT is shown to have multiple in vivo targets, demonstrating G-alpha protein modification, stimulation of proliferation markers and expression of active β-catenin in a tissue- and cell-specific manner. This highlights the usefulness of PMT as an important tool for dissecting the specific roles of different G-alpha proteins in vivo.
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Affiliation(s)
- Arshiya Banu
- Department of Microbiology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
- Centre for Craniofacial and Regenerative Biology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
| | - Alistair J. Lax
- Department of Microbiology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
| | - Agamemnon E. Grigoriadis
- Centre for Craniofacial and Regenerative Biology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
- Correspondence: ; Tel.: +44-(0)20-7188-1807
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Ebner JK, König GM, Kostenis E, Siegert P, Aktories K, Orth JHC. Activation of G q signaling by Pasteurella multocida toxin inhibits the osteoblastogenic-like actions of Activin A in C2C12 myoblasts, a cell model of fibrodysplasia ossificans progressiva. Bone 2019; 127:592-601. [PMID: 31376533 DOI: 10.1016/j.bone.2019.07.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 01/15/2023]
Abstract
The human disease fibrodysplasia ossificans progressiva (FOP) is a rare and highly disabling disorder of extensive heterotopic bone growth that is caused by a point mutation (R206H) in the activation domain of Alk2, a BMP (bone morphogenic protein) type 1 receptor. The mutation leads to extensive BMP-signaling induced by Activin A, which is normally an antagonist for wildtype receptors, resulting in excessive and uncontrolled bone formation. Here, we studied the effects of Pasteurella multocida toxin (PMT), which activates osteoclasts and inhibits osteoblast activity, in C2C12 myoblasts expressing the mutant Alk2(R206H) receptor as model of FOP. In our study, we mainly used alkaline phosphatase (ALP) activity as marker to determine osteoblast differentiation. BMP-4 stimulated an increase in ALP activity in C2C12-Alk2wt and C2C12-Alk2(R206H) cells. By contrast, Activin A only induced ALP activity in C2C12-Alk2(R206H) cells. In both cases, PMT acted as a potent inhibitor of ALP activity. PMT-induced inhibition of ALP activity was paralleled by a constitutive activation of the heterotrimeric Gq protein. Expression of a permanently active Gαq blocked Activin A/Alk2(R206H)-dependent increase in ALP activity. Inactivation of Gq by specific inhibitor FR900359 blocked the PMT effect. Similarly, canonical second messengers and effectors of Gαq (e.g. ionophore A23187-induced increase in intracellular Ca2+ and activation of PKC by PMA (phorbol 12-myristate 13-acetate)) inhibited Alk2(R206H)-mediated induction of ALP activity. Notably, Activin A-induced increase in ALP activity in C2C12-Alk2(R206H) cells was also inhibited by stimulation of the α1A-adrenoceptor, which couples to Gαq, by phenylephrine. PMT did not alter tail phosphorylation of the major downstream effectors of the Alk2 receptor, Smad1/5/9; neither did the toxin affect nuclear translocation of the Smad-complex. However, PMT diminished BMP responsive element-induced gene expression. The data indicate that PMT potently inhibits the induction of osteoblast markers in a FOP model via activation of G proteins. Moreover, our findings indicate that activation of G protein-coupled receptors and of G protein signaling might be a rationale for pharmacological therapy of FOP.
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Affiliation(s)
- Julia K Ebner
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Freiburg, Albertstr. 25, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany; Spemann Graduate School for Biology and Medicine, University of Freiburg, Albertstr. 19A, 79104 Freiburg, Germany
| | - Gabriele M König
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Evi Kostenis
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Peter Siegert
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Freiburg, Albertstr. 25, 79104 Freiburg, Germany
| | - Klaus Aktories
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Freiburg, Albertstr. 25, 79104 Freiburg, Germany; Spemann Graduate School for Biology and Medicine, University of Freiburg, Albertstr. 19A, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestr. 18, 79104 Freiburg, Germany.
