1
|
Kunishima H, Ichiki K, Ohge H, Sakamoto F, Sato Y, Suzuki H, Nakamura A, Fujimura S, Matsumoto K, Mikamo H, Mizutani T, Morinaga Y, Mori M, Yamagishi Y, Yoshizawa S. Japanese Society for infection prevention and control guide to Clostridioides difficile infection prevention and control. J Infect Chemother 2024; 30:673-715. [PMID: 38714273 DOI: 10.1016/j.jiac.2024.03.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 05/09/2024]
Affiliation(s)
- Hiroyuki Kunishima
- Department of Infectious Diseases. St. Marianna University School of Medicine, Japan.
| | - Kaoru Ichiki
- Department of Infection Control and Prevention, Hyogo Medical University Hospital, Japan
| | - Hiroki Ohge
- Department of Infectious Diseases, Hiroshima University Hospital, Japan
| | - Fumie Sakamoto
- Quality Improvement and Safety Center, Itabashi Chuo Medical Center, Japan
| | - Yuka Sato
- Department of Infection Control and Nursing, Graduate School of Nursing, Aichi Medical University, Japan
| | - Hiromichi Suzuki
- Department of Infectious Diseases, University of Tsukuba School of Medicine and Health Sciences, Japan
| | - Atsushi Nakamura
- Department of Infection Prevention and Control, Graduate School of Medical Sciences, Nagoya City University, Japan
| | - Shigeru Fujimura
- Division of Clinical Infectious Diseases and Chemotherapy, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, Japan
| | - Kazuaki Matsumoto
- Division of Pharmacodynamics, Faculty of Pharmacy, Keio University, Japan
| | - Hiroshige Mikamo
- Department of Clinical Infectious Diseases, Aichi Medical University, Japan
| | | | - Yoshitomo Morinaga
- Department of Microbiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Minako Mori
- Department of Infection Control, Hiroshima University Hospital, Japan
| | - Yuka Yamagishi
- Department of Clinical Infectious Diseases, Kochi Medical School, Kochi University, Japan
| | - Sadako Yoshizawa
- Department of Laboratory Medicine/Department of Microbiology and Infectious Diseases, Faculty of Medicine, Toho University, Japan
| |
Collapse
|
2
|
Tsuge H, Habuka N, Yoshida T. General ADP-Ribosylation Mechanism Based on the Structure of ADP-Ribosyltransferase-Substrate Complexes. Toxins (Basel) 2024; 16:313. [PMID: 39057953 PMCID: PMC11281641 DOI: 10.3390/toxins16070313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/06/2024] [Accepted: 07/09/2024] [Indexed: 07/28/2024] Open
Abstract
ADP-ribosylation is a ubiquitous modification of proteins and other targets, such as nucleic acids, that regulates various cellular functions in all kingdoms of life. Furthermore, these ADP-ribosyltransferases (ARTs) modify a variety of substrates and atoms. It has been almost 60 years since ADP-ribosylation was discovered. Various ART structures have been revealed with cofactors (NAD+ or NAD+ analog). However, we still do not know the molecular mechanisms of ART. It needs to be better understood how ART specifies the target amino acids or bases. For this purpose, more information is needed about the tripartite complex structures of ART, the cofactors, and the substrates. The tripartite complex is essential to understand the mechanism of ADP-ribosyltransferase. This review updates the general ADP-ribosylation mechanism based on ART tripartite complex structures.
Collapse
Affiliation(s)
- Hideaki Tsuge
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 6038555, Japan
| | - Noriyuki Habuka
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 6038555, Japan
| | - Toru Yoshida
- Faculty of Sciences, Japan Women’s University, Tokyo 1120015, Japan
| |
Collapse
|
3
|
Xu N, Jiang J, Jiang F, Dong G, Meng L, Wang M, Chen J, Li C, Shi Y, He S, Li R. CircCDC42-encoded CDC42-165aa regulates macrophage pyroptosis in Klebsiella pneumoniae infection through Pyrin inflammasome activation. Nat Commun 2024; 15:5730. [PMID: 38977695 PMCID: PMC11231140 DOI: 10.1038/s41467-024-50154-x] [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: 08/29/2023] [Accepted: 07/02/2024] [Indexed: 07/10/2024] Open
Abstract
The circular RNA (circRNA) family is a group of endogenous non-coding RNAs (ncRNAs) that have critical functions in multiple physiological and pathological processes, including inflammation, cancer, and cardiovascular diseases. However, their roles in regulating innate immune responses remain unclear. Here, we define Cell division cycle 42 (CDC42)-165aa, a protein encoded by circRNA circCDC42, which is overexpressed in Klebsiella pneumoniae (KP)-infected alveolar macrophages. High levels of CDC42-165aa induces the hyperactivation of Pyrin inflammasomes and aggravates alveolar macrophage pyroptosis, while the inhibition of CDC42-165aa reduces lung injury in mice after KP infection by inhibiting Pyrin inflammasome-mediated pyroptosis. Overall, these results demonstrate that CDC42-165aa stimulates Pyrin inflammasome by inhibiting CDC42 GTPase activation and provides a potential clinical target for pathogenic bacterial infection in clinical practice.
Collapse
Affiliation(s)
- Nana Xu
- Jiangsu Province Engineering Research Center of Cardiovascular Drugs Targeting Endothelial Cells, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
- Laboratory of Morphology, Xuzhou Medical University, Xuzhou, China
| | - Jiebang Jiang
- Jiangsu Province Engineering Research Center of Cardiovascular Drugs Targeting Endothelial Cells, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Fei Jiang
- Jiangsu Province Engineering Research Center of Cardiovascular Drugs Targeting Endothelial Cells, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
- Department of Laboratory Medicine, the Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Guokai Dong
- Jiangsu Province Engineering Research Center of Cardiovascular Drugs Targeting Endothelial Cells, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
- Laboratory of Morphology, Xuzhou Medical University, Xuzhou, China
| | - Li Meng
- Jiangsu Province Engineering Research Center of Cardiovascular Drugs Targeting Endothelial Cells, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
- Laboratory of Morphology, Xuzhou Medical University, Xuzhou, China
| | - Meng Wang
- Jiangsu Province Engineering Research Center of Cardiovascular Drugs Targeting Endothelial Cells, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
- Laboratory of Morphology, Xuzhou Medical University, Xuzhou, China
| | - Jing Chen
- Jiangsu Province Engineering Research Center of Cardiovascular Drugs Targeting Endothelial Cells, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Cong Li
- Xuzhou Key Laboratory of Emergency Medicine, the Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Yongping Shi
- Jiangsu Province Engineering Research Center of Cardiovascular Drugs Targeting Endothelial Cells, School of Life Sciences, Jiangsu Normal University, Xuzhou, China.
| | - Sisi He
- Department of Oncology, The Second Affiliated Hospital of Zunyi Medical University, Zunyi, China.
| | - Rongpeng Li
- Jiangsu Province Engineering Research Center of Cardiovascular Drugs Targeting Endothelial Cells, School of Life Sciences, Jiangsu Normal University, Xuzhou, China.
| |
Collapse
|
4
|
Zheng Y, Yang Q, Luo J, Zhang Y, Li X, He L, Ma C, Tao L. Identification of a hemorrhagic determinant in Clostridioides difficile TcdA and Paeniclostridium sordellii TcsH. Microbiol Spectr 2024; 12:e0035424. [PMID: 38709085 PMCID: PMC11237598 DOI: 10.1128/spectrum.00354-24] [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: 02/07/2024] [Accepted: 04/18/2024] [Indexed: 05/07/2024] Open
Abstract
Paeniclostridium sordellii hemorrhagic toxin (TcsH) and Clostridioides difficile toxin A (TcdA) are two major members of the large clostridial toxin (LCT) family. These two toxins share ~87% similarity and are known to cause severe hemorrhagic pathology in animals. Yet, the pathogenesis of their hemorrhagic toxicity has been mysterious for decades. Here, we examined the liver injury after systemic exposure to different LCTs and found that only TcsH and TcdA induce overt hepatic hemorrhage. By investigating the chimeric and truncated toxins, we demonstrated that the enzymatic domain of TcsH alone is not sufficient to determine its potent hepatic hemorrhagic toxicity in mice. Likewise, the combined repetitive oligopeptide (CROP) domain of TcsH/TcdA alone also failed to explain their strong hemorrhagic activity in mice. Lastly, we showed that disrupting the first two short repeats of CROPs in TcsH and TcdA impaired hemorrhagic toxicity without causing overt changes in cytotoxicity and lethality. These findings lead to a deeper understanding of toxin-induced hemorrhage and the pathogenesis of LCTs and could be insightful in developing therapeutic avenues against clostridial infections. IMPORTANCE Paeniclostridium sordellii and Clostridioides difficile infections often cause hemorrhage in the affected tissues and organs, which is mainly attributed to their hemorrhagic toxins, TcsH and TcdA. In this study, we demonstrate that TcsH and TcdA, but not other related toxins. including Clostridioides difficile toxin B and TcsL, induce severe hepatic hemorrhage in mice. We further determine that a small region in TcsH and TcdA is critical for the hemorrhagic toxicity but not cytotoxicity or lethality of these toxins. Based on these results, we propose that the hemorrhagic toxicity of TcsH and TcdA is due to an uncharacterized mechanism, such as the presence of an unknown receptor, and future studies to identify the interactive host factors are warranted.
Collapse
Affiliation(s)
- Yangling Zheng
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Qi Yang
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Jianhua Luo
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Yuanyuan Zhang
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Xingxing Li
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Liuqing He
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Chao Ma
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Liang Tao
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
- Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Research Center for Industries of the Future and Key Laboratory of Multi-omics in Infection and Immunity of Zhejiang Province, School of Medicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| |
Collapse
|
5
|
Barth H, Worek F, Steinritz D, Papatheodorou P, Huber-Lang M. Trauma-toxicology: concepts, causes, complications. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:2935-2948. [PMID: 37999755 PMCID: PMC11074020 DOI: 10.1007/s00210-023-02845-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 11/09/2023] [Indexed: 11/25/2023]
Abstract
Trauma and toxic substances are connected in several aspects. On the one hand, toxic substances can be the reason for traumatic injuries in the context of accidental or violent and criminal circumstances. Examples for the first scenario is the release of toxic gases, chemicals, and particles during house fires, and for the second scenario, the use of chemical or biological weapons in the context of terroristic activities. Toxic substances can cause or enhance severe, life-threatening trauma, as described in this review for various chemical warfare, by inducing a tissue trauma accompanied by break down of important barriers in the body, such as the blood-air or the blood-gut barriers. This in turn initiates a "vicious circle" as the contribution of inflammatory responses to the traumatic damage enhances the macro- and micro-barrier breakdown and often results in fatal outcome. The development of sophisticated methods for detection and identification of toxic substances as well as the special treatment of the intoxicated trauma patient is summarized in this review. Moreover, some highly toxic substances, such as the protein toxins from the pathogenic bacterium Clostridioides (C.) difficile, cause severe post-traumatic complications which significantly worsens the outcome of hospitalized patients, in particular in multiply injured trauma patients. Therefore, novel pharmacological options for the treatment of such patients are necessarily needed and one promising strategy might be the neutralization of the toxins that cause the disease. This review summarizes recent findings on the molecular and cellular mechanisms of toxic chemicals and bacterial toxins that contribute to barrier breakdown in the human body as wells pharmacological options for treatment, in particular in the context of intoxicated trauma patients. "trauma-toxicology" comprises concepts regrading basic research, development of novel pharmacological/therapeutic options and clinical aspects in the complex interplay and "vicious circle" of severe tissue trauma, barrier breakdown, pathogen and toxin exposure, tissue damage, and subsequent clinical complications.
Collapse
Affiliation(s)
- Holger Barth
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Center, Ulm, Germany.