| | - Joachim H C Orth
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Freiburg, Albertstr. 25, 79104 Freiburg, Germany
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Brink T, Leiss V, Siegert P, Jehle D, Ebner JK, Schwan C, Shymanets A, Wiese S, Nürnberg B, Hensel M, Aktories K, Orth JHC. Salmonella Typhimurium effector SseI inhibits chemotaxis and increases host cell survival by deamidation of heterotrimeric Gi proteins. PLoS Pathog 2018; 14:e1007248. [PMID: 30102745 PMCID: PMC6107295 DOI: 10.1371/journal.ppat.1007248] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 08/23/2018] [Accepted: 07/27/2018] [Indexed: 12/20/2022] Open
Abstract
Salmonella enterica serotype Typhimurium (S. Typhimurium) is one of the most frequent causes of food-borne illness in humans and usually associated with acute self-limiting gastroenteritis. However, in immunocompromised patients, the pathogen can disseminate and lead to severe systemic diseases. S. Typhimurium are facultative intracellular bacteria. For uptake and intracellular life, Salmonella translocate numerous effector proteins into host cells using two type-III secretion systems (T3SS), which are encoded within Salmonella pathogenicity islands 1 (SPI-1) and 2 (SPI-2). While SPI-1 effectors mainly promote initial invasion, SPI-2 effectors control intracellular survival and proliferation. Here, we elucidate the mode of action of Salmonella SPI-2 effector SseI, which is involved in control of systemic dissemination of S. Typhimurium. SseI deamidates a specific glutamine residue of heterotrimeric G proteins of the Gαi family, resulting in persistent activation of the G protein. Gi activation inhibits cAMP production and stimulates PI3-kinase γ by Gαi-released Gβγ subunits, resulting in activation of survival pathways by phosphorylation of Akt and mTOR. Moreover, SseI-induced deamidation leads to non-polarized activation of Gαi and, thereby, to loss of directed migration of dendritic cells. Salmonella Typhimurium is one of the most common causes of gastroenteritis in humans. In immunocompromised patients, the pathogen can cause systemic infections. Crucial virulence factors are encoded on two Salmonella pathogenicity islands SPI-1 and SPI-2. While SPI-1 encodes virulence factors essential for host cell invasion, intracellular proliferation of the pathogen depends mainly on SPI-2 effectors. Here, we elucidate the mode of action of Salmonella SPI-2 effector SseI. SseI activates heterotrimeric G proteins of the Gαi family by deamidation of a specific glutamine residue. Deamidation blocks GTP hydrolysis by Gαi, resulting in a persistently active G protein. Gi activation inhibits cAMP production and stimulates PI3Kγ by Gαi-released Gβγ subunits, resulting in activation of survival pathways by phosphorylation of Akt and mTOR. Moreover, deamidation of Gαi leads to a loss of directed migration in dendritic cells. The data offers a new perspective in the understanding of the actions of SseI.
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Affiliation(s)
- Thorsten Brink
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Veronika Leiss
- Abteilung für Pharmakologie und Experimentelle Therapie, Medizinische Fakultät und ICePhA, Eberhard-Karls-Universität Tübingen, Germany
| | - Peter Siegert
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Doris Jehle
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Julia K. Ebner
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
- Fakultät für Biologie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Carsten Schwan
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Aliaksei Shymanets
- Abteilung für Pharmakologie und Experimentelle Therapie, Medizinische Fakultät und ICePhA, Eberhard-Karls-Universität Tübingen, Germany
| | - Sebastian Wiese
- Zentrum für Biosystemanalyse, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Bernd Nürnberg
- Abteilung für Pharmakologie und Experimentelle Therapie, Medizinische Fakultät und ICePhA, Eberhard-Karls-Universität Tübingen, Germany
| | - Michael Hensel
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Osnabrück, Germany
| | - Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
- * E-mail:
| | - Joachim H. C. Orth
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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Heni H, Ebner JK, Schmidt G, Aktories K, Orth JHC. Involvement of Osteocytes in the Action of Pasteurella multocida Toxin. Toxins (Basel) 2018; 10:toxins10080328. [PMID: 30104531 PMCID: PMC6115833 DOI: 10.3390/toxins10080328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 08/06/2018] [Accepted: 08/08/2018] [Indexed: 01/24/2023] Open
Abstract
Pasteurella multocida toxin (PMT) causes progressive atrophic rhinitis with severe turbinate bone degradation in pigs. It has been reported that the toxin deamidates and activates heterotrimeric G proteins, resulting in increased differentiation of osteoclasts and blockade of osteoblast differentiation. So far, the action of PMT on osteocytes, which is the most abundant cell type in bone tissue, is not known. In MLO-Y4 osteocytes, PMT deamidated heterotrimeric G proteins, resulting in loss of osteocyte dendritic processes, stress fiber formation, cell spreading and activation of RhoC but not of RhoA. Moreover, the toxin caused processing of membrane-bound receptor activator of NF-κB ligand (RANKL) to release soluble RANKL and enhanced the secretion of osteoclastogenic TNF-α. In a co-culture model of osteocytes and bone marrow cells, PMT-induced osteoclastogenesis was largely increased as compared to the mono-culture model. The enhancement of osteoclastogenesis observed in the co-culture was blocked by sequestering RANKL with osteoprotegerin and by an antibody against TNF-α indicating involvement of release of the osteoclastogenic factors from osteocytes. Data support the crucial role of osteocytes in bone metabolism and osteoclastogenesis and identify osteocytes as important target cells of PMT in progressive atrophic rhinitis.
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Affiliation(s)
- Hannah Heni
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
- Hermann-Staudinger-Graduiertenschule, Universität Freiburg, 79104 Freiburg, Germany.
| | - Julia K Ebner
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
- Spemann Graduate School of Biology and Medicine (SGBM), Universität Freiburg, 79104 Freiburg, Germany.
- Faculty of Biology, Universität Freiburg, 79104 Freiburg, Germany.
| | - Gudula Schmidt
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
| | - Klaus Aktories
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
- BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany.
| | - Joachim H C Orth
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
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Eisenhardt AE, Sprenger A, Röring M, Herr R, Weinberg F, Köhler M, Braun S, Orth J, Diedrich B, Lanner U, Tscherwinski N, Schuster S, Dumaz N, Schmidt E, Baumeister R, Schlosser A, Dengjel J, Brummer T. Phospho-proteomic analyses of B-Raf protein complexes reveal new regulatory principles. Oncotarget 2018; 7:26628-52. [PMID: 27034005 PMCID: PMC5042004 DOI: 10.18632/oncotarget.8427] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 03/07/2016] [Indexed: 12/19/2022] Open
Abstract
B-Raf represents a critical physiological regulator of the Ras/RAF/MEK/ERK-pathway and a pharmacological target of growing clinical relevance, in particular in oncology. To understand how B-Raf itself is regulated, we combined mass spectrometry with genetic approaches to map its interactome in MCF-10A cells as well as in B-Raf deficient murine embryonic fibroblasts (MEFs) and B-Raf/Raf-1 double deficient DT40 lymphoma cells complemented with wildtype or mutant B-Raf expression vectors. Using a multi-protease digestion approach, we identified a novel ubiquitination site and provide a detailed B-Raf phospho-map. Importantly, we identify two evolutionary conserved phosphorylation clusters around T401 and S419 in the B-Raf hinge region. SILAC labelling and genetic/biochemical follow-up revealed that these clusters are phosphorylated in the contexts of oncogenic Ras, sorafenib induced Raf dimerization and in the background of the V600E mutation. We further show that the vemurafenib sensitive phosphorylation of the T401 cluster occurs in trans within a Raf dimer. Substitution of the Ser/Thr-residues of this cluster by alanine residues enhances the transforming potential of B-Raf, indicating that these phosphorylation sites suppress its signaling output. Moreover, several B-Raf phosphorylation sites, including T401 and S419, are somatically mutated in tumors, further illustrating the importance of phosphorylation for the regulation of this kinase.