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Dirk Steinritz
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Panagiotis Papatheodorou
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, University of Ulm Medical Center, Ulm, Germany
| | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, University of Ulm Medical Center, Ulm, Germany.
| |
Collapse
|
6
|
Popoff MR. Overview of Bacterial Protein Toxins from Pathogenic Bacteria: Mode of Action and Insights into Evolution. Toxins (Basel) 2024; 16:182. [PMID: 38668607 PMCID: PMC11054074 DOI: 10.3390/toxins16040182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 03/29/2024] [Accepted: 03/30/2024] [Indexed: 04/29/2024] Open
Abstract
Bacterial protein toxins are secreted by certain bacteria and are responsible for mild to severe diseases in humans and animals. They are among the most potent molecules known, which are active at very low concentrations. Bacterial protein toxins exhibit a wide diversity based on size, structure, and mode of action. Upon recognition of a cell surface receptor (protein, glycoprotein, and glycolipid), they are active either at the cell surface (signal transduction, membrane damage by pore formation, or hydrolysis of membrane compound(s)) or intracellularly. Various bacterial protein toxins have the ability to enter cells, most often using an endocytosis mechanism, and to deliver the effector domain into the cytosol, where it interacts with an intracellular target(s). According to the nature of the intracellular target(s) and type of modification, various cellular effects are induced (cell death, homeostasis modification, cytoskeleton alteration, blockade of exocytosis, etc.). The various modes of action of bacterial protein toxins are illustrated with representative examples. Insights in toxin evolution are discussed.
Collapse
Affiliation(s)
- Michel R Popoff
- Unité des Toxines Bactériennes, Institut Pasteur, Université Paris Cité, CNRS UMR 2001 INSERM U1306, F-75015 Paris, France
| |
Collapse
|
7
|
Verma A, De Pascalis R, Mocca CP, Li X, Burns DL. Visualization of immune pathways that enhance the neutralizing antibody response to vaccines after primary immunization. mBio 2024; 15:e0003724. [PMID: 38334423 PMCID: PMC10936199 DOI: 10.1128/mbio.00037-24] [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: 01/10/2024] [Accepted: 01/18/2024] [Indexed: 02/10/2024] Open
Abstract
We examined the relationship between the association of a vaccine antigen with immune cells in secondary lymphoid organs shortly after immunization and the resulting neutralizing antibody response induced by that antigen using three antigenic forms of anthrax protective antigen (PA) that induce qualitatively different antibody responses. The three PA forms used were wild-type PA, which binds to anthrax toxin receptors and elicits a robust antibody response that includes both neutralizing and non-neutralizing antibodies; a receptor-binding-deficient (RBD) mutant form of PA, which does not bind cellular receptors and elicits only barely detectable antibody responses; and an engineered chimeric form of PA, which binds cholera toxin receptors and elicits a robust total antibody response but a poor neutralizing antibody response. We found that both wild-type PA and the PA chimera associated with immune cells in secondary lymphoid organs after immunization, but the RBD mutant PA exhibited minimal association, revealing a relationship between antigen binding to toxin receptors on immune cells after immunization and subsequent antibody responses. A portion of wild-type PA that bound to immune cells was cell surface-associated and maintained its native conformation. Much lower amounts of conformationally intact PA chimera were associated with immune cells after immunization, correlating with the lower neutralizing antibody response elicited by the PA chimera. Thus, binding of an antigen to receptors on immune cells in secondary lymphoid organs after immunization and maintenance of conformational integrity of the cell-associated antigen help dictate the magnitude of the resulting neutralizing antibody response, but not necessarily the total antibody response.IMPORTANCEMany vaccines protect by the induction of antibodies that neutralize the action of the pathogen. Here, we followed the fate of three antigenic forms of a vaccine antigen in secondary lymphoid organs after immunization to investigate events leading to a robust neutralizing antibody response. We found that the magnitude of the neutralizing antibody response, but not the total antibody response, correlates with the levels of conformationally intact antigen associated with immune cells in secondary lymphoid organs after primary immunization. We believe that these results provide important insights into the genesis of neutralizing antibody responses induced by vaccine antigens and may have implications for vaccine design.
Collapse
Affiliation(s)
- Anita Verma
- Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Roberto De Pascalis
- Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Christopher P. Mocca
- Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Xiaohong Li
- Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Drusilla L. Burns
- Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| |
Collapse
|
8
|
Paparella AS, Brew I, Hong HA, Ferriera W, Cutting S, Lamiable-Oulaidi F, Popadynec M, Tyler PC, Schramm VL. Isofagomine Inhibits Multiple TcdB Variants and Protects Mice from Clostridioides difficile-Induced Mortality. ACS Infect Dis 2024; 10:928-937. [PMID: 38334357 DOI: 10.1021/acsinfecdis.3c00507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Clostridioides difficile causes life-threatening diarrhea and is one of the leading causes of nosocomial infections. During infection, C. difficile releases two gut-damaging toxins, TcdA and TcdB, which are the primary determinants of disease pathogenesis and are important therapeutic targets. Once in the cytosol of mammalian cells, TcdA and TcdB use UDP-glucose to glucosylate host Rho GTPases, which leads to cytoskeletal changes that result in a loss of intestinal integrity. Isofagomine inhibits TcdA and TcdB as a mimic of the glucocation transition state of the glucosyltransferase reaction. However, sequence variants of TcdA and TcdB across the clades of infective C. difficile continue to be identified, and therefore, evaluation of isofagomine inhibition against multiple toxin variants is required. Here, we show that isofagomine inhibits the glucosyltransferase domain of multiple TcdB variants and protects TcdB-induced cell rounding of the most common full-length toxin variants. Furthermore, we demonstrate that isofagomine protects against C. difficile-induced mortality in two murine models of C. difficile infection. Isofagomine treatment of mouse C. difficile infection also permitted the recovery of the gastrointestinal microbiota, an important barrier to preventing recurring C. difficile infection. The broad specificity of isofagomine supports its potential as a prophylactic to protect against C. difficile-induced morbidity and mortality.
Collapse
Affiliation(s)
- Ashleigh S Paparella
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Isabella Brew
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Huynh A Hong
- SporeGen Ltd., The London BioScience Innovation Centre, London NW1 0NH, U.K
| | - William Ferriera
- SporeGen Ltd., The London BioScience Innovation Centre, London NW1 0NH, U.K
| | - Simon Cutting
- SporeGen Ltd., The London BioScience Innovation Centre, London NW1 0NH, U.K
| | - Farah Lamiable-Oulaidi
- The Ferrier Research Institute, Victoria University of Wellington, Lower Hutt 5010, New Zealand
| | - Michael Popadynec
- The Ferrier Research Institute, Victoria University of Wellington, Lower Hutt 5010, New Zealand
| | - Peter C Tyler
- The Ferrier Research Institute, Victoria University of Wellington, Lower Hutt 5010, New Zealand
| | - Vern L Schramm
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| |
Collapse
|
9
|
Papatheodorou P, Minton NP, Aktories K, Barth H. An Updated View on the Cellular Uptake and Mode-of-Action of Clostridioides difficile Toxins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1435:219-247. [PMID: 38175478 DOI: 10.1007/978-3-031-42108-2_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Research on the human gut pathogen Clostridioides (C.) difficile and its toxins continues to attract much attention as a consequence of the threat to human health posed by hypervirulent strains. Toxin A (TcdA) and Toxin B (TcdB) are the two major virulence determinants of C. difficile. Both are single-chain proteins with a similar multidomain architecture. Certain hypervirulent C. difficile strains also produce a third toxin, namely binary toxin CDT (C. difficile transferase). C. difficile toxins are the causative agents of C. difficile-associated diseases (CDADs), such as antibiotics-associated diarrhea and pseudomembranous colitis. For that reason, considerable efforts have been expended to unravel their molecular mode-of-action and the cellular mechanisms responsible for their uptake. Many of these studies have been conducted in European laboratories. Here, we provide an update on our previous review (Papatheodorou et al. Adv Exp Med Biol, 2018) on important advances in C. difficile toxins research.
Collapse
Affiliation(s)
- Panagiotis Papatheodorou
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, Ulm, Germany.
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre, University of Nottingham, Nottingham, UK
| | - Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
| | - Holger Barth
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, Ulm, Germany
| |
Collapse
|
10
|
Wouters F, Bogie J, Wullaert A, van der Hilst J. Recent Insights in Pyrin Inflammasome Activation: Identifying Potential Novel Therapeutic Approaches in Pyrin-Associated Autoinflammatory Syndromes. J Clin Immunol 2023; 44:8. [PMID: 38129719 DOI: 10.1007/s10875-023-01621-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023]
Abstract
Pyrin is a cytosolic protein encoded by the MEFV gene, predominantly expressed in innate immune cells. Upon activation, it forms an inflammasome, a multimolecular complex that enables the activation and secretion of IL-1β and IL-18. In addition, the Pyrin inflammasome activates Gasdermin D leading to pyroptosis, a highly pro-inflammatory cell death. Four autoinflammatory syndromes are associated with Pyrin inflammasome dysregulation: familial Mediterranean fever, hyper IgD syndrome/mevalonate kinase deficiency, pyrin-associated autoinflammation with neutrophilic dermatosis, and pyogenic arthritis, pyoderma gangrenosum, and acne syndrome. In this review, we discuss recent advances in understanding the molecular mechanisms regulating the two-step model of Pyrin inflammasome activation. Based on these insights, we discuss current pharmacological options and identify a series of existing molecules with therapeutic potential for the treatment of pyrin-associated autoinflammatory syndromes.
Collapse
Affiliation(s)
- Flore Wouters
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590, Diepenbeek, Belgium.
| | - Jeroen Bogie
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590, Diepenbeek, Belgium
- University MS Center Hasselt, 3900, Pelt, Belgium
| | - Andy Wullaert
- Department of Internal Medicine and Paediatrics, Ghent University, 9052, Ghent, Belgium
- VIB-UGent Center for Inflammation Research VIB, 9052, Ghent, Belgium
- Laboratory of Protein Science, Proteomics and Epigenetic Signalling (PPES), Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Jeroen van der Hilst
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, 3590, Diepenbeek, Belgium.
- Department of Infectious Diseases and Immune Pathology, Jessa General Hospital and Limburg Clinical Research Center, Hasselt, Belgium.
| |
Collapse
|
11
|
Malik HS, Magnotti F, Loeven NA, Delgado JM, Kettenbach AN, Henry T, Bliska JB. Phosphoprotein phosphatase activity positively regulates oligomeric pyrin to trigger inflammasome assembly in phagocytes. mBio 2023; 14:e0206623. [PMID: 37787552 PMCID: PMC10653879 DOI: 10.1128/mbio.02066-23] [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: 08/08/2023] [Accepted: 08/14/2023] [Indexed: 10/04/2023] Open
Abstract
IMPORTANCE Pyrin, a unique cytosolic receptor, initiates inflammatory responses against RhoA-inactivating bacterial toxins and effectors like Yersinia's YopE and YopT. Understanding pyrin regulation is crucial due to its association with dysregulated inflammatory responses, including Familial Mediterranean Fever (FMF), linked to pyrin gene mutations. FMF mutations historically acted as a defense mechanism against plague. Negative regulation of pyrin through PKN phosphorylation is well established, with Yersinia using the YopM effector to promote pyrin phosphorylation and counteract its activity. This study highlights the importance of phosphoprotein phosphatase activity in positively regulating pyrin inflammasome assembly in phagocytic cells of humans and mice. Oligomeric murine pyrin has S205 phosphorylated before inflammasome assembly, and this study implicates the dephosphorylation of murine pyrin S205 by two catalytic subunits of PP2A in macrophages. These findings offer insights for investigating the regulation of oligomeric pyrin and the balance of kinase and phosphatase activity in pyrin-associated infectious and autoinflammatory diseases.