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Affiliation(s)
- Anja E Eisenhardt
- Institute of Molecular Medicine and Cell Research (IMMZ), Faculty of Medicine, Albert-Ludwigs-University (ALU), Freiburg, Germany.,Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany
| | - Adrian Sprenger
- Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Institute for Experimental and Clinical Pharmacology and Toxicology, ALU, Freiburg, Germany.,INSERM U976 and Universitéi Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Michael Röring
- Institute of Molecular Medicine and Cell Research (IMMZ), Faculty of Medicine, Albert-Ludwigs-University (ALU), Freiburg, Germany.,Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), ALU, Freiburg, Germany
| | - Ricarda Herr
- Institute of Molecular Medicine and Cell Research (IMMZ), Faculty of Medicine, Albert-Ludwigs-University (ALU), Freiburg, Germany.,Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany
| | - Florian Weinberg
- Institute of Molecular Medicine and Cell Research (IMMZ), Faculty of Medicine, Albert-Ludwigs-University (ALU), Freiburg, Germany.,Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany
| | - Martin Köhler
- Institute of Molecular Medicine and Cell Research (IMMZ), Faculty of Medicine, Albert-Ludwigs-University (ALU), Freiburg, Germany.,Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), ALU, Freiburg, Germany
| | - Sandra Braun
- Institute of Molecular Medicine and Cell Research (IMMZ), Faculty of Medicine, Albert-Ludwigs-University (ALU), Freiburg, Germany.,Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany
| | - Joachim Orth
- Institute for Experimental and Clinical Pharmacology and Toxicology, ALU, Freiburg, Germany
| | - Britta Diedrich
- Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Department of Dermatology, University Medical Centre, ALU, Freiburg, Germany
| | - Ulrike Lanner
- Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany
| | - Natalja Tscherwinski
- Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany
| | - Simon Schuster
- Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany
| | - Nicolas Dumaz
- INSERM U976 and Universitéi Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Enrico Schmidt
- Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany
| | - Ralf Baumeister
- Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Freiburg Institute for Advanced Studies (FRIAS), ALU, Freiburg, Germany.,Centre for Biological Signalling Studies BIOSS, ALU, Freiburg, Germany
| | - Andreas Schlosser
- Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Jörn Dengjel
- Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Department of Dermatology, University Medical Centre, ALU, Freiburg, Germany.,Freiburg Institute for Advanced Studies (FRIAS), ALU, Freiburg, Germany.,Centre for Biological Signalling Studies BIOSS, ALU, Freiburg, Germany.,Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Tilman Brummer
- Institute of Molecular Medicine and Cell Research (IMMZ), Faculty of Medicine, Albert-Ludwigs-University (ALU), Freiburg, Germany.,Institute of Biology III, Faculty of Biology, ALU, Freiburg, Germany.,Centre for Biological Systems Analysis (ZBSA), Freiburg, Germany.,Centre for Biological Signalling Studies BIOSS, ALU, Freiburg, Germany.,German Cancer Consortium (DKTK), Freiburg, Germany
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11
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Chakraborty S, Kloos B, Harre U, Schett G, Kubatzky KF. Pasteurella multocida Toxin Triggers RANKL-Independent Osteoclastogenesis. Front Immunol 2017; 8:185. [PMID: 28289415 PMCID: PMC5327351 DOI: 10.3389/fimmu.2017.00185] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 02/09/2017] [Indexed: 01/15/2023] Open
Abstract
Bone remodeling is a continuous process to retain the structural integrity and function of the skeleton. A tight coupling is maintained between osteoclast-mediated resorption of old or damaged bones and osteoblast-mediated formation of new bones for bone homeostasis. While osteoblasts differentiate from mesenchymal stem cells, osteoclasts are hematopoietic in origin and derived from myeloid precursor cells. Osteoclast differentiation is driven by two cytokines, cytokine receptor activator of NF-κB ligand (RANKL), and macrophage colony-stimulating factor. Imbalances in the activity of osteoblasts and osteoclasts result in the development of bone disorders. Bacterially caused porcine atrophic rhinitis is characterized by a loss of nasal ventral conche bones and a distortion