Collapse
Affiliation(s)
- Haleema S. Malik
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Flora Magnotti
- CIRI, Centre International de Recherche en Infectiologie, Inserm U111, Université Claude Bernard Lyon, CNRS, UMR5308, ENS de Lyon, Univ Lyon, Lyon, France
| | - Nicole A. Loeven
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jose M. Delgado
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Arminja N. Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Dartmouth Cancer Center, Lebanon, New Hampshire, USA
| | - Thomas Henry
- CIRI, Centre International de Recherche en Infectiologie, Inserm U111, Université Claude Bernard Lyon, CNRS, UMR5308, ENS de Lyon, Univ Lyon, Lyon, France
| | - James B. Bliska
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| |
Collapse
|
12
|
Paparella AS, Brew I, Hong HA, Ferriera W, Cutting S, Lamiable-Oulaidi F, Popadynec M, Tyler PC, Schramm VL. Isofagomine inhibits multiple TcdB variants and protects mice from Clostridioides difficile induced mortality. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.19.558375. [PMID: 37781587 PMCID: PMC10541099 DOI: 10.1101/2023.09.19.558375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Clostridioides difficile causes life-threatening diarrhea and is the leading cause of healthcare associated bacterial infections in the United States. During infection, C. difficile releases the gut-damaging toxins, TcdA and TcdB, the primary determinants of disease pathogenesis and are therefore therapeutic targets. TcdA and TcdB contain a glycosyltransferase domain that uses UDP-glucose to glycosylate host Rho GTPases, causing cytoskeletal changes that result in a loss of intestinal integrity. Isofagomine inhibits TcdA and TcdB as a mimic of the oxocarbenium ion transition state of the glycosyltransferase reaction. However, sequence variants of TcdA and TcdB across the clades of infective C. difficile continue to be identified and therefore, evaluation of isofagomine inhibition against multiple toxin variants are required. Here we show that Isofagomine inhibits the glycosyltransferase activity of multiple TcdB variants and also protects TcdB toxin-induced cell rounding of the most common full-length toxin variants. Further, isofagomine protects against C. difficile induced mortality in two murine models of C. difficile infection. Isofagomine treatment of mouse C. difficile infection permitted recovery of the gastrointestinal microbiota, an important barrier to prevent recurring C. difficile infection. The broad specificity of isofagomine supports its potential as a prophylactic to protect against C. difficile induced morbidity and mortality.
Collapse
Affiliation(s)
- Ashleigh S. Paparella
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Isabella Brew
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Huynh A. Hong
- SporeGen Ltd, The London BioScience Innovation Centre, London, United Kingdom
| | - William Ferriera
- SporeGen Ltd, The London BioScience Innovation Centre, London, United Kingdom
| | - Simon Cutting
- SporeGen Ltd, The London BioScience Innovation Centre, London, United Kingdom
| | - Farah Lamiable-Oulaidi
- The Ferrier Research Institute, Victoria University of Wellington, Lower Hutt, New Zealand
| | - Michael Popadynec
- The Ferrier Research Institute, Victoria University of Wellington, Lower Hutt, New Zealand
| | - Peter C. Tyler
- The Ferrier Research Institute, Victoria University of Wellington, Lower Hutt, New Zealand
| | - Vern L. Schramm
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA
| |
Collapse
|
13
|
Wevers C, Höhler M, Alcázar-Román AR, Hegemann JH, Fleig U. A Functional Yeast-Based Screen Identifies the Host Microtubule Cytoskeleton as a Target of Numerous Chlamydia pneumoniae Proteins. Int J Mol Sci 2023; 24:ijms24087618. [PMID: 37108781 PMCID: PMC10142024 DOI: 10.3390/ijms24087618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/13/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
Bacterial pathogens have evolved intricate ways to manipulate the host to support infection. Here, we systematically assessed the importance of the microtubule cytoskeleton for infection by Chlamydiae, which are obligate intracellular bacteria that are of great importance for human health. The elimination of microtubules in human HEp-2 cells prior to C. pneumoniae infection profoundly attenuated the infection efficiency, demonstrating the need for microtubules for the early infection processes. To identify microtubule-modulating C. pneumoniae proteins, a screen in the model yeast Schizosaccharomyces pombe was performed. Unexpectedly, among 116 selected chlamydial proteins, more than 10%, namely, 13 proteins, massively altered the yeast interphase microtubule cytoskeleton. With two exceptions, these proteins were predicted to be inclusion membrane proteins. As proof of principle, we selected the conserved CPn0443 protein, which caused massive microtubule instability in yeast, for further analysis. CPn0443 bound and bundled microtubules in vitro and co-localized partially with microtubules in vivo in yeast and human cells. Furthermore, CPn0443-transfected U2OS cells had a significantly reduced infection rate by C. pneumoniae EBs. Thus, our yeast screen identified numerous proteins encoded using the highly reduced C. pneumoniae genome that modulated microtubule dynamics. Hijacking of the host microtubule cytoskeleton must be a vital part of chlamydial infection.
Collapse
Affiliation(s)
- Carolin Wevers
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Mona Höhler
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Abel R Alcázar-Román
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Johannes H Hegemann
- Institute of Functional Microbial Genomics, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Ursula Fleig
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| |
Collapse
|
14
|
Gulen B, Casey A, Orth K. AMPylation of small GTPases by Fic enzymes. FEBS Lett 2023; 597:883-891. [PMID: 36239538 PMCID: PMC10050140 DOI: 10.1002/1873-3468.14516] [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: 07/06/2022] [Revised: 09/17/2022] [Accepted: 10/06/2022] [Indexed: 12/14/2022]
Abstract
Small GTPases orchestrate numerous cellular pathways, acting as molecular switches and regulatory hubs to transmit molecular signals and because of this, they are often the target of pathogens. During infection, pathogens manipulate host cellular networks using post-translational modifications (PTMs). AMPylation, the modification of proteins with AMP, has been identified as a common PTM utilized by pathogens to hijack GTPase signalling during infection. AMPylation is primarily carried out by enzymes with a filamentation induced by cyclic-AMP (Fic) domain. Modification of small GTPases by AMP renders GTPases impervious to upstream regulatory inputs, resulting in unregulated downstream effector outputs for host cellular processes. Here, we overview Fic-mediated AMPylation of small GTPases by pathogens and other related PTMs catalysed by Fic enzymes on GTPases.
Collapse
Affiliation(s)
- Burak Gulen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Amanda Casey
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Kim Orth
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX and Howard Hughes Medical Institute, Dallas, TX, USA
| |
Collapse
|
15
|
Xiao H, Wang G, Zhao M, Shuai W, Ouyang L, Sun Q. Ras superfamily GTPase activating proteins in cancer: Potential therapeutic targets? Eur J Med Chem 2023; 248:115104. [PMID: 36641861 DOI: 10.1016/j.ejmech.2023.115104] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 01/11/2023]
Abstract
To search more therapeutic strategies for Ras-mutant tumors, regulators of the Ras superfamily involved in the GTP/GDP (guanosine triphosphate/guanosine diphosphate) cycle have been well concerned for their anti-tumor potentials. GTPase activating proteins (GAPs) provide the catalytic group necessary for the hydrolysis of GTPs, which accelerate the switch by cycling between GTP-bound active and GDP-bound inactive forms. Inactivated GAPs lose their function in activating GTPase, leading to the continuous activation of downstream signaling pathways, uncontrolled cell proliferation, and eventually carcinogenesis. A growing number of evidence has shown the close link between GAPs and human tumors, and as a result, GAPs are believed as potential anti-tumor targets. The present review mainly summarizes the critically important role of GAPs in human tumors by introducing the classification, function and regulatory mechanism. Moreover, we comprehensively describe the relationship between dysregulated GAPs and the certain type of tumor. Finally, the current status, research progress, and clinical value of GAPs as therapeutic targets are also discussed, as well as the challenges and future direction in the cancer therapy.
Collapse
Affiliation(s)
- Huan Xiao
- State Key Laboratory of Biotherapy and Cancer Center, Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, National Clinical Research Center for Geriatrics, West China Hospital, Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Guan Wang
- State Key Laboratory of Biotherapy and Cancer Center, Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, National Clinical Research Center for Geriatrics, West China Hospital, Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Min Zhao
- State Key Laboratory of Biotherapy and Cancer Center, Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, National Clinical Research Center for Geriatrics, West China Hospital, Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Wen Shuai
- State Key Laboratory of Biotherapy and Cancer Center, Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, National Clinical Research Center for Geriatrics, West China Hospital, Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Liang Ouyang
- State Key Laboratory of Biotherapy and Cancer Center, Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, National Clinical Research Center for Geriatrics, West China Hospital, Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Qiu Sun
- State Key Laboratory of Biotherapy and Cancer Center, Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, National Clinical Research Center for Geriatrics, West China Hospital, Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, 610041, China.
| |
Collapse
|
16
|
Oda K, Wlodawer A. Overview of the Properties of Glutamic Peptidases That Are Present in Plant and Bacterial Pathogens and Play a Role in Celiac Disease and Cancer. Biochemistry 2023; 62:672-694. [PMID: 36705990 DOI: 10.1021/acs.biochem.2c00622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Seven peptidase (proteinase) families─aspartic, cysteine, metallo, serine, glutamic, threonine, and asparagine─are in the peptidase database MEROPS, version 12.4 (https://www.ebi.ac.uk/merops/). The glutamic peptidase family is assigned two clans, GA and GB, and comprises six subfamilies. This perspective summarizes the unique features of their representatives. (1) G1, scytalidoglutamic peptidase, has a β-sandwich structure containing catalytic residues glutamic acid (E) and glutamine (Q), thus the name eqolisin. Most family members are pepstatin-insensitive and act as plant pathogens. (2) G2, preneck appendage protein, originates in phages, is a transmembrane protein, and its catalytic residues consist of glutamic and aspartic acids. (3) G3, strawberry mottle virus glutamic peptidase, originates in viruses and has a β-sandwich structure with catalytic residues E and Q. Neprosin has propyl endopeptidase activity, is associated with celiac disease, has a β-sandwich structure, and contains catalytic residues E-E and Q-tryptophan. (4) G4, Tiki peptidase, of the erythromycin esterase family, is a transmembrane protein, and its catalytic residues are E-histidine pairs. (5) G5, RCE1 peptidase, is associated with cancer, is a transmembrane protein, and its catalytic residues are E-histidine and asparagine-histidine. Microcystinase, a bacterial toxin, is a transmembrane protein with catalytic residues E-histidine and asparagine-histidine. (6) G6, Ras/Rap1-specific peptidase, is a bacterial pathogen, a transmembrane protein, and its catalytic residues are E-histidine pairs. This family's common features are that their catalytic residues consist of a glutamic acid and another (variable) amino acid and that they exhibit a diversity of biological functions─plant and bacterial pathogens and involvement in celiac disease and cancer─that suggests they are viable drug targets.
Collapse
Affiliation(s)
- Kohei Oda
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-Ku, Kyoto 606-8585, Japan
| | - Alexander Wlodawer
- Center for Structural Biology, National Cancer Institute, Frederick, Maryland 21702, United States
| |
Collapse
|
17
|
Aktories K. From signal transduction to protein toxins-a narrative review about milestones on the research route of C. difficile toxins. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:173-190. [PMID: 36203094 PMCID: PMC9831965 DOI: 10.1007/s00210-022-02300-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/22/2022] [Indexed: 01/29/2023]
Abstract
Selected findings about Clostridioides difficile (formerly Clostridium difficile) toxins are presented in a narrative review. Starting with a personal view on research about G proteins, adenylyl cyclase, and ADP-ribosylating toxins in the laboratory of Günter Schultz in Heidelberg, milestones of C. difficile toxin research are presented with the focus on toxin B (TcdB), covering toxin structure, receptor binding, toxin up-take and refolding, the intracellular actions of TcdB, and the treatment of C. difficile infection.
Collapse
Affiliation(s)
- Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Albertstr. 25, 79104, Freiburg, Germany.
| |
Collapse
|
18
|
Chen P, Jin R. Receptor binding mechanisms of Clostridioides difficile toxin B and implications for therapeutics development. FEBS J 2023; 290:962-969. [PMID: 34862749 PMCID: PMC9344982 DOI: 10.1111/febs.16310] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/19/2021] [Accepted: 12/02/2021] [Indexed: 12/29/2022]
Abstract
Clostridioides difficile is classified as an urgent antibiotic resistance threat by the Centers for Disease Control and Prevention (CDC). C. difficile infection (CDI) is mainly caused by the C. difficile exotoxin TcdB, which invades host cells via receptor-mediated endocytosis. However, many natural variants of TcdB have been identified including some from the hypervirulent strains, which pose significant challenges for developing effective CDI therapies. Here, we review the recent research progress on the molecular mechanisms by which TcdB recognizes Frizzed proteins (FZDs) and chondroitin sulfate proteoglycan 4 (CSPG4) as two major host receptors. We suggest that the receptor-binding sites and several previously identified neutralizing epitopes on TcdB are ideal targets for the development of broad-spectrum inhibitors to protect against diverse TcdB variants.
Collapse
Affiliation(s)
- Peng Chen
- Department of Physiology and Biophysics, University of California Irvine, Irvine, California, 92697, USA
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California Irvine, Irvine, California, 92697, USA
| |
Collapse
|
19
|
Zhou K, Luo W, Liu T, Ni Y, Qin Z. Neurotoxins Acting at Synaptic Sites: A Brief Review on Mechanisms and Clinical Applications. Toxins (Basel) 2022; 15:18. [PMID: 36668838 PMCID: PMC9865788 DOI: 10.3390/toxins15010018] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/29/2022] Open
Abstract
Neurotoxins generally inhibit or promote the release of neurotransmitters or bind to receptors that are located in the pre- or post-synaptic membranes, thereby affecting physiological functions of synapses and affecting biological processes. With more and more research on the toxins of various origins, many neurotoxins are now widely used in clinical treatment and have demonstrated good therapeutic outcomes. This review summarizes the structural properties and potential pharmacological effects of neurotoxins acting on different components of the synapse, as well as their important clinical applications, thus could be a useful reference for researchers and clinicians in the study of neurotoxins.
Collapse
Affiliation(s)
- Kunming Zhou
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, College of Pharmaceutical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China
| | - Weifeng Luo
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Tong Liu
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong 226019, China
| | - Yong Ni
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Zhenghong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, College of Pharmaceutical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China
| |
Collapse
|
20
|
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.
Collapse
Affiliation(s)
- Katharina F. Kubatzky
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University, Heidelberg, Germany
| |
Collapse
|
21
|
YAP promotes cell-autonomous immune responses to tackle intracellular Staphylococcus aureus in vitro. Nat Commun 2022; 13:6995. [PMID: 36384856 PMCID: PMC9669043 DOI: 10.1038/s41467-022-34432-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022] Open
Abstract
Transcriptional cofactors YAP/TAZ have recently been found to support autophagy and inflammation, which are part of cell-autonomous immunity and are critical in antibacterial defense. Here, we studied the role of YAP against Staphylococcus aureus using CRISPR/Cas9-mutated HEK293 cells and a primary cell-based organoid model. We found that S. aureus infection increases YAP transcriptional activity, which is required to reduce intracellular S. aureus replication. A 770-gene targeted transcriptomic analysis revealed that YAP upregulates genes involved in autophagy/lysosome and inflammation pathways in both infected and uninfected conditions. The YAP-TEAD transcriptional activity promotes autophagic flux and lysosomal acidification, which are then important for defense against intracellular S. aureus. Furthermore, the staphylococcal toxin C3 exoenzyme EDIN-B was found effective in preventing YAP-mediated cell-autonomous immune response. This study provides key insights on the anti-S. aureus activity of YAP, which could be conserved for defense against other intracellular bacteria.
Collapse
|
22
|
Koh E, Kim U, Cho HS. Catalytic DxD motif caged in Asx-turn and Met-aromatic interaction attenuates the pathogenic glycosylation of SseK2/NleB2 effectors. Sci Rep 2022; 12:19288. [PMID: 36369343 PMCID: PMC9652389 DOI: 10.1038/s41598-022-22803-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/19/2022] [Indexed: 11/13/2022] Open
Abstract
Pathogenic bacteria encode virulent glycosyltransferases that conjugate various glycans onto host crucial proteins, which allows adhesion to mammalian cells and modulates host cellular processes for pathogenesis. Escherichia coli NleB1, Citrobacter rodentium NleB, and Salmonella enterica SseK1/3 type III effectors fatally glycosyltransfer N-acetyl glucosamine (GlcNAc) from UDP-GlcNAc to arginine residues of death domain-containing proteins that regulate host inflammation, intra-bacterial proteins, and themselves, whose post-translational modification disrupts host immune functions and prolongs bacterial viability inside host cells. However, unlike the similar NleB1/SseK1/SseK3, E. coli NleB2 and S. enterica SseK2 show deficient GlcNAcylation and neither intra-bacterial glycosylation nor auto-glycosylation. Here, as the major factor in SseK2/NleB2 deficiency, we focused on the catalytic Asp-x-Asp (DxD) motif conserved throughout all O-/N-glycosyltransferases to coordinate Mn2+. All DxD motifs in apo-glycosyltransferases form Type-I-turns for binding Mn2+, similar to the ligand-bound DxD motif, whereas TcnA/SseK2/NleB2 DxD motifs form Asx-turns, which are unable to bind Mn2+. Interestingly, methionine of the NleB2 DMD motif forms triple Met-aromatic interactions, as found in age-associated diseases and tumor necrosis factor (TNF) ligand-receptor complexes. The NleB1 A222M mutation induces triple Met-aromatic interactions to steeply attenuate glycosylation activity to 3% of that in the wild type. Thus, the characteristic conformation of the DxD motif is essential for binding Mn2+, donors, and glycosylate targets. This explains why SseK2/NleB2 effectors with the DxD motif caged in the Asp-/Asn-turn (Asx-turn) and triple Met-aromatic interactions have lower glycosyltransferase activity than that of other fatal NleB1/SseK1/SseK3 toxins.
Collapse
Affiliation(s)
- Eunhee Koh
- grid.15444.300000 0004 0470 5454Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722 Republic of Korea
| | - Uijin Kim
- grid.15444.300000 0004 0470 5454Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722 Republic of Korea
| | - Hyun-Soo Cho
- grid.15444.300000 0004 0470 5454Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722 Republic of Korea
| |
Collapse
|
23
|
Markelova NN, Semenova EF, Sineva ON, Sadykova VS. The Role of Cyclomodulins and Some Microbial Metabolites in Bacterial Microecology and Macroorganism Carcinogenesis. Int J Mol Sci 2022; 23:ijms231911706. [PMID: 36233008 PMCID: PMC9570213 DOI: 10.3390/ijms231911706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/24/2022] [Accepted: 09/26/2022] [Indexed: 11/16/2022] Open
Abstract
A number of bacteria that colonize the human body produce toxins and effectors that cause changes in the eukaryotic cell cycle—cyclomodulins and low-molecular-weight compounds such as butyrate, lactic acid, and secondary bile acids. Cyclomodulins and metabolites are necessary for bacteria as adaptation factors—which are influenced by direct selection—to the ecological niches of the host. In the process of establishing two-way communication with the macroorganism, these compounds cause limited damage to the host, despite their ability to disrupt key processes in eukaryotic cells, which can lead to pathological changes. Possible negative consequences of cyclomodulin and metabolite actions include their potential role in carcinogenesis, in particular, with the ability to cause DNA damage, increase genome instability, and interfere with cancer-associated regulatory pathways. In this review, we aim to examine cyclomodulins and bacterial metabolites as important factors in bacterial survival and interaction with the host organism to show their heterogeneous effect on oncogenesis depending on the surrounding microenvironment, pathological conditions, and host genetic background.
Collapse
Affiliation(s)
- Natalia N. Markelova
- Gause Institute of New Antibiotics, ul. Bolshaya Pirogovskaya, 11, 119021 Moscow, Russia
- Correspondence: (N.N.M.); (V.S.S.)
| | - Elena F. Semenova
- Institute of Biochemical Technology, Ecology and Pharmacy, V.I. Vernadsky Crimean Federal University, 295007 Simferopol, Russia
| | - Olga N. Sineva
- Gause Institute of New Antibiotics, ul. Bolshaya Pirogovskaya, 11, 119021 Moscow, Russia
| | - Vera S. Sadykova
- Gause Institute of New Antibiotics, ul. Bolshaya Pirogovskaya, 11, 119021 Moscow, Russia
- Correspondence: (N.N.M.); (V.S.S.)
| |
Collapse
|
24
|
Asiatic Acid Attenuates Inflammation Induced by Salmonella via Upregulating LncRNA TVX1 in Microglia. Int J Mol Sci 2022; 23:ijms231810978. [PMID: 36142890 PMCID: PMC9504590 DOI: 10.3390/ijms231810978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 09/11/2022] [Accepted: 09/15/2022] [Indexed: 11/17/2022] Open
Abstract
Salmonella typhimurium (S.T) induces damage to the central nervous system; however, the role of Asiatic acid (AA) in this is still unknown. Microglia play a role as macrophages to recognize the invaded pathogenic microbes in the brain. The aim of this study was to investigate the protective effect and mechanism of AA on the central nervous system through an in vitro model of S.T infection in microglia. We pre-treated microglia with AA before S.T infection and explored the anti-infection mechanism of AA by sequencing, quantitative reverse transcription PCR (RT-qPCR), and Western blotting. Long non-coding RNA (lncRNA) sequencing demonstrated that inflammation is a major factor in S.T infection of microglia. RT-qPCR data demonstrated that AA inhibited S.T-induced increases in the mRNA levels of the pro-inflammatory factors interleukin (IL)-1β, IL-6, and IL-18. Western blotting demonstrated that AA inhibited S.T-induced activation of the nuclear factor (NF)-κB pathway and activation of the NLR family, pyrin domain-containing 3 (NLRP3) inflammasome. Expression of the lncRNA TVX1 in microglia was decreased by S.T infection and increased by pretreatment with AA. Inhibition of TVX1 expression reversed the anti-inflammatory effect of AA, and overexpression of TVX1 in microglia suppressed S.T-induced inflammation. In conclusion, AA attenuated S.T-induced microglial inflammation by upregulating the expression of the lncRNA TVX1.
Collapse
|
25
|
Paparella A, Cahill SM, Aboulache BL, Schramm VL. Clostridioides difficile TcdB Toxin Glucosylates Rho GTPase by an S Ni Mechanism and Ion Pair Transition State. ACS Chem Biol 2022; 17:2507-2518. [PMID: 36038138 PMCID: PMC9486934 DOI: 10.1021/acschembio.2c00408] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Toxins TcdA and TcdB from Clostridioides difficile glucosylate human colon Rho GTPases. TcdA and TcdB glucosylation of RhoGTPases results in cytoskeletal changes, causing cell rounding and loss of intestinal integrity. Clostridial toxins TcdA and TcdB are proposed to catalyze glucosylation of Rho GTPases with retention of stereochemistry from UDP-glucose. We used kinetic isotope effects to analyze the mechanisms and transition-state structures of the glucohydrolase and glucosyltransferase activities of TcdB. TcdB catalyzes Rho GTPase glucosylation with retention of stereochemistry, while hydrolysis of UDP-glucose by TcdB causes inversion of stereochemistry. Kinetic analysis revealed TcdB glucosylation via the formation of a ternary complex with no intermediate, supporting an SNi mechanism with nucleophilic attack and leaving group departure occurring on the same face of the glucose ring. Kinetic isotope effects combined with quantum mechanical calculations revealed that the transition states of both glucohydrolase and glucosyltransferase activities of TcdB are highly dissociative. Specifically, the TcdB glucosyltransferase reaction proceeds via an SNi mechanism with the formation of a distinct oxocarbenium phosphate ion pair transition state where the glycosidic bond to the UDP leaving group breaks prior to attack of the threonine nucleophile from Rho GTPase.