of the snout. While Bordetella bronchiseptica strains cause mild and reversible symptoms, infection of pigs with toxigenic Pasteurella multocida strains causes a severe and irreversible decay. The responsible virulence factor Pasteurella multocida toxin (PMT) contains a deamidase activity in its catalytical domain that constitutively activates specific heterotrimeric G proteins to induce downstream signaling cascades. While osteoblasts are inhibited by the toxin, osteoclasts are activated, thus skewing bone remodeling toward excessive bone degradation. Still, the mechanism by which PMT interferes with bone homeostasis, and the reason for this unusual target tissue is not yet well understood. Here, we show that PMT has the potential to differentiate bone marrow-derived macrophages into functional osteoclasts. This toxin-mediated differentiation process is independent of RANKL, a cytokine believed to be indispensable for triggering osteoclastogenesis, as addition of osteoprotegerin to PMT-treated macrophages does not show any effect on PMT-induced osteoclast formation. Although RANKL is not a prerequisite, toxin-primed macrophages show enhanced responsiveness to low concentrations of RANKL, suggesting that the PMT-generated microenvironment offers conditions where low concentrations of RANKL lead to an increase in the number of osteoclasts resulting in increased resorption. PMT-mediated release of the osteoclastogenic cytokines such as IL-6 and TNF-α, but not IL-1, supports the differentiation process. Although the production of cytokines and the subsequent activation of signaling cascades are necessary for PMT-mediated differentiation into osteoclasts, they are not sufficient and PMT-induced activation of G protein signaling is essential for efficient osteoclastogenesis.
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Affiliation(s)
- Sushmita Chakraborty
- Zentrum für Infektiologie, Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Heidelberg , Heidelberg , Germany
| | - Bianca Kloos
- Zentrum für Infektiologie, Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Heidelberg , Heidelberg , Germany
| | - Ulrike Harre
- Department of Internal Medicine 3, Institute of Clinical Immunology, University of Erlangen-Nuremberg , Erlangen , Germany
| | - Georg Schett
- Department of Internal Medicine 3, Institute of Clinical Immunology, University of Erlangen-Nuremberg , Erlangen , Germany
| | - Katharina F Kubatzky
- Zentrum für Infektiologie, Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Heidelberg , Heidelberg , Germany
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12
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Liu H, Zhao Z, Xi X, Xue Q, Long T, Xue Y. Occurrence of Pasteurella multocida among pigs with respiratory disease in China between 2011 and 2015. Ir Vet J 2017; 70:2. [PMID: 28078081 PMCID: PMC5223352 DOI: 10.1186/s13620-016-0080-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 12/22/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Prior to the 1990s, P. multocida capsular serogroup A was the most prevalent in China, followed by serogroups B and D. Thirty years later, serogroup D became the most prevalent, followed by serogroups A and B. However, the P. multocida capsular serogroups currently circulating in China remain unclear. Therefore, the aim of the present study was to provide an update on P. multocida serogroups isolated from diagnostic samples collected from clinically diseased pigs in Central and Eastern China from 2011 to 2015. RESULTS Between February 2011 and October 2015, 296 isolates of Pasteurella multocida were collected from 3212 pigs with clinical respiratory disease in 12 provinces of China (isolation rate of 9.2%). Of the 296 collected isolates, 146 (49.3%) were P. multocida capsular type A, 141 (47.6%) were capsular type D, and one was capsular type B. Streptococcus suis (94/193; 48.7%), Haemophilus parasuis (76/193; 39.3%), Escherichia coli (53/193; 27.5%), and Bordetella bronchiseptica (26/193; 13.5%) were frequently isolated together with P. multocida. A total of 14 toxigenic P. multocida strains co-isolated with other pathogens from 32 cases of atrophic rhinitis were classified into serogroup D. The virulence of P. multocida capsular type A isolates was higher than that of capsular type D isolates based on LD50 studies in mice. CONCLUSIONS Over the past 5 years, P. multocida capsular type A was the most frequently isolated from diagnostic submissions in Central and Eastern China, followed by serogroups D and B.