Collapse
|
26
|
Kunishima H, Ohge H, Suzuki H, Nakamura A, Matsumoto K, Mikamo H, Mori N, Morinaga Y, Yanagihara K, Yamagishi Y, Yoshizawa S. Japanese Clinical Practice Guidelines for Management of Clostridioides (Clostridium) difficile infection. J Infect Chemother 2022; 28:1045-1083. [PMID: 35618618 DOI: 10.1016/j.jiac.2021.12.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/16/2021] [Accepted: 12/13/2021] [Indexed: 12/19/2022]
Affiliation(s)
- Hiroyuki Kunishima
- Department of Infectious Diseases, St. Marianna University School of Medicine, Japan.
| | - Hiroki Ohge
- Department of Infectious Diseases, Hiroshima University Hospital, Japan
| | - Hiromichi Suzuki
- Division of Infectious Diseases, Department of Medicine, Tsukuba Medical Center Hospital, Japan
| | - Atsushi Nakamura
- Division of Infection Control and Prevention, Nagoya City University Hospital, Japan
| | - Kazuaki Matsumoto
- Division of Pharmacodynamics, Faculty of Pharmacy, Keio University, Japan
| | - Hiroshige Mikamo
- Clinical Infectious Diseases, Graduate School of Medicine, Aichi Medical University, Japan
| | - Nobuaki Mori
- Division of General Internal Medicine and Infectious Diseases, National Hospital Organization Tokyo Medical Center, Japan
| | - Yoshitomo Morinaga
- Department of Microbiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Katsunori Yanagihara
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Japan
| | - Yuka Yamagishi
- Clinical Infectious Diseases, Graduate School of Medicine, Aichi Medical University, Japan
| | - Sadako Yoshizawa
- Department of Clinical Laboratory/Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Japan
| |
Collapse
|
27
|
Chen B, Liu Z, Perry K, Jin R. Structure of the glucosyltransferase domain of TcdA in complex with RhoA provides insights into substrate recognition. Sci Rep 2022; 12:9028. [PMID: 35637242 PMCID: PMC9151644 DOI: 10.1038/s41598-022-12909-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/17/2022] [Indexed: 01/05/2023] Open
Abstract
Clostridioides difficile is one of the most common causes of antibiotic-associated diarrhea in developed countries. As key virulence factors of C. difficile, toxin A (TcdA) and toxin B (TcdB) act by glucosylating and inactivating Rho and Ras family small GTPases in host cells, which leads to actin cytoskeleton disruption, cell rounding, and ultimately cell death. Here we present the co-crystal structure of the glucosyltransferase domain (GTD) of TcdA in complex with its substrate human RhoA at 2.60-angstrom resolution. This structure reveals that TcdA GTD grips RhoA mainly through its switch I and switch II regions, which is complemented by interactions involving RhoA's pre-switch I region. Comprehensive structural comparisons between the TcdA GTD-RhoA complex and the structures of TcdB GTD in complex with Cdc42 and R-Ras reveal both the conserved and divergent features of these two toxins in terms of substrate recognition. Taken together, these findings establish the structural basis for TcdA recognition of small GTPases and advance our understanding of the substrates selectivity of large clostridial toxins.
Collapse
Affiliation(s)
- Baohua Chen
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Zheng Liu
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Argonne National Laboratory, Cornell University, Argonne, IL, 60439, USA
| | - Rongsheng Jin
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, 92697, USA.
| |
Collapse
|
28
|
Nubbemeyer B, George AAP, Kühl T, Pepanian A, Beck MS, Maghraby R, Boushehri MS, Muehlhaupt M, Pfeil EM, Annala SK, Ammer H, Imhof D, Pei D. Targeting Gαi/s Proteins with Peptidyl Nucleotide Exchange Modulators. ACS Chem Biol 2022; 17:463-473. [PMID: 35042325 PMCID: PMC11002716 DOI: 10.1021/acschembio.1c00929] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chemical probes that specifically modulate the activity of heterotrimeric G proteins provide excellent tools for investigating G protein-mediated cell signaling. Herein, we report a family of selective peptidyl Gαi/s modulators derived from peptide library screening and optimization. Conjugation to a cell-penetrating peptide rendered the peptides cell-permeable and biologically active in cell-based assays. The peptides exhibit potent guanine-nucleotide exchange modulator-like activity toward Gαi and Gαs. Molecular docking and dynamic simulations revealed the molecular basis of the protein-ligand interactions and their effects on GDP binding. This study demonstrates the feasibility of developing direct Gαi/s modulators and provides a novel chemical probe for investigating cell signaling through GPCRs/G proteins.
Collapse
Affiliation(s)
- Britta Nubbemeyer
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany
| | - Ajay Abisheck Paul George
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany
- BioSolveIT GmbH, An der Ziegelei 79, 53757, Sankt Augustin, Germany
| | - Toni Kühl
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany
| | - Anna Pepanian
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany
| | - Maximilian Steve Beck
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany
| | - Rahma Maghraby
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany
| | - Maryam Shetab Boushehri
- Pharmaceutical Technology and Biopharmacy, University of Bonn, Gerhard-Domagk-Str. 3, 53121, Bonn, Germany
| | - Maximilian Muehlhaupt
- Institute of Pharmacology, Toxicology and Pharmacy, Veterinary Faculty, Ludwig Maximilian University of Munich, Königinstr. 16, 80539, Munich, Germany
| | - Eva Marie Pfeil
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115, Bonn, Germany
| | - Suvi Katariina Annala
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115, Bonn, Germany
| | - Hermann Ammer
- Institute of Pharmacology, Toxicology and Pharmacy, Veterinary Faculty, Ludwig Maximilian University of Munich, Königinstr. 16, 80539, Munich, Germany
| | - Diana Imhof
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany
| | - Dehua Pei
- Department of Chemistry and Biochemistry, The Ohio State University, 578 Biosciences Building, 484 W 12 Avenue, Columbus, OH 43210, USA
| |
Collapse
|
29
|
Kufer TA, Kaparakis-Liaskos M. A Brief Introduction to Effector-Triggered Immunity. Methods Mol Biol 2022; 2523:1-8. [PMID: 35759187 DOI: 10.1007/978-1-0716-2449-4_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Detection of microbes by the host is essential to restrict microbial colonization, to clear pathogens, and to mount adapted defense reactions, and thus is the key function of the innate immune systems of plants and mammals. Here we provide an introduction into pathogen recognition by the innate immune system of both plants and animals. We will particularly focus on the concept of effector-triggered immunity, and similarities and differences in its function between plants and animals.
Collapse
Affiliation(s)
- Thomas A Kufer
- Department of Immunology, Institute of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany.
| | - Maria Kaparakis-Liaskos
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, VIC, Australia
- Research Centre for Extracellular Vesicles, School of Molecular Sciences, La Trobe University, Melbourne, VIC, Australia
| |
Collapse
|
30
|
Bekere I, Huang J, Schnapp M, Rudolph M, Berneking L, Ruckdeschel K, Grundhoff A, Günther T, Fischer N, Aepfelbacher M. Yersinia remodels epigenetic histone modifications in human macrophages. PLoS Pathog 2021; 17:e1010074. [PMID: 34793580 PMCID: PMC8639070 DOI: 10.1371/journal.ppat.1010074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 12/02/2021] [Accepted: 10/28/2021] [Indexed: 01/10/2023] Open
Abstract
Various pathogens systematically reprogram gene expression in macrophages, but the underlying mechanisms are largely unknown. We investigated whether the enteropathogen Yersinia enterocolitica alters chromatin states to reprogram gene expression in primary human macrophages. Genome-wide chromatin immunoprecipitation (ChIP) seq analyses showed that pathogen-associated molecular patterns (PAMPs) induced up- or down-regulation of histone modifications (HMod) at approximately 14500 loci in promoters and enhancers. Effectors of Y. enterocolitica reorganized about half of these dynamic HMod, with the effector YopP being responsible for about half of these modulatory activities. The reorganized HMod were associated with genes involved in immune response and metabolism. Remarkably, the altered HMod also associated with 61% of all 534 known Rho GTPase pathway genes, revealing a new level in Rho GTPase regulation and a new aspect of bacterial pathogenicity. Changes in HMod were associated to varying degrees with corresponding gene expression, e. g. depending on chromatin localization and cooperation of the HMod. In summary, infection with Y. enterocolitica remodels HMod in human macrophages to modulate key gene expression programs of the innate immune response. Human pathogenic bacteria can affect epigenetic histone modifications to modulate gene expression in host cells. However, a systems biology analysis of this bacterial virulence mechanism in immune cells has not been performed. Here we analyzed genome-wide epigenetic histone modifications and associated gene expression changes in primary human macrophages infected with enteropathogenic Yersinia enterocolitica. We demonstrate that Yersinia virulence factors extensively modulate histone modifications and associated gene expression triggered by the pathogen-associated molecular patterns (PAMPs) of the bacteria. The epigenetically modulated genes are involved in several key pathways of the macrophage immune response, including the Rho GTPase pathway, revealing a novel level of Rho GTPase regulation by a bacterial pathogen. Overall, our findings provide an in-depth view of epigenetic and gene expression changes during host-pathogen interaction and might have further implications for understanding of the innate immune memory in macrophages.
Collapse
Affiliation(s)
- Indra Bekere
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
- * E-mail: (IB); (MA)
| | - Jiabin Huang
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Marie Schnapp
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Maren Rudolph
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Laura Berneking
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Klaus Ruckdeschel
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Adam Grundhoff
- Heinrich-Pette-Institute (HPI), Leibniz Institute for Experimental Virology, Research Group Virus Genomics, Hamburg, Germany
| | - Thomas Günther
- Heinrich-Pette-Institute (HPI), Leibniz Institute for Experimental Virology, Research Group Virus Genomics, Hamburg, Germany
| | - Nicole Fischer
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Martin Aepfelbacher
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
- * E-mail: (IB); (MA)
| |
Collapse
|
31
|
Arrieta-Ortiz ML, Immanuel SRC, Turkarslan S, Wu WJ, Girinathan BP, Worley JN, DiBenedetto N, Soutourina O, Peltier J, Dupuy B, Bry L, Baliga NS. Predictive regulatory and metabolic network models for systems analysis of Clostridioides difficile. Cell Host Microbe 2021; 29:1709-1723.e5. [PMID: 34637780 PMCID: PMC8595754 DOI: 10.1016/j.chom.2021.09.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/29/2021] [Accepted: 09/16/2021] [Indexed: 12/15/2022]
Abstract
We present predictive models for comprehensive systems analysis of Clostridioides difficile, the etiology of pseudomembranous colitis. By leveraging 151 published transcriptomes, we generated an EGRIN model that organizes 90% of C. difficile genes into a transcriptional regulatory network of 297 co-regulated modules, implicating genes in sporulation, carbohydrate transport, and metabolism. By advancing a metabolic model through addition and curation of metabolic reactions including nutrient uptake, we discovered 14 amino acids, diverse carbohydrates, and 10 metabolic genes as essential for C. difficile growth in the intestinal environment. Finally, we developed a PRIME model to uncover how EGRIN-inferred combinatorial gene regulation by transcription factors, such as CcpA and CodY, modulates essential metabolic processes to enable C. difficile growth relative to commensal colonization. The C. difficile interactive web portal provides access to these model resources to support collaborative systems-level studies of context-specific virulence mechanisms in C. difficile.
Collapse
Affiliation(s)
| | | | | | - Wei-Ju Wu
- Institute for Systems Biology, Seattle, WA 98109, USA
| | - Brintha P Girinathan
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jay N Worley
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Nicholas DiBenedetto
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Olga Soutourina
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-yvette 91198, France
| | - Johann Peltier
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-yvette 91198, France
| | - Bruno Dupuy
- Laboratoire Pathogenèse des Bactéries anaérobies, Institut Pasteur, Université de Paris, UMR CNRS 2001, Paris 75015, France
| | - Lynn Bry
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | |
Collapse
|
32
|
Inhibition of Clostridium difficile TcdA and TcdB toxins with transition state analogues. Nat Commun 2021; 12:6285. [PMID: 34725358 PMCID: PMC8560925 DOI: 10.1038/s41467-021-26580-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 10/11/2021] [Indexed: 12/20/2022] Open
Abstract
Clostridium difficile causes life-threatening diarrhea and is the leading cause of healthcare-associated bacterial infections in the United States. TcdA and TcdB bacterial toxins are primary determinants of disease pathogenesis and are attractive therapeutic targets. TcdA and TcdB contain domains that use UDP-glucose to glucosylate and inactivate host Rho GTPases, resulting in cytoskeletal changes causing cell rounding and loss of intestinal integrity. Transition state analysis revealed glucocationic character for the TcdA and TcdB transition states. We identified transition state analogue inhibitors and characterized them by kinetic, thermodynamic and structural analysis. Iminosugars, isofagomine and noeuromycin mimic the transition state and inhibit both TcdA and TcdB by forming ternary complexes with Tcd and UDP, a product of the TcdA- and TcdB-catalyzed reactions. Both iminosugars prevent TcdA- and TcdB-induced cytotoxicity in cultured mammalian cells by preventing glucosylation of Rho GTPases. Iminosugar transition state analogues of the Tcd toxins show potential as therapeutics for C. difficile pathology. The Clostridium difficile virulence factors TcdA and TcdB contain a glucosyltransferase domain (GTD), which has both glucohydrolase (GH) and glucosyltransferase (GT) activities. Here, the authors characterize the transition state features of the TcdA and TcdB GH reactions by measuring kinetic isotope effects and they identify two transition state analogues, isofagomine and noeuromycin that inhibit TcdA and TcdB. They also present the crystal structures of TcdB-GTD bound to these inhibitors and the reaction product UDP.
Collapse
|
33
|
Structural basis for selective AMPylation of Rac-subfamily GTPases by Bartonella effector protein 1 (Bep1). Proc Natl Acad Sci U S A 2021; 118:2023245118. [PMID: 33723071 PMCID: PMC8000347 DOI: 10.1073/pnas.2023245118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mammalian cells regulate diverse cellular processes in response to extracellular cues. Small GTPases of the Rho family act as molecular switches to rapidly regulate discrete cellular activities, such as cytoskeletal dynamics, cell movement, and innate immune responses. Numerous bacterial virulence factors modulate the function of Rho-family GTPases and thereby manipulate intracellular signaling. For many of these virulence factors we have gained detailed understanding how they covalently modify individual Rho-family GTPases to reprogram their activities; however, their mechanisms of selective targeting of distinct subsets of Rho-family GTPases remained elusive. Using a combination of structural biology and biochemistry, we demonstrate for the effector protein Bep1 exclusive specificity for Rac-subfamily GTPases and propose the underlying mechanism of target selectivity. Small GTPases of the Ras-homology (Rho) family are conserved molecular switches that control fundamental cellular activities in eukaryotic cells. As such, they are targeted by numerous bacterial toxins and effector proteins, which have been intensively investigated regarding their biochemical activities and discrete target spectra; however, the molecular mechanism of target selectivity has remained largely elusive. Here we report a bacterial effector protein that selectively targets members of the Rac subfamily in the Rho family of small GTPases but none in the closely related Cdc42 or RhoA subfamilies. This exquisite target selectivity of the FIC domain AMP-transferase Bep1 from Bartonella rochalimae is based on electrostatic interactions with a subfamily-specific pair of residues in the nucleotide-binding G4 motif and the Rho insert helix. Residue substitutions at the identified positions in Cdc42 enable modification by Bep1, while corresponding Cdc42-like substitutions in Rac1 greatly diminish modification. Our study establishes a structural understanding of target selectivity toward Rac-subfamily GTPases and provides a highly selective tool for their functional analysis.
Collapse
|
34
|
Wang WH, Yuan T, Qian MJ, Yan FJ, Yang L, He QJ, Yang B, Lu JJ, Zhu H. Post-translational modification of KRAS: potential targets for cancer therapy. Acta Pharmacol Sin 2021; 42:1201-1211. [PMID: 33087838 PMCID: PMC8285426 DOI: 10.1038/s41401-020-00542-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 09/16/2020] [Indexed: 02/02/2023] Open
Abstract
Aberrant activation of the RAS superfamily is one of the critical factors in carcinogenesis. Among them, KRAS is the most frequently mutated one which has inspired extensive studies for developing approaches to intervention. Although the cognition toward KRAS remains far from complete, mounting evidence suggests that a variety of post-translational modifications regulate its activation and localization. In this review, we summarize the regulatory mode of post-translational modifications on KRAS including prenylation, post-prenylation, palmitoylation, ubiquitination, phosphorylation, SUMOylation, acetylation, nitrosylation, etc. We also highlight the recent studies targeting these modifications having exhibited potent anti-tumor activities.
Collapse
Affiliation(s)
- Wei-Hua Wang
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Tao Yuan
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Mei-Jia Qian
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Fang-Jie Yan
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Liu Yang
- Key Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang Province, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, 310014, China
| | - Qiao-Jun He
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Bo Yang
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Jin-Jian Lu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
| | - Hong Zhu
- Zhejiang Province Key Laboratory of Anti-cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China.
| |
Collapse
|
35
|
Wang X, Cheng J, Shen J, Liu L, Li N, Gao N, Jiang F, Jin Q. Characterization of Photorhabdus Virulence Cassette as a causative agent in the emerging pathogen Photorhabdus asymbiotica. SCIENCE CHINA-LIFE SCIENCES 2021; 65:618-630. [PMID: 34185241 DOI: 10.1007/s11427-021-1955-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 05/25/2021] [Indexed: 10/21/2022]
Abstract
The extracellular contractile injection systems (eCISs) are encoded in the genomes of a large number of bacteria and archaea. We have previously characterized the overall structure of Photorhabdus Virulence Cassette (PVC), a typical member of the eCIS family. PVC resembles the contractile tail of bacteriophages and exerts its action by the contraction of outer sheath and injection of inner tube plus central spike. Nevertheless, the biological function of PVC effectors and the mechanism of effector translocation are still lacking. By combining cryo-electron microscopy and functional experiments, here we show that the PVC effectors Pdp1 (a new family of widespread dNTP pyrophosphatase effector in eCIS) and Pnf (a deamidase effector) are loaded inside the inner tube lumen in a "Peas in the Pod" mode. Moreover, we observe that Pdp1 and Pnf can be directly injected into J774A.1 murine macrophage and kill the target cells by disrupting the dNTP pools and actin cytoskeleton formation, respectively. Our results provide direct evidence of how PVC cargoes are loaded and delivered directly into mammalian macrophages.
Collapse
Affiliation(s)
- Xia Wang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Jiaxuan Cheng
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.,State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Jiawei Shen
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Liguo Liu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Feng Jiang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China.
| | - Qi Jin
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China.
| |
Collapse
|
36
|
Ras Isoforms from Lab Benches to Lives-What Are We Missing and How Far Are We? Int J Mol Sci 2021; 22:ijms22126508. [PMID: 34204435 PMCID: PMC8233758 DOI: 10.3390/ijms22126508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/09/2021] [Accepted: 06/11/2021] [Indexed: 11/21/2022] Open
Abstract
The central protein in the oncogenic circuitry is the Ras GTPase that has been under intense scrutiny for the last four decades. From its discovery as a viral oncogene and its non-oncogenic contribution to crucial cellular functioning, an elaborate genetic, structural, and functional map of Ras is being created for its therapeutic targeting. Despite decades of research, there still exist lacunae in our understanding of Ras. The complexity of the Ras functioning is further exemplified by the fact that the three canonical Ras genes encode for four protein isoforms (H-Ras, K-Ras4A, K-Ras4B, and N-Ras). Contrary to the initial assessment that the H-, K-, and N-Ras isoforms are functionally similar, emerging data are uncovering crucial differences between them. These Ras isoforms exhibit not only cell-type and context-dependent functions but also activator and effector specificities on activation by the same receptor. Preferential localization of H-, K-, and N-Ras in different microdomains of the plasma membrane and cellular organelles like Golgi, endoplasmic reticulum, mitochondria, and endosome adds a new dimension to isoform-specific signaling and diverse functions. Herein, we review isoform-specific properties of Ras GTPase and highlight the importance of considering these towards generating effective isoform-specific therapies in the future.
Collapse
|
37
|
Nubbemeyer B, Pepanian A, Paul George AA, Imhof D. Strategies towards Targeting Gαi/s Proteins: Scanning of Protein-Protein Interaction Sites To Overcome Inaccessibility. ChemMedChem 2021; 16:1696-1715. [PMID: 33615736 PMCID: PMC8252600 DOI: 10.1002/cmdc.202100039] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Indexed: 12/16/2022]
Abstract
Heterotrimeric G proteins are classified into four subfamilies and play a key role in signal transduction. They transmit extracellular signals to intracellular effectors subsequent to the activation of G protein-coupled receptors (GPCRs), which are targeted by over 30 % of FDA-approved drugs. However, addressing G proteins as drug targets represents a compelling alternative, for example, when G proteins act independently of the corresponding GPCRs, or in cases of complex multifunctional diseases, when a large number of different GPCRs are involved. In contrast to Gαq, efforts to target Gαi/s by suitable chemical compounds has not been successful so far. Here, a comprehensive analysis was conducted examining the most important interface regions of Gαi/s with its upstream and downstream interaction partners. By assigning the existing compounds and the performed approaches to the respective interfaces, the druggability of the individual interfaces was ranked to provide perspectives for selective targeting of Gαi/s in the future.
Collapse
Affiliation(s)
- Britta Nubbemeyer
- Pharmaceutical Biochemistry and BioanalyticsPharmaceutical InstituteUniversity of BonnAn der Immenburg 453121BonnGermany
| | - Anna Pepanian
- Pharmaceutical Biochemistry and BioanalyticsPharmaceutical InstituteUniversity of BonnAn der Immenburg 453121BonnGermany
| | | | - Diana Imhof
- Pharmaceutical Biochemistry and BioanalyticsPharmaceutical InstituteUniversity of BonnAn der Immenburg 453121BonnGermany
| |
Collapse
|
38
|
Bockaert J, Bécamel C, Chaumont-Dubel S, Claeysen S, Vandermoere F, Marin P. Novel and atypical pathways for serotonin signaling. Fac Rev 2021; 10:52. [PMID: 34195691 PMCID: PMC8204760 DOI: 10.12703/r/10-52] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Serotonin (5-HT) appeared billions of years before 5-HT receptors and synapses. It is thus not surprising that 5-HT can control biological processes independently of its receptors. One example is serotonylation, which consists of covalent binding of 5-HT to the primary amine of glutamine. Over the past 20 years, serotonylation has been involved in the regulation of many signaling mechanisms. One of the most striking examples is the recent evidence that serotonylation of histone H3 constitutes an epigenetic mark. However, the pathophysiological role of histone H3 serotonylation remains to be discovered. All but one of the 5-HT receptors are G-protein-coupled receptors (GPCRs). The signaling pathways they control are finely tuned, and new, unexpected regulatory mechanisms are being uncovered continuously. Some 5-HT receptors (5-HT2C, 5-HT4, 5-HT6, and 5-HT7) signal through mechanisms that require neither G-proteins nor β-arrestins, the two classical and almost universal GPCR signal transducers. 5-HT6 receptors are constitutively activated via their association with intracellular GPCR-interacting proteins (GIPs), including neurofibromin 1, cyclin-dependent kinase 5 (Cdk5), and G-protein-regulated inducer of neurite outgrowth 1 (GPRIN1). Interactions of 5-HT6 receptor with Cdk5 and GPRIN1 are not concomitant but occur sequentially and play a key role in dendritic tree morphogenesis. Furthermore, 5-HT6 receptor-mediated G-protein signaling in neurons is different in the cell body and primary cilium, where it is modulated by smoothened receptor activation. Finally, 5-HT2A receptors form heteromers with mGlu2 metabotropic glutamate receptors. This heteromerization results in a specific phosphorylation of mGlu2 receptor on a serine residue (Ser843) upon agonist stimulation of 5-HT2A or mGlu2 receptor. mGlu2 receptor phosphorylation on Ser843 is an essential step in engagement of Gi/o signaling not only upon mGlu2 receptor activation but also following 5-HT2A receptor activation, and thus represents a key molecular event underlying functional crosstalk between both receptors.
Collapse
Affiliation(s)
- Joël Bockaert
- The Institute of Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Carine Bécamel
- The Institute of Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Séverine Chaumont-Dubel
- The Institute of Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Sylvie Claeysen
- The Institute of Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Franck Vandermoere
- The Institute of Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Philippe Marin
- The Institute of Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| |
Collapse
|
39
|
Abstract
Pathogens have evolved smart strategies to invade hosts and hijack their immune responses. One such strategy is the targeting of the host RhoGTPases by toxins or virulence factors to hijack the cytoskeleton dynamic and immune processes. In response to this microbial attack, the host has evolved an elegant strategy to monitor the function of virulence factors and toxins by sensing the abnormal activity of RhoGTPases. This innate immune strategy of sensing bacterial effector targeting RhoGTPase appears to be a bona fide example of effector-triggered immunity (ETI). Here, we review recently discovered mechanisms by which the host can sense the activity of these toxins through NOD and NOD-like receptors (NLRs).