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Affiliation(s)
- Huisheng Liu
- Laboratory of Veterinary Microbiology, College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China
| | - Zhanqin Zhao
- Laboratory of Veterinary Microbiology, College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China
| | - Xiaojian Xi
- Laboratory of Veterinary Microbiology, College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China
| | - Qiao Xue
- Laboratory of Veterinary Microbiology, College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China
| | - Ta Long
- Laboratory of Veterinary Microbiology, College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China
| | - Yun Xue
- Laboratory of Medical Engineering, College of Medical Technology and Engineering, Henan University of Science and Technology, Luoyang, China
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13
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Kloos B, Chakraborty S, Lindner SG, Noack K, Harre U, Schett G, Krämer OH, Kubatzky KF. Pasteurella multocida toxin- induced osteoclastogenesis requires mTOR activation. Cell Commun Signal 2015; 13:40. [PMID: 26369790 PMCID: PMC4570759 DOI: 10.1186/s12964-015-0117-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/04/2015] [Indexed: 11/10/2022] Open
Abstract
Background Pasteurella multocida toxin (PMT) is a potent inducer of osteoclast formation. Pigs suffering from an infection with toxigenic Pasteurella multocida strains develop atrophic rhinitis characterised by a loss of turbinate bones and conchae. However, on the molecular level the process of bone loss remains largely uncharacterised. Results Recently it was found that PMT activates the serine/threonine kinase mammalian target of rapamycin (mTOR) in fibroblasts. Using RAW264.7 macrophages, we investigated the role of the mTOR complex 1 (mTORC1) in PMT-mediated osteoclast formation. PMT induces the differentiation of RAW264.7 macrophages into multinucleated, tartrate resistant acid phosphatase (TRAP) positive osteoclasts that are capable to resorb bone. In the presence of the mTORC1 inhibitor rapamycin, PMT was significantly less able to induce the formation of TRAP-positive osteoclasts. Accordingly, the resulting resorption of bone was strongly reduced. A major target of mTOR is the 70 kDa ribosomal protein S6 kinase 1 (p70 S6K1). Activated p70 S6K1 decreases the expression of programmed cell death protein 4 (PDCD4), a negative transcriptional regulator of osteoclastogenesis, at the protein and gene level. Ultimately this results in the activation of c-Jun, a component of the activator protein 1 (AP-1) complex, which is a major transcription factor for the induction of osteoclast-specific genes. We now demonstrate that c-Jun and its downstream target, the osteoclast-specific bone degrading protease cathepsin K, are upregulated upon PMT treatment in an mTOR-dependent manner. Conclusions Activation of mTOR signalling plays a central role in the formation of osteoclasts through the bacterial toxin PMT. On the molecular level, PMT-induced activation of mTOR leads to down regulation of PDCD4, a known repressor of AP-1 complex, culminating in the activation of c-Jun, an essential transcription factor for triggering osteoclastogenesis. Electronic supplementary material The online version of this article (doi:10.1186/s12964-015-0117-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bianca Kloos
- Zentrum für Infektiologie, Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Sushmita Chakraborty
- Zentrum für Infektiologie, Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Sonja G Lindner
- Zentrum für Infektiologie, Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Katrin Noack
- Center for Molecular Biomedicine (CMB), Department of Biochemistry, University of Jena, Hans Knöll Str. 2, 07745, Jena, Germany.,Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Erlanger Allee 101, 07747, Jena, Germany
| | - Ulrike Harre
- Department of Internal Medicine 3 and Institute of Clinical Immunology, University of Erlangen-Nuremberg, 91054, Erlangen, Germany
| | - Georg Schett
- Department of Internal Medicine 3 and Institute of Clinical Immunology, University of Erlangen-Nuremberg, 91054, Erlangen, Germany
| | - Oliver H Krämer
- Institute of Toxicology, Medical Center of the University Mainz, Obere Zahlbacher Str. 67, 55131, Mainz, Germany
| | - Katharina F Kubatzky
- Zentrum für Infektiologie, Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.
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