Collapse
Affiliation(s)
| | - Laurent Boyer
- Université Côte d’Azur, Inserm, C3M, Nice, France
- * E-mail:
| |
Collapse
|
40
|
Song N, Chen L, Zhou Z, Ren X, Liu B, Zhou S, Wang C, Wu Y, Waterfield NR, Yang J, Yang G. Genome-wide dissection reveals diverse pathogenic roles of bacterial Tc toxins. PLoS Pathog 2021; 17:e1009102. [PMID: 33540421 PMCID: PMC7861908 DOI: 10.1371/journal.ppat.1009102] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 10/26/2020] [Indexed: 12/21/2022] Open
Abstract
Tc toxins were originally identified in entomopathogenic bacteria, which are important as biological pest control agents. Tc toxins are heteromeric exotoxins composed of three subunit types, TcA, TcB, and TcC. The C-terminal portion of the TcC protein encodes the actual toxic domain, which is translocated into host cells by an injectosome nanomachine comprising the other subunits. Currently the pathogenic roles and distribution of Tc toxins among different bacterial genera remain unclear. Here we have performed a comprehensive genome-wide analysis, and established a database that includes 1,608 identified Tc loci containing 2,528 TcC proteins in 1,421 Gram-negative and positive bacterial genomes. Our findings indicate that TcCs conform to the architecture of typical polymorphic toxins, with C-terminal hypervariable regions (HVR) encoding more than 100 different classes of putative toxic domains, most of which have not been previously recognized. Based on further analysis of Tc loci in the genomes of all Salmonella and Yersinia strains in EnteroBase, a “two-level” evolutionary dynamics scenario is proposed for TcC homologues. This scenario implies that the conserved TcC RHS core domain plays a critical role in the taxonomical specific distribution of TcC HVRs. This study provides an extensive resource for the future development of Tc toxins as valuable agrochemical tools. It furthermore implies that Tc proteins, which are encoded by a wide range of pathogens, represent an important versatile toxin superfamily with diverse pathogenic mechanisms. Entomopathogenic bacteria deploy a range of toxins to combat their insect hosts. The Tc toxins were first identified in Photorhabdus as having potent oral toxicity to insects, with a mode of action distinct from the well-studied Bacillus thuringiensis Cry toxins. As such the Tc toxins have been considered as potential candidates for novel crop protection strategies. This could mitigate against the potential risks of pest insects developing resistance to the traditionally used Cry toxin-based systems. To date, the generality of diverse Tc toxins and their related pathogenic roles has remained mainly obscure. Our analysis has showed Tc toxins are widely distributed among Gram-negative and positive bacterial genomes. A database was constructed including thousands of Tc loci with hundreds of different putative TcC toxic domains, any one of which might represent candidates for the development of future pest control systems. Moreover, the findings of this study are of wider significance because Tc toxin homologues have been shown to be encoded by a range of human pathogens. These include Salmonella and Yersinia, suggesting their potential roles in human infectious diseases. Together, this study describes the characteristics and distribution of Tc toxins among diverse bacterial genera, and provides a new insight into their roles in different pathogenesis mechanisms. This study also describes findings of potential importance to their development as tools for biotechnological applications.
Collapse
Affiliation(s)
- Nan Song
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Lihong Chen
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhemin Zhou
- Warwick Medical School, Warwick University, Coventry, United Kingdom
| | - Xingmei Ren
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Bo Liu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Siyu Zhou
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Caihong Wang
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Yun Wu
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | | | - Jian Yang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail: (JY); (GY)
| | - Guowei Yang
- Beijing Institute of Tropical Medicine, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- * E-mail: (JY); (GY)
| |
Collapse
|
41
|
Song N, Chen L, Ren X, Waterfield NR, Yang J, Yang G. N-Glycans and sulfated glycosaminoglycans contribute to the action of diverse Tc toxins on mammalian cells. PLoS Pathog 2021; 17:e1009244. [PMID: 33539469 PMCID: PMC7861375 DOI: 10.1371/journal.ppat.1009244] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/18/2020] [Indexed: 01/11/2023] Open
Abstract
Tc toxin is an exotoxin composed of three subunits named TcA, TcB and TcC. Structural analysis revealed that TcA can form homopentamer that mediates the cellular recognition and delivery processes, thus contributing to the host tropism of Tc toxin. N-glycans and heparan sulfates have been shown to act as receptors for several Tc toxins. Here, we performed two independent genome-wide CRISPR-Cas9 screens, and have validated glycans and sulfated glycosaminoglycans (sGAGs) as Tc toxin receptors also for previously uncharacterized Tc toxins. We found that TcdA1 form Photorhabdus luminescens W14 (TcdA1W14) can recognize N-glycans via the RBD-D domain, corroborating previous findings. Knockout of N-glycan processing enzymes specifically blocks the intoxication of TcdA1W14-assembled Tc toxin. On the other hand, our results showed that sGAG biosynthesis pathway is involved in the cell surface binding of TcdA2TT01 (TcdA2 from P. luminescens TT01). Competition assays and biolayer interferometry demonstrated that the sulfation group in sGAGs is required for the binding of TcdA2TT01. Finally, based on the conserved domains of representative TcA proteins, we have identified 1,189 putative TcAs from 1,039 bacterial genomes. These TcAs are categorized into five subfamilies. Each subfamily shows a good correlation with both genetic organization of the TcA protein(s) and taxonomic origin of the genomes, suggesting these subfamilies may utilize different mechanisms for cellular recognition. Taken together, our results support the previously described two different binding modalities of Tc toxins, leading to unique host targeting properties. We also present the bioinformatics data and receptor screening strategies for TcA proteins, provide new insights into understanding host specificity and biomedical applications of Tc toxins. The Toxin complexes, also referred to as Tc toxins, are a family of A5BC exotoxins widely distributed among Gram-negative and positive bacteria. First identified in Entomopathogenic bacteria as key virulence factors to combat insect hosts, putative Tc toxin loci are also encoded by a range of human pathogens such as Salmonella and Yersinia. Previous studies indicated that several Tc toxins can target invertebrate and vertebrate cells via binding with N-glycans and heparan sulfates. Here our genome-wide CRISPR-Cas9 screens validated that different Tc toxins utilized distinct receptors for the adhesion to their targets, which is determined by TcA homopentamer. For example, TcdA1 from Photorhabdus luminescens W14 (TcdA1W14) relies on N-glycan binding to exert its toxic effects, while sulfate groups of sulfated glycosaminoglycans are critical for the cell targeting of other TcAs such as TcdA2TT01 (TcdA2 from P. luminescens TT01). Consistent with the previously described different binding modalities of Tc toxins, our results confirm that the receptor selectivity of TcAs contribute to the cellular tropism of Tc toxins. Furthermore we has also identified 1,189 TcA homologues and categorized them into five subfamilies. Each TcA subfamily shows a good correlation with the taxonomic origin of the genomes, suggesting these subfamilies are linked to diverse host tropisms via different binding modalities. Together, our findings provide mechanistic insights into understanding host specificity of distinct Tc toxins and the development of therapeutics for Tc toxin-related infections, as well as the adaptation of Tc-injectisomes as potential biotechnology tools and pest-control weapons.
Collapse
Affiliation(s)
- Nan Song
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Lihong Chen
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xingmei Ren
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | | | - Jian Yang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Guowei Yang
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- * E-mail:
| |
Collapse
|
42
|
Marlaire S, Dehio C. Bartonella effector protein C mediates actin stress fiber formation via recruitment of GEF-H1 to the plasma membrane. PLoS Pathog 2021; 17:e1008548. [PMID: 33508040 PMCID: PMC7842960 DOI: 10.1371/journal.ppat.1008548] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 10/09/2020] [Indexed: 02/06/2023] Open
Abstract
Bartonellae are Gram-negative facultative-intracellular pathogens that use a type-IV-secretion system (T4SS) to translocate a cocktail of Bartonella effector proteins (Beps) into host cells to modulate diverse cellular functions. BepC was initially reported to act in concert with BepF in triggering major actin cytoskeletal rearrangements that result in the internalization of a large bacterial aggregate by the so-called ‘invasome’. Later, infection studies with bepC deletion mutants and ectopic expression of BepC have implicated this effector in triggering an actin-dependent cell contractility phenotype characterized by fragmentation of migrating cells due to deficient rear detachment at the trailing edge, and BepE was shown to counterbalance this remarkable phenotype. However, the molecular mechanism of how BepC triggers cytoskeletal changes and the host factors involved remained elusive. Using infection assays, we show here that T4SS-mediated transfer of BepC is sufficient to trigger stress fiber formation in non-migrating epithelial cells and additionally cell fragmentation in migrating endothelial cells. Interactomic analysis revealed binding of BepC to a complex of the Rho guanine nucleotide exchange factor GEF-H1 and the serine/threonine-protein kinase MRCKα. Knock-out cell lines revealed that only GEF-H1 is required for mediating BepC-triggered stress fiber formation and inhibitor studies implicated activation of the RhoA/ROCK pathway downstream of GEF-H1. Ectopic co-expression of tagged versions of GEF-H1 and BepC truncations revealed that the C-terminal ‘Bep intracellular delivery’ (BID) domain facilitated anchorage of BepC to the plasma membrane, whereas the N-terminal ‘filamentation induced by cAMP’ (FIC) domain facilitated binding of GEF-H1. While FIC domains typically mediate post-translational modifications, most prominently AMPylation, a mutant with quadruple amino acid exchanges in the putative active site indicated that the BepC FIC domain acts in a non-catalytic manner to activate GEF-H1. Our data support a model in which BepC activates the RhoA/ROCK pathway by re-localization of GEF-H1 from microtubules to the plasma membrane. A wide variety of bacterial pathogens evolved numerous virulence factors to subvert cellular processes in support of a successful infection process. Likewise, bacteria of the genus Bartonella translocate a cocktail of effector proteins (Beps) via a type-IV-secretion system into infected cells in order to interfere with host signaling processes involved in cytoskeletal dynamics, apoptosis control, and innate immune responses. In this study, we demonstrate that BepC triggers actin stress fiber formation and a linked cell fragmentation phenotype resulting from distortion of rear-end retraction during cell migration. The ability of BepC to induce actin stress fiber formation is directly associated with its ability to bind GEF-H1, an activator of the RhoA pathway that is sequestered in an inactive state when bound to microtubules but becomes activated upon release to the cytoplasm. Our findings suggest that BepC is anchored via its BID domain to the plasma membrane where it recruits GEF-H1 via its FIC domain, eventually activating the RhoA/ROCK signaling pathway and leading to stress fiber formation.
Collapse
Affiliation(s)
| | - Christoph Dehio
- Biozentrum, University of Basel, Basel, Switzerland
- * E-mail:
| |
Collapse
|
43
|
Wang C, Zhang H, Fu J, Wang M, Cai Y, Ding T, Jiang J, Koehler JE, Liu X, Yuan C. Bartonella type IV secretion effector BepC induces stress fiber formation through activation of GEF-H1. PLoS Pathog 2021; 17:e1009065. [PMID: 33508039 PMCID: PMC7842913 DOI: 10.1371/journal.ppat.1009065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 10/13/2020] [Indexed: 12/27/2022] Open
Abstract
Bartonella T4SS effector BepC was reported to mediate internalization of big Bartonella aggregates into host cells by modulating F-actin polymerization. After that, BepC was indicated to induce host cell fragmentation, an interesting cell phenotype that is characterized by failure of rear-end retraction during cell migration, and subsequent dragging and fragmentation of cells. Here, we found that expression of BepC resulted in significant stress fiber formation and contractile cell morphology, which depended on combination of the N-terminus FIC (filamentation induced by c-AMP) domain and C-terminus BID (Bartonellaintracellular delivery) domain of BepC. The FIC domain played a key role in BepC-induced stress fiber formation and cell fragmentation because deletion of FIC signature motif or mutation of two conserved amino acid residues abolished BepC-induced cell fragmentation. Immunoprecipitation confirmed the interaction of BepC with GEF-H1 (a microtubule-associated RhoA guanosine exchange factor), and siRNA-mediated depletion of GEF-H1 prevented BepC-induced stress fiber formation. Interaction with BepC caused the dissociation of GEF-H1 from microtubules and activation of RhoA to induce formation of stress fibers. The ROCK (Rho-associated protein kinase) inhibitor Y27632 completely blocked BepC effects on stress fiber formation and cell contractility. Moreover, stress fiber formation by BepC increased the stability of focal adhesions, which consequently impeded rear-edge detachment. Overall, our study revealed that BepC-induced stress fiber formation was achieved through the GEF-H1/RhoA/ROCK pathway. Intracellular pathogens modulate host cell actin cytoskeleton by secreting an array of effector molecules to ensure their cell invasion and intracellular survival. The zoonotic pathogen Bartonella spp trigger massive F-actin polymerization of host cells resulting the internalization of large bacterial aggregates (called “invasome” structure), which is dependent on a functional VirB/VirD4 type IV secretion system (T4SS) and its translocated Bep effector proteins. Here, we have used cell infection and ectopic expression assay to identify that Bartonella T4SS effector BepC induces stress fiber formation in infected host cells. However, BepC also disrupts the balance of stress fiber formation and focal adhesion maturation, and eventually causes cell fragmentation. Using immunoprecipitation and RNAi approaches, we identify GEF-H1 is the host factor targeted by BepC. Interaction with BepC induces the release of GEF-H1 from microtubules to plasma membrane and subsequently activates RhoA-ROCK to induce stress fiber formation. These findings shed light on our understanding of how Bartonella invade host cell and establish infection.
Collapse
Affiliation(s)
- Chunyan Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
| | - Haoran Zhang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
| | - Jiaqi Fu
- Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Meng Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
| | - Yuhao Cai
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
| | - Tianyun Ding
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
| | - Jiezhang Jiang
- Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Jane E. Koehler
- Department of Medicine, Division of Infectious Diseases, and the Microbial Pathogenesis and Host Defense Program, University of California, San Francisco, California, United States of America
| | - Xiaoyun Liu
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- * E-mail: (XL); (CY)
| | - Congli Yuan
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, China
- * E-mail: (XL); (CY)
| |
Collapse
|
44
|
Jing W, Lo Pilato J, Kay C, Man SM. Activation mechanisms of inflammasomes by bacterial toxins. Cell Microbiol 2021; 23:e13309. [PMID: 33426791 DOI: 10.1111/cmi.13309] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/16/2020] [Accepted: 12/12/2020] [Indexed: 12/13/2022]
Abstract
Inflammasomes are cytosolic innate immune complexes, which assemble in mammalian cells in response to microbial components and endogenous danger signals. A major family of inflammasome activators is bacterial toxins. Inflammasome sensor proteins, such as the nucleotide-binding oligomerisation domain-like receptor (NLR) family members NLRP1b and NLRP3, and the tripartite motif family member Pyrin+ efflux triggered by pore-forming toxins or by other toxin-induced homeostasis-altering events such as lysosomal rupture. Pyrin senses perturbation of host cell functions induced by certain enzymatic toxins resulting in impairment of RhoA GTPase activity. Assembly of the inflammasome complex activates the cysteine protease caspase-1, leading to the proteolytic cleavage of the proinflammatory cytokines IL-1β and IL-18, and the pore-forming protein gasdermin D causing pyroptosis. In this review, we discuss the latest progress in our understanding on the activation mechanisms of inflammasome complexes by bacterial toxins and effector proteins and explore avenues for future research into the relationships between inflammasomes and bacterial toxins.
Collapse
Affiliation(s)
- Weidong Jing
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Jordan Lo Pilato
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Callum Kay
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Si Ming Man
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| |
Collapse
|
45
|
Yoshida T, Tsuge H. Common Mechanism for Target Specificity of Protein- and DNA-Targeting ADP-Ribosyltransferases. Toxins (Basel) 2021; 13:toxins13010040. [PMID: 33430384 PMCID: PMC7827354 DOI: 10.3390/toxins13010040] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/01/2021] [Accepted: 01/03/2021] [Indexed: 12/14/2022] Open
Abstract
Many bacterial pathogens utilize ADP-ribosyltransferases (ARTs) as virulence factors. The critical aspect of ARTs is their target specificity. Each individual ART modifies a specific residue of its substrates, which could be proteins, DNA, or antibiotics. However, the mechanism underlying this specificity is poorly understood. Here, we review the substrate recognition mechanism and target residue specificity based on the available complex structures of ARTs and their substrates. We show that there are common mechanisms of target residue specificity among protein- and DNA-targeting ARTs.
Collapse
Affiliation(s)
- Toru Yoshida
- Faculty of Science, Japan Women’s University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan;
| | - Hideaki Tsuge
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
- Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
- Center for Molecular Research in Infectious Diseases, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
- Correspondence: ; Tel.: +81-75-705-3117
| |
Collapse
|
46
|
Protein-membrane interactions in small GTPase signalling and pharmacology: perspectives from Arf GTPases studies. Biochem Soc Trans 2020; 48:2721-2728. [PMID: 33336699 DOI: 10.1042/bst20200482] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 11/17/2022]
Abstract
Small GTPases, in association with their GEFs, GAPs and effectors, control major intracellular processes such as signal transduction, cytoskeletal dynamics and membrane trafficking. Accordingly, dysfunctions in their biochemical properties are associated with many diseases, including cancers, diabetes, infections, mental disorders and cardiac diseases, which makes them attractive targets for therapies. However, small GTPases signalling modules are not well-suited for classical inhibition strategies due to their mode of action that combines protein-protein and protein-membrane interactions. As a consequence, there is still no validated drug available on the market that target small GTPases, whether directly or through their regulators. Alternative inhibitory strategies are thus highly needed. Here we review recent studies that highlight the unique modalities of the interaction of small GTPases and their GEFs at the periphery of membranes, and discuss how they can be harnessed in drug discovery.
Collapse
|
47
|
Cross-Kingdom Activation of Vibrio Toxins by ADP-Ribosylation Factor Family GTPases. J Bacteriol 2020; 202:JB.00278-20. [PMID: 32900828 DOI: 10.1128/jb.00278-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pathogenic Vibrio species use many different approaches to subvert, attack, and undermine the host response. The toxins they produce are often responsible for the devastating effects associated with their diseases. These toxins target a variety of host proteins, which leads to deleterious effects, including dissolution of cell organelle integrity and inhibition of protein secretion. Becoming increasingly prevalent as cofactors for Vibrio toxins are proteins of the small GTPase families. ADP-ribosylation factor small GTPases (ARFs) in particular are emerging as a common host cofactor necessary for full activation of Vibrio toxins. While ARFs are not the direct target of Vibrio cholerae cholera toxin (CT), ARF binding is required for its optimal activity as an ADP-ribosyltransferase. The makes caterpillars floppy (MCF)-like and the domain X (DmX) effectors of the Vibrio vulnificus multifunctional autoprocessing repeats-in-toxin (MARTX) toxin also both require ARFs to initiate autoprocessing and activation as independent effectors. ARFs are ubiquitously expressed in eukaryotes and are key regulators of many cellular processes, and as such they are ideal cofactors for Vibrio pathogens that infect many host species. In this review, we cover in detail the known Vibrio toxins that use ARFs as cross-kingdom activators to both stimulate and optimize their activity. We further discuss how these contrast to toxins and effectors from other bacterial species that coactivate, stimulate, or directly modify host ARFs as their mechanisms of action.
Collapse
|
48
|
EPEC Recruits a Cdc42-Specific GEF, Frabin, To Facilitate PAK Activation and Host Cell Colonization. mBio 2020; 11:mBio.01423-20. [PMID: 33144373 PMCID: PMC7642674 DOI: 10.1128/mbio.01423-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) is a leading cause of diarrhea in children, especially in the developing world. EPEC initiates infection by attaching to cells in the host intestine, triggering the formation of actin-rich “pedestal” structures directly beneath the adherent pathogen. These bacteria inject their own receptor into host cells, which upon binding to a protein on the pathogen surface triggers pedestal formation. Multiple other proteins are also delivered into the cells of the host intestine, which work together to hijack host signaling pathways to drive pedestal production. Here we show how EPEC hijacks a host protein, Frabin, which creates the conditions in the cell necessary for the pathogen to manipulate a specific pathway that promotes pedestal formation. This provides new insights into this essential early stage in disease caused by EPEC. Enteropathogenic Escherichia coli (EPEC) is an extracellular pathogen that tightly adheres to host cells by forming “actin pedestals” beneath the bacteria, a critical step in pathogenesis. EPEC injects effector proteins that manipulate host cell signaling cascades to trigger pedestal assembly. We have recently shown that one such effector, EspG, hijacks p21-activated kinase (PAK) and sustains its activated state to drive the cytoskeletal changes necessary for attachment of the pathogen to target cells. This EspG subversion of PAK required active Rho family small GTPases in the host cell. Here we show that EPEC itself promotes the activation of Rho GTPases by recruiting Frabin, a host guanine nucleotide exchange factor (GEF) for the Rho GTPase Cdc42. Cells devoid of Frabin showed significantly lower EPEC-induced PAK activation, pedestal formation, and bacterial attachment. Frabin recruitment to sites of EPEC attachment was driven by EspG and required localized enrichment of phosphatidylinositol 4,5-bisphosphate (PIP2) and host Arf6. Our findings identify Frabin as a key target for EPEC to ensure the activation status of cellular GTPases required for actin pedestal formation.
Collapse
|
49
|
Clostridial C3 Toxins Enter and Intoxicate Human Dendritic Cells. Toxins (Basel) 2020; 12:toxins12090563. [PMID: 32883045 PMCID: PMC7551598 DOI: 10.3390/toxins12090563] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 11/17/2022] Open
Abstract
C3 protein toxins produced by Clostridium (C.) botulinum and C. limosum are mono-ADP-ribosyltransferases, which specifically modify the GTPases Rho A/B/C in the cytosol of monocytic cells, thereby inhibiting Rho-mediated signal transduction in monocytes, macrophages, and osteoclasts. C3 toxins are selectively taken up into the cytosol of monocytic cells by endocytosis and translocate from acidic endosomes into the cytosol. The C3-catalyzed ADP-ribosylation of Rho proteins inhibits essential functions of these immune cells, such as migration and phagocytosis. Here, we demonstrate that C3 toxins enter and intoxicate dendritic cells in a time- and concentration-dependent manner. Both immature and mature human dendritic cells efficiently internalize C3 exoenzymes. These findings could also be extended to the chimeric fusion toxin C2IN-C3lim. Moreover, stimulated emission depletion (STED) microscopy revealed the localization of the internalized C3 protein in endosomes and emphasized its potential use as a carrier to deliver foreign proteins into dendritic cells. In contrast, the enzyme C2I from the binary C. botulinum C2 toxin was not taken up into dendritic cells, indicating the specific uptake of C3 toxins. Taken together, we identified human dendritic cells as novel target cells for clostridial C3 toxins and demonstrated the specific uptake of these toxins via endosomal vesicles.
Collapse
|
50
|
Korbmacher M, Fischer S, Landenberger M, Papatheodorou P, Aktories K, Barth H. Human α-Defensin-5 Efficiently Neutralizes Clostridioides difficile Toxins TcdA, TcdB, and CDT. Front Pharmacol 2020; 11:1204. [PMID: 32903430 PMCID: PMC7435013 DOI: 10.3389/fphar.2020.01204] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 07/23/2020] [Indexed: 12/21/2022] Open
Abstract
Infections with the pathogenic bacterium Clostridioides (C.) difficile are coming more into focus, in particular in hospitalized patients after antibiotic treatment. C. difficile produces the exotoxins TcdA and TcdB. Since some years, hypervirulent strains are described, which produce in addition the binary actin ADP-ribosylating toxin CDT. These strains are associated with more severe clinical presentations and increased morbidity and frequency. Once in the cytosol of their target cells, the catalytic domains of TcdA and TcdB glucosylate and thereby inactivate small Rho-GTPases whereas the enzyme subunit of CDT ADP-ribosylates G-actin. Thus, enzymatic activity of the toxins leads to destruction of the cytoskeleton and breakdown of the epidermal gut barrier integrity. This causes clinical symptoms ranging from mild diarrhea to life-threatening pseudomembranous colitis. Therefore, pharmacological inhibition of the secreted toxins is of peculiar medical interest. Here, we investigated the neutralizing effect of the human antimicrobial peptide α-defensin-5 toward TcdA, TcdB, and CDT in human cells. The toxin-neutralizing effects of α-defensin-5 toward TcdA, TcdB, and CDT as well as their medically relevant combination were demonstrated by analyzing toxins-induced changes in cell morphology, intracellular substrate modification, and decrease of trans-epithelial electrical resistance. For TcdA, the underlying mode of inhibition is most likely based on the formation of inactive toxin-defensin-aggregates whereas for CDT, the binding- and transport-component might be influenced. The application of α-defensin-5 delayed intoxication of cells in a time- and concentration-dependent manner. Due to its effect on the toxins, α-defensin-5 should be considered as a candidate to treat severe C. difficile-associated diseases.
Collapse
Affiliation(s)
- Michael Korbmacher
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Stephan Fischer
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Marc Landenberger
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | | | - Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
| | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| |
Collapse
|